A liquid crystal display apparatus includes a plurality of data lines each having a plurality of straight line portions and a plurality of curved portions connected to a plurality of the straight line portions; a plurality of gate lines intersecting the data lines; thin film transistors connected to the data lines and the gate lines; and pixel electrodes connected to the thin film transistors. Accordingly, even in a case where driver inversion becomes column inversion, apparent inversion can become dot inversion. As a result, it is possible to eliminate transverse line flicker and to increase a charging rate of pixels. In addition, uniformity of the pixels can be maintained, so that the inversion driving schemes can be applied to a PVA mode. As a result, it is possible to obtain a wide viewing angle and to improve side or lateral visibility.
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0. 31. A thin film transistor panel comprising:
thin film transistors having gate electrodes, source electrodes and drain electrodes, respectively;
a gate line connected to the gate electrodes of the thin film transistors;
dummy gate electrodes connected to and extended from the gate line in a same direction as the gate electrodes, the dummy gate electrodes having the same shape and size as the gate electrodes, and each dummy gate electrode being disposed between adjacent gate electrodes.
0. 36. A thin film transistor panel comprising:
thin film transistors arranged in a matrix, the thin film transistors having gate electrodes, source electrodes, and drain electrodes;
a first gate line connected to the gate electrodes of the thin film transistors disposed in a first row of the matrix;
a second gate line connected to the gate electrodes of the thin film transistors disposed in a second row of the matrix;
first dummy gate electrodes connected to and extended from the first gate lines in a same direction as the gate electrodes connected to the first gate line, the first dummy gate electrodes having the same shape and size as the gate electrodes connected to the first gate line, and each first dummy gate electrode being disposed between adjacent gate electrodes connected to the first gate line; and
second dummy gate electrodes connected to and extended from the second gate lines in a same direction as the gate electrodes connected to the second gate line, the second dummy gate electrodes having the same shape and size as the gate electrodes connected to the second gate line, and each second dummy gate electrode being disposed between adjacent gate electrodes connected to the second gate line.
0. 1. A liquid crystal display apparatus comprising:
a plurality of data lines, each of the plurality of data lines having a plurality of straight line portions and a plurality of curved portions connected to the plurality of straight line portions;
a plurality of gate lines disposed substantially perpendicular to the plurality of data lines;
a plurality of thin film transistors connected to the plurality of data lines and the plurality of gate lines; and
a plurality of pixel electrodes respectively connected to the plurality of thin film transistors,
wherein the plurality of straight line portions and the plurality of curved portions for each data line of the plurality of data lines are linearly aligned, and
wherein each of the plurality of curved portions comprises:
a substantially concave surface; and
a substantially convex surface opposing the substantially concave surface,
wherein a terminal of the substantially concave surface and a terminal of the substantially convex surface both meet a terminal of the straight line portion adjacent to the curved portion, and
wherein both the substantially concave surface and the substantially convex surface are disposed on a first side of two extended edges of the straight line portion adjacent to the curved portion, and
wherein a remainder of the curved portion is disposed on a second side of the two extended edges of the straight line portion and includes a first linear branch and a second linear branch disposed substantially opposite the first linear branch defining a space therebetween.
0. 2. The liquid crystal display apparatus of
0. 3. The liquid crystal display apparatus of
0. 4. The liquid crystal display apparatus of
0. 5. The liquid crystal display apparatus of
0. 6. The liquid crystal display apparatus of
0. 7. The liquid crystal display apparatus of
0. 8. The liquid crystal display apparatus of
0. 9. The liquid crystal display apparatus of
0. 10. The liquid crystal display apparatus of
0. 11. The liquid crystal display apparatus of
0. 12. The liquid crystal display apparatus of
0. 13. The liquid crystal display apparatus of
0. 14. The liquid crystal display apparatus of
0. 15. The liquid crystal display apparatus of
openings of a plurality of pixels associated with the plurality of pixel electrodes have substantially a same shape.
0. 16. A liquid crystal display apparatus comprising:
a plurality of data lines each having a plurality of first straight line portions, a plurality of second straight line portions alternately linearly disposed with the first straight line portions, and
a plurality of first and second curved portions alternately connected between the first and second straight line portions;
a plurality of pairs of first and second gate lines disposed substantially perpendicular to the plurality of data lines;
a plurality of pairs of first and second thin film transistors connected to the plurality of pairs of first and second gate lines, respectively, and the plurality of data lines; and
a plurality of pixel electrodes connected to the plurality of first and second thin film transistors, each of the plurality of pixel electrodes comprising first and second sub-pixel electrodes respectively connected to a pair of first and second thin film transistors of the plurality of pairs of first and second thin film transistors,
wherein the first and second thin film transistors comprise first and second drain electrodes connected to the first and second sub-pixel electrodes, respectively, the first and second drain electrodes each comprising a first end portion surrounded by one of the plurality of first and second curved portions, and a second end portion extending from the first end portion in a transverse direction substantially parallel to the first and second gate lines,
wherein each of the first and second curved portions comprises:
a substantially concave surface; and
a substantially convex surface opposing the substantially concave surface,
wherein a terminal of the concave surface and a terminal of the convex surface of each of the first and second curved portions both meet a terminal of one of the first and second straight line portions adjacent to each of the first and second curved portions, and
wherein both of the substantially concave surface and the substantially convex surface of at least one of the first curved portion and the second curved portion are disposed on a same side with respect to two extended edges of the first and second straight line portions adjacent to the at least one of the first and second curved portions.
