Liquid crystal display device

Abstract

Provided is a liquid crystal display device that can display a reflective mode and can be used as an in-cell touch panel. The liquid crystal display device of the present invention comprises: a first substrate; a second substrate disposed closer to the observer side than the first substrate; the liquid crystal layer is arranged between the first substrate and the second substrate, and the liquid crystal display device is provided with a plurality of pixels. Each of the pixels includes a reflective region for display in a reflective mode. The first substrate has: a substrate; a plurality of gate wirings extending in the row direction; a plurality of source wirings extending in the column direction; a thin film transistor disposed corresponding to each pixel; a pixel electrode electrically connected to the thin film transistor; and a reflective layer provided between the pixel electrodes and the substrate, the first substrate further having a plurality of touch sensor electrodes and touch wirings electrically connected to the respective touch sensor electrodes. The touch wiring is formed of the same conductive film as the source wiring, and is provided between the reflective layer and the substrate.

Description

Technical Field

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

[0002] Liquid crystal display devices are generally divided into transmissive liquid crystal display devices and reflective liquid crystal display devices. Transmissive liquid crystal display devices display in a transmissive mode using light emitted from a backlight source. Reflective liquid crystal display devices display in a reflective mode using ambient light. In addition, a liquid crystal display device is proposed, which includes a reflective area in which each pixel displays in a reflective mode and a transmissive area in which each pixel displays in a transmissive mode. Such a liquid crystal display device is called a semi-transmissive (Transflective) or a transmissive-reflective dual-purpose liquid crystal display device.

[0003] Reflective and semi-transmissive liquid crystal display devices are preferably used as small and medium-sized display devices for mobile use, for example, outdoors. A reflective liquid crystal display device is disclosed in Patent Document 1, for example. A semi-transmissive liquid crystal display device is disclosed in Patent Document 2, for example.

[0004] In addition, a touch sensor function is provided to a liquid crystal display device used in a smartphone, a tablet computer, etc. As a type of touch sensor, various types such as a resistive film type, an electrostatic capacitance type, and an optical type are known.

[0005] Liquid crystal display devices with touch sensors (hereinafter referred to as "touch panels") are generally divided into a method in which the touch sensor is externally mounted on the liquid crystal display device ("external type") and a method in which the touch sensor is built into the liquid crystal display device ("built-in type"). Built-in touch panels are more advantageous in terms of thinness and weight reduction than external touch panels, and have the advantage of increased 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 includes: an active matrix substrate (TFT substrate); an opposing substrate, which is arranged to be opposite to the TFT substrate; and a liquid crystal layer, which is arranged between the TFT substrate and the opposing substrate. In the "on-cell" type, the layer that performs the touch sensor function is arranged inside the display panel. In the "on-cell" type, the layer that performs the touch sensor function is arranged between the display panel and a polarizing plate arranged on the observer side of the display panel. Prior art literature Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2000-122094 Patent Document 2: Japanese Patent Application Publication No. 2003-131268 Summary of the invention Technical Problems to be Solved by the Invention

[0008] The embedded type can realize the thinnest and lightest touch panel in principle. In addition, as described above, the liquid crystal display device capable of displaying in the reflection mode is suitable for outdoor use. Therefore, although the embedded touch panel capable of displaying in the reflection mode is desired, it has not yet been realized.

[0009] The embodiments of the present invention have been made in view of the above-mentioned problems, and an object of the present invention is to provide a liquid crystal display device that can perform reflective mode display and can be used as an in-cell touch panel. Technical solutions for solving technical problems

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

[0011] [Project 1] A liquid crystal display device, comprising: a first substrate; a second substrate, which is arranged closer to the observer side than the first substrate; and a liquid crystal layer, which is arranged between the first substrate and the second substrate, and the liquid crystal display device has 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 displayed in a reflective mode, and the first substrate has: a substrate; a plurality of gate wirings extending in a row direction; a plurality of source wirings extending in a column direction; a plurality of thin film transistors, each of the plurality of thin film transistors is arranged corresponding to each of the plurality of pixels; a plurality of pixel electrodes, Each of the multiple pixel electrodes is electrically connected to a corresponding thin film transistor among the multiple thin film transistors; and a reflective layer, which is formed of a conductive material and is located at least within the reflective area, and the reflective layer is arranged between the pixel electrode and the substrate, and the first substrate also has: a plurality of touch sensor electrodes, which can be applied with mutually different signals; and a plurality of touch wirings, each of the plurality of touch wirings is electrically connected to a corresponding touch sensor electrode among the multiple touch sensor electrodes, and the plurality of touch wirings are formed of the same conductive film as the plurality of source wirings, and are arranged between the reflective layer and the substrate.

[0012] [Project 2] According to the liquid crystal display device according to item 1, each of the plurality of touch wirings is arranged between mutually adjacent source wirings among the plurality of source wirings.

[0013] [Item 3] According to the liquid crystal display device described in item 1 or 2, the first substrate has a first horizontal alignment film in contact with the liquid crystal layer, and the second substrate has a second horizontal alignment film in contact with the liquid crystal layer, and when no voltage is applied, the liquid crystal layer exhibits a twisted orientation.

[0014] [Item 4] According to the liquid crystal display device according to item 3, a twist angle of the liquid crystal layer is greater than or equal to 45° and less than or equal to 90° when no voltage is applied.

[0015] [Item 5] According to any one of items 1 to 4, 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] According to the liquid crystal display device of any one of items 1 to 5, at least a portion of the reflective layer has a concavo-convex surface structure.

[0017] [Item 7] According to the liquid crystal display device described in any one of items 1 to 6, the first substrate further has: a first interlayer insulating layer, arranged between the reflective layer and the thin film transistor; and a second interlayer insulating layer, arranged between the pixel electrode and the reflective layer.

