Liquid crystal display device

Abstract

To realize a pixel structure suitable for a liquid crystal display device capable of displaying in a reflection mode and being used as an in-cell type touch panel.SOLUTION: A liquid crystal display device comprises a first substrate, a second substrate arranged closer to a viewer side than the first substrate, and a liquid crystal layer provided between the first substrate and the second substrate, and has a plurality of pixels arrayed in a matrix. Each pixel includes a reflection region where display is performed in a reflection mode. The first substrate has thin film transistors each provided corresponding to each pixel, pixel electrodes electrically connected to the thin film transistors, and a reflective layer located opposite the liquid crystal layer with respect to the pixel electrodes. The first substrate further has a plurality of touch sensor electrodes, and a plurality of touch lines each electrically connected to a corresponding touch sensor electrode. The reflective layer is divided into a plurality of reflective segments that are electrically independent of each other, and each of the reflective segments overlaps two or more pixel electrodes in a plan view.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Liquid crystal display devices are generally broadly classified into transmissive liquid crystal display devices and reflective liquid crystal display devices. Transmissive liquid crystal display devices perform display in a transmissive mode using light emitted from a backlight. Reflective liquid crystal display devices perform display in a reflective mode using ambient light. Liquid crystal display devices have also been proposed in which each pixel includes a reflective region for displaying in a reflective mode and a transmissive region for displaying in a transmissive mode. Such liquid crystal display devices are called transflective or transflective liquid crystal display devices.

[0003] Reflective and semi-transmissive liquid crystal display devices are preferably used, for example, as small to medium-sized display devices for mobile outdoor use. A reflective liquid crystal display device is disclosed, for example, in Patent Document 1. A semi-transmissive liquid crystal display device is disclosed, for example, in Patent Document 2. Patent Document 3 proposes a liquid crystal display device that can improve the brightness of a reflective display. In the reflective or semi-transmissive liquid crystal display device disclosed in Patent Document 3, the reflectance is improved by a two-stage electrode structure in which a reflective electrode (reflective layer) and a transparent electrode (pixel electrode) are separated by an interlayer insulating layer.

[0004] Furthermore, a touch sensor function is provided to liquid crystal display devices used in smartphones, tablets, etc. There are various types of touch sensors known, such as a resistive type, a capacitive type, and an optical type.

[0005] Liquid crystal display devices equipped with touch sensors (hereafter referred to as "touch panels") are broadly divided into a type in which the touch sensor is externally attached to the liquid crystal display device ("external type") and a type in which the touch sensor is built into the liquid crystal display device ("built-in type"). Built-in touch panels are advantageous in that they can be made thinner and lighter than external touch panels, and have the advantage of being able to increase light transmittance.

[0006] There are two types of built-in touch panels: "on-cell" and "in-cell." Here, "cell" refers to the display panel. The display panel comprises an active matrix substrate (TFT substrate), a counter substrate arranged to face the TFT substrate, and a liquid crystal layer provided between the TFT substrate and the counter substrate. In the "in-cell" type, a layer that performs the touch sensor function is disposed within the display panel. In the "on-cell" type, the layer that performs the touch sensor function is disposed between the display panel and a polarizing plate provided on the viewer's side of the display panel. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2000-122094 A [Patent Document 2] JP 2003-131268 A [Patent Document 3] Patent Publication No. 2021-96461 Summary of the Invention [Problem to be solved by the invention]

[0008] In principle, the in-cell type can realize the thinnest and lightest touch panel. As already explained, liquid crystal display devices capable of displaying in reflective mode are suitable for outdoor use. Therefore, although an in-cell type touch panel capable of displaying in reflective mode is desired, it has not yet been realized.

[0009] An embodiment of the present invention has been made in consideration of the above problems, and its purpose is to realize a pixel structure suitable for a liquid crystal display device that is capable of reflective mode display and can be used as an in-cell touch panel. [Means for solving the problem]

[0010] This specification discloses liquid crystal display devices described in the following items.

[0011] [Item 1] A first substrate; A second substrate disposed closer to a viewer than the first substrate; a liquid crystal layer provided between the first substrate and the second substrate; a polarizing plate disposed on a viewer side of the liquid crystal layer; a retardation layer disposed between the polarizing plate and the liquid crystal layer; Equipped with A liquid crystal display device having a plurality of pixels arranged in a matrix including a plurality of rows and a plurality of columns, Each of the plurality of pixels includes a reflective area that performs display in a reflective mode; The first substrate is A plurality of gate wirings extending in a row direction; A plurality of source lines extending in a column direction; a plurality of thin film transistors each provided corresponding to one of the plurality of pixels; a plurality of pixel electrodes each electrically connected to a corresponding one of the plurality of thin film transistors; a reflective layer formed of a conductive material and located at least in the reflective region, the reflective layer being located on the opposite side of the pixel electrode from the liquid crystal layer; having The first substrate is A plurality of touch sensor electrodes to which different signals can be applied; a plurality of touch wirings each electrically connected to a corresponding one of the plurality of touch sensor electrodes; and the reflective layer is divided into a plurality of reflective segments that are electrically independent from one another; A liquid crystal display device, wherein each of the plurality of reflective segments overlaps, in a plan view, two or more pixel electrodes among the plurality of pixel electrodes.

[0012] [Item 2] Item 2. The liquid crystal display device according to item 1, wherein the two or more pixel electrodes overlapping each of the plurality of reflective segments are arranged in a plurality of rows and a plurality of columns.

[0013] [Item 3] 3. The liquid crystal display device according to item 1 or 2, wherein the number of the plurality of reflective segments is equal to or greater than the number of the plurality of touch sensor electrodes.

[0014] [Item 4] 4. The liquid crystal display device according to any one of items 1 to 3, wherein different voltages can be applied to the multiple reflective segments.

[0015] [Item 5] 5. The liquid crystal display device according to item 4, wherein each of the plurality of reflective segments is electrically connected to a corresponding touch sensor electrode among the plurality of touch sensor electrodes and a corresponding touch wiring among the plurality of touch wirings.

[0016] [Item 6] The liquid crystal display device described in item 5, wherein each of the multiple reflective segments is electrically connected to the corresponding touch sensor electrode via at least one first contact hole and is electrically connected to the corresponding touch wiring via at least one second contact hole.

[0017] [Item 7] 7. The liquid crystal display device according to item 6, wherein the at least one first contact hole is a plurality of first contact holes and / or the at least one second contact hole is a plurality of second contact holes.

[0018] [Item 8] Item 8. The liquid crystal display device according to item 6 or 7, wherein the at least one first contact hole is formed at a position different from that of the at least one second contact hole in a plan view.

[0019] [Item 9] Item 9. The liquid crystal display device of item 8, wherein any one of the at least one first contact hole is separated from each of the at least one second contact hole by at least one pixel in either or both of the row direction and the column direction.

[0020] [Item 10] the at least one first contact hole is a plurality of first contact holes, 10. The liquid crystal display device according to any one of items 6 to 9, wherein any one of the plurality of first contact holes is formed at a position different from other first contact holes in a planar view.

[0021] [Item 11] Item 11. The liquid crystal display device of item 10, wherein any one of the plurality of first contact holes is separated from another first contact hole by at least one pixel in either or both of the row direction and the column direction.

[0022] [Item 12] the at least one second contact hole is a plurality of second contact holes, 12. The liquid crystal display device according to any one of items 6 to 11, wherein any one of the plurality of second contact holes is formed at a position different from other second contact holes in a plan view.

[0023] [Item 13] Item 13. The liquid crystal display device of item 12, wherein any one of the plurality of second contact holes is separated from another second contact hole by at least one pixel in either or both of the row direction and the column direction.

[0024] [Item 14] Item 14. A liquid crystal display device according to any one of items 6 to 13, wherein at least one of the at least one first contact hole and the at least one second contact hole is located between adjacent pixel electrodes among the plurality of pixel electrodes.

[0025] [Item 15] 15. The liquid crystal display device according to any one of items 1 to 14, wherein at least one of the plurality of touch wirings overlaps an area between adjacent ones of the plurality of reflective segments in a planar view.

[0026] [Item 16] 16. The liquid crystal display device according to any one of items 1 to 15, wherein an area between adjacent touch sensor electrodes among the plurality of touch sensor electrodes and an area between adjacent pixel electrodes among the plurality of pixel electrodes overlap in a planar view.

[0027] [Item 17] 17. The liquid crystal display device according to any one of items 1 to 16, wherein each of the plurality of reflective segments, an area between adjacent touch sensor electrodes among the plurality of touch sensor electrodes, and an area between adjacent pixel electrodes among the plurality of pixel electrodes overlap in a planar view.

[0028] [Item 18] The touch wirings are adjacent to a lower surface of the reflective layer via a first insulating layer, Item 18. The liquid crystal display device according to any one of items 1 to 17, wherein the plurality of touch sensor electrodes or the plurality of pixel electrodes are adjacent to an upper surface of the reflective layer via a second insulating layer.

[0029] [Item 19] 19. The liquid crystal display device according to any one of items 1 to 18, wherein each of the plurality of touch wirings is arranged between adjacent gate wirings among the plurality of gate wirings, or between adjacent source wirings among the plurality of source wirings.

[0030] [Item 20] 20. The liquid crystal display device according to any one of items 1 to 19, wherein the plurality of touch wirings are formed from the same conductive film as the plurality of gate wirings or the plurality of source wirings.

