WO2019155320A1

WO2019155320A1 - Driving method for display device

Info

Publication number: WO2019155320A1
Application number: PCT/IB2019/050693
Authority: WO
Inventors: 山崎舜平; 楠紘慈; 宍戸英明; 井上聖子; 福留貴浩
Original assignee: 株式会社半導体エネルギー研究所
Priority date: 2018-02-09
Filing date: 2019-01-29
Publication date: 2019-08-15
Also published as: JP7267212B2; CN111684515B; JPWO2019155320A1; KR20200111215A; CN111684515A

Abstract

Provided is a liquid crystal display device that suppresses flickering. Specifically provided is a display device having a first display region, wherein the first display region has a plurality of second regions and a plurality of third regions. The second regions and the third regions are disposed in an alternating fashion. The second regions are non-display regions where display data is updated. The third regions are regions where an image is displayed. The second regions and the third regions move in one direction, the plurality of second regions each have a period that is selected simultaneously in order to update display data, and the plurality of third regions are driven so as to perform display simultaneously.

Description

Driving method of display device

One embodiment of the present invention relates to a display device and a driving method of the display device.

Note that one embodiment of the present invention is not limited to the above technical field. As a technical field of one embodiment of the present invention, a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an electronic device, a lighting device, an input device (eg, a touch sensor), an input / output device (eg, a touch panel) ), A driving method thereof, or a manufacturing method thereof can be given as an example.

As the display device, a flat panel display represented by a liquid crystal display device is widely used. In these display devices, methods for realizing high-resolution display are being studied. Patent Document 1 discloses a field sequential display method that does not use a color filter.

Patent Document 2 discloses a technique in which a transistor using a metal oxide as a semiconductor material is used as a switching element of a pixel of a display device.

JP 2012-129988 A JP 2007-123861 A

Another object of one embodiment of the present invention is to provide a liquid crystal display device that suppresses flicker. Another object of one embodiment of the present invention is to provide a liquid crystal display device with a high aperture ratio. Another object of one embodiment of the present invention is to provide a liquid crystal display device with low power consumption. Another object of one embodiment of the present invention is to provide a high-definition liquid crystal display device. Another object of one embodiment of the present invention is to provide a highly reliable liquid crystal display device. Another object is to provide a liquid crystal display device capable of stable operation in a wide temperature range.

Note that the description of these issues does not disturb the existence of other issues. One embodiment of the present invention does not necessarily have to solve all of these problems. Issues other than these can be extracted from the description, drawings, and claims.

One embodiment of the present invention is a method for driving a display device, which is a method for driving a display device having a first display region. The first display area has a plurality of second areas and a plurality of third areas. The second region and the third region are alternately present. The second area is an area where display data is updated and is not displayed. The third area is an area where an image is displayed. The second region and the third region move in one direction, the plurality of second regions have a period selected at the same time for updating the display data, and the plurality of third regions are simultaneously It is a method for driving a display device that is driven so as to be displayed.

In each of the above configurations, the first display area has a plurality of light shielding areas. The light shielding region is provided between the second region and the third region. The light shielding area can suppress the second area from being erroneously displayed by the light of the third area.

In each of the above configurations, the area of the non-display area that is the third area may be different from that of the display area that is the second area.

In each of the above configurations, the first display area includes an area that shifts from a display state to a non-display state, an area that maintains the display state, and an area that shifts from the non-display state to the display state.

In each of the above configurations, it is preferable that the plurality of third regions transmit light of different hues.

In each of the above configurations, the first display area has a plurality of pixels. The pixel includes a transistor. Note that the transistor includes a metal oxide in a semiconductor layer.

According to one embodiment of the present invention, a liquid crystal display device that suppresses flickering can be provided. Alternatively, according to one embodiment of the present invention, a liquid crystal display device with a high aperture ratio can be provided. Alternatively, according to one embodiment of the present invention, a liquid crystal display device with low power consumption can be provided. Alternatively, according to one embodiment of the present invention, a high-definition liquid crystal display device can be provided. Alternatively, according to one embodiment of the present invention, a highly reliable liquid crystal display device can be provided. Alternatively, according to one embodiment of the present invention, a liquid crystal display device capable of stable operation over a wide temperature range can be provided.

Note that the description of these effects does not disturb the existence of other effects. One embodiment of the present invention need not necessarily have all of these effects. Effects other than these can be extracted from the description, drawings, and claims.

FIGS. 5A and 5B are diagrams illustrating examples of display areas. FIGS. (A) A figure showing an example of a display field. FIG. 5B illustrates an example of a display device. FIG. 6 is a circuit diagram illustrating an example of a display device. (A) A circuit diagram showing an example of a pixel. (B) Timing chart. (C) A circuit diagram showing an example of a pixel. Timing chart. Timing chart. FIG. 11 is a block diagram illustrating an example of an electronic device. FIG. 4A is a perspective view illustrating an example of a display device. (B) Three views showing a display device. FIG. 4A is a perspective view illustrating an example of a display device. (B) Three views showing a display device. The perspective view which shows an example of a display apparatus. 4A and 4B are cross-sectional views illustrating an example of a display device. (A) (B) (C) Top view showing an example of a pixel. Sectional drawing which shows an example of a display apparatus. Sectional drawing which shows an example of a display apparatus. Sectional drawing which shows an example of a display apparatus. FIGS. 5A to 5C each illustrate an example of an electronic device. FIGS. FIGS. 5A to 5C each illustrate an example of an electronic device. FIGS. FIGS. 5A and 5B each illustrate an example of an electronic device. FIGS.

Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes 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 below.

Note that in the structures of the invention described below, the same portions or portions having similar functions are denoted by the same reference numerals in different drawings, and description thereof is not repeated. In addition, in the case where the same function is indicated, the hatch pattern is the same, and there is a case where no reference numeral is given.

Also, the position, size, range, etc. of each component shown in the drawings may not represent the actual position, size, range, etc. for easy understanding. Therefore, the disclosed invention is not necessarily limited to the position, size, range, or the like disclosed in the drawings.

Note that the terms “film” and “layer” can be interchanged with each other depending on circumstances or circumstances. For example, the term “conductive layer” can be changed to the term “conductive film”. Alternatively, for example, the term “insulating film” can be changed to the term “insulating layer”.

Note that in this specification, a high power supply voltage may be referred to as an H level (or V _DD ), and a low power supply voltage may be referred to as an L level (or GND).

Further, in this specification, the following embodiments can be appropriately combined. In the case where a plurality of structure examples are given in one embodiment, any of the structure examples can be combined as appropriate.

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

1A and 1B has a displayable area. The displayable area includes a plurality of non-display areas, a plurality of display areas, and a plurality of light shielding areas 10c. The display panel 10a has a plurality of pixels. As an example, the displayable area includes a non-display area 20 (with hatching) and a display area 21 (without hatching).

The non-display area 20 and the display area 21 are alternately present. The display data is updated in the non-display area 20, and the image is displayed in the display area 21. The non-display area 20 and the display area 21 move in one direction, and the plurality of display areas 21 can be driven to be displayed simultaneously.

In FIG. 1A, as an example, the non-display area 20 is updated with the image data B1a, and the display area 21 is displayed with the image data B1b. In the display area for displaying the image data, the non-display state is clearly indicated by hatching. In FIG. 1B, as an example, the non-display area 20 is updated with the image data R1a, a part of the display area 21 is displayed with the image data R1b, and the display area 21 is different. The area is displayed as image data R1c.

1A shows an example in which the non-display area 20 has the same area as the display area 21, but the non-display area 20 may not necessarily have the same area as the display area 21. As shown in FIG. 1B, the non-display area 20 may have a different area from the display area 21.

In FIG. 1B, a region in which a part of the display area 21 moves to the non-display area 20, an area that continues to be displayed as the display area 21, an area in which the non-display area 20 moves to the display area 21, The drive method which has is shown. Each display area 21 can simultaneously display light of different hues. Therefore, in the one frame period in which the display area of the display panel 10a is updated with image data, a plurality of display areas 21 can be displayed while moving in a wave shape.

¡Lights of different hues are displayed at the same time and move wavy with time. The human eye recognizes light of different hues displayed at the same time and light integrated by moving in a wave shape with time. Note that the human eye recognizes light that moves with time as integrated luminance. In the display panel 10 a having a plurality of display areas 21, the lights displayed in the display areas 21 are combined and integrated according to the size of the area of the display area 21. Furthermore, light of different hues can be synthesized and integrated while the display area 21 moves in a wave shape. When the integrated luminance is generated using a large area, flickering or color breaks due to afterimages are likely to occur. However, the integrated luminance generated in each display area 21 with a small area can suppress flickering and improve display quality.

The non-display area 20 and the display area 21 each have a plurality of pixels. The plurality of non-display areas 20 have periods selected at the same time for updating the display data, and the image data is updated, and the respective pixels included in the display area 21 are simultaneously displayed. However, if the pixels included in the display area 21 and the pixels included in the non-display area 20 exist in the vicinity, the light in the display area 21 may be given to the pixels in the non-display area as stray light.

Note that the display area of the display panel 10a preferably includes a plurality of light shielding areas 10c. For example, the light shielding region 10 c is provided between the non-display region 20 and the display region 21, and the light shielding region 10 c is disposed at a position in contact with the non-display region 20. Further, the light shielding area 10 c has an effect of suppressing stray light from being displayed on the display area 21 from affecting the non-display area 20. When the non-display area 20 is displayed due to stray light, display blur or the like occurs in the non-display area 20 in contact with the display area 21 and the display quality is deteriorated. Therefore, by providing the light shielding region 10c, stray light from the display region 21 can be suppressed and display quality can be improved.

2, the display panel 10a included in the display device will be described in detail. However, in FIG. 2A, an example in which the display panel 10a includes the

non-display areas

20R, 20G, and 20B and the

display areas

21R, 21G, and 21B will be described in order to simplify the description. The display panel 10a has image data R0b, G0a, G0b, B0a, B0b, R1a, R1b, and the image data R1a, R1b will be described as image data of the next frame. Therefore, the gradation of the image data R0b, R1a, R1b is preferably controlled by different image data.

FIG. 2B is a diagram illustrating an example of the display device 10. The display device 10 includes a display panel 10a, a gate driver 11, a source driver 12, and a light unit 13. The display panel 10a includes a plurality of scanning lines G, a plurality of signal lines S, and a plurality of pixels P. The display panel 10a has m pixels (m is an integer of 1 or more) in the column direction, n pixels in the row direction (n is an even number of 1 or more), and a total of m × n pixels P. The scanning line G has n rows, and the signal line S has m columns.

In FIG. 2B, as an example, the gate driver 11 can simultaneously select pixels in adjacent rows connected to the scanning line G. Note that the pixels in adjacent rows are not limited to two pixels, and three or more pixels can be selected simultaneously.

As an example, when a pixel connected to the scanning line G (jr) is described, the description will be made using the pixel P (x, yr) and the pixel P (x + 1, yr + 1). The scanning line G (jr) can select a plurality of pixels electrically connected to the yr row extending in the column direction and a plurality of pixels electrically connected to the yr + 1 row. . Similarly, the scanning line G (jg) selects a plurality of pixels electrically connected to the yg row extending in the column direction and a plurality of pixels electrically connected to the yg + 1 row. be able to. Similarly, the scanning line G (jb) selects a plurality of pixels electrically connected to the yb row extending in the column direction and a plurality of pixels electrically connected to the yb + 1 row. be able to. Note that jr, jg, and jb are integers of 1 to n / 2, x is an integer of 1 to m, and yr, yg, and yb are odd numbers of 1 to n.

