Display divice

Abstract

To provide a folding type display divice that is superior in portability.SOLUTION: There is provided a display device that has a flexible display panel, and can be folded compactly. The display device has a tri-folding mechanism, and can have a region where a first surface of the display device is folded into a facing state and a region where a second surface opposed to the first surface is folded into a facing state. Even a display panel which is relatively large in aspect ratio can be folded compactly by providing folds along a short axis to be improved in portability.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an article, a method, or a manufacturing method. Or, the present invention relates to a process, a machine , a manufacture, or a composition of matter. In particular , one aspect of the present invention relates to a semiconductor device, a light-emitting device, a display device, an electronic device, a lighting device, and their driving methods, or their manufacturing methods. In particular, it relates to a display device having a flexible display surface, its operation method or manufacturing method.

[0002] Note that in this specification and the like, the semiconductor device refers to all devices that can function by utilizing semiconductor characteristics . Transistors, semiconductor circuits, arithmetic units, storage devices, etc. are one aspect of semiconductor devices . Further, a light-emitting device, a display device, a lighting device, and an electronic device may have a semiconductor device .

Background Art

[0003] Electronic devices such as mobile phones, smartphones, tablet computers, and laptop computers are made in appropriate sizes according to their functions, ease of use, and portability . On the other hand, it is inconvenient to carry a plurality of electronic devices. Therefore, a form that can integrate the functions of a plurality of electronic devices is desired. For example, Patent Document 1 discloses a three-fold light-emitting panel . By using the light-emitting panel, it is possible to integrate the functions of a plurality of electronic devices and manufacture an electronic device with a variable size .

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] One object of one aspect of the present invention is to provide a foldable display device with excellent portability. Or, one object is to provide a foldable display device with excellent visibility of display. Or, one object is to provide a foldable display device having a power saving function. Or, one object is to provide a foldable display device with excellent ease of handling. Or, one object is to provide a novel display device. Or, one object is to provide a method of operating a novel display device.

[0006] Note that the description of these problems does not prevent the existence of other problems. One aspect of the present invention is not required to solve all of these problems. Further, problems other than the above will be apparent from the description in the specification and the like, and it is possible to extract problems other than the above from the description in the specification and the like.

MEANS FOR SOLVING THE PROBLEMS

[0007] One aspect of the present invention relates to a three-fold foldable display device with excellent portability.

[0008] One aspect of the present invention has a flexible display panel, and the display panel has a first region, a second region, and a third region. When flattened and unfolded, the first region, the second region, and the third region are respectively positioned parallel to form a surface, and the second region is provided between the first region and the third region, and from the first region to the second region, a first convex portion on the display surface side A function of forming a curved surface, and a second curved surface that is concave on the display surface side from the second region to the third region A function of forming a curved surface, and when folded, the radius of curvature R1 of the first curved surface is larger than that of the second A display device in which the radius of curvature R2 of the curved surface is larger.

[0009] Another aspect of the present invention has a flexible display panel. The display panel has a first region and , a second region, and a third region. When flattened, the first region, the second region And the third region are respectively positioned parallel to form a plane. The second region is located between the first region and the Third region, and from the first region to the second region, a first curved surface that is convex on the display surface side, a flat surface, and a third curved surface that is convex on the display surface side are continuously formed in this order, and A function of forming a third curved surface that is convex on the display surface side, A function of forming a second curved surface that is concave on the display surface side from the second region to the third region, and When folded, the radius of curvature R1 of the first curved surface is larger than the radius of curvature R2 of the second curved surface Also larger, the radius of curvature R3 of the third curved surface is larger than the radius of curvature R2, and the radius of curvature R1 is A display device that is substantially equal to the radius of curvature R3.

[0010] In the above two aspects, further, a first housing, a second housing, a third housing, and a first Hinge, a second hinge, and at least a part of the first region is fixed to the first housing Fixed, at least a part of the second region is fixed to the second housing, and at least a part of the third region is Also partly fixed to the third housing. A first hinge is provided between the first housing and the second housing Provided, a second hinge is provided between the second housing and the third housing. The first hinge Has a function of forming the first curved surface, and the second hinge has a function of forming the second curved surface. When it has and is flattened, the overall center of gravity is in the first housing or the third housing, and it can be made.

[0011] A battery may be provided in the first housing or the third housing.

[0012] A power receiving coil for wireless charging may be provided in the third housing.

[0013] The display panel preferably has a light emitting device.

[0014] Another aspect of the present invention is an operation method of a display device that performs display only in some regions when folded. Further, when the display panel is flattened, an operation of changing the orientation of the image according to the inclination of the display panel may be performed. When the display panel is flattened, an operation of changing the orientation of the image according to the inclination of the display panel may be performed. It may perform an operation of changing the orientation of the image according to the inclination of the display panel.

Advantages of the Invention

[0015] By using one aspect of the present invention, it is possible to provide a foldable display device with excellent portability. Or, it is possible to provide a foldable display device with excellent visibility of display. Or, it is possible to provide a foldable display device having a power saving function. Or, it is possible to provide a foldable display device with excellent ease of holding. Or, it is possible to provide a novel display device. Or, it is possible to provide a novel operation method of a display device. Or, it is possible to provide a foldable display device having a power saving function. Or, it is possible to provide a foldable display device with excellent ease of holding. Or, it is possible to provide a novel display device. Or, it is possible to provide a novel operation method of a display device. By using one aspect of the present invention, it is possible to provide a foldable display device with excellent portability. Or, it is possible to provide a foldable display device with excellent visibility of display. Or, it is possible to provide a foldable display device having a power saving function. Or, it is possible to provide a foldable display device with excellent ease of holding. Or, it is possible to provide a novel display device. Or, it is possible to provide a novel operation method of a display device.

[0016] Note that the description of these effects does not prevent the existence of other effects. Note that one aspect of the present invention does not necessarily have to have all of these effects. Note that other effects than these will become apparent from the description in the specification, drawings, claims, etc., and the specification, drawings Note that the description of these effects does not prevent the existence of other effects. Note that one aspect of the present invention does not necessarily have to have all of these effects. Note that other effects than these will become apparent from the description in the specification, drawings, claims, etc., and the specification, drawings will naturally become apparent from the description in the specification, drawings, claims, etc., and the specification, drawings ​From the description of the claims and the like, it is possible to extract effects other than these.

Brief Description of the Drawings

[0017]

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Embodiments for Carrying Out the Invention

[0018] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description without departing from the spirit and scope of the present invention, various changes can be made to its form and details which can be easily understood by those skilled in the art. Therefore, the present invention is not construed as being limited to the description of the embodiments shown below. In the configuration of the invention described below, the same reference numerals are commonly used for the same parts or parts having similar functions among different drawings and the repeated description thereof may be omitted. Note that the hatching of the same elements constituting the drawings may be appropriately omitted or changed among different drawings as well. In addition, even if an element is illustrated as a single element on a circuit diagram, the element may be composed of a plurality of elements as long as there is no functional inconvenience. For example, transistors operating as switches may be connected in series or in parallel. In addition, capacitors may be divided and arranged at a plurality of positions

[0019] Also, even if one conductor has a plurality of functions such as wiring, electrodes, and terminals, in this specification, a plurality of names may be used for the same element. Further, even if it is illustrated on a circuit diagram that elements are directly connected to each other, actually, the elements may be connected via one or a plurality of conductors, and in this specification such a configuration is also included in the category of direct connection

[0020] Moreover, there are cases where one conductor has a plurality of functions such as wiring, electrodes, and terminals, and in this specification, a plurality of names may be used for the same element. Also, even if it is illustrated on a circuit diagram that elements are directly connected to each other, actually, the elements may be connected via one or a plurality of conductors, and in this specification such a configuration is also included in the category of direct connection

[0021] (Embodiment 1) In this embodiment, a display device according to an aspect of the present invention will be described with reference to the drawings. Note that in this specification, the display device refers to all devices having a display function. That is ​​​An electronic device having a display unit is included in a display device. For example, a mobile phone, a smartphone, an electronic device having a display unit such as a smartwatch, a tablet computer, a television device, etc. is included in the display device.

[0022] One aspect of the present invention is a display device having a flexible display panel and capable of being folded small. The display device has a three-fold mechanism, and includes a region that is folded so that the first surfaces of the display device face each other, and a region that is folded so that the second surfaces facing the first surfaces face each other. Accordingly, for example, even a display panel having a relatively large aspect ratio such as 16:9, 18:9, 21 :9 can be folded small by providing a fold line in the short-axis direction, and portability can be improved. Also, when folded small, the power consumption can be greatly reduced by making the display area that cannot be viewed non-display. When folded small, the power consumption can be greatly reduced by making the display area that cannot be viewed non-display. can be.

[0023] <Display Device> FIG. 1A is a diagram showing a state in which a display device 100A according to one aspect of the present invention is folded to the minimum size. The display device 100A can be deformed as shown in FIGS. 2A to 2C. When initially folded (see FIG. 2A), it can be changed to a flat unfolded state (see FIG. 2C) through a deformed state (see FIG. 2B). If deformed in the reverse order, it can be folded. Note that the deformation of the display device 100A can be performed manually, but it may also use electrical power or mechanical power such as a spring. can also be used.

[0024] The display device 100A includes a flexible display panel 101, a housing 102a, and a housing 102 It has b, the housing 102c, the hinge 103a, and the hinge 103b. In this embodiment, for clarity of explanation, the display panel 101 is divided into three regions: region 101a, region 101b, and region 101c (see FIG. 2C). Regions 101a, 101b, and 101c are regions that form a plane parallel to the horizontal direction (the direction in which the surface of the display panel 101 extends) when the display panel 101 is flattened, and are regions bounded by the position where the hinge is provided or its vicinity. In reality, there is no structural difference between each of regions 101a to 101c and their boundaries. A single seamless flexible display panel can be used for the display panel 101. In this state, for clarity of explanation, the display panel 101 is divided into three regions: region 101a, region 101b, and region 101c (see FIG. 2C). Regions 101a, 101b, and 101c are regions that form a plane parallel to the horizontal direction (the direction in which the surface of the display panel 101 extends) when the display panel 101 is flattened, and are regions bounded by the position where the hinge is provided or its vicinity. In reality, there is no structural difference between each of regions 101a to 101c and their boundaries. A single seamless flexible display panel can be used for the display panel 101. Regions 101a, 101b, and 101c are regions that form a plane parallel to the horizontal direction (the direction in which the surface of the display panel 101 extends) when the display panel 101 is flattened, and are regions bounded by the position where the hinge is provided or its vicinity. In reality, there is no structural difference between each of regions 101a to 101c and their boundaries. A single seamless flexible display panel can be used for the display panel 101. In reality, there is no structural difference between each of regions 101a to 101c and their boundaries. A single seamless flexible display panel can be used for the display panel 101. In reality, there is no structural difference between each of regions 101a to 101c and their boundaries. A single seamless flexible display panel can be used for the display panel 101.

[0025] FIG. 1B is a view corresponding to the cross-section of A1 - A2 shown in FIG. 1A. The housing 102a is connected to the housing 102b via the hinge 103a. The housing 102b is connected to the housing 102c via the hinge 103b. The housing 102a is connected to the housing 102b via the hinge 103a. The housing 102b is connected to the housing 102c via the hinge 103b. The housing 102b is connected to the housing 102c via the hinge 103b.

[0026] The display panel 101 is provided on the first surface side of the housings 102a to 102c. At least a part of region 101a can be fixed to the housing 102a. At least a part of region 101b can be fixed to the housing 102b. At least a part of region 101c can be fixed to the housing 102c. At least a part of region 101a can be fixed to the housing 102a. At least a part of region 101b can be fixed to the housing 102b. At least a part of region 101c can be fixed to the housing 102c. At least a part of region 101b can be fixed to the housing 102b. At least a part of region 101c can be fixed to the housing 102c. At least a part of region 101c can be fixed to the housing 102c.

[0027] If the surface of the display panel 101 fixed to the housing is the non-display surface, and the surface opposite to the surface of the display panel 101 fixed to the housing is the display surface, then as shown in FIGS. 1A and 1B, when folded, the non-display surfaces of region 101a and region 101b face each other, and from region 101a to region 101b, the non-display surfaces of region 101a and region 101b face each other, and from region 101a to region 101b, the non-display surfaces of region 101a and region 101b face each other, and from region 101a to region A curved surface 104a that is convex across the domain 101b is formed on the display surface. The curved surface 104a is a region formed by a part of the region 101a and a part of the region 101b. Also, the display surfaces of the region 101b and the region 101c face each other, and a curved surface 104b that is concave across the display surface from the region 101b to the region 101c is formed. The curved surface 104b is a region formed by a part of the region 101b and a part of the region 101c.

[0028] The distance from the surface (display surface) of the above curved surface to the center of curvature is defined as the radius of curvature. When the display panel 101 is folded to its minimum size, the radius of curvature of the curved surface 104a is R1, and the radius of curvature of the curved surface 104 b is R2. At this time, it is preferable that R1 > R2.

[0029] R1 is the radius of curvature when the display surface is bent outward. Even if the thicknesses of the housings 102a and 102a are made thin within an appropriate range, it becomes a relatively large value, and the stress applied to the portion of the display panel 101 that forms the curved surface 104a is small. On the other hand, R2 is the radius of curvature when the display surface is bent inward, and regardless of the thicknesses of the housings 102b and 102c, it becomes a relatively small value, and the stress applied to the portion of the display panel 101 that forms the curved surface 104b is likely to be large. Therefore, by making R2 equal to or greater than R1, the stress applied to the curved surface 104b portion can be reduced, and the reliability can be improved. On the other hand, if R2 is increased,

[0030] the overall thickness when folded increases, so the portability deteriorates.

[0031] In one aspect of the present invention, in order to use a display panel that is resistant to bending stress, the reliability is impaired. It is possible to achieve R1 > R2 without. A display panel that is resistant to bending stress has a transistor (hereinafter referred to as an OS transistor) having a metal oxide (oxide semiconductor) in the channel formation region, which can be realized by using it in a pixel circuit.

[0032] The metal oxide can be formed by a film formation method such as sputtering, and can be fabricated by a relatively low-temperature process. Therefore, there is little residual stress in devices such as transistors and peripheral members such as protective films, and it has strong resistance to bending stress applied later.

[0033] On the other hand, as a transistor having electrical characteristics equivalent to those of an OS transistor, there is a transistor having silicon (low-temperature polysilicon, single-crystalline silicon, etc.) in the channel formation region (hereinafter referred to as an Si transistor). In the manufacturing process of a low-temperature polysilicon transistor, a laser crystallization process of a silicon film is used. The silicon film is heated to a high temperature (at least the melting point of silicon) in a short time in the laser crystallization process and then rapidly cooled. Therefore, there is a lot of residual stress in the silicon film and peripheral members, and when additional bending stress is applied later, the electrical characteristics deteriorate, reducing the reliability.

[0034] Therefore, in the display device according to one aspect of the present invention, it is easy to make R1 > R2, and it can be folded small without impairing the reliability. Note that the bending resistance varies depending on the radius of curvature and the number of bending times, etc., so an Si transistor may be used in the pixel circuit according to the situation.

[0035] As the semiconductor material used for the OS transistor, the energy gap is 2 eV or more, preferably Alternatively, a metal oxide having a bandgap of 2.5 eV or more, more preferably 3 eV or more, can be used. Typically, an oxide semiconductor containing indium can be used, for example, CAAC-OS or CAC-OS described later. CAAC-OS is suitable for transistors that require high reliability because the atoms constituting the crystal are stable. In addition, since CAC-OS exhibits high mobility characteristics, it is suitable for transistors that perform high-speed driving. OS transistors can exhibit extremely low off-current characteristics of several yA / μm (current value per 1 μm channel width) because the semiconductor layer has a large energy gap.

[0036] In addition, OS transistors have characteristics different from those of Si transistors, such as no impact ionization, avalanche breakdown, and short-channel effect, and can form highly reliable circuits. Further, variations in electrical characteristics due to non-uniform crystallinity, which are problems in Si transistors, are less likely to occur in OS transistors. The semiconductor layer of the OS transistor can be formed of a film represented by an In-M-Zn oxide containing, for example, indium, zinc, and a metal M (aluminum, titanium, gallium, germanium, yttrium, zirconium, lanthanum, cerium, tin, neodymium, or hafnium). In addition to the above In-M-Zn oxide, the semiconductor layer of the OS transistor may be formed of In oxide, In-Ga oxide, or In-Zn oxide. Note that by using a semiconductor layer having a high indium ratio, the on-current or field-effect mobility of the OS transistor can be increased. The In-M-Zn oxide can be, for example,

[0037] an In-M-Zn oxide containing indium, zinc, and a metal M (aluminum, titanium, gallium, germanium, yttrium, zirconium, lanthanum, cerium, tin, neodymium, or hafnium). In addition to the above In-M-Zn oxide, the semiconductor layer of the OS transistor may be formed of In oxide, In-Ga oxide, or In-Zn oxide. Note that by using a semiconductor layer having a high indium ratio, the on-current or field-effect mobility of the OS transistor can be increased. The In-M-Zn oxide can be, for example, an In-M-Zn oxide containing indium, zinc, and a metal M (aluminum, titanium, gallium, germanium, yttrium, zirconium, lanthanum, cerium, tin, neodymium, or hafnium). In addition to the above In-M-Zn oxide, the semiconductor layer of the OS transistor may be formed of In oxide, In-Ga oxide, or In-Zn oxide. Note that by using a semiconductor layer having a high indium ratio, the on-current or field-effect mobility of the OS transistor can be increased. For example, sputtering method, ALD (Atomic layer deposition) method , or MOCVD (Metal organic chemical vapor deposition) The film can be formed by using a deposition method or the like.

[0038] When forming an In-M-Zn oxide film by sputtering, the sputtering target The atomic ratio of the metal elements preferably satisfies In≧M and Zn≧M. The atomic ratio of the metal elements in the targeting target was In:M:Zn=1:1:1, In: M:Zn=1:1:1.2, In:M:Zn=3:1:2, In:M:Zn=4:2:3 , In:M:Zn=4:2:4.1, In:M:Zn=5:1:3, In:M:Zn=5 :1:6, In:M:Zn=5:1:7, In:M:Zn=5:1:8, In:M:Zn In addition, the oxide semiconductor constituting the semiconductor layer is preferably In-Zn oxide. In the case of a material, the metal element of the sputtering target used to form an In-Zn oxide film The atomic ratio of elements preferably satisfies In≧Zn. The atomic ratio of the metal elements in the ZnO solution is In:Zn=1:1, In:Zn=2:1, In:Z n=5:1, In:Zn=5:3, In:Zn=10:1, In:Zn=10:3 etc. are preferable. Desirable.

[0039] The semiconductor layer is made of an oxide semiconductor with a low carrier concentration. Carrier concentration is 1×10 17 / cm 3 Less than 1 × 10 15 / cm 3 Further details are as follows: Preferably 1 x 10 13 / cm 3Hereinafter, more preferably 1×10 11 / cm 3 Hereinafter, more preferably 1×10 / cm 10 / cm 3 less than, and an oxide semiconductor having a carrier concentration of 1×10 -9 / cm 3 or higher can be used. Such an oxide semiconductor is referred to as a high-purity intrinsic or substantially high-purity intrinsic oxide semiconductor. It can be said that the oxide semiconductor has a low defect level density and stable characteristics.

[0040] Note that the present invention is not limited to these, and an appropriate composition may be used according to the semiconductor characteristics and electrical characteristics (field effect mobility, threshold voltage, etc.) of the required transistor. Further, in order to obtain the semiconductor characteristics of the required transistor, it is preferable to make the carrier concentration, impurity concentration, defect density, atomic number ratio of metal element to oxygen, interatomic distance, density, etc. of the semiconductor layer appropriate.

[0041] Note that the hinges 103a and 103b are shown in an abstracted manner, and their forms are not limited. Specific examples of the hinges 103a and 103b will be described later, but an elastic body such as rubber, a connected columnar body, or a gear can be used. In FIGS. 1A and 1B, the housing and the hinge are shown as different elements, but the boundary is not clear, and there may be a case where the housing and the hinge are integrated. Also, the display panel 101 may not be in contact with the hinge.

[0042] <Modification Example 1 of Display Device> Further, one aspect of the present invention may have a configuration shown in FIG. 3A. The display device 10 0B shown in FIG. 3A has a configuration in which the hinge 103a of the display device 100A is replaced with a hinge 103c. ​

[0043] The hinge 103c of the display device 100B is configured to move the display device 100B from the region 101a to the region 101b when the display device 100B is bent. 101b, a curved surface 105a with the display surface being convex, a flat surface 105, and a curved surface 105b with the display surface being convex. The curved surface 105a is formed in part of the region 101a. The plane 105 is formed by a part of the region 101a and a part of the region 101b. The curved surface 105b is a region formed by a part of the region 101c.

[0044] As shown in the cross-sectional view of FIG. 3B, the radius of curvature of the curved surface 105a when folded to the minimum size is When the radius of curvature of the curved surface 105b is R3 and the radius of curvature of the curved surface 105b is R4, R3>R2 and R4>R2 are satisfied. By satisfying R3>R2 and R4>R2, the overall The thickness of the resistor R3 can be reduced. Also, R3 and R4 can be made equal or approximately equal. It is preferable that R3 and R4 are equal to each other to allow the folding to be performed symmetrically. If R3 and R4 are significantly different, the mechanism may not function properly even when folded. When the curved surface 105a is formed or when the curved surface 105b is formed, One side may bend more easily than the other, reducing reliability.

[0045] In the display device 100B shown in FIGS. 3A and 3B, when the display device 100B is folded, the hinge 103c Therefore, the proportion of the flat surface in the bent portion increases, and the image This can improve the visibility of the image.

[0046] <hinge> 4A to 4C show a hinge 103 that can be used in the display device 100A shown in FIG. 1A. This is a diagram for explaining an example of a.

[0047] The hinge 103a has a plurality of columnar bodies 111 whose cross-section in the minor axis direction is trapezoidal or substantially trapezoidal. Each columnar body 111 is connected such that the bottom surfaces (corresponding to the lower bases of the trapezoids) are continuous. Also, the bottom surface of the columnar body 111 at one end of the hinge 103a is connected so as to be continuous with the first surface of the housing 102a. Further, the bottom surface of the columnar body 111 at the other end of the hinge 103a is connected so as to be continuous with the first surface of the housing 102b. Note that the shape of the upper surface (corresponding to the upper base of the trapezoid) of each columnar body 111 is arbitrary within a range where there is no interference with other columnar bodies and the housing.

[0048] As shown in FIG. 4A, by deforming the side surfaces (corresponding to the legs of the trapezoid) of adjacent columnar bodies 111 so that they contact each other, it can be folded. At this time, since the bottom surfaces of the plurality of columnar bodies 11 1 are continuous at a certain angle, a region where the cross-section is substantially arc-shaped as a whole is formed. Therefore, the flexible display panel can form a curved surface at a portion overlapping with the region.

[0049] When a deformation operation (deployment operation) is performed from the state of FIG. 4A, as shown in FIG. 4B, the side surfaces of the respective columnar bodies 111 move in a direction away from each other, and change so that the radius of curvature of the above-mentioned substantially arc increases. At this time, the radius of curvature of the curved surface portion also changes so as to increase in the display panel.

[0050] When a further deformation operation is performed from the state of FIG. 4B, as shown in FIG. 4C, the first surface of the housing 102a, the bottom surfaces of the respective columnar bodies 111, and the first surface of the housing 102b become flat and are connected ​​At this time, the curved surface of the display panel changes to a flat surface, and the entire panel develops flat. The device can be folded by performing the above transformation steps in reverse order.