[0018] [Item 8] According to any one of items 1 to 7, the first substrate also has a common electrode, which is arranged to be opposite to the pixel electrode via a dielectric layer, and the common electrode is divided into a plurality of segments that function as the plurality of touch sensor electrodes, and at least one of the pixel electrode and the common electrode includes at least one slit.

[0019] [Item 9] According to the liquid crystal display device described in any one of items 1 to 8, the plurality of touch wirings are formed of the same conductive film as the plurality of gate wirings or the plurality of source wirings.

[0020] [Item 10] According to the liquid crystal display device described in any one of items 1 to 9, the plurality of source wirings and the plurality of touch wirings are located closer to the substrate than the plurality of gate wirings.

[0021] [Item 11] According to the liquid crystal display device described in any one of items 1 to 10, each of the plurality of pixels includes a transmissive region for displaying in a transmissive mode, and the reflective layer has an opening formed in the transmissive region. Beneficial Effects

[0022] According to the embodiment of the present invention, a pixel structure of a liquid crystal display device that can display a reflective mode and can be used as an in-cell touch panel can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a cross-sectional view schematically showing a liquid crystal display device 100 according to an embodiment of the present invention. Figure 2 2 is an equivalent circuit diagram of a plurality of pixels P included in the liquid crystal display device 100 . Figure 3 1 is a plan view schematically showing the liquid crystal display device 100 . Figure 4 is a cross-sectional view schematically showing the liquid crystal display device 100, and shows Figure 3 The cross-sectional structure of line 4A-4A' in FIG. Figure 5 1 is a plan view illustrating the arrangement relationship between the touch sensor electrodes TX and the touch wirings TL in the liquid crystal display device 100 . Figure 6 1 is a plan view schematically showing a liquid crystal display device 900 according to a comparative example. Figure 7 is a cross-sectional view schematically showing the liquid crystal display device 900 . Figure 8 is a cross-sectional view schematically showing another liquid crystal display device 200 according to an embodiment of the present invention. Fig. 9 is a cross-sectional view schematically showing another liquid crystal display device 300 according to an embodiment of the present invention. Fig.10 is a cross-sectional view schematically showing another liquid crystal display device 400 according to an embodiment of the present invention. Fig.11 is a cross-sectional view schematically showing another liquid crystal display device 500 according to an embodiment of the present invention. Fig.12 1 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 . DETAILED DESCRIPTION

[0024] The following describes an embodiment of the present invention with reference to the drawings. In addition, the embodiment of the present invention is not limited to the following exemplified contents.

[0025] [Implementation Method 1] Reference Figure 1 as well as Figure 2 , a liquid crystal display device 100 according to this embodiment will be described. The liquid crystal display device 100 is a reflective liquid crystal display device that performs display in a normally black mode. Figure 1 is a cross-sectional view schematically showing the liquid crystal display device 100 . Figure 2 2 is an equivalent circuit diagram of a plurality of pixels P included in the liquid crystal display device 100 .

[0026] like Figure 1 As shown, the liquid crystal display device 100 includes an active matrix substrate (hereinafter referred to as a "TFT substrate") 10, an opposing substrate (sometimes also referred to as a "color filter substrate") 20 arranged closer to the observer side than the TFT substrate 10, and a liquid crystal layer 30 provided between the TFT substrate 10 and the opposing substrate 20. The liquid crystal display device 100 also includes a polarizing plate 40 arranged closer to the observer side than the liquid crystal layer 30, and a phase difference layer 50 arranged between the polarizing plate 40 and the liquid crystal layer 30. Here, the polarizing plate 40 is arranged closer to the observer side than the opposing substrate 20, and the phase difference layer 50 is arranged between the polarizing plate 40 and the opposing substrate 20. The polarizing plate 40 is specifically an absorption-type linear polarizing plate. In the example shown in the figure, the phase difference layer 50 includes a λ / 2 plate 51 and a λ / 4 plate 52.

[0027] In addition, if Figure 2 As shown, the liquid crystal display device 100 has a plurality of pixels P. The plurality of pixels P are arranged in a matrix including a plurality of rows and a plurality of columns. The plurality of pixels P typically include a red pixel for displaying red, a green pixel for displaying green, and a blue pixel for displaying blue. As already described, the liquid crystal display device 100 is a reflective type. Therefore, each pixel P includes a reflective region Rf for displaying in a reflective mode.

[0028] The TFT substrate 10 includes a plurality of gate wirings (scanning wirings) GL, a plurality of source wirings (signal wirings) SL, a plurality of thin film transistors (TFTs) 11 , a plurality of pixel electrodes PE, and a common electrode CE.

[0029] A plurality of gate wirings GL extend in the row direction. Each gate wiring GL supplies a gate signal (scanning signal) to the corresponding TFT 11. A plurality of source wirings SL extend in the column direction intersecting (eg, substantially orthogonal to) the row direction. Each source wiring SL supplies a source signal (display signal) to the corresponding TFT 11.

[0030] A plurality of TFTs 11 are provided corresponding to each pixel P. The gate electrode and the source electrode of each TFT 11 are electrically connected to the corresponding gate wiring GL and the corresponding source wiring SL, respectively. A plurality of pixel electrodes PE are electrically connected to the corresponding TFT 11 (more specifically, the drain electrode DE of the corresponding TFT 11).

[0031] The common electrode CE is provided to face the pixel electrode PE via the dielectric layer 15, and can generate a lateral electric field (fringe electric field) together with the pixel electrode PE in the liquid crystal layer 30. As described later, the common electrode CE is divided into a plurality of segments.

[0032] Next, refer to Figure 3 and Figure 4 , a more specific structure of the TFT substrate 10 and the counter substrate 20 will be described. Figure 3 1 is a plan view schematically showing the liquid crystal display device 100 . Figure 4 is a cross-sectional view schematically showing the liquid crystal display device 100, and shows Figure 3 The cross-sectional structure of line 4A-4A' in FIG.