Further, it is preferable that the light unit 13 has at least three kinds of light of different hues. FIG. 2B shows an example having hues (LR: red, LG: green, LB: blue), but as light of different hues (LW: white, LC: cyan, LM: magenta, LY: Yellow) and the like. The hue of the light unit 13 can be combined according to the hue used for display. For example, the hue (LR: red, LG: green, LB: blue) may be combined with the hue (LW: white) as a complementary color, or only one of them may be used.

The light unit 13 is preferably capable of emitting a plurality of different lights from different openings. The light emitted from the different openings is given to the different display areas 20.

Although a detailed description of the source driver 12 is shown in FIG. 7, the source driver 12 may not be formed on the same substrate as the display panel 10 a and the gate driver 11. The source driver 12 may be connected to a substrate on which the display panel 10a and the gate driver 11 are formed via a flexible printed circuit board.

FIG. 2B shows the relationship between the

non-display areas

20G, 20B, and 20R, the

display areas

21R, 21G, and 21B of the display panel 10a of FIG. Yes.

For example, when the scanning line G (jr) is selected, the image data of a plurality of pixels connected to the yr row extending in the column direction and the yr + 1 row are simultaneously updated. When the scanning line G (jg) is selected, the image data of a plurality of pixels connected to the yg row extending in the column direction and the yg + 1 row are simultaneously updated. When the scanning line G (jr) is selected, the image data of a plurality of pixels connected to the yb row extending in the column direction and the yb + 1 row are updated simultaneously.

The pixels in the row selected by the scanning line correspond to the non-display area 20 (with hatching), and the pixels whose image data has not been updated are areas where the light unit 13 is lit as the display area 21 (without hatching). It is. However, for example, when the hue LR of the light unit 13 is turned on, the other hues are preferably turned off. In each display area 21, it is preferable to select a hue to be lit according to the image data updated in the non-display area 20. Note that two or more hues can be turned on simultaneously to combine lights of different hues. In addition, it is preferable that the image data of a plurality of pixels connected to the yr-th row and the yr + 1-th row be updated during a period when the hue LR of the light unit 13 is not lit. FIG. 2B shows an example in which the image data of a plurality of pixels connected to the yr row and the yr + 1 row are updated immediately after the hue LR of the light unit 13 is turned off. However, the update timing of the pixel image data is not limited.

FIG. 3 shows a more detailed circuit diagram of the display panel 10a shown in FIG. Note that in FIG. 3, in order to simplify the explanation, as an example, the scanning line G1 (jg), the pixel P (x, yg) electrically connected to the scanning line G2 (jg), and the pixel P ( x, yg + 1) will be described.

The pixel P (x, yg) includes a transistor 101, a transistor 102, a capacitor 104, and a display element 24. A detailed description of the display element 24 will be given with reference to FIG.

The gate of the transistor 101 is electrically connected to the scanning line G1 (jg). One of a source and a drain of the transistor 101 is electrically connected to the signal line S1 (i). The other of the source and the drain of the transistor 101 is electrically connected to one of the electrodes of the capacitor 104 and the display element 24. A gate of the transistor 102 is electrically connected to the scan line G2 (jg). One of a source and a drain of the transistor 102 is electrically connected to the signal line S2 (i). The other of the source and the drain of the transistor 102 is electrically connected to the other of the electrodes of the capacitor 104.

The pixel P (x, yg + 1) is electrically connected to the scanning line G1 (jg) and the scanning line G2 (jg). The pixel P (x, yg + 1) is different from the pixel P (x, yg) in that it is electrically connected to the signal line S1 (i + 1) and the signal line S2 (i + 1). That is, the scanning line G can simultaneously select a plurality of rows, and different signal lines S for simultaneously updating image data are connected to the pixels connected to the scanning line. In the circuit diagram shown in FIG. 3, an example in which the signal lines are connected from different directions is shown, but the signal lines may be connected from the same direction. By inputting signals from different directions, the pixel layout is arranged symmetrically. Therefore, there is an effect of widening the viewing angle of the display panel 10a.

In FIG. 4, the pixel is described in detail. Here, the operation of the display element 24 and the pixel will be described, and the description of the pixel connection described in FIG. 3 will be omitted.

Note that the pixel included in the display device of one embodiment of the present invention has a function of adding a correction signal to image data.

The correction signal is added to the image data by capacitive coupling and supplied to the liquid crystal element. Therefore, the corrected image can be displayed on the liquid crystal element. By this correction, for example, the liquid crystal element can express more gradations than can be expressed using only image data.

Further, the liquid crystal element can be driven at a voltage higher than the output voltage of the source driver 12 by the correction. Since the voltage supplied to the liquid crystal element can be changed to a desired value within the pixel, the existing source driver 12 can be diverted, and the cost for newly designing the source driver 12 can be reduced. Moreover, since it can suppress that the output voltage of the source driver 12 becomes high, the power consumption of the source driver 12 can be reduced.

By driving the liquid crystal element by applying a high voltage, the display device can be used in a wide temperature range, and display can be performed with high reliability in both a low temperature environment and a high temperature environment. For example, the display device can be used as an on-vehicle display device or a camera display device.

Also, a high voltage can be applied to drive the liquid crystal element. Therefore, a liquid crystal material having a high driving voltage such as a liquid crystal exhibiting a blue phase can be used.

Also, since the liquid crystal element can be driven by applying a high voltage, the response speed can be improved by overdrive driving.

The correction signal is generated by, for example, an external device and written to each pixel. The correction signal may be generated in real time using an external device, or the correction signal stored in the recording medium may be read out and synchronized with the image data.

In the display device of one embodiment of the present invention, the image data to be supplied is not changed, and new image data can be generated from the pixel to which the correction signal is supplied. Compared to the case where new image data itself is generated using an external device, the load on the external device can be reduced. Further, an operation for generating new image data with pixels can be performed with few steps, and a display device with a large number of pixels and a short horizontal period can be used.

4A, the display element 24 will be described. The display element 24 includes a liquid crystal element 24 a and a capacitor element 105. One of the electrodes of the liquid crystal element 24 a is electrically connected to one of the electrodes of the capacitor 105, one of the electrodes of the capacitor 104, and the other of the source or the drain of the transistor 101. The common electrode COM is electrically connected to the other electrode of the liquid crystal element 24 a and the other electrode of the capacitor 105. Note that the node NA is a node connected to one of the electrodes of the liquid crystal element 24 a, one of the electrodes of the capacitor 105, one of the electrodes of the capacitor 104, and the other of the source and the drain of the transistor 101.

FIG. 4B is a timing chart when the pixels are updated with image data.

At time T2, the transistor 101 and the transistor 22 are turned on by signals given to the scanning lines G1 and G2. An initialization voltage Vr corresponding to a gradation value of 0 is applied to the signal line S2, and image data Vp is applied to the signal line S1. The image data Vp is held in the node NA.

At time T3, the transistor 101 is turned off by a signal given to the scanning line G1, and the transistor 102 is kept on by the signal given to the scanning line G2. Image data Vs is applied to the signal line S2. The node NA is changed to the potential Vs + Vp by adding the image data Vs to the image data Vp due to capacitive coupling via the capacitive element 104.

At time T4, the transistor 102 is turned off by a signal applied to the scanning line G2. Therefore, the potential Vs + Vp is held at the node NA. Note that the transistor 101 and the transistor 102 are preferably transistors with low off-state current. As the transistor with low off-state current, a transistor including a metal oxide in a semiconductor layer described in Embodiment 2 is preferably used.

Note that FIG. 4C illustrates an example in which the transistor 101a and the transistor 102a each have a back gate. FIG. 4C illustrates an example in which the gate of the transistor is electrically connected to the back gate of the transistor. Note that the connection destination of the back gate is not limited to the gate of the transistor. The back gate may be connected to the source or the drain of the transistor, or may be connected to a wiring that can be controlled from the outside.

FIG. 5 illustrates the operation of the circuit described in FIG. 3 using a timing chart. When image data is given to the pixel P (x, yg), the image data given via the signal line S1 is represented as image data D (x, yg), and the image data given via the signal line S2 is It is expressed as image data DW (x, yg).

At time T11, a signal of “H” is given to the scanning line G1 (jg−1) and the scanning line G2 (jg−1). The pixel P (x, yg-2) is supplied with the image data D (x, yg-2) via the signal line S1 (i), and the initialization voltage Vr via the signal line S2 (i). Is given. The pixel P (x, yg−1) is supplied with the image data D (x, yg−1) via the signal line S1 (i + 1), and the initialization voltage Vr via the signal line S2 (i + 1). Is given.

At time T12, an "L" signal is applied to the scanning line G1 (jg-1) and an "H" signal is applied to the scanning line G2 (jg-1). Image data DW (x, yg-2) is given to the pixel P (x, yg-2) via the signal line S2 (i). Image data DW (x, yg-1) is given to the pixel P (x, yg-1) via the signal line S2 (i + 1). Although not shown in the figure, in the pixel P (x, yg-2), calculation of image data D (x, yg-2) + image data DW (x, yg-2) is performed on the display element. Is called. Similarly, in the pixel P (x, yg−1), calculation of image data D (x, yg−1) + image data DW (x, yg−1) is performed on the display element.

The gate driver 11 can update the image data by repeating the same operation at the time T11 and the time T12 according to the selected row. At time T13 and time T14, the image data of the pixel P (x, yg) and pixel P (x, yg + 1) is updated, and at time T15 and time T16, the pixel P (x, yg + 2) and pixel P (x , Yg + 3) image data can be updated.

In FIG. 6, a method for simultaneously updating the image data of the scanning lines in the different non-display areas 20 described in FIG. 2 will be described using a timing chart. FIG. 6 illustrates a method for updating image data in different non-display areas 20. It can be determined that the image data is updated at the same time even if the image data of the pixel is updated at different timings as long as the light unit is turned off. Note that image data of pixels in different non-display areas 20 is updated via signal lines S1 (i) and S2 (i).

In FIG. 6, in order to simplify the description, the pixel P (x, yr) to the pixel P (x, yr + 3), the pixel P (x, yg) to the pixel P (x, yg + 3), and the pixel P (x, yb) to pixel P (x, yb + 3) will be described. As shown in FIG. 2, the yr row, the yg row, or the yb row belong to different non-display areas 20.

At time T21, an “H” signal is applied to the scanning lines G1 (jr) and G2 (jr). The pixel P (x, yr) is supplied with the image data D (x, yr) through the signal line S1 (i) and the initialization voltage Vr through the signal line S2 (i). The pixel P (x, yr + 1) is supplied with the image data D (x, yr + 1) via the signal line S1 (i + 1) and the initialization voltage Vr via the signal line S2 (i + 1).

At time T22, a signal “H” is given to the scanning line G1 (jg) and the scanning line G2 (jg). Further, an “L” signal is supplied to the scanning line G1 (jr), and an “H” signal is supplied to the scanning line G2 (jr). The pixel P (x, yg) is supplied with the image data D (x, yg) via the signal line S1 (i) and the initialization voltage Vr via the signal line S2 (i). The pixel P (x, yg + 1) is supplied with the image data D (x, yg + 1) via the signal line S1 (i + 1) and the initialization voltage Vr via the signal line S2 (i + 1).

