JP2018141947A - Display device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device that can display an image of high luminance.SOLUTION: A display device has a first pixel, a second pixel adjacent to the first pixel in row direction, and a third pixel adjacent to the first pixel in column direction; each of the first to the third pixels has a first display area, a second display area, and a third display area; the first display area has a first display element; the second display area has a second display element; the third display area has a third display element; the first display element and the second display element emit light; the third display element reflects the light incident upon the third display element; the second pixel has a first display area at a position linearly symmetric with the first display area included in the first pixel, using a boundary between the first pixel and the second pixel with a symmetric axis; and the third pixel has a first display area at a position linearly symmetric with the first display area included in the first pixel, using a boundary between the first pixel and the third pixel with a symmetric axis.SELECTED DRAWING: Figure 3

Description

One embodiment of the present invention relates to a display device, a manufacturing method thereof, and an electronic device.

Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification and the like relates to an object, a method, or a manufacturing method. Alternatively, one embodiment of the present invention relates to a process, a machine, a manufacture, or a composition (composition of matter). Therefore, the technical field of one embodiment of the present invention disclosed in this specification and the like more specifically includes a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, a driving method thereof, or a manufacturing method thereof. Can be mentioned as an example.

There is known a liquid crystal display device that uses a light source that emits surface light as a backlight and combines a transmissive liquid crystal display device to achieve both reduction in power consumption and suppression of deterioration in display quality (see Patent Document 1). .

A display device in which a light emitting element and a reflective liquid crystal element are provided in one pixel has been proposed (Patent Document 2). In the display device, display using a liquid crystal element can be performed in an environment where there is sufficient external light, and display using a light-emitting element can be performed in an environment where sufficient brightness cannot be obtained.

JP 2011-248351 A Special table 2009-510527 gazette

As a method of displaying an image using a light emitting element, there is a color filter system that expresses each color such as red, green, and blue by passing white light emitted from a light emitting element having a white light emitting layer through a colored layer. In addition, there is a color coding method in which each pixel is provided with a light-emitting element having a red light-emitting layer, a light-emitting element having a green light-emitting layer, a light-emitting element having a blue light-emitting layer, and the like. In the color-coating method, it is not necessary to provide a colored layer, and thus light emitted from the light emitting element is not absorbed by the colored layer, so that a decrease in luminance of the light can be suppressed as compared with the color filter method. Thus, in the color painting method, the luminance of light emitted from the light emitting element can be reduced as compared with the color filter method, and the power consumption of the display device can be reduced. On the other hand, in the separate coloring method, when the size of a pixel is reduced due to high definition, the interval between adjacent pixels is reduced. When the emission colors of the light-emitting layers included in adjacent pixels are different, alignment misalignment or the like occurs due to the alignment accuracy of the metal mask used for painting, and higher definition is more difficult than the color filter method.

An object of one embodiment of the present invention is to provide a display device with reduced power consumption and a manufacturing method thereof. Another object of one embodiment of the present invention is to provide a display device with high definition and a manufacturing method thereof. Another object of one embodiment of the present invention is to provide a display device with high visibility and a manufacturing method thereof. Another object of one embodiment of the present invention is to provide a highly reliable display device and a manufacturing method thereof. Another object of one embodiment of the present invention is to provide a novel display device and a manufacturing method thereof.

Note that the description of these problems does not disturb the existence of other problems. Note that one embodiment of the present invention does not have to solve all of these problems. Problems other than these will be apparent from the description of the specification, drawings, claims, etc., and other problems can be extracted from the description of the specifications, drawings, claims, etc. It is.

One embodiment of the present invention includes a first pixel, a second pixel adjacent to the first pixel in the row direction, and a third pixel adjacent to the first pixel in the column direction. Each of the first to third pixels includes a first display area, a second display area, and a third display area, and the first display area includes a first display element. The second display area has a second display element, the third display area has a third display element, and the first display element and the second display element have a function of emitting light. The third display element has a function of reflecting light incident on the third display element, and the second pixel has a boundary between the first pixel and the second pixel as an axis of symmetry. The first pixel has a first display area at a position symmetrical to the first display area of one pixel, and the third pixel has a first axis with the boundary between the first pixel and the third pixel as a symmetry axis. The second pixel has The position of the display area and the line symmetry of a display device having a first display area.

Further, in the above aspect, the second pixel is located in a point-symmetrical position with respect to the second display area of the first pixel, with the central portion of the boundary between the first pixel and the second pixel as a symmetric point. You may have two display areas.

In the above aspect, the third pixel is located at a point symmetric with respect to the second display area of the first pixel with the central portion of the boundary between the first pixel and the third pixel as a symmetric point. You may have two display areas.

In the above aspect, the first to third pixels are rectangles having a long side a μm (a is a real number of 0 or more) and a short side b μm (b is a real number of 0 or more and a or less). The first display area is provided within a range of a / 4 μm in the long side direction and b / 4 μm in the short side direction from one of the vertices of the first pixel. The one display area is provided within a range of a / 4 μm in the long side direction and b / 4 μm in the short side direction from one of the vertices of the second pixel. The display area may be provided within a range of a / 4 μm in the long side direction and b / 4 μm in the short side direction from one vertex of the third pixel.

In the above aspect, the first display area and the second display area may emit light of different colors.

In the above embodiment, the third display region included in the first pixel, the third display region included in the second pixel, and the third display region included in the third pixel have different colors. It may have a function of emitting light.

In the above embodiment, each of the first to third pixels includes a fourth display area, the fourth display area includes a fourth display element, and the fourth display element emits light. The fourth display area may have a function of emitting light emitted from the first display area and light having a color different from that of the light emitted from the second display area. .

In the above aspect, the first to third pixels are rectangles having a long side a μm (a is a real number of 0 or more) and a short side b μm (b is a real number of 0 or more and a or less). The fourth display area is provided within a range of a / 4 μm in the long side direction and within b / 4 μm in the short side direction from one of the vertices of the first pixel. The display area 4 is provided within a range of a / 4 μm in the long side direction and b / 4 μm in the short side direction from one of the vertices of the second pixel. The display area may be provided within a range of a / 4 μm in the long side direction and b / 4 μm in the short side direction from one vertex of the third pixel.

An electronic device including the display device of one embodiment of the present invention and an input device for operation is also one embodiment of the present invention.

One embodiment of the present invention can provide a display device with reduced power consumption and a manufacturing method thereof. Alternatively, according to one embodiment of the present invention, a display device with high definition and a manufacturing method thereof can be provided. Alternatively, according to one embodiment of the present invention, a display device with high visibility and a manufacturing method thereof can be provided. Alternatively, according to one embodiment of the present invention, a highly reliable display device and a manufacturing method thereof can be provided. Alternatively, according to one embodiment of the present invention, a novel display device and a manufacturing method thereof can be provided.

Note that the description of these effects does not disturb the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. It should be noted that the effects other than these will be apparent from the description of the specification, drawings, claims, etc., and it is possible to extract the effects other than these from the description of the specifications, drawings, claims, etc. It is.

FIG. 11 is a block diagram illustrating a display device. FIG. 10 is a circuit diagram illustrating a pixel. The schematic diagram explaining the display area of a display element. The schematic diagram explaining the positional relationship of a display area. The schematic diagram explaining the positional relationship of a display area. The schematic diagram explaining the display area of a display element. FIG. 10 is a circuit diagram illustrating a pixel. The schematic diagram explaining the display area of a display element. Sectional drawing explaining a display element. The schematic diagram explaining the display area of a display element. The schematic diagram explaining the display area of a display element. FIG. 6 illustrates an example of a display device. FIG. 6 is a top view illustrating a configuration example of a pixel circuit and a transmissive portion and a light shielding portion of the pixel circuit. Sectional drawing explaining an example of a display apparatus. Sectional drawing explaining an example of a display apparatus. Sectional drawing explaining an example of a display apparatus. Sectional drawing explaining an example of a display apparatus. 8A and 8B each illustrate a use example of an electronic device for each display mode. 4A and 4B are a top view and cross-sectional views illustrating an example of a transistor used for a display device. 4A and 4B are a top view and cross-sectional views illustrating an example of a transistor used for a display device. 4A and 4B are a top view and cross-sectional views illustrating an example of a transistor used for a display device. 8A and 8B illustrate a structural example of an electronic device. A photograph showing a pixel configuration. The figure which shows the measuring system of a reflectance. The graph which shows the relationship between a reflectance and pixel density. The graph which shows the relationship between a brightness | luminance and the illumination intensity of surrounding environment. The photograph which shows the display result of a display device. The graph which shows the measurement result of an optical characteristic. The graph which shows the relationship between a reflectance and a wavelength. The photograph which shows the display result of a display device. The figure which shows the measuring system of a reflectance. The figure which shows the relationship between a reflectance and a light projection angle. The graph which shows the measurement result of an optical characteristic. The photograph which shows the display result of a display device. The graph which shows the relationship between a reflectance and a light projection angle, and the graph which shows the relationship between a reflectance and an aperture ratio. The graph which shows the measurement result of an optical characteristic.

Hereinafter, embodiments will be described with reference to the drawings. However, the embodiments can be implemented in many different modes, and it is easily understood by those skilled in the art that the modes and details can be variously changed without departing from the spirit and scope thereof. . Therefore, the present invention should not be construed as being limited to the description of the following embodiments.

In the drawings, the size, the thickness of layers, or regions are exaggerated for clarity in some cases. Therefore, it is not necessarily limited to the scale. The drawings schematically show an ideal example, and are not limited to the shapes or values shown in the drawings.

In addition, the ordinal numbers “first”, “second”, and “third” used in the present specification are attached to avoid confusion between components, and are not limited numerically. Appendices.

In addition, in this specification, terms indicating arrangements such as “above” and “below” are used for convenience to describe the positional relationship between components with reference to the drawings. Moreover, the positional relationship between components changes suitably according to the direction which draws each structure. Therefore, the present invention is not limited to the words and phrases described in the specification, and can be appropriately rephrased depending on the situation.

In this specification and the like, a transistor is an element having at least three terminals including a gate, a drain, and a source. A channel region is provided between the drain (drain terminal, drain region or drain electrode) and the source (source terminal, source region or source electrode), and between the source and drain through the channel formation region. A current can flow. Note that in this specification and the like, a channel region refers to a region through which a current mainly flows.

In addition, the functions of the source and drain may be switched when transistors having different polarities are employed or when the direction of current changes during circuit operation. Therefore, in this specification and the like, the terms source and drain can be used interchangeably.

In addition, in this specification and the like, “electrically connected” includes a case of being connected via “thing having some electric action”. Here, the “thing having some electric action” is not particularly limited as long as it can exchange electric signals between connection targets. For example, “things that have some electrical action” include electrodes, wiring, switching elements such as transistors, resistance elements, inductors, capacitors, and other elements having various functions.

In this specification and the like, the terms “film” and “layer” can be interchanged with each other. For example, the term “conductive layer” may be changed to the term “conductive film”. Alternatively, for example, the term “insulating film” may be changed to the term “insulating layer” in some cases.

In this specification and the like, a metal oxide layer is a metal oxide in a broad expression. The metal oxide layer is classified into an oxide insulating film, an oxide conductive film (including a transparent oxide conductive film), an oxide semiconductor film (also referred to as an Oxide Semiconductor or simply OS), and the like. For example, when a metal oxide layer is used for an active layer of a transistor, the metal oxide layer may be referred to as an oxide semiconductor film. That is, in the case where the metal oxide layer has at least one of an amplifying function, a rectifying function, and a switching function, the metal oxide layer can be referred to as a metal oxide semiconductor (abbreviated as OS). In the case of describing as an OS FET, it can be said to be a transistor having a metal oxide layer or an oxide semiconductor film.

In this specification and the like, a metal oxide layer containing nitrogen may be collectively referred to as a metal oxide layer. Further, the metal oxide layer containing nitrogen may be referred to as metal oxynitride.

Further, in this specification and the like, there are cases where they are described as CAAC (c-axis aligned crystal) and CAC (Cloud-aligned Composite). Note that CAAC represents an example of a crystal structure, and CAC represents an example of a function or a material structure.

In this specification and the like, a CAC-OS or a CAC-metal oxide has a conductive function in part of a material and an insulating function in part of the material, and the whole material is a semiconductor. It has the function of. Note that in the case where a CAC-OS or a CAC-metal oxide is used for an active layer of a transistor, the conductive function is a function of flowing electrons (or holes) serving as carriers, and the insulating function is an electron serving as carriers. It is a function that does not flow. By performing the conductive function and the insulating function in a complementary manner, a switching function (function to turn on / off) can be given to the CAC-OS or the CAC-metal oxide. In CAC-OS or CAC-metal oxide, by separating each function, both functions can be maximized.

In this specification and the like, a CAC-OS or a CAC-metal oxide includes a conductive region and an insulating region. The conductive region has the above-described conductive function, and the insulating region has the above-described insulating function. In the material, the conductive region and the insulating region may be separated at the nanoparticle level. In addition, the conductive region and the insulating region may be unevenly distributed in the material, respectively. In addition, the conductive region may be observed with the periphery blurred and connected in a cloud shape.

In CAC-OS or CAC-metal oxide, the conductive region and the insulating region are each dispersed in a material with a size of 0.5 nm to 10 nm, preferably 0.5 nm to 3 nm. There is.

Further, CAC-OS or CAC-metal oxide is composed of components having different band gaps. For example, CAC-OS or CAC-metal oxide includes a component having a wide gap caused by an insulating region and a component having a narrow gap caused by a conductive region. In the case of the configuration, when the carrier flows, the carrier mainly flows in the component having the narrow gap. In addition, the component having a narrow gap acts in a complementary manner to the component having a wide gap, and the carrier flows through the component having the wide gap in conjunction with the component having the narrow gap. Therefore, when the CAC-OS or the CAC-metal oxide is used for a channel region of a transistor, high current driving force, that is, high on-state current and high field-effect mobility can be obtained in the transistor on-state.

That is, CAC-OS or CAC-metal oxide can also be referred to as a matrix composite or a metal matrix composite.

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

<1-1. Configuration example of display device>
First, a configuration example of a display device will be described with reference to FIG. The display device 10 shown in FIG. 1 includes a display unit 12, a gate driver circuit unit 14a and a gate driver circuit unit 14b arranged outside the display unit 12, and a source driver circuit unit 16a arranged outside the display unit 12. And a source driver circuit portion 16b.

[Display section]
The display unit 12 includes pixels 13 arranged in X rows (X is a natural number of 2 or more) and Y columns (Y is a natural number of 2 or more). Each pixel 13 has two types of display elements, and the two types of display elements have different functions. One of the two types of display elements has a function of displaying an image by reflecting incident light, and the other of the two types of display elements has a function of displaying an image by emitting light. Details of the two types of display elements will be described later.

Although details will be described later, each pixel 13 has one of two kinds of display elements. On the other hand, each pixel 13 has a plurality of the other of the two types of display elements. For example, the pixel 13 has three or four of the other two types of display elements.

[Gate driver circuit]

The gate driver circuit portion 14a and the gate driver circuit portion 14b have a function of outputting a signal (scanning signal) for selecting the pixel 13.

The gate driver circuit portion 14a has a function of controlling the potential of a wiring to which a scanning signal is applied (hereinafter, the scanning line GL_L [m], the scanning line GL_L [m + 1], and the scanning line GL_L [X]), or initialization. It has a function of supplying a signal. In addition, the gate driver circuit portion 14b includes wirings to which scanning signals are applied (hereinafter, scanning lines GL_E1 [m], scanning lines GL_E1 [m + 1], scanning lines GL_E2 [m], scanning lines GL_E2 [m + 1], scanning lines GL_E1 [ X] and the potential of the scan line GL_E2 [X]), or a function of supplying an initialization signal. In the above, m represents a natural number equal to or less than X.

However, the gate driver circuit portion 14a and the gate driver circuit portion 14b are not limited to the above functions, and may have a function of controlling or supplying another signal.

Note that although FIG. 1 illustrates the configuration in which two gate driver circuit units 14a and 14b are provided as the gate driver circuit unit, the present invention is not limited thereto, and one gate driver circuit unit or Three or more gate driver circuit units may be provided.

[Source driver circuit]
The source driver circuit portion 16a has a function of generating a signal (data signal) for driving a display element included in the pixel 13 based on an image signal, and a wiring (signal line SL_L [n], signal line to which the data signal is applied. SL_L [n + 1] and the signal line SL_L [Y]), or a function of supplying an initialization signal. The source driver circuit portion 16b has a function of generating a data signal to be written in the pixel 13 based on an image signal, a wiring to which the data signal is applied (signal line SL_E1 [n], signal line SL_E1 [n + 1], signal line SL_E1 [Y] , Signal line SL_E2 [n], signal line SL_E2 [n + 1], and signal line SL_E2 [Y]), or a function of supplying an initialization signal. In the above, n represents a natural number equal to or less than Y.

However, the source driver circuit unit 16a and the source driver circuit unit 16b are not limited to the above functions, and may have a function of generating, controlling, or supplying another signal.

The source driver circuit unit 16a and the source driver circuit unit 16b are configured using a plurality of analog switches and the like. The source driver circuit unit 16a and the source driver circuit unit 16b can output a signal obtained by time-division of an image signal as a data signal by sequentially turning on a plurality of analog switches.

Note that although FIG. 1 illustrates a configuration in which two source driver circuit portions are provided, the present invention is not limited to this, and a configuration in which one source driver circuit portion or three or more source driver circuit portions may be provided may be employed. For example, only one source driver circuit portion is provided, and the signal driver SL_L [n], the signal line SL_L [n + 1], the signal line SL_L [Y], the signal line SL_E1 [n], and the signal line SL_E1 [ n + 1], signal line SL_E1 [Y], signal line SL_E2 [n], signal line SL_E2 [n + 1], and signal line SL_E2 [Y] may be controlled.

Part or all of the gate driver circuit unit 14a, the gate driver circuit unit 14b, the source driver circuit unit 16a, and the source driver circuit unit 16b are preferably formed on the same substrate as the display unit 12. Thereby, the number of parts and the number of terminals can be reduced. When some or all of the gate driver circuit unit 14a, the gate driver circuit unit 14b, the source driver circuit unit 16a, and the source driver circuit unit 16b are not formed on the same substrate as the display unit 12, COG (Chip On Glass) A drive circuit substrate (for example, a drive circuit substrate formed of a single crystal semiconductor film or a polycrystalline semiconductor film) prepared separately by COF (Chip On Film) or TAB (Tape Automated Bonding) is applied to the display device 10. It may be formed.

[Pixel]
In addition, the pixel 13 receives a pulse signal through one of the scan line GL_L [m], the scan line GL_L [m + 1], and the scan line GL_L [X], and receives the signal line SL_L [n] and the signal line SL_L [ n + 1], signal line SL_L [Y], signal line SL_E1 [n], signal line SL_E1 [n + 1], signal line SL_E1 [Y], signal line SL_E2 [n], signal line SL_E2 [n + 1], and signal line SL_E2 [ Y]), a data signal is input.

For example, the pixel 13 (m, n) in the m-th row and the n-th column receives a pulse signal from the gate driver circuit unit 14a via the scanning line GL_L [m], and receives a signal according to the potential of the scanning line GL_L [m]. A data signal is input from the source driver circuit portion 16a through the line SL_L [n].

In addition, the pixel 13 (m, n) in the m-th row and the n-th column receives a pulse signal from the gate driver circuit portion 14b through the scan line GL_E1 [m] and the scan line GL_E2 [m], and the scan line GL_E1 [m ] And the scanning line GL_E2 [m], the data signal is input from the source driver circuit portion 16b through the signal line SL_E1 [n] and the signal line SL_E2 [n].

Moreover, the pixel 13 (m, n) has two types of display elements as described above. The scan line GL_L [m], the scan line GL_L [m + 1], and the scan line GL_L [X] are wirings that control one potential of the two types of display elements. The scan line GL_E1 [m] and the scan line GL_E1 [ m + 1], the scanning line GL_E1 [X], the scanning line GL_E2 [m], the scanning line GL_E2 [m + 1], and the scanning line GL_E2 [X] are wirings for controlling the other potential of the two types of display elements.

The signal lines SL_L [n], SL_L [n + 1], and SL_L [Y] are wirings that control the potential of the data signal applied to one of the two types of display elements. The signal lines SL_E1 [n] and SL_E1 [N + 1], SL_E1 [Y], signal lines SL_E2 [n], SL_E2 [n + 1], and SL_E2 [Y] are wirings that control the potential of the data signal applied to the other of the two types of display elements.

[External circuit]
An external circuit 18 is connected to the display device 10. Note that the display device 10 may include the external circuit 18.

As shown in FIG. 1, the external circuit 18 is electrically connected to a wiring to which an anode potential is applied (hereinafter, ANODE or wiring AONDE).

<1-2. Example of pixel circuit configuration>
Next, an example of a circuit configuration of the pixel 13 (m, n), the pixel 13 (m, n + 1), the pixel 13 (m + 1, n), and the pixel 13 (m + 1, n + 1) will be described with reference to FIG.

In this specification and the like, the two pixels 13 in the same row and adjacent columns may be referred to as pixels 13 adjacent in the row direction. For example, it can be said that the pixel 13 (m, n) is adjacent to the pixel 13 (m, n + 1) in the row direction. In addition, two pixels 13 in the same column and adjacent rows may be referred to as pixels 13 adjacent in the column direction. For example, it can be said that the pixel 13 (m, n) is adjacent to the pixel 13 (m + 1, n) in the column direction.

