An imaging lens includes, in this order from an object side, an aperture stop ST, a positive first lens L1, a negative second lens L2 having a meniscus shape that directs a convex surface on the object side near an optical axis, a positive third lens L3, a positive fourth lens L4 having a meniscus shape that directs a concave surface on the object side near an optical axis, and a negative fifth lens L5 having a meniscus shape that directs a convex surface on the object side near an optical axis.
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0. 1. An imaging lens comprising:
a first lens having positive refractive power;
a second lens having negative refractive power;
a third lens having positive refractive power;
a fourth lens having positive refractive power; and
a fifth lens having negative refractive power in this order from an object side to an image side,
wherein said second lens is formed in a shape so that both a curvature radius of a surface thereof on the object side and a curvature radius of a surface thereof on the image side are positive,
said fourth lens is formed in a shape so that both a curvature radius of a surface thereof on the object side and a curvature radius of a surface thereof on the image side are negative,
said first lens and said second lens have a composite focal length f12, and said third lens and said fourth lens have a composite focal length f34 so that the following conditional expression is satisfied:
1.592≤f34/f12<4.0, and said first lens has an Abbe's number νd1, said second lens has an Abbe's number νd2, said third lens has an Abbe's number νd3, said fourth lens has an Abbe's number νd4, and said fifth lens has an Abbe's number νd5 so that the following conditional expressions are satisfied:
50<νd1<85 νd2<30 50<νd3<85 50<νd4<85 50<νd5<85. 0. 11. An imaging lens comprising:
a first lens having positive refractive power;
a second lens;
a third lens;
a fourth lens having positive refractive power; and
a fifth lens, arranged in this order from an object side to an image plane side,
wherein said first lens and said second lens have a composite focal length f12, and said third lens and said fourth lens have a composite focal length f34 so that the following conditional expression is satisfied:
1.592≤f34/f12<4.0, and said first lens has an Abbe's number νd1, said second lens has an Abbe's number νd2, said third lens has an Abbe's number νd3, said fourth lens has an Abbe's number νd4, and said fifth lens has an Abbe's number νd5 so that the following conditional expressions are satisfied:
50<νd1<85, νd2<30, 50<νd3<85, 50<νd4<85, 50<νd5<85. 0. 5. An imaging lens comprising:
a first lens having positive refractive power;
a second lens;
a third lens;
a fourth lens; and
a fifth lens having negative refractive power, arranged in this order from an object side to an image plane side,
wherein said first lens and said second lens have a composite focal length f12, and said third lens and said fourth lens have a composite focal length f34 so that the following conditional expressions are satisfied:
1.592≤f34/f12<4.0, and said first lens has an Abbe's number νd1, said second lens has an Abbe's number νd2, said third lens has an Abbe's number νd3, said fourth lens has an Abbe's number νd4, and said fifth lens has an Abbe's number νd5 so that the following conditional expressions are satisfied:
50<νd1<85, νd2<30, 50<νd3<85, 50<νd4<85, 50<νd5<85. 0. 17. An imaging lens comprising:
a first lens having positive refractive power;
a second lens;
a third lens;
a fourth lens; and
a fifth lens, arranged in this order from an object side to an image plane side,
wherein said third lens is formed in a shape so that a curvature radius of a surface thereof on the image plane side is positive,
said first lens and said second lens have a composite focal length f12, and said third lens and said fourth lens have a composite focal length f34 so that the following conditional expression is satisfied:
1.592≤f34/f12<4.0, and said first lens has an Abbe's number νd1, said second lens has an Abbe's number νd2, said third lens has an Abbe's number νd3, said fourth lens has an Abbe's number νd4, and said fifth lens has an Abbe's number νd5 so that the following conditional expressions are satisfied:
50<νd1<85, νd2<30, 50<νd3<85, 50<νd4<85, 50<νd5<85. 0. 2. The imaging lens according to
0. 3. The imaging lens according to
0.5<f34/f<5.0. 0. 4. The imaging lens according to
0.4<|f1/f2|<1.0. 0. 6. The imaging lens according to claim 5, wherein said third lens has positive refractive power.