[0031] [Item 21] Each of the plurality of pixels includes a transmissive region that performs display in a transmissive mode; Each of the plurality of reflective segments has an opening formed in the transmissive region; The liquid crystal display device includes a light source and a further polarizing plate disposed on the rear side of the first substrate, and a further retardation layer disposed between the further polarizing plate and the liquid crystal layer, 21. The liquid crystal display device according to any one of items 1 to 20, comprising:

[0032] [Item 22] the first substrate further includes an insulating layer formed to cover the plurality of reflective segments; Each of the plurality of reflective segments has a rough surface structure; 22. The liquid crystal display device according to any one of items 1 to 21, wherein the thickness of the insulating layer is greater than the height difference of the uneven surface structure.

[0033] [Item 23] Item 23. The liquid crystal display device according to item 22, wherein the thickness of the insulating layer is at least twice the height difference of the uneven surface structure.

[0034] [Item 24] an upper surface of the insulating layer at a portion that overlaps the uneven surface structure of the plurality of reflective segments has an uneven shape; Item 24. The liquid crystal display device according to item 22 or 23, wherein the height difference of the uneven shape of the insulating layer is equal to or less than half the height difference of the uneven surface structure of the plurality of reflective segments.

[0035] [Item 25] The touch sensor electrodes and the pixel electrodes are adjacent to each other via a dielectric layer, 25. The liquid crystal display device according to any one of items 1 to 24, wherein at least one of the plurality of touch sensor electrodes and the plurality of pixel electrodes includes at least one slit.

[0036] [Item 26] the first substrate has a first horizontal alignment film in contact with the liquid crystal layer; the second substrate has a second horizontal alignment film in contact with the liquid crystal layer, The liquid crystal layer has a twisted orientation when no voltage is applied, 26. The liquid crystal display device according to any one of items 1 to 25, wherein a twist angle of the liquid crystal layer when no voltage is applied is 45° or more and 90° or less.

[0037] [Item 27] 27. The liquid crystal display device according to any one of items 1 to 26, wherein substantially the same voltage can be applied to the multiple reflective segments at substantially the same timing.

[0038] [Item 28] 27. The liquid crystal display device according to any one of items 1 to 26, wherein substantially the same voltage can be applied at substantially the same timing to a group of pixel electrodes located in the same pixel row or the same pixel column among the plurality of pixel electrodes and to one or more reflective segments among the plurality of reflective segments that overlap the group of pixel electrodes in a planar view.

[0039] [Item 29] 29. The liquid crystal display device according to any one of items 1 to 28, wherein the reflective layer is located between the liquid crystal layer and the plurality of thin film transistors and at least partially overlaps the plurality of thin film transistors in a planar view. Effect of the Invention

[0040] According to the embodiment of the present invention, it is possible to realize a pixel structure suitable for a liquid crystal display device capable of displaying in a reflective mode and being used as an in-cell touch panel. [Brief description of the drawings]

[0041] [Figure 1] FIG. 1 is a cross-sectional view that diagrammatically illustrates a liquid crystal display device 100 according to an embodiment of the present invention. [Diagram 2] 2 is an equivalent circuit diagram of a plurality of pixels P included in the liquid crystal display device 100. FIG. [Diagram 3] FIG. 1 is a cross-sectional view that diagrammatically illustrates a liquid crystal display device 100. [Figure 4A] 1 is a plan view that illustrates a backplane circuit BP of a TFT substrate 10 included in a liquid crystal display device 100. FIG. [Figure 4B] 2 is a plan view diagrammatically illustrating a first interlayer insulating layer 12 of the TFT substrate 10. FIG. [Figure 4C] FIG. 2 is a plan view illustrating a schematic view of a reflective layer 13 of the TFT substrate 10. [Figure 4D] 2 is a plan view illustrating a schematic diagram of a second interlayer insulating layer 14 of the TFT substrate 10. FIG. [Figure 4E] FIG. 2 is a plan view illustrating a pixel electrode PE of the TFT substrate 10. [Figure 4F] 2 is a plan view illustrating a schematic diagram of a dielectric layer 15 of the TFT substrate 10. FIG. [Figure 4G] 2 is a plan view illustrating a common electrode CE of the TFT substrate 10. FIG. [Diagram 5] 1 is a plan view illustrating an example of the arrangement relationship between a reflective segment 13S and a touch wiring TL in the liquid crystal display device 100. FIG. [Figure 6] FIG. 1 is a cross-sectional view that diagrammatically illustrates a liquid crystal display device 900 of a comparative example. [Figure 7] FIG. 11 is a cross-sectional view that diagrammatically illustrates another liquid crystal display device 200 according to an embodiment of the present invention. [Figure 8] FIG. 11 is a cross-sectional view that diagrammatically illustrates a liquid crystal display device 300 according to still another embodiment of the present invention. [Figure 9A] 1 is a plan view that illustrates a common electrode CE of a TFT substrate 10 included in a liquid crystal display device 300. FIG. [Figure 9B] 1 is a plan view that illustrates a dielectric layer 15 of a TFT substrate 10 of a liquid crystal display device 300. FIG. [Figure 9C]1 is a plan view that illustrates a pixel electrode PE of a TFT substrate 10 of a liquid crystal display device 300. FIG. [Figure 10] FIG. 11 is a cross-sectional view that diagrammatically illustrates a liquid crystal display device 400 according to still another embodiment of the present invention. [Figure 11A] 1 is a plan view showing an example of an upper layer electrode UE. [Figure 11B] 13 is a plan view showing another example of the upper layer electrode UE. FIG. [Figure 11C] 13 is a plan view showing still another example of the upper layer electrode UE. FIG. [Figure 12] FIG. 2 is a cross-sectional view showing an example of a preferred configuration of a reflective layer 13 having a laminated structure including a metal layer 13a and a transparent conductive layer 13b. [Figure 13] FIG. 2 is a cross-sectional view showing an example of a preferred configuration of a reflective layer 13 having a laminated structure including a metal layer 13a and a transparent conductive layer 13b. [Figure 14] FIG. 11 is a cross-sectional view that illustrates a schematic diagram of a liquid crystal display device 500 according to still another embodiment of the present invention. [Figure 15] 2 is a diagram showing a reflective region Rf and a transmissive region Tr included in each pixel P of the liquid crystal display device 500. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments of the present invention are not limited to the following examples.

[0043] [Embodiment 1] A liquid crystal display device 100 according to the present embodiment will be described with reference to Fig. 1 and Fig. 2. The liquid crystal display device 100 is a reflective liquid crystal display device that performs display in a normally black mode. Fig. 1 is a cross-sectional view that shows a schematic diagram of the liquid crystal display device 100. Fig. 2 is an equivalent circuit diagram of a plurality of pixels P included in the liquid crystal display device 100.

[0044] As shown in FIG. 1, the liquid crystal display device 100 includes an active matrix substrate (hereinafter referred to as a "TFT substrate") 10, a counter substrate (sometimes referred to as a "color filter substrate") 20 arranged on the viewer side of the TFT substrate 10, and a liquid crystal layer 30 provided between the TFT substrate 10 and the counter substrate 20. The liquid crystal display device 100 further includes a polarizing plate 40 arranged on the viewer side of the liquid crystal layer 30, and a retardation layer 50 arranged between the polarizing plate 40 and the liquid crystal layer 30. Here, the polarizing plate 40 is arranged on the viewer side of the counter substrate 20, and the retardation layer 50 is arranged between the polarizing plate 40 and the counter substrate 20. Specifically, the polarizing plate 40 is an absorption-type linear polarizing plate. In the illustrated example, the retardation layer 50 includes a λ / 2 plate 51 and a λ / 4 plate 52.

[0045] As shown in Fig. 2, the liquid crystal display device 100 has a plurality of pixels P. The plurality of pixels P are arranged in a matrix shape including a plurality of rows and a plurality of columns. The plurality of pixels P typically include red pixels that display red, green pixels that display green, and blue pixels that display blue. As already described, the liquid crystal display device 100 is of a reflective type. Therefore, each pixel P includes a reflective region Rf that performs display in a reflective mode.

[0046] The TFT substrate 10 has a plurality of gate lines (scanning lines) GL, a plurality of source lines (signal lines) SL, a plurality of thin film transistors (TFTs) 11, a plurality of pixel electrodes PE, and a common electrode CE.

[0047] The gate lines GL extend in the row direction. Each gate line GL supplies a gate signal (scanning signal) to a corresponding TFT 11. The source lines SL extend in the column direction intersecting (e.g., substantially perpendicular to) the row direction. Each source line SL supplies a source signal (display signal) to a corresponding TFT 11.

[0048] Each of the plurality of TFTs 11 is provided corresponding to each pixel P. The gate electrode and source electrode of each TFT 11 are electrically connected to the corresponding gate line GL and the corresponding source line SL, respectively. Each of the plurality of pixel electrodes PE is electrically connected to the corresponding TFT 11 (more specifically, to the drain electrode of the corresponding TFT 11).

[0049] The common electrode CE, together with the pixel electrodes PE, can generate a lateral electric field (fringe electric field) in the liquid crystal layer 30. The common electrode CE is divided into a plurality of segments, as will be described later.

[0050] Next, the configurations of the TFT substrate 10 and the counter substrate 20 will be described in more detail with reference to Fig. 3 and Fig. 4A to Fig. 4G. Fig. 3 is a cross-sectional view that shows a liquid crystal display device 100. Fig. 4A to Fig. 4G are plan views that show each layer of the TFT substrate 10.

