Liquid crystal display device

Abstract

The present invention provides a liquid crystal display device that can suppress display unevenness, prevent insufficient charging of pixels even with high-frequency drive, and achieve high transmittance. [Solution] A liquid crystal display device comprising: a first substrate having a display area and a frame area arranged around the display area, wherein the display area has a first wiring, a second wiring, a pixel electrode electrically connected to the second wiring via a switching element, and a counter electrode, wherein the frame area has a driver circuit connected to the first wiring, and the second substrate includes a first light-shielding member that overlaps with the driver circuit in a plan view, a color filter layer including a plurality of color filters, and a second light-shielding member arranged between the first light-shielding member and the color filter layer, wherein the first light-shielding member is a metal light-shielding member and is connected to ground, and the first light-shielding member and the second light-shielding member are electrically independent.

Description

[Technical Field]

[0001] The following disclosure relates to liquid crystal display devices. [Background technology]

[0002] Liquid crystal display devices are display devices that utilize liquid crystal compositions for display purposes. A typical display method involves applying a voltage to a liquid crystal composition sealed between a pair of substrates, thereby changing the orientation of liquid crystal molecules in the composition according to the applied voltage, and controlling the amount of light transmitted. Such liquid crystal display devices are used in a wide range of fields, taking advantage of their features such as being thin, lightweight, and low power consumption.

[0003] For example, Patent Document 1 discloses a liquid crystal display device in which the scan line lead is covered by a shield electrode formed in the same layer as the counter electrode. In this device, studies are being conducted to prevent the phenomenon in which the inside of the counter substrate becomes charged due to the influence of the gate voltage applied to the scan line lead, causing white spots around the screen in an IPS-type liquid crystal display device.

[0004] Furthermore, Patent Document 2 discloses a liquid crystal display device equipped with a counter electrode that is provided in the frame region of the opposing substrate and overlaps with the entire inspection circuit or protection circuit in a plan view. This invention explores suppressing display unevenness that occurs in the display area near the connection between the wiring layer, such as the inspection circuit or protection circuit, and the gate wiring in a transverse electric field type liquid crystal display device.

[0005] Furthermore, Patent Document 3 discloses a liquid crystal display device and a method for manufacturing the same, which can prevent the inflow of electrostatic surges (ESD surges) into the liquid crystal display panel by designing a double black matrix. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2009-265484 [Patent Document 2] Japanese Patent Publication No. 2016-024288 [Patent Document 3] Japanese Patent Publication No. 2016-126341 [Patent Document 4] International Publication No. 2011 / 104945 [Overview of the project] [Problems that the invention aims to solve]

[0007] A substrate on which multiple switching elements such as thin-film transistors (TFTs) are arranged is also called a TFT substrate. Conventionally, gate drivers for driving the switching elements were placed as integrated circuit (IC) chips in the bezel area of ​​liquid crystal displays. However, in recent years, as one way to narrow the bezel of liquid crystal displays, the integral formation of gate drive circuits (also called gate drivers) on the TFT substrate has been considered (see, for example, Patent Document 4). A gate driver integrally formed on a TFT substrate is also called a gate driver monolithic.

[0008] According to the inventors' research, in a liquid crystal display device where a gate driver monolithic is arranged in the bezel region, display unevenness sometimes occurred where the area adjacent to the bezel region of the display area appeared whiter than the center of the display area. Furthermore, according to the inventors' research, when high-frequency driving such as 240Hz was performed, the waveform of the scanning signal became distorted, and the switching elements arranged for each pixel could not be sufficiently charged.

[0009] This invention has been made in view of the above-mentioned situation, and aims to provide a liquid crystal display device that can suppress display unevenness, suppress insufficient charging of pixels even with high-frequency drive, and obtain high transmittance. [Means for solving the problem]

[0010] (1) One embodiment of the present invention is a liquid crystal display device comprising a first substrate, a second substrate, and a liquid crystal layer sandwiched between the first substrate and the second substrate, wherein the first substrate has a display area and a frame area disposed around the display area, the display area has a first wiring extending in a first direction, a second wiring extending in a second direction intersecting the first wiring, a pixel electrode electrically connected to the second wiring via a switching element, and a counter electrode facing the pixel electrode, the frame area has a driver circuit connected to the first wiring, the second substrate is disposed so as to overlap with the frame area in a plan view and includes a first light-shielding member that overlaps with at least the driver circuit, a color filter layer including a plurality of color filters disposed so as to overlap with the display area, and a second light-shielding member disposed between the first light-shielding member and the color filter layer, the first light-shielding member is a metal light-shielding member and is connected to ground, and the first light-shielding member and the second light-shielding member are electrically independent.

[0011] (2) One embodiment of the present invention is a liquid crystal display device in which, in addition to the configuration of (1) above, the first light-shielding member and the second light-shielding member are arranged with a gap between them.

[0012] (3) One embodiment of the present invention is a liquid crystal display device in which, in addition to the configuration of (1) or (2) above, the second light-shielding member is a metal light-shielding member.

[0013] (4) One embodiment of the present invention is a liquid crystal display device in which, in addition to any of the configurations of (1) to (3) above, the second substrate further includes a third light-shielding member disposed between the plurality of color filters in a plan view, and the third light-shielding member is a metal light-shielding member.

[0014] (5) One embodiment of the present invention is a liquid crystal display device in which, in addition to any of the configurations of (1) to (3) above, the second substrate further includes a third light-shielding member disposed between the plurality of color filters in a plan view, and the third light-shielding member is a light-shielding member made of resin.

[0015] (6) In addition to the configuration of any one of (1) to (4) above, in one embodiment of the present invention, the first substrate further includes a fourth light-shielding member disposed so as to overlap a region between the first light-shielding member and the second light-shielding member that are spaced apart in a plan view, and is a liquid crystal display device.

[0016] (7) In addition to the configuration of (1), (2), (4), (5) or (6) above, in one embodiment of the present invention, the second light-shielding member is a resin light-shielding member, and is a liquid crystal display device.

[0017] (8) In addition to the configuration of (7) above, in one embodiment of the present invention, the first light-shielding member and the second light-shielding member are in contact with each other, and the resistance of the second light-shielding member is 10 14 Ω / cm or more, and is a liquid crystal display device.

[0018] (9) In addition to the configuration of any one of (1) to (8) above, in one embodiment of the present invention, the second substrate includes a conductive member electrically connected to the first light-shielding member, and is a liquid crystal display device.

[0019] (10) In addition to the configuration of any one of (1) to (9) above, in one embodiment of the present invention, the second substrate has a transparent conductive layer electrically connected to the conductive member on a surface opposite to the liquid crystal layer, and is a liquid crystal display device.

Advantages of the Invention

[0020] According to the present invention, it is possible to provide a liquid crystal display device that can suppress display unevenness, suppress insufficient charging of pixels even in high-frequency driving, and further obtain a higher transmittance.

Brief Description of the Drawings

[0021] [Figure 1] It is a plan schematic view of the liquid crystal display device 1-1 according to Embodiment 1. [Figure 2] It is a plan schematic view of the first substrate used in the liquid crystal display device shown in FIG. 1. [Figure 3]Figure 1 is a schematic plan view showing an enlarged view of the corner of the liquid crystal display device enclosed by the dotted line. [Figure 4] Figure 3 is a schematic cross-sectional view along the line X1-X2. [Figure 5] Figure 3 is a schematic cross-sectional view along the line X3-X4. [Figure 6] This is a schematic plan view showing a liquid crystal display device 1-2 according to a modified example of Embodiment 1. [Figure 7] Figure 6 is a schematic plan view showing an enlarged view of the corner of the liquid crystal display device enclosed by the dotted line. [Figure 8] Figure 7 is a schematic cross-sectional view along the line X5-X6. [Figure 9] This is a schematic plan view showing an enlarged corner of the liquid crystal display device 2-1 according to Embodiment 2. [Figure 10] Figure 9 is a schematic cross-sectional view along the line X7-X8. [Figure 11] Figure 9 is a schematic cross-sectional view along the line X9-X10. [Figure 12] This is a schematic plan view showing an enlarged corner of the liquid crystal display device 2-2 according to a modified example of Embodiment 2. [Figure 13] Figure 12 is a schematic cross-sectional view along the line X11-X12. [Figure 14] This is a schematic cross-sectional view of the liquid crystal display device R1 according to Comparative Example 1. [Figure 15] This is a schematic cross-sectional view of the liquid crystal display device R2 according to Comparative Example 2. [Figure 16] This is a schematic cross-sectional view of the liquid crystal display device R3 according to Comparative Example 3. [Figure 17] This is a schematic plan view illustrating the display unevenness occurring in the liquid crystal display device according to Comparative Example 2. [Modes for carrying out the invention]

[0022] The present invention will be described in more detail below with reference to the drawings, with the following examples of embodiments, but the present invention is not limited to these embodiments.

[0023] <Definition of Terms> In this specification, "observation side" means the side of the liquid crystal display device that is closer to the observer relative to the screen (display surface), and "back side" means the side of the liquid crystal display device that is further away from the screen (display surface).