0. 7. The imaging lens according to claim 5, wherein said fourth lens has positive refractive power.
0. 8. The imaging lens according to claim 5, wherein said second lens is formed in the shape so that a curvature radius of a surface thereof on the object side is positive, and
said fourth lens is formed in a shape so that a curvature radius of a surface thereof on the object side is negative.
0. 9. The imaging lens according to claim 5, wherein said third lens and said fourth lens have the composite focal length f34 so that the following conditional expression is satisfied:
0.5<f34/f<5.0, where f is a focal length of a whole lens system.
0. 10. The imaging lens according to claim 5, wherein said first lens has a focal length f1 and said second lens has a focal length f2 so that the following conditional expression is satisfied:
0.4<|f1/f2|<1.0. 0. 12. The imaging lens according to claim 11, wherein said third lens has positive refractive power.
0. 13. The imaging lens according to claim 11, wherein said fifth lens has negative refractive power.
0. 14. The imaging lens according to claim 11, wherein said second lens is formed in a shape so that a curvature radius of a surface thereof on the object side is positive, and
said fourth lens is formed in a shape so that a curvature radius of a surface thereof on the object side is negative.
0. 15. The imaging lens according to claim 11, wherein said third lens and said fourth lens have the composite focal length f34 so that the following conditional expression is satisfied:
0.5<f34/f<5.0, where f is a focal length of a whole lens system.
0. 16. The imaging lens according to claim 11, wherein said first lens has a focal length f1 and said second lens has a focal length f2 so that the following conditional expression is satisfied:
0.4<|f1/f2|<1.0. |
When the conditional expression (1) is satisfied, it is possible to restrain the field curvature and the astigmatism within satisfactory range while specifically restraining an incident angle of an off-axis light beam into an imaging element among light beams that are emitted from the imaging lens within certain range. As well known, there is so-called maximum incident angle, which is a limit in an incident angle of a light beam for an imaging element to receive due to its structure. In case a light beam outside the maximum incident angle range enters the imaging element, a resultant image has a dark periphery because of a shading phenomenon. Accordingly, it is necessary to restrain the incident angle of the light beam emitted from the imaging lens to the imaging element within a certain range.
On the other hand, the second lens having negative refractive power is disposed on the object side of the third lens, and the fifth lens similarly having negative refractive power is disposed on the image side of the fourth lens. More specifically, the third and the fourth lenses having positive refractive power are disposed between the second and the fifth lenses that have negative refractive power. When the conditional expression (1) is satisfied, it is also possible to satisfactorily correct the field curvature and the astigmatism in the aforementioned refractive power arrangement.
When the value exceeds the upper limit “5.0” in the conditional expression (1), the composite refractive power of the third and the fourths lenses decreases in comparison with refractive power of the whole lens system and the image surface tilts in the plus direction (on the image side), so that it becomes difficult to restrain the field curvature within preferred range. In addition, since the astigmatic difference increases, it is also difficult to obtain a flat image surface. On the other hand, when the value is below the lower limit “0.5”, the composite refractive power of the third and the fourth lenses increases in comparison with the refractive power of the whole lens system, and the image surface tilts in the minus direction (on the object side). Therefore, even in this case, it is difficult to restrain the field curvature and the astigmatism within preferred range. In addition, it is also difficult to restrain an incident angle of an off-axis light beam to an imaging element within certain range.
