Display device

Abstract

To provide a liquid crystal display device that is characteristic of high definition, a high aperture ratio, a high contrast ratio, excellent display quality, and the capability of low-voltage driving.SOLUTION: A display device has a pixel electrode, first common electrode, second common electrode, and liquid crystal layer between a pair of substrates. The pixel electrode and first common electrode are interposed between the liquid crystal layer and one of the substrates. The second common electrode is interposed between the liquid crystal layer and the other substrate. The same voltage is applied to the first common electrode and second common electrode. The first common electrode overlaps the second common electrode between display areas of two adjacent sub-pixels assuming different colors. At least one of the pixel electrode and first common electrode does not overlap the second common electrode in the display areas of the sub pixels.SELECTED DRAWING: Figure 1

Description

Technical Field

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

[0002] Note that one aspect of the present invention is not limited to the above technical field. The technical field of one aspect of the present invention includes, for example, semiconductor devices, display devices, light-emitting devices, power storage devices, storage devices, electronic devices, lighting devices, input devices (for example, touch sensors, etc.), input / output devices (for example, touch panels, etc.), their driving methods, or their manufacturing methods.

Background Art

[0003] Many flat panel displays such as liquid crystal display devices and light-emitting display devices use transistors composed of silicon semiconductors such as amorphous silicon, single-crystalline silicon, or polycrystalline silicon formed on a glass substrate. Further, transistors using such silicon semiconductors are also used in integrated circuits (ICs) and the like.

[0004] In recent years, technologies using metal oxides exhibiting semiconductor characteristics as transistors instead of silicon semiconductors have attracted attention. In this specification, metal oxides exhibiting semiconductor characteristics are referred to as oxide semiconductors. For example, Patent Document 1 and Patent Document 2 disclose technologies for manufacturing transistors using zinc oxide or In-Ga-Zn-based oxides as oxide semiconductors, and using such transistors as switching elements of pixels of display devices.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] One aspect of the present invention aims to provide a high-definition liquid crystal display device. Or, one aspect of the present invention aims to provide a liquid crystal display device with a high aperture ratio. Or, one aspect of the present invention aims to provide a liquid crystal display device with a high contrast ratio and good display quality. Or, one aspect of the present invention aims to provide a liquid crystal display device capable of low-voltage driving. Or, one aspect of the present invention aims to provide a liquid crystal display device with low power consumption. Or, one aspect of the present invention aims to provide a highly reliable liquid crystal display device. Or, one aspect of the present invention aims to provide a novel liquid crystal display device. It should be noted that the description of these problems does not prevent the existence of other problems. One aspect of the present invention does not necessarily need to solve all of these problems. It is possible to extract other problems from the description of the specification, drawings, and claims.

[0007] [Means for Solving the Problems]

[0008] A display device according to one aspect of the present invention has a pixel electrode, a first common electrode, a second common electrode, and a liquid crystal layer between a pair of substrates. The pixel electrode and the first common electrode are respectively located between the liquid crystal layer and one of the substrates. The second common electrode is located between the liquid crystal layer and the other substrate. The first common ​​​​​​​​​​​The same potential is supplied to the common electrode and the second common electrode. The first common electrode has a portion overlapping with the second common electrode between the display areas of two sub-pixels exhibiting adjacent different colors. 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 the display area of the sub-pixel.

[0009] The second common electrode preferably has an opening in the display area of the sub-pixel. When the thickness of the liquid crystal layer is d, the width of the opening is preferably d / 6 or more and narrower than the width of the sub-pixel. When the thickness of the liquid crystal layer is d, the interval between the openings is preferably d or more and 2.5d or less. 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. Or, the first common electrode and the second common electrode may be independently supplied with potentials. For example, the power supply lines to which the first common electrode and the second common electrode are electrically connected may be different.

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

[0012] It is preferable to have a transistor having an oxide semiconductor in the channel formation region. The transistor is electrically connected to the pixel electrode. For example, the semiconductor layer of the transistor preferably has indium, zinc, aluminum, gallium, yttrium, or tin.

[0013] It has scanning lines and signal lines. The direction in which the scanning lines extend intersects with the direction in which the signal lines extend, and the direction in which a plurality of sub-pixels exhibiting the same color are arranged intersects with the direction in which the signal lines extend.​​​​​​ is preferred.

[0014] One aspect of the present invention has a display device having any of the above configurations, and a flexible printed circuit board (Flexible printed circuit, hereinafter referred to as FPC) or a module to which a connector such as TCP (Tape Carrier Package) is attached, or a module such as a module in which an IC is mounted by a COG (Chip On Glass) method or a COF (Chi p On Film) method or the like.

[0015] In one aspect of the present invention, the above configuration may be applied to an input / output device (such as a touch panel) instead of a display device.

[0016] One aspect of the present invention is an electronic device having at least one of the above module, an antenna, a battery, a housing, a camera, a speaker , a microphone, or an operation button.

Advantages of the Invention

[0017] According to one aspect of the present invention, a high-definition liquid crystal display device can be provided. Or, according to one aspect of the present invention , a liquid crystal display device with a high aperture ratio can be provided. Or, according to one aspect of the present invention , a liquid crystal display device with a high contrast ratio and good display quality can be provided . Or, according to one aspect of the present invention, a liquid crystal display device capable of low voltage driving can be provided . Or, according to one aspect of the present invention, a liquid crystal display device with low power consumption can be provided . Or, according to one aspect of the present invention, a highly reliable liquid crystal display device can be provided . Or, according to one aspect of the present invention, a novel liquid crystal display device can be provided . ​​

[0018] Note that the description of these effects does not preclude the existence of other effects. One aspect of the present invention does not necessarily have to have all of these effects. From the description of the specification, drawings, and claims it is possible to extract other effects.

Brief Description of the Drawings

[0019]

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Mode for Carrying Out the Invention

[0020] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that the form and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments shown below. and without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments shown below. and it will be easily understood by those skilled in the art that the form and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments shown below. and it will be easily understood by those skilled in the art that the form and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments shown below.

[0021] In the configuration of the invention described below, the same reference numerals are commonly used for the same parts or parts having the same functions among different drawings, and the repeated description thereof is omitted. In addition, when referring to the same function, the hatching pattern may be the same and may not be particularly labeled. In the configuration of the invention described below, the same reference numerals are commonly used for the same parts or parts having the same functions among different drawings, and the repeated description thereof is omitted. In addition, when referring to the same function, the hatching pattern may be the same and may not be particularly labeled. In the configuration of the invention described below, the same reference numerals are commonly used for the same parts or parts having the same functions among different drawings, and the repeated description thereof is omitted. In addition, when referring to the same function, the hatching pattern may be the same and may not be particularly labeled.

[0022] In addition, the positions, sizes, ranges, etc. of the respective configurations shown in the drawings may not represent the actual positions, sizes, ranges, etc. for the sake of easy understanding. For this reason, the disclosed invention is not necessarily limited to the positions, sizes, ranges, etc. disclosed in the drawings. In addition, the positions, sizes, ranges, etc. of the respective configurations shown in the drawings may not represent the actual positions, sizes, ranges, etc. for the sake of easy understanding. For this reason, the disclosed invention is not necessarily limited to the positions, sizes, ranges, etc. disclosed in the drawings. In addition, the positions, sizes, ranges, etc. of the respective configurations shown in the drawings may not represent the actual positions, sizes, ranges, etc. for the sake of easy understanding. For this reason, the disclosed invention is not necessarily limited to the positions, sizes, ranges, etc. disclosed in the drawings.

[0023] Note that the terms "film" and "layer" may, in some cases or depending on the situation, and can be interchanged with each other. For example, the term "conductive layer" can be changed to the term "conductive film" . Or, for example, the term "insulating film" can be changed to the term " insulating layer".

[0024] (Embodiment 1) In this embodiment, a display device according to an aspect of the present invention will be described with reference to FIGS. 1 to 24.

[0025] A display device according to an aspect 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 and are located on the side opposite to the second common electrode. The same potential is supplied to the first common electrode and the second common electrode. The first common electrode has a portion overlapping the second common electrode between the display regions of two sub-pixels exhibiting adjacent different colors. At least one of the pixel electrode and the first common electrode has a portion that does not overlap the second common electrode in the display region of the sub-pixel .

[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, one pixel is composed of a sub-pixel exhibiting red, a sub-pixel exhibiting green, and a sub-pixel exhibiting blue, so that a full-color display can be performed in the display unit . Note that the colors exhibited by the sub-pixels are not limited to red, green, and blue. For the pixel, for example, sub-pixels exhibiting colors such as white, yellow, magenta, or cyan may be used . Note that in this specification and the like, a sub-pixel may sometimes 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, 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 appropriately inverted 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 alignment problems in 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 a surface electrode of the sub-pixel. The display area has a portion that does not overlap with the second common electrode. Thereby, even if the second common electrode is provided, it is possible to make it difficult to increase the driving voltage of the liquid crystal element.

[0032] <1-1. Configuration Example 1 of Display Device> Figures 1(A) to (D) show cross-sectional views of a display device according to an aspect of the present invention.

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

[0034] The display device shown in Figure 1(A) has display areas 68a and 68b. The display areas 68a and 68b are display areas of sub-pixels that exhibit different colors (also referred to as openings of sub-pixels).

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

[0036] The display device shown in Figure 1(A) has the first common electrode 112 on the substrate 119a, the insulating layer 220 on the first common electrode 112, and island-shaped pixel electrodes 111a and 111b on the insulating layer 220. The pixel electrodes are provided for each sub-pixel. In the display area, the pixel electrodes have openings or gaps (also referred to as slits, etc.).

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

[0038] The display device shown in Fig. 1(B) has island-shaped pixel electrodes 111a and 111b on a substrate 119a. It has an insulating layer 220 on the pixel electrodes 111a and 111b, and has a first common electrode 112 on the insulating layer 220. In the display area, the first common electrode 112 has an opening or a gap (also referred to as a slit or the like).

[0039] In each of the display areas 68a and 68b, a voltage can be applied between the pixel electrode and the first common electrode 112 (see the arrows shown in Figs. 1(A) and 1(B)). On the other hand, between the display areas 68a and 68b, the liquid crystal layer 113 is sandwiched between the first common electrode 112 and the second common electrode 244 to which the same potential (constant potential, common potential) is supplied. By applying a common potential to the electrode provided on the substrate 119b side, the spread of the electric field from the pixel electrode to the electrode of the adjacent sub-pixel can be suppressed. Therefore, the alignment defect of the liquid crystal can be suppressed, the light leakage can be reduced, and the contrast ratio of the display device can be increased.

[0040] Also, in Fig. 1(A), the first common electrode 112 has a portion that does not overlap with the second common electrode 244 in each of the display areas 68a and 68b. Also, in Fig. 1(B), the pixel electrode 111a has a portion that does not overlap with the second common electrode 244 in the display area 68a, and the pixel electrode 111b has a portion that does not overlap with the second common electrode 244 in the display area 68b. By partially providing the second common electrode 244 in the display area of the sub-pixel, the increase in the driving voltage of the liquid crystal element can be suppressed compared to the case where it is provided entirely.

[0041] In Figs. 1(A) and 1(B), the second common electrode 244 is provided in the display area of the sub-pixel. The length of the non-existing portion is shown as length L1. Also, provided across two sub-pixels The length of the second common electrode 244 is shown as length L2. Also, in Fig. 1(A), the pixel electrode and the thickness of the liquid crystal layer 113 between the second common electrode 244 are shown as d. In Fig. 1(B), the thickness of the liquid crystal layer 113 between the first common electrode 112 and the second common electrode 244 is shown as d is. 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, whichever is closer to the second common electrode 244 in the direction of the thickness of the liquid crystal layer 113, and the second common electrode 244. refers to the thickness of the liquid crystal layer 113 therebetween. The thickness d of the liquid crystal layer can also be said to be the cell gap, the shortest distance between the pixel electrode or the first common electrode 112, and the second common electrode 244.

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

[0043] Here, an example is shown in which one pixel is constituted by three sub-pixels: a red sub-pixel (R), a green sub-pixel (G), and a blue sub-pixel (B). The portion other than the display region 68 of the sub-pixel is shown as the non-display region 66.

[0044] In Fig. 2(A), an example is shown in which the second common electrode 244 has an opening. The opening is located in at least a part of the display region 68 and may extend into the non-display region 66.

[0045] In Fig. 2(A), the length L1 corresponds to the width of the opening. Also, the length L1 can be the length of the short side of the opening, the length of the opening in the direction in which sub-pixels presenting different colors are arranged, etc.

[0046] In Fig. 2(A), the length L2 corresponds to the interval between the openings. Also, the length L2 is the length of the interval between openings in which sub-pixels presenting different colors are arranged It can also be said, for example, in terms of the interval between openings in the direction in which the sub-pixels are arranged.

[0047] FIG. 2(B) shows an example in which a plurality of second common electrodes 244 are provided in a stripe shape. The direction in which the second common electrode 244 is arranged intersects with the direction in which sub-pixels presenting the same color are arranged. intersects.

[0048] One second common electrode 244 is arranged across two adjacent sub-pixels presenting different colors. For example, the second common electrode 244a is arranged across a red sub-pixel (R) and a green sub-pixel (G). is arranged across.

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

[0050] In FIG. 2(B), the length L2 corresponds to the width of the second common electrode. Also, the length L2 can be said to be the length of the short side of the second common electrode, the length of the second common electrode in the direction in which sub-pixels presenting different colors are arranged, etc. electrode, etc. electrode, etc.

[0051] Note that the second common electrode 244 shown in FIG. 2(B) can also be regarded as a single comb-shaped electrode. In this case, the second common electrodes 244a, 2 44b, 244c are connected at portions not shown in FIG. 2(B). The length L1 can be said to be the tooth interval, and the length L2 can be said to be the tooth width. 44b, 244c are connected at portions not shown in FIG. 2(B). The length L1 can be said to be the tooth interval, and the length L2 can be said to be the tooth width. can be said.

[0052] FIG. 2(C) shows an example in which the openings of the second common electrode 244 are provided across two adjacent sub-pixels presenting the same color. One opening may be located in the display regions 68 of a plurality of sub-pixels presenting the same color. sub-pixels presenting the same color. One opening may be located in the display regions 68 of a plurality of sub-pixels presenting the same color. sub-pixels presenting the same color.

[0053] The larger the area where the second common electrode 244 is provided, the lower the resistance of the second common electrode 244, which is preferable. For example, compared with FIGS. 2(B) and 2(C), the configuration shown in FIG. 2(A) can lower the resistance of the second common electrode 244.

[0054] Hereinafter, a case where the layout of the second common electrode 244 in FIGS. 1(A) to 1(D) corresponds to the layout shown in FIG. 2(A ) will be described as an example. In FIGS. 1(A) to 1(D), the second common electrode 244 has an opening in the display region 68. Also, in FIGS. 1(B) to 1(D), the first common electrode 112 has an opening in the display region 68.

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

[0056] As shown in FIG. 1(C), the first common electrode 112 may also have portions that do not overlap with the second common electrode 244 in the display regions 68a and 68b, respectively.

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

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

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

[0060] When viewed from a direction perpendicular to the thickness of the liquid crystal layer 113, from the end of the opening of the second common electrode 244 to the first The length to the end of the opening of the common electrode 112 is taken as length L3 in FIG. 1(C) and as length L4 in FIG. 1(D). is taken as length L4.

[0061] In a sub-pixel, the wider the portion where the second common electrode 244 is provided, the more the spread of the electric field from the pixel electrode to the electrode of an adjacent sub-pixel can be suppressed. That is, the shorter the length L1 and also the longer the length L2, the more the light leakage can be reduced. Also, the shorter the length L 3 shown in FIG. 1(C), the more the light leakage can be reduced. Also, the longer the length L4 shown in FIG. 1(D) is, the more the light leakage can be reduced.

[0062] In the display area of the sub-pixel, the wider the portion where the second common electrode 244 is not provided, the more the increase in the driving voltage of the liquid crystal element due to providing the second common electrode 244 can be suppressed. That is, the longer the length L1 or the shorter the length L2, the more the increase in the driving voltage of the liquid crystal element can be suppressed. Also, the longer the length L3 shown in FIG. 1(C), the more the increase in the driving voltage of the liquid crystal element can be suppressed. Also, the shorter the length L4 shown in FIG. 1(D), the more the increase in the driving voltage of the liquid crystal element can be suppressed.

[0063] Also, the smaller the thickness d of the liquid crystal layer, the stronger the influence of the second common electrode 244 can be, and the more the generation of a horizontal electric field between two sub-pixels can be suppressed. By reducing the thickness d of the liquid crystal layer, the length L1 can be increased (the length L2 can be decreased). By this means, while suppressing the increase in the driving voltage, the light leakage can be suppressed.

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

[0065] When the thickness of the liquid crystal layer is d, the length L2 is preferably not less than d and not more than 2.5d, more preferably not less than 1.2d and not more than 2.4d. The condition of this length L2 affects the contrast ratio of the display device. The condition of the above length L1 affects the driving voltage of the display device. Therefore, when manufacturing the display device, it is desirable to prioritize the condition of the length L2 that affects the display quality.

[0066] The thickness d of the liquid crystal layer is preferably not less than 1 μm and not more than 3 μm, more preferably not less than 1.5 μm and not more than 3 μm.

[0067] By applying one aspect of the present invention, light leakage between adjacent sub-pixels can be suppressed, so the distance between sub-pixels can be narrowed. Therefore, the aperture ratio of the sub-pixels can be increased. In addition, high definition of the display device becomes possible. Also, improvement in the display quality of the display device becomes possible. Also, an increase in the driving voltage can be suppressed. Also, by increasing the aperture ratio, the light extraction efficiency can be increased. Thereby, the power consumption of the display device can be reduced.

[0068] <1-2. Configuration Example 2 of Display Device> FIGS. 3(A) and 4(A) show an example of a display device. FIG. 3(A) is a perspective view of the display device 100A, and FIG. 4(A) is a cross-sectional view of the display device 100A. In FIG. 3(A), for clarity, components such as the polarizing plate 130 are omitted from the illustration. In FIG. 3(A), the substrate 61 is shown by a dashed line.

[0069] The display device 100A includes a display unit 62 and a drive circuit unit 64. An FPC 72 and an IC 73 are mounted on the display device 100A.

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

[0077] FIG. 4(A) is a cross-sectional view including the display unit 62, the drive circuit unit 64, and the wiring 65. FIG. 4( A) includes a cross-sectional view between the dashed-dotted line X1-X2 in FIG. 3(B). In the cross-sectional views of the display device shown subsequently from FIG. 4(A), as the display unit 62, a display area 68 of one sub-pixel and the non-display area 66 positioned around it are shown.

[0078] FIG. 3(B) is a top view of the laminated structure from the gate 223 to the first common electrode 112 among the sub-pixels ( see FIG. 4(A)) as viewed from the side of the first common electrode 112. In FIG. 3(B), the display area 68 of the sub-pixel is indicated by a thick dashed line frame. FIG. 3(C) is a top view of the laminated structure in FIG. 3(B) excluding the first common electrode 112.

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

[0080] As shown in FIG. 4(A), the display device 100A includes a substrate 51, transistors 201, trans istors 206, a liquid crystal element 40, auxiliary wiring 139, alignment films 133a, 133b, a connection part 204, an adhesive layer 141, a coloring layer 131, a light shielding layer 132, an overcoat 121, a substrate 6 1, and a polarizing plate 130, etc.

[0081] In the display area 68, a liquid crystal element 40 is provided. The liquid crystal element 40 is a liquid crystal element to which the FFS (Frin 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 has a liquid crystal layer 113. The electric field generated between the pixel electrode 111 and the first common electrode 112 can control the alignment of the liquid crystal layer 113. The liquid crystal layer 113 is located between an alignment film 133a and an alignment film 133b.

[0083] In the connection portion 69, the second common electrode 244 is electrically connected to a conductive layer provided on the substrate 51 side. Thereby, a potential can be supplied from the FPC 72 to the second common electrode 244. Therefore, it is not necessary to connect an FPC or the like to the substrate 61 side, which is preferable because the configuration of the display device can be made simpler.

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

[0085] The same potential can be supplied to the first common electrode 112 and the second common electrode 244. For example, if the first common electrode 112 and the conductive layer 284 are electrically connected, or if they are one film (the same film), the second common electrode 244 is electrically connected to the first common electrode 112.

[0086] Note that the second common electrode 244 does not have to be electrically connected to the first common electrode 112. When the power supply line electrically connected to the first common electrode 112 and the power supply line electrically connected to the second common electrode 244 are different, the same potential can be supplied to the two power supply lines, so that the same potential can be supplied to the first common electrode 112 and the second common electrode 244.

[0087] In the connection part 69, the conductive layer 281 and the conductive layer 282 are connected, the conductive layer 282 and the conductive layer 283 are connected, the conductive layer 283 and the conductive layer 284 are connected, the conductive layer 284 and the connector 243 are connected, and the connector 243 and the second common electrode 244 are connected. The conductive layer 281, the conductive layer 282, and the conductive layer 283 can be formed of the same material and in the same process as the gate 223, the gate 221 of the transistor, and the conductive layers 222a and 222b, respectively. In this way, if the conductive layers constituting the connection part 69 are manufactured of the same material and in the same process as the conductive layers used in the display part 62 and the drive circuit part 64, it is preferable because an increase in the number of processes can be prevented.

[0088] As the connector 243, for example, conductive particles can be used. As the conductive particles, those obtained by coating the surface of particles such as organic resin or silica with a metal material can be used. It is preferable to use nickel or gold as the metal material because the contact resistance can be reduced. Also, it is preferable to use particles coated with two or more kinds of metal materials in layers, such as coating nickel with gold. Also, it is preferable to use a material that elastically deforms or plastically deforms as the connector 243. At this time, the conductive particles may have a shape flattened in the vertical direction as shown in FIG. 4(A) and the like. By doing so, the contact area between the connector 243 and the conductive layer electrically connected thereto increases, the contact resistance can be reduced, and malfunctions such as poor connection can be suppressed.

[0089] The connector 243 is preferably arranged so as to be covered with the adhesive layer 141. For example, the connector 243 can be dispersed in the uncured adhesive layer 141.

[0090] ​In FIG. 4(A), the pixel electrode 111 is electrically connected to the low-resistance region 231b via the conductive layer 222b. It is electrically connected.

[0091] As shown in FIG. 4(B), the pixel electrode 111 may be directly connected to the low-resistance region 231b. At this time, it is preferable to use a material that transmits visible light, such as an oxide semiconductor, for the semiconductor layer (channel region 231a and low-resistance region 231b). Thereby, the connection portion between the pixel electrode 111 and the transistor can be provided in the display region 68. Therefore, the aperture ratio of the sub-pixel can be increased. Also, high definition of the display device becomes possible. Note that the conductive layer 222b may be electrically connected to the low-resistance region 231b. The conductive layer 222b can function as an auxiliary electrode for the low-resistance region 231b. Or, the transistor may not have the conductive layer 222b. It is preferable to use a material that transmits visible light, such as an oxide semiconductor, for the semiconductor layer (channel region 231a and low-resistance region 231b). Thereby, the connection portion between the pixel electrode 111 and the transistor can be provided in the display region 68. Therefore, the aperture ratio of the sub-pixel can be increased. Also, high definition of the display device becomes possible. Note that the conductive layer 222b may be electrically connected to the low-resistance region 231b. The conductive layer 222b can function as an auxiliary electrode for the low-resistance region 231b. Or, the transistor may not have the conductive layer 222b. It is preferable to use a material that transmits visible light, such as an oxide semiconductor, for the semiconductor layer (channel region 231a and low-resistance region 231b). Thereby, the connection portion between the pixel electrode 111 and the transistor can be provided in the display region 68. Therefore, the aperture ratio of the sub-pixel can be increased. Also, high definition of the display device becomes possible. Note that the conductive layer 222b may be electrically connected to the low-resistance region 231b. The conductive layer 222b can function as an auxiliary electrode for the low-resistance region 231b. Or, the transistor may not have the conductive layer 222b. It is preferable to use a material that transmits visible light, such as an oxide semiconductor, for the semiconductor layer (channel region 231a and low-resistance region 231b). Thereby, the connection portion between the pixel electrode 111 and the transistor can be provided in the display region 68. Therefore, the aperture ratio of the sub-pixel can be increased. Also, high definition of the display device becomes possible. Note that the conductive layer 222b may be electrically connected to the low-resistance region 231b. The conductive layer 222b can function as an auxiliary electrode for the low-resistance region 231b. Or, the transistor may not have the conductive layer 222b. It is preferable to use a material that transmits visible light, such as an oxide semiconductor, for the semiconductor layer (channel region 231a and low-resistance region 231b). Thereby, the connection portion between the pixel electrode 111 and the transistor can be provided in the display region 68. Therefore, the aperture ratio of the sub-pixel can be increased. Also, high definition of the display device becomes possible. Note that the conductive layer 222b may be electrically connected to the low-resistance region 231b. The conductive layer 222b can function as an auxiliary electrode for the low-resistance region 231b. Or, the transistor may not have the conductive layer 222b. It is preferable to use a material that transmits visible light, such as an oxide semiconductor, for the semiconductor layer (channel region 231a and low-resistance region 231b). Thereby, the connection portion between the pixel electrode 111 and the transistor can be provided in the display region 68. Therefore, the aperture ratio of the sub-pixel can be increased. Also, high definition of the display device becomes possible. Note that the conductive layer 222b may be electrically connected to the low-resistance region 231b. The conductive layer 222b can function as an auxiliary electrode for the low-resistance region 231b. Or, the transistor may not have the conductive layer 222b. It is preferable to use a material that transmits visible light, such as an oxide semiconductor, for the semiconductor layer (channel region 231a and low-resistance region 231b). Thereby, the connection portion between the pixel electrode 111 and the transistor can be provided in the display region 68. Therefore, the aperture ratio of the sub-pixel can be increased. Also, high definition of the display device becomes possible. Note that the conductive layer 222b may be electrically connected to the low-resistance region 231b. The conductive layer 222b can function as an auxiliary electrode for the low-resistance region 231b. Or, the transistor may not have the conductive layer 222b.

