Active matrix type liquid crystal display device

The present invention relates to an active matrix type liquid crystal display device used in a liquid crystal television, a notebook computer, or the like.

[0002] FIGS. 13 and 14 show a plan view and a cross-sectional view of a general active matrix type liquid crystal display device. The active matrix type liquid crystal display device is roughly composed of a liquid crystal panel 1, a gate drive circuit 2, a source drive circuit 3, and a backlight 4.

[0003] Further, the liquid crystal panel 1 is a deflecting plate (shown) which is closely attached to the outside of the active matrix substrate 5, the opposing substrate 6, the liquid crystal layer 7 sandwiched between the two substrates 5, and 6, and both substrates 5, 6. It is roughly composed of.

[0004] On the active matrix substrate 5, a plurality of scanning wirings (not shown) arranged in parallel, and a plurality of signal wirings arranged in parallel with the scanning wirings via the insulating film 8. 9. A thin film (TFT) 10 arranged near each intersection of the scanning wiring and the signal wiring 9, and a plurality of pixel electrodes 11 arranged in an area surrounded by the scanning wiring and the signal wiring 9 are formed. Has been done.

[0005] FIG. 15 shows a plan view of a pixel portion of the active matrix substrate 5. Since the pixel electrode 11 is formed on the same layer as the signal wiring 9, it is formed so as not to come into contact with the signal wiring 9 while maintaining a predetermined distance. The TFT 10 is a three-terminal element, and the conduction of current between the drain electrode 13 and the source electrode 14 is controlled by the voltage applied to the gate electrode 12. The gate electrode 12 is connected to the adjacent scanning wiring 15, the source electrode 14 is connected to the adjacent signal wiring 9, and the drain electrode 13 is connected to the pixel electrode 11.

[0006] On the other hand, on the opposed substrate 6, color filters 16 are formed in the order of arrangement of red, green, and blue at positions corresponding to the pixel electrodes 11. A black matrix 17, which is a light-shielding film that prevents light leakage from between the scanning wiring 15 and the signal wiring 9 and the pixel electrode 11, is formed between the color filters 16 and 16. Further, a counter electrode 18 made of a transparent conductive material is formed on the upper layer. The gate drive circuit 2 and the source drive circuit 3 are connected to the terminals of the scanning wiring 15 and the terminals of the signal wiring 9 arranged around the liquid crystal panel 1, respectively.

[0007] Next, a method of driving the active matrix type liquid crystal display device having the above configuration will be described.

[0008] In the driving method of the active matrix type liquid crystal display device, when writing the pixel array on the nth line, an on signal (potential at which TFT 10 is turned on:) is sent to the scanning wiring 15n on the nth line from the gate drive circuit 2. Vgh) is entered. At this time, an off signal (potential at which TFT 10 is turned off: Vgl) is input to the scanning wiring other than the scanning wiring 15n. Therefore, only TFT10 on the nth line is turned on. In this case, the source signal of the voltage to be charged to the pixel (pixel electrode 11 and liquid crystal layer 7) on the nth row is supplied from the source drive circuit 3 to each signal wiring 9.

[0009] As described above, when the writing to the array of the pixels in the nth row is completed, the off signal is input to the scanning wiring 15n, while the on signal is input to the scanning wiring 15 (n + 1). By repeating the above operation, all the pixels are charged with an arbitrary voltage value. Since the transmittance of the liquid crystal layer 7 between the pixel electrode 11 and the counter electrode 18 changes depending on the voltage applied between the electrodes 11 and 18, the light from the backlight 4 is adjusted to display an arbitrary image. Will be done.

By the way, a structure has also been proposed in which a pixel electrode is provided on an interlayer insulating film, the pixel electrode and the signal wiring are formed on a separate layer, and the pixel electrode is overlapped on the signal wiring (Japanese Patent Laid-Open No. 4-121712). Gazette, etc.). FIG. 16 shows a cross-sectional view of one pixel in an active matrix type liquid crystal display device having a structure in which the pixel electrodes are superposed on the signal wiring. Further, FIG. 17 shows a plan view of the active matrix substrate shown in FIG. In such a configuration, the pixel electrode 21 and the signal wiring 22 are formed in separate layers, and the pixel electrode 21 and the signal wiring 22 are overlapped with each other via the interlayer insulating film 23, so that the pixel electrode 21 and the signal wiring 22 are overlapped with each other. The gap with 22 can be eliminated. Therefore, the area (aperture ratio) of the pixel electrode 21 can be expanded, and the power consumption of the active matrix type liquid crystal display device can be suppressed. In addition, 24 is an active matrix substrate, 25 is a TFT, 26 is a liquid crystal layer, 27 is a counter electrode, 28 is a counter substrate, 29 is a scanning wiring, 30 is a contact hole, 31 is an auxiliary capacitance electrode, and 32 is an auxiliary capacitance wiring. ..

[0011] However, when the structure in which the pixel electrodes 21 are superposed on the signal wiring 22 as described above is adopted, as shown in FIG. 15, the conventional structure in which the pixel electrodes 11 are spaced from the signal wiring 9 at a predetermined distance. The capacitance Csd between the pixel electrode 21 and the signal wiring 22 is increased as compared with the above. In that case, as the capacitance Csd increases, the potential of the pixel tends to change depending on the source signal, and the display characteristic called shadowing deteriorates.