[0024] In this specification, two axes (directions) being orthogonal means that the angle (absolute value) between them is within the range of 90 ± 3°, preferably within the range of 90 ± 1°, more preferably within the range of 90 ± 0.5°, and particularly preferably 90° (perfectly orthogonal). Also in this specification, two axes (directions) being parallel means that the angle (absolute value) between them is within the range of 0 ± 3°, preferably within the range of 0 ± 1°, more preferably within the range of 0 ± 0.5°, and particularly preferably 0° (perfectly parallel).

[0025] <Embodiment 1> Figure 1 is a schematic plan view of a liquid crystal display device 1-1 according to Embodiment 1. Figure 2 is a schematic plan view of the first substrate used in the liquid crystal display device shown in Figure 1. Figure 3 is a schematic plan view showing an enlarged view of the corner of the liquid crystal display device enclosed by a dotted line in Figure 1. Figure 4 is a schematic cross-sectional view along the line X1-X2 in Figure 3. Figure 5 is a schematic cross-sectional view along the line X3-X4 in Figure 3. In this specification, in schematic plan views, cross-sectional views, etc., of the liquid crystal display device, the display area AA and frame area NA of the first substrate 100 shown in Figure 2, and the area that overlaps with them in a plan view are also referred to as display area AA and frame area NA, respectively. The liquid crystal display device according to Embodiment 1 comprises a first substrate 100, a second substrate 200, and a liquid crystal layer 300 sandwiched between the first substrate 100 and the second substrate 200. The first substrate 100 may be on the back side and the second substrate 200 may be on the observation side.

[0026] As shown in Figures 1 and 2, the liquid crystal display device 1-1 and the first substrate 100 according to Embodiment 1 have, in a plan view, a display area AA and a frame area NA arranged around the display area AA. Figure 1 illustrates the case where the frame area NA is arranged to surround the display area AA, but the frame area NA only needs to be located on at least one outer edge of the display area AA, and the display area AA does not need to be surrounded by the frame area NA. As shown in Figure 2, the display area AA has a plurality of pixels Px and is an area where a desired image or the like is displayed. Various wirings and switching elements for driving the plurality of pixels are arranged in the frame area NA. In this specification, the frame areas NA arranged on the upper, lower, left, and right sides of the display area AA are also referred to as the upper frame area, lower frame area, left frame area, and right frame area, respectively. The first substrate 100 may have a terminal area B below the lower frame area. Wirings for driving the source driver SD and the GDM described later are arranged in the terminal area B.

[0027] As shown in Figure 2, the display area AA is arranged with a first wiring 120G extending in a first direction D1 and a second wiring 120S extending in a second direction D2 intersecting the first direction D1. The first wiring 120G may be a gate wiring, and the second wiring may be a source wiring. The multiple gate wirings 120G are arranged on the first support substrate 110, parallel to each other in a plan view and extending along the first direction D1. The multiple source wirings 120S are arranged parallel to each other and extending along the second direction D2, intersecting each gate wiring 120G via a first insulating layer (gate insulating layer) 130. The multiple gate wirings 120G and the multiple source wirings 120S are formed as a grid to demarcate each pixel Px. A TFT 1 as a switching element is arranged at the intersection of each gate wiring 120G and each source wiring 120S. As shown in Figure 4, the display area AA is arranged with a pixel electrode 160 that is electrically connected to the second wiring 120S via a TFT1 acting as a switching element, and a counter electrode 140 that faces the pixel electrode 160.

[0028] Furthermore, dummy pixels may be placed near the boundary between the display area AA and the frame area NA. These dummy pixels are used to adjust the timing of the common signal and gate signal and do not directly contribute to image display, etc. Pixel electrodes may not be placed on these dummy pixels, and in a plan view, they may not overlap with the color filter layer 230 but may overlap with the light-shielding member placed on the second substrate 200.

[0029] Here, the liquid crystal display device 1-1 is preferably a horizontal orientation mode, which controls the orientation of liquid crystal molecules mainly by rotating them in a plane parallel to the substrate surface, for reasons such as easier acquisition of wide viewing angle characteristics. Examples of the above horizontal orientation modes include in-plane switching (IPS) mode and fringe field switching (FFS) mode. In an IPS mode liquid crystal display device, a pair of comb-shaped pixel electrodes 160 and a counter electrode 140 are arranged facing each other on the same plane for a single pixel. In an FFS mode liquid crystal display device, the pixel electrodes 160 and the counter electrode 140 are laminated with an insulating layer in between. The following describes an FFS mode liquid crystal display device, but the liquid crystal display device of this disclosure is not limited to this configuration.

[0030] The first substrate 100 comprises, in order from the back side toward the observation side, for example, a first support substrate 110, gate wiring 120G, a first insulating layer 130, source wiring 120S, a second insulating layer 131, a counter electrode 140, a fourth insulating layer 150, and a pixel electrode 160. A third insulating layer 132 may be further provided between the second insulating layer 131 and the counter electrode 140. The first support substrate 110 and the second support substrate 210, described later, are insulating substrates and are preferably transparent substrates, such as glass substrates and plastic substrates.

[0031] It is preferable that the pixel electrode 160 is arranged for each pixel. The pixel electrode 160 may have a slit. The pixel electrode 160 has a plurality of linear electrodes, and the region between the plurality of linear electrodes is the slit. The plurality of linear electrodes may have one end connected to each other, or both ends connected to each other.

[0032] The counter electrode 140 may be a planar electrode. The planar electrode refers to an electrode in which, at least in a planar view, no slits or the like are provided in the region that overlaps with the optical aperture of the pixel described later. The counter electrode 140 may be placed for each pixel Px, or it may be placed across multiple pixels Px regardless of the boundaries between multiple pixels Px.

[0033] It is preferable that transparent conductive materials be used for the counter electrode 140 and the pixel electrode 160. Examples of transparent conductive materials include indium tin oxide (ITO) and indium zinc oxide (IZO).

[0034] Liquid crystal display devices can be transmissive, reflective, or semi-transmissive. Figure 4, etc., illustrates a transmissive liquid crystal display device. Although not shown, if the liquid crystal display device is reflective or semi-transmissive, it is preferable that the TFT substrate has a reflective layer in the display area. The reflective layer may be arranged, for example, on the back side (support substrate 110) of the counter electrode 140, via an insulating layer. In addition, the reflective layer may have openings at positions that overlap with each pixel. In the case of a semi-transmissive type, light emitted from the backlight passes through the openings and is emitted to the observation surface side, thereby enabling transmissive display.

[0035] The reflective layer may preferably be made of a metal with high reflectivity, and may include, for example, a single or multi-layer metal layer made of aluminum, silver, etc. The reflective layer may also be a laminate of the metal layer and the transparent conductive layer. As the material for the transparent conductive layer, a known transparent conductive material such as ITO can be used.

[0036] Each of the multiple pixels Px is provided with an optical aperture through which light is transmitted. If the liquid crystal display device is transmissive, the optical aperture transmits light incident from the back side of the second substrate 200 toward the observation surface side of the first substrate 100. If the liquid crystal display device is reflective, the optical aperture transmits incident light incident from the observation surface side (outside) of the first substrate 100, and reflected light that is emitted toward the outside of the liquid crystal display device after the incident light has been reflected inside the liquid crystal display device. In plan view, the optical aperture may be superimposed on a transparent material such as a polarizing plate or a color filter.

[0037] The TFT1, as a switching element, is a switching element used to switch the pixels on and off, and for example, a thin-film transistor (TFT) can be used. The TFT1 is a three-terminal switch having, for example, a gate electrode protruding from the gate wiring 120G, a source electrode protruding from the source wiring 120S, a drain electrode 120D connected to the pixel electrode 160, and a semiconductor layer 121. Each pixel electrode 160 is electrically connected to the drain electrode 120D via a contact hole CH1 provided so as to penetrate the second insulating layer 131, the third insulating layer 132, and the fourth insulating layer 150.

[0038] The source electrode and drain electrode 120D are provided on the same source metal layer as the source wiring 120S, and the gate electrode may be provided on the same gate metal layer as the gate wiring 120G. The gate electrode is part of the gate wiring 120G and may be represented as 120G in the figure. The source electrode is part of the source wiring 120S and may be represented as 120S in the figure.

[0039] Examples of materials for the gate metal layer and source metal layer include metals such as copper, titanium, aluminum, molybdenum, and tungsten, or alloys thereof. The gate metal layer and source metal layer may be a single layer or multiple layers of the above metals or alloys.

[0040] A common potential maintained at a constant potential may be supplied to the counter electrode 140. When a scanning signal is input to the gate wiring 120G from the driver circuit (gate driver), the semiconductor layer 121 of the TFT1 placed on the corresponding pixel conducts, turning on the TFT1, and the pixel electrode 160 is electrically connected to the second wiring 120S via the TFT1, and a data signal is written from the source wiring 120S to the pixel electrode 160. By applying a voltage between the counter electrode 140 and the pixel electrode 160, a transverse electric field (fringe electric field) is generated in the liquid crystal layer 300, and the orientation of the liquid crystal molecules can be controlled.