FIG. 2 is a circuit diagram illustrating an example of the pixel 13 (m, n), the pixel 13 (m, n + 1), the pixel 13 (m + 1, n), and the pixel 13 (m + 1, n + 1) included in the display device 10.

The pixel 13 (m, n) includes the scan line GL_L [m], the scan line GL_E1 [m], the scan line GL_E2 [m], the signal line SL_L [n], the signal line SL_E1 [n], and the signal line SL_E2 [n. ]. The pixel 13 (m, n + 1) includes the scan line GL_L [m], the scan line GL_E1 [m], the scan line GL_E2 [m], the signal line SL_L [n + 1], the signal line SL_E1 [n + 1], and the signal line SL_E2 [n + 1]. ]. The pixel 13 (m + 1, n) includes the scan line GL_L [m + 1], the scan line GL_E1 [m + 1], the scan line GL_E2 [m + 1], the signal line SL_L [n], the signal line SL_E1 [n], and the signal line SL_E2 [n. ]. The pixel 13 (m + 1, n + 1) includes the scan line GL_L [m + 1], the scan line GL_E1 [m + 1], the scan line GL_E2 [m + 1], the signal line SL_L [n + 1], the signal line SL_E1 [n + 1], and the signal line SL_E2 [n + 1]. ].

In addition, the pixel 13 (m, n), the pixel 13 (m, n + 1), the pixel 13 (m + 1, n), and the pixel 13 (m + 1, n + 1) include a transistor MA1 to a transistor MA3, a transistor MB1 to a transistor MB3, respectively. The capacitor Cs_L, the capacitors Cs_EA1 to Cs_EA3, the capacitors Cs_EB1 to Cs_EB3, the display element 22, and the display element 24 are included. In FIG. 2, each of the pixel 13 (m, n), the pixel 13 (m, n + 1), the pixel 13 (m + 1, n), and the pixel 13 (m + 1, n + 1) has one display element 22. Three display elements 24 are provided (display element 24R, display element 24G, and display element 24B). 2 and the like, the display element 22 included in the pixel 13 (m, n) is referred to as a display element 22R, the display element 22 included in the pixel 13 (m, n + 1) is referred to as a display element 22G, and the pixel 13 ( The display element 22 included in m + 1, n) is referred to as a display element 22B, and the display element 22 included in the pixel 13 (m + 1, n + 1) is referred to as a display element 22W.

The display element 22 corresponds to one of two kinds of display elements and has a function of displaying an image by reflecting incident light. The display element 24 corresponds to the other of the two types of display elements and has a function of displaying an image by emitting light. For example, the display element 24R has a function of emitting red (wavelength 620 nm or more and less than 750 nm) light, the display element 24G has a function of emitting green (wavelength 500 nm or more and less than 570 nm) light, and the display element 24B is , Has a function of emitting blue (wavelength 450 nm or more and less than 500 nm) light. Note that the display element 24 having a function of emitting light such as purple (380 nm or more and less than 590 nm), yellow (570 nm or more and less than 590 nm), orange (590 nm or more and less than 620 nm), the display element 24R, the display element 24G, or the display element. It may be provided in place of any of 24B, or may be provided in addition to the display element 24. Alternatively, the display element 24R, the display element 24G, or the display element 24B may have a function of emitting white light.

In this specification and the like, color can be restated as spectral characteristics.

The pixel 13 (m, n), the pixel 13 (m, n + 1), the pixel 13 (m + 1, n), and the pixel 13 (m + 1, n + 1) each include a wiring TCOM, a wiring CATHODE, a wiring ANODE, and a wiring CSCOM.

The scanning line GL_L [m], the scanning line GL_L [m + 1], the signal line SL_L [n], the signal line SL_L [n + 1], the wiring TCOM, and the wiring CSCOM are wirings for driving the display element 22, respectively. In addition, the scanning line GL_E1 [m], the scanning line GL_E1 [m + 1], the scanning line GL_E2 [m], the scanning line GL_E2 [m + 1], the signal line SL_E1 [n], the signal line SL_E1 [n + 1], and the signal line SL_E2 [n] The signal line SL_E2 [n + 1], the wiring CATHODE, the wiring ANODE, and the wiring CSCOM are wirings for driving the display element 24, respectively.

In the pixel 13 (m, n), the gate electrode of the transistor MA4 is electrically connected to the scan line GL_L [m]. In addition, one of a source electrode and a drain electrode of the transistor MA4 is electrically connected to the signal line SL_L [n], and the other is electrically connected to one of the pair of electrodes of the display element 22. The transistor MA4 has a function of controlling data writing of the data signal by switching between an on state and an off state.

The other of the pair of electrodes of the display element 22 is electrically connected to the wiring TCOM.

One of the pair of electrodes of the capacitor Cs_L is electrically connected to the other of the source or drain electrode of the transistor MA4 and one of the pair of electrodes of the display element 22, and the other of the pair of electrodes of the capacitor Cs_L. Are electrically connected to the wiring CSCOM. The capacitor Cs_L has a function of holding data written in the pixel 13 (m, n).

In the pixel 13 (m, n), the gate electrode of the transistor MA1 is electrically connected to the scan line GL_E1 [m]. In addition, one of the source electrode and the drain electrode of the transistor MA1 is electrically connected to the signal line SL_E1 [n]. The other of the source electrode and the drain electrode of the transistor MA1 is electrically connected to the gate electrode of the transistor MB1, one of the pair of electrodes of the capacitor Cs_EA1, and one of the pair of electrodes of the capacitor Cs_EB1. The transistor MA1 has a function of controlling data writing of the data signal by switching between an on state and an off state.

In addition, one of the source electrode and the drain electrode of the transistor MB1 is electrically connected to one of the pair of electrodes of the display element 24R. The other of the source electrode and the drain electrode of the transistor MB1 is electrically connected to the other electrode of the capacitor Cs_EB1 and the wiring ANODE. The other of the pair of electrodes of the display element 24R is electrically connected to the wiring CATHODE. The other of the pair of electrodes of the capacitor C _{S —} EA1 is electrically connected to the wiring CSCOM. The transistor MB1 has a function as a so-called driving transistor that controls a current supplied to the display element 24R.

The capacitor Cs_EA1 and the capacitor Cs_EB1 have a function of holding data written in the pixel 13 (m, n). The transistor MB1 includes a back gate electrode, and the back gate electrode is electrically connected to the gate electrode of the transistor MB1.

In the pixel 13 (m, n), the gate electrode of the transistor MA2 is electrically connected to the scan line GL_E1 [m]. In addition, one of the source electrode and the drain electrode of the transistor MA2 is electrically connected to the signal line SL_E2 [n]. The other of the source electrode and the drain electrode of the transistor MA2 is electrically connected to the gate electrode of the transistor MB2, one of the pair of electrodes of the capacitor Cs_EA2, and one of the pair of electrodes of the capacitor Cs_EB2. The transistor MA2 has a function of controlling data writing of the data signal by switching between an on state and an off state.

In addition, one of the source electrode and the drain electrode of the transistor MB2 is electrically connected to one of the pair of electrodes of the display element 24G. The other of the source electrode and the drain electrode of the transistor MB2 is electrically connected to the other electrode of the capacitor Cs_EB2 and the wiring ANODE. The other of the pair of electrodes of the display element 24G is electrically connected to the wiring CATHODE. In addition, the other of the pair of electrodes of the capacitor C _{S —} EA2 is electrically connected to the wiring CSCOM. The transistor MB2 has a function as a so-called driving transistor that controls a current supplied to the display element 24G.

The capacitor Cs_EA2 and the capacitor Cs_EB2 have a function of holding data written in the pixel 13 (m, n). The transistor MB2 includes a back gate electrode, and the back gate electrode is electrically connected to the gate electrode of the transistor MB2.

In the pixel 13 (m, n), the gate electrode of the transistor MA3 is electrically connected to the scan line GL_E2 [m]. In addition, one of the source electrode and the drain electrode of the transistor MA3 is electrically connected to the signal line SL_E1 [n]. The other of the source electrode and the drain electrode of the transistor MA3 is electrically connected to the gate electrode of the transistor MB3, one of the pair of electrodes of the capacitor Cs_EA3, and one of the pair of electrodes of the capacitor Cs_EB3. The transistor MA3 has a function of controlling data writing of the data signal by switching between an on state and an off state.

In addition, one of the source electrode and the drain electrode of the transistor MB3 is electrically connected to one of the pair of electrodes of the display element 24B. The other of the source electrode and the drain electrode of the transistor MB3 is electrically connected to the other electrode of the capacitor Cs_EB3 and the wiring ANODE. The other of the pair of electrodes of the display element 24B is electrically connected to the wiring CATHODE. The other of the pair of electrodes of the capacitor C _{S —} EA3 is electrically connected to the wiring CSCOM. The transistor MB3 has a function as a so-called driving transistor that controls a current supplied to the display element 24B.

The capacitor Cs_EA3 and the capacitor Cs_EB3 have a function of holding data written in the pixel 13 (m, n). The transistor MB3 includes a back gate electrode, and the back gate electrode is electrically connected to the gate electrode of the transistor MB3.

With the structure in which the transistors MB1 to MB3 each include the back gate electrode, that is, the transistor has a plurality of gate electrodes, the reliability or driving ability of the transistor can be improved. For example, as shown in FIG. 2, the current drive capability of the transistor can be improved by connecting the back gate electrode to the gate electrode. Although not illustrated, the potential on the back channel side of the transistor can be fixed by connecting the back gate electrode to either the source electrode or the drain electrode.

In addition, the transistors (the transistors MA1 to MA4 and the transistors MB1 to MB3) used for the display device of one embodiment of the present invention preferably include a metal oxide layer. A transistor including a metal oxide layer can have a relatively high field-effect mobility, and thus can be driven at high speed. In addition, the off-state current of a transistor including a metal oxide layer is extremely small. Therefore, even if the refresh rate of the display device 10 is lowered, the luminance of the display device 10 can be maintained and power consumption can be suppressed.

<1-3. Configuration Example of Display Element 22>
The display element 22 has a function of controlling light reflection or light transmission. In particular, the display element 22 is preferably a so-called reflective display element that controls reflection of light. Since the display element 22 is a reflective display element, it is possible to perform display using external light, so that power consumption of the display device 10 can be suppressed. For example, the display element 22 may have a configuration in which a reflective layer, a liquid crystal element, and a polarizing plate are combined, or a configuration using a micro electro mechanical system (MEMS). The display element 22 may be a transmissive display element having no reflective layer.

<1-4. Configuration Example of Display Element 24>
The display element 24 includes a light emitting layer and has a function of emitting light, that is, a function of emitting light. Therefore, the display element 24 may be read as a light emitting element. For example, the display element 24 may be a self-luminous light emitting element such as an OLED (Organic Light Emitting Diode), an LED (Light Emitting Diode), a QLED (Quantum-Dot Light Emitting Diode), or a semiconductor laser. Good.

As described above, in the display device of one embodiment of the present invention, as illustrated in the display element 22 and the display element 24, display elements having different functions are used. For example, when one of the display elements is a liquid crystal element and the other is an EL element, a novel display device that is highly convenient or reliable can be provided. In addition, a liquid crystal element is used in an environment where the external light is bright, and an EL element is used in an environment where the external light is dark, whereby a display device with low power consumption and high display quality can be provided. .

<1-5. Example of display element driving method>
Next, a method for driving the display element 22 and the display element 24 will be described with reference to FIG. In the following description, a liquid crystal element is used for the display element 22 and a light-emitting element is used for the display element 24 (display element 24R, display element 24G, display element 24B).

The gate driver circuit portion 14a shown in FIG. 1 sequentially selects the pixels 13 in each row, and the data of the data signal is written by turning on the transistor MA4. The pixel 13 (m, n) in which data is written is brought into a holding state when the transistor MA4 is turned off. By sequentially performing this for each row, an image can be displayed on the display element 22. The above is an example of a method for driving the display element 22.

The gate driver circuit portion 14b shown in FIG. 1 sequentially selects the pixels 13 in each row, turns on the transistors MA1 to MA3, and writes data signals. The pixel 13 (m, n) in which data is written is brought into a holding state when the transistors MA1 to MA3 are turned off. Further, the amount of current flowing between the source electrode and the drain electrode of the transistor MB1 is controlled in accordance with the potential of the written data signal, and the display element 24 emits light with luminance corresponding to the amount of flowing current. By sequentially performing this for each row, an image can be displayed by the display element 24. The above is an example of a method for driving the display element 22.

As described above, in the display device of one embodiment of the present invention, the two display elements can be independently controlled using different transistors. Therefore, a display device with high display quality can be provided.

The display device 10 can perform gradation display using at least one of the display element 22 and the display element 24. For example, since the display element 22 is a liquid crystal element, visibility can be improved in an environment where the intensity of external light is strong. On the other hand, since the display element 24 is a so-called light emitting element, visibility can be improved in an environment where the intensity of external light is weak.

Note that the display device 10 may perform gradation display using both the display element 22 and the display element 24. By performing gradation display using both the display element 22 and the display element 24, visibility can be improved as compared with the case where gradation display is performed using either the display element 22 or the display element 24. it can.

The display elements included in the pixel 13 (m, n + 1), the pixel 13 (m + 1, n), and the pixel 13 (m + 1, n + 1) are also driven by the same method as the display element included in the pixel 13 (m, n). Can do.

<1-6. Display area 1 of display element>
Next, the display area of the pixel 13 will be described with reference to FIG. FIG. 3 is a schematic diagram illustrating the display area of the pixels 13 (pixels 13 (m, n) to (m + 3, n + 3)) for 4 rows and 4 columns.

The pixel 13 (m, n) has a display region 22Rd that functions as a display region of the display element 22R. The pixel 13 (m, n + 1) includes a display region 22Gd that functions as a display region of the display element 22G. The pixel 13 (m + 1, n) has a display area 22Bd that functions as a display area of the display element 22B. The pixel 13 (m + 1, n + 1) has a display area 22Wd that functions as a display area of the display element 22W.

The pixel 13 (m, n), the pixel 13 (m, n + 1), the pixel 13 (m + 1, n), and the pixel 13 (m + 1, n + 1) include a display area 24Rd that functions as a display area of the display element 24R; A display area 24Gd having a function as a display area of the display element 24G and a display area 24Bd having a function as a display area of the display element 24B are provided.

Note that, in the pixel 13 illustrated in FIG. 3, the same display area is provided in the area hatched in the same manner. For example, in FIG. 3, the display region 22Rd is provided in the pixel 13 (m, n + 2), the pixel 13 (m + 2, n), and the pixel 13 (m + 2, n + 2) in addition to the pixel 13 (m, n). Is shown. In addition to FIG. 3, in the diagrams representing the display areas, the areas with the same hatching may indicate that the same display area is provided.

In this specification and the like, a display region having a function as a display region of the display element 22 may be referred to as a display region 22d, and a display region having a function as a display region of the display element 24 may be referred to as a display region 24d. That is, the display area 22Rd, the display area 22Gd, the display area 22Bd, and the display area 22Wd may be collectively referred to as a display area 22d. The display area 24Rd, the display area 24Gd, and the display area 24Bd may be collectively referred to as a display area 24d.

The display area 22Rd, the display area 22Gd, the display area 22Bd, and the display area 22Wd have areas that reflect incident light. For example, the display region 22Rd, the display region 22Gd, the display region 22Bd, and the display region 22Wd are provided with a conductive film having a function as a reflective electrode described later.

A colored layer that transmits light of a specific color can be provided in the display region 22Rd, the display region 22Gd, and the display region 22Bd. For example, a colored layer that transmits red light can be provided in the display region 22Rd. For example, a colored layer that transmits green light can be provided in the display region 22Gd. For example, a colored layer that transmits blue light can be provided in the display region 22Bd. Thereby, for example, the display area 22Rd has a function of emitting red light, the display area 22Gd has a function of emitting green light, and the display area 22Bd has a function of emitting blue light. . Note that a colored layer is not provided in the display region 22Wd. Accordingly, the display region 22Wd has a function of emitting white light that is light reflected by the display element 22W.

The display area 24Rd has an area that transmits light emitted from the display element 24R, the display area 24Gd has an area that transmits light emitted from the display element 24G, and the display area 24Bd has light emitted from the display element 24B. It has a transparent area.

The display region 24Rd has a function of emitting light emitted from the display element 24R. The display area 24Gd has a function of emitting light emitted from the display element 24G. The display area 24Bd has a function of emitting light emitted from the display element 24B. For example, when the display element 24R has a function of emitting red light, the display region 24Rd has a function of emitting red light. For example, when the display element 24G has a function of emitting green light, the display region 24Gd has a function of emitting green light. For example, when the display element 24B has a function of emitting blue light, the display region 24Bd has a function of emitting blue light.

Note that a colored layer that transmits light of a specific color may be provided in the display region 24Rd, the display region 24Gd, and the display region 24Bd. In this case, it is preferable to provide a colored layer that transmits light of a color corresponding to the color of light emitted from the display element 24. For example, it is preferable to provide a colored layer that transmits red light in the display region 24Rd of the display element 24R having a function of emitting red light. For example, it is preferable to provide a colored layer that transmits green light in the display region 24Gd of the display element 24G having a function of emitting green light. It is preferable to provide a colored layer that transmits blue light in the display region 24Bd of the display element 24B having a function of emitting blue light. As described above, the color purity of light emitted from the display region 24Rd, the display region 24Gd, and the display region 24Bd can be increased.

Note that in the case where a colored layer that transmits light of a specific color is provided in the display region 24Rd, the display region 24Gd, and the display region 24Bd, the display element 24R, the display element 24G, and the display element 24B have a function of emitting white light. A display element can be used.

Further, for example, a region that emits light of purple, yellow, orange, or the like is provided instead of any of the display region 22Rd, the display region 22Gd, the display region 22Bd, the display region 22Wd, the display region 24Rd, the display region 24Gd, and the display region 24Bd. Alternatively, it may be provided in addition to the display area.

As described above, in the display device of one embodiment of the present invention, one pixel 13 represents one color in the display element 22 having a function of reflecting incident light. For example, as shown in FIG. 3, the pixel 13 (m, n) expresses red, the pixel 13 (m, n + 1) expresses green, the pixel 13 (m + 1, n) expresses blue, and the pixel 13 (M + 1, n + 1) expresses white. On the other hand, in the display element 24 having a function of emitting light, one pixel 13 expresses a plurality of colors (here, red, green, and blue). As a result, the display area 22Rd, the display area 22Gd, the display area 22Bd, and the display area 22Wd can be made larger than when the display element 22 represents a plurality of colors with one pixel 13 like the display element 24. it can. Thereby, the reflectance of the light incident on the display device 10 can be increased and the light emitted from the display region 22d can be increased as compared with the case where the display element 22 expresses a plurality of colors with one pixel 13 like the display element 24. The brightness of the light can be increased. Therefore, the light emission luminance of the display element 24 can be reduced, and the power consumption of the display device 10 can be reduced. Further, the deterioration of the display element 24 is reduced, and the reliability of the display device 10 can be increased.

In the display element 22, red, green, blue, and four pixels 13 including a pixel 13 (m, n), a pixel 13 (m, n + 1), a pixel 13 (m + 1, n), and a pixel 13 (m + 1, n + 1) And white is expressed. That is, when viewed from the display element 22, the pixel 13 (m, n), the pixel 13 (m, n + 1), the pixel 13 (m + 1, n), and the pixel 13 (m + 1, n + 1) constitute one pixel. Can do. In this specification and the like, the pixels 13 for 2 rows and 2 columns may be collectively referred to as pixels 43. For example, as illustrated in FIG. 3, the pixel 13 (m, n), the pixel 13 (m, n + 1), the pixel 13 (m + 1, n), and the pixel 13 (m + 1, n + 1) can be collectively referred to as a pixel 43. That is, the pixel 13 is a pixel having a function of displaying an image using the display element 24, and the pixel 43 is a pixel having a function of displaying an image using the display element 22.

As described above, in the display element 24, one pixel 13 can express red, green, and blue. On the other hand, in the display element 22, one pixel 43 including the pixels 13 for 2 rows and 2 columns can express red, green, blue, and white. That is, it can be said that the definition of the image displayed using the display element 22 is different from the definition of the image displayed using the display element 24. Specifically, it can be said that the definition of the image displayed on the display element 22 is, for example, ¼ of the definition of the image displayed on the display element 24.

2 and 3 illustrate a structure in which one pixel 13 includes one display element 22 and one display region 22d, but one embodiment of the present invention is not limited thereto. For example, one pixel 13 may have two or more display elements 22 and two display areas 22d. In this case, one pixel 13 can express two or more colors by the display element 22 having a function of reflecting incident light.

FIG. 4 is a schematic diagram illustrating the positional relationship between the display areas of the pixel 13 (m, n), the pixel 13 (m, n + 1), and the pixel 13 (m + 1, n). In FIG. 4, a line segment X1-X2 is a line segment indicating a boundary between the pixel 13 (m, n) and the pixel 13 (m + 1, n). The end portions of the line segment X1-X2 coincide with the end portions of the pixel 13 (m, n) and the pixel 13 (m + 1, n). In FIG. 4, a line segment Y1-Y2 is a line segment indicating the boundary between the pixel 13 (m, n) and the pixel 13 (m, n + 1). The ends of the line segments Y1-Y2 coincide with the ends of the pixel 13 (m, n) and the pixel 13 (m, n + 1).