[0012] Hereinafter, this mechanism will be described using the equivalent circuit of the active matrix substrate 24 shown in FIG. That is, when the ON signal Vgh is input to the scanning wiring Gn and the TFT 23 is turned on, the voltage Vs1 of the signal wiring S1 is charged to the pixel electrode P1.

Next, when the off signal Vgl is input to the scanning wiring Gn and the TFT 23 is turned off, the signal wiring S1 is supplied with the voltage Vs1'to be written to the pixel electrode P2 in the next stage. In that case, the voltage of the pixel electrode P1 changes under the influence of the voltage Vs1'of the signal wiring S1 via the capacitance Csd1. If the voltage of the pixel electrode P1 at that time is Vp1, then Vp1 = Vs1- (Csd1 (Vs1-Vs1') + Csd2 (Vs2-Vs2')) / (Cp + Csd1 + Csd2) ... (1). .. Here, Cp is the capacitance of the pixel electrode (Cp = liquid crystal capacitance Clc + auxiliary electrode capacitance Ccs), Csd1 is the capacitance between the signal wiring S1 and the pixel electrode P1, and Csd2 is the signal wiring S2 and the pixel electrode. It is the capacitance between P2, Vs1 and Vs2 are the voltages of the signal wirings S1 and S2 when the scanning wiring Gn in the nth row is on, and Vs1'and Vs2' are (n + 1). This is the voltage of the signal wirings S1 and S2 when the scanning wiring G (n + 1) in the column is in the ON state.

[0014] In the gate line inversion drive (1H inversion drive), which is a general driving method of an active matrix type liquid crystal display device, the polarity of the source signal is inverted for each gate line. Here, assuming that the gradations of the neighbors are the same, Vs = Vs1 = Vs2, Vs'= Vs1'= Vs2'... (2), so from equations (1) and (2), Vp1 = Vs- (Csd1 + Csd2) / (Cp + Csd1 + Csd2) · (Vs-Vs') ... (3). In this way, in the 1H inversion drive, the amount of change in the pixel potential is proportional to (Csd1 + Csd2). Therefore, shadowing appears remarkably as the capacitance Csd between the signal wiring S and the pixel electrode P increases.

On the other hand, dot inversion drive has been proposed as a drive method for suppressing a change in pixel potential due to capacitance Csd between the signal wiring S and the pixel electrode P. In this dot inversion drive, the polarity of the source signal is inverted for each gate line, and the source side also inputs a signal with the opposite polarity for each source line.

[0016] In the case of the dot inversion drive, assuming that the gradations of the adjacent dots are the same, Vs = Vs1 = -Vs2, Vs'= Vs1'=-Vs2'... (4). , From equations (1) and (4), Vp1 = Vs- (Csd1-Csd2) / (Cp + Csd1 + Csd2) · (Vs-Vs') ... (5). As described above, in the dot inversion drive, the amount of change in the pixel potential is proportional to the difference between the capacitance Csd1 and the capacitance Csd2. Therefore, the shadowing phenomenon can be significantly suppressed as compared with the case of 1H inversion drive, and the image quality of the liquid crystal display device can be improved. In particular, if the difference between the capacitance Csd1 and the capacitance Csd2 with respect to the pixels adjacent to the scanning wiring 29 in the extending direction is reduced, the shadowing phenomenon can be significantly suppressed.

However, in that case, the following new problems arise. That is, in the dot inversion drive, the transmission coefficient difference due to the variation in the capacitance Csd between the signal wiring S and the pixel electrode P becomes large. Therefore, when the photolithography process is performed in block units, the signal wiring is caused by the alignment deviation. So-called block division, in which the overlapping width of S and the pixel electrode P differs in block units, is likely to occur.

[0018] For example, as shown in FIG. 19, consider a case where an alignment deviation dx occurs in the photolithography step of the pixel electrode P. In that case, since the amount of overlap of the pixel electrode P with the signal wiring S1 increases, the capacitance Csd1 between the signal wiring S1 and the pixel electrode P increases, and conversely, the capacitance between the signal wiring S2 and the pixel electrode P increases. Csd2 decreases. FIG. 20 shows the relationship between the alignment deviation dx and the capacitance Csd1 or the capacitance Csd2 in the photolithography process. From FIG. 20, as the alignment deviation dx increases, the difference between the capacitance Csd1 and the capacitance Csd2 widens, and the amount of change in the pixel potential increases.

[0019] In order to solve such a problem, in an active matrix type liquid crystal display device having a structure in which the pixel electrodes are superposed on the signal wiring, the side edges of the two pixel electrodes adjacent to each other with the signal wiring in between. A structure has been proposed in which approximately 1/2 of each of the above is completely overlapped on the signal wiring. 21 and 22 show a cross-sectional view and a plan view of a structure in which approximately 1/2 of each side edge of each adjacent pixel electrode is completely overlapped on the signal wiring. In this case, approximately 1/2 of one side edge of the pixel electrode 45 completely overlaps the signal wiring 43 adjacent to one side. Further, approximately 1/2 of the other side edge of the pixel electrode 45 completely overlaps the signal wiring 43'adjacent to the other side. Therefore, Csd1 Csd2, and (Csd1-Csd2) in the above equation (5) decreases. Furthermore, since the adjacent pixel electrodes 45 ", 45 completely cover the signal wiring 43, (Csd1-Csd2) hardly changes even if an alignment shift occurs. Therefore, due to the shadowing as described above. It is possible to suppress block division.

