The invention provides a zoom lens system that is reduced in terms of both size and cost. The zoom lens system comprises a first positive lens group G1, a second negative lens group G2, a stop S, a third positive lens group G3 and a fourth positive lens group G4. During zooming from a wide-angle end to a telephoto end of the system, while the first lens group G1 remains fixed, the second lens group G2 moves from an object side to an image plane side of the system, the third lens group G3 moves from the image plane side to the object side, and the fourth lens group G4 moves to keep an image plane at a constant position. The first lens group G1 is made up of a negative meniscus lens convex on an object side and a double-convex lens, the second lens group G2 is made up of a double-concave lens and a positive meniscus lens convex on an object side thereof, with an aspherical surface being used for a surface of the positive meniscus lens that is located on an image side thereof, the third lens group G3 is made up of a double-convex lens and a negative meniscus lens convex on an object side thereof, with an aspherical surface being used for a surface of the double-convex lens that is located on an object side thereof, and the fourth lens group G4 is made up of one double-convex lens.
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34. A zoom lens system comprising, in order from an object side of said system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system, a third lens group that has positive refracting power and moves constantly from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and a fourth lens group that has positive refracting power and is movable during zooming, wherein each of said second and third lens groups comprises a doublet consisting of a positive lens and a negative lens.
1. A zoom lens system comprising in order from an object side of said system:
a first lens group having positive refracting power,
a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system,
a third lens group having positive refracting power, and
a fourth lens group that has positive refracting power and is movable during zooming, wherein:
said first lens group consists of two lenses, a negative lens and a positive lens, or one positive lens alone,
said third lens group comprises three lenses, a positive lens, a positive lens and a negative lens, or two lenses, a positive lens and a negative lens, and
said third lens group has at least one aspherical surface therein.
32. A zoom lens system comprising, in order from an object side of said system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system, a third lens group that has positive refracting power and moves constantly from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and a fourth lens group that has positive refracting power and is movable during zooming, wherein said third lens group comprises a doublet consisting of a positive lens and a negative lens, and said fourth lens group consists of one positive lens.
35. A zoom lens system comprising, in order from an object side of said system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system, a third lens group that has positive refracting power and moves constantly from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and a fourth lens group that has positive refracting power and is movable during zooming, wherein said third lens group consists of, in order from an object side thereof, a positive lens, and a doublet consisting of a positive lens and a negative lens.
38. A zoom lens system comprising, in order from an object side of said system, a first lens group having positive refracting power, a second lens group having negative refracting power, a third lens group having positive refracting power, and a fourth lens group having positive refracting power, wherein during zooming, a space between said first and second lens groups, a space between said second and third lens groups and a space between said third and fourth lens groups vary independently, said first lens group consists of two lenses or , a positive lens and a negative lens, said third lens group comprises three lenses, a positive lens, a positive lens and a negative lens, and said second or third lens group comprises a doublet consisting of at least one set of a positive lens and a negative lens.
36. A zoom lens system comprising, in order from an object side of said system, a first lens group having positive refracting power, a second lens group having negative refracting power, a third lens group having positive refracting power and a fourth lens group having positive refracting power, wherein during zooming, a space between said first and second lens groups, a space between said second and third lens groups and a space between said third and fourth lens groups vary independently, said third lens group consists of, in order from an object side thereof, a double-convex positive lens, and a doublet consisting of a positive meniscus lens convex on an object side thereof and a negative meniscus lens, and said fourth lens group consists of a double-convex lens having a large curvature on an object side surface thereof.
0. 40. A zoom lens system comprising, in order from an object side of said system, a first lens group having positive refracting power, a second lens group having negative refracting power, a third lens group that has positive refracting power and that moves constantly from an image plane side to an object side of said system during zooming from a wide-angle end to a telephoto end of said system, and a fourth lens group having positive refracting power, wherein during zooming, a space between said first and second lens groups, a space between said second and third lens groups and a space between said third and fourth lens groups vary independently, said first lens group consists of two lenses, a positive lens and a negative lens, and said second or third lens group comprises a doublet consisting of at least one set of a positive lens and a negative lens.
10. A zoom lens system comprising, in order from an object side of said system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system, a third lens group that has positive refracting power and moves from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and that comprises a doublet, and a fourth lens group that has positive refracting power and is movable during zooming, and satisfying the following condition (1):
0.5<|F2/F3|<1.2 (1) where Fi is a focal length of an i-th lens group.
0. 41. A zoom lens system comprising in order from an object side of said system:
a first lens group having positive refracting power,
a second lens group that has negative refracting power and is positioned on an image plane side of said system, closer to a telephoto end of said system than a wide-angle end of said system,
a third lens group that has positive refracting power, and
a fourth lens group that has positive refracting power and is movable during zooming, wherein:
said first lens group consists of two lenses, a negative lens and a positive lens,
said third lens group comprises three lenses, a positive lens, a positive lens and a negative lens, with a doublet consisting of the positive lens that is closest to the negative lens in the third lens group and the negative lens in the third lens group, and
said third lens group has at least one aspherical surface therein.
37. A zoom lens system comprising, in order from an object side of said system, a first lens group having positive refracting power, a second lens group having negative refracting power, a third lens group having positive refracting power and a fourth lens group having positive refracting power, wherein during zooming, a space between said first and second lens groups, a space between said second and third lens groups and a space between said third and fourth lens groups vary independently, said first lens group consists of one positive lens, said second lens group comprises three lenses or, in order from an object side thereof, a single lens and a doublet consisting of a negative lens and a positive lens, said third lens group comprises three lenses or, in order from an object side thereof, a single lens and a doublet consisting of a positive lens and a negative lens, and said fourth lens group consists of one positive lens.
11. A zoom lens system comprising, in order from an object side of said system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system, a third lens group that has positive refracting power and moves from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and that comprises a doublet, and a fourth lens group that has positive refracting power and is movable during zooming, and satisfying the following condition (2):
0.49<|L3/L2|<1 (2) where Li is an amount of movement of an i-th lens group from the wide-angle end to the telephoto end.
12. A zoom lens system comprising, in order from an object side of said system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system, a third lens group that has positive refracting power and moves from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and a fourth lens group that has positive refracting power and is movable during zooming, and satisfying the following condition (3):
2<(F3.4W)/IH<3.3 (3) where (F3.4W) is a composite focal length of said third and fourth lens group at the wide-angle end, and IH is a radius of an image circle.
0. 39. A zoom lens system comprising in order from an object side of said system:
a first lens group having positive refracting power,
a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system,
a third lens group that has positive refracting power and that moves constantly from an image plane side to an object side of said system during zooming from a wide-angle end to a telephoto end of said system, and
a fourth lens group that has positive refracting power and is movable during zooming, wherein:
said first lens group consists of two lenses, a negative lens and a positive lens, or one positive lens alone,
said third lens group comprises three lenses, a positive lens, a positive lens and a negative lens, or two lenses, a positive lens and a negative lens, and
said third lens group has at least one aspherical surface therein.
0. 44. A zoom lens system comprising in order from an object side of said system:
a first lens group having positive refracting power,
a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system,
a third lens group having positive refracting power, and
a fourth lens group that has positive refracting power and is movable during zooming, wherein:
said first lens group consists of two lenses, a negative lens and a positive lens, or one positive lens alone,
said third lens group comprises three lenses, a positive lens, a positive lens and a negative lens, or two lenses, a positive lens and a negative lens, and
said third lens group has at least one aspherical surface therein, and
wherein the positive lens that is closest to the negative lens in said third lens group and the negative lens in said third lens group constitute a doublet.
13. A zoom lens system comprising, in order from an object side of said system, a first lens group having positive refracting power, a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system, a third lens group having positive refracting power and a fourth lens group that has positive refracting power and is movable during zooming, wherein:
said third lens group comprises, in order from an object side thereof, a positive lens convex on an object side thereof and a doublet consisting of a positive lens convex on an object side thereof and a negative lens concave on an image side thereof, and peripheries of object side-directed convex surfaces of both said object-side positive lens and said doublet in said third lens group are held by a lens holder barrel while said concave surfaces are abutting at said peripheries or some points on said lens holder barrel.
27. A zoom lens system comprising, in order from an object side of said system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system, a third lens group that has positive refracting power and moves from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and a fourth lens group that has positive refracting power and is movable during zooming, wherein said first lens group consists of one positive lens, and a lens in said second lens group that is located nearest to an object side thereof is a negative lens that satisfies the following condition (7):
ν21<40 (7) where ν21 is an Abbe's number of said negative lens located nearest to the object side of said second lens group.
0. 42. A zoom lens system comprising in order from an object side of said system:
a first lens group having positive refracting power,
a second lens group that has negative refracting power and is positioned on an image plane side of said system, closer to a telephoto end of said system than a wide-angle end of said system,
a third lens group having positive refracting power, and
a fourth lens group that has positive refracting power and is movable during zooming, wherein:
said first lens group consists of two lenses, a negative lens and a positive lens, or one positive lens alone,
said third lens group comprises three lenses, a positive lens, a positive lens and a negative lens, or two lenses, a positive lens and a negative lens, with a doublet consisting of the positive lens or the positive lens that is closest to the negative lens in the third lens group and the negative lens in the third lens group,
said third lens group has at least one aspherical surface therein, and wherein the positive lens and negative lens in said third lens group are cemented together.
14. A zoom lens system comprising, in order from an object side of said system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system, a third lens group that has positive refracting power and moves from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and that comprises a doublet, and a fourth lens group that has positive refracting power and is movable during zooming, and satisfying the following conditions (1) and (2):
0.5<|F2/F3|<1.2 (1) 0.49<|L3/L2|<1 (2) where Fi is a focal length of an i-th lens group, and Li is an amount of movement of an i-th lens group from the wide-angle end to the telephoto end.
15. A zoom lens system comprising, in order from an object side of said system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system, a third lens group that has positive refracting power and moves from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and a fourth lens group that has positive refracting power and is movable during zooming, and satisfying the following conditions (1) and (3):
0.5<|F2/F3|<1.2 (1) 2<(F3.4W)/IH<3.3 (2) where Fi is a focal length of an i-th lens group, (F3.4W) is a composite focal length of said third and fourth lens groups at the wide-angle end, and IH, is a radius of an image circle.
