Liquid crystal display device

Abstract

To realize a highly reliable high-definition video signal line.SOLUTION: In a liquid crystal display device in which a first light-shielding film 105 extending in a first direction and a video signal line 52 are formed on a TFT board, the video signal line 52 includes a first part in which an extension direction extends at a first angle relative to a second direction orthogonal to the first direction in an area not overlapping with the first light-shielding film 105, a second part in which an extension direction extends at a second angle relative to the second direction in an area overlapping with the first light-shielding film, a third part in which the extension direction is the second direction, and a fourth par in which an extension direction extends at a fourth angle relative to the second direction, and the second angle and the fourth angle are larger than the first angle.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a high-definition liquid crystal display device. [Background technology]

[0002] In a liquid crystal display device, a TFT substrate on which pixels each having a pixel electrode and a thin film transistor (TFT) are formed in a matrix and a counter substrate is disposed opposite the TFT substrate, with liquid crystal sandwiched between the TFT substrate and the counter substrate. Images are formed by controlling the transmittance of light from a backlight for each pixel using liquid crystal molecules.

[0003] Liquid crystal display devices are also used in display devices that require high-definition screens, such as VR (Virtual Reality) display devices (hereinafter also referred to as VR). In high-definition screens, the pixel pitch becomes smaller, so the transmittance of the pixels becomes an issue.

[0004] On the other hand, liquid crystal can only control polarized light, so only light with a specific polarization method is taken in from the light from the backlight by the lower polarizer, which is then modulated by the liquid crystal layer, and light with a specific polarization direction is output as an image from the upper polarizer. When using polarized glasses, etc., images from a liquid crystal display device may become difficult to see due to the polarization direction of the light. Patent Document 1 describes a configuration that addresses this issue by changing the shape of the pixel electrodes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-15204 A Summary of the Invention [Problem to be solved by the invention]

[0006] In high-definition screens used in VR and the like, the pixel pitch is very small. For example, the size of a single pixel is very small, at 7 μm x 21 μm. Note that liquid crystal screens are composed of red, green, and blue pixels, and although each pixel is sometimes called a subpixel, in this specification they are called pixels. In such small pixels, there is a limit to how much the shape of the pixel electrode can be adjusted.

[0007] On the other hand, even if the pixel pitch becomes smaller, it is difficult to reduce the size of the through-holes formed in the organic passivation film to connect the pixel electrodes and the TFTs, because the organic passivation film needs to have a certain thickness. This raises the issue of how to arrange large through-holes within a small pixel.

[0008] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to solve the above problems and to provide a high-definition liquid crystal display device having a required image quality. [Means for solving the problem]

[0009] The present invention overcomes the above problems, and the specific means are as follows.

[0010] (1) A liquid crystal display device including a first light-shielding film extending in a first direction and a video signal line formed on a TFT substrate, wherein the video signal line has, in a region not overlapping with the first light-shielding film, a first portion whose extension direction extends at a first angle with respect to a second direction perpendicular to the first direction, and, in a region overlapping with the first light-shielding film, a second portion whose extension direction extends at a second angle with respect to the second direction, a third portion whose extension direction is the second direction, and a fourth portion whose extension direction extends at a fourth angle with respect to the second direction, and the second angle and the fourth angle are greater than the first angle.

[0011] (2) The liquid crystal display device according to (1), wherein the second angle and the fourth angle are the same.

[0012] (3) The liquid crystal display device according to (1), characterized in that a first video signal line has the configuration of the video signal line of claim 1, a second video signal line has the configuration of the video signal line of claim 1, a first region is located between the first portion of the first video signal line and the first portion of the second video signal line, a third region is located between the third portion of the first video signal line and the third portion of the second video signal line, and the distance between the first video signal line and the second video signal line is greater in the third region than in the first region.

[0013] (4) A liquid crystal display device as described in (3), characterized in that in the first region, a pixel electrode is present, and a TFT connecting the first video signal line and the pixel electrode is present, and in the third region, a through hole connecting the pixel electrode and the TFT is formed.

