Liquid crystal display device

Abstract

To provide a liquid crystal display device that can display in a reflective mode and may be suitably used as an in-cell touch panel.SOLUTION: A liquid crystal display device comprises a first substrate, a second substrate arranged closer to a viewer than the first substrate, and a liquid crystal layer provided between the first substrate and the second substrate, and has a plurality of pixels. Each pixel includes a reflective region where the display is performed in a reflective mode. The first substrate includes a substrate, gate lines extending in a row direction, source lines extending in a column direction, thin-film transistors provided corresponding to each pixel, pixel electrodes electrically connected to the thin-film transistors, and a reflective layer provided between the pixel electrodes and the substrate. The first substrate further includes a plurality of touch sensor electrodes and touch lines electrically connected to the respective touch sensor electrodes. The touch lines are formed from the same conducting film as that of the source lines, and are provided between the reflective layer and the substrate.SELECTED DRAWING: Figure 4

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.

[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 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 provide a liquid crystal display device that is capable of displaying in reflective mode and can be suitably used as an in-cell type 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; 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 substrate; 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 area, the reflective layer being provided between the pixel electrode and the substrate; 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 liquid crystal display device, wherein the plurality of touch wirings are formed from the same conductive film as the plurality of source wirings, and are provided between the reflective layer and the substrate.

[0012] [Item 2] 2. The liquid crystal display device according to item 1, wherein each of the plurality of touch wirings is disposed between adjacent source wirings among the plurality of source wirings.

[0013] [Item 3] 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, 3. The liquid crystal display device according to item 1 or 2, wherein the liquid crystal layer has a twisted alignment when no voltage is applied.

[0014] [Item 4] 4. The liquid crystal display device according to item 3, wherein a twist angle of the liquid crystal layer when no voltage is applied is between 45° and 90°.

[0015] [Item 5] The liquid crystal display device described in any one of items 1 to 4, wherein the reflective layer includes a portion that electrically connects any one of the plurality of touch sensor electrodes to a touch wiring corresponding to the one touch sensor electrode among the plurality of touch wirings.

[0016] [Item 6] 6. The liquid crystal display device according to any one of items 1 to 5, wherein at least a portion of the reflective layer has a concave-convex surface structure.

[0017] [Item 7] The first substrate is a first interlayer insulating layer provided between the reflective layer and the thin film transistor; a second interlayer insulating layer provided between the pixel electrode and the reflective layer; 7. The liquid crystal display device according to any one of items 1 to 6, further comprising:

[0018] [Item 8] the first substrate further includes a common electrode provided to face the pixel electrode via a dielectric layer; the common electrode is divided into a plurality of segments that function as the plurality of touch sensor electrodes; 8. The liquid crystal display device according to any one of items 1 to 7, wherein at least one of the pixel electrode and the common electrode includes at least one slit.

[0019] [Item 9] 9. The liquid crystal display device according to any one of items 1 to 8, wherein the source lines and the touch lines are located closer to the liquid crystal layer than the gate lines.

[0020] [Item 10] 9. The liquid crystal display device according to any one of items 1 to 8, wherein the source lines and the touch lines are located closer to the substrate than the gate lines.

[0021] [Item 11] Each of the plurality of pixels includes a transmissive region that performs display in a transmissive mode; 11. The liquid crystal display device according to any one of items 1 to 10, wherein the reflective layer has an opening formed in the transmissive region. Effect of the Invention

[0022] According to an embodiment of the present invention, it is possible to provide a liquid crystal display device that is capable of displaying in a reflective mode and that can be suitably used as an in-cell touch panel. [Brief description of the drawings]

[0023] [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 plan view that illustrates a liquid crystal display device 100. [Figure 4] FIG. 4 is a cross-sectional view that diagrammatically illustrates the liquid crystal display device 100, showing a cross section taken along line 4A-4A' in FIG. [Diagram 5] 2 is a plan view illustrating an example of the arrangement relationship between touch sensor electrodes TX and touch wirings TL in the liquid crystal display device 100. FIG. [Figure 6] FIG. 1 is a plan view that diagrammatically illustrates a liquid crystal display device 900 of a comparative example. [Figure 7] FIG. 1 is a cross-sectional view that diagrammatically illustrates a liquid crystal display device 900. [Figure 8] 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 9]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 10] FIG. 11 is a cross-sectional view that illustrates a schematic diagram of a liquid crystal display device 400 according to still another embodiment of the present invention. [Figure 11] FIG. 11 is a cross-sectional view that diagrammatically illustrates a liquid crystal display device 500 according to still another embodiment of the present invention. [Figure 12] 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

[0024] 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.