16. A zoom lens system comprising, in order from an object side of said system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system, a third lens group that has positive refracting power and moves from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and a fourth lens group that has positive refracting power and is movable during zooming, and satisfying the following conditions (2) and (3):
0.49<|L3/L2|<1 (1) 2<(F3.4W)/IH<3.3 (3) where Li is an amount of movement of an i-th lens group from the wide-angle end to the telephoto end, (F3.4W) is a composite focal length of said third and fourth lens groups at the wide-angle end, and IH is a radius of an image circle.
17. A zoom lens system comprising, in order from an object side of said system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system, a third lens group that has positive refracting power and moves from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and a fourth lens group that has positive refracting power and is movable during zooming, and satisfying the following conditions (1), (2) and (3):
0.5<|F2/F3|<1.2 (1) 0.49<|L3/L2|<1 (2) 2<(F3.4W)/IH<3.3 (3) where Fi is a focal length of an i-th lens group, Li is an amount of movement of an i-th lens group from the wide-angle end to the telephoto end, (F3.4W) is a composite focal length of said third and fourth lens groups at the wide-angle end, and IH is a radius of an image circle.
2. The zoom lens system according to
a first lens group having positive refracting power,
a second lens group that has negative refracting power and moves from an object side to an image plane side of said system during zooming from a wide-angle end to a telephoto end of said system,
a third lens group having positive refracting power, and
a fourth lens group that has positive refracting power and is movable during zooming, wherein:
said first lens group consists of two lenses, a negative lens and a positive lens, or one positive lens alone,
said third lens group comprises three lenses, a positive lens, a positive lens and a negative lens, or two lenses, a positive lens and a negative lens, and
said third lens group has at least one aspherical surface therein, and
wherein the positive lens and negative lens in said third lens group are cemented together.
3. The zoom lens system according to
4. The zoom lens system according to
5. The zoom lens system according to
6. The zoom lens according to claim 1 2, wherein said fourth lens group consists of one positive lens alone.
7. The zoom lens system according to
0.3<|L3|/|L2|<1.0 (a) where L2 is an amount of said second lens group from the wide-angle end to the telephoto end, and L3 is an amount of said third lens group from the wide-angle end to the telephoto end.
8. The zoom lens system according to
9. The zoom lens system according to
18. The zoom lens system according to any one of claims 10, 11, 12, and 14 to 17, which satisfies the following condition (4):
0.6<|F2/F3|<1 (4) where Fi is a focal length of an i-th lens group.
19. The zoom lens system according to
20. The zoom lens system according to
0.3<F3/F4<0.8 (5) wherein Fi is a focal length of an i-th lens group.
21. The zoom lens system according to
0.4<|β2T|<1 (6) where β2T is a lateral magnification of the second lens group of the telephoto end of said system.
22. The zoom lens system according to
23. The zoom lens system according to
24. The zoom lens system according to
25. The zoom lens system according to
26. The zoom lens system according to
28. The zoom lens system according to
ν21<35 (8). 29. The zoom lens system according to
ν21<40 (7) where ν21 is an Abbe's number of the negative lens located nearest to the object side of said second lens group.
30. The zoom lens system according to
ν21<35 (8) where ν21 is an Abbe's number of the negative lens located nearest to the object side of said second lens group.
31. The zoom lens system according to
33. The zoom lens system according to
0. 43. The zoom lens system according to
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where L2 is an amount of movement of the second lens group from the wide-angle end to the telephoto end, and L3 is an amount of movement of the third lens group from the wide-angle end to the telephoto end.
Preferably, the second lens group has at least one aspherical surface therein.
Preferably, the fourth lens group has at least one aspherical surface therein.
According to the second aspect of the present invention, there is provided a zoom lens system comprising, in order from an object side thereof, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from the object side to an image plane side of the system during zooming from a wide-angle end to a telephoto end of the system, a third lens group that has positive refracting power and moves from the image plane side to the object side during zooming from the wide-angle end to the telephoto end, and a fourth lens group that has positive refracting power and is movable during zooming, wherein:
According to the third aspect of the present invention, there is provided a zoom lens system comprising, in order from an object side thereof, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from the object side to an image plane side of the system during zooming from a wide-angle end to a telephoto end of the system, a third lens group that has positive refracting power and moves from the image plane side to the object side during zooming from the wide-angle end to the telephoto end, and a fourth lens group that has positive refracting power and is movable during zooming, wherein:
According to the fourth aspect of the present invention, there is provided a zoom lens system comprising, in order from an object side thereof, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from the object side to an image plane side of the system during zooming from a wide-angle end to a telephoto end of the system, a third lens group that has positive refracting power and moves from the image plane side to the object side during zooming from the wide-angle end to the telephoto end, and a fourth lens group that has positive refracting power and is movable during zooming, wherein:
According to the fifth aspect of the present invention, there is provided a zoom lens system comprising, in order from an object side thereof, a first lens group that has positive refracting power, a second lens group that has negative refracting power and moves from the object side to an image plane side of the system during zooming from a wide-angle end to a telephoto end of the system, a third lens group that has positive refracting power and a fourth lens group that has positive refracting power and is movable during zooming, wherein:
A detailed explanation will now be made of why the aforesaid arrangements are used, and how they work.
First of all, the zoom lens system according to the first aspect of the invention is described.
One possible approach to achieving a further side reduction of the zoom lens system disclosed in JP-A 6-94997 is to reduce the number of lenses used, thereby saving the space occupied by the lenses. In the system set forth in JP-A 6-94997, the fourth lens group consists of one positive lens, and the third lens group should comprise at least two lenses, a positive lens and a negative lens, because the negative lens is essentially required for correction of chromatic aberrations. In either case, there is no room for reducing the number of lenses. To reduce the number of lenses, the number of lenses in the first and second lens groups may be reduced. However, since each of the first and second lens groups should have one negative lens and one positive lens for correction of chromatic aberrations, it is the positive lens in the first lens group or the negative lens in the second lens group that can be eliminated. The greatest effect on size and cost reductions is obtained when the positive lens is removed from the first lens group, because that positive lens has a large diameter and a large thickness.
In the present invention, therefore, the first lens group is made up of two lenses, a negative lens and a positive lens. Further size and weight reductions may be achieved by constructing the second lens group of two lenses, a negative lens and a positive lens. Various aberrations can be reduced by constructing the third lens group of three lenses, a positive lens, a positive lens and a negative lens or two lenses, a positive lens and a negative lens, so that a great part of the zooming action can be shared by the third lens group. Consequently, the burden of the zooming action and correction of aberrations on the first and second lens groups can be relieved.
In addition, the power of the third lens group can be so increased that an axial bundle incident on the fourth lens group can be relatively largely converged. It is thus possible to reduce coma and astigmatism produced at the fourth lens group and, at the same time, achieve size reductions by a limited back focus. If the third lens group has a positive-negative power profile in order from the object side, a principal point throughout the third and fourth lens group, which define a so-called relay system, can then be shifted more closely to the object side. It is thus possible to shorten a composite focal length of the third and fourth lens groups with no variation in the image-forming magnification of the third and fourth lens groups and, hence, the overall length of the zoom lens system.
In the present invention, the fourth lens group can be made up of one positive lens alone, partly because chromatic aberrations produced throughout the third and fourth lens groups can be fully corrected by one negative lens in the third lens group, and partly because the power of the third lens group can be increased as mentioned above to relieve the burden of correction of aberrations that is imposed on the fourth lens group. This is also desired in view of size and weight reductions. Generally, a zoom lens system such as one contemplated in the present invention is designed to move forward the fourth lens group for focusing. According to the present invention, the load on focusing operation, too, can be reduced.
In the present invention, the amount of aberrations produced at the first and second lens groups is likely to become larger than that in the zoom lens system set forth in JP-A 6-94997 because each of the first and second lens groups comprise a reduced number of lenses. It is thus desired that the burden of the zooming action be shared by the third lens group as much as possible and, accordingly, the burden on the first and second lens groups be relieved. In other words, it is desired that the zoom lens system of the invention satisfy the following condition (a) with respect to zooming:
0.3<|L3|/|L2|<1.0 (a)
where L2 is the amount of movement of the second lens group during zooming, and L3 is the amount of movement of the third lens group during zooming. Thus, condition (a) defines the proportion of the amount of movement of the third lens group to the amount of movement of the second lens group. When the lower limit of 0.3 in condition (a) is not reached, the zooming action shared by the third lens group becomes too slender or the burden on the second lens group becomes too large, resulting in a deterioration in aberrations or failing to achieve compactness. When the upper limit of 1.0 is exceeded, on the other hand, the burden on the third lens group becomes too large, again resulting in a deterioration in aberrations.
In the zoom lens system of the invention, it is required that at least one surface in the third lens group be made up of an aspherical surface with positive power becoming weak farther off the optical axis so as to make correction for spherical aberrations, and especially coma and astigmatism at the wide-angle end. By constructing at least one surface in the second lens group of an aspherical surface with negative power becoming weak farther off the optical axis, it is also possible to make better correction for coma and astigmatism, and spherical aberrations at the telephoto end.
By applying to at least one surface in the fourth lens group an aspherical surface with positive power becoming weak farther off the optical axis, it is possible to make ever better correction for astigmatism in particular, etc.
Then, the second to fifth embodiments of the zoom lens system according to the invention are explained.
In the field of cameras with built-in electronic image pickup means such as camcorders, and digital cameras, too, demand for consumer-oriented, compact yet low-cost zoom lens systems has gone up recently. To meet such demand, JP-A's 6-94997 and 6-194572 have come up with such zoom lens systems as already noted. As previously mentioned, these have a zoom ratio of the order of 8 to 12, and a great part of the zooming action is shared by the second lens group. To keep an image point substantially constant in this case, the lateral magnification of the second lens group must be within the range of about −1 from the wide-angle end to the telephoto end.
At a zoom ratio lower than that, however, the amount of movement of the second lens group can become so small that size reductions can be achieved. It is thus efficient to reduce the space allowed between the first and second lens groups as much as possible for the purpose of size reductions.