[0014] (5) A liquid crystal display device as described in (4), characterized in that the pixel electrode is formed on an organic passivation film, the TFT is formed under the organic passivation film, and the through hole is formed in the organic passivation film. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a plan view of a liquid crystal display device. [Diagram 2] 2 is a cross-sectional view taken along line AA in FIG. 1. [Diagram 3] 2 is a cross-sectional view of a display area of ​​the liquid crystal display device according to the first embodiment. [Figure 4] FIG. 13 is a plan view of a pixel portion according to a comparative example. [Diagram 5] FIG. 11 is a plan view showing a comparison of intervals between video signal lines. [Figure 6] FIG. 2 is a plan view of a pixel portion according to the first embodiment of the present invention. [Figure 7] FIG. 11 is a cross-sectional view of a pixel portion according to a second embodiment of the present invention. [Figure 8] FIG. 11 is a plan view of a pixel portion according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The present invention will be described in detail below with reference to examples. There are two types of liquid crystal display devices: pixel electrode top and common electrode top, depending on the hierarchical relationship between the pixel electrode and the common voltage. Conventionally, color filters were often formed on the opposing substrate, but in high-definition liquid crystal display devices, they may be formed on the TFT substrate. This is called COA (Color Filter on Array). The present invention can be applied to either of these types. EXAMPLES

[0017] Fig. 1 is a plan view of a liquid crystal display device, and Fig. 2 is a cross-sectional view taken along the line AA in Fig. 1. In Figs. 1 and 2, a TFT substrate 100 and a counter substrate 200 are bonded to each other at their peripheries via a sealant 150, and liquid crystal 300 is sealed inside. A display region 50 is formed in an area where the TFT substrate 100 and the counter substrate 200 overlap. In the TFT substrate 100 within the display region 50, scanning lines 51 extend in the horizontal direction (x direction) and are arranged in the vertical direction (y direction). Furthermore, video signal lines 52 extend in the vertical direction and are arranged in the horizontal direction. Pixels 53 are formed in an area surrounded by the scanning lines 51 and the video signal lines 52.

[0018] The TFT substrate 100 is formed larger than the counter substrate 200, and the portion where the TFT substrate 100 does not overlap with the counter substrate 200 is a terminal region 60. A flexible wiring board 62 for supplying power and signals to the liquid crystal display device is connected to the terminal region 60. A driver IC 61 for generating video signals and the like is also disposed in the terminal region 60. When the area of ​​the terminal region 60 is small, the driver IC 62 may be mounted on the flexible wiring board side.

[0019] The gap between the TFT substrate 100 and the counter substrate 200, i.e., the thickness of the liquid crystal layer 300, must be kept constant throughout the entire display area. For this reason, in FIG. 2, columnar spacers 10 and 20 are arranged on the counter substrate 200 side to maintain the gap between the TFT substrate 100 and the counter substrate 200. The columnar spacers may be formed on the TFT substrate 100 side as shown in the following embodiment. The explanation of FIG. 2 illustrates the function of the columnar spacers by taking the case where the columnar spacers are formed on the counter substrate 200 side as an example, and the same function is obtained when the columnar spacers are formed on the TFT substrate 100 side as shown in FIG. 3 and FIG. 7. In addition, although not described in detail, a spacer formed on the counter substrate 200 side may be abutted against a spacer formed on the TFT substrate side, and the gap between the TFT substrate 100 and the counter substrate 200 may be maintained by the two spacers.

[0020] The columnar spacers include a main columnar spacer 10 and a sub columnar spacer 20. The main columnar spacer 10 defines the gap between the TFT substrate 100 and the counter substrate 200 in a normal state. The sub columnar spacer 20 is formed to be lower in height than the main columnar spacer 10. The sub columnar spacer 20 does not contact the TFT substrate 100 in a normal state, but when a pressure is applied to the counter substrate 200 or the TFT substrate 100, the sub columnar spacer 20 comes into contact with the TFT substrate 100, thereby preventing the gap between the TFT substrate 100 and the counter substrate 200 from becoming extremely small. The diameter of the sub columnar spacer 20 is larger than that of the main columnar spacer 10, and the number of the sub columnar spacers 20 is greater than the number of the main columnar spacers 10.