[0025] [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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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).

[0031] The common electrode CE is provided to face the pixel electrode PE via a dielectric layer, and together with the pixel electrode PE, can generate a transverse electric field (fringe electric field) in the liquid crystal layer 30. The common electrode CE is divided into a plurality of segments, as described later.

[0032] 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. 4. Fig. 3 is a plan view that shows a schematic diagram of a liquid crystal display device 100. Fig. 4 is a cross-sectional view that shows a schematic diagram of the liquid crystal display device 100, showing a cross section taken along line 4A-4A' in Fig. 3.

[0033] The TFT substrate 10 includes a substrate 10a, a TFT 11, a first interlayer insulating layer 12, and a reflective layer 13. The TFT substrate 10 further includes a second interlayer insulating layer 14, a common electrode CE, a dielectric layer 15, a pixel electrode PE, and a first horizontal alignment film 19.

[0034] 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.

[0035] 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 semiconductor layer SC, a gate insulating layer GI, a gate electrode GE, a source electrode SE, and a drain electrode DE. The gate electrode GE is electrically connected to a corresponding gate line GL, and the source electrode SE is electrically connected to a corresponding source line SL. The drain electrode DE is electrically connected to a pixel electrode PE. A circuit for driving the plurality of pixels P, including the TFT 11, the gate line GL, the source line SL, etc., is sometimes called a backplane circuit.

[0036] The illustrated TFT 11 has a top-gate structure. The semiconductor layer SC is provided on the substrate 10a. The semiconductor layer SC is a polycrystalline silicon layer (for example, a low-temperature polysilicon (LTPS) layer) here.

[0037] A gate insulating layer GI is formed so as to cover the semiconductor layer SC, and a gate electrode GE is provided on the gate insulating layer GI. The gate electrode GE faces a part (channel region) of the semiconductor layer SC via the gate insulating layer. Here, the gate electrode GE is formed integrally with the gate wiring GL.

[0038] A lower insulating layer 16 is formed so as to cover the gate electrode GE, and a source electrode SE and a drain electrode DE are provided on the lower insulating layer 16. The source electrode SE and the drain electrode DE are formed from the same conductive film as the source wiring SL (i.e., in the same layer as the source wiring SL). Here, the source electrode SE is formed integrally with the source wiring SL. The source electrode SE is contacted through a source contact hole CH formed in the lower insulating layer 16 and the gate insulating layer GI. S The drain electrode DE is electrically connected to the semiconductor layer SC through a drain contact hole CH formed in the lower insulating layer 16 and the gate insulating layer GI. D , it is electrically connected to the semiconductor layer SC.

[0039] The first interlayer insulating layer 12 is provided so as to cover the backplane circuit including the TFT 11. 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.

[0040] 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 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.

[0041] 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.

[0042] In the illustrated example, the reflective layer 13 includes a first portion 13a, a second portion 13b and a third portion 13c.

[0043] The first portion 13a of the reflective layer 13 occupies the majority of the reflective layer 13, and has an uneven shape on its surface. That is, the first portion 13a of the reflective layer 13 has an uneven surface structure. This uneven surface structure 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.

[0044] There is no particular limitation on the method for forming the uneven surface structure on at least a part of 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 at least a part of 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.

[0045] The second portion 13b of the reflective layer 13 functions as a "first contact electrode" for electrically connecting the drain electrode DE and the pixel electrode PE of the TFT 11, as described later. The third portion 13c of the reflective electrode 13 functions as a "second contact electrode" for electrically connecting the touch wiring TL and the touch sensor electrode TX, as described later. The first portion 13a, the second portion (first contact electrode) 13b, and the third portion (second contact electrode) 13c of the reflective layer 13 are electrically isolated from each other.

