Display device

Abstract

To provide a high-definition liquid crystal display device. To provide a liquid crystal display device with a high aperture ratio. The present invention provides a liquid crystal display device that has a high trust ratio and good display quality, and that can be driven at a low voltage. A display device is provided. A pixel electrode, a first common electrode, a second common electrode, and a liquid crystal layer are disposed between a pair of substrates. The pixel electrode and the first common electrode are connected to the liquid crystal layer and one of the substrates, respectively. The second common electrode is located between the liquid crystal layer and the other substrate. The first common electrode and the second common electrode are supplied with the same potential. The pixel has a portion overlapping with the second common electrode between the display areas of the two sub-pixels that exhibit a color. At least one of the first common electrode and the second common electrode is disposed in the display area of ​​the sub-pixel. and has a portion that does not overlap with the

Description

[Technical field]

[0001] One embodiment of the present invention relates to a liquid crystal display device, a module, and an electronic device.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. Examples of the semiconductor device include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an electronic device, a lighting device, Input devices (e.g., touch sensors, etc.), input / output devices (e.g., touch panels, etc.), These driving methods and manufacturing methods can be given as examples. [Background technology]

[0003] It is used in many flat panel displays such as liquid crystal displays and light emitting displays. The transistors are made of amorphous silicon, single crystal silicon, or The semiconductor device is made of silicon semiconductor such as polycrystalline silicon. Transistors that use conductors are also used in integrated circuits (ICs).

[0004] In recent years, metal oxides that exhibit semiconducting properties have been used in transistors instead of silicon semiconductors. In this specification, metal oxides that exhibit semiconducting properties are referred to as oxide semiconductors. For example, Patent Documents 1 and 2 describe the following as oxide semiconductors: A transistor using zinc oxide or In-Ga-Zn oxide is manufactured. A technique for using a transistor as a switching element for pixels of a display device has been disclosed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-123861 A [Patent Document 2] JP 2007-96055 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of one embodiment of the present invention is to provide a high-definition liquid crystal display device. An object of one embodiment of the present invention is to provide a liquid crystal display device with a high aperture ratio. One embodiment of the present invention is to provide a liquid crystal display device having a high contrast ratio and excellent display quality. Another object of one embodiment of the present invention is to provide a liquid crystal display device that can be driven at a low voltage. Another object of one embodiment of the present invention is to provide a liquid crystal display device with low power consumption. Another object of the present invention is to provide a highly reliable liquid crystal display device. Another object of the present invention is to provide a novel liquid crystal display device. One of the purposes of the present invention is to provide

[0007] Note that the description of these problems does not preclude the existence of other problems. However, it is not necessary to solve all of these problems. It is possible to extract other issues from the description in the section. [Means for solving the problem]

[0008] A display device according to one embodiment of the present invention includes a pixel electrode, a first common electrode, a second common electrode, and a second common electrode between a pair of substrates. The pixel electrode and the first common electrode are connected to the liquid crystal layer and one of the electrodes. The second common electrode is located between the liquid crystal layer and the other substrate. The same potential is supplied to the common electrode and the second common electrode. The pixel has a portion overlapping the second common electrode between the display regions of two sub-pixels that exhibit the same color. At least one of the pixel electrode and the first common electrode is provided in the display area of ​​the subpixel. It has a portion that does not overlap with the pole.

[0009] The second common electrode preferably has an opening in the display region of the sub-pixel. When d is used, the width of the opening is preferably d / 6 or more and narrower than the width of the subpixel. It is preferable that the distance between the openings is between d and 2.5d, where d is the thickness of the liquid crystal layer. The thickness d of the liquid crystal layer is preferably 1 μm or more and 3 μm or less.

[0010] The first common electrode may be electrically connected to the second common electrode. The common electrode and the second common electrode may be provided with potentials independently. The supply electrode and the second common electrode may be electrically connected to different power supply lines.

[0011] The anisotropy of the dielectric constant of the liquid crystal in the liquid crystal layer is preferably negative.

[0012] It is preferable that the semiconductor device has a transistor including an oxide semiconductor in a channel formation region. The transistor is electrically connected to the pixel electrode. Indium, zinc, aluminum, gallium, yttrium, or tin. It is preferable.

[0013] The scanning lines and the signal lines extend in a direction that intersects with the direction that the signal lines extend. The direction in which the sub-pixels each having one color are arranged crosses the direction in which the signal lines extend. is preferred.

[0014] One aspect of the present invention is a display device having any one of the above configurations, Flexible printed circuit (hereinafter referred to as FPC) or is equipped with a TCP (Tape Carrier Package) or other connector. Module, or COG (Chip On Glass) or COF (Chi Modules on which ICs are mounted using methods such as the 3D Print On Film (3D Printing On Film) method.

[0015] In one embodiment of the present invention, the above structure is not a display device but an input / output device (such as a touch panel). may be applied to.

[0016] One aspect of the present invention is a combination of the above module, an antenna, a battery, a housing, a camera, and a speaker. , a microphone, or an operation button. Effect of the Invention

[0017] According to one embodiment of the present invention, a high-definition liquid crystal display device can be provided. According to one embodiment of the present invention, a liquid crystal display device having a high aperture ratio can be provided. According to one embodiment, it is possible to provide a liquid crystal display device having a high contrast ratio and good display quality. According to one embodiment of the present invention, a liquid crystal display device that can be driven at a low voltage can be provided. According to one embodiment of the present invention, a liquid crystal display device with low power consumption can be provided. According to another embodiment of the present invention, a highly reliable liquid crystal display device can be provided. According to one embodiment of the present invention, a novel liquid crystal display device can be provided. .

[0018] The description of these effects does not preclude the existence of other effects. However, it is not necessary to have all of these effects. However, it is possible to extract effects other than these. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a liquid crystal element. [Diagram 2] FIG. 11 is a top view illustrating the layout of a second common electrode. [Diagram 3] 1A and 1B are a perspective view showing an example of a display device and a top view showing an example of a subpixel. [Figure 4] FIG. 1 is a cross-sectional view showing an example of a display device. [Diagram 5] 1A and 1B are diagrams showing examples of pixel arrangement and configuration; [Figure 6] FIG. 1 is a cross-sectional view showing an example of a display device. [Figure 7] FIG. 1 is a cross-sectional view showing an example of a display device. [Figure 8] FIG. 1 is a cross-sectional view showing an example of a display device. [Figure 9] FIG. 1 is a cross-sectional view showing an example of a display device. [Figure 10] FIG. 1 is a cross-sectional view showing an example of a display device. [Figure 11] FIG. 1 is a perspective view showing an example of a touch panel. [Figure 12] FIG. 1 is a cross-sectional view showing an example of a touch panel. [Figure 13] 1A and 1B are diagrams illustrating an example of an input device and an example of a driving method of the input device. [Figure 14] FIG. 1 is a perspective view showing an example of a touch panel. [Figure 15] FIG. 1 is a cross-sectional view showing an example of a touch panel. [Figure 16] FIG. 1 is a cross-sectional view showing an example of a touch panel. [Figure 17] FIG. 2 is a top view showing an example of an input device. [Figure 18] FIG. 2 is a top view showing an example of an input device. [Figure 19] FIG. 1 is a cross-sectional view showing an example of a touch panel. [Figure 20] FIG. 2 is a diagram showing an example of a detector element and a pixel. [Figure 21] 1A and 1B are diagrams showing an example of the operation of a detector element and a pixel. [Figure 22] FIG. 2 is a top view showing an example of a detector element and a pixel. [Diagram 23] FIG. 1 is a block diagram showing an example of a touch panel module. [Figure 24] FIG. 1 is a diagram showing an example of a touch panel module. [Diagram 25] FIG. 1 is a cross-sectional view illustrating an example of a transistor. [Figure 26] FIG. 1 is a cross-sectional view illustrating an example of a transistor. [Figure 27] FIG. 1 is a cross-sectional view illustrating an example of a transistor. [Figure 28] 1A and 1B are a top view and a cross-sectional view illustrating an example of a transistor. [Figure 29] 1A and 1B are a top view and a cross-sectional view illustrating an example of a transistor. [Diagram 30] 1A and 1B are a top view and a cross-sectional view illustrating an example of a transistor. [Diagram 31] 1A and 1B are a top view and a cross-sectional view illustrating an example of a transistor. [Diagram 32] 1A and 1B are a top view and a cross-sectional view illustrating an example of a transistor. [Diagram 33] 1A and 1B are a top view and a cross-sectional view illustrating an example of a transistor. [Diagram 34] 1A and 1B are a top view and a cross-sectional view illustrating an example of a transistor. [Diagram 35] 1A and 1B are a top view and a cross-sectional view illustrating an example of a transistor. [Diagram 36] FIG. 1 is a diagram showing an example of a touch panel module. [Figure 37] 1A and 1B are diagrams illustrating examples of electronic devices. [Figure 38] 1A and 1B are diagrams illustrating examples of electronic devices. [Figure 39] FIG. 2 is a diagram showing a pixel layout according to the first embodiment. [Diagram 40] 1 shows the results of an orientation simulation for Example 1. [Diagram 41]1 shows the results of an orientation simulation for Example 1. [Diagram 42] 1 shows the results of an orientation simulation for Example 1. [Diagram 43] 1 shows the results of an orientation simulation for Example 1. [Diagram 44] Simulation results of Example 1. [Diagram 45] 3A to 3C are a photograph showing a display result of the display device of Example 1 and an optical microscope photograph of the display portion. [Figure 46] Simulation results of Example 2. [Figure 47] Simulation results of Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The embodiment will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. The present invention is not limited to the above embodiment, and various changes and modifications may be made in the form and details without departing from the spirit and scope of the present invention. It will be easily understood by those skilled in the art that the above-mentioned invention can be obtained by the following embodiments. It should not be construed as being limited to the contents described.

[0021] In the configuration of the invention described below, the same parts or parts having similar functions are referred to as the same parts. The same reference numerals are used in common among different drawings, and the repeated explanations are omitted. When referring to a function, the same hatch pattern may be used and no particular reference number may be given.

[0022] In addition, the position, size, range, etc. of each component shown in the drawings are not necessarily the same as in the actual embodiment, in order to facilitate understanding. Therefore, the disclosed invention may not necessarily represent the position, size, range, etc. Furthermore, the present invention is not limited to the position, size, range, etc. disclosed in the drawings.

[0023] The words "film" and "layer" may be interchangeable depending on the circumstances. For example, the term "conductive layer" can be replaced with "conductive film" Alternatively, for example, the term "insulating film" can be changed to " The term "insulating layer" may be changed to "insulating layer."

[0024] (Embodiment 1) In this embodiment, a display device according to one embodiment of the present invention will be described with reference to FIGS.

[0025] A display device according to one embodiment of the present invention includes a pixel electrode, a first common electrode, a second common electrode, and a liquid crystal layer. The pixel electrode and the first common electrode sandwich the liquid crystal layer in the thickness direction of the display device. The first common electrode and the second common electrode are located on the opposite side. The first common electrode is connected to the display electrodes of two adjacent sub-pixels that exhibit different colors. The pixel electrode and the first common electrode have a portion overlapping the second common electrode between the regions. At least one of the subpixels has a portion in the display region that does not overlap with the second common electrode.

[0026] The display device has a plurality of pixels and has a function of displaying an image.

[0027] A pixel has a plurality of sub-pixels. For example, a sub-pixel that exhibits red, a sub-pixel that exhibits green, and Each pixel is composed of a blue sub-pixel and a green sub-pixel, so that a full-color display is possible on the display. The colors of the sub-pixels are not limited to red, green, and blue. The pixel may be, for example, a sub-pixel that exhibits a color such as white, yellow, magenta, or cyan. In this specification and the like, a subpixel may be simply referred to as a pixel.

[0028] The driving method for liquid crystal display devices is to invert the positive and negative polarities every frame (signal polarity Frame inversion driving, in which the positive and negative polarities are inverted for each row, In-line inversion drive, source line inversion drive in which the positive and negative polarities are inverted for each column, and Examples of such driving methods include dot line inversion driving, in which the positive and negative polarities are inverted for each pixel. By using this, the polarity of the signal can be inverted as necessary to prevent burn-in of the display. From the viewpoint of power consumption, the source line inversion driving can be preferably used.

[0029] As the resolution of liquid crystal display devices increases, the width between pixels (pixel spacing) and the width between sub-pixels (sub-pixel spacing) become smaller. Therefore, for example, in a display device using a lateral electric field type liquid crystal element, When source line inversion driving is applied to the liquid crystal display, a horizontal electric field is generated between adjacent sub-pixels, This can cause poor alignment of the crystals, leading to light leakage to adjacent subpixels. In addition, the display quality of the display device is degraded. In addition, the part where light leakage is likely to occur is covered with a light-shielding layer, etc. This can suppress the deterioration of the display quality, but may result in a decrease in the aperture ratio.

[0030] In view of this, in one embodiment of the present invention, a liquid crystal display (LCD) is provided between display regions of two sub-pixels that exhibit different colors. A pair of electrodes (a first common electrode and a second common electrode) to which the same potential is applied forms a liquid crystal layer. This makes it possible to suppress the generation of a horizontal electric field between two adjacent sub-pixels. Therefore, it is possible to suppress the alignment failure of the liquid crystal and reduce the light leakage, and the control of the display device is improved. The trust ratio can be increased.

[0031] In one aspect of the present invention, at least one of the pixel electrode and the first common electrode is The display area has a portion that does not overlap with the second common electrode. Even if the liquid crystal display device is turned on, the driving voltage of the liquid crystal element can be prevented from increasing.

[0032] <1-1. Display device configuration example 1> 1A to 1D show cross-sectional views of a display device according to one embodiment of the present invention.

[0033] The display device shown in FIG. 1A includes a substrate 119a, a substrate 119b, a pixel electrode 111a, a pixel electrode 111b, and a electrode 111b, a first common electrode 112, a liquid crystal layer 113, a second common electrode 244, and an insulating layer It has 220.

[0034] The display device shown in FIG. 1A has display areas 68a and 68b. The display regions (which can also be called the apertures of the sub-pixels) of the sub-pixels exhibiting different colors are designated by b.

[0035] The pixel electrodes 111a, 111b and the first common electrode 112 are connected to the liquid crystal layer 113. The second common electrode 244 is located between the liquid crystal layer 113 and the substrate 119b. The first common electrode 112 and the second common electrode 244 are supplied with the same potential. do.

[0036] The display device shown in FIG. 1A has a first common electrode 112 over a substrate 119a. An insulating layer 220 is provided on the conductive electrode 112, and island-shaped pixel electrodes 111a, 111b are provided on the insulating layer 220. The pixel electrodes are provided for each sub-pixel. The poles have openings or gaps (also called slits, etc.).

[0037] In the display device shown in FIG. 1B, the stacking order of the pixel electrode and the first common electrode is different from that in FIG. become.

[0038] The display device shown in FIG. 1B has island-shaped pixel electrodes 111a and 111b on a substrate 119a. An insulating layer 220 is provided on the pixel electrodes 111a and 111b, and a first common The first common electrode 112 has an opening or a gap ( It has a slit, etc.

[0039] In each of the display areas 68a and 68b, between the pixel electrodes and the first common electrode 112, A voltage can be applied (see the arrows in Figs. 1(A) and (B)). Between the electrodes 68a and 68b, the liquid crystal layer 113 is supplied with the same potential (constant potential, common potential). The first common electrode 112 and the second common electrode 244 are sandwiched between the first common electrode 112 and the second common electrode 244. By applying a common potential to the electrode, the electric field spreads from the pixel electrode to the electrode of the adjacent subpixel. Therefore, it is possible to suppress the alignment failure of the liquid crystal and reduce the light leakage, and the display The contrast ratio of the device can be increased.

[0040] In FIG. 1A, the first common electrode 112 is disposed in each of the display areas 68a and 68b. In addition, there is a portion that does not overlap with the second common electrode 244. The element electrode 111a is disposed in the display area 68a, and the pixel electrode 111b is disposed in the display area 68b. The second common electrode 244 has a portion that does not overlap with the second common electrode 244. By providing it partially in the region, the increase in the driving voltage of the liquid crystal element is suppressed compared to when it is provided over the entire region. It can be suppressed.

[0041] In FIG. 1(A) and (B), a second common electrode 244 is provided in the display region of the subpixel. The length of the portion that is not covered by the insulating film is indicated as L1. The length of the second common electrode 244 is indicated as L2. The thickness of the liquid crystal layer 113 between the first common electrode 241 and the second common electrode 244 is indicated as d. The thickness of the liquid crystal layer 113 between the first common electrode 112 and the second common electrode 244 is denoted as d. The thickness d of the liquid crystal layer is the thickness of the liquid crystal layer 113 between the pixel electrode and the first common electrode 112. Between the one closer to the second common electrode 244 in the direction and the second common electrode 244 The thickness d of the liquid crystal layer 113 is determined by the cell gap, the pixel electrode, or the first It can also be said to be the shortest distance between the common electrode 112 and the second common electrode 244.

[0042] 2(A) to 2(C) show an example of the layout of the second common electrode 244. In FIG.

[0043] Here, three sub-pixels, a red sub-pixel (R), a green sub-pixel (G), and a blue sub-pixel (B), are An example in which one pixel is composed of sub-pixels is shown. The area other than the display area 68 of the sub-pixels is Shown as non-display area 66 .

[0044] FIG. 2A shows an example in which the second common electrode 244 has an opening. The opening is located in the display area 68. The opening may also extend into non-display area 66.

[0045] In FIG. 2A, the length L1 corresponds to the width of the opening. Also, the length L1 corresponds to the length of the short side of the opening. It can also be said that the length of the aperture in the direction in which the sub-pixels exhibiting different colors are arranged. .

[0046] In FIG. 2(A), the length L2 corresponds to the interval between the openings. Also, the length L2 corresponds to the interval between the openings. It can also be expressed as the interval between the openings in the direction in which the corresponding sub-pixels are arranged.

[0047] FIG. 2B shows an example in which a plurality of second common electrodes 244 are provided in a stripe pattern. The direction in which the second common electrode 244 is disposed is the direction in which the sub-pixels exhibiting the same color are disposed. Intersects with.

[0048] One second common electrode 244 is disposed across two adjacent sub-pixels that exhibit different colors. For example, the second common electrode 244a is connected to the red subpixel (R) and the green subpixel (G). are placed across.

[0049] In FIG. 2(B), the length L1 corresponds to the distance between two adjacent second common electrodes.

[0050] In FIG. 2B, the length L2 corresponds to the width of the second common electrode. The length of the short side of the first common electrode, the length of the second common electrode in the direction in which the sub-pixels exhibiting different colors are arranged, It can also be referred to as the length of the pole.

[0051] The second common electrode 244 shown in FIG. 2B can be regarded as one comb-shaped electrode. In this case, the second common electrodes 244a and 244b may be provided in a portion not shown in FIG. 44b and 244c are connected. Length L1 is the tooth interval, and length L2 is the tooth width. This can be done.

[0052] In FIG. 2C, the second common electrode 244 has two adjacent openings that exhibit the same color. An example in which an aperture is provided across multiple sub-pixels is shown. One aperture covers multiple sub-pixels that exhibit the same color. may be located in the display area 68.

[0053] The larger the area where the second common electrode 244 is provided, the higher the resistance of the second common electrode 244. For example, the thickness of the slit shown in FIG. 2(A) can be reduced compared to the thicknesses of the slits shown in FIG. 2(B) and (C). The configuration can lower the resistance of the second common electrode 244.

[0054] In the following, the layout of the second common electrode 244 in FIGS. 1(A) to 1(D) will be explained. 1(A) to (D) will be described as an example corresponding to the layout shown in FIG. The second common electrode 244 has an opening in the display region 68. In this embodiment, the first common electrode 112 has an opening in the display area 68 .

[0055] In each of FIGS. 1C and 1D, the shape of the second common electrode 244 is different from that in FIG. 1B. .

[0056] As shown in FIG. 1C, the first common electrode 112 is also provided in the display areas 68a and 68b. In addition, it may have a portion that does not overlap with the second common electrode 244 .

[0057] In FIG. 1B, the width of the opening of the first common electrode 112 and the width of the opening of the second common electrode 244 are is equal to.

[0058] In FIG. 1C, the width of the opening of the second common electrode 244 is smaller than the width of the opening of the first common electrode 112. The width is longer.

[0059] In FIG. 1D, the width of the opening of the second common electrode 244 is smaller than the width of the opening of the first common electrode 112. The width is shorter.

[0060] When viewed from a direction perpendicular to the thickness of the liquid crystal layer 113, the first The length of the opening of the common electrode 112 to the edge of the opening is L3 in FIG. 1(C), and Let the length be L4.