[0092] The first common electrode 112 may have a comb-shaped upper surface shape (also referred to as a planar shape) or an upper surface shape provided with a slit. FIGS. 3(B), (C), and 4(A) show an example in which one opening of the first common electrode 112 is provided in the display region 68 of one sub-pixel. The first common electrode 112 may have a comb-shaped upper surface shape (also referred to as a planar shape) or an upper surface shape provided with a slit. FIGS. 3(B), (C), and 4(A) show an example in which one opening of the first common electrode 112 is provided in the display region 68 of one sub-pixel. The first common electrode 112 may have a comb-shaped upper surface shape (also referred to as a planar shape) or an upper surface shape provided with a slit. FIGS. 3(B), (C), and 4(A) show an example in which one opening of the first common electrode 112 is provided in the display region 68 of one sub-pixel. With the increase in the definition of the display device, the area of the display region 68 of one sub-pixel becomes smaller. Therefore, the number of openings provided in the first common electrode 112 is not limited to a plurality and can be one. That is, in a high-definition display device, since the area of the pixel (sub-pixel) is small, even if there is one opening in the first common electrode 112, an electric field sufficient to align the liquid crystal can be generated over the entire display region of the sub-pixel. With the increase in the definition of the display device, the area of the display region 68 of one sub-pixel becomes smaller. Therefore, the number of openings provided in the first common electrode 112 is not limited to a plurality and can be one. That is, in a high-definition display device, since the area of the pixel (sub-pixel) is small, even if there is one opening in the first common electrode 112, an electric field sufficient to align the liquid crystal can be generated over the entire display region of the sub-pixel. With the increase in the definition of the display device, the area of the display region 68 of one sub-pixel becomes smaller. Therefore, the number of openings provided in the first common electrode 112 is not limited to a plurality and can be one. That is, in a high-definition display device, since the area of the pixel (sub-pixel) is small, even if there is one opening in the first common electrode 112, an electric field sufficient to align the liquid crystal can be generated over the entire display region of the sub-pixel. With the increase in the definition of the display device, the area of the display region 68 of one sub-pixel becomes smaller. Therefore, the number of openings provided in the first common electrode 112 is not limited to a plurality and can be one. That is, in a high-definition display device, since the area of the pixel (sub-pixel) is small, even if there is one opening in the first common electrode 112, an electric field sufficient to align the liquid crystal can be generated over the entire display region of the sub-pixel. With the increase in the definition of the display device, the area of the display region 68 of one sub-pixel becomes smaller. Therefore, the number of openings provided in the first common electrode 112 is not limited to a plurality and can be one. That is, in a high-definition display device, since the area of the pixel (sub-pixel) is small, even if there is one opening in the first common electrode 112, an electric field sufficient to align the liquid crystal can be generated over the entire display region of the sub-pixel.

[0093] An insulating layer 220 is provided between the pixel electrode 111 and the first common electrode 112. The pixel The electrode 111 has a portion that overlaps with the first common electrode 112 via the insulating layer 220. Also , in a region where the pixel electrode 111 and the coloring layer 131 overlap, there is a portion on the pixel electrode 111 where the first common electrode 112 is not disposed. An auxiliary wiring 1 39 is provided on the first common electrode 112. The resistivity of the auxiliary wiring 139 is preferably lower than the resistivity of the first common electrode 112. By providing an auxiliary wiring that is electrically connected to the common electrode, the voltage drop caused by the resistance of the common electrode can be suppressed. Also, at this time, when the laminated structure is a laminated structure of a conductive layer containing a metal oxide and a conductive layer containing a metal, it is preferable to form it by a patterning technique using a halftone mask because the process can be simplified. The auxiliary wiring 139 is a film having a lower resistance value than the first common electrode 112. The auxiliary wiring 139 is, for example, made of a metal material such as molybdenum, titanium, chromium, tantalum, tungsten, aluminum, copper , silver, neodymium, scandium or an alloy material containing these elements, and can be formed in a single layer or a laminate.

[0094]

[0095] Preferably, the auxiliary wiring 139 is provided at a position that overlaps with the light shielding layer 132 or the like so as not to be visible to the user of the display device.

[0096]

[0097] It is preferable to provide an alignment film in contact with the liquid crystal layer 113. The alignment film can control the alignment of the liquid crystal layer 113. In the display device 100A, an alignment film 133a is located between the first common electrode 112 and the insulating layer 220 and the liquid crystal layer 113, and an alignment film 133b is located between the second common electrode 244 and the overcoat 121 and the liquid crystal layer 113.

[0097] ​ Liquid crystal materials include positive liquid crystal materials with a positive dielectric anisotropy (Δε) and negative liquid crystal materials. In one aspect of the present invention, either material can be used, and an optimal liquid crystal material can be used according to the applicable mode and design.

[0098] In one aspect of the present invention, it is preferable to use a negative liquid crystal material. In a negative liquid crystal, the flexoelectric effect derived from the polarization of liquid crystal molecules can be suppressed, and there is almost no difference in transmittance due to the polarity of the voltage applied to the liquid crystal layer. Therefore, it is possible to suppress the flicker from being visually recognized by the user of the display device. The flexoelectric effect is a phenomenon in which polarization occurs mainly due to the molecular shape and orientation distortion. Negative liquid crystal materials are less likely to cause orientation distortion such as spreading deformation and bending deformation. Here, an element to which the FFS mode is applied is used as the liquid crystal element 40, but it is not limited to this, and liquid crystal elements to which various modes are applied can be used. For example, VA (Vertical Alignment) mode, TN (Twisted Nematic) mode, IPS (In-Plane-Switching) mode, ASM (Axially Symmetric aligned Micro-cell) mode, OCB (Optically Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (AntiFerroelectric Liquid Crystal) mode, etc.

[0099] liquid crystal elements to which the mode is applied can be used. Here, an element to which the FFS mode is applied is used as the liquid crystal element 40, but it is not limited to this, and liquid crystal elements to which various modes are applied can be used. For example, VA (Vertical Alignment) mode, TN (Twisted Nematic) mode, IPS (In-Plane-Switching) mode, ASM (Axially Symmetric aligned Micro-cell) mode, OCB (Optically Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (AntiFerroelectric Liquid Crystal) mode, etc. mode, IPS (In-Plane-Switching) mode, ASM (Axially Symmetric aligned Micro-cell) mode, OCB (Optically Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (AntiFerroelectric Liquid Crystal) mode, etc. mode, IPS (In-Plane-Switching) mode, ASM (Axially Symmetric aligned Micro-cell) mode, OCB (Optically Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (AntiFerroelectric Liquid Crystal) mode, etc. mode, IPS (In-Plane-Switching) mode, ASM (Axially Symmetric aligned Micro-cell) mode, OCB (Optically Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (AntiFerroelectric Liquid Crystal) mode, etc. mode, IPS (In-Plane-Switching) mode, ASM (Axially Symmetric aligned Micro-cell) mode, OCB (Optically Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (AntiFerroelectric Liquid Crystal) mode, etc. mode, IPS (In-Plane-Switching) mode, ASM (Axially Symmetric aligned Micro-cell) mode, OCB (Optically Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (AntiFerroelectric Liquid Crystal) mode, etc. liquid crystal elements to which the mode is applied can be used.

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

[0101] Note that the 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 action of liquid crystal is controlled by an electric field applied to the liquid crystal (including a horizontal electric field, a vertical electric field, or an oblique electric field). As the liquid crystal used for the liquid crystal element, thermotropic liquid crystal, low molecular liquid crystal, high molecular liquid crystal, polymer dispersed liquid crystal (PDLC: Polymer Dispersed Liquid Crystal), ferroelectric liquid crystal, antiferroelectric liquid crystal, etc. can be used. These liquid crystal materials show a cholesteric phase, a smectic phase, a cubic phase, a chiral nematic phase, an isotropic phase, etc. depending on conditions. Liquid crystal, etc. can be used. These liquid crystal materials show a cholesteric phase, a smectic phase, a cubic phase, a chiral nematic phase, an isotropic phase, etc. depending on conditions. Dispersed Liquid Crystal), ferroelectric liquid crystal, antiferroelectric liquid crystal, etc. can be used. Crystal, etc. can be used. These liquid crystal materials show a cholesteric phase, a smectic phase, a cubic phase, a chiral nematic phase, an isotropic phase, etc. depending on conditions.

[0102] In addition, when adopting the horizontal electric field method, a liquid crystal showing a blue phase without using an alignment film may be used. The blue phase is one of the liquid crystal phases, and it is a phase that appears immediately before the cholesteric liquid crystal is heated and transitions from the cholesteric phase to the isotropic phase. Since the blue phase appears only in a narrow temperature range, a liquid crystal composition mixed with 5 wt% or more of a chiral agent is used for the liquid crystal layer 113 in order to improve the temperature range. The blue phase is a phase that appears immediately before the cholesteric liquid crystal is heated and transitions from the cholesteric phase to the isotropic phase. Since the blue phase appears only in a narrow temperature range, a liquid crystal composition mixed with 5 wt% or more of a chiral agent is used for the liquid crystal layer 113 in order to improve the temperature range. A liquid crystal composition containing a liquid crystal showing a blue phase and a chiral agent has a short response speed and shows optical isotropy. In addition, a liquid crystal composition containing a liquid crystal showing a blue phase and a chiral agent The crystal composition does not require alignment treatment and has low viewing angle dependence. Also, since no alignment film needs to be provided, rubbing treatment is not required either, so electrostatic breakdown caused by rubbing treatment can be prevented, and defects or breakage of the liquid crystal display device during the manufacturing process can be reduced. Since rubbing treatment is not required, electrostatic breakdown caused by rubbing treatment can be prevented, and defects or breakage of the liquid crystal display device during the manufacturing process can be reduced. Since rubbing treatment is not required, electrostatic breakdown caused by rubbing treatment can be prevented, and defects or breakage of the liquid crystal display device during the manufacturing process can be reduced. can be reduced.

[0103] Since the display device 100A is a transmissive liquid crystal display device, a conductive material that transmits visible light is used for both the pixel electrode 111 and the first common electrode 112. Also, when the second common electrode 244 is located in the display area 68, a conductive material that transmits visible light is also used for the second common electrode 244. Since the display device 100A is a transmissive liquid crystal display device, a conductive material that transmits visible light is used for both the pixel electrode 111 and the first common electrode 112. Also, when the second common electrode 244 is located in the display area 68, a conductive material that transmits visible light is also used for the second common electrode 244. Since the display device 100A is a transmissive liquid crystal display device, a conductive material that transmits visible light is used for both the pixel electrode 111 and the first common electrode 112. Also, when the second common electrode 244 is located in the display area 68, a conductive material that transmits visible light is also used for the second common electrode 244. material is used.

[0104] As the conductive material that transmits visible light, for example, a material containing one or more selected from indium (In), zinc (Zn), and tin (Sn) may be used. Specifically, indium oxide, indium tin oxide (ITO: Indium Tin Oxide), indium zinc oxide, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium tin oxide containing silicon oxide (ITSO), zinc oxide, zinc oxide containing gallium, etc. can be mentioned. Note that a film containing graphene can also be used. The film containing graphene can be formed, for example, by reducing a film containing graphene formed in a film shape. As the conductive material that transmits visible light, for example, a material containing one or more selected from indium (In), zinc (Zn), and tin (Sn) may be used. Specifically, indium oxide, indium tin oxide (ITO: Indium Tin Oxide), indium zinc oxide, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium tin oxide containing silicon oxide (ITSO), zinc oxide, zinc oxide containing gallium, etc. can be mentioned. Note that a film containing graphene can also be used. The film containing graphene can be formed, for example, by reducing a film containing graphene formed in a film shape. As the conductive material that transmits visible light, for example, a material containing one or more selected from indium (In), zinc (Zn), and tin (Sn) may be used. Specifically, indium oxide, indium tin oxide (ITO: Indium Tin Oxide), indium zinc oxide, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium tin oxide containing silicon oxide (ITSO), zinc oxide, zinc oxide containing gallium, etc. can be mentioned. Note that a film containing graphene can also be used. The film containing graphene can be formed, for example, by reducing a film containing graphene formed in a film shape. As the conductive material that transmits visible light, for example, a material containing one or more selected from indium (In), zinc (Zn), and tin (Sn) may be used. Specifically, indium oxide, indium tin oxide (ITO: Indium Tin Oxide), indium zinc oxide, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium tin oxide containing silicon oxide (ITSO), zinc oxide, zinc oxide containing gallium, etc. can be mentioned. Note that a film containing graphene can also be used. The film containing graphene can be formed, for example, by reducing a film containing graphene formed in a film shape. As the conductive material that transmits visible light, for example, a material containing one or more selected from indium (In), zinc (Zn), and tin (Sn) may be used. Specifically, indium oxide, indium tin oxide (ITO: Indium Tin Oxide), indium zinc oxide, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium tin oxide containing silicon oxide (ITSO), zinc oxide, zinc oxide containing gallium, etc. can be mentioned. Note that a film containing graphene can also be used. The film containing graphene can be formed, for example, by reducing a film containing graphene formed in a film shape. As the conductive material that transmits visible light, for example, a material containing one or more selected from indium (In), zinc (Zn), and tin (Sn) may be used. Specifically, indium oxide, indium tin oxide (ITO: Indium Tin Oxide), indium zinc oxide, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium tin oxide containing silicon oxide (ITSO), zinc oxide, zinc oxide containing gallium, etc. can be mentioned. Note that a film containing graphene can also be used. The film containing graphene can be formed, for example, by reducing a film containing graphene formed in a film shape. As the conductive material that transmits visible light, for example, a material containing one or more selected from indium (In), zinc (Zn), and tin (Sn) may be used. Specifically, indium oxide, indium tin oxide (ITO: Indium Tin Oxide), indium zinc oxide, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium tin oxide containing silicon oxide (ITSO), zinc oxide, zinc oxide containing gallium, etc. can be mentioned. Note that a film containing graphene can also be used. The film containing graphene can be formed, for example, by reducing a film containing graphene formed in a film shape. As the conductive material that transmits visible light, for example, a material containing one or more selected from indium (In), zinc (Zn), and tin (Sn) may be used. Specifically, indium oxide, indium tin oxide (ITO: Indium Tin Oxide), indium zinc oxide, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium tin oxide containing silicon oxide (ITSO), zinc oxide, zinc oxide containing gallium, etc. can be mentioned. Note that a film containing graphene can also be used. The film containing graphene can be formed, for example, by reducing a film containing graphene formed in a film shape. can be formed.

[0105] It is preferable to use an oxide conductive layer for at least one of the pixel electrode 111 and the first common electrode 112. The oxide conductive layer contains a metal element contained in the semiconductor layer of the transistor 206. It is preferable to use an oxide conductive layer for at least one of the pixel electrode 111 and the first common electrode 112. The oxide conductive layer contains a metal element contained in the semiconductor layer of the transistor 206. It is preferable to have one or more types. For example, the pixel electrode 111 preferably contains indium, and it is more preferably an In-M-Zn oxide (where M is Al, Ti, Ga, Ge, Y, Zr, La, Ce, Nd, Sn, or Hf) film. Similarly, the first common electrode 112 preferably contains indium and is more preferably an In-M-Zn oxide film. It is preferably an In-M-Zn oxide (where M is Al, Ti, Ga, Ge, Y, Zr, La, C e, Nd, Sn, or Hf) film. At least one of the pixel electrode 111 and the first common electrode 112 may be formed using an oxide semiconductor. By using an oxide semiconductor having the same metal element in two or more layers among the layers constituting the display device, it becomes possible to commonly use manufacturing equipment (for example, film forming equipment, processing equipment, etc.) in two or more processes, so that the manufacturing cost can be suppressed.

[0106] Among the pixel electrode 111 and the first common electrode 112, at least one may be formed using an oxide semiconductor. By using an oxide semiconductor having the same metal element in two or more layers among the layers constituting the display device, it becomes possible to commonly use manufacturing equipment (for example, film forming equipment, processing equipment, etc.) in two or more processes, so that the manufacturing cost can be suppressed.

[0107] The oxide semiconductor is a semiconductor material whose resistance can be controlled by at least one of oxygen vacancies in the film and the concentration of impurities such as hydrogen and water in the film. Therefore, by selecting a process in which at least one of oxygen vacancies and impurity concentration increases in the oxide semiconductor layer, or a process in which at least one of oxygen vacancies and impurity concentration decreases, the resistivity of the oxide conductive layer can be controlled. Therefore, by selecting a process in which at least one of oxygen vacancies and impurity concentration increases in the oxide semiconductor layer, or a process in which at least one of oxygen vacancies and impurity concentration decreases, the resistivity of the oxide conductive layer can be controlled. By selecting a process in which at least one of oxygen vacancies and impurity concentration increases in the oxide semiconductor layer, or a process in which at least one of oxygen vacancies and impurity concentration decreases, the resistivity of the oxide conductive layer can be controlled.

[0108] Note that, as described above, the oxide conductive layer formed using the oxide semiconductor layer can also be referred to as an oxide semiconductor layer with a high carrier density and low resistance, an oxide semiconductor layer having conductivity, or an oxide semiconductor layer with high conductivity. Note that, as described above, the oxide conductive layer formed using the oxide semiconductor layer can also be referred to as an oxide semiconductor layer with a high carrier density and low resistance, an oxide semiconductor layer having conductivity, or an oxide semiconductor layer with high conductivity. an oxide semiconductor layer with high conductivity.

[0109] In addition, by forming the oxide semiconductor layer and the oxide conductive layer with the same metal element, the manufacturing cost ​can be reduced. For example, by using a metal oxide target with the same metal composition, the manufacturing cost can be reduced. Also, by using a metal oxide target with the same metal composition, when processing the oxide semiconductor layer, the etching gas or etching solution can be commonly used. However, even if the oxide semiconductor layer and the oxide conductive layer have the same metal element, their compositions may be different. For example, during the manufacturing process of the display device, the metal element in the film may desorb and result in a different metal composition.

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

[0111] A transistor 206 is provided in the non-display area 66.

[0112] The transistor 206 has a gate 221, a gate 223, insulating layers 211, 213, and a semiconductor layer (a channel region 231a and a pair of low-resistance regions 231b). The resistivity of the low-resistance region 231b is lower than that of the channel region 231a. In this embodiment, the case where an oxide semiconductor layer is used as the semiconductor layer will be described as an example. The oxide semiconductor layer preferably contains indium, and is more preferably an In-M-Zn oxide (M is Al, Ti, Ga, Ge, Y, Zr, La, Ce, Nd, Sn, or Hf) film. The details of the oxide semiconductor layer will be described later.

[0113] The gate 221 overlaps the channel region 231a via the insulating layer 213. The gate 223 ​​overlaps with the channel region 231a through the insulating layer 211. The insulating layer 211 and the insulating layer 213 each function as a gate insulating layer. The conductive layer 222a is one of the low-resistance regions 231b and the conductive layer 222b is the other of the low-resistance regions 231b, and they are connected through the openings provided in the insulating layer 212 and the insulating layer 214.

[0114] The transistor 206 shown in FIG. 4(A) is a transistor having gates provided above and below the channel.

[0115] In the contact portion Q1 shown in FIG. 3(C), the gate 221 and the gate 223 are electrically connected. A transistor configured such that two gates are electrically connected can increase the field-effect mobility compared to other transistors, and can increase the on-current. As a result, a circuit capable of high-speed operation can be fabricated. Furthermore, the occupied area of the circuit portion can be reduced. By applying a transistor with a large on-current, even if the display device is enlarged or refined and the number of wirings increases, it is possible to reduce the signal delay in each wiring and suppress display unevenness. Also, by applying such a configuration, a highly reliable transistor can be realized.

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

[0117] In FIGS. 3(B) and 3(C), it can be said that one conductive layer functions as the scanning line 228 and the gate 223. Among the gate 221 and the gate 223, the one with lower resistance serves as the scanning line. It is preferably a conductive layer that still functions even if...

[0118] In FIGS. 3(B) and 3(C), one conductive layer can be said to function as the signal line 229 and the conductive layer 222a. It can also be said to function.

[0119] For the gates 221 and 223, either a metal material or an oxide conductor can be used alone as a single layer, or both can be laminated and used. For example, among the gates 221 and 223, an oxide conductor can be used for one, and a metal material can be used for the other.

[0120] The transistor 206 can be configured to use an oxide semiconductor layer as the semiconductor layer and use an oxide conductive layer for at least one of the gates 221 and the gate 223. At this time, it is preferable to form the oxide semiconductor layer and the oxide conductive layer using an oxide semiconductor.

[0121] By using a conductive layer that blocks visible light for the gate 223, it is possible to suppress the light of the backlight from irradiating the channel region 2 31a. Thereby, the reliability of the transistor can be enhanced.

[0122] The transistor 206 is covered by the insulating layer 212, the insulating layer 214, the insulating layer 215, and the insulating layer 216 Note that the insulating layer 212, the insulating layer 214, and further the insulating layer 216 can also be regarded as components of the transistor 206. The transistor is preferably covered with an insulating layer that has the effect of suppressing the diffusion of impurities into the semiconductor that constitutes the transistor. The insulating layer 215 can function as a planarization layer.

[0123] The insulating layers 211 and 213 preferably each have an excess oxygen region. Gate​​​ Since the gate insulating layer has an excess oxygen region, excess oxygen can be supplied into the channel region 231a. The oxygen deficiency that can be formed in the channel region 231a can be compensated for by the excess oxygen, so that a highly reliable transistor can be provided.

[0124] The insulating layer 212 preferably contains nitrogen or hydrogen. When the insulating layer 212 is in contact with the low-resistance region 231b, nitrogen or hydrogen in the insulating layer 212 is added into the low-resistance region 231b. By adding nitrogen or hydrogen, the carrier density of the low-resistance region 231b increases. Alternatively, the insulating layer 214 contains nitrogen or hydrogen, and the insulating layer 212 is permeable to nitrogen or hydrogen, so that nitrogen or hydrogen may be added into the low-resistance region 231b.

[0125] On the substrate 61 side of the liquid crystal layer 113 of the display device 100A, a colored layer 131 and a light-shielding layer 132 are provided. The colored layer 131 is located 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 region 66 of the pixel (sub-pixel). The light-shielding layer 132 overlaps at least a part of the transistor 206.

[0126] An overcoat 121 is preferably provided between the colored layer 131 and the light-shielding layer 132 and the liquid crystal layer 113. The overcoat 121 can suppress the diffusion of impurities contained in the colored layer 131 and the light-shielding layer 132 and the like into the liquid crystal layer 113. In FIG. 4(A), a second common electrode 244 is provided between the overcoat 121 and the alignment film 133b.

[0127] The substrate 51 and the substrate 61 are bonded together by an adhesive layer 141. 1. The liquid crystal layer 113 is sealed in the region surrounded by the adhesive layer 141.

[0128] When the display device 100A functions as a transmissive liquid crystal display device, two polarizing plates are arranged so as to sandwich the display unit 6 2. In Fig. 4(A), the polarizing plate 130 on the substrate 61 side is illustrated. The light 45 from the backlight arranged outside the polarizing plate provided on the substrate 51 side enters through the polarizing plate. At this time, the alignment of the liquid crystal layer 113 can be controlled by the voltage applied between the pixel electrode 111 and the first common electrode 112, and the optical modulation of the light can be controlled. That is, the intensity of the light emitted through the polarizing plate 130 can be controlled. Also, since the incident light has light outside a specific wavelength region absorbed by the coloring layer 131, the emitted light becomes light exhibiting, for example, red, blue, or green.