To permit the second lens group to have a lateral magnification of about −1 while the space between the first and second lens groups is kept as narrow as possible, however, it is required to increase the power of the first lens group with respect to the second lens group. This then causes an entrance pupil to be located at a farther position where the height of an off-axis ray passing through the first lens group increases, resulting in an increase in the size of the lens system in the first lens group and, hence, an increase in the thickness of the lenses in the first lens group. Further, the curvature of each lens in the first lens group must be increased to make sure of the edge thickness of each lens, resulting in a further increase in the thickness of each lens in the first lens group.
In accordance with the second embodiment of the zoom lens system of the present invention, this problem can be averted by allocating a great part of the burden of the zooming action to the third lens group, whereby a satisfactory zoom ratio and compactness are achieved with no considerable change in the power ratio between the first and second lens group. To allow the third lens group to have a great zooming action, it is then required that the third lens group have relatively large power, as defined by condition (1). When the lower limit of 0.5 in condition (1) is not reached or when the power of the third lens group becomes weak with respect to the power of the second lens group, the amount of movement of the third lens group during zooming becomes too large. With this, the amount of movement of the second lens group to keep the image plane at a constant position becomes large, failing to achieve compactness. When the upper limit of 1.2 is exceeded or when the power of the third lens group with respect to the second lens group becomes too strong, the amount of astigmatism produced at the third lens group becomes too large, and the distance between the third lens group and an object point therefor becomes too short. This in turn makes it impossible to provide a sufficient space between the second and third lens groups. More preferably, this embodiment of the zoom lens system should satisfy the following condition (4):
0.6<|F2/F3|<1 (4)
For the third embodiment of the zoom lens system according to the present invention, it is required that the amount of movement of the third lens group during zooming be increased so as to allocate a relatively large zooming action to the third lens group, as defined by condition (2). Thus, condition (2) gives a definition of the ratio of the amount of movement between the second and third lens groups from the wide-angle end to the telephoto end. Falling below the lower limit of 0.49 in condition (2) is not preferable because the amount of movement of the third lens group with respect to the second lens group becomes too small to allocate a sufficient zooming action to the third lens group. Exceeding the upper limit of 1 is again not preferable because the amount of movement of the third lens group with respect to the second lens group increases with the results that there is an excessive fluctuation in astigmatism, coma and other aberrations produced at the third lens group during zooming while the distance between the third lens group and an object point therefor at the telephoto end becomes too short. Consequently, no sufficient space can be provided between the second and third lens groups.
For a four-lens-group or a positive-negative-positive-positive power profile zoom lens system like the fourth embodiment of the zoom lens system according to the present invention, it is required to increase the composite power of the third and fourth lens groups, as defined by condition (3). This is because it is effective for reducing the overall length of the zoom lens system that the powers of the third and fourth lens groups for relaying a virtual image formed by the first and second lens groups to an image pickup plane be increased to reduce the distance between the position of the virtual image by the first and second lens groups and the image pickup plane. When the upper limit of 3.3 in condition (3) is exceeded or when the composite focal length of the third and fourth lens groups at the wide-angle end becomes large relative to the radius of the image circle (image height) IH (when the power becomes weak), no sufficient compactness is achieved for the aforesaid reason. Falling below the lower limit of 2 in condition (3) is not preferred. This is because the composite focal length of the third and fourth lens groups at the wide-angle end becomes small relative to the radius of the image circle with the results that astigmatism produced at the third and fourth lens groups becomes too large, while the distance between the third lens group and an object point therefor becomes too short. Consequently, no sufficient space can be provided between the second and third lens groups.
For a zoom lens system such as one contemplated in the present invention, it is preferable to perform focusing with the fourth lens group when the angle of incidence of an axial bundle is relatively small, because aberrational fluctuations during focusing are limited. Since the fourth lens group has a relatively small lens diameter and is light in weight, there is an additional advantage that the driving torque for focusing can be reduced.
It is also favorable for reducing the overall length of the zoom lens system that as much of the composite power of the third and fourth lens groups as possible is allocated to the third lens group. In this embodiment, therefore, relatively large power is allocated to the third lens group rather than to the fourth lens group, as defined by the following condition (5) giving a definition of the ratio of the focal length of the third lens group with respect to the focal length of the fourth lens group.
0.3<F3/F4<0.8 (5)
where Fi is a focal length of an i-th lens group. By meeting condition (5) or making the ratio of the focal length of the third lens group with respect to the focal length of the fourth lens group smaller than the upper limit of 0.8 therein, it is possible to achieve more compactness than would be possible with the prior art. Falling below the lower limit of 0.3 in condition (5) is not preferable because the ratio of the focal length of the third lens group with respect to the focal length of the fourth lens becomes small, with the results that the power of the fourth lens group becomes too weak, and the amount of movement of the fourth lens group for focusing becomes too large. There is thus a large aberrational fluctuation in association with focusing.
In the present invention, the power of the fourth lens group is relatively weaker than that of the third group; that is, it is desired for achieving compactness to construct the fourth lens group of one positive lens.
To reduce an astigmatism fluctuation due to zooming, it is desired that at least one surface in the fourth lens group be provided by an aspherical surface.
Preferably in the present invention, the following condition (6) is satisfied:
0.4<|β2T|<1 (6)
Here β2T is a lateral magnification of the second lens group at the telephoto end.
Condition (6) gives a definition of the absolute value of the lateral magnification of the second lens group at the telephoto end. When the lower limit of 0.4 is not reached or when the absolute value of the lateral magnification of the second lens group at the telephoto end becomes small, no lens compactness can be achieved because the zooming action of the second lens group becomes insufficient, and the power of the first lens group becomes too weak. When the upper limit of 1 is exceeded or when the absolute value of the lateral magnification of the second lens group at the telephoto end becomes large, no compactness can again be achieved because the zooming action of the third lens group becomes insufficient, and the power of the first lens group becomes too strong, resulting an increase in the size of the lens system in the first lens group.
Preferably, the third lens group contributes to a size reduction of the zoom lens system by increasing its power without varying its image-forming magnification. It is then preferable that the principal point of the third lens group is located as close to the object side as possible, thereby avoiding interference between the second and third lens groups at the telephoto end of the system, which may be caused when the distance between the third lens group and an object point for the third lens group is short. For this reason, it is preferable that the third lens group is made up of three lenses or, in order from an object side thereof, a positive lens, a positive lens and a negative lens. To make correction for spherical aberrations, it is further preferable that an aspherical surface is used for at least one surface in the third lens group.
By using an aspherical surface for at least one surface in the second lens group, it is possible to make better correction for fluctuations in astigmatism and coma in association with zooming.
In the present invention, the burden of correction of aberrations on the first and second lens groups can be relieved because the third lens group shares a relatively great part of the zooming action as previously mentioned, and so the first lens group may be made up of one positive lens. It is then preferable that the lens in the second lens group that is located nearest to an object side thereof is made up of a negative lens having relatively large dispersion so as to make correction for chromatic aberration of magnification produced at the first lens group. This is defined by the following condition (7) that gives a definition of the Abbe's number of the negative lens in the second lens group that is located nearest to the object side thereof.
ν21<40 (7)
where ν21 is an Abbe's number of negative lens in the second lens group that is located nearest to the object side thereof.
To make correction for chromatic aberration of magnification produced at the positive lens in the first lens group as mentioned above, it is preferable that the Abbe's number of the negative lens located nearest to the object side of the second lens group does not exceed the upper limit of 40 in condition (7). If the following condition (8) is satisfied, it is then possible to make better correction for the chromatic aberration of magnification.
ν21<35 (8)
When, as contemplated in the invention, the third lens group is made up of three lenses, i.e., a positive lens, a positive lens and a negative lens in order from an object side thereof, a principal point throughout the third lens group should be located as close to the object side as possible for the achievement of compactness. It is then preferable that both the positive lenses are convex on object sides thereof and the negative lens is strongly concave on an image plane side thereof. The performance of the convex surfaces (opposing to the object side) of the two positive lenses having strong refracting power and the performance of the concave surface (opposing to the image side) of the negative lens are often adversely affected by an error of decentration of such lenses with respect to optical axes at the time of lens fabrication. For this reason, it is preferable that the positive lens on the image plane side and negative lens are cemented together, and that when the third lens group is held in a lens holder barrel, the positive lens on the object side and the doublet are held by the lens holder barrel while their convex surfaces opposing to the object side are abutting at their peripheries or some points on the lens holder barrel.
According to one specific aspect of the present invention, there is provided a zoom lens system comprising, in order from an object side of the system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from the object side to an image plane side of the system during zooming from a wide-angle end to a telephoto end of the system, a third lens group that has positive refracting power and moves constantly from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and a fourth lens group that has positive refracting power and is movable during zooming, wherein said third lens group comprises a doublet consisting of a positive lens and a negative lens, and said fourth lens group comprises one positive lens.
In this embodiment, during zooming from the wide-angle end to the telephoto end, the second lens group having negative refracting power can move from the object side to the image plane side while the third lens group having positive refracting power can move from the image plane side to the object side, so that the burden of zooming so far shared by the second lens group can be allocated to the second and third lens groups. It is thus possible to achieve compactness while a satisfactory zoom ratio is maintained, without increasing the power ratio of the first lens group to the second lens group. In other words, by allocating a great part of the zooming action to the third lens group, it is possible to achieve compactness while a satisfactory zoom ratio is maintained, without increasing the power ratio of the first lens group to the second lens group.
Reference is then made to what action and effect are obtained when the third lens group comprises a doublet consisting of a positive lens and a negative lens. When the third lens group is designed as a group movable during zooming, the burden on the third lens group of correction of aberrational fluctuations in association with zooming does not only become heavy, but it is also required to make good correction for chromatic aberrations. For this reason, it is necessary for the third lens group to comprise at least a positive lens component and a negative lens component. Relative decentration between the positive and negative lenses gives rise to a considerable deterioration in the image-forming capability. This decentration between the positive and negative lenses can be easily reduced by using the doublet consisting of a positive lens and a negative lens in the third lens group. It is thus possible to allocate a great part of the zooming action to the third lens group, make good correction for chromatic aberrations, and make an image quality drop due to decentration unlikely to occur. In this embodiment, the burden of zooming so far shared by the second lens group is allocated to the second and third lens groups so that the burden of correction of aberrations on the fourth lens group can be successfully reduced. By constructing the fourth lens group of one positive lens, it is possible to achieve compactness while the image-forming capability is kept.