[0046] In the illustrated example, a transparent conductive layer 17 is interposed between the reflective layer 13 and the first interlayer insulating layer 12. Examples of transparent conductive materials for forming the transparent conductive layer 17 include indium tin oxide (ITO), indium zinc oxide (IZO (registered trademark)), or a mixture thereof. In the transparent conductive layer 17, portions 17a, 17b, and 17c located directly below the first portion 13a, the second portion 13b, and the third portion 13c of the reflective layer 13 are referred to as the "first portion," the "second portion," and the "third portion" of the transparent conductive layer 17, respectively. The transparent conductive layer 17 may be omitted.

[0047] 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.

[0048] The common electrode CE is provided on the second interlayer insulating layer 14. The common electrode CE is made of a transparent conductive material. The transparent conductive material for forming the common electrode CE may be the same material as that for the transparent conductive layer 17. The dielectric layer 15 is provided so as to cover the common electrode CE. The dielectric layer 15 may be made of, for example, an inorganic insulating material.

[0049] The pixel electrode PE is provided in each of the multiple pixels P. Moreover, the pixel electrode PE is provided on the dielectric layer 15. Therefore, it can be said that the second interlayer insulating layer 14 is provided between the pixel electrode PE and the reflective layer 13. Moreover, it can be said that 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 (i.e., between the pixel electrode PE and the substrate 10a).

[0050] The pixel electrode PE is made of a transparent conductive material. The transparent conductive material for forming the pixel electrode PE may be the same as that for the transparent conductive layer 17. The pixel electrode PE is electrically connected to the TFT 11.

[0051] In the illustrated example, the pixel electrode PE is electrically connected to the drain electrode DE of the TFT 11 via the first contact electrode 13b. The first interlayer insulating layer 12 has a first pixel contact hole CH P1 The first contact electrode 13b is formed through the first pixel contact hole CH P1 The first contact electrode 13b is electrically connected to the drain electrode DE of the TFT 11 at the drain electrode DE. Here, a second portion 17b of the transparent conductive layer 17 is interposed between the first contact electrode 13b and the drain electrode DE. In addition, the second interlayer insulating layer 14 is provided with a second pixel contact hole CH P2 The pixel electrode PE is formed through the second pixel contact hole CH P2 The pixel electrode PE is electrically connected to the first contact electrode 13b at the pixel electrode PE. Here, a third contact electrode 18 formed from the same transparent conductive film as the common electrode CE is interposed between the pixel electrode PE and the first contact electrode 13b. The third contact electrode 18 may be omitted.

[0052] The pixel electrode PE has at least one (here, multiple) slit s. By forming the slit s in the pixel electrode PE, 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.

[0053] The first horizontal alignment film 19 is provided on the pixel electrodes PE and the dielectric layer 15, and is in contact with the liquid crystal layer 30. Therefore, it can be said that the pixel electrodes 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 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.

[0054] The counter substrate 20 has a substrate 20a, a color filter layer 21, an overcoat layer 22, and a second horizontal alignment film 29. Although not shown here, the counter substrate 20 further has a plurality of columnar spacers.

[0055] 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.

[0056] 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. If color display is not performed, the color filter layer 21 is omitted.

[0057] The overcoat layer (planarization layer) is provided so as to cover the color filter layer 21. Depending on the transparent conductive material (for the transparent conductive layer 19, pixel electrode PE, and 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.

[0058] The columnar spacers define the thickness (cell gap) of the liquid crystal layer 30. The columnar spacers can be formed from a photosensitive resin.

[0059] The second horizontal alignment film 29 is provided on the overcoat layer 22 and is in contact with the liquid crystal layer 30 .

[0060] 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.

[0061] 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.

[0062] 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. 4. 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.

[0063] 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.

[0064] 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. The plurality of touch wirings TL extends in the column direction (the same direction as the source wirings SL), and each touch wiring TL is disposed between adjacent source wirings SL. The plurality of touch wirings TL is 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 is covered with the first interlayer insulating layer 12, and is located between the reflective layer 13 and the substrate 10a.