The position of the display region 24Rd included in the pixel 13 (m, n) and the position of the display region 24Rd included in the pixel 13 (m, n + 1) are in a line-symmetric relationship with respect to the line segment Y1-Y2. The position of the display area 24Gd included in the pixel 13 (m, n) and the position of the display area 24Gd included in the pixel 13 (m, n + 1) have a line-symmetric relationship with respect to the line segment Y1-Y2. The position of the display region 24Bd included in the pixel 13 (m, n) and the position of the display region 24Bd included in the pixel 13 (m, n + 1) have a point-symmetric relationship with respect to the center of the line segment Y1-Y2. Note that in this specification and the like, the center of the line segment Y1-Y2 may be referred to as a center portion of the boundary between the pixel 13 (m, n) and the pixel (m, n + 1).

The position of the display region 24Rd included in the pixel 13 (m, n) and the position of the display region 24Rd included in the pixel 13 (m + 1, n) are in a line-symmetric relationship with respect to the line segment X1-X2. The position of the display region 24Gd included in the pixel 13 (m, n) and the position of the display region 24Gd included in the pixel 13 (m + 1, n) are in a line-symmetric relationship with respect to the line segment Y1-Y2. Further, the position of the display area 24Bd of the pixel 13 (m, n) in the pixel 13 (m, n) and the position of the pixel 13 (m + 1, n) of the display area 24Bd of the pixel 13 (m + 1, n). The position inside is in the same relationship. For example, in the pixel 13 (m, n), when the display area 24Bd is provided near the upper left vertex of the pixel 13 (m, n), the display area 24Bd is the pixel 13 (m + 1, n) in the pixel 13 (m + 1, n). n) near the upper left apex.

When the shape of the pixel 13 is, for example, a rectangle, the display region 24Rd and the display region 24Gd can be provided near the vertex of the pixel 13, as shown in FIG. Further, as described above, in the adjacent pixels 13, the position of the display region 24Rd can be a line-symmetric relationship, and the position of the display region 24Gd can be a line-symmetric relationship. As described above, the four display areas 24Rd and the four display areas 24Gd can be concentrated as shown by the broken line portion in FIG. As a result, the areas of the display region 24Rd and the display region 24Gd can be reduced, so that the area of the display region 22d can be increased. Therefore, the reflectance, which is the ratio of light incident on the display device 10 that is reflected by the display element 22 or the like, can be increased, and the luminance of the light emitted from the display region 22d can be increased. Therefore, the light emission luminance of the display element 24 can be reduced, and the power consumption of the display device 10 can be reduced. Further, the deterioration of the display element 24 is reduced, and the reliability of the display device 10 can be increased.

Note that in this specification and the like, the term rectangle includes a square.

Note that according to one embodiment of the present invention, the reflectance of light incident on the display device 10 can be, for example, 40% or more, 50% or more, or 55% or more. In the present embodiment and the like, the reflectance is a value measured in a measurement system that receives light incident from a polar angle of 30 ° at 0 °, for example, a standard white diffuse reflector such as Ba ₂ SO ₄ . The reflectance can be set to 100%.

In addition, the area of the display region 24Rd can be, for example, 15% or less of the area of the pixel 13, or 10% or less, or 5% or less, or 4% or less. be able to. The area of the display region 24Gd can be 15% or less of the area of the pixel 13, or 10% or less, or 5% or less, or 4% or less. Can do. Further, the area of the display region 24Bd can be 15% or less of the area of the pixel 13, or 10% or less, or 5% or less, or 4% or less. Can do.

Further, in the four adjacent pixels, the display area 24Rd and the display area 24Gd are densely packed, so that the distance between the different display areas 24d can be increased. For example, the distance between the display area 24Rd and the display area 24Gd can be increased. As a result, the light emitting layer included in the display element 24R and the light emitting layer included in the display element 24G can be formed by a separate coating method. Thereby, the power consumption of the display apparatus 10 can be reduced. Details of the manufacturing method of the display element 24 will be described later.

For example, when the pixel 13 is a square of 50 μm, the display region 24Rd and the display region 24Gd are preferably provided in a range of 15 μm square from the vertex of the pixel 13, and provided in a range of 10 μm square from the vertex of the pixel 13. Is more preferable. For example, when the pixel 13 is a square of a μm square (a is a real number of 0 or more), the display region 24Rd and the display region 24Gd are preferably provided in a range of a / 4 μm square from the apex of the pixel 13. It is more preferable to provide in the range of a / 5 μm square from the apex. For example, when the pixel 13 is a rectangle having a long side a μm and a short side b μm (b is a real number not smaller than 0 and not larger than a), the display region 24Rd and the display region 24Gd extend from the apex of the pixel 13 to the long side direction of the pixel 13. Are preferably provided within a / 4 μm and within a range of b / 4 μm in the short side direction of the pixel 13. Furthermore, it is more preferable to provide a range within a / 5 μm in the long side direction of the pixel 13 and within b / 5 μm in the short side direction of the pixel 13.

FIGS. 3 and 4 show the case where the position of the display area 24Rd and the position of the display area 24Gd are axisymmetric in the adjacent pixel 13, but the position is changed to the position of the display area 24Rd or the position of the display area 24Gd. Thus, the position of the display area 24Bd may be a line-symmetric relationship. For example, in the adjacent pixel 13, the position of the display region 24Gd and the position of the display region 24Bd may be in a line-symmetric relationship, or the position of the display region 24Rd and the position of the display region 24Bd may be in a line-symmetric relationship. In the adjacent pixel 13, when the position of the display region 24Gd and the position of the display region 24Bd are in a line-symmetric relationship, the light emitting layer included in the display element 24G and the light emitting layer included in the display element 24B are formed by a separate coating method. can do. In the adjacent pixel 13, when the position of the display region 24Rd and the position of the display region 24Bd are in a line-symmetric relationship, the light emitting layer included in the display element 24R and the light emitting layer included in the display element 24B are formed by a separate coating method. can do.

In the adjacent pixel 13, the display region 24 d that is not line-symmetrical may not be provided near the vertex of the pixel 13. For example, in the case shown in FIG. 3, the display region 24Bd may be provided at or near the center of the pixel 13.

FIG. 5 is a schematic diagram showing the positional relationship between the display areas of the pixel 13 (m, n), the pixel 13 (m, n + 1), and the pixel 13 (m + 1, n), and is a modification of FIG. In FIG. 5, the position in the pixel 13 (m, n) of the display region 24Bd included in the pixel 13 (m, n) and the pixel 13 (m, n + 1) in the display region 24Bd included in the pixel 13 (m, n + 1). ) And the position in the same relationship. For example, in the pixel 13 (m, n), when the display region 24Bd is provided near the upper left vertex of the pixel 13 (m, n), the display region 24Bd in the pixel 13 (m, n + 1) is the pixel 13 (m, n). n + 1) near the upper left vertex. On the other hand, the position of the display region 24Bd included in the pixel 13 (m, n) and the position of the display region 24Bd included in the pixel 13 (m + 1, n) have a point-symmetric relationship with respect to the center of the line segment X1-X2. . The above points differ from the positional relationship shown in FIG.

Note that in this specification and the like, the center of the line segment X1-X2 may be referred to as the center of the boundary between the pixel 13 (m, n) and the pixel (m + 1, n).

FIG. 6 is a schematic diagram illustrating a display area of pixels 13 (pixels 13 (m, n) to pixels 13 (m + 3, n + 3)) for four rows and four columns, and is a modification of FIG. 3. 3 is different from FIG. 3 in that all the display areas 22d having areas that reflect incident light are display areas 22Wd, that is, display areas having a function of emitting white light. The pixel 13 illustrated in FIG. 6 has a configuration in which no coloring layer is provided in the display region 22d. Thereby, since the light incident on the display region 22d is not absorbed by the colored layer, the reflectance of the light incident on the display device 10 can be increased, and the luminance of the light emitted from the display region 22d can be increased. Therefore, the light emission luminance of the display element 24 can be reduced, and the power consumption of the display device 10 can be reduced. Further, the deterioration of the display element 24 is reduced, and the reliability of the display device 10 can be increased.

FIG. 7 is a circuit diagram illustrating an example of the pixel 13 (m, n), the pixel 13 (m, n + 1), the pixel 13 (m + 1, n), and the pixel 13 (m + 1, n + 1) included in the display device 10. It is a modification of FIG. In FIG. 6, the pixel 13 (m, n), the pixel 13 (m, n + 1), the pixel 13 (m + 1, n), and the pixel 13 (m + 1, n + 1) have the display element 24W. Different. The display element 24W has a function of emitting white light. Note that in this specification and the like, the display element 24 may represent not only the display element 24R, the display element 24G, and the display element 24B but also the display element 24W.

In the pixel 13 (m, n) having the configuration illustrated in FIG. 7, the gate electrode of the transistor MA5 is electrically connected to the scan line GL_E2 [m]. In addition, one of the source electrode and the drain electrode of the transistor MA5 is electrically connected to the signal line SL_E2 [n]. The other of the source electrode and the drain electrode of the transistor MA5 is electrically connected to the gate electrode of the transistor MB5, one of the pair of electrodes of the capacitor Cs_EA5, and one of the pair of electrodes of the capacitor Cs_EB5. The transistor MA5 has a function of controlling data writing of the data signal by switching between an on state and an off state.

In addition, one of the source electrode and the drain electrode of the transistor MB5 is electrically connected to one of the pair of electrodes of the display element 24W. The other of the source electrode and the drain electrode of the transistor MB5 is electrically connected to the other electrode of the capacitor Cs_EB5 and the wiring ANODE. The other of the pair of electrodes of the display element 24W is electrically connected to the wiring CATHODE. The other of the pair of electrodes of the capacitor C _{S —} EA5 is electrically connected to the wiring CSCOM. The transistor MB5 has a function as a so-called driving transistor that controls a current supplied to the display element 24R.

The capacitor Cs_EA5 and the capacitor Cs_EB5 have a function of holding data written in the pixel 13 (m, n). The transistor MB5 includes a back gate electrode, and the back gate electrode is electrically connected to the gate electrode of the transistor MB1. Note that the transistors MA5 and MB5 each preferably include a metal oxide layer.

FIG. 8 is a schematic diagram for explaining a display area of the pixel 13 having the configuration shown in FIG. 7, and is a modification of FIG. 8 is different from FIG. 3 in that the pixel 13 includes a display region 24Wd having a function as a display region of the display element 24W. In FIG. 8, the display region 24Wd is provided near the apex of the pixel 13, but one embodiment of the present invention is not limited thereto. For example, the display region 24Wd may be provided at the center of the pixel 13 or near the center.

By providing the display region 24Wd having the display element 24W in the pixel 13, the luminance of the image displayed on the display device 10 can be increased. Thereby, the light emission luminance of the display element 24R, the display element 24G, and the display element 24B can be reduced, and the power consumption of the display device 10 can be reduced.

2 and 3 show a case where one pixel 13 has three display elements 24 and three display areas 24d. In FIGS. 7 and 8, one pixel 13 includes one display element 24 and display area 24d. However, one embodiment of the present invention is not limited to this. For example, one pixel 13 may have two display elements 24 and two display areas 24d, or may have five or more.

<1-7. Example of configuration of display element>
FIG. 9 is a cross-sectional view illustrating a configuration example of the display element 24R, the display element 24G, and the display element 24B. The display element 24R, the display element 24G, and the display element 24B include a conductive layer 31, a semi-transmissive layer 32 on the conductive layer 31, and a hole transport layer 33 on the semi-transmissive layer 32. The conductive layer 31 functions as one of a pair of electrodes of the display element 24R, the display element 24G, and the display element 24B.

The display element 24R includes a hole transport layer 33R on the hole transport layer 33, a light emitting layer 34R on the hole transport layer 33R, and a light emitting layer 34B on the light emitting layer 34R. The hole transport layer 33R has the same configuration as the hole transport layer 33.

The display element 24G includes a light emitting layer 34G on the hole transport layer 33 and a light emitting layer 34B on the light emitting layer 34G. The display element 24 </ b> B has a light emitting layer 34 </ b> B on the hole transport layer 33. The light emitting layer 34R has a function of emitting red light, for example, the light emitting layer 34G has a function of emitting green light, for example, and the light emitting layer 34B has a function of emitting blue light, for example.

The display element 24R, the display element 24G, and the display element 24B have an electron transport layer 35 on the light emitting layer 34B, and a conductive layer 36 on the electron transport layer 35. The conductive layer 36 functions as the other of the pair of electrodes of the display element 24R, the display element 24G, and the display element 24B.

Note that, among the layers illustrated in FIG. 9, the layers excluding the conductive layer 31 and the conductive layer 36 are collectively referred to as an EL layer 30.

In the display element having the configuration shown in FIG. 9, after the formation of the conductive layer 31, the semi-transmissive layer 32, and the hole transport layer 33, the hole transport layer 33R is formed, and the light emitting layer 34R is formed on the hole transport layer 33R. To do. Thereby, the distance between the light emitting layer 34R and the conductive layer 31 and the distance between the light emitting layer 34R and the conductive layer 36 can be adjusted. Therefore, the light emitted from the light emitting layer 34R can be amplified by applying the microcavity method.

In addition, after forming the hole transport layer 33, a hole transport layer may be further formed on the display element 24G, and the light emitting layer 34G may be formed on the hole transport layer. Thereby, the distance between the light emitting layer 34G and the conductive layer 31 and the distance between the light emitting layer 34G and the conductive layer 36 can be adjusted. Therefore, the light emitted from the light emitting layer 34G can be amplified by applying the microcavity method.

Further, after forming the hole transport layer 33, a hole transport layer may be further formed on the display element 24B, and the light emitting layer 34B may be formed on the hole transport layer. Thereby, the distance between the light emitting layer 34B and the conductive layer 31 and the distance between the light emitting layer 34B and the conductive layer 36 can be adjusted. Therefore, the light emitted from the light emitting layer 34B can be amplified by applying the microcavity method.

The distance between the light emitting layer 34R and the conductive layer 31, the distance between the light emitting layer 34G and the conductive layer 31, and the distance between the light emitting layer 34B and the conductive layer 31 are adjusted by the semi-transmissive layer 32. You can also

In the display element having the configuration shown in FIG. 9, the light emitting layer 34R and the light emitting layer 34G can be formed by using, for example, a separate coating method. On the other hand, the light emitting layer 34B can be formed by, for example, film formation on the entire surface without using a separate coating method. As described above, in one embodiment of the present invention, the display region 24Rd including the display element 24R and the display region 24Gd including the display element 24G are densely provided near the apex of the pixel 13. Thereby, the distance between the light emitting layer 34R and the light emitting layer 34G can be ensured, and the light emitting layer 34R and the light emitting layer 34G can be formed using a separate coating method. On the other hand, since the light emitting layer 34B can be formed without using a separate coating method, occurrence of misalignment can be suppressed when the light emitting layer 34B is formed. Therefore, the distance between the light emitting layer 34B and the light emitting layer 34G and the distance between the light emitting layer 34B and the light emitting layer 34R can be shortened.

Note that although the light emitting layer 34B is provided on the light emitting layer 34R and the light emitting layer 34G, the light emission of the light emitting layer 34B on the light emitting layer 34R and the light emitting layer 34B on the light emitting layer 34G is controlled by controlling the carrier balance. Can be suppressed.

In FIG. 9, the light emitting layer 34 </ b> R and the light emitting layer 34 </ b> G are formed using, for example, a coloring method, and the light emitting layer 34 </ b> B is formed without using, for example, a coloring method, but one embodiment of the present invention is not limited thereto. For example, the light emitting layer 34R and the light emitting layer 34B may be formed by using a separate coating method, and the light emitting layer 34G may be formed without using the separate coating method. Alternatively, for example, the light-emitting layer 34G and the light-emitting layer 34B may be formed using a separate coating method, and the light-emitting layer 34R may be formed without using a separate coating method.

<1-8. Display area 2 of display element>
FIG. 10 is a schematic diagram illustrating the display area of the pixel 13. In one embodiment of the present invention, the pixel 13 may include a sub-pixel 13a, a sub-pixel 13b, and a sub-pixel 13c.

The sub-pixel 13a includes a display area 22Md having the display element 22 and a display area 24Rd having the display element 24R. The sub-pixel 13b has a display area 22Yd having the display element 22 and a display area 24Gd having the display element 24G. The sub-pixel 13c has a display area 22Cd having the display element 22 and a display area 24Bd having the display element 24B. As described above, the display area 24Rd has a function of emitting red light, for example, the display area 24Gd has a function of emitting green light, for example, and the display area 24Bd has a function of emitting blue light, for example. Have. On the other hand, the display area 22Md has a function of emitting magenta light, for example, the display area 22Yd has a function of emitting yellow light, for example, and the display area 22Cd has a function of emitting cyan light, for example. That is, the display element 24 having a function of emitting light can express, for example, red, green, and blue, and the display element 22 having a function of reflecting light can express, for example, magenta, yellow, and cyan. In the display element 22, for example, magenta, yellow, and cyan are expressed, whereby the reflectance of light incident on the display device 10 can be increased, and the luminance of light emitted from the display region 22d (22Md, 22Yd, 22Cd). Can be increased. Thereby, the area of the display region 24d can be increased. Therefore, even if the light emission luminance of the display element 24 is lowered, high luminance light can be emitted from the display region 24d, and the power consumption of the display device 10 can be reduced.

The display region 22Md can have a function of emitting magenta light by providing a colored layer that transmits magenta light. Note that the display region 22Yd can have a function of emitting yellow light by providing a colored layer that transmits yellow light. Note that the display region 22Cd can have a function of emitting cyan light by providing a colored layer that transmits cyan light.

10 and 11, the area ratio between the display region 22d and the display region 24d can be arbitrarily set. Note that the colors of light emitted from the display area 22d are magenta, yellow, and cyan, and the colors of light emitted from the display area 24d are red, green, and blue. The present invention is not limited, and any color can be used as long as the color of light emitted from the display area 22d is a complementary color of the color of light emitted from the display area 24d. Further, in one pixel 13, the number of colors of light emitted from the display area 22d and the display area 24d is three, but it may be one color or two colors. It may be more than each color.

When the pixel 13 has the configuration illustrated in FIG. 10, in the display element 22, one pixel 13 can express magenta, yellow, and cyan. In the display element 24, one pixel 13 can express red, green, and blue. That is, it can be said that the definition of the image displayed using the display element 22 is equal to the definition of the image displayed using the display element 24. This corresponds to the pixel 43 having one pixel 13.

FIG. 11 is a schematic diagram illustrating a display area of pixels 13 (pixels 13 (m, n) to pixels 13 (m + 3, n + 3)) for four rows and four columns, and is a modification of FIG. 3. 11 is different from the configuration shown in FIG. 3 in that a display area 22Md, a display area 22Yd, and a display area 22Cd are provided instead of the display area 22Rd, the display area 22Gd, and the display area 22Bd. That is, FIG. 11 can be said to be a combination of FIG. 3 and FIG. As a result, for example, the display element 22 capable of expressing magenta, yellow, and cyan displays the definition using the display element 24 that can express redness, green, and blue. It is possible to vary the definition of the image to be displayed. Specifically, it can be said that the definition of the image displayed on the display element 22 is, for example, ¼ of the definition of the image displayed on the display element 24. Thereby, the reflectance of the light incident on the display device 10 can be increased and the light emitted from the display region 22d can be increased as compared with the case where the display element 22 expresses a plurality of colors with one pixel 13 like the display element 24. The brightness of the light can be increased. Therefore, the light emission luminance of the display element 24 can be reduced, and the power consumption of the display device 10 can be reduced. Further, the deterioration of the display element 24 is reduced, and the reliability of the display device 10 can be increased.

This embodiment can be implemented in combination with any of the structures described in the other embodiments or examples as appropriate.

(Embodiment 2)
In this embodiment, one embodiment of the display device 10 which is one embodiment of the present invention will be described with reference to drawings.

<2-1. Configuration example>
FIG. 12A is a schematic perspective view of the display device 10. The display device 10 has a configuration in which a substrate 351 and a substrate 361 are bonded to each other. In FIG. 12, the substrate 361 is indicated by a broken line.

The display device 10 includes a display unit 12, a peripheral circuit region 234, wirings 365, and the like. FIG. 12 shows an example in which an IC (Integrated Circuit) 64 and an FPC (Flexible Printed Circuits) 372 are mounted on the display device 10.

The peripheral circuit region 234 includes a circuit for supplying a signal to the display unit 12. Examples of the circuit included in the peripheral circuit region 234 include a gate driver.

The wiring 365 has a function of supplying a signal and power to the display portion 12 and the peripheral circuit region 234. The signal and power are input to the wiring 365 from the outside through the FPC 372 or from the IC 164.

FIG. 12A illustrates an example in which the IC 164 is provided over the substrate 351 by a COG method, a COF method, or the like. For example, an IC having a gate driver circuit or a source driver circuit can be applied. Note that the IC 164 may be mounted on the FPC by a COF method or the like.

FIG. 12A shows an enlarged view of a part of the display unit 12. A plurality of pixels 13 are arranged in a matrix on the display unit 12. The pixel 13 includes a display element 24 and a display element 22 as display elements.

FIG. 12B shows a schematic perspective view of the pixel 13. The pixel 13 includes a pixel circuit 236 for driving the display element. The display element 24 and the display element 22 included in the pixel 13 overlap with each other through the pixel circuit 236. The pixel circuit 236 includes a first circuit for driving the display element 24 and a second circuit for driving the display element 22.

