JP7267212B2 - liquid crystal display - Google Patents

Description

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

Note that one embodiment of the present invention is not limited to the above technical field. Technical fields of one embodiment of the present invention include semiconductor devices, display devices, light-emitting devices, power storage devices, memory devices, electronic devices, lighting devices, input devices (e.g., touch sensors), and input/output devices (e.g., touch panels). ), their driving methods, or their manufacturing methods.

2. Description of the Related Art Flat panel displays typified by liquid crystal display devices are widely used as display devices. For these display devices, methods for realizing high-resolution display are being studied. Japanese Patent Application Laid-Open No. 2002-200001 discloses a display method based on a field sequential system that does not use color filters.

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 Japanese Patent Application Laid-Open No. 2007-123861

An object of one embodiment of the present invention is to provide a liquid crystal display device that suppresses flickering. Another object of one embodiment of the present invention is to provide a liquid crystal display device with a high aperture ratio. Alternatively, an 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. Alternatively, an 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 that can operate stably over a wide temperature range.

The description of these problems does not preclude the existence of other problems. One aspect of the present invention does not necessarily have to solve all of these problems. Problems other than these can be extracted from the descriptions of the specification, 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 area and the third area alternately exist. The second area is a non-display area where the display data is updated. The third area is the area where the image is displayed. The second region and the third region move in one direction, the plurality of second regions having a period selected simultaneously to update the display data, and the plurality of third regions simultaneously A display device driving method for driving to be displayed.

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

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

In each of the above configurations, the first display area has an area that transitions from the display state to the non-display state, an area that retains the display state, and an area that transitions 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 lights of different hues.

In each of the above structures, the first display region has a plurality of pixels. A pixel has 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, one embodiment of the present invention can provide a highly reliable liquid crystal display device. Alternatively, one embodiment of the present invention can provide a liquid crystal display device that can operate stably over a wide temperature range.

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

(A) and (B) are diagrams showing examples of display regions. 1A shows an example of a display area; FIG. 1B illustrates an example of a display device; FIG. A circuit diagram showing an example of a display device. 1A is a circuit diagram showing an example of a pixel; FIG. (B) Timing chart. (C) A circuit diagram showing an example of a pixel. Timing chart. Timing chart. 1 is a block diagram showing an example of an electronic device; FIG. 1A is a perspective view illustrating an example of a display device; FIG. (B) A trihedral view showing a display device. 1A is a perspective view illustrating an example of a display device; FIG. (B) A trihedral view showing a display device. 1 is a perspective view showing an example of a display device; FIG. 1A and 1B are cross-sectional views illustrating examples of display devices; (A), (B), and (C) are top views showing examples of pixels. 1 is a cross-sectional view showing an example of a display device; FIG. 1 is a cross-sectional view showing an example of a display device; FIG. 1 is a cross-sectional view showing an example of a display device; FIG. (A), (B), and (C) each illustrate an example of an electronic device; (A), (B), (C), (D), and (E) each illustrate an example of an electronic device; 1A and 1B each illustrate an example of an electronic device; FIG.

Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and those skilled in the art will easily understand that various changes can be made in form and detail without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the descriptions of the embodiments shown below.

In the configuration of the invention to be described below, the same reference numerals are used in common for the same parts or parts having similar functions in different drawings, and repeated description thereof will be omitted. Moreover, when referring to similar functions, the hatch patterns may be the same and no particular reference numerals may be attached.

In addition, the position, size, range, etc. of each configuration shown in the drawings may not represent the actual position, size, range, etc. for ease of understanding. Therefore, the disclosed invention is not necessarily limited to the position, size, range, etc. disclosed in the drawings.

It should be noted that the terms "film" and "layer" can be interchanged depending on the case or situation. 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”.

In this specification, the high power supply voltage may be called H level (or V _DD ), and the low power supply voltage may be called L level (or GND).

In addition, the present specification can be appropriately combined with the following embodiments. Moreover, when a plurality of configuration examples are shown in one embodiment, the configuration 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.

The display panel 10a shown in FIGS. 1A and 1B has a displayable area. The displayable area has multiple non-display areas, multiple display areas, and multiple light shielding areas 10c. Note that the display panel 10a has a plurality of pixels. As an example, the displayable area has a non-display area 20 (hatched) and a display area 21 (not hatched).

The non-display areas 20 and the display areas 21 alternately exist. Display data is updated in the non-display area 20 and an image is displayed in the display area 21 . The non-display area 20 and the display area 21 can be moved in one direction, and multiple display areas 21 can be driven to be displayed simultaneously.

As an example, FIG. 1A shows that 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 addition, in the display area for displaying the image data, the non-display state is clarified by hatching. FIG. 1B shows, as an example, that the non-display area 20 is updated with the image data R1a, a partial area of the display area 21 is displayed with the image data R1b, and further, the display area 21 is updated with the image data R1b. This indicates that the area is displayed with the image data R1c.

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

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

Different hues of light are displayed simultaneously and move in waves with time. The human eye perceives light of different hues displayed at the same time and light integrated by moving in waves with time. It should be noted that the human eye perceives light that moves with time as integrated luminance. In the display panel 10a having a plurality of display areas 21, the light displayed by each display area 21 is synthesized and integrated according to the area size of the display area 21. FIG. Furthermore, while the display area 21 moves like a wave, light of different hues can be combined and integrated. When the integrated luminance is generated using a large area, flickering and color break due to afterimages are likely to occur. However, the integrated luminance generated in each display area 21 in 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 multiple non-display areas 20 have periods selected simultaneously to update the display data and update the image data, and the respective pixels of the display area 21 are displayed simultaneously. However, if the pixels of the display region 21 and the pixels of the non-display region 20 are adjacent to each other, the light of the display region 21 may be given to the pixels of the non-display region as stray light.

The display area of the display panel 10a preferably has 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 arranged at a position in contact with the non-display region 20 . Also, the light shielding region 10 c has the effect of suppressing the influence of stray light on the non-display region 20 when the display region 21 displays. When the non-display area 20 is displayed by stray light, display blurring occurs in the non-display area 20 in contact with the display area 21, and the quality of display deteriorates. Therefore, by providing the light shielding region 10c, it is possible to suppress stray light from the display region 21 and improve display quality.

In FIG. 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 has non-display areas 20R, 20G and 20B and display areas 21R, 21G and 21B will be described for the sake of simplicity of explanation. The display panel 10a has image data R0b, G0a, G0b, B0a, B0b, R1a, and R1b, and the image data R1a and R1b will be described as image data of the next frame. Therefore, it is preferable that the image data R0b, R1a, and R1b have their gradations controlled by different image data.

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

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

As an example, when describing the pixels connected to the scanning line G(jr), the pixel P(x, yr) and the pixel P(x+1, yr+1) will be used. The scanning line G(jr) can select a plurality of pixels electrically connected to the yr-th 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 from 1 to n/2, x is an integer from 1 to m, and yr, yg, and yb are odd numbers from 1 to n.

Moreover, 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 light of different hues (LW: white, LC: cyan, LM: magenta, LY: yellow). The hues of the light unit 13 can be combined according to the hues 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 through different openings. Light emitted from different openings is provided to different display areas 20 .

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

FIG. 2B shows the non-display areas 20G, 20B, and 20R, the display areas 21R, 21G, and 21B of the display panel 10a in FIG. there is

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

The pixels in the rows selected by the scanning lines correspond to the non-display area 20 (hatched), and the pixels whose image data have not been updated correspond to the display area 21 (not hatched) where the light unit 13 lights up. is. However, for example, when the hue LR of the light unit 13 is on, it is preferable that the other hues are off. It is preferable that each display area 21 has a lighting hue selected according to the image data updated in the non-display area 20 . It is also possible to light two or more hues at the same time to synthesize light of different hues. Further, it is preferable that the image data of the plurality of pixels connected to the yr-th row and the yr+1-th row are updated during the period in which 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-th row and the yr+1-th 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. 2(B). In FIG. 3, to simplify the explanation, as an example, a pixel P (x, yg) and a pixel P ( x, yg+1) will be described.