[0065] In the illustrated example, each touch wiring TL and the corresponding touch sensor electrode TX are electrically connected via a second contact electrode 13c. The first interlayer insulating layer 12 has a first touch contact hole CH T1 The second contact electrode 13c is formed through the first touch contact hole CH T1 The second contact electrode 13c is electrically connected to the touch wiring TL at the third portion 17c of the transparent conductive layer 17. The third portion 17c of the transparent conductive layer 17 is interposed between the second contact electrode 13c and the touch wiring TL. The second interlayer insulating layer 14 also has a second touch contact hole CH T2 The touch sensor electrode TX is formed through the second touch contact hole CH T2 1, the second contact electrode 13c is electrically connected to the second contact electrode 13c.

[0066] Fig. 5 is a plan view illustrating an example of the arrangement relationship between the touch sensor electrodes TX and the touch wiring TL. 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."

[0067] In the display region DR, the common electrode CE is divided into a plurality of segments (touch sensor electrodes) TX. Each touch sensor electrode TX is electrically connected to a corresponding touch wiring TL. A connection portion TC between the touch sensor electrode TX and the touch wiring TL is called a "touch wiring contact portion."

[0068] The touch wiring TL is connected to a touch drive unit TD provided in the non-display region FR. The touch drive 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. For example, in the display mode, the touch drive unit TD applies a common signal to the touch sensor electrodes TX (common electrodes CE) via the touch wiring TL. On the other hand, in the touch detection mode, the touch drive unit TD applies a touch drive signal to the touch sensor electrodes TX via the touch wiring TL.

[0069] A common signal (common voltage) different from the common signal applied to the touch sensor electrode TX may be input from the non-display area FR to the first portion 13a (portion having an uneven surface structure) of the reflective layer 13. However, the present invention is not limited to such an embodiment, and there is no particular limit to the voltage applied to the first portion 13a of the reflective layer 13. The first portion 13a of the reflective layer 13 may be, for example, in an electrically floating state.

[0070] The touch wirings TL extend in the column direction (the same direction as the source bus lines SL). Some of the touch wirings TL extend to a corresponding touch sensor electrode TX across one or more other touch sensor electrodes TX.

[0071] Focusing on a certain touch sensor electrode TX, a first touch wiring TL1 that supplies a signal to that touch sensor electrode TX extends to a touch wiring contact portion TC, and a second touch wiring TL2 that supplies a signal to another touch sensor electrode TX extends across that touch sensor electrode TX. Depending on the position of the touch sensor electrode TX, two or more touch wirings TL may be arranged to extend across that touch sensor electrode TX, or no touch wiring TL may be arranged to cross that touch sensor electrode TX.

[0072] 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 gate signals to the gate bus lines GL and a source driver that supplies source signals to the source bus lines 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.

[0073] As described above, in the liquid crystal display device 100 of this embodiment, the touch wiring TL is formed from the same conductive film as the source wiring SL (i.e., in the same layer as the source wiring SL), and is provided between the reflective layer 13 and the substrate 10a (i.e., on the opposite side of the liquid crystal layer 30 with respect to the reflective layer 13). This makes it possible to simplify the manufacturing process and reduce manufacturing costs, compared to the case where the configuration of a conventional in-cell touch panel is simply applied to a reflective liquid crystal display device. The reason why such an advantage is obtained will be explained below.

[0074] 6 and 7 are a plan view and a cross-sectional view that typically show a comparative liquid crystal display device 900. The comparative liquid crystal display device 900 can be said to be a simple application of the configuration of a conventional in-cell touch panel to a reflective liquid crystal display device.

[0075] The liquid crystal display device 900 of the comparative example differs from the liquid crystal display device 100 in that the touch wiring TL is formed from a conductive film different from that of the source wiring SL (i.e., in a layer separate from the source wiring SL). In the liquid crystal display device 900, the touch wiring TL is provided on the second insulating layer 14, and an upper insulating layer 61 is formed so as to cover the touch wiring TL. The upper insulating layer 61 may be, for example, an organic insulating layer formed from a photosensitive resin or an inorganic insulating layer formed from silicon nitride (SiNx). The upper insulating layer 61 has a touch contact hole CH that exposes a part of the touch wiring TL. T This touch contact hole CH T In the upper insulating layer 61, the touch wiring TL is electrically connected to the touch sensor electrode TX located on the upper insulating layer 61. The touch wiring TL is located between the reflective layer 13 and the liquid crystal layer 30 (i.e., on the liquid crystal layer 30 side with respect to the reflective layer 13). The touch wiring TL overlaps with the source wiring SL in a planar view.