When the first lens has a focal length f and the second lens has a focal length f2, it is preferred to satisfy the following conditional expression (2):
0.4<|f1/f2|<1.0 (2)
When the conditional expression (2) is satisfied, it is possible to restrain the spherical aberration and the field curvature in a balanced manner within satisfactory range, while restraining the axial chromatic aberration and the off-axis chromatic aberration of magnification within satisfactory range. When the value exceeds the upper limit “1.0”, since the refractive power of the second lens increases in comparison with the refractive power of the first lens, the axial chromatic aberration and the off-axis chromatic aberration of magnification is excessively corrected (that of short wavelength is in the plus direction in relative to that of a reference wavelength). Furthermore, since the spherical aberration and the field curvature increase in the plus direction (on the image side), it is difficult to obtain satisfactory imaging performance. On the other hand, when the value is below the lower limit “0.4”, since the refractive power of the second lens decreases in comparison with the refractive power of the first lens, the axial chromatic aberration and the off-axis chromatic aberration of magnification are insufficiently corrected (that of a short wavelength is in the minus direction in relative to that of a reference wavelength). In addition, in this case, the spherical aberration and the field curvature increase in the minus direction (on the object side), so that it is still difficult to obtain satisfactory imaging performance.
When a composite focal length of the first lens and the second lens is f12 and a composite focal length of the third lens and the fourth lens is f34, it is preferred to satisfy the conditional expression (3):
0.2<f34/f12<4.0 (3)
When the conditional expression (3) is satisfied, it is possible to attain miniaturization of the imaging lens and restrain an incident angle of the off-axis light beam emitted from the imaging lens to the imaging element within certain range, while restraining the aberrations in a balance manner within the preferred range. When the value exceeds the upper limit “4.0”, composite refractive power of the first lens and the second lens increases in comparison with composite refractive power of the third lens and the fourth lens, and it is advantageous to attain miniaturization of the imaging lens. At the same time, however, it is difficult to restrain the incident angles of the off-axis light beams emitted from the imaging lens to the imaging element within certain range. Moreover, since the inward coma aberration by an off-axis light beam is generated, it is difficult to obtain satisfactory imaging performance. On the other hand, when the value is below the lower limit “0.2”, composite refractive power of the first lens and the second lens decreases in comparison with composite refractive power of the third lens and the fourth lens, and it is advantageous to restrain the incident angles within certain range, but it is difficult to attain miniaturization of the imagine lens.
When Abbe's number of the first lens is νd1, Abbe's number of the second lens is νd2, Abbe's number of the third lens is νd3, Abbe's number of the fourth lens is νd4, and Abbe's number of the fifth lens is νd5, it is preferred to satisfy the following conditional expressions (4) to (8):
50<νd1<85 (4)
νd2<30 (5)
50<νd3<85 (6)
50<νd4<85 (7)
50<νd5<85 (8)
When the conditional expressions (4) to (8) are satisfied, it is possible to more satisfactorily correct the axial chromatic aberration and the off-axis chromatic aberration of magnification. As a method of correcting those chromatic aberrations, it has been known to combine a highly-dispersed material and a low-dispersed material. In case of an imaging lens of a five-lens configuration, it is possible to correct chromatic aberration by using the method to alternately combine a highly-dispersed material and a low-dispersed material. However, in case of correcting chromatic aberrations by the method, a chromatic aberration of magnification frequently turns to an excessively corrected state from an insufficiently corrected state as it is close to a periphery from a center of the image surface, when the length (thickness) of the imaging lens along the optical axis thereof decreases, especially in case of off-axis light beams. Therefore, it is difficult to satisfactorily correct chromatic aberration of magnification. According to the imaging lens of the invention, since Abbe's numbers of four out of the five lenses are greater than 50 when the conditional expressions (4) to (8) are satisfied, the axial chromatic aberration and the off-axis chromatic aberration of magnification are more satisfactorily corrected.
According to the imaging lens of the invention, it is possible to both reduce a size of the imaging lens and correct the aberration properly, thereby making it possible to provide the imaging lens with the small size capable of correcting aberrations properly.
Hereunder, referring to the accompanying drawings, an embodiment of the present invention will be fully described.