[0020] 41 is a TFT, 42 is a scanning wiring, 44 is an interlayer insulating film, 46 is a contact hole, 47 is an auxiliary capacitance electrode, and 48 is an auxiliary capacitance wiring.

However, the conventional active matrix type liquid crystal display device shown in FIGS. 21 and 22 has the following problems. That is, as described above, the active matrix type liquid crystal display device having a structure in which approximately 1/2 of the side edges of the adjacent pixel electrodes as shown in FIGS. 21 and 22 are completely overlapped on the signal wiring is driven by dot inversion. As a result, the shadowing phenomenon due to the coupling capacitance Csd between the signal wiring 43 and the pixel electrode 45 can be suppressed, and the block division due to the variation in the coupling capacitance Csd can be suppressed.

However, in the case of the above-mentioned structure, the two pixel electrodes 45 ", 45 located on both sides of the signal wiring 43 and adjacent to each other are arranged so as to completely cover the signal wiring 43. Therefore, at the point where the pixel electrodes 45 "and 45 covering the signal wiring 43 are interchanged, there is always a region where the signal wiring 43 cannot be covered by any of the adjacent pixel electrodes 45" and 45. Therefore, the coupling capacitance Csd between the surrounding pixel electrodes 45 (45 ") and the signal wiring 43 in the above region due to the change in the spacing between the pixel electrodes 45" and 45 due to the misalignment between the layers, and thus the above The coupling capacitance Csd of the signal wiring 43 portion covered with the pixel electrode 45 (45 ") other than the region with the pixel electrode 45 (45") fluctuates greatly.

[0023] For example, in a high-definition active matrix liquid crystal display device having a definition of 130 PPI to 200 PPI or more, an active matrix liquid crystal display device in which the interlayer insulating film needs to be thin due to its configuration, the above-mentioned influence becomes large. It is a problem.

[0024] Therefore, an object of the present invention is to provide an active matrix type liquid crystal display device capable of preventing deterioration of image quality due to the coupling capacitance between the signal wiring and the pixel electrode and suppressing block division due to the variation in the coupling capacitance. To do.

[Means for Solving the Problems] In order to achieve the above object, the first invention is<u style="single">、</u><u style="single">Absolute</u>A plurality of scanning wirings formed on the edge substrate, auxiliary capacitance wirings arranged in parallel with the scanning wirings, a plurality of signal wirings intersecting the scanning wirings, and respective intersection positions of the scanning wirings and the signal wirings. In an active matrix type liquid crystal display device having a plurality of switching elements arranged in a matrix in the vicinity and pixel electrodes connected to the output terminals of each switching element and arranged in a matrix, the signal wirings are adjacent to each other. It is bent in the vicinity of the first and second pixel electrodes, one is covered in the width direction by the first pixel electrode with the bent portion as a boundary, and the other is covered in the width direction by the second pixel electrode with the bending as a boundary. The auxiliary capacitance wiring is provided so as to overlap the bent portion of the signal wiring.

[0026] According to the above configuration, the signal wiring is bent in the vicinity of the first and second pixel electrodes adjacent to each other, and one is covered with the first pixel electrode in the width direction with the bent portion as a boundary. The other is covered in the width direction by the second pixel electrode. Therefore, paying attention to one pixel electrode, the first capacitance between the pixel electrode and the signal wiring adjacent to one side and the first capacitance between the pixel electrode and the signal wiring adjacent to the other side are the first. 2 The difference between the capacitance and the capacitance becomes small, and the shadowing phenomenon is greatly suppressed by performing dot inversion drive.

[0027] At that time, the auxiliary capacitance wiring is arranged so as to overlap the bent portion of the signal wiring. Therefore, the capacitance between the bent portion of the signal wiring and the pixel electrode is reduced. As a result, the change in capacitance between the layers and the pixel electrode at the bent portion of the signal wiring due to the misalignment between the layers is significantly reduced, and the block division is suppressed.

[0028] Also,<u style="single">No. 2</u>The present invention includes a plurality of scanning wirings formed on an insulating substrate, auxiliary capacitance wirings arranged in parallel with the scanning wirings, a plurality of signal wirings intersecting the scanning wirings, and the scanning wirings and signal wirings. In an active matrix type liquid crystal display device having a plurality of switching elements arranged in a matrix in the vicinity of each intersection position and pixel electrodes connected to the output terminals of each switching element and arranged in a matrix, the above signal wiring is used. , Bend in the vicinity of the first and second pixel electrodes adjacent to each other, one is covered in the width direction by the first pixel electrode with the bent portion as a boundary, and the other is the second pixel with the bend as a boundary. The auxiliary capacitance wiring is covered with electrodes in the width direction, and is characterized by having an electrode portion extending to a position overlapping the bent portion of the signal wiring.