[0021] In FIG. 1, a scanning signal driving circuit for generating a scanning signal is formed in the frame portions on both sides of the display area 50, as described later in FIG. 3 and FIG. 7. In this embodiment, oxide semiconductor TFTs are used for the TFTs in the display area 50, and polysilicon semiconductor TFTs are used for the peripheral driving circuits such as the above-mentioned scanning signal driving circuit. Polysilicon semiconductors have a higher mobility than oxide semiconductors, and are therefore suitable for forming peripheral driving circuits. On the other hand, TFTs using oxide semiconductors have a lower mobility than polysilicon semiconductors, but a smaller leakage current than TFTs using polysilicon semiconductors, and are therefore suitable as switching elements in pixels.

[0022] 3 is a cross-sectional view of a pixel region having an oxide semiconductor TFT and a peripheral drive circuit having a polysilicon semiconductor TFT formed in a frame region in a liquid crystal display device according to a comparative example. In FIG. 3, the left side is a cross-sectional view of the peripheral drive circuit, and the right side is a cross-sectional view of the pixel section. Since the pixel section and the peripheral drive circuit are formed by the same process, the same layers are numbered the same in both the peripheral drive circuit section and the pixel section. In the peripheral drive circuit, details of the circuit are omitted, and only the TFT using the polysilicon semiconductor 102 used in the circuit is shown.

[0023] 3, for example, an undercoat film 101 is formed on a TFT substrate 100 made of glass. The role of the undercoat film 101 is to prevent impurities from the glass substrate 100, etc., from contaminating a polysilicon semiconductor 102 or an oxide semiconductor 107. The undercoat film 101 generally has a two-layer structure of a silicon nitride layer (hereinafter also referred to as a SiN layer) and a silicon oxide layer (hereinafter also referred to as a SiO layer).

[0024] In the peripheral driving circuit, a polysilicon semiconductor film 102 is formed on the base film 101. The polysilicon semiconductor film 102 is initially an a-Si film, which is then converted to polysilicon by an excimer laser. The base film 101 and the a-Si film are formed successively by CVD (Chemical Vapor Deposition).

[0025] A first gate insulating film 103 is formed covering the polysilicon semiconductor film 102. The first gate insulating film 103 is a SiO film made of TEOS (Tetraethoxysilane). A first gate electrode 104 is formed on the first gate insulating film 103. The first gate electrode 104 is formed of a laminated film of MoW, Ti, or Ti-Al-Ti. On the other hand, on the pixel side, a first light-shielding film 105 is formed of the same material and by the same process as the first gate electrode 104. The first light-shielding film 105 extends in the same direction as the scanning lines 51 in FIG. 1 and is arranged in the same direction as the scanning lines 51. The first light-shielding film 105 covers the oxide semiconductor TFT, the through-holes 130, etc. from below to block light from the backlight.

[0026] The following description will be given of the cross-sectional structure of a pixel. A first gate insulating film 103 made of a SiO film is formed to cover an undercoat film 101. A second gate insulating film 106 is formed to cover a first light-shielding layer 105 formed on the first gate insulating film 103. An oxide semiconductor film 107 formed on the second gate insulating film 106 forms a channel of a TFT under a second gate electrode 109 and above the first light-shielding film 105.

[0027] A third gate insulating film 110 is formed to cover the oxide semiconductor film 107. The third gate insulating film 110 is formed of two SiO layers. The portion corresponding to the channel portion of the oxide semiconductor film 107 is an oxygen-rich first SiO layer, and the other portion is a dense second SiO film. The first SiO film is an oxygen-rich film so that oxygen can be supplied to the oxide semiconductor film 107.

[0028] A second gate electrode 109 is formed on the third gate insulating film 110. The second gate electrode 109 can be made of the same material as the first gate electrode 103. In FIG. 3, a top gate is formed in which a channel part of the TFT is formed under the second gate electrode 109, but if a gate voltage is applied to the first light-shielding film 105, a dual-gate TFT can be formed. In this case, the first light-shielding film 105 is made of the same metal material as the first gate electrode 104, and in the display region 50, it also serves as a second scanning line, the same as the scanning line 51.

[0029] After the third gate insulating film 110 is formed, in the peripheral driving circuit, a through hole 1112 is formed in the three insulating films, i.e., the first gate insulating film 103, the second gate insulating film 106, and the third gate insulating film 110, to form a first drain electrode 1111, and a through hole 1122 is formed to form a second source electrode 1121. The first drain electrode 1111 and the first source electrode 1121 are made of the same material as the second gate electrode 109, formed by the same process, and connected to the polysilicon semiconductor film 102.