[0051] In the above description, the cross section of the pillar 111 is trapezoidal, but it may also be triangular. The structure for connecting the columns and the housing is not limited. A stopper may be provided to prevent bending. A spacer may be provided to maintain the hinge of the display panel. These may be changed to a shape suitable for installation. These also apply to the hinge 103c described next. It can be used.

[0052] 5A to 5C show a hinge 103 that can be used in the display device 100B shown in FIG. 3A. FIG. 10 is a diagram illustrating an example of c.

[0053] The hinge 103c is made up of units 113a and 113b having elements substantially equivalent to those of the hinge 103a. b. The units 113a and 113b have the same number of pillars as the hinge 103a. In addition, there is a flat bottom between the unit 113a and the unit 113b. The pillars 114 have side surfaces perpendicular to the bottom surface. The top surface shape of the pillars 114 is The size is arbitrary as long as it does not interfere with other pillars and the housing.

[0054] As shown in FIG. 5A, the side surface of the pillars of the unit 113a, the pillars 114 and The side surfaces of the pillars 113a and 113b are deformed so as to contact each other, and the pillars are folded. At this time, the bottom surface of the columnar body of the unit 113a is fixed. Since they are connected in an angled manner, a region is formed where the cross-section is substantially arc-shaped. The same applies to unit 113b. Therefore, the flexible display panel can form a curved surface, a flat surface, or a curved surface at a portion overlapping with the said region. The same applies. Therefore, the flexible display panel can form a curved surface, a flat surface, or a curved surface at a portion overlapping with the said region.

[0055] The columnar bodies of unit 113a, as well as the columnar body 114 and the columnar bodies of unit 113b, are connected such that their bottom surfaces are continuous. Also, the bottom surface of a columnar body at one end of unit 113a is connected so as to be continuous with the first surface of the housing 102a. Further, the bottom surface of a columnar body at one end of unit 113b is connected so as to be continuous with the first surface of the housing 102b. The columnar bodies of unit 113a, as well as the columnar body 114 and the columnar bodies of unit 113b, are connected such that their bottom surfaces are continuous. Also, the bottom surface of a columnar body at one end of unit 113a is connected so as to be continuous with the first surface of the housing 102a. Further, the bottom surface of a columnar body at one end of unit 113b is connected so as to be continuous with the first surface of the housing 102b. The bottom surface of a columnar body at one end of unit 113a is connected so as to be continuous with the first surface of the housing 102a. Also, the bottom surface of a columnar body at one end of unit 113b is connected so as to be continuous with the first surface of the housing 102b. The bottom surface of a columnar body at one end of unit 113b is connected so as to be continuous with the first surface of the housing 102b. in such a manner.

[0056] When a deformation operation (deployment operation) is performed starting from the state of FIG. 5A, as shown in FIG. 5B, the side surfaces of the respective columnar bodies of units 113a and 113b move in a direction away from each other, and the radius of curvature of the said approximate arc changes to become larger. At this time, the radius of curvature of the curved surface portion also changes to become larger in the display panel. When a deformation operation (deployment operation) is performed starting from the state of FIG. 5A, as shown in FIG. 5B, the side surfaces of the respective columnar bodies of units 113a and 113b move in a direction away from each other, and the radius of curvature of the said approximate arc changes to become larger. At this time, the radius of curvature of the curved surface portion also changes to become larger in the display panel. the radius of curvature of the curved surface portion also changes to become larger in the display panel. in the display panel.

[0057] When a further deformation operation is performed starting from the state of FIG. 5B, as shown in FIG. 5C, the first surface of the housing 102a, the bottom surface of the columnar body of unit 113a, the bottom surface of the columnar body 114, the bottom surface of the columnar body of unit 113b, and the first surface of the housing 102b are connected so as to be flat. At this time, the portion that was a curved surface in the display panel also changes to be flat, and the entire display panel becomes in a flatly deployed state. If the deformation operation is performed in the reverse order of the above, it can be folded. the first surface of the housing 102a, the bottom surface of the columnar body of unit 113a, the bottom surface of the columnar body 114, the bottom surface of the columnar body of unit 113b, and the first surface of the housing 102b are connected so as to be flat. At this time, the portion that was a curved surface in the display panel also changes to be flat, and the entire display panel becomes in a flatly deployed state. If the deformation operation is performed in the reverse order of the above, it can be folded. the bottom surface of the columnar body of unit 113b, and the first surface of the housing 102b are connected so as to be flat. At this time, the portion that was a curved surface in the display panel also changes to be flat, and the entire display panel becomes in a flatly deployed state. If the deformation operation is performed in the reverse order of the above, it can be folded. the portion that was a curved surface in the display panel also changes to be flat, and the entire display panel becomes in a flatly deployed state. If the deformation operation is performed in the reverse order of the above, it can be folded. If the deformation operation is performed in the reverse order of the above, it can be folded.

[0058] FIGS. 6A to 6C are diagrams for explaining an example of the hinge 103b that can be used for the display device 100A shown in FIG. 1A or the display device 100B shown in FIG. 3A. FIGS. 6A to 6C are diagrams for explaining an example of the hinge 103b that can be used for the display device 100A shown in FIG. 1A or the display device 100B shown in FIG. 3A.

[0059] The hinge 103b has a plurality of pillars 115 each having a rectangular cross section in the minor axis direction. The pillars 115 are connected so that their bottom surfaces are continuous. The bottom surfaces of the pillars 115 are connected so as to be continuous with the first surface of the housing 102a. The bottom surface of the pillar 115 at the other end of the hinge 103b is in contact with the first surface of the housing 102c. The shape of the top surface of each pillar 115 is connected to the other pillars. This is optional as long as it does not interfere with the body or housing.

[0060] As shown in FIG. 6A, the side surfaces of adjacent pillars 115 are deformed in a direction away from each other. At this time, the bottom surfaces of the plurality of pillars 115 are aligned. Since the two are connected at a fixed angle, an area is formed in which the cross section as a whole is approximately arc-shaped. Therefore, the flexible display panel can form a curved surface in the area that overlaps with the area. Cut.

[0061] When deformation (deployment) is performed from the state shown in FIG. 6A, each columnar shape is expanded as shown in FIG. 6B. The side of the body 115 moves in the direction approaching, and the radius of curvature of the approximately circular arc changes to become larger. At this time, the radius of curvature of the curved surface of the display panel also changes to become larger.

[0062] When a further deformation operation is performed from the state of FIG. 6B, as shown in FIG. 6C, the first The surface of the pillars 115, the bottom surface of each pillar 115 and the first surface of the housing 102c are connected so as to be flat. At this time, the curved surface of the display panel also becomes flat, and the entire panel is developed flat. If you perform the transformation steps in the reverse order, it will fold.

[0063] Since the cross-section of the columnar body 115 is rectangular, when it is flattened and developed, the sides of the columnar body 115 will be in contact with each other. Therefore, the hinge 103b can eliminate the need for a stopper as it does not cause reverse bending of the display panel. Note that a spacer may be provided to maintain a gap between the housings during folding. Also, the housing or the hinge may be appropriately deformed into a shape suitable for installing the display panel.

[0064] Figures 7A to 7C are diagrams for explaining another example of the hinge 103b.

[0065] The hinge 103b has a gear 116a and a gear 116b. The gear 116a is fixed to the housing 102 a. The gear 116b is fixed to the housing 102b. The central axis of the gear 116a is preferably overlapped with the first surface of the housing 102a. Also, the central axis of the gear 116b is preferably overlapped with the first surface of the housing 102b.

[0066] As shown in Figure 7A, when in the folded state, the gears 116a and 1 16b are engaged with each other at a specific position. At this time, since the central axes of the two gears are on the first surface of the housing, a gap is generated between the housings (between the opposing display surfaces of the display panel). Therefore, the flexible display panel can form a curved surface with a radius of curvature approximately equal to half of the gap.

[0067] When a deformation operation (deployment operation) is performed from the state of Figure 7A, the housings 102b and 102c are synchronized according to the engagement of the gears 116a and 116b and move to open with the hinge 103b as a fulcrum (see Figure 7B). At this time, even in the display panel, the radius of curvature of the curved surface part ​​​​​​​​​ It changes so as to become larger.

[0068] When further deformation operation is performed from the state of FIG. 7B, as shown in FIG. 7C, the first surface of the housing 102b and the first surface of the housing 102c are connected so as to be flat. At this time, even the display panel The curved surface part becomes flat and is in a state of being flatly developed as a whole. If the deformation operation is performed in the reverse order of the above, it can be folded. The part that was a curved surface becomes flat, and it becomes a state of being flatly developed as a whole. If the deformation operation is performed in the reverse order of the above, it can be folded. If the deformation operation is performed in the reverse order, it can be folded.

[0069] In addition, a mechanism for holding the meshing of the gears 116a and 116b may be provided. Also, when flatly developed, the side surface of the housing 102c and the side surface of the housing 102c will be in contact. Therefore, the hinge 103b can eliminate the need for a stopper without causing reverse bending of the display panel. In addition, a spacer for maintaining the gap between the housings during folding may be provided. Or, a mechanism for maintaining the gap may be provided in the gears 116a and 116b. Also, the housing or hinge may be appropriately deformed into a shape suitable for the installation of the display panel. Therefore, the hinge 103b can eliminate the need for a stopper without causing reverse bending of the display panel. Therefore, the hinge 103b can eliminate the need for a stopper without causing reverse bending of the display panel. In addition, a spacer for maintaining the gap between the housings during folding may be provided. Therefore, the hinge 103b can eliminate the need for a stopper without causing reverse bending of the display panel. In addition, a spacer for maintaining the gap between the housings during folding may be provided. Or, a mechanism for maintaining the gap may be provided in the gears 116a and 116b. Also, the housing or hinge may be appropriately deformed into a shape suitable for the installation of the display panel. Therefore, the hinge 103b can eliminate the need for a stopper without causing reverse bending of the display panel. In addition, a spacer for maintaining the gap between the housings during folding may be provided. Or, a mechanism for maintaining the gap may be provided in the gears 116a and 116b. Also, the housing or hinge may be appropriately deformed into a shape suitable for the installation of the display panel. Therefore, the hinge 103b can eliminate the need for a stopper without causing reverse bending of the display panel. In addition, a spacer for maintaining the gap between the housings during folding may be provided. Or, a mechanism for maintaining the gap may be provided in the gears 116a and 116b. Also, the housing or hinge may be appropriately deformed into a shape suitable for the installation of the display panel.

[0070] <Second Modification of Display Device> FIG. 8A is a diagram for explaining a display device 100C which is a modification of the display device 100A. The display device 100C has a different shape of the housing 102c from that of the display device 100A.

[0071] The housing 102c of the display device 100C is formed thicker than the housings 102a and 102b. As shown in FIG. 8B, by forming the housing 102c thick, a relatively large-sized battery 117 can be incorporated, and the display device can operate for a long time. As shown in FIG. 8B, by forming the housing 102c thick, a relatively large-sized battery 117 can be incorporated, and the display device can operate for a long time. As shown in FIG. 8B, by forming the housing 102c thick, a relatively large-sized battery 117 can be incorporated, and the display device can operate for a long time. Also, by incorporating a relatively heavy battery 117 in the housing 102c, 、not only in the state of FIG. 8A but also in the state of FIG. 8B, the center of gravity position of the display device 100C can be made to be inside the housing 102c. Due to the thickness of the housing 102c and the presence of the center of gravity inside the housing 102c, when the display device is flattened, the ease of holding the display device can be improved .

[0072] Also, the display device 100C is configured to be easy to operate regardless of the dominant hand. FIG. 9A shows a case where the housing 102c side of the display device 100C is held with the left hand and a screen touch operation is performed with the right hand . Further, FIG. 9B is a diagram showing a case where the housing 102c side of the display device 100C is held with the right hand and a screen touch operation is performed with the left hand. In either case, an image can be displayed in a direction that is easy for the user to view .

[0073] This operation is performed by the sensor 120 (either an acceleration sensor or a gyro sensor) that the display device 100C has detecting the inclination of the display device 100C and determining the display direction of the image from the inclination . Also, the sensor 120 can detect the shaking of the display device 100C from the change in inclination. Since there are individual differences in shaking, the user can be determined by having artificial intelligence (AI) learn the information on shaking. Using this function, personal authentication can also be performed. Note that the sensor 120 can also be provided in other display devices shown in this embodiment .

[0074] FIG. 10 is a flowchart for determining the display image direction and performing personal authentication using the sensor 120 .

[0075] The path from S1 to S2 utilizes the inclination detection result by the sensor to determine the display direction of the image​ It is an operation to determine. Note that there are multiple directions for the inclination, and the inclinations A, B, and C include the conditions for the inclination in multiple directions. Here, the inclination A is shown in FIG. 9A for the display device 1 in the range including the inclination of 00C, the inclination C is in the range including the inclination of the display device 100C shown in FIG. 9B, and the incl ination B is in the range including the inclination when the long axis direction of the display device 100C is in the vertical direction. Note that since there are two cases where the up and down are reversed for the inclination B, actually, the determination may be made for four ranges of inclination.

[0076] When it is determined as the inclination A, the A display is performed. The A display is a mode of displaying an image in the direction shown in FIG. 9A. When it is determined as the inclination C, the C display is performed. The C display is a mode of displaying an image in the direction shown in FIG. 9 B. When it is determined as the inclination B, the B display is performed. The B display is, for example, a mode of displaying the image of the display device 100C shown in FIG. 9A rotated by approximately 90 degrees. In this way, by using the sensor 120, the display can be performed by changing the orientation of the image so as to be easily visible.

[0077] The paths of S1, S3, and S4 are operations of accumulating the data of the shake detected by the sensor 120 and registering the data and the individual. The data registered here becomes data for discriminating the individual. Note that the data can be updated every time the display device is used.

[0078] The path through S1, S5, and S6 is an operation of collating the above data with the data regarding the shake output from the sensor 120 in real time to authenticate the individual. For the collation, an artificial intelligence (AI) that deep - learns the accumulated data of the individual regarding the shake can be used. Note that the The operation can be performed after the personal information is stored in the above database. Thus , personal authentication can be performed using the sensor 120.

[0079] If the individual can be identified, the orientation of the display device 100C that the individual prefers to use can be known , so the default display orientation can be set in advance. When determining the angle of the display device 100C with only the sensor 120 , the sensor 120 may react sensitively due to a slight shake of the display device 100C or the like. In such a situation, it may take time until the image can be viewed normally, such as the image rotating frequently . Also, it will consume unnecessary power. By setting the default display orientation, the time required for viewing can be shortened and the power consumption can be reduced.

[0080] For example, if an individual often holds the display device 100C as shown in FIG. 9A, A display can be set as the default. Conversely, if an individual often holds the display device 100C as shown in FIG. 9B , C display can be set as the default. Note that, without using this function, only the operation using the sensor 120 may be performed.

[0081] Also, FIGS. 8C and 8D are diagrams for explaining the display device 100D having a battery inside the housing 102a . The display device 100D has a grip portion 106 that is easy to hold at the end of the housing 102a , and the battery 117 can be internally provided in the grip portion 106. Since the center of gravity of the display device 100D is located in the grip portion 106 where the heavy battery 117 is internally provided, the ease of holding can be improved. Also, as shown in FIG. 8D, when it is flattened and unfolded ​​​The grip portion serves as legs, enabling it to be used in a stable form even on a plane. Also, the display surface is inclined, which can also improve visibility.

[0082] Also, as shown in FIGS. 8B and 8D, it is preferable to provide a protection circuit 118 for the battery 117. As the battery 117, it is preferable to use a lithium-ion battery that can have a large capacity. However, occasionally, a fire accident may occur due to an abnormality inside the battery (such as a micro short circuit).

[0083] As shown in FIG. 11A, the protection circuit 118 can be configured to include a comparator 121, a transistor 122, and a capacitor 123. The comparator 121 compares the voltage (V ) of the battery 117 with a reference potential (V bat ) that is, for example, the lower limit of the normal value, and ref compares them. When V is lower than V [[ID=We have made the necessary corrections in the translation. The following is the corrected content:]] bat and V ref falls below V , it inverts the logical value output from the output terminal (OUT). V ref can be written and held at a node N to which one of the input terminals of the transistor 122, the capacitor 123, and the comparator 121 is connected.

[0084] Since the potential written at the node N can be held using the transistor 122 and the capacitor 123, the circuit formed by combining the transistor 122 and the capacitor 123 can be referred to as a memory circuit or a DOSRAM (Dynamic Oxide Semi conductor Random Access Memory). Since the DOSRAM can be composed of one transistor and one capacitor, the memory . Since the DOSRAM can be composed of one transistor and one capacitor, the High-density packing of memory can be achieved. Also, by using an OS transistor, the data retention period can be extended.

[0085] V ref is rewritten at regular intervals according to the voltage change associated with the charge and discharge of the battery 117. In the protection circuit 118, it is preferable to use an OS transistor for the transistor 122. The OS transistor has a low off-current and can hold the potential written to the node N substantially unchanged for a long time.

[0086] Also, when an OS transistor is used for the transistor 122, the protection circuit 118 including the memory circuit may be referred to as BTOS (Battery operating system, or Battery oxide semiconductor).

[0087] As shown in FIG. 11B, the battery 117 is electrically connected to the protection circuit 118, and the output of the protection circuit 118 is connected to the control circuit 119. When the protection circuit 118 detects a sudden voltage drop of the battery 117 or the like, it inverts the logical value of the signal output to the control circuit 119. At this time, the control circuit 119 controls to cut off the charge and discharge of the battery 117 to ensure the safety of the user.

[0088] Also, as shown in FIGS. 8B and 8D, it is preferable to provide an antenna 125 and an antenna 126 inside the housing 102a. The antenna 125 is an antenna for the fourth-generation mobile communication system (4G) communication, and the antenna 126 is an antenna for the fifth-generation mobile communication system (5G) communication. 5G communication can perform high-speed communication 10 to 20 times faster than 4G communication.

[0089] In FIGS. 8B and 8D, both the antenna 125 and the antenna 126 are provided. Although the configuration has been illustrated, it is not limited thereto. For example, in the housing 102a, a configuration in which only the antenna 125 is provided or a configuration in which only the antenna 126 is provided may be used. Also, in FIGS. 8 B and 8D, a configuration in which one antenna 125 and one antenna 126 are provided respectively has been illustrated, but it is not limited thereto. For example, a configuration in which a plurality of antennas 125 are provided , or a configuration in which a plurality of antennas 126 are provided may be used.

[0090] By providing both the antenna 125 and the antenna 126 on the housing 102a, good communication becomes easier. Since the user often uses the device in a way that allows for easy viewing of the display even when folded (such as placement, holding method, etc.), the housing 102a is often oriented in the direction in which radio waves propagate (upward, outward side), making it easier to receive radio waves.

[0091] In FIGS. 8A and 8B, an example in which the shape of the housing 102c is made thicker than other housings to accommodate a battery or the like has been shown. However, the shape of the housing 102a may be made thicker than other housings, as in the display device 100E shown in FIG. 12A. In this case, by appropriately bending the hinge 103a corresponding to outward bending, it can be placed on an airplane or the like with good balance.

[0092] Also, since the flat portion of the display surface can be divided into two at the hinge 103a, when displaying a plurality of images for example, appropriate images can be assigned to each flat portion, improving visibility. Also, by making one of the flat portions non-displayed, power-saving operations can be performed.

[0093] In addition, as shown in FIG. 12B, a power receiving coil 107 and a power receiving circuit 108 may be further provided in the housing 102c of the display device 100C. By overlapping the power receiving coil 107 with the power transmitting coil of the charger 1 09, wireless charging can be performed.

[0094] When a current flows through the power transmitting coil of the charger 109, a magnetic flux is generated, and a current is generated in the power receiving coil 107 by electromagnetic induction. The current is rectified by the power receiving circuit 108 and used to charge the battery connected to the power receiving circuit 108.

[0095] In the display device 100C, the housing 102c with a center of gravity can be placed in contact with the charger 109. Therefore, as shown in FIG. 12B, it can be stably placed on the charger 109 even in the unfolded state. Also, it can be used without impairing visibility even during charging. Note that the power receiving coil 107 can be provided on any two or any one of the housings 102a, 102b, and 102c.

[0096] <Display operation example 1> FIGS. 13A to 13C are diagrams for explaining an operation example common to the display devices 100A to 100E according to one aspect of the present invention. Note that FIGS. 13A to 13C show a case where the display device 100A is typically used. FIG. 13A shows an operation in which when the flat surface of the region 101a is in the display state in the folded state, the curved surface 104a is in the non-display state. At this time, as shown in the cross-sectional view taken along B1 - B2 shown in FIG. 13B, it is preferable that the regions that cannot be visually recognized when folded (the region 101b including the curved surface 104b and the region 101c) are also in the non-display state.

[0097] Alternatively, as shown in FIG. 13C, when the flat portion of the region 101a is in a non-display state, the curved surface 1 Similarly, the area that is folded and cannot be seen may be hidden. In this way, in the folded state, only a part of the area is displayed. This allows for power saving operation.

[0098] <Display operation example 2> 14A to 14C show three display units of display devices 100A to 100D according to one embodiment of the present invention. FIG. 10 is a diagram showing an example of use in a divided plane.

[0099] In FIG. 14A, the angle formed between the housing 102c and the housing 102b is an obtuse angle, and the angle formed between the housing 102b and the housing 102c is an obtuse angle. This is a diagram showing an example where the angle formed by a is set to an acute angle, allowing the device to be placed on a desk in a balanced manner. By using 102a as legs, it can be used like a laptop computer. For example, the keyboard 131 is in the area 101c, the icon 132 is in the curved surface 104b, and the area 101 Display the image 130 of the application software on b and operate it by touching the screen. It is possible to do so.

[0100] At this time, as shown in FIG. 14B, the same image 130 as that in the area 101b is displayed in the area 101a. If you set it to the display mode, the person opposite you can see the same image with good visibility. Alternatively, as shown in FIG. 14C, the area 101a is kept in a non-display state and the device is operated in a power-saving mode. That's fine.

[0101] <Display operation example 3> 15A to 15C show two display units of display devices 100A to 100E according to one embodiment of the present invention. FIG. 10 is a diagram showing an example of use in a divided plane.

[0102] FIG. 15A shows an example in which the angle formed between the housing 102a and the housing 102b is approximately 60° or more and less than 180° (for example, For example, the angle between the housings 102b and 102c is set to approximately 180°. This shows an example of a well-balanced installation on a desk by adjusting the area 101b and the area 10. 1c as a continuous plane to make a large screen, and the housing 102a as a leg to make the display surface (area The visibility can be improved by tilting the area 101b and the area 101c.

[0103] At this time, as shown in FIG. 15B, the area 101a is in a non-display state and the device operates in a power-saving mode. It is also acceptable to do so.

[0104] FIG. 15C shows a case where the angle formed between the housing 102c and the housing 102b is less than approximately 180° and is equal to or less than 90°. (for example, about 135°), and the angle formed by the housing 102b and the housing 102a is about 18°. 10 is a diagram showing an example in which the camera is placed on a desk in a well-balanced manner by setting the angle of the camera to 0°. By placing the housing 102b parallel to a flat surface such as a desk, input using a stylus 150 or the like can be performed. In addition, by tilting the area 101c, visibility can be improved. This can be done.

[0105] <Application example 1> 16A and 16B show the display device according to the present embodiment as an information terminal such as a smartphone. It should be noted that the elements common to the above-mentioned display device include the same The display device 200 includes audio input / output units 135a and 135b, The sensor includes sensors 136a and 136b, sensors 137, and sensors 120.