At time T23, a signal of “H” is given to the scanning line G1 (jb) and the scanning line G2 (jb). Further, an “L” signal is supplied to the scanning line G1 (jr), and an “H” signal is supplied to the scanning line G2 (jr). In addition, an “L” signal is applied to the scanning line G1 (jg), and an “H” signal is applied to the scanning line G2 (jg). The pixel P (x, yb) is supplied with the image data D (x, yb) via the signal line S1 (i) and the initialization voltage Vr via the signal line S2 (i). The pixel P (x, yb + 1) is supplied with the image data D (x, yb + 1) via the signal line S1 (i + 1) and the initialization voltage Vr via the signal line S2 (i + 1).

At time T24, an “L” signal is applied to the scanning line G1 (jr), and an “H” signal is applied to the scanning line G2 (jr). Further, an “L” signal is supplied to the scanning line G1 (jr), and an “H” signal is supplied to the scanning line G2 (jr). In addition, an "L" signal is supplied to the scanning line G1 (jb), and an "H" signal is supplied to the scanning line G2 (jb). Image data DW (x, yr) is given to the pixel P (x, yr) via the signal line S2 (i). Image data DW (x, yr + 1) is given to the pixel P (x, yr + 1) via the signal line S2 (i + 1).

At time T25, an “L” signal is supplied to the scanning line G1 (jr) and the scanning line G2 (jr). Further, an “L” signal is applied to the scanning line G1 (jg), and an “H” signal is applied to the scanning line G2 (jg). In addition, an “L” signal is applied to the scanning line G1 (jb) and an “H” signal is applied to the scanning line G2 (jb). Image data DW (x, yg) is given to the pixel P (x, yg) via the signal line S2 (i). Image data DW (x, yg + 1) is given to the pixel P (x, yg + 1) via the signal line S2 (i + 1).

At time T26, an "L" signal is given to the scanning line G1 (jr) and the scanning line G2 (jr). An “L” signal is supplied to the scanning line G1 (jg) and the scanning line G2 (jg). Further, an “L” signal is applied to the scanning line G1 (jb), and an “H” signal is applied to the G2 (jb). Image data DW (x, yb) is given to the pixel P (x, yb) via the signal line S2 (i). Image data DW (x, yb + 1) is given to the pixel P (x, yb + 1) via the signal line S2 (i + 1).

The gate dry 11 can update the image data by repeating the same operation from the time T21 to the time T26 according to the row of the scanning line to be selected. For example, from time T27 to time T32, the pixel P (x, yr + 2), the pixel P (x, yr + 3), the pixel P (x, yg + 2), the pixel P (x, yg + 3), the pixel P (x, yb + 2), and The image data of the pixel P (x, yb + 3) can be updated.

FIG. 7 shows a block diagram of the electronic device 30. The electronic device 30 includes a display device 10, a source driver 12, a light unit 13, a timing generation circuit 14, a display controller 15, a storage device 16, a processor 17, a communication module 18, a sensor 19, and an image sensor 20.

The display device 10 includes a display panel 10a, a gate driver 11, a source driver 12, and a light unit 13. However, the gate driver 11 or the source driver 12 does not have to be formed on the same substrate as the display panel 10a, and may be separately formed to be an IC. The connection method of the gate driver 11 or the source driver 12 made into an IC is not particularly limited, and a COG (Chip On Glass) method, a wire bonding method, a TAB (Tape Automated Bonding) method, or the like may be used. it can.

The timing generation circuit 14 has a function of generating a timing signal for displaying the display device 10 and a function of controlling display and non-display of the light unit 13 in synchronization with the image data of the source driver 12.

The display controller 15 has a function of converting data received from the communication module 18 via the storage device 16 or the processor 17 into image data.

The communication module 18 has a wireless communication function and a wired communication function. Therefore, the electronic device 30 transmits / receives data to / from the data server using either wireless communication or wired communication. For example, when performing wireless communication, data can be transmitted and received using a carrier wave.

When performing wireless communication, it is possible to use specifications standardized by IEEE such as wireless LAN (Local Area Network), Wi-Fi (registered trademark), Bluetooth (registered trademark), ZigBee (registered trademark), etc. . Or when performing wired communication, the specification standardized by ISO (International Organization for Standardization) such as wired LAN or CAN (Controller Area Network) can be used.

Examples of sensors that can be provided in the sensor 19 include a temperature sensor, a humidity sensor, a strain sensor, a heat flow sensor, an optical sensor, a gas sensor, a pressure sensor, a displacement sensor, an acceleration sensor, a flow velocity sensor, a rotation sensor, a density sensor, and a gyro sensor. In addition, an ultrasonic sensor, an optical fiber sensor, a biosensor, an odor sensor, a taste sensor, an iris sensor, a fingerprint authentication sensor, a palm print authentication sensor, a vein authentication sensor, or the like can be used. The sensor provided in the sensor 19 may be a micro electro mechanical system (MEMS). The content displayed on the display device can be changed using various information acquired by the sensor.

The image sensor 20 has a function of acquiring an image, and the acquired image can be displayed on the display device via the storage device 16 or the processor 17.

FIG. 8A shows a perspective view of the display device 10. The display device 10 includes a display panel 10a, an adhesive layer 10b, a light guide layer 10d, and a light unit 13a. In the example, the gate driver 11 is formed on the same substrate as the display panel 10a. The adhesive layer 10b is provided with a black matrix or the like for forming a light shielding region 10c disposed between the non-display region 20 and the display region 21. Alternatively, it is preferable that the black matrix is arranged at a position overlapping the scanning lines G1 and G2. By disposing the light shielding region 10c at a position overlapping the scanning lines G1 and G2, it is possible to suppress a decrease in the aperture ratio of the pixel.

The light unit 13a has a plurality of openings 13b, and can emit a plurality of different lights from the different openings 13b. For example, the light emitted from the opening 13b can be emitted by switching light of hue (LR: red, LG: green, LB: blue). In addition, the light inject | emitted from the opening part 13b may add the light of a different hue, and may combine several different light. In addition, the shape of the opening 13b is indicated by a circle in FIG. A shape having a plurality of sides may be used, and a corner formed by two sides may be rounded.

The interval Δd between the light shielding regions 10c is preferably the same as the interval between the pixels connected to the scanning lines that can be simultaneously selected by the gate driver 11 or the interval between the openings 13b of the light unit 13a. The center of each opening 13b of the light unit 13a is preferably arranged at a position overlapping the center of the interval Δd of the light shielding region 10c.

The light guide layer 10d can uniformly supply the light of the light unit 13a to the display panel 10a. In FIG. 8A, the light L1 and the light L2 emitted from the light unit 13a are emitted to the display panel 10a with the same luminance. The light of the light unit 13a emitted to the light guide layer 10d can be prevented from diffusing by the light shielding region 10c disposed on the adhesive layer 10b. Light in the display area 21 can be prevented from leaking to the non-display area 20 as stray light, and display defects such as display flickering can be suppressed. The adhesive layer 10b has a function of adhering the light guide layer 10d to the display panel 10a. Furthermore, the adhesive layer 10b may have a function of diffusing light.

FIG. 8B is a three-side view of the display device 10. In FIG. 8B, a light-transmitting counter substrate 10e is disposed on the upper side of the display panel 10a. On the counter substrate 10e, a black matrix may be disposed as the light shielding region 10f at a position overlapping the scanning lines G1 and G2. The display device 10 illustrated in FIG. 8B illustrates an example in which the display panel 10a, the adhesive layer 10b, and the light guide layer 10d are disposed at overlapping positions. The light unit 13a is provided at a position where the light unit 13a is located on the side surface of the display panel and emits light to the light guide. The light unit 13a may be provided at a position for emitting light to the side surface of the display panel 10a. In that case, the adhesive layer 10b and the light guide layer 10d may not be provided.

9 shows a display device 10 different from FIG. The display device 10 of FIG. 9 is different in that the light shielding region 10 g is provided in the light guide layer 10 d and the light unit 13 c is disposed at a position overlapping the gate driver 11. Furthermore, the light unit 13c is different from the opening 13b that emits light of a plurality of hues, and includes an LED (Light Emitting Diode) that emits light of each hue as it is to the light guide layer 10d.

It is preferable that LEDs having a plurality of hues are arranged in the light unit 13c in the interval Δd of the light shielding region 10g. Light emitted from the LED can be emitted by switching light of a hue (LR: red, LG: green, LB: blue). In addition, the light inject | emitted from LED may add the light of a different hue, and may combine several different light. In the light unit shown in FIG. 9B, the LEDs are arranged in parallel with the display panel 10a, but the LEDs may be arranged in a vertical product.

FIG. 9 shows an example in which the display panel 10a displays six display areas simultaneously. However, the number of display areas that the display panel 10a displays simultaneously is not limited. By applying the timing chart shown in FIG. 6, more display areas can be displayed simultaneously.

The

light shielding regions

10c, 10f, and 10g can be used either alone or in combination. By combining a plurality of light shielding regions, light leakage such as stray light can be reduced. Thus, a display device having favorable display quality that can suppress display flicker and the like can be obtained. Note that although not described in FIG. 8 or FIG. 9, a black matrix having a function of a light shielding region may be provided in the display panel 10a.

FIG. 10 shows a display device 10 different from those shown in FIGS. FIG. 10 differs in having a light unit 13d on the lower side of the display panel 10a. The light unit 13d has a plurality of openings 13b, and can emit light of a plurality of hues from the openings 13b.

Since the plurality of display areas 21 display different hues at the same time and the display area moves in a wavy manner, the hue can be synthesized and the integrated luminance can be generated in a small area, so that it can be operated at high speed. Thus, even better display quality can be obtained.

Also, since each pixel can display light of a plurality of hues, a color filter is not necessary. Therefore, since a sub pixel for each hue is not required, the definition can be increased. Therefore, higher definition display quality can be obtained. Further, by increasing the aperture ratio, the light extraction efficiency is improved. Accordingly, the luminance of the light unit 13 can be lowered, and the power consumption can be reduced.

This embodiment can be combined with any of the other embodiments as appropriate. In this specification, in the case where a plurality of structure examples are given in one embodiment, any of the structure examples can be combined as appropriate.

(Embodiment 2)
<Configuration example of display device>
A structure example of a display device including two transistors and two capacitors in a pixel will be described with reference to FIGS.

FIG. 11A is a cross-sectional view of a transmissive liquid crystal display device. A liquid crystal display device illustrated in FIG. 11A includes a substrate 31, a transistor 101, a transistor 102, an insulating layer 215, a conductive layer 46, an insulating layer 44, a pixel electrode 41, an insulating layer 45, a common electrode 43, a liquid crystal layer 42, and A substrate 32 is provided.

The transistor 101 and the transistor 102 are located on the substrate 31. The insulating layer 215 is located over the transistor 101 and the transistor 102. The conductive layer 46 is located on the insulating layer 215. The insulating layer 44 is located over the transistor 101, the transistor 102, the insulating layer 215, and the conductive layer 46. The pixel electrode 41 is located on the insulating layer 44. The insulating layer 45 is located on the pixel electrode 41. The common electrode 43 is located on the insulating layer 45. The liquid crystal layer 42 is located on the common electrode 43. The common electrode 43 has a region overlapping the conductive layer 46 with the pixel electrode 41 interposed therebetween. The pixel electrode 41 is electrically connected to the source or drain of the transistor 101. The conductive layer 46 is electrically connected to the source or drain of the transistor 102. The conductive layer 46, the pixel electrode 41, and the common electrode 43 each have a function of transmitting visible light.