In the instant embodiment, it is preferable that an aspherical surface is used for at least one surface of the positive lens in the fourth lens group.
When the fourth lens group is constructed of one positive lens, it is preferable that the fourth lens group has one aspherical surface therein because the burden of zooming can be allocated to the second and third lens groups and correction of aberrations shared by the fourth lens group can be well performed, resulting in the achievement of cost and size reductions. It is here to be noted that the aspherical surface may be formed by a so-called glass pressing process, a so-called hybrid process wherein a thin resin layer is stacked on a glass or other substrate, or a plastic molding process.
According to another specific aspect of the present invention, there is provided a zoom lens system comprising, in order from an object side of the system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from the object side to an image plane side of the system during zooming from a wide-angle end to a telephoto end of the system, a third lens group that has positive refracting power and moves constantly from the image plane side to the object side during zooming from the wide-angle end of the telephoto end and a fourth lens group that has positive refracting power and is movable during zooming, wherein each of said recovery lens group and said third lens group comprises a doublet consisting of a positive lens and a negative lens.
In this embodiment, during zooming from the wide-angle end to the telephoto end, the second lens group having negative refracting power can move from the object side to the image plane side while the third lens group having positive refracting power can move from the image plane side to the object side, so that the burden of zooming so far shared by the second lens group can be allocated to the second and third lens groups. It is thus possible to achieve compactness while a satisfactory zoom ratio is maintained, without increasing the power ratio of the first lens group to the second lens group. In other words, by allocating a great part of the zooming action to the third lens group, it is possible to achieve compactness while a satisfactory zoom ratio is maintained, without increasing the power ratio of the first lens group to the second lens group.
Reference is then made to what action and effect are obtained when the third lens group comprises a doublet consisting of a positive lens and a negative lens. When the third lens group is designed as a group movable during zooming, the burden on the third lens group of correction of aberration fluctuations in associated with zooming does not only become heavy, but it is also required to make good correction for chromatic aberrations. For this reason, it is necessary for the third lens group to comprise at least a positive lens component and a negative lens component. Relative decentration between the positive and negative lenses then gives rise to a considerable deterioration in the image-forming capability. This decentration between the positive and negative lenses can be easily reduced by using the doublet consisting of a positive lens and a negative lens in the third lens group. It is thus possible to allocate a great part of the zooming action to the third lens group, make good correction for chromatic aberrations, and make an image quality drop due to decentration unlikely to occur. Although the burden of zooming on the second lens group is reduced, yet the burden on the second lens group of correction of aberrational fluctuations in association with zooming is still heavy because the second lens group is a group movable during zooming. It is thus required to make good correction for chromatic aberrations. For this reason, it is necessary for the second lens group to comprise at least a positive lens component and a negative lens component. Relative decentration between the positive and negative lenses then gives rise to a considerable deterioration in the image-forming capability. This decentration between the positive and negative lenses can be easily reduced by using the doublet consisting of a positive lens and a negative lens in the second lens group. It is thus possible to make an image quality drop due to decentration unlikely to occur.
According to yet another specific embodiment of the present invention, there is provided a zoom lens system comprising, in order from an object side of the system, a first lens group that has positive refracting power and remains fixed during zooming, a second lens group that has negative refracting power and moves from the object side to an image plane side of the system during zooming from a wide-angle end to a telephoto end of the system, a third lens group that has positive refracting power and moves constantly from the image plane side to the object side during zooming from the wide-angle end to the telephoto end and a fourth lens group that has positive refracting power and is movable during zooming, wherein said third lens group comprises, in order from an object side thereof, a positive lens and a doublet consisting of a positive lens and a negative lens.
In this embodiment, during zooming from the wide-angle end to the telephoto end, the second lens group having negative refracting power can move from the object side to the image plane side while the third lens group having positive refracting power can move from the image plane side to the object side, so that the burden of zooming so far shared by the second lens group can be allocated to the second and third lens groups. It is thus possible to achieve compactness while a satisfactory zoom ratio is maintained, without increasing the power ratio of the first lens group to the second lens group. In other words, by allocating a great part of the zooming action to the third lens group, it is possible to achieve compactness while a satisfactory zoom ratio is maintained, without increasing the power ratio of the first lens group to the second lens group. Further, since the third lens group is made up of, in order from the object side, a positive lens, a positive lens and a negative lens, a principal point throughout the third lens group can be located on the object side for the achievement of a further size reduction. Stated otherwise, the negative lens is required for correction of chromatic aberration, and two positive lenses are located to obtain strong positive power and achieve a size reduction (simple structure) of the third lens group itself. Furthermore, this power profile (positive-positive-negative in order from the object side) of third lens group allows various aberrations to be well corrected with a reduced number of lenses. In addition, the principal point throughout the third lens group is located on the object side so that the principal point positions of the second and third lens groups can effectively be brought close to each other at the telephoto end of the system, thereby achieving a further size reduction of the system.
According to a further specific aspect of the present invention, there is provided a zoom lens system comprising, in order from an object side of said system, a first lens group having positive refracting power, a second lens group having negative refracting power, a third lens group having positive refracting power and a fourth lens group having positive refracting power, wherein during zooming, a space between said first and second lens groups, a space between said second and third lens groups and a space between said third and fourth lens groups vary independently, said third lens group comprises, in order from an object side thereof, a double-convex positive lens, and a doublet consisting of a positive meniscus lens convex on an object side thereof and a negative meniscus lens, and said fourth lens group comprises a double-convex lens having a large curvature on an object side surface thereof.
In this embodiment, the third lens group is constructed of, in order from the object side, a positive lens convex on an object side thereof and a doublet consisting of a positive meniscus lens convex on an object side thereof and a negative meniscus lens, so that a principal object throughout the third lens group can be located closer to the object side, thereby achieving a size reduction of the lens system. Use of the doublet consisting of a positive meniscus lens and a negative meniscus lens can reduce a performance drop due to decentration. Since the third lens group has such an arrangement, the fourth lens group can be constructed of one single lens. By using a double-convex lens having a large curvature on an object side thereof as the single lens, it is possible to make a light ray incident on the image plane substantially telecentric and obtain a satisfactory back focus while the number of lenses in the third and fourth lens groups is reduced to the minimum, thereby achieving the aforesaid another object of the present invention.
According to a still further specific aspect of the present invention, there is provided a zoom lens system comprising, in order from an object side of said system, a first lens group having positive refracting power, a second lens group having negative refracting power, a third lens group having positive refracting power and a fourth lens group having positive refracting power, wherein during zooming, a space between said first and second lens groups, a space between said second and third lens groups and a space between said third and fourth lens groups vary independently, said first lens group comprises one positive lens, said second lens group comprise three lenses or, in order from an object side thereof, a single lens and a doublet consisting of a negative lens and a positive lens, said third lens group comprises three lenses or, in order from an object side thereof, a single lens and a doublet consisting of a positive lens and a negative lens, and said fourth lens group comprises one positive lens.
With this arrangement, it is possible to achieve a positive-negative-positive-positive power profile zoom lens system that can have good image-forming capability with a reduced number of lenses and so can be well suited for use with digital cameras. By allowing the burden of correction of aberrations to be concentrated on the second and third lens groups, each of the first and fourth lens groups taking no great part in correction of aberrations can be constructed of one positive lens. By allowing the second lens group sharing a great part of correction of aberrations to be constructed of, in order from the object side, a single lens and a doublet consisting of a negative lens and a positive lens, it is possible to reduce, with a minimum number of lenses, various aberrations inclusive of chromatic aberrations produced at the second lens group alone, thereby achieving a further size reduction. Use of the doublet consisting of a negative lens and a positive lens in the second lens group can reduce a performance drop due to decentration. By allowing the third lens group sharing a great part of the burden of correction of aberrations to be constructed of, in order from the object side, a single lens and a doublet consisting of a positive lens and a negative lens, it is possible to reduce, with a minimum number of lenses, various aberrations inclusive of chromatic aberrations produced at the third lens group alone, thereby achieving a further size reduction. Use of the doublet consisting of a positive lens and a negative lens in the third lens group can reduce a performance drop due to decentration.
In this embodiment, it is preferable to make the power of the first lens group weak because the amount of aberrations produced at the first lens group can be so reduced that the burden of correction of aberrations produced at the first lens group on the second and third lens groups can be relieved. Further, it is preferable that this embodiment satisfies the following condition (9):
8<F1/IH<20 (9)
where F1 is a focal length of the first lens group, and IH is an image height (a length from the center to the periphery of an image or the radius of an image circle). Falling below the lower limit of 8 in condition (9) is not preferable because the amount of aberrations produced at the first lens group increases. When the upper limit of 20 is exceeded, on the other hand, the power of the first lens group becomes weak, failing to obtain a satisfactory zoom ratio or achieve size reductions.
According to a still further specific aspect of the present invention, there is provided a zoom lens system comprising, in order from an object side of said system, a first lens group having positive refracting power, a second lens group having negative refracting power, a third lens group having positive refracting power and a fourth lens group having positive refracting power, wherein during zooming, a space between said first and second lens groups, a space between said second and third lens groups and a space between said third and fourth lens groups vary independently, said first lens group comprises two lenses or a positive lens and a negative lens, and said second or third lens group comprises a doublet consisting of at least one set of a positive lens and a negative lens.
In this embodiment, the first lens group is constructed of two lenses, i.e., a positive lens and a negative lens, whereby chromatic aberrations produced at the first lens group can be reduced irrespective of the power of the first lens group. This in turn allows the subsequent burden of correction of aberrations to be relieved, resulting in a size reduction of the optical system. By using the doublet consisting of a positive lens and a negative lens in the second or third lens group, it is then possible to reduce chromatic aberrations produced at other lens groups and prevent a deterioration in the image-forming capability due to decentration, etc. Consequently, it is possible to achieve an optical system favorable in view of the number of lenses, fabrication cost, and size reductions.