[0106] When one of the audio input / output units 135a and 135b functions as a microphone, the other functions as a It can function as a speaker. Therefore, when using the phone function, etc., one can talk without inconvenience even when holding it in any orientation. The microphone function and the speaker function can be switched by the sensor 120 that detects the inclination. Also, the cameras 136a , 136b can also be made to function preferentially by the sensor 120 in the same way.

[0107] The input / output units 135a, 135b may have both a device that functions as a microphone and a device that functions as a speaker, or may have one device having both functions.

[0108] Also, both of the input / output units 135a, 135b can be made to function as microphones to record stereo sound. Also, both of the input / output units 135a, 135b can be made to function as speakers to play back stereo sound.

[0109] Also, both of the cameras 136a, 136b can be made to function to capture a 3D image. The sensor 137 is a light sensor and can adjust the brightness of the display so as to be easily visible according to the ambient illuminance.

[0110] Also, as shown in FIG. 16B, a display panel 138 may be provided on the rear surface opposite to the front surface where the display panel 101 of the display device 200 is provided. The display panel 138 can display the same image as the display panel 101, and can also be used as a sub-display for displaying simple information, pictures, patterns, photos, etc., or as illumination. For the display panel 138, a display panel using a light-emitting device or a liquid crystal device can be used, and it can also be a low power consumption ​​​​​​​​An electronic paper or the like may be used. The display panel 138 may also use a display panel with a rigid substrate as a support. The display panel can also be used.

[0111] Note that the display panel 138 may be provided in each of the housings 102a to 102c as shown in FIG. 17A. Alternatively, as shown in FIG. 17B, a flexible display panel 139 may be provided on the rear surface of the display device 200. In this case, since the display panel 139 can be bent, it can be provided across the housings 102a to 102c in the same manner as the display panel 101 provided on the front surface. Or, as shown in FIG. 17B, a flexible display panel 139 may be provided on the rear surface of the display device 200. In this case, since the display panel 139 can be bent, it can be provided across the housings 102a to 102c in the same manner as the display panel 101 provided on the front surface. it can be provided across the housings 102a to 102c in the same manner as the display panel 101 provided on the front surface.

[0112] Also, as shown in FIG. 17C, a solar cell 140 may be provided on the rear surface of the display device 200. The electric power generated by the solar cell 140 can be used to charge the battery in the display device 200. In addition, electric power can be supplied to the outside via the external interface 145.

[0113] Note that FIG. 17C shows an example of a solar cell having a rigid support. Examples of such a solar cell include a silicon solar cell using crystalline silicon as a photoelectric conversion layer, or a solar cell having a tandem structure of a silicon solar cell and a perovskite solar cell. Examples of such a solar cell include a silicon solar cell using crystalline silicon as a photoelectric conversion layer, or a solar cell having a tandem structure of a silicon solar cell and a perovskite solar cell. Examples of such a solar cell include a silicon solar cell using crystalline silicon as a photoelectric conversion layer, or a solar cell having a tandem structure of a silicon solar cell and a perovskite solar cell. can be used.

[0114] Alternatively, as shown in FIG. 17D, a solar cell having a flexible substrate as a support may be used. Examples of such a solar cell include thin-film solar cells such as amorphous silicon solar cells, CIGS (Cu-In-Ga-Se) type solar cells, organic solar cells, or perovskite solar cells. Examples of such a solar cell include thin-film solar cells such as amorphous silicon solar cells, CIGS (Cu-In-Ga-Se) type solar cells, organic solar cells, or perovskite solar cells. Examples of such a solar cell include thin-film solar cells such as amorphous silicon solar cells, CIGS (Cu-In-Ga-Se) type solar cells, organic solar cells, or perovskite solar cells. 141 can be used. A solar cell having a flexible substrate as a support can be provided across the housings 102a to 102c in the same manner as the display panel 139. A solar cell having a flexible substrate as a support can be provided across the housings 102a to 102c in the same manner as the display panel 139.

[0115] <Application Example 2> FIGS. 18A and 18B are diagrams showing an example of selectively using the display units of display devices 100A to 100D according to an aspect of the present invention depending on the application.

[0116] FIGS. 18A and 18B are diagrams showing an example of applying the display device shown in the present embodiment as an order terminal in a restaurant or the like. Note that the same reference numerals are assigned to the elements common to the display devices described above. The display device 210 includes a transmission / reception unit 146, a speaker 147, a camera 148, a microphone 149, and the like. Note that the display device 210 may have some functions of an aspect of the present invention or may have functions of a general tablet computer. Normally, as shown in FIG. 18A, it can be in a folded state, and the function of calling a store clerk or an intercom function can be used. When it is unfolded, a menu is displayed and an order can be placed. The order content can be transmitted via the transmission / reception unit 146. In addition, the total amount of the order can be displayed and payment can be made using a barcode imaged by the camera 148.

[0117]

[0118] FIG. 19 is a block diagram showing an example of applying the display device shown in the present embodiment as a television device.

[0119] In FIG. 19, the components are classified by function and shown as independent blocks for each other. However, in actual components, it is difficult to completely separate them by function, and one component may be related to multiple functions.

[0120] ​​​​​​​​​​​​The television device 600 includes a control unit 601, a storage unit 602, a communication control unit 603, an image processing circuit 604, a decoder circuit 605, a video signal receiving unit 606, a timing controller 60 7, a source driver 608, a gate driver 609, a display panel 620, etc.

[0121] The display panel 620 corresponds to the display panel 101 shown in the first embodiment, and the other elements can be incorporated in any of the housings 102a to 102c. Note that some elements such as the source dri ver 608 and the gate driver 609 may be elements of the display panel 101.

[0122] The control unit 601 can function as, for example, a central processing unit (CPU: Central Processing Unit). For example, the control unit 601 controls components such as the storage unit 602, the communication control unit 603, the image processing circuit 604, the decoder circuit 605, and the video signal receiving unit 606 via a system bus 630.

[0123] Signals are transmitted between the control unit 601 and each component via the system bus 630. Further, the control unit 601 has functions of processing signals input from each component connected via the system bus 630, generating signals to be output to each component, etc., and thus can comprehensively control each component connected to the system bus 630.

[0124] The storage unit 602 functions as registers, cache memories, main memories, secondary memories, etc. that can be accessed by the control unit 601 and the image processing circuit 604.

[0125] As a storage device that can be used as a secondary memory, for example, a rewritable non-volatile storage device to which a memory is applied can be used. For example, a flash memory, an MRA M (Magnetoresistive Random Access Memory) PRAM (Phase change RAM), ReRAM (Resistive RAM), FeRAM (Ferroelectric RAM), etc. can be used.

[0126] Also, as a storage device that can be used as a temporary memory such as a register, a cache memory, or a main memory, volatile memories such as DRAM (Dynamic RAM) or SRAM (Stat ic Random Access Memory) may be used.

[0127] For example, as the RAM provided in the main memory, for example, DRAM is used, and a memory space is virtually allocated and used as the working space of the control unit 601. The operating system, application programs, program modules stored in the storage unit 602, program data, etc. are loaded into the RAM for execution. These data, programs, and program modules loaded into the RAM are directly accessed and operated on by the control unit 601.

[0128] On the other hand, the ROM can store a BIOS (Basic Input / Outp ut System) and firmware that do not require rewriting. As the ROM, a mask ROM, an OTPROM (One Time Programmable Read Only Memory), an EPROM (Erasable Programmabl Only Memory), etc. can be used. It is possible to use, for example, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, etc. As the EPROM, a UV-EPROM (Ultra-Violet Erasable Programmable Read Only Memory) that enables the erasure of stored data by ultraviolet irradiation, an EEPROM (Electrically Erasable Programmable Read Only Memory), a flash memory, etc. can be mentioned.

[0129] In addition to the storage unit 602, it may be configured to be able to connect a removable storage device. For example, it is preferable to have a recording medium drive such as a hard disk drive (HDD) or a solid state drive (SSD) that functions as a storage device, a flash memory, a Blu-ray disc, a DVD, etc., or a terminal for connecting to a recording medium such as a flash memory, a Blu-ray disc, a DVD, etc. Thereby, images can be recorded.

[0130] The communication control unit 603 has a function of controlling communication performed via a computer network. That is, the television device 600 applies Internet of Things (IoT) technology.

[0131] The communication control unit 603, for example, controls a control signal for connecting to a computer network in response to a command from the control unit 601, and transmits the signal to the computer network. As a result, the Internet, which is the basis of the World Wide Web (WWW), an intranet, an extranet, a PAN (Personal Area Network), etc. ​​​​​​​​​​​ork), LAN (Local Area Network), CAN (Campus Area Network), MAN (Metropolitan Area Netw ork), WAN (Wide Area Network), GAN (Global A rea Network), etc., and can communicate with a computer network such as this. It can be done.

[0132] In addition, the communication control unit 603 may have a function of communicating with a computer network or other electronic devices using communication standards such as Wi-Fi (registered trademark), Bluetooth (registered trademark), and ZigBee (registered trademark).

[0133] The communication control unit 603 may have a function of communicating wirelessly. For example, an antenna and a high frequency circuit (RF circuit) may be provided to perform transmission and reception of RF signals. The high frequency circuit mutually converts an electromagnetic signal in a frequency band defined by national laws and an electrical signal, and uses this electromagnetic signal to communicate wirelessly with other communication devices. As practical frequency bands, several tens of kHz to several tens of GHz are generally used. The high frequency circuit connected to the antenna has a high frequency circuit section corresponding to a plurality of frequency bands, and the high frequency circuit section can be configured to have an amplifier ( amp), mixer, filter, DSP, RF transceiver, etc.

[0134] The video signal receiving unit 606 has, for example, an antenna, a demodulation circuit, and an A-D conversion circuit (analog -digital conversion circuit), etc. The demodulation circuit has a function of demodulating a signal input from the antenna. Also, the A-D conversion circuit converts the demodulated analog signal into a digital signal. It has a function. The signal processed by the video signal receiving unit 606 is sent to the decoder circuit 605. to.

[0135] The decoder circuit 605 has a function of decoding the video data included in the digital signal input from the video signal receiving unit 606 according to the specifications of the broadcast standard to be transmitted, and generating a signal to be transmitted to the image processing circuit. For example, as broadcast standards in 8K broadcasting, there are H.265 | MPEG-H High Efficiency Video Coding (abbreviation: HEVC), etc. HEVC), etc.

[0136] Examples of the broadcast radio waves that can be received by the antenna of the video signal receiving unit 606 include terrestrial waves and radio waves transmitted from satellites. Also, examples of the broadcast radio waves that can be received by the antenna include analog broadcasts, digital broadcasts, etc., and there are also broadcasts of video and audio, or audio only. For example, it can receive broadcast radio waves transmitted in a specific frequency band within the UHF band (about 300 MHz to 3 GHz) or the VHF band (3 0 MHz to 300 MHz). Also, for example, by using a plurality of data received in a plurality of frequency bands, the transfer rate can be increased, and more information can be obtained. As a result, a video having a resolution exceeding full high definition can be displayed on the display panel 620. For example, a video having a resolution of 4K2K, 8K4K, 16K8K, or higher can be displayed. displayed. Also, the video signal receiving unit 606 and the decoder circuit 605 use the broadcast data transmitted by the data transmission technology via a computer network to send it to the image processing circuit 604. displayed.

[0137] Also, the video signal receiving unit 606 and the decoder circuit 605 use the broadcast data transmitted by the data transmission technology via a computer network to send it to the image processing circuit 604. to. ​It may be configured to generate a signal to be trusted. At this time, when the received signal is a digital signal the video signal receiving unit 606 may not have a demodulation circuit, an A-D conversion circuit, etc. .

[0138] The image processing circuit 604 has a function of generating a video signal to be output to the timing controller 607 based on the video signal input from the decoder circuit 605.

[0139] Based on the synchronization signal included in the video signal processed by the image processing circuit 604, etc., the timing controller 607 has a function of generating signals (such as a clock signal, a start pulse signal, etc.) to be output to the gate driver 609 and the source driver 608. Also, in addition to the above signals, the timing controller 607 has a function of generating a video signal to be output to the source driver 608. [[ID=1s5]] (signals such as a clock signal, a start pulse signal)

[0140] The display panel 620 has a plurality of pixels 621. Each pixel 621 is driven by signals supplied from the gate driver 609 and the source driver 608. Here, an example of a display panel having a resolution corresponding to the 8K4K standard with 7680×4320 pixels is shown. Note that the resolution of the display panel 620 is not limited to this, and it may have a resolution corresponding to a standard such as full high vision (1920×1080 pixels) or 4K2K (3840×2160 pixels).

[0141] The control unit 601 and the image processing circuit 604 shown in FIG. 19 may be configured to have, for example, a processor. For example, the control unit 601 can use a processor that functions as a CPU. Also, as the image processing circuit 604, for example, a DSP (Digital ​ Signal Processor), GPU (Graphics Processing unit), and other processors can be used. Also, the control unit 601 and the image processing circuit 604 can be configured with the above processors implemented by FPGA (Field Programmable G ate Array) or FPAA (Field Programmable Analo g Array), which are types of PLD (Programmable Logic Devic e).

[0142] The processor interprets and executes instructions from various programs to perform various data processing and program control. Programs that can be executed by the processor may be stored in the memory area of the processor or may be stored in a separately provided storage device .

[0143] Also, among the functions of the control unit 601, the storage unit 602, the communication control unit 603, the image processing circuit 604, the decoder circuit 605, the video signal receiving unit 606, and the timing controller 607, two or more functions can be integrated into one IC chip to form a system LSI . For example, it may be a system LSI having a processor, a decoder circuit, a tuner circuit, an A-D conversion circuit , DRAM, SRAM, etc. .

[0144] In addition, a transistor with an extremely low off-current realized by using an oxide semiconductor in the channel formation region can be used for the control unit 601 and ICs of other components . Since the off-current of the transistor is extremely low, the transistor can be used as a memory . By using it as a switch for holding the charge (data) that has flowed into the capable capacity, the holding period of data can be ensured over a long period. By using this characteristic in a register such as the control unit 601 or a cache memory, the control unit 601 is operated only when necessary, and in other cases, the information of the previous process is saved in the memory, so that normal-off operation can be achieved. As a result, the power consumption of the television apparatus 600 can be reduced.

[0145] Note that the configuration of the television apparatus 600 in FIG. 19 is an example, and it is not necessary to include all the components. The television apparatus 600 may have only the necessary components among the components shown in FIG. 19. Further, the television apparatus 600 may have components other than the components shown in FIG. 19.

[0146] For example, in addition to the configuration shown in FIG. 19, the television apparatus 600 may have an external interface, an audio output unit, a touch panel unit, a sensor unit, a camera unit, etc. For example, as the external interface, there are, for example, USB (Universal Serial Bus) terminals, LAN (Local Area Network) connection terminals, power supply and reception terminals, audio output terminals, audio input terminals, video output terminals, video input terminals and other external connection terminals, optical communication transceivers using infrared rays, visible light, ultraviolet rays, etc., physical buttons provided on the housing, etc. Also, for example, as the audio input / output unit, there are a sound controller, a microphone, a speaker,

[0147] Hereinafter, the image processing circuit 604 will be described in more detail.

[0148] The image processing circuit 604 preferably has a function of performing image processing based on the video signal input from the decoder circuit 605. It is preferable that.

[0149] Examples of the image processing include noise removal processing, gradation conversion processing, color tone correction processing, and luminance correction processing. Examples of the color tone correction processing and the luminance correction processing include gamma correction. etc.

[0150] In addition, the image processing circuit 604 preferably has a function of performing processing such as pixel interpolation processing accompanying up-conversion of the resolution and inter-frame interpolation processing accompanying up-conversion of the frame frequency. It is preferable that. For example, as the noise removal processing, various noises such as mosquito noise generated around the contour of characters, block noise generated in high-speed moving images, random noise causing flicker, and dot noise generated by up-conversion of the resolution are removed.

[0151] For example, as the noise removal processing, various noises such as mosquito noise generated around the contour of characters, block noise generated in high-speed moving images, random noise causing flicker, and dot noise generated by up-conversion of the resolution are removed. For example, as the noise removal processing, various noises such as mosquito noise generated around the contour of characters, block noise generated in high-speed moving images, random noise causing flicker, and dot noise generated by up-conversion of the resolution are removed. For example, as the noise removal processing, various noises such as mosquito noise generated around the contour of characters, block noise generated in high-speed moving images, random noise causing flicker, and dot noise generated by up-conversion of the resolution are removed.

[0152] The gradation conversion processing is a process of converting the gradation of an image into a gradation corresponding to the output characteristics of the display panel 620. For example, when increasing the number of gradations, for an image input with a small number of gradations, a process of smoothing the histogram can be performed by interpolating and assigning gradation values corresponding to each pixel. For example, when increasing the number of gradations, for an image input with a small number of gradations, a process of smoothing the histogram can be performed by interpolating and assigning gradation values corresponding to each pixel. In addition, high dynamic range (HDR) processing for expanding the dynamic range is also included in the gradation conversion processing. processing is also included in the gradation conversion processing.

[0153] In addition, the pixel interpolation processing interpolates data that does not originally exist when the resolution is up-converted. For example, by referring to the pixels around the target pixel and interpolating the data so as to display the intermediate color among them. For example, by referring to the pixels around the target pixel and interpolating the data so as to display the intermediate color among them.

[0154] Also, the color correction process is a process for correcting the color tone of an image. Also, the brightness correction process is a process for correcting the brightness (luminance contrast) of an image. For example, the television device 600 detects the type, brightness, or color purity of the illumination in the space where it is installed, and corrects the brightness and color tone of the image to be displayed on the display panel 620 accordingly. Or, the displayed image is collated with images of various scenes in a previously stored image list, and the image to be displayed may have a function of correcting the image to a brightness and color tone suitable for the image of the closest scene.

[0155] Inter-frame interpolation generates an image of a frame (interpolation frame) that does not originally exist when increasing the frame frequency of the video to be displayed. For example, an image of an interpolation frame to be inserted between two images is generated from the difference between two images. Or, a plurality of interpolation frame images can be generated between two images. For example, when the frame frequency of the video signal input from the decoder circuit 605 is 60 Hz, a plurality of interpolation frames are generated, and the frame frequency of the video signal output to the timing controller 607 can be increased to 2 times 12 0 Hz, or 4 times 240 Hz, or 8 times 480 Hz, etc.

[0156] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be implemented by appropriately combining at least a part of them with other configuration examples, or drawings, etc.

[0157] This embodiment can be implemented by appropriately combining at least a part of it with other embodiments described in this specification. ​​​​​​

[0158] (Embodiment 2) In this embodiment, a configuration example of a display panel applicable to a display device according to an aspect of the present invention will be described.

[0159] <Configuration Example> Fig. 20 shows a top view of a display panel 700. The display panel 700 is a display panel to which a flexible support substrate 745 is applied and which can be used as a flexible display. The display panel 700 also has a pixel portion 702 provided on the flexible support substrate 745. Also, a source driver circuit portion 704, a pair of gate driver circuit portions 706, wirings 710, etc. are provided on the support substrate 745. Further, a plurality of display devices are provided in the pixel portion 702.

[0160] Also, an FPC terminal portion 708 to which an FPC 716 (FPC: Flexible print ed circuit) is connected is provided in a part of the support substrate 745. Through the FPC 71 6, various signals, etc. are supplied to each of the pixel portion 702, the source driver circuit portion 704, and the gate driver circuit portion 706 via the FPC terminal portion 708 and the wiring 710. are supplied.

[0161] The pair of gate driver circuit portions 706 are provided on both sides with the pixel portion 702 interposed therebetween. Note that the gate driver circuit portion 706 and the source driver circuit portion 704 may each be separately formed on a semiconductor substrate or the like and be in the form of a packaged IC chip. The IC chip can be mounted on the support substrate 745 by COF (Chip On Film) technology or the like. can be.

[0162] It is preferable to apply an OS transistor to the transistors included in the pixel portion 702, the source driver circuit portion 704, and the gate driver circuit portion 706.

[0163] As the display device provided in the pixel portion 702, a light-emitting device or the like can be used. As the light-emitting device, self-luminous light-emitting devices such as an LED (Light Emitting Diode), an OLED (Organic LED), a QLED (Quantum-dot LED), and a semiconductor laser can be mentioned. Further, as the display device, a liquid crystal device such as a transmissive liquid crystal device, a reflective liquid crystal device, or a transflective liquid crystal device can be used. Further, an MEMS (Micro Electro Mechanical Systems) device of a shutter method or an optical interference method, a microcapsule method, an electrophoresis method, an electrowetting method, or a display device to which an electronic ink (registered trademark) method or the like is applied can also be used.

[0164] Further, FIG. 20 shows an example in which a portion of the support substrate 745 where the FPC terminal portion 708 is provided has a protruding shape. A part including the FPC terminal portion 708 of the support substrate 745 can be folded back to the back side in the region P1 in FIG. 2 0. By folding back a part of the support substrate 745 and arranging the FPC 716 on the back side of the pixel portion 702, the display panel 700 can be mounted on an electronic device or the like, and space saving and miniaturization of the electronic device or the like can be achieved.

[0165] Further, an IC 717 is mounted on the FPC 716 connected to the display panel 700. IC717 has functions such as that of a source driver circuit. At this time, the source driver circuit section 704 in the display panel 700 can be configured to include at least one of a protection circuit, a buffer circuit, a demultiplexer circuit, etc.

[0166] <Cross-sectional configuration example> Hereinafter, a configuration using an organic EL as a display device will be described with reference to FIGS. 21 and 22. FIGS. 21 and 22 are schematic cross-sectional views taken along the chain double-dashed line S-T of the display panel 700 shown in FIG. 20, respectively.

[0167] First, the common parts of the display panels shown in FIGS. 21 and 22 will be described.

[0168] FIGS. 21 and 22 show a cross-section including a pixel section 702, a gate driver circuit section 706, and an FPC terminal section 708. The pixel section 702 has a transistor 750 and a capacitor 790. The gate driver circuit section 706 has a transistor 752.

[0169] The transistor 750 and the transistor 752 are transistors in which an oxide semiconductor is applied to a semiconductor layer in which a channel is formed. Note that the present invention is not limited to this, and a transistor using silicon (amorphous silicon, polycrystalline silicon, or single-crystalline silicon) or an organic semiconductor for the semiconductor layer can also be applied.

[0170] The transistor used in this embodiment has an oxide semiconductor film with high purity and suppression of the formation of oxygen vacancies. The transistor can significantly reduce the off-current. Therefore, a pixel to which such a transistor is applied can increase the holding time of an electrical signal such as an image signal, and the image The writing interval of signals and the like can also be set long. Therefore, the frequency of the refresh operation can be reduced, and the power consumption can be reduced. Therefore, the power consumption can be reduced.

[0171] In addition, the transistor used in this embodiment can obtain a relatively high field-effect mobility, so it can be driven at high speed. For example, by using such a transistor capable of high-speed driving in a display panel, the switching transistor in the pixel portion and the drive transistor used in the drive circuit portion can be formed on the same substrate. That is, a configuration that does not apply a drive circuit formed by a silicon wafer or the like is also possible, and the number of components of the display device can be reduced. In addition, in the pixel portion, by using a transistor capable of high-speed driving, a high-quality image can be provided. In addition, in the pixel portion, by using a transistor capable of high-speed driving, a high-quality image can be provided.