[0076] When manufacturing the liquid crystal display device 900 of the comparative example, it is necessary to add a step of depositing and patterning a new conductive film for forming the touch wiring TL, a step of depositing and patterning a new insulating layer (upper insulating layer 61) covering the touch wiring TL, etc. This increases the manufacturing process and manufacturing costs.

[0077] In contrast, in the liquid crystal display device 100 of the present embodiment, the touch wiring TL is formed from the same conductive film as the source wiring SL (i.e., in the same layer as the source wiring SL), and therefore, in manufacturing the liquid crystal display device 100, there is no need to add a step of depositing and patterning a new conductive film for forming the touch wiring TL, a step of forming a new insulating layer covering the touch wiring TL, etc. Therefore, compared with the liquid crystal display device 900 of the comparative example, it is possible to simplify the manufacturing process and reduce the manufacturing cost.

[0078] In addition, in the liquid crystal display device 100 of this embodiment, the touch wiring TL is provided between the reflective layer 13 and the substrate 10a (i.e., on the opposite side of the liquid crystal layer 30 with respect to the reflective layer 13), so that the decrease in the reflective aperture ratio and the reflectance caused by the touch wiring TL is small. In an in-cell touch panel using a transmissive liquid crystal display device, if the touch wiring is formed from the same conductive film as the source wiring, it is considered that the manufacturing process can be simplified and the manufacturing cost can be reduced. In that case, however, since the touch wiring cannot be arranged overlapping with the source wiring, the region where the touch wiring is provided cannot be used for transmissive display, and the transmittance decreases, that is, the optical performance decreases. In contrast, in the liquid crystal display device 100 of this embodiment, the touch wiring TL is located between the reflective layer 13 and the substrate 10a, so that the reflective aperture ratio and the reflectance are hardly decreased, and it can be said that the above-mentioned decrease in the optical performance hardly occurs.

[0079] In the above description, the pixel electrode PE is provided above the common electrode CE, but the common electrode CE may be provided above the pixel electrode PE. In the following, the pixel electrode PE and the common electrode CE that are located relatively higher may be referred to as the "upper layer electrode" and the lower electrode that are 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 lateral electric field, at least the upper layer electrode includes at least one slit in each pixel P.

[0080] 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).

[0081] 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.

[0082] In the configuration in which the pixel electrode PE is provided above the common electrode CE, a slit for generating a fringe electric field cannot be provided in the pixel electrode PE in the region where the pixel contact hole is formed, and an opening 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 the 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.

[0083] Furthermore, as already explained, the reduction in reflectance due to the area in which the pixel contact hole 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), so 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.

[0084] 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.

[0085] [Embodiment 2] A liquid crystal display device 200 according to the present embodiment will be described with reference to Fig. 8. Fig. 8 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.

[0086] The liquid crystal display device 200 of this embodiment differs from the liquid crystal display device 100 of embodiment 1 in that the semiconductor layer SC of the TFT 11 is an oxide semiconductor layer. The oxide semiconductor layer may be made of, for example, an In-Ga-Zn-O based semiconductor.

[0087] In the configuration illustrated in FIG. 8, the TFT 11 has a bottom gate structure. The gate electrode GE is provided on the substrate 10a, and a gate insulating layer GI is formed so as to cover the gate electrode GE. A semiconductor layer SC, which is an oxide semiconductor layer, is provided on the gate insulating layer GI. The source electrode SE and the drain electrode GE are provided on the semiconductor layer SC and the gate insulating layer GI. In the configuration illustrated in FIG. 8, the first insulating layer 12 has a laminated structure including an inorganic insulating layer 12a and an organic insulating layer 12b formed on the inorganic insulating layer 12a.

[0088] In the liquid crystal display device 200 of the present embodiment, the touch wiring TL is also formed from the same conductive film as the source wiring SL (i.e., in the same layer as the source wiring SL). Therefore, the touch wiring TL is provided in the gate insulating layer GI, and is located between the reflective layer 13 and the substrate 10a (i.e., on the opposite side of the reflective layer 13 from the liquid crystal layer 30).