0. 17. The liquid crystal display apparatus of
0. 18. The liquid crystal display apparatus of
0. 19. The liquid crystal display apparatus of
0. 20. The liquid crystal display apparatus of
0. 21. The liquid crystal display apparatus of
0. 22. The liquid crystal display apparatus of
0. 23. The liquid crystal display apparatus of
0. 24. A liquid crystal display apparatus comprising:
a plurality of pixels arrayed in a matrix and each of the plurality of pixels having pixel electrodes;
a plurality of gate lines connected to the plurality of pixels and each of the plurality of gate lines having a plurality of gate electrodes;
a plurality of data lines disposed substantially perpendicular to the plurality of gate lines and having a plurality of source electrodes; and
a plurality of drain electrodes facing respective source electrodes of the plurality of source electrodes and connected to the respective pixel electrodes,
wherein each of the plurality of drain electrodes comprises:
a first end portion disposed substantially opposite a respective source electrode of the plurality of source electrodes;
a second end portion extending from the first end portion substantially parallel to the plurality of gate lines the second end portion being directly connected with the first end portion;
a first portion extending from a connection point between the first end portion and the second end portion in a direction substantially parallel to the plurality of data lines, the first portion extending away from both the first end portion and the second end portion, the first portion comprising an end disposed at the connection point between the first end portion and the second end portion; and
an enlarged portion connected to another end of the first portion and connected to the respective pixel electrode of the plurality of pixel electrodes.
0. 25. The liquid crystal display apparatus of
0. 26. The liquid crystal display apparatus of
0. 27. The liquid crystal display apparatus of
0. 28. The liquid crystal display apparatus of
0. 29. The liquid crystal display apparatus of
0. 30. The liquid crystal display apparatus of
wherein openings of the plurality of pixels have substantially a same shape.
0. 32. The thin film transistor panel of claim 31, wherein the gate electrodes are separated from each other by a first pitch, and the dummy gate electrodes are separated from each other by a second pitch which is equal to the first pitch.
0. 33. The thin film transistor panel of claim 31, further comprising:
pixel electrodes connected to the drain electrodes of the thin film transistors; and
dummy drain electrodes connected to the pixel electrodes, the dummy drain electrodes having the same shape with each other.
0. 34. The thin film transistor panel of claim 33, further comprising:
a protective film disposed between the thin film transistors and the pixel electrode, and having contact holes exposing the dummy drain electrodes, the pixel electrodes being connected to the dummy drain electrodes through the contact holes.
0. 35. The thin film transistor panel of claim 33, further comprising a storage electrode line having branches overlapping the pixel electrodes.
0. 37. The thin film transistor panel of claim 36, wherein the gate electrodes connected to the first gate line are separated from each other by a first pitch, and the first dummy gate electrodes are separated from each other by a second pitch which is equal to the first pitch.
0. 38. The thin film transistor panel of claim 37, wherein the gate electrodes connected to the second gate line are separated from each other by the first pitch, and the second dummy gate electrodes are separated from each other by the second pitch.
0. 39. The thin film transistor panel of claim 36, further comprising:
a first pixel electrode connected to one of the thin film transistors disposed in the first row;
a second pixel electrode connected to one of the thin film transistors disposed in the second row, the second pixel electrode being longitudinally adjacent to the first pixel electrode;
a first dummy drain electrode connected to the first pixel electrode; and
a second dummy drain electrode connected to the second pixel electrode,
wherein a location of the first dummy drain electrode with respect to the first pixel electrode is different from a location of the second dummy drain electrode with respect to the second pixel electrode.
0. 40. The thin film transistor panel of claim 39, wherein the second dummy drain electrode has the same shape as the first dummy drain electrode.
0. 41. The thin film transistor panel of claim 39, further comprising:
a protective film disposed between the thin film transistors and the pixel electrodes, and having contact holes exposing the dummy drain electrodes, the pixel electrodes being connected to the dummy drain electrodes through the contact holes.
0. 42. The thin film transistor panel of claim 39, further comprising a storage electrode line having branches overlapping the pixel electrodes.
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Here, since CCP/(CCP+CLCb) is always lower than 1, Vb is always lower than Va.
In this way, the two sub-pixel electrodes 190a and 190b are provided within one pixel, and the coupling capacitor CCP is disposed between the sub-pixel electrodes 190a and 190b, so that these sub-pixel electrodes can be charged with different voltages.
Accordingly, a side gamma curve can be close to a front gamma curve due to the two sub-pixel electrodes 190a and 190b by adjusting the coupling capacitor CCP or the like, thus making it is possible to improve lateral or side visibility.
On the other hand, similar to the above-described embodiment, as shown in
Accordingly, it is possible to eliminate transverse line flicker. In addition, it is possible to increase a charging rate of pixels.
Now, an example of the liquid crystal display apparatus will be described in detail with reference to
As shown in
First, in the thin film transistor panel 100, a plurality of gate lines 121 including a plurality of gate electrodes 124, a plurality of pairs of storage electrode lines 131p and 131q, and a plurality of coupling electrodes 126 are formed on a dielectric substrate 110 (see
The storage electrode lines 131p and 131q extend mainly in a transverse direction (
The coupling electrodes 126 are separated by a predetermined interval between the storage electrode lines 131p and 131q, and are also separated from the gate lines 121. The coupling electrodes 126 are substantially rectangularly shaped, but the shape thereof can be different.
A gate insulating film 140, a plurality of semiconductors 154 and 156, and a plurality of island-shaped ohmic contact members 163 and 165 are sequentially formed on the gate lines 121, the storage electrode lines 131p and 131q, and the coupling electrodes 126.
A plurality of data lines 171 and a plurality of drain electrodes 175 are formed on the ohmic contact members 163 and 165 and the gate insulating film 140.