[0172] The capacitor 790 has a lower electrode formed by processing the same film as the first gate electrode of the transistor 750, and an upper electrode formed by processing the same metal oxide film as the semiconductor layer. The upper electrode is made to have a low resistance similar to the source region and the drain region of the transistor 750. Also, a part of the insulating film that functions as the first gate insulating layer of the transistor 750 is provided between the lower electrode and the upper electrode. That is, the capacitor 790 has a stacked structure in which an insulating film that functions as a dielectric film is sandwiched between a pair of electrodes. The upper electrode is made to have a low resistance similar to the source region and the drain region of the transistor 750. Also, a part of the insulating film that functions as the first gate insulating layer of the transistor 750 is provided between the lower electrode and the upper electrode. That is, the capacitor 790 has a stacked structure in which an insulating film that functions as a dielectric film is sandwiched between a pair of electrodes. The upper electrode is made to have a low resistance similar to the source region and the drain region of the transistor 750. Also, a part of the insulating film that functions as the first gate insulating layer of the transistor 750 is provided between the lower electrode and the upper electrode. That is, the capacitor 790 has a stacked structure in which an insulating film that functions as a dielectric film is sandwiched between a pair of electrodes. The upper electrode is made to have a low resistance similar to the source region and the drain region of the transistor 750. Also, a part of the insulating film that functions as the first gate insulating layer of the transistor 750 is provided between the lower electrode and the upper electrode. That is, the capacitor 790 has a stacked structure in which an insulating film that functions as a dielectric film is sandwiched between a pair of electrodes. The upper electrode is made to have a low resistance similar to the source region and the drain region of the transistor 750. Also, a part of the insulating film that functions as the first gate insulating layer of the transistor 750 is provided between the lower electrode and the upper electrode. That is, the capacitor 790 has a stacked structure in which an insulating film that functions as a dielectric film is sandwiched between a pair of electrodes. The upper electrode is made to have a low resistance similar to the source region and the drain region of the transistor 750. Also, a part of the insulating film that functions as the first gate insulating layer of the transistor 750 is provided between the lower electrode and the upper electrode. That is, the capacitor 790 has a stacked structure in which an insulating film that functions as a dielectric film is sandwiched between a pair of electrodes. A wiring obtained by processing the same film as the source electrode and the drain electrode of the transistor 750 is connected to the upper electrode.

[0173] In addition, an insulating layer 770 that functions as a planarization film is provided on the transistor 750, the transistor 752, and the capacitor 790. In addition, an insulating layer 770 that functions as a planarization film is provided on the transistor 750, the transistor 752, and the capacitor 790.

[0174] The transistor 750 included in the pixel portion 702 and the transistor 752 included in the gate driver circuit portion 706 may use transistors with different structures. For example, a top-gate type transistor may be applied to one of them, and a bottom-gate type transistor may be applied to the other to form a configuration. Note that the same applies to the source driver circuit portion 704 as to the gate driver circuit portion 706.

[0175] The FPC terminal portion 708 includes a wiring 760 that partially functions as a connection electrode, an anisotropic conductive film 780 , and an FPC 716. The wiring 760 is electrically connected to the terminal included in the FPC 71 6 via the anisotropic conductive film 780. Here, the wiring 760 is formed of the same conductive film as the source electrode and the drain electrode of the transistor 750 etc.

[0176] Subsequently, the display panel 700 shown in FIG. 21 will be described.

[0177] The display panel 700 shown in FIG. 21 includes a support substrate 745 and a support substrate 740. As the support substrate 745 and the support substrate 740, for example, a flexible substrate such as a glass substrate or a plastic substrate can be used.

[0178] The transistor 750, the transistor 752, the capacitor 790, etc. are provided on the insulating layer 744. The support substrate 745 and the insulating layer 744 are bonded together by an adhesive layer 742 .

[0179] The display panel 700 also includes a light-emitting device 782, a coloring layer 736, a light-shielding layer 738, etc.

[0180] The light-emitting device 782 has a conductive layer 772, an EL layer 786, and a conductive layer 788. The conductive layer 772 is electrically connected to the source electrode or the drain electrode of the transistor 750. The conductive layer 772 is provided on the insulating layer 770 and functions as a pixel electrode. Also, an insulating layer 730 is provided to cover the end of the conductive layer 772, and the EL layer 786 and the conductive layer 788 are laminated on the insulating layer 730 and the conductive layer 772.

[0181] For the conductive layer 772, a material having reflectivity for visible light can be used. For example, a material containing aluminum, silver, etc. can be used. Also, for the conductive layer 788, a material having transparency for visible light can be used. For example, an oxide material containing indium, zinc, tin, etc. may be used. Therefore, the light-emitting device 782 is a top-emission type light-emitting device that emits light on the side opposite to the surface to be formed (the support substrate 740 side).

[0182] The EL layer 786 has an organic compound or an inorganic compound such as quantum dots. The EL layer 78 6 contains a light-emitting material that exhibits blue light when current flows.

[0183] As the light-emitting material, a fluorescent material, a phosphorescent material, a thermally activated delayed fluorescence (TADF) material, an inorganic compound (such as a quantum dot material), etc. can be used. As the material that can be used for quantum dots, colloidal quantum dot materials, alloy-type quantum dot materials, core-shell type quantum dot materials, core-type quantum dot materials, etc. can be mentioned.

[0184] ​The light-shielding layer 738 and the coloring layer 736 are provided on one surface of the insulating layer 746. The coloring layer 7 36 is provided at a position overlapping with the light-emitting device 782. Also, the light-shielding layer 738 is provided in a region in the pixel portion 702 that does not overlap with the light-emitting device 782. Further, the light-shielding layer 738 may also be provided so as to overlap with the gate driver circuit portion 706 and the like.

[0185] The support substrate 740 is bonded to the other surface of the insulating layer 746 by an adhesive layer 747. Also, the support substrate 740 and the support substrate 745 are bonded by a sealing layer 732. .

[0186] Here, as the EL layer 786 of the light-emitting device 782, a light-emitting material that exhibits white light emission is applied. The white light emitted by the light-emitting device 782 is colored by the coloring layer 736 and emitted to the outside. The EL layer 786 is provided across pixels exhibiting different colors. By arranging in a matrix pixels provided with a coloring layer 736 that transmits any one of red (R), green (G), or blue (B) in the pixel portion, the display panel 700 can perform full-color display. Here, as the EL layer 786 of the light-emitting device 782, a light-emitting material that exhibits white light emission is applied. The white light emitted by the light-emitting device 782 is colored by the coloring layer 736 and emitted to the outside. The EL layer 786 is provided across pixels exhibiting different colors. By arranging in a matrix pixels provided with a coloring layer 736 that transmits any one of red (R), green (G), or blue (B) in the pixel portion, the display panel 700 can perform full-color display. Here, as the EL layer 786 of the light-emitting device 782, a light-emitting material that exhibits white light emission is applied. The white light emitted by the light-emitting device 782 is colored by the coloring layer 736 and emitted to the outside. The EL layer 786 is provided across pixels exhibiting different colors. By arranging in a matrix pixels provided with a coloring layer 736 that transmits any one of red (R), green (G), or blue (B) in the pixel portion, the display panel 700 can perform full-color display. Here, as the EL layer 786 of the light-emitting device 782, a light-emitting material that exhibits white light emission is applied. The white light emitted by the light-emitting device 782 is colored by the coloring layer 736 and emitted to the outside. The EL layer 786 is provided across pixels exhibiting different colors. By arranging in a matrix pixels provided with a coloring layer 736 that transmits any one of red (R), green (G), or blue (B) in the pixel portion, the display panel 700 can perform full-color display. Here, as the EL layer 786 of the light-emitting device 782, a light-emitting material that exhibits white light emission is applied. The white light emitted by the light-emitting device 782 is colored by the coloring layer 736 and emitted to the outside. The EL layer 786 is provided across pixels exhibiting different colors. By arranging in a matrix pixels provided with a coloring layer 736 that transmits any one of red (R), green (G), or blue (B) in the pixel portion, the display panel 700 can perform full-color display. Here, as the EL layer 786 of the light-emitting device 782, a light-emitting material that exhibits white light emission is applied. The white light emitted by the light-emitting device 782 is colored by the coloring layer 736 and emitted to the outside. The EL layer 786 is provided across pixels exhibiting different colors. By arranging in a matrix pixels provided with a coloring layer 736 that transmits any one of red (R), green (G), or blue (B) in the pixel portion, the display panel 700 can perform full-color display.

[0187] Also, as the conductive layer 788, a conductive film having semi-transparency and semi-reflectivity may be used. In this case, a microcavity structure can be realized between the conductive layer 772 and the conductive layer 788, and the configuration can be such that light of a specific wavelength is enhanced and emitted. Also, at this time, an optical adjustment layer for adjusting the optical distance is arranged between the conductive layer 7 Also, as the conductive layer 788, a conductive film having semi-transparency and semi-reflectivity may be used. In this case, a microcavity structure can be realized between the conductive layer 772 and the conductive layer 788, and the configuration can be such that light of a specific wavelength is enhanced and emitted. Also, at this time, an optical adjustment layer for adjusting the optical distance is arranged between the conductive layer 7 Also, as the conductive layer 788, a conductive film having semi-transparency and semi-reflectivity may be used. In this case, a microcavity structure can be realized between the conductive layer 772 and the conductive layer 788, and the configuration can be such that light of a specific wavelength is enhanced and emitted. Also, at this time, an optical adjustment layer for adjusting the optical distance is arranged between the conductive layer 7 72 and the conductive layer 788, and by making the thickness of the optical adjustment layer different between pixels of different colors, the color purity of the light emitted from each pixel can be increased. 72 and the conductive layer 788, and by making the thickness of the optical adjustment layer different between pixels of different colors, the color purity of the light emitted from each pixel can be increased. 72 and the conductive layer 788, and by making the thickness of the optical adjustment layer different between pixels of different colors, the color purity of the light emitted from each pixel can be increased.

[0188] In addition, when the EL layer 786 is formed in an island shape for each pixel or in a striped shape for each pixel column, that is, by painting it may be configured not to provide the coloring layer 736 and the above-described optical adjustment layer. This is also acceptable.

[0189] Here, it is preferable to use inorganic insulating films for the insulating layer 744 and the insulating layer 746, which each function as a barrier film with low moisture permeability. By sandwiching the light-emitting device 782, the transistor 750, etc. between such an insulating layer 744 and an insulating layer 746, the deterioration of these can be suppressed, and a highly reliable display panel can be realized.

[0190] In the display panel 700A shown in FIG. 22, a resin layer 743 is provided between the adhesive layer 742 and the insulating layer 744 shown in FIG. 21. Further, instead of the support substrate 740, a protective layer 749 is provided.

[0191] The resin layer 743 is a layer containing an organic resin such as polyimide or acrylic. The insulating layer 744 includes an inorganic insulating film such as silicon oxide, silicon oxynitride, or silicon nitride. The resin layer 743 and the support substrate 745 are bonded together by the adhesive layer 742. The resin layer 743 is preferably thinner than the support substrate 745.

[0192] The protective layer 749 is bonded to the sealing layer 732. As the protective layer 749, a glass plate, a resin film, etc. can be used. Further, as the protective layer 749, an optical member such as a polarizing plate (including a circular polarizing plate), a diffusing plate, an input device such as a touch sensor panel, or a configuration in which two or more of these are laminated may be applied.

[0193] Further, the EL layer 786 included in the light-emitting device 782 is provided in an island shape on the insulating layer 730 and the conductive layer 772. By making the EL layer 786 different in light-emitting color for each sub-pixel, color display can be realized without using the color filter layer 736.

[0194] Further, a protective layer 741 is provided to cover the light-emitting device 782. The protective layer 741 has a function of preventing impurities such as water from diffusing into the light-emitting device 782. The protective layer 741 has a laminated structure in which an insulating layer 741a, an insulating layer 741b, and an insulating layer 741c are laminated in this order from the conductive layer 788 side. At this time, it is preferable to use an inorganic insulating film having a high barrier property against impurities such as water for the insulating layer 741a and the insulating layer 741c, and an organic insulating film functioning as a planarization film for the insulating layer 741b. Further, the protective layer 741 is preferably also extended and provided to the gate driver circuit portion 706.

[0195] Further, it is preferable that an organic insulating film covering the transistors 750, 752, etc. is formed in an island shape inside the sealing layer 732. In other words, it is preferable that the end portion of the organic insulating film is located inside the sealing layer 732 or in a region overlapping with the end portion of the sealing layer 732. FIG. 22 shows an example in which the insulating layer 770, the insulating layer 730, and the insulating layer 741b are processed in an island shape. For example, in a portion overlapping with the sealing layer 732, the insulating layer 741c and the insulating layer 741a are provided in contact with each other. By adopting a configuration in which the surface of the organic insulating film covering the transistors 750 and 752 is not exposed outside the sealing layer 732, the transistors 750 and 752 can be protected from the outside through the organic insulating film. ​​​​​​​​It is possible to suitably prevent the diffusion of water and hydrogen. As a result, fluctuations in the electrical characteristics of the transistor can be suppressed, and a highly reliable display device can be realized. Furthermore, in FIG. 22, in the foldable region P1, there are portions where inorganic insulating films such as the support substrate 745 and the adhesive layer 742, and the insulating layer 744 are not provided. Also, in the region P1, in order to prevent the wiring 760 from being exposed, the insulating layer 770 containing an organic material has a configuration that covers the wiring 760.

[0196] In the foldable region P1, by providing as few inorganic insulating films as possible, and forming a structure in which only a conductive layer containing a metal or an alloy and a layer containing an organic material are laminated, it is possible to prevent cracks from occurring when bent. Also, by not providing the support substrate 745 in the region P1, a part of the display panel 700A can be bent with an extremely small radius of curvature. Furthermore, in FIG. 22, a conductive layer 761 is provided on the protective layer 741. The conductive layer 761 can be used as a wiring or an electrode. Moreover, when a touch sensor is provided overlaid on the display panel 700A, the conductive layer 761 can function as an electrostatic shielding film to prevent electrical noise generated when driving the pixels from being transmitted to the touch sensor. At this time, a predetermined fixed potential may be applied to the conductive layer 761. Alternatively, the conductive layer 761 can be used, for example, as an electrode of a touch sensor. Thus, the display panel 700A can function as a touch panel. For example, the conductive layer 761 can be used as an electrode of a touch sensor. Thus, the display panel 700A can function as a touch panel. For example, the conductive layer 761 can be used as an electrode of a touch sensor. Thus, the display panel 700A can function as a touch panel. For example, the conductive layer 761 can be used as an electrode of a touch sensor. Thus, the display panel 700A can function as a touch panel. For example, the conductive

[0197] Furthermore, in FIG. 22, a conductive layer 761 is provided on the protective layer 741. The conductive layer 761 can be used as a wiring or an electrode. The conductive layer 761 can be used as a wiring or an electrode.

[0198] Also, when a touch sensor is provided overlaid on the display panel 700A, the conductive layer 761 can function as an electrostatic shielding film to prevent electrical noise generated when driving the pixels from being transmitted to the touch sensor. At this time, a predetermined fixed potential may be applied to the conductive layer 761. At this time, a predetermined fixed potential may be applied to the conductive layer 761. At this time, a predetermined fixed potential may be applied to the conductive layer 761.

[0199] Alternatively, the conductive layer 761 can be used, for example, as an electrode of a touch sensor. As a result, the display panel 700A can function as a touch panel. For example, the conductive The layer 761 can be used as an electrode or wiring for a capacitive touch sensor. At this time, the conductive layer 761 is a wiring or electrode to which the detection circuit is connected, or a wiring or electrode to which a sensor signal is input. In this way, the light-emitting device 782 can be provided with a wiring or an electrode. By incorporating a touch sensor, the number of parts can be reduced, reducing the manufacturing costs of electronic devices. It is possible.

[0200] The conductive layer 761 is preferably provided in a portion that does not overlap with the light-emitting device 782. For example, the conductive layer 761 can be provided in a position overlapping with the insulating layer 730. As the conductive layer 761, it is not necessary to use a transparent conductive film having a relatively low conductivity, and a gold film having a high conductivity can be used. Since metals and alloys can be used, the sensitivity of the sensor can be increased.

[0201] The conductive layer 761 can be used to configure a touch sensor. Not limited to the volume type, but also includes resistive film type, surface acoustic wave type, infrared type, optical type, pressure sensitive type, etc. A variety of methods can be used, or two or more of these can be used in combination. .

[0202] <Components> Components such as transistors that can be applied to a display device will be described below.

[0203] [Transistor] A transistor includes a conductive layer that functions as a gate electrode, a semiconductor layer, and a gate electrode that functions as a source electrode. a conductive layer acting as a drain electrode; a conductive layer acting as a gate insulating layer; and an edge layer.

[0204] Note that the structure of a transistor included in a display device of one embodiment of the present invention is not particularly limited. It may be a planar transistor, a staggered transistor, or an inverse staggered transistor. Also, it may be any of the top gate type or bottom gate type transistor structures. Alternatively, gate electrodes may be provided above and below the channel as well.

[0205] The crystallinity of the semiconductor material used for the transistor is not particularly limited, and any of amorphous semiconductors, semiconductors having crystallinity (microcrystalline semiconductors, polycrystalline semiconductors, single crystal semiconductors, or semiconductors having a crystalline region in part) may be used. Using a semiconductor having crystallinity is preferable because deterioration of transistor characteristics can be suppressed.

[0206] <Conductive layer> In addition to the gate, source, and drain of the transistor, materials that can be used for conductive layers such as various wirings and electrodes constituting the display device include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, or tungsten, or alloys having these as main components. Further, films containing these materials can be used as a single layer or in a laminated structure. For example, a single layer structure of an aluminum film containing silicon, a two-layer structure in which an aluminum film is laminated on a titanium film, a two-layer structure in which an aluminum film is laminated on a tungsten film, a two-layer structure in which a copper film is laminated on a copper-magnesium-aluminum alloy film, a two-layer structure in which a copper film is laminated on a titanium film, a two-layer structure in which a copper film is laminated on a tungsten film, a three-layer structure in which a titanium film or a titanium nitride film is overlapped with an aluminum film or a copper film thereon, and a titanium film or a titanium nitride film is further formed thereon ​​​​​​​​​​​Structure, a molybdenum film or a molybdenum nitride film, and an aluminum film or copper film are laminated thereon, and a three-layer structure or the like in which a molybdenum film or a molybdenum nitride film is further formed thereon exists. In addition, oxides such as indium oxide, tin oxide, or zinc oxide may be used. Also , using copper containing manganese is preferable because the controllability of the shape by etching is enhanced.

[0207] <Insulating layer> Examples of insulating materials that can be used for each insulating layer include resins such as acrylic and epoxy resins, resins having a siloxane bond, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide can also be used.

[0208] Also, the light-emitting device is preferably provided between a pair of insulating films with low water permeability . Thereby, it is possible to suppress the intrusion of impurities such as water into the light-emitting device, and to suppress reduction in the reliability of the device.

[0209] Examples of insulating films with low water permeability include films containing nitrogen and silicon such as silicon nitride films and silicon oxynitride films, and films containing nitrogen and aluminum such as aluminum nitride films. Also, silicon oxide films, silicon oxynitride films, aluminum oxide films, etc. may be used.

[0210] For example, the water vapor transmission rate of the insulating film with low water permeability is 1×10 -5 [g / (m 2 ·day)] or less, preferably 1×10 <> -6 [g / (m 2 ·day)] or less, more preferably 1×10 -7 [g / (m 2 ·day)] or less, even more preferably 1×10 -8 [g / (m2 ·da shall be as follows.

[0211] The above is the description of the components.

[0212] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be implemented by appropriately combining at least a part with other configuration examples, or drawings, etc.

[0213] This embodiment can be implemented by appropriately combining at least a part of it with other embodiments described in this specification in combination.

[0214] (Embodiment 3) In this embodiment, a configuration example of the display device will be described with reference to FIGS. 23A, 23B, and 23C. Explanation will be given.

[0215] The display device shown in FIG. 23A includes a pixel unit 502, a driving circuit unit 504, a protection circuit 506, and a terminal unit 507. Note that the protection circuit 506 may not be provided.

[0216] The pixel unit 502 includes a plurality of pixel circuits 501 that drive a plurality of display devices arranged in X rows and Y columns (X and Y are each independently natural numbers of 2 or more).

[0217] The driving circuit unit 504 includes a gate driver 504a that outputs a scanning signal to gate lines GL_1 to GL_X, and a source driver 50 4b that supplies a data signal to data lines DL_1 to DL_Y, and other driving circuits. The gate driver 504a may be configured to include at least a shift register. Also, the source driver 504b is configured using, for example, a plurality of analog switches. etc. Further, the source driver 504b can be configured using a shift register or the like. It may be configured.

[0218] The terminal portion 507 refers to a portion where terminals for inputting power, a control signal, an image signal, etc. from an external circuit to the display device are provided. It refers to a portion where terminals for inputting power, a control signal, an image signal, etc. from an external circuit to the display device are provided.

[0219] The protection circuit 506 is a circuit that makes a wiring to which it is connected and another wiring in a conductive state when a potential outside a certain range is applied to the wiring to which it is connected. The protection circuit 506 shown in FIG. 23A is, for example, connected to various wirings such as a gate line GL which is a wiring between the gate driver 504a and the pixel circuit 501, or a data line DL which is a wiring between the source driver 504b and the pixel circuit 501. connected to various wirings such as a gate line GL which is a wiring between the gate driver 504a and the pixel circuit 501, or a data line DL which is a wiring between the source driver 504b and the pixel circuit 501. connected to various wirings such as a gate line GL which is a wiring between the gate driver 504a and the pixel circuit 501, or a data line DL which is a wiring between the source driver 504b and the pixel circuit 501. connected to various wirings such as a gate line GL which is a wiring between the gate driver 504a and the pixel circuit 501, or a data line DL which is a wiring between the source driver 504b and the pixel circuit 501.

[0220] Also, the gate driver 504a and the source driver 504b may be provided on the same substrate as the pixel portion 502, or a substrate on which a gate driver circuit or a source driver circuit is separately formed (for example, a driving circuit substrate formed of a single crystal semiconductor film or a polycrystalline semiconductor film) may be mounted on the substrate by COF, TCP (Tape Carrier Package), COG (Chip On Glass), etc. Also, the gate driver 504a and the source driver 504b may be provided on the same substrate as the pixel portion 502, or a substrate on which a gate driver circuit or a source driver circuit is separately formed (for example, a driving circuit substrate formed of a single crystal semiconductor film or a polycrystalline semiconductor film) may be mounted on the substrate by COF, TCP (Tape Carrier Package), COG (Chip On Glass), etc. Also, the gate driver 504a and the source driver 504b may be provided on the same substrate as the pixel portion 502, or a substrate on which a gate driver circuit or a source driver circuit is separately formed (for example, a driving circuit substrate formed of a single crystal semiconductor film or a polycrystalline semiconductor film) may be mounted on the substrate by COF, TCP (Tape Carrier Package), COG (Chip On Glass), etc. Also, the gate driver 504a and the source driver 504b may be provided on the same substrate as the pixel portion 502, or a substrate on which a gate driver circuit or a source driver circuit is separately formed (for example, a driving circuit substrate formed of a single crystal semiconductor film or a polycrystalline semiconductor film) may be mounted on the substrate by COF, TCP (Tape Carrier Package), COG (Chip On Glass), etc. Also, the gate driver 504a and the source driver 504b may be provided on the same substrate as the pixel portion 502, or a substrate on which a gate driver circuit or a source driver circuit is separately formed (for example, a driving circuit substrate formed of a single crystal semiconductor film or a polycrystalline semiconductor film) may be mounted on the substrate by COF, TCP (Tape Carrier Package), COG (Chip On Glass), etc.

[0221] Also, the plurality of pixel circuits 501 shown in FIG. 23A may have, for example, the configurations shown in FIGS. 23B and 23C. Also, the plurality of pixel circuits 501 shown in FIG. 23A may have, for example, the configurations shown in FIGS. 23B and 23C.