In the liquid crystal display device of this embodiment, the pixel electrode 41 and the common electrode 43 are stacked with an insulating layer 45 interposed therebetween, and operate in an FFS (Fringe Field Switching) mode. The pixel electrode 41, the liquid crystal layer 42, and the common electrode 43 can function as the liquid crystal element 106.

The conductive layer 46, the insulating layer 44, and the pixel electrode 41 can function as one capacitor element 104. Further, the pixel electrode 41, the insulating layer 45, and the common electrode 43 can function as one capacitor 105. As described above, the liquid crystal display device of this embodiment includes two capacitors in a pixel.

The two capacitive elements are both made of a material that transmits visible light and have regions that overlap each other. Thus, the pixel can have a high aperture ratio and further have a plurality of storage capacitors.

By increasing the aperture ratio of the transmissive liquid crystal display device (also referred to as the aperture ratio of pixels), it becomes possible to increase the definition of the liquid crystal display device. Moreover, the light extraction efficiency can be increased by increasing the aperture ratio. Thereby, the power consumption of a liquid crystal display device can be reduced.

The capacity of the capacitor 104 is preferably larger than the capacity of the capacitor 105. For example, the area of the region where the pixel electrode 41 and the conductive layer 46 overlap is preferably larger than the area of the region where the pixel electrode 41 and the common electrode 43 overlap. Further, the thickness T1 of the insulating layer 44 located between the conductive layer 46 and the pixel electrode 41 is preferably thinner than the thickness T2 of the insulating layer 45 located between the pixel electrode 41 and the common electrode 43. .

The configuration of the display device in this embodiment can also be applied to a touch panel. FIG. 11B illustrates an example in which the touch sensor TC is mounted on the display device illustrated in FIG. By providing the touch sensor TC at a position close to the display surface of the display device, the sensitivity of the touch sensor TC can be increased.

There is no limitation on a detection element (also referred to as a sensor element) included in the touch panel of one embodiment of the present invention. Various sensors that can detect the proximity or contact of an object to be detected, such as a finger or a stylus, can be used as the detection element.

As the sensor method, various methods such as a capacitance method, a resistance film method, a surface acoustic wave method, an infrared method, an optical method, and a pressure-sensitive method can be used.

As the capacitance method, there are a surface capacitance method, a projection capacitance method, and the like. In addition, examples of the projected capacitance method include a self-capacitance method and a mutual capacitance method. The mutual capacitance method is preferable because simultaneous multipoint detection is possible.

The touch panel of one embodiment of the present invention includes a structure in which a separately manufactured display device and a detection element are bonded, a structure in which an electrode or the like that forms the detection element is provided on one or both of the substrate that supports the display element and the counter substrate, and the like Various configurations can be applied.

≪Top layout of pixels≫
12A, 12B, and 12C are top views of pixels. FIG. 12A is a top view of the stacked structure from the gate 221a and the gate 221b to the common electrode 43a as viewed from the common electrode 43a side. 12B is a top view in which the common electrode 43a is removed from the stacked structure in FIG. 12A, and FIG. 12C is the common electrode 43a and the pixel electrode 41 in the stacked structure in FIG. FIG.

The pixel has a connection part 73 and a connection part 74. In the connection portion 73, the pixel electrode 41 is electrically connected to the transistor 101. Specifically, the conductive layer 222a functioning as the source or drain of the transistor 101 is in contact with the conductive layer 46b, and the conductive layer 46b is in contact with the pixel electrode 41. In the connection portion 74, the conductive layer 46 a is electrically connected to the transistor 102. Specifically, the conductive layer 46 a is in contact with the conductive layer 222 c functioning as the source or drain of the transistor 102.

The common electrode 43a may have one or a plurality of slits, or may have a comb-like upper surface shape. A common electrode 43a illustrated in FIG. 12A has an upper surface shape provided with a plurality of slits. The pixel electrode 41 has both a region overlapping with the common electrode 43a and a region not overlapping with the common electrode 43a.

Further, the pixel electrode 41 may have one or a plurality of slits, or may have a comb-like upper surface shape. Since the area overlapping with the common electrode 43a can be widened, the pixel electrode 41 is preferably formed with a wide area. Therefore, the pixel electrode 41 is preferably formed in an island shape without a slit.

<< Cross-sectional structure of display module >>
FIG. 13 shows a cross-sectional view of the display module. Note that the cross-sectional structure of the pixel corresponds to a cross-sectional view taken along dashed-dotted line B1-B2 in FIG.

The display module shown in FIG. 13 includes a display device 10, an FPC 172, and the like.

The display device 10 is an active matrix liquid crystal display device to which the FFS mode is applied. The display device 10 is a transmissive liquid crystal display device.

The display device 10 includes a substrate 31, a substrate 32, a transistor 102, a conductive layer 46a, a conductive layer 46b, an insulating layer 44, an insulating layer 45, a pixel electrode 41, a liquid crystal layer 42, a common electrode 43a, a conductive layer 43b, a conductive layer 222e, An alignment film 133a, an alignment film 133b, an adhesive layer 141, an overcoat 135, a light shielding layer 38, an adhesive layer 10b, a light guide layer 10d, and the like are included.

The transistor 101 and the transistor 102 are located on the substrate 31. As an example, the transistor 101 includes a gate 221a, a gate insulating layer 211, a semiconductor layer 231a, a conductive layer 222a, a conductive layer 222b, an insulating layer 212, an insulating layer 213, a gate insulating layer 225a, and a gate 223a. The transistor 102 includes a gate 221b, a gate insulating layer 211, a semiconductor layer 231b, a conductive layer 222c, a conductive layer 222d, an insulating layer 212, an insulating layer 213, a gate insulating layer 225b, and a gate 223b.

The transistor 101 and the transistor 102 illustrated in FIG. 13 have gates above and below the channel. The two gates are preferably electrically connected. A transistor in which two gates are electrically connected can have higher field-effect mobility than another transistor, and can increase on-state current. As a result, a circuit capable of high speed operation can be manufactured. Furthermore, the area occupied by the circuit portion can be reduced. By applying a transistor with a large on-state current, signal delay in each wiring can be reduced and display unevenness can be suppressed even if the number of wirings is increased by increasing the size or definition of the display device. Is possible. In addition, since the area occupied by the circuit portion can be reduced, the display device can be narrowed. In addition, by applying such a structure, a highly reliable transistor can be realized.

The semiconductor layer 231 (231a, 231b) includes a pair of low resistance regions 231n and a channel formation region 231i sandwiched between the pair of low resistance regions 231n.

The channel formation region 231i overlaps with the gate 221 (221a, 221b) through the gate insulating layer 211 and overlaps with the gate 223 (223a, 223b) through the gate insulating layer 225 (225a, 225b).

Here, the case where a metal oxide is used for the semiconductor layer 231 is described as an example.

The gate insulating layer 211 and the gate insulating layer 225 in contact with the channel formation region 231i are preferably oxide insulating layers. Note that in the case where the gate insulating layer 211 or the gate insulating layer 225 has a stacked structure, it is preferable that at least a layer in contact with the channel formation region 231i be an oxide insulating layer. Accordingly, generation of oxygen vacancies in the channel formation region 231i can be suppressed, and the reliability of the transistor can be improved.

One or both of the insulating layer 213 and the insulating layer 214 is preferably a nitride insulating layer. Thus, impurities can be prevented from entering the semiconductor layer 231 and the reliability of the transistor can be increased.

The insulating layer 215 preferably has a planarization function, and is preferably an organic insulating layer, for example. Note that one or both of the insulating layer 214 and the insulating layer 215 are not necessarily formed.

The low resistance region 231n has a lower resistivity than the channel formation region 231i. The low resistance region 231n is a region in contact with the insulating layer 212 in the semiconductor layer 231. Here, the insulating layer 212 preferably contains nitrogen or hydrogen. Thereby, nitrogen or hydrogen in the insulating layer 212 enters the low resistance region 231n, and the carrier concentration of the low resistance region 231n can be increased. Alternatively, the low resistance region 231n may be formed by adding an impurity using the gate 223 as a mask. Examples of the impurity include hydrogen, helium, neon, argon, fluorine, nitrogen, phosphorus, arsenic, antimony, boron, and aluminum. The impurity is added by an ion implantation method or an ion doping method. Can do. In addition to the impurities, the low resistance region 231n may be formed by adding indium or the like which is one of the constituent elements of the semiconductor layer 231. By adding indium, the concentration of indium may be higher in the low resistance region 231n than in the channel formation region 231i.

In addition, after the gate insulating layer 225 and the gate 233 are formed, a first layer is formed so as to be in contact with a part of the semiconductor layer 231, and heat treatment is performed, so that the resistance of the region is reduced. A resistance region 231n can be formed.

As the first layer, a film containing at least one of metal elements such as aluminum, titanium, tantalum, tungsten, chromium, and ruthenium can be used. In particular, at least one of aluminum, titanium, tantalum, and tungsten is preferably included. Alternatively, a nitride containing at least one of these metal elements or an oxide containing at least one of these metal elements can be preferably used. In particular, a metal film such as a tungsten film or a titanium film, a nitride film such as an aluminum titanium nitride film, a titanium nitride film, or an aluminum nitride film, or an oxide film such as an aluminum titanium oxide film can be preferably used.

The thickness of the first layer can be, for example, 0.5 nm to 20 nm, preferably 0.5 nm to 15 nm, more preferably 0.5 nm to 10 nm, and further preferably 1 nm to 6 nm. Typically, it can be about 5 nm or about 2 nm. Even when the first layer is thin like this, the resistance of the semiconductor layer 231 can be sufficiently reduced.

It is important that the low resistance region 231n has a higher carrier density than the channel formation region 231i. For example, the low-resistance region 231n can be a region containing more hydrogen than the channel formation region 231i or a region containing more oxygen vacancies than the channel formation region 231i. When an oxygen vacancy and a hydrogen atom in an oxide semiconductor are combined, a carrier generation source is obtained.

By performing heat treatment in a state where the first layer is provided in contact with a part of the semiconductor layer 231, oxygen in the region is attracted to the first layer, and oxygen vacancies are increased in the region. Can be formed. Thereby, the low resistance region 231n can be a very low resistance region.

The low resistance region 231n formed in this manner has a feature that it is difficult to increase the resistance by a subsequent process. For example, even when heat treatment in an atmosphere containing oxygen, film formation treatment in an atmosphere containing oxygen, or the like, there is no fear that the conductivity of the low resistance region 231n is impaired, and thus the electrical characteristics are good. In addition, a highly reliable transistor can be realized.

When the first layer after the heat treatment has conductivity, it is preferable to remove the first layer after the heat treatment. On the other hand, in the case where the first layer has an insulating property, the first layer can function as a protective insulating film by remaining it.

The conductive layer 46 b is located on the insulating layer 215, the insulating layer 44 is located on the conductive layer 46 b, and the pixel electrode 41 is located on the insulating layer 44. The pixel electrode 41 is electrically connected to the conductive layer 222a. Specifically, the conductive layer 222a is connected to the conductive layer 46b, and the conductive layer 46b is connected to the pixel electrode 41.

The conductive layer 46a is located on the insulating layer 215. The conductive layer 46a is electrically connected to the conductive layer 222c. Specifically, the conductive layer 46 a is in contact with the conductive layer 222 c through an opening provided in the insulating layer 214 and the insulating layer 215.

The substrate 31 and the substrate 32 are bonded together by an adhesive layer 141.