As best seen with reference to
Each of the drain electrodes 175 includes enlarged portions 177p, 177q, and 176, which overlap with the storage electrodes 133p and 133q and the coupling electrodes 126, respectively. In addition, each of the drain electrodes 175 includes longitudinal portions 174p and 174q, which are connected between the enlarged portions 177p and 177q and the enlarged portion 176, respectively (
Referring to
A protective film 180 is formed on the data lines 171, the drain electrodes 175 and exposed portions of the semiconductors 154. In the protective film 180, a plurality of contact holes 182, 185p, and 185q which expose the end portions 179 of the data lines 171 and the enlarged portions 177p and 177q of the drain electrodes 175 are formed, and in the protective film 180 and the gate insulating film 140, a plurality of contact holes 181 and 186 which expose the end portions 129 of the gate lines 121 and the coupling electrodes 126 are formed.
On the protective film 180, a plurality of the pixel electrodes 190 including the first and second sub-pixel electrodes 190a and 190b, the shielding electrodes 88, and a plurality of the contact assistant members 81 and 82 are formed.
As best seen with reference to
The coupling capacitor CCP is constructed by overlapping the enlarged portion 176 of the drain electrode 175 and the coupling electrode 126. The coupling capacitor CCP transmits a voltage lower than the data voltage from the drain electrode 175 to the coupling electrode 126.
The second sub-pixel electrode 190b is physically and electrically connected through the contact hole 186 to the coupling electrode 126, so that the second sub-pixel electrode 190b is applied with a voltage lower than the data voltage from the coupling electrode 126. The second sub-pixel electrode 190b applied with such a voltage together with the common electrode 270 generates an electric field, and the two electrodes 190b and 270 constitute the second liquid crystal capacitor CLCb.
A pair of the first and second sub-pixel electrodes 190a and 190b constituting the pixel electrode 190 face each other with gaps 94p and 94q interposed therebetween. An outer boundary of the pixel electrode 190 is substantially rectangularly shaped. The right sides of the trapezoidal portions 190p and 190q of the first sub-pixel electrode 190a are longer than the left sides thereof, and each of the trapezoidal portions 190p and 190q have slanted sides forming an angle of about 45° with respect to the gate line 121. The second sub-pixel electrode 190b has a shape of a rotated equilateral trapezoid, which has a left side longer than a right side and a pair of upper and lower sides facing the slanted sides of the first sub-pixel electrode 190a. The gaps 94p and 94q between the first and second sub-pixel electrodes 190a and 190b have a substantially uniform width. Hereinafter, for the convenience of description, the gaps 94p and 94q are denoted as cut portions.
The pixel electrode 190 has central cut portions 92 and 93, lower cut portions 94p and 95p, and upper cut portions 94q and 95q. The pixel electrode 190 is divided into a plurality of domains by the cut portions 92 to 95q. The cut portions 92 to 95q have approximate inversion symmetry with respect to the coupling electrode 126.
The lower and upper cut portions 94p and 94q extend in a slanted direction from the left side of the pixel electrode 190 to the right side thereof, and the lower and upper cut portions 95p and 95q extend in a slanted or angled direction from the lower and upper sides of the pixel electrodes 190 to the right side thereof. The lower cut portions 94p and 95p and the upper cut portions 94q and 95q are disposed in lower and upper half regions, respectively, of the pixel electrode 190 divided by the coupling electrode 126, and form an angle of about 45° with respect to the gate line 121 to extend perpendicular to each other.
The central cut portion 92 has an inlet at the left side of the second sub-pixel electrode 190b, and a transverse portion which extends from the inlet along the coupling electrode 126. The inlet of the cut portion 92 has a pair of slanted or angled portions having an angle of about 45° with respect to the gate line 121. The central cut portion 93 has a central transverse portion which extends substantially from the right side of the second sub-pixel electrode 190b in the transverse direction and a pair of slanted or angled portions which extend from the end of the central transverse portion with a slanted angle with respect to the central transverse portion toward the left side of the pixel electrode 190.
An alignment film 11 is coated on the pixel electrodes 190, the shielding electrode 88, the contact assistant members 81 and 82 and the protective film 180.
In the common electrode panel 200, shielding members 220, a plurality of color filters 230, a cover film 250, a common electrode 270 having a plurality of cut portions 73, 74p, 74q, 75p, 75q, 76p, and 76q, and an alignment film 21 are formed on a dielectric substrate 210.
The cut portions 73 to 76q of the common electrode 270 include the central cut portion 73 which is located across the lower and upper half regions of the pixel electrode 190, the cut portions 74p, 75p, and 76p which are located in the lower half region, and the cut portions 74q, 75q, and 76q which are located in the upper half region.
The aforementioned features of the liquid crystal display apparatus of
In
As shown in
On the contrary, in the (i+1)-th pixel row, the thin film transistors are located at the right side of the pixels. The inlets of the curved portions 173 of the data line 171 are oriented to the left side. However, similar to the i-th pixel row, the drain electrode 175 has an extension portion 175r which extends from the longitudinal portion connected to the enlarged portion 177p in the down direction to the curved portions 173 of the adjacent data line 171.
On the other hand, the pixel-electrode formed on the data metal layer has the same cut portions for every pixel.
By forming the thin film transistors Q and the drain electrodes 175 in such a manner, the shapes and areas of the domains of the pixels can be substantially uniform even in a case where the positions of the thin film transistors Q change every pixel row. Therefore, the inversion driving scheme according to the present invention can be applied to a PVA mode having a plurality of domains.
Accordingly, it is possible to obtain a wide viewing angle and to improve side or lateral visibility.