A 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.

A gate of the transistor 101 is electrically connected to the scan line G1(jg). One of the source and drain of the transistor 101 is electrically connected to the signal line S1(i). The other of the source and drain of the transistor 101 is electrically connected to one electrode 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 the source and 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 .

Pixel P(x, yg+1) is electrically connected to scanning line G1(jg) and scanning line G2(jg). Pixel P(x, yg+1) is different from pixel P(x, yg) in that it is electrically connected to signal line S1(i+1) and signal line S2(i+1). That is, the scanning line G can simultaneously select a plurality of rows, and the pixels connected to the scanning line are connected to different signal lines S for simultaneously updating the image data. Although the circuit diagram shown in FIG. 3 shows an example in which the signal lines are connected from different directions, 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.

FIG. 4 provides a detailed description of the pixels. Here, the display element 24 and the operation of the pixels will be described, and the description of the connection of the pixels described with reference to FIG. 3 will be omitted.

Note that a 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 liquid crystal element can display a corrected image. With this correction, for example, the liquid crystal element can express more gradations than can be expressed using only image data.

Further, the correction enables the liquid crystal element to be driven at a voltage higher than the output voltage of the source driver 12 . 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 used, and the cost of designing a new source driver 12 can be reduced. Moreover, since the output voltage of the source driver 12 can be suppressed from increasing, the power consumption of the source driver 12 can be reduced.

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

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

In addition, since the liquid crystal element can be driven by applying a high voltage, the response speed can be improved by overdriving.

The correction signal is generated, for example, by 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, new image data can be generated from pixels to which correction signals are supplied without changing image data to be supplied. The load on the external device can be reduced compared to the case where the new image data itself is generated using the external device. In addition, the operation for generating new image data with pixels can be performed in a small number of steps, and a display device with a large number of pixels and a short horizontal period can also be used.

The display element 24 will be described with reference to FIG. The display element 24 has a liquid crystal element 24 a and a capacitive 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 and 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 element 105 . Note that the node NA is a node connected to one electrode of the liquid crystal element 24 a , one electrode of the capacitor 105 , one electrode of the capacitor 104 , and the other of the source and drain of the transistor 101 .

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

At time T2, the transistors 101 and 22 are turned on by the signals applied 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. Image data Vp is held in node NA.

At time T3, the transistor 101 is turned off by the signal applied to the scan line G1, and the transistor 102 is kept on by the signal applied to the scan line G2. Image data Vs is applied to the signal line S2. Image data Vs is added to image data Vp by capacitive coupling via capacitive element 104, and node NA changes to Vs+Vp potential.

At time T4, the transistor 102 is turned off by a signal applied to the scanning line G2. Therefore, the potential of Vs+Vp is held at the node NA. Note that the transistors 101 and 102 preferably have low off-state current. As the transistor with low off-state current, the transistor including a metal oxide in a semiconductor layer, which is 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 shows 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 drain of the transistor, or may be connected to wiring that can be controlled from the outside.

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

At time T11, a signal of "H" is applied to scanning line G1(jg-1) and scanning line G2(jg-1). Image data D(x, yg-2) is supplied to pixel P(x, yg-2) through signal line S1(i), and initialization voltage Vr is applied through signal line S2(i). is given. Image data D(x, yg-1) is supplied to pixel P(x, yg-1) through signal line S1(i+1), and initialization voltage Vr is applied through signal line S2(i+1). is given.

At time T12, a signal of "L" is applied to the scanning line G1(jg-1) and a signal of "H" is applied to the scanning line G2(jg-1). Image data DW (x, yg-2) is applied to the pixel P (x, yg-2) through the signal line S2(i). Image data DW (x, yg-1) is applied to the pixel P (x, yg-1) through the signal line S2 (i+1). Although not shown in the figure, in the pixel P (x, yg-2), an operation of image data D (x, yg-2) + image data DW (x, yg-2) is performed on the display element. will be Similarly, for the pixel P(x, yg-1), the 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 as at time T11 and time T12 depending on the selected row. At time T13 and time T14, the image data of pixel P(x, yg) and pixel P(x, yg+1) are updated, and at time T15 and time T16, pixel P(x, yg+2) and pixel P(x , yg+3) can be updated.

In FIG. 6, a method for simultaneously updating the image data of the scanning lines of the different non-display areas 20 explained with reference to FIG. 2 will be explained using a timing chart. A method for updating image data in different non-display areas 20 will be described with reference to FIG. As long as the light unit is turned off, even if the image data of the pixels are updated at different timings, it can be determined that the image data are updated at the same time. 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, pixels P (x, yr) to P (x, yr+3), pixels P (x, yg) to P (x, yg+3), and pixels P (x, yg+3) yb) to pixel P(x, yb+3) will be described. In addition, as shown in FIG. 2, the yr row, the yg row, and the yb row belong to different non-display areas 20, respectively.

At time T21, a signal of "H" 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) via the signal line S1(i), and is supplied with the initialization voltage Vr via 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 is supplied with the initialization voltage Vr via the signal line S2(i+1).

At time T22, a signal of "H" is applied to the scanning line G1 (jg) and the scanning line G2 (jg). A signal of "L" is applied to the scanning line G1 (jr), and a signal of "H" is applied 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 is supplied with 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) through the signal line S1(i+1), and is supplied with the initialization voltage Vr through the signal line S2(i+1).

At time T23, a signal of "H" is applied to the scanning line G1 (jb) and the scanning line G2 (jb). A signal of "L" is applied to the scanning line G1 (jr), and a signal of "H" is applied to the scanning line G2 (jr). A signal of "L" is applied to the scanning line G1 (jg), and a signal of "H" 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 is supplied with 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 is supplied with the initialization voltage Vr via the signal line S2(i+1).

At time T24, a signal of "L" is applied to the scanning line G1 (jr) and a signal of "H" is applied to the scanning line G2 (jr). A signal of "L" is applied to the scanning line G1 (jr), and a signal of "H" is applied to the scanning line G2 (jr). A signal of "L" is applied to the scanning line G1 (jb), and a signal of "H" is applied to the scanning line G2 (jb). Image data DW (x, yr) is applied to the pixel P (x, yr) via the signal line S2(i). Image data DW (x, yr+1) is applied to the pixel P (x, yr+1) through the signal line S2 (i+1).

At time T25, a signal of "L" is applied to the scanning line G1 (jr) and the scanning line G2 (jr). In addition, a signal of "L" is applied to the scanning line G1 (jg) and a signal of "H" is applied to the scanning line G2 (jg). A signal of "L" is applied to the scanning line G1 (jb) and a signal of "H" is applied to the scanning line G2 (jb). Image data DW (x, yg) is applied to the pixel P (x, yg) via the signal line S2(i). Image data DW (x, yg+1) is applied to the pixel P (x, yg+1) through the signal line S2 (i+1).

At time T26, a signal of "L" is applied to the scanning line G1 (jr) and the scanning line G2 (jr). A signal of "L" is applied to the scanning line G1 (jg) and the scanning line G2 (jg). A signal of "L" is applied to the scanning line G1 (jb), and a signal of "H" is applied to the scanning line G2 (jb). Image data DW (x, yb) is applied to the pixel P (x, yb) through the signal line S2(i). Image data DW (x, yb+1) is applied to the pixel P (x, yb+1) through the signal line S2 (i+1).

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

FIG. 7 shows a block diagram of the electronic device 30. As shown in FIG. The electronic device 30 has 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 has a display panel 10 a, a gate driver 11 , a source driver 12 and a light unit 13 . However, the gate driver 11 or the source driver 12 may not be formed on the same substrate as the display panel 10a, and may be formed separately and integrated into an IC. A connection method of the gate driver 11 or the source driver 12 integrated 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 can be used. 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/non-display of the light unit 13 in synchronization with 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 and the processor 17 into image data.

