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

[0006] , , ,

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

Background Art

[0002] In a liquid crystal display device, a pixel having a pixel electrode and a thin film transistor (TFT) or the like is formed in a matrix on a TFT substrate, a counter substrate is disposed opposite to the TFT substrate, and liquid crystal is sandwiched between the TFT substrate and the counter substrate. Then, for each pixel, an image is formed by controlling the transmittance of light from a backlight by liquid crystal molecules.

[0003] Liquid crystal display devices are also used in display devices that require a high-definition screen, such as VR (Virtual Reality) display devices (hereinafter also referred to as VR). In a high-definition screen, since the pixel pitch becomes small, the transmittance of pixels becomes a problem.

[0004] On the other hand, since liquid crystal can only control polarized light, among the light from the backlight, only the light of a specific polarization method is taken in by the lower polarizing plate, modulated by the liquid crystal layer, and light having a specific polarization direction is emitted as an image from the upper polarizing plate. When using polarized glasses or the like, the image from the liquid crystal display device may be difficult to see due to the relationship of the deflection direction of light. Patent Document 1 describes a configuration for solving this problem by changing the shape of the pixel electrode.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In high-resolution screens used in VR and other applications, the pixel pitch becomes extremely small. For example, the size of a single pixel can be as small as 7 μm × 21 μm. Note that liquid crystal displays are composed of red, green, and blue pixels, and while each of these pixels is sometimes called a subpixel, in this specification, they will be referred to simply as pixels. With such small pixels, there are limitations to adjusting the shape of the pixel electrodes.

[0007] On the other hand, even if the pixel pitch is reduced, it is difficult to reduce the size of the through-holes formed in the organic passivation film that connects the pixel electrodes and the TFT. This is because the organic passivation film requires a certain thickness. Therefore, the problem becomes how to arrange large through-holes within small pixels.

[0008] The objective of this invention is to solve the above-mentioned problems and to enable a high-definition liquid crystal display device with the necessary 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 comprising a first light-shielding film extending in a first direction and video signal lines formed on a TFT substrate, wherein the video signal lines have a first portion in a region not overlapping with the first light-shielding film, in which the extending direction is at a first angle with respect to a second direction perpendicular to the first direction; a second portion in a region overlapping with the first light-shielding film, in which the extending direction is at a second angle with respect to the second direction; a third portion in which the extending direction is the second direction; and a fourth portion in which the extending direction is at a fourth angle with respect to the second direction, wherein the second angle and the fourth angle are greater than the first angle.

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

[0012] (3) The liquid crystal display device according to (1), wherein 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, the first region is located between the first portion of the first video signal line and the first portion of the second video signal line, the 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) The liquid crystal display device according to (3), characterized in that a pixel electrode is present in the first region, a TFT is present connecting the first video signal line and the pixel electrode, and a through-hole connecting the pixel electrode and the TFT is formed in the third region.

[0014] (5) The liquid crystal display device according to (4), characterized in that the pixel electrodes are formed on an organic passivation film, the TFT is formed below the organic passivation film, and the through-holes are formed in the organic passivation film. [Brief explanation of the drawing]

[0015] [Figure 1] This is a plan view of a liquid crystal display device. [Figure 2] This is a cross-sectional view AA in Figure 1. [Figure 3] This is a cross-sectional view of the display area of ​​a liquid crystal display device according to Example 1. [Figure 4] This is a plan view of the pixel portion using a comparative example. [Figure 5] This is a plan view showing a comparison of the spacing between video signal lines. [Figure 6] This is a plan view of the pixel portion according to Embodiment 1 of the present invention. [Figure 7] This is a cross-sectional view of a pixel portion according to Embodiment 2 of the present invention. [Figure 8] This is a plan view of the pixel portion according to Embodiment 2 of the present invention.

Best Mode for Carrying Out the Invention

[0016] The content of the present invention will be described in detail below with reference to embodiments. In a liquid crystal display device, depending on the vertical relationship between the pixel electrode and the common voltage, there are pixel electrode top and common electrode top methods. Conventionally, color filters were often formed on the counter substrate, but in high-definition liquid crystal display devices, they may also be formed on the TFT substrate. This is called COA (Color Filter on Array). The present invention can be applied to any of these methods.