The FPC 172 is electrically connected to the conductive layer 222e. Specifically, the FPC 172 is in contact with the connection body 242, the connection body 242 is in contact with the conductive layer 43b, and the conductive layer 43b is in contact with the conductive layer 222e. The conductive layer 43b is formed on the insulating layer 45, and the conductive layer 222e is formed on the insulating layer 214. The conductive layer 43b can be formed using the same process and the same material as the common electrode 43a. The conductive layer 222e can be formed using the same process and the same material as the conductive layers 222a to 222d.

The conductive layer 46 a, the insulating layer 44, and the pixel electrode 41 can function as one capacitor element 104. Further, the pixel electrode 41, the insulating layer 45, and the common electrode 43 a can function as one capacitor element 105. As described above, the display device 10 has two capacitors in one pixel.

The two capacitive elements are both made of a material that transmits visible light and have regions that overlap each other. Thereby, the pixel can achieve both a high aperture ratio and a large storage capacity.

The capacity of the capacitor 104 is preferably larger than the capacity of the capacitor 105. Therefore, the area of the region where the pixel electrode 41 and the conductive layer 46a overlap is preferably larger than the area of the region where the pixel electrode 41 and the common electrode 43a overlap. The thickness of the insulating layer 44 located between the conductive layer 46a and the pixel electrode 41 is preferably thinner than the thickness of the insulating layer 45 located between the pixel electrode 41 and the common electrode 43a.

FIG. 13 shows an example in which the adhesive layer 10b has a light shielding layer 38a.

FIG. 13 illustrates an example in which both the transistor 101 and the transistor 102 have a back gate (gate 223); however, one or both of the transistor 101 and the transistor 102 may not have a back gate.

FIG. 13 illustrates an example in which the gate insulating layer 225 is formed only over the channel formation region 231i and does not overlap the low resistance region 231n. However, the gate insulating layer 225 overlaps at least part of the low resistance region 231n. May be. FIG. 14 shows an example in which the gate insulating layer 225 is formed in contact with the low resistance region 231n and the gate insulating layer 211. The gate insulating layer 225 illustrated in FIGS. 14A and 14B has advantages such that the number of steps for processing the gate insulating layer 225 using the gate 223 as a mask can be reduced, and a step on the formation surface of the insulating layer 214 can be reduced.

FIG. 14 shows an example in which the light guide layer 10d has a light shielding layer 38b.

15 is different from FIGS. 13 and 14 in the structure of the transistor 101 and the transistor 102.

15 includes a gate 221a, a gate insulating layer 211, a semiconductor layer 231a, a conductive layer 222a, a conductive layer 222b, an insulating layer 217, an insulating layer 218, an insulating layer 215, and a gate 223a. The transistor 102 includes a gate 221b, a gate insulating layer 211, a semiconductor layer 231b, a conductive layer 222c, a conductive layer 222d, an insulating layer 217, an insulating layer 218, an insulating layer 215, and a gate 223b. One of the conductive layer 222a and the conductive layer 222b functions as a source, and the other functions as a drain. The insulating layer 217, the insulating layer 218, and the insulating layer 215 function as gate insulating layers.

The gate insulating layer 211 and the insulating layer 217 in contact with the semiconductor layer 231 are preferably oxide insulating layers. Note that in the case where the gate insulating layer 211 or the insulating layer 217 has a stacked structure, at least a layer in contact with the semiconductor layer 231 is preferably an oxide insulating layer. Accordingly, generation of oxygen vacancies in the semiconductor layer 231 can be suppressed, and the reliability of the transistor can be improved.

The insulating layer 218 is preferably a nitride insulating layer. Thus, impurities can be prevented from entering the semiconductor layer 231 and the reliability of the transistor can be increased.

The insulating layer 215 preferably has a planarization function, and is preferably an organic insulating layer, for example. Note that the insulating layer 215 is not necessarily formed, and the conductive layer 46 a may be formed in contact with the insulating layer 218.

The conductive layer 46a is located on the insulating layer 215. The insulating layer 44 and the insulating layer 45 are located on the conductive layer 46a. A common electrode 43 a is located on the insulating layer 45. The common electrode 43a is electrically connected to the conductive layer 46a. Specifically, the common electrode 43 a is in contact with the conductive layer 46 a through an opening provided in the insulating layer 44 and the insulating layer 45.

≪Component material≫
Next, details of materials and the like that can be used for each component of the display device and the display module of this embodiment will be described.

There is no major limitation on the material of the substrate included in the display device, 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, a plastic substrate, or the like can be used.

By using a thin substrate, the display device can be reduced in weight and thickness. Furthermore, a flexible display device can be realized by using a flexible substrate.

There are two types of liquid crystal materials: positive liquid crystal materials having a positive dielectric anisotropy (Δε) and negative liquid crystal materials having a negative dielectric constant. In one embodiment of the present invention, either material can be used, and an optimum liquid crystal material can be used depending on a mode to be applied and a design.

In the display device of this embodiment mode, liquid crystal elements to which various modes are applied can be used. In addition to the FFS mode described above, for example, an IPS mode, a TN mode, an ASM (Axial Symmetrically aligned Micro-cell) mode, an OCB (Optically Compensated BirefringenceCriff mode), and an FLC (FerroelectricLiquidFrequencyLiquidCrCF) Further, a liquid crystal element to which an ECB (Electrically Controlled Birefringence) mode, a VA-IPS mode, a guest host mode, or the like is applied can be used.

The liquid crystal element is an element that controls transmission or non-transmission of light by an optical modulation action of liquid crystal. The optical modulation action of the 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 in the liquid crystal element, a thermotropic liquid crystal, a low molecular liquid crystal, a polymer liquid crystal, a polymer dispersed liquid crystal (PDLC), a ferroelectric liquid crystal, an antiferroelectric liquid crystal, or the like can be used. . These liquid crystal materials exhibit a cholesteric phase, a smectic phase, a cubic phase, a chiral nematic phase, an isotropic phase, and the like depending on conditions.

As described above, since the display device of this embodiment can drive a liquid crystal element by applying a high voltage, liquid crystal exhibiting a blue phase may be used. The blue phase is one of the liquid crystal phases. When the temperature of the cholesteric liquid crystal is increased, the blue phase appears immediately before the transition 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% by weight or more of a chiral agent is used for the liquid crystal layer in order to improve the temperature range. A liquid crystal composition containing a liquid crystal exhibiting a blue phase and a chiral agent has a short response speed and exhibits optical isotropy. In addition, a liquid crystal composition including a liquid crystal exhibiting a blue phase and a chiral agent does not require alignment treatment and has a small viewing angle dependency. In addition, since it is not necessary to provide an alignment film, rubbing treatment is unnecessary, electrostatic breakdown caused by the rubbing treatment can be prevented, and defects or breakage of the display panel during the manufacturing process can be reduced.

Since the display device of this embodiment is a transmissive liquid crystal display device, a conductive material that transmits visible light is used for both of the pair of electrodes (the pixel electrode 41 and the common electrode 43a). In addition, the conductive layer 46b is also formed using a conductive material that transmits visible light, so that a reduction in the aperture ratio of the pixel can be suppressed even when the capacitor 104 is provided. Note that a silicon nitride film is suitable for the insulating layer 44 and the insulating layer 45 that function as a dielectric of the capacitor.

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 zinc oxide, indium oxide including tungsten oxide, indium zinc oxide including tungsten oxide, indium oxide including titanium oxide, and titanium oxide are included. Examples thereof include indium tin oxide, indium tin oxide containing silicon oxide (ITSO), zinc oxide, and zinc oxide containing gallium. Note that a film containing graphene can also be used. The film containing graphene can be formed by, for example, reducing a film containing graphene oxide.

The conductive film that transmits visible light can be formed using an oxide semiconductor (hereinafter also referred to as an oxide conductive layer). The oxide conductive layer preferably includes, for example, indium, and further includes an In-M-Zn oxide (M is Al, Ti, Ga, Y, Zr, La, Ce, Nd, Sn, or Hf). preferable.

An oxide semiconductor is a semiconductor material whose resistance can be controlled by at least one of oxygen vacancies in the film and impurity concentrations such as hydrogen and water in the film. Therefore, the resistivity of the oxide conductive layer is controlled by selecting a treatment in which at least one of oxygen deficiency and impurity concentration is increased or a treatment in which at least one of oxygen deficiency and impurity concentration is reduced in the oxide semiconductor layer. be able to.

Note that an oxide conductive layer formed using an oxide semiconductor in this manner is an oxide semiconductor layer with high carrier density and low resistance, an oxide semiconductor layer with conductivity, or an oxide semiconductor with high conductivity. It can also be called a layer.

The transistor included in the display device of this embodiment may have a top-gate structure or a bottom-gate structure. Alternatively, gate electrodes may be provided above and below the channel. A semiconductor material used for the transistor is not particularly limited, and examples thereof include an oxide semiconductor, silicon, and germanium.

There is no particular limitation on the crystallinity of a semiconductor material used for the transistor, and either an amorphous semiconductor or a semiconductor having crystallinity (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor partially including a crystal region) May be used. It is preferable to use a crystalline semiconductor because deterioration of transistor characteristics can be suppressed.

For example, a Group 14 element, a compound semiconductor, or an oxide semiconductor can be used for the semiconductor layer. Typically, a semiconductor containing silicon, a semiconductor containing gallium arsenide, an oxide semiconductor containing indium, or the like can be used for the semiconductor layer.

It is preferable to apply an oxide semiconductor to a semiconductor in which a transistor channel is formed. In particular, an oxide semiconductor having a larger band gap than silicon is preferably used. It is preferable to use a semiconductor material with a wider band gap and lower carrier density than silicon because current in an off state of the transistor can be reduced.

By using an oxide semiconductor, a change in electrical characteristics is suppressed and a highly reliable transistor can be realized.

Further, due to the low off-state current, the charge accumulated in the capacitor through the transistor can be held for a long time. By applying such a transistor to a pixel, the driving circuit can be stopped while maintaining the gradation of the displayed image. As a result, a display device with extremely reduced power consumption can be realized.

The transistor preferably includes an oxide semiconductor layer that is highly purified and suppresses formation of oxygen vacancies. Thus, the current value (off-current value) in the off state of the transistor can be reduced. Therefore, the holding time of an electric signal such as an image signal can be increased, and the writing interval can be set longer in the power-on state. Therefore, since the frequency of the refresh operation can be reduced, there is an effect of suppressing power consumption.

In addition, a transistor including an oxide semiconductor can be driven at high speed because a relatively high field-effect mobility can be obtained. By using such a transistor capable of high-speed driving for a display device, the transistor in the display portion and the transistor in the driver circuit portion can be formed over the same substrate. That is, it is not necessary to separately use a semiconductor device formed of a silicon wafer or the like as the drive circuit, so that the number of parts of the display device can be reduced. In the display portion, a high-quality image can be provided by using a transistor that can be driven at high speed.

The transistor included in the gate driver 11 and the transistor included in the display panel 10a may have the same structure or different structures. The transistors included in the gate driver may all have the same structure, or two or more kinds of structures may be used in combination. Similarly, all the transistors included in the display panel 10a may have the same structure, or two or more kinds of structures may be used in combination.