Now, a liquid crystal display apparatus according to other exemplary embodiments of the present invention will be described in detail with reference to
As shown in
As seen in the equivalent circuit schematic diagram, the liquid crystal display panel assembly 300 includes a plurality of pixels PX connected to a plurality of display signal lines G1a to Gnb and D1 to Dm and are arrayed substantially in a matrix.
The display signal lines G1a to Gnb and D1 to Dm include a plurality of gate lines G1a to Gnb for transmitting gate signals and a plurality of data lines D1 to Dm for transmitting data signals. The gate lines G1a to Gnb extend parallel to each other substantially in a row direction, and the data lines D1 to Dm extend parallel to each other substantially in a column direction.
As seen in the equivalent circuit schematic diagram of the display signal lines Gia, Gib, and Dj, the display signal lines further include storage electrode lines SL (only one shown) which extend substantially parallel to the gate lines Gia and Gib.
Each pixel PX includes a pair of sub-pixels PXa and PXb. Each sub-pixel PXa/PXb includes a switching device Qa/Qb connected to the respective gate line Gia/Gib and the data line Dj, a liquid crystal capacitor CLCa/CLCb connected to the switching device Qa/Qb, and a storage capacitor CSTa/CSTb connected to the switching device Qa/Qb and the storage line SL. The storage capacitors CSTa and CSTb may be omitted, as needed. In this case, the storage lines SL are unnecessary.
Since the sub-pixels PXa and PXb are substantially the same as the pixels shown in
As shown in
Referring to
The grayscale voltage generator 800 generates two grayscale voltage sets (or reference grayscale voltage sets) associated with transmittance of pixels. The two grayscale voltage sets are independently applied to the two sub-pixels of one pixel. Each grayscale voltage set includes one having a positive value with reference to the common voltage Vcom and the other having a negative value with reference to the common voltage Vcom. However, instead of two (reference) grayscale voltage sets, one (reference) grayscale voltage set may be generated.
The data driver 500 is connected to the data lines D1 to Dm of the liquid crystal display assembly 300 to select one of the two grayscale voltage sets from the grayscale voltage generator 800 and apply one grayscale voltage of the selected grayscale voltage set to the pixel as a data voltage. However, in a case where the grayscale voltage generator 800 does not provide all the grayscale voltages but only the reference grayscale voltage, the data driver 500 divides the reference grayscale voltage to generate the grayscale voltages or all the grayscales and selects the data voltage from the grayscale voltages.
Now, display operations of the liquid crystal display apparatus will be described in detail.
The signal controller 600 receives input image signals R, G, and B and input control signals that are externally applied and generates a gate control signal CONT1, a data control signal CONT2 and processed image data DAT. After that, the signal controller 600 transmits the generated control signals and image data to the gate drivers 400a, 400b, and 401, and the data driver 500.
In response to the data control signal CONT2 from the signal controller 600, the data driver 500 receives the image data DAT for a pair of the sub-pixels PXa and PXb, selects one of the two grayscale voltage sets from the grayscale voltage generator 800, and selects a gray voltage corresponding to the image data DAT from the selected grayscale voltage set, so that the image data DAT is converted into the associated data voltage. After that, the data voltage is applied to the associated data lines D1 to Dm.
Alternatively, instead of the data driver 500, a separately provided external selection circuit (not shown) may select one of the two grayscale voltage sets and transmit the selected one to the data driver 500. Otherwise, the grayscale voltage generator 800 may provide a reference voltage having a variable value, and the date driver 500 may divide the reference voltage, so that the grayscale voltage can be generated.
In response to the gate control signal CONT1 from the signal controller 600, the gate drivers 400a, 400b and 401 apply the gate-on voltage Von to the gate lines G1a to Gnb to turn on the switching devices Qa and Qb connected to the gate lines G1a to Gnb. As a result, the data voltages applied to the data lines D1 to Dm are applied to the associated sub-pixels PXa and PXb through the turned-on switching devices Qa and Qb.
The two above-described grayscale voltage sets represent different gamma curves and are applied to the two sub-pixels PXa and PXb of one pixel PX, so that the gamma curve of the one pixel PX is a composite curve of the gamma curves. In the determination of the two grayscale voltage sets, the composite gamma curve is determined to be close to the reference gamma curve for the front surface. For example, the composite gamma curve for the front surface is determined to be equal to the reference gamma curve for the front surface which is most suitable, and the composite gamma curve for the side surface is determined to be closest to the reference gamma curve for the front surface. By doing so, it is possible to further improve side or lateral visibility.
In units of half a horizontal period (or ½ H), the data driver 500 and the gate drivers 400a, 400b and 401 repeatedly perform the aforementioned operations. In this manner, during one frame, the gate-on voltage Von is sequentially applied to all of the gate lines G1a to Gnb, so that the data voltages are applied to all the pixels. When one frame ends, the next frame starts, and a state of the reverse signal RVS applied to the data driver 500 is controlled so that the polarity of the data signal applied to each of the pixels is opposite to the polarity in the previous frame. In addition, as described above, the polarities of the data voltages applied to the adjacent data lines D1 to Dm in one frame are inverted, so that the driver inversion becomes column inversion, but the apparent inversion becomes 1×1 dot inversion.
Now, an example of the liquid crystal display apparatus will be described in detail with reference to
As shown in
First, in the thin film transistor panel 100, a plurality of gate lines 121a and 121b and a plurality of storage electrode lines 131 including a plurality of storage electrodes 133 are formed on a dielectric substrate 110.
The first and second gate lines 121a and 121b are disposed in upper and lower sides, respectively, and include end portions 129a and 129b, respectively, having a wide area for connection to a plurality of first and second gate electrodes 124a and 124b, respectively, protruding in up and down directions, other layers, or external driving circuits.