[0061] In the subpixel, the larger the area where the second common electrode 244 is provided, the greater the distance from the pixel electrode. In other words, the shorter the length L1, the smaller the electric field spread to the electrode of the adjacent subpixel. The longer the length L2, the more the light leakage can be reduced. The shorter the length L3, the more the light leakage can be reduced. The more the light leakage can be reduced, the more

[0062] In the display region of the subpixel, the larger the portion where the second common electrode 244 is not provided, the By providing the second common electrode 244, it is possible to suppress an increase in the driving voltage of the liquid crystal element. In other words, the longer the length L1 is, or the shorter the length L2 is, the smaller the driving voltage of the liquid crystal element is. In addition, the longer the length L3 shown in FIG. 1(C), the more the liquid crystal element The increase in the driving voltage can be suppressed. In addition, the shorter the length L4 shown in FIG. An increase in the driving voltage of the liquid crystal element can be suppressed.

[0063] In addition, the smaller the thickness d of the liquid crystal layer is, the stronger the effect of the second common electrode 244 can be. The thickness of the liquid crystal layer is preferably 100 nm to 200 nm, and more preferably 100 nm to 200 nm. By reducing d, the length L1 can be increased (the length L2 can be decreased). This makes it possible to suppress an increase in driving voltage and to suppress light leakage.

[0064] From the above, when the thickness of the liquid crystal layer is d, the length L1 is preferably d / 6 or more. / 2 or more is more preferable.

[0065] The length L2 is preferably d or more and 2.5d or less, and more preferably 1.2d or less, where d is the thickness of the liquid crystal layer. It is more preferable that the length L2 is 2.4d or less. This condition of the length L2 affects the contrast ratio of the display device. The above condition of the length L1 affects the driving voltage of the display device. In manufacturing the LCD panel, it is desirable to give priority to the length L2, which affects the display quality.

[0066] The thickness d of the liquid crystal layer is preferably 1 μm or more and 3 μm or less, more preferably 1.5 μm or more and 3 μm or less. preferable.

[0067] By applying one embodiment of the present invention, light leakage between adjacent sub-pixels can be suppressed. Therefore, the aperture ratio of the sub-pixel can be increased. In addition, it is possible to realize a high-definition display device, and to improve the display quality of the display device. In addition, the increase in driving voltage can be suppressed. In addition, the light extraction efficiency can be improved by increasing the aperture ratio. This makes it possible to reduce the power consumption of the display device.

[0068] <1-2. Display device configuration example 2> 3A and 4A show an example of a display device. FIG. 3A shows a display device 100A. FIG. 4(A) is a perspective view of the display device 100A, and FIG. 4(A) is a cross-sectional view of the display device 100A. For clarity, components such as the polarizing plate 130 are omitted. Plate 61 is shown in dashed lines.

[0069] The display device 100A includes a display unit 62 and a drive circuit unit 64. FPC72 and IC73 are implemented.

[0070] The display unit 62 has a plurality of pixels and has a function of displaying an image.

[0071] The display device 100A includes a scanning line driving circuit and / or a signal line driving circuit. Alternatively, both the scanning line driver circuit and the signal line driver circuit may not be provided. When the display device 100A has a sensor such as a touch sensor, the display device 100A In the present embodiment, the driving circuit section 64 includes a scanning line The display unit 62 includes a scanning line driver circuit that applies a scanning signal to the scanning lines of the display unit 62. It has the function of outputting.

[0072] In the display device 100A, the IC 73 is mounted on the substrate 51 by a mounting method such as the COG method. The IC 73 includes, for example, a signal line driving circuit, a scanning line driving circuit, and a sensor driving circuit. It has one or more of the following paths.

[0073] The display device 100A is electrically connected to an FPC 72. Signals and power are supplied from the outside to the C73 and the drive circuit section 64. A signal can be output from IC73 to the outside via this pin.

[0074] An IC may be mounted on the FPC 72. For example, the FPC 72 may include a signal line drive circuit. An IC having one or more of a scanning line driver circuit, a scanning line driver circuit, and a sensor driver circuit is mounted. It may be possible.

[0075] Signals and power are supplied to the display unit 62 and the drive circuit unit 64 through wiring 65. Signals and power are input to the wiring 65 from the IC 73 or from the outside via the FPC 72. do.

[0076] 3B and 3C are top views of sub-pixels included in the display device 100A.

[0077] FIG. 4A is a cross-sectional view including a display section 62, a driving circuit section 64, and wiring 65. FIG. 4(A) includes a cross-sectional view taken along the dashed line X1-X2 in FIG. 3(B). In the cross-sectional view of the display device, the display section 62 is a display region 68 of one subpixel and a display region 68 surrounding the display region. 4 shows the non-display area 66 in which the image is located.

[0078] FIG. 3B shows the stacked structure ( FIG. 4(A) is a top view of the first common electrode 112. The display area 68 of the subpixel is indicated by a thick dotted frame. FIG. 1 is a top view in which the first common electrode 112 is removed.

[0079] The display device 100A is an example of a transmissive liquid crystal display device using a lateral electric field type liquid crystal element. .

[0080] As shown in FIG. 4A, the display device 100A includes a substrate 51, a transistor 201, a transistor A resistor 206, a liquid crystal element 40, an auxiliary wiring 139, an alignment film 133a, an alignment film 133b, and a connection part 204, adhesive layer 141, colored layer 131, light-shielding layer 132, overcoat 121, substrate 6 1, and a polarizing plate 130.

[0081] The display area 68 is provided with a liquid crystal element 40. The liquid crystal element 40 is a FFS (Frin This is a liquid crystal element to which the GE Field Switching (GE Field Switching) mode is applied.

[0082] The liquid crystal element 40 includes a pixel electrode 111, a first common electrode 112, a second common electrode 244, and The liquid crystal layer 113 is formed by an electric field generated between the pixel electrode 111 and the first common electrode 112. The liquid crystal layer 113 is aligned with the alignment film 133a. It is located between the apical membrane 133b.

[0083] At the connection portion 69, the second common electrode 244 is electrically connected to a conductive layer provided on the substrate 51 side. This allows a potential to be supplied from the FPC 72 to the second common electrode 244. Therefore, there is no need to connect an FPC or the like to the substrate 61 side, and the display device This is preferable because it allows the configuration to be further simplified.

[0084] The connection unit 69 may be provided as a part of the display unit 62. Alternatively, the connection unit 69 may be It may be provided outside the display unit 62, for example, between the display unit 62 and the drive circuit unit 64. It may be provided.

[0085] The first common electrode 112 and the second common electrode 244 can be supplied with the same potential. For example, the first common electrode 112 and the conductive layer 284 are electrically connected to each other, or one If it is the same film, the second common electrode 244 is electrically connected to the first common electrode 112. To be continued.

[0086] The second common electrode 244 does not have to be electrically connected to the first common electrode 112. A power line electrically connected to the first common electrode 112 and a power line electrically connected to the second common electrode 244 are If the power supply lines electrically connected to the power supply are different, the same potential can be supplied to the two power supply lines. , the first common electrode 112 and the second common electrode 244 can be supplied with the same potential.

[0087] At the connection portion 69, the conductive layer 281 and the conductive layer 282 are connected, and the conductive layer 282 and the conductive layer 283 are The conductive layer 283 and the conductive layer 284 are connected, the conductive layer 284 and the connector 243 are connected, The connector 243 and the second common electrode 244 are connected to each other. The gate 223, gate 221, and conductive layer 283 of the transistor are connected to each other, respectively. The conductive layer 222a and the conductive layer 222b can be formed using the same material and in the same process. In this way, the conductive layer constituting the connection section 69 is the same as the conductive layer used in the display section 62 and the drive circuit section 64. It is preferable to use the same material and the same process to manufacture the two components, since this can prevent an increase in the number of processes.

[0088] The connector 243 may be, for example, a conductive particle. The surface of organic resin or silica particles coated with a metal material can be used. It is preferable to use nickel or gold as the metal material, since this can reduce the contact resistance. The particles are coated with layers of two or more metal materials, such as nickel coated with gold. It is preferable that the connector 243 is made of a material that undergoes elastic or plastic deformation. At this time, the conductive particles are preferably crushed in the vertical direction as shown in FIG. In this way, the connecting body 243 and the conductive body electrically connected thereto may be formed in a shape similar to that shown in FIG. The contact area with the layer is increased, which reduces contact resistance and suppresses problems such as poor connection. do.

[0089] It is preferable that the connector 243 is disposed so as to be covered with the adhesive layer 141. For example, The connectors 243 may be dispersed in the adhesive layer 141 .

[0090] In FIG. 4A, the pixel electrode 111 is provided with a low resistance region 231b via a conductive layer 222b. and is electrically connected to

[0091] As shown in FIG. 4B, the pixel electrode 111 is directly connected to the low resistance region 231b. At this time, the semiconductor layer (channel region 231a and low resistance region 231b) may be formed with an oxide. It is preferable to use a material that transmits visible light, such as a semiconductor. The connection between the transistor and the pixel can be provided in the display area 68. The aperture ratio can be increased. Also, the display device can have a higher resolution. The conductive layer 222b may be electrically connected to the low resistance region 231b. Alternatively, the transistor may function as an auxiliary electrode for the conductive layer 231b. 22b may not be included.

[0092] The first common electrode 112 has a comb-like upper surface shape (also called a planar shape) or has slits. In Fig. 3(B), (C) and Fig. 4(A), one An example is shown in which one opening of the first common electrode 112 is provided in the display region 68 of the sub-pixel. As the resolution of a display device increases, the area of ​​the display region 68 of one subpixel becomes smaller. In addition, the number of openings provided in the first common electrode 112 is not limited to a plurality of openings, and may be one. That is, in a high-definition display device, the area of ​​a pixel (subpixel) is small, so that the first common Even if the electrode 112 has only one opening, the liquid crystal can be aligned over the entire display area of ​​the subpixel. It is possible to generate an electric field sufficient for

[0093] An insulating layer 220 is provided between the pixel electrode 111 and the first common electrode 112. The electrode 111 has a portion overlapping with the first common electrode 112 via the insulating layer 220. In the region where the pixel electrode 111 and the colored layer 131 overlap, a first common layer is formed on the pixel electrode 111. The first common electrode 112 has a portion where the conductive electrode 112 is not arranged. The resistivity of the auxiliary wiring 139 is higher than the resistivity of the first common electrode 112. By providing an auxiliary wiring electrically connected to the common electrode, In addition, the voltage drop caused by the resistance of the metal oxide can be suppressed. When a laminated structure of a conductive layer and a conductive layer containing a metal is used, a pattern is formed using a half-tone mask. Forming the plate by turning technology is preferable because it simplifies the process.

[0094] The auxiliary wiring 139 is a film having a lower resistance than the first common electrode 112. For example, molybdenum, titanium, chromium, tantalum, tungsten, aluminum, copper , silver, neodymium, scandium, or other metal materials or alloy materials containing these elements. , it can be formed as a single layer or a laminate.

[0095] The auxiliary wiring 139 is arranged so as to overlap the light-shielding layer 132 and the like so as not to be visible to the user of the display device. It is preferable that the sensor is provided at a position where the sensor is located.

[0096] It is preferable to provide an alignment film in contact with the liquid crystal layer 113. The alignment film adjusts the alignment of the liquid crystal layer 113. In the display device 100A, the first common electrode 112 and the insulating layer 220 An alignment film 133a is disposed between the liquid crystal layer 113 and the second common electrode 244 and the overcoat layer 133b. An alignment film 133 b is located between the gate 121 and the liquid crystal layer 113 .

[0097] There are two types of liquid crystal materials: positive type, in which the anisotropy of the dielectric constant (Δε) is positive, and negative type, in which the anisotropy is negative. In one embodiment of the present invention, either material can be used, and the applied model The optimum liquid crystal material can be used depending on the mode and design.

[0098] In one embodiment of the present invention, it is preferable to use a negative type liquid crystal material. The influence of the flexoelectric effect caused by the polarization of molecules can be suppressed, and the applied voltage to the liquid crystal layer There is almost no difference in transmittance depending on the polarity of the voltage applied. The flexoelectric effect is mainly due to the molecular shape. This is a phenomenon in which polarization occurs due to orientation distortion. Negative liquid crystal materials spread and deform. Orientation distortion due to bending deformation is unlikely to occur.

[0099] In this embodiment, an element to which the FFS mode is applied is used as the liquid crystal element 40. It is possible to use liquid crystal elements with various modes. For example, VA (Ver (Twisted Nematic) mode, mode, IPS (In-Plane-Switching) mode, ASM (Axiall y Symmetric aligned Micro-cell) mode, OCB(O (Fptically Compensated Birefringence) mode, LC (Ferroelectric Liquid Crystal) mode, AFLC (AntiFerroelectric Liquid Crystal) mode is suitable. A liquid crystal element used in the present invention can be used.

[0100] In addition, the display device 100A is a normally black type liquid crystal display device, for example, a vertical alignment (VA A transmissive liquid crystal display device using a vertical alignment mode may be used. MVA (Multi-Domain Vertical Alignment) mode, PVA (Patterned Vertical Alignment) mode, ASV (Advanced Super View) mode, etc. can be used.

[0101] A liquid crystal element is an element that controls the transmission or non-transmission of light by the optical modulation action of liquid crystal. The optical modulation of liquid crystals is achieved by applying an electric field (horizontal electric field, vertical electric field, or The liquid crystal used in the liquid crystal element is thermoplastic. ropic liquid crystal, low molecular liquid crystal, polymer liquid crystal, polymer dispersed liquid crystal (PDLC) Dispersed Liquid Crystal, Ferroelectric Liquid Crystal, Antiferroelectric Liquid Crystal These liquid crystal materials can exhibit a cholesteric phase, a smectic phase, etc., depending on the conditions. These phases include cubic phase, chiral nematic phase, isotropic phase, etc.

[0102] In addition, when the in-plane switching system is adopted, liquid crystal that exhibits a blue phase without using an alignment film may be used. The blue phase is one of the liquid crystal phases. When the temperature of a cholesteric liquid crystal is increased, the cholesteric The blue phase appears just before the transition from the crystalline phase to the isotropic phase. In order to improve the temperature range, a liquid crystal composition containing 5% by weight or more of chiral agent is used. The liquid crystal composition containing a liquid crystal exhibiting a blue phase and a chiral agent is used for the liquid crystal layer 113. The response speed is short and the liquid crystal exhibits optical isotropy. The crystal composition does not require alignment treatment and has little viewing angle dependency. Since the rubbing process is unnecessary, electrostatic damage caused by the rubbing process is eliminated. This can prevent defects or damage to the liquid crystal display device during the manufacturing process. Cut.

[0103] Since the display device 100A is a transmissive liquid crystal display device, the pixel electrode 111 and the first common Both electrodes 112 are made of a conductive material that transmits visible light. When the second common electrode 244 is located in the display area 68, the second common electrode 244 is also made of a conductive material that transmits visible light. Fees are used.

[0104] Examples of conductive materials that transmit visible light include indium (In), zinc (Zn), and tin. It is preferable to use a material containing one or more selected from the group consisting of indium oxide, tin, and tin. Indium, Indium Tin Oxide (ITO), Indium Zinc oxide, indium oxide with tungsten oxide, indium oxide with tungsten oxide Indium zinc oxide, indium oxide with titanium oxide, indium stannate with titanium oxide oxide, indium tin oxide (ITSO), zinc oxide, gallium oxide Examples of the film include zinc oxide. A film containing graphene can also be used. The graphene oxide-containing film can be formed, for example, by reducing a film containing graphene oxide. can be done.

[0105] At least one of the pixel electrode 111 and the first common electrode 112 is made of an oxide conductive layer. The oxide conductive layer is preferably a metal element contained in the semiconductor layer of the transistor 206. For example, the pixel electrode 111 may contain indium. is preferred, and In-M-Zn oxide (wherein M is Al, Ti, Ga, Ge, Y, Zr, La, C It is more preferable that the first common electrode 1 is a thin film of Nd, Sn or Hf. 12 preferably contains indium, and is further preferably an In-M-Zn oxide film. preferable.

[0106] At least one of the pixel electrode 111 and the first common electrode 112 is made of an oxide semiconductor. The oxide semiconductors having the same metal element may be used for the layers constituting the display device. By using it for two or more layers, manufacturing equipment (e.g., deposition equipment, processing equipment, etc.) can be used for two or more processes. Since the manufacturing process can be shared, the manufacturing cost can be reduced.

[0107] The oxide semiconductor has at least one of oxygen vacancies and impurity concentrations such as hydrogen and water in the film. On the other hand, oxide semiconductors are semiconductor materials whose resistance can be controlled. A process that increases at least one of oxygen deficiency and impurity concentration in a layer, or By selecting a treatment that reduces at least one of the concentrations of the oxide conductive layer, The resistivity can be controlled.

[0108] Note that the oxide conductive layer formed using the oxide semiconductor layer has a carrier density of A high-resistance and low-resistance oxide semiconductor layer, a conductive oxide semiconductor layer, or a highly conductive oxide semiconductor layer It can also be called a solid semiconductor layer.

[0109] In addition, by forming the oxide semiconductor layer and the oxide conductive layer using the same metal element, the manufacturing cost can be reduced. For example, by using a metal oxide target of the same metal composition, In addition, the manufacturing cost can be reduced by using a metal oxide target having the same metal composition. By using the above-mentioned gas, the etching gas or the etching However, the oxide semiconductor layer and the oxide conductive layer may be formed in the same manner. Even if the metal elements are included, the composition may be different. For example, In some cases, metal elements in the film may be released, resulting in a different metal composition.

[0110] For example, the insulating layer 220 is made of a silicon nitride film containing hydrogen, and the pixel electrode 111 is made of an oxide semiconductor. When the oxide semiconductor is used, the conductivity of the oxide semiconductor is increased by hydrogen supplied from the insulating layer 220. It is possible.

[0111] In the non-display area 66, a transistor 206 is provided.

[0112] The transistor 206 includes a gate 221, a gate 223, an insulating layer 211, an insulating layer 213, and The low resistance region 231b is a semiconductor layer having a channel region 231a and a pair of low resistance regions 231b. The resistivity of the region 231b is lower than the resistivity of the channel region 231a. The case where an oxide semiconductor layer is used as the semiconductor layer will be described as an example. In-M-Zn oxide (wherein M is Al, Ti, Ga, Ge, Y, More preferably, the oxide semiconductor is a film of Zr, La, Ce, Nd, Sn or Hf. The body layers will be described in detail below.

[0113] The gate 221 overlaps the channel region 231a via the insulating layer 213. , and overlaps with the channel region 231a via the insulating layer 211. The conductive layer 222a is one of the low resistance regions 231b. The conductive layer 222b is provided on the other of the low resistance regions 231b, the insulating layer 212 and the insulating layer 214. The connection is made through a hole provided in the

[0114] The transistor 206 shown in FIG. 4A is a transistor in which gates are provided above and below the channel. It is a ninja.

[0115] In the contact portion Q1 shown in FIG. 3C, the gate 221 and the gate 223 are electrically A transistor with two gates electrically connected in this way is The field-effect mobility of the MOSFET can be increased compared to other transistors, and the on-current As a result, a circuit capable of high speed operation can be fabricated. Furthermore, it is possible to reduce the area occupied by the circuit section. By applying this, even if the display device becomes larger or has higher resolution, and the number of wirings increases, It is possible to reduce the signal delay in each wiring, and to suppress display unevenness. In addition, by applying such a configuration, a highly reliable transistor can be realized. This can be done.

[0116] In the contact portion Q2 shown in FIG. 3C, the conductive layer 222b is connected to the pixel electrode 111. is doing.

[0117] In FIG. 3B and FIG. 3C, one conductive layer functions as a scan line 228 and a gate 223. Of the gate 221 and the gate 223, the one with the lower resistance serves as a scanning line. It is preferable that the conductive layer is also functional.

[0118] In FIGS. 3B and 3C, one conductive layer is formed as the signal line 229 and the conductive layer 222a. It can also be said that it works.

[0119] The gates 221 and 223 are each provided with a single layer of either a metal material or an oxide conductor. For example, the gate 221 and the gate 223 may be stacked together. An oxide conductor may be used for one of the electrodes, and a metal material may be used for the other electrode.

[0120] The transistor 206 includes an oxide semiconductor layer as a semiconductor layer, and has a gate 221 and a gate At least one of the layers 223 may be an oxide conductive layer. In this case, the oxide semiconductor layer and the oxide conductive layer are preferably formed using an oxide semiconductor.

[0121] By using a conductive layer that blocks visible light for the gate 223, the light from the backlight is blocked by the channel region 2 This can prevent the radiation from reaching the surface of the transistor 31a. It can be improved.

[0122] The transistor 206 includes an insulating layer 212, an insulating layer 214, an insulating layer 215, and an insulating layer 216. The insulating layer 212, the insulating layer 214, and the insulating layer 216 are covered with a transistor. The transistors can be regarded as components of the transistor 206. It is preferable that the semiconductor substrate is covered with an insulating layer that has an effect of suppressing the diffusion of impurities into the semiconductor. The insulating layer 215 can function as a planarizing layer.