[0051] The TFT substrate 10 has a substrate 10a, TFTs 11, a first interlayer insulating layer 12, and a reflective layer 13. The TFT substrate 10 also has a second interlayer insulating layer 14, a pixel electrode PE, a dielectric layer 15, a common electrode CE, and a first horizontal alignment film 19. Figures 4A to 4G respectively show a backplane circuit BP including the TFTs 11, the first interlayer insulating layer 12, the reflective layer 13, the second interlayer insulating layer 14, the pixel electrode PE, the dielectric layer 15, and the common electrode CE, and show an area corresponding to 8 rows and 11 columns of pixels P.

[0052] The substrate 10a supports the TFT 11 etc. The substrate 10a is transparent and insulating and is, for example, a glass substrate or a plastic substrate.

[0053] The TFT 11 is provided on the substrate 10a. The TFT 11 is provided corresponding to each of the plurality of pixels P. The TFT 11 has a gate electrode GE, a gate insulating layer GI, a semiconductor layer SC, a source electrode SE, and a drain electrode DE. The gate electrode GE is electrically connected to the corresponding gate line GL, and the source electrode SE is electrically connected to the corresponding source line SL. The drain electrode DE is electrically connected to the pixel electrode PE. A circuit for driving the plurality of pixels P, including the TFT 11, the gate line GL, the source line SL, and the like, is sometimes called a backplane circuit BP. Note that, although FIG. 3 illustrates the TFT 11 having a bottom gate structure, the TFT 11 may have a top gate structure or a double gate structure.

[0054] The first interlayer insulating layer 12 is provided so as to cover the backplane circuit BP. The first interlayer insulating layer 12 is a layer formed from an organic insulating material, and can be formed using, for example, a photosensitive resin.

[0055] The reflective layer 13 is provided on the first interlayer insulating layer 12 so as to be located at least within the reflective region Rf. That is, the reflective layer 13 is disposed on the backplane circuit BP via the first interlayer insulating layer 12, in other words, the first interlayer insulating layer 12 is provided between the reflective layer 13 and the TFT 11. In other words, the reflective layer 13 is adjacent to the TFT 11 via at least the first interlayer insulating layer 12.

[0056] The reflective layer 13 is made of a conductive material that reflects light. More specifically, the reflective layer 13 is made of a metal material with high reflectivity. Examples of the material of the reflective layer 13 include a silver alloy, aluminum, and an aluminum alloy.

[0057] The surface of the reflective layer 13 has an uneven shape. That is, the reflective layer 13 has an uneven surface structure. The uneven surface structure of the reflective layer 13 is sometimes called MRS (Micro Reflective Structure) and is provided to diffusely reflect ambient light and realize a display close to paper white. The uneven surface structure can be composed of a plurality of protrusions p randomly arranged such that the center distance between adjacent protrusions p is, for example, 5 μm to 50 μm, preferably 10 μm to 20 μm. When viewed from the normal direction of the substrate 10a, the shape of the protrusions p is approximately circular or approximately polygonal. The area of ​​the protrusions p that occupy the pixel P is, for example, about 20% to 40%. The height of the protrusions p is, for example, 1 μm to 5 μm.

[0058] There is no particular limitation on the method for forming the uneven surface structure on the reflective layer 13. For example, as shown in the figure, a first interlayer insulating layer 12 having an uneven surface structure is formed, and then a reflective layer 13 is formed thereon, thereby imparting an uneven shape reflecting the uneven surface structure of the first interlayer insulating layer 12 to the surface of the reflective layer 13. The first interlayer insulating layer 12 having the uneven surface structure can be formed by, for example, the method disclosed in Japanese Patent No. 3394926.

[0059] Moreover, the reflective layer 13 is located between the liquid crystal layer 30 and the TFT 11. Furthermore, the reflective layer 13 at least partially overlaps the TFT 11 when viewed from the normal direction of the display surface (that is, in a plan view).

[0060] The second interlayer insulating layer 14 is provided on the first interlayer insulating layer 12 so as to cover the reflective layer 13. Therefore, it can be said that the reflective layer 13 is provided between the first interlayer insulating layer 12 and the second interlayer insulating layer 14. The second interlayer insulating layer 14 is a planarizing layer made of an organic insulating material, and can be formed using, for example, a photosensitive resin.

[0061] The pixel electrode PE is provided in each of the multiple pixels P. The pixel electrode PE is also provided on the second interlayer insulating layer 14. That is, the pixel electrode PE is adjacent to the upper surface of the reflective layer 13 via the second interlayer insulating layer 14, in other words, the second interlayer insulating layer 14 is provided between the pixel electrode PE and the reflective layer 13. In other words, the reflective layer 13 is adjacent to the pixel electrode PE at least via the second interlayer insulating layer 14, and is located on the opposite side of the pixel electrode PE to the liquid crystal layer 30 (that is, on the rear side of the pixel electrode PE).

[0062] The pixel electrode PE is made of a transparent conductive material. Examples of the transparent conductive material include indium tin oxide (ITO), indium zinc oxide (IZO (registered trademark)), or a mixture thereof. The pixel electrode PE is electrically connected to the TFT11.

[0063] In the illustrated example, the pixel electrode PE is electrically connected to the drain electrode DE of the TFT 11 via a contact electrode 16. The contact electrode 16 may be formed from the same metal film as the reflective layer 13 (i.e., in the same layer as the reflective layer 13). The first interlayer insulating layer 12 has a drain contact hole CH that exposes at least a part of the drain electrode DE of the TFT 11. D The contact electrode 16 is formed through a drain contact hole CH D The contact electrode 16 is connected to the drain electrode DE of the TFT 11 at the pixel electrode 16a. The contact electrode 16 is connected to the drain electrode DE of the TFT 11 at the pixel electrode 16b ... P The pixel electrode PE is formed through a pixel contact hole CH P In addition, the drain contact hole CH D and pixel contact hole CH P An opening 13o is formed in the area where the opening 13o overlaps the opening 13a.

[0064] In this manner, the pixel electrode PE is D and pixel contact hole CH PIn plan view, the drain contact hole CH D and the pixel contact hole CH P In addition, in this case, the drain contact hole CH D and pixel contact hole CH P It does not overlap with.

[0065] The dielectric layer 15 is provided to cover the pixel electrode PE. The dielectric layer 15 can be made of, for example, an inorganic insulating material.

[0066] The common electrode CE is provided on the dielectric layer 15. That is, the common electrode CE is adjacent to the pixel electrode PE via the dielectric layer 15. The common electrode CE is formed of a transparent conductive material. The transparent conductive material for forming the common electrode CE can be the same material as that of the pixel electrode PE. Although not shown in FIG. 3 and FIG. 4G, the common electrode CE includes, for each pixel P, a plurality of strip-shaped portions and at least one slit located between two adjacent strip-shaped portions. By forming the slit in the common electrode CE, a fringe electric field (horizontal electric field) is generated in the liquid crystal layer 30 in response to the potential difference between the pixel electrode PE and the common electrode CE.

[0067] The first horizontal alignment film 19 is provided on the common electrode CE and is in contact with the liquid crystal layer 30. Therefore, it can be said that the pixel electrode PE and the common electrode CE are provided between the second interlayer insulating layer 14 and the first horizontal alignment film 19. It can also be said that the dielectric layer 15 is provided between the second interlayer insulating layer 14 and the first horizontal alignment film 19, and here, the pixel electrode PE is provided between the second interlayer insulating layer 14 and the dielectric layer 15, and the common electrode CE is provided between the dielectric layer 15 and the first horizontal alignment film 19.

[0068] The counter substrate 20 has a substrate 20a, a color filter layer 21, and a second horizontal alignment film 29. Although not shown here, the counter substrate 20 further has a plurality of columnar spacers.

[0069] The substrate 20a supports the color filter layer 21 etc. The substrate 20a is transparent and insulating and is, for example, a glass substrate or a plastic substrate.

[0070] The color filter layer 21 typically includes a red color filter provided in an area corresponding to a red pixel, a green color filter provided in an area corresponding to a green pixel, and a blue color filter provided in an area corresponding to a blue pixel. The red color filter, the green color filter, and the blue color filter transmit red light, green light, and blue light, respectively.

[0071] When color display is not performed, the color filter layer 21 is omitted.

[0072] If necessary, an overcoat layer (planarization layer) may be provided to cover the color filter layer 21. In addition, depending on the transparent conductive material (for the pixel electrode PE and the common electrode CE), the organic insulating material (for the first interlayer insulating layer 12 and the second interlayer insulating layer 14), the inorganic insulating material (for the dielectric layer 15), and the alignment film material (for the first horizontal alignment film 19 and the second horizontal alignment film 29) used, the white display may have a yellowish tinge. In that case, the overcoat layer may be formed of a blue resist to perform chromaticity adjustment (blue shift) and bring the chromaticity of the white display closer to that of a D65 light source, for example.

[0073] The columnar spacers define the thickness (cell gap) of the liquid crystal layer 30. The columnar spacers can be formed from a photosensitive resin.

[0074] The second horizontal alignment film 29 is provided on the color filter layer 21 and is in contact with the liquid crystal layer 30 .

[0075] The liquid crystal layer 30 includes a nematic liquid crystal material having a positive dielectric anisotropy Δε (i.e., positive type) or a nematic liquid crystal material having a negative dielectric anisotropy Δε (i.e., negative type). The dielectric anisotropy Δε is expressed by the dielectric constant ε / / and the dielectric constant in the minor axis direction ε ⊥ (i.e., ε / / -ε ⊥ ) The liquid crystal layer 30 may further contain a chiral agent as necessary. The liquid crystal layer 30 can be formed by, for example, a dropping method. The thickness of the liquid crystal layer 30 is not particularly limited.