Still other objects and advantages of the invention will be part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.
Examples 1 to 16 of the zoom lens system according to the present invention are given. Lens data regarding the zoom lens system of each example will be given later.
The first lens group G1 is made up of, in order from an object side thereof, a negative meniscus lens convex on an object side thereof and a double-convex lens. The two lenses are separated from each other. The second lens group G2 is made up of, in order from an object side thereof, a double-concave lens and a positive meniscus lens convex on an object side thereof, with an aspherical surface being used for an image-side surface of the positive meniscus lens. The third lens group G3 is made up of, in order from an object side thereof, a double-convex lens and a negative meniscus lens convex on an object side thereof, with an aspherical surface being used for an object-side surface of the double-convex lens. The fourth lens group G4 is made up of one double-convex lens. Also, the zoom lens system of Example 1 satisfies the aforesaid condition (a).
A first lens group G1 is made up of, in order from an object side thereof, a negative meniscus lens convex on object side thereof, and a double-convex lens. The two lenses are separated from each other. A second lens group G2 is made up of, in order from an object side thereof, a double-concave lens, a negative meniscus lens convex on an object side thereof, and a positive meniscus lens convex on an object side thereof. The negative and positive meniscus lenses are cemented together, with an aspherical surface being used for an image-side surface of the positive meniscus lens. A third lens group G3 is made up of, in order from an object side thereof, a double-convex lens, a positive meniscus lens convex on an object side thereof, and a negative meniscus lens convex on an object side thereof. The positive and negative meniscus lenses are cemented together, with an aspherical surface being used for an object-side surface of the double-convex lens. A fourth lens group G4 is made up of one double-convex lens. Also, the zoom lens system of Example 2 satisfies the aforesaid condition (a).
A first lens group G1 is made up of, in order from an object side thereof, a negative meniscus lens convex on an object side thereof, and a double-convex lens. The two lenses are cemented together. A second lens group G2 is made up of, in order from an object side thereof, a double-concave lens, and a positive lens, with an aspherical surface being used for an image-side surface of the positive lens. A third lens group G3 is made up of, in order from an object side thereof, a double-convex lens, a positive meniscus lens convex on an object side thereof, and a negative meniscus lens convex on an object side thereof, with an aspherical surface being used for an object-side surface of the double-convex lens. A fourth lens group G4 is made up of one double-convex lens, with an aspherical surface being used for an object-side surface thereof. Also, the zoom lens system of Example 3 satisfies the aforesaid condition (a).
A first lens group G1 is made up of, in order from an object side thereof, a negative meniscus lens convex on an object side thereof, and a double-convex lens. The two lenses are separated from each other. A second lens group G2 is made up of, in order from an object side thereof, a double-concave lens, and a positive meniscus lens convex on an object side thereof, with an aspherical surface being used for an image-side surface of the positive meniscus lens. A third lens group G3 is made up of, in order from an object side thereof, a double-convex lens, a positive meniscus lens convex on an object side thereof, and a negative meniscus lens convex on an object side thereof, with an aspherical surface being used for an object-side surface of the double-convex lens. A fourth lens group G4 is made up of one double-convex lens. Also, the zoom lens system of Example 4 satisfies the aforesaid condition (a).
A first lens group G1 is made up of, in order from an object side thereof, a negative meniscus lens convex on an object side thereof, and a double-convex lens. The two lenses are cemented together. A second lens group G2 is made up of, in order from an object side thereof, a double-concave lens, a positive lens, and a double-concave lens, with an aspherical surface being used for an image-side surface of the positive lens. A third lens group G3 is made up of, in order from an object side thereof, a double-convex lens, a positive meniscus lens convex on an object side thereof, and a negative meniscus lens convex on an object side thereof, with an aspherical surface being used for an object-side surface of the double-convex lens. A fourth lens group G4 is made up of one positive meniscus lens convex on an object side thereof, with an aspherical surface being used for an object-side surface thereof. Also, the zoom lens system of Example 5 satisfies the aforesaid condition (a).
A first lens group G1 is made up of, in order from an object side thereof, a negative meniscus lens convex on an object side thereof, and a positive meniscus lens convex on an object side thereof. The two lens are cemented together. A second lens group G2 is made up of, in order from an object side thereof, a negative meniscus lens convex on an object side thereof, a double-concave lens, and a positive meniscus lens concave on an object side thereof. A third lens group G3 is made up of, in order from an object side thereof, two double-convex lenses, and a negative meniscus lens convex on an object side thereof, with an aspherical surface being used for an object-side surface of the double-convex lens located nearest to the object side. A fourth lens group G4 is made up of one double-convex lens. Also, the zoom lens system of Example 6 satisfies the aforesaid condition (a).
Example 7 is directed to a zoom lens system having a focal length of 5.50 to 15.75 and a field angle of 66.42° to 24°. As illustrated in
Example 8 is directed to a zoom lens system having a focal length of 5.52 to 15.91 and a field angle of 67.04° to 23.72°. As shown in
Example 9 is directed to a zoom lens system having a focal length of 5.50 to 15.81 and a field angle of 66.82° to 23.88°. As can be seen from
Example 10 is directed to a zoom lens system having a focal length of 5.50 to 15.87 and a field angle of 64.93° to 24.87°. As depicted in