[0033] The TFT substrate 10 includes a substrate 10 a , a TFT substrate 11 , a first interlayer insulating layer 12 , and a reflective layer 13 . The TFT substrate 10 also 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 and the like. The substrate 10a is transparent and has insulating properties. The substrate 10a is, for example, a glass substrate or a plastic substrate.

[0035] TFT11 is provided on substrate 10a. TFT11 is provided corresponding to a plurality of pixels P, respectively. TFT11 comprises semiconductor layer SC, gate insulating layer GI, gate electrode GE, source electrode SE and drain electrode DE. Gate electrode GE is electrically connected to corresponding gate wiring GL, and source electrode SE is electrically connected to corresponding source wiring SL. Drain electrode DE is electrically connected to pixel electrode PE. A circuit for driving a plurality of pixels P, including TFT11, gate wiring GL and source wiring SL, is sometimes also referred to as a backplane circuit.

[0036] The TFT 11 shown in the example has a top gate structure, for example. The semiconductor layer SC is provided on the substrate 10a. The semiconductor layer SC is a polysilicon layer (for example, a low temperature polysilicon (LTPS) layer) in this example.

[0037] The gate insulating layer GI is formed 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 portion (channel region) of the semiconductor layer SC via the gate insulating layer GI. Here, the gate electrode GE is formed integrally with the gate wiring GL.

[0038] A lower insulating layer 16 is formed 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 of the same conductive film as the source wiring SL (that is, the same layer as the source wiring SL). In addition, here, the source electrode SE is formed integrally with the source wiring SL. The source electrode SE is formed in the source contact hole CH formed in the lower insulating layer 16 and the gate insulating layer GI. S The drain electrode DE is formed in the drain contact hole CH formed in the lower insulating layer 16 and the gate insulating layer GI. D In the middle, it is electrically connected to the semiconductor layer SC.

[0039] The first interlayer insulating layer 12 is provided to cover the bottom board circuit including the TFT 11. The first interlayer insulating layer 12 is a layer formed of 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 in such a manner as to be located at least in the reflective region Rf. That is, the reflective layer 13 is arranged 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 further other words, the reflective layer 13 is adjacent to the TFT 11 via the first interlayer insulating layer 12.

[0041] The reflective layer 13 is formed of a conductive material that reflects light. More specifically, the reflective layer 13 is formed of a metal material with high reflectivity. As the material of the reflective layer 13, for example, a silver alloy, aluminum, or an aluminum alloy can be used.

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

[0043] The first part 13a of the reflective layer 13 occupies most of the reflective layer 13 and has a concavo-convex shape on its surface. That is, the first part 13a of the reflective layer 13 has a concavo-convex surface structure. The concavo-convex surface structure is also called MRS (Micro Reflective Structure), which is provided to diffusely reflect the surrounding light to achieve a display close to paper white. The concavo-convex surface structure can be composed of a plurality of convex portions p randomly arranged in such a manner that the center interval between adjacent convex portions p is 5 μm or more and 50 μm or less, preferably 10 μm or more and 20 μm or less. When observed from the normal direction of the substrate 10a, the shape of the convex portion p is roughly circular or roughly polygonal. The area occupied by the convex portion p in the pixel P is, for example, about 20% to 40%. The height of the convex portion p is, for example, 1 μm or more and 5 μm or less.

[0044] There is no particular limitation on the method of forming the concavo-convex surface structure on at least a portion of the reflective layer 13. For example, as shown in the figure, by forming the first interlayer insulating layer 12 having the concavo-convex surface structure and forming the reflective layer 13 thereon, it is possible to give a concavo-convex shape reflecting the concavo-convex surface structure of the first interlayer insulating layer 12 to the surface of at least a portion of the reflective layer 13. The first interlayer insulating layer 12 having the concavo-convex surface structure can be formed by the method disclosed in Japanese Patent No. 3394926, for example.

[0045] As described later, the second portion 13b of the reflective layer 13 functions as a "first contact electrode" for electrically connecting the drain electrode DE of the TFT 11 to the pixel electrode PE. In addition, 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 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 separated from each other.

[0046] In the example shown in the figure, a transparent conductive layer 17 is present between the reflective layer 13 and the first interlayer insulating layer 12. As a transparent conductive material for forming the transparent conductive layer 17, for example, indium tin oxide (ITO), indium zinc oxide (IZO (registered trademark)), or a mixture thereof can be used. 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 in the transparent conductive layer 17 are respectively referred to as the "first portion", "second portion", and "third portion" of the transparent conductive layer 17. In addition, the transparent conductive layer 17 may be omitted.

[0047] The second interlayer insulating layer 14 is provided on the first interlayer insulating layer 12 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 planarization layer formed of an organic insulating material, for example, a photosensitive resin.

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

[0049] The pixel electrode PE is provided in each of the plurality of pixels P. In addition, 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. In addition, the reflective layer 13 is adjacent to the pixel electrode PE via the second interlayer insulating layer 14, and is located on the side opposite to the liquid crystal layer 30 (i.e., between the pixel electrode PE and the substrate 10a) relative to the pixel electrode PE.

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

[0051] In the example shown in the figure, the pixel electrode PE is electrically connected to the drain electrode DE of the TFT 11 via the first contact electrode 13b. A first pixel contact hole CH is formed in the first interlayer insulating layer 12 to expose at least a portion of the drain electrode DE of the TFT 11. P1 The first contact electrode 13b is located at the first pixel contact hole CH P1 The first contact electrode 13b is connected to the drain electrode DE of the TFT 11. Here, the second portion 17b of the transparent conductive layer 17 is sandwiched between the first contact electrode 13b and the drain electrode DE. In addition, a second pixel contact hole CH is formed in the second interlayer insulating layer 14 to expose a portion of the first contact electrode 13b. P2 The pixel electrode PE is in the second pixel contact hole CH P2 Here, between the pixel electrode PE and the first contact electrode 13b, there is a third contact electrode 18 formed of the same transparent conductive film as the common electrode CE. The third contact electrode 18 may be omitted.