[0029] According to the above configuration, the signal wiring is bent in the vicinity of the first and second pixel electrodes adjacent to each other, and one is covered with the first pixel electrode in the width direction with the bent portion as a boundary. The other is covered in the width direction by the second pixel electrode. Therefore, as in the case of the third invention, the shadowing phenomenon is significantly suppressed by performing the dot inversion drive.

At that time, an electrode portion extending from the auxiliary capacitance wiring is arranged so as to overlap the bent portion of the signal wiring. Therefore, as in the case of the third invention, the capacitance between the pixel electrode and the signal electrode at the bent portion of the signal wiring is reduced, and the capacitance varies between the pixel electrode and the signal wiring. The block division is suppressed.

[0031] Further, the first invention described above.<u style="single">Or the second</u>It is desirable that the active matrix type liquid crystal display device of the present invention includes a light-shielding film arranged at positions between pixel electrodes adjacent to each other on the insulating substrate.

[0032] Generally, the alignment accuracy between the insulating substrate on which the pixel electrodes are formed and the opposing substrate facing the insulating substrate is about ± 5 μm, whereas the alignment accuracy between the layers on the insulating substrate is about ± 5 μm. Is less than ± 1 μm. According to the above configuration, the light-shielding film is arranged at a position between the pixel electrodes adjacent to each other on the insulating substrate. Therefore, the width of the light-shielding film is formed narrower than that of the black matrix arranged on the opposite substrate side, and the black matrix is deleted to improve the aperture ratio.

[0033] Further, since the area of the black matrix arranged on the facing substrate side is reduced, the bonding margin between the insulating substrate and the facing substrate is widened.

[0034] Further, the first invention described above.<u style="single">Or the second</u>In the active matrix type liquid crystal display device of the present invention, it is desirable to electrically connect the light-shielding film to the auxiliary capacitance wiring or the scanning wiring.

[0035] According to the above configuration, a part of the lines of electric force from the signal wiring is terminated by the electric field shielding effect of the light-shielding film arranged in the vicinity of the signal wiring. Therefore, the first capacitance between the pixel electrode and the signal wiring adjacent to one side and the second capacitance between the pixel electrode and the signal wiring adjacent to the other side become smaller. As a result, the shadowing phenomenon caused by the difference between the first capacitance and the second capacitance is further suppressed, and the block division is further reduced.

[Embodiments of the Invention] Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. &lt;First Embodiment&gt; FIG. 1 is a plan view of an active matrix substrate in the active matrix type liquid crystal display device of the present embodiment. FIG. 2 is a cross-sectional view taken along the line corresponding to AA'of FIG. 1 in the active matrix type liquid crystal display device. Further, FIG. 3 is a cross-sectional view taken along the line corresponding to BB'of FIG. 1 in the active matrix type liquid crystal display device.

The active matrix substrate side has the following configuration. That is, in FIGS. 1 to 3, a plurality of gate wirings (scanning wirings) 52 made of metals such as Al and Ta are arranged in parallel on the insulating substrate 51 as the active matrix substrate made of glass. The film thickness of this gate wiring 52 is 2000 Å to 5000 Å. Further, on this upper layer, a plurality of source wirings 54, 54'made of metals such as Al and Ta are arranged orthogonal to the gate wiring 52 via a gate insulating film 53 made of SiNx or the like. The thickness of the gate insulating film 53 is about 2000 Å to 4000 Å, and the relative permittivity is about 3 to 8. The film thickness of the source wiring 54,54'is 1000 Å to 5000 Å.

[0038] Amorphous silicon TFT 55 is arranged in the vicinity of each intersection position between the gate wiring 52 and the source wiring 54, 54'. The amorphous silicon TFT 55 is composed of a gate electrode 56, a gate insulating film 53, an amorphous semiconductor layer 57, an impurity-added semiconductor layer 58, a source electrode 59, and a drain electrode 60 laminated. The gate electrode 56 is made of the same material as the gate wiring 52. The source electrode 59 and the drain electrode 60 are made of the same material as the source wiring 54, 54'. The amorphous semiconductor layer 57 is made of amorphous silicon formed by CVD (Chemical Vapor Deposition), and its film thickness is about 500 Å to 2000 Å. The gate electrode 56 is connected to the adjacent gate wiring 52, and the source electrode 59 is connected to the adjacent source wiring 54.

[0039] The auxiliary capacitance wiring 63 is formed on the same layer as the gate wiring 52 (that is, on the insulating substrate 51), and the drain electrode 60 extends over the auxiliary capacitance wiring 63 via the gate insulating film 53. The auxiliary capacitance electrode 64 is formed by the end portion of the drain electrode 60. The interlayer insulating film 61 is made of an organic material or an inorganic material, its film thickness is 1 μm to 4 μm, and its relative permittivity is about 2 to 4. A contact hole 65 is provided at the position of the auxiliary capacitance electrode 64 in the interlayer insulating film 61, and the drain electrode 60 is connected to the pixel electrode 62 by the contact hole 65 via the auxiliary capacitance electrode 64.