[0076] Each of the first horizontal alignment film 19 and the second horizontal alignment film 29 has been subjected to an alignment treatment and determines the alignment direction of the liquid crystal molecules 31 contained in the liquid crystal layer 30. The alignment direction determined by the first horizontal alignment film 19 and the alignment direction determined by the second horizontal alignment film 29 are different from each other.

[0077] Since the first horizontal alignment film 19 and the second horizontal alignment film 29 are provided on both sides of the liquid crystal layer 30, the liquid crystal molecules 31 of the liquid crystal layer 30 are horizontally aligned at least when no voltage is applied to the liquid crystal layer 30 (i.e., the pretilt angle is substantially 0°). As already explained, the alignment direction determined by the first horizontal alignment film 19 and the alignment direction determined by the second horizontal alignment film 29 are different, so that the liquid crystal layer 30 has a twisted alignment when no voltage is applied, as shown in Fig. 3. When a voltage is applied to the liquid crystal layer 30, that is, when a transverse electric field (fringe electric field) is generated in the liquid crystal layer 30 by the pixel electrode PE and the common electrode CE, the alignment state of the liquid crystal layer 30 changes due to the transverse electric field.

[0078] In the liquid crystal display device 100 of this embodiment, the common electrode CE is divided into a plurality of segments TX. Different signals (voltages) can be applied to the plurality of segments TX, and therefore the segments TX can function as "touch sensor electrodes" in an in-cell touch panel. In other words, the TFT substrate 10 of the liquid crystal display device 100 has a plurality of touch sensor electrodes TX. Each touch sensor electrode TX is provided corresponding to two or more pixels P.

[0079] The TFT substrate 10 further includes a plurality of touch wirings TL. Each of the plurality of touch wirings TL is electrically connected to a corresponding one of the plurality of touch sensor electrodes TX. Here, as shown in FIG. 4A, the plurality of touch wirings TL extend in the column direction (the same direction as the source wirings SL), and each touch wiring TL is disposed between adjacent source wirings SL. Here, the plurality of touch wirings TL are formed from the same conductive film as the plurality of source wirings SL (i.e., in the same layer as the plurality of source wirings SL). Therefore, the plurality of touch wirings TL are covered with the first interlayer insulating layer 12, and are adjacent to the lower surface of the reflective layer 13 via the first interlayer insulating layer 12.

[0080] The touch wirings TL are connected to a touch drive unit provided in the non-display area. The touch drive unit is configured to switch, for example, between a display mode in which the touch sensor electrodes TX function as a common electrode CE and a touch detection mode in which the touch sensor electrodes TX function as the touch sensor electrodes TX in a time-division manner. For example, in the display mode, the touch drive unit applies a common signal to the touch sensor electrodes TX (common electrodes CE) via the touch wirings TL. On the other hand, in the touch detection mode, the touch drive unit applies a touch drive signal to the touch sensor electrodes TX via the touch wirings TL.

[0081] In the liquid crystal display device 100 of this embodiment, the reflective layer 13 is divided into a plurality of reflective segments 13S that are electrically independent from each other. Each of the plurality of reflective segments 13S overlaps two or more of the plurality of pixel electrodes PE in a planar view. Here, the two or more pixel electrodes PE overlapping each of the reflective segments 13S are arranged in a plurality of rows and a plurality of columns. FIG. 4C shows an example in which each of the reflective segments 13S overlaps with 54 pixel electrodes PE arranged in 6 rows and 9 columns.

[0082] The number of the reflective segments 13S is equal to or greater than the number of the touch sensor electrodes TX. Here, the number of the reflective segments 13S is the same as the number of the touch sensor electrodes TX, but the number of the reflective segments 13S may be greater than the number of the touch sensor electrodes TX. In other words, the reflective layer 13 may be divided more finely than the common electrode CE.

[0083] Different voltages can be applied to the multiple reflective segments 13S. Each reflective segment 13S is electrically connected to a corresponding touch sensor electrode TX among the multiple touch sensor electrodes TX and a corresponding touch wiring TL among the multiple touch wirings TL.

[0084] A plurality of first contact holes CH1 are formed across both the second interlayer insulating layer 14 and the dielectric layer 15, and a plurality of second contact holes CH2 are formed in the first interlayer insulating layer 12. Each reflective segment 13S is electrically connected to a corresponding touch sensor electrode TX via at least one first contact hole CH1, and is electrically connected to a corresponding touch wiring TL via at least one second contact hole CH2. In the illustrated example, each reflective segment 13X is electrically connected to a corresponding touch sensor electrode TX via a plurality (specifically, three) of first contact holes CH1, and is electrically connected to a corresponding touch wiring TL via a plurality (specifically, three) of second contact holes CH2.

[0085] In this manner, each of the reflective segments 13S is electrically connected to the corresponding touch sensor electrode TX and the corresponding touch wiring TL. In other words, the touch sensor electrode TX is electrically connected to the touch wiring TL via the reflective segment 13S.

[0086] As described above, in the liquid crystal display device 100 of the present embodiment, the reflective layer 13 is divided into a plurality of reflective segments 13S that are electrically independent from each other. Therefore, compared to a case where the reflective layer 13 is not divided, the load on the touch sensor electrode TX (parasitic capacitance formed by the touch sensor electrode TX and the reflective segments 13S) can be reduced.

[0087] In the present embodiment, a configuration in which different voltages can be applied to the multiple reflective segments 13S has been exemplified, but the reflective segments 13S may not be electrically connected to other members and may be in an electrically floating state (floating). By adopting a configuration in which different voltages can be applied to the multiple reflective segments 13S as in the present embodiment, the load on the touch sensor electrode TX can be further reduced. For example, as exemplified in the present embodiment, when the reflective segments 13S are electrically connected to the touch sensor electrode TX, the reflective segments 13S do not become an electrical load on the touch sensor electrode TX, improving the degree of freedom in the wiring design of the touch sensor electrode TX.

[0088] By adopting a configuration in which each reflective segment 13S is electrically connected to the touch sensor electrode TX via at least one first contact hole CH1 and is electrically connected to the touch wiring TL via at least one second contact hole CH2, the flatness of the surface of the touch sensor electrode TX (common electrode CE) is improved and a decrease in the contrast ratio caused by the contact holes is suppressed compared to a configuration in which the touch sensor electrode TX is directly connected to the touch wiring TL (a configuration in which contact holes are formed through the first interlayer insulating layer 12, the second interlayer insulating layer 14 and the dielectric layer 15).

[0089] At least one first contact hole CH1 and at least one second contact hole CH2 corresponding to each reflective segment 13S are formed at different positions from each other in a plan view, thereby improving the flatness of the surface of the touch sensor electrode TX and suppressing a decrease in the contrast ratio caused by the contact holes. From the viewpoint of suppressing a decrease in the contrast ratio, it is preferable that any one of the at least one first contact hole CH1 corresponding to each reflective segment 13S is separated from each of the at least one second contact hole CH2 by one pixel or more in either or both of the row direction and the column direction.

[0090] By adopting a configuration in which the number of first contact holes CH1 for electrically connecting each reflective segment 13S to the touch sensor electrode TX is two or more, and / or the number of second contact holes CH2 for electrically connecting each reflective segment 13X to the touch wiring TL is two or more, the electrical connection between the reflective segment 13S and the touch sensor electrode TX and / or the electrical connection between the reflective segment 13S and the touch wiring TL can be made redundant. In addition, the resistivity of the touch wiring TL can be reduced and the touch sensitivity can be improved. Note that the number of first contact holes CH1 and the number of second contact holes CH2 corresponding to each reflective segment 13S are not limited to the example shown in the figure (each is three).

[0091] When there are a plurality of first contact holes CH1 corresponding to each reflective segment 13S, it is preferable that any one of the plurality of first contact holes CH1 is formed at a position different from the other first contact holes CH1 in a plan view. This makes it possible to provide redundancy in the electrical connection between the reflective segment 13S and the touch sensor electrode TX and to suppress the occurrence of sesame-like display unevenness. From the viewpoint of suppressing display unevenness, it is preferable that any one of the plurality of first contact holes CH1 is separated from the other first contact holes CH1 by one pixel or more in either or both of the row direction and the column direction.

[0092] When there are multiple second contact holes CH2 corresponding to each reflective segment 13S, it is preferable that any one of the multiple second contact holes CH2 is formed at a position different from the other second contact holes CH2 in a plan view. This makes it possible to provide redundancy in the electrical connection between the reflective segment 13S and the touch wiring TL and to suppress the occurrence of sesame-like display unevenness. From the viewpoint of suppressing display unevenness, it is preferable that any one of the multiple second contact holes CH2 is separated from the other second contact holes CH2 by one pixel or more in either or both of the row direction and the column direction.

[0093] When at least one of the at least one first contact hole CH1 and at least one second contact hole CH2 corresponding to each reflective segment 13S is located between adjacent pixel electrodes PE among the multiple pixel electrodes PE, the reflectance during white display can be improved.

[0094] At least one of the touch wirings TL preferably overlaps an area between adjacent reflection segments 13S in a plan view, thereby reducing the load on the touch wiring TL and improving the touch sensitivity.

[0095] It is preferable that a region R1 (see FIG. 3, hereinafter also referred to as a "first region") between adjacent touch sensor electrodes TX among the plurality of touch sensor electrodes TX and a region R2 (see FIG. 3, hereinafter also referred to as a "second region") between adjacent pixel electrodes PE among the plurality of pixel electrodes PE overlap in a plan view. This makes it possible to equalize the parasitic capacitance of the pixel electrodes PE and improve lattice-like display unevenness.