As shown in
In an imaging lens of the aforementioned configuration, the first lens L1 is formed in a shape so that a curvature radius of a surface on the object side R2 is positive and a curvature radius of a surface on the image side R3 is negative, i.e., a shape to be biconvex lens near the optical axis thereof. Here, the shape of the first lens L1 is not limited to such shape having a biconvex lens near the optical axis thereof, and may be any as long as the curvature radius of a surface on the object side R2 is positive, so that various shapes may be employed. Numerical Data Examples 1 and 3 are examples that the shape of the first lens L1 is a biconvex lens near the optical axis thereof, whereas Numerical Data Examples 2 and 4 are examples that the first lens L1 is formed in a shape so that both curvature radii R2 and R3 are positive, i.e. the shape to be a meniscus lens that directs a convex surface on the object side near the optical axis thereof.
The second lens L2 is formed in a shape so that both a curvature radius of a surface thereof on the object side R4 and a curvature radius of a surface on the image side R5 are positive and is shaped to form a meniscus lens that directs a convex surface on the object side near the optical axis thereof. The third lens L3 is formed in a shape so that both a curvature radius of a surface thereof on the object side R6 and a curvature radius of a surface on the image side R7 are positive and is shaped to forma meniscus lens that directs a convex surface on the object side near the optical axis thereof. The shape of the third lens L3 is not limited to a shape of a meniscus lens that directs a convex surface on the object side near the optical axis thereof. Other than the ones described above, the third lens L3 may have a shape of a biconvex lens near the optical axis thereof, or a shape having negative curvature radii R6 and R7, i.e. a shape to be a meniscus lens that directs a concave surface on the object side.
The fourth lens L4 is formed in a shape so that both a curvature radius of a surface thereof on the object side R8 and a curvature radius of a surface thereof on the image side R9 are negative, i.e. a shape to be a meniscus lens that directs a concave surface on the objects side near the optical axis thereof. The fifth lens L5 is formed in a shape so that both a curvature radius of a surface thereof on the object side R10 and a curvature radius of a surface on the image surface R11 are positive, and is shaped to form a meniscus lens that directs a convex surface on the object side near the optical axis thereof. Here, the shape of the fifth lens is not limited to the shape of a meniscus lens that directs a convex surface on the object side near the optical axis thereof, and may be shaped to form a meniscus lens that directs a concave surface on the object side near the optical axis thereof, or formed in a shape so that a curvature radius R10 is negative and a curvature radius R11 is positive, i.e. a shape to be a biconcave lens near the optical axis thereof.
In addition, a surface of the fifth lens L5 on the image side has an aspheric shape that is convex on the object side near the optical axis thereof and concave on the object side at the periphery. Because of the shape of the fifth lens like this, an incident angle of a light beam emitted from an imaging lens to an image plane is restrained. The imaging lens of this embodiment satisfies the following conditional expressions (1) to (3):
0.5<f34/f<5.0 (1)
0.4<|f1/f2|<0.9 (2)
0.2<f34/f12<4.0 (3)
In the above conditional expressions,
f: Focal length of the whole lens system
f1: Focal length of the first lens L1
f2: Focal length of the second lens L2
f34: Composite focal length of the third lens L3 and the fourth lens L4
In addition, the imaging lens of this embodiment satisfies the following conditional expressions (4) to (8) in addition to the above-described conditional expressions (1) to (3), in order to satisfactorily correct chromatic aberrations:
50<νd1<85 (4)
νd2<30 (5)
50<νd3<85 (6)
50<νd4<85 (7)
50<νd5<85 (8)
In the Above expressions,
νd1: Abbe's number of the first lens L1 at a d line
νd2: Abbe's number of the second lens L2 at a d line
νd3: Abbe's number of the third lens L3 at a d line
νd4: Abbe's number of the fourth lens L4 at a d line
νd5: Abbe's number of the fifth lens L5 at a d line
Here, it is not necessary to satisfy all of the conditional expressions (1) to (8). When any single one of the conditional expressions (1) to (8) is individually satisfied, it is possible to obtain an effect corresponding to the respective conditional expression.