[0222] The pixel circuit 501 shown in FIG. 23B includes a liquid crystal device 570, a transistor 550, and a capacitor 560. Also, a data line DL_n, a gate line GL_m, a potential supply line VL, etc. are connected to the pixel circuit 501. The pixel circuit 501 shown in FIG. 23B includes a liquid crystal device 570, a transistor 550, and a capacitor 560. Also, a data line DL_n, a gate line GL_m, a potential supply line VL, etc. are connected to the pixel circuit 501. The pixel circuit 501 shown in FIG. 23B includes a liquid crystal device 570, a transistor 550, and a capacitor 560. Also, a data line DL_n, a gate line GL_m, a potential supply line VL, etc. are connected to the pixel circuit 501.

[0223] One of the potentials of a pair of electrodes of the liquid crystal device 570 is appropriately set according to the specifications of the pixel circuit 501. The liquid crystal device 570 has its alignment state set according to the data to be written. In addition, a common potential (common potential) may be applied to one of a pair of electrodes of the liquid crystal device 570 included in each of the plurality of pixel circuits 501. Alternatively, different potentials may be applied to one of a pair of electrodes of the liquid crystal device 570 of the pixel circuits 501 in each row.

[0224] Also, the pixel circuit 501 shown in FIG. 23C includes transistors 552 and 554, a capacitor 5 62, and a light-emitting device 572. Data lines DL_n , gate lines GL_m, potential supply lines VL_a, potential supply lines VL_b, etc. are connected to the pixel circuit 501.

[0225] A high power supply potential VDD is applied to one of the potential supply line VL_a and the potential supply line VL_b, and a low power supply potential VSS is applied to the other. The current flowing through the light-emitting device 572 is controlled according to the potential applied to the gate of the transistor 554, thereby controlling the emission luminance from the light-emitting device 572.

[0226] The configuration examples illustrated in this embodiment, and the corresponding drawings and the like can be implemented in appropriate combination with at least a part of them and other configuration examples or drawings and the like.

[0227] This embodiment can be implemented in appropriate combination with at least a part of it and other embodiments described in this specification.

[0228] (Embodiment 4) Hereinafter, a pixel circuit including a memory for correcting the gradation displayed on a pixel and a display device having the same will be described. ​

[0229] <Circuit configuration> FIG. 24A shows a circuit diagram of a pixel circuit 400. The pixel circuit 400 includes a transistor M1, a transistor M2, a capacitor C1, and a circuit 401. Further, wiring S1, wiring S2, wiring G1, and wiring G2 are connected to the pixel circuit 400.

[0230] The gate of the transistor M1 is connected to the wiring G1, one of the source and the drain is connected to the wiring S1, and the other is connected to one electrode of the capacitor C1, respectively. The gate of the transistor M2 is connected to the wiring G2, one of the source and the drain is connected to the wiring S2, and the other is connected to the other electrode

[0231] of the capacitor C1 and the circuit 401, respectively. The circuit 401 is a circuit including at least one display device. Various devices can be used as the display device, but typically, a light-emitting device such as an organic EL device or an LED device, a liquid crystal device, or a MEMS (Micro Electro

[0232] Mechanical Systems) device, etc. can be applied. Let the node connecting the transistor M1 and the capacitor C1 be the node N1, and the node

[0233] connecting the transistor M2 and the circuit 401 be the node N2. The pixel circuit 400 can hold the potential of the node N1 by turning off the transistor M1. Further, the potential of the node N2 can be held by turning off the transistor M2. Also, by writing a predetermined potential to the node N1 through the transistor M1 with the Accordingly, the potential of node N2 can be changed according to the displacement of the potential of node N1.

[0234] Here, one or both of the transistors M1 and M2 may be the transistors to which the oxide semiconductor exemplified in Embodiment 1 is applied. Therefore, due to an extremely low off-current, the potentials of node N1 and node N2 can be held for a long period. Note that when the period during which the potential of each node is held is short (specifically, when the frame frequency is 30 Hz or more, etc.), transistors using semiconductors such as silicon may be used.

[0235] <Example of driving method> Next, with reference to FIG. 24B, an example of an operation method of the pixel circuit 400 will be described. FIG. 24B is a timing chart related to the operation of the pixel circuit 400. Here, for ease of explanation, various resistances such as wiring resistance, parasitic capacitances of transistors and wiring, and the influence of threshold voltages of transistors are not considered.

[0236] In the operation shown in FIG. 24B, one frame period is divided into a period T1 and a period T2. The period T1 is a period during which a potential is written to node N2, and the period T2 is a period during which a potential is written to node N1.

[0237] In the period T1, potentials for turning on the transistors are applied to both the wiring G1 and the wiring G2. In addition, a potential V ref which is a fixed potential is supplied to the wiring S1, and a first data potential V w is supplied to the wiring S2.

[0238] To node N1, a potential V refis given. Also, at node N2, the first data potential V is supplied from wiring S2 via transistor M2 w is given to. Therefore, the potential difference V w -V ref is held in the capacitor C1.

[0239] Subsequently, in period T2, a potential for turning on transistor M1 is applied to wiring G1, and a potential for turning off transistor M2 is applied to wiring G2. Also, the second data potential V data is supplied to wiring S1. A predetermined fixed potential or floating may be applied to wiring S2.

[0240] At node N1, the second data potential V is supplied from wiring S1 via transistor M1 data is given to. At this time, due to capacitive coupling by capacitor C1, the potential of node N2 changes by potential dV according to data the second data potential V . That is, a potential obtained by adding the first data potential Vw and potential dV is input to circuit 401. Note that in FIG. 24B, potential dV is shown as a positive value, but it may be a negative value. That is, the second data potential V data may be lower than potential V ref . That is, the second data potential V

[0241] Here, potential dV is generally determined by the capacitance value of capacitor C1 and the capacitance value of circuit 401 . When the capacitance value of capacitor C1 is sufficiently larger than the capacitance value of circuit 401, potential dV becomes a potential close to the second data potential V data .

[0242] In this way, the pixel circuit 400 combines two types of data signals to include a display device Since it is possible to generate the potential supplied to the circuit 401, gradation correction can be performed within the pixel circuit 400. This becomes possible.

[0243] Also, the pixel circuit 400 can generate a potential exceeding the maximum potential that can be supplied to the wiring S1 and the wiring S2. For example, when a light-emitting device is used, high dynamic range (HDR) display or the like can be performed. Also, when a liquid crystal device is used, overdrive driving or the like can be realized. For example, when using a light-emitting device, high dynamic range (HDR) display or the like can be performed. Also, when using a liquid crystal device, overdrive driving or the like can be realized. For example, when using a light-emitting device, high dynamic range (HDR) display or the like can be performed. Also, when using a liquid crystal device, overdrive driving or the like can be realized. For example, when using a light-emitting device, high dynamic range (HDR) display or the like can be performed. Also, when using a liquid crystal device, overdrive driving or the like can be realized.

[0244] <Application Example> [Example using a liquid crystal device] The pixel circuit 400LC shown in FIG. 24C has a circuit 401LC. The circuit 401LC has a liquid crystal device LC and a capacitor C2. The liquid crystal device LC has one electrode connected to the node N2 and one electrode of the capacitor C2, and the other electrode connected to the wiring to which the potential V

[0245] is applied. The capacitor C2 has the other electrode connected to the wiring to which the potential V is applied. com2 is applied. The capacitor C2 has the other electrode connected to the wiring to which the potential V co m1 is applied.

[0246] The capacitor C2 functions as a holding capacitor. If the capacitor C2 is not necessary, it can be omitted. This can be omitted.

[0247] Since the pixel circuit 400LC can supply a high voltage to the liquid crystal device LC, for example, high-speed display can be realized by overdrive driving, and a liquid crystal material with a high driving voltage can be applied. Also, by supplying a correction signal to the wiring S1 or the wiring S2, gradation can be corrected according to the use temperature, the deterioration state of the liquid crystal device LC, etc. For example, high-speed display can be realized by overdrive driving, and a liquid crystal material with a high driving voltage can be applied. Also, by supplying a correction signal to the wiring S1 or the wiring S2, gradation can be corrected according to the use temperature, the deterioration state of the liquid crystal device LC, etc. For example, high-speed display can be realized by overdrive driving, and a liquid crystal material with a high driving voltage can be applied. Also, by supplying a correction signal to the wiring S1 or the wiring S2, gradation can be corrected according to the use temperature, the deterioration state of the liquid crystal device LC, etc. For example, high-speed display can be realized by overdrive driving, and a liquid crystal material with a high driving voltage can be applied. Also, by supplying a correction signal to the wiring S1 or the wiring S2, gradation can be corrected according to the use temperature, the deterioration state of the liquid crystal device LC, etc.

[0248] [Example using a light-emitting device] The pixel circuit 400EL shown in FIG. 24D has a circuit 401EL. The circuit 401EL has a light-emitting device EL, a transistor M3, and a capacitor C2.

[0249] The transistor M3 has its gate connected to one of the electrodes of the node N2 and the capacitor C2, one of its source and drain connected to a wiring to which a potential V H is applied, and the other connected to one of the electrodes of the light-emitting device EL. The capacitor C2 has its other electrode connected to a wiring to which a potential V com is applied. The light-emitting device EL has its other electrode connected to a wiring to which a potential V L is applied.

[0250] The transistor M3 has a function of controlling the current supplied to the light-emitting device EL. The capacitor C 2 functions as a holding capacitor. The capacitor C2 can be omitted if not necessary.

[0251] Here, a configuration is shown in which the anode side of the light-emitting device EL is connected to the transistor M3, but the transistor M3 may be connected to the cathode side. In that case, the values of the potential V H and the potential V L ] can be appropriately changed.

[0252] By applying a high potential to the gate of the transistor M3, the pixel circuit 400EL can pass a large current through the light-emitting device EL, so that, for example, HDR display can be realized. 6] Also, by supplying a correction signal to the wiring S1 or the wiring S2, it is possible to correct variations in the electrical characteristics of the transistor M3 and the light-emitting device EL.

[0253] Note that the present invention is not limited to the circuits illustrated in FIGS. 24C and 24D, and transistors, capacitors, etc. may be separately added. It may also be configured with an additional

[0254] This embodiment may be appropriately combined with at least a part of another embodiment described in this specification. It can be implemented in combination.

[0255] (Embodiment 5) An example of the structure of a pixel in a display panel of one embodiment of the present invention will be described below.

[0256] 25A to 25E show examples of the configuration of the pixel 300. FIG.

[0257] The pixel 300 includes a plurality of pixels 301. Each of the plurality of pixels 301 includes a sub-pixel. A single pixel 300 is made up of multiple pixels 301 each exhibiting a different color. This allows the display unit to display in full color.

[0258] Each of the pixels 300 shown in FIGS. 25A and 25B has three sub-pixels. The pixel 300 shown in FIG. 1 has a pixel 301, which exhibits a combination of red (R), green (G), and The color combinations exhibited by the pixel 301 included in the pixel 300 shown in FIG. The combination is cyan (C), magenta (M), and yellow (Y).

[0259] Each of the pixels 300 shown in Figures 25C to 25E has four sub-pixels. The color combination of the pixel 301 of the pixel 300 shown in FIG. Blue (B) and white (W). By using a sub-pixel that displays white, the brightness of the display area is increased. The color combination of the pixel 301 in the pixel 300 shown in FIG. , red (R), green (G), blue (B), and yellow (Y). The combination of colors exhibited by pixel 301 is cyan (C), magenta (M), yellow (Y), and white (W).

[0260] By increasing the number of sub-pixels that function as one pixel and appropriately combining sub-pixels that exhibit colors such as red, green, blue, cyan, magenta, and yellow, the reproducibility of halftones can be enhanced. Thus, the display quality can be improved.

[0261] Also, the display device according to one aspect of the present invention can reproduce color gamuts of various standards. For example, PAL (Phase Alternating Line) standard used in television broadcasting and NTSC (National Television System Com mittee) standard, sRGB (standard RGB) standard widely used in display devices for electronic devices such as personal computers, digital cameras, and printers, and also Adobe RGB standard, ITU-R BT.709 (International Telecommunication Union Radiocom munication Sector Broadcasting Service (Television) 709) standard used in HDTV (High Definition Television, also called high vision), DCI-P3 (Digital Cinema Initiatives P3) standard used in digital cinema projection, and ITU-R BT.2020 (REC.2020 (Recommendation 2020)) standard used in UHDTV (Ultra High Definition Television, also called super high vision), etc. ​

[0262] Also, when the pixels 300 are arranged in a 1920×1080 matrix, a full-color display device with a so-called full high vision (also referred to as "2K resolution", "2K1K", or "2K") resolution can be realized. Also, for example, when the pixels 300 are arranged in a 38 40×2160 matrix, a full-color display device with a so-called ultra-high vision (also referred to as "4K resolution", "4K2K", or "4K") resolution can be realized. Also, for example, when the pixels 300 are arranged in a 7680×4320 matrix, a full-color display device with a so-called super-high vision (also referred to as "8K resolution", "8K4K ", or "8K") resolution can be realized. By increasing the number of pixels 300, it is also possible to realize a full-color display device with a 16K or 32K resolution. Also, when the pixels 300 are arranged in a 7680×4320 matrix, a full-color display device with a so-called super-high vision (also referred to as "8K resolution", "8K4K ", or "8K") resolution can be realized. By increasing the number of pixels 300, it is also possible to realize a full-color display device with a 16K or 32K resolution. ", or "8K") resolution can be realized. By increasing the number of pixels 300, it is also possible to realize a full-color display device with a 16K or 32K resolution. By increasing the number of pixels 300, it is also possible to realize a full-color display device with a 16K or 32K resolution. It is also possible to realize a full-color display device with a 16K or 32K resolution.

[0263] This embodiment can be implemented in appropriate combination with at least some of the other embodiments described in this specification. It can be implemented in appropriate combination with at least some of the other embodiments described in this specification.

[0264] (Embodiment 6) In this embodiment, CAC-OS (Cloud-Aligned Composite Oxide Semiconductor), which is a metal oxide that can be used for the OS transistor described in other embodiments, and CAAC-OS (c-axis Aligned Crystalline Oxide Semiconductor) will be described. ide Semiconductor), and CAAC-OS (c-axis Ali gned Crystalline Oxide Semiconductor) will be described. gned Crystalline Oxide Semiconductor) will be described. will be described.

[0265] <Configuration of Metal Oxide> CAC-OS or CAC-metal oxide has a conductive function in part of the material and an insulating function in part of the material, and has a semiconductor function as a whole . When CAC-OS or CAC-metal oxide is used for the active layer of a transistor , the conductive function is the function of flowing electrons (or holes) serving as carriers , and the insulating function is the function of not flowing electrons serving as carriers. By causing the conductive function and the insulating function to act complementarily, respectively, a switching function (On / Of f function) can be imparted to CAC-OS or CAC-metal oxide . In CAC-OS or CAC-metal oxide, by separating the respective functions , both functions can be maximally enhanced.

[0266] Also, CAC-OS or CAC-metal oxide has 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. Also, in the material, the conductive region and the insulating region may be separated at the nanoscale . Also, the conductive region and the insulating region may be unevenly distributed in the material respectively. Also, the conductive region may be observed to be blurred at the periphery and connected in a cloud shape .

[0267] Also, in CAC-OS or CAC-metal oxide, the conductive region and the insu lating region may be dispersed in the material at sizes of 0.5 nm or more and 10 nm or less, preferably 0.5 nm or more and 3 nm or less respectively.

[0268] In addition, CAC-OS or CAC-metal oxide is composed of components having different band gaps. For example, CAC-OS or CAC-metal oxi de is composed of a component having a wide band gap due to an insulating region and a component having a narrow band gap due to a conductive region. In this configuration, when carriers flow, carriers mainly flow in the component having a narrow band gap. In addition, the component having a narrow band gap acts complementarily on the component having a wide band gap, and carriers also flow in the component having a wide band gap in conjunction with the component having a narrow band gap. Therefore, when the above CAC-OS or CAC-metal oxide is used in the channel formation region of a transistor, a high current driving force, that is, a large on-current, and a high field effect mobility can be obtained in the on-state of the transistor. That is, CAC-OS or CAC-metal oxide can also be referred to as a matrix composite

[0269] (matrix composite), or a metal matrix composite (metal matrix composite).

[0270] <Structure of Metal Oxide> Oxide semiconductors can be divided into single crystal oxide semiconductors and other non-single crystal oxide semiconductors. Examples of non-single crystal oxide semiconductors include CAAC-OS, polycrystalline oxide semiconductors, nc-OS (nanocrystalline oxide semiconducto r), pseudo-amorphous oxide semiconductors (a-like OS: amorphous-like oxide semiconductor), and amorphous oxide semiconductors.

[0271] In addition, when focusing on the crystal structure, oxide semiconductors may be classified differently from the above. Here, the classification of the crystal structure in oxide semiconductors will be described with reference to FIG. 26A. FIG. 26A is a diagram for explaining the classification of the crystal structure of an oxide semiconductor, typically IGZO (metal oxide containing In, Ga, and Zn).

[0272] As shown in FIG. 26A, IGZO is roughly classified into Amorphous (amorphous), Crystalline (crystalline), and Crystal (crystal). Further, completely amorphous is included in Amorphous. In addition, CAAC (c-axis aligned crystalline), nc (nanocrystalline), and CAC (Column-Aligned Composite) are included in Crystalline. Note that single crystal, poly crystal, and completely amorphous are excluded from the classification of Crystalline. Further, single crystal and poly crystal are included in Crystal.

[0273] Note that the structure within the thick frame shown in FIG. 26A is an intermediate state between Amorphous (amorphous) and Crystal (crystal), and belongs to a new boundary region (New crystalline phase). The structure is in the boundary region between Amorphous and Crystal. That is, the structure can be regarded as a structure completely different from the energetically unstable Amorphous or Crystal. ​ It is possible.

[0274] Note that the crystal structure of the film or substrate can be evaluated using an X-ray diffraction (XRD) image. Here, the XRD spectra of quartz glass and IGZO (also referred to as crystalline IGZO) having a crystal structure classified as Crystalline are shown in FIGS. 26B and 26C. Further, FIG. 26B is the XRD spectrum of quartz glass, and FIG. 26C is the XRD spectrum of crystalline IGZO. Note that the composition of the crystalline IGZO shown in FIG. 26C is in the vicinity of In:Ga:Zn = 4:2:3 [atomic ratio]. Also, the thickness of the crystalline IGZO shown in FIG. 26C is 500 nm. on) image. Here, the XRD spectra of quartz glass and IGZO (also referred to as crystalline IGZO) having a crystal structure classified as Crystalline are shown in FIGS. 26B and 26C. Further, FIG. 26B is the XRD spectrum of quartz glass, and FIG. 26C is the XRD spectrum of crystalline IGZO. Note that the composition of the crystalline IGZO shown in FIG. 26C is in the vicinity of In:Ga:Zn = 4:2:3 [atomic ratio]. Also, the thickness of the crystalline IGZO shown in FIG. 26C is 500 nm. ine having a crystal structure classified as Crystalline are shown in FIGS. 26B and 26C. Further, FIG. 26B is the XRD spectrum of quartz glass, and FIG. 26C is the XRD spectrum of crystalline IGZO. Note that the composition of the crystalline IGZO shown in FIG. 26C is in the vicinity of In:Ga:Zn = 4:2:3 [atomic ratio]. Also, the thickness of the crystalline IGZO shown in FIG. 26C is 500 nm. As shown by the arrow in FIG. 26B, quartz glass has an XRD spectrum peak shape that is approximately left-right symmetric. On the other hand, as shown by the arrow in FIG. 26C, crystalline IGZO has an XRD spectrum peak shape that is left-right asymmetric. The fact that the XRD spectrum peak shape is left-right asymmetric indicates the presence of crystals. In other words, if the XRD spectrum peak shape is not left-right symmetric, it cannot be said to be amorphous. Note that FIG. 26C clearly shows a crystal phase (IGZO crystal phase) at 2θ = 31° or in its vicinity. It is presumed that the origin of the left-right asymmetry in the shape of the XRD spectrum peak is due to the crystal phase (microcrystals). As shown by the arrow in FIG. 26B, quartz glass has an XRD spectrum peak shape that is approximately left-right symmetric. On the other hand, as shown by the arrow in FIG. 26C, crystalline IGZO has an XRD spectrum peak shape that is left-right asymmetric. The fact that the XRD spectrum peak shape is left-right asymmetric indicates the presence of crystals. In other words, if the XRD spectrum peak shape is not left-right symmetric, it cannot be said to be amorphous. Note that FIG. 26C clearly shows a crystal phase (IGZO crystal phase) at 2θ = 31° or in its vicinity. It is presumed that the origin of the left-right asymmetry in the shape of the XRD spectrum peak is due to the crystal phase (microcrystals). In:Ga:Zn = 4:2:3 [atomic ratio] vicinity. Also, the thickness of the crystalline IG shown in FIG. 26C ZO is 500 nm.

[0275] As shown by the arrow in FIG. 26B, quartz glass has an XRD spectrum peak shape that is approximately left-right symmetric. On the other hand, as shown by the arrow in FIG. 26C, crystalline IGZO has an XRD spectrum peak shape that is left-right asymmetric. The fact that the XRD spectrum peak shape is left-right asymmetric indicates the presence of crystals. In other words, if the XRD spectrum peak shape is not left-right symmetric, it cannot be said to be amorphous. Note that FIG. 26C clearly shows a crystal phase (IGZO crystal phase) at 2θ = 31° or in its vicinity. It is presumed that the origin of the left-right asymmetry in the shape of the XRD spectrum peak is due to the crystal phase (microcrystals). As shown by the arrow in FIG. 26B, quartz glass has an XRD spectrum peak shape that is approximately left-right symmetric. On the other hand, as shown by the arrow in FIG. 26C, crystalline IGZO has an XRD spectrum peak shape that is left-right asymmetric. The fact that the XRD spectrum peak shape is left-right asymmetric indicates the presence of crystals. In other words, if the XRD spectrum peak shape is not left-right symmetric, it cannot be said to be amorphous. Note that FIG. 26C clearly shows a crystal phase (IGZO crystal phase) at 2θ = 31° or in its vicinity. It is presumed that the origin of the left-right asymmetry in the shape of the XRD spectrum peak is due to the crystal phase (microcrystals). As shown by the arrow in FIG. 26C, crystalline IGZO has an XRD spectrum peak shape that is left-right asymmetric. The fact that the XRD spectrum peak shape is left-right asymmetric indicates the presence of crystals. In other words, if the XRD spectrum peak shape is not left-right symmetric, it cannot be said to be amorphous. Note that FIG. 26C clearly shows a crystal phase (IGZO crystal phase) at 2θ = 31° or in its vicinity. It is presumed that the origin of the left-right asymmetry in the shape of the XRD spectrum peak is due to the crystal phase (microcrystals). As shown by the arrow in FIG. 26C, crystalline IGZO has an XRD spectrum peak shape that is left-right asymmetric. The fact that the XRD spectrum peak shape is left-right asymmetric indicates the presence of crystals. In other words, if the XRD spectrum peak shape is not left-right symmetric, it cannot be said to be amorphous. Note that FIG. 26C clearly shows a crystal phase (IGZO crystal phase) at 2θ = 31° or in its vicinity. It is presumed that the origin of the left-right asymmetry in the shape of the XRD spectrum peak is due to the crystal phase (microcrystals). As shown by the arrow in FIG. 26C, crystalline IGZO has an XRD spectrum peak shape that is left-right asymmetric. The fact that the XRD spectrum peak shape is left-right asymmetric indicates the presence of crystals. In other words, if the XRD spectrum peak shape is not left-right symmetric, it cannot be said to be amorphous. Note that FIG. 26C clearly shows a crystal phase (IGZO crystal phase) at 2θ = 31° or in its vicinity. It is presumed that the origin of the left-right asymmetry in the shape of the XRD spectrum peak is due to the crystal phase (microcrystals). 2θ = 31°, or in its vicinity, clearly shows a crystal phase (IGZO crystal phase). 2θ = 31°, or in its vicinity, clearly shows a crystal phase (IGZO crystal phase). It is presumed that the origin of the left-right asymmetry in the shape of the XRD spectrum peak is due to the crystal phase (microcrystals).