[0041] The semiconductor layer 121 of the TFT1 can be made of, for example, amorphous silicon or an oxide semiconductor containing at least one metal element from indium, gallium, and zinc. Examples of such oxide semiconductors include In-Ga-Zn-O based oxide semiconductors (IGZO).

[0042] A driver circuit connected to the first wiring is arranged in the frame region NA. When the first wiring is a gate wiring, the driver circuit is also called a gate driver. Preferably, the gate driver is a gate driver monolithic (GDM) integrally formed on the first substrate. In a GDM, instead of IC chips etc. being arranged on the TFT substrate, for example, the TFT1 constituting the display area, the gate wiring 120G and source wiring 120S that drive the TFT1, and the gate driver are formed on the TFT substrate. The gate wiring 120G extending to the frame region NA is also called a gate lead-out wiring, and the source wiring 120S extending to the frame region NA is also called a source lead-out wiring.

[0043] The configuration of the GDM is not particularly limited, and for example, the configuration disclosed in Patent Document 4 can be adopted. The GDM may include, for example, a plurality of shift registers for sequentially driving a plurality of gate wirings 120G arranged in the display area AA, and a plurality of bus lines 123, 127 for driving the shift registers. Although not shown, one shift register corresponds to one gate wiring 120G and is electrically connected by connecting wires. The shift registers output a scanning signal of a predetermined value to the gate wiring 120G at a predetermined timing. In this specification, the area where the plurality of shift registers are arranged is also referred to as the TFT area GDM-TFT, and the area where the plurality of bus lines are arranged is also referred to as the wiring area GDM-BL.

[0044] A single shift register may include multiple circuits, each containing multiple TFTs (TFT2 and TFT3 in the figure). Depending on the number of circuits, it may include two or more TFTs. TFT2 and TFT3 may have the same configuration as TFT1, which is placed in the display area, and may include, for example, a gate electrode 124, a gate insulating layer (first insulating layer) 130, a semiconductor layer 121, a source electrode 126, a drain electrode, a second insulating layer 131, etc.

[0045] Examples of the multiple bus lines 123 and 127 mentioned above include multiple clock signal lines, a start pulse signal line that supplies a pulse signal to the first circuit to be driven, a reset signal line that resets the state of the shift register, a low-level power supply line for supplying a low-level potential, a high-level power supply line that supplies a potential higher than the low-level potential, gate wiring 120G extending to the frame region NA, source wiring 120S extending to the frame region NA, etc. Each of the multiple bus lines is connected to each circuit (TFT2, TFT3, etc.) included in the shift register and supplies a clock signal to each circuit to input the timing of its operation. For example, -12V to -2V is applied to the low-level power supply line, and for example, +12V to +24V is applied to the high-level power supply line.

[0046] Multiple bus lines 123 and 127 may be arranged in the bezel area NA. Multiple source lines 120S may each be connected to a source driver SD via source lead lines. The source driver SD may be located, for example, in the terminal area B. In addition, the multiple bus lines 123 and 127 may include source lines for panel testing. Panel testing source lines are used, for example, during the manufacturing, before shipment, or repair of the liquid crystal display device to check the behavior of the liquid crystal display device, and are not used during normal display of the liquid crystal display device. Panel testing source lines may extend from the upper bezel area of ​​the liquid crystal display device to at least one of the left bezel area or the right bezel area, as shown in Figures 2, 4, and 5, and be connected to a source driver in the terminal area B.

[0047] The first insulating layer 130, the second insulating layer 131, and the fourth insulating layer 150 are preferably made of an inorganic insulating film (PAS). As the inorganic insulating film, for example, an inorganic insulating film containing silicon nitride (SiNx) or silicon oxide (SiO2), and laminates thereof can be used.

[0048] The third insulating layer 132 is preferably an organic insulating film (JAS). As the organic insulating film, for example, an organic insulating film containing an acrylic resin, an organic insulating film containing a polyimide resin, an organic insulating film containing a novolac resin, and a laminate thereof can be used.

[0049] The second substrate 200 includes a color filter layer 230 that overlaps with the display area AA in a plan view, and is also called a color filter substrate. A specific configuration of the second substrate 200 is, for example, as shown in Figures 4 and 5, a second support substrate 210, and a first light-shielding member 221M, a second light-shielding member 222M, and a color filter layer 230 on the liquid crystal layer side of the second support substrate 210. In Figures 4 and 5, a red color filter 230R is shown as the color filter layer 230.

[0050] The color filter layer 230 includes multiple color filters. For example, the color filter layer 230 includes a red color filter 230R, a green color filter 230G, and a blue color filter 230B. The arrangement of the color filters of each color is not particularly limited, but for example, a stripe arrangement may be used in which different color filters are arranged along either the first direction or the second direction, and the same color filters are arranged along the other direction. For each pixel Px, one color filter is arranged to overlap. Figure 3 illustrates the case in which different color filters are arranged along the first direction D1, and the same color filters are arranged along the second direction D2. Typically, a combination of the red color filter 230R, the green color filter 230G, and the blue color filter 230B is considered a single display unit, also called a pixel. By controlling the amount of light transmitted through each color filter for each pixel and mixing the colors, the desired color can be obtained in the pixel.

[0051] The red color filter 230R, the green color filter 230G, and the blue color filter 230B are obtained, for example, by curing a resin composition containing pigments of each respective color. The pigments and resin compositions are not particularly limited, and those commonly used in the field of liquid crystal display devices can be used.

[0052] The second substrate 200 includes a first color filter and a second light-shielding member 222M. As shown in Figure 3, the first light-shielding member 221M is positioned to overlap with the frame region NA in a plan view. As shown in Figure 4, the first light-shielding member 221M is positioned to overlap with at least the driver circuit GDM. The first light-shielding member 221M is a metallic light-shielding member and is connected to ground. The second light-shielding member 222 is positioned between the first light-shielding member 221M and the color filter layer 230, and the first light-shielding member 221M and the second light-shielding member 222 are electrically independent.

[0053] The statement that the first light-shielding member 221M and the second light-shielding member 222 are electrically independent means that the first light-shielding member 221M and the second light-shielding member 222 are insulated from each other. Examples include cases where the first light-shielding member 221M and the second light-shielding member 222 are arranged with an insulator in between, or where the second light-shielding member 222 is an insulator. For example, as explained using Figure 4, the first light-shielding member 221M and the second light-shielding member 222 are insulated from each other by the first support substrate 110 and / or the overcoat layer 240. The case where the second light-shielding member is an insulator will be described in detail in Embodiment 2. Whether or not the first light-shielding member 221M and the second light-shielding member 222 are electrically independent can be confirmed, for example, by measuring the resistance value and voltage of the first light-shielding member 221M and the second light-shielding member 222 using a general digital multimeter or the like.

[0054] In the liquid crystal display device 1-1 according to Embodiment 1, the first light-shielding member 221M and the second light-shielding member 222M are arranged with a gap between them, thereby enabling the first light-shielding member 221M and the second light-shielding member 222M to be electrically independent. In this specification, the region between the first light-shielding member 221M and the second light-shielding member 222, which are arranged with a gap W between them, is also referred to as the region where no light-shielding member is formed.

[0055] Here, as described above, high voltage is applied to the high-level power lines, shift registers, etc. included in the GDM. In addition, gate voltage leakage may occur from multiple bus lines, including gate lead wires extending from the gate wiring 120G to the bezel region NA. Due to these factors, if the first light-shielding member 221M is not placed, components such as the color filter layer 230 placed on the second substrate 200 may become charged, and such charging is particularly likely to occur near the boundary between the display region AA and the bezel region NA where the driver circuit is located. When these components become charged, an unwanted vertical electric field is generated in the liquid crystal layer 300, and in particular, in liquid crystal display devices in horizontal alignment mode, the unwanted vertical electric field generated in the liquid crystal layer 300 can disrupt the orientation of liquid crystal molecules in the region adjacent to the bezel region NA of the display region AA, causing display unevenness that makes the display region AA appear whiter than the center.

[0056] In the liquid crystal display device of this embodiment, the first light-shielding member 221M, which is made of metal and is positioned to overlap with the driver circuit GDM and connected to ground, and the second light-shielding member 222, which is positioned to overlap with the display area AA, are electrically independent. This configuration suppresses the charging of components positioned on the second substrate 200 side, such as the color filter layer 230. As a result, display unevenness in the area adjacent to the bezel area NA of the display area AA can be suppressed. Furthermore, since unnecessary vertical electric fields are less likely to be generated in the liquid crystal layer, high transmittance can be obtained. In addition, by positioning the first light-shielding member 221M on the second substrate 200 side, the distance between the GDM and the multiple bus lines 123, 127 positioned on the first substrate 100 and the first light-shielding member 221M can be increased, and the capacitance formed between the GDM and the multiple bus lines 123, 127 and the first light-shielding member 221M can be reduced. As a result, the time constant per trace of multiple bus lines 123 and 127 can be reduced, and waveform distortion of the scan signal can be suppressed even with high-frequency drive, thereby suppressing undercharging of the pixels.