[0030] A first interlayer insulating film 125 is formed to cover the second gate electrode 109. The third gate insulating film 110 also often has a two-layer structure of a SiN layer and a SiO layer. The SiO layer is often the lower layer. This is to prevent oxygen from being removed from the oxide semiconductor film 107.

[0031] After forming the first interlayer insulating film 125, in the peripheral driving circuit, a through hole is formed in the first interlayer insulating film 125 to form the first drain wiring 111, and another through hole is formed to form the first source wiring 112, which are connected to the first drain electrode 1111 and the first source electrode 1121, respectively. At the same time, in the pixel region, a through hole 131 is formed in the second gate insulating film 110 and the first interlayer insulating film 125 to form the video signal line 52 and the second drain electrode 113, and the second drain electrode 113 is connected to the oxide semiconductor film 107. Thereafter, a second interlayer insulating film 126 made of an inorganic material such as a SiN film is formed so as to cover the video signal line 52, the first drain wiring 111, and the first source wiring 112, and a second source electrode 114 is formed on the second interlayer insulating film 126. The second source electrode 114 is connected to the oxide semiconductor film 107 through the through hole 132. The first drain wiring 111, the first source wiring 112, and the second drain electrode 113 are made of metal, while the second source electrode 114 is made of ITO (Indium Tin Oxide), which is a transparent electrode, and is connected to the pixel electrode 116. In the through hole 131, the video signal line 52 plays the role of the drain electrode 113 and is connected to the oxide semiconductor film 107 that is given conductivity. The material of the video signal line 52, like the first gate electrode 104, can be MoW, Ti, or a Ti-Al-Ti laminated film, or the like.

[0032] An organic passivation film 115 is formed covering the second interlayer insulating film 126. The organic passivation film 115 is formed to a thickness of 2 to 4 μm in order to act as a planarizing film and to suppress capacitive coupling between the video signal lines 52 and the pixel electrodes 116 or the common electrodes 119.

[0033] 3 shows a common electrode top configuration, so the pixel electrode 116 is formed of ITO, a transparent conductive film, on the organic passivation film 115. The pixel electrode 116 is rectangular to match the shape of the pixel. A through hole 130 is formed in the organic passivation film 115 to connect the pixel electrode 116 and the second source electrode 114.

[0034] 3, a capacitive insulating film 117 is formed on a pixel electrode 116, a second light-shielding film 118 is formed on the capacitive insulating film 117 using a metal, and a common electrode 119 is formed on the second light-shielding film 118 using ITO. The capacitive insulating film 117 is so named because it constitutes a pixel capacitance formed between the pixel electrode 116 and the common electrode 119. The capacitive insulating film 117 is made of SiN, which has a large relative dielectric constant. The second light-shielding film 118 and the common electrode 119 are formed on the capacitive insulating film 117.

[0035] The second light-shielding film 118 is made of a metal, such as molybdenum (Mo), titanium (Ti), or aluminum (Al). The second light-shielding film 118 blocks unnecessary light from the backlight, improving the contrast of the image. In the configuration of FIG. 3, the counter substrate 200 is also formed with a black matrix 202 having a light-shielding effect, but by disposing the second light-shielding film 118, it is possible to provide effects such as blocking light that cannot be completely blocked by the black matrix 202, preventing color mixing of light from the inside, and preventing a voltage drop in the common electrode 119.

[0036] However, since the light transmittance is reduced by forming the second light-shielding film 118, the second light-shielding film 118 may be omitted depending on the image quality required when the black matrix 202 is present on the opposing substrate 200. Alternatively, the second light-shielding film 118 may be used with a different shape in order to prevent a voltage drop in the common electrode 119, rather than for the purpose of the light-shielding effect.

[0037] The common electrode 119 is made of ITO. Since ITO has a relatively high resistance, the resistance can be reduced by laminating a second light-shielding film 118 made of a metal, thereby maintaining the uniformity of the image. The common electrode 119 is formed in common to a plurality of pixels, and a slit 1191 is formed for each pixel.