Embodiment

[0017] FIG. 1 is a plan view of a liquid crystal display device, and FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1. In FIGS. 1 and 2, the TFT substrate 100 and the counter substrate 200 are adhered to each other through a sealing material 150 at the periphery, and liquid crystal 300 is sealed inside. A display area 50 is formed in the area where the TFT substrate 100 and the counter substrate 200 overlap. On the TFT substrate 100 within the display area 50, scanning lines 51 extend in the horizontal direction (x direction) and are arranged in the vertical direction (y direction). Also, video signal lines 52 extend in the vertical direction and are arranged in the horizontal direction. Pixels 53 are formed in the 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 of the TFT substrate 100 that does not overlap the counter substrate 200 is the terminal area 60. A flexible wiring board 62 for supplying power and signals to the liquid crystal display device is connected to the terminal area 60. Also, a driver IC 61 for forming video signals and the like is arranged in the terminal area 60. When the area of the terminal area 60 is small, the driver IC 62 may be mounted on the flexible wiring board side.

[0019] The distance between the TFT substrate 100 and the counter substrate 200, that is, the thickness of the liquid crystal layer 300, needs to be kept constant across the entire display area. For this purpose, in FIG. 2, the columnar spacers 10 and 20 are arranged on the side of the counter substrate 200 to maintain the distance between the TFT substrate 100 and the counter substrate 200. Note that the columnar spacers may be formed on the side of the TFT substrate 100 as shown in the following embodiments. The description of FIG. 2 explains the function of the columnar spacers by taking the case where the columnar spacers are formed on the side of the counter substrate 200 as an example, and the same function is achieved when the columnar spacers are formed on the side of the TFT 100 substrate as shown in FIGS. 3 and 7. Also, although not described in detail, spacers formed on the TFT substrate side may be brought into contact with spacers formed on the side of the counter substrate 200, and the distance between the TFT substrate 100 and the counter substrate 200 may be maintained by the two spacers.

[0020] There are main columnar spacers 10 and sub-columnar spacers 20 in the columnar spacers. In the normal state, the main columnar spacers 10 define the distance between the TFT substrate 100 and the counter substrate 200. The sub-columnar spacers 20 are formed to have a lower height than the main columnar spacers 10. The sub-columnar spacers 20 do not contact the TFT substrate 100 in the normal state, but when a pressing force is applied to the counter substrate 200 or the TFT substrate 100, they contact the TFT substrate 100 to prevent the gap between the TFT substrate 100 and the counter substrate 200 from becoming extremely small. The diameter of the sub-columnar spacers 20 is larger than the diameter of the main columnar spacers 10, and the number of the sub-columnar spacers 20 is larger than the number of the main columnar spacers 10.

[0021] In Figure 1, scanning signal driving circuits that form scanning signals are formed in the frame portions on both sides of the display area 50, as will be described later in Figures 3 and 7. In this embodiment, an oxide semiconductor TFT is used for the TFT of the display area 50, and a polysilicon semiconductor TFT is used for peripheral driving circuits such as the scanning signal driving circuit described above. Polysilicon semiconductors have a higher mobility than oxide semiconductors, making them suitable for forming peripheral driving circuits. On the other hand, TFTs using oxide semiconductors have a lower mobility than polysilicon semiconductors, but their leakage current is lower than that of TFTs using polysilicon semiconductors, making them suitable as switching elements in pixels.

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

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

[0024] On the base film 101, a polysilicon semiconductor film 102 is formed in the peripheral drive circuit. The polysilicon semiconductor film 102 is initially formed as an a-Si film, which is converted to polysilicon by an excimer laser. The base film 101 and the a-Si film are formed continuously 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 an SiO film made from TEOS (Tetraethoxysilane). A first gate electrode 104 is formed on the first gate insulating film 103. The first gate electrode 104 is formed from MoW, Ti, or a Ti-Al-Ti multilayer film, etc. On the pixel side, a first light-shielding film 105 is formed from 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 scan lines 51 in Figure 1 and is aligned in the same direction as the scan lines 51. The first light-shielding film 105 covers the oxide semiconductor TFT, through-holes 130, etc. from below, shielding it from light from the backlight.