A gate insulating film 140, a plurality of island-shaped semiconductors 154a, 154b, and 156, and a plurality of island-shaped ohmic contact members 163b and 165b are sequentially formed on the gate lines 121a and 121b and the storage electrode lines 131.
A plurality of data lines 171 and a plurality of pairs of the first and second drain electrodes 175a and 175b are formed on the ohmic contact members 163a, 163b, 165a, and 165b and the gate insulating film 140.
The data lines 171 include a plurality of pairs of first and second straight line portions 172p and 172q, and a plurality of pairs of first and second curved portions 173a and 173b, and end portions 179 having enlarged widths.
The first and second straight line portions 172p and 172q are alternately disposed along one straight line, and the second straight line portion 172q is longer than the first straight line portion 172p and intersects the storage electrode lines 131. The first and second curved portions 173a and 173b are alternately connected between the first and second straight line portions 172p and 172q and are disposed on the semiconductors 154a and 154b.
The first and second drain electrodes 175a and 175b have enlarged portions 177a and 177b having a large area which extend from bar-shaped end portions on the semiconductors 154a and 154b and overlap the storage electrodes 133, as best seen in
A protective film 180 is formed on the data lines 171, the drain electrodes 175a and 175b, and exposed portions of the semiconductors 154a and 154b. In the protective film 180, a plurality of contact holes 182, 185a, and 185b which expose the end portions 179 of the data lines 171 and the enlarged portions 177a and 177b of the drain electrodes 175a and 175b are formed. A plurality of contact holes 181 are formed in the protective film 180 and the gate insulating film 140, the plurality of contact holes 181 expose the end portions 129 of the gate lines 121.
A plurality of the pixel electrodes 191 including the first and second sub-pixel electrodes 191a and 191b, the shielding electrodes 88, and a plurality of the contact assistant members 81 and 82 are formed on the protective film 180.
The first/second sub-pixel electrode 191a/191b is physically and electrically connected through the contact hole 185a/185b to the first/second drain electrode 175a/175b, so that the first/second sub-pixel electrode 191a/191b is applied with a data voltage from the first/second drain electrode 175a/175b. Different data voltages that are predetermined for one input image signal are applied to a pair of the sub-pixel electrodes 191a and 191b, and the intensities thereof may be determined according to the sizes and shapes of the sub-pixel electrodes 191a and 191b. In addition, the areas of the sub-pixel electrodes 191a and 191b may be different from each other. As an example, the second sub-pixel electrode 191b may be applied with a higher voltage than the first sub-pixel electrode 191a, and the area of the second sub-pixel electrode 191b may be smaller than that of the first sub-pixel electrode 191a.
The upper right corner of each pixel electrode 191 is cut, and the cut side has an angle of about 45° with respect to the gate lines 121a and 121b.
A pair of first and second sub-pixel electrodes 191a and 191b constituting one pixel electrode 191 is engaged with each other with the gap 94 interposed therebetween, and an outer boundary of the pixel electrode 191 is substantially rectangularly shaped. The second sub-pixel electrode 191b has a shape of a rotated equilateral trapezoid of which a base side is recessed in a shape of a trapezoid, and most of second sub-pixel electrode 191b is surrounded by the first sub-pixel electrode 191a. The first sub-pixel electrode 191a is constructed with upper, lower, and central trapezoidal portions, which are connected to each other at the left side. The first sub-pixel electrode 191a has cut portions 95a, 95b and 95c, which extend from the upper side of the upper trapezoidal portion and the lower side of the lower trapezoidal portion toward the right side. The gate line 121a is disposed between the cut portions 95a and 95b. The central trapezoidal portion of the first sub-pixel electrode 191a is engaged with the recessed base side of the second sub-pixel electrode 191b. The first sub-pixel electrode 191a has a cut portion 92, which extends along the storage electrode line 131. The cut portion 92 has an inlet at the left side of the first sub-pixel electrode 191a and a transverse portion which extends from the inlet in the transverse direction. The inlet of the cut portion 92 has a pair of slanted or angled sides having an angle of about 45° with respect to the storage electrode line 131. In addition, the gap 94 between the first and second sub-pixel electrodes 191a and 191b includes upper and lower slanted or angled portions having a substantially uniform width and an angle of about 45° with respect to the gate lines 121a and 121b and three longitudinal portions having a substantially uniform width. Hereinafter, for the convenience of description, the gap 94 is denoted as a cut portion.
The pixel electrode 191 has the cut portions 92, 94, 95a, and 95b, and the pixel electrode 191 is divided into a plurality of domains by the cut portions 92, 94, 95a, and 95b. The cut portions 92, 94, 95a, and 95b extend substantially from the left side of the pixel electrode 191 to the right side thereof in a slanted or angled direction and have approximate inversion symmetry with respect to the storage electrode line 131. The cut portions 92, 94, 95a, and 95b have an angle of about 45° with respect to the gate lines 121a and 121b to extend perpendicular to each other.
An alignment film 11 is coated on the pixel electrodes 191, the shielding electrodes 88, the contact assistant members 81 and 82, and the protective film 180.
In the common electrode panel 200, shielding members 220, a plurality of color filters 230, a cover film 250, a common electrode 270 having a plurality of cut portions 73, 74, 75a, 75b, 76a, and 76b, and an alignment film 21 are formed on a dielectric substrate 210.
The cut portions 73 to 76b of a common electrode 270 include the central cut portions 73 and 74 which are located across the lower and upper half regions of the pixel electrode 191, the cut portions 75a and 76a which are located in the lower half region, and the cut portions 75b and 76b which are located in the lower half region.