[0052] The pixel electrode PE has at least one (here, a plurality of) slits s. Since the slits are formed in the pixel electrode PE, a fringe electric field (lateral electric field) is generated in the liquid crystal layer 30 according 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 electrode PE and the dielectric layer 15, 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. In addition, it can be said that the dielectric layer 15 is also provided between the second interlayer insulating layer 14 and the first horizontal alignment film 19, in which case 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 includes a substrate 20a, a color filter layer 21, an overcoat layer 22, and a second horizontal alignment film 29. Although not shown in the figure, the counter substrate 20 also includes a plurality of columnar spacers.

[0055] The substrate 20a supports the color filter layer 21 and the like. The substrate 20a is transparent and has insulating properties. The substrate 20a is, for example, a glass substrate or a plastic substrate.

[0056] The color filter layer 21 typically includes: a red filter disposed in an area corresponding to a red pixel, a green filter disposed in an area corresponding to a green pixel, and a blue filter disposed in an area corresponding to a blue pixel. The red filter, the green filter, and the blue filter transmit red light, green light, and blue light, respectively. In addition, when color display is not performed, the color filter layer 21 is omitted.

[0057] The overcoat layer (planarization layer) 22 is provided in a manner covering the color filter layer 21. In addition, depending on the transparent conductive material (for the transparent conductive layer 19, 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 sometimes have a yellow tint. In this case, the overcoat layer may be formed with a blue resist to adjust the chromaticity (blue shift) so that the chromaticity of the white display is close to the chromaticity of the D65 light source, for example.

[0058] The columnar spacer defines the thickness (cell gap) of the liquid crystal layer 30. The columnar spacer is formed of a photosensitive resin.

[0059] The second horizontal alignment film 29 is disposed on the overcoat layer 22 and contacts the liquid crystal layer 30 .

[0060] The liquid crystal layer 30 includes a nematic liquid crystal material having a positive dielectric anisotropy Δε or a nematic liquid crystal material having a negative dielectric anisotropy Δε. The dielectric anisotropy Δε is the dielectric constant ε of the liquid crystal molecule 31 in the long axis direction. / / and the dielectric constant ε in the short axis direction ⊥ The difference (i.e. ε / / -ε ⊥ ). The liquid crystal layer 30 may further contain a chiral agent as required. The liquid crystal layer 30 may be formed, for example, by a dropping method. The thickness of the liquid crystal layer 30 is not particularly limited.

[0061] The first horizontal alignment film 19 and the second horizontal alignment film 29 are each subjected to an alignment treatment to define the alignment direction of the liquid crystal molecules 31 included in the liquid crystal layer 30. The alignment direction defined by the first horizontal alignment film 19 and the alignment direction defined 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 (i.e., the pretilt angle is substantially 0°) at least when no voltage is applied to the liquid crystal layer 30. As described above, the alignment direction defined by the first horizontal alignment film 19 and the alignment direction defined by the second horizontal alignment film 29 are different. Figure 4 As shown, the liquid crystal layer 30 is twisted when no voltage is applied. When a voltage is applied to the liquid crystal layer 30, that is, when a lateral electric field (fringe electric field) is generated in the liquid crystal layer 30 through the pixel electrode PE and the common electrode CE, the orientation state of the liquid crystal layer 30 changes according to the lateral 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. The plurality of segments TX can apply different signals (voltages) to each other, and thus can function as "touch sensor electrodes" in the embedded touch panel. That is, 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] In addition, the TFT substrate 10 also has a plurality of touch wirings TL. The plurality of touch wirings TL are electrically connected to corresponding touch sensor electrodes TX in the plurality of touch sensor electrodes TX, respectively. 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 arranged between adjacent source wirings SL. In addition, the plurality of touch wirings TL are formed of 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 by the first interlayer insulating layer 12 and are located between the reflective layer 13 and the substrate 10a.

[0065] In the example shown in the figure, each touch wiring TL is electrically connected to the corresponding touch sensor electrode TX via the second contact electrode 13c. The first interlayer insulating layer 12 has a first touch contact hole CH formed therein to expose a portion of the touch wiring TL. T1 The second contact electrode 13c is located at the first touch contact hole CH T1 Here, the third portion 17c of the transparent conductive layer 17 is interposed between the second contact electrode 13c and the contact wiring TL. In addition, a second touch contact hole CH is formed in the second interlayer insulating layer 14 to expose a portion of the second contact electrode 13c.T2 , in the second touch contact hole CH T2 At , the touch sensor electrode TX is electrically connected to the second contact electrode 13c.

[0066] Figure 5 2 is a top view illustrating the configuration relationship between the touch sensor electrode TX and the touch wiring TL. Figure 5 As shown, the liquid crystal display device 100 includes a display region DR and a non-display region FR. Figure 2 ) is used to define the display region DR. The non-display region FR is located at the periphery of the display region DR and is sometimes also referred to as a “peripheral region” or a “frame region”.

[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 referred to as 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, for example, to switch 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 a plurality of touch sensor electrodes TX function in a time-sharing manner. For example, in the display mode, the touch drive unit TD applies a common signal to the touch sensor electrode TX (common electrode 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 electrode TX via the touch wiring TL.

[0069] In addition, a common signal (common voltage) different from the common signal applied to the touch sensor electrode TX can be input from the non-display region FR to the first portion 13a (the portion having the concavo-convex surface structure) of the reflective layer 13. However, the present invention is not limited to such a mode, and the voltage supplied to the first portion 13a of the reflective layer 13 is not particularly limited. In addition, the first portion 13a of the reflective layer 13 may be in an electrically floating state (floating connection), for example.

[0070] The plurality of touch wirings TL extend in the column direction (the same direction as the source wiring SL). A portion of the touch wiring TL extends across one or more other touch sensor electrodes TX to the corresponding touch sensor electrode TX.