[0026] The following explanation will describe the cross-sectional structure of the pixel. A first gate insulating film 103 made of SiO film is formed covering the underlayer film 101. A second gate insulating film 106 is formed covering the first light-shielding layer 105 formed on the first gate insulating film 103. The oxide semiconductor film 107 formed on the second gate insulating film 106 forms the channel of the TFT under the second gate electrode 109 and on the first light-shielding layer 105.

[0027] A third gate insulating film 110 is formed covering the oxide semiconductor film 107. The third gate insulating film 110 is made up of two SiO layers. The portion of the oxide semiconductor film 107 corresponding to the channel is an oxygen-rich first SiO layer, and the other portion is a dense second SiO layer. The first SiO layer is oxygen-rich in order to supply oxygen to the oxide semiconductor film 107.

[0028] A second gate electrode 109 is formed on the third gate insulating film 110. The material of the second gate electrode 109 can be the same as that of the first gate electrode 103. Incidentally, in Figure 3, the TFT channel is formed below the second gate electrode 109, making it a top gate. However, by applying a gate voltage to the first light-shielding film 105, it can be made into a dual-gate TFT. In this case, the first light-shielding film 105 is made of the same metallic material as the first gate electrode 104, and in the display area 50, it also serves as the second scan line, which is the same as the scan line 51.

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

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

[0031] After the first interlayer insulating film 125 is formed, in the peripheral drive circuit, through-holes are formed in the first interlayer insulating film 125 to form the first drain wiring 111 and other through-holes to form the first source wiring 112, which are connected to the first drain electrode 1111 and the first source electrode 1121, respectively. Simultaneously, in the pixel region, through-holes 131 are 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, which are connected to the oxide semiconductor film 107. Subsequently, a second interlayer insulating film 126 made of an inorganic material such as a SiN film is formed 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 a through-hole 132. The first drain wiring 111, the first source wiring 112, and the second drain electrode 113 are made of metal, but the second source electrode 114 is made of transparent electrode ITO (Indium Tin Oxide) and is connected to the pixel electrode 116. In the through-hole 131, the video signal line 52 acts as the drain electrode 113 and is connected to the conductive oxide semiconductor film 107. The material of the video signal line 52 can be made of MoW, Ti, or a Ti-Al-Ti multilayer film, similar to the first gate electrode 104, etc.

[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 planarization film and to suppress capacitive coupling between the video signal lines 52 and the pixel electrodes 116 or common electrodes 119.

[0033] Figure 3 shows a common electrode top configuration, in which the pixel electrode 116 is formed on the organic passivation film 115 using a transparent conductive film called ITO. The pixel electrode 116 is rectangular in shape to match the shape of the pixel. Through-holes 130 are formed in the organic passivation film 115 to connect the pixel electrode 116 and the second source electrode 114.

[0034] In Figure 3, a capacitive insulating film 117 is formed on the pixel electrode 116, a second light-shielding film 118 is formed on top of it using metal, and a common electrode 119 is formed on top of that using ITO. The capacitive insulating film 117 is so named because it constitutes the 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 high relative permittivity. The second light-shielding film 118 and the common electrode 119 are formed on top of the capacitive insulating film 117.

[0035] The second light-shielding film 118 is made of metal, and materials such as molybdenum (Mo), titanium (Ti), and aluminum (Al) are used. The second light-shielding film 118 blocks unwanted light from the backlight and improves image contrast. In the configuration shown in Figure 3, a black matrix 202 with a light-shielding effect is also formed on the opposing substrate 200, but by placing the second light-shielding film 118, it is possible to block light that could not be completely blocked by the black matrix 202, prevent color mixing of light from within, and prevent voltage drop at the common electrode 119.

[0036] However, since the light transmittance decreases when the second light-shielding film 118 is formed, the second light-shielding film 118 may be omitted if a black matrix 202 is present on the opposing substrate 200, depending on the image quality requirements. Alternatively, it may be used with a modified shape not for the purpose of light shielding, but to prevent voltage drop at the common electrode 119.