The communication module 18 has a function of wireless communication and a function of wired communication. Therefore, the electronic device 30 transmits and receives data to and from the data server using either wireless communication or wired communication. For example, when communicating wirelessly, a carrier wave may be used to transmit and receive data.

When performing wireless communication, specifications standardized by IEEE for communication such as wireless LAN (Local Area Network), Wi-Fi (registered trademark), Bluetooth (registered trademark), ZigBee (registered trademark), etc. can be used. . Alternatively, when performing wired communication, specifications 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 sensor, a rotation sensor, a density sensor, and a gyro sensor. , 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, or a combination thereof. Further, the sensor provided in the sensor 19 may use a microelectromechanical system (MEMS). Various information acquired by the sensor can be used to change the content displayed on the display device.

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

FIG. 8A shows a perspective view of the display device 10. FIG. The display device 10 has a display panel 10a, an adhesive layer 10b, a light guide layer 10d, and a light unit 13a. The gate driver 11 shows an example formed on the same substrate as the display panel 10a. A black matrix or the like is provided on the adhesive layer 10b to form a light shielding region 10c arranged between the non-display region 20 and the display region 21. FIG. Alternatively, it is preferable that the black matrix be arranged at a position overlapping the scanning lines G1 and G2. By arranging 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 the light of hue (LR: red, LG: green, LB: blue). It should be noted that light of different hues may be added to the light emitted from the opening 13b, or a plurality of different lights may be combined. Further, although the shape of the opening 13b is shown as a circle in FIG. 8A, the shape is not limited. 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 pixels connected to 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 light from the light unit 13a to the display panel 10a. In FIG. 8A, light L1 and light L2 emitted from the light unit 13a are emitted to the display panel 10a with the same brightness. The light from the light unit 13a emitted to the light guide layer 10d can be prevented from diffusing by the light shielding region 10c arranged 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 shows a trihedral view of the display device 10. FIG. In FIG. 8B, a translucent counter substrate 10e is arranged above the display panel 10a. On the opposing substrate 10e, a black matrix may be arranged as a light shielding region 10f at positions overlapping the scanning lines G1 and G2. The display device 10 shown in FIG. 8B shows an example in which the display panel 10a, the adhesive layer 10b, and the light guide layer 10d are arranged at overlapping positions. The light unit 13a is located on the side surface of the display panel and is provided at a position where light is emitted to the light guide path. Note that the light unit 13a may be provided at a position where light is emitted 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.

FIG. 9 shows a display device 10 different from that of FIG. The display device 10 of FIG. 9 is different in that the light shielding region 10g is provided in the light guide layer 10d and the light unit 13c is arranged at a position overlapping the gate driver 11. FIG. Further, the light unit 13c is provided with LEDs (Light Emitting Diodes) that directly emit light of each hue to the light guide layer 10d, unlike the opening 13b that emits light of a plurality of hues.

It is preferable that LEDs having a plurality of hues are arranged in the light unit 13c at intervals Δd of the light shielding region 10g. The light emitted from the LED can be emitted by switching the light of hue (LR: red, LG: green, LB: blue). The light emitted from the LED may be light of different hues, or may be a combination of a plurality of different lights. Also, in the light unit shown in FIG. 9B, the LEDs are arranged parallel to the display panel 10a, but the LEDs may be arranged vertically.

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

Any one of the light shielding regions 10c, 10f, and 10g can be used, or a plurality of them can be used in combination. Light leakage such as stray light can be reduced by combining a plurality of light shielding regions. Therefore, it is possible to obtain a display device that can suppress display flicker and have good display quality. Although not explained in FIG. 8 or 9, the black matrix having the function of the light shielding region may be provided in the display panel 10a.

FIG. 10 shows a display device 10 different from that shown in FIGS. FIG. 10 is different in that a light unit 13d is provided below 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 simultaneously display different hues and move in a wavy manner, the hues can be combined in a small area and the integrated luminance can be generated. Therefore, high-speed operation is possible. , a better display quality can be obtained.

Also, since each pixel can display light of a plurality of hues, no color filter is required. Therefore, since a sub-pixel for each hue is not required, the definition can be increased. Therefore, even higher definition display quality can be obtained. Further, by increasing the aperture ratio, the light extraction efficiency is improved. Therefore, it is possible to reduce the luminance of the light unit 13, thereby reducing the power consumption.

This embodiment can be appropriately combined with other embodiments. Further, in this specification, when a plurality of configuration examples are shown in one embodiment, the configuration examples can be combined as appropriate.

(Embodiment 2)
<Configuration example of display device>
Structural examples of a display device in which a pixel includes two transistors and two capacitors are described with reference to FIGS.

FIG. 11A shows a cross-sectional view of a transmissive liquid crystal display device. A liquid crystal display device illustrated in FIG. It has a substrate 32 .

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

The liquid crystal display device of the present embodiment has a pixel electrode 41 and a common electrode 43 laminated with an insulating layer 45 interposed therebetween, and operates in FFS (Fringe Field Switching) mode. The pixel electrode 41 , liquid crystal layer 42 and 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 104 . Also, the pixel electrode 41 , the insulating layer 45 , and the common electrode 43 can function as one capacitor 105 . Thus, the liquid crystal display device of this embodiment mode has two capacitors in a pixel.

Both of the two capacitive elements are made of a material that transmits visible light, and have regions that overlap each other. This allows the pixel to have a high aperture ratio and a plurality of storage capacitors.

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

The capacitance of the capacitor 104 is preferably larger than that 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. Also, the thickness T1 of the insulating layer 44 positioned between the conductive layer 46 and the pixel electrode 41 is preferably thinner than the thickness T2 of the insulating layer 45 positioned between the pixel electrode 41 and the common electrode 43. .

The structure of the display device of this embodiment can also be applied to a touch panel. FIG. 11B shows an example in which a touch sensor TC is mounted on the display device shown in FIG. 11A. 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 enhanced.

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

As the sensor system, various systems such as an electrostatic capacity system, a resistive film system, a surface acoustic wave system, an infrared system, an optical system, and a pressure-sensitive system can be used.

The capacitance method includes a surface capacitance method, a projected capacitance method, and the like. Also, the projective capacitance method includes a self-capacitance method, a mutual capacitance method, and the like. It is preferable to use the mutual capacitance method because it enables simultaneous multi-point detection.

A touch panel of one embodiment of the present invention includes a structure in which a display device and a detection element that are separately manufactured are attached to each other, a structure in which an electrode or the like that constitutes a detection element is provided on one or both of a substrate that supports a display element and a counter substrate, and the like. , various configurations can be applied.

≪Pixel Top Layout≫
12A, 12B, and 12C show top views of pixels. FIG. 12A is a top view of the laminated structure from the gates 221a and 221b to the common electrode 43a, viewed from the common electrode 43a side. FIG. 12B is a top view of the layered structure of FIG. 12A with the common electrode 43a removed, and FIG. 12C is a layered structure of FIG. It is a top view except

The pixel has a connection portion 73 and a connection portion 74 . The pixel electrode 41 is electrically connected to the transistor 101 at the connection portion 73 . Specifically, the conductive layer 222 a functioning as the source or drain of the transistor 101 is in contact with the conductive layer 46 b and the conductive layer 46 b is in contact with the pixel electrode 41 . The conductive layer 46 a is electrically connected to the transistor 102 at the connection portion 74 . 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, and may have a comb-like upper surface shape. A common electrode 43a shown in FIG. 12A has a top surface shape provided with a plurality of slits. The pixel electrode 41 has both a region overlapping the common electrode 43a and a region not overlapping the common electrode 43a.

Further, the pixel electrode 41 may have one or more slits, or may have a comb-like upper surface shape. Since the area overlapping with the common electrode 43a can be increased, it is preferable to form the pixel electrode 41 with a large area. Therefore, the pixel electrode 41 is preferably formed in an island shape without slits.

≪Cross-sectional structure of the display module≫
FIG. 13 shows a cross-sectional view of the display module. Note that the cross-sectional structure of the pixel corresponds to the cross-sectional view along the dashed-dotted line B1-B2 in FIG. 12A.