[0038] Incidentally, columnar spacers are necessary to maintain the distance between the TFT substrate 100 and the counter substrate 200. However, when the pixel pitch becomes smaller, it becomes difficult to secure the arrangement position of the columnar spacers. In the first embodiment, a filler 30 is formed in the through hole 130, and the columnar spacer 10 is formed using this filler 30. The filler 30 is a photosensitive resin formed of acrylic resin or the like. By using a photosensitive resin, it is not necessary to form a resist for photolithography separately. Also, the same material as the organic passivation film can be used as the material of the filler 30.

[0039] The columnar spacer in FIG. 3 is a main columnar spacer 10, which is in contact with the opposing substrate 200, but it is also possible to form a sub-columnar spacer that does not contact the opposing substrate 200. Also, columnar spacers are not formed in all pixels. In pixels where columnar spacers are not formed, the through-hole 130 is filled with the filler 30, and the upper surface of the through-hole 130 is flattened. The main columnar spacer 10, the sub-columnar spacer 20, and the flattening structure using the filler 30 can all be formed by the same process. That is, a photosensitive acrylic resin is applied to the entire display area with a predetermined thickness, and the exposure intensity is controlled for each location using a mask so that the acrylic resin of the required thickness remains in each location.

[0040] A first alignment film 120 is formed covering the common electrode 119. The first alignment film 120, together with a second alignment film 204 formed on the opposing substrate 200, determines the initial alignment of liquid crystal molecules. The alignment films 120 and 204 are formed of polyimide. The alignment treatment of the alignment films 120 and 204 may be a rubbing method or a photo-alignment treatment using polarized ultraviolet light. In FIG. 3, the first alignment film 120 is not formed on the columnar spacer 10, but this varies depending on the viscosity of the alignment film material when applied, leveling during the drying process, and the like, so the first alignment film 120 may also be formed on the columnar spacer 10.

[0041] When a voltage is applied to the pixel electrode 116, electric lines of force are generated in the slits 1191 of the common electrode 119, passing through the liquid crystal layer 300 from the pixel electrode 116 toward the common electrode 119, causing the liquid crystal molecules to rotate and changing the transmittance of the liquid crystal layer 300. An image is formed by changing the transmittance of the liquid crystal layer 300 for each pixel. That is, an IPS (In Plane Switching) operation is performed.

[0042] The area of ​​the pixel in Example 1 is very small. On the other hand, since the thickness of the organic passivation film 115 cannot be reduced, it is difficult to reduce the through hole 130. Therefore, in order to save space, in FIG. 3, the through hole 130 in the organic passivation film 115 is formed directly above the TFT.

[0043] In FIG. 3, an opposing substrate 200 is disposed with a liquid crystal layer 300 sandwiched therebetween. A color filter 201 and a black matrix 202 are formed on the opposing substrate 200. The color filter 201 is for forming a color image, and the black matrix 202 is for improving the contrast of the image. An overcoat film 203 is formed covering the color filter 201 and the black matrix 202. The overcoat film 203 prevents the color pigment in the color filter 201 from seeping into the liquid crystal layer 300. A second alignment film 204 is formed covering the overcoat film 203. The role of the second alignment film 204 is the same as that described for the first alignment film 120.

[0044] Fig. 4 is a plan view of a pixel in a comparative example. In Fig. 4, a first light-shielding film 105 and a scanning line 51 extend in a horizontal direction (x direction) and are arranged in a vertical direction (y direction). Furthermore, a video signal line 52 extends in a vertical direction and is arranged in a horizontal direction. However, the video signal line 52 is inclined at a first angle with respect to the vertical direction (y direction) in a region not overlapping with the first light-shielding film 105, and is inclined at a second angle in the opposite direction in a region overlapping with the first light-shielding film 105. The alignment direction of the first alignment film in this case is the vertical direction, which is AL in Fig. 4.

[0045] 4, the pixel electrodes 116 and the slits 1191 of the common electrode 119, which are indicated by dotted lines, are also inclined at a first angle with respect to the vertical direction in accordance with the video signal lines 52. The pixel electrodes 116 and the slits 1191 of the common electrode 119 are inclined with respect to the vertical direction in this manner in order to form a first angle with the alignment direction of the first alignment film 120. This prevents the occurrence of domains in the pixels. The first angle is, for example, 8 degrees to 15 degrees.