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

[0038] By the way, columnar spacers are necessary to maintain the distance between the TFT substrate 100 and the opposing substrate 200. However, as the pixel pitch decreases, it becomes difficult to secure a suitable position for the columnar spacers. In Example 1, a filler material 30 is formed inside the through-hole 130, and this filler material 30 is used to form the columnar spacers 10. The filler material 30 is made of a photosensitive resin, such as acrylic resin. By using a photosensitive resin, it becomes unnecessary to form a separate resist for photolithography. In addition, the same material as the organic passivation film can be used as the material for the filler material 30.

[0039] The columnar spacer in Figure 3 is the main columnar spacer 10, which is in contact with the opposing substrate 200, but it is also possible to form sub-columnar spacers that do not come into contact with the opposing substrate 200. Furthermore, columnar spacers are not formed for all pixels. In pixels where columnar spacers are not formed, the through-hole 130 is filled with filler material 30 to flatten the upper surface of the through-hole 130. The main columnar spacer 10, sub-columnar spacer 20, and flattening configuration using filler material 30 can all be formed using the same process. That is, a photosensitive acrylic resin is applied to the entire display area to a predetermined thickness, and the exposure intensity is controlled by a mask to leave the required thickness of acrylic resin 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 side, defines the initial orientation of the 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 by a rubbing method or by photo-alignment treatment using polarized ultraviolet light. In Figure 3, the first alignment film 120 is not shown to be formed on the columnar spacer 10, but this can vary depending on the viscosity of the alignment film material during coating, leveling during the drying process, etc., 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 field lines are generated at the slit 1191 of the common electrode 119, passing through the liquid crystal layer 300 from the pixel electrode 116 toward the common electrode 119. This rotates the liquid crystal molecules and changes the transmittance of the liquid crystal layer 300. By changing the transmittance of the liquid crystal layer 300 for each pixel, an image is formed. In other words, IPS (In-Plane Switching) operation is performed.

[0042] The pixel area in Example 1 is very small. On the other hand, the thickness of the organic passivation film 115 cannot be reduced, so it is difficult to reduce the size of the through-holes 130 as well. Therefore, in order to save space, in Figure 3, the through-holes 130 of the organic passivation film 115 are formed directly above the TFT.

[0043] In Figure 3, a counter substrate 200 is positioned on either side of the liquid crystal layer 300. A color filter 201 and a black matrix 202 are formed on the counter 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 pigments 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] Figure 4 is a plan view of the pixels in the comparative example. In Figure 4, the first light-shielding film 105 and the scan lines 51 extend in the horizontal direction (x direction) and are arranged in the vertical direction (y direction). Also, the video signal lines 52 extend in the vertical direction and are arranged in the horizontal direction. However, in the region where the video signal lines 52 do not overlap with the first light-shielding film 105, they are tilted at a first angle with respect to the vertical direction (y direction), and in the region where they overlap with the first light-shielding film 105, they are tilted at a second angle in the opposite direction. In this case, the orientation direction of the first alignment film is the vertical direction, which is AL in Figure 4.

[0045] In Figure 4, the angles of the pixel electrode 116 and the slit 1191 of the common electrode 119, shown by the dotted line, are also tilted at a first angle with respect to the vertical direction, in line with the video signal line 52. The reason for tilting the slit 1191 of the pixel electrode 116 and the common electrode 119 with respect to the vertical direction is to form a first angle with the orientation direction of the first alignment film 120. This prevents the generation of domains in the pixels. The first angle is, for example, 8 to 15 degrees.

[0046] In Figure 4, since the orientation angle of the first alignment film 120 is in the vertical direction, the pixel electrodes 116, etc., are tilted by a first angle with respect to the vertical direction. If the angle of the first alignment film is tilted by a predetermined angle from the vertical direction, the angle of the pixel electrodes 116, etc., will be tilted by a first angle with respect to the predetermined angle.

[0047] In Figure 4, the first light-shielding film 105 extends laterally, but the video signal line 52, in the region overlapping with the first light-shielding film 105, is tilted in the opposite direction by a second angle greater than the first angle, thereby offsetting the lateral displacement of the video signal line 52. The function of Figure 4 will be explained below.