[0276] Specifically, in the XRD spectrum of crystalline IGZO shown in FIG. 26C, it has a peak at 2θ = 34 ° or in its vicinity. Also, the microcrystals have a peak at 2θ = 31° or in its vicinity. -clause. When evaluating the oxide semiconductor film using an X-ray diffraction image, as shown in Fig. 26C the width of the spectrum on the lower angle side than the peak at 2θ = 34° or in its vicinity becomes wider. This suggests that there are microcrystals having a peak at 2θ = 31° or in its vicinity in the oxide semiconductor film. inside.

[0277] Also, the crystal structure of the film can be evaluated by the diffraction pattern (also called the nano-beam electron diffraction pattern) observed by the nano-beam electron diffraction method (NBED: Nano Beam Electron Diffraction). The diffraction pattern of the IGZO film formed with the substrate temperature at room temperature is shown in Fig. 26D. Note that the IGZO film shown in Fig. 26D is formed by sputtering using an oxide target with In:Ga: Zn = 1:1:1 [atomic ratio]. Also, in the nano-beam electron diffraction method, electron diffraction was performed with a probe diameter of 1 nm. film formed with the substrate temperature at room temperature is shown in Fig. 26D. Note that the IGZO film shown in Fig. 26D is formed by sputtering using an oxide target with In:Ga: Zn = 1:1:1 [atomic ratio]. Also, in the nano-beam electron diffraction method, electron diffraction was performed with a probe diameter of 1 nm. performed. film formed with the substrate temperature at room temperature is shown in Fig. 26D. Note that the IGZO film shown in Fig. 26D is formed by sputtering using an oxide target with In:Ga:

[0278] As shown in Fig. 26D, in the diffraction pattern of the IGZO film formed at room temperature, a spot-like pattern rather than a halo is observed. Therefore, the IGZO film formed at room temperature is in an intermediate state that is neither crystalline nor amorphous, and it is presumed that it cannot be concluded that it is in an amorphous state. film formed with the substrate temperature at room temperature is shown in Fig. 26D. Note that the IGZO film shown in Fig. 26D is formed by sputtering using an oxide target with In:Ga: film formed with the substrate temperature at room temperature is shown in Fig. 26D. Note that the IGZO film shown in Fig. 26D is formed by sputtering using an oxide target with In:Ga: not.

[0279] CAAC-OS has a c-axis orientation, and a plurality of nano-crystals are connected in the a-b plane direction, resulting in a crystal structure with strain. Note that the strain refers to a location where the lattice arrangement changes between a region with an aligned lattice arrangement and another region with an aligned lattice arrangement in the region where a plurality of nano-crystals are connected. region, between a region where the lattice arrays are aligned and another region where the lattice arrays are aligned, where the direction of the lattice array changes. points to.

[0280] The nanocrystals are based on a hexagonal shape, but are not necessarily regular hexagonal shapes and may be non-regular hexagonal shapes. In addition, in the case of strain, there may be lattice arrays such as pentagons and heptagons. In CAAC-OS, even in the vicinity of strain, no distinct grain boundaries (also called grain boundaries) can be confirmed. That is, it can be seen that the formation of grain boundaries is suppressed by the strain of the lattice arrangement. This is presumably because CAAC-OS can tolerate strain due to the fact that the arrangement of oxygen atoms is not dense in the a-b plane direction and the interatomic bond distance changes due to the substitution of metal elements.

[0281] A crystal structure in which distinct grain boundaries (grain boundaries) are confirmed is called a so-called polycrystal. Grain boundaries serve as recombination centers, and there is a high possibility of capturing carriers and causing a decrease in the on-current of the transistor or a decrease in the field-effect mobility. Therefore, CAAC-OS in which no distinct grain boundaries are confirmed is one of the crystalline oxides having a crystal structure suitable for the semiconductor layer of the transistor. In addition, for CAAC-OS to be

[0282] In addition, CAAC-OS tends to have a layered crystal structure (also called a layered structure) in which a layer containing indium and oxygen (hereinafter, In layer) and a layer containing element M, zinc, and oxygen (hereinafter, (M,Zn) layer) are laminated. Note that indium and element M can be substituted for each other. When element M in the (M,Zn) layer is substituted with indium, (In,M,Zn) ​​​​​​​​​​​​​It can also be expressed as a layer. Further, when indium in the In layer is replaced with element M, it can be expressed as an (In,M ) layer.

[0283] CAAC-OS is a highly crystalline oxide semiconductor. On the other hand, since clear grain boundaries cannot be confirmed in CAAC-OS, it can be said that a decrease in electron mobility due to grain boundaries does not occur. Further, since the crystallinity of the oxide semiconductor may be lowered due to the incorporation of impurities or the generation of defects, CAAC-OS can also be said to be an oxide semiconductor with few impurities and defects (such as oxygen deficiencies). Therefore, the physical properties of the oxide semiconductor having CAAC-OS are stable. For this reason, the oxide semiconductor having CAAC-OS is heat-resistant and highly reliable. Moreover, CAAC-OS is stable even against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, when CAAC-OS is used for an OS transistor, it becomes possible to expand the degree of freedom in the manufacturing process. nc-OS has periodicity in the atomic arrangement in a minute region (for example, a region of 1 nm or more and 10 nm or less, particularly a region of 1 nm or more and 3 nm or less). Further, nc-OS does not show regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is observed in the entire film. Thus, depending on the analysis method, nc-OS may not be distinguishable from a-like OS or an amorphous oxide semiconductor. a-like OS is an oxide semiconductor having a structure between nc-OS and an amorphous oxide semiconductor. a-like OS has a loose or low-density region. That is, a-like OS has lower crystallinity compared to nc-OS and CAAC-OS. Also, CAAC-OS is stable even against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, when CAAC-OS is used for an OS transistor, it becomes possible to expand the degree of freedom in the manufacturing process. Therefore, when CAAC-OS is used for an OS transistor, it becomes possible to expand the degree of freedom in the manufacturing process. nc-OS has periodicity in the atomic arrangement in a minute region (for example, a region of 1 nm or more and 10 nm or less, particularly a region of 1 nm or more and 3

[0284] nm or less). Further, nc-OS does not show regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is observed in the entire film. Thus, depending on the analysis method, nc-OS may not be distinguishable from a-like OS or an amorphous oxide semiconductor. nm or less). Further, nc-OS does not show regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is observed in the entire film. Thus, depending on the analysis method, nc-OS may not be distinguishable from a-like OS or an amorphous oxide semiconductor. Therefore, no orientation is observed in the entire film. Thus, depending on the analysis method, nc-OS may not be distinguishable from a-like OS or an amorphous oxide semiconductor. Thus, depending on the analysis method, nc-OS may not be distinguishable from a-like OS or an amorphous oxide semiconductor. from a-like OS or an amorphous oxide semiconductor.

[0285] a-like OS is an oxide semiconductor having a structure between nc-OS and an amorphous oxide semiconductor. a-like OS has a loose or low-density region. That is, a-like OS is an oxide semiconductor having a structure between nc-OS and an amorphous oxide semiconductor. a-like OS has a loose or low-density region. That is, a-like OS has lower crystallinity compared to nc-OS and CAAC-OS.

[0286] Oxide semiconductors have various structures, each having different characteristics. In one aspect of the present invention, the oxide semiconductor may have two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, an nc -OS, and a CAAC-OS.

[0287] <Transistor having an oxide semiconductor> Subsequently, the case of using the above oxide semiconductor in a transistor will be described.

[0288] By using the above oxide semiconductor in a transistor, a transistor with high field-effect mobility can be realized. Also, a highly reliable transistor can be realized.

[0289] In addition, it is preferable to use an oxide semiconductor with a low carrier concentration in the transistor. When lowering the carrier concentration of the oxide semiconductor film, the impurity concentration in the oxide semiconductor film should be lowered and the density of defect levels should be lowered. In this specification and the like, a low impurity concentration and a low density of defect levels are referred to as high-purity intrinsic or substantially high-purity intrinsic.

[0290] In addition, an oxide semiconductor film that is high-purity intrinsic or substantially high-purity intrinsic may have a low density of defect levels and thus may also have a low trap level density.

[0291] In addition, the charge trapped in the trap levels of the oxide semiconductor takes a long time to disappear and may behave as if it were a fixed charge. Therefore, a transistor in which a channel formation region is formed in an oxide semiconductor with a high trap level density may have unstable electrical characteristics in some cases.

[0292] ​​Therefore, in order to stabilize the electrical characteristics of the transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. Also, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to reduce the impurity concentration in the adjacent film. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, silicon, and the like.

[0293] <Impurity> Here, the effects of various impurities in the oxide semiconductor will be described.

[0294] When silicon or carbon, which is one of the Group 14 elements, is contained in the oxide semiconductor, defect levels are formed in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon near the interface with the oxide semiconductor (the concentration obtained by secondary ion mass spectrometry SIMS: Secondary Ion Mass Spectrometry) are set to 2×10 or less, preferably 2×10 atoms / cm 18 3 or less. 17 at oms / cm 3

[0295] In addition, when an alkali metal or an alkaline earth metal is contained in the oxide semiconductor, defect levels may be formed and carriers may be generated. Therefore, it is preferable to reduce the concentration of the alkali metal or the alkaline earth metal in the oxide semiconductor. Specifically, the concentration of the alkali metal or the alkaline earth metal in the oxide semiconductor obtained by SIMS is set to 1×10 or less. For this reason, a transistor using an oxide semiconductor containing an alkali metal or an alkaline earth metal tends to have normally-on characteristics. atoms / cm 18 3 ​​​​​​​​Below, preferably 2 x 1 0 16 atoms / cm 3 Do the following:

[0296] In addition, when nitrogen is contained in an oxide semiconductor, electrons that act as carriers are generated, and the carriers As a result, the concentration of nitrogen in the oxide semiconductor increases, making it easier to convert it into an n-type semiconductor. Therefore, the transistor using the oxide semiconductor is likely to be normally on. In the present invention, it is preferable that the nitrogen content is reduced as much as possible. For example, the nitrogen content in the oxide semiconductor is The element concentration is 5×10 19 atoms / cm 3 Less than 5x1 0 18 atoms / cm 3 Less than 1×10, more preferably 18 atoms / cm 3 below, More preferably, 5 × 10 17 atoms / cm 3 The following applies.

[0297] In addition, hydrogen contained in oxide semiconductors reacts with oxygen that bonds with metal atoms to form water. When hydrogen enters the oxygen vacancy, the electrons acting as carriers are released. In addition, some of the hydrogen may combine with the oxygen that is bonded to the metal atom, forming a carrier. Therefore, oxide semiconductors containing hydrogen can generate electrons. The transistor using this MOSFET tends to be normally on. It is preferable that the amount of S be reduced as much as possible. The hydrogen concentration obtained by IMS was 1×10 20 atoms / cm 3 Less than 1 x10 19 atoms / cm3 less than, more preferably 5×10 18 atoms / cm 3 less than, even more preferably 1×10 18 atoms / cm 3 than.

[0298] Using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor can impart stable electrical characteristics.

[0299] This embodiment can be implemented in appropriate combination with at least some of the other embodiments described in this specification.

[0300] (Embodiment 7) In this embodiment, a light-emitting device applicable to a display device according to one aspect of the present invention, and a light-emitting model of the device will be described.

[0301] Figures 27A to 27D are cross-sectional views for explaining the configuration of the light-emitting device. Note that Figure 27A is a cross-sectional view of a single-structure light-emitting device, and Figures 27B to 27D are cross-sectional views of a tandem-structure light-emitting device.

[0302] <Single-structure light-emitting device> First, the single-structure light-emitting device shown in Figure 27A will be described.

[0303] The light-emitting device shown in Figure 27A has an EL layer 1103 between a first electrode 1101 and a second electrode 1102. Also, the EL layer 1103 has a hole injection layer 1111, a hole transport layer 1 112, a light-emitting layer 1113, an electron transport layer 1114, and an electron injection layer 1115. .

[0304] Hereinafter, materials that can be used in the light-emitting device according to one aspect of the present invention will be described. .

[0305] <The first electrode and the second electrode> The first electrode 1101 has the function of either the anode or the cathode. Also, the second electrode 1102 has the function of either the anode or the cathode. In the present embodiment, , the first electrode 1101 is described as the anode and the second electrode 1102 is described as the cathode. Also, in the present embodiment, the first electrode 1101 has reflectivity with respect to visible light, and the second electrode 1102 has transmissivity with respect to visible light. However, one aspect of the present invention is not limited to this, and the second electrode 1102 may have reflectivity with respect to visible light and transmissivity with respect to visible light. For example, when manufacturing a light-emitting device having a microcavity structure, an electrode having reflectivity with respect to visible light and an electrode having both reflectivity and transmissivity with respect to visible light can be preferably used.

[0306] As the first electrode 1101 and the second electrode 1102, metals, alloys, electrically conductive compounds, and mixtures thereof can be appropriately used, respectively. Specifically, In -Sn oxide (also referred to as ITO), In-Si-Sn oxide (also referred to as ITSO), In -Zn oxide, In-W-Zn oxide can be mentioned. In addition, aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium ​​Metals such as palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium ( Nd), etc., and alloys containing these appropriately combined can also be used. And in addition, elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (for example, lithium (Li), cesium (Cs), calcium (Ca), strontium (Sr)), rare earth metals such as europium (Eu), ytterbium (Yb), etc., and alloys containing these appropriately combined, graphene, etc. can be used.

[0307] Note that the first electrode 1101 and the second electrode 1102 can be formed using a sputtering method or a vacuum evaporation method.

[0308] <Hole injection layer> The hole injection layer 1111 preferably has a first organic compound and a second organic compound. The first organic compound is a material that shows electron-accepting properties with respect to the second organic compound. Also, the second organic compound is a material having a relatively deep highest occupied molecular orbital level (HOMO level) of -5.7 eV or more and -5 .4 eV or less. Since the second organic compound has a relatively deep HOMO level, the injection of holes into the hole transport layer 1112 becomes easy.

[0309] The first organic compound can use an organic compound having an electron-withdrawing group (especially a halogen group such as a fluoro group or a cyano group), etc., and from such materials, a material showing electron-accepting properties with respect to the above-mentioned second organic compound can be appropriately selected. As such an organic compound, for example, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (Abbreviation: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano- 1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3 ,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-T CNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octa fluoro-7H-pyrene-2-ylidene) malononitrile, etc. can be mentioned. In particular , compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having a plurality of heteroatoms like HAT-CN are thermally stable and preferable. Further, [3]radialene derivatives having an electron-withdrawing group (especially a halogen group such as a fluoro group or a cyano group) are preferably used because of their very high electron-accepting property. Specifically, α,α’,α’’-1,2,3-cyclopropanetriylidene tris 4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α’,α ’’-1,2,3-cyclopropanetriylidene tris[2,6-dichloro-3,5-di fluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α’,α’’- 1,2,3-cyclopropanetriylidene tris[2,3,4,5,6-pentafluoro benzeneacetonitrile], etc. can be mentioned.

[0310] The second organic compound is preferably an organic compound having hole-transporting properties, and preferably has at least one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, an aromatic amine having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine having a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group is preferably used. is preferably used. amine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group It may be a noamine.

[0311] In addition, when the second organic compound is a material having an N,N-bis(4-biphenyl)amino group, it is preferable because a light-emitting device with good lifetime can be fabricated.

[0312] <Hole transport layer> The hole transport layer 1112 preferably has a laminated structure of two or more layers. For example, the hole transport layer 11 12 has a first layer and a second layer on the first layer, and the first layer preferably contains a third organic compound, and the second layer preferably contains a fourth organic compound.

[0313] The third organic compound and the fourth organic compound are each preferably an organic compound having hole transport properties. The third organic compound and the fourth organic compound can use the same materials as the organic compounds that can be used as the above-mentioned second organic compound.

[0314] In the HOMO levels of the second organic compound and the third organic compound, the HOMO level of the third organic compound is deeper, and it is preferable to select the materials so that the difference is 0.2 eV or less. In addition, it is more preferable that the second organic compound and the third organic compound are the same material.

[0315] Also, in the HOMO levels of the third organic compound and the fourth organic compound, it is preferable that the HOMO level of the fourth organic compound is deeper. Furthermore, it is advisable to select the materials so that the difference is 0.2 eV or less. Due to the HOMO levels of the second organic compound to the fourth organic compound being in the above relationship, holes are smoothly injected into each layer, It is possible to prevent an increase in driving voltage and a state in which there are insufficient holes in the light-emitting layer.

[0316] It is preferable that each of the second to fourth organic compounds has a hole-transporting skeleton. The hole transporting skeleton is preferably formed by adding an organic compound having a HOMO level that is too shallow. Carbazole skeleton, dibenzofuran skeleton, dibenzothiophene skeleton and anthracene skeleton In addition, the hole transporting skeleton is preferably a material of adjacent layers (for example, the second (organic compound and third organic compound or third organic compound and fourth organic compound) In particular, the hole transporting skeleton is preferably is preferably a dibenzofuran skeleton.

[0317] In addition, materials contained in adjacent layers (for example, a second organic compound and a third organic compound, or If the third organic compound and the fourth organic compound are the same material, hole injection will be smoother. This is a preferable configuration because it is possible to obtain a desired result. In particular, when the second organic compound and the third organic compound are made of the same material, A configuration in which:

[0318] <Light-emitting layer> The light-emitting layer 1113 preferably contains a fifth organic compound and a sixth organic compound. The organic compound in 5 is a material having a light-emitting center material (also called a light-emitting material or a guest material). The sixth organic compound is a host material for dispersing the fifth organic compound. and a sixth organic compound (for example, a host material and an assist material) The one or more organic compounds may be: One or both of the hole transporting material and the electron transporting material described in this embodiment are used. In addition, a bipolar material can be used as one or more organic compounds. Good too.

[0319] The light-emitting layer 1113 may have a single layer structure or a laminated structure of two or more layers. In the case of a laminated structure of two or more layers, different light-emitting materials may be contained in the multiple layers.

[0320] The fifth organic compound is a light-emitting material, and the light-emitting color of the light-emitting material is blue, purple, or the like. The color may be blue, purple, green, yellow-green, yellow, orange, red, or the like. In this case, when the light-emitting layer 1113 contains a fluorescent material, the emitted light color is preferably blue. It is preferable that:

[0321] The light-emitting material that can be used for the light-emitting layer 1113 is not particularly limited. Luminescent materials (fluorescent materials) that convert excitation energy into light in the visible or near-infrared region or an emitter that converts triplet excitation energy into light in the visible or near-infrared region. Optical materials (phosphorescent materials or thermally activated delayed fluorescent materials) d delayed fluorescence (TADF) material can be used. do.

[0322] <Fluorescent materials> Examples of light-emitting materials that convert singlet excitation energy into light include fluorescent materials, such as For example, pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, Rubazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxazone Sarin derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthracene Examples include anthracene derivatives, naphthalene derivatives, etc. In particular, pyrene derivatives are preferred because of their high photoluminescence quantum yields. Specific examples of pyrene derivatives include N,N'-bis(3-methylphenyl) -N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene -1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-diphenyl -N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene -1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(dibenzofura n-2-yl)-N,N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6FrA Prn), N,N'-bis(dibenzothiophen-2-yl)-N,N'-diphenylpy rene-1,6-diamine (abbreviation: 1,6ThAPrn), N,N'-(pyrene-1,6- diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-6-amine (abbreviation: 1,6BnfAPrn), N,N'-(pyrene-1,6-diyl)bis[(N -phenylbenzo[b]naphtho[1,2-d]furan)-8-amine](abbreviation: 1,6B nfAPrn-02), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphe nylbenzo[b]naphtho[1,2-d]furan)-8-amine](abbreviation: 1,6BnfA Prn-03), etc.

[0323] In addition, 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2, 2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl- 9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2B Py), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N' -Diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carb azol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-di phenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-di phenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbaz ole-3-amine (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4 '-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PC BAPA), 4-[4-(10-phenyl-9-anthryl)phenyl]-4'-(9- phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPBA ), perylene, 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: TBP ), N,N''-(2-tert-butylanthracene-9,10-diyl-di-4,1- phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine](abbre viation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-a ntryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N -[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-tri phenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), etc. can be used.

[0324] As a luminescent material that converts triplet excitation energy into luminescence, for example, phosphorescent materials and TADF materials that exhibit thermally activated delayed fluorescence can be mentioned. For details of TADF materials, they will be described later. ​​ .

[0325] <Phosphorescent materials> Examples of phosphorescent materials include those having a 4H-triazole skeleton, a 1H-triazole skeleton, and an iridium ion. Organometallic compounds having a midazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton complexes (especially iridium complexes), which have phenylpyridine derivatives with electron-withdrawing groups as ligands Examples of the metal complex include organometallic complexes (particularly iridium complexes), platinum complexes, and rare earth metal complexes.

[0326] It has a blue or green color and the peak wavelength of the emission spectrum is between 450 nm and 570 nm. Some phosphorescent materials include the following:

[0327] For example, tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl )-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium (III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4 -diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir (Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl [Ir(iPrp)] tz-3b)3]), tris[3-(5-biphenyl)-5-isopropyl-4-phenyl [Ir(iPr5 btz)3]), organometallic complexes with a 4H-triazole skeleton, such as tris[3- Methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato ]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), tris(1-methyl Ruthenium(II) 5-phenyl-3-propyl-1H-1,2,4-triazolato Organometallic complexes having a 1H-triazole skeleton such as (I) (abbreviation: [Ir(Prptz1-Me)3]) fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi)3 ), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f] phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3 ), organometallic complexes having an imidazole skeleton such as bis[2-(4’,6’-difluoro phenyl)pyridinato-N,C iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4’,6’-difluorophenyl)py 2’ ridinato-N,C iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3’,5’-bis(trifluoromethyl)phenyl]pyridinato-N,C 2’}iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]) 2’ }iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]) bis[2-(4’,6’-difluorophenyl)pyridinato-N,C 2’ iridium (III) acetylacetonate (abbreviation: FIr(acac)), and organometallic complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand, and the like. Examples include organometallic complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand, and the like.

[0328] Examples of the phosphorescent material that exhibits green or yellow and has a peak wavelength of the emission spectrum in the range of 495 nm or more and 590 nm or less include the following materials. Examples of the phosphorescent material that exhibits green or yellow and has a peak wavelength of the emission spectrum in the range of 495 nm or more and 590 nm or less include the following materials.