The display module shown in FIG. 13 has 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, It has 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.

A transistor 101 and a 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 has 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 transistors 101 and 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 and on-state current than other transistors. As a result, a circuit capable of high speed operation can be manufactured. Furthermore, it is possible to reduce the area occupied by the circuit section. By using a transistor with a large on-state current, signal delay in each wiring can be reduced and display unevenness can be suppressed even when the number of wirings increases due to a larger display device or a higher definition display device. is possible. In addition, since the area occupied by the circuit portion can be reduced, the frame of the display device can be narrowed. Further, by applying such a structure, a highly reliable transistor can be realized.

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

The channel forming region 231i overlaps the gates 221 (221a, 221b) with the gate insulating layer 211 interposed therebetween, and overlaps the gates 223 (223a, 223b) with the gate insulating layers 225 (225a, 225b) interposed therebetween.

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

The gate insulating layers 211 and 225 in contact with the channel formation region 231i are preferably oxide insulating layers. Note that when the gate insulating layer 211 or the gate insulating layer 225 has a stacked-layer structure, at least a layer in contact with the channel formation region 231i is preferably an oxide insulating layer. Accordingly, the occurrence 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 insulating layer 213 and insulating layer 214 are preferably nitride insulating layers. Thus, impurities can be prevented from entering the semiconductor layer 231, and the reliability of the transistor can be improved.

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 may not be formed.

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

After the gate insulating layer 225 and the gate 233 are formed, a first layer is formed so as to be in contact with part of the semiconductor layer 231 and heat treatment is performed to lower the resistance of the region. A resistive 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, it preferably contains at least one of aluminum, titanium, tantalum, and tungsten. 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, an oxide film such as an aluminum titanium oxide film, or the like can be preferably used.

The thickness of the first layer can be, for example, 0.5 nm or more and 20 nm or less, preferably 0.5 nm or more and 15 nm or less, more preferably 0.5 nm or more and 10 nm or less, still more preferably 1 nm or more and 6 nm or less. 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. A bond between oxygen vacancies and hydrogen atoms in the oxide semiconductor serves as a carrier generation source.

Heat treatment is performed in a state where the first layer is in contact with part of a region of the semiconductor layer 231, whereby oxygen in the region is absorbed by the first layer, and oxygen vacancies are increased in the region. can be formed. As a result, the low-resistance region 231n can be made extremely low-resistance region.

The low-resistance region 231n formed in this manner has a feature that it is difficult to increase the resistance in subsequent processing. For example, heat treatment in an atmosphere containing oxygen, film formation treatment in an atmosphere containing oxygen, or the like does not impair the conductivity of the low-resistance region 231n. Moreover, a highly reliable transistor can be realized.

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

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

Conductive layer 46 a is located on 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 openings provided in the insulating layers 214 and 215 .

The substrates 31 and 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 43 b is formed on the insulating layer 45 and the conductive layer 222 e is formed on the insulating layer 214 . The conductive layer 43b can be formed in the same process and with the same material as the common electrode 43a. The conductive layer 222e can be formed using the same material in the same step 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 104 . Also, the pixel electrode 41 , the insulating layer 45 , and the common electrode 43 a can function as one capacitor 105 . Thus, the display device 10 has two capacitive elements in one pixel.

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

The capacitance of the capacitor 104 is preferably larger than that 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. Moreover, the thickness of the insulating layer 44 positioned between the conductive layer 46a and the pixel electrode 41 is preferably thinner than the thickness of the insulating layer 45 positioned 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.

Although FIG. 13 shows an example in which both the transistors 101 and 102 have back gates (gates 223), one or both of the transistors 101 and 102 may not have back gates.

Further, although FIG. 13 shows an example in which the gate insulating layer 225 is formed only on the channel forming region 231i and does not overlap with the low resistance region 231n, the gate insulating layer 225 overlaps at least part of the low resistance region 231n. may 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. FIG. The gate insulating layer 225 illustrated in FIGS. 14A and 14B has advantages such as a step of processing the gate insulating layer 225 using the gate 223 as a mask and a step on the surface on which the insulating layer 214 is formed can be reduced.

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

A display device 10 illustrated in FIG. 15 is different in structures of transistors 101 and 102 from those illustrated in FIGS.

The transistor 101 illustrated in FIG. 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 has 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 layers 222a and 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.

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

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-layer structure, at least a layer in contact with the semiconductor layer 231 is preferably an oxide insulating layer. Accordingly, the occurrence of oxygen vacancies in the semiconductor layer 231 can be suppressed, and the reliability of the transistor can be improved.

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 improved.

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

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

Conductive layer 46 a is located on insulating layer 215 . An insulating layer 44 and an insulating layer 45 are positioned 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 openings provided in the insulating layers 44 and 45 .

≪Materials of components≫
Next, details such as materials that can be used for each component of the display device and the display module of this embodiment are described.

There is no particular 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 weight and thickness of the display device can be reduced. Furthermore, a flexible display device can be realized by using a substrate that is thick enough to be flexible.

Liquid crystal materials include positive-type liquid crystal materials whose dielectric constant anisotropy (Δε) is positive and negative-type liquid crystal materials whose dielectric anisotropy (Δε) is negative. In one aspect of the present invention, either material can be used, and the most suitable liquid crystal material can be used depending on the mode and design to be applied.

Liquid crystal elements to which various modes are applied can be used in the display device of this embodiment mode. In addition to the FFS mode described above, for example, IPS mode, TN mode, ASM (Axially Symmetrically aligned Micro-cell) mode, OCB (Optically Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (Anti Fer electronic liquid crystal) mode , an electrically controlled birefringence (ECB) mode, a VA-IPS mode, a guest-host mode, or the like can be used.

Note that the liquid crystal element is an element that controls transmission or non-transmission of light by the optical modulation action of liquid crystal. The optical modulation action of liquid crystals is controlled by electric fields (including lateral, vertical, or oblique electric fields) applied to the liquid crystal. Thermotropic liquid crystals, low molecular weight liquid crystals, polymer liquid crystals, polymer dispersed liquid crystals (PDLC), ferroelectric liquid crystals, antiferroelectric liquid crystals, and the like can be used as liquid crystals used in the liquid crystal element. . These liquid crystal materials exhibit a cholesteric phase, a smectic phase, a cubic phase, a chiral nematic phase, an isotropic phase, etc., depending on conditions.

As described above, in the display device of this embodiment mode, the liquid crystal element can be driven by applying a high voltage; therefore, a liquid crystal exhibiting a blue phase may be used. The blue phase is one of the liquid crystal phases, and is a phase that appears immediately before the cholesteric phase transitions to the isotropic phase when the temperature of the cholesteric liquid crystal is increased. Since the blue phase is expressed 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. Further, a liquid crystal composition containing 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, rubbing treatment is not required because an alignment film is not required, and electrostatic breakdown caused by 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 mode 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). Further, by forming the conductive layer 46b using a conductive material that transmits visible light, even if the capacitor 104 is provided, a decrease in the aperture ratio of the pixel can be suppressed. A silicon nitride film is suitable for the insulating layer 44 and the insulating layer 45 functioning as a dielectric of the capacitor.

As the conductive material that transmits visible light, for example, a material containing at least one selected from indium (In), zinc (Zn), and tin (Sn) may be used. Specifically, it includes indium oxide, indium tin oxide (ITO), indium zinc oxide, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, and titanium oxide. Examples 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. A film containing graphene can be formed, for example, by reducing a film containing graphene oxide.

A 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 contains, for example, indium, and more preferably contains In--M--Zn oxide (where 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 the concentration of impurities such as hydrogen and water in the film. Therefore, the resistivity of the oxide conductive layer is controlled by selecting treatment for increasing at least one of oxygen vacancies and impurity concentration in the oxide semiconductor layer or treatment for reducing at least one of oxygen vacancy and impurity concentration. be able to.