Light 237 emitted from the display element 24 passes through the pixel circuit 236 and the display element 22 and is emitted to the outside. In addition, light 238 incident from the outside passes through the display element 22 and the pixel circuit 236, is reflected by the electrode of the display element 24, passes through the pixel circuit 236 and the display element 22 again, and is emitted to the outside as reflected light. .

FIG. 13A illustrates a planar configuration example of the pixel circuit 236. A pixel circuit 236 illustrated in FIG. 13A includes elements such as a transistor 271, a capacitor 272, a transistor 281, a capacitor 282, and a transistor 283. In addition, the pixel circuit 236 includes part of the scan line 273, part of the signal line 274, part of the common potential line 275, part of the scan line 284, part of the signal line 285, and part of the power supply line 286. including.

As described above, the light 237 passes through the pixel circuit 236 once. The light 238 passes through the pixel circuit 236 twice. Therefore, the pixel circuit 236 preferably includes a light-transmitting material.

At least one of the transistor 271, the capacitor 272, the transistor 281, the capacitor 282, and the transistor 283 is preferably formed using a light-transmitting conductive material. In addition, it is preferable that the electrodes connected to these in the pixel circuit 236 be formed using a light-transmitting material.

As the light-transmitting conductive material, for example, a conductive oxide such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, or zinc oxide to which gallium is added may be used. In particular, a conductive material having an energy band gap of 2.5 eV or more is preferable because it has a high visible light transmittance.

On the other hand, a light-transmitting conductive material has a higher resistivity than a light-blocking conductive material such as copper or aluminum. Therefore, the bus lines such as the scan line 273, the signal line 274, the scan line 284, the signal line 285, and the power supply line 286 are made of a conductive material (metal material) having a low resistivity and a light-shielding property. It is preferable to form by using. However, a conductive material having a light-transmitting property may be used for the bus line depending on the size of the display portion 12, the width of the bus line, the thickness of the bus line, or the like.

In general, the common potential line 275 is used to give a constant potential in the pixel circuit 236, and a large current does not flow through the common potential line 275. Therefore, the common potential line 275 can be formed using a light-transmitting conductive material with high resistivity. However, in the case where a method of changing the potential of the common potential line 275 is used as a method for driving the display element, it is preferable to use a light-shielding metal material having a low resistivity for the common potential line 275.

FIG. 13B is a plan view showing a transmission region 291 and a light shielding region 292 of the pixel circuit 236. The light 237 and the light 238 are emitted through the transmission region 291. Therefore, in the plan view, the extraction efficiency of the light 237 and the light 238 can be increased as the ratio of the transmission region 291 to the occupied area of the pixel 13 (also referred to as “aperture ratio”) is larger. That is, the power consumption of the display device 10 can be reduced. In addition, the visibility of the display device 10 can be improved. Further, the display quality of the display device 10 can be improved.

In the display device 10 of one embodiment of the present invention, the element included in the pixel circuit 236 is formed using a light-transmitting material, whereby the aperture ratio can be 60% or more, further 80% or more. In addition, since the display element 24 and the display element 22 can be provided to overlap each other, the total of the light emitting area of the display element 24 and the reflection area of the display element 22 can be equal to or larger than the area of the pixel 13. In other words, when the occupation area of the pixel 13 is 100%, the total area of the light emission area and the reflection area can be 100% or more. That is, it can be said that the aperture ratio can be 100% or more.

For example, when obtaining a certain light emission luminance (light emission amount) per pixel, the light emission luminance per unit area can be lowered by increasing the light emission area of the display element 24. Therefore, deterioration of the display element 24 is reduced, and the reliability of the display device 10 can be improved.

The display element 24 is preferably a self-luminous light emitting element such as an organic EL element, an inorganic EL element, an LED, a QLED, or a semiconductor laser. Further, as the display element 24, a transmissive liquid crystal in which a light source (for example, LED) and a liquid crystal are combined may be used. In the present embodiment, the display element 24 is described as an organic EL element.

[Cross-section configuration example]
14, a part of the region including the FPC 372, a part of the region including the peripheral circuit region 234, and a part of the region including the display portion 12 of the display device 10 illustrated in FIG. An example of a cross section is shown.

A display device 10 illustrated in FIG. 14 includes a transistor 201, a transistor 203, a transistor 205, a transistor 206, a capacitor 202, a display element 22, a display element 24, an insulating layer 220, a coloring layer 131, and the like between a substrate 351 and a substrate 361. Have The substrate 361 and the insulating layer 220 are bonded via an adhesive layer 141. The substrate 351 and the insulating layer 194 are bonded through an adhesive layer 142.

The substrate 361 is provided with a coloring layer 131, a light shielding layer 132, an insulating layer 121, an electrode 113 functioning as a common electrode of the display element 22, an alignment film 133b, an insulating layer 117, and the like. The insulating layer 121 may function as a planarization layer. Since the surface of the electrode 113 can be substantially flattened by the insulating layer 121, the alignment state of the liquid crystal 112 can be made uniform. The insulating layer 117 functions as a spacer for maintaining the cell gap of the display element 22. When the insulating layer 117 transmits visible light, the insulating layer 117 may be disposed so as to overlap the display region of the display element 22.

Note that a functional member 135 such as an optical member can be disposed on the outer surface of the substrate 361. Examples of the optical member include a polarizing plate, a retardation plate, a light diffusion layer (diffusion film, etc.), an antireflection layer (also referred to as “Anti Reflection layer” or “AR layer”), an antiglare layer (“Anti Glare layer”) or And an “AG layer”) and a light collecting film. Examples of the functional member other than the optical member include an antistatic film that suppresses adhesion of dust, a water-repellent film that makes it difficult to adhere dirt, and a hard coat film that suppresses the occurrence of scratches due to use. A combination of the above members may be used as the functional member 135. For example, you may use the circularly-polarizing plate which combined the linearly-polarizing plate and the phase difference plate.

The AR layer has a function of reducing regular reflection (specular reflection) of external light by utilizing light interference action. In the case where an AR layer is used as the functional member 135, the AR layer is formed using a material having a refractive index different from that of the substrate 361. The AR layer can be formed using a material such as zirconium oxide, magnesium fluoride, aluminum oxide, or silicon oxide, for example.

Further, an antiglare layer (also referred to as “Anti Glare layer” or “AG layer”) may be provided instead of the AR layer. The AG layer has a function of reducing regular reflection (specular reflection) by diffusing incident external light.

As a method for forming the AG layer, a method of providing fine irregularities on the surface, a method of mixing materials having different refractive indexes, a method of combining both, and the like are known. For example, an AG layer can be formed by mixing nanofibers such as cellulose fibers, inorganic beads such as silicon oxide, or resin beads with a light-transmitting resin.

An AG layer may be provided over the AR layer. By providing a stack of the AR layer and the AG layer, it is possible to further enhance the function of preventing reflection or reflection of external light. By using an AR layer and / or an AG layer, the external light reflectance on the surface of the display device 10 may be less than 1%, preferably less than 0.3%.

The display element 22 described in this embodiment is a reflective liquid crystal element that uses the conductive layer 36 of the display element 24 as a reflective electrode. The display element 22 has a stacked structure in which the electrode 311, the liquid crystal 112, and the electrode 113 are stacked. The electrode 311 and the electrode 113 transmit visible light. An alignment film 133 a is provided between the liquid crystal 112 and the electrode 311. An alignment film 133 b is provided between the liquid crystal 112 and the electrode 113.

By using the reflective electrode of the display element 22 also as the conductive layer 36 of the display element 24, the reflective electrode dedicated to the display element 22 can be reduced. Thus, a display device can be manufactured at low cost. In addition, the productivity of the display device 10 can be increased.

In this embodiment, a circularly polarizing plate is used as the functional member 135. Light incident from the substrate 361 side is polarized by the functional member 135 (circularly polarizing plate), passes through the electrode 113, the liquid crystal 112, and the electrode 311, and is reflected by the conductive layer 36. Then, the light passes through the liquid crystal 112 and the electrode 113 again and reaches the functional member 135 (circularly polarizing plate). At this time, the orientation of the liquid crystal can be controlled by the voltage applied between the electrode 311 and the electrode 113, and the optical modulation of light can be controlled. That is, the intensity of light emitted through the functional member 135 (circularly polarizing plate) can be controlled. In addition, when the light other than the specific wavelength region is absorbed by the colored layer 131, the extracted light is, for example, red light.

In the connection portion 207, the electrode 311 is electrically connected to the conductive layer 222b included in the transistor 206 through the conductive layer 221b. The transistor 206 has a function of controlling driving of the display element 22.

A connection portion 252 is provided in a part of the region where the adhesive layer 141 is provided. In the connection portion 252, a conductive layer obtained by processing the same conductive film as the electrode 311 and a part of the electrode 113 are electrically connected by a connection body 243. Therefore, a signal or a potential input from the FPC 372 can be supplied to the electrode 113 formed on the substrate 361 side through the connection portion 252.

As the connection body 243, for example, conductive particles can be used. As the conductive particles, particles obtained by coating the surface of particles such as organic resin or silica with a metal material can be used. It is preferable to use nickel or gold as the metal material because the contact resistance can be reduced. In addition, it is preferable to use particles in which two or more kinds of metal materials are coated in layers, such as further coating nickel with gold. Further, it is preferable to use a material that is elastically deformed or plastically deformed as the connection body 243. At this time, the connection body 243, which is a conductive particle, may have a shape crushed in the vertical direction as shown in FIG. By doing so, the contact area between the connection body 243 and the conductive layer electrically connected to the connection body 243 can be increased, the contact resistance can be reduced, and the occurrence of problems such as poor connection can be suppressed. For example, the connection body 243 may be dispersed in the adhesive layer 141 before curing. Note that the connection body 243 is preferably arranged so as to be covered with the adhesive layer 141.

The display element 24 can be, for example, a bottom emission type light emitting element. The display element 24 has a stacked structure in which the conductive layer 31, the EL layer 30, and the conductive layer 36 are stacked in this order from the insulating layer 220 side. The conductive layer 31 is connected to a conductive layer 222 b included in the transistor 205 through an opening provided in the insulating layer 214. The transistor 205 has a function of controlling driving of the display element 24. An insulating layer 216 covers the end portion of the conductive layer 31. The conductive layer 36 has a function of reflecting visible light, and the conductive layer 31 has a function of transmitting visible light. An insulating layer 194 is provided to cover the conductive layer 36. Light emitted from the display element 24 is emitted to the substrate 361 side through the insulating layer 220, the electrode 311, the colored layer 131, and the like.

The emission color of the display element 24 can be changed to white, red, green, blue, cyan, magenta, yellow, or the like depending on the material constituting the EL layer 30. The reflected light controlled by the display element 22 can be changed to white, red, green, blue, cyan, magenta, yellow, or the like depending on the material forming the colored layer 131. The display element 24 and the display element 22 can realize color display by changing the color of light controlled by the pixels.

In addition, the EL layer 30 that emits white light may be used for the display element 24 and the coloring layer 131 may be used for coloring.

In order to realize color display, the emission color of the display element 24 and the color of the colored layer combined with the display element 22 are not only combinations of red, green and blue, but also combinations of yellow, cyan and magenta. Good. What is necessary is just to set the color of the colored layer to combine suitably according to the objective or a use.

The transistor 201, the transistor 203, the transistor 205, the transistor 206, and the capacitor 202 are all formed over the surface of the insulating layer 220 on the substrate 351 side. In FIG. 14, top-gate transistors are illustrated as the transistor 201, the transistor 203, the transistor 205, and the transistor 206.

The transistor 203 is a transistor (also referred to as a switching transistor or a selection transistor) that controls pixel selection / non-selection. The transistor 205 is a transistor (also referred to as a drive transistor) that controls a current flowing through the display element 24.

Insulating layers such as an insulating layer 211, an insulating layer 212, an insulating layer 213, and an insulating layer 214 are provided on the substrate 351 side of the insulating layer 220. The insulating layer 212 and the insulating layer 213 are provided so as to cover the gate electrodes and the like of the transistor 201, the transistor 203, the transistor 205, and the transistor 206. The insulating layer 214 functions as a planarization layer. Note that the number of insulating layers covering the transistor is not limited, and may be a single layer or two or more layers.

It is preferable to use a material in which impurities such as water and hydrogen hardly diffuse for at least one of the insulating layers covering each transistor. Thereby, the insulating layer can function as a barrier film. With such a structure, impurities can be effectively prevented from diffusing from the outside with respect to the transistor, and a highly reliable display device can be realized.

The capacitor 202 includes a conductive layer 217 and a conductive layer 218 having regions overlapping with each other with the insulating layer 211 interposed therebetween. The conductive layer 217 can be formed using a material and a method similar to those of the conductive layer 225. The conductive layer 218 can be formed using a material and a method similar to those of the conductive layer 223. Note that the conductive layer 223, the conductive layer 225, and the conductive layer 222a are preferably formed using a light-transmitting material.

The transistor 203, the transistor 205, and the transistor 206 are formed using a light-transmitting material. As described above, a light-transmitting conductive material has a higher resistivity than a light-blocking conductive material such as copper or aluminum. Therefore, a conductive layer used for the transistor 201 included in the peripheral circuit region 234, which is required to operate at high speed, is formed using a light-blocking conductive material (metal material) with low resistivity.

The transistor 203, the transistor 205, and the transistor 206 include a conductive layer 223 functioning as a gate, an insulating layer 224 functioning as a gate insulating layer, conductive layers 222a and 222b functioning as a source and a drain, and a semiconductor layer 231. . Here, the same hatching pattern is given to a plurality of layers obtained by processing the same conductive film. In addition, the transistor 205 includes a conductive layer 225 that can function as a gate.

Similarly, the transistor 201 includes a conductive layer functioning as a gate, an insulating layer functioning as a gate insulating layer, a conductive layer functioning as a source, a conductive layer functioning as a drain, and a semiconductor layer. In addition, the transistor 201 includes a conductive layer 221a functioning as a gate. The conductive layer 221a and the conductive layer 221b can be obtained by processing the same conductive film.

A structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates is applied to the transistor 201 and the transistor 205. With such a structure, the threshold voltage of the transistor can be controlled. The transistor may be driven by connecting two gates and supplying the same signal thereto. Such a transistor can have higher field-effect mobility than other transistors, and can increase on-state current. As a result, a circuit that can be driven at high speed can be manufactured. Furthermore, the area occupied by the circuit portion can be reduced. By applying a transistor with a large on-state current, even if the number of wirings increases when the display device is enlarged or high-definition, signal delay in each wiring can be reduced, and display unevenness is suppressed. can do.

Alternatively, the threshold voltage of the transistor can be controlled by applying a potential for controlling the threshold voltage to one of the two gates and applying a potential for driving to the other of the two gates.

There is no limitation on the structure of the transistor included in the display device. The transistor included in the peripheral circuit region 234 and the transistor included in the display portion 12 may have the same structure or different structures. The plurality of transistors included in the peripheral circuit region 234 may all have the same structure, or two or more kinds of structures may be used in combination. Similarly, the plurality of transistors included in the display portion 12 may all have the same structure, or two or more kinds of structures may be used in combination.

A conductive material containing an oxide may be used for the conductive layer functioning as a gate. By forming the conductive layer in an atmosphere containing oxygen, oxygen can be supplied to the gate insulating layer. The proportion of oxygen gas in the film forming gas is preferably in the range of 90% to 100%. Oxygen supplied to the gate insulating layer is supplied to the semiconductor layer by a later heat treatment, so that oxygen vacancies in the semiconductor layer can be reduced.

A connection portion 204 is provided in a region where the substrate 351 and the substrate 361 do not overlap. In the connection portion 204, the wiring 365 is electrically connected to the FPC 372 through the connection layer 242. The connection unit 204 has the same configuration as the connection unit 207. On the upper surface of the connection portion 204, a conductive layer obtained by processing the same conductive film as the electrode 311 is exposed. Accordingly, the connection unit 204 and the FPC 372 can be electrically connected via the connection layer 242.

As the display element 22, for example, a liquid crystal element to which a vertical alignment (VA) mode is applied can be used. As the vertical alignment mode, an MVA (Multi-Domain Vertical Alignment) mode, a PVA (Patterned Vertical Alignment) mode, an ASV (Advanced Super View) mode, or the like can be used.

As the display element 22, liquid crystal elements to which various modes are applied can be used. For example, in addition to the VA mode, a TN (Twisted Nematic) mode, an IPS (In-Plane-Switching) mode, a VA-IPS mode, an FFS (Fringe Field Switching) mode, an ASM (Axial Symmetrical Aligned MicroB) mode A liquid crystal element to which an Optically Compensated Birefringence (FLC) mode, an FLC (Ferroelectric Liquid Crystal) mode, an AFLC (Anti-Ferroelectric Liquid Crystal) mode, a guest-host mode, or the like can be used.

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

As the liquid crystal material, either a positive type liquid crystal or a negative type liquid crystal may be used, and an optimal liquid crystal material may be used according to an applied mode or design.

In order to control the alignment of the liquid crystal, an alignment film can be provided. Note that in the case of employing a horizontal electric field mode, liquid crystal exhibiting a blue phase for which an alignment film is unnecessary may be used. The blue phase is one of the liquid crystal phases. When the temperature of the cholesteric liquid crystal is increased, the blue phase appears immediately before the transition from the cholesteric phase to the isotropic phase. Since the blue phase appears only in a narrow temperature range, a liquid crystal composition mixed with several percent by weight or more of a chiral agent is used for the liquid crystal 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 is optically isotropic. In addition, a liquid crystal composition including a liquid crystal exhibiting a blue phase and a chiral agent does not require alignment treatment and has a small viewing angle dependency. Further, since it is not necessary to provide an alignment film, a rubbing process is not required, so that electrostatic breakdown caused by the rubbing process can be prevented, and defects or breakage of the liquid crystal display device during the manufacturing process can be reduced. .

In addition, the reflective liquid crystal display device using a circularly polarizing plate is switched between the on state and the off state (switching between the bright state and the dark state) by aligning the major axis of the liquid crystal molecules in a direction substantially perpendicular to the substrate, It is done by aligning in a substantially horizontal direction. In general, a liquid crystal element that operates in a lateral electric field mode such as an IPS mode is difficult to use in a reflective liquid crystal display device because the major axis of liquid crystal molecules is aligned in a direction substantially horizontal to the substrate in both the on state and the off state.

A liquid crystal element that operates in the VA-IPS mode operates in a lateral electric field mode, and switches between an on state and an off state so that the major axis of the liquid crystal molecules is aligned in a direction substantially perpendicular to the substrate, or is substantially horizontal to the substrate. It is done by aligning the direction. Therefore, when a liquid crystal element that operates in a horizontal electric field mode is used for a reflective liquid crystal display device, a liquid crystal element that operates in a VA-IPS mode is preferably used.

A front light may be provided outside the functional member 135. As the front light, an edge light type front light is preferably used. It is preferable to use a front light including an LED (Light Emitting Diode) because power consumption can be reduced.

As the adhesive layer, various curable adhesives such as an ultraviolet curable photocurable adhesive, a reactive curable adhesive, a thermosetting adhesive, and an anaerobic adhesive can be used. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenol resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, EVA (ethylene vinyl acetate) resins, and the like. In particular, a material with low moisture permeability such as an epoxy resin is preferable. Alternatively, a two-component mixed resin may be used. Further, an adhesive sheet or the like may be used.

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

Examples of the light emitting element include a top emission type, a bottom emission type, and a dual emission type. A conductive film that transmits visible light is used for the electrode from which light is extracted. In addition, a conductive film that reflects visible light is preferably used for the electrode from which light is not extracted. The display element 24 can be referred to as a bottom emission type light emitting element.

The EL layer 30 has at least a light emitting layer. The EL layer 30 is a layer other than the light-emitting layer, and is a substance having a high hole injection property, a substance having a high hole transport property, a hole blocking material, a substance having a high electron transport property, a substance having a high electron injection property, or a bipolar property. A layer containing a substance (a substance having a high electron transporting property and a high hole transporting property) or the like may be included.

The emission color of the display element 24 can be changed to white, red, green, blue, cyan, magenta, yellow, or the like depending on the material constituting the EL layer 30.

As a method for realizing color display, there are a method in which a display element 24 having a white emission color and a colored layer are combined, and a method in which a display element 24 having a different emission color is provided for each sub-pixel. The former method is more productive than the latter method. On the other hand, in the latter method, it is possible to obtain an emission color with higher color purity than in the former method. Further, in the latter method, since light absorption by the colored layer 131 is suppressed as compared with the former method, the power consumption of the display device 10 can be reduced. In addition to the latter method, the color purity can be further enhanced by providing the display element 24 with a microcavity structure.

For the EL layer 30, either a low molecular compound or a high molecular compound can be used, and an inorganic compound may be included. The layers constituting the EL layer 30 can be formed by a method such as a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an ink jet method, or a coating method.

The EL layer 30 may have an inorganic compound such as a quantum dot. For example, a quantum dot can be used for a light emitting layer to function as a light emitting material.

The quantum dots are semiconductor nanocrystals having a size of several nm, and are composed of about 1 × 10 ³ to 1 × 10 ⁶ atoms. Quantum dots shift their energy depending on their size, so even if the quantum dots are made of the same material, the emission wavelength differs depending on the size, and the emission wavelength can be easily adjusted by changing the size of the quantum dots used be able to.