[0057] The first light-shielding member 221M is positioned so as to overlap with at least the driver circuit. Figure 2 illustrates a case where the driver circuit GDM is positioned in the right and left frame regions of the first substrate 100. In this case, the first light-shielding member 221M only needs to be positioned so as to overlap with the left and right frame regions, but it may also be positioned so as to overlap with the upper frame region.

[0058] The second light-shielding member 222 is positioned between the first light-shielding member 221M and the color filter layer 230 in a plan view. The second light-shielding member 222 only needs to be positioned between the frame region on the side where the driver circuit is located and the color filter layer 230, and it is preferable that it is positioned at a distance from the first light-shielding member 221M, which is positioned to overlap with the frame region on the side where the driver circuit is located. When the driver circuit GDM is positioned in the left frame region and the right frame region of the first substrate 100, it is preferable that the second light-shielding member 222 is positioned between the first light-shielding member 221M, which is positioned to overlap with the left frame region and the color filter layer 230, and between the first light-shielding member 221M, which is positioned to overlap with the right frame region and the color filter layer 230.

[0059] Furthermore, the first light-shielding member 221M may be positioned to overlap with all four frame areas on the left, right, top, and bottom. If the first light-shielding member 221M is positioned to overlap with all four frame areas, the second light-shielding member 222M may be positioned to surround the color filter layer 230, and furthermore, the first light-shielding member 221M may be positioned with a gap between them to surround the second light-shielding member 222M.

[0060] The first light-shielding member 221M is a metal light-shielding member. The metal light-shielding member is preferably one with low surface resistivity and low light transmittance, and more preferably one that appears black. The surface resistivity of the first light-shielding member 221M is preferably lower than that of a transparent electrode such as ITO, and may be, for example, 10 Ω / □ or less. The surface resistivity of the first light-shielding member 221M is more preferably 5 Ω / □ or less, even more preferably 1 Ω / □ or less, and particularly preferably 0.15 Ω / □ or more and 0.1 Ω / □ or less. The surface resistivity can be measured by a method compliant with JIS K7194:1994.

[0061] Examples of materials for the above-mentioned metallic light-shielding member include metals such as molybdenum, tungsten, titanium, and tantalum, or nitrides of the above metals, as well as alloys containing the above metals or nitrides. The above-mentioned metallic light-shielding member may be a single layer or a laminate of two or more layers. Examples of the above-mentioned laminate of two or more layers include a single or multi-layer metal film containing the above metal, a nitride of the above metal, or an alloy thereof; a laminate of the above-mentioned single or multi-layer metal film and a nitride film or oxide film (hereinafter also referred to as nitride film, etc.). More specifically, examples include a laminate of a titanium-containing metal film and a nitride film, etc., a laminate of a molybdenum-containing metal film and a nitride film, etc., a laminate of a tungsten-containing metal film and a nitride film, etc. Examples of the above-mentioned nitride film, etc. include silicon nitride and silicon oxide.

[0062] A silver oxide film can also be used as the above-mentioned metallic light-shielding member. By using a silver oxide film, a low-resistance, black light-shielding member can be formed. For example, the silver oxide thin film can be formed by using silver as a sputtering target, introducing oxygen and performing sputtering to create a silver oxide thin film, then blocking the oxygen and performing sputtering again, and finally reintroducing oxygen to form the silver oxide thin film. The obtained silver oxide thin film can be patterned using, for example, a mixture of ammonia water and hydrogen peroxide water, allowing for selective etching of only silver and silver oxide in a single step.

[0063] The second substrate 200 preferably further includes a third light-shielding member 223 arranged between a plurality of color filters in a plan view. The third light-shielding member 223 may be arranged between color filters adjacent in a first direction D1, or between color filters adjacent in a second direction D2. It is preferable that the third light-shielding member 223 is arranged at least between color filters of different colors. For example, in the case of a stripe arrangement as shown in Figure 3, it is preferable that the third light-shielding member 223 is arranged between color filters adjacent in a first direction D1, along the second direction D2. This arrangement prevents mixing of colors between color filters of different colors. The third light-shielding member 223 may be arranged both between color filters adjacent in a first direction D1, and between color filters adjacent in a second direction D2. In this case, the third light-shielding member 223 is arranged in a grid pattern and is positioned outside the optical opening of each pixel. The third light-shielding member 223 is preferably arranged to overlap with either the gate wiring 120G or the source wiring 120S of the display area AA in a plan view, and more preferably to overlap with both.

[0064] The third light-shielding member 223 may be positioned to surround each color filter in a plan view, as shown in Figure 3. In this case, the third light-shielding member 223 is positioned between the color filter layer 230 and the second light-shielding member 222.

[0065] The second light-shielding member 222 may be a metal light-shielding member or a resin light-shielding member, and the third light-shielding member 223 may be a metal light-shielding member or a resin light-shielding member. In this specification, when the second light-shielding member and the third light-shielding member are metal light-shielding members, they will be referred to as the second light-shielding member 222M and the third light-shielding member 223M, and when they are resin light-shielding members, they will be referred to as the second light-shielding member 222R and the third light-shielding member 223R. When there is no need to distinguish between metal and resin, they will be referred to as the second light-shielding member 222 and the third light-shielding member 223, respectively.

[0066] Embodiment 1 describes the case where the first light-shielding member 221M, the second light-shielding member 222M, and the third light-shielding member 223M are made of metal. The metal light-shielding members used for the second light-shielding member 222M and the third light-shielding member 223M can be the same as those used for the first light-shielding member 221M. Resin light-shielding members will be described later. Note that when the second light-shielding member 222M and the third light-shielding member 223M are made of the same material, the boundary between the second light-shielding member 222M and the third light-shielding member 223M is not visually distinguishable.

[0067] From the viewpoint of reducing the number of steps in manufacturing a liquid crystal display device, it is preferable that the second light-shielding member 222 and the third light-shielding member 223 are also made of metal. Since metal light-shielding members can be processed to be thinner than resin light-shielding members, using metal light-shielding members for the second light-shielding member 222 and the third light-shielding member 223 makes it easier to ensure the flatness of the color filter layer. As a result, misalignment of liquid crystal molecules is less likely to occur, and in particular, in liquid crystal display devices with horizontal alignment mode, the brightness during black display is reduced and high contrast can be obtained. This is especially effective in transmissive or semi-transmissive liquid crystal display devices in transmissive mode, where light emitted from the backlight is transmitted to the observation surface. Furthermore, since metal light-shielding members can be processed with higher precision than resin light-shielding members, the aperture ratio of the pixels can be increased.

[0068] The second light-shielding member 222 and the third light-shielding member 223 can be made of the same materials as the first light-shielding member 221M, such as metals such as molybdenum, tungsten, titanium, and tantalum, or nitrides of the above metals, and alloys containing the above or nitride metals. The second light-shielding member 222 and the third light-shielding member 223 can be made of single-layer or multi-layer metal films as exemplified in the first light-shielding member 221M; laminates of the above single-layer or multi-layer metal films and the above nitride films, etc.; or the above silver oxide films, etc.

[0069] Below is an example of a method for manufacturing the second substrate 200 when the first light-shielding member 221M, the second light-shielding member 222M, and the third light-shielding member 223M are made of metal. The first light-shielding member 221M, the second light-shielding member 222, and the third light-shielding member 223 may be formed in the same layer, or for example, they may all be formed on the second support substrate 210.

[0070] First, a metal film is formed on the second support substrate 210 using the material for the metal light-shielding member by sputtering or the like. When a nitride film is to be laminated on the metal film, the nitride film is formed on the metal film by sputtering or the like. Then, a resist mask is formed in the area where the light-shielding member is to be placed by photolithography or the like. Specifically, the resist mask is formed in the area between the first light-shielding member 221M and the second light-shielding member 222M, excluding the area where the light-shielding member is not formed, and the optical apertures of each pixel. Then, the metal film and the nitride film are patterned by etching or the like. The etching may be dry etching or wet etching. After that, the resist mask is peeled off to form the first light-shielding member 221M, the second light-shielding member 222M, and the third light-shielding member 223M.

[0071] The color filter layer 230 can be fabricated by known methods. For example, one method involves sequentially forming resist materials of each color in the region (optical aperture) surrounded by the third light-shielding member 223 by spin coating, slit coating, etc., and then patterning it by photolithography, etc. Examples of the resist material include photosensitive resins containing colorants.

[0072] Here, it is preferable that the first substrate 100 further has a fourth light-shielding member that is positioned to overlap with the region between the first light-shielding member 221M and the second light-shielding member 222, which are positioned at the above-mentioned interval, in a plan view (region where no light-shielding member is formed). By positioning the fourth light-shielding member, it is possible to prevent light incident from the back side of the second substrate 200 from passing through the gap between the first light-shielding member 221M and the second light-shielding member 222 to the observation surface side. The material of the fourth light-shielding member can be the same as that of the gate wiring 120G and source wiring 120S. The fourth light-shielding member does not need to be electrically connected to the driver, signal line, ground, etc., and may be in a floating state with an independent potential. The fourth light-shielding member may be positioned on the gate metal layer or on the source metal layer. For example, the fourth light-shielding member may be a light-shielding member 125 positioned on the gate metal layer as shown in Figure 4, or a light-shielding member 128 positioned on the source metal layer as shown in Figure 5.