[0046] 4, the orientation angle of the first alignment film 120 is vertical, so the pixel electrodes 116, etc. are inclined at a first angle with respect to the vertical direction. If the angle of the first alignment film is inclined at a predetermined angle from the vertical direction, the angles of the pixel electrodes 116, etc. will be inclined at the first angle with respect to the predetermined angle.

[0047] 4, the first light-shielding film 105 extends in the horizontal direction, but the video signal lines 52 are inclined in the opposite direction at a second angle larger than the first angle in the region overlapping with the first light-shielding film 105, thereby offsetting the lateral deviation of the video signal lines 52. The function of FIG. 4 will be described below.

[0048] In FIG. 4, a TFT is formed above the first light-shielding film 105. That is, the TFT and the like are shielded from light from the backlight. In FIG. 4, an oxide semiconductor film 107 as a drain wiring extends vertically in the pixel from a through hole 131 formed on the video signal line 52 to the scanning line 51 side. The oxide semiconductor film 107 is given conductivity and is transparent, so it does not significantly reduce the light transmittance. A channel of the TFT is formed at the portion where the scanning line 51 and the oxide semiconductor film 107 intersect. In addition, when the first light-shielding film 105 also serves as the second scanning line, a channel of the TFT is formed at the portion where the first light-shielding film 105 and the oxide semiconductor film 107 intersect.

[0049] 4, the oxide semiconductor film 107 that has been given conductivity extends further downward and is connected to a second source electrode 114 made of ITO at a through hole 132. The second source electrode 114 is formed parallel to the video signal line 52, extends upward in the y direction, and is connected to the pixel electrode 116 at a through hole 130. In FIG. 4, the oxide semiconductor film 107 and the second source electrode 114 are formed to overlap with each other from the through hole 132 to the through hole 130 in a plan view.

[0050] Incidentally, the columnar spacers 10 for maintaining the gap between the TFT substrate 100 and the counter substrate 200 are formed in the through-holes 130, like the filler 30 described in Fig. 3. However, the main columnar spacers 10 or the sub columnar spacers 20 are not formed in the through-holes 130 of all pixels.

[0051] 4, the pixel electrode 116 has a portion formed in a parallelogram shape along the shape of the pixel. The common electrode 119 is formed in common to a plurality of pixels, and a slit 1191 is formed at a position overlapping with the pixel electrode 116.

[0052] The pixel electrode 116 is connected to the second source electrode 114 at the through hole 130. When a voltage is applied to the pixel electrode 116, electric field lines passing through the liquid crystal are generated at the slit 1191 between the pixel electrode 116 and the common electrode 119, causing the liquid crystal molecules to rotate and controlling the light transmittance of the pixel.

[0053] However, when the pixel pitch becomes smaller, the arrangement of the through-hole 130 formed in the organic passivation film 115 for connecting the pixel electrode 116 and the second source electrode 114 of the TFT becomes a problem. In this portion, the video signal line 52 is significantly inclined with respect to the vertical direction, so the space problem becomes more serious.

[0054] FIG. 5 is a schematic diagram showing this state. The left side of FIG. 5 shows the case where the video signal lines 52 extend in the vertical direction (y direction). In this case, the distance between the video signal lines 52 is d1. On the other hand, the right side of FIG. 5 shows the case where the video signal lines 52 are inclined at a predetermined angle with respect to the vertical direction, for example, the second angle. In this case, the distance between the video signal lines 52 is d2. And d2 < d1. That is, in addition to the problem that the pixel pitch becomes smaller due to higher definition, the problem that the distance between the video signal lines 52 becomes even smaller occurs due to the diagonal wiring.

[0055] In particular, in the vicinity of the through hole 130 that connects the pixel electrode 116 and the second source electrode 114, the wiring is intricate, so interference with adjacent pixels in this region becomes a problem. Also, if the distance between adjacent video signal lines 52 is narrow, it becomes difficult to secure sufficient space for connecting the pixel electrode 116 and the second source electrode 114. The present invention addresses such problems.