[0123] Each of the insulating layers 211 and 213 preferably has an excess oxygen region. The gate insulating layer has an excess oxygen region, which supplies excess oxygen into the channel region 231a. The oxygen vacancies that may be formed in the channel region 231a can be compensated for by the excess oxygen. Therefore, a highly reliable transistor can be provided.

[0124] The insulating layer 212 preferably contains nitrogen or hydrogen. When the insulating layer 212 comes into contact with the low resistance region 231b, the nitrogen or hydrogen in the insulating layer 212 is absorbed into the low resistance region 231b. The low resistance region 231b is doped with nitrogen or hydrogen, and thus the carrier density is increased. Alternatively, the insulating layer 214 may have nitrogen or hydrogen, and the insulating layer 212 may have nitrogen or hydrogen. By allowing hydrogen to permeate, nitrogen or hydrogen may be added to the low resistance region 231b.

[0125] In the display device 100A, a colored layer 131 and a light-shielding layer 13 are provided on the substrate 61 side of the liquid crystal layer 113. The colored layer 131 is provided at least in a portion overlapping with the display region 68 of the sub-pixel. A light-shielding layer 132 is provided in the non-display area 66 of the pixel (sub-pixel). The light-shielding layer 132 overlaps at least a portion of the transistor 206.

[0126] An overcoat 121 is provided between the colored layer 131 and the light-shielding layer 132 and the liquid crystal layer 113. It is preferable to provide the overcoat 121 in the form of a colored layer 131, a light-shielding layer 132, etc. It is possible to prevent impurities contained in the liquid crystal layer 113 from diffusing into the liquid crystal layer 113. A second common electrode 244 is provided between the gate 121 and the alignment film 133b.

[0127] The substrate 51 and the substrate 61 are bonded together by an adhesive layer 141. A liquid crystal layer 113 is sealed in the area surrounded by the adhesive layer 141 and the insulating layer 142 .

[0128] When the display device 100A is made to function as a transmissive liquid crystal display device, the polarizing plate is In FIG. 4A, the polarizing plate 130 on the substrate 61 side is shown. The light 45 from the backlight arranged on the outer side of the polarizing plate provided on the substrate 51 side is At this time, the light is applied between the pixel electrode 111 and the first common electrode 112. The orientation of the liquid crystal layer 113 can be controlled by the applied voltage, and the optical modulation of light can be controlled. That is, the intensity of the light emitted through the polarizing plate 130 can be controlled. Since light outside a specific wavelength range is absorbed by the colored layer 131, the emitted light is, for example, For example, red, blue, or green light.

[0129] In addition to the polarizing plate, for example, a circular polarizing plate can be used. For example, a linear polarizing plate and a quarter-wave retardation plate can be laminated. This makes it possible to reduce the viewing angle dependency of the display device.

[0130] The drive circuit unit 64 includes a transistor 201 .

[0131] The transistor 201 includes a gate 221, a gate 223, an insulating layer 211, an insulating layer 213, a semiconductor A conductor layer (a channel region 231a and a pair of low resistance regions 231b), a conductive layer 222a, and One of the conductive layer 222a and the conductive layer 222b is used as a source. The conductive layer 222a functions as a drain and the other functions as a drain. The conductive layer 222b is electrically connected to the other of the low resistance regions 231b.

[0132] In the connection portion 204, the wiring 65 and the conductive layer 251 are connected to each other, and the conductive layer 251 and the connection body 24 2 are connected to each other. That is, in the connection portion 204, the wiring 65 is connected to the conductive layer 251. The connector 242 is electrically connected to the FPC 72. Signals and power can be supplied to the wiring 65 from the FPC 72 .

[0133] The wiring 65 is formed of the same material as the conductive layers 222a and 222b of the transistor 206. The conductive layer 251 can be formed by the process of forming the pixel electrode 111 of the liquid crystal element 40. In this way, the connecting portion 204 can be formed of the same material and in the same process. The conductive layer is made of the same material and in the same process as the conductive layers used in the display section 62 and the drive circuit section 64. This is preferable because it is possible to prevent an increase in the number of steps.

[0134] The transistors 201 and 206 may have the same structure or different structures. The transistors in the driver circuit section 64 and the transistors in the display section 62 are the same. The driving circuit section 64 may have a plurality of structures. The display unit 62 may have a transistor having a plurality of structures. For example, a shift register circuit, a buffer circuit, and a storage circuit included in the scanning line driver circuit may be A transistor having two gates electrically connected to one or more of the protection circuits. It is preferable to use a stencil.

[0135] 5(A) and (B) show examples of pixel arrangement. In FIG. 5(A) and (B), An example is shown in which one pixel is composed of a green subpixel G and a blue subpixel B. In A) and B), a plurality of scanning lines 81 extend in the x direction, and a plurality of signal lines 82 extend in the y direction. The scanning lines 81 and the signal lines 82 extend in the same direction.

[0136] As shown in the double-dashed line frame in FIG. 5A, the subpixel includes a transistor 206, a capacitor element 3 4, and a liquid crystal element 40. The gate of the transistor 206 is electrically connected to the scan line 81. One of the source and drain of the transistor 206 is connected to the signal line 82. The other end is electrically connected to one electrode of the capacitance element 34 and one electrode of the liquid crystal element 40. The other electrode of the capacitance element 34 and the other electrode of the liquid crystal element 40 are electrically connected to each other. A constant potential is applied to each.

[0137] 5A and 5B show an example of applying source line inversion driving. Signals B1 and B2 are signals of the same polarity. Signal A1 and Signal B2 are signals of the same polarity. Signal A2 and signal B2 are signals with opposite polarities. It is.

[0138] As the resolution of a display device increases, the distance between sub-pixels becomes narrower. As shown in the dashed line frame, in the sub-pixel to which the signal A1 is input, In the vicinity of the signal line 82, the liquid crystal is easily affected by the potentials of both the signal A1 and the signal B1. This makes the liquid crystal alignment more likely to be poor.

[0139] In FIG. 5A, the direction in which a plurality of sub-pixels exhibiting the same color are arranged is the y direction. As shown in the dashed line frame in FIG. A subpixel having a different color is adjacent to the long side of the subpixel.

[0140] In FIG. 5B, the direction in which a plurality of sub-pixels exhibiting the same color are arranged is the x direction. As shown in the dashed line frame in FIG. On the short side of each pixel, sub-pixels exhibiting the same color are adjacent to each other.

[0141] As shown in FIG. 5B, in the subpixel, a side that is approximately parallel to the direction in which the signal line 82 extends is In contrast, when the liquid crystal is aligned on the short side, the alignment of the liquid crystal is more likely to be poor than when the liquid crystal is aligned on the long side (FIG. 5(A)). As shown in FIG. 5(B), the area where the alignment defect of the liquid crystal is likely to occur can be narrowed. When the area is located between sub-pixels that exhibit the same color, and when it is located between sub-pixels that exhibit different colors, Compared to FIG. 5(A), display defects are less likely to be visually recognized by the user of the display device. In one embodiment, the direction in which the sub-pixels exhibiting the same color are arranged is the direction in which the signal line 82 extends. It is preferable that the direction of the wire be perpendicular to the longitudinal direction.

[0142] In addition, since the display device of one embodiment of the present invention includes the second common electrode 244, the alignment of the liquid crystal is poor. Therefore, in one embodiment of the present invention, as shown in FIG. The direction in which the sub-pixels exhibiting different colors are arranged crosses the direction in which the signal lines 82 extend. The configuration can also be applied.

[0143] 6 shows a cross-sectional view of the display device 100B. Since this is similar to the display device 100A shown in FIG. 3(A), a description thereof will be omitted here.

[0144] In the display device 100A, an example in which a transistor has two gates is shown. In 00B, the transistor 201 and the transistor 206 have only the gate 221. In addition, the display device 100B has a spacer 117. A detailed description of the parts similar to those of the device 100A will be omitted.

[0145] The transistor 201 and the transistor 206 are provided over an insulating layer 211. The transistor 206 includes a gate 221, an insulating layer 213, and a and a semiconductor layer (a channel region 231a and a pair of low resistance regions 231b). 22a is one side of the low resistance region 231b, and the conductive layer 222b is the other side of the low resistance region 231b. The insulating layer 212 and the insulating layer 214 are connected through an opening provided in the insulating layer 215. , can function as a planarization layer.

[0146] At the connection portion 69, the conductive layer 281 and the conductive layer 282 are connected, and the conductive layer 282 and the conductive layer 283 are The conductive layer 283 and the connector 243 are connected, and the connector 243 and the second common electrode 244 are connected. The conductive layer 281 and the conductive layer 282 are connected to the gate 22 of the transistor. 1, and the conductive layer 222a and the conductive layer 222b are formed of the same material and in the same process. In this way, the conductive layer constituting the connection section 69 can be connected to the display section 62 and the drive circuit section 64. If the conductive layer is fabricated using the same material and process as the conductive layer, an increase in the number of processes can be prevented, which is preferable. I wish.

[0147] The spacer 117 has a function of preventing the distance between the substrate 51 and the substrate 61 from becoming closer than a certain distance. do.

[0148] FIG. 6 shows an example in which the bottom surface of the spacer 117 is in contact with the overcoat 121. The embodiment of the invention is not limited to this. The spacer 117 may be provided on the substrate 51 side. Alternatively, it may be provided on the substrate 61 side.

[0149] In FIG. 6, the alignment film 133a and the alignment film 133b are in contact with each other at the portion where the alignment film 133a and the spacer 117 overlap. In the example shown, the alignment layers are not necessarily in contact with each other, but they may be in contact with each other. The spacer 117 may or may not be in contact with a structure provided on the other substrate. For example, the liquid crystal layer 113 may be located between the spacer 117 and the structure. stomach.

[0150] Granular spacers may be used as the spacers 117. For the granular spacers, silica The spacer may be made of a material having elasticity, such as resin or rubber. In this case, the granular spacers may be crushed in the vertical direction. There is.

[0151] Next, details of materials that can be used for each component of the display device of this embodiment will be described. In addition, the description of components that have already been described may be omitted. The following materials are also used for the display device and touch panel described below, as well as their components. It can be used as appropriate.

[0152] <Substrates 51 and 61> There is no particular limitation on the material of the substrate of the display device of one embodiment of the present invention, and various substrates can be used. For example, a glass substrate, a quartz substrate, a sapphire substrate, a semiconductor substrate, a ceramic substrate, A composite substrate, a metal substrate, a plastic substrate, or the like can be used.

[0153] By using a thin substrate, the display device can be made lighter and thinner. In addition, by using a substrate that is thick enough to provide flexibility, a flexible display device can be realized. Cut.

[0154] In the display device of one embodiment of the present invention, a transistor or the like is formed over a formation substrate, and then a By using a fabrication substrate, the characteristics of Formation of good transistors, formation of transistors with low power consumption, and durable display devices To manufacture, impart heat resistance to a display device, and to reduce the weight or thickness of the display device. The substrate on which the transistor is transferred is a substrate on which a transistor can be formed. Not limited to substrates, paper substrates, cellophane substrates, stone substrates, wood substrates, cloth substrates (natural fibers (silk , cotton, linen), synthetic fibers (nylon, polyurethane, polyester) or regenerated fibers (a acetate, cupra, rayon, recycled polyester, etc.), leather substrate, or rubber A substrate such as a rubber substrate can be used.

[0155] <Transistors 201, 206> The transistor included in the display device of one embodiment of the present invention is a top-gate or bottom-gate transistor. Alternatively, gate electrodes are provided above and below the channel. The semiconductor material used for the transistor is not particularly limited, and examples thereof include an oxide semiconductor, a silicon semiconductor, and the like. Examples of such materials include silicon and germanium.

[0156] The crystallinity of the semiconductor material used in the transistor is not particularly limited. A semiconductor having crystallinity (microcrystalline semiconductor, polycrystalline semiconductor, single crystal semiconductor, or semiconductor with partially crystalline regions) If a semiconductor having crystallinity is used, the This is preferable because it is possible to suppress deterioration of the resistor characteristics.

[0157] For example, Group 14 elements, compound semiconductors, or oxide semiconductors can be used for the semiconductor layer. Typically, a semiconductor containing silicon, a semiconductor containing gallium arsenide, or an indium An oxide semiconductor containing the above-mentioned compound can be used for the semiconductor layer.

[0158] An oxide semiconductor is preferably used as a semiconductor in which a channel of a transistor is formed. In particular, it is preferable to use an oxide semiconductor having a band gap larger than that of silicon. If a semiconductor material with a wider band gap and lower carrier density than silicon is used, This is preferable because the current in an off state of the transistor (off-state current) can be reduced.

[0159] The oxide semiconductor preferably contains at least indium (In) or zinc (Zn). More preferably, In-M-Zn oxide (wherein M is Al, Ti, Ga, Ge, Y, Zr , La, Ce, Nd, Sn or Hf) are included.

[0160] In particular, the semiconductor layer has a plurality of crystal parts, and the c-axes of the crystal parts are aligned along the surface on which the semiconductor layer is formed, Alternatively, the crystals are oriented approximately perpendicular to the upper surface of the semiconductor layer and have no grain boundaries between adjacent crystal portions. It is preferable to use a thin oxide semiconductor layer.

[0161] By using such oxide semiconductors in the semiconductor layer, fluctuations in electrical characteristics are suppressed, and reliability is improved. This makes it possible to realize highly reliable transistors.

[0162] In addition, due to its low off-state current, the charge stored in the capacitance can be released through the transistor for a long period of time. By applying such transistors to pixels, It is also possible to stop the driving circuit while maintaining the gradation of the image displayed. A display device with reduced power consumption can be realized.

[0163] The transistors 201 and 206 are made of a highly purified oxide semiconductor layer in which the formation of oxygen vacancies is suppressed. This can reduce the off-state current of the transistor. This allows the retention time of electrical signals such as image signals to be extended, and writing is possible while the power is on. The write interval can also be set longer, which reduces the frequency of refresh operations. This has the effect of reducing power consumption.

[0164] In addition, the transistors 201 and 206 have a relatively high field effect mobility, and therefore can operate at high speed. By using such a transistor capable of high-speed driving in a display device, In addition, the transistors in the display section and the transistors in the driver circuit section can be formed on the same substrate. That is, a semiconductor device formed of a silicon wafer or the like can be used as a driving circuit. Since it is not necessary to use a display device, the number of parts of the display device can be reduced. By using transistors that can be driven at high speed, it is possible to provide high-quality images. can be done.

[0165] <Oxide semiconductor layer> The oxide semiconductor layer contains at least indium (In), zinc (Zn) and M (Al, Ti, In-M- containing metals such as Ga, Ge, Y, Zr, La, Ce, Nd, Sn or Hf It is preferable that the transistor includes a film represented by Zn oxide. To reduce the variation in the electrical characteristics of the transistors, stabilizers may be included with them. preferable.

[0166] The stabilizer includes the metals described above under M, such as gallium (Ga), tin, etc. (Sn), hafnium (Hf), aluminum (Al), or zirconium (Zr), etc. Other stabilizers include the lanthanides lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Samarium (Sm), Uropium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (D y), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium ( Yb), lutetium (Lu), etc.

[0167] Examples of oxide semiconductors constituting the oxide semiconductor layer include In-Ga-based oxides and In-Z n-type oxides, In-Ga-Zn-type oxides, In-Al-Zn-type oxides, In-Sn-Zn In-Hf-Zn oxide, In-La-Zn oxide, In-Ce-Zn oxide Oxide, In-Pr-Zn oxide, In-Nd-Zn oxide, In-Sm-Zn oxide oxides, In-Eu-Zn oxides, In-Gd-Zn oxides, In-Tb-Zn oxides In-Dy-Zn oxide, In-Ho-Zn oxide, In-Er-Zn oxide , In-Tm-Zn oxide, In-Yb-Zn oxide, In-Lu-Zn ​​oxide, In-Sn-Ga-Zn oxide, In-Hf-Ga-Zn oxide, In-Al-Ga -Zn oxide, In-Sn-Al-Zn oxide, In-Sn-Hf-Zn oxide, In-Hf-Al-Zn based oxides can be used.

[0168] In this case, the In-Ga-Zn oxide is an oxide having In, Ga, and Zn as main components. It means oxide, and the ratio of In, Ga, and Zn does not matter. Also, In, Ga, and Zn Metal elements other than those may be included.

[0169] When the oxide semiconductor layer is an In-M-Zn oxide, the sum of In and M is 100 at When the atomic percentage is 100%, In is preferably higher than 25 atomic percent and M is preferably 75 atomic percent. mic%, more preferably In is higher than 34 atomic % and M is 66 atomic %. Less than ic%.

[0170] The oxide semiconductor layer has an energy gap of 2 eV or more, preferably 2.5 eV or more. The energy gap is preferably 3 eV or more. By doing so, the off-state current of the transistor can be reduced.

[0171] The thickness of the oxide semiconductor layer is 3 nm to 200 nm, preferably 3 nm to 100 nm. Further, the thickness is more preferably 3 nm or more and 50 nm or less.

[0172] The oxide semiconductor layer is In-M-Zn oxide (M is Al, Ti, Ga, Ge, Y, Zr, La , Ce, Nd, Sn or Hf) is used to deposit In-M-Zn oxide. The atomic ratio of the metal elements in the sputtering target must satisfy the following conditions: In≧M, Zn≧M. The atomic ratio of the metal elements in such a sputtering target is preferably In:M :Zn=1:1:1, In:M:Zn=1:1:1.2, In:M:Zn=3:1:2, Examples include In:M:Zn=1:3:4 and In:M:Zn=1:3:6. The atomic ratio of the oxide semiconductor layer to be formed is determined by the above sputtering target as an error. This includes a variation of ±40% in the atomic ratio of the metal elements contained in the material.

[0173] As the oxide semiconductor layer, an oxide semiconductor layer having a low carrier density is used. For example, The semiconductor layer has a carrier density of 1×10 17 / cm 3 Less than or equal to 1×10 15 / cm 3 Less than 1×10, more preferably 13 / cm 3 Less than or equal to 1×10 11 / c m 3 The following oxide semiconductor layer is used.

[0174] In addition, the semiconductor characteristics and electrical characteristics (field effect An appropriate composition is used depending on the material (e.g., mobility, threshold voltage, etc.).

[0175] When the oxide semiconductor layer contains silicon or carbon, which is one of Group 14 elements, The oxygen vacancies in the oxide semiconductor layer increase, causing the oxide semiconductor to become n-type. The concentrations of silicon and carbon in the layer (obtained by secondary ion mass spectrometry) were Each, 2×10 18 atoms / cm 3 Less than or equal to 2×10 17 atoms / c m 3 The following applies.

[0176] In addition, in the oxide semiconductor layer, an alkali metal or is the concentration of alkaline earth metals, 1×10 18atoms / cm 3 Below, preferably 2 x 1 0 16 atoms / cm 3 Alkali metals and alkaline earth metals are oxide semiconductors. When it bonds with a conductor, it can generate carriers, which increases the off-state current of the transistor. For this reason, the concentration of alkali metal or alkaline earth metal in the oxide semiconductor layer It is preferable to reduce the degree of

[0177] In addition, when nitrogen is contained in the oxide semiconductor layer, electrons that serve as carriers are generated, and the carrier density is increased. As a result, transistors using oxide semiconductors containing nitrogen are Therefore, in the oxide semiconductor layer, the nitride It is preferable that the amount of oxygen is reduced as much as possible. For example, the amount of oxygen is reduced by secondary ion mass spectrometry. The nitrogen concentration is 5×10 18 atoms / cm 3 It is preferable to do the following:

[0178] The oxide semiconductor layer may have a non-single crystal structure. AC-OS(C Axis Aligned-Crystalline Oxide S emissive), polycrystalline, microcrystalline, or amorphous structures. In terms of crystal structure, the amorphous structure has the highest density of defect states, and the CAAC-OS has the lowest density of defect states. The level density is low.

[0179] The oxide semiconductor layer may have, for example, an amorphous structure. The oxide semiconductor layer having an amorphous structure is, for example, The atomic arrangement is disordered and does not have any crystalline components. Alternatively, an oxide film having an amorphous structure is, for example, For example, it has a completely amorphous structure and does not have any crystalline parts.

[0180] The oxide semiconductor layer may have an amorphous structure, a microcrystalline structure, a polycrystalline structure, or a C The film may be a mixed film having two or more of the AAC-OS region and the single crystal structure region. The film may have regions of amorphous structure, regions of microcrystalline structure, regions of polycrystalline structure, CAAC-O The crystal structure may have a single layer structure having two or more regions of either an S region or a single crystal structure region. The mixed film may have an amorphous structure, a microcrystalline structure, a polycrystalline structure, a C In the case where the layer structure has two or more types of regions, either the AAC-OS region or the single crystal structure region, There is a match.