[0073] The second substrate 200 may have a conductive member 500 electrically connected to the first light-shielding member 221M. The conductive member 500 may be arranged on the side of the second substrate 200, for example, and preferably, in a plan view, it is arranged along the outer edge of the frame region NA where the driver circuit is arranged. When the driver circuit is arranged in the left and right frame regions of the first substrate 100 (see Figure 2), the conductive member 500 only needs to be formed along the outer edges of the left and right frame regions of the second substrate 200, but as shown in Figure 1, it may also be formed along the outer edge of the upper frame region. The outer edge of the frame region NA refers to the edge on the side furthest from the display region AA in a plan view. Also, as shown in Figures 4 and 5, the first light-shielding member 221M may be formed up to the outer edge of the second substrate, and it is preferable that the first light-shielding member 221M and the conductive member 500 are electrically connected at the outer edge.

[0074] The conductive member 500 can be formed, for example, by a conductive paste, solder, etc. Examples of conductive pastes include those containing metal fine particles such as silver. The conductive paste may also contain a binder resin, a dispersion medium such as an organic solvent, etc.

[0075] The second substrate may have a transparent conductive layer 600 on the side opposite to the liquid crystal layer 300 that is electrically connected to the conductive member 500. The transparent conductive layer 600 may be formed on a portion of the side of the second substrate opposite to the liquid crystal layer 300, but it is preferable that it be formed on the entire surface of the side of the second substrate opposite to the liquid crystal layer 300. Examples of materials for the transparent conductive layer 600 include transparent conductive materials such as ITO and IZO. It is preferable that the first light-shielding member 221M and the transparent conductive layer 600 are electrically connected via the conductive member 500. As shown in Figures 4 and 5, the conductive member 500 may also be formed on a portion of the surface on the observation side of the transparent conductive layer 600 so as to overlap with the outer edge of the transparent conductive layer 600 in a plan view.

[0076] The first light-shielding member 221M may be grounded itself, or it may be grounded via the conductive member 500, or it may be grounded via the conductive member 500 and the transparent conductive layer 600. Methods for grounding the first light-shielding member 221M include, for example, frame grounding by electrically connecting it to a metal frame, earthing, or a common potential, but earthing is preferred. The second light-shielding member 222M may be in a floating state.

[0077] The second substrate 200 may further include an overcoat layer 240 on the liquid crystal layer 300 side that covers the first light-shielding member 221M, the second light-shielding member 222M, and the color filter layer 230. By arranging the overcoat layer 240, the surface of the second substrate 200 on the liquid crystal layer 300 side can be made flat, and impurities in the color filter layer 230 can be prevented from leaching to the liquid crystal layer 300 side. The overcoat layer 240 also functions as a base for the second alignment film 420. Furthermore, the thickness of the insulating layer between the first light-shielding member 221M and the multiple bus lines, GDM, etc. can be increased, thereby reducing gate voltage leakage.

[0078] Examples of materials for the overcoat layer 240 include photocurable or thermosetting transparent resins. The photocurable transparent resin is preferably used together with, for example, a photopolymerization initiator, additives, a solvent, etc.

[0079] The liquid crystal layer 300 contains liquid crystal molecules. The amount of light transmitted through the liquid crystal layer 300 can be controlled by changing the orientation of the liquid crystal molecules in response to the electric field generated within the liquid crystal layer 300 by the voltage applied between the counter electrode 140 and the pixel electrode 160.

[0080] The above liquid crystal molecules may have a positive or negative dielectric anisotropy (Δε) defined by the following formula (L). Liquid crystal molecules with positive dielectric anisotropy are also called positive-type liquid crystals, and liquid crystal molecules with negative dielectric anisotropy are also called negative-type liquid crystals. The liquid crystal layer 300 of this embodiment preferably contains liquid crystal molecules with a positive Δε. Δε = (dielectric constant in the major axis direction) - (dielectric constant in the minor axis direction) (Equation L)

[0081] In a liquid crystal display device in horizontal alignment mode, when no voltage is applied between the counter electrode 140 and the pixel electrode 160 (no voltage applied), the liquid crystal molecules are preferably horizontally aligned by the restricting force of the first alignment film 410 and the second alignment film 420, which will be described later. When a voltage is applied between the counter electrode 140 and the pixel electrode 160 (no voltage applied), the liquid crystal molecules are preferably rotated in the in-plane direction in response to the transverse electric field generated within the liquid crystal layer 300. Note that "no voltage applied" also includes the case where a voltage below the threshold for liquid crystal molecules is applied to the liquid crystal layer 300.

[0082] The above liquid crystal display device may have a first alignment film 410 between a first substrate 100 and a liquid crystal layer 300, and a second alignment film 420 between a second substrate 200 and a liquid crystal layer 300. The first alignment film 410 and the second alignment film 420 are layers that have undergone alignment treatment to control the orientation of liquid crystal molecules, and alignment films common in the field of liquid crystal display devices can be used. Examples of materials for the first alignment film 410 and the second alignment film 420 include polymers having a main chain such as polyimide, polyamic acid, and polysiloxane. Photo-alignment film materials having photoreactive sites (functional groups) in the main chain or side chains are also preferably used. Examples of the above photoreactive sites include cinnamate groups, azobenzene groups, chalcone groups, stilbene groups, and coumarin groups.

[0083] The first alignment film 410 and the second alignment film 420 are preferably horizontal alignment films that can be controlled so that the long axes of the liquid crystal molecules are aligned horizontally with respect to the first alignment film 410 and the second alignment film 420 when no voltage is applied. Here, horizontal alignment of liquid crystal molecules means that the tilt angle of the liquid crystal molecules is preferably 0° or more and 5° or less, more preferably 0° or more and 3° or less, and even more preferably 0° or more and 1° or less. The tilt angle of the liquid crystal molecules means the angle at which the long axis (optical axis) of the liquid crystal molecules is inclined with respect to the surfaces of the first alignment film 410 and the second alignment film 420.

[0084] Although not shown in the figures, the liquid crystal display device may further include polarizers. If the liquid crystal display device is transmissive or semi-transmissive, it may include a first linear polarizer on the side of the first substrate 100 opposite to the liquid crystal layer 300, and a second linear polarizer on the side of the second substrate 200 opposite to the liquid crystal layer 300. It is preferable that the absorption axis of the first linear polarizer and the absorption axis of the second linear polarizer are arranged orthogonally. Absorbing linear polarizers commonly used in the field of liquid crystal displays can be used as the first and second linear polarizers. When no voltage is applied to the liquid crystal layer 300, it is preferable that the long axis of the liquid crystal molecules is arranged orthogonally or parallel to the absorption axis of the first linear polarizer. This state is called black display and is the state with the lowest brightness (0 gradation).

[0085] If the liquid crystal display device is of the reflective type, it is preferable to have a circular polarizer on the side of the first substrate 100 opposite to the liquid crystal layer 300. The circular polarizer may be, for example, a laminate of the first linear polarizer and a λ / 4 plate. If the liquid crystal display device is of the semi-transparent type, the first linear polarizer and the λ / 4 plate may be laminated. If the liquid crystal display device has a transparent conductive layer 600, the first polarizer or the circular polarizer may be positioned further towards the observation surface than the transparent conductive layer 600.

[0086] The λ / 4 plate described above may be, for example, a phase difference layer that imparts an in-plane phase difference of 107.5 nm to 167.5 nm to light with a wavelength of 550 nm. Here, the phase difference layer is a layer that has the function of changing the state of incident polarization by applying a phase difference to two orthogonal polarization components using a birefringent material or the like. As the λ / 4 plate described above, one that is commonly used in the field of liquid crystal display devices can be used, and may be made of a photopolymerizable liquid crystal material having photopolymerizable groups such as acrylate groups and methacrylate groups, or it may be a stretched polymer film.

[0087] If the liquid crystal display device 1-1 is transmissive or semi-transmissive, the liquid crystal display device 1-1 may also be provided with a backlight (not shown) on the back side of the first substrate 100 (opposite side from the liquid crystal layer 300). The backlight is not particularly limited as long as it emits light toward the first substrate 100, and may be direct-lit, edge-lit, or any other type.

[0088] The liquid crystal display device of this embodiment is composed of a backlight, optical films such as a viewing angle widening film and a brightness enhancing film, and multiple other components such as a bezel (frame). Some components may be incorporated into other components. Components other than those already described are not particularly limited, and those commonly used in the field of liquid crystal displays can be used, so their description is omitted.

[0089] <Modified form of Embodiment 1> Figure 6 is a schematic plan view showing a modified liquid crystal display device 1-2 according to Embodiment 1. Figure 7 is a schematic plan view showing an enlarged view of the corner of the liquid crystal display device enclosed by a dotted line in Figure 6. Figure 8 is a schematic cross-sectional view along the line X5-X6 in Figure 7. The schematic cross-sectional view along the first direction D1, including the left frame region of the liquid crystal display device 1-2, is the same as in Figure 4 and is therefore omitted. Furthermore, since it is the same as Embodiment 1 except for the difference in the arrangement of the first light-shielding member 221M and the second light-shielding member 222M, redundant explanations are omitted.