In the embodiment, the lens surfaces of all lenses are shaped to form an aspheric surface as necessary. When the aspheric surface applied to the lens surfaces have an axis Z in the optical axis direction, a height H in a direction perpendicular to the optical axis thereof, a conical coefficient k, and aspheric coefficients A4, A6, A8, A10, A12, A14, and A16, the aspheric surfaces of the lens surfaces may be expressed as follows:
Next, Numerical Data Examples of the embodiment will be described. In each of Numerical Data Examples, f represents a focal length of a whole lens system, Fno represents an F number, and ω represents a half angle of view, respectively. In addition, i represents a surface number counted from the object side, R represents a curvature radius, d represents a distance between lens surfaces (an on-axis surface spacing) on the optical axis, Nd represents a refractive index at a d line, and νd represents Abbe's number at the d line. Here, the aspheric surfaces are indicated with surface numbers affixed with * (asterisk). For reference, sum of surface spacing from a surface of the first lens L1 on the object side to a surface of the fifth lens L5 on the image side is indicated as L15.
Basic lens data are shown below.
f = 5.690 mm, Fno = 3.000, ω = 34.18°
Unit: mm
Surface Data
Surface
Number i
R
d
Nd
νd
(Object)
∞
∞
1 (Stop)
∞
0.00000
2*
1.7839
0.53697
1.53460
56.3 (=νd1)
3*
−36.8497
0.08287
4*
8.1562
0.30000
1.61420
26.0 (=νd2)
5
2.0240
0.49004
6*
4.7722
0.54460
1.53460
56.3 (=νd3)
7*
6.5369
0.48711
8*
−1.6692
0.44978
1.53460
56.3 (=νd4)
9*
−1.7486
0.27430
10*
3.1053
0.99632
1.53460
56.3 (=νd5)
11*
2.6949
0.90000
12
∞
0.21000
1.51633
64.12
13
∞
1.09751
(image
∞
plane)
f1 = 3.198
f2 = −4.466
f3 = 29.857
f4 = 70.689
f5 = −247.269
f12 = 7.370
f34 = 22.808
L15 = 4.16199
Aspheric Surface Data
Second Surface
k = 0.00000000, A4 = −0.76414807E−02, A6 = 0.34244562E−01,
A8 = −0.35162391E−01, A10 = 0.72884223E−02,
A12 = 0.16282392E−01, A14 = −0.13286570E−01
Third Surface
k = 0.00000000, A4 = 0.79211780E−01, A6 = −0.43839669E−01,
A8 = −0.76746172E−02, A10 = −0.11892911E−01,
A12 = −0.10264347E−01, A14 = 0.13571981E−01
Fourth Surface
k = 0.00000000, A4 = 0.68255774E−01, A6 = −0.55078565E−01,
A8 = −0.84020557E−02, A10 = −0.13405905E−01,
A12 = −0.33193102E−02, A14 = 0.14026150E−01
Sixth Surface
k = 0.00000000, A4 = −0.68806298E−01, A6 = 0.55162308E−02,
A8 = 0.95610071E−02, A10 = −0.77026230E−02,
A12 = −0.11260551E−01, A14 = 0.51394464E−02
Seventh Surface
k = 0.00000000, A4 = −0.83816907E−01, A6 = 0.64066471E−02,
A8 = −0.78499370E−02, A10 = −0.19790795E−01,
A12 = 0.40753526E−02, A14 = 0.18631791E−03
Eighth Surface
k = 0.00000000, A4 = 0.11254679, A6 = −0.13203205,
A8 = 0.14635128, A10 = −0.90218095E−01,
A12 = 0.27510752E−02, A14 = 0.62647402E−02
Ninth Surface
k = −0.91589860, A4 = 0.35033555E−01, A6 = 0.47692822E−02,
A8 = 0.10837748E−01, A10 = −0.53011858E−02,
A12 = 0.35563263E−03, A14 = 0.70837290E−04
Tenth Surface
k = 0.00000000, A4 = −0.91591404E−01, A6 = 0.31997817E−01,
A8 = −0.80405225E−02, A10 = 0.81598968E−03,
A12 = 0.12913470E−03, A14 = −0.42574901E−04,
A16 = 0.30352929E−05
Eleventh Surface
k = −7.26384200, A4 = −0.46752322E−01, A6 = 0.13616036E−01,
A8 = −0.34575303E−02, A10 = 0.57070286E−03,
A12 = −0.60882678E−04, A14 = 0.42759142E−05,
A16 = −0.17802666E−06
The values of the conditional expressions (1) to (8) are shown below.