[0181] <Insulating layer> Insulating material that can be used for various insulating layers, overcoats, spacers, etc. in display devices As the insulating material, an organic insulating material or an inorganic insulating material can be used. For example, acrylic resin, epoxy resin, polyimide resin, polyamide resin, polyamide Examples include diimide resins, siloxane resins, benzocyclobutene resins, and phenol resins. The inorganic insulating layer may be a silicon oxide film, a silicon oxynitride film, or a silicon nitride oxide film. silicon nitride film, aluminum oxide film, hafnium oxide film, yttrium oxide film, Zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film, lanthanum oxide film Examples of the thin film include a tungsten film, a cerium oxide film, and a neodymium oxide film.

[0182] <Conductive layer> In addition to the gate, source, and drain of a transistor, various wirings and electrodes of a display device The conductive layer is made of aluminum, titanium, chromium, nickel, copper, yttrium, and zirconium. Metals such as aluminum, molybdenum, silver, tantalum, or tungsten, or those mainly composed of these The alloy may be used as a single layer or a multilayer structure. A two-layer structure in which a titanium film is laminated on a tungsten film, a two-layer structure in which a titanium film is laminated on a tungsten film, A two-layer structure with a copper film laminated on a molybdenum film, and an alloy film containing molybdenum and tungsten A two-layer structure with a copper film laminated on top of a copper-magnesium-aluminum alloy film. A layer structure, a titanium film or a titanium nitride film, and an alumina layer on the titanium film or the titanium nitride film. An aluminum film or a copper film is laminated, and then a titanium film or a titanium nitride film is formed on the aluminum film or a copper film. A three-layer structure consisting of a molybdenum film or molybdenum nitride film and a molybdenum film or molybdenum nitride film. An aluminum or copper film is layered on top of the molybdenum film, and then a molybdenum film or For example, when the conductive layer has a three-layer structure, In this case, the first and third layers are titanium, titanium nitride, molybdenum, tungsten, molybdenum, alloys containing tungsten and tungsten, alloys containing molybdenum and zirconium, or molybdenum nitride The first layer is made of copper, aluminum, gold or silver, or copper and manganese. It is preferable to form a film made of a low resistance material such as an alloy of tungsten. Indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, titanium oxide Indium oxide containing tungsten, indium tin oxide containing titanium oxide, indium zinc oxide Alternatively, a conductive material having light transmitting properties, such as an oxide or ITSO, may be used.

[0183] Note that the oxide conductive layer may be formed by controlling the resistivity of the oxide semiconductor.

[0184] ≪Adhesive layer 141≫ The adhesive layer 141 may be made of a thermosetting resin, a photocurable resin, or a two-liquid mixed curable resin. Curable resins can be used, such as acrylic resins, urethane resins, and epoxy resins. Alternatively, a siloxane resin or the like can be used.

[0185] <Connector 242> The connectors 242 and 243 may be, for example, anisotropic conductive films (ACFs). Anisotropic Conductive Film, or Anisotropic Conductive Paste (ACP) nisotropic conductive paste) can be used. .

[0186] ≪Colored layer 131≫ The colored layer 131 is a colored layer that transmits light in a specific wavelength range. Possible materials include metal materials, resin materials, and resin materials containing pigments or dyes. Examples include:

[0187] ≪Light-shielding layer 132≫ The light-shielding layer 132 is provided, for example, between adjacent colored layers 131 of different colors. For example, A black matrix formed using a metal material or a resin material containing a pigment or dye. The light-shielding layer 132 may be made of a material other than the driving circuit section 64. If the light emitting device is provided in an area other than the display unit 62, light leakage due to guided light can be suppressed. I wish.

[0188] The thin films (insulating film, semiconductor film, conductive film, etc.) that make up the display device are each formed by sputtering. method, Chemical Vapor Deposition (CVD) method , vacuum deposition, pulsed laser deposition (PLD) ion) method, Atomic Layer Deposition (ALD) The CVD method can be used to form the film. An example of the CVD method is plasma-enhanced chemical vapor deposition (PE Examples of the thermal CVD method include the metal-organic chemical vapor deposition (MOCVD) method and the thermal CVD method. Examples of such a method include the metal organic chemical vapor deposition (MOCVD) method.

[0189] The thin films (insulating films, semiconductor films, conductive films, etc.) that make up the display device are formed by spin coating, Dip, spray application, inkjet printing, dispensing, screen printing, offset Printing, doctor knife, slit coat, roll coat, curtain coat, knife coat The film can be formed by a method such as a coating method.

[0190] The thin films constituting the display device can be processed using a photolithography method or the like. Alternatively, an island-shaped thin film may be formed by a film formation method using a shielding mask. Even if the thin film is processed by imprinting, sandblasting, or lift-off, The photolithography method involves forming a resist mask on the thin film to be processed, The thin film is processed by etching or the like, and the resist mask is removed. a method of forming a thin film by exposure and development, and then processing the thin film into a desired shape; There is.

[0191] In the photolithography method, the light used for exposure is, for example, i-line (wavelength 365 nm) ), g-line (wavelength 436 nm), h-line (wavelength 405 nm), and a mixture of these. In addition, ultraviolet light, KrF laser light, ArF laser light, etc. can also be used. Exposure may also be performed by immersion lithography. Ultraviolet light (EUV: Extreme Ultraviolet) and X-rays In addition, electron beams can be used instead of light for exposure. Extreme ultraviolet light, X-rays Alternatively, the use of an electron beam is preferable because it enables extremely fine processing. When the exposure is performed by scanning a beam such as a photodiode, a photomask is not required. do.

[0192] For etching thin films, there are dry etching, wet etching, and sandblasting methods. etc. can be used.

[0193] <1-3. Display device configuration example 3> 7 to 10 show examples of the display device. FIG. 7 is a cross-sectional view of a display device 100C. 8A is a cross-sectional view of the display device 100D, and FIG. 9A is a cross-sectional view of the display device 100 10 is a cross-sectional view of the display device 100F. 3(A), the display device 100D, the display device 100E, and the display device 100F are shown in perspective views in FIG. ) and therefore description thereof will be omitted here.

[0194] The display device 100C shown in FIG. 7 is the same as the display device 100A shown above, except that the pixel electrode 111 and the first The positional relationship of the common electrodes 112 is different.

[0195] The display device 100A shown in FIG. 4A has a structure in which the alignment film 133a and the first common electrode 112 are in contact with each other. On the other hand, the display device 100C shown in FIG. The configuration is such that the and are in contact with each other.

[0196] A display device 100D shown in FIG. 8 is a display device 100A shown above, and further includes a pixel electrode 111 and a first The shape of the common electrode 112 is different.

[0197] Both the pixel electrode 111 and the first common electrode 112 have a comb-like upper surface shape (also called a planar shape). ), or may have a top surface shape with slits.

[0198] In the display device 100D shown in FIG. 8, the pixel electrode 111 and the first common electrode 112 are disposed on the same plane. is provided on the surface.

[0199] Or, when viewed from above, the end of the slit of one electrode and the end of the slit of the other electrode The cross-sectional view of this case is shown in Figure 8(B).

[0200] Alternatively, when viewed from above, the portion where the pixel electrode 111 and the first common electrode 112 overlap each other is A cross-sectional view of this case is shown in FIG.

[0201] Alternatively, when viewed from above, the display unit 62 includes both the pixel electrodes 111 and the first common electrode 112. The cross-sectional view of this case is shown in FIG.

[0202] A display device 100E shown in FIG. 9A and a display device 100F shown in FIG. The shape of the transistors is different from that of the display device 100A shown in FIG.

[0203] In FIG. 9A, the transistor 201 and the transistor 206 are connected to the gate 22 1, an insulating layer 213, a conductive layer 222a, a conductive layer 222b, and a semiconductor layer 231.

[0204] The gate 221 overlaps with the semiconductor layer 231 via the insulating layer 213. The conductive layer 222a and the conductive layer 222b function as an insulating layer. One of the conductive layers 222a and 222b is a source electrode. The transistor 201 and the transistor 202 function as a drain electrode and the other function as a drain electrode. 206 is covered with an insulating layer 212 and an insulating layer 214 .

[0205] In FIG. 9A, the pixel electrode 111 is connected to the conductive layer 222b. As shown, the pixel electrode 111 may be connected to the semiconductor layer 231. It is preferable to use a material that transmits visible light, such as an oxide semiconductor, for the conductor layer 231. This allows the connection portion between the pixel electrode 111 and the transistor to be provided in the display region 68 . Therefore, the aperture ratio of the sub-pixel can be increased. Note that the conductive layer 222b may be electrically connected to the semiconductor layer 231. 2b can function as an auxiliary electrode for the semiconductor layer 231. may not have the conductive layer 222b.

[0206] In FIG. 10, transistor 201 and transistor 206 are connected to gates 221 and 222, respectively. Gate 223, insulating layer 212, insulating layer 213, insulating layer 214, conductive layer 222a, conductive layer 2 22b, and a semiconductor layer 231.

[0207] The gate 221 overlaps with the semiconductor layer 231 via the insulating layer 213. The insulating layer 212 and the insulating layer 214 overlap with the semiconductor layer 231. The conductive layer 222a and the insulating layer 214 function as gate insulating layers. The conductive layer 222a and the conductive layer 222b each have a portion connected to the semiconductor layer 231. One of the conductive layers 222b functions as a source electrode and the other functions as a drain electrode. The transistor 201 and the transistor 206 are covered with an insulating layer 215. 222 b is connected to the pixel electrode 111 .

[0208] As described above, the display device of one embodiment of the present invention includes transistors and liquid crystal elements having various shapes. can be applied.

[0209] <1-4. Display device configuration example 4> One embodiment of the present invention is a display device (an input / output device or a touch panel) equipped with a touch sensor. The configuration of each of the above-mentioned display devices can be applied to a touch panel. In the present embodiment, the display device 100A is mainly provided with a touch sensor. will be explained.

[0210] There is no limitation on a detection element (also referred to as a sensor element) included in a touch panel of one embodiment of the present invention. We offer a variety of sensors that can detect the proximity or contact of a finger, stylus, or other object. , can be applied as a sensing element.

[0211] The sensor type may be, for example, a capacitance type, a resistive film type, a surface acoustic wave type, or an infrared type. Various methods can be used, such as a pressure-sensitive method, an optical method, or a pressure-sensitive method.

[0212] In this embodiment, a touch panel having a capacitance type sensing element will be described as an example. .

[0213] The capacitive touch sensor includes a surface capacitive touch sensor and a projected capacitive touch sensor. The electrostatic capacitance type includes the self-capacitance type and the mutual capacitance type. This is preferable because it enables simultaneous multi-point detection.

[0214] The touch panel according to one embodiment of the present invention is formed by bonding a display device and a sensing element that are separately manufactured. A structure in which a substrate supporting a display element and / or an opposing substrate are provided with electrodes constituting a sensing element. Various configurations can be applied, such as a configuration in which a pole or the like is provided.

[0215] 11 and 12 show an example of a touch panel. FIG. 11(A) shows a touch panel 350. FIG. 11(B) is a perspective view of FIG. 11(A). For clarity, only representative components are shown. 12 is a cross-sectional view of touch panel 350A. do.

[0216] The touch panel 350A is constructed by bonding a display device and a sensing element that are separately manufactured. be.

[0217] The touch panel 350A has an input device 375 and a display device 370, which are overlapped. It is provided.

[0218] The input device 375 includes a substrate 162, an electrode 127, an electrode 128, a plurality of wirings 137, and a plurality of The FPC 72b has the plurality of wirings 137 and the plurality of wirings 138. The FPC 72b is electrically connected to the IC 73b.

[0219] The display device 370 has a substrate 51 and a substrate 61 disposed opposite each other. The substrate 51 includes a display section 62 and a driving circuit section 64. Wiring 65 and the like are provided on the substrate 51. The FPC 72a is electrically connected to the wiring 65. The FPC 72a includes an IC 73a. It is provided.

[0220] Signals and power are supplied to the display unit 62 and the drive circuit unit 64 through wiring 65. The signal and power are input to the wiring 65 from the outside or IC 73a via the FPC 72a. .

[0221] FIG. 12 shows a region including the display section 62, the drive circuit section 64, and the FPC 72a, and a region including the FPC 72b. 1 is a cross-sectional view of a region including the above.

[0222] The substrate 51 and the substrate 61 are bonded together by an adhesive layer 141. The substrate 51 and the substrate 61 are attached to each other by an adhesive layer 169. Each layer in the figure corresponds to a display device 370. In addition, each layer from the substrate 162 to the electrode 124 This corresponds to the input device 375. In other words, the adhesive layer 169 is It can be said that the two are pasted together.

[0223] The configuration of the display device 370 shown in FIG. 12 is the same as that of the display device 100A shown in FIG. Therefore, a detailed description will be omitted.

[0224] A polarizing plate 165 is attached to the substrate 51 by an adhesive layer 167. A backlight 161 is attached to the substrate 5 via an adhesive layer 163.

[0225] A polarizing plate 166 is attached to the substrate 162 by an adhesive layer 168. A protection substrate 160 is attached to the substrate 66 by an adhesive layer 164. When the touch panel 350A is assembled, the protection board 160 is placed in a position where a finger, a stylus, or the like is to be detected. The protective substrate 160 may be used as a substrate that comes into direct contact with the body. The protection substrate 160 can be a substrate that can be used for the substrate 51 and the A structure in which a protective layer is formed on the surface of a substrate that can be used for the substrate 61, etc., or a reinforced glass It is preferable to use a protective layer such as a ceramic coating. Alternatively, the protective layer may be made of silicon oxide, aluminum oxide, yttrium oxide, yttrium oxide, or yttrium oxide. It can be formed using an inorganic insulating material such as thoria-stabilized zirconia (YSZ).

[0226] A polarizing plate 166 may be disposed between the input device 375 and the display device 370. In that case, as shown in FIG. 2, the protective substrate 160, the adhesive layer 164, and the adhesive layer 168 may not be provided. The touch panel 350A may have a structure in which the substrate 162 is located on the top surface thereof. It is preferable to use a material that can be used for the protection substrate 160 described above for 62 .

[0227] An electrode 127 and an electrode 128 are provided on the substrate 61 side of the substrate 162. The electrodes 127 and 128 are formed on the same plane. The insulating layer 125 is The electrode 124 is provided so as to cover the insulating layer 125 through an opening. The electrode 127 is electrically connected to two electrodes 128 disposed on either side of the electrode 127 .

[0228] Among the conductive layers of the input device 375, the conductive layers overlapping the display area 68 (electrodes 127, 12 8, etc.) are made of materials that transmit visible light.

[0229] The wiring 137 obtained by processing the same conductive layer as the electrodes 127 and 128 is the same as the electrode 124. The conductive layer 126 is connected to the conductive layer 126 obtained by processing the conductive layer of the connecting body 24. 2b and is electrically connected to FPC 72b.

[0230] Next, with reference to FIG. 13, an input device (a touch sensor) that can be used in the display device of one embodiment of the present invention will be described. An example of a driving method for the liquid crystal display 10 will be described.

[0231] FIG. 13A is a block diagram showing the configuration of a mutual capacitance type touch sensor. FIG. 13(A) shows a pulse voltage output circuit 601 and a current detection circuit 602. ) is provided with an electrode 621 to which a pulse is applied and an electrode 622 to detect a change in current. The wires are shown as six wires, X1-X6 and Y1-Y6. The number of electrodes is In FIG. 13A, the electrode 621 and the electrode 622 may overlap each other, or the electrodes 621 and 622 may be arranged in a different shape. The figure shows a capacitance 603 formed by arranging a pole 621 and an electrode 622 in close proximity to each other. The functions of the electrodes 621 and 622 may be interchangeable.

[0232] For example, electrode 127 corresponds to either electrode 621 or electrode 622, and electrode 128 corresponds to electrode 623. 21 or the other of electrodes 622.

[0233] The pulse voltage output circuit 601 is a circuit for inputting pulse voltages to the wirings X1-X6 in sequence, for example. The current detection circuit 602 detects the current flowing through each of the wirings Y1-Y6, for example. It is a circuit for detecting

[0234] When a pulse voltage is applied to one of the wirings X1-X6, a capacitance 603 is formed. An electric field is generated between the electrode 621 and the electrode 622, and a current flows through the electrode 622. A part of the electric field generated by the sensor is blocked by the proximity or contact of a detected object such as a finger or pen. The strength of the electric field generated between the electrodes changes. As a result, the magnitude of the current flowing through the electrode 622 changes. To become.

[0235] For example, when there is no proximity or contact of the object to be detected, the magnitude of the current flowing through the wires Y1-Y6 is The value depends on the size of the capacitance 603. On the other hand, when the object to be detected approaches or touches the When the part is shielded, a change in the magnitude of the current flowing through the wiring Y1-Y6 is detected. By utilizing this, the proximity or contact of a sensing object can be detected.

[0236] The current detection circuit 602 may detect the (temporal) integral value of the current flowing through one wiring. In this case, for example, an integrating circuit can be used. Or, the peak value of the current can be detected. In that case, for example, the current may be converted into a voltage and the peak value of the voltage may be detected. .

[0237] FIG. 13B shows input and output waveforms in the mutual capacitance type touch sensor shown in FIG. 13A. An example of a timing chart of the above is shown in FIG. 13B. In FIG. 13B, the detection of each matrix in one sensing period is shown. In FIG. 13B, when the contact or proximity of the object to be detected is not detected, (non-touched) and when contact or proximity of a detected object is detected (touched). Here, for the wirings Y1-Y6, the magnitude of the current to be detected is 4 shows the corresponding voltage waveforms.

[0238] As shown in FIG. 13B, pulse voltages are sequentially applied to the wirings X1-X6. When the touch panel is not touched, current flows through the wires Y1-Y6. In response to the change in voltage, the same current flows through the wires Y1-Y6, so On the other hand, when touching, the output waveforms of the wirings Y1-Y6 are the same. The current flowing through the wiring in the area where the detection object is in contact or in close proximity is reduced, so as shown in Figure 13 The output waveform changes as shown in (B).

[0239] In FIG. 13B, the object to be detected is located at or near the intersection of the wire X3 and the wire Y3. An example of contact or proximity is shown.

[0240] In this way, in the mutual capacitance method, the electric field generated between a pair of electrodes is shielded, and By detecting the change in the flow, the position information of the object to be detected can be obtained. When the output sensitivity is high, the object to be detected is far from the detection surface (e.g. the surface of a touch panel). It is also possible to detect the coordinates of the object.

[0241] In addition, in the touch panel, the display period of the display unit and the sensing period of the touch sensor are By using a driving method in which the driving voltage is shifted, the detection sensitivity of the touch sensor can be increased. For example, a display period and a sensing period may be separated during one frame period. In this case, it is preferable to provide two or more sensing periods in one frame period. By increasing the frequency of scanning, the detection sensitivity can be further increased.

[0242] The pulse voltage output circuit 601 and the current detection circuit 602 are formed in, for example, one IC. It is preferable that the IC is mounted on a touch panel, for example, or It is preferable that the touch panel is mounted on a substrate inside the housing of the child device. In this case, the parasitic capacitance increases at the bent portion, and the effect of noise becomes greater. Therefore, it is preferable to use an IC that uses a driving method that is less susceptible to noise. For example, it is desirable to use an IC that uses a driving method that enhances the signal-to-noise ratio (S / N ratio). It is preferable that

[0243] <1-5. Display device configuration example 5> 14 and 15 show an example of a touch panel. FIG. 14(A) shows a touch panel 350. FIG. 14(B) is a perspective view of FIG. 14(A). For clarity, only representative components are shown. In FIG. 14(B), the substrate 61 is indicated by a dashed line. 15 is a cross-sectional view of touch panel 350B.

[0244] The touch panel 350B has a function of displaying an image and a function as a touch sensor. It is an in-cell type touch panel.

[0245] The touch panel 350B has a configuration in which electrodes constituting sensing elements are provided only on the opposing substrate. This structure is advantageous compared to a structure in which a display device and a detector element are fabricated separately and then bonded together. In all cases, the touch panel can be made thinner or lighter, or the The number of parts can be reduced.

[0246] 14(A) and (B), the input device 376 is provided on the substrate 61. The wiring 137 and the wiring 138 of the input device 376 are connected to an FPC 7 provided on the display device 379. 2 and electrically connected.

[0247] With this configuration, the FPC connected to the touch panel 350B is located on one board side ( In this case, it can be arranged only on the substrate 51 side. The FPC may be attached to the upper part of the board, but as shown in Figures 14(A) and (B), The switch panel 350B is provided with one FPC 72, and the FPC 72 is connected to a display device 379 and an input device. It is preferable to provide a signal to both the device 376 because this can simplify the configuration. .