[0090] In Embodiment 1, when driver circuits such as GDM are arranged in the left and right frame regions, the conductive member 500 is shown as being arranged along the outer edges of the left frame region, the right frame region, and the upper frame region in a plan view. However, as shown in Figure 6, the conductive member 500 only needs to be arranged along the outer edges of the left and right frame regions, and does not need to be arranged along the outer edge of the upper frame region.

[0091] Furthermore, in Embodiment 1, the first light-shielding member 221M was arranged to surround the second light-shielding member 222M. However, the first light-shielding member 221M does not have to be arranged to overlap with the upper frame region and / or the lower frame region. As shown in Figure 7, the first light-shielding member 221M may be arranged along the vertical direction of the liquid crystal display device 1-2 up to the upper end of the frame region.

[0092] The second light-shielding member 222M only needs to be positioned at a distance from the first light-shielding member 221M which overlaps with the frame area on which the GDM is placed. As shown in Figure 7, the second light-shielding member 222M may be positioned continuously from the display area AA to the upper frame area. Although not shown, the second light-shielding member 222M may be positioned continuously from the display area AA to the lower frame area. In other words, in a modified embodiment of Embodiment 1, a region without a light-shielding member may be provided between the second light-shielding member 222M and the first light-shielding member 1-2, extending to the upper and lower ends.

[0093] In the modified embodiment of Embodiment 1, the first light-shielding member 221M and the second light-shielding member 222M, both made of metal and positioned to overlap the frame area on which the GDM is placed and connected to ground, are electrically independent. In the modified embodiment of Embodiment 1, the first light-shielding member 221M and the second light-shielding member 222M can be positioned with a gap between them and be electrically independent; the configuration is not limited to that shown in Figure 7.

[0094] <Embodiment 2> Figure 9 is a schematic plan view showing an enlarged corner of the liquid crystal display device 2-1 according to Embodiment 2. Figure 10 is a schematic cross-sectional view along the line X7-X8 in Figure 9. Figure 11 is a schematic cross-sectional view along the line X9-X10 in Figure 9. Descriptions of configurations that overlap with Embodiment 1 are omitted.

[0095] The liquid crystal display device 2-1 according to Embodiment 2 has a first light-shielding member 221M made of metal and a second light-shielding member 222R made of resin. By making the first light-shielding member 221M out of metal and the second light-shielding member 222R out of resin, the first light-shielding member 221M and the second light-shielding member 222R can be insulated and electrically independent. In Embodiment 2 as well, display unevenness in the area adjacent to the frame area NA of the display area AA can be suppressed. The first light-shielding member 221M and the second light-shielding member 222R may be in contact with each other.

[0096] As the material for the above-mentioned resin light-shielding member, a resin composition used as a black matrix material in the field of liquid crystal display devices can be used. The second light-shielding member 222R can be formed, for example, by a known method such as photolithography, which involves coating a photosensitive resin composition containing a black colorant and a resin component, forming a film, and then performing exposure and development.

[0097] Examples of the resin components mentioned above include acrylic resin, epoxy resin, and epoxy acrylate resin. Examples of the black coloring agents mentioned above include carbon black, titanium black such as titanium oxynitride and titanium nitride, and metal oxides such as iron oxide.

[0098] If the second light-shielding member 222R is a resin light-shielding member, the resistance of the second light-shielding member 222R is 10 14 It is preferable that the resistance be Ω / cm or higher. With this configuration, sufficient insulation can be achieved even when the first light-shielding member 221M and the second light-shielding member 222R are in contact. The upper limit of the resistance of the second light-shielding member 222R is, for example, 10 16 The resistance may be expressed in Ω / cm. The above resistance can be measured by a method compliant with JIS K 6911:2006.

[0099] From the viewpoint of simplifying the manufacturing process, it is preferable that the third light-shielding member 223 is a resin light-shielding member 223R. Figure 9 illustrates the case where the second light-shielding member 222 and the third light-shielding member 223 are resin light-shielding members 222R and 223R. The material of the third light-shielding member 223R can be the same as that of the second light-shielding member 222R, and it is formed, for example, in a grid pattern by a known method such as photolithography. The formation order of the first light-shielding member 221M, the second light-shielding member 222R, and the third light-shielding member 223R is not particularly limited, and any order may be formed first.

[0100] On the other hand, as mentioned above, from the viewpoint of increasing the transmittance of the image and increasing the contrast, the third light-shielding member 223 may be a metal light-shielding member 223M. The third light-shielding member 223M may be made of the same material as the first light-shielding member 221M, or a different material, but it is preferable to use the same material. For example, the first light-shielding member 221M and the third light-shielding member 223M may be patterned by the method described above, and then the second light-shielding member 222R may be formed using the resin material.

[0101] <Modified form of Embodiment 2> Figure 12 is a schematic plan view showing an enlarged view of the corner of the liquid crystal display device 2-2 according to a modified example of Embodiment 2. Figure 13 is a schematic cross-sectional view along the line X11-X12 in Figure 12. A schematic cross-sectional view along the first direction D1, including the left frame region of the liquid crystal display device 2-2, is the same as in Figure 10 and is therefore omitted. In the modified example of Embodiment 2, the case in which the second light-shielding member 222 is a resin light-shielding member 222M and the third light-shielding member 223 is a resin light-shielding member 223R will be described.

[0102] In Embodiment 2, the first light-shielding member 221M was arranged to surround the second light-shielding member 222R. However, in a modified version of Embodiment 2, as shown in Figure 12, the first light-shielding member 221M may be arranged along the vertical direction of the liquid crystal display device 1-2 up to the upper edge of the frame area. The second light-shielding member 222R may also be arranged adjacent to the first light-shielding member 221M up to the upper edge of the frame area.

[0103] In the modified embodiment of Embodiment 2, the first light-shielding member 221M, made of metal and connected to ground, is positioned to overlap with the frame area where the GDM is located, and the second light-shielding member 222R, made of resin, is electrically independent. In the modified embodiment of Embodiment 2, the first light-shielding member 221M is a metal light-shielding member and the second light-shielding member 222R is a resin light-shielding member, and they are electrically independent; the configuration is not limited to that shown in Figure 12. [Examples]

[0104] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0105] (Example 1) As a specific example of Embodiment 1, a liquid crystal display device 1-1 according to Embodiment 1 was fabricated. Figures 1 to 5 are also drawings of the liquid crystal display device of Embodiment 1.

[0106] The TFT substrate was fabricated using a method consistent with the general method for fabricating gate driver monolithic FFS mode TFT substrates. A gate metal layer was formed on the first support substrate 110. The gate metal layer includes gate wiring 120G and gate electrodes formed in the display area AA, gate electrodes 124 included in TFTs 2 and 3 formed in the GDM-TFT region of the GDM, a plurality of bus lines 123 formed in the wiring area GDM-BL, and a fourth light-shielding member 125 that superimposes on the area where the light-shielding member is not formed in a plan view. Subsequently, a first insulating layer (gate insulating layer) 130 was formed using silicon nitride to cover the gate metal layer. The plurality of bus lines 123 may include gate lead wiring. The plurality of bus lines 123 and the plurality of bus lines 127 described later were formed from a laminated film of copper and titanium.

[0107] After forming semiconductor layers 121 for TFTs 1-3 on the first insulating layer 130, a source metal layer was formed. The source metal layer includes source wiring 120S formed in the display area AA, source electrodes and drain electrodes 120D, source electrodes 126 included in TFTs 2 and 3 formed in the GDM-TFT region of the GDM, a plurality of bus lines 127 formed in the wiring area GDM-BL, and a fourth light-shielding member 128 that superimposes on the area where the light-shielding member is not formed in a plan view. The plurality of bus lines 127 may include source lead wiring. Subsequently, a second insulating layer 131 was formed using silicon nitride so as to cover the source metal layer.

[0108] Subsequently, a third insulating layer 132 was formed using acrylic resin, and in the display area AA, a counter electrode 140 was formed on the third insulating layer 132 using a transparent conductive material, and a fourth insulating layer 150 was formed using silicon nitride. Then, a contact hole CH1 was formed that penetrates the second insulating layer 131, the third insulating layer 132, and the fourth insulating layer 150. A pixel electrode 160 was formed for each pixel, and the pixel electrode 160 was electrically connected to the drain electrode 120D through the contact hole CH1. With the above steps, the gate driver monolithic TFT substrate was completed.

[0109] The CF substrate was fabricated using the following method. Below is an example of the manufacturing method for the first to third light-shielding members 221M, 222M, and 223M. In the following, the first light-shielding member 221M, the second light-shielding member 222M, and the third light-shielding member 223M are illustrated by using a laminate of tungsten and nitride film as the material. Specifically, the case in which a four-layer laminate is formed in which SiNx, W (tungsten), SiNx, and W are laminated in this order is described. First, silicon nitride (SiNx) was laminated onto a glass substrate (second support substrate 210) to a thickness of 50-60 nm by chemical vapor deposition (CVD). Next, W was laminated to a thickness of 10 nm or less by PVD. After that, SiNx was laminated to a thickness of 40-50 nm by CVD. Finally, W was laminated to a thickness of 100 nm or more by PVD to form a four-layer laminate.