Example 11 is directed to a zoom lens system having a focal length of 5.50 to 15.86 and a field angle of 68.30° to 24.54°. As illustrated in
As can be seen from
Example 12 is directed to a zoom lens system having a focal length of 6.608 to 19.098 and a field angle of 67.32° to 25.95°. As shown in
Example 13 is directed to a zoom lens system having a focal length of 6.613 to 18.999 and a field angle of 67.68° to 26.08°. As depicted in
Example 14 is directed to a zoom lens system having a focal length of 6.548 to 19 and a field angle of 67.80° to 26.08°. As illustrated in
Example 15 is directed to a zoom lens system having a focal length of 6.562 to 19 and a field angle of 67.69° to 26.08°. As shown in
Example 16 is directed to a zoom lens system having a focal length of 6.46 to 19 and a field angle of 68.52° to 26.08°. As shown in
Enumerated below are numerical data in each example. Symbols used hereinafter but not hereinbefore have the following meanings.
f = 5.50˜9.52˜15.94
FNO = 2.79˜3.39˜4.22
2ω = 63.5˜39.3˜24.1
r1 = 17.3312
d1 = 1.200
nd1 = 1.84666
νd1 = 23.78
r2 = 14.2714
d2 = 0.550
r3 = 19.0981
d3 = 2.566
nd2 = 1.69680
νd2 = 55.53
r4 = −211.9146
d4 = (Variable)
r5 = −99.9978
d5 = 0.840
nd3 = 1.77250
νd3 = 49.60
r6 = 4.9137
d6 = 1.765
r7 = 16.3236
d7 = 1.760
nd4 = 1.80518
νd4 = 25.42
r8 = 99.9991 (Aspheric)
d8 = (Variable)
r9 = ∞ (Stop)
d9 = (Variable)
r10 = 4.9282 (Aspheric)
d10 = 2.900
nd5 = 1.58913
νd5 = 61.18
r11 = −21.5942
d11 = 0.316
r12 = 8.1812
d12 = 0.700
nd6 = 1.84666
νd6 = 23.78
r13 = 3.9286
d13 =
(Variable)
r14 = 12.8501
d14 = 2.100
nd7 = 1.69680
νd7 = 55.53
r15 = −35.2750
Zooming Spaces
f
5.50
9.52
15.94
d4
0.989
4.786
8.395
d8
8.706
4.910
1.300
d9
5.958
2.921
0.936
d13
2.295
4.273
4.368
Aspherical Coefficients
8th surface
K = 0
A4 = −6.0228 × 10−4
A6 = −8.2596 × 10−6
A8 = −2.9515 × 10−8
A10 = −3.1439 × 10−8
10th surface
K = −0.2184
A4 = −9.2750 × 10−4
A6 = −4.4012 × 10−6
A8 = −3.1389 × 10−7
A10 = −2.1537 × 10−8
|L3|/L2| = 0.678
f = 5.33˜9.23˜15.45
FNO = 2.79˜3.11˜3.56
2ω = 65.1˜40.5˜24.8
r1 = 17.5585
d1 = 1.200
nd1 = 1.84666
νd1 = 23.78
r2 = 12.7200
d2 = 1.068
r3 = 16.3917
d3 = 3.679
nd2 = 1.69680
νd2 = 55.53
r4 = −84.4913
d4 = (Variable)
r5 = −48.2980
d5 = 0.840
nd3 = 1.77250
νd3 = 49.60
r6 = 5.3611
d6 = 1.827
r7 = 19.9998
d7 = 0.600
nd4 = 1.48749
νd4 = 70.21
r8 = 8.1444
d8 = 1.800
nd5 = 1.84666
νd5 = 23.78
r9 = 18.3790 (Aspheric)
d9 = (Variable)
r10 = ∞ (Stop)
d10 =
(Variable)
r11 = 5.9522 (Aspheric)
d11 = 2.300
nd6 = 1.58913
νd6 = 61.18
r12 = −23.5594
d12 = 0.1500
r13 = 8.1391
d13 = 1.500
nd7 = 1.60311
νd7 = 60.64
r14 = 19.5373
d14 = 0.100
r15 = 12.8481
d15 = 0.700
nd8 = 1.84666
νd8 = 23.78
r16 = 4.0598
d16 =
(Variable)
r17 = 9.9038
d17 = 2.100
nd9 = 1.69680
νd9 = 55.53
r18 = −33.9009
Zooming Spaces
f
5.33
9.23
15.45
d4
0.903
5.403
8.750
d9
9.247
4.746
1.400
d10
3.751
2.293
0.936
d16
3.894
3.917
3.510
Aspherical Coefficients
9th surface
K = 0
A4 = −3.8188 × 10−4
A6 = −5.4534 × 10−6
A8 = −5.0916 × 10−8
A10 = −1.5222 × 10−8
11th surface
K = −0.2184
A4 = −7.0868 × 10−4
A6 = 2.5182 × 10−5
A8 = −3.9567 × 10−6
A10 = −1.7645 × 10−7
|L3|/|L2| = 0.359
f = 5.50˜9.53˜15.81
FNO = 2.79˜3.35˜4.33
2ω = 63.4˜39.3˜24.3
r1 = 19.0896
d1 = 1.200
nd1 = 1.84666
νd1 = 23.78
r2 = 14.7521
d2 = 3.097
nd2 = 1.60311
νd2 = 60.64
r3 = −7692.3867
d3 = (Variable)
r4 = −76.4386
d4 = 0.840
nd3 = 1.77250
νd3 = 49.60
r5 = 4.8598
d5 = 1.811
r6 = 18.2814
d6 = 1.760
nd4 = 1.80518
νd4 = 25.42
r7 = ∞ (Aspheric)
d7 = (Variable)
r8 = ∞ (Stop)
d8 = (Variable)
r9 = 7.3400 (Aspheric)
d9 = 2.642
nd5 = 1.58913
νd5 = 61.18
r10 = −22.1205
d10 = 0.150
r11 = 8.0241
d11 = 1.973
nd6 = 1.72916
νd6 = 54.68
r12 = 52.4926
d12 = 0.150
r13 = 14.0423
d13 = 0.700
nd7 = 1.84666
νd7 = 23.78
r14 = 4.0797
d14 =
(Variable)
r15 = 10.1820 (Aspheric)
d15 = 1.745
nd8 = 1.58913
νd8 = 61.14
r18 = 1133.0330
Zooming Spaces
f
5.50
9.53
15.81
d3
1.157
5.471
8.096
d7
8.238
3.924
1.300
d8
5.647
3.626
0.936
d14
2.073
3.422
4.464
Aspherical Coefficients
7th surface
K = 0
A4 = −5.8146 × 10−4
A6 = −3.5256 × 10−7
A8 = −1.1100 × 10−6
A10 = 9.7216 × 10−9
9th surface
K = −0.2184
A4 = −5.1506 × 10−4
A6 = −2.2707 × 10−6
A8 = 2.5686 × 10−7
A10 = −1.0482 × 10−8
15th surface
K = 0
A4 = −2.2630 × 10−4
A6 = 1.7763 × 10−5
A8 = −1.5096 × 10−6
A10 = −9.3766 × 10−8
|L3|/|L2| = 0.679
f = 5.50˜9.53˜15.95
FNO = 2.79˜3.14˜3.97
2ω = 63.4˜39.3˜24.1
r1 = 19.3574
d1 = 1.200
nd1 = 1.84666
νd1 = 23.78
r2 = 14.9375
d2 = 0.349
r3 = 17.7409
d3 = 2.752
nd2 = 1.69680
νd2 = 55.53
r4 = −175.9537
d4 = (Variable)
r5 = −99.9969
d5 = 0.840
nd3 = 1.77250
νd3 = 49.60
r6 = 4.6050
d6 = 1.733
r7 = 14.5468
d7 = 1.760
nd4 = 1.80518
νd4 = 25.42
r8 = 60.0003 (Aspheric)
d8 = (Variable)
r9 = ∞ (Stop)
d9 = (Variable)
r10 = 6.3631 (Aspheric)
d10 = 2.300
nd5 = 1.58913
νd5 = 61.18
r11 = −29.3771
d11 = 0.150
r12 = 12.3021
d12 = 1.270
nd6 = 1.60311
νd6 = 60.64
r13 = 69.7876
d13 = 0.650
r14 = 11.6182
d14 = 0.700
nd7 = 1.84666
νd7 = 23.78
r15 = 4.4105
d15 =
(Variable)
r16 = 15.0443
d16 = 2.100
nd8 = 1.69680
νd8 = 55.53
r17 = −22.9162
Zooming Spaces
f
5.50
9.53
15.95
d4
1.089
5.514
8.193
d6
8.404
3.979
1.300
d8
5.452
3.557
0.936
d15
2.363
2.908
3.253
Aspherical Coefficients
8th surface
K = 0
A4 = −6.0060 × 10−4
A6 = −2.5355 × 10−5
A8 = 1.4947 × 10−6
A10 = −1.2788 × 10−7
10th surface
K = −0.2184
A4 = −6.2370 × 10−4
A6 = −6.8746 × 10−7
A8 = 1.5135 × 10−7
A10 = 1.2164 × 10−8
|L3|/|L2| = 0.636
f = 5.34˜9.26˜15.34
FNO = 2.79˜3.36˜4.48
2ω = 64.9˜40.3˜25.0
r1 = 19.0276
d1 = 1.200
nd1 = 1.84666
νd1 = 23.78
r2 = 13.5393
d2 = 3.589
nd2 = 1.60311
νd2 = 60.64
r3 = −422.2925
d3 = (Variable)
r4 = −644.1560
d4 = 0.840
nd3 = 1.77250
νd3 = 49.60
r5 = 4.6769
d5 = 1.796
r6 = 12.4221
d6 = 1.760
nd4 = 1.80518
νd4 = 25.42
r7 = ∞ (Aspheric)
d7 = 0.300
r8 = −19.3978
d8 = 0.800
nd5 = 1.51633
νd5 = 64.14
r9 = 112.3274
d9 = (Variable)
r10 = ∞ (Stop)
d10 =
(Variable)
r11 = 7.4109 (Aspheric)
d11 = 2.727
nd6 = 1.58913
νd6 = 61.18
r12 = −19.0346
d12 = 0.150
r13 = 8.1629
d13 = 2.046
nd7 = 1.72916
νd7 = 54.68
r14 = 103.6201
d14 = 0.150
r15 = 14.0489
d15 = 0.700
nd8 = 1.84666
νd8 = 23.78
r16 = 3.9993
d16 =
(Variable)
r17 = 10.7947 (Aspheric)
d17 = 1.676
nd9 = 1.58913
νd9 = 61.14
r18 = 244.0022
Zooming Spaces
f
5.50
9.53
15.34
d3
0.983
4.951
6.943
d9
7.260
3.292
1.300
d10
5.781
3.776
0.936
d16
2.140
3.006
3.335
Aspherical Coefficients
7th surface
K = 0
A4 = −5.8146 × 10−4
A6 = −3.5256 × 10−7
A8 = −1.1100 × 10−6
A10 = 9.7216 × 10−9
11th surface
K = −0.2184
A4 = −6.0173 × 10−4
A6 = −3.9633 × 10−6
A8 = 5.1710 × 10−7
A10 = −1.9276 × 10−8