[0040] In the present embodiment, the auxiliary capacitance wiring 63 is arranged at a position where the pixel electrode 62 is bisected on the TFT 55 side and the anti-TFT 55 side. Approximately 1/2 of the position of the auxiliary capacitance wiring 63 on the pixel electrode 62 on the TFT 55 side overlaps with the source wiring 54'adjacent to one side via the interlayer insulating film 61. On the other hand, approximately 1/2 of the side of the pixel electrode 62 opposite to the TFT 55 from the position of the auxiliary capacitance wiring 63 overlaps with the source wiring 54 adjacent to the other side via the interlayer insulating film 61. That is, both side edges of the pixel electrode 62 are bent at the position of the auxiliary capacitance wiring 63.

[0041] On the other hand, the opposite substrate side has the following configuration. That is, on the insulating substrate 66 as the opposed substrate made of glass, the color filters 67 are arranged in the order of arrangement of red, green, and blue at the positions corresponding to the respective pixel electrodes 62, 62', 62 ". A black matrix 68, which is a light-shielding film that prevents light leakage from between adjacent pixel electrodes 62', 62 ", is arranged between the color filters 67 and 67. Further, a counter electrode 69 made of a transparent conductive material is arranged on the upper layer.

Then, the active matrix substrate 51 and the facing substrate 66 are arranged at predetermined intervals so that the pixel electrodes 62, 62', 62 "side and the facing electrode 69 side face each other, and between the two substrates 51, 66. The liquid crystal layer 70 is sandwiched between the two and sealed with a sealing material to form the active matrix type liquid crystal display device.

As described above, in the present embodiment, the pixel electrode 62 is recessed along the contact hole 65 on the auxiliary capacitance wiring 63 and is electrically connected to the auxiliary capacitance electrode 64 (drain electrode 60). ing. Focusing on the source wiring 54 on the left side of FIG. 1, the portion on the TFT55 side of the auxiliary capacitance wiring 63 arranged at the position where the pixel electrode 62 is equally divided into the TFT55 side and the anti-TFT55 side is concerned. The pixel electrode 62 "on the left side of FIG. 1 with respect to the source wiring 54 covers the source wiring 54. On the other hand, in the portion on the anti-TFT55 side of the auxiliary capacitance wiring 63, with respect to the source wiring 54. The pixel electrode 62 on the right side in FIG. 1 covers the source wiring 54, and the same applies to the source wiring 54'on the right side in FIG.

That is, both side edges of the pixel electrode 62 are bent at a position bisected in the extending direction of the source wiring 54 and at a position on the auxiliary capacitance wiring 63.

As shown in FIG. 22, when the auxiliary capacitance wiring 48 is not arranged at a position that bisects the pixel electrode 45 into the TFT 41 side and the anti-TFT 41 side, both sides of the pixel electrode 45 The bent portion that exists at the position that bisects the edge does not exist at the position of the auxiliary capacitance wiring 48. Therefore, due to the misalignment between the layers, the coupling capacitance Csd of the bent portion where the signal wiring 43 is not covered by the adjacent pixel electrodes 45 ", 45 fluctuates greatly. This means that the pixel electrodes 62 The same applies even when the position of the bent portion is not in a position that divides the source wiring 54 into two equal parts in the extending direction. The point is that the auxiliary capacitance wiring is not arranged so as to overlap the bent portion of the pixel electrode. , The fluctuation of the coupling capacitance Csd of the bent portion due to the alignment deviation is large.

[0046] On the other hand, in the present embodiment, the auxiliary capacitance wiring 63 is arranged so that the pixel electrode 62 is divided into the TFT 55 side and the anti-TFT 55 side. Therefore, the bent portion provided at a position that bisects both side edges of the pixel electrode 62 is located on the auxiliary capacitance wiring 63. Therefore, since the source wiring 54, 54'and the auxiliary capacitance wiring 63 form a coupling capacitance, a part of the electric lines of force from the source wiring 54, 54'is terminated on the auxiliary capacitance wiring 63 side. , The coupling capacitance Csd between the pixel electrode 62 and the source wiring 54, 54'at the bent portion will decrease.

Therefore, even if the alignment is misaligned between the layers, the change in the coupling capacitance Csd with the source wiring 54 at the bent portion where the source wiring 54 is not covered by the adjacent pixel electrodes 62, 62 "is small. As a result, the amount of change in the coupling capacitance Csd1 between the source wiring 54 and the pixel electrode 62 and the coupling capacitance Csd2 between the source wiring 54'and the pixel electrode 62 is significantly reduced, and the block division can be suppressed. ..

That is, according to the present embodiment, it is possible to suppress the block division due to the variation in the coupling capacitance Csd between the source wiring 54, 54'and the pixel electrode 62.

&lt;Second Embodiment&gt; In the first embodiment, the position where the auxiliary capacitance wiring 63 is equally divided into the TFT 55 side and the anti-TFT 55 side, that is, the center of the pixel electrode 62. It is placed in. However, in many cases, the auxiliary capacitance wiring cannot be arranged in the center of the pixel electrode for reasons such as an improvement in the aperture ratio and an improvement in the manufacturing yield. The present embodiment deals with such a case.

[0050] FIG. 4 is a plan view of an active matrix substrate in the active matrix type liquid crystal display device of the present embodiment. FIG. 5 is a cross-sectional view taken along the line corresponding to CC'of FIG. 4 in the active matrix type liquid crystal display device. Further, FIG. 6 is a cross-sectional view taken along the line corresponding to D-D'of FIG. 4 in the active matrix type liquid crystal display device.