[0110] After applying a resist to the above four-layer stack, the first to third light-shielding members 221M, 222M, and 223M were formed by exposure and development using a photomask designed to form them, followed by dry etching of all four layers at once.

[0111] The above method is just one example; the insulating film used in the multilayer film can be adjusted as needed, and for example, SiOx can be used instead of SiNx. Also, instead of W, Ti (titanium), Mo (molybdenum), etc., can be used as the conductive film. Furthermore, although this disclosure exemplifies a multilayer film of a transparent film and a metal, other conductive black inorganic materials such as tantalum can also be used, or a combination of conductive films can be used in which the surface is a black material and the conductive material is placed in the middle, such as a laminate in which silver oxide, silver, and silver oxide are stacked in that order.

[0112] Subsequently, a color filter layer 230 was formed in the optical opening surrounded by the third light-shielding member 223M, in the same manner as the general method for manufacturing color filters. Then, an overcoat layer 240 was formed using acrylic resin to cover the first to third light-shielding members and the color filter layer. With these steps completed, the CF substrate was finished.

[0113] A horizontal alignment film was formed on the surfaces of the TFT substrate and the CF substrate, and then a liquid crystal material was sealed between the TFT substrate and the CF substrate to complete the liquid crystal panel. The liquid crystal material used was one with positive dielectric anisotropy (Δε=4.9).

[0114] Thereafter, a transparent conductive layer 600 was formed on the entire surface of the CF substrate on the side opposite to the liquid crystal layer (the surface on the observation surface side) using ITO. Further, a conductive paste (silver paste) was applied to the sides other than the terminal region B, and the first light-shielding member 221M, the conductive paste 500, and the transparent conductive layer 600 were electrically connected. As a method for grounding the first light-shielding member 221M, for example, (i) a method of connecting the transparent conductive layer 600 to the ground existing in a drive circuit such as a PCBA (Printed Circuit Board Assembly) with a conductive tape as the conductive member 500, (ii) a method of connecting the ground existing in a drive circuit such as a PCBA to a backlight bezel made of metal and connecting the backlight bezel and the transparent conductive layer 600, or (iii) a method of connecting the ground existing in the terminal region B and the transparent conductive layer 600 with the conductive paste 500, etc. can be mentioned. By electrically connecting the ground existing in the drive circuit, the backlight bezel or the terminal region B, etc. to the transparent conductive layer 600 by the methods such as (i) to (iii) above, the first light-shielding member 221M can be grounded.

[0115] The surface resistivity and line width per wiring of the plurality of bus lines 123 and 127, and the dielectric constant and thickness of each insulating layer are summarized in Table 1 below. In the figure, the thickness of the first insulating layer 130 is T 130 and the thickness of the second insulating layer 131 is T 131 and the thickness of the third insulating layer 132 is T 132 and the thickness of the fourth insulating layer 150 is T 150 and the thickness of the liquid crystal layer 300 is T 300 and the thickness of the overcoat layer 240 is T 240 and the thickness of the color filter layer 230 is T 230 as shown.

[0116]

Table 1

[0117] (Comparative Example 1) Figure 14 is a schematic cross-sectional view of the liquid crystal display device R1 according to Comparative Example 1. Figure 14 corresponds to the schematic cross-sectional view along the line X1-X2 at the corner of the liquid crystal display device shown in Figure 4. As shown in Figure 14, in the liquid crystal display device R1 according to Comparative Example 1, a resin light-shielding member 221R is arranged connecting the frame area NA and the display area AA, and the light-shielding member 221R and the red color filter 230R are in contact.

[0118] In Comparative Example 1, a shield electrode 140a was formed on the TFT substrate 100 using ITO so as to overlap with the TFT region GDM-TFT and the wiring region GDM-BL of the GDM. The shield electrode 140a may be formed simultaneously when the counter electrode 140 is formed on the third insulating layer 132. After forming the fourth insulating layer 150 on the counter electrode 140 and the shield electrode 140a, a contact hole CH4 penetrating the fourth insulating layer 150 and a contact hole CH5 penetrating the second insulating layer 131, the third insulating layer 132, and the fourth insulating layer 150 were formed. In Comparative Example 1, a dummy image without an image electrode 160 was placed near the boundary between the display region AA and the frame region NA. The shield electrode 140a is electrically connected to the source wiring 129 via the contact electrodes 161a through the contact holes CH4 and CH5. With this configuration, in Comparative Example 1, the same common potential as the counter electrode 140 is applied to the shield electrode 140a, preventing gate voltage leakage to the second substrate 200. In Comparative Example 1, the second substrate 200 has a transparent conductive layer 600 on the surface opposite to the liquid crystal layer 300, but the transparent conductive layer 600 and the shield electrode 140a are not electrically connected, and the transparent conductive layer 600 is connected to the frame ground or earth.

[0119] (Comparative Example 2) Figure 15 is a schematic cross-sectional view of the liquid crystal display device R2 according to Comparative Example 2. Figure 15 corresponds to the schematic cross-sectional view along the line X1-X2 at the corner of the liquid crystal display device shown in Figure 4. As shown in Figure 15, in Comparative Example 2, similar to Comparative Example 1, a resin light-shielding member 221R is arranged connecting the frame area NA and the display area AA, and the light-shielding member 221R and the red color filter 230R are in contact.

[0120] In Comparative Example 2, the liquid crystal display device R2 had a shield electrode 601 formed using ITO on the liquid crystal layer 300 side of the second substrate 200 (on the overcoat layer 240 in Figure 15) so as to overlap with the area where the GDM was formed in a plan view. Also, similar to Example 1, a transparent conductive layer 600 was formed using ITO on the side of the second substrate 200 opposite to the liquid crystal layer 300. Furthermore, a conductive paste 500 was applied to the side surface of the second substrate 200, and the transparent conductive layer 600 and the shield electrode 601 were electrically connected via the conductive paste 500.

[0121] (Comparative Example 3) Figure 16 is a schematic cross-sectional view of the liquid crystal display device R3 according to Comparative Example 3. Figure 16 corresponds to the schematic cross-sectional view along the line X1-X2 at the corner of the liquid crystal display device shown in Figure 4. In Comparative Example 3, a metal light-shielding member 221M is arranged connecting the frame region NA and the display region AA, and the light-shielding member 221M and the red color filter 230R are in contact. Comparative Example 3 has the same configuration as Example 1, except that there is no gap between the light-shielding member overlapping the frame region NA and the light-shielding member overlapping the display region AA, and a fourth light-shielding member 125 (see Figure 4) is not provided on the TFT substrate side.

[0122] (Time constant) Table 2 below shows the capacitance and resistance per wire for the multiple bus lines arranged in the frame area of ​​Examples 1 and 2 and Comparative Examples 1 and 2. The time constant, expressed as the product of the resistance per wire and the capacitance per wire, is also listed. Capacitance and resistance can be calculated from the surface resistivity, relative permittivity, and design data mentioned above.

[0123] [Table 2]

[0124] As shown in Table 2, Comparative Example 1 has a larger capacitance per bus line, resulting in a larger time constant than Examples 1 and 2. Comparing the configurations of Comparative Example 1 with Examples 1 and 2, Comparative Example 1 has a shield electrode 140a formed on the TFT substrate 100 side. The distance between the shield electrode 140a and the multiple bus lines 123 and 127 in Comparative Example 1, indicated by the dotted double arrow in Figure 14, is shorter than the distance between the first light-shielding member 221M and the multiple bus lines 123 and 127 in Example 1, indicated by the dotted double arrow in Figure 4. Therefore, in Comparative Example 1, a larger capacitance is formed between the shield electrode 140a and the multiple bus lines 123 and 127 than in Examples 1 and 2, resulting in a tendency for the waveform of the scanned signal to be distorted. The waveform distortion can be confirmed using an oscilloscope or the like.

[0125] The following describes the case of displaying in 4K Full High Definition (QFHD: Quad Full High Definition) with a resolution of 3840 x 2160 pixels. When using conventional 60Hz drive, even in Comparative Example 1, a gate-on time of about 7 μsec can be secured, so the impact of a large time constant is small. However, when using a high-frequency drive of 600 Hz in QFHD, Comparative Example 1 can only secure a gate-on time of about 1 μsec, which distorts the waveform of the scanning signal of TFT1, which is placed for each pixel, resulting in insufficient charging of TFT1 and preventing the application of the desired voltage to the corresponding pixel.

[0126] On the other hand, in Examples 1 and 2, a first light-shielding member 221M, which is a metal light-shielding member, is placed on the second substrate 200 side. In Examples 1 and 2, the distance between the first light-shielding member 221M and the multiple bus lines 123 and 127 is longer than in Comparative Example 1, so in Examples 1 and 2, the time constant per bus line was reduced to about 1 / 6 of that in Comparative Example 1. Even when driven at 600 Hz, Examples 1 and 2 were able to sufficiently charge the TFT1 placed in the display area without distortion of the waveform of the scanning signal. In Comparative Example 2, although the time constant was reduced more than in Comparative Example 1, the time constant was larger than that of Examples 1 and 2.