As an insulating material that can be used for each insulating layer, overcoat, and the like included in the display device, an organic insulating material or an inorganic insulating material can be used. Examples of the organic insulating material include acrylic resin, epoxy resin, polyimide resin, polyamide resin, polyimide amide resin, siloxane resin, benzocyclobutene resin, and phenol resin. As the inorganic insulating layer, silicon oxide film, silicon oxynitride film, silicon nitride oxide film, silicon nitride film, aluminum oxide film, hafnium oxide film, yttrium oxide film, zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide Examples thereof include a film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film.

In addition to the gate, source, and drain of the transistor, conductive layers such as various wirings and electrodes of the display device include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten. Alternatively, an alloy containing this as a main component can be used as a single layer structure or a stacked 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, or an alloy film containing molybdenum and tungsten Two-layer structure in which a copper film is laminated, 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 copper layered on the titanium film or titanium nitride film Laminating a film, and further forming a three-layer structure for forming a titanium film or a titanium nitride film thereon, a molybdenum film or a molybdenum nitride film, and an aluminum film or a copper film stacked on the molybdenum film or the molybdenum nitride film, Further, there is a three-layer structure on which a molybdenum film or a molybdenum nitride film is formed. For example, when the conductive layer has a three-layer structure, the first and third layers include titanium, titanium nitride, molybdenum, tungsten, an alloy containing molybdenum and tungsten, an alloy containing molybdenum and zirconium, or a film made of molybdenum nitride. 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, 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. You may use the electroconductive material which has. Note that the oxide conductive layer may be formed by controlling the resistivity of the oxide semiconductor.

As the adhesive layer 141, a curable resin such as a thermosetting resin, a photocurable resin, or a two-component mixed curable resin can be used. For example, an acrylic resin, a urethane resin, an epoxy resin, a siloxane resin, or the like can be used.

As the connecting body 242, for example, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), or the like can be used.

The light shielding layer 38 and the

light shielding regions

10c and 10g are provided so as to overlap, for example, the scanning line G1, the scanning line G2, and the transistor. For example, a black matrix formed using a metal material or a resin material containing a pigment or dye can be used as the light shielding layer 38 and the

light shielding regions

10c and 10g. Note that it is preferable to provide the light shielding layer 38 and the

light shielding regions

10c and 10g in regions other than the display portion 162 such as the drive circuit portion 164 because light leakage due to guided light or the like can be suppressed.

The light unit 13 can be an edge light type light unit, a direct type light unit, or the like. As the light source, an LED (Light Emitting Diode), an organic EL (Electroluminescence) element, or the like can be used.

Thin films (insulating film, semiconductor film, conductive film, etc.) constituting the display device are respectively formed by sputtering, chemical vapor deposition (CVD), vacuum evaporation, and pulsed laser deposition (PLD: Pulsed Laser Deposition). ) Method, atomic layer deposition (ALD: Atomic Layer Deposition) method, or the like. Examples of the CVD method include a plasma enhanced chemical vapor deposition (PECVD) method, a thermal chemical vapor deposition (PECVD) method, a thermal CVD method, and the like. An example of the thermal CVD method is a metal organic chemical vapor deposition (MOCVD) method.

Thin films (insulating films, semiconductor films, conductive films, etc.) that constitute display devices are spin coat, dip, spray coating, ink jet printing, dispensing, screen printing, offset printing, doctor knife, slit coat, roll coat, curtain, respectively. It can be formed by a method such as coating or knife coating.

The thin film constituting the display device can be processed using a photolithography method or the like. Alternatively, an island-shaped thin film may be formed by a film formation method using a shielding mask. Alternatively, the thin film may be processed by a nanoimprint method, a sand blast method, a lift-off method, or the like. As a photolithography method, a resist mask is formed on a thin film to be processed, the thin film is processed by etching or the like, and the resist mask is removed. After forming a photosensitive thin film, exposure and development are performed. And a method for processing the thin film into a desired shape.

In the photolithography method, examples of light used for exposure include 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, ArF laser light, or the like can be used. Further, exposure may be performed by an immersion exposure technique. Examples of light used for exposure include extreme ultraviolet light (EUV: Extreme-violet) and X-rays. Further, an electron beam can be used instead of the light used for exposure. It is preferable to use extreme ultraviolet light, X-rays, or an electron beam because extremely fine processing is possible. Note that a photomask is not necessary when exposure is performed by scanning a beam such as an electron beam.

For etching the thin film, a dry etching method, a wet etching method, a sand blasting method, or the like can be used.

[Metal oxide]
A metal oxide functioning as an oxide semiconductor is preferably used for the semiconductor layer of the transistor included in the display device of this embodiment. Below, the metal oxide applicable to a semiconductor layer is demonstrated.

The metal oxide preferably contains at least indium or zinc. In particular, indium and zinc are preferably included. In addition to these, it is preferable that aluminum, gallium, yttrium, tin, or the like is contained. One or more kinds selected from boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and the like may be included.

Here, a case where the metal oxide is an In-M-Zn oxide containing indium, an element M, and zinc is considered. Note that the element M is aluminum, gallium, yttrium, tin, or the like. Other elements applicable to the element M include boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium. However, as the element M, a plurality of the above-described elements may be combined.

Note that in this specification and the like, metal oxides containing nitrogen may be collectively referred to as metal oxides. In addition, a metal oxide containing nitrogen may be referred to as a metal oxynitride. For example, a metal oxide containing nitrogen such as zinc oxynitride (ZnON) may be used for the semiconductor layer.

An oxide semiconductor (metal oxide) is classified into a single crystal oxide semiconductor and a non-single crystal oxide semiconductor. As the non-single-crystal oxide semiconductor, for example, a CAAC-OS (c-axis aligned crystal oxide semiconductor), a polycrystalline oxide semiconductor, an nc-OS (nanocrystalline oxide semiconductor), a pseudo-amorphous oxide semiconductor (a-like oxide semiconductor) OS: amorphous-like oxide semiconductor) and amorphous oxide semiconductor.

The CAAC-OS has a c-axis orientation and a crystal structure in which a plurality of nanocrystals are connected in the ab plane direction and has a strain. Note that the strain refers to a portion where the orientation of the lattice arrangement changes between a region where the lattice arrangement is aligned and a region where another lattice arrangement is aligned in a region where a plurality of nanocrystals are connected.

Nanocrystals are based on hexagons, but are not limited to regular hexagons and may be non-regular hexagons. In addition, there may be a lattice arrangement such as a pentagon and a heptagon in terms of distortion. Note that in the CAAC-OS, it is difficult to check a clear crystal grain boundary (also referred to as a grain boundary) even in the vicinity of strain. That is, it can be seen that the formation of crystal grain boundaries is suppressed by the distortion of the lattice arrangement. This is because the CAAC-OS can tolerate distortion due to the fact that the arrangement of oxygen atoms is not dense in the ab plane direction and the bond distance between atoms changes due to substitution of metal elements. Because.

The CAAC-OS is a layered crystal in which a layer containing indium and oxygen (hereinafter referred to as an In layer) and a layer including elements M, zinc, and oxygen (hereinafter referred to as (M, Zn) layers) are stacked. There is a tendency to have a structure (also called a layered structure). Note that indium and the element M can be replaced with each other, and when the element M in the (M, Zn) layer is replaced with indium, it can also be expressed as an (In, M, Zn) layer. Further, when indium in the In layer is replaced with the element M, it can also be expressed as an (In, M) layer.

CAAC-OS is a metal oxide with high crystallinity. On the other hand, since it is difficult to confirm a clear crystal grain boundary in the CAAC-OS, it can be said that a decrease in electron mobility due to the crystal grain boundary hardly occurs. Moreover, since the crystallinity of the metal oxide that may be reduced by such generation of contamination and defects impurities, CAAC-OS impurities and defects (oxygen deficiency _(V O:. Oxygen vacancy also referred) etc.) with less metal It can be said that it is an oxide. Therefore, the physical properties of the metal oxide including the CAAC-OS are stable. Therefore, a metal oxide including a CAAC-OS is resistant to heat and has high reliability.

Nc-OS has periodicity in atomic arrangement in a minute region (for example, a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In addition, the nc-OS has no regularity in crystal orientation between different nanocrystals. Therefore, orientation is not seen in the whole film. Therefore, the nc-OS may not be distinguished from an a-like OS or an amorphous oxide semiconductor depending on an analysis method.

Note that indium-gallium-zinc oxide (hereinafter referred to as IGZO), which is a kind of metal oxide including indium, gallium, and zinc, may have a stable structure by using the above-described nanocrystal. is there. In particular, since IGZO tends to be difficult to grow in the atmosphere, a crystal smaller than a large crystal (here, a crystal of several millimeters or a crystal of several centimeters) (for example, the above-mentioned nanocrystal) is used. However, it may be structurally stable.

A-like OS is a metal oxide having a structure between nc-OS and an amorphous oxide semiconductor. The a-like OS has a void or a low density region. That is, the a-like OS has lower crystallinity than the nc-OS and the CAAC-OS.

Oxide semiconductors (metal oxides) have various structures and have different characteristics. The oxide semiconductor of one embodiment of the present invention may include two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, an nc-OS, and a CAAC-OS.

The metal oxide film functioning as a semiconductor layer can be formed using one or both of an inert gas and an oxygen gas. Note that there is no particular limitation on the flow rate ratio of oxygen (oxygen partial pressure) during the formation of the metal oxide film. However, in the case of obtaining a transistor with high field effect mobility, the flow rate ratio of oxygen (oxygen partial pressure) during the formation of the metal oxide film is preferably 0% or more and 30% or less, and 5% or more and 30% or less. Is more preferably 7% or more and 15% or less.

The energy gap of the metal oxide is preferably 2 eV or more, more preferably 2.5 eV or more, and further preferably 3 eV or more. In this manner, off-state current of a transistor can be reduced by using a metal oxide having a wide energy gap.

The metal oxide film can be formed by a sputtering method. In addition, a PLD method, a PECVD method, a thermal CVD method, an ALD method, a vacuum evaporation method, or the like may be used.

As described above, since the display device of one embodiment of the present invention has two capacitors that transmit visible light overlapped with a pixel, the pixel can achieve both a high aperture ratio and a large storage capacitor. .

In addition, since the display device of one embodiment of the present invention has a function of adding a correction signal to an image signal, the liquid crystal element can be driven with a voltage higher than the output voltage of the source driver.

(Embodiment 3)
In this embodiment, a structure of a CAC (Cloud-Aligned Composite) -OS that can be used for the OS transistor described in the above embodiment is described.

The CAC-OS is one structure of a material in which elements constituting a metal oxide are unevenly distributed with a size of 0.5 nm to 10 nm, preferably 1 nm to 2 nm, or the vicinity thereof. In the following, in the metal oxide, one or more metal elements are unevenly distributed, and the region having the metal element has a size of 0.5 nm to 10 nm, preferably 1 nm to 2 nm, or the vicinity thereof. The state mixed with is also referred to as mosaic or patch.

Note that the metal oxide preferably contains at least indium. In particular, it is preferable to contain indium and zinc. In addition, aluminum, gallium, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, etc. One kind selected from the above or a plurality of kinds may be included.

For example, a CAC-OS in In-Ga-Zn oxide (In-Ga-Zn oxide among CAC-OSs may be referred to as CAC-IGZO in particular) is an indium oxide (hereinafter referred to as InO). _X1 (X1 is greater real than 0) and.), or indium zinc oxide _{_{_{(hereinafter, in X2 Zn Y2 O Z2 (}}} X2, Y2, and Z2 is larger real than 0) and a.), gallium An oxide (hereinafter referred to as GaO _X3 (X3 is a real number greater than 0)) or a gallium zinc oxide (hereinafter referred to as Ga _X4 Zn _Y4 O _Z4 (where X4, Y4, and Z4 are greater than 0)) to.) and the like, the material becomes mosaic by separate into, mosaic _{InO X1,} or _in X2 _Zn Y2 _{O Z2} is configured uniformly distributed in the film (hereinafter, cloud Also referred to.) A.