[0071] If we focus on a certain touch sensor electrode TX, the first touch wiring TL1 that provides a signal to the touch sensor electrode Tx extends to the touch wiring contact portion TC, and the second touch wiring TL2 that provides a signal to other touch sensor electrodes Tx extends across the touch sensor electrode TX. In addition, depending on the position of the touch sensor electrode Tx, there are cases where two or more touch wirings TL are configured to extend across the touch sensor electrode Tx, and there are also cases where no touch wiring TL is configured to extend across the touch sensor electrode Tx.

[0072] In addition, although not shown, in the non-display region FR, in addition to the touch drive unit TD, peripheral circuits including a gate driver that provides a gate signal to the gate wiring GL, a source driver that provides a source signal to the source wiring SL, and other drive circuits are also provided. These drive circuits can be mounted on the TFT substrate 10, for example, or can be formed integrally (monolithically). A semiconductor chip including a part or all of the drive circuits can also be mounted in the non-display region FR.

[0073] As described above, 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., 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 relative to the reflective layer 13). As a result, compared with the case where the structure of the existing in-cell touch panel is simply applied to the reflective liquid crystal display device, the manufacturing process can be simplified and the manufacturing cost can be reduced. The reasons for obtaining such advantages are described below.

[0074] Figure 6 as well as Figure 7 1 and 2 are a plan view and a cross-sectional view schematically showing a liquid crystal display device 900 of a comparative example. The liquid crystal display device 900 of the comparative example is a liquid crystal display device in which the structure of a conventional in-cell touch panel is simply applied to a reflective liquid crystal display device.

[0075] The touch wiring TL of the liquid crystal display device 900 of the comparative example is formed from a conductive film different from the source wiring SL (i.e., a layer different from the source wiring SL), which is different from the liquid crystal display device 100. 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 in a manner covering the touch wiring TL. The upper insulating layer 61 can be, for example, an organic insulating layer formed of a photosensitive resin or an inorganic insulating layer formed of silicon nitride (SiNx). A touch contact hole CH is formed in the upper insulating layer 61 to expose a portion of the touch wiring TL. T , in the touch contact hole CH TIn the embodiment, 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 (that is, located on the liquid crystal layer 30 side relative to the reflective layer 13). In addition, the touch wiring TL overlaps with the source wiring SL in a plan view.

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

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

[0078] In addition, in the liquid crystal display device 100 of the present embodiment, since the touch wiring TL is provided between the reflective layer 13 and the substrate 10a (i.e., on the side opposite to the liquid crystal layer 30 relative to the reflective layer 13), the reduction in the reflective aperture ratio and the reflectivity caused by the touch wiring TL is very small. In the embedded touch panel using a transmissive liquid crystal display device, it is believed that if the touch wiring is formed by the same conductive film as the source wiring, the manufacturing process can be simplified and the manufacturing cost can be reduced. However, in this case, since the touch wiring and the source wiring cannot be overlapped, the area where the touch wiring is provided cannot be used for transmissive display, and the transmittance is reduced, that is, the optical performance is reduced. In contrast, in the liquid crystal display device 100 of the present embodiment, since the touch wiring TL is located between the reflective layer 13 and the substrate 10a, the reflective aperture ratio and the reflectivity are almost not reduced, so it can be said that the above-mentioned reduction in optical performance is almost not generated.

[0079] In addition, in the above description, the pixel electrode PE is illustrated as being disposed above the common electrode CE, but conversely, the common electrode CE may also be disposed above the pixel electrode PE. Hereinafter, the electrode relatively located above the pixel electrode PE and the common electrode CE is sometimes referred to as the "upper electrode", and the electrode relatively located below is sometimes referred to as the "lower electrode". The upper electrode and the lower electrode are adjacent to each other via the dielectric layer 15. In order to generate a lateral electric field, at least the upper 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 preferred that the pixel electrode PE is arranged above the common electrode CE. In the configuration in which the pixel electrode PE is arranged above the common electrode CE, there is no need to form a slit in the common electrode CE, so the increase in the resistivity (surface resistivity) of the common electrode CE is suppressed compared to the configuration in which the common electrode CE is arranged above the pixel electrode PE. If the resistivity of the common electrode CE increases, the supply speed of the charge supplied to the common electrode CE decreases, and poor display conditions (such as flickering, shadows, etc.) are likely to occur due to the need to supply a large amount of charge to the common electrode CE (for example, images with biased pixel polarity, checkerboard patterns, striped patterns, or images in which a partial area of ​​the display is composed of these patterns).

[0081] In addition, in the structure in which the pixel electrode PE is arranged above the common electrode CE, it is necessary to form a slit in the pixel electrode PE, so the resistivity of the pixel electrode PE increases, but the area of ​​the pixel electrode PE is sufficiently smaller than that of the common electrode CE (for example, less than 1 millionth), so the amount of charge to be supplied is also small, and the charge is supplied from the TFT11 connected in units of pixels, so it is not easy to be affected by the displayed image and it is not easy to cause display defects.

[0082] In addition, in the configuration in which the pixel electrode PE is arranged above the common electrode CE, the pixel electrode PE in the area where the pixel contact hole is formed cannot be provided with a slit for generating a fringe electric field, and thus an opening portion needs to be provided in the common electrode CE in this area. Therefore, this area does not generate an effective fringe electric field, does not contribute to reflective display, and the reflectivity may decrease compared with the configuration in which the common electrode CE is arranged above the pixel electrode PE. Since the area of ​​the area that does not contribute to reflective display such as the contact hole does not depend on the size of the area of ​​the pixel P but requires a certain degree of area, the smaller the area of ​​the pixel P (i.e., high resolution), the higher the proportion of the area that does not contribute to reflective display in the pixel P, and the greater the reduction in the above reflectivity. Conversely, in a relatively large liquid crystal display device, it is easy to further reduce the proportion of the area that does not contribute to reflective display in the pixel P, so it is easy to suppress the reduction in the above reflectivity. For these reasons, in a relatively large liquid crystal display device (the area of ​​the pixel P is relatively large), it is advantageous to arrange the pixel electrode PE above the common electrode CE.