The aforementioned features of the liquid crystal display apparatus of
In
As shown in
On the contrary, in the (i+1)-th pixel row, the thin film transistors Qa and Qb are located at the right side of the pixels. The inlets of the curved portions 173a and 173b of the data line 171 are oriented to the left side. However, similar to the i-th pixel row, the drain electrodes 175a and 175b have extension portions 175p and 175q which extend from the longitudinal portions connected to the enlarged portions 177a and 177b to the curved portions 173a and 173b of the adjacent data line 171.
Now, another exemplary embodiment of a liquid crystal display apparatus according to the present invention will be described in detail with reference to
As shown in
As seen in the equivalent circuit block diagram, the liquid crystal display panel assembly 300 includes a plurality of display signal lines G1 to G2n and D1 to Dm, and a plurality of pixels PX connected thereto and arrayed substantially in a matrix.
The display signal lines G1 to G2n and D1 to Dm include a plurality of gate lines G1 to G2n for transmitting gate signals (sometimes referred to as scan signals) and a plurality of data lines D1 to Dm for transmitting data signals. The gate lines G1 to G2n extend parallel to each other substantially in a row direction, and the data lines D1 to Dm extend parallel to each other substantially in a column direction.
Since the pixels PX are substantially the same as the pixels shown in
In the pixel array of the liquid crystal display apparatus, as shown in
A plurality of pairs of the gate lines G1 to G2n connected to the pixel electrodes 192 at the upper and lower sides thereof are connected through the switching devices Q disposed on the pixel electrodes 192 at the upper or lower side thereof to the associated pixel electrodes 192.
Namely, in the odd-numbered pixel row, the switching devices Q disposed at the left side of the data lines D1 to Dm are connected to the gate lines G1, G5, G9, . . . disposed on the upper side, and the switching devices Q disposed at the right side of the data lines D1 to Dm are connected to the gate lines G2, G6, G10, . . . disposed on the lower side. On the contrary, in the even-numbered pixel row, the connection between the upper gate lines G3, G7, G11, . . . , the lower gate lines G4, G8, G12, . . . , and the switching device Q is opposite to the connection in the odd-numbered pixel row. Namely, the switching devices Q disposed at the right side of the data lines D1 to Dm are connected to the gate lines G3, G7, G11, disposed on the upper side, and the switching devices Q disposed at the left side of the data lines D1 to Dm are connected to the gate lines G4, G8, G12, . . . disposed on the lower side.
Among the pixel electrodes 192 of the odd-numbered pixel row, the pixel electrodes 192 disposed at the left side of the data lines D1 to Dm are connected through the switching devices Q to the adjacent data lines D1 to Dm, and the pixel electrodes 192 disposed at the right side of the data lines D1 to Dm are connected through the switching devices Q to the next adjacent data lines D1 to Dm. Among the pixel electrodes 192 of the even-numbered pixel row, the pixel electrodes 192 disposed at the left side of the data lines D1 to Dm are connected through the switching devices Q to the previous data lines D1 to Dm, and the pixel electrodes 192 disposed at the right side of the data lines D1 to Dm are connected through the switching devices Q to the adjacent data lines D1 to Dm.
The switching devices Q are formed at positions so as to be easily connected to the data lines D1 to Dm, namely, so as to shorten connection lengths as much as possible. Therefore, in the pixel array shown in
On the contrary, the positions of the switching devices Q disposed in the odd-numbered pixel rows are opposite to the positions thereof in the adjacent pixel rows. Namely, among a pair of the pixels disposed in the even-numbered pixel row, the switching devices Q are formed in a lower left region of the pixels disposed at the left side of the data lines D1 to Dm, and the switching devices Q are formed in a upper left region of the pixels disposed at the right side of the data lines D1 to Dm.
In summary of the connection between the pixel electrodes 192 and the data lines D1 to Dm shown in
Next, similar to
In the connection between the pixel electrodes 192 shown in
The positions of the switching devices Q disposed on the pixels change every pixel row. Namely, on the pixels disposed in the odd-numbered pixel row, the switching devices Q are sequentially formed on upper right, lower left, lower right, and upper left regions thereof, and on the pixels disposed in the even-numbered pixel row, the switching devices Q are sequentially formed on lower right, upper left, upper right, and lower left regions thereof.
The arrays shown in
Returning to
The gate driver 402 is connected to the gate lines G1 to G2n of the liquid crystal display panel assembly 300 to apply gate signals (formed in a combination of a gate-on voltage Von and a gate-off voltage Voff that are externally supplied) to the gate lines G1 to G2n.
The data driver 501 is connected to the data lines D1 to Dm of the liquid crystal display panel assembly 300 to select grayscale voltages from the grayscale voltage generator 800 and apply the selected grayscale voltages to the pixels as data signals.
The signal controller 600 controls operations of the gate driver 402, the data driver 501, and the like.
Now, display operations of the liquid crystal display apparatus according to the present exemplary embodiment will be described in detail.
The signal controller 600 receives input image signals R, G, and B and input control signals that are externally applied and transmits a gate control signal CONT1, a data control signal CONT2, and processed image data DAT to the gate driver 402 and the data driver 501. Here, the processing for the image signals R, G and B includes operations for re-arranging the image data R, G and B according to the pixel array of the liquid crystal display panel assembly 300 shown in
In response to the data control signal CONT2, the data driver 501 sequentially receives the image data DAT for half the pixels of one pixel row and selects a gray voltage corresponding to the image data DAT from the selected grayscale voltages from the grayscale voltage generator 800, so that the image data DAT is converted into the associated data voltage. After that, the data voltage is applied to the associated data lines D1 to Dm.