[0129] In addition to the polarizing plate, for example, a circular polarizing plate can be used. As the circular polarizing plate, for example, a laminate of a linear polarizing plate and a quarter-wave retardation plate can be used. By using the circular polarizing plate, the viewing angle dependence of the display of the display device can be reduced.

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

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

[0132] In the connection part 204, the wiring 65 and the conductive layer 251 are connected to each other, and the conductive layer 251 and the connector 24 2 are connected to each other. That is, in the connection part 204, the wiring 65 is connected to the conductive layer 251 and is electrically connected to the FPC 72 via the connector 242. With such a configuration, signals and power can be supplied from the FPC 72 to the wiring 65.

[0133] The wiring 65 can be formed of the same material and in the same process as the conductive layers 222a and 222b of the transistor 206. The conductive layer 251 can be formed of the same material and in the same process as the pixel electrode 111 of the liquid crystal element 40. Thus, forming the conductive layer constituting the connection part 204 using the same material and in the same process as the conductive layers used in the display part 62 and the drive circuit part 64 is preferable because it can prevent an increase in the number of processes.

[0134] The transistors 201 and 206 may have the same structure or different structures. That is, the transistors in the drive circuit part 64 and the transistors in the display part 62 may have the same structure or different structures. Also, the drive circuit part 64 may have transistors of a plurality of structures, or the display part 62 may have transistors of a plurality of structures. For example, it is preferable to use transistors configured such that two gates are electrically connected in one or more of the shift register circuit, buffer circuit, and protection circuit in the scanning line drive circuit. Examples of pixel arrangements are shown in FIGS. 5(A) and (B). FIGS. 5(A) and (B) show an example in which one pixel is composed of a red sub-pixel R, a green sub-pixel G, and a blue sub-pixel B. FIG. 5(

[0135] ​​​​ 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, and the scanning lines 81 and the signal lines 82 intersect.

[0136] As shown in the frame of the dashed-two-dot line in FIG. 5(A), the sub-pixel has 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 scanning line 81. Of the source and drain of the transistor 206, one is electrically connected to the signal line 82, and the other is electrically connected to one electrode of the capacitor element 34 and one electrode of the liquid crystal element 40. A fixed potential is applied to the other electrode of the capacitor element 34 and the other electrode of the liquid crystal element 40, respectively.

[0137] In FIGS. 5(A) and (B), an example of applying source line inversion driving is shown. Signal A1 and signal A 2 are signals with the same polarity. Signal B1 and signal B2 are signals with the same polarity. Signal A1 and signal B1 are signals with different polarities from each other. Signal A2 and signal B2 are signals with different polarities from each other.

[0138] As the display device becomes more high-definition, the distance between sub-pixels becomes narrower. Therefore, for example, as shown in the frame of the dashed-one-dot line in FIG. 5(A), in the vicinity of the signal line 82 to which signal B1 is input in the sub-pixel to which signal A1 is input, the liquid crystal is likely to be affected by the potentials of both signal A1 and signal B1. As a result, the alignment failure of the liquid crystal is likely to occur.

[0139] In FIG. 5(A), the direction in which a plurality of sub-pixels presenting the same color are arranged is the y direction, and is substantially parallel to the direction in which the signal line 82 extends. As shown in the frame of the dashed-one-dot line in FIG. 5(A), 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. One aspect of the invention is not limited to this. The spacer 117 may be provided on the substrate 51 side or may be provided on the substrate 61 side.

[0149] In FIG. 6, an example is shown in which the alignment films 133a and 133b are not in contact at the portion overlapping with the spacer 117, but the alignment films may be in contact with each other. Further, the spacer 117 provided on one substrate may be in contact with or not in contact with a structure provided on the other substrate. For example, a liquid crystal layer 113 may be located between the spacer 117 and the structure.

[0150] Granular spacers may be used as the spacer 117. As the granular spacers, materials such as silica can be used. It is preferable to use a material having elasticity such as resin or rubber for the spacer. At this time, the granular spacer may be in a shape crushed in the vertical direction.

[0151] Next, details of materials and the like that can be used for each component of the display device according to the present embodiment will be described. Note that descriptions of components that have already been described may be omitted. Also, the following materials can be appropriately used for the display device, the touch panel, and their components described below.

[0152] ≪Substrates 51 and 61≫ There is no significant limitation on the material of the substrate included in the display device according to one aspect 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 metal substrate, or a plastic substrate can be used.

[0153] ​​​​​​​​By using a thin substrate, weight reduction and thickness reduction of the display device can be achieved. Further more, by using a substrate with a thickness that provides flexibility, a flexible display device can be realized.

[0154] A display device according to one aspect of the present invention is manufactured by forming transistors and the like on a production substrate and then transferring the transistors and the like to another substrate. By using the production substrate, it is possible to form transistors with good characteristics, form transistors with low power consumption, manufacture a display device that is difficult to break, impart heat resistance to the display device, reduce the weight of the display device, or reduce the thickness of the display device. The substrate to which the transistors are transferred is not limited to a substrate on which transistors can be formed, and paper substrates, cellophane substrates, stone substrates, wood substrates, cloth substrates (including natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane, polyester), or recycled fibers (acetate, cupra, rayon, recycled polyester)), leather substrates, or rubber substrates can be used.

[0155] ≪Transistors 201, 206≫ The transistors included in a display device according to one aspect of the present invention may have any structure, either a top-gate type or a bottom-gate type. Alternatively, gate electrodes may be provided above and below the channel. The semiconductor material used for the transistors is not particularly limited, and examples include oxide semiconductors, silicon, germanium, and the like.

[0156] The crystallinity of the semiconductor material used for the transistors is also not particularly limited, and it may be an amorphous semiconductor, a semiconductor having crystallinity (microcrystalline semiconductor, polycrystalline semiconductor, single-crystalline semiconductor, or a semiconductor having a crystalline region in part). ​​​​​​​​​​​​​Any of those having a domain) may be used. Using a semiconductor having crystallinity is preferable because deterioration of transistor characteristics can be suppressed. For example, an element of Group 14, a compound semiconductor, or an oxide semiconductor may be used for the semiconductor layer. Typically, a semiconductor containing silicon, a semiconductor containing gallium arsenide, or an oxide semiconductor containing indium can be applied to the semiconductor layer.

[0157] For example, an element of Group 14, a compound semiconductor, or an oxide semiconductor may be used for the semiconductor layer. Typically, a semiconductor containing silicon, a semiconductor containing gallium arsenide, or an oxide semiconductor containing indium can be applied to the semiconductor layer. For example, an element of Group 14, a compound semiconductor, or an oxide semiconductor may be used for the semiconductor layer. Typically, a semiconductor containing silicon, a semiconductor containing gallium arsenide, or an oxide semiconductor containing indium can be applied to the semiconductor layer.

[0158] It is preferable to apply an oxide semiconductor to the semiconductor in which the channel of the transistor is formed. In particular, it is preferable to apply an oxide semiconductor having a larger band gap than silicon. Using a semiconductor material having a wider band gap and a smaller carrier density than silicon is preferable because the current (off-current) in the off state of the transistor can be reduced. Using a semiconductor material having a wider band gap and a smaller carrier density than silicon is preferable because the current (off-current) in the off state of the transistor can be reduced. Using a semiconductor material having a wider band gap and a smaller carrier density than silicon is preferable because the current (off-current) in the off state of the transistor can be reduced.

[0159] The oxide semiconductor preferably contains at least indium (In) or zinc (Zn). More preferably, it contains an oxide represented by In-M-Zn oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, La, Ce, Nd, Sn, or Hf). The oxide semiconductor preferably contains at least indium (In) or zinc (Zn). More preferably, it contains an oxide represented by In-M-Zn oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, La, Ce, Nd, Sn, or Hf). The oxide semiconductor preferably contains at least indium (In) or zinc (Zn). More preferably, it contains an oxide represented by In-M-Zn oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, La, Ce, Nd, Sn, or Hf).

[0160] In particular, as the semiconductor layer, it is preferable to use an oxide semiconductor layer having a plurality of crystal parts, wherein the c-axis of the crystal part is oriented substantially perpendicular to the surface to be formed of the semiconductor layer or the upper surface of the semiconductor layer, and there is no grain boundary between adjacent crystal parts. In particular, as the semiconductor layer, it is preferable to use an oxide semiconductor layer having a plurality of crystal parts, wherein the c-axis of the crystal part is oriented substantially perpendicular to the surface to be formed of the semiconductor layer or the upper surface of the semiconductor layer, and there is no grain boundary between adjacent crystal parts. In particular, as the semiconductor layer, it is preferable to use an oxide semiconductor layer having a plurality of crystal parts, wherein the c-axis of the crystal part is oriented substantially perpendicular to the surface to be formed of the semiconductor layer or the upper surface of the semiconductor layer, and there is no grain boundary between adjacent crystal parts.

[0161] By using such an oxide semiconductor for the semiconductor layer, fluctuations in electrical characteristics can be suppressed, and a highly reliable transistor can be realized. By using such an oxide semiconductor for the semiconductor layer, fluctuations in electrical characteristics can be suppressed, and a highly reliable transistor can be realized.

[0162] In addition, due to the low off-current, the charge accumulated in the capacitor through the transistor can be held for a long period of time. By applying such a transistor to the pixel, it becomes possible to stop the drive circuit while maintaining the gradation of the displayed image. As a result, a display device with extremely low power consumption can be realized. The transistors 201 and 206 preferably have an oxide semiconductor layer with high purity and suppressed formation of oxygen vacancies. This can lower the off-current of the transistor. Therefore, the holding time of electrical signals such as image signals can be lengthened, and the writing interval can also be set longer in the power-on state.

[0163] Thus, the frequency of the refresh operation can be reduced, resulting in an effect of suppressing power consumption. In addition, since the transistors 201 and 206 can obtain a relatively high field-effect mobility, they can be driven at high speed. By using such a transistor capable of high-speed driving in the display device, the transistors in the display section and the transistors in the drive circuit section can be formed on the same substrate. That is, as the drive circuit, there is no need to use a semiconductor device formed separately by a silicon wafer or the like, so the number of components of the display device can be reduced. Also, by using a transistor capable of high-speed driving in the display section, a high-quality image can be provided.

[0164] <<Oxide Semiconductor Layer>> The oxide semiconductor layer contains at least indium (In), zinc (Zn), and M (a metal such as Al, Ti, Ga, Ge, Y, Zr, La, Ce, Nd, Sn, or Hf), and is an In-M-

[0165] ​​​​​​​It is preferable to include a film represented by zinc oxide. Further, together with them, in order to reduce the variation in the electrical characteristics of the transistor, it is preferable to include a stabilizer.

[0166] Examples of the stabilizer include metals described as M above, such as gallium (Ga), tin (Sn), hafnium (Hf), aluminum (Al), or zirconium (Zr). Further, examples of other stabilizers include lanthanoids such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (D y), holmium (Ho), erbium (Er), thulium (Tm), ytterbium ( Yb), lutetium (Lu).

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

[0168] Here, the In-Ga-Zn based oxide means an oxide mainly composed of In, Ga, and Zn, and the ratio of In, Ga, and Zn does not matter. Also, other metal elements may be contained in addition to In, Ga, and Zn. Here, the In-Ga-Zn based oxide means an oxide mainly composed of In, Ga, and Zn, and the ratio of In, Ga, and Zn does not matter. Also, other metal elements may be contained in addition to In, Ga, and Zn. Here, the In-Ga-Zn based oxide means an oxide mainly composed of In, Ga, and Zn, and the ratio of In, Ga, and Zn does not matter. Also, other metal elements may be contained in addition to In, Ga, and Zn.

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

[0170] The oxide semiconductor layer has an energy gap of 2 eV or more, preferably 2.5 eV or more, more preferably 3 eV or more. By using such an oxide semiconductor with a wide energy gap, the off-current of the transistor can be reduced. The oxide semiconductor layer has an energy gap of 2 eV or more, preferably 2.5 eV or more, more preferably 3 eV or more. By using such an oxide semiconductor with a wide energy gap, the off-current of the transistor can be reduced. The oxide semiconductor layer has an energy gap of 2 eV or more, preferably 2.5 eV or more, more preferably 3 eV or more. By using such an oxide semiconductor with a wide energy gap, the off-current of the transistor can be reduced.

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

[0172] When the oxide semiconductor layer is an In-M-Zn oxide (M is Al, Ti, Ga, Ge, Y, Zr, La, Ce, Nd, Sn, or Hf), the atomic ratio of the metal elements of the sputtering target used to form the In-M-Zn oxide preferably satisfies In≧M and Zn≧M. As such an atomic ratio of the metal elements of the sputtering target, In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 3:1:2, When the oxide semiconductor layer is an In-M-Zn oxide (M is Al, Ti, Ga, Ge, Y, Zr, La, Ce, Nd, Sn, or Hf), the atomic ratio of the metal elements of the sputtering target used to form the In-M-Zn oxide preferably satisfies In≧M and Zn≧M. As such an atomic ratio of the metal elements of the sputtering target, In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 3:1:2, When the oxide semiconductor layer is an In-M-Zn oxide (M is Al, Ti, Ga, Ge, Y, Zr, La, Ce, Nd, Sn, or Hf), the atomic ratio of the metal elements of the sputtering target used to form the In-M-Zn oxide preferably satisfies In≧M and Zn≧M. As such an atomic ratio of the metal elements of the sputtering target, In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 3:1:2, When the oxide semiconductor layer is an In-M-Zn oxide (M is Al, Ti, Ga, Ge, Y, Zr, La, Ce, Nd, Sn, or Hf), the atomic ratio of the metal elements of the sputtering target used to form the In-M-Zn oxide preferably satisfies In≧M and Zn≧M. As such an atomic ratio of the metal elements of the sputtering target, In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 3:1:2, When the oxide semiconductor layer is an In-M-Zn oxide (M is Al, Ti, Ga, Ge, Y, Zr, La, Ce, Nd, Sn, or Hf), the atomic ratio of the metal elements of the sputtering target used to form the In-M-Zn oxide preferably satisfies In≧M and Zn≧M. As such an atomic ratio of the metal elements of the sputtering target, 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, In:M:Zn = 1:3:6, etc. Note that for the oxide semiconductor layer to be formed, the atomic ratio includes a variation of plus or minus 40% of the atomic ratio of the metal elements contained in the above sputtering target as an error respectively.

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

[0174] Note that it is not limited to these, and those with an appropriate composition are used according to the required semiconductor characteristics and electrical characteristics (field effect mobility, threshold voltage, etc.) of the transistor.

[0175] In the oxide semiconductor layer, if silicon or carbon, which is one of the Group 14 elements, is included, the oxygen deficiency in the oxide semiconductor layer increases and it becomes n-type. Therefore, the concentrations of silicon and carbon in the oxide semiconductor layer (concentrations obtained by secondary ion mass spectrometry) are each set to 2×10 atoms / cm 18 or less, preferably 2×10 3 atoms / c 17 m or less. 3

[0176] Also, in the oxide semiconductor layer, the concentration of alkali metal or alkaline earth metal obtained by secondary ion mass spectrometry is set to 1×10 18 ​atoms / cm 3 Preferably, it is 2×1 or less hereinafter. 0 16 atoms / cm 3 It is preferably made less hereinafter. When an alkali metal and an alkaline earth metal combine with an oxide semiconductor, carriers may be generated, and the off-current of the transistor may increase. Therefore, it is preferable to reduce the concentration of the alkali metal or alkaline earth metal in the oxide semiconductor layer. When nitrogen is contained in the oxide semiconductor layer, electrons, which are carriers, are generated, the carrier density increases, and it tends to be n-type. As a result, a transistor using an oxide semiconductor containing nitrogen tends to have normally-on characteristics. Therefore, in the oxide semiconductor layer, it is preferable that nitrogen is reduced as much as possible. For example, the nitrogen concentration obtained by secondary ion mass spectrometry is preferably 5×10 or less. When nitrogen is contained in the oxide semiconductor layer, electrons, which are carriers, are generated, the carrier density increases, and it tends to be n-type. As a result, a transistor using an oxide semiconductor containing nitrogen tends to have normally-on characteristics. Therefore, in the oxide semiconductor layer, it is preferable that nitrogen is reduced as much as possible. For example, the nitrogen concentration obtained by secondary ion mass spectrometry is preferably 5×10 or less. It is preferably made less hereinafter. When an alkali metal and an alkaline earth metal combine with an oxide semiconductor, carriers may be generated, and the off-current of the transistor may increase. Therefore, it is preferable to reduce the concentration of the alkali metal or alkaline earth metal in the oxide semiconductor layer.

[0177] When nitrogen is contained in the oxide semiconductor layer, electrons, which are carriers, are generated, the carrier density increases, and it tends to be n-type. As a result, a transistor using an oxide semiconductor containing nitrogen tends to have normally-on characteristics. Therefore, in the oxide semiconductor layer, it is preferable that nitrogen is reduced as much as possible. For example, the nitrogen concentration obtained by secondary ion mass spectrometry is preferably 5×10 or less. When nitrogen is contained in the oxide semiconductor layer, electrons, which are carriers, are generated, the carrier density increases, and it tends to be n-type. As a result, a transistor using an oxide semiconductor containing nitrogen tends to have normally-on characteristics. Therefore, in the oxide semiconductor layer, it is preferable that nitrogen is reduced as much as possible. For example, the nitrogen concentration obtained by secondary ion mass spectrometry is preferably 5×10 or less. When nitrogen is contained in the oxide semiconductor layer, electrons, which are carriers, are generated, the carrier density increases, and it tends to be n-type. As a result, a transistor using an oxide semiconductor containing nitrogen tends to have normally-on characteristics. Therefore, in the oxide semiconductor layer, it is preferable that nitrogen is reduced as much as possible. For example, the nitrogen concentration obtained by secondary ion mass spectrometry is preferably 5×10 or less. When nitrogen is contained in the oxide semiconductor layer, electrons, which are carriers, are generated, the carrier density increases, and it tends to be n-type. As a result, a transistor using an oxide semiconductor containing nitrogen tends to have normally-on characteristics. Therefore, in the oxide semiconductor layer, it is preferable that nitrogen is reduced as much as possible. For example, the nitrogen concentration obtained by secondary ion mass spectrometry is preferably 5×10 or less. atoms / cm 18 atoms / cm 3 It is preferably made less hereinafter. When an alkali metal and an alkaline earth metal combine with an oxide semiconductor, carriers may be generated, and the off-current of the transistor may increase. Therefore, it is preferable to reduce the concentration of the alkali metal or alkaline earth metal in the oxide semiconductor layer.

[0178] Also, the oxide semiconductor layer may have, for example, a non-single crystal structure. The non-single crystal structure includes, for example, CAAC-OS (C Axis Aligned-Crystalline Oxide Semiconductor), polycrystalline structure, microcrystalline structure, or amorphous structure. In the non-single crystal structure, the amorphous structure has the highest density of defect levels, and CAAC-OS has the lowest density of defect levels. AC-OS(C Axis Aligned-Crystalline Oxide S emiconductor), polycrystalline structure, microcrystalline structure, or amorphous structure. In the non-single crystal structure, the amorphous structure has the highest density of defect levels, and CAAC-OS has the lowest density of defect levels. In the non-single crystal structure, the amorphous structure has the highest density of defect levels, and CAAC-OS has the lowest density of defect levels. In the non-single crystal structure, the amorphous structure has the highest density of defect levels, and CAAC-OS has the lowest density of defect levels.

[0179] The oxide semiconductor layer may have, for example, an amorphous structure. The oxide semiconductor layer with an amorphous structure has, for example, a disordered atomic arrangement and no crystal component. Or, the oxide film with an amorphous structure has, for example, a completely amorphous structure and no crystal part. The oxide semiconductor layer may have, for example, an amorphous structure. The oxide semiconductor layer with an amorphous structure has, for example, a disordered atomic arrangement and no crystal component. Or, the oxide film with an amorphous structure has, for example, a completely amorphous structure and no crystal part. The oxide semiconductor layer may have, for example, an amorphous structure. The oxide semiconductor layer with an amorphous structure has, for example, a disordered atomic arrangement and no crystal component. Or, the oxide film with an amorphous structure has, for example, a completely amorphous structure and no crystal part.

[0180] Note that the oxide semiconductor layer may be a mixed film having two or more of an amorphous structure region, a microcrystalline structure region, a polycrystalline structure region, a C AAC-OS region, and a single crystal structure region. The mixed film may be, for example, a single layer structure having any two or more regions of an amorphous structure region, a microcrystalline structure region, a polycrystalline structure region, a CAAC-O S region, and a single crystal structure region. Also, the mixed film may have, for example, a laminated structure of any two or more regions of an amorphous structure region, a microcrystalline structure region, a polycrystalline structure region, a C AAC-OS region, and a single crystal structure region in some cases.

[0181] ≪Insulating layer≫ As the insulating material that can be used for each insulating layer, overcoat, spacer, etc. of the display device organic insulating materials or inorganic insulating materials can be used. Examples of the organic insulating material include acrylic resins, epoxy resins, polyimide resins, polyamide resins, polyami doimide resins, siloxane resins, benzocyclobutene-based resins, and phenolic resins, etc. Examples of the inorganic insulating layer include silicon oxide films, silicon oxynitride films, silicon nitride oxide films, silicon nitride films, aluminum oxide films, hafnium oxide films, yttrium oxide films, zirconium oxide films, gallium oxide films, tantalum oxide films, magnesium oxide films, lanthanum oxide films, cerium oxide films, and neodymium oxide films, etc.

[0182] ≪Conductive layer≫ In addition to the gate, source, and drain of the transistor, for the conductive layers of various wirings and electrodes etc. that the display device has aluminum, titanium, chromium, nickel, copper, yttrium, zirconium Metals such as um, molybdenum, silver, tantalum, or tungsten, or alloys having these as main components can be used in a single-layer structure or a laminated structure. For example, a two-layer structure in which a titanium film is laminated on an aluminum film, a two-layer structure in which a titanium film is laminated on a tungsten film, a two-layer structure in which a copper film is laminated on a molybdenum film, a two-layer structure in which a copper film is laminated on an alloy film containing molybdenum and tungsten, a two-layer structure in which a copper film is laminated on a copper-magnesium-aluminum alloy film, a titanium film or a titanium nitride film, and an aluminum film or a copper film is laminated on the titanium film or the titanium nitride film, and further a titanium film or a titanium nitride film is formed thereon a three-layer structure, a molybdenum film or a molybdenum nitride film, and an aluminum film or a copper film is laminated on the molybdenum film or the molybdenum nitride film, and further a molybdenum film is formed thereon or a three-layer structure such as a molybdenum nitride film. For example, when the conductive layer has a three-layer structure in the first and third layers, a film made of titanium, titanium nitride, molybdenum, tungsten, an alloy containing molybdenum and tungsten, an alloy containing molybdenum and zirconium, or molybdenum nitride is formed, and in the second layer, it is preferable to form a film made of a low-resistance material such as copper, aluminum, gold or silver, or an alloy of copper and manganese. In addition, a conductive material having translucency such as ITO, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium zinc oxide, ITSO, etc. may be used. In addition, an oxide conductive layer may be formed by controlling the resistivity of the oxide semiconductor.

[0183]

[0184] <<Adhesive layer 141>> As the next layer 141, a curable resin such as a thermosetting resin, a photocurable resin, or a two-component curable resin can be used. For example, an acrylic resin, a urethane resin, an epoxy resin , or a siloxane resin can be used.

[0185] ≪Connector 242≫ As the connectors 242 and 243, for example, an anisotropic conductive film (ACF: Anisotropic Conductive Film), or an anisotropic conductive paste (ACP: Anisotropic Conductive Paste) can be used. opic Conductive Film), or an anisotropic conductive paste (ACP: A nisotropic Conductive Paste) can be used. .

[0186] ≪Coloring layer 131≫ The coloring layer 131 is a colored layer that transmits light in a specific wavelength range. Materials that can be used for the coloring layer 131 include metal materials, resin materials, and resin materials containing pigments or dyes. Examples include metal materials, resin materials, and resin materials containing pigments or dyes. are listed.

[0187] ≪Light-shielding layer 132≫ The light-shielding layer 132 is provided, for example, between adjacent coloring layers 131 of different colors. For example, a black matrix formed using a metal material or a resin material containing a pigment or a dye can be used as the light-shielding layer 132. Note that if the light-shielding layer 132 is also provided in areas other than the display unit 62, such as the drive circuit unit 64, light leakage due to guided light can be suppressed, which is preferable. It is preferable because light leakage due to guided light and the like can be suppressed. .

[0188] The thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device are each formed by sputtering method, chemical vapor deposition (CVD: Chemical Vapor Deposition) method , vacuum evaporation method, pulse laser deposition (PLD: Pulse Laser Deposit methods such as ion implantation and atomic layer deposition (ALD) It can be formed using methods such as CVD. Examples of CVD methods include plasma enhanced chemical vapor deposition (PECVD) and thermal CVD. Examples of thermal CVD methods include metal organic chemical vapor deposition (MOCVD).