[0248] The IC 73 may have a function to drive the input device 376. An IC for driving the input device 376 may be provided on the FPC 72. It may be mounted on a substrate 51 .

[0249] FIG. 15 shows a region including the FPC 72 in FIG. 14(A), a connection section 63, a drive circuit section 64, 13 is a cross-sectional view including a display unit 62.

[0250] In the connection portion 63, one of the wirings 137 (or wiring 138) and a conductor provided on the substrate 51 side are The conductive layer is electrically connected to the conductive layer via a connector 243.

[0251] A light-shielding layer 132 is provided in contact with the substrate 61. The light-shielding layer 132 is covered with the insulating layer 122. An electrode 127 is provided between the insulating layer 122 and the insulating layer 125. An electrode 128 is provided between the electrode 125 and the insulating layer 123. A colored layer 131 is provided in contact with the insulating layer 123. As shown in FIG. 16, a light-shielding layer 132b is provided in contact with the substrate 61. In addition, a light-shielding layer 132 a may be disposed in contact with the insulating layer 123 .

[0252] The wiring 137 obtained by processing the same conductive layer as the electrode 127 is formed by the same conductive layer as the electrode 128. The conductive layer 285 is connected to the second common electrode 24. The conductive layer 286 is connected to the conductive layer 286 obtained by processing the same conductive layer as the conductive layer 4. It is electrically connected to the conductive layer 284 via the connector 243 .

[0253] The touch panel 350B uses one FPC to transmit signals for driving pixels and signals for driving sensing elements. This makes it easy to incorporate into electronic devices and reduces the number of parts. It becomes possible.

[0254] <1-6. Touch sensor configuration example> An example of the configuration of the input device (touch sensor) will be described below.

[0255] FIG. 17A shows a top view of an input device 415. The input device 415 has multiple The electrode 471 includes a number of electrodes, a number of electrodes, a number of wirings, and a number of wirings. The substrate 416 includes a plurality of wirings 476 and a plurality of wirings 477. In FIG. 17(A), the FPC450 is provided with the IC449. This shows an example of how this is being used.

[0256] FIG. 17B shows an enlarged view of the area surrounded by the dashed line in FIG. 17A. The electrode 471 is A plurality of diamond-shaped electrode patterns are arranged in a row in the horizontal direction. The electrode patterns are electrically connected to each other. Similarly, the electrode 472 is also formed of a plurality of diamond-shaped The electrode patterns are arranged vertically, and the diamond-shaped electrode patterns are arranged in a row. The electrodes 471 and 472 are electrically connected to each other. At this intersection, the electrodes 471 and 472 are electrically short-circuited (short circuit). The insulation is clamped to prevent the

[0257] As shown in FIG. 17(C), the electrode 472 is made up of a plurality of diamond-shaped electrodes 473 and a block. The island-shaped electrodes 473 may be arranged vertically. The two adjacent electrodes 473 are electrically connected by a bridge electrode 474. With this structure, the electrode 473 and the electrode 471 can be formed by processing the same conductive film. Therefore, the variation in the thickness of these films can be suppressed. This makes it possible to suppress variations in the resistance value and light transmittance of each electrode depending on the location. In this embodiment, the electrode 472 has a bridge electrode 474. Such a configuration may be used.

[0258] As shown in FIG. 17(D), the diamond-shaped electrodes 471 and 472 shown in FIG. 17(B) are The inside of the pole pattern may be hollowed out to leave only the outline. In the case where the width of the electrodes 471 and 472 is thin enough not to be visually recognized by the user, In this way, the electrodes 471 and 472 may be made of a light-shielding material such as a metal or an alloy. In addition, the electrode 471 or the electrode 472 shown in FIG. 17(D) has the bridge electrode 474. The configuration may be such that:

[0259] One electrode 471 is electrically connected to one wiring 476. One electrode 472 is The electrode 471 and the electrode 472 are electrically connected to one wiring 477. One corresponds to a row wiring, and the other corresponds to a column wiring.

[0260] IC449 has the function of driving the touch sensor. The signal output from IC449 is The signal is supplied to either electrode 471 or electrode 472 via wiring 476 or wiring 477. The current (or potential) flowing through either the electrode 471 or the electrode 472 is 6 or wire 477 to IC449. 0, IC 449 may be mounted on substrate 416.

[0261] When the input device 415 is placed on the display surface of the display panel, the electrodes 471 and 472 are transparent. It is preferable to use a conductive material having optical transparency. The light from the display panel is taken out through the electrode 471 or the electrode 472. In this case, a conductive film containing the same conductive material is provided between the adjacent electrodes 471 and 472. It is preferable to place the electrodes 471 and 472 as dummy patterns. By filling part of the gap between the substrate and the substrate with a dummy pattern, the variation in light transmittance is reduced. As a result, unevenness in the luminance of the light passing through the input device 415 can be reduced.

[0262] Examples of the conductive material having a light-transmitting property include indium oxide, indium tin oxide, and indium zinc. Conductive oxides such as lead oxide, zinc oxide, zinc oxide containing gallium, etc. can be used. A film containing graphene may also be used. The film containing graphene may be, for example, a film-like The graphene oxide-containing film formed on the substrate can be reduced to form the graphene oxide-containing film. An example of such a method is the application of heat.

[0263] Alternatively, a metal or alloy that is thin enough to have light transmission properties can be used. For example, gold, Silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt Metals such as copper, palladium, or titanium, or alloys containing such metals can be used. Alternatively, a nitride of the metal or alloy (for example, titanium nitride) may be used. A laminated film in which two or more conductive films containing the above-mentioned materials are laminated may be used.

[0264] In addition, the electrodes 471 and 472 are provided with thin conductors that are not visible to the user. For example, such a conductive film may be processed into a lattice (mesh) shape. In this way, it is possible to obtain both high electrical conductivity and high visibility of the display device. 30 nm or more and 100 μm or less, preferably 50 nm or more and 50 μm or less, more preferably 5 It is preferable that the width of the portion is 0 nm or more and 20 μm or less. A conductive film having a pattern width is preferable because it is extremely difficult for a user to visually recognize the conductive film.

[0265] As an example, FIGS. 18(A) to 18(D) are schematic diagrams in which the region 460 shown in FIG. 17(B) is enlarged. Shows.

[0266] FIG. 18A shows an example in which a lattice-shaped conductive film 461 is used. The conductive film 461 is arranged so as not to overlap with a display element of the device. In this case, the orientation of the lattice is the same as the arrangement of the display elements. It is preferable that the period of the grating is an integer multiple of the period of the array of display elements.

[0267] FIG. 18B shows a lattice-shaped conductive film 462 processed to form triangular openings. This configuration reduces the resistance compared to the case shown in FIG. It is possible to lower

[0268] As shown in FIG. 18C, a conductive film 463 having a non-periodic pattern is With such a configuration, moire is prevented when the display unit of the display device is overlapped. It is possible to suppress the occurrence of such problems.

[0269] Alternatively, a conductive nanowire may be used for the electrode 471 and the electrode 472. 4 shows an example in which nanowires 464 are used. By dispersing the particles at an appropriate density so that they come into contact with each other, a two-dimensional network is formed. For example, the average diameter of the nm or more and 100 nm or less, preferably 5 nm or more and 50 nm or less, more preferably 5 nm or more and 100 nm or less. Nanowires of up to 25 nm or less can be used. Metal nanowires such as Cu nanowires and Al nanowires, or carbon nanowires For example, Ag nanowires have a light transmittance of 89% or more. In addition, a sheet resistance value of 40 Ω / □ or more and 100 Ω / □ or less can be achieved.

[0270] 17B. A more detailed configuration example of the electrode 471 and the electrode 472 in FIG. 17B is shown in FIG. FIG. 18(E) shows a structure in which the electrode 471 and the electrode 472 are each processed into a lattice shape. This is an example of a case where a conductive film is used.

[0271] In FIG. 17A and the like, the top surfaces of the electrodes 471 and 472 are formed of a plurality of diamonds arranged in one direction. However, the shape of the electrodes 471 and 472 is not limited to this example. The upper surface can be shaped in various ways, such as a strip (rectangular), a strip with curves, a zigzag shape, etc. In the above, the electrodes 471 and 472 are arranged so as to be perpendicular to each other. Although shown as being orthogonal to each other, these do not necessarily have to be arranged orthogonally. The angle formed by these may be less than 90 degrees.

[0272] <1-7. Display device configuration example 6> An example of a touch panel is shown in Fig. 19. Fig. 19 is a cross-sectional view of a touch panel 350D. .

[0273] The touch panel 350D has a function of displaying an image and a function as a touch sensor. It is an in-cell type touch panel.

[0274] The touch panel 350D has electrodes and the like that constitute the sensing elements only on the substrate that supports the display elements. This type of structure is achieved by bonding a display device and a detector element that are separately manufactured. Compared to a configuration in which the sensing element is placed on the opposing substrate or a configuration in which the sensing element is placed on the opposing substrate, the touch panel can be made thinner. It is possible to reduce the size or weight of the touch panel, or to reduce the number of parts in the touch panel. Cut.

[0275] The touch panel 350D shown in FIG. 19 differs from the display device 100A shown above in that it has a common electrode and a complementary electrode. The layout of the auxiliary wiring 139 is different.

[0276] The auxiliary wirings 139 are connected to the first common electrode 112a or the first common electrode 11 2b.

[0277] In the touch panel 350D shown in FIG. 19, the first common electrode 112a and the first common electrode 1 12b, the capacitance formed between the sensor and the sensor is used to detect the proximity or contact of the object to be detected. That is, in the touch panel 350D, the first common electrodes 112a and 112b serves as both a common electrode for the liquid crystal element and an electrode for the detection element.

[0278] In this way, in the touch panel according to one embodiment of the present invention, the electrodes constituting the liquid crystal element are Since the electrode also serves as a component of the electrode, the manufacturing process can be simplified and the manufacturing cost can be reduced. In addition, the touch panel can be made thinner and lighter.

[0279] The common electrode is electrically connected to the auxiliary wiring 139. By providing the auxiliary wiring 139, The resistance of the electrodes of the sensing element can be reduced. Therefore, the time constant of the electrodes of the detection element can be made small. The higher the detection sensitivity, the higher the detection accuracy.

[0280] The time constant of the electrodes of the sensing element is, for example, greater than 0 seconds and less than 1×10 -4 seconds or less, preferably 0 Seconds greater than 5 x 10 -5 seconds or less, more preferably greater than 0 seconds and 5×10 -6 seconds or less, More preferably, it is greater than 0 seconds and is 5×10 -7 seconds or less, more preferably greater than 0 seconds and 2× 10 -7 It is preferable that the time constant is less than 1×10 -6By keeping it to less than 2 seconds, noise It is possible to achieve high detection sensitivity while suppressing the influence of the above.

[0281] The touch panel 350D uses a single FPC to transmit signals to drive the pixels and signals to drive the sensing elements. This makes it easy to incorporate into electronic devices and reduces the number of parts. It becomes possible.

[0282] An example of how touch panel 350D operates will be described below.

[0283] FIG. 20A shows a part of a pixel circuit provided in a display unit 62 of a touch panel 350D. FIG.

[0284] One pixel (subpixel) includes at least a transistor 206 and a liquid crystal element 40. A wiring 3501 is electrically connected to the gate of the transistor 206. A wiring 3502 is electrically connected to one of the source and drain of the capacitor 206 .

[0285] The pixel circuit includes a plurality of wirings (for example, wiring 3510_1, wiring 3510_ 2) and a plurality of wirings (for example, wiring 3511_1) extending in the Y direction, which are mutually The electrodes are arranged to cross each other, forming a capacitance therebetween.

[0286] In addition, among the pixels provided in the pixel circuit, some of the adjacent pixels are provided The electrodes of the liquid crystal elements are electrically connected to each other to form one block. The blocks are divided into island-like blocks (e.g., block 3515_1, block 3515_2) and Linear blocks extending in the X or Y direction (e.g., blocks extending in the Y direction) 3516). In addition, FIG. 20(A) shows only a part of the pixel circuit. However, in reality, these two types of blocks are arranged repeatedly in the X and Y directions. Here, one electrode of the liquid crystal element may be, for example, a common electrode. The other electrode of the liquid crystal element is, for example, a pixel electrode.

[0287] The wiring 3510_1 (or 3510_2) extending in the X direction is arranged in an island-shaped block 3515 _1 (or block 3515_2). The wiring 3510_1 extending in the X direction is discontinuously arranged along the X direction via a line-shaped block. The island-shaped blocks 3515_1 are electrically connected to each other. The wiring 3511_1 is electrically connected to a linear block 3516.

[0288] FIG. 20B shows a plurality of wirings (wirings 3510_1 to 3510_6) extending in the X direction. , collectively referred to as wiring 3510), and a plurality of wirings extending in the Y direction (wirings 3511_1 3 through 3511_6, collectively also referred to as wiring 3511) is an equivalent circuit diagram showing the connection configuration of Each of the wirings 3510 extending in the X direction and each of the wirings 3511 extending in the Y direction A common potential can be input to each of the wirings 3510 extending in the X direction. A pulse voltage can be input from the pulse voltage output circuit to the Each of the wirings 3511 can be electrically connected to a detection circuit. 10 and wiring 3511 can be interchanged.

[0289] An example of an operation method of the touch panel 350D will be described with reference to FIGS. 21(A) and 21(B). do.

[0290] Here, one frame period is divided into a writing period and a detection period. This is the period in which image data is written, and the wiring 3501 (also called the gate line or scanning line) On the other hand, the detection period is a period during which sensing is performed by the detection element. do.

[0291] 21A is an equivalent circuit diagram during the writing period. A common potential is input to both the wiring 3510 extending in the Y direction and the wiring 3511 extending in the Y direction. do.

[0292] FIG. 21B is an equivalent circuit diagram during the detection period. Each of the wirings 3511 is electrically connected to a detection circuit. A pulse voltage is input to 10 from a pulse voltage output circuit.

[0293] FIG. 21C is a timing chart of input and output waveforms in a mutual capacitance type sensing element. Here is an example.

[0294] In FIG. 21C, detection of an object is performed in each row and column in one frame period. In FIG. 21C, the difference between when the object to be detected is not detected (non-touch) and when the object to be detected is not detected (non-touch) during the detection period is shown. The two cases shown are detection of a sensory object (touch) and detection of a sensory object (sensing).

[0295] The wirings 3510_1 to 3510_6 are supplied with a pulse voltage from a pulse voltage output circuit. A pulse voltage is applied to the wirings 3510_1 to 3510_6. An electric field is generated between the pair of electrodes that form the capacitance, and a current flows through the capacitance. The electric field generated by the sensor changes when it is blocked by a finger or pen. This causes a change in the capacitance of the capacitor. It can be detected.

[0296] The wirings 3511_1 to 3511_6 are each 1 to 3511_6. In the lines 3511_1 to 3511_6, the proximity or contact of the object to be detected is not detected. When the capacitance value decreases due to the proximity or contact of the object to be detected, the current value does not change. In this case, the current value decreases. The current may be detected by detecting the total amount of current. In this case, the detection may be performed using an integrating circuit or the like. Alternatively, the peak value of the current may be detected. In that case, the current may be converted into a voltage and the peak value of the voltage may be detected.

[0297] In FIG. 21C, the wirings 3511_1 to 3511_6 are detection The waveform is a voltage value corresponding to the current value. It is desirable to synchronize the timing of the display operation and the timing of the detection operation. stomach.

[0298] In response to the pulse voltages applied to the wirings 3510_1 to 3510_6, the wirings 35 The waveforms in the wirings 11_1 to 3511_6 change. In this case, the wiring 3511_1 is turned on in response to a change in the voltage of the wiring 3510_1 to the wiring 3510_6. The waveform of the wiring 3511_6 changes uniformly. Since the current value decreases at this point, the waveform of the corresponding voltage value also changes.

[0299] In this way, the proximity or contact of a detection object is detected by detecting the change in capacitance value. In addition, when a detected object such as a finger or pen is placed close to the touch panel without touching it, Even if the signal is not detected, a signal may still be detected.

[0300] In FIG. 21C, the common potential applied to the wiring 3510 during the writing period is In the example shown in FIG. 1, the low potentials applied during the detection period are equal to each other. However, one embodiment of the present invention is not limited thereto. The common potential and the low potential may be different potentials.

[0301] The pulse voltage output circuit and the detection circuit may be formed in a single IC. The IC is preferably mounted on, for example, a touch panel or a housing of an electronic device. It is preferable to mount the touch panel on a substrate inside the housing. However, parasitic capacitance increases at the bent parts, which may increase the effect of noise. It is preferable to use an IC that uses a driving method that is less susceptible to noise. For example, It is preferable to use an IC that employs a driving method that enhances the signal-to-noise ratio (S / N ratio). It is nice.

[0302] In this way, the image writing period and the sensing period by the detector element are independent. This prevents the sensing element from sensing noise caused by pixel writing noise. The decrease in the degree of reflection can be suppressed.

[0303] In one embodiment of the present invention, as shown in FIG. 21(D), one frame period includes a writing period and a sensing period. Alternatively, as shown in FIG. 21(E), By providing multiple detection periods in one frame period, the detection sensitivity can be improved. For example, if one frame period has two to four detection periods, It may be possible.

[0304] Next, an example of the upper surface configuration of the sensing element of the touch panel 350D will be described with reference to FIG. Reveal.

[0305] 22A is a top view of the sensing element. The sensing element includes a conductive layer 56a and a conductive layer 56b. The conductive layer 56a functions as one electrode of the sensing element, and the conductive layer 56b functions as a sensing The sensing element is formed between conductive layer 56a and conductive layer 56b. The capacitance thus formed can be used to detect the proximity or contact of a detection object. The conductive layer 56a and the conductive layer 56b have a comb-like upper surface shape or a slit-like upper surface shape. There are cases where the surface has a shape, but this is omitted here.

[0306] In one embodiment of the present invention, the conductive layer 56a and the conductive layer 56b are used as a common electrode of a liquid crystal element. It also has the function of.

[0307] The conductive layers 56a arranged in the Y direction each extend in the X direction. In addition, the conductive layers 56b arranged in the Y direction are connected to the conductive layer 58 extending in the Y direction. In FIG. 22A, m conductive layers 56a and n conductive layers 56b are electrically connected. 5 shows an example having a conductive layer 58.

[0308] In addition, the conductive layer 56a may be provided in a plurality of layers in the X direction. In this case, the conductive layer 56a extends in the Y direction. Also, the conductive layer 58 extending in the X direction may be provided. A plurality of conductive layers 56b arranged in the same direction may be electrically connected to each other.

[0309] As shown in FIG. 22B, the conductive layer 56 functioning as an electrode of the sensing element is The conductive layer 56 is provided over the conductive layers 56a and 56b in FIG. The pixel 60 is made up of a number of sub-pixels each of which exhibits a different color. In B), an example in which a pixel 60 is composed of three sub-pixels 60a, 60b, and 60c is shown. show.

[0310] In addition, the pair of electrodes of the detection element are electrically connected to the auxiliary wiring. As shown in FIG. 22C, the conductive layer 56 is electrically connected to the auxiliary wiring 57. In addition, in FIG. 22C, an auxiliary wiring is provided on the conductive layer. An example is shown, but a conductive layer may be provided overlapping the auxiliary wiring. The conductive layer 56 may be electrically connected to a conductive layer 58 via an auxiliary wiring 57 .

[0311] The resistance of the conductive layer that transmits visible light may be relatively high. It is preferable to reduce the resistance of each of the pair of electrodes of the sensing element by connecting the pair of electrodes to the sensing element. It is nice.

[0312] By reducing the resistance of the pair of electrodes of the detection element, the time constant of each of the pair of electrodes can be reduced. This can improve the detection sensitivity of the detection element and further reduce the This can improve the accuracy of detecting children.

[0313] <1-8. Touch panel module> Next, a touch panel module including an input / output device according to one embodiment of the present invention and an IC will be described. This will be described with reference to FIG. 23 and FIG.

[0314] FIG. 23 shows a block diagram of the touch panel module 6500. The module 6500 includes a touch panel 6510 and an IC 6520. The input / output device of one embodiment of the present invention can be applied to the above.

[0315] The touch panel 6510 includes a display unit 6511, an input unit 6512, and a scanning line driver circuit 651 The display portion 6511 has a plurality of pixels, a plurality of signal lines, and a plurality of scanning lines. The input unit 6512 has a function of displaying an image. It has multiple detection elements that detect contact or proximity and functions as a touch sensor. The scanning line driver circuit 6513 has a function of outputting a scanning signal to the scanning lines of the display unit 6511. Yes.

[0316] For ease of explanation, the touch panel 6510 is configured as a display unit 6511. The input unit 6512 is shown separately, but it has a function of displaying an image and a function as a touch sensor. It is preferable to use a so-called in-cell type touch panel having both functions.