[0083] In addition, as described above, the smaller the area of ​​the pixel P (i.e., the higher the resolution), the higher the reduction in reflectivity caused by the fact that the area where the pixel contact hole is formed does not contribute to the reflective display. Therefore, in a liquid crystal display device with a relatively high resolution (i.e., the area of ​​the pixel P is relatively small), the common electrode CE is preferably arranged above the pixel electrode PE.

[0084] In addition, in the liquid crystal display device 100 of the present embodiment, the liquid crystal layer 30 is displayed in a transverse electric field mode in which a twisted orientation is exhibited when no voltage is applied. More specifically, the liquid crystal layer 30 is displayed in an FFS mode (referred to as a "TW-FFS mode") in which a twisted orientation is exhibited when no voltage is applied. Thus, compared with the case in which the liquid crystal layer 30 does not exhibit a twisted orientation when no voltage is applied (i.e., the twist angle of the liquid crystal layer 30 is 0°) and displays in a general FFS mode, the contrast ratio of the reflective display can be improved. From the viewpoint of improving the contrast ratio, the twist angle of the liquid crystal layer 30 when no voltage is applied is preferably greater than 45° and less than 90°.

[0085] [Implementation Method 2] Reference Figure 8 , a liquid crystal display device 200 according to this embodiment is described. Figure 8 2 is a cross-sectional view schematically showing the liquid crystal display device 200. Hereinafter, the liquid crystal display device 200 of this embodiment will be described mainly with respect to differences from the liquid crystal display device 100 of Embodiment 1.

[0086] The liquid crystal display device 200 of this embodiment is different 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 is formed of, for example, an In-Ga-Zn-O-based semiconductor.

[0087] exist Figure 8 In the illustrated configuration, 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 to cover the gate electrode GE. A semiconductor layer SC as an oxide semiconductor layer is provided on the gate insulating layer GI. A source electrode SE and a drain electrode DE are provided on the semiconductor layer SC and on the gate insulating layer GI. Figure 8 In the illustrated configuration, the first insulating layer 12 has a stacked structure including an inorganic insulating layer 12 a and an organic insulating layer 12 b formed on the inorganic insulating layer 12 a .

[0088] In the liquid crystal display device 200 of this embodiment, the touch wiring TL is formed of the same conductive film as the source wiring SL (i.e., 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] In the liquid crystal display device 200 of the present embodiment, compared with a case where the structure of a conventional in-cell touch panel is simply applied to a reflective liquid crystal display device, the manufacturing process can be simplified and the manufacturing cost can be reduced.

[0090] [Implementation method 3] Reference Fig. 9 , describing the liquid crystal display device 300 of this embodiment. Fig. 9 2 is a cross-sectional view schematically showing a liquid crystal display device 300. The following mainly describes the differences between the liquid crystal display device 300 of this embodiment and the liquid crystal display device 100 of Embodiment 1.

[0091] The liquid crystal display device 300 of this embodiment is different 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 concavo-convex surface structure. Fig. 9 As shown, the first interlayer insulating layer 12 does not have a concavo-convex surface structure, and therefore, the first portion 13a of the reflective layer 13 does not have a concavo-convex surface structure (ie, has a substantially flat surface).

[0092] In the liquid crystal display device 300 of the present embodiment, since the touch line TL is formed of the same conductive film as the source line SL (that is, the same layer as the source line SL), the manufacturing process can be simplified and the manufacturing cost can be reduced.

[0093] In addition, the liquid crystal display device 300 of this embodiment may also include a light scattering layer. By using the reflective layer 13 and the light scattering layer in combination, a display close to paper white can be achieved. The light scattering layer may be, for example, a light scattering sheet disposed on the observer side of the counter substrate 20 .

[0094] [Implementation Method 4] Reference Fig.10 , describing a liquid crystal display device 400 of this embodiment. Fig.10 2 is a cross-sectional view schematically showing a liquid crystal display device 400. The following mainly describes the differences between the liquid crystal display device 400 of this embodiment and the liquid crystal display device 200 of Embodiment 2.

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

[0096] like Fig.10 As shown, 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, the source electrode SE and the drain electrode DE of the TFT 11 are formed of the same conductive film as the light shielding layer LS (ie, the same layer as the light shielding layer LS).

[0097] A lower insulating layer 16' is formed to cover the light shielding layer LS and the like. A semiconductor layer SC as an oxide semiconductor layer is provided on the lower insulating layer 16'. The light shielding layer LS is opposite to at least the channel region in the semiconductor layer SC via the lower insulating layer 16'. The semiconductor layer SC is provided in the source contact hole CH formed in the lower insulating layer 16'. S and drain contact hole CH D In the embodiment, it is electrically connected to the source electrode SE and the drain electrode DE.

[0098] A gate insulating layer GI is formed 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. P1 The first interlayer insulating layer 12, the gate insulating layer GI and the lower insulating layer 16' are formed.

[0099] In the liquid crystal display device 400, the touch wiring TL is formed of the same conductive film as the source wiring SL (ie, the same layer as the source wiring SL). Therefore, the touch wiring TL is covered by the lower insulating layer 16', and the first touch contact hole CH T1 The first interlayer insulating layer 12, the gate insulating layer GI and the lower insulating layer 16' are formed.

[0100] In a general top-gate oxide semiconductor TFT, the following structure is generally adopted: a gate electrode is arranged on a part of the oxide semiconductor layer through a gate insulating layer, and a source electrode, a drain electrode and a source wiring are arranged on the insulating layer covering the gate electrode. That is, the source metal layer including the source wiring is located above the gate metal layer including the gate electrode. Here, such a structure is called an "upper source structure".

[0101] On the other hand, 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). Such a structure is referred to as a "lower source structure".

[0102] In the liquid crystal display device 400 of the present embodiment adopting the bottom source structure, the touch wiring TL is formed from the same conductive film as the source wiring SL (ie, the same layer as the source wiring SL), so that the manufacturing process can be simplified and the manufacturing cost can be reduced.