[0189] The thin films (such as insulating films, semiconductor films, and conductive films) that make up the display device can be formed by methods such as spin coating, dipping, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor blade, slit coating, roll coating, curtain coating, knife coating, etc.

[0190] The thin films that make up the display device can be processed using methods such as photolithography. Alternatively, island-shaped thin films can be formed by a film-forming method using a masking mask. Or, the thin films can be processed by methods such as nanoimprinting, sandblasting, or lift-off. As for photolithography, there are methods of forming a resist mask on the thin film to be processed, processing the thin film by etching, etc., and then removing the resist mask, and methods of forming a photosensitive thin film, followed by exposure and development to process the thin film into a desired shape.

[0191] In photolithography, the light used for exposure includes, for example, i-line (wavelength 365 nm) , g-line (wavelength 436 nm), h-line (wavelength 405 nm), and light obtained by mixing these. In addition, ultraviolet light, KrF laser light, or ArF laser light, etc. can also be used. ​​​​​​​​​​This is possible. Also, exposure may be performed using immersion exposure technology. As the light used for exposure, extreme ultraviolet light (EUV: Extreme Ultra-violet) and X-rays, etc. may be mentioned. In addition to the light used for exposure, an electron beam can also be used. Using extreme ultraviolet light, X-rays or an electron beam is preferable because extremely fine processing becomes possible. Note that when exposure is performed by scanning a beam such as an electron beam, a photomask is not necessary.

[0192] For etching the thin film, a dry etching method, a wet etching method, a sandblasting method etc. can be used.

[0193] <1-3. Configuration Example 3 of Display Device> Examples of the display device are shown in FIGS. 7 to 10 respectively. FIG. 7 is a cross-sectional view of the display device 100C, FIG. 8(A) is a cross-sectional view of the display device 100D, FIG. 9(A) is a cross-sectional view of the display device 100 E, and FIG. 10 is a cross-sectional view of the display device 100F. Note that the perspective views of the display devices 100 C, the display device 100D, the display device 100E, and the display device 100F are the same as the display device 100A shown in FIG. 3(A ), so the description here is omitted.

[0194] The display device 100C shown in FIG. 7 has a different positional relationship between the pixel electrode 111 and the first common electrode 112 from the display device 100A shown above.

[0195] In the display device 100A shown in FIG. 4(A), the alignment film 133a and the first common electrode 112 are in contact . On the other hand, in the display device 100C shown in FIG. 7, the alignment film 133a and the pixel electrode 111 are in contact.

[0196] ​The display device 100D shown in FIG. 8 is different from the display device 100A shown above in the shapes of the pixel electrode 111 and the first common electrode 112.

[0197] Both the pixel electrode 111 and the first common electrode 112 may have a comb-shaped upper surface shape (also referred to as a planar shape) or an upper surface shape provided with slits.

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

[0199] Alternatively, when viewed from above, the shape may be such that the ends of the slits of one electrode are aligned with the ends of the slits of the other electrode. A cross-sectional view in this case is shown in FIG. 8(B).

[0200] Alternatively, when viewed from above, the pixel electrode 111 and the first common electrode 112 may have a portion that overlaps with each other. A cross-sectional view in this case is shown in FIG. 8(C).

[0201] Alternatively, the display unit 62 may have a portion where neither the pixel electrode 111 nor the first common electrode 112 is provided when viewed from above. A cross-sectional view in this case is shown in FIG. 8(D).

[0202] The display device 100E shown in FIG. 9(A) and the display device 100F shown in FIG. 10 are each different from the display device 100A shown above in the shape of the transistor.

[0203] In FIG. 9(A), the transistor 201 and the transistor 206 each have a 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 the semiconductor layer 231 with the insulating layer 213 interposed therebetween. The insulating layer 213 is the gate functions as an insulating layer. The conductive layer 222a and the conductive layer 222b each have a portion connected to the semiconductor layer 23 1. One of the conductive layer 222a and the conductive layer 222b functions as a source electrode and the other functions as a drain electrode. The transistor 201 and the transistor 206 are covered with the insulating layer 212 and the insulating layer 214.

[0205] In FIG. 9(A), the pixel electrode 111 is connected to the conductive layer 222b. Also, as shown in FIG. 9(B), the pixel electrode 111 may be connected to the semiconductor layer 231. At this time, it is preferable to use a material that transmits visible light, such as an oxide semiconductor, for the semiconductor layer 231. Thereby, the connection portion between the pixel electrode 111 and the transistor can be provided in the display region 68. Therefore, the aperture ratio of the sub-pixel can be increased. Also, high definition of the display device becomes possible. Note that the conductive layer 222b may be electrically connected to the semiconductor layer 231. The conductive layer 22 2b can function as an auxiliary electrode of the semiconductor layer 231. Or, the transistor may not have the conductive layer 222b.

[0206] In FIG. 10, the transistor 201 and the transistor 206 each have a gate 221, a gate 223, an insulating layer 212, an insulating layer 213, an insulating layer 214, a conductive layer 222a, a conductive layer 2 22b, and a semiconductor layer 231.

[0207] The gate 221 overlaps the semiconductor layer 231 with the insulating layer 213 in between. The gate 223 overlaps the semiconductor layer 231 with the insulating layer 212 and the insulating layer 214 in between. The insulating layer 212, the insulating layer 21 3, and the insulating layer 214 each function as a gate insulating layer. The conductive layer 222a and the conductive layer 222b function as source and drain electrodes, respectively. Layer 222b each has a portion connected to semiconductor layer 231. Conductive layer 222a and Conductive layer 222b, one functions as a source electrode and the other functions as a drain electrode . Transistors 201 and 206 are covered by insulating layer 215. Conductive layer 222b is connected to pixel electrode 111.

[0208] As described above, in the display device according to one aspect of the present invention, transistors and liquid crystal elements of various shapes can be applied.

[0209] <1-4. Configuration example 4 of display device> One aspect of the present invention can be applied to a display device (also referred to as an input / output device or a touch panel ). The configuration of each of the above-described display devices can be applied to a touch panel . In the present embodiment, an example in which a touch sensor is mounted on display device 100A will be mainly described.

[0210] There is no limitation on the detection element (also referred to as a sensor element) included in the touch panel according to one aspect of the present invention. Various sensors capable of detecting the proximity or contact of a detected object such as a finger or a stylus can be applied as the detection element.

[0211] As the sensor method, for example, various methods such as a capacitance method, a resistive film method, a surface acoustic wave method, an infrared method , an optical method, and a pressure-sensitive method can be used.

[0212] In the present embodiment, a touch panel having a capacitance-type detection element will be described as an example .

[0213] As the capacitance method, there are a surface capacitance method, a projected capacitance method, etc. Also, projection As the capacitance type, there are a self-capacitance type, a mutual-capacitance type, etc. Using the mutual-capacitance type is preferable because simultaneous multi-point detection becomes possible.

[0214] The touch panel according to one aspect of the present invention has a configuration in which a separately manufactured display device and a detection element are bonded together and various configurations can be applied, such as a configuration in which electrodes and the like constituting the detection element are provided on one or both of the substrate supporting the display element and the counter substrate.

[0215] FIGS. 11 and 12 show an example of a touch panel. FIG. 11(A) is a perspective view of a touch panel 350 A. FIG. 11(B) is a schematic perspective view of the expanded FIG. 11(A). For clarity, only representative components are shown. In FIG. 11(B), the substrates 61 and 162 are outlined by broken lines. FIG. 12 is a cross-sectional view of the touch panel 350A

[0216] The touch panel 350A has a configuration in which a separately manufactured display device and a detection element are bonded together.

[0217] The touch panel 350A has an input device 375 and a display device 370, and these are provided overlapping each other.

[0218] The input device 375 has a substrate 162, electrodes 127, electrodes 128, a plurality of wirings 137, and a plurality of wirings 138. The FPC 72b is electrically connected to each of the plurality of wirings 137 and the plurality of wirings 138. An IC 73b is provided on the FPC 72b.

[0219] The display device 370 has a substrate 51 and a substrate 61 provided opposite to each other. The display device 370 It has a display unit 62 and a drive circuit unit 64. Wiring 65 etc. are provided on the substrate 51 and exist. The FPC 72a is electrically connected to the wiring 65. An IC 73a is provided on the FPC 72a.

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

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

[0222] The substrate 51 and the substrate 61 are bonded together by an adhesive layer 141. The substrate 61 and the substrate 1 62 are bonded together by an adhesive layer 169. Here, each layer from the substrate 51 to the substrate 61 corresponds to the display device 370. Also, each layer from the substrate 162 to the electrode 124 corresponds to the input device 375. That is, it can be said that the adhesive layer 169 bonds the display device 370 and the input device 375 .

[0223] The configuration of the display device 370 shown in FIG. 12 is the same as the configuration of the display device 100A shown in FIG. 4(A) , so detailed description is omitted.

[0224] A polarizing plate 165 is bonded to the substrate 51 by an adhesive layer 167. A backlight 161 is bonded to the polarizing plate 16 5 by an adhesive layer 163.

[0225] A polarizing plate 166 is bonded to the substrate 162 by an adhesive layer 168. A protective substrate 160 is bonded to the polarizing plate 1 66 by an adhesive layer 164. To the electronic device When incorporating the touch panel 350A, the protective substrate 160 may be used as a substrate directly touched by a detected object such as a finger or a stylus. The protective substrate 160 can be applied with substrates that can be used for the substrate 51, the substrate 61, and the like. The protective substrate 160 can be applied with substrates that can be used for the substrate 51 and the substrate 61 and the like, and a configuration in which a protective layer is formed on the surface of the substrate, or strengthened glass and the like are preferably used. The protective layer can be formed by a ceramic coat. Alternatively, the protective layer can be formed using an inorganic insulating material such as silicon oxide, aluminum oxide, yttrium oxide, and yttria-stabilized zirconia (YSZ).

[0226] A polarizing plate 166 may be disposed between the input device 375 and the display device 370. In that case, it is not necessary to provide the protective substrate 160, the adhesive layer 164, and the adhesive layer 168 shown in FIG. 1 2. That is, a configuration can be adopted in which the substrate 162 is located on the outermost surface of the touch panel 350A. It is preferable to apply a material that can be used for the above-described protective substrate 160 to the substrate 1 62.

[0227] Electrodes 127 and 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 provided so as to cover the electrodes 127 and 1 28. The electrode 124 is electrically connected to two electrodes 128 provided so as to sandwich the electrode 127 through an opening provided in the insulating layer 125.

[0228] Among the conductive layers included in the input device 375, a conductive layer (electrodes 127, 12 8, etc.) overlapping the display area 68 uses a material that transmits 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 wiring is 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 electrode 621 and electrode 622, and current flows through electrode 622. An electric current is generated between these electrodes. When a detection object such as a finger or a pen approaches or contacts, part of the electric field generated between the electrodes is shielded, and the intensity of the electric field generated between the electrodes changes. As a result, the magnitude of the current flowing through electrode 622 changes.

[0235] For example, when there is no approach or contact of the detection object, the magnitude of the current flowing through wirings Y1 - Y6 becomes a value corresponding to the magnitude of capacitor 603. On the other hand, when part of the electric field is shielded due to the approach or contact of the detection object, a change in which the magnitude of the current flowing through wirings Y1 - Y6 decreases is detected. By utilizing this, the approach or contact of the detection object can be detected.

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

[0237] FIG. 13(B) shows an example of a timing chart of input / output waveforms in the mutual capacitance type touch sensor shown in FIG. 13(A). In FIG. 13(B), it is assumed that detection of each matrix is performed in one sensing period. Also in FIG. 13(B), two cases are shown side by side: when the contact or proximity of the detection object is not detected (non-touch) and when the contact or proximity of the detection object is detected (touch). Here, for wirings Y1 - Y6, waveforms of voltages corresponding to the magnitudes of the detected currents are shown.

[0238] As shown in FIG. 13(B), pulse voltages are sequentially applied to wirings X1 - X6. In response to this,​​​​​​​​​​ Accordingly, current flows through the wirings of wirings Y1 - Y6. When not touched, since similar current flows through the wirings of wirings X1 - X6, the voltage change of the wirings of wirings X1 - X6 causes similar current to flow through the wirings of wirings Y1 - Y6, so that the respective output waveforms of the wirings of wirings Y1 - Y6 become similar waveforms. On the other hand, when touched, since the current flowing through the wiring located at the position where the detected object makes contact or is in proximity among the wirings of wirings Y1 - Y6 decreases, the output waveform changes as shown in FIG. 13(B). In FIG. 13(B), an example is shown where the detected object makes contact or is in proximity to a location where wiring X3 and wiring Y3 intersect or in the vicinity thereof. As described above, in the mutual capacitance method, the position information of the detected object can be acquired by detecting the change in current caused by the shielding of the electric field generated between a pair of electrodes. When the detection sensitivity is high, even if the detected object is separated from the detection surface (for example, the surface of the touch panel), its coordinates can also be detected. In the touch panel, by using a driving method in which the display period of the display unit and the sensing period of the touch sensor are shifted, the detection sensitivity of the touch sensor can be increased. For example, during one frame period of the display, the display period and the sensing period may be separated. At this time, it is preferable to provide two or more sensing periods during one frame period. By increasing the frequency of sensing, the detection sensitivity can be further increased. (B) shows an example of the case where the detected object makes contact or is in proximity to a location where wiring X3 and wiring Y3 intersect or in the vicinity thereof.

[0239] In FIG. 13(B), an example is shown where the detected object makes contact or is in proximity to a location where wiring X3 and wiring Y3 intersect or in the vicinity thereof. As described above, in the mutual capacitance method, the position information of the detected object can be acquired by detecting the change in current caused by the shielding of the electric field generated between a pair of electrodes. When the detection sensitivity is high, even if the detected object is separated from the detection surface (for example, the surface of the touch panel), its coordinates can also be detected.

[0240] As described above, in the mutual capacitance method, the position information of the detected object can be acquired by detecting the change in current caused by the shielding of the electric field generated between a pair of electrodes. When the detection sensitivity is high, even if the detected object is separated from the detection surface (for example, the surface of the touch panel), its coordinates can also be detected. In the touch panel, by using a driving method in which the display period of the display unit and the sensing period of the touch sensor are shifted, the detection sensitivity of the touch sensor can be increased. For example, during one frame period of the display, the display period and the sensing period may be separated. At this time, it is preferable to provide two or more sensing periods during one frame period. By increasing the frequency of sensing, the detection sensitivity can be further increased. In FIG. 13(B), an example is shown where the detected object makes contact or is in proximity to a location where wiring X3 and wiring Y3 intersect or in the vicinity thereof. As described above, in the mutual capacitance method, the position information of the detected object can be acquired by detecting the change in current caused by the shielding of the electric field generated between a pair of electrodes. When the detection sensitivity is high, even if the detected object is separated from the detection surface (for example, the surface of the touch panel), its coordinates can also be detected.

[0241] In the touch panel, by using a driving method in which the display period of the display unit and the sensing period of the touch sensor are shifted, the detection sensitivity of the touch sensor can be increased. For example, during one frame period of the display, the display period and the sensing period may be separated. At this time, it is preferable to provide two or more sensing periods during one frame period. By increasing the frequency of sensing, the detection sensitivity can be further increased. The pulse voltage output circuit 601 and the current detection circuit 602 are preferably formed, for example, in one IC. The IC is preferably mounted on, for example, the touch panel or electrically... Accordingly, current flows through the wirings of wirings Y1 - Y6. When not touched, since similar current flows through the wirings of wirings X1 - X6, the voltage change of the wirings of wirings X1 - X6 causes similar current to flow through the wirings of wirings Y1 - Y6, so that the respective output waveforms of the wirings of wirings Y1 - Y6 become similar waveforms. On the other hand, when touched, since the current flowing through the wiring located at the position where the detected object makes contact or is in proximity among the wirings of wirings Y1 - Y6 decreases, the output waveform changes as shown in FIG. 13(B). In FIG. 13(B), an example is shown where the detected object makes contact or is in proximity to a location where wiring X3 and wiring Y3 intersect or in the vicinity thereof. As described above, in the mutual capacitance method, the position information of the detected object can be acquired by detecting the change in current caused by the shielding of the electric field generated between a pair of electrodes. When the detection sensitivity is high, even if the detected object is separated from the detection surface (for example, the surface of the touch panel), its coordinates can also be detected.

[0242] The pulse voltage output circuit 601 and the current detection circuit 602 are preferably formed, for example, in one IC. The IC is preferably mounted on, for example, the touch panel or electrically... The pulse voltage output circuit 601 and the current detection circuit 602 are preferably formed, for example, in one IC. The IC is preferably mounted on, for example, the touch panel or electrically... It is preferably mounted on a substrate inside the housing of the slave device. Also, a flexible touch panel In the case of using, the parasitic capacitance increases at the bent portion, and the influence of noise becomes large Therefore, it is preferable to use an IC to which a driving method that is less affected by noise is applied For example, it is preferable to use an IC to which a driving method for increasing the signal-to-noise ratio (S / N ratio) is applied is applied.

[0243] <1-5. Configuration example 5 of the display device> FIGS. 14 and 15 show an example of a touch panel. FIG. 14(A) is a perspective view of the touch panel 350 B. FIG. 14(B) is a schematic perspective view of FIG. 14(A) unfolded. Note that only representative components are shown for clarity. In FIG. 14(B), the substrate 61 is shown by a dashed line only outlining the contour. FIG. 15 is a cross-sectional view of the touch panel 350B.

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

[0245] The touch panel 350B has a configuration in which electrodes and the like constituting the detection element are provided only on the counter substrate is. Such a configuration can make the touch panel thinner or lighter than a configuration in which a separately manufactured display device and a detection element are bonded together, or can reduce the number of parts of the touch panel can be reduced. is.

[0246] In FIGS. 14(A) and (B), the input device 376 is provided on the substrate 61. Also, Wiring 137 and wiring 138 of the input device 376 are electrically connected to the FPC7 provided in the display device 379.

[0247] With such a configuration, the FPC connected to the touch panel 350B can be arranged only on one substrate side ( here, the substrate 51 side). Also, although it may be configured to attach two or more FPCs to the touch panel 350B, as shown in FIGS. 14(A) and (B), one FPC 72 is provided on the touch panel 350B, and a configuration in which signals are supplied from the FPC 72 to both the display device 379 and the input device 376 is preferable because the configuration can be further simplified. .

[0248] The IC 73 may have a function of driving the input device 376. An IC for driving the input device 376 may be further provided on the FPC 72. Alternatively, an IC for driving the input device 376 may be mounted on the substrate 51.

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

[0250] In the connection portion 63, one of the wirings 137 (or 138) is electrically connected to the conductive layer provided on the substrate 51 side via the connection body 243.

[0251] A light-shielding layer 132 is provided in contact with the substrate 61. Therefore, it is possible to suppress the conductive layer used for the touch sensor from being visually recognized by the user. The light-shielding layer 132 is covered by 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 insulating layer 125 and the insulating layer 123. Metals or alloys can be used for the electrodes 127 and 128. A colored layer 131 is provided in contact with the insulating layer 123. Note that, as shown in FIG. 16, the light-shielding layer 132b provided in contact with the substrate 61 is different from the above. from the light-shielding layer 132 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 pattern has a shape that is continuous in the vertical direction, and the diamond-shaped electrode patterns arranged in a row are each electrically connected. Part of the electrode 471 and the electrode 472 overlap with each other and cross each other. An insulator is sandwiched at this crossing portion so that the electrode 471 and the electrode 472 do not electrically short-circuit (short).

[0257] As shown in FIG. 17(C), the electrode 472 may be composed of a plurality of diamond-shaped electrodes 473 and a bridge electrode 474. The island-shaped electrodes 473 are arranged side by side in the vertical direction and two adjacent electrodes 473 are electrically connected by the bridge electrode 474. With such a configuration, the electrode 473 and the electrode 471 can be formed simultaneously by processing the same conductive film. Therefore, variations in their film thicknesses can be suppressed, and variations in the resistance values and light transmittance of each electrode depending on the location can be suppressed. Here, the electrode 472 has a configuration having the bridge electrode 474, but the electrode 471 may have such a configuration as well.

[0258] As shown in FIG. 17(D), it may be shaped such that the inside of the diamond-shaped electrode pattern of the electrode 471 and the electrode 472 shown in FIG. 17(B) is hollowed out and only the contour portion remains. At this time, when the widths of the electrode 471 and the electrode 472 are thin enough not to be visually recognized by the user, a light-shielding material such as metal or alloy may be used for the electrode 471 and the electrode 472 as described later. Also, the electrode 471 or the electrode 472 shown in FIG. 17(D) may have the above-described bridge electrode 474.

[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 It can be formed by reducing a film containing graphene oxide formed thereon. Examples of the reduction method include applying heat and the like.

[0263] Alternatively, a metal or alloy thin enough to have translucency can be used. For example, gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt , copper, palladium, or titanium and the like, or an alloy containing the metal can be used. . Alternatively, a nitride of the metal or alloy (for example, titanium nitride) may be used. Also , a laminated film obtained by laminating two or more of the conductive films containing the above-described materials may be used.

[0264] Further, for the electrodes 471 and 472, a conductive film processed to be thin enough not to be visually recognized by the user may be used. For example, by processing such a conductive film into a lattice shape (mesh shape), both high conductivity and high visibility of the display device can be obtained. At this time, the conductive film preferably has a portion with a width of 30 nm or more and 100 μm or less, more preferably 50 nm or more and 50 μm or less, still more preferably 5 0 nm or more and 20 μm or less. In particular, a conductive film having a pattern width of 10 μm or less is preferable because it is extremely difficult for the user to visually recognize.

[0265] As an example, FIGS. 18(A) to (D) show schematic diagrams obtained by magnifying the region 460 shown in FIG. 17(B).

[0266] FIG. 18(A) shows an example when a lattice-shaped conductive film 461 is used. At this time, by arranging the conductive film 461 so as not to overlap with the display element of the display device, it is preferable because light from the display element is not blocked. In that case, the direction of the lattice is the same as the arrangement of the display elements . It is preferable that the direction is [direction] and the period of the grating is an integral multiple of the period of the array of display elements.

[0267] FIG. 18(B) shows an example of a lattice-shaped conductive film 462 processed so that triangular openings are formed. With such a configuration, the resistance can be made lower than in the case shown in FIG. 18(A). It becomes possible to lower it.

[0268] Also, as shown in FIG. 18(C), a conductive film 463 having a pattern shape without periodicity may be used. With such a configuration, it is possible to suppress the occurrence of moiré when overlapping with the display portion of the display device. It can be suppressed from occurring.

[0269] Further, conductive nanowires may be used for the electrodes 471 and 472. FIG. 18(D) shows an example of the case where nanowires 464 are used. By dispersing them at an appropriate density so that adjacent nanowires 464 are in contact with each other, a two-dimensional network is formed, and it can function as a highly transparent conductive film. For example, nanowires having an average diameter of 1 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 25 nm or less can be used. As the nanowires 464, metal nanowires such as Ag nanowires, Cu nanowires, and Al nanowires, or carbon nanotubes etc. can be used. For example, in the case of Ag nanowires, a light transmittance of 89% or more and a sheet resistance value of 40 Ω / □ or more and 100 Ω / □ or less can be realized.

[0270] It can be realized.

[0270] Further, a more detailed configuration example of the electrodes 471 and 472 in FIG. 17(B) is shown in FIG. 18(E ). FIG. 18(E) shows that each of the electrodes 471 and 472 is processed in 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 plurality of auxiliary wirings 139 are each electrically 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 proximity or contact of the object to be detected can be detected by using the capacitance formed between the first common electrode 112a and the first common electrode 1 12b. That is, in the touch panel 350D, the first common electrodes 112a and 112b serve as both the common electrode of the liquid crystal element and the electrode of the detection element.

[0278] Thus, in the touch panel according to one aspect of the present invention, since the electrode constituting the liquid crystal element also serves as the electrode constituting the detection element, the manufacturing process can be simplified and the manufacturing cost can be reduced. Also 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 electrode of the detection element can be reduced. By reducing the resistance of the electrode of the detection element the time constant of the electrode of the detection element can be made smaller. The smaller the time constant of the electrode of the detection element the higher the detection sensitivity can be, and furthermore, the detection accuracy can be improved.

[0280] The time constant of the electrode of the detection element is, for example, greater than 0 seconds and 1×10 -4 seconds or less, preferably 0 seconds or more and 5×10 -5 seconds or less, more preferably greater than 0 seconds and 5×10 -6 seconds or less, more preferably greater than 0 seconds and 5×10 -7 seconds or less, more preferably greater than 0 seconds and 2× 10 -7 seconds or less. In particular, the time constant is 1×10 -6By setting it to less than one second, noise can be suppressed while achieving high detection sensitivity.

[0281] The touch panel 350D has a single FPC that supplies signals for driving pixels and signals for driving sensing elements. Therefore, it can be easily incorporated into electronic devices and the number of components can be reduced.