[0096] In the present embodiment, the touch wirings TL are adjacent to the lower surface of the reflective layer 13 via the first interlayer insulating layer 12, and the pixel electrodes PE are adjacent to the upper surface of the reflective layer 13 via the second interlayer insulating layer 14. With this configuration, the number of masks and processes required for manufacturing the liquid crystal display device 100 can be reduced, and costs can be reduced. For example, as illustrated, when the touch wirings TL are disposed between the adjacent source wirings SL, the number of masks and processes can be reduced by forming the touch wirings TL from the same conductive film as the source wirings SL. Note that the touch wirings TL may extend in the row direction (the same direction as the gate wirings GL), and the touch wirings TL may be disposed between the adjacent gate wirings GL. In this case, the number of masks and processes can be reduced by forming the touch wirings TL from the same conductive film as the gate wirings GL (i.e., in the same layer as the gate wirings GL).

[0097] In the present embodiment, when the reflective layer 13 (i.e., each reflective segment 13S) has an uneven surface structure, the thickness of the second interlayer insulating layer 14 is preferably larger than the height difference of the uneven surface structure of each reflective segment 13S. If the uneven shape reflecting the uneven surface structure of the reflective segment 13S exists on the surface of the TFT substrate 10 on the liquid crystal layer 30 side (the interface between the TFT substrate 10 and the liquid crystal layer 30), the cell thickness (thickness of the liquid crystal layer 30) becomes non-uniform, and there is a concern of a decrease in the contrast ratio. Since the thickness of the second interlayer insulating layer 14 is larger than the height difference of the uneven surface structure of the reflective segment 13S, the uneven surface structure of the reflective segment 13S can be flattened by the second interlayer insulating layer 14, so that the uneven surface structure of the reflective segment 13S is less likely to be reflected on the surface of the TFT substrate 10 on the liquid crystal layer 30 side, and a decrease in the contrast ratio caused by the non-uniformity of the cell thickness can be suppressed. It is also possible to use a light scattering sheet (for example, by placing a light scattering sheet on the observer side of the opposing substrate 20) instead of forming an uneven surface structure on the reflective segment 13S. However, even in this case, there is still a concern that the contrast may decrease depending on the specifications of the light scattering sheet used.

[0098] From the viewpoint of suppressing a decrease in the contrast ratio caused by non-uniformity in the cell thickness, the thickness of the second interlayer insulating layer 14 is preferably at least twice the height difference of the uneven surface structure. Furthermore, depending on the thickness of the second interlayer insulating layer 14, the uneven surface structure of the reflective segment 13S may not be completely flattened. In that case, the upper surface of the portion of the second interlayer insulating layer 14 that overlaps with the uneven surface structure of the reflective segment 13S has an uneven shape, but the height difference of the uneven shape is preferably 1 / 2 or less of the height difference of the uneven surface structure of the reflective segment 13S.

[0099] Here, the configuration in which the common electrode CE is provided above the pixel electrode PE has been exemplified, but conversely, the pixel electrode PE may be provided above the common electrode CE as described in the later-described embodiment 3. Hereinafter, the electrode located relatively higher among the pixel electrode PE and the common electrode CE may be referred to as the "upper layer electrode", and the electrode located relatively lower may be referred to as the "lower layer electrode". The upper layer electrode and the lower layer electrode are adjacent to each other via a dielectric layer 15. In order to generate a transverse electric field, at least the upper layer electrode includes a plurality of strip portions and at least one slit located between two adjacent strip portions in each pixel P.

[0100] Moreover, in the liquid crystal display device 100 of this embodiment, display is performed in a transverse electric field mode in which the liquid crystal layer 30 has a twisted orientation when no voltage is applied. More specifically, display is performed in an FFS mode (referred to as a "TW-FFS mode") in which the liquid crystal layer 30 has a twisted orientation when no voltage is applied. This makes it possible to improve the contrast ratio of the reflective display compared to display in a general FFS mode in which the liquid crystal layer 30 does not have a twisted orientation when no voltage is applied (i.e., the twist angle of the liquid crystal layer 30 is 0°). From the viewpoint of improving the contrast ratio, it is preferable that the twist angle of the liquid crystal layer 30 when no voltage is applied is 45° or more and 90° or less.

[0101] Furthermore, in this embodiment, the reflective layer 13 is located between the liquid crystal layer 30 and the TFT 11, and at least partially overlaps the TFT 11 in a plan view. By adopting such a configuration, the reflective aperture ratio can be increased, and a brighter reflective display can be realized. In addition, the TFT 11 can be protected from external light, improving reliability.

[0102] In the configuration in which the touch sensor electrode TX is electrically connected to the touch wiring TL via the reflective segment 13S as in the present embodiment, substantially the same voltage (touch drive signal) may be applied to all the reflective segments 13S at substantially the same timing in the touch detection mode. Alternatively, substantially the same voltage (touch drive signal) may be applied to a group of pixel electrodes PE located in the same pixel row or the same pixel column and one or more reflective segments 13S overlapping the group in a planar view at substantially the same timing.

[0103] FIG. 5 is a plan view illustrating an example of the arrangement relationship between the reflective segments 13S and the touch wiring TL in the liquid crystal display device 100. As shown in FIG.

[0104] As shown in Fig. 5, the liquid crystal display device 100 has a display area DR and a non-display area FR. The display area DR is defined by a plurality of pixels P (see Fig. 2) arranged in a matrix. The non-display area FR is located on the periphery of the display area DR, and is sometimes called a "peripheral area" or a "frame area."

[0105] In the display region DR, the reflective layer 13 is divided into a plurality of reflective segments 13S. Each reflective segment 13S is electrically connected to a corresponding touch wiring TL.

[0106] The touch wiring TL is connected to a touch driving unit TD provided in the non-display region FR. The touch driving unit TD is configured to switch, for example, between a display mode in which a plurality of touch sensor electrodes TX function as a common electrode CE and a touch detection mode in which the touch sensor electrodes TX function as the touch sensor electrodes TX in a time-division manner. In the display mode, the touch driving unit TD applies a common signal to the reflective segment 13S via the touch wiring TL. On the other hand, in the touch detection mode, the touch driving unit TD applies a touch driving signal to the reflective segment 13S via the touch wiring TL.

[0107] Although not shown, in addition to the touch drive unit TD, the non-display area FR is provided with peripheral circuits including drive circuits such as a gate driver that supplies a gate signal to the gate line GL and a source driver that supplies a source signal to the source line SL. These drive circuits may be mounted on the TFT substrate 10, for example, or may be formed integrally (monolithically). A semiconductor chip including some or all of the drive circuits may be mounted on the non-display area FR.

[0108] Here, advantages of the liquid crystal display device 100 of this embodiment will be described in comparison with a liquid crystal display device 900 of a comparative example shown in Fig. 6. The liquid crystal display device 900 of the comparative example is a reflective liquid crystal display device having a two-stage electrode structure to which the configuration of a transmissive in-cell touch panel is simply applied. In the following description, among the components of the liquid crystal display device 900 of the comparative example, components having the same functions as those of the liquid crystal display device 100 of this embodiment are given the same reference symbols, and their description may be omitted.

[0109] The liquid crystal display device 900 of the comparative example differs from the liquid crystal display device 100 of the present embodiment in that the touch wiring TL is provided on the second interlayer insulating layer 14. The touch wiring TL of the liquid crystal display device 900 is covered with a dielectric layer 17 that is different from the dielectric layer 15 located between the pixel electrode PE and the common electrode CE (touch sensor electrode TX), and the pixel electrode PE is provided on this dielectric layer 17. The touch wiring TL is connected to the contact holes CH formed in the dielectric layers 15 and 17. T1, the reflective layer 13 is connected to the touch sensor electrode TX at 100. In the liquid crystal display device 900 of the comparative example, the reflective layer 13 is not divided into a plurality of reflective segments that are electrically independent from one another.

[0110] In the liquid crystal display device 900 of the comparative example, the touch wiring TL is provided on the second interlayer insulating layer 14 and is located on the viewer side of the reflective layer 13. Therefore, there is a risk that the glare of the reflective display will be increased due to regular reflection from the touch wiring TL, or that the reflective aperture ratio will be reduced. Thus, there is a risk that the quality of the reflective display will be reduced in the liquid crystal display device 900 of the comparative example.

[0111] In contrast, in the liquid crystal display device 100 of the present embodiment, the touch wiring TL is provided between the gate insulating layer GI and the first interlayer insulating layer 12, and is located on the rear surface side of the reflective layer 13. This suppresses degradation of the quality of the reflective display.

[0112] In addition, in the liquid crystal display device 900 of the comparative example, there is a concern that the number of masks and processes required for manufacturing will increase significantly, resulting in an increase in costs. In the liquid crystal display device 900 of the comparative example, for example, deposition and patterning of a conductive film for forming the touch wiring TL, deposition and patterning of a dielectric layer 17 (contact hole CH T (Formation of an opening that will become part of the structure)

[0113] In contrast, in the liquid crystal display device 100 of the present embodiment, since there is no dielectric layer corresponding to the dielectric layer 17 in the liquid crystal display device 900 of the comparative example, a mask and a process for forming such a dielectric layer are not required. Moreover, if the touch wiring TL is formed from the same conductive film as the source wiring SL or the same conductive film as the gate wiring GL, there is no need to add a mask and a process for forming the touch wiring TL. Therefore, the number of masks and processes required for manufacturing can be reduced, and costs can be reduced.

[0114] [Embodiment 2] A liquid crystal display device 200 according to the present embodiment will be described with reference to Fig. 7. Fig. 7 is a cross-sectional view that illustrates the liquid crystal display device 200. The following description will focus on the differences between the liquid crystal display device 200 according to the present embodiment and the liquid crystal display device 100 according to the first embodiment.