[0103] [Oxide semiconductor TFT] As the TFT 11 provided in each pixel P, an oxide semiconductor TFT can be preferably used, as exemplified in the liquid crystal display device 200 of Embodiment 2 and the liquid crystal display device 400 of Embodiment 4. In the oxide semiconductor TFT, an oxide semiconductor is used as a material for the active layer. That is, the oxide semiconductor TFT includes an oxide semiconductor layer as the active layer. In recent years, oxide semiconductors are materials that have attracted attention as active layer materials replacing 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 films can be formed using a simpler process than polycrystalline silicon layers, so they can also be used in devices that require a large area.

[0105] In addition, the oxide semiconductor TFT has excellent off-leak characteristics, so it is also possible to use an operating mode that reduces the frequency of image rewriting for display. For example, when displaying a static image, the image data can be rewritten once per second. This driving method is called dormant driving or low-frequency driving, which can significantly reduce the power consumption of the liquid crystal display device.

[0106] By adopting pause driving and performing touch detection during a period when image rewriting is not being performed, it is possible to suppress a decrease in sensitivity of touch operation due to noise from the drive circuit, and to increase the S / N ratio (signal-to-noise ratio) by, for example, about 10 times that of the prior art.

[0107] In addition, oxide semiconductor TFTs are also advantageous in miniaturizing TFT size, so a configuration (called "MIP (Memory In Pixels)") in which a memory circuit is provided for each pixel P can also be preferably realized. The specific configuration of MIP is well known, and thus its description is omitted here.

[0108] The oxide semiconductor included 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 crystalline oxide semiconductors include polycrystalline oxide semiconductors, microcrystalline oxide semiconductors, and crystalline oxide semiconductors whose c-axis is oriented substantially perpendicular to the layer surface.

[0109] The oxide semiconductor layer may have a stacked structure of more than two 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 multiple crystalline oxide semiconductor layers having different crystal structures. In addition, the oxide semiconductor layer having a stacked structure may also include multiple amorphous oxide semiconductor layers. In the case where the oxide semiconductor layer has a two-layer structure including an upper layer and a lower layer, the energy gap of the oxide semiconductor contained in the lower layer may be different from the energy gap of the oxide semiconductor contained in the upper layer.

[0110] The materials, structures, film formation methods, and composition of oxide semiconductor layers having a stacked structure of amorphous oxide semiconductors and the above-mentioned crystalline oxide semiconductors are described in, for example, Japanese Patent Application Laid-Open No. 2014-007399. The entire disclosure of Japanese Patent Application Laid-Open No. 2014-007399 is cited in this specification for reference.

[0111] The oxide semiconductor layer may contain, for example, at least one metal element selected from In, Ga, and Zn. In the present embodiment, the oxide semiconductor layer may contain, for example, an In-Ga-Zn-O semiconductor (e.g., indium gallium zinc oxide). Here, the In-Ga-Zn-O 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 may include, 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 may be formed by an oxide semiconductor film containing an In-Ga-Zn-O semiconductor.

[0112] The In-Ga-Zn-O semiconductor may be amorphous or crystalline. A crystalline In-Ga-Zn-O semiconductor whose c-axis is oriented substantially perpendicular to the layer is preferred.

[0113] In addition, the crystal structure of the semiconductor of the crystalline In-Ga-Zn-O system is disclosed in, for example, the above-mentioned Japanese Patent Publication No. 2014-007399, Japanese Patent Publication No. 2012-134475, and Japanese Patent Publication No. 2014-209727. For reference, the entire disclosure of Japanese Patent Publication No. 2012-134475 and Japanese Patent Publication No. 2014-209727 is cited in this specification. The TFT having a semiconductor layer of the In-Ga-Zn-O system has high mobility (more than 20 times compared with a-SiTFT) and low leakage current (less than one percent compared with a-SiTFT), and is therefore preferably used as a driving TFT (for example, a TFT present in a driving circuit, which is arranged in the periphery of a display area including a plurality of pixels and on the same substrate as the display area) and a pixel TFT (a TFT provided in a pixel).

[0114] The oxide semiconductor layer may include other oxide semiconductors instead of In-Ga-Zn-O semiconductors. For example, it may include In-Sn-Zn-O semiconductors (e.g., In2O3-SnO2-ZnO; InSnZnO). In-Sn-Zn-O semiconductors are ternary oxides of In (indium), Sn (tin), and Zn (zinc). Alternatively, the oxide semiconductor layer 11 may also include In-Al-Zn-O series semiconductors, In-Al-Sn-Zn-O series semiconductors, Zn-O series semiconductors, In-Zn-O series semiconductors, Zn-Ti-O series semiconductors, Cd-Ge-O series semiconductors, Cd-Pb-O series semiconductors, CdO (cadmium oxide), Mg-Zn-O series semiconductors, In-Ga-Sn-O series semiconductors, In-Ga-O series semiconductors, Zr-In-Zn-O series semiconductors, Hf-In-Zn-O series semiconductors, Al-Ga-Zn-O series semiconductors, Ga-Zn-O series semiconductors, In-Ga-Zn-Sn-O series semiconductors, etc.

[0115] [Transflective type] In the above description, the reflective liquid crystal display devices 100, 200, 300, and 400 are exemplified, but the liquid crystal display device according to the embodiment of the present invention may be a semi-transmissive liquid crystal display device. Fig.11 , describing the structure of a semi-transmissive liquid crystal display device 500.

[0116] The liquid crystal display device 500 is different from the liquid crystal display devices 100 , 200 , 300 and 400 in that the liquid crystal display device 500 includes an additional polarizing plate 40 ′, an additional phase difference layer 50 ′ and an illumination device (backlight source) 70 .

[0117] The polarizing plate 40 ′ is disposed on the back side of the liquid crystal layer 30 . More specifically, the polarizing plate 40 ′ is disposed on the back side of the TFT substrate 10 .