In addition, since the quantum dot has a narrow emission spectrum peak width, light emission with good color purity can be obtained. Furthermore, the theoretical external quantum efficiency of quantum dots is said to be almost 100%, which is much higher than 25% of organic compounds that exhibit fluorescence and is equivalent to organic compounds that exhibit phosphorescence. For this reason, a light-emitting element with high emission efficiency can be obtained by using quantum dots as a light-emitting material. In addition, since the quantum dot which is an inorganic compound is excellent in the essential stability, a preferable light-emitting element can be obtained from the viewpoint of life.

Materials constituting the quantum dot include periodic table group 14 element, periodic table group 15 element, periodic table group 16 element, compound composed of a plurality of periodic table group 14 elements, periodic table group 4 to periodic table. Compound of group 14 element and periodic table group 16 element, periodic table group 2 element and periodic table group 16 element, periodic table group 13 element and periodic table group 15 element A compound of a periodic table group 13 element and a periodic table group 17 element, a compound of a periodic table group 14 element and a periodic table group 15 element, a periodic table group 11 element and a periodic table group 17 element Examples thereof include compounds, iron oxides, titanium oxides, chalcogenide spinels, and various semiconductor clusters.

Specifically, cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide, zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, indium arsenide, indium phosphide, gallium arsenide , Gallium phosphide, indium nitride, gallium nitride, indium antimonide, gallium phosphide, aluminum arsenide, aluminum arsenide, aluminum antimonide, lead selenide, lead telluride, lead sulfide, indium selenide, indium telluride, sulfide Indium, gallium selenide, arsenic sulfide, arsenic selenide, arsenic telluride, antimony sulfide, antimony selenide, antimony telluride, bismuth sulfide, bismuth selenide, bismuth telluride, silicon, silicon carbide, germanium, tin, selenium, Tellurium, Hou , Carbon, phosphorus, boron nitride, boron phosphide, boron arsenide, aluminum nitride, aluminum sulfide, barium sulfide, barium selenide, barium telluride, calcium sulfide, calcium selenide, calcium telluride, beryllium sulfide, beryllium selenide, Beryllium telluride, magnesium sulfide, magnesium selenide, germanium sulfide, germanium selenide, germanium telluride, tin sulfide, tin selenide, tin telluride, lead oxide, copper fluoride, copper chloride, copper bromide, copper iodide , Copper oxide, copper selenide, nickel oxide, cobalt oxide, cobalt sulfide, triiron tetroxide, iron oxide, manganese oxide, molybdenum sulfide, vanadium oxide, tungsten oxide, tantalum oxide, titanium oxide, zirconium oxide, silicon nitride, nitride Germanium, aluminum oxide Barium titanate, selenium, zinc and cadmium compound, indium, arsenic and phosphorus compound, cadmium, selenium and sulfur compound, cadmium, selenium and tellurium compound, indium, gallium and arsenic compound, indium, gallium and selenium compound Examples thereof include, but are not limited to, compounds of indium, selenium and sulfur, compounds of copper, indium and sulfur, and combinations thereof. Moreover, you may use what is called an alloy type quantum dot whose composition is represented by arbitrary ratios. For example, an alloy type quantum dot of cadmium, selenium, and sulfur is one of effective means for obtaining blue light emission because the emission wavelength can be changed by changing the content ratio of elements.

The structure of the quantum dot includes a core type, a core-shell type, a core-multishell type, and any of them may be used, but the shell is covered with another inorganic material that covers the core and has a wider band gap. By forming, the influence of defects and dangling bonds existing on the nanocrystal surface can be reduced. Thereby, in order to greatly improve the quantum efficiency of light emission, it is preferable to use a core-shell type or core-multishell type quantum dot. Examples of the shell material include zinc sulfide and zinc oxide.

In addition, since the quantum dots have a high ratio of surface atoms, they are highly reactive and tend to aggregate. Therefore, it is preferable that a protective agent is attached to the surface of the quantum dot or a protective group is provided. Aggregation can be prevented and solubility in a solvent can be increased by attaching the protective agent or providing a protective group. It is also possible to reduce the reactivity and improve the electrical stability. Examples of the protective agent (or protecting group) include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, tripropylphosphine, tributylphosphine, trihexylphosphine, Trialkylphosphines such as octylphosphine, polyoxyethylene alkylphenyl ethers such as polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, tri (n-hexyl) amine, tri (n-octyl) Tertiary amines such as amine, tri (n-decyl) amine, tripropylphosphine oxide, tributylphosphine oxide, trihexylphosphine oxide, trioctylphosphine Organic phosphorus compounds such as oxyoxide, tridecylphosphine oxide, polyethylene glycol diesters such as polyethylene glycol dilaurate and polyethylene glycol distearate, and organic nitrogen compounds such as nitrogen-containing aromatic compounds such as pyridine, lutidine, collidine and quinolines , Hexylamine, octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine and other amino alkanes, dibutyl sulfide and other dialkyl sulfides, dimethyl sulfoxide and dibutyl sulfoxide and other dialkyl sulfoxides, and thiophene Organic sulfur compounds such as sulfur-containing aromatic compounds, higher fatty acids such as palmitic acid, stearic acid and oleic acid, alcohols, sorbitan fatty acid esters , Fatty acid-modified polyesters, tertiary amine modified polyurethanes and polyethylene imines, and the like.

Since the quantum dot has a band gap that increases as the size decreases, the size of the quantum dot is appropriately adjusted so that light having a desired wavelength can be obtained. As the crystal size decreases, the emission of quantum dots shifts to the blue side, that is, to the higher energy side, so changing the size of the quantum dots changes the wavelength of the spectrum in the ultraviolet, visible, and infrared regions. The emission wavelength can be adjusted over a region. The size (diameter) of the quantum dots is usually 0.5 nm to 20 nm, preferably 1 nm to 10 nm. In addition, as the quantum dot has a narrower size distribution, the emission spectrum becomes narrower and light emission with good color purity can be obtained. The shape of the quantum dots is not particularly limited, and may be spherical, rod-shaped, disk-shaped, or other shapes. In addition, since the quantum rod which is a rod-shaped quantum dot exhibits the light which has the directivity polarized in the c-axis direction, the light emitting element with more favorable external quantum efficiency can be obtained by using a quantum rod as a luminescent material. .

In many cases, EL elements increase luminous efficiency by dispersing a light emitting material in a host material, but the host material needs to be a substance having a singlet excitation energy or triplet excitation energy higher than that of the light emitting material. is there. In particular, in the case of using a blue phosphorescent material, it is extremely difficult to develop a host material having a triplet excitation energy higher than that and having an excellent lifetime. On the other hand, since the quantum dots can maintain the light emission efficiency even if the light emitting layer is composed of only the quantum dots without using a host material, a light emitting element that is preferable from this point of view can also be obtained. When the light emitting layer is formed only with quantum dots, the quantum dots preferably have a core-shell structure (including a core-multishell structure).

In the display device 10 of one embodiment of the present invention, no substrate is provided between the display element 24 and the display element 22. For this reason, the distance in the thickness direction between the display element 24 and the display element 22 can be less than 30 μm, preferably less than 10 μm, and more preferably less than 5 μm. Thereby, in the display which uses the display element 24 and the display element 22 simultaneously or alternately, the parallax produced between both can be reduced. Alternatively, the weight of the display device 10 can be reduced. Alternatively, the thickness of the display device 10 can be reduced. Alternatively, the display device 10 can be easily bent.

[substrate]
There is no particular limitation on the materials used for the substrate 351 and the substrate 361. Depending on the purpose, it may be determined in consideration of the presence / absence of translucency, heat resistance enough to withstand heat treatment, and the like. For example, a glass substrate such as barium borosilicate glass or alumino borosilicate glass, a ceramic substrate, a quartz substrate, a sapphire substrate, or the like can be used. Further, a semiconductor substrate, a flexible substrate (flexible substrate), a bonded film, a base film, or the like may be used.

Examples of the semiconductor substrate include a single semiconductor substrate made of silicon or germanium, or a compound semiconductor substrate made of silicon carbide, silicon germanium, gallium arsenide, indium phosphide, zinc oxide, or gallium oxide. is there. The semiconductor substrate may be a single crystal semiconductor or a polycrystalline semiconductor.

Note that a flexible substrate (flexible substrate), a bonded film, a base film, or the like may be used for the substrate 351 and the substrate 361 in order to increase the flexibility of the display device 10.

Examples of materials such as a flexible substrate, a laminated film, and a base film include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resins, acrylic resins, polyimide resins, and polymethyl methacrylate. Resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyurethane resin, polyvinyl chloride resin, polychlorinated resin Vinylidene resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, and the like can be used.

By using the above material as the substrate, a lightweight display device can be provided. In addition, by using the above material as the substrate, a display device that is resistant to impact can be provided. In addition, by using the above material for the substrate, a display device which is not easily damaged can be provided.

As the flexible substrate used for the substrate 351 and the substrate 361, a lower linear expansion coefficient is preferable because deformation due to the environment is suppressed. The flexible substrate used for the substrate 351 and the substrate 361 is made of, for example, a material whose linear expansion coefficient is 1 × 10 ⁻³ / K or less, 5 × 10 ⁻⁵ / K or less, or 1 × 10 ⁻⁵ / K or less. Use it. In particular, since aramid has a low coefficient of linear expansion, it is suitable as a flexible substrate.

[Conductive layer]
In addition to the gate, source, and drain of a transistor, materials that can be used for conductive layers such as various wirings and electrodes constituting a display device include aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, A metal such as tantalum or tungsten, or an alloy containing this as a main component can be used. A film containing any of these materials can be used as a single layer or a stacked structure.

As the light-transmitting conductive material, conductive oxide such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide to which gallium is added, or graphene can be used. Alternatively, an oxide conductor can be used as the light-transmitting conductive material. Alternatively, a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, or an alloy material containing the metal material can be used. Alternatively, a nitride (eg, titanium nitride) of the metal material may be used. Note that in the case where a metal material or an alloy material (or a nitride thereof) is used, it may be thin enough to have a light-transmitting property. In addition, a stacked film of the above materials can be used as a conductive layer. For example, it is preferable to use a laminated film of an alloy of silver and magnesium and indium tin oxide because the conductivity can be increased. These can also be used for conductive layers such as various wirings and electrodes constituting the display device and conductive layers (conductive layers functioning as pixel electrodes and common electrodes) included in the display element.

Here, the oxide conductor will be described. In this specification and the like, the oxide conductor may be referred to as OC (Oxide Conductor). As an oxide conductor, for example, when an oxygen vacancy is formed in a metal oxide and hydrogen is added to the oxygen vacancy, a donor level is formed in the vicinity of the conduction band. As a result, the metal oxide becomes highly conductive and becomes a conductor. The conductive metal oxide can be referred to as an oxide conductor. In general, an oxide semiconductor has a large energy gap and thus has a light-transmitting property with respect to visible light. On the other hand, an oxide conductor is a metal oxide having a donor level near the conduction band. Therefore, the oxide conductor is less influenced by absorption due to the donor level, and has a light-transmitting property similar to that of an oxide semiconductor with respect to visible light.

[Insulation layer]
Examples of the insulating material that can be used for each insulating layer include resin materials such as acrylic and epoxy, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

[Colored layer]
Examples of materials that can be used for the colored layer include metal materials, resin materials, resin materials containing pigments or dyes, and the like.

[Shading layer]
Examples of the material that can be used for the light-shielding layer include carbon black, titanium black, metal, metal oxide, and composite oxide containing a solid solution of a plurality of metal oxides. The light shielding layer may be a film containing a resin material or a thin film of an inorganic material such as a metal. Alternatively, a stacked film of a film containing a material for the colored layer can be used for the light shielding layer. For example, a stacked structure of a film including a material used for a colored layer that transmits light of a certain color and a film including a material used for a colored layer that transmits light of another color can be used. It is preferable to use a common material for the coloring layer and the light-shielding layer because the apparatus can be shared and the process can be simplified.

For the coloring layer and the light-shielding layer, it is preferable to use an inkjet method or a screen printing method because a photomask is unnecessary. For example, in the case where the three color layers 131 and the light shielding layer 132 are provided over the substrate 361, a total of four photomasks can be reduced compared to the case where these layers are formed by photolithography.

[Modification 1]
A modification of the display device 10 is shown in FIG. The display device 10 having the configuration shown in FIG. 15 is different from the display device 10 having the configuration shown in FIG. 14 in that the functional member 135 is not included. By using a liquid crystal material that operates in the guest-host mode for the display element 22, functional members such as a light diffusion layer and a polarizing plate can be omitted as shown in FIG. Therefore, the productivity of the display device 10 can be increased. Moreover, the reflective brightness | luminance of the display element 22 can be raised by not providing functional members, such as a polarizing plate. Therefore, the visibility of the display device 10 can be improved.

[Modification 2]
A modification of the display device 10 is shown in FIG. The display device 10 having the configuration shown in FIG. 16 is different from the display device 10 having the configuration shown in FIG. 14 in that the display device 10 has no colored layer 131. Since other configurations are the same as those of the display device 10, detailed description thereof is omitted.

In the display device 10 having the configuration illustrated in FIG. 16, the display element 22 exhibits white. Since the colored layer 131 is not provided, the display device 10 can perform display in black and white or gray scale using the display element 22.

[Modification 3]
A modification of the display device 10 is shown in FIG. The display device 10 having the configuration illustrated in FIG. 17 includes a touch sensor 370 between the substrate 361 and the coloring layer 131. In this embodiment, the touch sensor 370 includes a conductive layer 374, an insulating layer 375, a conductive layer 376a, a conductive layer 376b, a conductive layer 377, and an insulating layer 378.

The conductive layers 376a, 376b, and 377 are preferably formed using a light-transmitting conductive material. However, in general, a conductive material having a light-transmitting property has a higher resistivity than a metal material having no light-transmitting property. Therefore, the conductive layer 376a, the conductive layer 376b, and the conductive layer 377 may be formed using a metal material with low resistivity in order to increase the size and definition of the touch sensor.

In the case where the conductive layer 376a, the conductive layer 376b, and the conductive layer 377 are formed using a metal material, it is preferable to reduce external light reflection. In general, a metal material is a material having a high reflectance, but by performing an oxidation treatment or the like, the reflectance can be reduced and a dark color can be obtained.

Alternatively, the conductive layer 376a, the conductive layer 376b, and the conductive layer 377 may be a stack of a metal layer and a layer with low reflectance (also referred to as a “dark color layer”). Since the dark color layer has high resistivity, it is preferable to form a stack of a metal layer and a dark color layer. Examples of the dark color layer include a layer containing copper oxide, a layer containing copper chloride or tellurium chloride, and the like. Further, the dark color layer is made of metal particles such as Ag particles, Ag fibers, Cu particles, nanocarbon particles such as carbon nanotubes (CNT) or graphene, and conductive polymers such as PEDOT, polyaniline, or polypyrrole. May be formed.

Further, as the touch sensor 370, an optical touch sensor using a photoelectric conversion element or the like may be used in addition to a resistive film type or capacitive type touch sensor. Examples of the electrostatic capacity method include a surface electrostatic capacity method and a projection electrostatic capacity method. As the projected capacitance method, there are a self-capacitance method, a mutual capacitance method, etc. mainly due to a difference in driving method. The mutual capacitance method is preferable because simultaneous multipoint detection is possible.

Since other configurations are the same as those of the display device 10, detailed description thereof is omitted.

Alternatively, the touch sensor may be provided so as to overlap the substrate 361 of the display device 10 without providing the touch sensor 370 between the substrate 361 and the coloring layer 131. For example, a sheet-like touch sensor 176 may be provided so as to overlap the display unit 12.

[About transistors]
In one embodiment of the present invention, the structure of the transistor included in the display device is not particularly limited. For example, a planar transistor, a staggered transistor, or an inverted staggered transistor may be used. Further, any transistor structure of a top gate structure or a bottom gate structure may be employed. Alternatively, gate electrodes may be provided above and below the channel.

[Semiconductor materials]
There is no major limitation on the crystallinity of the semiconductor material used for the semiconductor layer of the transistor. Any of an amorphous semiconductor and a semiconductor having crystallinity (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor partially including a crystal region) may be used. Note that it is preferable to use a crystalline semiconductor because deterioration of transistor characteristics can be suppressed.

For example, silicon, germanium, or the like can be used as a semiconductor material used for a semiconductor layer of the transistor. Alternatively, a compound semiconductor such as silicon carbide, gallium arsenide, or a nitride semiconductor, an organic semiconductor, or the like can be used.

For example, polycrystalline silicon (polysilicon), amorphous silicon (amorphous silicon), or the like can be used as a semiconductor material used for the transistor.

As the transistor, an OS transistor using a metal oxide can be used. An OS transistor is preferable because current flowing between the source and the drain in the off state of the transistor can be reduced.

<2-2. Display mode>
The display device 10 can be operated in three display modes. The first display mode (mode 1) is a mode for displaying an image using only the display element 22, that is, a display mode for displaying an image as, for example, a reflective liquid crystal display device. The second display mode (mode 2) is a mode in which an image is displayed using only the display element 24, that is, a display mode in which an image is displayed as, for example, a light emitting display device. The third display mode (mode 3) is a mode in which an image is displayed using both the display element 22 and the display element 24, that is, a display mode in which, for example, the first display mode and the second display mode act simultaneously.

[First display mode]
Since the first display mode does not require a light source, it is a display mode with extremely low power consumption. For example, it is particularly effective when the illuminance of outside light is sufficiently large and the outside light is white light or light in the vicinity thereof. The first display mode is particularly effective when used in an environment where the illuminance is greater than about 300 lx, for example, in the daytime. However, the display device 10 may be operated in the first display mode even in an environment where the illuminance is smaller than about 300 lx depending on the purpose or application.

The first display mode is a display mode suitable for displaying character information such as books and documents. Since reflected light is used to display an image, it is possible to perform display that is gentle to the eyes, and the effect that the eyes are less tired.

FIG. 18A1 illustrates that the electronic device 910 is used outdoors during the daytime. In FIG. 18A1, the display device of the electronic device 910 operates in the first display mode. The electronic device 910 is, for example, a portable information terminal such as a smartphone. The electronic device 910 includes the display device 10 of one embodiment of the present invention.

FIG. 18A2 illustrates incident light 901 incident on the display device 10 of the electronic device 910 and reflected light 902 reflected by the display device 10.

[Second display mode]
The second display mode is a display mode capable of performing extremely vivid (high contrast and high color reproducibility) display regardless of the illuminance and chromaticity of external light. For example, it is effective when the illuminance of outside light is small, such as at night or indoors. The second display mode is particularly effective when used in an environment where the illuminance is less than about 5000 lx. However, the display device 10 may be operated in the second display mode even in an environment where the illuminance is greater than about 5000 lx depending on the purpose or application. In addition, when the illuminance of external light is small, the user may feel dazzled when performing bright display. In order to prevent this, it is preferable to perform display with reduced luminance in the second display mode. Thereby, in addition to suppressing glare, power consumption can also be reduced. The second display mode is a mode suitable for displaying vivid images, smooth moving images, and the like.

FIG. 18B1 illustrates that the electronic device 910 is used outdoors at night. Moreover, the electronic device 920 in the figure is an electronic device used for digital signage. In FIG. 18B1, the display devices of the electronic device 910 and the electronic device 920 operate in the second display mode. The electronic device 920 includes the display device 10 of one embodiment of the present invention.

FIG. 18B2 illustrates light emission 903 emitted from the display device 10 of the electronic device 910 and light emission 903 emitted from the display device 10 of the electronic device 920.

[Third display mode]
The third display mode is a display mode in which display is performed using both reflected light in the first display mode and light emission in the second display mode. For example, when it is necessary to emit light from the display device 10 that is equal to or higher than the maximum reflection luminance in the first display mode, the necessary light amount can be supplemented by light emission in the second display mode. Further, for example, it is possible to drive to express one color by mixing the reflected light in the first display mode and the light emission in the second display mode.

In the third display mode, it is possible to suppress power consumption more than in the second display mode while displaying more vividly than in the first display mode. For example, it is effective when the illuminance of outside light is relatively low, such as under room lighting or in the morning or evening hours, or when the chromaticity of outside light is not white.

The third display mode is particularly effective when used in an environment where the illuminance is less than about 5000 lx. However, the display apparatus 10 may be operated in the third display mode even in an environment where the illuminance is greater than about 5000 lx depending on the purpose or application.

FIG. 18C1 illustrates a state where the electronic device 910 is used indoors. In addition, an electronic device 930 in the figure is an electronic device that can function as a television or a monitor. Also, the electronic device 940 in the figure is a notebook personal computer. In FIG. 18C1, the display device included in the electronic device 910, the electronic device 930, and the electronic device 940 operates in the third display mode. The electronic device 930 and the electronic device 940 each include the display device 10 of one embodiment of the present invention.

FIG. 18C2 illustrates light emission 903 emitted from the display device 10 of the electronic device 910, incident light 901 incident on the display device 10 of the electronic device 910, and reflected light 902 reflected by the display device 10 of the electronic device 910. Show. Further, light emission 903 emitted from the display device 10 of the electronic device 930, incident light 901 incident on the display device 10 of the electronic device 930, and reflected light 902 reflected by the display device 10 of the electronic device 930 are shown. The display device 10 of the electronic device 940 can function similarly to the other display devices 10.