[0115] In the liquid crystal display device 100 of embodiment 1, as shown in FIG. 3, a region (first region) R1 between adjacent touch sensor electrodes TX and a region R3 (hereinafter sometimes referred to as the “third region”) between adjacent reflective segments 13S overlap in a planar view.

[0116] In contrast, in the liquid crystal display device 200 of this embodiment, as shown in Fig. 7, the first region R1 and the third region R3 are misaligned in plan view. That is, each reflective segment 13S and the first region R1 overlap in plan view. In the example shown, each reflective segment 13S and the first region R1 also overlap in plan view with the region (second region) R2 between the adjacent pixel electrodes PE. In this way, when the first region R1 and the third region R3 are misaligned in plan view, it is possible to reduce the adverse effect on display of the electric field disturbance in the first region R1.

[0117] [Embodiment 3] A liquid crystal display device 300 according to the present embodiment will be described with reference to Fig. 8 and Figs. 9A to 9C. Fig. 8 is a cross-sectional view that shows the liquid crystal display device 300. Figs. 9A to 9C are plan views that show the common electrode CE, dielectric layer 15, and pixel electrode PE of the TFT substrate 10 included in the liquid crystal display device 300. The backplane circuit BP, first interlayer insulating layer 12, reflective layer 13, and second interlayer insulating layer 14 may have the same configuration as the liquid crystal display device 100 of embodiment 1, so see Figs. 4A to 4D.

[0118] In the liquid crystal display device 100 of the first embodiment, the common electrode CE is provided above the pixel electrodes PE. In contrast, in the liquid crystal display device 300 of the present embodiment, the pixel electrodes PE are provided above the common electrodes CE, as shown in FIG.

[0119] The common electrode CE is provided on the second interlayer insulating layer 14. Thus, the plurality of touch sensor electrodes TX are adjacent to the upper surface of the reflective layer 13 via the second interlayer insulating layer 14. Each touch sensor electrode TX is connected to a corresponding reflective segment 13S at a first contact hole CH1 formed in the second interlayer insulating layer 14. The dielectric layer 15 is provided so as to cover the common electrode CE, and the pixel electrode PE is provided on the dielectric layer 15. The pixel electrode PE is connected to the corresponding reflective segment 13S at a pixel contact hole CH1 formed across both the dielectric layer 15 and the second interlayer insulating layer 14. P The pixel contact hole CH P An opening op is formed in the region where the pixel electrode PE and the common electrode CE overlap with the liquid crystal layer 30. In this embodiment as well, the reflective layer 13 is located on the opposite side of the liquid crystal layer 30 with respect to the pixel electrode PE and the common electrode CE (i.e., on the rear side of the pixel electrode PE and the common electrode CE). It can be said that the pixel electrode PE and the common electrode CE are provided between the second interlayer insulating layer 14 and the first horizontal alignment film 19, and the dielectric layer 15 is also provided between the second interlayer insulating layer 14 and the first horizontal alignment film 19. In this embodiment, the common electrode CE is provided between the second interlayer insulating layer 14 and the dielectric layer 15, and the pixel electrode PE is provided between the dielectric layer 15 and the first horizontal alignment film 19.

[0120] 8 and 9C, the pixel electrode PE has a plurality of strips and at least one slit located between two adjacent strips. The slits formed in the pixel electrode PE generate a fringe electric field in the liquid crystal layer 30 in response to the potential difference between the pixel electrode PE and the common electrode CE.

[0121] In the liquid crystal display device 300 of the present embodiment, the reflective layer 13 is divided into a plurality of reflective segments 13S that are electrically independent from each other, as in the liquid crystal display device 100 of embodiment 1. This makes it possible to reduce the load on the touch sensor electrode TX (parasitic capacitance formed by the touch sensor electrode TX and the reflective segments 13S).

[0122] As already explained, in a configuration in which the pixel electrode PE is provided above the common electrode CE, a slit is formed at least in the pixel electrode PE, and in a configuration in which the common electrode CE is provided above the pixel electrode PE, a slit is formed at least in the common electrode CE.

[0123] In a relatively large liquid crystal display device (i.e., the area of ​​the pixel P is relatively large), it is preferable that the pixel electrode PE is provided above the common electrode CE. In a configuration in which the pixel electrode PE is provided above the common electrode CE, it is not necessary to form a slit in the common electrode CE, and therefore an increase in the resistivity (sheet resistivity) of the common electrode CE is suppressed more than in a configuration in which the common electrode CE is provided above the pixel electrode PE. If the resistivity of the common electrode CE increases, the speed at which charges are supplied to the common electrode CE decreases, and display defects (e.g., flicker, shadow, etc.) are more likely to occur in images that require a large amount of charge to be supplied to the common electrode CE (e.g., checkered patterns, striped patterns, or images in which a part of the display area is composed of these patterns in which the polarity of the pixels is biased).

[0124] In a configuration in which the pixel electrode PE is provided above the common electrode CE, it is necessary to form a slit in the pixel electrode PE, which increases the resistivity of the pixel electrode PE. However, the pixel electrode PE has an area sufficiently smaller than that of the common electrode CE (for example, less than one millionth), and therefore the amount of charge to be supplied is small. In addition, since charge is supplied from the TFT11 connected on a pixel-by-pixel basis, the pixel electrode PE is less susceptible to the effects of the displayed image and display defects are less likely to occur.

[0125] In addition, in a configuration in which the pixel electrode PE is provided above the common electrode CE, the pixel contact hole CH PIn the pixel electrode PE in the region where the fringe electric field is formed, a slit for generating a fringe electric field cannot be provided, and an opening op must be provided in the common electrode CE in that region. Therefore, an effective fringe electric field is not generated in that region, and the region does not contribute to the reflective display, so that the reflectance may be lower than in the configuration in which the common electrode CE is provided above the pixel electrode PE. Since a certain amount of area of ​​the region that does not contribute to the reflective display, such as a contact hole, is required regardless of the size of the area of ​​the pixel P, the ratio of the region that does not contribute to the reflective display in the pixel P increases as the area of ​​the pixel P decreases (i.e., the resolution increases), and the above-mentioned decrease in reflectance increases. In other words, in a relatively large liquid crystal display device, the ratio of the region that does not contribute to the reflective display in the pixel P is easier to reduce, so that the above-mentioned decrease in reflectance is easier to suppress. For these reasons, in a relatively large liquid crystal display device (where the area of ​​the pixel P is relatively large), a configuration in which the pixel electrode PE is provided above the common electrode CE is advantageous.

[0126] As already explained, the pixel contact hole CH P The reduction in reflectance due to the area in which the common electrode CE is formed not contributing to the reflective display becomes greater as the area of ​​the pixel P becomes smaller (i.e., as the resolution increases), and therefore, in a liquid crystal display device with a relatively high resolution (i.e., in which the area of ​​the pixel P is relatively small), it is preferable that the common electrode CE is provided above the pixel electrode PE.

[0127] [Embodiment 4] A liquid crystal display device 400 according to the present embodiment will be described with reference to Fig. 10. Fig. 10 is a cross-sectional view that illustrates the liquid crystal display device 400. The following description will focus on the differences between the liquid crystal display device 400 according to the present embodiment and the liquid crystal display device 300 according to the third embodiment.

[0128] In the liquid crystal display device 300 of embodiment 3, as shown in FIG. 8, a region (first region) R1 between adjacent touch sensor electrodes TX and a region (third region) R3 between adjacent reflective segments 13S overlap in a planar view.

[0129] In contrast, in the liquid crystal display device 400 of this embodiment, as shown in Fig. 10, the first region R1 and the third region R3 are misaligned in plan view. That is, each reflective segment 13S and the first region R1 overlap in plan view. In the example shown, each reflective segment 13S and the first region R1 also overlap in plan view with the region (second region) R2 between the adjacent pixel electrodes PE. In this way, when the first region R1 and the third region R3 are misaligned in plan view, it is possible to reduce the adverse effect on display of the electric field disturbance in the first region R1.

[0130] [Slits in the upper electrode] As already described, at least the upper layer electrode of the pixel electrode PE and the common electrode CE includes at least one slit.

[0131] An example of the upper layer electrode UE is shown in Fig. 11A. The upper layer electrode UE shown in Fig. 11A includes a plurality of strip portions sp and a plurality of slits sl. Needless to say, the number of strip portions sp and the number of slits sl are not limited to the example shown in Fig. 11A.

[0132] Fig. 11B shows another example of the upper layer electrode UE. The upper layer electrode UE shown in Fig. 11B includes a plurality of strip portions sp and a plurality of slits sl, similar to the example shown in Fig. 11A. In addition, in the example shown in Fig. 11B, each strip portion sp includes a first portion spa extending in a certain direction (first direction) and a second portion spb extending in a direction (second direction) different from the first direction. When the upper layer electrode UE has such a configuration, two liquid crystal domains with different alignment directions are formed in each pixel when a voltage is applied (hereinafter referred to as "dual domain alignment"), so that color changes (display coloring) and grayscale changes accompanying changes in the viewing angle direction can be suppressed.

[0133] Fig. 11C shows yet another example of the upper layer electrode UE. The upper layer electrode UE shown in Fig. 11C includes a plurality of strip portions sp and a plurality of slits sl, similar to the examples shown in Figs. 11A and 11B. In the example shown in Fig. 11C, the plurality of strip portions sp include at least one (four in this case) first strip portion sp1 extending in a certain direction (first direction) and at least one (four in this case) second strip portion sp2 extending in a direction (second direction) different from the first direction. The upper layer electrode UE having such a configuration can also realize a dual domain orientation.