[0317] The display unit 6511 supports HD (1280 x 720 pixels) and FHD (1920 x 108 0), WQHD (pixel count 2560 x 1440), WQXGA (pixel count 2560 x 1600 ), 4K (3840 x 2160 pixels), 8K (7680 x 4320 pixels) It is preferable for the image quality to be as high as possible, particularly 4K, 8K, or higher resolution. It is preferable that the pixel density (resolution) of the pixels provided in the display portion 6511 is 300. ppi or more is preferable, 500 ppi or more is more preferable, and 800 ppi or more is more preferable. It is preferable that the resolution is 1000 ppi or more, and more preferable that the resolution is 1200 ppi or more. The display unit 6511 has such high resolution and high definition that it is suitable for portable and home use. In any personal use, it will be possible to further enhance the sense of realism and depth. .

[0318] The IC 6520 includes a circuit unit 6501, a signal line driver circuit 6502, and a sensor driver circuit 65 The circuit unit 6501 includes a timing controller 6503 and a detection circuit 6504. The image processing circuit 6505 includes an image processing circuit 6506.

[0319] The signal line driver circuit 6502 outputs an analog signal to a signal line of the display unit 6511. The signal line driver circuit 6502 has a function of outputting a signal (also called a video signal). For example, it may have a configuration in which a shift register circuit and a buffer circuit are combined. The touch panel 6510 may also have a demultiplexer circuit connected to the signal lines. good.

[0320] The sensor driving circuit 6503 outputs a signal for driving the detection element of the input unit 6512. The sensor driver circuit 6503 includes, for example, a shift register circuit and a buffer circuit. A configuration combining an analog circuit can be used.

[0321] The detection circuit 6504 receives an output signal from the detection element of the input section 6512 and outputs it to the circuit unit 6 For example, the detection circuit 6504 may include an amplifier circuit and an analog A digital conversion circuit (ADC: Analog-Digital Converter) In this case, the detection circuit 6504 receives the output from the input section 6512. An input analog signal is converted into a digital signal and output to the circuit unit 6501 .

[0322] The image processing circuit 6506 of the circuit unit 6501 is a display unit of the touch panel 6510. The function of generating and outputting a signal to drive the input section 6511 and the function of generating a signal to drive the input section 6512 are and a function of analyzing the signal output from the input unit 6512 and outputting the signal. and a function of outputting the same to the

[0323] As a more specific example, the image processing circuit 6506 performs the following in accordance with an instruction from the CPU 6540: The image processing circuit 6506 has a function of generating a video signal. The video signal is then processed according to the user's needs, converted into an analog video signal, and sent to the signal line driver circuit 6. The image processing circuit 6506 also has a function of supplying the image data to the CPU 6540. It has a function of generating a drive signal to be output to the sensor drive circuit 6503 according to the command. The image processing circuit 6506 analyzes the signal input from the detection circuit 6504 and outputs position information and and outputting the result to the CPU 6540.

[0324] The timing controller 6505 controls the image signal etc. that has been processed by the image processing circuit 6506. Based on the included synchronization signal, signals such as a clock signal and a start pulse signal are generated and scanned. The signal line driver circuit 6513 and the sensor driver circuit 6503 have a function of outputting the signal. The timing controller 6505 determines the timing at which the detection circuit 6504 outputs a signal. The timing controller 65 may have a function of generating and outputting a signal. 05 is a signal to be output to the scanning line driver circuit 6513 and a signal to be output to the sensor driver circuit 6503. It is preferable to output a signal synchronized with the signal of the display unit 6511. The period for rewriting pixel data and the period for sensing by the input unit 6512 are separated. For example, one frame period is preferably divided into a period for rewriting pixel data and a period for storing pixel data. The touch panel 6510 can be driven in a divided period for sensing and a period for detecting the touch. For example, by providing two or more sensing periods in one frame period, the detection sensitivity and detection accuracy can be improved. The degree can be increased.

[0325] The image processing circuit 6506 can be configured to include, for example, a processor. For example, DSP (Digital Signal Processor), GPU (Gr Using a microprocessor such as a 3D Processing Unit These microprocessors can be implemented as FPGAs (Field Programmable Gate Arrays). e Gate Array) and FPAA (Field Programmable An PLDs (Programmable Logic Devices) such as The processor may execute various programs. It performs various data processing and program control by interpreting and executing instructions. The program that can be executed by the above may be stored in a memory area of ​​the processor. Alternatively, the information may be stored in a separately provided storage device.

[0326] Note that the display portion 6511 or the scanning line driver circuit 6513 of the touch panel 6510, The circuit unit 6501, the signal line driver circuit 6502, and the sensor driver circuit included in the IC 6520 6503, or a detection circuit 6504, or an external CPU 6540, etc. A transistor that uses an oxide semiconductor in the panel formation region and has an extremely low off-state current is used. Since the off-state current of the transistor is extremely low, The capacitor functions as a memory element, and the switch is used to hold the charge (data) that has flowed into the capacitor. By using it as a switch, data retention period can be secured for a long period. For example, This characteristic is used for at least one of the register and cache memory of the image processing circuit 6506. By doing so, the image processing circuit 6506 operates only when necessary, and in other cases, the previous processing By storing the information in the storage element, normally-off computing becomes possible. This enables the touch panel module 6500 and the electronic device in which it is mounted to have low power consumption. This will enable us to strengthen our capabilities.

[0327] In this example, the circuit unit 6501 is a timing controller 6505 and an image processing circuit. However, the image processing circuit 6506 itself or the image processing circuit 6506 A circuit having some of the functions of the image processing circuit 6506 may be provided externally. For example, the circuit unit 6501 may be a signal processor. A signal line driver circuit 6502, a sensor driver circuit 6503, a detection circuit 6504, and a timing controller It may also be configured with a controller 6505.

[0328] In this example, the IC 6520 includes the circuit unit 6501. The 6501 can be configured not to be included in the IC6520. In this case, the IC6520 is A configuration including a signal line driver circuit 6502, a sensor driver circuit 6503, and a detection circuit 6504. For example, when multiple ICs are mounted on the touch panel module 6500, In the touch panel module 6500, a circuit unit 6501 is provided outside the touch panel module 6500. It is also possible to arrange a plurality of ICs 6520 that do not have a slot 6501, or to arrange ICs 6520 and It is also possible to combine and arrange an IC having only the signal line driver circuit 6502 .

[0329] In this way, the touch panel 6510 has a function of driving the display unit 6511 and an input unit 6512. The touch panel module is made by incorporating the function to drive the touch panel and the touch panel driver into a single IC. This reduces the number of ICs mounted on the module 6500, which reduces costs. do.

[0330] 24(A), (B), and (C) show a touch panel module 65 equipped with IC6520. 00 is a schematic diagram.

[0331] In FIG. 24A, the touch panel module 6500 includes a substrate 6531 and an opposing substrate 653 2. Multiple FPC6533, IC6520, IC6530, etc. Also, touch panel The display module 6500 includes a display section 6511, an input section 6512, and a scanning line driver circuit 651. The IC6520 and IC6530 are based on the COG method and other mounting methods. It is mounted on board 6531.

[0332] The IC6530 is the above-mentioned IC6520, except that only the signal line driver circuit 6502 or The IC 6520 includes a signal line driver circuit 6502 and a circuit unit 6501. Signals are supplied to IC6530 from the outside via FPC6533. 533, a signal is output from at least one of IC6520 and IC6530 to the outside. It is possible.

[0333] In FIG. 24A, two scanning line driver circuits 6513 are provided so as to sandwich a display portion 6511. Also shown is a configuration having IC6530 in addition to IC6520. Such a configuration is suitable for use when the display unit 6511 has an extremely high resolution. can be done.

[0334] Figure 24(B) shows an example where one IC6520 and one FPC6533 are mounted. In this way, by consolidating the functions into one IC6520, the number of parts can be reduced. In FIG. 24B, the scanning line driver circuit 6513 is connected to the second display unit 6511. This shows an example of placement along one of the two short sides that is closer to the FPC6533.

[0335] FIG. 24C shows a PCB (Printed Circuit) on which an image processing circuit 6506 and the like are mounted. The figure shows an example of a configuration having an IC on a substrate 6531. 6520 and IC6530 are electrically connected to PCB6534 by FPC6533. Here, the IC 6520 does not have the image processing circuit 6506 described above. can be applied.

[0336] In each diagram of FIG. 24, IC6520 and IC6530 are each on a substrate 6531. For example, IC6520 and IC6530 may be mounted on FPC6533 instead of C It can be mounted on FPC6533 using mounting methods such as OF or TAB. .

[0337] As shown in FIG. 24(A) and (B), the FPC 6533 and the IC The configuration in which IC6520 (and IC6530) etc. are arranged allows for a narrow frame, so for example It can be suitably used in electronic devices such as smartphones, mobile phones, and tablet terminals. In addition, the configuration using PCB6534 as shown in FIG. 24(C) is suitable for use in televisions, for example. Suitable for use in mobile devices, monitors, tablet terminals, and notebook personal computers. It can be used appropriately.

[0338] As described above, the display device according to one embodiment of the present invention includes a substrate provided with a pixel electrode and a first common electrode. A second common electrode is provided on a counter substrate other than the plate. The second common electrode is connected to the first common electrode. By applying the same potential, it is possible to suppress light leakage and improve the display quality of the display device. In addition, it is possible to realize a display device with a high aperture ratio and high definition. By providing the second common electrode in a part of the display area, the driving voltage of the liquid crystal element increases even if the second common electrode is provided. This can be suppressed.

[0339] This embodiment mode can be combined with other embodiment modes as appropriate.

[0340] (Embodiment 2) In this embodiment, a transistor that can be used in a display device of one embodiment of the present invention will be described. This will be described with reference to FIGS.

[0341] The display device of one embodiment of the present invention includes a bottom-gate transistor or a top-gate transistor. The present invention can be fabricated using various types of transistors, such as transistors. The semiconductor layer materials and transistor structures used can be easily replaced to suit the production line. It is possible.

[0342] [Bottom-gate transistor] FIG. 25(A1) shows a channel protection transistor, which is a type of bottom gate transistor. 5 is a cross-sectional view of a transistor 410. The transistor 410 is formed on a substrate 571 with an insulating layer 572 interposed therebetween. The semiconductor layer 542 is disposed on the electrode 546 via an insulating layer 526. The electrode 546 can function as a gate electrode. The insulating layer 526 can function as a gate insulator. It can function as an edge layer.

[0343] In addition, an insulating layer 522 is provided on a channel formation region of the semiconductor layer 542. Electrode 544a and electrode 544b are provided on insulating layer 526 in contact with a portion of electrode 542. A portion of electrode 44 a and a portion of electrode 544 b are formed on insulating layer 522 .

[0344] The insulating layer 522 can function as a channel protection layer. By providing the edge layer 522, the semiconductor layer 5 generated during the formation of the electrodes 544a and 544b is Therefore, when the electrodes 544a and 544b are formed, the semiconductor This can prevent the channel formation region of the conductor layer 542 from being etched. According to one embodiment, a transistor with good electrical characteristics can be realized.

[0345] The transistor 410 is also provided with an insulating layer 522 and an electrode 544a. A layer 528 is provided, and an insulating layer 529 is provided over the insulating layer 528 .

[0346] When an oxide semiconductor is used for the semiconductor layer 542, the electrodes 544a and 544b are At least in the portion in contact with the semiconductor layer 542, oxygen is taken from a portion of the semiconductor layer 542, and oxygen is It is preferable to use a material that can generate defects. The carrier concentration in the region where the loss occurs increases, and the region becomes n-type, and the n-type region (n + Layer) Therefore, the region can function as a source region or a drain region. Examples of materials that can remove oxygen from an oxide semiconductor and cause oxygen vacancies include Examples include tungsten and titanium.

[0347] The source region and the drain region are formed in the semiconductor layer 542, whereby the electrodes 544a and In addition, the contact resistance between the electrode 544b and the semiconductor layer 542 can be reduced. The electrical characteristics of the transistor, such as the mobility and threshold voltage, can be improved. Cut.

[0348] When a semiconductor such as silicon is used for the semiconductor layer 542, the semiconductor layer 542 and the electrode 544a and between the semiconductor layer 542 and the electrode 544b. It is preferable to provide a layer that functions as an n-type semiconductor or a p-type semiconductor. It can function as a source or drain region of a transistor.

[0349] The insulating layer 528 and the insulating layer 529 prevent impurities from diffusing into the transistor from the outside. It is preferable to form the insulating layer using a material having a function of reducing the resistance. Layer 529 may also be omitted.

[0350] When an oxide semiconductor is used for the semiconductor layer 542, the insulating layer 52 After the formation of the insulating layer 529, a heat treatment may be performed once or a plurality of times. By the heat treatment, oxygen contained in the insulating layer 528, the insulating layer 529, and other insulating layers is deoxidized. By diffusing the oxygen into the conductor layer 542, oxygen vacancies in the semiconductor layer 542 can be compensated for. In the above, one or both of the insulating layers 528 and 529 are formed while being heated, so that the semiconductor device is The oxygen vacancies in the conductor layer 542 can be compensated for.

[0351] The transistor 411 in FIG. 25A2 has an insulating layer 529 which functions as a back gate. The transistor 523 is different from the transistor 410 in that it has an electrode 523 that can be It can be formed using the same materials and methods as the electrode 546 .

[0352] <About the back gate> Generally, the back gate is formed of a conductive layer. The gate and the back gate are both semiconductor layers. The back gate is placed on either side of the channel forming region. The potential of the back gate may be the same as that of the gate electrode, or may be equal to the GND potential. Alternatively, the back gate potential may be set independently of the gate potential. By changing the potential, the threshold voltage of the transistor can be changed.

[0353] Both the electrode 546 and the electrode 523 can function as a gate. The edge layer 526, the insulating layer 528, and the insulating layer 529 each function as a gate insulating layer. The electrode 523 may be provided between the insulating layer 528 and the insulating layer 529. .

[0354] In addition, one of the electrodes 546 and 523 may be referred to as a "gate" or a "gate electrode." In this case, the other is called the "back gate" or "back gate electrode." For example, In 411, when the electrode 523 is called a "gate electrode", the electrode 546 is called a "back gate When the electrode 523 is used as a gate electrode, the transistor 4 The transistor 11 can be considered as a type of top-gate transistor. Either the first gate electrode or the electrode 523 is referred to as the "first gate" or the "first gate electrode." The other may be referred to as the "second gate" or "second gate electrode."

[0355] By providing the electrode 546 and the electrode 523 with the semiconductor layer 542 interposed therebetween, By setting the electrode 523 at the same potential, the region in which carriers flow in the semiconductor layer 542 is Since the thickness of the film increases, the amount of carrier movement increases. As the on-current of the transistor 411 increases, the field effect mobility increases.

[0356] Therefore, the transistor 411 is a transistor having a large on-current relative to its area. That is, the area occupied by the transistor 411 is determined for the required on-current. According to one aspect of the present invention, the area occupied by a transistor can be reduced. As a result, it is possible to realize a display device with a high aperture ratio or high resolution. .

[0357] In addition, since the gate and back gate are made of conductive layers, the electric field generated outside the transistor is The function of preventing magnetic fields from acting on the semiconductor layer in which the channel is formed (especially against static electricity, etc.) The back gate is made larger than the semiconductor layer, By covering the semiconductor layer with a gate, the electric field shielding function can be improved.

[0358] In addition, the electrode 546 (gate) and the electrode 523 (back gate) are each Since it has a function of shielding an electric field, the charge generated on the insulating layer 572 side or above the electrode 523 is The charge of the particles does not affect the channel formation region of the semiconductor layer 542. As a result, Experiments (e.g., applying a negative charge to the gate - GBT (Gate Bias-Temper Degradation caused by the drain voltage (stress test) is suppressed. This reduces the change in the gate voltage (rise voltage) at which the on-current begins to flow. This effect can be obtained when the electrode 546 and the electrode 523 are at the same potential or different potentials. This occurs in the following cases.

[0359] The GBT stress test is a type of accelerated test that detects the breakdown voltage and other voltages that occur during long-term use. It is possible to quickly evaluate the change in characteristics (aging) of a transistor. The amount of change in the threshold voltage of a transistor before and after testing is an important factor in determining reliability. The smaller the threshold voltage fluctuation, the more reliable the transistor is. can.

[0360] In addition, the electrode 546 and the electrode 523 are provided, and the electrode 546 and the electrode 523 are set to the same potential. This reduces the variation in threshold voltage. At the same time, the variation in thermal characteristics is reduced.

[0361] Also, a transistor with a back gate applies a positive charge to the gate. The variation in threshold voltage before and after the backgate test was smaller than that of a transistor without a backgate. small.

[0362] In addition, by forming the back gate using a conductive film having a light-shielding property, the semiconductor This can prevent light from entering the conductor layer. This prevents the semiconductor layer from being photodegraded, and reduces the This makes it possible to prevent deterioration of electrical characteristics, such as a shift in the threshold voltage of a transistor.

[0363] According to one embodiment of the present invention, a transistor with high reliability can be provided. A highly reliable display device can be realized.

[0364] FIG. 25(B1) shows a channel-protection transistor, which is one of the bottom-gate transistors. 4 shows a cross-sectional view of transistor 420. Transistor 420 has a similar structure to transistor 410. The insulating layer 522 having the openings 531a and 531b is formed on the semiconductor layer 5 The opening 531a and the opening 531b overlap the semiconductor layer 542. The insulating layer 522 is formed by selectively removing a portion of the insulating layer 522 .

[0365] The semiconductor layer 542 and the electrode 544a are electrically connected in the opening 531a. At the opening 531b, the semiconductor layer 542 and the electrode 544b are electrically connected to each other. By providing the insulating layer 22, the thickness of the semiconductor layer 542 generated when the electrodes 544a and 544b are formed can be reduced. Therefore, when the electrodes 544a and 544b are formed, the semiconductor layer 5 The region of the insulating layer 522 that overlaps with the channel formation region is It can function as a channel protection layer.

[0366] The transistor 421 in FIG. 25B2 has an insulating layer 529 which functions as a back gate. The transistor 420 differs from the transistor 420 in that it has an electrode 523 that can be turned on.

[0367] In addition, the transistors 420 and 421 are the transistors 410 and The distance between the electrodes 544a and 546 and the distance between the electrodes 544b and 546 are smaller than those of the electrode 411. Therefore, the parasitic capacitance between the electrode 544a and the electrode 546 is reduced. In addition, the parasitic capacitance between the electrode 544b and the electrode 546 can be reduced. According to one embodiment of the present invention, a transistor with favorable electrical characteristics can be provided. .

[0368] The transistor 425 illustrated in FIG. 25C1 is a bottom-gate transistor. The transistor 425 is a channel-etched transistor. Instead, an electrode 544a and an electrode 544b are formed in contact with the semiconductor layer 542. Therefore, a part of the semiconductor layer 542 exposed during the formation of the electrodes 544a and 544b is etched. On the other hand, since the insulating layer 522 is not provided, the productivity of the transistor can be improved. It is possible.

[0369] The transistor 426 in FIG. 25C2 has an insulating layer 529 and functions as a back gate. The transistor 425 differs from the transistor 425 in that it has an electrode 523 that can be turned on.

[0370] [Top-gate transistor] FIG. 26A1 shows a cross-sectional view of a transistor 430, which is a type of top-gate transistor. The transistor 430 is formed by forming a semiconductor layer 54 on a substrate 571 with an insulating layer 572 interposed therebetween. 2, which are on the semiconductor layer 542 and the insulating layer 572 and are in contact with a part of the semiconductor layer 542 The semiconductor layer 542, the electrode 544a, and the electrode 544b are An insulating layer 526 is provided on the semiconductor device 4b, and an electrode 546 is provided on the insulating layer 526.

[0371] The transistor 430 is connected to the electrodes 546 and 544a, and the electrodes 546 and 544b. 4b do not overlap, the parasitic capacitance generated between the electrode 546 and the electrode 544a and the The parasitic capacitance between the electrode 546 and the electrode 544b can be reduced. After forming the electrode 546, the impurity 555 is introduced into the semiconductor layer 542 using the electrode 546 as a mask. By introducing the impurity into the semiconductor layer 542, an impurity region is formed in a self-aligned manner in the semiconductor layer 542. According to one embodiment of the present invention, the electrical characteristics of the A good transistor can be realized.