[0329] For example, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation : [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)i ridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bi s(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(m ppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4 -phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)2(a cac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenyl pyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]) , (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-pheni lpyramidato]iridium(III) (abbreviation: [Ir(mpmppm)2(acac) ), (acetylacetonato)bis{4,6-dimethyl-2-[6-(2,6-dimethyl phenyl)-4-pyrimidinyl-κN3]phenyl-κC}iridium(III) (abbreviation : [Ir(dmppm-dmp)2(acac)]), (acetylacetonato)bis(4 ,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2( acac)]) and other organometallic iridium complexes having a pyrimidine skeleton, (acetylac etonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) ( abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5 -isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]) and other organometallic Iridium complex, tris(2-phenylpyridinato-N,C 2’ )iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C 2’ )irid ium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis (benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [I r(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(II I)(abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C 2’ ) iridium(III)(abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato- N,C 2’ )iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(a cac)]), [2-(4-phenyl-2-pyridinyl-κN)phenyl-κC]bis 2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir( ppy)2(4dppy)]), bis[2-(2-pyridinyl-κN)phenyl-κC] [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC] such as organometallic iridium complexes having a pyridine skeleton, bis(2,4-diphenyl-1,3-ox oxazolato-N,C 2’ )iridium(III) acetylacetonate (abbreviation: [Ir( dpo)2(acac)]), bis{2-[4’-(perfluorophenyl)phenyl] pyridinato-N,C 2’}iridium(III) acetylacetonate (abbreviation: [Ir( p-PF-ph)2(acac)]), bis(2-phenylbenzothiazolato-N,C 2 ’Iridium(III) acetylacetonate (abbreviation: [Ir(bt)2(acac) ), in addition to organometallic complexes such as tris(acetylacetonato)(monophenanthroline) terbium(III) (abbreviation: [Tb(acac)3(Phen)]) and other rare earth metal complexes can be mentioned.

[0330] Exhibiting yellow or red, and having a peak wavelength of the emission spectrum in the range of 570 nm or more and 750 nm or less As a phosphorescent material, the following materials can be mentioned.

[0331] For example, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrim idinato]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bi s[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iri dium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-di (naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III )(abbreviation: [Ir(d1npm)2(dpm)]), tris(4-t-butyl-6-phe nylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]) and the like organometallic complexes having a pyrimidine skeleton, (acetylacetonato)bis(2,3,5-tri phenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr)2(acac )]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridi um(III) (abbreviation: [Ir(tppr)2(dpm)]), bis{4,6-dimethyl -2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]ph enyl-κC}(2,6-dimethyl-3,5-heptanedionato-κ2 O,O’)-iridium (III) (abbreviation: [Ir(dmdppr-P)2(dibm)]), bis{4,6 -dimethyl-2-[5-(4-cyano-2,6-dimethylphenyl)-3-(3,5-di methylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetra methyl-3,5-heptanedionato-κ 2 O,O’)-iridium(III) (abbreviation: [I r(dmdppr-dmCP)2(dpm)]), (acetylacetonato)bis[2-meth yl-3-phenylquinoxalinato-N,C 2’ iridium(III) (abbreviation: [Ir (mpq)2(acac)]), (acetylacetonato)bis(2,3-diphenylquin oxalinato-N,C 2’ )iridium(III) (abbreviation: [Ir(dpq)2(acac )]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxa linato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), bis{ 4,6-dimethyl-2-[5-(5-cyano-2-methylphenyl)-3-(3,5-di methylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetra methyl-3,5-heptanedionato-κ2O,O’)-iridium(III) (abbreviation: [I r(dmdppr-m5CP)2(dpm)]) and other organometallic complexes having a pyrazine skeleton, tris(1-phenylisoquinolinato-N,C 2’ )iridium(III) (abbre viation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’ )iridi um(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]), bi bis[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κC](2,4-pentaerythroyl) Tandione-κ 2 O,O') Iridium(III) and other organic compounds with a pyridine skeleton Metal complex, 2,3,7,8,12,13,17,18-octaethyl-21H,23H- Platinum complexes such as porphyrin platinum(II) (abbreviation: [PtOEP]), tris(1,3 -diphenyl-1,3-propanedionato)(monophenanthroline)europium(I II) (abbreviation: [Eu(DBM)3(Phen)]), tris[1-(2-thenoyl)- 3,3,3-Trifluoroacetonato](monophenanthroline)europium(III) ) (abbreviation: [Eu(TTA)3(Phen)])

[0332] The organic compounds used in the light-emitting layer (host material, assist material, etc.) are those that Select one or more materials that have an energy gap larger than the energy gap. It can be used as such.

[0333] As an organic compound (host material) used in combination with a fluorescent material, The energy level of the triplet excited state is high and the energy level of the triplet excited state is low. It is preferable to do so.

[0334] Although some of the examples overlap with those above, preferred examples of the light-emitting materials (fluorescent light-emitting materials, phosphorescent light-emitting materials) From the viewpoint of combination, specific examples of organic compounds are shown below.

[0335] Organic compounds (host materials) that can be used in combination with fluorescent materials include anthracene derivatives, tetracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene Examples thereof include condensed polycyclic aromatic compounds such as derivatives and dibenzo[g,p]chrysene derivatives.

[0336] Specific examples of the organic compound (host material) used in combination with the fluorescent material include 9-f enyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3,6-diphenyl-9-[4-(10-phenyl-9- anthryl)phenyl]-9H-carbazole (abbreviation: DPCzPA), 3-[4-(1-na phthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9,1 0-diphenylanthracene (abbreviation: DPAnth), N,N-diphenyl-9-[4- (10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbre viation: CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine (abbre viation: DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-( 10-phenyl-9-anthryl)phenyl]phenyl}-9H-carbazole-3-a mine (abbreviation: PCAPBA), N-(9,10-diphenyl-2-anthryl)-N,9 -diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), 6,12-di methoxy-5,11-diphenylchrysene, N,N,N’,N’,N’’,N’’,N’ ’’,N’’’-octaphenyldibenzo[g,p]chrysene-2,7,10,15-te traamine (abbreviation: DBC1), 9-[4-(10-phenyl-9-anthracenyl)f enyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9- anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCz PA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzo[b naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-{4 -(9-phenyl-9H-fluoren-9-yl)-biphenyl-4'-yl}-anth racene (abbreviation: FLPPA), 9,10-bis(3,5-diphenylphenyl)anthra cene (abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA) , 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-Bu DNA), 9,9'-bianthryl (abbreviation: BANT), 9,9'-(stilbene-3, 3'-diyl)diphenanthrene (abbreviation: DPNS), 9,9'-(stilbene-4,4 '-diyl)diphenanthrene (abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl )benzene (abbreviation: TPB3), 5,12-diphenyltetracene, 5,12-bis(bi phenyl-2-yl)tetracene, etc. can be mentioned.

[0337] As the organic compound (host material) used in combination with the phosphorescent material, an organic compound having a triplet excitation energy (energy difference between the ground state and the triplet excited state) larger than that of the luminescent material may be selected.

[0338] When using a plurality of organic compounds (for example, a first host material and a second host material (or assist material), etc.) in combination with the luminescent material to form an exciplex, these plural organic compounds are preferably used by mixing with a phosphorescent material (especially an organometallic complex).

[0339] By adopting such a configuration, the energy transfer from the exciplex to the luminescent material, which is Ex By using TET (Exciplex-Triplet Energy Transfer), efficient emission can be obtained. As a combination of a plurality of organic compounds, those that are likely to form an exciplex are preferable, and it is particularly preferable to combine a compound that easily receives holes (hole transporting material) and a compound that easily receives electrons (electron transporting material). By selecting a combination that forms an exciplex that exhibits emission overlapping with the wavelength of the absorption band on the lowest energy side of the luminescent material, energy transfer becomes smooth, and efficient emission can be obtained. Specific examples of the hole transporting material and the electron transporting material can be the materials shown in this embodiment. With this

[0340] configuration, high efficiency, low voltage, and long life of the light-emitting device can be realized simultaneously. As a combination of materials that form an exciplex, it is preferable that the HOMO level of the hole transporting material is a value equal to or higher than the HOMO level of the electron transporting material. It is preferable that the LUMO level (lowest unoccupied molecular orbital level) of the

[0341] hole transporting material is a value equal to or higher than the LUMO level of the electron transporting material. The LUMO level and HOMO level of the material can be derived from the electrochemical characteristics (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV) measurement. Transient photoluminescence (PL) of materials, transient PL of electron transporting materials, and transient PL of a mixed film obtained by mixing these materials are compared, and the transient PL lifetime of the mixed film has a longer lifetime component than the transient PL lifetime of each material, or the difference in transient response such as an increase in the ratio of the delayed component can be confirmed by observing. Also, the above-mentioned transient PL may be read as transient electroluminescence (EL). That is, transient EL of a hole transporting material, transient EL of a material having electron transporting properties, and transient EL of a mixed film thereof are compared, and the formation of an exciplex can also be confirmed by observing the difference in transient response . As organic compounds that can be used in combination with a phosphorescent material, aromatic amines (compounds having an aromatic amine skeleton), carbazole derivatives (compounds having a carbazole skeleton), dibenzothiophene derivatives (thiophene derivatives), dibenzofuran derivatives (furan derivatives), zinc or aluminum-based metal complexes, oxadiazole derivatives, triazole derivatives,

[0342] benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyrimidine derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenanthroline derivatives, etc. can be mentioned . Specific examples of aromatic amines, carbazole derivatives, dibenzothiophene derivatives, and dibenzofuran derivatives, which are organic compounds having high hole transporting properties, include the following materials . Examples of carbazole derivatives include bicarbaazole derivatives (e.g., 3,3'-bicarbaazole derivatives), aromatic amines having a carbazolyl group, etc .

[0343]

[0344]

[0345] ​​​​​ As for the bicarbazole derivative (for example, 3,3'-bicarbazole derivative), specifically are 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9 '-bis(1,1'-biphenyl-4-yl)-3,3'-bi-9H-carbazole, 9 ,9'-bis(1,1'-biphenyl-3-yl)-3,3'-bi-9H-carbazole , 9-(1,1'-biphenyl-3-yl)-9'-(1,1'-biphenyl-4-yl )-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-naph thyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCC P), etc. can be mentioned.

[0346] As for the aromatic amine having a carbazolyl group, specifically, PCBA1BP, N-(4 -biphenyl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9-phenyl yl-9H-carbazole-3-amine (abbreviation: PCBiF), PCBBiF, PCBBi 1BP, PCBANB, PCBNBB, 4-phenyldiphenyl-(9-phenyl-9H -carbazole-3-yl)amine (abbreviation: PCA1BP), N,N'-bis(9-phen ylcarbazole-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B ), N,N',N''-triphenyl-N,N',N''-tris(9- phenylcarbazole-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3 B), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole yl-3-yl)phenyl]fluorene-2-amine (abbreviation: PCBAF), PCBASF , 3-[N-(9-Phenylcarbazol-3-yl)-N-phenylamino]-9-phenyl carbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PC zPCA2), 3-[N-(1-Naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1), 3-[N-(4- Diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation : PCzDPA1), 3,6-bis[N-(4-Diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N -(4-Diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2), 2-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]spiro-9,9’-bifluorene (abbreviation: PCASF), N -[4-(9H-Carbazol-9-yl)phenyl]-N-(4-phenyl)phenyl aniline (abbreviation: YGA1BP), N,N’-bis[4-(carbazol-9-yl)phenyl]-N,N’-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation : YGA2F), 4,4’,4’’-tris(carbazol-9-yl)triphenyl amine (abbreviation: TCTA) and the like can be mentioned. In addition to the above, as carbazole derivatives, 3-[4-(9-Phenanthryl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), PCPN, 1,3- bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4’-di(N-carbazolyl

[0347] ​​​​​​​ ) Biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-fluorenylcarbazole (abbreviation: CzTP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), CzPA, etc. are included.

[0348] As thiophene derivatives (compounds having a thiophene skeleton) and furan derivatives (compounds having a furan skeleton), specifically, 4,4’,4’’-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV) and other compounds having a thiophene skeleton, 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II) etc. are included.

[0349] As aromatic amines, specifically, 4,4’-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), N,N’-bis(3-methylphenyl)-N,N’-diphenyl-[1,1’-biphenyl]-4,4’-diamine (abbreviation: TPD), 4,4’-bis[N-(spiro-9,9’-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), BPAFLP, mBPAFLP, N-(9,9-dimethyl-9H-fluoren-2-yl)-N-{9,9-dimethyl-9H-fluoren-2-yl}-9,9-dimethyl-9H-fluoren-2-ylamine -2-[N'-Phenyl-N'-(9,9-dimethyl-9H-fluoren-2-yl)amino -9H-fluoren-7-yl}phenylamine (abbreviation: DFLADFL), N- (9,9-Dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenyl amine (abbreviation: DPNF), 2-[N-(4-Diphenylaminophenyl)-N-phenyl amino]spiro-9,9'-bifluorene (abbreviation: DPASF), 2,7-bis[N- (4-Diphenylaminophenyl)-N-phenylamino]-spiro-9,9'-bifluo rene (abbreviation: DPA2SF), 4,4',4''-Tris[N-(1-naphthyl)-N -phenylamino]triphenylamine (abbreviation: 1'-TNATA), 4,4',4'' -Tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4, 4',4''-Tris[N-(3-methylphenyl)-N-phenylamino]triphenyl amine (abbreviation: MTDATA), N,N'-Di(p-tolyl)-N,N'-diphenyl -p-phenylenediamine (abbreviation: DTDPPA), 4,4'-Bis[N-(4-diphe nylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4' -Bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl }-N-phenylamino)biphenyl (abbreviation: DNTPD), 1,3,5-Tris[N- (4-Diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B ) etc. can be mentioned.

[0350] As an organic compound with high hole transport properties, poly(N-vinylcarbazole) (abbreviation: PVK ), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{ N’-[4-(4-diphenylamino)phenyl]phenyl-N’-phenylamino}phenyl enyl)methacrylamide](abbreviation: PTPDMA), poly[N,N’-bis(4-butyl lphenyl)-N,N’-bis(phenyl)benzidine](abbreviation: Poly-TPD), etc. Any of these polymer compounds can be used.

[0351] Specific examples of zinc- or aluminum-based metal complexes, which are organic compounds with high electron-transporting properties, include , tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tris(4- methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), bis(10 -hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis (2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), etc., and metal complexes having a quinoline skeleton or a benzoquinoline skeleton, etc. can be mentioned. In addition, metal complexes having oxazole-based or thiazole-based ligands such as bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: Zn

[0352] PBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: Zn BTZ), etc. can also be used. Specific examples of oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phenanthroline derivatives, which are organic compounds with high electron-transporting properties, include 2-(4-biphenylyl)-5-(4-tert-but yl).

[0353] yl). yl), quinoxaline derivatives, dibenzoquinoxaline derivatives, phenanthroline derivatives, include 2-(4-biphenylyl)-5-(4-tert-but yl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, 1,3,5-triphenyl-2-(4- 1,3-bis[5-(phenyl)-1,3,4-oxadiazole (abbreviation: PBD) (p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene OXD-7, 9-[4-(5-phenyl-1,3,4-oxadiazole- 2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-(4-biphenylyl) (4-tert-butylphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazolium (abbreviation: TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl) p-EtTAZ , 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H- benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl )phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II ), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: B zOs, Bathophenanthroline (abbreviated as Bphen), Bathocuproine (abbreviated as BCP) ), 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenane thoroline (abbreviation: NBphen), 2-[3-(dibenzothiophen-4-yl)phenyl] 1]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3' -(Dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinox Sarin (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9 -yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mCzBP DBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl Dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(di benzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7m DBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II) and the like can be mentioned.

[0354] Heterocyclic compounds having a diazine skeleton, heterocyclic compounds having a triazine skeleton, and heterocyclic compounds having a pyridine skeleton, which are organic compounds with high electron transport properties. Specific examples include 4,6 -bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPn P2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation : 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 2-{4-[3-(N-f enyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl} -4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3 -(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9’-phen yl-2,3’-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 3,5 -bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCz PPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmP yPB) and the like can be mentioned.

[0355] Organic compounds with high electron transport properties include poly(2,5-pyridinediyl) (abbreviation: PPy​​ ) Poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3 ,5-diyl)] (abbreviation: PF-Py), poly[(9,9-dioctylfluorene-2, 7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-B Py) and the like can also be used.

[0356] <TADF Material> A TADF material is a material that has a small difference between the S1 level (energy level of the singlet excited state) and the T1 level (energy level of the triplet excited state), and has the function of converting triplet excitation energy into singlet excitation energy by reverse intersystem crossing. Therefore, triplet excitation energy can be up-converted (reverse intersystem crossing) into singlet excitation energy by a small amount of thermal energy, and the singlet excited state can be efficiently generated. In addition, triplet excitation energy can be converted into light emission. Conditions for efficiently obtaining thermally activated delayed fluorescence include that the energy difference between the S1 level and the T1 level is 0 eV or more and 0. 2 eV or less, preferably 0 eV or more and 0.1 eV or less. Also, the delayed fluorescence in a TADF material refers to light emission that has the same spectrum as normal fluorescence but has a significantly long lifetime. Its lifetime is 10 seconds or more, preferably 10 seconds or more.

[0357] -6 -3

[0358] An exciplex that forms an excited state with two types of materials has a very small difference between the S1 level and the T1 level, and has the function as a TADF material capable of converting triplet excitation energy into singlet excitation energy.

[0358] ​​As an index of the T1 level, a phosphorescence spectrum observed at a low temperature (for example, from 77 K to 10 K) may be used. As the TADF material, a tangent is drawn at the trailing edge on the short-wavelength side of its fluorescence spectrum, and the energy of the wavelength of the extrapolated line is defined as the S1 level. When a tangent is drawn at the trailing edge on the short-wavelength side of the phosphorescence spectrum and the energy of the wavelength of the extrapolated line is defined as the T1 level, it is preferable that the difference between S1 and T1 is 0.3 eV or less, and more preferably 0.2 eV or less.

[0359] Examples of the TADF material include fullerenes and their derivatives, acridine derivatives such as proflavine, eosin, etc. In addition, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd), etc. can be mentioned. Examples of the metal-containing porphyrin include protoporphyrin-tin fluoride complex (abbreviation: SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (abbreviation: SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (abbreviation: SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (abbreviation: SnF2(Copro III- 4Me)), octaethylporphyrin-tin fluoride complex (abbreviation: SnF2(OEP)), ethylporphyrin-tin fluoride complex (abbreviation: SnF2(Etio I)), octaethylporphyrin-platinum chloride complex (abbreviation: PtCl2OEP), etc.

[0360] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo 2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-T RZ), PCCzPTzn, 2-[4-(10H-phenoxazin-10-yl)phenyl yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3- 4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5 -diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9- dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: AC RXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridin)phenyl sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10’H-spiro acridine-9,9’-anthracene]-10’-one (abbreviation: ACRSA), 4-(9 ’-phenyl-3,3’-bi-9H-carbazol-9-yl)benzofuro[3,2-d pyrimidine (abbreviation: 4PCCzBfpm), 4-[4-(9’-phenyl-3,3’- bi-9H-carbazol-9-yl)phenyl]benzofuro[3,2-d]pyrimidine( abbreviation: 4PCCzPBfpm), 9-[3-(4,6-diphenyl-1,3,5-tri azine-2-yl)phenyl]-9’-phenyl-2,3’-bi-9H-carbazole (abbre viation: mPCCzPTzn-02), etc., heterocyclic compounds having a π-electron-excessive heteroaromatic ring and a π-electron-deficient heteroaromatic ring can be used. Since the heterocyclic compound has a π-electron-excessive heteroaromatic ring and a π-electron-deficient heteroaromatic ring,

[0361] it has both high electron transportability and hole transportability, which is preferable. Among them, the π-electron-deficient heteroaromatic ring ​Among the skeletons having [a certain structure], a pyridine skeleton, a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and a triazine skeleton are preferable because they are stable and have good reliability. In particular, a benzofuropyrimidine skeleton, a benzothienopyrimidine skeleton, a benzofuropyrazine skeleton, and a benzothienopyrazine skeleton are preferable because they have high electron-accepting properties and good reliability.

[0362] Also, among the skeletons having a π-electron-excessive heteroaromatic ring, an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton are stable and have good reliability, so it is preferable to have at least one of these skeletons. Note that as the furan skeleton, a dibenzofuran skeleton is preferable, and as the thiophene skeleton, a dibenzothiophene skeleton is preferable. Also, as the pyrrole skeleton, an indole skeleton, a carbazole skeleton, an indolocarbazole skeleton, a bicarbaazole skeleton, and a 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton are particularly preferable.

[0363] Note that a material in which a π-electron-excessive heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded has both the strong electron-donating property of the π-electron-excessive heteroaromatic ring and the strong electron-accepting property of the π-electron-deficient heteroaromatic ring, and the energy difference between the S1 level and the T1 level becomes small, so it is particularly preferable because thermally activated delayed fluorescence can be efficiently obtained. Note that instead of the π-electron-deficient heteroaromatic ring, an aromatic ring to which an electron-withdrawing group such as a cyano group is bonded may be used. Also, as the π-electron-excessive skeleton, an aromatic amine skeleton, a phenazine skeleton, etc. can be used. Also, as the π-electron-deficient skeleton a xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, etc. can be used. - A pyrrole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane or borantrene, a nitrile group or a cyano group such as benzonitrile or cyanobenzene, having an aromatic ring or a heteroaromatic ring, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, etc. can be used.

[0364] Thus, at least one of a π-electron-deficient heteroaromatic ring and a π-electron-excessive heteroaromatic ring can be replaced with at least one of a π-electron-deficient skeleton and a π-electron-excessive skeleton.

[0365] When using a TADF material, it can also be used in combination with other organic compounds. In particular, it can be combined with the above-described host material, hole-transporting material, and electron-transporting material. When using a TADF material, it is preferable that the S1 level of the host material is higher than the S1 level of the TADF material. Also, it is preferable that the T1 level of the host material is higher than the T1 level of the TADF material.

[0366] Alternatively, a TADF material can be used as the host material and a fluorescent light-emitting material can be used as the guest material. When using a TADF material as the host material, the triplet excitation energy generated by the TADF material is converted into singlet excitation energy by reverse intersystem crossing, and further the energy is transferred to the light-emitting material, so that the luminous efficiency of the light-emitting device can be increased. At this time, the TADF material functions as an energy donor and the light-emitting material functions as an energy acceptor. Therefore, using a TADF material as the host material is very effective when using a fluorescent light-emitting material as the guest material. Also, at this time, in order to obtain high luminous efficiency, ​​​​​, the S1 level of the TADF material is preferably higher than the S1 level of the fluorescent material. Also, the T1 level of the TADF material is preferably higher than the S1 level of the fluorescent material. Therefore, the T1 level of the TADF material is preferably higher than the T1 level of the fluorescent material.

[0367] Also, it is preferable to use a TADF material that exhibits emission overlapping with the wavelength of the absorption band on the lowest energy side of the fluorescent material. By doing so, the transfer of excitation energy from the TADF material to the fluorescent material becomes smooth, and efficient emission can be obtained, which is preferable. Also, in order for singlet excitons to be efficiently generated from triplet excitons by reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. Also, it is preferable that the triplet excitons generated in the TADF material do not transfer to the triplet excitons of the fluorescent material. For this purpose, it is preferable that the fluorescent material has a protecting group around the emitting group (the skeleton that causes emission) of the fluorescent material. As the protecting group, a substituent having no π bond is preferable, a saturated hydrocarbon is preferable, specifically, an alkyl group having 3 or more and 10 or less carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 or more and 10 or less carbon atoms, and a trialkylsilyl group having 3 or more and 10 or less carbon atoms can be mentioned, and it is more preferable that there are a plurality of protecting groups. A substituent having no π bond has poor function of transporting carriers, so it can keep the distance between the TADF material and the emitting group of the fluorescent material far without hardly affecting carrier transport and carrier recombination. Here, the emitting group refers to an atomic group (skeleton) that causes emission in the fluorescent material. The emitting group preferably has a skeleton having a π bond and preferably contains an aromatic ring.