[0134] [Reflective layer] The reflective layer 13 may have a laminated structure including a metal layer and a transparent conductive layer. A preferred example of the configuration in which the reflective layer 13 has such a laminated structure will be described with reference to FIG.

[0135] 12, the reflective layer 13 includes a transparent conductive layer 13b made of a transparent conductive material and a metal layer 13a made of a metal material and provided on the transparent conductive layer 13b. The metal layer 13a has at least one opening 13ao, and the transparent conductive layer 13b is formed to include a portion that overlaps with the opening 13ao of the metal layer 13a.

[0136] The openings 13ao of the metal layer 13a are formed, for example, in the same number as the number of the first contact holes CH1, that is, in correspondence with the first contact holes CH1. As shown in Fig. 12, when viewed from the normal direction of the display surface, the first contact holes CH1 overlap with the corresponding openings 13ao. That is, in the region where the common electrode CE is connected to the reflective layer 13, the metal material of the metal layer 13a is removed, and the common electrode 13 is connected to the transparent conductive layer 13b.

[0137] In the vicinity of the first contact hole CH1, the cell thickness and the fringe electric field are different from those in other regions, so that alignment disturbance occurs. In particular, in the black display state, the vicinity of the first contact hole CH1 shines white (or gray) due to the alignment disturbance, and the contrast ratio decreases. As shown in FIG. 12, the first contact hole CH1 overlaps the opening 13ao of the metal layer 13a, so that the decrease in the contrast ratio caused by the alignment disturbance in the vicinity of the first contact hole CH1 can be suppressed.

[0138] In the laminated structure shown in Fig. 12, the metal layer 13a is provided on the transparent conductive layer 13b, but the transparent conductive layer 13b may be provided on the metal layer 13a as shown in Fig. 13. Also in the example shown in Fig. 13, the first contact hole CH1 overlaps with the opening 13ao of the metal layer 13a, thereby suppressing a decrease in the contrast ratio.

[0139] Figures 12 and 13 show an example in which a laminated reflective layer 13 is adopted in a configuration in which the common electrode CE is provided below the pixel electrode PE, but it goes without saying that a laminated reflective layer 13 may also be adopted in a configuration in which the common electrode CE is provided above the pixel electrode PE.

[0140] [Oxide Semiconductor TFT] As the TFT 11 provided in each pixel P, for example, an oxide semiconductor TFT can be suitably used (although, of course, the present invention is not limited to this). In the oxide semiconductor TFT, an oxide semiconductor is used as a material for an active layer. In other words, the oxide semiconductor TFT includes an oxide semiconductor layer as an active layer. In recent years, the oxide semiconductor is a material that has attracted attention as an active layer material to replace amorphous silicon and polycrystalline silicon.

[0141] Oxide semiconductors have higher mobility than amorphous silicon. Therefore, oxide semiconductor TFTs can operate at higher speeds than amorphous silicon TFTs. In addition, oxide semiconductor layers can be formed in a simpler process than polycrystalline silicon layers, so they can be used in devices that require a large area.

[0142] Furthermore, since oxide semiconductor TFTs have excellent off-leak characteristics, it is possible to use a driving method that reduces the frequency of image rewriting for display. For example, when displaying a still image, it is possible to operate the device so that image data is rewritten once per second. This type of driving method is called pause driving or low-frequency driving, and it is possible to significantly reduce the power consumption of liquid crystal display devices.

[0143] By adopting pause drive and performing touch detection during periods when the image is not being rewritten, it is possible to suppress the reduction in sensitivity of touch operations caused by noise from the drive circuit, and to increase the S / N ratio (signal-to-noise ratio) to, for example, approximately 10 times that of the conventional method.

[0144] In addition, since the oxide semiconductor TFT is advantageous in terms of miniaturizing the TFT size, it is also possible to suitably realize a configuration (called "Memory In Pixels (MIP)") in which a memory circuit is provided for each pixel P. The specific configuration of the MIP is well known, and therefore a description thereof will be omitted here.

[0145] The oxide semiconductor contained in the active layer (oxide semiconductor layer) of the oxide semiconductor TFT may be an amorphous oxide semiconductor or a crystalline oxide semiconductor having a crystalline portion. Examples of the crystalline oxide semiconductor include a polycrystalline oxide semiconductor, a microcrystalline oxide semiconductor, and a crystalline oxide semiconductor whose c-axis is oriented approximately perpendicular to the layer surface.

[0146] The oxide semiconductor layer may have a stacked structure of two or more layers. The oxide semiconductor layer having a stacked structure may include an amorphous oxide semiconductor layer and a crystalline oxide semiconductor layer, or may include a plurality of crystalline oxide semiconductor layers having different crystal structures. The oxide semiconductor layer having a stacked structure may include a plurality of amorphous oxide semiconductor layers. When the oxide semiconductor layer has a two-layer structure including an upper layer and a lower layer, the energy gap of the oxide semiconductor included in the lower layer may be different from the energy gap of the oxide semiconductor included in the upper layer.

[0147] The materials, structures, film formation methods, and configurations of oxide semiconductor layers having a laminated structure of the amorphous oxide semiconductor and the above-mentioned crystalline oxide semiconductors are described in, for example, JP 2014-007399 A. For reference, the entire disclosure of JP 2014-007399 A is incorporated herein by reference.

[0148] The oxide semiconductor layer may contain at least one metal element selected from, for example, In, Ga, and Zn. In this embodiment, the oxide semiconductor layer contains, for example, an In-Ga-Zn-O-based semiconductor (for example, indium gallium zinc oxide). Here, the In-Ga-Zn-O-based semiconductor is a ternary oxide of In (indium), Ga (gallium), and Zn (zinc), and the ratio (composition ratio) of In, Ga, and Zn is not particularly limited, and includes, for example, In:Ga:Zn=2:2:1, In:Ga:Zn=1:1:1, In:Ga:Zn=1:1:2, etc. Such an oxide semiconductor layer 11 may be formed from an oxide semiconductor film containing an In-Ga-Zn-O-based semiconductor.

[0149] The In-Ga-Zn-O based semiconductor may be amorphous or crystalline. As the crystalline In-Ga-Zn-O based semiconductor, a crystalline In-Ga-Zn-O based semiconductor in which the c-axis is oriented approximately perpendicular to the layer surface is preferable.

[0150] The crystal structure of the crystalline In-Ga-Zn-O-based semiconductor is disclosed in, for example, the above-mentioned JP 2014-007399 A, JP 2012-134475 A, JP 2014-209727 A, etc. For reference, the entire disclosure of JP 2012-134475 A and JP 2014-209727 A is incorporated herein by reference. Since a TFT having an In-Ga-Zn-O-based semiconductor layer has high mobility (more than 20 times that of an a-Si TFT) and low leakage current (less than 1 / 100 that of an a-Si TFT), it is suitable for use as a driving TFT (for example, a TFT included in a driving circuit provided on the same substrate as the display area around a display area including a plurality of pixels) and a pixel TFT (a TFT provided in a pixel).

[0151] The oxide semiconductor layer may contain other oxide semiconductors instead of the In-Ga-Zn-O based semiconductor. For example, an In-Sn-Zn-O based semiconductor (e.g., In 2 O 3 -SnO 2 In-ZnO; InSnZnO). The In-Sn-Zn-O based semiconductor is a ternary oxide of In (indium), Sn (tin) and Zn (zinc). Alternatively, the oxide semiconductor layer 11 may include an In-Al-Zn-O based semiconductor, an In-Al-Sn-Zn-O based semiconductor, a Zn-O based semiconductor, an In-Zn-O based semiconductor, a Zn-Ti-O based semiconductor, a Cd-Ge-O based semiconductor, a Cd-Pb-O based semiconductor, CdO (cadmium oxide), an Mg-Zn-O based semiconductor, an In-Ga-Sn-O based semiconductor, an In-Ga-O based semiconductor, a Zr-In-Zn-O based semiconductor, an Hf-In-Zn-O based semiconductor, an Al-Ga-Zn-O based semiconductor, a Ga-Zn-O based semiconductor, an In-Ga-Zn-Sn-O based semiconductor, or the like.

[0152] [Semi-transparent type] In the above description, the reflective liquid crystal display devices 100, 200, 300, and 400 have been illustrated as examples, but the liquid crystal display devices according to the embodiments of the present invention may be semi-transmissive. The configuration of a semi-transmissive liquid crystal display device 500 will be described with reference to FIG.

[0153] The liquid crystal display device 500 differs from the liquid crystal displays 100, 200, 300, and 400 in that it includes an additional polarizing plate 40', an additional retardation layer 50', and an illumination device (backlight) .

[0154] The polarizing plate 40' is disposed on the rear side of the liquid crystal layer 30. More specifically, the polarizing plate 40' is disposed on the rear side of the TFT substrate .

[0155] The retardation layer 50' is disposed between the polarizing plate 40' and the liquid crystal layer 30. More specifically, the retardation layer 50' is disposed between the polarizing plate 40' and the TFT substrate 10. The retardation layer 50 may include, for example, a λ / 2 plate and a λ / 4 plate.

[0156] The illumination device 70 is disposed on the rear side of the polarizing plate 40' (the rear side of the TFT substrate 10). In the example shown in the figure, the illumination device 70 has a light source (e.g., an LED) 71 that emits light, a light guide plate 72 that guides the light from the light source 71 to the polarizing plate 40', and a reflector 73 disposed on the rear side of the light guide plate 72. The illumination device 70 may further have a prism sheet and a diffusion sheet disposed on the front side (or rear side) of the light guide plate 72.