[0089] The liquid crystal display device 200 of this embodiment also enables a simplified manufacturing process and reduced manufacturing costs, compared to the case where the configuration of a conventional in-cell touch panel is simply applied to a reflective liquid crystal display device.

[0090] [Embodiment 3] A liquid crystal display device 300 according to the present embodiment will be described with reference to Fig. 9. Fig. 9 is a cross-sectional view that illustrates the liquid crystal display device 300. The following description will focus on the differences between the liquid crystal display device 300 according to the present embodiment and the liquid crystal display device 100 according to the first embodiment.

[0091] The liquid crystal display device 300 of this embodiment differs from the liquid crystal display device 100 of embodiment 1 in that the first portion 13a of the reflective layer 13 does not have a concave-convex surface structure. In the liquid crystal display device 300, as shown in Fig. 9, the first interlayer insulating layer 12 does not have a concave-convex surface structure, and therefore the first portion 13a of the reflective layer 13 also does not have a concave-convex surface structure (i.e., has a substantially flat surface).

[0092] Also in the liquid crystal display device 300 of the present embodiment, the touch lines TL are formed from the same conductive film as the source lines SL (that is, in the same layer as the source lines SL), which makes it possible to simplify the manufacturing process and reduce manufacturing costs.

[0093] The liquid crystal display device 300 of this embodiment may further include a light scattering layer. By using the reflective layer 12 and the light scattering layer in combination, a display close to paper white can be realized. The light scattering layer may be, for example, a light scattering sheet disposed on the viewer side of the counter substrate 20.

[0094] [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 200 according to the second embodiment.

[0095] In the liquid crystal display device 200 of the second embodiment, the source lines SL and the touch lines TL are located closer to the liquid crystal layer 30 than the gate lines GL. In contrast, as described below, in the liquid crystal display device 400 of the present embodiment, the source lines SL and the touch lines TL are located closer to the substrate 10a than the gate lines GL.

[0096] 10, the TFT substrate 10 of the liquid crystal display device 400 further includes a light-shielding layer LS. The light-shielding layer LS is provided on the substrate 10a. The source wiring SL and the source electrode SE and drain electrode DE of the TFT 11 are formed from the same conductive film as the light-shielding layer LS (i.e., in the same layer as the light-shielding layer LS).

[0097] A lower insulating layer 16' is formed so as to cover the light-shielding layer LS and the like. A semiconductor layer SC, which is an oxide semiconductor layer, is provided on the lower insulating layer 16'. The light-shielding layer LS faces at least a channel region of the semiconductor layer SC via the lower insulating layer 16'. The semiconductor layer SC is in contact with a source contact hole CH formed in the lower insulating layer 16'. S and drain contact hole CH D , the transistor S1 is electrically connected to a source electrode SE and a drain electrode DE.

[0098] A gate insulating layer GI is formed so as to cover the semiconductor layer SC, and a gate electrode GE and a gate wiring GL are provided on the gate insulating layer GI. The gate electrode GE faces the channel region of the semiconductor layer SC via the gate insulating layer GI. A first pixel contact hole CH P1 is formed across the first interlayer insulating layer 12, the gate insulating layer GI, and the lower insulating layer 16'.

[0099] In the liquid crystal display device 400, the touch wiring TL is also formed from the same conductive film as the source wiring SL (i.e., in the same layer as the source wiring SL). Therefore, the touch wiring TL is covered with the lower insulating layer 16′, and the first touch contact hole CH T1 is formed across the first interlayer insulating layer 12, the gate insulating layer GI, and the lower insulating layer 16'.

[0100] In a typical top-gate oxide semiconductor TFT, a gate electrode is disposed on a part of an oxide semiconductor layer via a gate insulating layer, and a source electrode, a drain electrode, and a source wiring are disposed on the insulating layer covering the gate electrode. In other words, a source metal layer including a source wiring is located above a gate metal layer including a gate electrode. Here, such a configuration is called an "upper source structure."

[0101] In contrast, in the TFT substrate 10 of the liquid crystal display device 400, the source metal layer is located below the gate metal layer (that is, on the substrate 10a side). Here, such a configuration is called a "lower source structure".

[0102] Even in the liquid crystal display device 400 of this embodiment, in which a bottom source structure is adopted, the touch wiring TL is formed from the same conductive film as the source wiring SL (i.e., in the same layer as the source wiring SL), thereby making it possible to simplify the manufacturing process and reduce manufacturing costs.