[0056] FIG. 6 is a plan view of Example 1 according to the present invention that addresses the above problems. In the configuration of FIG. 6, the video signal line 52 has a first portion that extends at a first angle with respect to the vertical direction (y direction) in a region that does not overlap with the first light shielding film 105, that is, in a region adjacent to the pixel electrode 116. In the region overlapping with the first light shielding film 105, it has a second portion that extends at a second angle in the direction opposite to the first angle with respect to the vertical direction, a third portion that extends in the vertical direction, and a fourth portion that extends at a fourth angle with respect to the vertical direction. Note that the fourth angle can be different from the second angle, but in many cases, it is formed at the same angle as the second angle. Therefore, hereinafter, when referring to the second angle in this specification, it includes the fourth angle.

[0057] 6 differs from FIG. 4 in the configuration near the through-hole 130 that connects the pixel electrode 116 and the second source electrode 114. This region overlaps with the first light-shielding film 105. That is, in this region, the video signal line 52 has a second portion that is greatly inclined with respect to the vertical direction, a third portion that extends in the vertical direction, and a fourth portion that is greatly inclined with respect to the vertical direction. The width of the video signal line 52 in the third region is larger than the first, second, and fourth regions.

[0058] 6 is used in order to increase the distance between adjacent video signal lines 52 in the region where the through holes 130 are formed. In the region where the through holes 130 are formed, the video signal lines 52 extend in the vertical direction, so that the distance between adjacent video signal lines 52 can be increased. Therefore, the size of the through holes 130 formed in the organic passivation film 115 can also be increased. In addition, the layout margin for wiring that overlaps with the through holes 130 or is formed near the through holes 130 can be increased, thereby improving reliability.

[0059] In Fig. 6, except for the through-hole 130 and the configuration in the vicinity thereof, the configuration is the same as that described in Fig. 4. The effect of the configuration shown in Fig. 6 increases as the angle of the video signal line 52 with respect to the vertical direction increases. In this way, the configuration of the first embodiment shown in Fig. 6 can increase the margin for wiring arrangement, and a highly reliable, high-definition liquid crystal display device can be realized. EXAMPLES

[0060] In the first embodiment, a configuration in which the color filter 201 and the black matrix 202 are formed on the counter substrate 200 side has been described. In this case, the alignment accuracy of the TFT substrate 100 and the counter substrate 200 affects the transmittance and the like of the liquid crystal display device. If the pixel pitch is large, it is possible to absorb errors in the alignment accuracy of the TFT substrate 100 and the counter substrate 200. However, as the resolution of the screen increases, there are cases in which this error cannot be ignored.

[0061] This problem can be solved by forming the color filter 201 and the black matrix 202 on the TFT substrate 100. This is because the error caused by photolithography on the TFT substrate 100 side is much smaller than the error caused by the alignment accuracy between the TFT substrate 100 and the counter substrate 200.

[0062] Fig. 7 is a cross-sectional view of Example 2. The main difference between Fig. 7 and Fig. 3 of Example 1 is that in the display region 50 of the counter substrate 200, the color filter 201 and the black matrix 202 are not formed, and only the second alignment film 204 is formed on the overcoat film 203. On the other hand, in the frame region, the black matrix 202 overlapping the sealant 150 is formed. Therefore, the alignment accuracy of the counter substrate 200 and the TFT substrate 100 does not affect the performance of the liquid crystal display device. However, the overcoat film 203 may be omitted.

[0063] In FIG. 7, on the TFT substrate 100 side, a color filter 201 is formed under the organic passivation film 115. A third interlayer insulating film 127 made of an inorganic material such as a SiN film is formed between the color filter 201 and the second source electrode 141, and the third interlayer insulating film 127 has a through hole at a position overlapping with the through hole 130 of the organic passivation film 115, and connects the pixel electrode 116 and the second source electrode 114. A second light-shielding film 118 plays the role of a black matrix 202. The second light-shielding film 118 is formed of a laminated film of metal films, and constitutes an anti-reflection film together with the ITO film. Therefore, it can play the role of the black matrix 202.

[0064] In addition, the second light-shielding film 118 has the effect of preventing color mixing between adjacent pixels and preventing a voltage drop in the common electrode 119, in addition to serving as an anti-reflection film. In addition, although the organic passivation film 115 is formed on the color filter 201 in FIG. 7, the organic passivation film 115 may be formed below the color filter 201.

[0065] Fig. 8 is a plan view of a pixel unit according to Example 2. In Fig. 8, the area where the second light-shielding film 118 is formed is indicated by dot shading. The second light-shielding film 118 is formed by stacking it with the common electrode 119 formed over the entire display area, and therefore can be formed in any position.