17th surface
K = 0
A4 = −9.0648 × 10−5
A6 = 1.6145 × 10−5
A8 = −1.1806 × 10−6
A10 = 1.0627 × 10−7
|L3|/|L2| = 0.813
f = 5.52˜9.54˜15.91
FNO = 2.78˜3.39˜4.22
2ω = 63.2˜39.2˜24.1
r1 = 18.1384
d1 = 1.200
nd1 = 1.84666
νd1 = 23.78
r2 = 12.8515
d2 = 5.173
nd2 = 1.60311
νd2 = 60.64
r3 = 229.0114
d3 = (Variable)
r4 = 41.3044
d4 = 0.783
nd3 = 1.65160
νd3 = 58.55
r5 = 5.1749
d5 = 3.535
r6 = −33.2963
d6 = 0.700
nd4 = 1.56384
νd4 = 60.67
r7 = 20.7633
d7 = 0.000
r8 = 8.2198
d8 = 1.760
nd5 = 1.80518
νd5 = 25.42
r9 = 13.1948
d9 = (Variable)
r10 = ∞ (Stop)
d10 =
(Variable)
r11 = 12.3402 (Aspheric)
d11 = 3.698
nd6 = 1.67790
νd6 = 55.34
r12 = −11.8524
d12 = 0.858
r13 = 11.4834
d13 = 2.355
nd7 = 1.60311
νd7 = 60.64
r14 = −18.6404
d14 = 0.130
r15 = 48.4996
d15 = 0.700
nd8 = 1.84666
νd8 = 23.78
r16 = 5.5496
d16 =
(Variable)
r17 = 14.2502
d17 = 1.722
nd9 = 1.58913
νd9 = 61.14
r18 = −86.9086
Zooming Spaces
f
5.52
9.54
15.91
d3
0.684
4.781
7.816
d9
8.425
4.327
1.300
d10
5.375
3.214
0.936
d18
1.927
3.500
3.547
Aspherical Coefficients
11th surface
K = −0.2184
A4 = −7.1086 × 10−4
A6 = 2.9893 × 10−5
A8 = −3.3152 × 10−6
A10 = −1.3762 × 10−7
|L3|/|L2| = 0.622
f = 5.505˜9.536˜15.745
FNO = 2.792˜3.216˜4.113
r1 = 186.5411
d1 = 1.2000
nd1 = 1.84666
νd1 = 23.78
r2 = 39.3312
d2 = 3.9807
nd2 = 1.48749
νd2 = 70.23
r3 = −56.8902
d3 = 0.1800
r4 = 14.7260
d4 = 3.2694
nd3 = 1.69680
νd3 = 55.53
r5 = 62.1210
d5 = (Variable)
r6 = 74.5065
d6 = 0.8400
nd4 = 1.77250
νd4 = 49.60
r7 = 5.5423
d7 = 2.9761
r8 = −9.7293
d8 = 0.8400
nd5 = 1.48749
νd5 = 70.21
r9 = 11.8229
d9 = 1.8000
nd6 = 1.84666
νd6 = 23.78
r10 = −139.7255
d10 =
(Variable)
r11 = ∞ (Stop)
d11 =
(Variable)
r12 = 11.6742 (Aspheric)
d12 = 1.9422
nd7 = 1.58913
νd7 = 61.18
r13 = −23.0900
d13 = 0.1500
r14 = 8.6783
d14 = 2.6167
nd8 = 1.72916
νd8 = 54.68
r15 = −12.4135
d15 = 0.3000
r16 = 26.9742
d16 = 0.7000
nd9 = 1.84666
νd9 = 23.78
r17 = 4.2272
d17 =
(Variable)
r18 = 9.6808
d18 = 1.6130
nd10 = 1.72916
νd10 = 54.68
r19 = 32.9326
Zooming Spaces
f
5.505
9.536
15.745
d5
0.9695
4.4520
6.3793
d10
6.7009
3.2199
1.3000
d11
4.8930
3.4069
0.9360
d17
2.4323
3.4685
5.3700
Aspherical Coefficients
12th surface
K = −0.2184
A4 = −9.0556 × 10−4
A6 = −2.5457 × 10−5
A8 = 1.4387 × 10−6
A10 = −9.7103 × 10−8
|F2/F3| = 0.714
F3/F4 = 0.539
|β2T | = 0.897
|L3/L2| = 0.73
(F3,4W)/IH = 2.44
F1/IH = 6.97
f = 5.524˜9.537˜15.914
FNO = 2.784˜3.389˜4.215
r1 = 18.1384
d1 = 1.2000
nd1 = 1.84666
νd1 = 23.78
r2 = 12.8515
d2 = 5.1730
nd2 = 1.60311
νd2 = 60.64
r3 = 229.0224
d3 = (Variable)
r4 = 41.3044
d4 = 0.7827
nd3 = 1.65160
νd3 = 58.55
r5 = 5.1749
d5 = 3.5350
r6 = −33.2963
d6 = 0.7000
nd4 = 1.56384
νd4 = 60.67
r7 = 20.7633
d7 = −0.0132
r8 = 8.2198
d8 = 1.7596
nd5 = 1.80518
νd5 = 25.42
r9 = 13.1948
d9 = (Variable)
r10 = ∞ (Stop)
d10 =
(Variable)
r11 = 12.3402 (Aspheric)
d11 = 3.6983
nd6 = 1.67790
νd6 = 55.34
r12 = −11.8524
d12 = 0.8580
r13 = 11.4834
d13 = 2.3550
nd7 = 1.60311
νd7 = 60.64
r14 = −18.6404
d14 = 0.1297
r15 = 48.4996
d15 = 0.7000
nd8 = 1.84666
νd8 = 23.78
r16 = 5.5496
d16 =
(Variable)
r17 = 14.2502
d17 = 1.7219
nd9 = 1.58913
νd9 = 61.14
r18 = −86.9086
Zooming Spaces
f
5.524
9.537
15.914
d3
0.6836
4.7810
7.8162
d9
8.4251
4.3267
1.3000
d10
5.3747
3.2145
0.9360
d16
1.9272
3.5002
3.5470
Aspherical Coefficients
11th surface
K = −0.2184
A4 = −7.1086 × 10−4
A6 = 2.9893 × 10−5
A8 = −3.3152 × 10−6
A10 = = 1.3762 × 10−7
|F2/F3| = 0.837
F3/F4 = 0.475
|β2T | = 0.501
|L3/L2| = 0.62
(F3,4W)/IH = 2.58
F1/IH = 10.99
f = 5.505˜9.528˜15.810
FNO = 2.786˜3.348˜4.330
r1 = 19.0896
d1 = 1.2000
nd1 = 1.84666
νd1 = 23.78
r2 = 14.7521
d2 = 3.0968
nd2 = 1.60311
νd2 = 60.64
r3 = −7692.3867
d3 = (Variable)
r4 = −76.4386
d4 = 0.8400
nd3 = 1.77250
νd3 = 49.60
r5 = 4.8598
d5 = 1.8112
r6 = 18.2814
d6 = 1.7596
nd4 = 1.80518
νd4 = 25.42
r7 = ∞ (Aspheric)
d7 = (Variable)
r8 = ∞ (Stop)
d8 = (Variable)
r9 = 7.3400 (Aspheric)
d9 = 2.6421
nd5 = 1.58913
νd5 = 61.18
r10 = −22.1205
d10 = 0.1500
r11 = 8.0241
d11 = 1.9734
nd6 = 1.72916
νd6 = 54.68
r12 = 52.4926
d12 = 0.1500
r13 = 14.0423
d13 = 0.7000
nd7 = 1.84666
νd7 = 23.78
r14 = 4.0797
d14 =
(Variable)
r15 = 10.1820 (Aspheric)
d15 = 1.7446
nd8 = 1.58913
νd8 = 61.14
r16 = 1133.0330
Zooming Spaces
f
5.505
9.528
15.810
d3
1.1566
5.4711
8.0959
d7
8.2383
3.9238
1.3000
d8
5.6465
3.6256
0.9360
d14
2.0735
3.4220
4.4638
Aspherical Coefficients
7th surface
K = 0
A4 = −5.8146 × 10−4
A6 = −3.5256 × 10−7
A8 = −1.1100 × 10−6
A10 = 9.7216 × 10−9
9th surface
K = −0.2184
A4 = −5.1506 × 10−4
A6 = −2.2707 × 10−6
A8 = 2.5686 × 10−7
A10 = −1.0482 × 10−8
15th surface
K = 0
A4 = −2.2630 × 10−4
A6 = −1.7763 × 10−5
A8 = −1.5096 × 10−6
A10 = −9.3766 × 10−8
|F2/F3| = 0.866
F3/F4 = 0.591
|β2T| = 0.575
|L3/L2| = 0.68
(F3,4W)/IH = 2.52
F1/IH = 10.06
f = 5.502˜9.509˜15.873
FNO = 2.777˜3.341˜4.352
r1 = 16.5657
d1 = 3.6105
nd1 = 1.48749
νd1 = 70.23
r2 = 570.4842
d2 = (Variable)
r3 = 33.8910
d3 = 0.8356
nd2 = 1.84666
νd2 = 23.78
r4 = 5.4863
d4 = 2.6452
r5 = −13.8594
d5 = 0.8000
nd3 = 1.48749
νd3 = 70.23
r6 = 7.7346
d6 = 2.6020
nd4 = 1.84666
νd4 = 23.78
r7 = 423.2622
d7 = (Variable)
r8 = ∞ (Stop)
d8 = (Variable)
r9 = 8.6181 (Aspheric)
d9 = 3.3470
nd5 = 1.56384
νd5 = 60.67
r10 = −16.8991
d10 = 0.1208
r11 = 7.7569
d11 = 2.8653
nd6 = 1.77250
νd6 = 49.60
r12 = 258.5476
d12 = 0.7000
nd7 = 1.84666
νd7 = 23.78
r13 = 4.5291
d13 =
(Variable)
r14 = 9.7155 (Aspheric)
d14 =2.4486
nd8 = 1.56384
νd8 = 60.67
r15 = −47.1886
Zooming Spaces
f
5.502
9.509
15.873
d2
0.9830
5.3731
8.0323
d7
8.3593
3.9739
1.3000
d8
6.5283
4.2008
0.9360
d13
2.2562
3.7723
5.1579
Aspherical Coefficients
9th surface
K = −0.2184
A4 = −3.1865 × 10−4
A6 = 2.3167 × 10−7
A8 = 1.3223 × 10−8
A10 = 1.9200 × 10−10
14th surface
K = 0
A4 = −1.1041 × 10−4
A6 = −2.7188 × 10−6
A8 = 3.7776 × 10−7
A10 = 0
|F2/F3| = 0.779
F3/F4 = 0.794
|β2T| = 0.586
|L3/L2| = 0.792
(F3,4W)/IH = 2.71
F1/IH = 9.98
f = 5.504˜9.432˜15.856
FNO = 1.990˜2.273˜2.711
r1 = 18.2001
d1 = 1.1730
nd1 = 1.80518
νd1 = 25.42
r2 = 13.0296
d2 = 0.3357
r3 = 13.9728
d3 = 4.8470
nd2 = 1.69680
νd2 = 5553
r4 = 3102.7527
d4 = (Variable)
r5 = 424.6070
d5 = 0.8000
nd3 = 1.77250
νd3 = 49.60
r6 = −5.6105
d6 = 2.9586
r7 = −105.0017
d7 = 0.8000
nd4 = 1.48749
νd4 = 70.23
r8 = −10.6618
d8 = 2.3225
nd5 = 1.77250
νd5 = 29.20
r9 = −71.1193 (Aspheric)
d9 = (Variable)
r10 = ∞ (Stop)
d10 =
(Variable)
r11 = 9.2181 (Aspheric)
d11 = 2.9948
nd6 = 1.66910
νd6 = 55.40
r12 = −30.4447
d12 = 0.1424
r13 = −7.5345
d13 = 2.5546
nd7 = 1.67790
νd7 = 55.34
r14 = −80.3022
d14 = 0.7000
nd8 = 1.84666
νd8 = 23.78
r15 = −4.9693
d15 =
(Variable)