[0048] In Figure 4, a TFT is formed above the first light-shielding film 105. That is, the TFT is shielded from the backlight. In Figure 4, an oxide semiconductor film 107, which serves as drain wiring, extends vertically within the pixel towards the scan line 51 from a through-hole 131 formed on the video signal line 52. The oxide semiconductor film 107 is conductive and transparent, so it does not significantly reduce light transmittance. A channel of the TFT is formed at the intersection of the scan line 51 and the oxide semiconductor 107. Furthermore, if the first light-shielding film 105 also serves as the second scan line, a channel of the TFT will be formed at the intersection of the first light-shielding film 105 and the oxide semiconductor film 107.

[0049] In Figure 4, the conductive oxide semiconductor film 107 extends further downward and connects to a second source electrode 114 formed 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 connects to a pixel electrode 116 at a through-hole 130. In Figure 4, from through-hole 132 to through-hole 130, the oxide semiconductor film 107 and the second source electrode 114 overlap when viewed in plan view.

[0050] Incidentally, the columnar spacers 10, which maintain the gap between the TFT substrate 100 and the opposing substrate 200, are formed in the through-holes 130, as shown in the filler material 30 described in Figure 3. However, not all through-holes 130 of pixels have main columnar spacers 10 or sub-columnar spacers 20 formed in them.

[0051] In Figure 4, the pixel electrode 116 has a portion that is formed in a parallelogram shape following the shape of the pixel. The common electrode 119 is formed in common for multiple pixels, and a slit 1191 is formed at a position that overlaps with the pixel electrode 116.

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

[0053] Incidentally, as the pixel pitch decreases, the arrangement of the through-holes 130 formed in the organic passivation film 115 for connecting the pixel electrode 116 and the second source electrode 114 of the TFT becomes problematic. In this area, the video signal line 52 is tilted significantly with respect to the vertical direction, making the space problem even 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 interval 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 interval 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 interval between the video signal lines 52 becomes even smaller occurs due to the diagonal wiring.

[0055] Particularly, in the vicinity of the through hole 130 connecting the pixel electrode 116 and the second source electrode 114, since the wirings are intricate, interference with adjacent pixels in this region becomes a problem. Also, if the interval 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. Although the fourth angle can be made different from the second angle, 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] The difference between Figure 6 and Figure 4 lies in the configuration near the through-hole 130 connecting the pixel electrode 116 and the second source electrode 114. This region overlaps with the first light-shielding film 105. In this region, the video signal line 52 has a second portion that is significantly inclined with respect to the vertical direction, a third portion that extends in the vertical direction, and a fourth portion that is also significantly inclined with respect to the vertical direction. The width of the video signal line 52 is greater in the third region than in the first, second, and fourth regions.

[0058] The configuration shown in Figure 6 is intended to increase the spacing 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, allowing for wider spacing between adjacent video signal lines 52. Consequently, the size of the through-holes 130 formed in the organic passivation film 115 can also be increased. Furthermore, the margin for wiring arrangements that overlap with or are formed near the through-holes 130 can be increased, thereby improving reliability.

[0059] In Figure 6, the configuration is the same as that described in Figure 4, except for the through-hole 130 and its vicinity. The configuration shown in Figure 6 becomes more effective as the angle of the video signal line 52 with respect to the vertical increases. Thus, the configuration of Embodiment 1 shown in Figure 6 allows for a larger margin of error in wiring arrangement, making it possible to realize a highly reliable, high-definition liquid crystal display device. [Examples]

[0060] Example 1 describes a configuration in which the color filter 201 and black matrix 202 are formed on the opposing substrate 200. In this case, the alignment accuracy of the TFT substrate 100 and the opposing substrate 200 affects the transmittance of the liquid crystal display device. If the pixel pitch is large, the error in the alignment accuracy of the TFT substrate 100 and the opposing substrate 200 can be absorbed. However, as the screen resolution increases, this error may become unacceptable.

[0061] This problem can be solved by fabricating the color filter 201 and black matrix 202 on the TFT substrate 100 side. In other words, the error caused by photolithography on the TFT substrate 100 side is far smaller than the error caused by the alignment accuracy between the TFT substrate 100 and the opposing substrate 200.