[0372] The introduction of the impurity 555 is performed by an ion implantation device, an ion doping device, or a plasma processing device. This can be done using:

[0373] The impurities 555 are, for example, at least one of Group 13 elements and Group 15 elements. When an oxide semiconductor is used for the semiconductor layer 542, one type of element can be used. The impurity 555 is at least one of rare gases, hydrogen, and nitrogen. It is also possible that

[0374] The transistor 431 in FIG. 26A2 includes an electrode 523 and an insulating layer 527. The transistor 431 is different from the transistor 430. The transistor 431 has an electrode formed on an insulating layer 572. 523 and an insulating layer 527 formed on the electrode 523. The electrode 523 is Thus, the insulating layer 527 can function as a gate insulating layer. The insulating layer 527 can be formed using a material and a method similar to those of the insulating layer 526. It is possible.

[0375] Like the transistor 411, the transistor 431 has a large on-state current relative to its area. That is, for the required on-current, the transistor 4 According to one aspect of the present invention, the area occupied by the transistor 31 can be reduced. Therefore, according to one embodiment of the present invention, a display device having a large aperture can be provided. It is possible to achieve higher speed or higher definition.

[0376] The transistor 440 illustrated in FIG. 26B1 is a top-gate transistor. The transistor 440 is formed by forming the semiconductor layer 544a and the electrode 544b. 26B2 is different from the transistor 430 in that the transistor 542 is formed. The transistor 441 is different from the transistor 440 in that it includes the electrode 523 and the insulating layer 527. In the transistors 440 and 441, a part of the semiconductor layer 542 A portion of the semiconductor layer 542 is formed on the electrode 544a, and another portion of the semiconductor layer 542 is formed on the electrode 544b. .

[0377] Like the transistor 411, the transistor 441 has a large on-state current relative to the area it occupies. That is, for the required on-current, the transistor 4 According to one aspect of the present invention, the area occupied by the transistor 41 can be reduced. This allows the area required to be reduced, thereby enabling a display device with a high aperture ratio or high resolution. It is possible.

[0378] The transistor 442 illustrated in FIG. 27A1 is a top-gate transistor. The transistor 442 has an electrode 544a and an electrode 544b over the insulating layer 529. The electrodes 544a and 544b are formed through openings formed in the insulating layers 528 and 529. At this point, it is electrically connected to the semiconductor layer 542 .

[0379] Also, a portion of the insulating layer 526 that does not overlap with the electrode 546 is removed. A portion of the insulating layer 526 of the capacitor 442 extends beyond the end of the electrode 546 .

[0380] The electrode 546 and the insulating layer 526 are used as a mask to introduce an impurity 555 into the semiconductor layer 542. By this, an impurity region is formed in the semiconductor layer 542 in a self-aligned manner. (See FIG. 27(A3)).

[0381] At this time, the impurity 555 is not introduced into the region of the semiconductor layer 542 that overlaps with the electrode 546, and the Impurities 555 are introduced into the region that does not overlap with the electrode 546. The impurity concentration in the region where the impurity 555 is introduced through the insulating layer 526 is The electrode 546 in the semiconductor layer 542 is lower than the region where the impurity 555 is introduced. A LDD (Lightly Doped Drain) region is formed in the region adjacent to .

[0382] The transistor 443 shown in FIG. 27A2 has an electrode 523 below a semiconductor layer 542. The electrode 523 is connected to the semiconductor layer 522 through an insulating layer 572. The electrode 523 overlaps with the electrode 542. The electrode 523 can function as a backgate electrode.

[0383] In addition, the transistor 444 shown in FIG. 27B1 and the transistor As shown in 445, the insulating layer 526 may be entirely removed in a region that does not overlap with the electrode 546. In addition, the transistor 446 shown in FIG. 27C1 and the transistor 447 shown in FIG. As in 47, the insulating layer 526 may be left unremoved except for the opening.

[0384] After forming the electrode 546, the transistors 444 to 447 are also As a result, the semiconductor layer 542 is doped with impurities 555 using the mask. It is possible to form an impurity region in a self-aligned manner.

[0385] [s-channel transistor] FIG. 28 illustrates an example of a transistor including an oxide semiconductor as the semiconductor layer 542. FIG. 28(A) is a top view of a transistor 451. FIG. 28(B) is a top view of the transistor 451 shown in FIG. FIG. 28(C) is a cross-sectional view taken along dashed line L1-L2 (a cross-sectional view in the channel length direction). 28(A) is a cross-sectional view taken along dashed line W1-W2 (cross-sectional view in the channel width direction).

[0386] The transistor 451 includes a semiconductor layer 542, an insulating layer 526, an insulating layer 572, an insulating layer 582, and an insulating The edge layer 574 includes an electrode 524, an electrode 543, an electrode 544a, and an electrode 544b. 543 can function as a gate. Electrode 524 functions as a back gate. The insulating layer 526, the insulating layer 572, the insulating layer 582, and the insulating layer 574 form a gate The electrode 544a can function as an insulating layer. The electrode 544b can function as either a source electrode or a drain electrode. It can function as a

[0387] An insulating layer 575 is provided on a substrate 571, and an electrode 524 and an insulating layer 573 are formed on the insulating layer 575. An insulating layer 574 is provided on the electrode 524 and the insulating layer 573. In addition, an insulating layer 582 is provided over the insulating layer 574, and an insulating layer 572 is provided over the insulating layer 582. It is provided.

[0388] A semiconductor layer 542a is provided on the protrusion formed on the insulating layer 572. A semiconductor layer 542b is provided on the semiconductor layer 542b. In addition, an electrode 544a and An electrode 544b is provided. The region of the semiconductor layer 542b that overlaps with the electrode 544a is a transistor. The semiconductor layer 5 can function as either the source or the drain of the transistor 451. The region overlapping with the electrode 544b of the transistor 42b is the source or drain of the transistor 451. It can function as a

[0389] A semiconductor layer 542c is provided in contact with a part of the semiconductor layer 542b. An insulating layer 526 is provided on the conductor layer 542c, and an electrode 543 is provided on the insulating layer 526. There are.

[0390] In FIG. 28C, the transistor 451 is In addition, the side surface of the semiconductor layer 542a is covered with the semiconductor layer 542c. By providing the semiconductor layer 542b above the protrusion provided on the substrate 72, the side surface of the semiconductor layer 542b is The transistor 451 can be covered with the electrode 543. That is, the transistor 451 can be connected to the electric field of the electrode 543. Therefore, the semiconductor layer 542b can be electrically surrounded. The electric field of the conductive film electrically surrounds the semiconductor layer in which the channel is formed. The structure of the star is called the surrounded channel (s-channel) structure. A transistor having an s-channel structure is called an "s-channel type transistor." It is also called an "s-channel transistor."

[0391] In the s-channel structure, a channel is formed in the entire (bulk) of the semiconductor layer 542b. In the s-channel structure, the drain current of the transistor can be increased. In addition, the electric field of the electrode 543 can be used to obtain a larger on-state current. As a result, the entire channel formation region formed in the semiconductor layer 542b can be depleted. Therefore, in the s-channel structure, the off-state current of the transistor can be further reduced. It is possible.

[0392] In addition, by making the protrusion of the insulating layer 572 high and reducing the channel width, The n-nel structure can increase the on-current and reduce the off-current. In addition, when processing the semiconductor layer 542b, the exposed semiconductor layer 542a may be removed. In this case, the side surfaces of the semiconductor layer 542a and the semiconductor layer 542b may be aligned.

[0393] In addition, an insulating layer 528 is provided over the transistor 451, and an insulating layer 529 is provided over the insulating layer 528. In addition, an electrode 525a, an electrode 525b, and an electrode 52 The electrode 525a is provided through an opening provided in the insulating layer 529 and the insulating layer 528. At the mouth, the electrode 525 is electrically connected to the electrode 544a via a contact plug. b denotes an opening provided in the insulating layer 529 and the insulating layer 528 through a contact plug. The electrode 525c is electrically connected to the insulating layer 529 and the insulating layer 52 8, which is electrically connected to the electrode 543 via a contact plug. do.

[0394] The contact plug may be made of a material having high embedding properties, such as tungsten or polysilicon. A conductive material can be used. The side and bottom surfaces of the material can be covered with a titanium layer, titanium nitride layer, or the like. The metal layer may be covered with a barrier layer (diffusion prevention layer) made of a metal layer or a laminate of these. The barrier layer may also be referred to as a contact plug.

[0395] The insulating layer 582 is made of hafnium oxide, aluminum oxide, tantalum oxide, or aluminum. By forming the insulating layer 582 from silicate or the like, the insulating layer 582 can function as a charge trap layer. By injecting electrons into the insulating layer 582, the threshold voltage of the transistor can be changed. It is possible to inject electrons into the insulating layer 582 by using, for example, the tunnel effect. By applying a positive voltage to the electrode 524, tunnel electrons are injected into the insulating layer 582. You can enter.

[0396] Depending on the purpose, the electrode 524 functioning as a back gate may not be provided. FIG. 29(A) is a top view of a transistor 451a. FIG. 29(C) is a cross-sectional view taken along the dashed line L1-L2 shown in FIG. The transistor 451a receives current from the transistor 451. The electrode 524, the insulating layer 573, the insulating layer 574, and the insulating layer 582 are omitted. By not providing these electrodes and insulating layers, the productivity of the transistor can be improved. This makes it possible to increase the productivity of the display device.

[0397] Another example of an s-channel transistor is shown in FIG. FIG. 30B is a top view of the star 452. Fig. 30(C) is a cross-sectional view taken along the dashed line W1-W2 in Fig. 30(A). FIG.

[0398] The transistor 452 has a similar structure to the transistor 451, but has electrodes 544a and The difference is that an electrode 544b is in contact with the side surfaces of the semiconductor layer 542a and the semiconductor layer 542b. In addition, the insulating layer 528 covering the transistor 452 has a flat surface similar to that of the transistor 451. An insulating layer having a smooth surface may be used. 25b, and electrode 525c may also be provided.

[0399] Another example of an s-channel transistor is shown in FIG. FIG. 31B is a top view of the star 453. 4 is a cross-sectional view of the transistor 453 in the same manner as the transistor 451. The semiconductor layer 542a and the semiconductor layer 542b are provided on the protrusions provided on the insulating layer 572. In addition, an electrode 544a and an electrode 544b are provided on the semiconductor layer 542b. The region of the semiconductor layer 542b that overlaps with the electrode 544a is the source or drain of the transistor 453. The area of ​​the semiconductor layer 542b that overlaps with the electrode 544b can function as one of the drains. The region can function as the other of the source or drain of the transistor 453. Therefore, a region 569 of the semiconductor layer 542b sandwiched between the electrodes 544a and 544b is It can function as a channel forming region.

[0400] The transistor 453 is formed by removing a part of the insulating layer 528 to form an opening in a region overlapping the region 569. A semiconductor layer 542c is provided along the side and bottom surfaces of the opening. An insulating layer 5 is formed in the opening via a semiconductor layer 542c and along the side and bottom surfaces of the opening. 26 is provided in the opening. Electrodes 543 are provided along the side and bottom surfaces of the opening.

[0401] In addition, the opening is formed between the semiconductor layer 542a and the semiconductor layer 542b in the cross section in the channel width direction. b. Therefore, in the region 569, the semiconductor layer 542a and the semiconductor The side surface of the conductor layer 542b is covered with a semiconductor layer 542c.

[0402] In addition, an insulating layer 529 is provided over the insulating layer 528, and an insulating layer 577 is provided over the insulating layer 529. In addition, an electrode 525a, an electrode 525b, and an electrode 525c are provided on an insulating layer 577. The electrode 525a is provided on one of the insulating layers 577, 529, and 528. In the opening formed by removing the portion, the contact plug is electrically connected to the electrode 544a. The electrode 525b is connected to the insulating layer 577, the insulating layer 529, and the insulating layer 52 In the opening formed by removing a part of 8, the electrode 544b is connected to the electrode 544 via a contact plug. The electrode 525c is electrically connected to the insulating layer 577 and a part of the insulating layer 529. In the opening formed by the removal, the electrode 543 is electrically connected via a contact plug. It is being done.

[0403] Depending on the purpose, the electrode 524 functioning as a back gate may not be provided. FIG. 32(A) is a top view of a transistor 453a. FIG. 32(B) is a top view of the transistor 453a shown in FIG. 1 is a cross-sectional view taken along dashed lines L1-L2 and W1-W2 in FIG. A structure in which the electrode 524, the insulating layer 574, and the insulating layer 582 are omitted from the transistor 453 is shown. By not providing these electrodes or insulating layers, the productivity of the transistor can be improved. Therefore, the productivity of the display device can be improved.

[0404] Another example of an s-channel transistor is shown in FIG. 33. FIG. 33(A) shows a transistor. FIG. 33B is a top view of the star 454. FIG. 33B is a top view of the star 454 between the dashed dotted line L1 and L2 shown in FIG. FIG. 33(C) is a cross-sectional view taken along the dashed line W1-W2 shown in FIG. be.

[0405] The transistor 454 is a type of bottom-gate transistor having a back gate electrode. In the transistor 454, an electrode 543 is formed over an insulating layer 574. An insulating layer 526 is provided to cover the electrode 543. The semiconductor layer 542 included in the transistor 454 is a semiconductor It has a laminate of a conductor layer 542a and a semiconductor layer 542b.

[0406] In addition, an electrode 544a and an electrode 544b are provided on the insulating layer 526 in contact with a part of the semiconductor layer 542. In addition, an electrode 544a and an electrode 544b are formed in contact with a part of the semiconductor layer 542. An insulating layer 528 is formed on the insulating layer 529. An electrode 524 is formed on the insulating layer 529 in a region overlapping with the semiconductor layer 542. There are.

[0407] The electrode 524 provided on the insulating layer 529 is connected to the insulating layer 529, the insulating layer 528, and the insulating layer 5 26 is electrically connected to the electrode 543 through the openings 547a and 547b. Therefore, the same potential is supplied to the electrodes 524 and 543. One or both of the openings 47a and 547b may be omitted. When neither 547b nor 547c is provided, different potentials can be applied to the electrodes 524 and 543. can be done.

[0408] Depending on the purpose, the electrode 524 functioning as a back gate may not be provided. FIG. 34(A) is a top view of a transistor 454a. FIG. 34(B) is a top view of the transistor 454a shown in FIG. FIG 34(C) is a cross-sectional view taken along the dashed line L1-L2 shown in FIG 34(A). The transistor 454a receives current from the transistor 454. The electrode 524, the opening 547a, and the opening 547b are omitted. By not providing an opening, the productivity of the transistor can be increased. Productivity can be increased.

[0409] FIG. 35 shows an example of a transistor having an s-channel structure. The transistor 448 has a configuration similar to that of the transistor 447 described above. The transistor 448 is a type of top-gate transistor having a back gate. FIG. 35(A) is a top view of a transistor 448. FIG. 35(B) is a top view of the transistor 448 shown in FIG. FIG. 35(C) is a cross-sectional view taken along the dashed line L1-L2 in FIG. FIG. 1 is a cross-sectional view taken along line 1-W2.

[0410] FIG. 35 shows a semiconductor layer 542 constituting a transistor 448, in which an inorganic semiconductor layer such as silicon is used. In FIG. 35, an electrode 524 is provided on a substrate 571. An insulating layer 572 is provided on the electrode 524. A semiconductor layer 542 is formed thereon.

[0411] The semiconductor layer 542 includes a semiconductor layer 542i, two semiconductor layers 542t, and two semiconductor layers 542i and 542t. The semiconductor layer 542i is disposed between two semiconductor layers 542t. In addition, the semiconductor layer 542i and the two semiconductor layers 542t are disposed between the two semiconductor layers 542u. An electrode 543 is provided in a region overlapping with the semiconductor layer 542i.

[0412] When the transistor 448 is on, a channel is formed in the semiconductor layer 542i. The semiconductor layer 542i functions as a channel formation region. The semiconductor layer 542u functions as a high concentration impurity region (LDD region). In addition, one or both of the two semiconductor layers 542t may function as a semiconductor layer 542. In addition, one of the two semiconductor layers 542u, the semiconductor layer 54 2u functions as a source region, and the other semiconductor layer 542u functions as a drain region. .

[0413] The electrode 544a provided on the insulating layer 529 is connected to the insulating layers 526, 528, and 529. An opening 547c is provided in the semiconductor layer 529, and the opening 547c is electrically connected to one of the semiconductor layers 542u. The electrode 544b provided on the insulating layer 529 is connected to the insulating layer 526 and the insulating layer 52 8, and an opening 547d provided in the insulating layer 529 is electrically connected to the other of the semiconductor layer 542u. are electrically connected.

[0414] The electrode 543 provided on the insulating layer 526 is a layer provided on the insulating layer 526 and the insulating layer 572. The openings 547a and 547b are electrically connected to the electrode 524. The same potential is supplied to the electrodes 543 and 524. It is also possible to provide neither the opening 547a nor the opening 547b. If this is not possible, electrodes 524 and 543 can be supplied with different potentials.

[0415] This embodiment mode can be combined with other embodiment modes as appropriate.

[0416] (Embodiment 3) In this embodiment, a touch panel module and an electronic device including the display device of one embodiment of the present invention will be described. The devices will be described with reference to FIGS.

[0417] The touch panel module 8000 shown in FIG. 36 includes an upper cover 8001 and a lower cover 8002. Between the FPC8003 and the frame 8009, It includes a printed circuit board 8010 and a battery 8011 .

[0418] The display device of one embodiment of the present invention can be used for the touch panel 8004, for example.

[0419] The upper cover 8001 and the lower cover 8002 are designed to fit the size of the touch panel 8004. The shape and dimensions can be changed appropriately.

[0420] The display device of one embodiment of the present invention can function as a touch panel. The panel 8004 is a resistive or capacitive touch panel according to one embodiment of the present invention. The touch panel 8004 can be used by overlapping it with a display device. It is also possible to provide a touch panel function to the touch panel. It is also possible to provide an optical sensor in each pixel of 8004 to make it into an optical touch panel.

[0421] When a transmissive liquid crystal element is used, a backlight 8007 is provided as shown in FIG. The backlight 8007 has a light source 8008. Although the configuration in which the light source 8008 is disposed on the light 8007 has been illustrated, the present invention is not limited to this. For example, a light source 8008 is arranged at the end of a backlight 8007, and a light diffusion plate is also arranged. In addition, when a self-luminous light-emitting element such as an organic EL element is used, In the case of a reflective panel, the backlight 8007 may not be provided. stomach.

[0422] The frame 8009 protects the touch panel 8004 and also supports the movement of the printed circuit board 8010. It also functions as an electromagnetic shield to block electromagnetic waves generated by the operation of the frame. The frame 8009 may also function as a heat sink.

[0423] The printed circuit board 8010 includes a power supply circuit, a signal circuit for outputting a video signal, and a clock signal. The power supply circuit is supplied with power from an external commercial power source. Alternatively, the power source may be a battery 8011 provided separately. This can be omitted if a commercial power source is used.

[0424] The touch panel 8004 is equipped with additional components such as a polarizing plate, a retardation plate, and a prism sheet. It is okay.

[0425] 37(A) to (H) and FIG. 38 are diagrams showing electronic devices. These electronic devices are A body 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, and an operation key 50 05 (including the power switch or operation switch), connection terminal 5006, sensor 5007 (force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemicals quality, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, (including a function for measuring infrared rays or light), microphone 5008, etc. This can be done.

[0426] FIG. 37(A) shows a mobile computer, which includes, in addition to the above, a switch 5009, The portable terminal 5010 may have an infrared port 5010. FIG. A type of image reproducing device (for example, a DVD reproducing device) that, in addition to the above, also has a second display 37C shows a television. The device may include a stand 5012 and the like in addition to the above. The revision device can be operated using an operation switch provided on the housing 5000 or a separate remote control. The remote control 5013 can be used to operate the channel by using the operation keys provided thereon. The channel and volume can be controlled, and the image displayed on the display unit 5001 can be controlled. The information output from the remote control device 5013 is FIG. 37(D) shows a portable game machine. In addition to the above, the device may have a recording medium reading unit 5011, etc. This is a digital camera with a TV receiving function. In addition to the above, it also has an antenna 5014, a shutter The mobile phone may have a touch button 5015, an image receiving unit 5016, etc. In addition to the above, the second display unit 5002, the recording medium reading unit 5011, FIG. 37(G) shows a portable television receiver, which includes the above-mentioned In addition, a charger 5017 capable of transmitting and receiving signals may be provided. is a wristwatch type information terminal, and in addition to the above, it includes a band 5018, a clasp 5019, The display unit 5001 is mounted on a housing 5000 that also serves as a bezel. The display unit 5001 has a non-rectangular display area. 38A shows a digital signage. Figure 38(B) shows a cylindrical pillar. It is a digital signage installed in

[0427] The electronic devices shown in FIGS. 37(A) to (H) and 38 can have various functions. For example, the function to display various information (still images, videos, text images, etc.) on the display, Panel function, calendar, date or time display function, various software ( A function to control processing by a program, wireless communication function, and various functions using wireless communication function Functions for connecting to computer networks, transmitting various data using wireless communication functions, or receiving the program or data recorded on the recording medium, and displaying the program or data. The electronic device may have a function of displaying information on a display unit. In this case, one display unit is used mainly for displaying image information, and another display unit is used mainly for displaying text. A function that displays text information, or a function that displays images that take parallax into account on multiple displays Furthermore, electronic equipment having an image receiving unit can have a function of displaying a physical image. The camera has the functions of taking still images, taking videos, and storing the images automatically or manually. function to automatically correct the image, and to store the captured image on a recording medium (external or built-in to the camera) The camera can have a function of displaying the captured image on the display unit. The functions that the electronic device shown in FIG. 38 may have are not limited to those described above, and may include various other functions. It can have various functions.