Note that the oxide conductive layer formed using an oxide semiconductor as described above may be 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 either 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 a transistor is not particularly limited, and examples thereof include oxide semiconductors, silicon, germanium, and the like.

The crystallinity of a semiconductor material used for a transistor is not particularly limited, either an amorphous semiconductor or a semiconductor having crystallinity (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a partially crystalline 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 applied to the semiconductor layer.

An oxide semiconductor is preferably used for a semiconductor in which a channel of a transistor is formed. In particular, it is preferable to use an oxide semiconductor having a wider bandgap than silicon. A semiconductor material with a wider bandgap and a lower carrier density than silicon is preferably used because the current in the off state of the transistor can be reduced.

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

In addition, due to the low off-state current, charge accumulated in the capacitor through the transistor can be held for a long time. By applying such a transistor to a pixel, it is possible to stop the driver circuit while maintaining the gradation of the displayed image. As a result, a display device with extremely low power consumption can be realized.

The transistor preferably has a highly purified oxide semiconductor layer in which formation of oxygen vacancies is suppressed. Accordingly, 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 lengthened, and the writing interval can be set long in the power-on state. Therefore, the frequency of the refresh operation can be reduced, which has the effect of suppressing power consumption.

In addition, since a transistor including an oxide semiconductor has relatively high field-effect mobility, it can be driven at high speed. By using such a transistor that can be driven at high speed 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, since there is no need to separately use a semiconductor device formed of a silicon wafer or the like as a driver circuit, the number of components of the display device can be reduced. Also in the display portion, a high-quality image can be provided by using a transistor that can be driven at high speed.

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

An organic insulating material or an inorganic insulating material can be used as an insulating material that can be used for each insulating layer, overcoat, or the like of the display device. Examples of organic insulating materials include acrylic resins, epoxy resins, polyimide resins, polyamide resins, polyimideamide resins, siloxane resins, benzocyclobutene resins, and phenol resins. Examples of inorganic insulating layers include silicon oxide films, silicon oxynitride films, silicon nitride oxide films, silicon nitride films, aluminum oxide films, hafnium oxide films, yttrium oxide films, zirconium oxide films, gallium oxide films, tantalum oxide films, and magnesium oxide films. films, lanthanum oxide films, cerium oxide films, neodymium oxide films, and the like.

Metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten are used in conductive layers such as gates, sources, and drains of transistors as well as various wirings and electrodes of display devices. , or an alloy containing it as a main component can be used as a single layer structure or a laminated structure. For example, a two-layer structure in which a titanium film is laminated on an aluminum film, a two-layer structure in which a titanium film is laminated on a tungsten film, a two-layer structure in which a copper film is laminated on a molybdenum film, and an alloy film containing molybdenum and tungsten. A 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 titanium nitride film, and an aluminum film or copper film overlaid on the titanium film or titanium nitride film a three-layer structure in which a film is laminated and a titanium film or a titanium nitride film is formed thereon, a molybdenum film or a molybdenum nitride film is laminated on the molybdenum film or the molybdenum nitride film, and an aluminum film or a copper film is laminated thereon; Furthermore, there is a three-layer structure in which a molybdenum film or a molybdenum nitride film is formed thereon. For example, when the conductive layer has a three-layer structure, the first and third layers are films made of titanium, titanium nitride, molybdenum, tungsten, an alloy containing molybdenum and tungsten, an alloy containing molybdenum and zirconium, or molybdenum nitride. and, as the second layer, a film made of a low resistance material such as copper, aluminum, gold or silver, or an alloy of copper and manganese. Note that translucent materials such as ITO, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium zinc oxide, and ITSO are used. You may use the conductive 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-liquid mixed curable resin can be used. For example, acrylic resin, urethane resin, epoxy resin, siloxane resin, or the like can be used.

As the connector 242, for example, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), 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 transistors. For example, a black matrix formed using a metal material or a resin material containing pigments or dyes can be used as the light shielding layer 38 and the light shielding regions 10c and 10g. 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.

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

The thin films (insulating film, semiconductor film, conductive film, etc.) constituting the display device are formed by sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), respectively. ) method, Atomic Layer Deposition (ALD) method, or the like. Examples of CVD methods include plasma enhanced chemical vapor deposition (PECVD) and thermal CVD. Examples of thermal CVD methods include metal organic chemical vapor deposition (MOCVD) methods.

The thin films (insulating film, semiconductor film, conductive film, etc.) that make up the display device can be spin-coated, dipped, spray-coated, inkjet-printed, dispensed, screen-printed, offset-printed, doctor-knife, slit-coated, roll-coated, curtain It can be formed by a method such as coating or knife coating.

A thin film forming a 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 sandblast method, a lift-off method, or the like. Photolithography includes a method of forming a resist mask on a thin film to be processed, processing the thin film by etching or the like, and removing the resist mask, and a method of forming a photosensitive thin film, followed by exposure and development. and a method of processing the thin film into a desired shape.

In photolithography, the light used for exposure includes, for example, i-line (wavelength: 365 nm), g-line (wavelength: 436 nm), h-line (wavelength: 405 nm), and mixed light of these. In addition, ultraviolet rays, KrF laser light, ArF laser light, or the like can also be used. Moreover, you may expose by a liquid immersion exposure technique. Light used for exposure includes extreme ultraviolet light (EUV: Extreme Ultra-violet), X-rays, and the like. An electron beam can also be used instead of the light used for exposure. The use of extreme ultraviolet light, X-rays, or electron beams is preferable because extremely fine processing is possible. A photomask is not necessary when exposure is performed by scanning a beam such as an electron beam.

A dry etching method, a wet etching method, a sandblasting method, or the like can be used for etching the thin film.

[Metal oxide]
A metal oxide that functions as an oxide semiconductor is preferably used for a semiconductor layer of a transistor included in the display device of this embodiment. Metal oxides that can be applied to the semiconductor layer are described below.

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

Consider here the case where the metal oxide is an In--M--Zn oxide having indium, the element M, and zinc. Note that the element M is aluminum, gallium, yttrium, tin, or the like. Other elements applicable to 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 elements may be combined in some cases.

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

Oxide semiconductors (metal oxides) are classified into single-crystal oxide semiconductors and non-single-crystal oxide semiconductors. Non-single-crystal oxide semiconductors include, for example, CAAC-OS (c-axis aligned crystalline oxide semiconductor), polycrystalline oxide semiconductors, nc-OS (nanocrystalline oxide semiconductors), pseudo-amorphous oxide semiconductors (a-like (OS: amorphous-like oxide semiconductor), amorphous oxide semiconductor, and the like.

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

Although nanocrystals are basically hexagonal, they are not limited to regular hexagons and may have non-regular hexagons. Also, the strain may have a lattice arrangement such as a pentagon or a heptagon. In CAAC-OS, it is difficult to confirm clear crystal grain boundaries (also called grain boundaries) even in the vicinity of strain. That is, it can be seen that the distortion of the lattice arrangement suppresses the formation of grain boundaries. This is because the CAAC-OS can tolerate strain 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 the substitution of metal elements. It's for.

CAAC-OS is a layered crystal in which a layer containing indium and oxygen (hereinafter referred to as an In layer) and a layer containing the element M, zinc, and oxygen (hereinafter referred to as a (M, Zn) layer) are stacked. It tends to have a structure (also called a layered structure). Note that indium and the element M can be substituted with each other, and when the element M in the (M, Zn) layer is substituted with indium, the layer can also be expressed as an (In, M, Zn) layer. In addition, 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 highly crystalline metal oxide. On the other hand, in CAAC-OS, since it is difficult to confirm a clear crystal grain boundary, it can be said that the decrease in electron mobility due to the crystal grain boundary is unlikely to occur. In addition, since the crystallinity of metal oxides may be degraded by the contamination of impurities and the generation of defects, CAAC-OS is made of a metal with few impurities and defects (such as oxygen vacancy (V _O )). It can also be called an oxide. Therefore, metal oxides with CAAC-OS have stable physical properties. Therefore, a metal oxide containing CAAC-OS is heat resistant and highly reliable.