In response to the gate control signal CONT1 from the signal controller 600, the gate driver 402 applies the gate-on voltage Von to the gate lines G1 to G2n to turn on the switching devices Q connected to the gate lines G1 to G2n. As a result, the data voltages applied to the data lines D1 to Dm are applied to the associated pixels through the turned-on switching devices Q.
In units of half a horizontal period (or ½ H), the data driver 501 and the gate driver 402 repeatedly perform the aforementioned operations. In this manner, during one frame, the gate-on voltage Von is sequentially applied to all of the gate lines G1 to G2n, so that the data voltages are applied to all of the pixels. When one frame ends, the next frame starts, and a state of the reverse signal RVS applied to the data driver 501 is controlled, so that the polarity of the data signal applied to each of the pixels is opposite to the polarity in the previous frame (frame inversions).
In addition, as described above, the data driver 501 inverts the polarities of the data voltages applied to the adjacent data lines D1 to Dm in one frame, so that the polarities of the pixel voltages of the pixels applied with the data voltages also change. However, since the connection of the pixels and the data lines D1 to Dm may be formed in various manners as shown in
Now, types of inversion according to another exemplary embodiment of the present invention will be described in detail with reference to
In
In
In this manner, if the apparent inversion becomes the dot inversion, the brightness difference (caused by kick-back voltages when the pixel voltage is a positive polarity and when the pixel voltage is a negative polarity) is dispersed, thus making it is possible to reduce transverse line defects.
Now, structures of a thin film transistor display panel 100 and a common electrode panel 200 of the liquid crystal display panel assembly 300 will be described in detail with reference to
As shown in
First, in the thin film transistor panel 100, a plurality of gate lines 121a and 121b and a plurality of storage electrode lines 131 are formed on a dielectric substrate 110.
The gate lines 121a and 121b extend mainly in a transverse direction. A portion of the gate line 121a protrudes in a downward direction to constitute a gate electrode 124a and a dummy gate electrode 126a. Likewise, a portion of the gate line 121b protrudes in an upward direction to constitute a gate electrode 124b and a dummy gate electrode 126b. The two gate lines 121a and 121b are adjacent to each other to constitute a pair.
The storage electrode lines 131 extend mainly in the transverse direction and include a plurality of pairs of branch groups constructed with first to fourth storage electrodes 133a, 133b, 134a, and 134b.
A gate insulating film 140, a plurality of island-shaped semiconductors 154a, 154b, 156a, and 156b, and a plurality of island-shaped ohmic contact members 163a, 163b, 165a, 165b, and 166 are sequentially formed on the gate lines 121a and 121b and the storage electrode lines 131. The semiconductors 154a and 154b are disposed on the gate electrodes 124a and 124b, respectively, and semiconductors 156a and 156b are disposed on dummy gate electrodes 126a and 126b, respectively. The contact member 163a/163b and the contact member 165a/165b constitute a pair and are disposed on the island-shaped semiconductor 154a/154b.
A plurality of data lines 171 (see
The data lines 171 mainly extend in a longitudinal direction to intersect the gate lines 121a and 121b and the storage electrode lines 131. The data lines 171 transmit the data voltages. On the data lines 171, a plurality of branches which extend toward the drain electrodes 175a and 175b in the left and right directions constitute source electrodes 173a and 173b, respectively. The drain electrodes 175a and 175b extend from bar-shaped end portions surrounded by the source electrodes 173a and 173b in the transverse direction. The source electrodes 173a and 173b are formed to be curved so as to surround the straight line portions of the drain electrodes 175a and 175b. The positions of the dummy drain electrodes 176a and 176b in the pixels are substantially the same as the positions of the drain electrodes 175a and 175b in the pixels.
The gate electrode 124a/124b, the source electrode 173a/173b and the drain electrode 175a/175b together with the island-shaped semiconductor 154a/154b constitute a thin film transistor. The channel of the thin film transistor is formed in the island-shaped semiconductor 154a/154b between the source electrode 173a/173b and the drain electrode 175a/175b.
A protective film 180 is formed on the data lines 171, the drain electrodes 175a and 175b, the dummy drain electrodes 176a and 176b, and exposed portions of the semiconductors 154a and 154b.
In the protective film 180, a plurality of contact holes 185a, 185b, 186a, and 186b are formed, which expose the drain electrodes 175a and 175b and the dummy drain electrodes 176a and 176b. The contact holes 186a and 186b are dummy contact holes, which may be omitted.
On the protective film 180, a plurality of the pixel electrodes 192a and 192b are formed. The pixel electrodes 192a and 192b are physically and electrically connected through the contact holes 185a and 185b to the drain electrodes 175a and 175b, respectively, so that the pixel electrodes 192a and 192b are applied with data voltages from the drain electrodes 175a and 175b, respectively.
The outer boundaries of the pixel electrodes 192a and 192b are formed along the gate lines 121a and 121b, the gate electrodes 124a and 124b, the dummy gate electrodes 126a and 126b, and the storage electrodes 133a, 133b, 134a and 134b. The pixel electrodes 192a and 192b include central cut portions 91a and 91b, lower cut portions 94a and 94b, and the upper cut portions 96a and 96b. The pixel electrodes 192a and 192b are divided into a plurality of domains by the cut portions 91a to 96b. The cut portions 91a to 96b have approximate inversion symmetry with respect to the storage electrode lines 131.