[0118] The phase difference layer 50' is disposed between the polarizing plate 40' and the liquid crystal layer 30. More specifically, the phase difference layer 50' is disposed between the polarizing plate 40' and the TFT substrate 10. The phase difference layer 50 may include, for example, a λ / 2 plate and a λ / 4 plate.

[0119] The lighting device 70 is arranged on the back side of the polarizing plate 40' (the back side of the TFT substrate 10). In the example shown in the figure, the lighting device 70 includes a light source (e.g., LED) 71 that emits light, a light guide plate 72 that guides the light from the light source 71 to the polarizing plate 40' side, and a reflective plate 73 arranged on the back side of the light guide plate 72. The lighting device 70 may further include a prism sheet and a diffusion sheet arranged on the front side (or back side) of the light guide plate 72.

[0120] like Fig.12 As shown, each pixel P of the liquid crystal display device 500 includes a reflective region Rf for displaying in a reflective mode and a transmissive region Tr for displaying 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 according to the purpose, for example, to be greater than 20% and less than 90%. In addition, the position and shape of the transmissive region Tr in the pixel P can also be appropriately set according to the purpose, etc. [Industrial Applicability]

[0121] According to the embodiment of the present invention, a pixel structure of a liquid crystal display device capable of displaying a reflective mode and being used as an in-cell touch panel can be provided. The embodiment of the present invention is applicable to reflective and semi-transmissive liquid crystal display devices. Description of Reference Numerals

[0122] 10Active matrix substrate (TFT substrate) 10a, 20a substrate 11Thin Film Transistor (TFT) 12. First interlayer insulation layer 13 Reflection layer 13a The first part of the reflective layer 13b The second part of the reflective layer (first contact electrode) 13c The third portion of the reflective layer (the second contact electrode) 13o Opening 14 Second interlayer insulation layer 15 Dielectric layer 16, 16' lower insulation layer 17 Transparent conductive layer 17a The first part of the transparent conductive layer 17b The second part of the transparent conductive layer 17c The third part of the transparent conductive layer 183 Third contact electrode 19. First horizontal alignment film 20 Counter substrate (color filter substrate) 21 Color filter layer 22 Outer coating 29 second horizontal alignment film 30 Liquid crystal layer 31 liquid crystal molecules 40 Polarizing Plate 40' Polarizing Plate 50 phase difference layer 50' phase difference layer 51λ / 2 plate 52λ / 4 plate 70 lighting device (backlight source) 71 Light Source 72 Light guide plate 73 Reflector 100, 200, 300, 400, 500 LCD devices P Pixel PE pixel electrode CE common electrode TX Touch Sensor Electrode s Slit GL Gate wiring SL Source Routing TL contact wiring SC Semiconductor layer GE Gate Electrode SE source electrode DE Drain Electrode GI Gate Insulator 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 Second touch contact hole LS light shielding layer DR Display Area FR Non-display area TD touch driver Rf reflection area Tr Transmission area

Claims

1. A liquid crystal display device, comprising: a first substrate; A second substrate, which is arranged closer to the observer side than the first substrate; as well as a liquid crystal layer disposed between the first substrate and the second substrate, The liquid crystal display device has a plurality of pixels arranged in a matrix including a plurality of rows and a plurality of columns, and the liquid crystal display device is characterized in that: Each of the plurality of pixels includes a reflective area for displaying in a reflective mode, The first substrate has: substrate; A plurality of gate wirings extending in a row direction; a plurality of source wirings extending in a column direction; A plurality of thin film transistors, each of the plurality of thin film transistors being arranged corresponding to each of the plurality of pixels; A plurality of pixel electrodes, each of the plurality of pixel electrodes being electrically connected to a corresponding thin film transistor among the plurality of thin film transistors; as well as a reflective layer, which is formed of a conductive material and is located at least in the reflective region, and the reflective layer is disposed between the pixel electrode and the substrate, The first substrate further comprises: a plurality of touch sensor electrodes to which mutually different signals can be applied; as well as a plurality of touch wirings, each of the plurality of touch wirings being electrically connected to a corresponding touch sensor electrode among the plurality of touch sensor electrodes, The plurality of touch wirings are formed of 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 arranged between mutually adjacent source wirings among the plurality of source wirings.

3. The liquid crystal display device according to claim 1 or 2, characterized in that: 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. When no voltage is applied, the liquid crystal layer exhibits a twisted orientation.

4. The liquid crystal display device according to claim 3, characterized in that: The twist angle of the liquid crystal layer when no voltage is applied is greater than or equal to 45° and less than or equal to 90°.

5. The liquid crystal display device according to claim 1 or 2, characterized in that: 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 of the plurality of touch wirings.

6. The liquid crystal display device according to claim 1 or 2, characterized in that: At least a portion of the reflective layer has a concavo-convex surface structure.

7. The liquid crystal display device according to claim 1 or 2, characterized in that: The first substrate further comprises: a first interlayer insulating layer disposed between the reflective layer and the thin film transistor; and a second interlayer insulating layer disposed between the pixel electrode and the reflective layer.

8. The liquid crystal display device according to claim 1 or 2, characterized in that: The first substrate further includes a common electrode disposed opposite to the pixel electrode via a dielectric layer. The common electrode is divided into a plurality of segments functioning as the plurality of touch sensor electrodes, 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 or 2, characterized in that: The plurality of source wirings and the plurality of touch wirings are located closer to the liquid crystal layer than the plurality of gate wirings.

10. The liquid crystal display device according to claim 1 or 2, characterized in that: The plurality of source wirings and the plurality of touch wirings are located closer to the substrate than the plurality of gate wirings.

11. The liquid crystal display device according to claim 1 or 2, characterized in that: Each of the plurality of pixels includes a transmissive region for displaying in a transmissive mode, and the reflective layer includes an opening formed in the transmissive region.

Images