[0051] In FIGS. 4 to 6, active matrix substrate 71, gate wiring 72, gate insulating film 73, source wiring 74, TFT 75, interlayer insulating film 81, pixel electrode 82, facing substrate 86, color filter 87, black matrix 88. The counter electrode 89 and the liquid crystal layer 90 are the active matrix substrate 51, the gate wiring 52, the gate insulating film 53, the source wiring 54, 54', the TFT 55, and the interlayer insulating film 61 in the first embodiment shown in FIGS. It has the same configuration as the pixel electrode 62, the counter electrode 66, the color filter 67, the black matrix 68, the counter electrode 69, and the liquid crystal layer 70, and functions in the same manner.

[0052] The auxiliary capacitance wiring 83 in the present embodiment is arranged parallel to the gate wiring 72 closer to the TFT 75 than the center of the pixel electrode 82. Then, the drain electrode 80 of the TFT 75 extends over the auxiliary capacitance wiring 83, and the auxiliary capacitance electrode 84 is formed by the end portion of the drain electrode 80. Further, the auxiliary capacitance electrode 84 is connected to the pixel electrode 82 at the position of the contact hole 85.

[0053] Further, the auxiliary capacitance wiring 83 is provided with an electrode portion 91 extending under each source wiring 74 to the central portion of the pixel electrode 82. In this way, as shown in FIG. 4, the bent portion of the pixel electrode 82 provided at a position that bisects both side edges of the pixel electrode 82 is present on the electrode portion 91 having the same potential as the auxiliary capacitance wiring 83. ..

Therefore, according to the present embodiment, even when the auxiliary capacitance wiring 83 cannot be arranged at the center of the pixel electrode 82, the bent portion of the pixel electrode 82 may be on the auxiliary capacitance wiring 83. It can work in the same way. That is, the source wiring 74 and the electrode portion 91 at the bent portion form a coupling capacitance. As a result, the coupling capacitance Csd between the pixel electrode 82 and the source wiring 74 at the bent portion can be reduced.

[0055] In this case, when the pixel electrode 82 is bent on the auxiliary capacitance wiring 83, the bending position is not the center of the pixel electrode 82, so Csd1 Csd2, and (Csd1 in the above equation (5)). -The value of Csd2) increases. Therefore, even if the dot inversion drive is adopted, the shadowing phenomenon due to the coupling capacitance Csd between the pixel electrode 82 and the source wiring 74 is likely to occur.

&lt;Third Embodiment&gt; FIG. 7 is a plan view of an active matrix substrate in the active matrix type liquid crystal display device of the present embodiment. FIG. 8 is a cross-sectional view taken along the line corresponding to EE'of FIG. 7 in the active matrix type liquid crystal display device. Further, FIG. 9 is a cross-sectional view taken along the line corresponding to FF'of FIG. 7 in the active matrix type liquid crystal display device.

[0057] In FIGS. 7 to 9, active matrix substrate 101, gate wiring 102, gate insulating film 103, TFT 105, interlayer insulating film 106, auxiliary capacitance wiring 108, auxiliary capacitance electrode 109, contact hole 110, facing substrate 111, color. The filter 112, the black matrix 113, the counter electrode 114, and the liquid crystal layer 115 are the active matrix substrate 51, the gate wiring 52, the gate insulating film 53, the TFT 55, the interlayer insulating film 61, according to the first embodiment shown in FIGS. It has the same configuration as the auxiliary capacitance wiring 63, auxiliary capacitance electrode 64, contact hole 65, facing substrate 66, color filter 67, black matrix 68, facing electrode 69, and liquid crystal layer 70, and functions in the same manner.

[0058] The pixel electrode 107 in the present embodiment has both side edges that are not bent as in the first embodiment, but are linear and formed in a rectangular shape. On the other hand, the source wiring 104 is bent at the position of the auxiliary capacitance wiring 108 which is arranged at a position where the pixel electrode 107 is bisected on the TFT 105 side and the anti-TFT 105 side. Approximately 1/2 of the position of the auxiliary capacitance wiring 108 in the source wiring 104 on the TFT 105 side overlaps with the pixel electrode 107'located on one side via the interlayer insulating film 106. On the other hand, approximately 1/2 of the source wiring 104 on the opposite side of the auxiliary capacitance wiring 108 from the position of the TFT 105 overlaps with the pixel electrode 107 located on the other side via the interlayer insulating film 106.

That is, in the present embodiment, the source wiring 104 is bent instead of bending both side edges of the pixel electrodes as in the first embodiment. By doing so, it is possible to reduce the coupling capacitance Csd between the pixel electrode 107 and the source wiring 104 at the bent portion, as in the case of the first embodiment. Therefore, it is possible to suppress the block division caused by the misalignment between the layers.

[0060] Further, according to the present embodiment, the pixel electrode 107 can be formed in a rectangular shape like the conventional active matrix type liquid crystal display device shown in FIGS. 15 and 17. Therefore, the color filter 112 and the black matrix 113 can be easily formed.