That, CAC-OS includes a region _{GaO X3} is the main _component, In _{X2 Zn} Y2 _{O _Z2,} or _{InO X1} there is a region which is a main component, a composite metal oxide having a structure that is mixed. Note that in this specification, for example, the first region indicates that the atomic ratio of In to the element M in the first region is larger than the atomic ratio of In to the element M in the second region. It is assumed that the concentration of In is higher than that in the second region.

Note that IGZO is a common name and sometimes refers to one compound of In, Ga, Zn, and O. As a typical example, InGaO ₃ (ZnO) _m1 (m1 is a natural number) or In _{(1 + x0)} Ga _(1-x0) O ₃ (ZnO) _m0 (−1 ≦ x0 ≦ 1, m0 is an arbitrary number) A crystalline compound may be mentioned.

The crystalline compound has a single crystal structure, a polycrystalline structure, or a CAAC structure. The CAAC structure is a crystal structure in which a plurality of IGZO nanocrystals have c-axis orientation and are connected without being oriented in the ab plane.

On the other hand, CAC-OS relates to a material structure of a metal oxide. CAC-OS refers to a region that is observed in the form of nanoparticles mainly composed of Ga in a material structure including In, Ga, Zn, and O, and nanoparticles that are partially composed mainly of In. The region observed in a shape is a configuration in which the regions are randomly dispersed in a mosaic shape. Therefore, in the CAC-OS, the crystal structure is a secondary element.

Note that the CAC-OS does not include a stacked structure of two or more kinds of films having different compositions. For example, a structure composed of two layers of a film mainly containing In and a film mainly containing Ga is not included.

Incidentally, a region _{GaO X3} is the main _component, In _{X2 Zn} Y2 _{O _Z2,} or the region _{InO X1} is the main component, it may clear boundary can not be observed.

Instead of gallium, selected from aluminum, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, etc. In the case where one or more types are included, the CAC-OS includes a region observed in a part of a nanoparticle mainly including the metal element and a nano part mainly including In. The region observed in the form of particles refers to a configuration in which each region is randomly dispersed in a mosaic shape.

The CAC-OS can be formed by sputtering, for example, under the condition that the substrate is not heated. In the case where a CAC-OS is formed by a sputtering method, any one or more selected from an inert gas (typically argon), an oxygen gas, and a nitrogen gas may be used as a deposition gas. Good. Further, the flow rate ratio of the oxygen gas to the total flow rate of the deposition gas during film formation is preferably as low as possible. For example, the flow rate ratio of the oxygen gas is 0% to less than 30%, preferably 0% to 10%. .

The CAC-OS has a feature that a clear peak is not observed when measurement is performed using a θ / 2θ scan by an out-of-plane method, which is one of X-ray diffraction (XRD) measurement methods. Have. That is, from the X-ray diffraction measurement, it can be seen that no orientation in the ab plane direction and c axis direction of the measurement region is observed.

In addition, in the CAC-OS, an electron diffraction pattern obtained by irradiating an electron beam with a probe diameter of 1 nm (also referred to as a nanobeam electron beam) has a ring-like region having a high luminance and a plurality of bright regions in the ring region. A point is observed. Therefore, it can be seen from the electron beam diffraction pattern that the crystal structure of the CAC-OS has an nc (nano-crystal) structure having no orientation in the planar direction and the cross-sectional direction.

Further, for example, in a CAC-OS in an In—Ga—Zn oxide, a region in which GaO _X3 is a main component is obtained by EDX mapping obtained by using energy dispersive X-ray spectroscopy (EDX). It can be confirmed that a region in which In _X2 Zn _Y2 O _Z2 or InO _X1 is a main component is unevenly distributed and mixed.

The CAC-OS has a structure different from that of the IGZO compound in which the metal element is uniformly distributed, and has a property different from that of the IGZO compound. That is, in the CAC-OS, a region in which GaO _X3 or the like is a main component and a region in which In _X2 Zn _Y2 O _Z2 or InO _X1 is a main component are phase-separated from each other, and a region in which each element is a main component. Has a mosaic structure.

Here, the region containing In _X2 Zn _Y2 O _Z2 or InO _X1 as a main component is a region having higher conductivity than a region containing GaO _X3 or the like as a main component. _That, In _{X2 Zn} Y2 _{O _Z2,} or _{InO X1} is a region which is a main component, by carriers flow, conductive metal oxide is expressed. Therefore, a high field effect mobility (μ) can be realized by the region where In _X2 Zn _Y2 O _Z2 or InO _X1 is a main component distributed in a cloud shape in the metal oxide.

On the other hand, areas such as _{GaO X3} is the main _component, In _{X2 Zn} Y2 _{O _Z2,} or _{InO X1} is compared to region which is a main component, has a high area insulation. That is, since the region mainly composed of GaO _X3 or the like is distributed in the metal oxide, a leakage current can be suppressed and a good switching operation can be realized.

Therefore, when CAC-OS is used for a semiconductor element, the insulating property caused by GaO _{X3 and the} like and the conductivity caused by In _X2 Zn _Y2 O _Z2 or InO _X1 act complementarily, thereby increasing the An on-current (I _on ) and high field effect mobility (μ) can be realized.

In addition, a semiconductor element using a CAC-OS has high reliability. Therefore, the CAC-OS is optimal for various semiconductor devices including a display.

(Embodiment 4)
In this embodiment, electronic devices of one embodiment of the present invention will be described with reference to FIGS.

The electronic device of this embodiment includes the display device of one embodiment of the present invention in the display portion. Thereby, the display part of an electronic device can display a high quality image | video. In addition, display can be performed with high reliability in a wide temperature range.

For example, full high-definition video, 2K, 4K, 8K, 16K, or more can be displayed on the display unit of the electronic device of this embodiment. The screen size of the display unit can be 20 inches or more diagonal, 30 inches or more diagonal, 50 inches diagonal, 60 inches diagonal, or 70 inches diagonal.

Examples of an electronic device that can use the display device of one embodiment of the present invention include a television device, a desktop or notebook personal computer, a monitor for a computer, a digital signage (digital signage), a pachinko machine, and the like. In addition to electronic devices having a relatively large screen such as large game machines such as digital cameras, digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, portable information terminals, sound reproduction devices, and the like can be given. . The display device of one embodiment of the present invention can also be favorably used for a portable electronic device, a wearable electronic device (wearable device), a VR (Virtual Reality) device, an AR (Augmented Reality) device, and the like. .

The electronic device of one embodiment of the present invention may have a secondary battery, and it is preferable that the secondary battery can be charged using non-contact power transmission.

Secondary batteries include, for example, lithium ion secondary batteries such as lithium polymer batteries (lithium ion polymer batteries) using gel electrolyte, nickel metal hydride batteries, nickel-cadmium batteries, organic radical batteries, lead storage batteries, air secondary batteries, nickel A zinc battery, a silver zinc battery, etc. are mentioned.

The electronic device of one embodiment of the present invention may have an antenna. By receiving a signal with an antenna, video, information, and the like can be displayed on the display unit. In the case where the electronic device has an antenna and a secondary battery, the antenna may be used for non-contact power transmission.

The electronic device of one embodiment of the present invention includes a sensor (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, It may have a function of measuring voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared).

The electronic device of one embodiment of the present invention can have various functions. For example, a function for displaying various information (still images, moving images, text images, etc.) on the display unit, a touch panel function, a function for displaying a calendar, date or time, a function for executing various software (programs), and wireless communication It can have a function, a function of reading a program or data recorded in a recording medium, and the like.

Further, in an electronic apparatus having a plurality of display units, a function of displaying image information mainly on one display unit and mainly displaying character information on another display unit, or considering parallax in the plurality of display units By displaying an image, a function of displaying a stereoscopic image can be provided. Furthermore, in an electronic device having an image receiving unit, a function for photographing a still image or a moving image, a function for automatically or manually correcting the photographed image, and a function for saving the photographed image in a recording medium (externally or incorporated in the electronic device) A function of displaying the photographed image on the display portion can be provided. Note that the functions of the electronic device of one embodiment of the present invention are not limited thereto, and the electronic device can have various functions.

FIG. 16A illustrates a television device 1810. A television device 1810 includes a display portion 1811, a housing 1812, a speaker 1813, and the like. Furthermore, an LED lamp, operation keys (including a power switch or an operation switch), connection terminals, various sensors, a microphone, and the like can be provided.

The television device 1810 can be operated by a remote controller 1814.

Broadcasting radio waves that can be received by the television device 1810 include terrestrial waves or radio waves transmitted from satellites. As broadcast radio waves, there are analog broadcasts, digital broadcasts, etc., and there are video and audio, or only audio broadcasts. For example, broadcast radio waves transmitted in a specific frequency band in the UHF band (about 300 MHz to 3 GHz) or the VHF band (30 MHz to 300 MHz) can be received. In addition, for example, by using a plurality of data received in a plurality of frequency bands, the transfer rate can be increased and more information can be obtained. Accordingly, an image having a resolution exceeding full high-definition can be displayed on the display unit 1811. For example, an image having a resolution of 4K, 8K, 16K, or higher can be displayed.

A configuration for generating an image to be displayed on the display unit 1811 using broadcast data transmitted by a data transmission technique via a computer network such as the Internet, a LAN (Local Area Network), or Wi-Fi (registered trademark). It is good. At this time, the television device 1810 may not have a tuner.

FIG. 16B shows a digital signage 1820 attached to a cylindrical column 1822. The digital signage 1820 has a display portion 1821.

The wider the display unit 1821, the more information can be provided at one time. Moreover, the wider the display portion 1821 is, the easier it is to be noticed by humans. For example, the advertising effect of advertisement can be enhanced.

It is preferable to apply a touch panel to the display unit 1821 so that not only a still image or a moving image is displayed on the display unit 1821 but also a user can operate intuitively. In addition, when it is used for providing information such as route information or traffic information, usability can be improved by an intuitive operation.

FIG. 16C shows a notebook personal computer 1830. The personal computer 1830 includes a display portion 1831, a housing 1832, a touch pad 1833, a connection port 1834, and the like.

The touch pad 1833 functions as an input means such as a pointing device or a pen tablet, and can be operated with a finger or a stylus.

Further, a display element is incorporated in the touch pad 1833. For example, by displaying the input key 1835 on the surface of the touch pad 1833, the touch pad 1833 can be used as a keyboard. At this time, when the input key 1835 is touched, a vibration module may be incorporated in the touch pad 1833 in order to realize tactile sensation by vibration.

FIGS. 17A and 17B show a portable information terminal 800. FIG. The portable information terminal 800 includes a housing 801, a housing 802, a display portion 803, a display portion 804, a hinge portion 805, and the like.

The housing 801 and the housing 802 are connected by a hinge portion 805. The portable information terminal 800 can open the housing 801 and the housing 802 as illustrated in FIG. 17B from the folded state as illustrated in FIG.

For example, document information can be displayed on the display portion 803 and the display portion 804, and can also be used as an electronic book terminal. In addition, still images and moving images can be displayed on the display portion 803 and the display portion 804.