[0282] Examples of the operation method of the touch panel 350D and the like are shown below.

[0283] FIG. 20(A) is an equivalent circuit diagram of a part of a pixel circuit provided in the display unit 62 of the touch panel 350D.

[0284] One pixel (sub-pixel) has at least a transistor 206 and a liquid crystal element 40. Wiring 3501 is electrically connected to the gate of the transistor 206. Also, wiring 3502 is electrically connected to one of the source or drain of the transistor 206.

[0285] The pixel circuit has a plurality of wirings extending in the X direction (e.g., wiring 3510_1, wiring 3510_ 2) and a plurality of wirings extending in the Y direction (e.g., wiring 3511_1), which are provided intersecting each other, and a capacitance is formed therebetween.

[0286] Among the pixels provided in the pixel circuit, some adjacent pixels have one electrode of the liquid crystal element provided therein electrically connected to form one block. The block is an island-shaped block (e.g., block 3515_1, block 3515_2) and a line-shaped block extending in the X direction or Y direction (e.g., a block extending in the Y direction 3515_3 extending in the Y direction). ​​​​​​​​They are classified into two types in (3516). Note that in FIG. 20(A), only a part of the pixel circuit is shown However, in reality, these two types of blocks are repeatedly arranged in the X direction and the Y direction . Here, as one electrode of the liquid crystal element, for example, a common electrode can be mentioned. On the other hand, as the other electrode of the liquid crystal element, for example, a pixel electrode can be mentioned .

[0287] The wiring 3510_1 (or 3510_2) extending in the X direction is electrically connected to the island-shaped block 3515 _1 (or block 3515_2). Although not shown, the wiring 3510_1 extending in the X direction electrically connects a plurality of island-shaped blocks 3515_1 arranged discontinuously along the X direction via a line-shaped block . Also, the wiring 3511_1 extending in the Y direction is electrically connected to the line-shaped block 3516 .

[0288] FIG. 20(B) is an equivalent circuit diagram showing the connection configuration of a plurality of wirings extending in the X direction (wirings 3510_1 to 3510_6, also collectively referred to as wiring 3510) and a plurality of wirings extending in the Y direction (wirings 3511_1 to 3511_6, also collectively referred to as wiring 3511). A common potential can be input to each of the wirings 3510 extending in the X direction and each of the wirings 3511 extending in the Y direction. Also, a pulse voltage can be input to each of the wirings 3510 extending in the X direction from a pulse voltage output circuit. Also, each of the wirings 3511 extending in the Y direction can be electrically connected to a detection circuit. Note that the wiring 35 10 and the wiring 3511 can be interchanged .

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

[0290] Here, one frame period is divided into a writing period and a detection period. The writing period is the period for writing image data into pixels, and the wiring 3501 (also called a gate line or a scanning line) is sequentially selected. On the other hand, the detection period is the period for performing sensing by the detection element. The wiring 3501 (also called a gate line or a scanning line) is sequentially selected. On the other hand, the detection period is the period for performing sensing by the detection element. Here, one frame period is divided into a writing period and a detection period. The writing period is the period for writing image data into pixels, and the wiring 3501 (also called a gate line or a scanning line) is sequentially selected. On the other hand, the detection period is the period for performing sensing by the detection element. It is.

[0291] FIG. 21(A) is an equivalent circuit diagram in the writing period. In the writing period, a common potential is input to both the wiring 3510 extending in the X direction and the wiring 3511 extending in the Y direction. FIG. 21(A) is an equivalent circuit diagram in the writing period. In the writing period, a common potential is input to both the wiring 3510 extending in the X direction and the wiring 3511 extending in the Y direction. It is.

[0292] FIG. 21(B) is an equivalent circuit diagram in the detection period. In the detection period, each of the wirings 3511 extending in the Y direction is electrically connected to the detection circuit. Further, a pulse voltage is input from the pulse voltage output circuit to the wiring 3510 extending in the X direction. FIG. 21(B) is an equivalent circuit diagram in the detection period. In the detection period, each of the wirings 3511 extending in the Y direction is electrically connected to the detection circuit. Further, a pulse voltage is input from the pulse voltage output circuit to the wiring 3510 extending in the X direction. FIG. 21(B) is an equivalent circuit diagram in the detection period. In the detection period, each of the wirings 3511 extending in the Y direction is electrically connected to the detection circuit. Further, a pulse voltage is input from the pulse voltage output circuit to the wiring 3510 extending in the X direction.

[0293] FIG. 21(C) is an example of a timing chart of input / output waveforms in the detection element of the mutual capacitance method. It is.

[0294] In FIG. 21(C), it is assumed that the object to be detected in each matrix is detected in one frame period. Further, in FIG. 21(C), two cases are shown: the case where the object to be detected is not detected (non-touch) and the case where the object to be detected is detected (touch) in the detection period. In FIG. 21(C), it is assumed that the object to be detected in each matrix is detected in one frame period. Further, in FIG. 21(C), two cases are shown: the case where the object to be detected is not detected (non-touch) and the case where the object to be detected is detected (touch) in the detection period. In FIG. 21(C), it is assumed that the object to be detected in each matrix is detected in one frame period. Further, in FIG. 21(C), two cases are shown: the case where the object to be detected is not detected (non-touch) and the case where the object to be detected is detected (touch) in the detection period.

[0295] The wirings 3510_1 to 3510_6 are the wirings to which a pulse voltage is applied from the pulse voltage output circuit. When a pulse voltage is applied to the wirings 3510_1 to 3510_6, an electric field is generated between a pair of electrodes forming a capacitance, and a current flows through the capacitance. An electric current is generated between these electrodes. The wirings 3510_1 to 3510_6 are the wirings to which a pulse voltage is applied from the pulse voltage output circuit. When a pulse voltage is applied to the wirings 3510_1 to 3510_6, an electric field is generated between a pair of electrodes forming a capacitance, and a current flows through the capacitance. An electric current is generated between these electrodes. The wirings 3510_1 to 3510_6 are the wirings to which a pulse voltage is applied from the pulse voltage output circuit. When a pulse voltage is applied to the wirings 3510_1 to 3510_6, an electric field is generated between a pair of electrodes forming a capacitance, and a current flows through the capacitance. An electric current is generated between these electrodes. The capacitance value changes due to shielding or the like caused by touching with a finger or a pen, etc. That is, due to touching or the like a change occurs in the capacitance value of the capacitor. By using this fact, the proximity or contact of the object to be detected can be detected.

[0296] Wiring 3511_1 to wiring 3511_6 are connected to a detection circuit for detecting a change in current in wiring 3511_ 1 to wiring 3511_6 due to a change in the capacitance value of the capacitor. In wiring 3511_ 1 to wiring 3511_6, when there is no proximity or contact of the object to be detected, there is no change in the detected current value, but when the capacitance value decreases due to the proximity or contact of the object to be detected, the current value decreases. Note that the detection of current may be performed by detecting the total amount of current. In that case, detection may be performed using an integration 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 value may be detected.

[0297] In FIG. 21(C), for wiring 3511_1 to wiring 3511_6, waveforms corresponding to the detected current values are shown. Note that, as in FIG. 21(C), it is desirable that the timing of the display operation and the timing of the detection operation be synchronized.

[0298] According to the pulse voltages applied to wiring 3510_1 to wiring 3510_6, the waveforms in wiring 35 11_1 to wiring 3511_6 change. When there is no proximity or contact of the object to be detected, the waveforms in wiring 3511_1 to wiring 3511_6 change uniformly in response to the change in the voltage of wiring 3510_1 to wiring 3510_6. On the other hand, at the location where the object to be detected is in proximity or contact, since the current value decreases, the waveforms of the voltage values corresponding thereto also change. ​​​

[0299] In this way, by detecting a change in the capacitance value, it is possible to detect the proximity or contact of the object to be detected. Note that for an object to be detected such as a finger or a pen, even when it does not touch the touch panel but is in the vicinity, a signal may be detected.

[0300] Note that in FIG. 21(C), an example is shown in which the common potential applied during the writing period and the low potential applied during the detection period are equal in the wiring 3510. However, one aspect of the present invention is not limited to this, and the common potential and the low potential may be different potentials.

[0301] Also, the pulse voltage output circuit and the detection circuit are preferably formed, for example, in one IC. The IC is preferably mounted on, for example, a touch panel or a substrate inside the housing of an electronic device. When a flexible touch panel is used, the parasitic capacitance increases at the bent portion, and there is a risk that the influence of noise becomes large. Therefore, it is preferable to use an IC to which a driving method that is less affected by noise is applied. For example, it is preferable to use an IC to which a driving method for increasing the signal-to-noise ratio (S / N ratio) is applied.

[0302] In this way, it is preferable to separately provide the writing period of the image and the period for sensing by the sensing element. Thereby, it is possible to suppress a decrease in the sensitivity of the sensing element due to noise during pixel writing.

[0303] In one aspect of the present invention, as shown in FIG. 21(D), there is one writing period and one detection period in one frame period. Alternatively, as shown in FIG. 21(E), there is one detection period in one frame period. ​​​​​​​​​​​​It may have two periods. By providing a plurality of detection periods in one frame period, the detection sensitivity can be further enhanced. For example, it may have two or more and four or less detection periods in one frame period .

[0304] Next, an example of the upper surface configuration of the detection element included in the touch panel 350D will be described with reference to FIG. 22.

[0305] FIG. 22(A) shows a top view of the detection element. The detection element has a conductive layer 56a and a conductive layer 56b. The conductive layer 56a functions as one electrode of the detection element, and the conductive layer 56b functions as the other electrode of the detection element. The detection element can detect the proximity or contact of the object to be detected by utilizing the capacitance formed between the conductive layer 56a and the conductive layer 56b. Note that the conductive layer 56a and the conductive layer 56b may have a comb-shaped upper surface shape or an upper surface shape provided with slits, but these are omitted here.

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

[0307] The plurality of conductive layers 56a arranged in the Y direction each extend in the X direction. Also, the plurality of conductive layers 56b arranged in the Y direction are electrically connected by a conductive layer 58 extending in the Y direction. FIG. 22(A) shows an example having m conductive layers 56a and n conductive layers 58.

[0308] Note that the conductive layer 56a may be arranged in a plurality in the X direction, and in that case, it may extend in the Y direction. Also, by a conductive layer 58 extending in the X direction, the X side A plurality of conductive layers 56b arranged in a direction may be electrically connected.

[0309] As shown in FIG. 22(B), the conductive layer 56 that functions as an electrode of the detection element is provided over a plurality of pixels 6 0. The conductive layer 56 corresponds to each of the conductive layers 56a and 56b in FIG. 22(A). Each pixel 60 is composed of a plurality of sub-pixels that exhibit different colors. In FIG. 22( B), an example in which the pixel 60 is constituted by three sub-pixels 60a, 60b, and 60c is shown.

[0310] Also, it is preferable that each of the pair of electrodes of the detection element is electrically connected to an auxiliary wiring. As shown in FIG. 22(C), the conductive layer 56 may be electrically connected to the auxiliary wiring 57. Note that FIG. 22(C) shows an example in which the auxiliary wiring is provided overlapping the conductive layer, but the conductive layer may be provided overlapping the auxiliary wiring. A plurality of conductive layers 56 arranged in the X direction may be electrically connected to the conductive layer 58 via the auxiliary wiring 57.

[0311] The resistance value of the conductive layer that transmits visible light may be relatively high. Therefore, by connecting it electrically to the auxiliary wiring, it is preferable to reduce the resistance of each of the pair of electrodes of the detection element.

[0312] By reducing the resistance of each of the pair of electrodes of the detection element, the time constant of each of the pair of electrodes can be made smaller. Thereby, the detection sensitivity of the detection element can be improved, and further, the detection accuracy of the detection element can be improved.

[0313] <1-8. Touch Panel Module> Next, a touch panel module having the input / output device and the IC according to one aspect of the present invention will be described.​​​​​​​​​ This will be described with reference to FIGS. 23 and 24.

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

[0315] The touch panel 6510 includes a display unit 6511, an input unit 6512, and a scanning line driving circuit 651 3. The display unit 6511 includes a plurality of pixels, a plurality of signal lines, and a plurality of scanning lines, and has a function of displaying an image. The input unit 6512 includes a plurality of detection elements that detect contact or proximity of a detected object to the touch panel 6510, and has a function as a touch sensor. The scanning line driving circuit 6513 has a function of outputting a scanning signal to the scanning lines included in the display unit 6511.

[0316] Here, for ease of explanation, the configuration of the touch panel 6510 is explicitly separated into the display unit 6511 and the input unit 6512. However, it is preferable to use a so-called in-cell type touch panel that has both functions of displaying an image and a touch sensor.

[0317] The display unit 6511 preferably has a very high resolution such as HD (number of pixels: 1280 × 720), FHD (number of pixels: 1920 × 108 0), WQHD (number of pixels: 2560 × 1440), WQXGA (number of pixels: 2560 × 1600 ), 4K (number of pixels: 3840 × 2160), 8K (number of pixels: 7680 × 4320). In particular, it is preferable to have a resolution of 4K, 8K, or higher. The pixel density (resolution) of the pixels provided in the display unit 6511 is 300 Preferably above ppi, more preferably above 500 ppi, even more preferably above 800 ppi, even more preferably above 1000 ppi, and still more preferably above 1200 ppi. With such a display unit 6511 having a high resolution and high definition, it is possible to enhance the sense of presence and depth in any personal use, such as portable or household applications. .

[0318] IC6520 includes a circuit unit 6501, a signal line driving circuit 6502, a sensor driving circuit 65 03, and a detection circuit 6504. The circuit unit 6501 includes a timing controller 6505 and an image processing circuit 6506, etc.

[0319] The signal line driving circuit 6502 has a function of outputting a video signal, which is an analog signal (also referred to as a video signal), to the signal lines of the display unit 6511. As the signal line driving circuit 6502, for example, a configuration combining a shift register circuit and a buffer circuit can be adopted. Also, the touch panel 6510 may have a demultiplexer circuit connected to the signal lines.

[0320] The sensor driving circuit 6503 has a function of outputting a signal for driving the detection elements of the input unit 6512. As the sensor driving circuit 6503, for example, a configuration combining a shift register circuit and a buffer circuit can be used.

[0321] The detection circuit 6504 has a function of outputting the output signal from the detection elements of the input unit 6512 to the circuit unit 6501. For example, as the detection circuit 6504, an amplifier circuit and an analog-to-digital conversion circuit (ADC: The configured components can be used. At this time, the detection circuit 6504 converts the analog signal input from the input unit 6512 into a digital signal and outputs it to the circuit unit 6501. The analog signal input from the input unit 6512 is converted into a digital signal and output to the circuit unit 6501.

[0322] The image processing circuit 6506 included in the circuit unit 6501 has functions of generating and outputting a signal for driving the display unit 6511 of the touch panel 6510, generating and outputting a signal for driving the input unit 6512, and analyzing the signal output from the input unit 6512 and outputting it to the CPU 6540. The image processing circuit 6506 included in the circuit unit 6501 has functions of generating and outputting a signal for driving the display unit 6511 of the touch panel 6510, generating and outputting a signal for driving the input unit 6512, and analyzing the signal output from the input unit 6512 and outputting it to the CPU 6540. The image processing circuit 6506 included in the circuit unit 6501 has functions of generating and outputting a signal for driving the display unit 6511 of the touch panel 6510, generating and outputting a signal for driving the input unit 6512, and analyzing the signal output from the input unit 6512 and outputting it to the CPU 6540. The image processing circuit 6506 included in the circuit unit 6501 has functions of generating and outputting a signal for driving the display unit 6511 of the touch panel 6510, generating and outputting a signal for driving the input unit 6512, and analyzing the signal output from the input unit 6512 and outputting it to the CPU 6540.

[0323] As a more specific example, the image processing circuit 6506 has a function of generating a video signal according to an instruction from the CPU 6540. The image processing circuit 6506 also has a function of performing signal processing on the video signal according to the format of the display unit 6511, converting it into an analog video signal, and supplying it to the signal line driving circuit 6502. The image processing circuit 6506 also has a function of performing signal processing on the video signal according to the format of the display unit 6511, converting it into an analog video signal, and supplying it to the signal line driving circuit 6502. The image processing circuit 6506 also has a function of generating a driving signal to be output to the sensor driving circuit 6503 according to an instruction from the CPU 6540. The image processing circuit 6506 also has a function of generating a driving signal to be output to the sensor driving circuit 6503 according to an instruction from the CPU 6540. The image processing circuit 6506 also has a function of analyzing the signal input from the detection circuit 6504, combining it with position information, and outputting it to the CPU 6540. The image processing circuit 6506 also has a function of analyzing the signal input from the detection circuit 6504, combining it with position information, and outputting it to the CPU 6540.

[0324] Based on the synchronization signal included in the video signal processed by the image processing circuit 6506, the timing controller 6505 generates signals such as a clock signal and a start pulse signal and outputs them to the scan line driving circuit 6513 and the sensor driving circuit 6503. Based on the synchronization signal included in the video signal processed by the image processing circuit 6506, the timing controller 6505 generates signals such as a clock signal and a start pulse signal and outputs them to the scan line driving circuit 6513 and the sensor driving circuit 6503. Based on the synchronization signal included in the video signal processed by the image processing circuit 6506, the timing controller 6505 generates signals such as a clock signal and a start pulse signal and outputs them to the scan line driving circuit 6513 and the sensor driving circuit 6503. The timing controller 6505 may also have a function of generating and outputting a signal for defining the timing at which the detection circuit 6504 outputs a signal. Here, the timing controller 6505... 05 preferably outputs signals synchronized with the signals output to the scanning line driving circuit 6513 and the signals output to the sensor driving circuit 6503, respectively. In particular, it is preferable to divide the period for rewriting the pixel data of the display unit 6511 and the period for sensing in the input unit 6512, respectively. For example, the touch panel 6510 can be driven by dividing one frame period into a period for rewriting the pixel data and a period for sensing. Also, for example, by providing two or more sensing periods within one frame period, the detection sensitivity and detection accuracy can be increased. The image processing circuit 6506 can be configured to have a processor, for example. For example, a microprocessor such as a DSP (Digital Signal Processor) or a GPU (Graphics Processing Unit) can be used. These microprocessors can also be configured to be realized by a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array) or an FPAA (Field Programmable Analog Array). The processor interprets and executes instructions from various programs to perform various data processing and program controls. The programs that can be executed by the processor may be stored in the memory area of the processor or in a separately provided storage device. Note that the display unit 6511 or the scanning line driving circuit 6513 included in the touch panel 6510

[0325]

[0326] The circuit unit 6501, signal line drive circuit 6502, sensor drive circuit 6503, or detection circuit 6504, or the CPU 6540 provided externally, etc., In the channel formation region, a transistor using an oxide semiconductor and having an extremely low off-current can also be used. Since the off-current of the transistor is extremely low, by using the transistor as a switch for holding the charge (data) flowing into the capacitive element functioning as a memory element, the data retention period can be ensured over a long period. For example, by using this characteristic in at least one of the registers and cache memories of the image processing circuit 6506, the image processing circuit 6506 is operated only when necessary, and in other cases, the information of the previous process is saved in the memory element, so that normal-off computing becomes possible, and the low power consumption of the touch panel module 6500 and the electronic device on which it is mounted can be achieved. Note that here, the circuit unit 6501 has the configuration including the timing controller 6505 and the image processing circuit 6506. However, the image processing circuit 6506 itself, or a circuit having some functions of the image processing circuit 6506 may be provided externally. Or, the functions of the image processing circuit 6506, or some functions may be borne by the CPU 6540. For example, the circuit unit 6501 may have the configuration including the signal line drive circuit 6502, sensor drive circuit 6503, detection circuit 6504, and timing controller 6505. Note that here, an example in which the IC 6520 includes the circuit unit 6501 is shown. However, the circuit unit Note that here, an example in which the IC 6520 includes the circuit unit 6501 is shown, but the circuit unit 6506. By using this characteristic in at least one of the registers and cache memories of the image processing circuit 6506, the image processing circuit 6506 is operated only when necessary, and in other cases, the information of the previous process is saved in the memory element, so that normal-off computing becomes possible, and the low power consumption of the touch panel module 6500 and the electronic device on which it is mounted can be achieved.

[0327] Here, the circuit unit 6501 has the configuration including the timing controller 6505 and the image processing circuit 6506. However, the image processing circuit 6506 itself, or a circuit having some functions of the image processing circuit 6506 may be provided externally. Or, the functions of the image processing circuit 6506, or some functions may be borne by the CPU 6540. For example, the circuit unit 6501 may have the configuration including the signal line drive circuit 6502, sensor drive circuit 6503, detection circuit 6504, and timing controller 6505. Here, the circuit unit 6501 has the configuration including the timing controller 6505 and the image processing circuit 6506. However, the image processing circuit 6506 itself, or a circuit having some functions of the image processing circuit 6506 may be provided externally. Or, the functions of the image processing circuit 6506, or some functions may be borne by the CPU 6540. For example, the circuit unit 6501 may have the configuration including the signal line drive circuit 6502, sensor drive circuit 6503, detection circuit 6504, and timing controller 6505.

[0328] Note that here, an example in which the IC 6520 includes the circuit unit 6501 is shown. However, the circuit unit 6501 can also be configured not to be included in IC6520. At this time, IC6520 may have a configuration including a signal line drive circuit 6502, a sensor drive circuit 6503, and a detection circuit 6504 For example, when multiple ICs are mounted on the touch panel module 6500 the circuit unit 6501 can be provided outside the touch panel module 6500, and multiple IC6520s without the circuit unit 6501 can be arranged. Or, IC6520 and an IC having only the signal line drive circuit 6502 can be arranged in combination.

[0329] In this way, by integrating the function of driving the display unit 6511 of the touch panel 6510 and the function of driving the input unit 6512 into one IC, the number of ICs mounted on the touch panel module 6500 can be reduced, thus reducing the cost.

[0330] Figs. 24(A), (B), and (C) are schematic diagrams of the touch panel module 6500 on which IC6520 is mounted.

[0331] In Fig. 24(A), the touch panel module 6500 includes a substrate 6531, a counter substrate 6532, a plurality of FPCs 6533, IC6520, IC6530, etc. Also, the touch panel module 6500 has a display unit 6511, an input unit 6512, and a scanning line drive circuit 6513. IC6520 and IC6530 are mounted on the substrate 6531 by a mounting method such as the COG method. IC6530 is an IC that has only the signal line drive circuit 6502 or both the signal line drive circuit 6502 and the circuit unit 6501 in the above-described IC6520. IC6520 and

[0332] ​ The signal is supplied to IC6530 from the outside via FPC6533. Also, a signal can be output to the outside from at least one of IC6520 and IC6530 via FPC6533.

[0333] In FIG. 24(A), an example of a configuration in which two scanning line driving circuits 6513 are provided so as to sandwich the display unit 6511 is shown. Also, a configuration having IC6530 in addition to IC6520 is shown. Such a configuration can be preferably used when the display unit 6511 has an extremely high resolution.

[0334] FIG. 24(B) shows an example in which one IC6520 and one FPC6533 are mounted. In this way, by integrating the functions into one IC6520, the number of components can be reduced, which is preferable. In FIG. 24(B), an example in which the scanning line driving circuit 6513 is arranged along the side closer to FPC6533 among the two short sides of the display unit 6511 is shown.

[0335] FIG. 24(C) shows an example of a configuration having a PCB (Printed Circuit Board) 6534 on which an image processing circuit 6506 or the like is mounted. The IC6520 and IC6530 on the substrate 6531 and the PCB6534 are electrically connected by FPC6533. Here, a configuration in which the above-described image processing circuit 6506 is not provided in IC6520 can be applied.

[0336] In each of the diagrams in FIG. 24, IC6520 and IC6530 may be mounted on FPC6533 without being on the substrate 6531. For example, IC6520 and IC6530 may be C ​​​​​​​​​​​​It can be implemented on the FPC6533 by an implementation method such as the OF method or the TAB method 。

[0337] As shown in FIGS. 24(A) and (B), a configuration in which the FPC6533 and the IC 6520 (and IC6530) etc. are arranged on the short side of the display unit 6511 enables a narrow bezel, so for example, it can be suitably used for electronic devices such as smartphones, mobile phones, or tablet terminals. Also, a configuration using the PCB6534 as shown in FIG. 24(C) can be suitably used for, for example, television devices, monitor devices, tablet terminals, or notebook personal computers etc. suitably.

[0338] As described above, the display device according to one aspect of the present invention has a second common electrode on a counter substrate different from the substrate provided with the pixel electrode and the first common electrode. By applying the same potential to the second common electrode as the first common electrode, light leakage can be suppressed and the display quality of the display device can be improved. Also, it becomes possible to increase the aperture ratio and the definition of the display device. Further, by providing the second common electrode in a part of the display area of the pixel, it is possible to suppress the increase in the driving voltage of the liquid crystal element even when the second common electrode is provided.