Note that the display using the third display mode can be said to be a hybrid display mode. Hybrid display is a method of displaying characters or images on one panel by using reflected light and self-light emission in combination with each other to complement color tone or light intensity. Alternatively, the hybrid display is a method for displaying characters and / or images using light from a plurality of display elements in the same pixel or the same sub-pixel. However, when a display device that performs hybrid display (also referred to as “hybrid display device” or “hybrid display”) is viewed locally, pixels or subpixels displayed using any one of a plurality of display elements And a pixel or sub-pixel displayed using two or more of the plurality of display elements.

Note that in this specification and the like, a display that satisfies any one or a plurality of expressions of the above configuration is referred to as a hybrid display.

The hybrid display has a plurality of display elements in the same pixel or the same sub-pixel. Examples of the plurality of display elements include a reflective element that reflects light and a self-luminous element that emits light. Note that the reflective element and the self-luminous element can be controlled independently. The hybrid display has a function of displaying characters and / or images in the display unit using either or both of reflected light and self-light emission.

This embodiment can be implemented in combination with any of the structures described in the other embodiments or examples as appropriate.

(Embodiment 3)
In this embodiment, a structural example of the OS transistor described in the above embodiment will be described.

<3-1. OS transistor configuration example 1>
First, as an example of the structure of the transistor, a transistor 3200a will be described with reference to FIGS. FIG. 19A is a top view of the transistor 3200a. 19B corresponds to a cross-sectional view of the cross section taken along the dashed-dotted line X1-X2 in FIG. 19A, and FIG. 19C illustrates the area between the dashed-dotted line Y1-Y2 shown in FIG. This corresponds to a cross-sectional view of the cut surface in FIG. Note that in FIG. 19A, some components (such as an insulating layer functioning as a gate insulating layer) of the transistor 3200a are not illustrated in order to avoid complexity. In the following description, the alternate long and short dash line X1-X2 direction may be referred to as a channel length direction, and the alternate long and short dash line Y1-Y2 direction may be referred to as a channel width direction. Note that in the top view of the transistor, in the subsequent drawings, some components may be omitted in the same manner as in FIG.

The transistor 3200a includes a conductive layer 3221 over the insulating layer 3224, an insulating layer 3211 over the insulating layer 3224 and the conductive layer 3221, a metal oxide layer 3231 over the insulating layer 3211, and a conductive layer 3222a over the metal oxide layer 3231. A conductive layer 3222b over the metal oxide layer 3231; an insulating layer 3212 over the metal oxide layer 3231, a conductive layer 3222a, and a conductive layer 3222b; a conductive layer 3223 over the insulating layer 3212; An insulating layer 3213 over the layer 3223.

In addition, the insulating layer 3211 and the insulating layer 3212 have an opening 3235. The conductive layer 3223 is electrically connected to the conductive layer 3221 through the opening 3235.

Here, the insulating layer 3211 functions as the first gate insulating layer of the transistor 3200a, the insulating layer 3212 functions as the second gate insulating layer of the transistor 3200a, and the insulating layer 3213 includes: The transistor 3200a functions as a protective insulating layer. In the transistor 3200a, the conductive layer 3221 functions as a first gate, the conductive layer 3222a functions as one of a source and a drain, and the conductive layer 3222b serves as the other of the source and the drain. It has the function of. In the transistor 3200a, the conductive layer 3223 functions as a second gate.

Note that the transistor 3200a is a so-called channel etch transistor and has a dual-gate structure.

The transistor 3200a can be formed without the conductive layer 3223. In this case, the transistor 3200a is a so-called channel etch transistor and has a bottom gate structure.

As shown in FIGS. 19B and 19C, the metal oxide layer 3231 is located so as to face the conductive layer 3221 and the conductive layer 3223, and is sandwiched between conductive layers having functions of two gates. Yes. The length of the conductive layer 3223 in the channel length direction is longer than the length of the metal oxide layer 3231 in the channel length direction, and the length of the conductive layer 3223 in the channel width direction is longer than the length of the metal oxide layer 3231 in the channel width direction. It is getting longer. The entire metal oxide layer 3231 is covered with the conductive layer 3223 with the insulating layer 3212 interposed therebetween.

In other words, the conductive layer 3221 and the conductive layer 3223 have a region which is connected to the opening 3235 provided in the insulating layer 3211 and the insulating layer 3212 and located outside the side end portion of the metal oxide layer 3231.

With such a structure, the metal oxide layer 3231 included in the transistor 3200a can be electrically surrounded by the electric fields of the conductive layers 3221 and 3223. A device structure of a transistor in which a metal oxide layer in which a channel region is formed is electrically surrounded by an electric field of a first gate and a second gate as in the transistor 3200a is a surrounded channel (s-channel) structure. Can do.

Since the transistor 3200a has an s-channel structure, an electric field for inducing a channel by the conductive layer 3221 having a first gate function can be effectively applied to the metal oxide layer 3231. Therefore, the current driving capability of the transistor 3200a is improved, and high on-current characteristics can be obtained. Further, since the on-state current can be increased, the transistor 3200a can be miniaturized. The transistor 3200a has a structure in which the metal oxide layer 3231 is surrounded by the conductive layer 3221 having the function of the first gate and the conductive layer 3223 having the function of the second gate. Strength can be increased.

For example, the metal oxide layer 3231 includes In and M (M is gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, and cerium. , Neodymium, hafnium, tantalum, tungsten, or magnesium) and Zn.

The metal oxide layer 3231 preferably includes a region where the atomic ratio of In is larger than the atomic ratio of M. As an example, the ratio of the number of In, M, and Zn atoms in the metal oxide layer 3231 is preferably in the vicinity of In: M: Zn = 4: 2: 3. Here, in the vicinity, when In is 4, M is 1.5 or more and 2.5 or less, and Zn is 2 or more and 4 or less. Alternatively, the ratio of the number of In, M, and Zn atoms in the metal oxide layer 3231 is preferably in the vicinity of In: M: Zn = 5: 1: 6.

The metal oxide layer 3231 is preferably a CAC-OS. When the metal oxide layer 3231 has a region where the atomic ratio of In is larger than the atomic ratio of M and is a CAC-OS, the field-effect mobility of the transistor 3200a can be increased. Details of the CAC-OS will be described later.

Further, since the transistor 3200a having an s-channel structure has high field effect mobility and high driving capability, by using the transistor 3200a for a driver circuit, typically a gate driver for generating a gate signal, the frame width can be reduced. A narrow display device (also referred to as a narrow frame) can be provided. In addition, when the transistor 3200a is used for a source driver (particularly, a demultiplexer connected to an output terminal of a shift register included in the source driver) that supplies a signal from a signal line included in the display device, the transistor 3200a is connected to the display device. A display device with a small number of wirings can be provided.

Further, since each of the transistors 3200a is a channel-etched transistor, the number of manufacturing steps is smaller than that of a transistor using low-temperature polysilicon. In addition, since the transistor 3200a uses a metal oxide layer for a channel, a laser crystallization step is unnecessary unlike a transistor using low-temperature polysilicon. Therefore, manufacturing cost can be reduced even in a display device using a large-area substrate. Furthermore, in high-resolution displays such as Ultra Hi-Vision (“4K resolution”, “4K2K”, “4K”) and Super Hi-Vision (“8K resolution”, “8K4K”, “8K”), and in large display devices, transistors Using a transistor with high field-effect mobility such as 3200a for a driver circuit and a display portion is preferable because writing in a short time can be performed and display defects can be reduced.

The insulating layer 3211 and the insulating layer 3212 which are in contact with the metal oxide layer 3231 are preferably oxide insulating films and have a region containing excess oxygen (excess oxygen region) than the stoichiometric composition. Is more preferable. In other words, the insulating layer 3211 and the insulating layer 3212 are insulating films capable of releasing oxygen. Note that in order to provide an excess oxygen region in the insulating layer 3211 and the insulating layer 3212, for example, the insulating layer 3211 and the insulating layer 3212 are formed in an oxygen atmosphere, or the insulating layer 3211 and the insulating layer 3212 after film formation are oxygenated. Heat treatment may be performed in an atmosphere.

As the metal oxide layer 3231, an oxide semiconductor which is a kind of metal oxide can be used.

In the case where the metal oxide layer 3231 is an In-M-Zn oxide, the atomic ratio of the metal elements of the sputtering target used for forming the In-M-Zn oxide preferably satisfies In> M. As the atomic ratio of the metal elements of such a sputtering target, In: M: Zn = 2: 1: 3, In: M: Zn = 3: 1: 2, In: M: Zn = 4: 2: 4. 1, In: M: Zn = 5: 1: 6, In: M: Zn = 5: 1: 7, In: M: Zn = 5: 1: 8, In: M: Zn = 6: 1: 6, In: M: Zn = 5: 2: 5 etc. are mentioned.

In the case where the metal oxide layer 3231 is formed using In-M-Zn oxide, a target including polycrystalline In-M-Zn oxide is preferably used as the sputtering target. By using a target including a polycrystalline In-M-Zn oxide, the metal oxide layer 3231 having crystallinity can be easily formed. Note that the atomic ratio of the metal oxide layer 3231 to be formed includes a variation of plus or minus 40% of the atomic ratio of the metal element included in the sputtering target. For example, when the composition of the sputtering target used for the metal oxide layer 3231 is In: Ga: Zn = 4: 2: 4.1 [atomic ratio], the composition of the metal oxide layer 3231 to be formed is In: It may be in the vicinity of Ga: Zn = 4: 2: 3 [atomic ratio].

The metal oxide layer 3231 has an energy gap of 2 eV or more, preferably 2.5 eV or more. In this manner, off-state current of a transistor can be reduced by using an oxide semiconductor with a wide energy gap.

The metal oxide layer 3231 preferably has a non-single crystal structure. The non-single-crystal structure includes, for example, CAAC (C Axis Aligned Crystalline), a polycrystalline structure, a microcrystalline structure, or an amorphous structure. In a non-single crystal structure, an amorphous structure has the highest defect level density, and CAAC has the lowest defect level density.

As the metal oxide layer 3231, a metal oxide film with a low impurity concentration and a low density of defect states is preferably used because a transistor having excellent electrical characteristics can be manufactured. Here, low impurity concentration and low defect level density (low oxygen deficiency) are referred to as high purity intrinsic or substantially high purity intrinsic. Note that typical examples of impurities in the metal oxide film include water and hydrogen. In this specification and the like, reducing or removing water and hydrogen from a metal oxide film is sometimes referred to as dehydration or dehydrogenation. In addition, the addition of oxygen to a metal oxide film or an oxide insulating film is sometimes referred to as oxygenation, and the state of oxygenation and excessive oxygen in excess of the stoichiometric composition is exceeded. Sometimes expressed as an oxygenated state.

A metal oxide film that is highly purified intrinsic or substantially highly purified intrinsic has few carrier generation sources, and thus can have a low carrier density. Therefore, a transistor in which a channel region is formed in the metal oxide film rarely has electrical characteristics (also referred to as normally-on) in which the threshold voltage is negative. In addition, since a highly purified intrinsic or substantially highly purified intrinsic metal oxide film has a low defect level density, the trap level density may also be low. In addition, a highly pure intrinsic or substantially highly purified intrinsic metal oxide film has an extremely small off-state current, a channel width of 1 × 10 ⁶ μm, and a channel length L of 10 μm. When the voltage between the drain electrodes (drain voltage) is in the range of 1V to 10V, it is possible to obtain a characteristic that the off-current is less than the measurement limit of the semiconductor parameter analyzer, that is, 1 × 10 ⁻¹³ A or less.

The insulating layer 3213 includes one or both of hydrogen and nitrogen. Alternatively, the insulating layer 3213 includes nitrogen and silicon. The insulating layer 3213 has a function of blocking oxygen, hydrogen, water, alkali metal, alkaline earth metal, or the like. By providing the insulating layer 3213, diffusion of oxygen from the metal oxide layer 3231 to the outside, diffusion of oxygen contained in the insulating layer 3212 to the outside, hydrogen, water, and the like from the outside to the metal oxide layer 3231 Can be prevented from entering.

As the insulating layer 3213, for example, a nitride insulating film can be used. Examples of the nitride insulating film include silicon nitride, silicon nitride oxide, aluminum nitride, and aluminum nitride oxide.

<3-2. OS Transistor Configuration Example 2>
Next, as an example of the structure of the transistor, a transistor 3200b will be described with reference to FIGS. 20A, 20B, and 20C. FIG. 20A is a top view of the transistor 3200b. 20B corresponds to a cross-sectional view of a cross-sectional surface taken along the dashed-dotted line X1-X2 in FIG. 20A, and FIG. 20C is between the dashed-dotted line Y1-Y2 shown in FIG. This corresponds to a cross-sectional view of the cut surface in FIG.

The transistor 3200b is different from the transistor 3200a in that the metal oxide layer 3231, the conductive layer 3222a, the conductive layer 3222b, and the insulating layer 3212 have a stacked structure.

The insulating layer 3212 includes an insulating layer 3212a over the metal oxide layer 3231, the conductive layer 3222a, and the conductive layer 3222b, and an insulating layer 3212b over the insulating layer 3212a. The insulating layer 3212 has a function of supplying oxygen to the metal oxide layer 3231. That is, the insulating layer 3212 contains oxygen. The insulating layer 3212a is an insulating layer that can transmit oxygen. Note that the insulating layer 3212a also functions as a damage reducing film for the metal oxide layer 3231 when an insulating layer 3212b to be formed later is formed.

As the insulating layer 3212a, silicon oxide, silicon oxynitride, or the like with a thickness of 5 nm to 150 nm, preferably 5 nm to 50 nm can be used.

The insulating layer 3212a preferably has a small amount of defects. Typically, the ESR measurement shows that the spin density of a signal appearing at g = 2.001 derived from a dangling bond of silicon is 3 × 10 ¹⁷ spins / It is preferable that it is cm ³ or less. This is because when the density of defects included in the insulating layer 3212a is large, oxygen is bonded to the defects and oxygen permeability in the insulating layer 3212a is reduced.

Note that in the insulating layer 3212a, not all oxygen that enters the insulating layer 3212a from the outside moves to the outside of the insulating layer 3212a, and some oxygen remains in the insulating layer 3212a. Further, oxygen enters the insulating layer 3212a and oxygen contained in the insulating layer 3212a moves to the outside of the insulating layer 3212a, so that oxygen may move in the insulating layer 3212a. When an oxide insulating layer that can transmit oxygen is formed as the insulating layer 3212a, oxygen released from the insulating layer 3212b provided over the insulating layer 3212a is transferred to the metal oxide layer 3231 through the insulating layer 3212a. Can be made.

The insulating layer 3212a can be formed using an oxide insulating layer having a low level density due to nitrogen oxides. Note that the level density caused by the nitrogen oxide can be formed between the energy (Ev_os) at the upper end of the valence band of the metal oxide film and the energy (Ec_os) at the lower end of the conduction band of the metal oxide film. There is a case. As the oxide insulating layer, a silicon oxynitride film with a low emission amount of nitrogen oxide, an aluminum oxynitride film with a low emission amount of nitrogen oxide, or the like can be used.

Note that a silicon oxynitride film with a small amount of released nitrogen oxide is a film having a larger amount of released ammonia than a released amount of nitrogen oxide in a thermal desorption gas analysis (TDS) method. Specifically, the released amount of ammonia is 1 × 10 ¹⁸ / cm ³ or more and 5 × 10 ¹⁹ / cm ³ or less. Note that the amount of ammonia released is the amount released by heat treatment at a film surface temperature of 50 ° C. to 650 ° C., preferably 50 ° C. to 550 ° C.

Nitrogen oxide (NO _x , x is larger than 0 and 2 or less, preferably 1 or more and 2 or less), typically NO ₂ or NO forms a level in the insulating layer 3212a or the like. The level is located in the energy gap of the metal oxide layer 3231. Therefore, when nitrogen oxide diffuses to the interface between the insulating layer 3212a and the metal oxide layer 3231, the level may trap electrons on the insulating layer 3212a side. As a result, trapped electrons remain in the vicinity of the interface between the insulating layer 3212a and the metal oxide layer 3231, so that the threshold voltage of the transistor is shifted in the positive direction.

Nitrogen oxide reacts with ammonia and oxygen in heat treatment. Since nitrogen oxide contained in the insulating layer 3212a reacts with ammonia contained in the insulating layer 3212b in the heat treatment, nitrogen oxide contained in the insulating layer 3212a is reduced. Therefore, electrons are hardly trapped at the interface between the insulating layer 3212a and the metal oxide layer 3231.

By using the oxide insulating layer as the insulating layer 3212a, a shift in threshold voltage of the transistor can be reduced, and fluctuation in electric characteristics of the transistor can be reduced.

The oxide insulating layer has a nitrogen concentration of 6 × 10 ²⁰ atoms / cm ³ or less as measured by SIMS.

By forming the oxide insulating layer using a PECVD method using silane and dinitrogen monoxide with a substrate temperature of 220 ° C. or higher and 350 ° C. or lower, a dense and high hardness film is formed. be able to.

The insulating layer 3212b is an oxide insulating layer containing more oxygen than oxygen that satisfies the stoichiometric composition. Part of oxygen is released from the oxide insulating layer by heating. Note that in TDS, the above oxide insulating layer has a region where the amount of released oxygen is 1.0 × 10 ¹⁹ atoms / cm ³ or more, preferably 3.0 × 10 ²⁰ atoms / cm ³ or more. The amount of released oxygen is the total amount when the temperature of the heat treatment in TDS is 50 ° C. or higher and 650 ° C. or lower, or 50 ° C. or higher and 550 ° C. or lower. The amount of released oxygen is the total amount in terms of oxygen atoms in TDS.

As the insulating layer 3212b, silicon oxide, silicon oxynitride, or the like with a thickness of 30 nm to 500 nm, preferably 50 nm to 400 nm can be used.

The insulating layer 3212b preferably has a small amount of defects. Typically, the ESR measurement shows that the spin density of a signal appearing at g = 2.001 derived from dangling bonds in silicon is 1.5 × 10 ^18. It is preferably less than spins / cm ³ and more preferably 1 × 10 ¹⁸ spins / cm ³ or less. Note that the insulating layer 3212b is farther from the metal oxide layer 3231 than the insulating layer 3212a, and thus may have a higher defect density than the insulating layer 3212a.

Further, since the insulating layer 3212 can be formed using the same kind of insulating layer, the interface between the insulating layer 3212a and the insulating layer 3212b may not be clearly confirmed in some cases. Therefore, in this embodiment, the interface between the insulating layer 3212a and the insulating layer 3212b is illustrated by a broken line. Note that although a two-layer structure of the insulating layer 3212a and the insulating layer 3212b has been described in this embodiment mode, the present invention is not limited thereto, and for example, a single-layer structure of the insulating layer 3212a or a stacked structure of three or more layers may be used. Good.

In the transistor 3200b, the metal oxide layer 3231 includes a metal oxide layer 3231_1 over the insulating layer 3211 and a metal oxide layer 3231_2 over the metal oxide layer 3231_1. Note that the metal oxide layer 3231_1 and the metal oxide layer 3231_2 each have the same element. For example, the metal oxide layer 3231_1 and the metal oxide layer 3231_2 preferably each independently include the element included in the above-described metal oxide layer 3231.

The metal oxide layer 3231_1 and the metal oxide layer 3231_2 preferably each independently have a region in which the atomic ratio of In is larger than the atomic ratio of M. As an example, the ratio of the number of In, M, and Zn atoms in the metal oxide layer 3231_1 and the metal oxide layer 3231_2 is preferably in the vicinity of In: M: Zn = 4: 2: 3. Here, in the vicinity, when In is 4, M is 1.5 or more and 2.5 or less, and Zn is 2 or more and 4 or less. Alternatively, the ratio of the number of In, M, and Zn atoms in the metal oxide layer 3231_1 and the metal oxide layer 3231_2 is preferably in the vicinity of In: M: Zn = 5: 1: 6. Thus, when the metal oxide layer 3231_1 and the metal oxide layer 3231_2 have substantially the same composition, the same sputtering target can be used, so that manufacturing costs can be suppressed. In the case where the same sputtering target is used, the metal oxide layer 3231_1 and the metal oxide layer 3231_2 can be successively formed in a vacuum in the same chamber; thus, the metal oxide layer 3231_1 and the metal oxide layer 3231_2 are formed. Impurities can be prevented from being taken into the interface.

Here, the metal oxide layer 3231_1 may have a region with lower crystallinity than the metal oxide layer 3231_2. Note that the crystallinity of the metal oxide layer 3231_1 and the metal oxide layer 3231_2 can be analyzed using, for example, X-ray diffraction (XRD: X-Ray Diffraction) or transmission electron microscope (TEM: Transmission Electron Microscope). ) Can be used for analysis.

A region where the crystallinity of the metal oxide layer 3231_1 is low serves as a diffusion path of excess oxygen, and excess oxygen can be diffused also into the metal oxide layer 3231_2 having higher crystallinity than the metal oxide layer 3231_1. In this manner, a highly reliable transistor can be provided by using a stacked structure of metal oxide layers having different crystal structures and using a region with low crystallinity as a diffusion path of excess oxygen.

In addition, since the metal oxide layer 3231_2 includes a region with higher crystallinity than the metal oxide layer 3231_1, impurities that can be mixed into the metal oxide layer 3231 can be suppressed. In particular, by increasing the crystallinity of the metal oxide layer 3231_2, damage when the conductive layers 3222a and 3222b are processed can be suppressed. The surface of the metal oxide layer 3231, that is, the surface of the metal oxide layer 3231_2 is exposed to an etchant or an etching gas when the conductive layers 3222a and 3222b are processed. However, in the case where the metal oxide layer 3231_2 has a region with high crystallinity, the metal oxide layer 3231_2 has excellent etching resistance as compared with the metal oxide layer 3231_1 with low crystallinity. Therefore, the metal oxide layer 3231_2 functions as an etching stopper.