[0062] Figure 7 is a cross-sectional view of Example 2. The main difference between Figure 7 and Figure 3 of Example 1 is that, in the display area 50, the color filter 201 and black matrix 202 are not formed on the opposing substrate 200, and only the second alignment film 204 is formed on the overcoat film 203. On the other hand, in the frame area, the black matrix 202 overlapping with the sealing material 150 is formed. Therefore, the alignment accuracy of the opposing 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 Figure 7, a color filter 201 is formed beneath the organic passivation film 115 on the TFT substrate 100 side. 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. The third interlayer insulating film 127 has through holes in positions that overlap with the through holes 130 of the organic passivation film 115, connecting the pixel electrode 116 and the second source electrode 114. Furthermore, a second light-shielding film 118 acts as a black matrix 202. The second light-shielding film 118 is formed as a laminated metal film and, together with the ITO film, constitutes an anti-reflective film. Therefore, it can function as a black matrix 202.

[0064] Furthermore, the second light-shielding film 118 not only acts as an anti-reflective film, but also has effects such as preventing color mixing between adjacent pixels and preventing voltage drop of the common electrode 119. In Figure 7, the organic passivation film 115 is formed on top of the color filter 201, but conversely, the organic passivation film 115 may be formed below the color filter 201.

[0065] Figure 8 is a plan view of the pixel area according to Embodiment 2. Figure 8 shows the area where the second light-shielding film 118 is formed using dot shading. Since the second light-shielding film 118 is formed by stacking it with the common electrode 119 formed over the entire display area, it can be formed at any position.

[0066] In the configuration shown in Figure 8, the second light-shielding film 118 is formed overlapping with the first light-shielding film 105 and the video signal lines 52 when viewed in plan view. This is the same area as the area covered by the black matrix 202 of the display area 50 formed on the opposing substrate 200 in Embodiment 1.

[0067] Thus, the present invention can also be applied to COA (Color Filter on Array). [Explanation of Symbols]

[0068] 10…Main columnar spacer, 20…Sub columnar spacer, 30…Filler material, 50…Display area, 51…Scan 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, 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 comprising a first light-shielding film extending in a first direction and video signal lines formed on a TFT substrate, The aforementioned video signal line is In a region that does not overlap with the first light-shielding film, a first portion extends with its extending direction inclined at a first angle with respect to a second direction perpendicular to the first direction, In the region overlapping with the first light-shielding film, a second portion extends with its extending direction at a second angle with respect to the second direction and inclined in the opposite direction to the first portion, The material has a third portion whose extending direction is the second direction, and a fourth portion whose extending direction forms a fourth angle with respect to the second direction and extends inclined in the opposite direction to the first portion. A liquid crystal display device characterized in that the first part, the second part, the third part, and the fourth part are arranged and connected in this order, and the second angle and the fourth angle are greater than the first angle.

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

3. The first video signal line has the configuration of the video signal line according to claim 1. The second video signal line has the configuration of the video signal line according to claim 1. The first region is located between the first portion of the first video signal line and the first portion of the second video signal line. The third region is located between the third portion of the first video signal line and the third portion of the second video signal line. The liquid crystal display device according to claim 1, characterized in that 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.

4. In region XL1, a pixel electrode is present, A TFT exists that connects the first video signal line and the pixel electrode. The liquid crystal display device according to claim 3, characterized in that 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, and the TFT is formed beneath the organic passivation film. The liquid crystal display device according to claim 4, characterized in that the through-holes are formed in the organic passivation film.

6. The common electrode is formed overlapping with the pixel electrode via a capacitive insulating film. The liquid crystal display device according to claim 4, characterized in that a second light-shielding film is formed overlapping with the common electrode.

7. The liquid crystal display device according to claim 6, characterized in that the 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.

8. A counter substrate is positioned opposite the TFT substrate, The liquid crystal display device according to claim 4, characterized in that the distance between the TFT substrate and the opposing substrate is maintained by columnar spacers formed in the through-holes.

9. A counter substrate is positioned opposite the TFT substrate, The liquid crystal display device according to claim 3, characterized in that the color filter and the black matrix are formed on the opposing substrate.

10. A counter substrate is positioned opposite the TFT substrate, The liquid crystal display device according to claim 5, characterized in that the color filter is formed overlapping with the organic passivation film on the TFT substrate.

11. The liquid crystal display device according to claim 10, characterized in that the color filter is formed beneath the organic passivation film.

12. The liquid crystal display device according to claim 11, characterized in that the 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, characterized in that a black matrix is ​​not present in the display area of ​​the opposing substrate.

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