[0339] This embodiment can be appropriately combined with other embodiments.

[0340] (Embodiment 2) In this embodiment, the transistor that can be used for the display device according to one aspect of the present invention will be described with reference to FIGS. 25 to 35.

[0341] The display device according to one aspect of the present invention includes a bottom gate type transistor and a top gate type transistor It can be manufactured using various forms of transistors such as diodes. Therefore, according to the existing manufacturing line, it is possible to easily replace the material of the semiconductor layer and the structure of the transistor used.

[0342] 〔Bottom Gate Transistor〕 FIG. 25(A1) is a cross-sectional view of a channel protection type transistor 410, which is a type of bottom gate transistor. The transistor 410 has an electrode 546 on a substrate 571 via an insulating layer 572. Also, a semiconductor layer 542 is provided 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 insulating layer.

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

[0344] The insulating layer 522 can function as a channel protection layer. By providing the insulating layer 522 on the channel formation region, it is possible to prevent the exposure of the semiconductor layer 542 that occurs during the formation of the electrodes 544a and 544b. Therefore, it is possible to prevent the channel formation region of the semiconductor layer 542 from being etched during the formation of the electrodes 544a and 544b. According to one aspect of the present invention, a transistor with good electrical characteristics can be realized.

[0345] Also, the transistor 410 has an insulating layer 528 on the electrode 544a, the electrode 544b, and the insulating layer 522, and an insulating layer 529 on the insulating layer 528. ​

[0346] When an oxide semiconductor is used for the semiconductor layer 542, at least a portion of the electrodes 544a and 544b that is in contact with the semiconductor layer 542 preferably uses a material that can extract oxygen from a part of the semiconductor layer 542 to cause oxygen deficiency. When an oxide semiconductor is used for the semiconductor layer 542, at least a portion of the electrodes 544a and 544b that is in contact with the semiconductor layer 542 preferably uses a material that can extract oxygen from a part of the semiconductor layer 542 to cause oxygen deficiency. When an oxide semiconductor is used for the semiconductor layer 542, at least a portion of the electrodes 544a and 544b that is in contact with the semiconductor layer 542 preferably uses a material that can extract oxygen from a part of the semiconductor layer 542 to cause oxygen deficiency. The region where oxygen deficiency occurs in the semiconductor layer 542 has an increased carrier concentration, and the region becomes n-type, becoming an n-type region (n-layer). + The region where oxygen deficiency occurs in the semiconductor layer 542 has an increased carrier concentration, and the region becomes n-type, becoming an n-type region (n-layer). Therefore, the region can function as a source region or a drain region. Examples of materials that can extract oxygen from an oxide semiconductor to cause oxygen deficiency include tungsten and titanium. Examples of materials that can extract oxygen from an oxide semiconductor to cause oxygen deficiency include tungsten and titanium.

[0347] When source regions and drain regions are formed in the semiconductor layer 542, the contact resistance between the electrodes 544a and 544b and the semiconductor layer 542 can be reduced. Thus, the electrical characteristics of the transistor, such as the field-effect mobility and the threshold voltage, can be made good. When source regions and drain regions are formed in the semiconductor layer 542, the contact resistance between the electrodes 544a and 544b and the semiconductor layer 542 can be reduced. Thus, the electrical characteristics of the transistor, such as the field-effect mobility and the threshold voltage, can be made good. When source regions and drain regions are formed in the semiconductor layer 542, the contact resistance between the electrodes 544a and 544b and the semiconductor layer 542 can be reduced. Thus, the electrical characteristics of the transistor, such as the field-effect mobility and the threshold voltage, can be made good. When source regions and drain regions are formed in the semiconductor layer 542, the contact resistance between the electrodes 544a and 544b and the semiconductor layer 542 can be reduced. Thus, the electrical characteristics of the transistor, such as the field-effect mobility and the threshold voltage, can be made good.

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

[0349] The insulating layers 528 and 529 are preferably formed using a material having a function of preventing or reducing the diffusion of impurities from the outside into the transistor. Note that the insulating layer 529 can be omitted as necessary. The insulating layers 528 and 529 are preferably formed using a material having a function of preventing or reducing the diffusion of impurities from the outside into the transistor. Note that the insulating layer 529 can be omitted as necessary. The insulating layers 528 and 529 are preferably formed using a material having a function of preventing or reducing the diffusion of impurities from the outside into the transistor. Note that the insulating layer 529 can be omitted as necessary.

[0350] When an oxide semiconductor is used for the semiconductor layer 542, heat treatment may be performed one or more times before the formation of the insulating layer 528, after the formation of the insulating layer 52 8, and after the formation of the insulating layer 529. By performing the heat treatment, oxygen contained in the insulating layer 528, the insulating layer 529, and other insulating layers can be diffused into the semiconductor layer 542 to compensate for oxygen vacancies in the semiconductor layer 542. Also it is possible to compensate for oxygen vacancies in the semiconductor layer 542 by forming the insulating layer 528 and / or the insulating layer 529 while heating.

[0351] The transistor 411 shown in FIG. 25(A2) is different from the transistor 410 in that it has an electrode 523 that can function as a back gate on the insulating layer 529. The electrode 523 can be formed by the same material and method as the electrode 546.

[0352] <Regarding the back gate> Generally, the back gate is formed of a conductive layer. The gate and the back gate are arranged so as to sandwich the channel formation region of the semiconductor layer between the two. The back gate can function in the same manner as the gate. The potential of the back gate may be the same as the potential of the gate electrode, or may be the GND potential or any arbitrary potential. Also, by changing the potential of the back gate independently without linking it to the gate, the threshold voltage of the transistor can be changed.

[0353] Both the electrode 546 and the electrode 523 can function as gates. Therefore, the insulating layer 526, the insulating layer 528, and the insulating layer 529 can each function as a gate insulating layer. Note that the electrode 523 may be provided between the insulating layer 528 and the insulating layer 529. ​

[0354] In addition, when one of the electrodes 546 or 523 is referred to as "gate" or "gate electrode", the other is referred to as "back gate" or "back gate electrode". For example, in the transistor 411, when the electrode 523 is referred to as the "gate electrode", the electrode 546 is referred to as the "back gate electrode". When the electrode 523 is used as the "gate electrode", the transistor 411 can be considered as a kind of top-gate transistor. Also, either one of the electrodes 546 and 523 may be referred to as "first gate" or "first gate electrode", and the other may be referred to as "second gate" or "second gate electrode". By providing the electrodes 546 and 523 with the semiconductor layer 542 interposed therebetween, and further by setting the electrodes 546 and 523 to the same potential, the region where carriers flow in the semiconductor layer 542 becomes larger in the film thickness direction, so that the amount of carrier movement increases. As a result, the on-current of the transistor 411 increases and the field-effect mobility becomes higher. Therefore, the transistor 411 is a transistor having a large on-current with respect to the occupied area. That is, the occupied area of the transistor 411 can be reduced with respect to the required on-current. According to one aspect of the present invention, the occupied area of the transistor can be reduced. Thus, it is possible to achieve a higher aperture ratio or higher definition of the display device. In addition, since the gate and the back gate are formed of a conductive layer, electricity generated outside the transistor

[0355]

[0356]

[0357] ​​​​​​​​​​​​​The boundary has a function of preventing the world from acting on the semiconductor layer where the channel is formed (especially an electric field shielding function against static electricity, etc.). Note that by forming the back gate larger than the semiconductor layer and covering the semiconductor layer with the back gate, the electric field shielding function can be enhanced. In addition, since the electrode 546 (gate) and the electrode 523 (back gate) each have a function of shielding an external electric field, charges such as charged particles generated on the insulating layer 572 side or above the electrode 523 do not affect the channel formation region of the semiconductor layer 542. As a result, deterioration due to a stress test (for example, a -GBT (Gate Bias - Temperature) stress test in which a negative charge is applied to the gate) is suppressed. Also, it is possible to reduce the phenomenon in which the gate voltage (turn - on voltage) at which the on - current starts to flow changes depending on the magnitude of the drain voltage. Note that this effect occurs when the electrode 546 and the electrode 523 are at the same potential or different potentials. Note that the GBT stress test is a type of acceleration test and can evaluate the characteristic changes (aging changes) of transistors that occur due to long - term use in a short time. In particular, the amount of variation in the threshold voltage of the transistor before and after the GBT stress test is an important indicator for examining reliability. It can be said that the smaller the amount of variation in the threshold voltage, the higher the reliability of the transistor.

[0358] Also, by having the electrode 546 and the electrode 523 and setting the electrode 546 and the electrode 523 to the same potential, the amount of variation in the threshold voltage is reduced. For this reason, the variation in the electrical characteristics among a plurality of transistors is also reduced at the same time. Moreover, since the electrode 546 (gate) and the electrode 523 (back gate) each have a function of shielding an external electric field, charges such as charged particles generated on the insulating layer 572 side or above the electrode 523 do not affect the channel formation region of the semiconductor layer 542. As a result, deterioration due to a stress test (for example, a -GBT (Gate Bias - Temperature) stress test in which a negative charge is applied to the gate) is suppressed. Also, it is possible to reduce the phenomenon in which the gate voltage (turn - on voltage) at which the on - current starts to flow changes depending on the magnitude of the drain voltage. Note that this effect occurs when the electrode 546 and the electrode 523 are at the same potential or different potentials. Moreover, since the electrode 546 (gate) and the electrode 523 (back gate) each have a function of shielding an external electric field, charges such as charged particles generated on the insulating layer 572 side or above the electrode 523 do not affect the channel formation region of the semiconductor layer 542. As a result, deterioration due to a stress test (for example, a -GBT (Gate Bias - Temperature) stress test in which a negative charge is applied to the gate) is suppressed. Also, it is possible to reduce the phenomenon in which the gate voltage (turn - on voltage) at which the on - current starts to flow changes depending on the magnitude of the drain voltage. Note that this effect occurs when the electrode 546 and the electrode 523 are at the same potential or different potentials. Moreover, since the electrode 546 (gate) and the electrode 523 (back gate) each have a function of shielding an external electric field, charges such as charged particles generated on the insulating layer 572 side or above the electrode 523 do not affect the channel formation region of the semiconductor layer 542. As a result, deterioration due to a stress test (for example, a -GBT (Gate Bias - Temperature) stress test in which a negative charge is applied to the gate) is suppressed. Also, it is possible to reduce the phenomenon in which the gate voltage (turn - on voltage) at which the on - current starts to flow changes depending on the magnitude of the drain voltage. Note that this effect occurs when the electrode 546 and the electrode 523 are at the same potential or different potentials. Moreover, since the electrode 546 (gate) and the electrode 523 (back gate) each have a function of shielding an external electric field, charges such as charged particles generated on the insulating layer 572 side or above the electrode 523 do not affect the channel formation region of the semiconductor layer 542. As a result, deterioration due to a stress test (for example, a -GBT (Gate Bias - Temperature) stress test in which a negative charge is applied to the gate) is suppressed. Also, it is possible to reduce the phenomenon in which the gate voltage (turn - on voltage) at which the on - current starts to flow changes depending on the magnitude of the drain voltage. Note that this effect occurs when the electrode 546 and the electrode 523 are at the same potential or different potentials. Moreover, since the electrode 546 (gate) and the electrode 523 (back gate) each have a function of shielding an external electric field, charges such as charged particles generated on the insulating layer 572 side or above the electrode 523 do not affect the channel formation region of the semiconductor layer 542. As a result, deterioration due to a stress test (for example, a -GBT (Gate Bias - Temperature) stress test in which a negative charge is applied to the gate) is suppressed. Also, it is possible to reduce the phenomenon in which the gate voltage (turn - on voltage) at which the on - current starts to flow changes depending on the magnitude of the drain voltage. Note that this effect occurs when the electrode 546 and the electrode 523 are at the same potential or different potentials. Moreover, since the electrode 546 (gate) and the electrode 523 (back gate) each have a function of shielding an external electric field, charges such as charged particles generated on the insulating layer 572 side or above the electrode 523 do not affect the channel formation region of the semiconductor layer 542. As a result, deterioration due to a stress test (for example, a -GBT (Gate Bias - Temperature) stress test in which a negative charge is applied to the gate) is suppressed. Also, it is possible to reduce the phenomenon in which the gate voltage (turn - on voltage) at which the on - current starts to flow changes depending on the magnitude of the drain voltage. Note that this effect occurs when the electrode 546 and the electrode 523 are at the same potential or different potentials. Moreover, since the electrode 546 (gate) and the electrode 523 (back gate) each have a function of shielding an external electric field, charges such as charged particles generated on the insulating layer 572 side or above the electrode 523 do not affect the channel formation region of the semiconductor layer 542. As a result, deterioration due to a stress test (for example, a -GBT (Gate Bias - Temperature) stress test in which a negative charge is applied to the gate) is suppressed. Also, it is possible to reduce the phenomenon in which the gate voltage (turn - on voltage) at which the on - current starts to flow changes depending on the magnitude of the drain voltage. Note that this effect occurs when the electrode 546 and the electrode 523 are at the same potential or different potentials.

[0359] Note that the GBT stress test is a type of acceleration test and can evaluate the characteristic changes (aging changes) of transistors that occur due to long - term use in a short time. In particular, the amount of variation in the threshold voltage of the transistor before and after the GBT stress test is an important indicator for examining reliability. It can be said that the smaller the amount of variation in the threshold voltage, the higher the reliability of the transistor. Note that the GBT stress test is a type of acceleration test and can evaluate the characteristic changes (aging changes) of transistors that occur due to long - term use in a short time. In particular, the amount of variation in the threshold voltage of the transistor before and after the GBT stress test is an important indicator for examining reliability. It can be said that the smaller the amount of variation in the threshold voltage, the higher the reliability of the transistor. Note that the GBT stress test is a type of acceleration test and can evaluate the characteristic changes (aging changes) of transistors that occur due to long - term use in a short time. In particular, the amount of variation in the threshold voltage of the transistor before and after the GBT stress test is an important indicator for examining reliability. It can be said that the smaller the amount of variation in the threshold voltage, the higher the reliability of the transistor. Note that the GBT stress test is a type of acceleration test and can evaluate the characteristic changes (aging changes) of transistors that occur due to long - term use in a short time. In particular, the amount of variation in the threshold voltage of the transistor before and after the GBT stress test is an important indicator for examining reliability. It can be said that the smaller the amount of variation in the threshold voltage, the higher the reliability of the transistor. Note that the GBT stress test is a type of acceleration test and can evaluate the characteristic changes (aging changes) of transistors that occur due to long - term use in a short time. In particular, the amount of variation in the threshold voltage of the transistor before and after the GBT stress test is an important indicator for examining reliability. It can be said that the smaller the amount of variation in the threshold voltage, the higher the reliability of the transistor.

[0360] Also, by having the electrode 546 and the electrode 523 and setting the electrode 546 and the electrode 523 to the same potential, the amount of variation in the threshold voltage is reduced. For this reason, the variation in the electrical characteristics among a plurality of transistors is also reduced at the same time. Also, by having the electrode 546 and the electrode 523 and setting the electrode 546 and the electrode 523 to the same potential, the amount of variation in the threshold voltage is reduced. For this reason, the variation in the electrical characteristics among a plurality of transistors is also reduced at the same time. Also, by having the electrode 546 and the electrode 523 and setting the electrode 546 and the electrode 523 to the same potential, the amount of variation in the threshold voltage is reduced. For this reason, the variation in the electrical characteristics among a plurality of transistors is also reduced at the same time.

[0361] In addition, a transistor having a back gate has a +GBT stress test in which a positive charge is applied to the gate, and the variation in the threshold voltage before and after the stress test is also smaller than that of a transistor without a back gate. In addition, by forming the back gate with a conductive film having light-shielding properties, light incident on the semiconductor layer from the back gate side can be prevented. Therefore, light deterioration of the semiconductor layer can be prevented, and deterioration of electrical characteristics such as a shift in the threshold voltage of the transistor can be prevented. Small.

[0362] Also, by forming the back gate with a conductive film having light-shielding properties, light incident on the semiconductor layer from the back gate side can be prevented. Therefore, light deterioration of the semiconductor layer can be prevented, and deterioration of electrical characteristics such as a shift in the threshold voltage of the transistor can be prevented. Also, by forming the back gate with a conductive film having light-shielding properties, light incident on the semiconductor layer from the back gate side can be prevented. Therefore, light deterioration of the semiconductor layer can be prevented, and deterioration of electrical characteristics such as a shift in the threshold voltage of the transistor can be prevented. According to one aspect of the present invention, a highly reliable transistor can be realized. In addition, a highly reliable display device can be realized.

[0363] According to one aspect of the present invention, a highly reliable transistor can be realized. In addition, a highly reliable display device can be realized. A highly reliable display device can be realized.

[0364] FIG. 25(B1) shows a cross-sectional view of a channel protection type transistor 420, which is one of the bottom gate type transistors. The transistor 420 has substantially the same structure as the transistor 410, but is different in that an insulating layer 522 having openings 531a and 531b covers the semiconductor layer 542. The openings 531a and 531b are formed by selectively removing a part of the insulating layer 522 overlapping the semiconductor layer 542. The transistor 420 has substantially the same structure as the transistor 410, but is different in that an insulating layer 522 having openings 531a and 531b covers the semiconductor layer 542. The openings 531a and 531b are formed by selectively removing a part of the insulating layer 522 overlapping the semiconductor layer 542. The openings 531a and 531b are formed by selectively removing a part of the insulating layer 522 overlapping the semiconductor layer 542. The openings 531a and 531b are formed by selectively removing a part of the insulating layer 522 overlapping the semiconductor layer 542.

[0365] At the opening 531a, the semiconductor layer 542 and the electrode 544a are electrically connected. Also, at the opening 531b, the semiconductor layer 542 and the electrode 544b are electrically connected. By providing the insulating layer 522, exposure of the semiconductor layer 542 that occurs during the formation of the electrodes 544a and 544b can be prevented. Therefore, thinning of the semiconductor layer 542 during the formation of the electrodes 544a and 544b can be prevented. The region of the insulating layer 522 overlapping the channel formation region is At the opening 531a, the semiconductor layer 542 and the electrode 544a are electrically connected. Also, at the opening 531b, the semiconductor layer 542 and the electrode 544b are electrically connected. By providing the insulating layer 522, exposure of the semiconductor layer 542 that occurs during the formation of the electrodes 544a and 544b can be prevented. Therefore, thinning of the semiconductor layer 542 during the formation of the electrodes 544a and 544b can be prevented. The region of the insulating layer 522 overlapping the channel formation region is By providing the insulating layer 522, exposure of the semiconductor layer 542 that occurs during the formation of the electrodes 544a and 544b can be prevented. Therefore, thinning of the semiconductor layer 542 during the formation of the electrodes 544a and 544b can be prevented. The region of the insulating layer 522 overlapping the channel formation region is By providing the insulating layer 522, exposure of the semiconductor layer 542 that occurs during the formation of the electrodes 544a and 544b can be prevented. Therefore, thinning of the semiconductor layer 542 during the formation of the electrodes 544a and 544b can be prevented. The region of the insulating layer 522 overlapping the channel formation region is By providing the insulating layer 522, exposure of the semiconductor layer 542 that occurs during the formation of the electrodes 544a and 544b can be prevented. Therefore, thinning of the semiconductor layer 542 during the formation of the electrodes 544a and 544b can be prevented. The region of the insulating layer 522 overlapping the channel formation region is It can function as a channel protection layer.

[0366] The transistor 421 shown in Fig. 25 (B2) is different from the transistor 420 in that it has an electrode 523 that can function as a back gate on the insulating layer 529.

[0367] Also, the transistors 420 and 421 have a longer distance between the electrode 544a and the electrode 546 and a longer distance between the electrode 544b and the electrode 546 than the transistors 410 and 411. Therefore, the parasitic capacitance generated between the electrode 544a and the electrode 546 can be reduced, and the parasitic capacitance generated between the electrode 544b and the electrode 546 can be reduced. According to one aspect of the present invention, a transistor with good electrical characteristics can be realized.

[0368] The transistor 425 shown in Fig. 25 (C1) is a channel etching type transistor that is one of the bottom gate type transistors. In the transistor 425, the electrodes 544a and 544b are formed in contact with the semiconductor layer 542 without providing the insulating layer 522. Therefore, a part of the semiconductor layer 542 exposed during the formation of the electrodes 544a and 544b may be etched. On the other hand, since the insulating layer 522 is not provided, the productivity of the transistor can be increased.

[0369] The transistor 426 shown in Fig. 25 (C2) is different from the transistor 425 in that it has an electrode 523 that can function as a back gate on the insulating layer 529.

[0370] 〔Top gate type transistor〕 Fig. 26 (A1) shows a cross-section of a transistor 430 that is a type of top gate type transistor.​​​​​​​​​​​​ The plan view is shown. Transistor 430 has semiconductor layer 542 on substrate 571 via insulating layer 572, and has electrodes 544a and 544b which are in contact with a part of semiconductor layer 542 respectively on semiconductor layer 542 and insulating layer 572, and has insulating layer 526 on semiconductor layer 542, electrode 544a, and electrode 544b, and has electrode 546 on insulating layer 526. Transistor 430 has electrodes 544a and 544b which are in contact with a part of semiconductor layer 542 respectively on semiconductor layer 542 and insulating layer 572, and has insulating layer 526 on semiconductor layer 542, electrode 544a, and electrode 544b, and has electrode 546 on insulating layer 526. Transistor 430 has electrodes 544a and 544b which are in contact with a part of semiconductor layer 542 respectively on semiconductor layer 542 and insulating layer 572, and has insulating layer 526 on semiconductor layer 542, electrode 544a, and electrode 544b, and has electrode 546 on insulating layer 526. Transistor 430 has electrodes 544a and 544b which are in contact with a part of semiconductor layer 542 respectively on semiconductor layer 542 and insulating layer 572, and has insulating layer 526 on semiconductor layer 542, electrode 544a, and electrode 544b, and has electrode 546 on insulating layer 526.

[0371] Since electrodes 546 and 544a, and electrodes 546 and 544b do not overlap in transistor 430, the parasitic capacitances generated between electrode 546 and electrode 544a, and between electrode 546 and electrode 544b can be reduced. Also, after forming electrode 546, by using electrode 546 as a mask to introduce impurity 555 into semiconductor layer 542, impurity regions can be formed self-alignedly in semiconductor layer 542 (see Fig. 26(A3)). According to one aspect of the present invention, a transistor with good electrical characteristics can be realized. Since electrodes 546 and 544a, and electrodes 546 and 544b do not overlap in transistor 430, the parasitic capacitances generated between electrode 546 and electrode 544a, and between electrode 546 and electrode 544b can be reduced. Also, after forming electrode 546, by using electrode 546 as a mask to introduce impurity 555 into semiconductor layer 542, impurity regions can be formed self-alignedly in semiconductor layer 542 (see Fig. 26(A3)). According to one aspect of the present invention, a transistor with good electrical characteristics can be realized. Since electrodes 546 and 544a, and electrodes 546 and 544b do not overlap in transistor 430, the parasitic capacitances generated between electrode 546 and electrode 544a, and between electrode 546 and electrode 544b can be reduced. Also, after forming electrode 546, by using electrode 546 as a mask to introduce impurity 555 into semiconductor layer 542, impurity regions can be formed self-alignedly in semiconductor layer 542 (see Fig. 26(A3)). According to one aspect of the present invention, a transistor with good electrical characteristics can be realized. Since electrodes 546 and 544a, and electrodes 546 and 544b do not overlap in transistor 430, the parasitic capacitances generated between electrode 546 and electrode 544a, and between electrode 546 and electrode 544b can be reduced. Also, after forming electrode 546, by using electrode 546 as a mask to introduce impurity 555 into semiconductor layer 542, impurity regions can be formed self-alignedly in semiconductor layer 542 (see Fig. 26(A3)). According to one aspect of the present invention, a transistor with good electrical characteristics can be realized. Since electrodes 546 and 544a, and electrodes 546 and 544b do not overlap in transistor 430, the parasitic capacitances generated between electrode 546 and electrode 544a, and between electrode 546 and electrode 544b can be reduced. Also, after forming electrode 546, by using electrode 546 as a mask to introduce impurity 555 into semiconductor layer 542, impurity regions can be formed self-alignedly in semiconductor layer 542 (see Fig. 26(A3)). According to one aspect of the present invention, a transistor with good electrical characteristics can be realized. Since electrodes 546 and 544a, and electrodes 546 and 544b do not overlap in transistor 430, the parasitic capacitances generated between electrode 546 and electrode 544a, and between electrode 546 and electrode 544b can be reduced. Also, after forming electrode 546, by using electrode 546 as a mask to introduce impurity 555 into semiconductor layer 542, impurity regions can be formed self-alignedly in semiconductor layer 542 (see Fig. 26(A3)). According to one aspect of the present invention, a transistor with good electrical characteristics can be realized. Since electrodes 546 and 544a, and electrodes 546 and 544b do not overlap in transistor 430, the parasitic capacitances generated between electrode 546 and electrode 544a, and between electrode 546 and electrode 544b can be reduced. Also, after forming electrode 546, by using electrode 546 as a mask to introduce impurity 555 into semiconductor layer 542, impurity regions can be formed self-alignedly in semiconductor layer 542 (see Fig. 26(A3)). According to one aspect of the present invention, a transistor with good electrical characteristics can be realized.