[0157] As shown in Fig. 15, each pixel P of the liquid crystal display device 500 includes a reflective region Rf for performing display in a reflective mode and a transmissive region Tr for performing display in a transmissive mode. The reflective layer 13 (each reflective segment 13S) of the TFT substrate 10 has an opening 13o formed in the transmissive region Tr. The proportion of the area of ​​the transmissive region Tr in the pixel P can be appropriately set depending on the application, etc., and is, for example, 20% or more and 90% or less. The position and shape of the transmissive region Tr in the pixel P can also be appropriately set depending on the application, etc. [Industrial Applicability]

[0158] According to the embodiment of the present invention, it is possible to realize a pixel structure suitable for a liquid crystal display device capable of displaying in a reflective mode and being used as an in-cell touch panel. The embodiment of the present invention is suitable for use in reflective and semi-transmissive liquid crystal display devices. [Explanation of symbols]

[0159] 10 Active matrix substrate (TFT substrate) 10a, 20a board 11 Thin-film transistor (TFT) 12 First interlayer insulating layer 13 Reflective layer 13o opening 13a metal layer 13ao Metal layer opening 13b Transparent conductive layer 13X Reflection Segment 14 Second interlayer insulating layer 15 Dielectric layer 16 Contact electrode 19 First horizontal alignment film 20 Counter substrate (color filter substrate) 21 Color filter layer 29 Second horizontal alignment film 30 Liquid crystal layer 31 Liquid crystal molecules 40 Polarizing plate 40' More polarizers 50 Retardation layer 50' Further retardation layer 51 λ / 2 plate 52 λ / 4 plate 70 Lighting device (backlight) 71 Light source 72 Light guide plate 73 Reflector 100, 200, 300, 400, 500 LCD display device P pixels PE pixel electrode CE Common electrode UE upper layer electrode GL Gate wiring SL Source wiring BP Backplane circuit CH1 1st Contact Hole CH2 2nd Contact Hole CH D Drain Contact Hole CH P Pixel Contact Hole sp Top electrode strip spa First part of the belt spb Second part of the belt sp1 1st band sp2 Second band sl Slit in the upper electrode DR display area FR hidden area TL Touch Wiring TX touch sensor electrode TD Touch Drive Unit Rf reflective area Tr transmission area

Claims

1. A first substrate; A second substrate disposed closer to a viewer than the first substrate; a liquid crystal layer provided between the first substrate and the second substrate; a polarizing plate disposed on a viewer side of the liquid crystal layer; a retardation layer disposed between the polarizing plate and the liquid crystal layer; Equipped with A liquid crystal display device having a plurality of pixels arranged in a matrix including a plurality of rows and a plurality of columns, Each of the plurality of pixels includes a reflective area that performs display in a reflective mode; The first substrate is A plurality of gate wirings extending in a row direction; A plurality of source lines extending in a column direction; a plurality of thin film transistors each provided corresponding to one of the plurality of pixels; a plurality of pixel electrodes each electrically connected to a corresponding one of the plurality of thin film transistors; a reflective layer formed of a conductive material and located at least in the reflective region, the reflective layer being located on the opposite side of the pixel electrode from the liquid crystal layer; having The first substrate is A plurality of touch sensor electrodes to which different signals can be applied; a plurality of touch wirings each electrically connected to a corresponding one of the plurality of touch sensor electrodes; and the reflective layer is divided into a plurality of reflective segments that are electrically independent from one another; A liquid crystal display device, wherein each of the plurality of reflective segments overlaps, in a plan view, two or more pixel electrodes among the plurality of pixel electrodes.

2. The liquid crystal display device according to claim 1 , wherein the two or more pixel electrodes overlapping the respective reflective segments are arranged in a plurality of rows and a plurality of columns.

3. The liquid crystal display device according to claim 1 , wherein the number of the plurality of reflective segments is equal to or greater than the number of the plurality of touch sensor electrodes.

4. The liquid crystal display device according to claim 1 , wherein different voltages can be applied to the plurality of reflective segments.

5. The liquid crystal display device according to claim 4 , wherein each of the plurality of reflective segments is electrically connected to a corresponding touch sensor electrode among the plurality of touch sensor electrodes and a corresponding touch wiring among the plurality of touch wirings.

6. 6. The liquid crystal display device according to claim 5, wherein each of the plurality of reflective segments is electrically connected to the corresponding touch sensor electrode via at least one first contact hole and is electrically connected to the corresponding touch wiring via at least one second contact hole.

7. 7. The liquid crystal display device according to claim 6, wherein the at least one first contact hole is a plurality of first contact holes and / or the at least one second contact hole is a plurality of second contact holes.

8. The liquid crystal display device according to claim 6 , wherein the at least one first contact hole is formed at a position different from that of the at least one second contact hole in a plan view.

9. 9. The liquid crystal display device of claim 8, wherein any one of the at least one first contact hole is separated from each of the at least one second contact hole by at least one pixel in either or both of the row direction and the column direction.

10. the at least one first contact hole is a plurality of first contact holes, The liquid crystal display device according to claim 6 , wherein any one of the plurality of first contact holes is formed at a position different from other first contact holes in a plan view.

11. The liquid crystal display device according to claim 10 , wherein any one of the plurality of first contact holes is separated from another first contact hole by at least one pixel in either or both of the row direction and the column direction.

12. the at least one second contact hole is a plurality of second contact holes, 7. The liquid crystal display device according to claim 6, wherein any one of the plurality of second contact holes is formed at a position different from other second contact holes in a plan view.

13. 13. The liquid crystal display device according to claim 12, wherein any one of the plurality of second contact holes is separated from another second contact hole by at least one pixel in either or both of the row direction and the column direction.

14. 7. The liquid crystal display device according to claim 6, wherein at least one of the at least one first contact hole and the at least one second contact hole is located between adjacent pixel electrodes of the plurality of pixel electrodes.

15. The liquid crystal display device according to claim 1 , wherein at least one of the plurality of touch wirings overlaps, in a plan view, a region between adjacent ones of the plurality of reflective segments.

16. 3. The liquid crystal display device according to claim 1, wherein an area between adjacent touch sensor electrodes among the plurality of touch sensor electrodes and an area between adjacent pixel electrodes among the plurality of pixel electrodes overlap in a planar view.

17. 3. The liquid crystal display device according to claim 1, wherein each of the plurality of reflective segments, an area between adjacent touch sensor electrodes among the plurality of touch sensor electrodes, and an area between adjacent pixel electrodes among the plurality of pixel electrodes overlap in a planar view.

18. The touch wirings are adjacent to a lower surface of the reflective layer via a first insulating layer, The liquid crystal display device according to claim 1 , wherein the plurality of touch sensor electrodes or the plurality of pixel electrodes are adjacent to an upper surface of the reflective layer via a second insulating layer.

19. 3. The liquid crystal display device according to claim 1, wherein each of the plurality of touch wirings is disposed between adjacent gate wirings among the plurality of gate wirings, or between adjacent source wirings among the plurality of source wirings.

20. The liquid crystal display device according to claim 1 , wherein the plurality of touch wirings are formed from the same conductive film as the plurality of gate wirings or the plurality of source wirings.

21. Each of the plurality of pixels includes a transmissive region that performs display in a transmissive mode; Each of the plurality of reflective segments has an opening formed in the transmissive region; The liquid crystal display device includes a light source and a further polarizing plate disposed on the rear side of the first substrate, and a further retardation layer disposed between the further polarizing plate and the liquid crystal layer, The liquid crystal display device according to claim 1 , further comprising:

22. The first substrate further includes an insulating layer formed to cover the plurality of reflective segments, Each of the plurality of reflective segments has a rough surface structure; 3. The liquid crystal display device according to claim 1, wherein the thickness of the insulating layer is greater than the height difference of the concave-convex surface structure.

23. 23. The liquid crystal display device according to claim 22, wherein the thickness of the insulating layer is at least twice the height difference of the uneven surface structure.

24. an upper surface of the insulating layer at a portion that overlaps the uneven surface structure of the plurality of reflective segments has an uneven shape; 23. The liquid crystal display device according to claim 22, wherein a height difference of the uneven shape of the insulating layer is equal to or less than half a height difference of the uneven surface structure of the plurality of reflective segments.

25. The touch sensor electrodes and the pixel electrodes are adjacent to each other via a dielectric layer, The liquid crystal display device according to claim 1 , wherein at least one of the plurality of touch sensor electrodes and the plurality of pixel electrodes includes at least one slit.

26. the first substrate has a first horizontal alignment film in contact with the liquid crystal layer; the second substrate has a second horizontal alignment film in contact with the liquid crystal layer, The liquid crystal layer has a twisted orientation when no voltage is applied, 3. The liquid crystal display device according to claim 1, wherein a twist angle of said liquid crystal layer when no voltage is applied is equal to or greater than 45 degrees and equal to or less than 90 degrees.

27. 3. The liquid crystal display device according to claim 1, wherein substantially the same voltage can be applied to the plurality of reflective segments at substantially the same timing.

28. 3. The liquid crystal display device according to claim 1, wherein substantially the same voltage can be applied at substantially the same timing to a group of pixel electrodes among the plurality of pixel electrodes located in the same pixel row or the same pixel column, and to one or more reflective segments among the plurality of reflective segments that overlap the group of pixel electrodes in a planar view.

29. 3. The liquid crystal display device according to claim 1, wherein the reflective layer is located between the liquid crystal layer and the plurality of thin film transistors and at least partially overlaps the plurality of thin film transistors in a plan view.

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