[0066] 8, the second light-shielding film 118 is formed to overlap the first light-shielding film 105 and the video signal lines 52 in a plan view. This is the same as the area covered by the black matrix 202 of the display area 50 formed on the counter substrate 200 in the first embodiment.

[0067] In this way, the present invention can also be applied to the case of a COA (Color Filter on Array). [Explanation of symbols]

[0068] 10...main columnar spacer, 20...sub columnar spacer, 30...filler, 50...display area, 51...scanning line, 52...video signal line, 53...pixel, 60...terminal area, 61...driver IC, 62...flexible wiring board, 70...TFT circuit layer, 100...TFT substrate, 101...undercoat film, 102...polysilicon semiconductor film, 103...first gate insulating film, 104...first gate electrode, 105...first light-shielding film, 106...second gate insulating film, 107...oxide semiconductor film, 109...second gate electrode, 110...third gate insulating film, 111...first drain wiring, 112...first source wiring, 113...second drain electrode, 114...second source electrode, 115...organic passivation film, 116...pixel electrode, 117...capacitive insulating film, 118...second light-shielding film, 119...common electrode, 120...first alignment film, 125...first interlayer insulating film, 126...second interlayer insulating film, 127...third interlayer insulating film, 130...pixel through-hole, 131...first through-hole, 132...second through-hole, 150...sealing material, 200...opposite substrate, 201...color filter, 202...black matrix, 203...overcoat film, 204...second alignment film, 300...liquid crystal layer, 1111...first drain electrode, 1112...through-hole, 1121...first source electrode, 1122...through-hole, 1191...slit

Claims

1. A liquid crystal display device having a first light-shielding film extending in a first direction and video signal lines formed on a TFT substrate, wherein the video signal lines in a region not overlapping with the first light-shielding film, a first portion extending at a first angle with respect to a second direction whose extending direction is orthogonal to the first direction; in a region overlapping with the first light-shielding film, a second portion extending at a second angle with respect to the second direction, a third portion whose extending direction is the second direction, and a fourth portion extending at a fourth angle with respect to the second direction; wherein the second angle and the fourth angle are larger than the first angle.

2. The liquid crystal display device according to claim 1, wherein the second angle and the fourth angle are the same.

3. The first video signal line has the configuration of the video signal line of claim 1, the second video signal line has the configuration of the video signal line of claim 1, a first region is located between the first portion of the first video signal line and the first portion of the second video signal line, a third region is located between the third portion of the first video signal line and the third portion of the second video signal line, wherein the distance between the first video signal line and the second video signal line is larger in the third region than in the first region.

4. In the first region, there is a pixel electrode, there is a TFT connecting between the first video signal line and the pixel electrode, wherein a through hole connecting the pixel electrode and the TFT is formed in the third region.

5. The pixel electrode is formed on an organic passivation film, the TFT is formed under the organic passivation film, wherein the through hole is formed in the organic passivation film.

6. A common electrode is formed overlapping with the pixel electrode via a capacitive insulating film, wherein a second light-shielding film is formed overlapping with the common electrode.

7. The liquid crystal display device according to claim 6, wherein the second light-shielding film is formed overlapping with the first light-shielding film, the first video signal line, and the second video signal line.

8. An opposing substrate is disposed opposite to the TFT substrate. The liquid crystal display device according to claim 4, wherein a distance between the TFT substrate and the opposing substrate is maintained by columnar spacers formed in the through holes.

9. An opposing substrate is disposed opposite to the TFT substrate. The liquid crystal display device according to claim 3, wherein a color filter and a black matrix are formed on the opposing substrate.

10. An opposing substrate is disposed opposite to the TFT substrate. The liquid crystal display device according to claim 5, wherein the color filter is formed to overlap with the organic passivation film of the TFT substrate.

11. The liquid crystal display device according to claim 10, wherein the color filter is formed under the organic passivation film.

12. The liquid crystal display device according to claim 11, wherein a second light-shielding film is formed to overlap with the first light-shielding film, the first video signal line, and the second video signal line.

13. The liquid crystal display device according to claim 12, wherein no black matrix exists in a display area of the opposing substrate.

Images