[0372] The introduction of impurity 555 can be performed using an ion implantation device, an ion doping device, or a plasma processing device. The introduction of impurity 555 can be performed using an ion implantation device, an ion doping device, or a plasma processing device.

[0373] As impurity 555, for example, at least one kind of element among group 13 elements and group 15 elements can be used. Also, when using an oxide semiconductor for semiconductor layer 542, as impurity 555, at least one kind of element among noble gases, hydrogen, and nitrogen can be used. As impurity 555, for example, at least one kind of element among group 13 elements and group 15 elements can be used. Also, when using an oxide semiconductor for semiconductor layer 542, as impurity 555, at least one kind of element among noble gases, hydrogen, and nitrogen can be used. As impurity 555, for example, at least one kind of element among group 13 elements and group 15 elements can be used. Also, when using an oxide semiconductor for semiconductor layer 542, as impurity 555, at least one kind of element among noble gases, hydrogen, and nitrogen can be used. As impurity 555, for example, at least one kind of element among group 13 elements and group 15 elements can be used. Also, when using an oxide semiconductor for semiconductor layer 542, as impurity 555, at least one kind of element among noble gases, hydrogen, and nitrogen can be used.

[0374] The transistor 431 shown in Fig. 26(A2) has the points of having electrode 523 and insulating layer 527. It is different from the transistor 430. The transistor 431 has an electrode 523 formed on the insulating layer 572 and has an insulating layer 527 formed on the electrode 523. The electrode 523 can function as a back gate. Therefore, the insulating layer 527 can function as a gate insulating layer The insulating layer 527 can be formed by the same material and method as the insulating layer 526.

[0375] Similar to the transistor 411, the transistor 431 is a transistor having a large on-current with respect to the occupied area. That is, the occupied area of the transistor 4 31 can be reduced with respect to the required on-current. According to one aspect of the present invention, the occupied area of the transistor can be reduced. Therefore, according to one aspect of the present invention, a high aperture ratio or high definition of the display device can be realized.

[0376] The transistor 440 illustrated in FIG. 26(B1) is one of the top-gate type transistors. The transistor 440 is different from the transistor 430 in that the semiconductor layer 542 is formed after forming the electrodes 544a and 544b. Also, the transistor 441 illustrated in FIG. 26(B2) is different from the transistor 440 in that it has the electrode 523 and the insulating layer 527. In the transistor 440 and the transistor 441, a part of the semiconductor layer 542 is formed on the electrode 544a, and another part of the semiconductor layer 542 is formed on the electrode 544b.

[0377] Similar to the transistor 411, the transistor 441 is a transistor having a large on-current with respect to the occupied area. That is, the occupied area of the transistor 4 41 can be reduced with respect to the required on-current. ​​​​​​​The occupied area of 41 can be reduced. According to one aspect of the present invention, the occupied area of the transistor can be reduced. Therefore, a display device with a higher aperture ratio or higher resolution can be realized.

[0378] The transistor 442 illustrated in FIG. 27(A1) is one of the top-gate type transistors. The transistor 442 has an electrode 544a and an electrode 544b on the insulating layer 529. The electrodes 544a and 544b are electrically connected to the semiconductor layer 542 at the openings formed in the insulating layer 528 and the insulating layer 529.

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

[0380] By introducing the impurity 555 into the semiconductor layer 542 using the electrode 546 and the insulating layer 526 as a mask, an impurity region can be formed self-alignedly in the semiconductor layer 542 (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 impurity 555 is introduced into the region that does not overlap with the electrode 546. Also, the impurity concentration of the region where the impurity 555 is introduced through the insulating layer 526 of the semiconductor layer 542 is lower than that of the region where the impurity 555 is introduced without passing through the insulating layer 526. Therefore, an LDD (Lightly Doped Drain) region is formed in the region adjacent to the electrode 546 in the semiconductor layer 542.

[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. can do. The insulating layers 526, 572, 582, and 574 can function as gate insulating layers. The electrode 544a can function as one of the source electrode or the drain electrode The electrode 544b can function as the other of the source electrode or the drain electrode can do.

[0387] An insulating layer 575 is provided on the substrate 571, and an electrode 524 and an insulating layer 573 are provided on the insulating layer 575. Also, an insulating layer 574 is provided on the electrode 524 and the insulating layer 573 is provided. Also, an insulating layer 582 is provided on the insulating layer 574, and an insulating layer 572 is provided on the insulating layer 582.

[0388] A semiconductor layer 542a is provided on the convex portion formed in the insulating layer 572, and a semiconductor layer 542b is provided on the semiconductor layer 542a. Also, 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 can function as one of the source or drain of the transistor 451 The region of the semiconductor layer 542b that overlaps with the electrode 544b can function as the other of the source or drain of the transistor 451 The region of the semiconductor layer 542b that overlaps with the electrode 544b can function as the other of the source or drain of the transistor 451 can do.

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

[0390] In FIG. 28(C), the transistor 451 has a structure in which the upper surface and side surfaces of the semiconductor layer 542b, and also the side surface of the semiconductor layer 542a are covered by the semiconductor layer 542c. Also, the insulating layer 5 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. is provided. Also, electrode 525a, electrode 525b, and electrode 52 5c are provided on the insulating layer 529. Electrode 525a is provided at the opening formed in the insulating layer 529 and the insulating layer 528, and is electrically connected to electrode 544a through a contact plug. Electrode 525 b is provided at the opening formed in the insulating layer 529 and the insulating layer 528, and is electrically connected to electrode 544b through a contact plug. Electrode 525c is provided at the opening formed in the insulating layer 529 and the insulating layer 52 8, and is electrically connected to electrode 543 through a contact plug. is.

[0394] As the contact plug, for example, a highly embedable conductive material such as tungsten or polysilicon can be used. Also, the side surface and the bottom surface of the material may be covered with a barrier layer (diffusion prevention layer) made of a titanium layer, a titanium nitride layer, or a laminate thereof. In this case, it may be referred to as a contact plug including the barrier layer.

[0395] Note that by forming the insulating layer 582 with hafnium oxide, aluminum oxide, tantalum oxide, aluminum silicate, etc., the insulating layer 582 can function as a charge trapping layer. By injecting electrons into the insulating layer 582, it is possible to vary the threshold voltage of the transistor. The injection of electrons into the insulating layer 582 may utilize, for example, the tunnel effect. By applying a positive voltage to electrode 524, tunnel electrons can be injected into the insulating layer 582.

[0396] Also, depending on the purpose, electrode 524 that functions as a back gate may not be provided. Fig. 29(A) is a top view of the transistor 451a. Fig. 29(B) is in Fig. 29(A) ​​​​​​​​​​It is a cross-sectional view between the dashed-dotted lines L1 - L2 shown. FIG. 29(C) is a cross-sectional view between the dashed-dotted lines W1 - W2 shown in FIG. 29(A). The transistor 451a has a configuration in which 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 increased. Thus, the productivity of the display device can be increased. Another example of an s-channel type transistor is shown in FIG. 30. FIG. 30(A) is a top view of the transistor 452. FIG. 30(B) is a cross-sectional view between the dashed-dotted lines L1 - L2 shown in FIG. 30(A). FIG. 30(C) is a cross-sectional view between the dashed-dotted lines W1 - W2 shown in FIG. 30(A). The transistor 452 has the same configuration as the transistor 451, but is different in that the electrodes 544a and 544b are in contact with the side surfaces of the semiconductor layers 542a and 542b. Also, as the insulating layer 528 covering the transistor 452, an insulating layer having a flat surface similar to that of the transistor 451 may be used. Also, electrodes 525a, 525b, and 525c may be provided on the insulating layer 529. Another example of an s-channel type transistor is shown in FIG. 31. FIG. 31(A) is a top view of the transistor 453. FIG. 31(B) is a cross-sectional view between the dashed-dotted lines L1 - L2 and W1 - W2 shown in FIG. 31(A). The transistor 453 also has the semiconductor layers 542a and 542b provided on the convex portions provided in the insulating layer 572, similar to the transistor 451. Also, the electrodes 544a and 544b are provided on the semiconductor layer 542b.

[0397] s-channel type transistor's another example is shown in FIG. 30. FIG. 30(A) is a top view of the transistor 452. FIG. 30(B) is a cross-sectional view between the dashed-dotted lines L1 - L2 shown in FIG. 30(A). FIG. 30(C) is a cross-sectional view between the dashed-dotted lines W1 - W2 shown in FIG. 30(A). FIG. 30(C) is a cross-sectional view between the dashed-dotted lines W1 - W2 shown in FIG. 30(A). FIG. 30(C) is a cross-sectional view between the dashed-dotted lines W1 - W2 shown in FIG. 30(A).

[0398] The transistor 452 has the same configuration as the transistor 451, but is different in that the electrodes 544a and 544b are in contact with the side surfaces of the semiconductor layers 542a and 542b. Also, as the insulating layer 528 covering the transistor 452, an insulating layer having a flat surface similar to that of the transistor 451 may be used. Also, electrodes 525a, 525b, and 525c may be provided on the insulating layer 529. Also, as the insulating layer 528 covering the transistor 452, an insulating layer having a flat surface similar to that of the transistor 451 may be used. Also, electrodes 525a, 525b, and 525c may be provided on the insulating layer 529. Also, as the insulating layer 528 covering the transistor 452, an insulating layer having a flat surface similar to that of the transistor 451 may be used. Also, electrodes 525a, 525b, and 525c may be provided on the insulating layer 529. Also, as the insulating layer 528 covering the transistor 452, an insulating layer having a flat surface similar to that of the transistor 451 may be used. Also, electrodes 525a, 525b, and 525c may be provided on the insulating layer 529.

[0399] Another example of an s-channel type transistor is shown in FIG. 31. FIG. 31(A) is a top view of the transistor 453. FIG. 31(B) is a cross-sectional view between the dashed-dotted lines L1 - L2 shown in FIG. 31(A). FIG. 31(B) is a cross-sectional view between the dashed-dotted lines L1 - L2 shown in FIG. 31(A). FIG. 31(B) is a cross-sectional view between the dashed-dotted lines L1 - L2 shown in FIG. 31(A). The transistor 453 also has the semiconductor layers 542a and 542b provided on the convex portions provided in the insulating layer 572, similar to the transistor 451. Also, the electrodes 544a and 544b are provided on the semiconductor layer 542b. The region overlapping with the electrode 544a of the semiconductor layer 542b can function as one of the source or drain of the transistor 453. The region overlapping with the electrode 544b of the semiconductor layer 542b can function as the other of the source or drain of the transistor 453. Therefore, the region 569 of the semiconductor layer 542b sandwiched between the electrode 544a and the electrode 544b can function as a channel formation region. The transistor 453 has an opening provided in a region overlapping with the region 569 by removing a part of the insulating layer 528, and the semiconductor layer 542c is provided along the side surface and the bottom surface of the opening. Also, the insulating layer 526 is provided in the opening through the semiconductor layer 542c and along the side surface and the bottom surface of the opening. Further, the electrode 543 is provided in the opening through the semiconductor layer 542c and the insulating layer 526 and along the side surface and the bottom surface of the opening. Note that the opening is provided larger than the semiconductor layer 542a and the semiconductor layer 542b in the cross section in the channel width direction. Therefore, in the region 569, the side surfaces of the semiconductor layer 542a and the semiconductor layer 542b are covered with the semiconductor layer 542c.

[0400] The insulating layer 529 is provided on the insulating layer 528, and the insulating layer 577 is provided on the insulating layer 529. Also, the electrodes 525a, 525b, and 525c are provided on the insulating layer 577. The electrode 525a is electrically connected to the electrode 544a through a contact plug in an opening formed by removing a part of the insulating layer 577, the insulating layer 529, and the insulating layer 528. Also, the electrode 525b is... The transistor 453 has an opening provided in a region overlapping with the region 569 by removing a part of the insulating layer 528, and the semiconductor layer 542c is provided along the side surface and the bottom surface of the opening. Also, the insulating layer 526 is provided in the opening through the semiconductor layer 542c and along the side surface and the bottom surface of the opening. Further, the electrode 543 is provided in the opening through the semiconductor layer 542c and the insulating layer 526 and along the side surface and the bottom surface of the opening. The insulating layer 526 is provided in the opening through the semiconductor layer 542c and along the side surface and the bottom surface of the opening. Also, the insulating layer 526 is provided in the opening through the semiconductor layer 542c and along the side surface and the bottom surface of the opening. The electrode 543 is provided in the opening through the semiconductor layer 542c and the insulating layer 526 and along the side surface and the bottom surface of the opening.

[0401] The opening is provided larger than the semiconductor layer 542a and the semiconductor layer 542b in the cross section in the channel width direction. Therefore, in the region 569, the side surfaces of the semiconductor layer 542a and the semiconductor layer 542b are covered with the semiconductor layer 542c. The opening is provided larger than the semiconductor layer 542a and the semiconductor layer 542b in the cross section in the channel width direction. Therefore, in the region 569, the side surfaces of the semiconductor layer 542a and the semiconductor layer 542b are covered with the semiconductor layer 542c. The side surfaces of the semiconductor layer 542a and the semiconductor layer 542b are covered with the semiconductor layer 542c.

[0402] The insulating layer 529 is provided on the insulating layer 528, and the insulating layer 577 is provided on the insulating layer 529. Also, the electrodes 525a, 525b, and 525c are provided on the insulating layer 577. The insulating layer 529 is provided on the insulating layer 528, and the insulating layer 577 is provided on the insulating layer 529. Also, the electrodes 525a, 525b, and 525c are provided on the insulating layer 577. The electrode 525a is electrically connected to the electrode 544a through a contact plug in an opening formed by removing a part of the insulating layer 577, the insulating layer 529, and the insulating layer 528. The electrode 525a is electrically connected to the electrode 544a through a contact plug in an opening formed by removing a part of the insulating layer 577, the insulating layer 529, and the insulating layer 528. The electrode 525b is... In the opening formed by removing a part of 8, it is electrically connected to the electrode 544b through the contact plug. Also, the electrode 525c is electrically connected to the electrode 543 through the contact plug in the opening formed by removing a part of the insulating layer 577 and the insulating layer 529. And it is electrically connected.

[0403] Also, depending on the purpose, the electrode 524 that functions as a back gate may not be provided. FIG. 32(A) is a top view of the transistor 453a. FIG. 32(B) is a cross-sectional view between the dashed lines L1 - L2 and W1 - W2 shown in FIG. 32(A). The transistor 453a has a configuration in which the electrode 524, the insulating layer 574, and the insulating layer 582 are omitted from the transistor 453. By not providing these electrodes and insulating layers, the productivity of the transistor can be increased. Therefore, the productivity of the display device can be increased.

[0404] Another example of an s-channel type transistor is shown in FIG. 33. FIG. 33(A) is a top view of the transistor 454. FIG. 33(B) is a cross-sectional view between the dashed lines L1 - L2 shown in FIG. 33(A). FIG. 33(C) is a cross-sectional view between the dashed lines W1 - W2 shown in FIG. 33(A).

[0405] The transistor 454 is a type of bottom gate transistor having a back gate electrode. In the transistor 454, the electrode 543 is formed on the insulating layer 574, and the insulating layer 526 is provided to cover the electrode 543. Also, a semiconductor layer 542 is formed in a region overlapping the electrode 543 on the insulating layer 526. The semiconductor layer 542 included in the transistor 454 has a stack of a semiconductor layer 542a and a semiconductor layer 542b.

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

[0407] The electrode 524 provided on the insulating layer 529 is electrically connected to the electrode 543 at the openings 547a and 547b provided in the insulating layer 529, the insulating layer 528, and the insulating layer 5 26. Therefore, the same potential is supplied to the electrode 524 and the electrode 543. Also, the openings 5 47a and the opening 547b may not be provided, either one or both. When neither the opening 547a nor the opening 547b is provided, different potentials can be supplied to the electrode 524 and the electrode 543. are. is possible.

[0408] Also, depending on the purpose, the electrode 524 that functions as a back gate may not be provided. FIG. 34(A) is a top view of the transistor 454a. FIG. 34(B) is a cross-sectional view taken along the dashed line L1-L2 shown in FIG. 34(A). FIG. 34(C) is a cross-sectional view taken along the dashed line W1-W2 shown in FIG. 34(A). The transistor 454a has a configuration in which the electrode 524, the opening 547a, and the opening 547b are omitted from the transistor 454. By not providing these electrodes and openings, the productivity of the transistor can be increased. Therefore, the productivity of the display device can be increased. chain line. The transistor 454a has a configuration in which the electrode 524, the opening 547a, and the opening 547b are omitted from the transistor 454. By not providing these electrodes and openings, the productivity of the transistor can be increased. Therefore, the electrode 524, the opening 547a, and the opening 547b. By not providing these electrodes and openings, the productivity of the transistor can be increased. Therefore, the productivity of the display device can be increased. productivity of the display device can be increased.

[0409] FIG. 35 shows an example of a transistor having an s-channel structure. Illustrated in FIG. 35 The transistor 448 has substantially the same configuration as 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 the transistor 448. FIG. 35(B) is a cross-sectional view taken along the dashed line L1-L2 shown in FIG. 35(A). FIG. 35(C) is a cross-sectional view taken along the dashed line W1-W2 shown in FIG. 35(A).

[0410] FIG. 35 shows a configuration example in the case where an inorganic semiconductor layer such as silicon is used for the semiconductor layer 542 constituting the transistor 448. In FIG. 35, an electrode 524 is provided on a substrate 571, and an insulating layer 572 is provided on the electrode 524. Further, a semiconductor layer 542 is formed on a convex portion of the

[0411] insulating layer 572. The semiconductor layer 542 includes a semiconductor layer 542i, two semiconductor layers 542t, and two semiconductor layers 542u. The semiconductor layer 542i is disposed between the two semiconductor layers 542t. Further, the semiconductor layer 542i and the two

[0412] semiconductor layers 542t are disposed between the two semiconductor layers 542u. Also, an electrode 543 is provided in a region overlapping with the semiconductor layer 542i. When the transistor 448 is in the on state, a channel is formed in the semiconductor layer 542i. Therefore, the semiconductor layer 542i functions as a channel formation region. Also, the semiconductor layer 542t functions as a low-concentration impurity region (LDD One of the semiconductor layers 542u 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 electrically connected to one of the semiconductor layers 542u at the opening 547c provided in the insulating layers 526, 528, and 529. 。 The electrode 544b provided on the insulating layer 529 is electrically connected to the other of the semiconductor layers 542u at the opening 547d provided in the insulating layers 526, 528, and 529. 。 。

[0414] The electrode 543 provided on the insulating layer 526 is electrically connected to the electrode 524 at the openings 547a and 547b provided in the insulating layers 526 and 572. Therefore, the same potential is supplied to the electrode 543 and the electrode 524. Also, the openings 547a and 547b may not be provided at all, or either one of them may not be provided. If neither of the openings 547a and 547b is provided, different potentials can be supplied to the electrode 524 and the electrode 543. 。 。 。 。

[0415] This embodiment can be appropriately combined with other embodiments.

[0416] (Embodiment 3) In this embodiment, a touch panel module and an electronic device having a display device according to one aspect of the present invention will be described with reference to FIGS. 36 to 38. 。

[0417] The touch panel module 8000 shown in FIG. 36 includes a touch panel 8004, a frame 8009, a printed circuit board 8010, and a battery 8011 connected to an FPC 8003 between an upper cover 8001 and a lower cover 8002. 。 。

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

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

[0420] The display device according to one aspect of the present invention can have a function as a touch panel. Touch The panel 8004 can be used by superimposing a touch panel of a resistive film type or a capacitive type on the display device according to one aspect of the present invention. Further, it is also possible to provide the touch panel function to the counter substrate (sealing substrate) of the touch panel 8004. Further, it is also possible to provide an optical sensor in each pixel of the touch panel 8004 to form an optical touch panel. and can be used by superimposing a touch panel of a resistive film type or a capacitive type on the display device according to one aspect of the present invention. Further, it is also possible to provide the touch panel function to the counter substrate (sealing substrate) of the touch panel 8004. Further, it is also possible to provide an optical sensor in each pixel of the touch panel 8004 to form an optical touch panel. and can be used by superimposing a touch panel of a resistive film type or a capacitive type on the display device according to one aspect of the present invention. Further, it is also possible to provide the touch panel function to the counter substrate (sealing substrate) of the touch panel 8004. Further, it is also possible to provide an optical sensor in each pixel of the touch panel 8004 to form an optical touch panel. When a transmissive liquid crystal element is used, a backlight 8007 may be provided as shown in FIG. 36. The backlight 8007 has a light source 8008. In FIG. 36, the configuration in which the light source 8008 is disposed on the backlight 8007 is illustrated, but the present invention is not limited thereto. For example, the light source 8008 may be disposed at an end of the backlight 8007, and a light diffusion plate may be further used. When a self-luminous light-emitting element such as an organic EL element is used, or in the case of a reflective panel or the like, the backlight 8007 may not be provided.

[0421] When a transmissive liquid crystal element is used, a backlight 8007 may be provided as shown in FIG. 36. The backlight 8007 has a light source 8008. In FIG. 36, the configuration in which the light source 8008 is disposed on the backlight 8007 is illustrated, but the present invention is not limited thereto. For example, the light source 8008 may be disposed at an end of the backlight 8007, and a light diffusion plate may be further used. When a self-luminous light-emitting element such as an organic EL element is used, or in the case of a reflective panel or the like, the backlight 8007 may not be provided. When a transmissive liquid crystal element is used, a backlight 8007 may be provided as shown in FIG. 36. The backlight 8007 has a light source 8008. In FIG. 36, the configuration in which the light source 8008 is disposed on the backlight 8007 is illustrated, but the present invention is not limited thereto. For example, the light source 8008 may be disposed at an end of the backlight 8007, and a light diffusion plate may be further used. When a self-luminous light-emitting element such as an organic EL element is used, or in the case of a reflective panel or the like, the backlight 8007 may not be provided. When a transmissive liquid crystal element is used, a backlight 8007 may be provided as shown in FIG. 36. The backlight 8007 has a light source 8008. In FIG. 36, the configuration in which the light source 8008 is disposed on the backlight 8007 is illustrated, but the present invention is not limited thereto. For example, the light source 8008 may be disposed at an end of the backlight 8007, and a light diffusion plate may be further used. When a self-luminous light-emitting element such as an organic EL element is used, or in the case of a reflective panel or the like, the backlight 8007 may not be provided. When a transmissive liquid crystal element is used, a backlight 8007 may be provided as shown in FIG. 36. The backlight 8007 has a light source 8008. In FIG. 36, the configuration in which the light source 8008 is disposed on the backlight 8007 is illustrated, but the present invention is not limited thereto. For example, the light source 8008 may be disposed at an end of the backlight 8007, and a light diffusion plate may be further used. When a self-luminous light-emitting element such as an organic EL element is used, or in the case of a reflective panel or the like, the backlight 8007 may not be provided. When a transmissive liquid crystal element is used, a backlight 8007 may be provided as shown in FIG. 36. The backlight 8007 has a light source 8008. In FIG. 36, the configuration in which the light source 8008 is disposed on the backlight 8007 is illustrated, but the present invention is not limited thereto. For example, the light source 8008 may be disposed at an end of the backlight 8007, and a light diffusion plate may be further used. When a self-luminous light-emitting element such as an organic EL element is used, or in the case of a reflective panel or the like, the backlight 8007 may not be provided. When a transmissive liquid crystal element is used, a backlight 8007 may be provided as shown in FIG. 36. The backlight 8007 has a light source 8008. In FIG. 36, the configuration in which the light source 8008 is disposed on the backlight 8007 is illustrated, but the present invention is not limited thereto. For example, the light source 8008 may be disposed at an end of the backlight 8007, and a light diffusion plate may be further used. When a self-luminous light-emitting element such as an organic EL element is used, or in the case of a reflective panel or the like, the backlight 8007 may not be provided. When a transmissive liquid crystal element is used, a backlight 8007 may be provided as shown in FIG. 36. The backlight 8007 has a light source 8008. In FIG. 36, the configuration in which the light source 8008 is disposed on the backlight 8007 is illustrated, but the present invention is not limited thereto. For example, the light source 8008 may be disposed at an end of the backlight 8007, and a light diffusion plate may be further used. When a self-luminous light-emitting element such as an organic EL element is used, or in the case of a reflective panel or the like, the backlight 8007 may not be provided.