The nc-OS has periodic atomic arrangement in a minute region (eg, a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). Also, nc-OS shows no regularity in crystal orientation between different nanocrystals. Therefore, no orientation is observed in the entire film. Therefore, an nc-OS may be indistinguishable from an a-like OS or an amorphous oxide semiconductor depending on the analysis method.

Note that indium-gallium-zinc oxide (hereinafter referred to as IGZO), which is a type of metal oxide containing indium, gallium, and zinc, may have a stable structure when formed into the above-described nanocrystals. be. In particular, since IGZO tends to be difficult to crystallize in the atmosphere, it is preferable to use smaller crystals (for example, the above-mentioned nanocrystals) than large crystals (here, crystals of several mm or crystals of several cm). can be structurally stable.

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

Oxide semiconductors (metal oxides) have various structures, each of which has different characteristics. An 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.

A metal oxide film that functions as a semiconductor layer can be formed using either one or both of an inert gas and an oxygen gas. Note that there is no particular limitation on the oxygen flow rate (oxygen partial pressure) during the formation of the metal oxide film. However, in order to obtain a transistor with high field effect mobility, the oxygen flow ratio (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 preferable, and 7% or more and 15% or less is even more preferable.

The metal oxide preferably has an energy gap of 2 eV or more, more preferably 2.5 eV or more, and even more preferably 3 eV or more. By using a metal oxide with a wide energy gap in this manner, off-state current of a transistor can be reduced.

A 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 deposition method, or the like may be used.

As described above, in the display device of one embodiment of the present invention, two capacitors that transmit visible light are overlapped in the pixel; therefore, the pixel can have both a high aperture ratio and a large storage capacitance. .

Further, 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.

This embodiment can be appropriately combined with other embodiments. Further, in this specification, when a plurality of configuration examples are shown in one embodiment, the configuration examples can be combined as appropriate.

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

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

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

For example, CAC-OS in In—Ga—Zn oxide (In—Ga—Zn oxide among CAC-OS may be particularly referred to as CAC-IGZO) is indium oxide (hereinafter, InO _{and gallium _ _} oxide (hereinafter referred to as GaO _X3 (X3 is a real number greater than 0)) or gallium zinc oxide (hereinafter Ga _X4 Zn _Y4 O _Z4 (X4, Y4, and Z4 are real numbers greater than 0); ) and the like, and the material is separated into a mosaic shape, and the mosaic InO _X1 or In _X2 Zn _Y2 O _Z2 is uniformly distributed in the film (hereinafter also referred to as a cloud shape). be.

In other words, CAC-OS is a composite metal oxide having a structure in which a region containing GaO _{2 X3} as a main component and a region containing In _{2 X2} Zn _Y2 O _Z2 or InO _{2 X1} as a main component are mixed. In this specification, for example, the first region means that the atomic ratio of In to the element M in the first region is greater than the atomic ratio of In to the element M in the second region. Assume that the concentration of In is higher than that of the region No. 2.

Note that IGZO is a common name and may refer to one compound of In, Ga, Zn, and O. Representative examples are represented by 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). Crystalline compounds are 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.

CAC-OS, on the other hand, relates to the material composition of metal oxides. CAC-OS is a material composition containing In, Ga, Zn, and O, in which a region that is observed in the form of nanoparticles containing Ga as the main component in part and nanoparticles containing In as the main component in part. The regions observed in a pattern refer to a configuration in which the regions are randomly dispersed in a mosaic pattern. Therefore, in CAC-OS the crystal structure is a secondary factor.

Note that CAC-OS does not include a stacked structure of two or more films with different compositions. For example, it does not include a structure consisting of two layers, a film containing In as a main component and a film containing Ga as a main component.

In some cases, a clear boundary cannot be observed between a region containing GaO _X3 as a main component and a region containing In _X2 Zn _Y2 O _Z2 or InO _X1 as a main component.

Instead of gallium, aluminum, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, etc. CAC-OS contains one or more of the metal elements, part of which is observed in the form of nanoparticles containing the metal element as the main component, and part of which contains nanoparticles containing In as the main component. The regions observed as particles refer to a configuration in which the regions are randomly dispersed in a mosaic pattern.

A CAC-OS can be formed by a sputtering method, for example, under the condition that the substrate is not heated. Further, when the CAC-OS is formed by a sputtering method, one or more selected from an inert gas (typically argon), oxygen gas, and nitrogen gas may be used as the film forming gas. good. Further, the flow rate ratio of oxygen gas to the total flow rate of film formation gas during film formation is preferably as low as possible. .

CAC-OS is characterized by the fact that no clear peak is observed when measured using θ/2θ scanning by the Out-of-plane method, which is one of X-ray diffraction (XRD) measurement methods. have. That is, it can be seen from the X-ray diffraction measurement that the orientation in the ab plane direction and the c-axis direction of the measurement region is not observed.

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

Further, for example, in CAC-OS in In-Ga-Zn oxide, EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) reveals a region in which GaO _X3 is the main component. , and a region containing In _X2 Zn _Y2 O _Z2 or InO _X1 as a main component are unevenly distributed and mixed.

CAC-OS has a structure different from IGZO compounds in which metal elements are uniformly distributed, and has properties different from those of IGZO compounds. That is, the CAC-OS is phase-separated into a region containing GaO 2 _X3 or the like as a main component and a region containing In _X2 Zn _Y2 O _Z2 or InO _{2 X1} as a main component, and a region containing each element as a main component. has a mosaic structure.

Here, the region containing In _X2 Zn _Y2 O _Z2 or InO _X1 as the main component has higher conductivity than the region containing GaO _X3 or the like as the main component. That is, when carriers flow through a region containing In _X2 Zn _Y2 O _Z2 or InO _X1 as a main component, conductivity as a metal oxide is developed. Therefore, a region containing In _X2 Zn _Y2 O _Z2 or InO _X1 as a main component is distributed like a cloud in the metal oxide, so that a high field effect mobility (μ) can be realized.

On the other hand, a region containing GaO _{2 X3} or the like as a main component has higher insulating properties than a region containing In _X2 Zn _Y2 O _Z2 or InO _{2 X1} as a main component. In other words, by distributing the region mainly composed of GaO _{2 X3} or the like in the metal oxide, it is possible to suppress leakage current and realize good switching operation.

Therefore, when CAC-OS is used for a semiconductor element, the insulation properties caused by GaO _X3 and the like and the conductivity caused by In _X2 Zn _Y2 O _Z2 or InO _X1 act in a complementary manner, resulting in high On-current (I _on ) and high field effect mobility (μ) can be achieved.

In addition, a semiconductor element using CAC-OS has high reliability. Therefore, CAC-OS is most suitable for various semiconductor devices including displays.

This embodiment can be appropriately combined with other embodiments. Further, in this specification, when a plurality of configuration examples are shown in one embodiment, the configuration examples can be combined as appropriate.

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

The electronic devices of this embodiment each include the display device of one embodiment of the present invention in a display portion. As a result, the display unit of the electronic device can display high-quality images. In addition, display can be performed with high reliability over a wide temperature range.

The display portion of the electronic device of this embodiment mode can display images having a resolution of, for example, full high definition, 2K, 4K, 8K, 16K, or higher. The screen size of the display unit can be 20 inches or more diagonal, 30 inches or more diagonal, 50 inches or more diagonal, 60 inches or more diagonal, or 70 inches or more diagonal.

Examples of electronic devices in which the display device of one embodiment of the present invention can be used include television devices, desktop or notebook personal computers, computer monitors, digital signage (electronic signage), and pachinko machines. In addition to electronic devices with relatively large screens such as large game machines such as machines, digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, sound playback devices, etc. . Further, the display device of one embodiment of the present invention can be suitably used for portable electronic devices, wearable electronic devices (wearable devices), VR (virtual reality) devices, AR (augmented reality) devices, and the like. .

An electronic device of one embodiment of the present invention may include a secondary battery, and it is preferable that the secondary battery can be charged using contactless power transmission.