f34/f = 4.008
|f1/f2| = 0.716
f34/f12 = 3.095
νd1 = 56.3
νd2 = 26.0
νd3 = 56.3
νd4 = 56.3
νd5 = 56.3
Accordingly, the imaging lens of Numerical Data Example 1 satisfies the conditional expressions (1) to (8).
Basic lens data are shown below.
f = 5.888 mm, Fno = 3.000, ω = 33.27°
Unit: mm
Surface Data
Surface
Number i
R
d
Nd
νd
(Object)
∞
∞
1 (Stop)
∞
0.00000
2*
1.9102
0.64885
1.53460
56.3 (=νd1)
3*
31.7016
0.15138
4*
32.2938
0.30000
1.61420
26.0 (=νd2)
5*
3.1263
0.49796
6*
5.0203
0.54150
1.53460
56.3 (=νd3)
7*
17.7320
0.71595
8*
−1.7385
0.79514
1.53460
56.3 (=νd4)
9*
−1.1945
0.06004
10*
23.4771
0.97150
1.53460
56.3 (=νd5)
11*
1.8913
0.90000
12
∞
0.21000
1.51633
64.12
13
∞
0.90271
(image
∞
plane)
f1 = 3.774
f2 = −5.658
f3 = 12.908
f4 = 4.731
f5 = −3.909
f12 = 7.941
f34 = 3.981
L15 = 4.68232
Aspheric Surface Data
Second Surface
k = 0.00000000, A4 = −0.60935179E−02, A6 = −0.14836487E−02,
A8 = 0.58172177E−01, A10 = −0. 92636605E−01,
A12 = 0.64338649E−01, A14 = −0.18000000E−01
Third Surface
k = 0.00000000, A4 = −0.37213898E−01, A6 = 0.59495237E−01,
A8 = −0.10530910E−01, A10 = −0.11123351E−01,
A12 = −0.65206414E−02
Fourth Surface
k = 0.00000000, A4 = −0.93113075E−01, A6 = 0.17824848,
A8 = −0.15616907, A10 = 0.72633906E−01,
A12 = −0.27141522E−01
Fifth Surface
k = 0.00000000, A4 = −0.71937469E−01, A6 = 0.16732493,
A8 = −0.16595257, A10 = 0.84793690E−01,
A12 = −0.16793256E−01
Sixth Surface
k = 0.13693290E+02, A4 = −0.53326105E−01, A6 = −0.11942210E−01,
A8 = 0.12893456E−01, A10 = −0.60447418E−02
Seventh Surface
k = 0.17790910E+03, A4 = −0.38719591E−01, A6 = −0.20287221E−01,
A8 = 0.27230067E−02, A10 = −0.18941862E−02
Eighth Surface
k = −0.01131517, A4 = 0.14642524E−01, A6 = −0.51671204E−01,
A8 = 0.44911419E−01, A10 = −0.22777822E−01,
A12 = 0.24872721E−02
Ninth Surface
k = −0.85604290, A4 = 0.66111100E−01, A6 = −0.27225762E−01,
A8 = 0.19417970E−01, A10 = −0.52722030E−02,
A12 = 0.50122117E−03
Tenth Surface
k = 0.82941990E+02, A4 = −0.56542244E−01, A6 = 0.30227928E−01,
A8 = −0.84060662E−02, A10 = 0.79169059E−03,
A12 = 0.13962874E−03, A14 = −0.42788235E−04,
A16 = 0.30748826E−05
Eleventh Surface
k = −8.75909800, A4 = −0.46100654E−01, A6 = 0.14779860E−01,
A8 = −0.36296237E−02, A10 = 0.59179333E−03,
A12 = −0.62985700E−04, A14 = 0.38534296E−05,
A16 = −0.10603576E−06
The values of the conditional expressions (1) to (8) are shown below.
f34/f = 0.676
|f1/f2| = 0.667
f34/f12 = 0.501
νd1 = 56.3
νd2 = 26.0
νd3 = 56.3
νd4 = 56.3
νd5 = 56.3
Accordingly, the imaging lens of Numerical Data Example 2 satisfies the conditional expressions (1) to (8).