[0103] [Oxide Semiconductor TFT] As the TFT 11 provided in each pixel P, an oxide semiconductor TFT can be suitably used, as exemplified in the liquid crystal display device 200 of the second embodiment and the liquid crystal display device 400 of the fourth embodiment. In the oxide semiconductor TFT, an oxide semiconductor is used as a material for an active layer. That is, 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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).

[0114] The oxide semiconductor layer may contain other oxide semiconductors instead of the In-Ga-Zn-O-based semiconductor. For example, it may contain an In-Sn-Zn-O-based semiconductor (e.g., In2O3-SnO2-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.

[0115] [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 device according to the embodiments of the present invention may be a semi-transmissive type. The configuration of a semi-transmissive liquid crystal display device 500 will be described with reference to FIG.

[0116] 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) .

[0117] 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 .

[0118] 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.

[0119] 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.

[0120] As shown in Fig. 12, 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 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]

[0121] According to an embodiment of the present invention, it is possible to provide a liquid crystal display device capable of displaying in a reflective mode and suitable for use 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]

[0122] 10 Active matrix substrate (TFT substrate) 10a, 20a board 11 Thin-film transistor (TFT) 12 First interlayer insulating layer 13 Reflective layer 13a First portion of reflective layer 13b Second portion of reflective layer (first contact electrode) 13c Third portion of reflective layer (second contact electrode) 13o opening 14 Second interlayer insulating layer 15 Dielectric layer 16, 16' Lower insulation layer 17 Transparent conductive layer 17a: First portion of transparent conductive layer 17b second portion of transparent conductive layer 17c Third portion of transparent conductive layer 18 Third contact electrode 19 First horizontal alignment film 20 Counter substrate (color filter substrate) 21 Color filter layer 22 Overcoat 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 TX touch sensor electrode s slit GL Gate wiring SL Source wiring TL Touch Wiring SC Semiconductor layer GE gate electrode SE source electrode DE Drain electrode GI Gate Insulation Layer CH S Source Contact Hole CH D Drain Contact Hole CH P1 First pixel contact hole CH P2 Second pixel contact hole CH T1 First touch contact hole CH T2 2nd touch contact hole LS light shielding layer DR display area FR hidden area 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; 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 substrate; 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 area, the reflective layer being provided between the pixel electrode and the substrate; 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 liquid crystal display device, wherein the plurality of touch wirings are formed from the same conductive film as the plurality of source wirings, and are provided between the reflective layer and the substrate.

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

3. 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, 3. The liquid crystal display device according to claim 1, wherein the liquid crystal layer has a twisted alignment when no voltage is applied.

4. 4. The liquid crystal display device according to claim 3, wherein a twist angle of said liquid crystal layer when no voltage is applied is equal to or greater than 45[deg.] and equal to or less than 90[deg.].

5. 3. The liquid crystal display device according to claim 1, wherein the reflective layer includes a portion that electrically connects any one of the plurality of touch sensor electrodes to a touch wiring that corresponds to the one touch sensor electrode among the plurality of touch wirings.

6. The liquid crystal display device according to claim 1 , wherein at least a portion of the reflective layer has an uneven surface structure.

7. The first substrate is a first interlayer insulating layer provided between the reflective layer and the thin film transistor; a second interlayer insulating layer provided between the pixel electrode and the reflective layer; The liquid crystal display device according to claim 1 , further comprising:

8. the first substrate further includes a common electrode provided to face the pixel electrode via a dielectric layer; the common electrode is divided into a plurality of segments that function as the plurality of touch sensor electrodes; The liquid crystal display device according to claim 1 , wherein at least one of the pixel electrode and the common electrode includes at least one slit.

9. The liquid crystal display device according to claim 1 , wherein the source wirings and the touch wirings are located closer to the liquid crystal layer than the gate wirings.

10. The liquid crystal display device according to claim 1 , wherein the source wirings and the touch wirings are located closer to the substrate than the gate wirings.

11. Each of the plurality of pixels includes a transmissive region that performs display in a transmissive mode; The liquid crystal display device according to claim 1 , wherein the reflective layer has an opening formed in the transmissive region.

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