r16 = −9.4973 (Aspheric)
d16 = 2.8365
nd9 = 1.66910
νd9 = 55.40
r17 = −38.4689
Zooming Spaces
f
5.504
9.432
15.856
d4
0.7566
5.0506
8.1970
d9
8.7125
4.4098
1.3000
d10
4.9718
3.2094
0.9360
d15
2.2537
3.0666
3.9604
Aspherical Coefficients
9th surface
K = 0
A4 = −2.6558 × 10−4
A6 = 4.2392 × 10−6
A8 = −5.4464 × 10−7
A10 = 1.2756 × 10−8
11th surface
K = 0.2184
A4 = −1.8121 × 10−4
A6 = −1.3295 × 10−6
A8 = 1.4549 × 10−7
A10 = −4.6461 × 10−9
16th surface
K = 0
A4 = −2.5114 × 10−4
A6 = 3.1103 × 10−6
A8 = −1.1345 × 10−8
A10 = 0
|F2/F3| = 0.628
F3/F4 = 1.088
|β2T| = 0.760
|L3/L2| 0.54
(F3,4W)/IH = 2.67
F1/IH = 8.73
f = 6.608˜11.270˜19.098
FNO = 2.03˜2.36˜2.91
r1 = 36.688
d1 = 4.14
nd1 = 1.48749
νd1 = 70.23
r2 = ∞
d2 = (Variable)
r3 = 21.750
d3 = 1.25
nd2 = 1.84666
νd2 = 23.78
r4 = 8.054
d4 = 5.45
r5 = −27.511
d5 = 1.00
nd3 = 1.48749
νd3 = 70.23
r6 = 10.412
d6 = 4.50
nd4 = 1.84666
νd4 = 23.78
r7 = 40.550
d7 = (Variable)
r8 = ∞ (Stop)
d8 = (Variable)
r9 = 17.583 (Aspheric)
d9 = 3.42
nd5 = 1.58913
νd5 = 61.30
r10 = −35.670
d10 = 0.20
r11 = 9.390
d11 = 4.35
nd6 = 1.77250
νd6 = 49.60
r12 = 87.943
d12 = 0.90
nd7 = 1.84666
νd7 = 23.78
r13 = 6.609
d13 =
(Variable)
r14 = 13.553 (Aspheric)
d14 = 3.28
nd8 = 1.58913
νd8 = 61.30
r15 = −30.808
Zooming Spaces
f
6.608
11.270
19.098
d2
1.00
9.66
15.80
d7
16.20
7.55
1.50
d8
8.66
5.46
1.50
d13
3.46
5.00
5.71
Aspherical Coefficients
9th surface
K = 0.000
A4 = −4.66054 × 10−5
A6 = −1.33346 × 10−6
A8 = 6.88261 × 10−8
A10 = −1.18171 × 10−9
A12 = 1.21868 × 10−12
14th surface
K = 0.000
A4 = −9.93375 × 10−5
A6 = −9.76311 × 10−7
A8 = 3.21037 × 10−7
A10 = −1.95172 × 10−8
A12 = 3.74139 × 10−12
|F2/F3| = 0.77
F3/F4 = 1.12
|β2T| = 0.35
|L3/L2| 0.48
(F3,4W)/IH = 3.06
F1/IH = 17.10
f = 6.613˜11.256˜18.999
FNO = 2.64˜3.01˜3.85
r1 = 27.567
d1 = 4.40
nd1 = 1.48749
νd1 = 70.23
r2 = ∞
d2 = (Variable)
r3 = 34.610
d3 = 1.00
nd2 = 1.84666
νd2 = 23.78
r4 = 7.611
d4 = 4.17
r5 = −26.015
d5 = 0.95
nd3 = 1.48749
νd3 = 70.23
r6 = 9.781
d6 = 3.36
nd4 = 1.84666
νd4 = 23.78
r7 = 77.491
d7 = (Variable)
r8 = ∞ (Stop)
d8 = (Variable)
r9 = 9.059 (Aspheric)
d9 = 3.46
nd5 = 1.58913
νd5 = 61.28
r10 = −28.867
d10 = 0.20
r11 = 13.765
d11 = 3.12
nd6 = 1.77250
νd6 = 49.60
r12 = 81.243
d12 = 0.90
nd7 = 1.84666
νd7 = 23.78
r13 = 6.376
d13 =
(Variable)
r14 = 16.883
d14 = 2.54
nd8 = 1.80400
νd8 = 46.57
r15 = −22.639
d15 = 0.90
r16 = −13.830
d16 = 1.00
nd9 = 1.84666
νd9 = 23.78
r17 = −20.854
Zooming Spaces
f
6.613
11.256
18.999
d2
1.00
8.49
13.22
d7
13.73
6.24
1.50
d8
8.03
5.46
1.30
d13
2.38
3.71
5.53
Aspherical Coefficients
9th surface
K = 0.000
A4 = −2.44569 × 10−4
A6 = 1.63587 × 10−6
A8 = −2.54100 × 10−7
A10 = 1.25155 × 10−8
A12 = −2.30862 × 10−10
|F2/F3| = 0.76
F3/F4 = 1.09
|β2T| = 0.50
|L3/L2| 0.55
(F3,4W)/IH = 2.79
F1/IH = 12.85
f = 6.548˜11.266˜19.000
FNO = 2.02˜2.33˜2.80
r1 = 28.972
d1 = 1.50
nd1 = 1.84666
νd1 = 23.78
r2 = 19.691
d2 = 0.22
r3 = 20.405
d3 = 4.96
nd2 = 1.77250
νd2 = 49.60
r4 = 196.549
d4 = (Variable)
r5 = 42.098
d5 = 1.00
nd3 = 1.77250
νd3 = 449.60
r6 = 7.090
d6 = 4.71
r7 = −42.098
d7 = 0.95
nd4 = 1.57250
νd4 = 57.74
r8 = 7.798
d8 = 3.63
nd5 = 1.80100
νd5 = 34.97
r9 = 51.433
d9 = (Variable)
r10 = ∞ (Stop)
d10 =
(Variable)
r11 = 13.438 (Aspheric)
d11 = 2.85
nd6 = 1.58913
νd6 = 61.30
r12 = −33.468
d12 = 0.20
r13 = 16.565
d13 = 5.00
nd7 = 1.77250
νd7 = 49.60
r14 = 9.106
d14 = 0.90
nd8 = 1.68893
νd8 = 31.07
r15 = 7.645
d15 =
(Variable)
r16 = 13.914 (Aspheric)
d16 = 5.00
nd9 = 1.58913
νd9 = 61.30
r17 = −26.414
Zooming Spaces
f
6.548
11.266
19.000
d4
1.00
7.40
12.09
d9
12.59
6.19
1.50
d10
7.10
4.41
1.35
d15
2.01
3.28
3.97
Aspherical Coefficients
11th surface
K = 0.000
A4 = −1.15802 × 10−4
A6 = −2.30929 × 10−6
A8 = 9.29778 × 10−8
A10 = −1.70572 × 10−9
16th surface
K = 0.000
A4 = −1.50902 × 10−4
A6 = 7.59738 × 10−6
A8 = −4.34345 × 10−7
A10 = 9.20410 × 10−9
|F2/F3| = 0.64
F3/F4 = 1.07
|β2T| = 0.56
|L3/L2| 0.52
(F3,4W)/IH = 2.81
F1/IH = 10.96
f = 6.562˜11.266˜19.000
FNO = 2.03˜2.41˜2.98
r1 = 27.565
d1 = 1.80
nd1 = 1.84666
νd1 = 23.78
r2 = 22.250
d2 = 5.28
nd2 = 1.69680
νd2 = 55.53
r3 = 146.290
d3 = (Variable)
r4 = 33.155
d4 = 1.20
nd3 = 1.84666
νd3 = 23.78
r5 = 7.643
d5 = 5.94
r6 = −32.864
d6 = 0.95
nd4 = 1.58913
νd4 = 61.14
r7 = 9.442
d7 = 5.00
nd5 = 1.84666
νd5 = 23.78
r8 = 72.713
d8 = (Variable)
r9 = ∞ (Stop)
d9 = (Variable)
r10 = 13.995 (Aspheric)
d10 = 4.65
nd6 = 1.58913
νd6 = 61.30
r11 = −26.315
d11 = 0.20
r12 = 11.896
d12 = 5.00
nd7 = 1.77250
νd7 = 49.60
r13 = −19.763
d13 = 0.90
nd8 = 1.80518
νd8 = 25.42
r14 = 7.049
d14 =
(Variable)
r15 = 12.657 (Aspheric)
d15 = 5.00
nd9 = 1.58913
νd9 = 61.30
r16 = −36.523
Zooming Spaces
f
6.562
11.266
19.000
d3
1.00
7.09
11.56
d8
12.07
5.98
1.50
d9
7.83
4.88
1.35
d14
1.29
3.19
4.54
Aspherical Coefficients
10th surface
K = 0.000
A4 = −8.42531 × 10−5
A6 = −1.06102 × 10−6
A8 = 4.82414 × 10−8
A10 = −7.21004 × 10−10
15th surface
K = 0.00
A4 = −1.53723 × 10−4
A6 = 8.03934 × 10−6
A8 = −4.64104 × 10−7
A10 = 9.96594 × 10−9
|F2/F3| = 0.72
F3/F4 = 0.96
|β2T| = 0.55
|L3/L2| 0.61
(F3,4W)/IH = 2.73
F1/IH = 11.41
f = 6.460˜11.267˜19.000
FNO = 2.03˜2.36˜2.86
r1 = 45.399
d1 = 1.50
nd1 = 1.84666
νd1 = 23.78
r2 = 30.450
d2 = 3.42
nd2 = 1.77250
νd2 = 49.60
r3 = 73.068
d3 = 0.20
r4 = 30.537
d4 = 4.00
nd3 = 1.60311
νd3 = 60.64
r5 = 114.998
d5 = (Variable)
r6 = 37.983
d6 = 1.00
nd4 = 1.80610
νd4 = 40.92
r7 = 7.134
d7 = 4.94
r8 = −34.697
d8 = 0.95
nd5 = 1.59551
νd5 = 39.24
r9 = 7.910
d9 = 3.74
nd6 = 1.80518
νd6 = 25.42
r10 = 61.919
d10 =
(Variable)
r11 = ∞ (Stop)
d11 =
(Variable)
r12 = 20.148 (Aspheric)
d12 = 3.82
nd7 = 1.58913
νd7 = 61.30
r13 = −27.415
d13 = 0.20
r14 = 11.775
d14 = 5.00
nd8 = 1.77250
νd8 = 49.60
r15 = −16.598
d15 = 0.90
nd9 = 1.74077
νd9 = 27.79
r16 = 7.678
d16 =
(Variable)
r17 = 14.447 (Aspheric)
d17 = 5.00
nd10 = 1.58913
νd10 = 61.30
r18 = −24.089
Zooming Spaces
f
6.460
11.267
19.000
d5
1.00
7.29
11.76
d10
12.25
5.96
1.50
d11
7.87
4.72
1.35
d16
2.96
4.38
4.80
Aspherical Coefficients
12th surface
K = 0.000
A4 = −4.84618 × 10−5
A6 = −1.50477 × 10−6
A8 = 6.27337 × 10−8
A10 = 9.73311 × 10−10
17th surface
K = 0.000
A4 = −1.24232 × 10−4
A6 = 4.55032 × 10−6
A8 = −2.09257 × 10−7
A10 = 3.76691 × 10−9
|F2/F3| = 0.59
F3/F4 = 1.08
|β2T| = 0.55
|L3/L2| 0.61
(F3,4W)/IH = 2.96
F1/IH = 11.19
Aberration curve diagrams of Example 1 are shown in
As can be understood from the foregoing explanation, the present invention can provide a compact yet low-cost zoom lens system with well-corrected aberrations.
Miyauchi, Yuji, Ishii, Atsujiro
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