Basic lens data are shown below.
f = 4.766 mm, Fno = 2.900, ω = 35.50°
Unit: mm
Surface Data
Surface
Number i
R
d
Nd
νd
(Object)
∞
∞
1 (Stop)
∞
0.00000
2*
2.3150
0.56000
1.53500
56.2 (=νd1)
3*
−5.6670
0.15600
4*
14.2000
0.29500
1.63400
23.9 (=νd2)
5*
2.3500
0.48500
6*
7.5400
0.42800
1.54340
56.0 (=νd3)
7*
98.2570
0.44600
8*
−1.3860
0.65200
1.54340
56.0 (=νd4)
9*
−1.0050
0.10000
10*
5.1110
0.88200
1.53500
56.2 (=νd5)
11*
1.4780
0.80000
12
∞
0.30000
1.51633
64.12
13
∞
0.84091
(image
∞
plane)
f1 = 3.149
f2 = −4.485
f3 = 15.004
f4 = 4.198
f5 = −4.246
f12 = 7.148
f34 = 3.600
L15 = 4.00400
Aspheric Surface Data
Second Surface
k = 0.00000000, A4 = −0.20609735E−01, A6 = −0.86635750E−02,
A8 = −0.41092465E−01, A10 = 0.14610217E−01
Third Surface
k = 0.00000000, A4 = 0.29740191E−01, A6 = −0.58777750E−01,
A8 = −0.22460108E−01, A10 = 0.25927431E−01
Fourth Surface
k = 0.00000000, A4 = 0.57597969E−01, A6 = −0.32080574E−01,
A8 = −0.83064180E−02, A10 = 0.26550300E−01
Fifth Surface
k = 0.00000000, A4 = 0.37999286E−02, A6 = 0.20353948E−01,
A8 = −0.98598681E−02, A10 = 0.10758619E−01
Sixth Surface
k = 0.00000000, A4 = −0.63793469E−01, A6 = 0.55178545E−02,
A8 = −0.64178800E−02, A10 = 0.81174025E−02
Seventh Surface
k = 0.00000000, A4 = −0.31834097E−01, A6 = −0.48702563E−02,
A8 = −0.25983774E−02, A10 = 0.20212526E−02
Eighth Surface
k = −0.46194440, A4 = 0.69350049E−01, A6 = −0.51916822E−02,
A8 = 0.18682594E−01, A10 = −0.89429170E−02,
A12 = 0.13942614E−02
Ninth Surface
k = −1.01311200, A4 = 0.81085778E−01, A6 = −0.41721302E−01,
A8 = 0.23744754E−01, A10 = −0.38004290E−02,
A12 = 0.74937061E−04
Tenth Surface
k = −0.82922410E+02, A4 = −0.26011142E−01, A6 = −0.77102124E−02,
A8 = 0.61622809E−02, A10 = −0.15640982E−02,
A12 = 0.13063488E−04, A14 = 0.55529881E−04,
A16 = −0.62996500E−05
Eleventh Surface
k = −8.24681400, A4 = −0.45770587E−01, A6 = 0.12151448E−01,
A8 = −0.31734309E−02, A10 = 0.61093272E−03,
A12 = −0.87817174E−04, A14 = 0.78389771E−05,
A16 = −0.31638966E−06
The values of the conditional expressions (1) to (8) are shown below.
f34/f = 0.755
|f1/f2| = 0.702
f34/f12 = 0.504
νd1 = 56.2
νd2 = 23.9
νd3 = 56.0
νd4 = 56.0
νd5 = 56.2
Accordingly, the imaging lens of Numerical Data Example 3 satisfies the conditional expressions (1) to (8).