Thus, since the portable information terminal 800 can be folded when being carried, it has excellent versatility.

Note that the housing 801 and the housing 802 may include a power button, an operation button, an external connection port, a speaker, a microphone, and the like.

FIG. 17C shows an example of a portable information terminal. A portable information terminal 810 illustrated in FIG. 17C includes a housing 811, a display portion 812, operation buttons 813, an external connection port 814, a speaker 815, a microphone 816, a camera 817, and the like.

The portable information terminal 810 includes a touch sensor in the display unit 812. Any operation such as making a call or inputting characters can be performed by touching the display portion 812 with a finger or a stylus.

Further, by operating the operation button 813, the power ON / OFF operation and the type of image displayed on the display unit 812 can be switched. For example, the mail creation screen can be switched to the main menu screen.

Further, by providing a detection device such as a gyro sensor or an acceleration sensor inside the portable information terminal 810, the orientation (portrait or landscape) of the portable information terminal 810 is determined, and the screen display orientation of the display unit 812 is changed. It can be switched automatically. The screen display orientation can also be switched by touching the display portion 812, operating the operation buttons 813, or inputting voice using the microphone 816.

The portable information terminal 810 has one or a plurality of functions selected from, for example, a telephone, a notebook, an information browsing device, or the like. Specifically, it can be used as a smartphone. The portable information terminal 810 can execute various applications such as mobile phone, electronic mail, text browsing and creation, music playback, video playback, Internet communication, and games.

FIG. 17D shows an example of a camera. The camera 820 includes a housing 821, a display portion 822, operation buttons 823, a shutter button 824, and the like. A removable lens 826 is attached to the camera 820.

Here, the camera 820 is configured such that the lens 826 can be removed from the housing 821 and replaced, but the lens 826 and the housing may be integrated.

The camera 820 can capture a still image or a moving image by pressing the shutter button 824. In addition, the display portion 822 has a function as a touch panel and can capture an image by touching the display portion 822.

Note that the camera 820 can be separately equipped with a strobe device, a viewfinder, and the like. Alternatively, these may be incorporated in the housing 821.

An electronic device 830 illustrated in FIG. 17E includes a housing 831, a display device 834, a lighting 833, and an optical module 832. The housing 831 includes an opening 835 and an opening 835a (not shown in the drawing). The electronic device 830 can be incorporated in an inner wall or an outer wall of a house or a building, a partition of a space (a door, a window, a wall, a room, a desk partition), or the like. Further, the display device 834 can provide a transparent display device 834 that can visually recognize the opposite side of the display device 834 by providing a region through which light passes in a pixel formed in the TFT layer.

FIG. 17E shows a scene where the user touches the display screen on which the cherry blossom petals pour. The display device 834 can detect touched information from different display surfaces. Note that the electronic device 830 can cause a digital signage to execute a game. Thereby, an unspecified number of users can participate and enjoy the game at the same time.

18A and 18B, an example in which an electronic device including the display device of one embodiment of the present invention is mounted on a vehicle will be described.

FIG. 18A shows an example in which a vehicle 5000 includes a plurality of cameras 5005. The vehicle 5000 includes a camera 5005a, a camera 5005b, a camera 5005c, a camera 5005d,

cameras

5005d, 5005e, and 5005f. For example, the camera 5005a has a function of imaging the front situation, the camera 5005b has a function of imaging the rear situation, the camera 5005c has a function of imaging the right front situation, and the camera 5005d. Has a function of imaging the situation on the left front, the camera 5005e has a function of imaging the situation on the right rear, and the camera 5005f has a function of imaging the situation on the left rear. However, the number of cameras 5005 that capture the periphery of the vehicle is not limited to the above configuration. For example, you may provide the camera 5005 etc. which image the back from the front of a vehicle.

Next, FIG. 18B shows an example of the internal configuration of the vehicle 5000. The vehicle 5000 includes a display portion 5001,

display panels

5008a and 5008b, and a display panel 5009. As the display portion 5001, the

display panels

5008a and 5008b, and the display panel 5009, the display portion of the display system of one embodiment of the present invention can be used. Note that FIG. 18B illustrates an example in which the display portion 5001 is mounted on a right-hand drive vehicle, but there is no particular limitation, and the display portion 5001 can also be mounted on a left-hand drive vehicle. In this case, the left and right arrangements of the configuration shown in FIG.

FIG. 18B shows a dashboard 5002, a handle 5003, a windshield 5004, and the like arranged around the driver's seat and the passenger seat. The display unit 5001 is disposed at a predetermined position on the dashboard 5002, specifically around the driver, and has a substantially T-shape. FIG. 18B illustrates an example in which one display portion 5001 formed using a plurality of display panels 5007 (

display panels

5007a, 5007b, 5007c, and 5007d) is provided along the dashboard 5002. However, the display unit 5001 may be divided into a plurality of locations.

Furthermore, the

display panels

5008a and 5008b are display panels provided in the pillar portion. For example, an image 5008c from an imaging unit (for example, the camera 5005 shown in FIG. 18A) provided on the vehicle body is displayed on the

display panels

5008a and 5008b, thereby complementing the view blocked by the pillar. it can. Further, the display panel 5009 may display an image from the rear imaging means. Alternatively, legal speed, traffic information, and the like can be displayed on the

display panels

5008a and 5008b.

Note that the plurality of display panels 5007 may have flexibility. In this case, the display portion 5001 can be processed into a complicated shape, and the display portion 5001 is displayed along a curved surface such as the dashboard 5002 or displayed on a connection portion of a handle, a display portion of an instrument, an air outlet 5006, or the like. A configuration in which the display area of the portion 5001 is not provided can be easily realized.

Further, the

display panels

5008a and 5008b preferably have flexibility. Since the biller portion has an aspect, it is preferable that image distortion when the driver's seat sees the pillar portion is corrected. The video distortion is preferably corrected using a neural network.

Further, a plurality of cameras 5005b for photographing the rear side situation may be provided outside the vehicle. Although FIG. 18A shows an example in which a plurality of cameras 5005 are installed instead of the side mirrors, both side mirrors and cameras may be installed.

As the camera 5005, a CCD camera, a CMOS camera, or the like can be used. In addition to these cameras, an infrared camera may be used in combination. Since the infrared camera has a higher output level as the temperature of the subject increases, it can detect or extract a living body such as a person or an animal.

The image captured by the camera 5005 can be output to any one or a plurality of display panels 5007. The display unit 5001 is mainly used to assist driving of the vehicle. By photographing the rear side situation with a wide angle of view by the camera 5005 and displaying the image on the display panel 5007, the driver's blind spot area can be visually recognized, and the occurrence of an accident can be prevented.

Further, by using the display system of one embodiment of the present invention, video discontinuity at the joints of the

display panels

5007a, 5007b, 5007c, and 5007d can be corrected. Accordingly, it is possible to display an image in which the joints are not conspicuous, and the visibility of the display unit 5001 during driving can be improved.

Further, a distance image sensor may be provided on the roof of a car, and an image obtained by the distance image sensor may be displayed on the display unit 5001. As the distance image sensor, an image sensor or a rider (LIDAR: Light Detection and Ranging) can be used. By displaying the image obtained by the image sensor and the image obtained by the distance image sensor on the display unit 5001, more information can be provided to the driver and driving can be supported.

In addition, the display unit 5001 may have a function of displaying map information, traffic information, TV video, DVD video, and the like. For example, the map information can be displayed in a large size using the

display panels

5007a, 5007b, 5007c, and 5007d as one display screen. Note that the number of display panels 5007 can be increased in accordance with displayed images.

Also, the images displayed on the

display panels

5007a, 5007b, 5007c, and 5007d can be freely set according to the driver's preference. For example, a TV image and a DVD image are displayed on the left display panel 5007d, map information is displayed on the central display panel 5007b, instruments are displayed on the right display panel 5007c, and audio is displayed in the vicinity of the transmission gear. Display on the display panel 5007a (between the seat and the passenger seat). Further, by combining a plurality of display panels 5007, a fail-safe function can be added to the display portion 5001. For example, even if a certain display panel 5007 breaks down for some reason, the display area can be changed and display can be performed using another display panel 5007.

Further, the windshield 5004 has a display panel 5004a. The display panel 5004a has a function of transmitting visible light and can visually recognize a background. Note that the display panel 5004a has a function of performing display or the like for alerting the driver. FIG. 18B illustrates the structure in which the display panel 5004a is provided on the windshield 5004; however, the present invention is not limited to this. For example, the windshield 5004 may be replaced with the display panel 5004a.

As described above, an electronic device can be obtained by using the display device of one embodiment of the present invention. The application range of the display device is extremely wide and can be applied to electronic devices in all fields.

G1: scanning line, G2: scanning line, S1: signal line, S2: signal line, 10: display device, 10a: display panel, 10b: adhesive layer, 10c: light shielding region, 10d: light guide layer, 10e: counter substrate 10f: light shielding region, 10g: light shielding region, 11: gate driver, 12: source driver, 13: light unit, 13b: opening, 13d: light unit, 14: timing generation circuit, 15: display controller, 16: memory Device: 17: Processor, 18: Communication module, 19: Sensor, 20: Image sensor, 22: Transistor, 24: Display element, 24a: Liquid crystal element, 30: Electronic device, 31: Substrate, 32: Substrate, 38: Light shielding Layer, 38a: light shielding layer, 38b: light shielding layer, 41: pixel electrode, 42: liquid crystal layer, 43: common electrode, 43a: common electrode, 43b: Electrical layer 44: Insulating layer 45: Insulating layer 46: Conductive layer 46a: Conductive layer 46b: Conductive layer 73: Connection part 74: Connection part 101: Transistor 101a: Transistor 102: Transistor 102a: transistor, 104: capacitive element, 105: capacitive element, 106: liquid crystal element, 133a: alignment film, 133b: alignment film, 135: overcoat, 141: adhesive layer, 162: display unit, 164: drive circuit unit, 172: FPC, 211: gate insulating layer, 212: insulating layer, 213: insulating layer, 214: insulating layer, 215: insulating layer, 217: insulating layer, 218: insulating layer, 221: gate, 221a: gate, 221b: Gate, 222a: conductive layer, 222b: conductive layer, 222c: conductive layer, 222d: conductive layer, 222e: conductive layer, 223: gate, 223 : Gate, 223b: gate, 225: gate insulating layer, 225a: gate insulating layer, 225b: gate insulating layer, 231: semiconductor layer, 231a: semiconductor layer, 231b: semiconductor layer, 233: gate 242: connecting member

Claims

A driving method of a display device having a first display area,
The first display area has a plurality of second areas and a plurality of third areas,
The second region and the third region are alternately present,
The second area is a non-display area in which display data is updated,
The third area is an area where an image is displayed;
The second region and the third region move in one direction;
The plurality of second regions have a period that is simultaneously selected to update the display data,
A method for driving a display device, wherein the plurality of third regions are driven to be displayed simultaneously.
In claim 1,
The first display area has a plurality of light shielding areas,
The light shielding region is provided between the second region and the third region,
The light-shielding region is a display device driving method that suppresses erroneous display of the second region by the light of the third region.
In claim 1 or claim 2,
A method for driving a display device, wherein an area of the third region is different from that of the second region.
In claims 1 to 3,
A driving method of a display device in which a plurality of the third regions transmit light of different hues.
In Claim 1, The said 1st display area has a plurality of pixels,
The pixel has a transistor,
The transistor is a method for driving a display device in which a semiconductor layer includes a metal oxide.