The lower and upper cut portions 94a, 94b, 96a and 96b extend substantially from the left sides of the pixel electrodes 192a and 192b to the right sides thereof in a slanted or angled direction. The lower cut portions 94a and 94b and the upper cut portions 96a and 96b are disposed in lower and upper half regions, respectively, of the pixel electrodes 192a and 192b divided by the storage electrode lines 131, and form an angle of about 45° with respect to the gate lines 121a and 121b to extend perpendicular to each other.
The central cut portions 91a and 91b extend from the storage electrode lines 131 to the right side in a slanted or angled direction and include a pair of slanted sides which are substantially parallel to the respective lower cut portions 94a and 94b and the upper cut portions 96a and 96b. The slanted sides also form an angle of about 45° with respect to the gate lines 121a and 121b to extend perpendicular to each other.
Accordingly, each of the upper and lower half regions of the pixel electrode 192a/192b is divided into three domains by the cut portions 91a to 96a/91b to 96b. Here, the number of domains or the number of cut portions may vary according to a size of pixel, an aspect ratio of the pixel electrode 192a/192b, a type or characteristics of the liquid crystal layer 3, or other design factors.
The pixel electrodes 192a and 192b have substantially the same openings. Namely, the dummy gate electrodes 126a and 126b have substantially the same shapes as the gate electrodes 124a and 124b. The positions of the dummy drain electrodes 176a and 176b are the same as the positions of the drain electrodes 175a and 175b. In addition, the cut portions 91a to 96a and 91b to 96b of the pixel electrodes 192a and 192b have substantially the same shapes. In addition, the patterns within the openings of the pixel electrodes 192a and 192b have a substantially up and down symmetry. In this manner, if the shape of the pixel electrodes 192a and 192b and openings thereof are the same, even though the positions of the switching devices of the pixels are different from each other, optical characteristics of all the pixels become equal to each other, thus making it is possible to prevent deterioration of image quality.
Now, the common electrode panel 200 will be described. As best seen with reference to
A plurality of color filters 230, a cover film 250, and a common electrode 270 are sequentially formed on the substrate 210 and the shielding members 220.
The common electrode 270 has a plurality of sets of cut portions 71a, 72a, 77a, 78a, 71b, 72b, 77b, and 78b. Since the cut portions 71b to 78b and the cut portions 71a to 78a have the same shapes, only the cut portions 71a to 78a will be described.
One set of the cut portions 71a to 78a faces one pixel electrode 192a and includes central cut portions 71a and 72a, a lower cut portion 77a, and an upper cut portion 78a. The cut portions 71a to 78a are disposed between the cut portions 91a to 96a of the adjacent pixel electrodes 192a and between edge cut portions 94a and 96a and corners of the pixel electrode 192a (see
Each of the lower and upper cut portions 72a and 77a includes a slanted or angled portion which extends from the right side of the pixel electrode 192a toward the lower or upper side thereof, and longitudinal and transverse portions which extend from the ends of the slanted or angled portion along the sides of the pixel electrode 192a forming an obtuse angle with respect to the slanted or angled portion and overlap the sides of the pixel electrode 192a.
The central cut portion 71a includes a longitudinal portion which extends along the left side of the pixel electrode 192a and overlaps the left side thereof, a pair of slanted or angled portions which extend from the ends of the longitudinal portion and toward the right side of the pixel electrode 192a, and a distal longitudinal portion which extends from the ends of each of the slanted or angled portions along the right side of the pixel electrode 192a forming an obtuse angle with respect to the slanted or angled portions and overlaps the right side. The central cut portion 72a includes a pair of slanted or angled portions which extend substantially from the storage electrode line 131 and toward the right side of the pixel electrode 192a forming a slanted angle with respect to the storage electrode line 131 and distal end portions which extend from the each of the ends of the slanted or angled portions along the right side of the pixel electrode 192a forming an obtuse angle with respect to the slanted portions and overlap the right side thereof.
Notches having a shape of a “V” or triangle are formed in the slanted or angled portions on opposite sides of the cut portions 71a, 77, and 78a. The notches may have a shape of a rectangle, a trapezoid, or a semicircle, and may have a convex or concave shape. An alignment direction of the liquid crystal molecules located in domain boundaries corresponding to the cut portions 71a, 77, and 78a can be determined due to the notches.
On the other hand, a plurality of the pixels shown in
The aforementioned features of the liquid crystal display apparatus of
The present invention described in the exemplary embodiments can be applied to a case where pixels having different shapes are disposed within a liquid crystal display panel assembly. Particularly, the present invention can be employed to a structure such as a VA mode LCD where a plurality of domains are formed.
According to the present invention, by alternately disposing thin film transistors at left and right sides of the pixels, driver inversion becomes column inversion, but apparent inversion becomes dot inversion. Accordingly, it is possible to eliminate transverse line flicker and to increase a charging rate of the pixels.
In addition, by providing source electrodes along data lines and extending drain electrodes to the source electrodes of adjacent pixels, it is possible to maintain uniformity of the pixels even though the thin film transistors are alternately disposed at right and left sides of the pixels. In addition, inversion driving schemes according to the present invention can be applied to a PVA mode. As a result, it is possible to obtain a wide viewing angle.
In addition, by dividing one pixel into a pair of sub-pixels and applying different data voltages to the sub-pixels, it is possible to improve side or lateral visibility.
Further, by forming a plurality of dummy gate electrodes and a plurality of dummy drain electrodes, it is possible to prevent deterioration in image quality.
Although exemplary embodiments and modified examples of the present invention have been described, the present invention is not limited to the embodiments and examples, but may be modified in various forms without departing from the scope of the appended claims, the detailed description and the accompanying drawings of the present invention. Therefore, it is natural that such modifications belong to the scope of the present invention.
Baek, Seung-Soo, Kim, Dong-Gyu
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