As shown in
Basic lens data are shown below.
f = 5.977 mm, Fno = 3.000, ω = 32.88°
Unit: mm
Surface Data
Surface
Number i
R
d
Nd
νd
(Object)
∞
∞
1 (Stop)
∞
0.00000
2*
1.7580
0.53427
1.53460
56.3 (=νd1)
3*
59.9873
0.08287
4*
9.8172
0.30000
1.61420
26.0 (=νd2)
5
2.2598
0.49985
6*
4.6361
0.60038
1.53460
56.3 (=νd3)
7*
8.0048
0.61367
8*
−1.6178
0.47743
1.53460
56.3 (=νd4)
9*
−1.5926
0.46474
10*
4.0915
0.89810
1.53460
56.3 (=νd5)
11*
2.4733
0.90000
12
∞
0.21000
1.51633
64.12
13
∞
0.92015
(image
∞
plane)
f1 = 3.377
f2 = −4.853
f3 = 19.402
f4 = 25.166
f5 = −14.502
f12 = 7.582
f34 = 12.071
L15 = 4.47131
Aspheric Surface Data
Second Surface
k = 0.00000000, A4 = −0.33152569E−02, A6 = 0.13173300E−01,
A8 = 0.77191632E−03
Third Surface
k = 0.00000000, A4 = 0.32319580E−01, A6 = 0.28036656E−01,
A8 = −0.32979603E−01
Fourth Surface
k = 0.00000000, A4 = 0.28140071E−01, A6 = 0.95468218E−02,
A8 = −0.34624463E−01
Sixth Surface
k = 0.00000000, A4 = −0.37529209E−01, A6 = −0.15021746E−01,
A8 = 0.10801104E−01, A10 = −0.86227102E−02
Seventh Surface
k = 0.00000000, A4 = −0.31957513E−01, A6 = −0.17064039E−01,
A8 = −0.21703745E−02, A10 = −0.60001032E−02
Eighth Surface
k = 0.00000000, A4 = 0.82909571E−01, A6 = −0.84515903E−01,
A8 = 0.67645260E−01, A10 = −0.33427795E−01
Ninth Surface
k = −0.74063050, A4 = 0.49847310E−01, A6 = −0.22906063E−01,
A8 = 0.18211377E−01, A10 = −0.51316845E−02,
A12 = 0.46696366E−03
Tenth Surface
k = 0.00000000, A4 = −0.81469036E−01, A6 = 0.31668591E−01,
A8 = −0.82919297E−02, A10 = 0.83175228E−03,
A12 = 0.13683655E−03, A14 = −0.42038213E−04,
A16 = 0.28326573E−05
Eleventh Surface
k = −0.10882180E+02, A4 = −0.37826192E−01, A6 = 0.12120123E−01,
A8 = −0.34424448E−02, A10 = 0.60541930E−03,
A12 = −0.63639649E−04, A14 = 0.38587184E−05,
A16 = −0.12352911E−06
The values of the conditional expressions (1) to (8) are shown below.
f34/f = 2.020
|f1/f2| = 0.696
f34/f12 = 1.592
νd1 = 56.3
νd2 = 26.0
νd3 = 56.3
νd4 = 56.3
νd5 = 56.3
Accordingly, the imaging lens of Numerical Data Example 4 satisfies the conditional expressions (1) to (8).
Accordingly, when the imaging lens of the embodiment is applied to an imaging optical system of a cellular phone, a digital still camera, a portable information terminal, a security camera, an onboard camera, a network camera, and the like, it is possible to obtain the high performance and the small size for the camera or the like.
The invention may be applicable to the imaging lens of a device that is required to have a small size and satisfactory aberration correction ability, e.g., the imaging lenses used in the cellular phones, the digital still cameras, and the like.
Kubota, Yoji, Kurihara, Ichiro
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