Secondary batteries include, for example, lithium ion secondary batteries such as lithium polymer batteries (lithium ion polymer batteries) using a gel electrolyte, nickel-metal hydride batteries, nickel-cadmium batteries, organic radical batteries, lead-acid batteries, air secondary batteries, nickel zinc batteries, silver-zinc batteries, and the like.

An electronic device of one embodiment of the present invention may have an antenna. An image, information, or the like can be displayed on the display portion by receiving a signal with the antenna. Moreover, when an electronic device has an antenna and a secondary battery, the antenna may be used for contactless power transmission.

The electronic device of one embodiment of the present invention includes sensors (force, displacement, position, speed, acceleration, angular velocity, number of rotations, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared).

An electronic device of one embodiment of the present invention can have various functions. For example, functions to display various information (still images, moving images, text images, etc.) on the display unit, touch panel functions, functions to display calendars, dates or times, functions to execute various software (programs), wireless communication function, a function of reading a program or data recorded on a recording medium, and the like.

Furthermore, in an electronic device having a plurality of display units, one display unit mainly displays image information and another display unit mainly displays character information, or a plurality of display units has a function of displaying parallax. By displaying an image, it can have a function of displaying a stereoscopic image. In addition, in electronic devices with an image receiving unit, the function of shooting still images or moving images, the function of automatically or manually correcting the captured image, the function of saving the captured image to a recording medium (external or built into the electronic device) , a function of displaying a captured image on a display portion, and the like. Note that the electronic device of one embodiment of the present invention is not limited to these functions, and can have various functions.

FIG. 16A shows a television set 1810. FIG. A television device 1810 includes a display portion 1811, a housing 1812, speakers 1813, and the like. Furthermore, it can have an LED lamp, an operation key (including a power switch or an operation switch), connection terminals, various sensors, a microphone, and the like.

Television device 1810 can be operated by remote controller 1814 .

Broadcast radio waves that can be received by the television device 1810 include terrestrial waves and radio waves transmitted from satellites. Broadcast radio waves include analog broadcasting, digital broadcasting, and the like, as well as broadcasting of video and audio, or audio only. For example, it is possible to receive airwaves transmitted in a specific frequency band of the UHF band (approximately 300 MHz to 3 GHz) or the VHF band (30 MHz to 300 MHz). Also, 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 higher than full high definition can be displayed on the display portion 1811 . For example, images having resolutions of 4K, 8K, 16K, or higher can be displayed.

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

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

As the display portion 1821 is wider, the amount of information that can be provided at one time can be increased. Also, the wider the display portion 1821, the more conspicuous it is, and the more effective the advertisement can be, for example.

By applying a touch panel to the display portion 1821, not only a still image or a moving image can be displayed on the display portion 1821 but also the user can intuitively operate the display portion 1821, which is preferable. Further, when used for providing information such as route information or traffic information, usability can be enhanced by intuitive operation.

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

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

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

17A and 17B show a portable information terminal 800. FIG. A mobile 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 mobile information terminal 800 can be opened from the folded state shown in FIG. 17A to the housings 801 and 802 shown in FIG. 17B.

For example, the display portion 803 and the display portion 804 can display document information and can be used as an electronic book terminal. A still image or a moving image can also be displayed on the display portion 803 and the display portion 804 .

As described above, the portable information terminal 800 can be folded when being carried, and thus has excellent versatility.

Note that the housing 801 and the housing 802 may have 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 mobile 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.

Portable information terminal 810 includes a touch sensor in display portion 812 . All operations such as making a call or inputting characters can be performed by touching the display unit 812 with a finger, a stylus, or the like.

Further, by operating the operation button 813 , the power can be turned on and off, and the type of image displayed on the display portion 812 can be switched. For example, it is possible to switch from the mail creation screen to the main menu screen.

In addition, by providing a detection device such as a gyro sensor or an acceleration sensor inside the mobile information terminal 810, the orientation (vertical or horizontal) of the mobile information terminal 810 is determined, and the screen display orientation of the display unit 812 is determined. You can switch automatically. Switching of the orientation of the screen display can also be performed by touching the display portion 812, operating the operation button 813, voice input using the microphone 816, or the like.

The mobile information terminal 810 has one or more functions selected from, for example, a telephone, a notebook, an information viewing device, and the like. Specifically, it can be used as a smartphone. Personal digital assistant 810 is capable of executing various applications such as mobile phone, e-mail, text viewing and composition, music playback, video playback, Internet communication, and games, for example.

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

Here, the camera 820 has a configuration in which 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 still images or moving images by pressing a shutter button 824 . Further, the display portion 822 has a function as a touch panel, and an image can be captured 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 , lighting 833 , and an optical module 832 . The housing 831 has an opening 835 and an opening 835a (not shown in the drawing). The electronic device 830 can be incorporated into an inner wall or outer wall of a house or building, space partitions (doors, windows, walls, rooms, desk partitions), and the like. Furthermore, the display device 834 can provide a transparent display device 834 that allows the other side of the display device 834 to be viewed by providing a light-transmitting region in a pixel formed in the TFT layer.

FIG. 17E shows a scene where the user touches the display screen on which cherry blossom petals are pouring down from both sides. The display device 834 can detect information touched from different display surfaces. Note that the electronic device 830 can also cause the digital signage to execute a game. This allows an unspecified number of users to simultaneously participate in and enjoy the game.

An example of mounting an electronic device including a display device of one embodiment of the present invention in a vehicle will be described with reference to FIGS.

FIG. 18A shows an example in which a vehicle 5000 has multiple cameras 5005 . Vehicle 5000 has camera 5005a, camera 5005b, camera 5005c, camera 5005d, cameras 5005d, 5005e, and 5005f. For example, the camera 5005a has a function of imaging the situation in front, the camera 5005b has a function of imaging the situation behind, the camera 5005c has a function of imaging the situation in front of the right, and the camera 5005d. has a function of capturing an image of the left front situation, a camera 5005e has a function of capturing an image of the right rear situation, and a camera 5005f has a function of capturing an image of the left rear situation. However, the number of cameras 5005 that capture images of the surroundings of the vehicle is not limited to the configuration described above. For example, a camera 5005 or the like that captures images from the front of the vehicle to the rear may be provided.

Next, FIG. 18B shows an example of the internal configuration of the vehicle 5000. As shown in FIG. Vehicle 5000 has display unit 5001 , display panels 5008 a and 5008 b , and display panel 5009 . For 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. Although FIG. 18B shows an example in which the display unit 5001 is mounted on a right-hand drive vehicle, it is not particularly limited, and can be mounted on a left-hand drive vehicle. In this case, the left and right arrangement of the configuration shown in FIG. 18B is changed.

FIG. 18(B) shows a dashboard 5002, a steering wheel 5003, a windshield 5004, etc. arranged around the driver's seat and passenger's seat. The display unit 5001 is arranged at a predetermined position on the dashboard 5002, specifically around the driver, and has a general T shape. FIG. 18B shows 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 portion 5001 may be divided and arranged in a plurality of places.

Further, display panels 5008a and 5008b are display panels provided in pillar portions. For example, by projecting an image 5008c from an imaging means (for example, a camera 5005 shown in FIG. 18A) provided on the vehicle body to the display panels 5008a and 5008b, the field of view blocked by the pillars can be complemented. can. Also, the display panel 5009 may display an image from the rear image capturing means. Alternatively, the legal speed limit, 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 can be provided along the curved surface of the dashboard 5002 or the like, or can be displayed on the connection portion of the steering wheel, the display portion of the instrument, the air outlet 5006, or the like. A configuration in which the display area of the portion 5001 is not provided can be easily realized.

Moreover, the display panels 5008a and 5008b preferably have flexibility. Since the biller portion has a curved surface, it is preferable that the image distortion when the driver's seat looks at the pillar portion is corrected. Image distortion is preferably corrected using a neural network.