[0428] The electronic device of the present embodiment is characterized by having a display unit for displaying some information. The display device of one embodiment of the present invention can be used for the display portion.

[0429] This embodiment mode can be combined with other embodiment modes as appropriate. EXAMPLES

[0430] In this example, a liquid crystal display device according to one embodiment of the present invention will be described.

[0431] <Study of semiconductor materials> In this embodiment, an oxide semiconductor is used for the semiconductor layer of the transistor. C-OS was used.

[0432] A transistor using CAAC-OS (CAAC-OS FET) is a low-temperature polysilicon (LTPS (Low Temperature Poly-Silicon)) The off-state current is smaller than that of transistors (LTPS FETs).

[0433] After writing data, a voltage is applied between the source and drain of the selection transistor of the pixel during the non-selection period. When the off current flows, the charge gradually decreases. This causes the charge applied to the liquid crystal molecules to The voltage changes and the change in optical characteristics is visible. In such a device, data needs to be written constantly, which leads to an increase in power consumption. AC-OS FETs have a smaller off-current than LTPS FETs, so they are In particular, the charge hardly moves and the voltage applied to the liquid crystal does not change. It is possible to prevent the increase in power consumption according to the number of times the switching is performed.

[0434] <Examination of transistor structure> In this embodiment, two types of pixel layouts for 1058 ppi in FFS mode were created. For those who are looking for a Bottom-Gate Top-Conta The other transistor is a self-aligned top gate transistor. The transistor has a Top-Gate Self-Aligned (TGSA) structure. Then, the orientation simulation was carried out in the FFS mode for each of them.

[0435] Figures 39(A) and (B) show the pixel layout when a BGTC transistor is used. In FIG. 39A, a transistor, a pixel electrode 111, and a first common electrode 112 are The BGTC transistor includes a gate 221, a semiconductor layer 231, and a The conductive layers 222a and 222b are a source electrode and a drain electrode. 39(A) is a top view of the laminated structure from which the first common electrode 112 is removed. FIG.

[0436] In FIG. 39(A) and (B), one conductive layer is formed on both the scan line 228 and the gate 221. In addition, in Fig. 39(A) and (B), one conductive layer functions as a signal. It can be said that the conductive layer 222 functions as both the wire 229 and the conductive layer 222a.

[0437] The pixel layout when using a TGSA transistor is the same as that shown in Figures 3(B) and (C). It seems that.

[0438] In this embodiment, a design simulator for liquid crystal displays: LCD Master 3D Full The set FEM mode (Shintech Co., Ltd.) was used. The boundary condition was period In the simulation of this embodiment, a structure including two adjacent sub-pixels is assumed. In addition, two sub-pixels shown in FIG. 3(B) or FIG. 39(A) are arranged horizontally, and the sub-pixel on the left side is displayed white. The right subpixel is displayed in black (a voltage of 0 V to 6 V is applied to the pixel electrode 111), and the right subpixel is displayed in black (a voltage of 0 V to 6 V is applied to the pixel electrode 111). A voltage of 0 V was applied to 111. The size of one sub-pixel was 8 μm×24 μm.

[0439] The simulation uses a negative type liquid crystal material (Δε=-3) and a cell gap of 3.5 μm. The test was performed under the condition that 0 V was applied to the first common electrode 112.

[0440] FIG. 40(A) shows a case where a BGTC structure transistor is used, and FIG. 40(B) shows a case where a TGSA The results of an orientation simulation using a transistor with the structure shown in FIG. , (B) show the in-plane distribution at maximum transmittance, respectively.

[0441] The results of the orientation simulation showed that the TGSA structure has a higher aperture ratio than the BGTC structure. It was confirmed that the liquid crystal transmittance and effective transmittance are increased. The aperture ratio of the GaN structure is 37.0%, which is 1.016 times that of the BGTC structure (36.4%). The liquid crystal transmittance of the TGSA structure is 1.030 times that of the BGTC structure. The effective transmittance of the GSA structure was 1.044 times that of the BGTC structure.

[0442] Based on the above results, we decided to use a TGSA-structure transistor in the following study. In the present embodiment, in the subsequent simulations, the sub-pixels shown in FIG. The left sub-pixel displayed white, and the right sub-pixel displayed black.

[0443] <Examination of liquid crystal materials> Next, by performing an orientation simulation, the positive type liquid crystal material (Δε=3.8) and the negative type liquid crystal The orientation state was compared with that of a crystalline material (Δε=-3).

[0444] In FIG. 41(A), a positive-type liquid crystal material is used, and in FIG. 41(B), a negative-type liquid crystal material is used. The results of the orientation simulation are shown in Fig. 41(A) and (B), respectively. The in-plane distribution at maximum transmittance is shown.

[0445] The simulation was performed with a cell gap of 3.5 μm, positive polarity applied, and a flexoelectric The flexoelectric effect is mainly due to the molecular shape. This is a phenomenon in which polarization occurs due to orientation distortion. The alignment distortion that causes the change can be made smaller with negative liquid crystal materials than with positive liquid crystal materials. All subsequent simulations in the example are performed under the condition that the flexoelectric effect is present. went.

[0446] As shown in FIG. 41(A), when a positive type liquid crystal material is used, alignment defects occur in the subpixels that display white. In addition, the transmittance of the adjacent subpixel (black display subpixel) was decreased. Light leakage was confirmed.

[0447] As shown in FIG. 41(B), when a negative type liquid crystal material is used, the entire subpixel displaying white is transparent. In addition, the light leakage observed in the periphery of the adjacent subpixel (black display subpixel) was This was less than when a positive type liquid crystal material was used.

[0448] Based on the above results, we decided to use negative type liquid crystal materials in the following studies.

[0449] Next, we performed alignment simulations for positive and negative polarities when using negative liquid crystal materials. The results of the positive polarity were compared. The simulation was performed under the condition that voltages from 0V to 6V were applied to 1. The simulation was performed under the condition that a voltage ranging from 0 V to −6 V was applied to the pixel electrode 111 of the subpixel displaying white. We held a workshop.

[0450] Here, we performed orientation simulation under two conditions. In the second condition, the cell gap was set to 2.5 μm and The second common electrode (applied with 0 V) ​​was used. The second common electrode was the same as the first common electrode in FIG. The layout of the common electrode 112 is the same as that of the common electrode 112. The conductive electrodes have openings of the same size at the same positions. The width of the openings (the first common The lateral length of the opening in electrode 112 was set to 3 μm.

[0451] Figure 42(A) and (B) show the results of the alignment simulation when the cell gap is 3.5 μm. The results are shown in Fig. 43(A) and (B). The results of the alignment simulation when a common electrode (applied 0 V) ​​is used are shown in FIG. 42(A) and 43(B) show the in-plane distribution at the maximum transmittance, respectively. A) shows the case where a voltage of positive polarity is applied, and FIG. 42(B) and FIG. 43( B) is the case where a negative voltage is applied.

[0452] As shown in Fig. 43(A) and (B), the cell gap is narrowed to 2.5 μm, and the second common By adopting electrodes, it was found that alignment defects in adjacent pixels can be suppressed. There was no significant difference in the distribution of transmittance of the white display subpixels or in the degree of light leakage between adjacent pixels. The variation in optical characteristics due to polarity is small, so there is no flicker in the display device. In addition, since there is little light leakage, it is not necessary to provide a wide light-shielding area. This eliminates the need for a second electrode, and the aperture ratio can be increased.

[0453] Here, the aperture ratio of the pixel layout in FIG. 39(A) (without the second common electrode) is 36.4%. , the aperture ratio of the pixel layout of FIG. 3(B) (without the second common electrode) was 37.0%. However, by adopting a second common electrode in the pixel layout of FIG. 3(B), the aperture ratio can be increased to 41.0 We were able to increase this to %.

[0454] Next, we simulated the voltage-transmittance (VT) characteristics of the pixel. (Δε) was set to three values: -3, -5, and -7. Figure 44 shows the results of the simulation. vinegar.

[0455] As shown in Figure 44, by increasing the absolute value of Δε, the saturation voltage decreases, and Δε = It was found that the maximum transmittance was about 4V at -7.

[0456] <Fabrication of Liquid Crystal Display Device> Based on the results of the above simulations, we have developed a pixel layout using a second common electrode and A transmissive liquid crystal display device was fabricated by combining GaAs type liquid crystal materials.

[0457] The specifications of the display device are as follows: The display size is 4.16 inches diagonally, and the number of effective pixels is 384. 0(H)×RGB×2160(V), resolution is 1058ppi, sub-pixel size is 8μm (H) × 24 μm (V).

[0458] The display element used was a liquid crystal element in the FFS mode. The liquid crystal material used was a negative type liquid crystal material. The color filter method was used. The driving frequency was 6 The video signal format was analog line sequential. The source driver also has a built-in analog switch and uses COG.

[0459] The display device has a cell gap of approximately 2.5 μm by providing spacers with a height of approximately 2.5 μm. The anisotropy of the dielectric constant of the liquid crystal, Δε, was set to −8, and the anisotropy of the refractive index of the liquid crystal, Δ The value of n was set to 0.118. The width of the opening in the second common electrode was set to about 3 μm. The second common electrode was fabricated so that the spacing between the openings was about 5 μm.

[0460] FIG. 45(A) is a photograph showing the display state of the display device produced in this example. FIG. 45(C) is an optical microscope photograph of the display section. FIG. 45(B) shows the case of white display. 45(C) is the case of green display.

[0461] As shown in FIG. 45(B), a good alignment state was confirmed in the white display. ) in green display, light leakage from sub-pixels other than the green sub-pixel is suppressed. was confirmed.

[0462] Top-gate CAAC-OS FET with advantages in terms of low power consumption, high aperture ratio, and high transmittance By combining this with a negative type liquid crystal material from the viewpoints of good alignment and low voltage operation, We were able to create a high-definition, 4K resolution LCD display device, exceeding 10,000 ppi. EXAMPLES

[0463] In the first embodiment, alignment stains with positive and negative polarities were measured when a negative type liquid crystal material was used. As one of the conditions for the simulation, the cell gap was set to 2.5 μm and the second common The conditions for the electrode (applied 0 V) ​​are shown.

[0464] In this embodiment, the width of the opening of the second common electrode and the cell gap are taken into consideration. The results of the simulation will be explained below.

[0465] In this embodiment, a design simulator for liquid crystal displays: LCD Master 3D Full The set FEM mode (Shintech Co., Ltd.) was used. The boundary condition was period In the simulation of this embodiment, a structure including two adjacent sub-pixels is assumed. 3B are arranged horizontally, the left subpixel displays white (pixel electrode 111 The right subpixel is displayed in black (a voltage of 0 V to 6 V is applied to pixel electrode 111). V was applied. The size of one subpixel is 8 μm × 24 μm. The width of the aperture (Figure 3 The horizontal length of the opening in the first common electrode 112 shown in (B) was set to 3 μm.

[0466] The simulation uses a negative type liquid crystal material (Δε=−3) and the first common electrode 112 and The test was performed under the condition that 0 V was applied to the second common electrode.

[0467] First, the width of the opening of the second common electrode is set to 2 μm, 3 μm, 4 μm, 5 μm, and 8 μm. The alignment simulation was carried out for five different conditions, where the second common electrode The width of the opening of the electrode is set to be equal to the width of the portion where the second common electrode 244 shown in FIGS. 1(A) and 1(B) is not provided. As mentioned above, the size of one subpixel is 8 μm × 24 μm. Therefore, the condition of length L1 = 8 μm corresponds to the condition where the second common electrode is not provided in the subpixel. In addition, when the length L1 is 3 μm, the second common electrode corresponds to the first common electrode in FIG. It can be said that this layout is similar to that of electrode 112. The cell gap was set to 3 μm.

[0468] In this example, an orientation simulation was performed to calculate the transmittance and contrast. The transmittance is the average transmittance of the subpixels that display white. The contrast is the average transmittance of the subpixels that display white. This is the average transmittance divided by the average transmittance of the subpixels displaying black.

[0469] FIG. 46(A) shows the simulation results of the voltage-transmittance characteristics, and FIG. 46(B) shows the transmittance characteristics. The results of a simulation of the transmittance-contrast characteristics are shown below. When compared, it was found that the smaller the width of the opening of the second common electrode, the higher the contrast. In addition, the larger the width of the opening of the second common electrode, the lower the voltage at the maximum transmittance. It was discovered that...

[0470] Next, we set the cell gap to three different conditions: 2.5 μm, 2.75 μm, and 3 μm. An orientation simulation was performed on the openings of the first common electrode and the second common electrode. The width of each was set to 3 μm.

[0471] FIG. 47(A) shows the simulation results of the voltage-transmittance characteristics, and FIG. 47(B) shows the transmittance characteristics. The simulation results of the transmittance-contrast characteristic are shown below. From these results, it is clear that the cell gap The smaller the cell gap, the higher the contrast. It was found that the transmittance increased. [Explanation of symbols]

[0472] 34 Capacitive element 40 Liquid crystal element 45 light 51 Substrate 56 Conductive Layer 56a conductive layer 56b Conductive layer 57 Auxiliary wiring 58 Conductive Layer 60 pixels 60a subpixel 60b subpixel 60c subpixel 61 Substrate 62 Display section 63 Connection 64 Drive circuit section 65 Wiring 66 Hidden area 68 Display area 68a Display area 68b Display area 69 Connection 72 FPC 72a FPC 72b FPC 73 IC 73a IC 73b IC 81 scan lines 82 Signal Line 100A display device 100B display device 100C display device 100D display device 100E display unit 100F display device 111 Pixel electrode 111a Pixel electrode 111b Pixel electrode 112 First common electrode 112a First common electrode 112b First common electrode 113 Liquid crystal layer 117 Spacer 119a Board 119b Board 121 Overcoat 122 Insulating layer 123 Insulating Layer 124 electrodes 125 Insulating layer 126 Conductive Layer 127 Electrode 128 electrode 130 Polarizing Plate 131 Colored layer 132 Light blocking layer 132a Light blocking layer 132b Light blocking layer 133a Alignment film 133b Alignment film 137 Wiring 138 Wiring 139 Auxiliary wiring 141 Adhesive layer 160 Protection Board 161 Backlight 162 Substrate 163 Adhesive layer 164 Adhesive layer 165 Polarizing Plate 166 Polarizing Plate 167 Adhesive layer 168 Adhesive layer 169 Adhesive layer 201 Transistor 204 Connection 206 Transistor 211 Insulating layer 212 Insulating layer 213 Insulating Layer 214 Insulating layer 215 Insulating Layer 216 Insulating Layer 220 Insulating layer Gate 221 222a conductive layer 222b Conductive layer Gate 223 228 scan lines 229 Signal Line 231 Semiconductor Layer 231a Channel Region 231b Low resistance region 242 Connectors 242b Connection 243 Connectors 244 Second common electrode 244a Second common electrode 244b Second common electrode 244c second common electrode 251 Conductive Layer 281 Conductive Layer 282 Conductive Layer 283 Conductive Layer 284 Conductive Layer 285 Conductive Layer 286 Conductive Layer 350A Touch Panel 350B Touch Panel 350D Touch Panel 370 Display device 375 Input Device 376 Input Devices 379 Display device 410 Transistor 411 Transistor 415 Input Device 416 Substrate 420 Transistor 421 Transistor 425 Transistor 426 Transistor 430 Transistor 431 Transistor 440 Transistor 441 Transistor 442 Transistor 443 Transistor 444 Transistor 445 Transistor 446 Transistor 447 Transistor 448 Transistor 449 IC 450 FPC 451 Transistor 451a Transistor 452 Transistor 453 Transistor 453a Transistor 454 Transistor 454a Transistor 460 areas 461 Conductive Film 462 Conductive Film 463 Conductive Film 464 Nanowires 471 Electrode 472 Electrode 473 Electrode 474 Bridge Electrode 476 Wiring 477 Wiring 522 Insulating layer 523 Electrode 524 Electrode 525a electrode 525b electrode 525c electrode 526 Insulating Layer 527 Insulating Layer 528 Insulating Layer 529 Insulating Layer 531a aperture 531b aperture 542 Semiconductor layer 542a Semiconductor layer 542b Semiconductor layer 542c Semiconductor layer 542i Semiconductor layer 542t Semiconductor layer 542u Semiconductor layer 543 Electrode 544a electrode 544b electrode 546 Electrode 547a aperture 547b aperture 547c aperture 547d aperture 555 Impurities 569 areas 571 Substrate 572 Insulating layer 573 Insulating Layer 574 Insulating Layer 575 Insulating Layer 577 Insulating Layer 582 Insulating layer 601 Pulse voltage output circuit 602 Current Detection Circuit 603 capacity 621 Electrode 622 Electrode 3501 Wiring 3502 Wiring 3510 Wiring 3511 Wiring 3515_1 Block 3515_2 Block 3516 Block 5000 cabinet 5001 Display section 5002 Display section 5003 Speaker 5004 LED Lamp 5005 Operation key 5006 Connection terminal 5007 Sensor 5008 Microphone 5009 Switch 5010 Infrared port 5011 Recording medium reading unit 5012 Stand 5013 Remote control device 5014 Antenna 5015 Shutter button 5016 Image receiving unit 5017 charger 5018 Band 5019 Clasp 5020 Icon 5021 Icon 6500 Touch Panel Module 6501 Circuit Unit 6502 Signal line driver circuit 6503 Sensor driver circuit 6504 Detection circuit 6505 Timing Controller 6506 Image processing circuit 6510 Touch Panel 6511 Display section 6512 Input section 6513 Scanning line driver circuit 6520 IC 6530 IC 6531 Board 6532 Opposing substrate 6533 FPC 6534 PCB 6540 CPU 8000 Touch Panel Module 8001 Top cover 8002 Lower cover 8003 FPC 8004 Touch Panel 8007 Backlight 8008 light source 8009 Frame 8010 Printed Circuit Board 8011 Battery

Claims

1. A display device including a pixel having a plurality of sub-pixels, a pixel electrode, a first common electrode, a second common electrode, and a liquid crystal layer; Each of the plurality of sub-pixels has a display area, the pixel electrode and the first common electrode are located on the opposite side to the second common electrode across the liquid crystal layer in a thickness direction of the display device, The first common electrode and the second common electrode are supplied with the same potential; the first common electrode has a portion overlapping with the second common electrode between the display regions of two adjacent sub-pixels that exhibit different colors among the plurality of sub-pixels; At least one of the pixel electrode and the first common electrode has a portion that does not overlap with the second common electrode in a display region of the subpixel, In each of the plurality of sub-pixels, when a length of a portion of the display region where the second common electrode is not provided is L1 and a thickness of the liquid crystal layer is d, L1 is equal to or greater than d / 6; L1 is a length in a first direction in which the two sub-pixels exhibiting different colors are arranged, Among the plurality of sub-pixels, the second common electrode is provided across two sub-pixels exhibiting different colors, When the length of the second common electrode provided across the two sub-pixels exhibiting different colors is L2, L2 is equal to or greater than d and equal to or less than 2.5d, A display device, wherein L2 is a length in the first direction.

2. A display device including a pixel having a plurality of sub-pixels, a pixel electrode, a first common electrode, a second common electrode, and a liquid crystal layer; Each of the plurality of sub-pixels has a display area, the pixel electrode and the first common electrode are located on the opposite side to the second common electrode across the liquid crystal layer in a thickness direction of the display device, The first common electrode and the second common electrode are supplied with the same potential; the first common electrode has a portion overlapping with the second common electrode between the display regions of two adjacent sub-pixels that exhibit different colors among the plurality of sub-pixels; At least one of the pixel electrode and the first common electrode has a portion that does not overlap with the second common electrode in a display region of the subpixel, In each of the plurality of sub-pixels, when a length of an opening of the second common electrode in the display region is L1 and a thickness of the liquid crystal layer is d, L1 is d / 6 or more; L1 is a length in a first direction in which the two sub-pixels exhibiting different colors are arranged, Among the plurality of sub-pixels, the second common electrode is provided across two sub-pixels exhibiting different colors, When the length of the second common electrode provided across the two sub-pixels exhibiting different colors is L2, L2 is equal to or greater than d and equal to or less than 2.5d, A display device, wherein L2 is a length in the first direction.

Images