In addition, the metal oxide layer 3231_1 has a region with lower crystallinity than the metal oxide layer 3231_2, so that the carrier density may be increased.

Further, when the carrier density of the metal oxide layer 3231_1 is increased, the Fermi level may be relatively higher than the conduction band of the metal oxide layer 3231_1. Accordingly, the lower end of the conduction band of the metal oxide layer 3231_1 is lowered, and the energy between the lower end of the conduction band of the metal oxide layer 3231_1 and the trap level that can be formed in the gate insulating film (the insulating layer 3211 in this case). The difference may be large. When the energy difference is increased, the charge trapped in the gate insulating film is reduced, and the variation in the threshold voltage of the transistor may be reduced in some cases. Further, when the carrier density of the metal oxide layer 3231_1 is increased, the field-effect mobility of the metal oxide layer 3231 can be increased.

Note that in the transistor 3200b, the example in which the metal oxide layer 3231 has a two-layer structure is described; however, the present invention is not limited to this, and a structure in which three or more layers are stacked may be employed.

A conductive layer 3222a included in the transistor 3200b includes a conductive layer 3222a_1, a conductive layer 3222a_2 over the conductive layer 3222a_1, and a conductive layer 3222a_3 over the conductive layer 3222a_2. The conductive layer 3222b included in the transistor 3200b includes a conductive layer 3222b_1, a conductive layer 3222b_2 over the conductive layer 3222b_1, and a conductive layer 3222b_3 over the conductive layer 3222b_2.

For example, the conductive layer 3222a_1, the conductive layer 3222b_1, the conductive layer 3222a_3, and the conductive layer 3222b_3 include one or more selected from titanium, tungsten, tantalum, molybdenum, indium, gallium, tin, and zinc. It is preferable. The conductive layer 3222a_2 and the conductive layer 3222b_2 preferably include any one or more selected from copper, aluminum, and silver.

More specifically, an In—Sn oxide or an In—Zn oxide is used for the conductive layer 3222a_1, the conductive layer 3222b_1, the conductive layer 3222a_3, and the conductive layer 3222b_3, and copper is used for the conductive layer 3222a_2 and the conductive layer 3222b_2. it can.

The end portion of the conductive layer 3222a_1 has a region located outside the end portion of the conductive layer 3222a_2, and the conductive layer 3222a_3 covers a top surface and a side surface of the conductive layer 3222a_2 and is in contact with the conductive layer 3222a_1. Have. The end portion of the conductive layer 3222b_1 has a region located outside the end portion of the conductive layer 3222b_2, and the conductive layer 3222b_3 covers a top surface and side surfaces of the conductive layer 3222b_2 and is in contact with the conductive layer 3222b_1. Have.

The above structure is preferable because the wiring resistance of the conductive layers 3222a and 3222b can be reduced and copper diffusion into the metal oxide layer 3231 can be suppressed.

<3-3. OS Transistor Configuration Example 3>
Next, as an example of the structure of the transistor, a transistor 3200c will be described with reference to FIGS. FIG. 21A is a top view of the transistor 3200c. 21B corresponds to a cross-sectional view of a cross-sectional surface taken along the dashed-dotted line X1-X2 in FIG. 21A, and FIG. 21C is between the dashed-dotted line Y1-Y2 shown in FIG. This corresponds to a cross-sectional view of the cut surface in FIG.

A transistor 3200c illustrated in FIGS. 21A, 21B, and 21C includes a conductive layer 3221 over the insulating layer 3224, an insulating layer 3211 over the conductive layer 3221, and a metal oxide layer 3231 over the insulating layer 3211. The insulating layer 3212 over the metal oxide layer 3231, the conductive layer 3223 over the insulating layer 3212, the insulating layer 3211, the metal oxide layer 3231, and the insulating layer 3213 over the conductive layer 3223 are included. Note that the metal oxide layer 3231 includes a channel region 3231 i overlapping with the conductive layer 3223, a source region 3231 s in contact with the insulating layer 3213, and a drain region 3231 d in contact with the insulating layer 3213.

The insulating layer 3213 contains nitrogen or hydrogen. When the insulating layer 3213 is in contact with the source region 3231s and the drain region 3231d, nitrogen or hydrogen in the insulating layer 3213 is added to the source region 3231s and the drain region 3231d. In the source region 3231s and the drain region 3231d, carrier density is increased by adding nitrogen or hydrogen.

The transistor 3200c includes an insulating layer 3215 over the insulating layer 3213, a conductive layer 3222a electrically connected to the source region 3231s through the insulating layer 3213 and an opening 3236a provided in the insulating layer 3215, and an insulating layer The conductive layer 3222b electrically connected to the drain region 3231d may be provided through an opening 3236b provided in the layer 3213 and the insulating layer 3215.

As the insulating layer 3215, an oxide insulating film can be used. As the insulating layer 3215, a stacked film of an oxide insulating film and a nitride insulating film can be used. As the insulating layer 3215, for example, silicon oxide, silicon oxynitride, silicon nitride oxide, aluminum oxide, hafnium oxide, gallium oxide, Ga—Zn oxide, or the like may be used. The insulating layer 3215 is preferably a film that functions as an external barrier film such as hydrogen or water.

The insulating layer 3211 has a function as a first gate insulating film, and the insulating layer 3212 has a function as a second gate insulating film. The insulating layers 3213 and 3215 function as protective insulating films.

The insulating layer 3212 has an excess oxygen region. When the insulating layer 3212 includes the excess oxygen region, excess oxygen can be supplied to the channel region 3231i included in the metal oxide layer 3231. Accordingly, oxygen vacancies that can be formed in the channel region 3231i can be filled with excess oxygen, so that a highly reliable semiconductor device can be provided.

Note that in order to supply excess oxygen into the metal oxide layer 3231, excess oxygen may be supplied to the insulating layer 3211 formed below the metal oxide layer 3231. In this case, excess oxygen contained in the insulating layer 3211 can be supplied to the source region 3231s and the drain region 3231d included in the metal oxide layer 3231. When excess oxygen is supplied into the source region 3231s and the drain region 3231d, the resistance of the source region 3231s and the drain region 3231d may be increased.

On the other hand, with the structure in which excess oxygen is included in the insulating layer 3212 formed above the metal oxide layer 3231, excess oxygen can be selectively supplied only to the channel region 3231i. Alternatively, after excess oxygen is supplied to the channel region 3231i, the source region 3231s, and the drain region 3231d, the carrier density of the source region 3231s and the drain region 3231d is selectively increased, so that the source region 3231s and the drain region 3231d It can suppress that resistance becomes high.

The source region 3231s and the drain region 3231d included in the metal oxide layer 3231 preferably each include an element that forms oxygen vacancies or an element that combines with oxygen vacancies. As an element that forms oxygen vacancies or an element that combines with oxygen vacancies, typically, hydrogen, boron, carbon, nitrogen, fluorine, phosphorus, sulfur, chlorine, titanium, a rare gas, or the like can be given. Typical examples of rare gas elements include helium, neon, argon, krypton, and xenon. In the case where one or more elements that form oxygen vacancies are included in the insulating layer 3213, the insulating layer 3213 diffuses from the insulating layer 3213 to the source region 3231s and the drain region 3231d, and / or the source region 3231s is subjected to impurity addition treatment, and It is added into the drain region 3231d.

When the impurity element is added to the oxide semiconductor film, the bond between the metal element and oxygen in the oxide semiconductor film is cut, so that an oxygen vacancy is formed. Alternatively, when an impurity element is added to the oxide semiconductor film, oxygen bonded to the metal element in the oxide semiconductor film is bonded to the impurity element, so that oxygen is released from the metal element and oxygen vacancies are formed. The As a result, the carrier density in the oxide semiconductor film is increased and the conductivity is increased.

The conductive layer 3221 has a function as a first gate electrode, the conductive layer 3223 has a function as a second gate electrode, the conductive layer 3222a has a function as a source electrode, The conductive layer 3222b functions as a drain electrode.

In addition, as illustrated in FIG. 21C, the insulating layer 3211 and the insulating layer 3212 are provided with openings 3237. In addition, the conductive layer 3221 is electrically connected to the conductive layer 3223 through the opening 3237. Therefore, the same potential is applied to the conductive layer 3221 and the conductive layer 3223. Note that different potentials may be applied to the conductive layer 3221 and the conductive layer 3223 without providing the opening 3237. Alternatively, the conductive layer 3221 may be used as the light-blocking film without providing the opening 3237. For example, when the conductive layer 3221 is formed using a light-blocking material, light from below irradiated to the channel region 3231i can be suppressed.

21B and 21C, the metal oxide layer 3231 includes a conductive layer 3221 functioning as a first gate electrode and a conductive layer 3223 functioning as a second gate electrode. It is located so as to face each other and is sandwiched between conductive films functioning as two gate electrodes.

The transistor 3200c has an S-channel structure similarly to the transistors 3200a and 3200b. With such a structure, the metal oxide layer 3231 included in the transistor 3200c is electrically converted by an electric field of the conductive layer 3221 functioning as the first gate electrode and the conductive layer 3223 functioning as the second gate electrode. Can be surrounded.

Since the transistor 3200c has an S-channel structure, an electric field for inducing a channel by the conductive layer 3221 or the conductive layer 3223 can be effectively applied to the metal oxide layer 3231; thus, the current driving capability of the transistor 3200c Thus, high on-current characteristics can be obtained. In addition, since the on-state current can be increased, the transistor 3200c can be miniaturized. In addition, since the transistor 3200c has a structure in which the metal oxide layer 3231 is surrounded by the conductive layer 3221 and the conductive layer 3223, the mechanical strength of the transistor 3200c can be increased.

Note that the transistor 3200c may be referred to as a TGSA (Top Gate Self Align) FET because of the position of the conductive layer 3223 with respect to the metal oxide layer 3231 or the formation method of the conductive layer 3223.

Note that the transistor 3200c may have a structure in which two or more metal oxide layers 3231 are stacked as in the transistor 3200b.

In the transistor 3200c, the insulating layer 3212 is provided only in a portion overlapping with the conductive layer 3223; however, the present invention is not limited to this, and the insulating layer 3212 can cover the metal oxide layer 3231. Alternatively, the conductive layer 3221 may be omitted.

<3-4. Configuration of CAC-OS>
A structure of a CAC-OS that can be used for the transistor disclosed in one embodiment of the present invention is described below.

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

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

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

That, CAC-OS includes a region _{GaO X3} is the main _component, and In _{X2 Zn} Y2 _{O Z2,} or _{InO X1} is the main component region is a composite oxide semiconductor having a structure that is mixed. Note that in this specification, for example, the first region indicates that the atomic ratio of In to the element M in the first region is larger than the atomic ratio of In to the element M in the second region. It is assumed that the concentration of In is higher than that in the second region.

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

The crystalline compound has a single crystal structure, a polycrystalline structure, or a CAAC (C-Axis Crystalline Oxide Semiconductor or C-Axis Aligned and A-B-Plane Attached Crystal Oxidon Secon. The CAAC structure is a crystal structure in which a plurality of IGZO nanocrystals have c-axis orientation and are connected without being oriented in the ab plane.

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

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

Incidentally, a region _{GaO X3} is the main _component, and In _{X2 Zn} Y2 _{O Z2} or _{InO X1} is the main component region, in some cases clear boundary can not be observed.

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

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

The CAC-OS is characterized in that no clear peak is observed when it is measured using a θ / 2θ scan by the out-of-plane method, which is one of the X-ray diffraction (XRD) measurement methods. Have. That is, it can be seen from X-ray diffraction that no orientation in the ab plane direction and c-axis direction of the measurement region is observed.

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

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

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

Here, the region containing In _X2 Zn _Y2 O _Z2 or InO _X1 as a main component is a region having higher conductivity than the region containing GaO _X3 or the like as a main component. _That, In _{X2 Zn} Y2 _{O Z2} or _{InO X1,} is an area which is the main component, by carriers flow, expressed the conductivity of the oxide semiconductor. Accordingly, a region where In _X2 Zn _Y2 O _Z2 or InO _X1 is a main component is distributed in a cloud shape in the oxide semiconductor, whereby high field-effect mobility (μ) can be realized.

On the other hand, regions _{GaO X3,} etc. as a main _component, as compared to the In _{X2 Zn} Y2 _{O Z2} or _{InO X1} is the main component area, it is highly regions insulating. That is, the region whose main component is GaO _X3 or the like is distributed in the oxide semiconductor, whereby leakage current can be suppressed and good switching operation can be realized.

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

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

This embodiment can be implemented in combination with any of the structures described in the other embodiments or examples as appropriate.

(Embodiment 4)
In this embodiment, electronic devices to which the display device of one embodiment of the present invention can be applied will be described.

Examples of electronic devices to which the display device of one embodiment of the present invention can be applied include a television device, a desktop or notebook personal computer, a monitor for a computer, a digital camera, a digital video camera, a digital photo frame, a mobile phone, and the like. Examples thereof include a large game machine such as a telephone, a portable game machine, a portable information terminal, a sound reproducing device, and a pachinko machine.

22A, 22B, and 22C show a portable information terminal. The portable information terminal of the present embodiment has one or more functions selected from, for example, a telephone, a notebook, an information browsing device, or the like. Specifically, it can be used as a smartphone or a smart watch. The portable information terminal of the present embodiment can execute various applications such as mobile phone, e-mail, text browsing and creation, music playback, video playback, Internet communication, and games.
The portable information terminal illustrated in FIGS. 22A, 22B, and 22C can have a variety of functions. For example, a function for displaying various information (still images, moving images, text images, etc.) on a display unit, a touch panel function, a function for displaying a calendar, date or time, a function for controlling processing by various software (programs), Wireless communication function, function for connecting to various computer networks using the wireless communication function, function for transmitting or receiving various data using the wireless communication function, and reading and displaying the program or data recorded on the recording medium It can have a function of displaying on the section. Note that the functions of the portable information terminal illustrated in FIGS. 22A, 22B, and 22C are not limited to these, and may have other functions.

The portable information terminal shown in FIGS. 22A, 22B, and 22C can execute various applications such as mobile phone, e-mail, text browsing and creation, music playback, Internet communication, and computer games. . In addition, the portable information terminal shown in FIGS. 22A, 22B, and 22C can execute short-range wireless communication with a communication standard. For example, the wristwatch-type portable information terminal 820 illustrated in FIG. 22C can talk hands-free by communicating with a headset capable of wireless communication.

A portable information terminal 800 illustrated in FIG. 22A includes a housing 811, a display portion 812, operation buttons 813, an external connection port 814, a speaker 815, a microphone 816, and the like. Display unit 812 of portable information terminal 800 has a flat surface.

A portable information terminal 810 illustrated in FIG. 22B includes a housing 811, a display portion 812, operation buttons 813, an external connection port 814, a speaker 815, a microphone 816, a camera 817, and the like. The display unit 812 of the portable information terminal 810 has a curved surface.

FIG. 22C illustrates a wristwatch-type portable information terminal 820. The portable information terminal 820 includes a housing 811, a display portion 812, a speaker 815, operation keys 818 (including a power switch or an operation switch), and the like. The external shape of the display unit 812 of the portable information terminal 820 can be a circular shape. The display unit 812 of the portable information terminal has a flat surface. The operation key can also be referred to as an input device for operation.

The display device of one embodiment of the present invention can be used for the display portion 812. Thereby, a portable information terminal with reduced power consumption can be manufactured.

The portable information terminal of this embodiment includes a touch sensor in the display portion 812. All operations such as making a call or inputting characters can be performed by touching the display portion 812 with a finger, a stylus, or the like.

In addition, 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, the mail creation screen can be switched to the main menu screen.

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

A computer 830 illustrated in FIG. 22D includes a main body 831, a housing 832, a display portion 833, a keyboard 834, an external connection port 835, a pointing device 836, and the like. Note that the computer is manufactured using the display device of one embodiment of the present invention for the display portion 833. Thus, a computer with reduced power consumption can be manufactured.

A camera 840 illustrated in FIG. 22E includes a housing 841, a display portion 842, operation buttons 843, a shutter button 844, and the like. A removable lens 846 is attached to the camera 840.

The display device of one embodiment of the present invention can be used for the display portion 842. Thereby, a camera with reduced power consumption can be manufactured.

Here, the camera 840 is configured such that the lens 846 can be removed from the housing 841 and replaced, but the lens 846 and the housing 841 may be integrated.

The camera 840 can capture a still image or a moving image by pressing the shutter button 844. In addition, the display portion 842 has a function as a touch panel and can capture an image by touching the display portion 842.

The camera 840 can be separately attached with a strobe device, a viewfinder, and the like. Alternatively, these may be incorporated in the housing 841.

In a television device 850 illustrated in FIG. 22F, a display portion 852 is incorporated in a housing 851. The display portion 852 can display an image. The display device of one embodiment of the present invention can be used for the display portion 852. Thus, a television device with reduced power consumption can be manufactured. Here, a configuration in which the casing 851 is supported by a stand 853 is shown.

The television device 850 can be operated with an operation switch provided in the housing 851 or a separate remote controller 861. The operation keys of the remote controller 861 can be used to perform channel and volume operations, and an image displayed on the display portion 852 can be operated. The remote controller 861 may be provided with a display unit that displays information output from the remote controller 861.

Note that the television set 850 is provided with a receiver, a modem, and the like. General TV broadcasts can be received by a receiver, and connected to a wired or wireless communication network via a modem, so that it can be unidirectional (sender to receiver) or bidirectional (sender and receiver). It is also possible to perform information communication between each other or between recipients.

This embodiment can be implemented in combination with any of the structures described in the other embodiments or examples as appropriate.

In the present embodiment, measurement results and the like regarding the characteristics of the display device 10 will be described. In the present embodiment, the display element 22 is a reflective liquid crystal, and the display element 24 is an OLED. In the following embodiments, the display element 22 is a reflective liquid crystal and the display element 24 is an OLED.

In this embodiment, the pixel 13 means a pixel having a function of displaying an image using the display element 24, and the pixel 43 is a pixel having a function of displaying an image using the display element 22. means. In the following embodiments, the pixel 13 means a pixel having a function of displaying an image using the display element 24, and the pixel 43 has a function of displaying an image using the display element 22. It may mean a pixel.

FIGS. 23A and 23B are photographs showing the configuration of the pixel 13 and the pixel 43 included in the display device 10 which has been measured in this embodiment. In the configuration shown in FIG. 23A, one pixel 13 has a display area 22Rd, a display area 22Gd, a display area 22Bd, a display area 24Rd, a display area 24Gd, and a display area 24Bd. That is, it can be said that the pixel density of the pixel 13 and the pixel density of the pixel 43 are equal.

In the configuration illustrated in FIG. 23B, one pixel 13 includes a display region 24Rd, a display region 24Gd, a display region 24Bd, and a display region 24Wd. On the other hand, one pixel 13 has only one of the display area 22Rd, the display area 22Gd, the display area 22Bd, and the display area 22Wd. That is, it is equivalent to the configuration shown in FIG. 3, and when the unit of pixel density is ppi, it can be said that the pixel density of the pixel 43 is ½ of the pixel density of the pixel 13.

In this embodiment, the reflectance of light incident on the display device 10 having the pixel structure shown in FIG. 23A and the reflection of light incident on the display device 10 having the pixel structure shown in FIG. The rate was measured. FIG. 24 shows a measurement system for the reflectance of the light.

In the measurement system shown in FIG. 24, the light projecting unit 61 is provided at a position where the polar angle is 30 °, and the light receiving unit 62 is provided at a position where the polar angle is 0 °. That is, the angle 63 between the light projecting unit 61 and the light receiving unit 62 is set to 30 °. The display unit 12 was irradiated with light from the light projecting unit 61, and the reflectance was measured based on the luminance of the light received by the light receiving unit 62. In this example, the reflectance of light incident on the standard white plate, measured by the measurement system shown in FIG. 24, was set to 100%. Also in the following examples, the reflectance of light incident on the standard white plate was set to 100%.

FIG. 25 is a graph showing the relationship between the reflectance of light incident on the display device 10 and the pixel density of the pixels 43. In FIG. 25, “reflection type liquid crystal display” indicates the reflectance in the reflection type liquid crystal display described in the document “D. Kubota, et al., Ekisho 20 (2), 85-91, 016-06-25”. It is the result plotted against the pixel density. In FIG. 25, a straight line passing through the plot “reflection type liquid crystal display” is indicated by a broken line.

The “display device 10 (estimation)” is the reflectance of the light incident on the display device 10 having the pixel having the configuration shown in FIG. 23A estimated from the straight line passing through the plot “reflection type liquid crystal display”. This is a result plotted with respect to the pixel density of the pixel 43. In FIG. 25, the reflectance when the pixel density of the pixel 13 and the pixel density of the pixel 43 are both 513 ppi and the reflectance when the pixel density of the pixel 13 and the pixel density of the pixel 43 are both 292 ppi are plotted. Yes. When the pixel density of the pixel 13 and the pixel 43 is 513 ppi, the reflectance is estimated to be 27%, and when the pixel density of the pixel 13 and the pixel 43 is 292 ppi, the reflectance is estimated to be 33%. Although not shown in FIG. 23A, the measured value measured by the measurement system shown in FIG. 24 of the reflectance when the pixel density of both the pixel 13 and the pixel 43 is 292 ppi is 34.3%. Met. Further, when the pixel density of both the pixel 13 and the pixel 43 is 292 ppi, the pixel pitch of the pixel 13 is 87 μm.