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

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

An image captured by the camera 5005 can be output to one or more of the display panels 5007 . The display unit 5001 is mainly used to assist driving of the vehicle. The camera 5005 captures the rear side situation with a wide angle of view, and displays the image on the display panel 5007, so that the driver can visually recognize the blind spot area, and the occurrence of an accident can be prevented.

Further, by using the display system of one embodiment of the present invention, discontinuity of images at the joints of the display panels 5007a, 5007b, 5007c, and 5007d can be corrected. As a result, it is possible to display an image in which the seams are inconspicuous, and the visibility of the display unit 5001 during driving can be improved.

Alternatively, a distance image sensor may be provided on the roof of a car or the like, 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, a lidar (LIDAR: Light Detection and Ranging), or the like 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 to assist driving.

Further, the display unit 5001 may have a function of displaying map information, traffic information, television images, DVD images, and the like. For example, the display panels 5007a, 5007b, 5007c, and 5007d can be used as one display screen to display map information in a large size. Note that the number of display panels 5007 can be increased according to the images to be displayed.

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, TV images and DVD images may be displayed on the left display panel 5007d, map information may be displayed on the central display panel 5007b, instruments may be displayed on the right display panel 5007c, and audio may be displayed near the transmission gear (driving gear). It can be displayed on the display panel 5007a between the seat and the front passenger seat. By combining a plurality of display panels 5007, the display portion 5001 can have a fail-safe function. For example, even if one display panel 5007 fails for some reason, the display area can be changed and another display panel 5007 can be used for display.

The windshield 5004 also has a display panel 5004a. The display panel 5004a has a function of transmitting visible light, and the background can be viewed. In addition, the display panel 5004a has a function of displaying a warning to the driver. FIG. 18B illustrates the structure in which the display panel 5004a is provided over the windshield 5004; however, the present invention is not limited to this. For example, the windshield 5004 may be replaced with a display panel 5004a.

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

This embodiment can be appropriately combined with other embodiments. Further, in this specification, when a plurality of configuration examples are shown in one embodiment, the configuration examples can be combined as appropriate.

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 area, 10g: light shielding area, 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: Conductive layer 44: Insulating layer 45: Insulating layer 46: Conductive Layer 46a: conductive layer 46b: conductive layer 73: connection portion 74: connection portion 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, 223a: 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: connector

Claims (3)

having first to seventh regions extending in the row direction;
The first to seventh regions are provided in order in the column direction,
in the first period,
the first region displays blue;
the display data of the second area is updated and is not displayed;
the third region displays green;
the display data of the fourth area is updated and is not displayed;
the fifth region displays a red color;
the display data of the sixth area is updated and is not displayed;
the seventh region displays blue;
In a second period following the first period,
the display data of the first area is updated and is hidden;
the second region displays blue;
the display data of the third area is updated and is not displayed;
the fourth region displays green;
the display data of the fifth area is updated and is not displayed;
the sixth region displays a red color;
the display data of the seventh area is updated and is not displayed;
each of the first region to the seventh region has a pixel,
the pixel includes a first transistor, a second transistor, a first capacitive element, a second capacitive element, and a liquid crystal element;
the gate of the first transistor is always conductive with the first scanning line;
one of the source and the drain of the first transistor is always conductive with the first signal line;
the other of the source and the drain of the first transistor is always conductive with one electrode of the first capacitive element;
the other of the source and the drain of the first transistor is always conductive with one electrode of the liquid crystal element;
the other of the source and the drain of the first transistor is always conductive with one electrode of the second capacitive element;
the gate of the second transistor is always conductive with the second scanning line;
one of the source and the drain of the second transistor is always conductive with the second signal line;
the other of the source and the drain of the second transistor is always conductive with the other electrode of the first capacitive element;
the other electrode of the liquid crystal element is always electrically connected to the common wiring;
the other electrode of the second capacitive element is always electrically connected to the common wiring;
At time 1,
A signal applied to the first scanning line turns on the first transistor,
By applying the first image data to the first signal line, one electrode of the first capacitor, one electrode of the liquid crystal element, and one electrode of the second capacitor are connected. , is provided with the first image data,
A signal applied to the second scanning line turns on the second transistor,
By applying the initialization voltage to the second signal line, the initialization voltage is applied to the other electrode of the first capacitive element,
At time 2 following time 1,
A signal applied to the first scanning line turns off the first transistor,
a signal applied to the second scan line causes the second transistor to remain on;
By applying the second image data to the second signal line, the second image data is applied to the other electrode of the first capacitive element, and capacitive coupling via the first capacitive element , one electrode of the first capacitive element, one electrode of the liquid crystal element, and one electrode of the second capacitive element, the second image data is added to the first image data; is given to the third image data with
At time 3 following time 2,
the first transistor remains off;
A signal applied to the second scan line turns off the second transistor,
the third image data is held in one electrode of the first capacitive element, one electrode of the liquid crystal element, and one electrode of the second capacitive element;
In the liquid crystal display device, the operations at the time 1 to the time 3 are performed in the non-display in each of the first region to the seventh region. having first to seventh regions extending in the row direction;
The first to seventh regions are provided in order in the column direction,
in the first period,
all the pixels included in the first region display blue;
the display data of the second area is updated and is not displayed;
all the pixels included in the third region display green;
the display data of the fourth area is updated and is not displayed;
all pixels included in the fifth region display red;
the display data of the sixth area is updated and is not displayed;
all the pixels included in the seventh region display blue;
In a second period following the first period,
the display data of the first area is updated and is hidden;
all pixels included in the second region display blue;
the display data of the third area is updated and is not displayed;
all pixels included in the fourth region display green;
the display data of the fifth area is updated and is not displayed;
all pixels included in the sixth region display red;
the display data of the seventh area is updated and is not displayed;
each of the first region to the seventh region has a pixel,
the pixel includes a first transistor, a second transistor, a first capacitive element, a second capacitive element, and a liquid crystal element;
the gate of the first transistor is always conductive with the first scanning line;
one of the source and the drain of the first transistor is always conductive with the first signal line;
the other of the source and the drain of the first transistor is always conductive with one electrode of the first capacitive element;
the other of the source and the drain of the first transistor is always conductive with one electrode of the liquid crystal element;
the other of the source and the drain of the first transistor is always conductive with one electrode of the second capacitive element;
the gate of the second transistor is always conductive with the second scanning line;
one of the source and the drain of the second transistor is always conductive with the second signal line;
the other of the source and the drain of the second transistor is always conductive with the other electrode of the first capacitive element;
the other electrode of the liquid crystal element is always electrically connected to the common wiring;
the other electrode of the second capacitive element is always electrically connected to the common wiring;
At time 1,
A signal applied to the first scanning line turns on the first transistor,
By applying the first image data to the first signal line, one electrode of the first capacitor, one electrode of the liquid crystal element, and one electrode of the second capacitor are connected. , is provided with the first image data,
A signal applied to the second scanning line turns on the second transistor,
By applying the initialization voltage to the second signal line, the initialization voltage is applied to the other electrode of the first capacitive element,
At time 2 following time 1,
A signal applied to the first scan line turns off the first transistor,
a signal applied to the second scan line causes the second transistor to remain on;
By applying the second image data to the second signal line, the second image data is applied to the other electrode of the first capacitive element, and capacitive coupling via the first capacitive element , one electrode of the first capacitive element, one electrode of the liquid crystal element, and one electrode of the second capacitive element, the second image data is added to the first image data; is given to the third image data with
At time 3 following time 2,
the first transistor remains off;
A signal applied to the second scan line turns off the second transistor,
the third image data is held in one electrode of the first capacitive element, one electrode of the liquid crystal element, and one electrode of the second capacitive element;
In the liquid crystal display device, the operations at the time 1 to the time 3 are performed in the non-display in each of the first region to the seventh region. In claim 1 or 2,
Between the first region and the second region, between the second region and the third region, between the third region and the fourth region, between the fourth region and the fourth region 5, between the fifth region and the sixth region, and between the sixth region and the seventh region.

Images