[0061] In the present embodiment, the auxiliary capacitance wiring 108 is arranged at a position where the pixel electrode 107 is bisected on the TFT 105 side and the anti-TFT 105 side. However, when the auxiliary capacitance wiring cannot be arranged in the center of the pixel electrode 107, the auxiliary capacitance wiring extends under each source wiring 104 to the bent portion of the source wiring 104 as in the second embodiment. An electrode portion may be provided so that the bent portion of the source wiring 104 exists on the electrode portion having the same potential as the auxiliary capacitance wiring.

&lt;Fourth Embodiment&gt; FIG. 10 is a plan view of an active matrix substrate in the active matrix type liquid crystal display device of the present embodiment. FIG. 11 is a cross-sectional view taken along the line corresponding to GG'in FIG. 10 in the active matrix type liquid crystal display device. Further, FIG. 12 is a cross-sectional view taken along the line corresponding to HH'of FIG. 10 in the active matrix type liquid crystal display device.

[0063] In FIGS. 10 to 12, active matrix substrate 121, gate wiring 122, gate insulating film 123, source wiring 124, TFT 125, interlayer insulating film 126, pixel electrode 127, auxiliary capacitance electrode 129, contact hole 130, facing substrate. 131, the counter electrode 134 and the liquid crystal layer 135 are the insulating substrate 51, the gate wiring 52, the gate insulating film 53, the source wiring 54, 54', the TFT 55, and the interlayer insulating film 61 in the first embodiment shown in FIGS. It has the same configuration as the pixel electrode 62, auxiliary capacitance electrode 64, contact hole 65, facing substrate 66, facing electrode 69, and liquid crystal layer 70, and functions in the same manner.

[0064] In the present embodiment, a light-shielding film 136 made of the same material as the gate wiring 122 is arranged in the same layer as the gate wiring 122 to block light between the adjacent pixel electrodes 127 and 127. Therefore, it is not necessary to arrange the black matrix 133 at the position between the adjacent pixel electrodes 127 and 127 on the facing substrate 131, and it is sufficient to form the black matrix 133 only on the TFT 125.

[0065] Generally, the alignment accuracy between the active matrix substrate 121 and the facing substrate 131 is about ± 5 μm. On the other hand, the alignment accuracy between the layers of the active matrix substrate 121 is ± 1 μm or less. Therefore, by arranging the light-shielding film 136 on the active matrix substrate 121 side, the width of the light-shielding film 136 can be made narrower than that of the black matrix 133, and the black matrix 133 can be deleted. As a result, the area of the color filter 132 can be increased to improve the aperture ratio.

Further, since the area of the black matrix 133 arranged on the facing substrate 131 side is reduced, the bonding margin between the active matrix substrate 121 and the facing substrate 131 can be widened.

[0067] Further, the light-shielding film 136 is connected to the auxiliary capacitance wiring 128. Therefore, the electric field shielding effect of the light-shielding film 136 can reduce the coupling capacitance Csd between the source wiring 124 and the pixel electrode 127, and further suppress the shadowing phenomenon due to the coupling capacitance Csd. Further, since the absolute amount of the coupling capacitance Csd is reduced, the amount of change in the coupling capacitance Csd due to the misalignment between the layers is also reduced, and the block division is further suppressed. Here, the light-shielding film 136 may be connected to the gate wiring 122, or may not be connected to the auxiliary capacitance wiring 128 or the gate wiring 122.

[0068] In the present embodiment, the arrangement of the light-shielding film 136 and the deletion of the black matrix 133 by the arrangement are applied to the first embodiment, but the second and third embodiments are applied. It does not matter at all even if it is applied to the form of. Further, in each of the above embodiments, the bent portion of the pixel electrodes 62,82,127 and the bent portion of the source wiring 104 are provided in the center of each of the pixel electrodes 62,82,107,127. However, in order to suppress the shadowing phenomenon, it is not necessary to provide the bent portion exactly at the center of the pixel electrode. Therefore, the present invention does not limit the position of the bent portion provided in the pixel electrode or the source wiring to only the center of each pixel electrode.

[0069] Further, the present invention has a portion on both sides of the pixel electrode that is slightly not covered in the width direction of the source wiring (signal wiring) to the extent that the same effect as that of each of the above embodiments is obtained. There is no problem.

[Effect of the Invention] As is clear from the above, the active matrix type liquid crystal display device of the first invention is<u style="single">, Mutual</u>The signal wiring located near the first and second pixel electrodes adjacent to each other is bent, and one is covered in the width direction by the first pixel electrode with the bent portion as a boundary, and the other is covered with the bending as a boundary. Since it is covered in the width direction by the second pixel electrode, when focusing on one pixel electrode, the first capacitance between the pixel electrode and the signal wiring adjacent to one side and the pixel electrode The difference from the second capacitance between the signal wiring adjacent to the other side can be reduced. Therefore, the shadowing phenomenon can be significantly suppressed by performing the dot inversion drive.

Further, since the auxiliary capacitance wiring arranged in parallel with the scanning wiring is arranged so as to overlap the bent portion of the signal wiring, the capacitance between the bent portion of the signal wiring and the pixel electrode can be reduced. .. Therefore, it is possible to significantly suppress the change in capacitance between the layer and the pixel electrode at the bent portion of the signal wiring due to the misalignment between the layers, and it is possible to suppress the block division when the photolithography process is performed in block units. Can be done.