Further, “display device 10 (actual measurement)” is a plot of actual measurement values measured by the measurement system shown in FIG. 24 of the reflectance of light incident on the display device 10 having the pixel configuration shown in FIG. It is a result. The pixel density of the pixel 13 was 257 ppi, and the pixel density of the pixel 43 was 513 ppi. The pixel pitch of the pixels 13 was 49.5 μm.

The measured value of the reflectance of the light incident on the display device 10 having the configuration shown in FIG. 23B was 54.1%, which was higher than the estimated value.

FIG. 26 is a graph showing the relationship between the luminance of light emitted from the display element and the illuminance of the surrounding environment. In FIG. 26, “commercial OLED display” is an actual measurement value obtained by plotting the luminance of light emitted from an OLED in a commercially available OLED display against the illuminance of the surrounding environment. When the illuminance in the surrounding environment increases, the brightness of the OLED increases in order to improve visibility. In addition, since there is a limit to the luminance of light that can be emitted by the OLED, when the illuminance of the surrounding environment exceeds a certain value, the luminance of the light emitted by the OLED is saturated, and the contrast increases as the illuminance of the surrounding environment increases. descend.

The “display device 10 (display element 22)” indicates the relationship between the luminance of light reflected by the display element 22 included in the display device 10 and the illuminance of the surrounding environment. “Display device 10 (display element 24)” indicates the relationship between the luminance of light emitted from the display element 24 included in the display device 10 and the illuminance of the surrounding environment. In FIG. 26, the relationship between the luminance of light reflected by the display element 22 provided in the display device 10 including the pixel having the structure illustrated in FIG. 23A and the illuminance of the surrounding environment, and the display device 10 is provided. The relationship between the brightness | luminance of the light emitted from the displayed display element 24 and the illumination intensity of surrounding environment is shown. In FIG. 26, the relationship between the luminance of light reflected by the display element 22 provided in the display device 10 including the pixel having the configuration illustrated in FIG. 23B and the illuminance of the surrounding environment, and the display device 10. The relationship between the brightness | luminance of the light emitted from the display element 24 provided in, and the illumination intensity of surrounding environment is shown. In FIG. 26, the display device 10 having the pixel configuration shown in FIG. 23A is referred to as “(A)”, and the display device 10 having the pixel configuration shown in FIG. 23B is “(B)”. And

Note that as in the case where the reflectance of light incident on the display device 10 is actually measured, in the display device 10 including the pixel having the structure illustrated in FIG. 23A, the pixel density of the pixel 13 and the pixel density of the pixel 43 are any. And 292 ppi, and the pixel pitch of the pixels 13 was 87 μm × 87 μm. Further, as described above, the reflectance of the light incident on the display device 10 was 34.3%. In the display device 10 including the pixel having the structure illustrated in FIG. 23B, the pixel density of the pixel 13 is 513 ppi, the pixel density of the pixel 43 is 257 ppi, and the pixel pitch of the pixel 13 is 49.5 μm × 49.5 μm. Further, as described above, the reflectance of light incident on the display device 10 was 54.1%.

In the display device 10, the luminance of light reflected by the display element 22 increases as the illuminance in the surrounding environment increases. Thereby, the brightness | luminance of the display element 24 can be reduced. In particular, in the case where the display device 10 includes the pixel having the structure illustrated in FIG. 23B, the reflectance of light incident on the display device 10 is increased, whereby the luminance of the light reflected by the display element 22 is increased. 10 is higher than when the pixel has the structure shown in FIG. Therefore, the luminance of light emitted from the display element 24 in the case where the display device 10 includes the pixel having the structure illustrated in FIG. 23B is the luminance of the light emitted from the display element 24. The luminance of the light emitted from the display element 24 can be made lower. In the case where the display device 10 includes the pixel having the structure illustrated in FIG. 23B, an image having a luminance necessary for ensuring sufficient visibility even when the illuminance of the surrounding environment is 9000 lx or more without using the display element 24. It was confirmed that can be displayed.

Note that the structure described in this example can be combined as appropriate with any of the structures described in the other embodiments or examples.

In this embodiment, a display result when an image is displayed by the display device 10 having the configuration shown in FIG. 3 and optical characteristics of the display device 10 will be described.

Table 1 shows the specifications of the display device 10 that performed image display and measurement of optical characteristics. In Table 1, the display element 22 is expressed as R-LC, and the display element 24 is expressed as OLED. In the following embodiments, the display element 22 may be expressed as R-LC and the display element 24 may be expressed as OLED. In Table 1, the R-LC pixel indicates the pixel 43, and the OLED pixel indicates the pixel 13.

An image displayed using only the display element 22 is shown in FIG. 27A, and an image displayed using only the display element 24 is shown in FIG. In addition, the measurement results of the optical characteristics are shown in FIG. In FIG. 28, “R-LC mode” indicates a case where an image is displayed using only the display element 22, and “OLED mode” indicates a case where an image is displayed using only the display element 24.

As shown in FIGS. 27A and 27B, the image displayed by the display device 10 has good display quality both when the display element 22 is used and when the display element 24 is used. It was confirmed.

In addition, it is confirmed from FIG. 28 that the NTSC ratio of the display element 22 is 121% by forming the light emitting layer of the display element 24 by the RGB coating method and using a material corresponding to the color gamut of the BT2020 standard. It was done. The NTSC ratio of the display element 22 was 21%.

Note that the structure described in this example can be combined as appropriate with any of the structures described in the other embodiments or examples.

In the present embodiment, measurement results and the like regarding characteristics of the display device 10 having the pixel 13 having the configuration shown in FIG. 10 will be described.

FIG. 29A shows a display device having a pixel 13 having a configuration in which the display area 22Md shown in FIG. 10 is changed to the display area 22Rd, the display area 24Gd is changed to the display area 22Gd, and the display area 24Bd is changed to the display area 22Bd. This is the relationship between the reflectance, which is the ratio of light incident on the display device, reflected by the display element 22 and the like, and the wavelength of the incident light. In this embodiment, the pixel 13 having such a configuration is referred to as a pixel 13 having a conventional configuration. In the following embodiments, the pixel 13 having such a configuration may be referred to as a pixel 13 having a conventional configuration.

In the pixel 13 having the conventional configuration, the definition of the image displayed by the display element 22 is not different from the definition of the image displayed by the display element 24. In the pixel 13 having the conventional configuration, red, green, and blue light is emitted from both the display area 22d and the display area 24d.

FIG. 29B shows a reflectance which is a ratio of the light incident on the display device reflected by the display element 22 and the like and the incident light in the display device 10 having the pixel 13 having the structure shown in FIG. It is the relationship with the wavelength. That is, the definition of the image displayed by the display element 22 is not different from the definition of the image displayed by the display element 24. On the other hand, magenta, yellow, and cyan light are emitted from the display area 22d, and red, green, and blue light are emitted from the display area 24d.

In the display device 10 including the pixel 13 having the configuration illustrated in FIG. 10, the display region 22Cd can transmit blue light and green light, and the display region 22Md transmits blue light and red light. The display area 22Yd can transmit green light and red light. Accordingly, as shown in FIGS. 29A and 29B, the total reflectance of light having a wavelength of 380 nm to 780 nm incident on the pixel 13 having the configuration shown in FIG. 10 is incident on the pixel 13 having the conventional configuration. It was confirmed that the total reflectance of light having a wavelength of 380 nm to 780 nm was about twice as much.

FIG. 30A shows an image displayed using only the display element 22 in a display device having the pixel 13 having a conventional configuration. FIG. 30B shows an image displayed using only the display element 22 in the display device 10 including the pixel 13 having the configuration shown in FIG. Table 2 shows specifications of the display device 10 that displays the image shown in FIG.

As shown in FIGS. 30A and 30B, the display quality of the image displayed by the display device 10 having the pixel 13 having the configuration shown in FIG. 10 is displayed by the display device having the pixel 13 having the conventional configuration. Compared to the display quality of the image, it was confirmed that the quality was excellent.

Further, the dependency of the reflectance on the parallel light projection angle in the display device 10 having the specifications shown in Table 2 was measured. FIG. 31 is a schematic diagram showing a measurement system used when measuring the dependency of the reflectance on the parallel light projection angle. Light was irradiated from the light projecting unit 51 to the display unit 12, and the reflectance was measured based on the luminance of the light received by the light receiving unit 52. The angle between the display unit 12 and the light projecting unit 51 when the position parallel to the display unit 12 indicated by a broken line in FIG. The light receiving part 52 was provided in a direction perpendicular to the display part 12, and the parallel light projection angle dependency was measured by moving the light projection part to change the parallel light projection angle 53.

FIG. 32 shows the measurement result of the parallel light projection angle dependency of the vertically reflected light. In FIG. 32, RGB is a measurement result in the display device having the pixel 13 of the conventional configuration, and CMY is a measurement result in the display device 10 having the specifications shown in Table 2. As shown in FIG. 32, it is confirmed that the reflectance of light incident on the display device 10 having the pixel 13 having the configuration shown in FIG. 10 is about twice the reflectance of light incident on the pixel 13 having the conventional configuration. It was done.

FIG. 33A shows a measurement result of optical characteristics when an image is displayed using only the display element 22. FIG. 33B shows the measurement results of the optical characteristics when an image is displayed using only the display element 24. The optical characteristics shown in FIG. 33A were measured with a parallel projection angle of 30 ° and a light receiving portion position angle of 0 °.

33A and 33B, CMY is an optical characteristic in the display device 10 having the specifications shown in Table 2, and CMY-W indicates white coordinates when an image is displayed by the display device 10. In FIGS. 33A and 33B, RGB is an optical characteristic in a display device having a pixel 13 having a conventional configuration, and RGB-W indicates white coordinates when an image is displayed by the display device.

33A, in the display device 10 having the specifications shown in Table 2, the NTSC ratio of an image displayed using only the display element 22 is 19.1%, and the white coordinates are (0.350, 0.369). ). On the other hand, in the display device having the pixel 13 of the conventional configuration, it is confirmed that the NTSC ratio of the image displayed using only the display element 22 is 36.2% and the white coordinates are (0.344, 0.362). It was done.

33B, in the display device 10 having the specifications shown in Table 2, the NTSC ratio of the image displayed using only the display element 24 is 94%, and the white coordinates are (0.312, 0.331). It was confirmed that there was. On the other hand, in the display device having the pixel 13 of the conventional configuration, it was confirmed that the NTSC ratio of the image displayed using only the display element 24 is 103% and the white coordinates are (0.306, 0.334). .

Note that the structure described in this example can be combined as appropriate with any of the structures described in the other embodiments or examples.

In this example, measurement results and the like regarding characteristics of the display device 10 having the pixel 13 having the configuration shown in FIG. 11 will be described.

34A and 34B show results of displaying an image on the display device 10 having the pixel 13 having the configuration shown in FIG. FIG. 34A is an image displayed using only the display element 22, and FIG. 34B is an image displayed using only the display element 24. Table 3 shows the specifications of the display device 10 displaying the images shown in FIGS. 34 (A) and 34 (B). In Table 3, the R-LC pixel indicates the pixel 43, and the OLED pixel indicates the pixel 13.

As shown in FIGS. 34A and 34B, the image displayed by the display device 10 having the pixel 13 having the configuration shown in FIG. 11 is obtained when the display element 22 is used and when the display element 24 is used. In any of the cases, it was confirmed that the display quality was good.

FIG. 35A shows the measurement result of the parallel light projection angle dependency of the reflected light. FIG. 35B is a graph showing the relationship between the reflectance and the aperture ratio of the display element 22 (the ratio of the display region 22d to the area occupied by the pixel 43). The reflectance was measured by the measurement system shown in FIG.

35A and 35B, layout A shows a case where the pixel density of the pixel 43 is equal to the pixel density of the pixel 13, and layout B shows that the pixel density of the pixel 43 is equal to the pixel density of the pixel 13. The case where it is 1/2 is shown. RGB indicates a case where the pixel 43 includes the display area 22Rd, the display area 22Gd, and the display area 22Bd. RGBW indicates that the pixel 43 includes the display area 22Rd, the display area 22Gd, the display area 22Bd, and the display area 22Wd. The case where it has is shown. CMY indicates a case where the pixel 43 has a display area 22Cd, a display area 22Md, and a display area 22Yd. CMYW indicates that the pixel 43 has a display area 22Cd, a display area 22Md, a display area 22Yd, and a display area 22Wd. The case where it has is shown. That is, the layout A-RGB shows a case where the pixel 13 and the pixel 43 have the conventional configuration, and the layout A-CMY shows a case where the pixel 13 and the pixel 43 have the configuration shown in FIG. The layout B-RGBW shows a case where the pixel 13 and the pixel 43 have the configuration shown in FIG. 3, and the layout B-CMYW shows a case where the pixel 13 and the pixel 43 have the configuration shown in FIG. In the layout A-CMY, the specifications of the display device 10 are the same as in Table 2, and in the layout B-CMYW, the use of the display device 10 is the same as in Table 3.

35A and 35B, the layout B has a lower aperture ratio than the layout A, but it has been confirmed that the reflectance is increased by providing the display region 22Wd.

FIG. 36A shows the measurement result of the optical characteristics of the image displayed by the display device 10 having the pixel 13 and the pixel 43 configured as shown in FIG. FIG. 36B shows the measurement result of the optical characteristics of the image displayed by the display device 10 having the specifications shown in Table 3. The optical characteristics shown in FIGS. 36A and 36B were measured with a parallel projection angle of 30 ° and a light receiving portion position angle of 0 °.

36A and 36B, R-LC indicates optical characteristics of an image displayed using only the display element 22, and R-LC-W indicates an image displayed using only the display element 22. The white coordinates are shown. In FIGS. 36A and 36B, OLED indicates the optical characteristics of an image displayed using only the display element 24, and OLED-W indicates the white coordinate of the image displayed using only the display element 24. Indicates.

36A, in the display device 10 having the pixel 13 and the pixel 43 configured as shown in FIG. 3, the NTSC ratio of an image displayed using only the display element 22 is 18%, and the white coordinate is (0.344). , 0.372). On the other hand, it was confirmed that the NTSC ratio of an image displayed using only the display element 24 is 113% and the white coordinates are (0.310, 0.330).

36B, in the display device 10 having the specifications shown in Table 3, the NTSC ratio of an image displayed using only the display element 22 is 11%, and the white coordinates are (0.354, 0.373). It was confirmed. On the other hand, it was confirmed that the NTSC ratio of an image displayed using only the display element 24 is 94% and the white coordinates are (0.308, 0.329).

Note that the structure described in this example can be combined as appropriate with any of the structures described in the other embodiments or examples.

DESCRIPTION OF SYMBOLS 10 Display apparatus 12 Display part 13 Pixel 13a Subpixel 13b Subpixel 13c Subpixel 14a Gate driver circuit part 14b Gate driver circuit part 16a Source driver circuit part 16b Source driver circuit part 18 External circuit 22 Display element 22B Display element 22Bd Display area 22Cd Display area 22d Display area 22G Display element 22Gd Display area 22Md Display area 22R Display element 22Rd Display area 22Wd Display area 22Yd Display area 24 Display element 24B Display element 24Bd Display area 24d Display area 24G Display element 24Gd Display area 24R Display element 24Rd Display area 24 Wd Display area 30 EL layer 31 Conductive layer 32 Transflective layer 33 Hole transport layer 33R Hole transport layer 34B Light emitting layer 34G Light emitting layer 34R Light emitting layer 35 Electron transport layer 36 Conductive layer 43 Pixel 51 Projection unit 5 Receiving portion 53 parallel projection angle 61 light emitting portion 62 receiving portion 63 corner 112 LCD 113 electrode 117 insulating layer 121 insulating layer 131 a colored layer 132 light-shielding layer 133a alignment film 133b alignment film 135 functional member 141 adhesive layer 142 adhesive layer 164 IC
176 Touch sensor 194 Insulating layer 201 Transistor 202 Capacitor element 203 Transistor 204 Connection part 205 Transistor 206 Transistor 207 Connection part 211 Insulating layer 212 Insulating layer 213 Insulating layer 214 Insulating layer 216 Insulating layer 217 Conducting layer 218 Conducting layer 220 Insulating layer 221a Conducting layer 221b Conductive layer 222a Conductive layer 222b Conductive layer 223 Conductive layer 224 Insulating layer 225 Conductive layer 231 Semiconductor layer 234 Peripheral circuit region 236 Pixel circuit 237 Light 238 Light 242 Connection layer 243 Connection body 252 Connection portion 271 Transistor 272 Capacitance element 273 Scan line 274 Signal line 275 Common potential line 281 Transistor 282 Capacitance element 283 Transistor 284 Scan line 285 Signal line 286 Power line 291 Transmission area 292 Light-shielding area 311 Electrode 351 Substrate 3 1 substrate 365 wiring 370 touch sensor 372 FPC
374 Conductive layer 375 Insulating layer 376a Conductive layer 376b Conductive layer 377 Conductive layer 378 Insulating layer 800 Portable information terminal 810 Portable information terminal 811 Case 812 Display unit 813 Operation button 814 External connection port 815 Speaker 816 Microphone 817 Camera 818 Operation key 820 Carrying Information terminal 830 Computer 831 Main body 832 Case 833 Display unit 834 Keyboard 835 External connection port 836 Pointing device 840 Camera 841 Case 842 Display unit 843 Operation button 844 Shutter button 846 Lens 850 Television device 851 Case 852 Display unit 853 Stand 861 Remote controller 901 Incident light 902 Reflected light 903 Light emission 910 Electronic device 920 Electronic device 930 Electronic device 940 Electronic device 2020 BT
3200a transistor 3200b transistor 3200c transistor 3211 insulating layer 3212 insulating layer 3212a insulating layer 3212b insulating layer 3213 insulating layer 3215 insulating layer 3221 conductive layer 3222a conductive layer 3222a_1 conductive layer 3222a_2 conductive layer 3222a_3 conductive layer 3222b_2 conductive layer 3222b_1 conductive layer 3222b_1 Layer 3223 Conductive layer 3224 Insulating layer 3231 Metal oxide layer 3231_1 Metal oxide layer 3231_2 Metal oxide layer 3231d Drain region 3231i Channel region 3231s Source region 3235 Opening 3236a Opening 3236b Opening 3237 Opening

Claims (9)

A first pixel; a second pixel adjacent to the first pixel in a row direction; and a third pixel adjacent to the first pixel in a column direction;
Each of the first to third pixels has a first display area, a second display area, and a third display area,
The first display area includes a first display element,
The second display area has a second display element,
The third display area has a third display element,
The first display element and the second display element have a function of emitting light,
The third display element has a function of reflecting light incident on the third display element,
The second pixel has the first display at a position symmetrical to the first display area of the first pixel, with a boundary between the first pixel and the second pixel as an axis of symmetry. Has an area,
The third pixel has the first display at a position symmetrical to the first display area of the first pixel, with a boundary between the first pixel and the third pixel as an axis of symmetry. A display device comprising a region. In claim 1,
The second pixel is located at a point symmetric with the second display area of the first pixel, with the center of the boundary between the first pixel and the second pixel as a symmetric point. A display device having two display areas. In claim 1,
The third pixel is located at a point symmetric with the second display area of the first pixel, with a central portion of the boundary between the first pixel and the third pixel as a symmetric point. A display device having two display areas. In any one of Claims 1 thru | or 3,
The first to third pixels are rectangles having a long side a μm (a is a real number of 0 or more) and a short side b μm (b is a real number of 0 or more and a or less),
In the first pixel, the first display area is within a / 4 μm in the long side direction and within b / 4 μm in the short side direction from one of the vertices of the first pixel. Provided,
In the second pixel, the first display area is within a / 4 μm in the long side direction and within b / 4 μm in the short side direction from one of the vertices of the second pixel. Provided,
In the third pixel, the first display area is within a / 4 μm in the long side direction and within b / 4 μm in the short side direction from one of the vertices of the third pixel. A display device provided. In any one of Claims 1 thru | or 4,
The display device, wherein the first display area and the second display area have a function of emitting light of different colors. In any one of Claims 1 thru | or 5,
The third display area of the first pixel, the third display area of the second pixel, and the third display area of the third pixel have different colors. A display device having a function of emitting light. In any one of Claims 1 thru | or 6,
Each of the first to third pixels has a fourth display area,
The fourth display area has a fourth display element,
The fourth display element has a function of emitting light,
The fourth display area has a function of emitting light emitted from the first display area and light having a different color from the light emitted from the second display area. . In claim 7,
The first to third pixels are rectangles having a long side a μm (a is a real number of 0 or more) and a short side b μm (b is a real number of 0 or more and a or less),
In the first pixel, the fourth display region is within a / 4 μm in the long side direction and within b / 4 μm in the short side direction from one of the vertices of the first pixel. Provided,
In the second pixel, the fourth display area is within a / 4 μm in the long side direction and within b / 4 μm in the short side direction from one of the vertices of the second pixel. Provided,
In the third pixel, the fourth display area is within a / 4 μm in the long side direction and within b / 4 μm in the short side direction from one of the vertices of the third pixel. A display device provided. A display device according to any one of claims 1 to 8,
And an input device for operation.