[0422] The frame 8009 has a function as an electromagnetic shield for blocking electromagnetic waves generated by the operation of the printed circuit board 8010 in addition to the protection function of the touch panel 8004. The frame 8009 may also have a function as a heat sink. The frame 8009 has a function as an electromagnetic shield for blocking electromagnetic waves generated by the operation of the printed circuit board 8010 in addition to the protection function of the touch panel 8004. The frame 8009 may also have a function as a heat sink. The frame 8009 has a function as an electromagnetic shield for blocking electromagnetic waves generated by the operation of the printed circuit board 8010 in addition to the protection function of the touch panel 8004. The frame 8009 may also have a function as a heat sink.

[0423] The printed circuit board 8010 has a power supply circuit and a signal processing circuit for outputting video signals and clock signals. As a power supply for supplying power to the power supply circuit, an external commercial power supply or a power supply by a separately provided battery 8011 may be used. The battery 8011 can be omitted when using a commercial power supply. When using a commercial power supply, it can be omitted. When using a commercial power supply, it can be omitted.

[0424] Members such as a polarizing plate, a retardation plate, and a prism sheet may be added to the touch panel 8004. Members such as a polarizing plate, a retardation plate, and a prism sheet may be added to the touch panel 8004.

[0425] Figs. 37(A) to (H) and Fig. 38 are diagrams showing electronic devices. These electronic devices can include a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, operation keys 5005 (including a power switch or an operation switch), connection terminals 5006, a sensor 5007 (having a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, or infrared rays), a microphone 5008, etc. Figs. 37(A) to (H) and Fig. 38 are diagrams showing electronic devices. These electronic devices can include a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, operation keys 5005 (including a power switch or an operation switch), connection terminals 5006, a sensor 5007 (having a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, or infrared rays), a microphone 5008, etc. Figs. 37(A) to (H) and Fig. 38 are diagrams showing electronic devices. These electronic devices can include a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, operation keys 5005 (including a power switch or an operation switch), connection terminals 5006, a sensor 5007 (having a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, or infrared rays), a microphone 5008, etc. Figs. 37(A) to (H) and Fig. 38 are diagrams showing electronic devices. These electronic devices can include a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, operation keys 5005 (including a power switch or an operation switch), connection terminals 5006, a sensor 5007 (having a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, or infrared rays), a microphone 5008, etc. Figs. 37(A) to (H) and Fig. 38 are diagrams showing electronic devices. These electronic devices can include a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, operation keys 5005 (including a power switch or an operation switch), connection terminals 5006, a sensor 5007 (having a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, or infrared rays), a microphone 5008, etc. Figs. 37(A) to (H) and Fig. 38 are diagrams showing electronic devices. These electronic devices can include a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, operation keys 5005 (including a power switch or an operation switch), connection terminals 5006, a sensor 5007 (having a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, or infrared rays), a microphone 5008, etc. Figs. 37(A) to (H) and Fig. 38 are diagrams showing electronic devices. These electronic devices can include a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, operation keys 5005 (including a power switch or an operation switch), connection terminals 5006, a sensor 5007 (having a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, or infrared rays), a microphone 5008, etc.

[0426] Fig. 37(A) is a mobile computer, which can have a switch 5009, an infrared port 5010, etc. in addition to the above-mentioned components. Fig. 37(B) is a portable image playback device equipped with a recording medium (for example, a DVD playback device), which can have a second display unit 5002, a recording medium reading unit 5011, etc. in addition to the above-mentioned components. Fig. 37(C) is a television set, which can have a stand 5012, etc. in addition to the above-mentioned components. Fig. 37(A) is a mobile computer, which can have a switch 5009, an infrared port 5010, etc. in addition to the above-mentioned components. Fig. 37(B) is a portable image playback device equipped with a recording medium (for example, a DVD playback device), which can have a second display unit 5002, a recording medium reading unit 5011, etc. in addition to the above-mentioned components. Fig. 37(C) is a television set, which can have a stand 5012, etc. in addition to the above-mentioned components. Fig. 37(A) is a mobile computer, which can have a switch 5009, an infrared port 5010, etc. in addition to the above-mentioned components. Fig. 37(B) is a portable image playback device equipped with a recording medium (for example, a DVD playback device), which can have a second display unit 5002, a recording medium reading unit 5011, etc. in addition to the above-mentioned components. Fig. 37(C) is a television set, which can have a stand 5012, etc. in addition to the above-mentioned components. Fig. 37(A) is a mobile computer, which can have a switch 5009, an infrared port 5010, etc. in addition to the above-mentioned components. Fig. 37(B) is a portable image playback device equipped with a recording medium (for example, a DVD playback device), which can have a second display unit 5002, a recording medium reading unit 5011, etc. in addition to the above-mentioned components. Fig. 37(C) is a television set, which can have a stand 5012, etc. in addition to the above-mentioned components. Fig. 37(A) is a mobile computer, which can have a switch 5009, an infrared port 5010, etc. in addition to the above-mentioned components. Fig. 37(B) is a portable image playback device equipped with a recording medium (for example, a DVD playback device), which can have a second display unit 5002, a recording medium reading unit 5011, etc. in addition to the above-mentioned components. Fig. 37(C) is a television set, which can have a stand 5012, etc. in addition to the above-mentioned components. The operation of the revision device can be performed by the operation switches provided in the housing 5000 or by a separate remote control operation unit 5013. By operating keys provided on the remote control operation unit 5013, operations such as changing the channel and volume can be performed, and the video displayed on the display unit 5001 can be operated . It is also possible to provide a display unit on the remote control operation unit 5013 for displaying information output from the remote control operation unit 5013 . FIG. 37(D) shows a portable game machine, which can have, in addition to the above-described components, a recording medium reading unit 5011 and the like . FIG. 37(E) shows a digital camera with a TV reception function, which can have, in addition to the above-described components, an antenna 5014, a shutter button 5015, an imaging unit 5016 and the like . FIG. 37(F) shows a portable game machine, which can have, in addition to the above-described components, a second display unit 5002, a recording medium reading unit 5011 and the like . FIG. 37(G) shows a portable TV receiver, which can have, in addition to the above-described components, a charger 5017 capable of transmitting and receiving signals and the like . FIG. 37(H) shows a wristwatch-type information terminal, which can have, in addition to the above-described components, a band 5018, a buckle 5019 and the like . The display unit 5001 mounted on the housing 5000 that also serves as a bezel portion has a non-rectangular display area . The display unit 5001 can display an icon 5020 representing time, other icons 5021 and the like . FIG. 38(A) shows a digital signage . FIG. 38(B) shows a digital signage attached to a cylindrical pillar . The electronic devices shown in FIGS. 37(A) to (H) and FIG. 38 can have various functions . For example, functions such as displaying various information (still images, moving images, text images, etc.) on the display unit, tapping . .

[0427] . . For example, a function of displaying various information (such as still images, moving images, text images, etc.) on the display unit, a tapping chip panel function, function to display a calendar, date, or time, function to control processing by various software ( programs), wireless communication function, function to connect to various computer networks using the wireless communication function, function to transmit or receive various data using the wireless communication function, function to read a program or data recorded on a recording medium and display it on a display unit, etc. can be provided. Further, in an electronic device having a plurality of display units, one display unit mainly displays image information, and another display unit mainly displays character information, or it can have a function to display a stereoscopic image by displaying an image considering parallax on a plurality of display units, etc. Further, in an electronic device having an imaging unit, it can have a function to capture a still image, a function to capture a moving image, a function to automatically or manually correct the captured image, a function to save the captured image on a recording medium (external or built-in to the camera), a function to display the captured image on a display unit, etc. Note that the functions that the electronic devices shown in FIGS. 37(A) to (H) and FIG. 38 can have are not limited to these, and they can have various functions. The electronic device of the present embodiment is characterized by having a display unit for displaying some kind of information. The display device of one aspect of the present invention can be applied to the display unit. Note that FIGS. 37(A) to (H) and FIG. 38 are not limited to these, and various functions can be provided. The electronic device of the present embodiment is characterized by having a display unit for displaying some kind of information. The display device of one aspect of the present invention can be applied to the display unit. The present embodiment can be appropriately combined with other embodiments.

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

[0429] The present embodiment can be appropriately combined with other embodiments.

Example

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

[0431] <Examination of Semiconductor Materials> In this embodiment, an oxide semiconductor was used for the semiconductor layer of the transistor. Specifically, CAA C-OS was used.

[0432] A transistor using CAAC-OS (CAAC-OS FET) has a smaller off-current value than a transistor using low-temperature poly-silicon (LTPS (Low Temperature Poly-Silicon)).

[0433] After writing data, if an off-current flows between the source and drain of the selection transistor of the pixel during the non-selection period, the charge will gradually decrease. As a result, the voltage applied to the liquid crystal molecules will change and the change in optical characteristics will be visible. Therefore, in a display device with a large off-current value, it is necessary to constantly write data, which leads to an increase in power consumption. CA AC-OS FET has a smaller off-current than LTPS FET, so during the non-selection period, the voltage applied to the liquid crystal hardly changes because the charge hardly moves. Therefore, it is possible to prevent an increase in power consumption according to the number of write cycles.

[0434] <Examination of Transistor Structure> In this embodiment, two types of pixel layouts with 1058 ppi in the FFS mode were fabricated. One used a transistor with a bottom-gate top-contact (BGTC) structure. The other used a transistor with a top-gate self-aligned (TGSA) structure. And orientation simulations in the FFS mode were performed for each.

[0435] Fig. 39(A) and (B) show the pixel layout when a transistor with a BGTC structure is used. In Fig. 39(A), a transistor, a pixel electrode 111, and a first common electrode 112 are shown. The transistor with a BGTC structure has a gate 221, a semiconductor layer 231, and conductive layers 222a and 222b that are a source electrode and a drain electrode. Fig. 39(B) is a top view of the laminated structure of Fig. 39(A) excluding the first common electrode 112.

[0436] In Fig. 39(A) and (B), it can be said that one conductive layer functions as both the scanning line 228 and the gate 221. Also, in Fig. 39(A) and (B), it can be said that one conductive layer functions as both the signal line 229 and the conductive layer 222a.

[0437] The pixel layout when a transistor with a TGSA structure is used is the same as that in Fig. 3(B) and (C).

[0438] In this embodiment, a liquid crystal display design simulator: LCD Master 3D Full set FEM mode (manufactured by Syntec Co., Ltd.) was used. The boundary condition was set as periodic. In the simulation of this embodiment, a structure including two adjacent sub-pixels was assumed. Two sub-pixels shown in Fig. 3(B) or Fig. 39(A) were arranged horizontally side by side. The left sub-pixel was set to white display (a voltage of 0 V to 6 V was applied to the pixel electrode 111), and the right sub-pixel was set to black display (a voltage of 0 V was applied to the pixel electrode 111). The size of one sub-pixel is 8 μm × 24 μm.

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

[0440] Figure 40(A) shows the result of the alignment simulation when a transistor with a BGTC structure is used, and Figure 40(B) shows the result of the alignment simulation when a transistor with a TGSA structure is used. Figure 40(A) , (B) shows the in-plane distribution at the maximum transmittance, respectively.

[0441] From the results of the alignment simulation, it was confirmed that the TGSA structure has higher aperture ratio, liquid crystal transmittance, and effective transmittance than the BGTC structure. Specifically, the aperture ratio of the TGSA structure is 37.0%, which is 1.016 times that of the BGTC structure (36.4%), and the liquid crystal transmittance of the TGSA structure is 1.030 times that of the BGTC structure, and the effective transmittance of the TGSA structure is 1.044 times that of the BGTC structure. Based on the above results, in the subsequent studies, transistors with a TGSA structure were used.

[0442] In this example, in the subsequent simulations, two sub-pixels shown in Figure 3(B) were arranged horizontally , the left sub-pixel was set to white display, and the right sub-pixel was set to black display.

[0443] <Examination of liquid crystal materials> Next, by performing alignment simulation, the alignment states of a positive liquid crystal material (Δε = 3.8) and a negative liquid crystal material (Δε = -3) were compared.

[0444] Figure 41(A) shows the result of the alignment simulation when a positive liquid crystal material is used, and Figure 41(B) shows the result of the alignment simulation when a negative liquid crystal material is used. Figure 41(A), (B) shows the in-plane distribution at the maximum transmittance, respectively.

[0445] The simulation was performed with a cell gap of 3.5 μm, a positive polarity applied, and a flexoelectric It was carried out under conditions with the flexoelectric effect. The flexoelectric effect is a phenomenon in which polarization occurs due to orientation strain mainly caused by the molecular shape. The orientation strain that causes the flexoelectric effect can be made smaller in the negative-type liquid crystal material than in the positive-type liquid crystal material. All subsequent simulations in this example were carried out under conditions with the flexoelectric effect. As shown in Fig. 41(A), when a positive-type liquid crystal material was used, a region with a reduced transmittance due to an orientation defect was confirmed within the white-display sub-pixel. Also, light leakage was confirmed in the adjacent sub-pixel (black-display sub-pixel). As shown in Fig. 41(B), when a negative-type liquid crystal material was used, a transmission region was confirmed throughout the white-display sub-pixel. Also, the light leakage confirmed at the outer peripheral part of the adjacent sub-pixel (black-display sub-pixel) was less than that when a positive-type liquid crystal material was used. Based on the above results, in subsequent investigations, a negative-type liquid crystal material was used.

[0446] Next, the results of the alignment simulations with positive and negative polarities when using a negative-type liquid crystal material were compared. For the positive polarity, simulations were carried out under the condition of applying a voltage from 0 V to 6 V to pixel electrode 111 of the white-display sub-pixel (left sub-pixel), and for the negative polarity, simulations were carried out under the condition of applying a voltage from 0 V to -6 V to pixel electrode 111 of the white-display sub-pixel. Here, alignment simulations were carried out under two types of conditions. In the first condition, cell gap...

[0447]

[0448]

[0449]

[0450] The cell gap was set to 3.5 μm. In the second condition, the cell gap was set to 2.5 μm, and the second common electrode (applied with 0 V) was adopted. The second common electrode adopted the same layout as the first common electrode 112 in Fig. 3(B). That is, the first common electrode 112 and the second common electrode have openings of the same size at the same position. The width of the opening (the horizontal length of the opening of the first common electrode 112 shown in Fig. 3(B)) was set to 3 μm.

[0451] Figs. 42(A) and (B) show the results of the alignment simulation when the cell gap is 3.5 μm. Figs. 43(A) and (B) show the results of the alignment simulation when the cell gap is 2.5 μm and the second common electrode (applied with 0 V) is adopted. Figs. 42 and 43 show the in-plane distribution at the maximum transmittance, respectively. Figs. 42(A) and 43( A) are the cases where a positive-polarity voltage is applied, respectively, and Figs. 42(B) and 43( B) are the cases where a negative-polarity voltage is applied, respectively. As shown in Figs. 43(A) and (B), it was found that by narrowing the cell gap to 2.5 μm and adopting the second common

[0452] electrode, the alignment defect of adjacent pixels can be suppressed. Furthermore, regardless of the polarity, there was no significant difference in the transmittance distribution of the white display sub-pixels and the degree of light leakage in adjacent pixels. Since the variation in optical characteristics due to polarity is small, the occurrence of flicker in the display device can be suppressed. Also, since there is little light leakage, it is not necessary to provide a wide light-shielding region, and the aperture ratio can be increased. Here, the aperture ratio of the pixel layout in Fig. 39(A) (without the second common electrode) is 36.4%

[0453] ​​​​, the aperture ratio of the pixel layout in Fig. 3(B) (without the second common electrode) was 37.0%. However, by adopting the second common electrode in the pixel layout of Fig. 3(B), the aperture ratio could be increased to 41.0 %.

[0454] Next, a simulation of the voltage-transmittance (V-T) characteristics of the pixels was performed. The anisotropy of the dielectric constant (Δε) was set to three values: -3, -5, and -7. Fig. 44 shows the results of the simulation. Shown.

[0455] As shown in Fig. 44, by increasing the absolute value of Δε, the saturation voltage decreased, and it was found that when Δε = -7, the maximum transmittance was about 4V.

[0456] <Fabrication of Liquid Crystal Display Device> Based on the results of the above simulation, a transmissive liquid crystal display device was fabricated by combining the pixel layout using the second common electrode and a negative-type liquid crystal material. The specifications of the display device are described. The size of the display unit is 4.16 inches diagonal, the number of effective pixels is 384 0(H)×RGB×2160(V), the fineness is 1058ppi, and the size of the sub-pixels is 8μm

[0457] (H)×24μm(V).

[0458] As the display element, a liquid crystal element in the FFS mode was used. As the liquid crystal material, a negative-type liquid crystal material was used. As the colorization method, the CF (color filter) method was used. The driving frequency was 6 0Hz. As the video signal format, analog line sequential was used. Also, the gate driver was built-in. Also, the source driver incorporated an analog switch and used COG.

[0459] ​The display device was fabricated such that the cell gap was approximately 2.5 μm by providing a spacer with a height of approximately 2.5 μm. The anisotropy of the dielectric constant Δε of the liquid crystal was set to -8, and the anisotropy of the refractive index Δ n of the liquid crystal was set to 0.118. The width of the opening of the second common electrode was fabricated to be approximately 3 μm. The interval between the openings of the second common electrode was fabricated to be approximately 5 μm.

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

[0461] As shown in Figure 45(B), a good alignment state was confirmed in white display. As shown in Figure 45(C ), it was confirmed that light leakage from outside the green sub-pixels was suppressed in green display.

[0462] By combining a top-gate structure CAAC-OS FET, which is superior in terms of low power consumption, high aperture ratio, and high transmittance, with a negative-type liquid crystal material from the viewpoints of good alignment state and low-voltage driving, a high-definition liquid crystal display device with a resolution of 4K and over 1 000 ppi was fabricated.

Example

[0463] In Example 1, as one of the conditions for the alignment simulation in the case of using a negative-type liquid crystal material, the cell gap was set to 2.5 μm, and the condition of adopting the second common electrode (applying 0 V) was shown. In this example, paying attention to the width of the opening of the second common electrode and the cell gap, the alignment simulation was respectively performed.

[0464] Describe the results of the duration test.

[0465] In this example, a liquid crystal display design simulator: LCD Master 3D Full set FEM mode (manufactured by Syntec Co., Ltd.) was used. The boundary condition was period ic. In the simulation of this example, a structure including two adjacent sub-pixels was assumed and two sub-pixels shown in Fig. 3(B) were arranged horizontally. The left sub-pixel was set to white display (applying a voltage from 0V to 6V to the pixel electrode 111 ), and the right sub-pixel was set to black display (applying a voltage of 0 V to the pixel electrode 111). The size of one sub-pixel was 8μm × 24μm. The width of the opening (the horizontal length of the opening of the first common electrode 112 shown in Fig. 3 (B)) was set to 3μm.

[0466] The simulation was performed using a negative liquid crystal material (Δε = -3) with the condition of applying 0V to the first common electrode 112 and the second common electrode.

[0467] First, alignment simulations were performed for five conditions where the widths of the openings of the second common electrode were 2μm, 3μm, 4μm, 5μm, and 8μ m, respectively. Here, the width of the opening of the second common electrode corresponds to the length L1 of the portion where the second common electrode 244 shown in Figs. 1(A) and (B) is not provided. As described above, since the size of one sub-pixel is 8μm × 24μm , the condition of length L1 = 8μm corresponds to the condition where the second common electrode is not provided in the sub-pixel. Also, when the length L1 = 3μm, it can be said that the second common electrode has the same layout as the first common electrode 112 in Fig. 3(B). The cell gap was set to 3μm. As described above, since the size of one sub-pixel is 8μm × 24μm For the condition of length L1 = 8μm, it corresponds to the condition where the second common electrode is not provided in the sub-pixel. Also, when the length L1 = 3μm, it can be said that the second common electrode has the same layout as the first common electrode 112 in Fig. 3(B). The cell gap was set to 3μm. When the length L1 = 3μm, the second common electrode has the same layout as the first common electrode 112 in Fig. 3(B). The cell gap was set to 3μm. The cell gap was set to 3μm.

[0468] In this embodiment, orientation simulation was performed to calculate the transmittance and contrast. Here the transmittance is the average transmittance of the sub-pixels in white display. The contrast is the value obtained by dividing the average transmittance of the sub-pixels in white display by the average transmittance of the sub-pixels in black display.

[0469] Fig. 46(A) shows the simulation results of the voltage-transmittance characteristics, and Fig. 46(B) shows the simulation results of the transmittance-contrast characteristics. From these results, it was found that when compared at the same transmittance, the smaller the width of the opening of the second common electrode, the higher the contrast was. Also, it was found that the larger the width of the opening of the second common electrode, the lower the voltage at the maximum transmittance became. Next, orientation simulation was performed under three conditions where the cell gap was set to 2.5 μm, 2.75 μm, and 3 μm respectively. Note that the width of the opening of the first common electrode and the second common electrode

[0470] was both 3 μm.

[0471] Fig. 47(A) shows the simulation results of the voltage-transmittance characteristics, and Fig. 47(B) shows the simulation results of the transmittance-contrast characteristics. From these results, it was found that the smaller the cell gap, the higher the contrast was. Also, it was found that the larger the cell gap, the higher the transmittance became.

Explanation of Signs

[0472] 34 Capacitor 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 sub-pixel 60b sub-pixel 60c sub-pixel 61 substrate 62 display unit 63 connection unit 64 drive circuit unit 65 wiring 66 non-display area 68 display area 68a display area 68b display area 69 connection unit 72 FPC 72a FPC 72b FPC 73 IC 73a IC 73b IC 81 scanning line 82 signal line 100A display device 100B display device 100C display device 100D display device 100E display device 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 substrate 119b substrate 121 overcoat 122 insulating layer 123 insulating layer 124 electrode 125 insulating layer 126 conductive layer 127 electrode 128 electrode 130 polarizer 131 coloring layer 132 light shielding layer 132a Light-shielding layer 132b Light-shielding layer 133a Alignment layer 133b Alignment layer 137 Wiring 138 Wiring 139 Auxiliary wiring 141 Adhesive layer 160 Protective substrate 161 Backlight 162 Substrate 163 Adhesive layer 164 Adhesive layer 165 Polarizer 166 Polarizer 167 Adhesive layer 168 Adhesive layer 169 Adhesive layer 201 Transistor 204 Connection part 206 Transistor 211 Insulating layer 212 Insulating layer 213 Insulating layer 214 Insulating layer 215 Insulating layer 216 Insulating layer 220 Insulating layer 221 Gate 222a Conductive layer 222b Conductive layer 223 Gate 228 Scanning line 229 Signal line 231 Semiconductor layer 231a Channel region 231b Low-resistance region 242 Connector 242b Connector 243 Connector 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 device 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 Region 461 Conductive film 462 Conductive film 463 Conductive film 464 Nanowire 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 Opening 531b Opening 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 Opening 547b Opening 547c Opening 547d Opening 555 Impurity 569 Region 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 Capacitance 621 Electrode 622 Electrode 3501 Wiring 3502 Wiring 3510 Wiring 3511 Wiring 3515_1 Block 3515_2 Block 3516 Block 5000 Housing 5001 Display Unit 5002 Display Unit 5003 Speaker 5004 LED Lamp 5005 Operation Key 5006 Connection Terminal 5007 Sensor 5008 Microphone 5009 Switch 5010 Infrared Port 5011 Recording Medium Reader 5012 Stand 5013 Remote Control Operation Unit 5014 Antenna 5015 Shutter Button 5016 Image Receiving Unit 5017 Charger 5018 Band 5019 Fastener 5020 Icon 5021 Icon 6500 Touch Panel Module 6501 Circuit Unit 6502 Signal Line Driving Circuit 6503 Sensor Driving Circuit 6504 Detection Circuit 6505 Timing Controller 6506 Image Processing Circuit 6510 Touch Panel 6511 Display Unit 6512 Input Unit 6513 Scanning Line Driving Circuit 6520 IC 6530 IC 6531 Substrate 6532 Opposite Substrate 6533 FPC 6534 PCB 6540 CPU 8000 Touch Panel Module 8001 Upper Cover 8002 Lower Cover 8003 FPC 8004 Touch Panel 8007 Backlight 8008 Light Source 8009 Frame 8010 Printed Circuit Board 8011 Battery

Claims

【Claim 1】 A display device including pixels each having a plurality of sub-pixels, the pixels having a pixel electrode, a first common electrode, a second common electrode, and a liquid crystal layer, each of the plurality of sub-pixels having a display area, each of the pixel electrode and the first common electrode being located on a side opposite to the second common electrode with the liquid crystal layer interposed therebetween in a thickness direction of the display device, the same potential being supplied to the first common electrode and the second common electrode, the first common electrode having a portion overlapping with the second common electrode between display areas of two adjacent sub-pixels presenting different colors, at least one of the pixel electrode and the first common electrode having a portion not overlapping with the second common electrode in the display area of the sub-pixel.

Images