[0072] In addition,<u style="single">No. 2</u>In the active matrix type liquid crystal display device of the present invention, signal wirings located in the vicinity of the first and second pixel electrodes adjacent to each other are bent, and one of them is covered in the width direction by the first pixel electrode with the bent portion as a boundary. Since the other is covered in the width direction by the second pixel electrode with the bending as a boundary, the shadowing phenomenon is significantly suppressed by performing the dot inversion drive as in the case of the third invention. be able to.

[0073] Further, since the auxiliary capacitance wiring arranged in parallel with the scanning wiring has an electrode portion extending to a position overlapping the bending portion of the signal wiring, the auxiliary capacitance wiring is connected to the pixel electrode at the bending portion of the signal wiring. Capacitance can be reduced. Therefore, as in the case of the third invention, the block division due to the misalignment between the layers can be suppressed.

[0074] Further, the first invention described above.<u style="single">Or the second</u>In the active matrix type liquid crystal display device of the present invention, if a light-shielding film is arranged at a position between pixel electrodes adjacent to each other on the insulating substrate, the alignment accuracy between the layers on the insulating substrate is higher than that of the insulating substrate and the facing substrate. Since it is smaller than the alignment accuracy of, the width of the light-shielding film can be made narrower than that of the black matrix arranged on the opposite substrate side. Therefore, in combination with the fact that the black matrix can be deleted, the aperture ratio can be improved.

[0075] Further, since the area of the black matrix arranged on the facing substrate side is reduced, the bonding margin between the insulating substrate and the facing substrate can be widened.

[0076] Further, the first invention described above.<u style="single">Or the second</u>In the active matrix type liquid crystal display device of the present invention, if the light-shielding film is electrically connected to the auxiliary capacitance wiring or the scanning wiring, the pixel electrode is produced by the electric field shielding effect of the light-shielding film arranged in the vicinity of the signal wiring. The first capacitance between the and the signal wiring adjacent to one side and the second capacitance between the pixel electrode and the signal wiring adjacent to the other side can be reduced. Therefore, the shadowing phenomenon caused by the difference between the first capacitance and the second capacitance can be further suppressed, and the block division can be further reduced.

BRIEF DESCRIPTION OF THE DRAWINGS [FIG. 1] FIG. 1 is a plan view of an active matrix substrate in the active matrix type liquid crystal display device of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA'in FIG.

FIG. 3 is a cross-sectional view taken along the line BB'in FIG.

FIG. 4 is a plan view of an active matrix substrate different from that of FIG.

5 is a cross-sectional view taken along the line CC'in FIG. 4. FIG.

FIG. 6 is a cross-sectional view taken along the line D-D'in FIG.

FIG. 7 is a plan view of an active matrix substrate different from FIGS. 1 and 4.

8 is a cross-sectional view taken along the line E-E'in FIG. 7. FIG.

9 is a cross-sectional view taken along the line FF'in FIG. 7. FIG.

10 is a plan view of an active matrix substrate different from FIGS. 1, 4 and 7. FIG.

11 is a cross-sectional view taken along the line GG'in FIG. 10. FIG.

12 is a cross-sectional view taken along the line HH'in FIG. 10. FIG.

FIG. 13 is a plan view of a general active matrix type liquid crystal display device.

FIG. 14 is a cross-sectional view of a pixel portion of the active matrix type liquid crystal display device shown in FIG.

15 is a plan view of a pixel portion of the active matrix type liquid crystal display device shown in FIG. 13. FIG.

FIG. 16 is a cross-sectional view of a conventional active matrix type liquid crystal display device in which pixel electrodes are superposed on signal wiring.

17 is a plan view of the active matrix substrate in FIG. 16. FIG.

FIG. 18 is an equivalent circuit diagram of the active matrix substrate shown in FIG.

FIG. 19 is an explanatory diagram of a pixel electrode alignment deviation.

FIG. 20 is a diagram showing a relationship between a pixel electrode alignment deviation and a capacitance between a pixel electrode / adjacent signal wiring.

FIG. 21 is a cross-sectional view of a conventional active matrix type liquid crystal display device in which approximately 1/2 of each side edge of each adjacent pixel electrode is superposed on a signal wiring.

22 is a plan view of the active matrix substrate in FIG. 21. FIG.

[Description of Code] 51,71,101,121 ... Active Matrix Board, 52,72,102,122 ... Gate Wiring (Scanning Wiring), 54,54', 74,104,124 ... Source Wiring (Signal Wiring), 55,75,105,125 ... TFT, 60,80 ... drain electrode, 61,81,106,126 ... interlayer insulating film, 62,62', 62 ", 82,107,127 ... pixel electrode, 63,83,108,128 ... auxiliary capacitance wiring, 64,84,109,129. .. Auxiliary capacitance electrode, 65,85,110,130 ... contact hole, 66,86,111,131 ... facing substrate, 67,87,112,132 ... color filter, 68,88,113,133 ... black matrix, 69,89,114,134 ... facing electrode , 70,90,115,135 ... liquid crystal layer, 91 ... electrode part, 136 ... light-shielding film.