[0127] (Consideration of display inconsistencies) In Examples 1 and 2, and Comparative Examples 1 and 2, when black was set to 0 gradations and white brightness (the highest brightness state) to 256 gradations, all color pixels were lit at the same brightness to display gray midtones in 64 gradations. In addition, a single-color highlighting display was performed by lit only the blue pixels overlapping with the blue color filter at maximum brightness, while the red pixels overlapping with the red color filter and the green pixels overlapping with the green color filter were set to 0 gradations. Specifically, AC voltages of +16V and -12V at 600Hz were applied as gate voltages to the gate lead wiring from the gate driver. That is, the voltage difference ΔVg applied to the gate wiring was 28V. For the above midtone display, AC voltages of +2V and -2V at 600Hz were applied as source voltages to the source lead wiring from the source driver, and for the above highlighting display, AC voltages of +5.7V and -5.7V were applied.

[0128] Figure 17 is a schematic plan view illustrating the display unevenness occurring in the liquid crystal display device according to Comparative Example 2. As shown in Figure 17, when halftone display was performed in Comparative Example 2, display unevenness was observed where the outer edge of the display area along the vertical direction of the liquid crystal display device became whitish. When highlighting was performed in Comparative Example 2, the whiteness of the area adjacent to the frame area NA where the GDM of display area AA is located became even more noticeable, and the display unevenness was clearly observed.

[0129] Upon examining the display unevenness described above, it is thought that the resin light-shielding member 221R of Comparative Example 2 became charged when a high voltage of ΔVg = 28V was repeatedly applied to the gate driver monolithic (GDM). Since the resin light-shielding member 221R is connected to the frame region NA and the display region AA, it is thought that an unintended vertical electric field is generated between the charged resin light-shielding member 221R and the pixels placed in the display region AA in the region adjacent to the frame region NA where the GDM of the display region AA is located. It is thought that this vertical electric field disrupts the orientation of the liquid crystal molecules in the liquid crystal layer 300, causing the region adjacent to the frame region NA of the display region AA to appear whiter than the central part of the display region AA when halftone display and highlighting are performed.

[0130] On the other hand, in Examples 1 and 2 and Comparative Example 1, no display unevenness was observed in either the halftone display or the highlight display. In Examples 1 and 2, as with Comparative Example 2, the first light-shielding member 221M became charged, but since it was grounded via the conductive paste 500 and the transparent conductive layer 600, it was possible to discharge the static electricity, which is thought to have suppressed display unevenness. The shield electrode 601 of Comparative Example 2, which is made of ITO, has a surface resistance of several kΩ□, whereas the metal first light-shielding member 221M of Examples 1 and 2 has a surface resistance of about several Ω□, making it easier for electricity to flow from the surface. Therefore, it is thought that Examples 1 and 2 were able to prevent charging of the color filter more effectively than Comparative Example 2. In Comparative Example 1, it is thought that the charging of the color filter was suppressed by the shield electrode placed on the TFT substrate side.

[0131] (transmittance) The transmittance was measured for Examples 1 and 2 and Comparative Examples 1 to 3. The transmittances of Examples 1 and 2 and Comparative Examples 2 and 3, with the transmittance of Comparative Example 1 set to 100%, are summarized in Table 3 below. A 14-inch module (liquid crystal panel) was created, and ±5.7V was applied to the module as the gate voltage and source voltage described above. The white brightness of the liquid crystal panel was measured at the center of the liquid crystal panel using a spectroradiometer. Subsequently, the brightness of the backlight at the same location was measured, and the transmittance was calculated using the formula: transmittance = white brightness of the liquid crystal panel / brightness of the backlight.

[0132] [Table 3]

[0133] As shown in Table 3, Examples 1 and 2 and Comparative Example 2 had the same transmittance as Comparative Example 1, while Comparative Example 3 had a lower transmittance. In Comparative Example 3, the metal light-shielding member 221M, which is positioned connected to the frame area NA and the display area AA, is connected to ground. This is thought to have generated a vertical electric field between the light-shielding member 221M and the pixel electrode 160, resulting in a decrease in transmittance.

[0134] In contrast, in Example 1, the first light-shielding member 221M, which overlaps with the GDM, is connected to ground, and the second light-shielding member 222M is positioned at a distance from the first light-shielding member 221M. In Example 2, since the second light-shielding member 222R is made of resin, it is electrically independent even when in contact with the ground-connected first light-shielding member. Therefore, in Examples 1 and 2, it is believed that no longitudinal electric field is generated between the second light-shielding members 222M and 222R and the pixel electrodes 160 of the TFT substrate 100, resulting in high transmittance.

[0135] From the above considerations, in Comparative Example 1, although the charging of the color filter layer 230 can be prevented by placing a shield electrode 140a made of ITO and to which a common potential is applied on the TFT substrate 100, the time constant becomes large, causing waveform distortion and insufficient charging of the TFT 1 when driven at high frequency. In Comparative Example 2, although the time constant can be reduced, the high resistance of the ITO shield electrode 601 placed on the second substrate 200 prevented sufficient suppression of the charging of the color filter layer 230. In Comparative Example 3, an unwanted vertical electric field was generated between the metal light-shielding member 221M, which is placed connected to the frame region NA and the display region AA, and the pixel electrode 160, resulting in low transmittance.

[0136] In contrast, in Examples 1 and 2, the first light-shielding member 221M and the second light-shielding member, which are connected to ground, are electrically independent of each other. This suppresses the occurrence of display unevenness in the area adjacent to the frame area NA of the display area AA, and results in a liquid crystal display device that can be sufficiently charged even with high-frequency drive and has high transmittance. [Explanation of Symbols]

[0137] 1-1, 1-2, 2-1, 2-2, R1, R2, R3: Liquid crystal display device 100: First substrate (TFT substrate) 110: First support substrate 120D: Drain electrode 120G: First wiring (gate wiring) 120S: Second wiring (source wiring) 121: Semiconductor layer 123, 127: Multiple bus lines 124: Gate Tube 125, 128: Fourth light-shielding member 126: Source electrode 129: Source Wiring 130: First insulating layer 131: Second insulating layer 132: The third insulating layer 140: Counter electrode 140a: Shielding electrode 150: The fourth insulating layer 160: Particle Electrode 161a: Contact electrode 200: Second board (CF board) 210: Second support substrate 221M: First light-shielding member 221M, 221R: First light-shielding member 222, 222M, 222R: Second light-shielding member 223, 223M, 223R: Third light-shielding component 230: Color filter layer 230B: Blue color filter 230G: Green color filter 230R: Red color filter 240: Overcoat layer 300: Liquid crystal layer 410: First alignment layer 420: Second alignment layer 500: Conductive material (conductive paste) 600: Transparent conductive layer 601: Shielding electrode

Claims

1. The device comprises a first substrate, a second substrate, and a liquid crystal layer sandwiched between the first substrate and the second substrate. The first substrate has a display area and a frame area arranged around the display area. The display area is provided with a first wiring extending in a first direction, a second wiring extending in a second direction intersecting the first direction, a pixel electrode electrically connected to the second wiring via a switching element, and a counter electrode facing the pixel electrode. A driver circuit connected to the first wiring is arranged in the frame area. The second substrate includes, in a plan view, a first light-shielding member arranged to overlap with the frame region and at least overlap with the driver circuit, a color filter layer including a plurality of color filters arranged to overlap with the display region, and a second light-shielding member arranged between the first light-shielding member and the color filter layer. The first light-shielding member is a metal light-shielding member and is connected to ground. A liquid crystal display device in which the first light-shielding member and the second light-shielding member are electrically independent.

2. The liquid crystal display device according to claim 1, wherein the first light-shielding member and the second light-shielding member are arranged with a gap between them.

3. The liquid crystal display device according to claim 2, wherein the second light-shielding member is a metal light-shielding member.

4. The second substrate further includes a third light-shielding member positioned between the plurality of color filters in a plan view, The liquid crystal display device according to claim 1 or 2, wherein the third light-shielding member is a metal light-shielding member.

5. The second substrate further includes a third light-shielding member positioned between the plurality of color filters in a plan view, The liquid crystal display device according to claim 1 or 2, wherein the third light-shielding member is a resin light-shielding member.

6. The liquid crystal display device according to claim 2, wherein the first substrate further comprises a fourth light-shielding member arranged in a plan view to overlap with the region between the first light-shielding member and the second light-shielding member, which are spaced apart.

7. The liquid crystal display device according to claim 1, wherein the second light-shielding member is a resin light-shielding member.

8. The first light-shielding member and the second light-shielding member are in contact with each other. The resistance of the second light-shielding member is 10 １４ The liquid crystal display device according to claim 7, wherein the density is Ω / cm or greater.

9. The liquid crystal display device according to claim 1, wherein the second substrate has a conductive member electrically connected to the first light-shielding member.

10. The liquid crystal display device according to claim 9, wherein the second substrate has a transparent conductive layer on the side opposite to the liquid crystal layer that is electrically connected to the conductive member.

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