[0368] ​​​​​​​​​​​​​is preferable, and it is preferable to have a condensed aromatic ring or a condensed heteroaromatic ring. The condensed aromatic ring or the condensed heteroaromatic ring includes a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a pheno xazine skeleton, a phenothiazine skeleton, etc. In particular, a fluorescent emitting material having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene bone skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, a naphthobisbenzofuran skeleton is preferable because of its high fluorescence quantum yield. In addition, the above TADF material may be used as a host material for the light emitting layer.

[0369] <Electron transport layer>

[0370] The electron transport layer 1114 is provided in contact with the light emitting layer 1113. Also, the electron transport layer 1114 has electron transporting properties and preferably contains a seventh organic compound having a HOMO level of -6.0 eV or more. Also, the seventh organic compound preferably contains an anthracene skeleton. In addition, the electron transport layer 1114 may further contain an eighth organic compound in addition to the seventh organic compound. The eighth organic compound preferably contains an organic complex of an alkali metal or an alkaline earth metal. That is, as the configuration of the electron transport layer 1114, there are a configuration formed only by the seventh organic compound, a configuration formed by a plurality of organic compounds including the seventh organic compound and the eighth organic compound, etc.

[0371] Furthermore, it is more preferable that the seventh organic compound contains an anthracene skeleton and a heterocyclic skeleton. As the heterocyclic skeleton, a nitrogen-containing 5-membered ring skeleton is preferable. As the nitrogen-containing 5-membered ring skeleton, it is like a pyrazole ring, an imidazole ring, an oxazole ring, or a thiazole ring, etc. with 2​​​​​​​​ It is particularly preferred to have one complex atom in the ring.

[0372] In addition, as a material having electron transporting properties that can be used as the seventh organic compound, a material having electron transporting properties that can be used for the above host material, or the above fluorescent emitting material a material that can be used as a host material of can be used.

[0373] In addition, as the organic complex of the above alkali metal or alkaline earth metal, an organic complex of lithium is preferred, and in particular, 8-quinolinolato-lithium (abbreviation: Liq) is preferred.

[0374] In addition, the material constituting the electron transport layer 1114 has a square root of the electric field strength [V / cm] of 60 0 and an electron mobility of 1×10 -7 cm 2 / Vs or more and 5×10 -5 cm 2 / Vs or less is preferable.

[0375] In addition, the square root of the electric field strength [V / cm] of the material constituting the electron transport layer 1114 at 600 has an electron mobility smaller than the electron mobility at 600 of the square root of the electric field strength [V / cm] of the sixth organic compound or the material constituting the light emitting layer 1113. By reducing the electron transporting property in the electron transport layer the injection amount of electrons into the light emitting layer can be controlled, and it is possible to prevent the light emitting layer from being in a state of excessive electrons.

[0376] <Electron injection layer> The electron injection layer 1115 is a layer that enhances the injection efficiency of electrons from the second electrode 1102. The value of the work function of the material of the second electrode 1102 and the LUMO of the material used for the electron injection layer 1115 The difference between the level value and [the value] is preferably small (within 0.5 eV).

[0377] For the electron injection layer 1115, lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), lithium 8-(quinolinolato) (abbreviation : Liq), lithium 2-(2-pyridyl)phenolate (abbreviation: LiPP), 2-(2- pyridyl)-3-pyridinolato lithium (abbreviation: LiPPy), 4-phenyl-2-(2 -pyridyl)phenolate lithium (abbreviation: LiPPP), lithium oxide (LiO x ), alkali metals, alkaline earth metals, or their compounds such as cesium carbonate can be used. In addition, rare earth metal compounds such as erbium fluoride (ErF3) can be used. Also, electrides may be used for the electron injection layer. Examples of electrides include materials obtained by adding electrons at a high concentration to a mixed oxide of calcium and aluminum. In addition, the materials constituting the above-described electron transport layer can also be used.

[0378] In addition, a composite material containing an electron transporting material and a donor material (electron donating material) may be used for the electron injection layer 1115. Such a composite material is excellent in electron injection and electron transport because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material excellent in transporting the generated electrons. Specifically, for example, [[ID=,33]] the above-described electron transporting materials (metal complexes, heteroaromatic compounds, etc.) can be used. As the electron donor, any material that exhibits electron donating properties to the organic compound may be used. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferred, and lithium, cesium, magnesium are preferred. ​ Examples include mu, calcium, erbium, ytterbium, etc. Also, alkali metal oxides and alkaline earth metal oxides are preferred, and examples include lithium oxide, calcium oxide, barium oxide, etc. Also, a Lewis base such as magnesium oxide can be used . Also, an organic compound such as tetrathiafulvalene (abbreviation: TTF) can be used .

[0379] In addition, for the production of the light-emitting device according to one aspect of the present invention, a vacuum process such as a vapor deposition method or a solution process such as a spin coating method or an inkjet method can be used. When using the vapor deposition method , a physical vapor deposition method (PVD method) such as a sputtering method, an ion plating method, an ion beam vapor deposition method, a molecular beam vapor deposition method, a vacuum vapor deposition method, etc., or a chemical vapor deposition method (CVD method) etc. can be used . In particular, for the functional layers (hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer) contained in the EL layer, a vapor deposition method (such as a vacuum vapor deposition method), a coating method (dip coating method, die coating method, bar coating method, spin coating method, spray coating method, etc.), a printing method (inkjet method, screen (stencil printing) method, offset (lithographic printing) method, flexo (letterpress printing) method , gravure method, microcontact method, etc.) can be used to form them.

[0380] Also, the materials of each functional layer constituting the light-emitting device are not limited to the above-mentioned materials . For example, as the material of the functional layer, a polymer compound (oligomer, dendrimer, polymer, etc. ), a medium molecule compound (a compound in the intermediate region between low molecules and high molecules: molecular weight 400 to 4000), an inorganic compound (quantum dot material, etc.) can be used. As the quantum dot material, Lloyd-shaped quantum dot materials, alloy-type quantum dot materials, core-shell type quantum dot materials, core type quantum dot materials, etc. can be used.

[0381] In addition, in the light-emitting device according to one aspect of the present invention, it may have a functional layer other than the layers described above. As the functional layer, various layers such as a carrier blocking layer and an exciton blocking layer can be applied.

[0382] <Regarding the light emission model in the light-emitting device> Next, the light emission model in the light-emitting device according to one aspect of the present invention will be described with reference to FIGS. 28A to 2 8C.

[0383] FIGS. 28A to 28C are schematic diagrams for explaining the light emission model in the light-emitting device. In FIGS. 28A to 28C, the light emission region in the light-emitting device is represented as the light emission region 112 0.

[0384] FIG. 28A is a light emission model showing the light emission region 1120 in a state where the light emitting layer 1113 has an excess of electrons. FIGS. 28B and 28C are light emission models showing the light emission region 1120 in the light-emitting device according to one aspect of the present invention.

[0385] As shown in FIG. 28A, when the light emitting layer 1113 is in a state of having an excess of electrons, a light emission region 1120 is formed in a local region within the light emitting layer 1113. In other words, the width of the light emission region 1120 is narrow. Therefore, in the local region of the light emitting layer 1113, recombination of electrons and holes occurs intensively, so that deterioration is promoted. Also, in the light emitting layer 1113, electrons that cannot recombine pass through the light emitting layer 1113, which may cause a decrease in lifetime or light emission efficiency.

[0386] On the other hand, as shown in FIGS. 28B and 28C, in the light-emitting device of one embodiment of the present invention, By reducing the electron transport property in the electron transport layer 1114, in the light-emitting layer 1113 it is possible to widen the width of the light-emitting region 1120. By widening the width of the light-emitting region 1120 it is possible to disperse the recombination region of electrons and holes in the light-emitting layer 1113. Therefore, it is possible to provide a light-emitting device with a long lifespan and good luminous efficiency.

[0387] In addition, in the light-emitting device of one embodiment of the present invention, in the luminance degradation curve obtained by a driving test under the condition of a constant current density, the degradation curve may have a maximum value. In other words, the light-emitting device of one embodiment of the present invention may exhibit a behavior of increasing luminance over time. This behavior can offset the rapid degradation (so-called initial degradation) at the initial stage of driving. Therefore, it is possible to provide a light-emitting device with small initial degradation and a very good driving lifespan.

[0388] Note that when taking the derivative of the degradation curve having a maximum value, there is a portion where the value becomes 0. Thus, a light-emitting device in which there is a portion where the derivative of the degradation curve becomes 0 can be rephrased as the light-emitting device of one embodiment of the present invention.

[0389] Here, the normalized luminance over time in the light-emitting device of one embodiment of the present invention and the comparative light-emitting device will be described with reference to FIG. 28D.

[0390] In FIG. 28D, the thick solid line is the degradation curve of the normalized luminance of the light-emitting device of one embodiment of the present invention, and the thick dashed line is the degradation curve of the normalized luminance of the comparative light-emitting device.

[0391] As shown in Fig. 28D, the light-emitting device of one aspect of the present invention and the light-emitting device for comparison have different slopes of the degradation curves of the normalized luminance. Specifically, the slope θ2 of the degradation curve of the light-emitting device of one aspect of the present invention is smaller than the slope θ1 of the degradation curve of the light-emitting device for comparison.

[0392] As shown in Fig. 28D, the light-emitting device of one aspect of the present invention may exhibit a shape having a maximum value in the luminance degradation curve obtained by a driving test under the condition of a constant current density . That is, the degradation curve of the light-emitting device of one aspect of the present invention may have a shape having a portion where the luminance increases over time. A light-emitting device showing such a degradation behavior can cancel out the rapid degradation at the initial stage of driving, so-called initial degradation, by the increase in luminance, and can be a light-emitting device having a small initial degradation and a very long driving life .

[0393] Further, as shown in Fig. 28B, in the light-emitting device of one aspect of the present invention, at the initial stage of driving, the light-emitting region 1120 formed in the light-emitting layer 1113 may spread to the side of the electron transport layer 1114 .

[0394] That is, in the light-emitting device of one aspect of the present invention, at the initial stage of driving, the hole injection barrier is small, and due to the relatively low electron transport property of the electron transport layer 1114, the light-emitting region 1120 (that is, the recombination region) is formed in a state closer to the side of the electron transport layer 1114. Further, since the HOMO level of the seventh organic compound contained in the electron transport layer 1114 is relatively high at -6.0 eV or more, a part of the holes reaches the electron transport layer 1114, and in the electron transport layer 1114 . Recombination also occurs, forming a non-emissive recombination region. This phenomenon may also occur when the difference in the HOMO levels of the sixth organic compound and the seventh organic compound is within 0.2 eV. In addition, in the light-emitting device of one embodiment of the present invention, as the driving time elapses, the carrier balance changes, and as shown in FIG. 28C, the light-emitting region 1120 (recombination region) moves to the hole transport layer

[0395] 1112 side and comes to be located within the light-emitting layer 1113. As shown in FIGS. 28B and 28C above, in the light-emitting device of one embodiment of the present invention, as the driving time elapses, by moving the light-emitting region 1120 within the light-emitting layer 1113, it becomes possible to effectively contribute the energy of the recombined carriers to light emission, and the luminance

[0396] can rise compared to the initial stage of driving. This increase in luminance cancels out the sharp decrease in luminance that appears at the initial stage of driving of the light-emitting device, i.e., the so-called initial degradation, resulting in a small initial degradation and a long driving life of the light-emitting device can be provided. In this specification and the like, the above light-emitting device is sometimes referred to as a Recombinati on-Site Tailoring Injection structure (ReSTI structure). In addition, in the light-emitting device of one embodiment of the present invention, the electron transport layer 1114 preferably has portions with different mixing ratios of an electron transport material and an organometallic complex of an alkali metal or an alkaline earth metal, or portions with different concentrations of the organometallic complex of an alkali metal or an alkaline earth metal in the thickness direction. The concentration of the organometallic complex of an alkali metal or an alkaline earth metal in the electron transport layer 1114

[0397]

[0397]

[0398]

[0398] Regarding the degree, it can be estimated from the detection amounts of atoms and molecules obtained by time-of-flight secondary ion mass spectrometry (ToF-SIMS).

[0399] The content of the organometallic complex in the electron transport layer 1114 is preferably less on the side of the second electrode 1102 than on the side of the first electrode 1101. That is, the concentration of the organometallic complex increases from the side of the second electrode 1102 toward the side of the first electrode 1101, and it is preferable that the electron transport layer 1114 is formed. That is, the electron transport layer 1114 has a portion where the abundance of the electron transport material is smaller on the light-emitting layer 1113 side than in a portion where the abundance of the electron transport material is large. In other words, the electron transport layer 1114 has a structure having a portion where the abundance of the organometallic complex is larger on the light-emitting layer 1113 side than in a portion where the abundance of the organometallic complex is small.

[0400] The electron mobility in a portion where the abundance of the electron transport material is large (a portion where the abundance of the organometallic complex is small) is preferably 1×10 cm -7 / Vs or more and 5×10 2 cm / Vs or less when the square root of the electric field strength [V / cm] is 600. -5 2

[0401] For example, the content of the organometallic complex in the electron transport layer 1114, that is, the concentration of the organometallic complex in the electron transport layer 1114, can be configured as shown in FIGS. 29A to 29D. FIGS. 29A and 29B show cases where there is no clear boundary in the electron transport layer 1114. ​​​​​​​​​​​​Figures 29C and 29D illustrate the case where there is a distinct boundary within the electron transport layer 1114.

[0402] When there is no distinct boundary within the electron transport layer 1114, the concentrations of the electron transporting material and the organometallic complex change continuously as shown in FIGS. 29A and 29B. Also, when there is a distinct boundary within the electron transport layer 1114, the concentrations of the electron transporting material and the organometallic complex change stepwise as shown in FIGS. 29C and 29D. In the case of stepwise change, it is suggested that the electron transport layer 1 114 is laminated by a plurality of layers. For example, FIG. 29C represents the case where the electron transport layer 1114 has a two-layer laminated structure, and FIG. 29D represents the case where the electron transport layer 1114 has three layers. In FIGS. 29C and 29D, the dashed lines represent the regions of the boundaries of the plurality of layers.

[0403] Also, the change in carrier balance in the light-emitting device according to one aspect of the present invention is considered to be brought about by the change in the electron mobility of the electron transport layer 1 114. The light-emitting device according to one aspect of the present invention has a concentration difference of an organometallic complex of an alkali metal or an alkaline earth metal inside the electron transport layer 1114. The electron transport layer 1114 has a region with a high concentration of the organometallic complex between the region with a low concentration of the organometallic complex and the light-emitting layer 1113. That is, it has a configuration in which the region with a low concentration of the organometallic complex is located closer to the second electrode 1102 than the high-concentration region.

[0404] The light-emitting device according to one aspect of the present invention having the above-described configuration has a very long lifespan. In particular, when the initial luminance is set to 100%, the time until the luminance reaches 95% (also referred to as LT95) can be made extremely long.

[0405] <Tandem Structure Light-Emitting Device> Next, the tandem structure light-emitting device shown in FIGS. 27B to 27D will be described.

[0406] The light-emitting devices shown in FIGS. 27B to 27D have a plurality of light-emitting units between the first electrode 1101 and the second electrode 11 02. As shown in FIGS. 27B to 27D, it is preferable to provide a charge generation layer 1109 between two light -emitting units.

[0407] Note that the light-emitting unit 1123(1) and the light-emitting unit 1123(2) each have a hole injection layer 1111, a hole transport layer 1112, a light-emitting layer 1113, an electron transport layer 1114, an electron injection layer 1115, etc., as shown in FIG. 27A.

[0408] <Charge Generation Layer> When a voltage is applied to the first electrode 1101 and the second electrode 1102, the charge generation layer 1109 has a function of injecting electrons into one of the light-emitting unit 1123(1) and the light-emitting unit 1123(2) and injecting holes into the other. Therefore, in FIG. 27B, when a voltage is applied so that the potential of the first electrode 1101 is higher than that of the second electrode 1102 , electrons are injected from the charge generation layer 1109 into the light-emitting unit 1123(1), and holes are injected into the light-emitting unit 1123(2). Note that the charge generation layer 1109 preferably transmits visible light (specifically, the transmittance of visible light of the charge generation layer 1109 is 40% or more) from the viewpoint of light extraction efficiency. Also the charge generation layer 1109 can function even with a lower conductivity than that of the first electrode 1101 or the second electrode 1102.

[0409]

[0410] The EL layer 1103 shown in FIG. 27C has a charge generation layer 1109 between the first light emitting unit 1123(1) and the second light emitting unit 1123(2), and has a charge generation layer 1109 between the second light emitting unit 1123(2) and the third light emitting unit 1123(3). Moreover, the light emitting device shown in FIG. 27D has an m-layer light emitting unit (m is a natural number of 2 or more) and an n-layer light emitting unit (n is a natural number of m or more), and has a charge generation layer 1109 between each light emitting unit. In addition, the third light emitting unit 1123(3), the light emitting unit 1123(m), and the light emitting unit 1123(n) each have a hole injection layer 1111, a hole transport layer 1112, a light emitting layer 1113, an electron transport layer 1114, an electron injection layer 1115, etc. shown in FIG. 27A. Here, the behavior of electrons and holes in the charge generation layer 1109 provided between the light emitting unit 1123(m) and the light emitting unit 1123(m + 1) will be described. When a voltage higher than the threshold voltage of the light emitting device is applied between the first electrode 1101 and the second electrode 1102, holes and electrons are generated in the charge generation layer 1109. The holes move to the light emitting unit 1123(m + 1) provided on the second electrode 1102 side, and the electrons move to the light emitting unit 1123(m) provided on the first electrode 1101 side. The holes injected into the light emitting unit 1123(m + 1) recombine with the electrons injected from the second electrode 1102 side, and the light emitting material contained in the light emitting unit 1123(m + 1) emits light. In addition, the holes injected into the light emitting unit 1123(m) recombine with the electrons injected from the first electrode 1101 side, and the light emitting material contained in the light emitting unit 1123(m) emits light. Moreover, the third light emitting unit 1123(3), the light emitting unit 1123(m), and the light emitting unit 1123(n) each have a hole injection layer 1111, a hole transport layer 1112, a light emitting layer 1113, an electron transport layer 1114, an electron injection layer 1115, etc. shown in FIG. 27A. Note that each light emitting unit may have the same configuration or different configurations.

[0411] Here, the behavior of electrons and holes in the charge generation layer 1109 provided between the light emitting unit 1123(m) and the light emitting unit 1123(m + 1) will be described. When a voltage higher than the threshold voltage of the light emitting device is applied between the first electrode 1101 and the second electrode 1102, holes and electrons are generated in the charge generation layer 1109. The holes move to the light emitting unit 1123(m + 1) provided on the second electrode 1102 side, and the electrons move to the light emitting unit 1123(m) provided on the first electrode 1101 side. When a voltage higher than the threshold voltage of the light emitting device is applied between the first electrode 1101 and the second electrode 1102, holes and electrons are generated in the charge generation layer 1109. The holes move to the light emitting unit 1123(m + 1) provided on the second electrode 1102 side, and the electrons move to the light emitting unit 1123(m) provided on the first electrode 1101 side. The holes injected into the light emitting unit 1123(m + 1) recombine with the electrons injected from the second electrode 1102 side, and the light emitting material contained in the light emitting unit 1123(m + 1) emits light. Moreover, the holes injected into the light emitting unit 1123(m) recombine with the electrons injected from the first electrode 1101 side, and the light emitting material contained in the light emitting unit 1123(m) emits light. The holes injected into the light emitting unit 1123(m + 1) recombine with the electrons injected from the second electrode 1102 side, and the light emitting material contained in the light emitting unit 1123(m + 1) emits light. The injected electrons recombine with the holes injected from the first electrode 1101 side, and the light-emitting material contained in the light-emitting unit 1 123(m) emits light. Therefore, the holes and electrons generated in the charge generation layer 1109 emit light in different light-emitting units respectively.

[0412] In addition, when a structure same as that of the charge generation layer 1109 is formed between the light-emitting units by providing the light-emitting units in contact with each other, the light-emitting units can be provided in contact with each other without passing through the charge generation layer 1109. For example, when a charge generation region is formed on one surface of the light-emitting unit, the light-emitting unit can be provided in contact with that surface.

[0413] Compared with a single-structure light-emitting device, a tandem-structure light-emitting device has higher current efficiency and requires less current to emit light at the same luminance. Therefore, the lifespan and reliability of the light-emitting device can be enhanced.

[0414] In addition, the plurality of light-emitting units may have the same light-emitting material or different light-emitting materials. Also, the light-emitting materials of each light-emitting unit are not particularly limited. To enhance reliability, it is preferable that a plurality of fluorescence-emitting light-emitting units are stacked. For example, when having the same light-emitting material, a highly reliable light-emitting device can be provided by combining a blue fluorescence-emitting light-emitting unit and a blue fluorescence-emitting light-emitting unit. Also, one or more fluorescence-emitting light-emitting units and one or more phosphorescence-emitting light-emitting units may be stacked respectively. For example, a light-emitting device capable of emitting white light can be provided by combining a blue fluorescence-emitting light-emitting unit, a red phosphorescence-emitting light-emitting unit, and a green light-emitting unit. ​​​​​​​​​​​​Alternatively, as a combination of highly reliable light-emitting units, each of blue, red, and green may be a fluorescence-emitting light-emitting unit.

[0415] In addition, when combining the above-described blue fluorescence-emitting unit and the blue fluorescence-emitting unit, it is preferable to use it in combination with a device (for example, a quantum dot device, etc.) having a function of converting the blue light emitted from the light-emitting unit into another color.

[0416] This embodiment can be implemented in appropriate combination with at least a part of other embodiments described in this specification.

Description of Reference Numerals

[0417] 100A: Display device, 100B: Display device, 100C: Display device, 100D: Display device, 100E: Display device, 101: Display panel, 101a: Region, 101b: Region, 101c : Region, 102a: Housing, 102b: Housing, 102c: Housing, 103a: Hinge, 103 b: Hinge, 103c: Hinge, 104a: Curved surface, 104b: Curved surface, 105: Plane, 10 5a: Curved surface, 105b: Curved surface, 106: Grip portion, 107: Power receiving coil, 108: Power receiving circuit, 109: Charger, 111: Columnar body, 113a: Unit, 113b: Unit, 1 14: Columnar body, 115: Columnar body, 116a: Gear, 116b: Gear, 117: Battery, 118: Protection circuit, 119: Control circuit, 120: Sensor, 121: Comparator, 122 : Transistor, 123: Capacitor, 125: Antenna, 126: Antenna, 130: Image, 131: Keyboard, 132: Icon, 135a: Input / output unit, 135b: Input / output unit, 136a: Camera, 136b: Camera, 137: Sensor, 138: Display Panel, 139: Display panel, 140: Solar cell, 141: Thin-film solar cell, 145: External Interface, 146: Transceiver unit, 147: Speaker, 148: Camera, 14 9: Microphone, 150: Stylus, 200: Display device, 210: Display device, 300: Pixel , 301: Pixel, 400: Pixel circuit, 400EL: Pixel circuit, 400LC: Pixel circuit, 4 01: Circuit, 401EL: Circuit, 401LC: Circuit, 501: Pixel circuit, 502: Pixel section , 504: Driving circuit section, 504a: Gate driver, 504b: Source driver, 506 : Protection circuit, 507: Terminal section, 550: Transistor, 552: Transistor, 554: Transistor, 560: Capacitor, 562: Capacitor, 570: Liquid crystal device, 57 2: Light-emitting device, 600: Television device, 601: Control section, 602: Memory section, 60 3: Communication control section, 604: Image processing circuit, 605: Decoder circuit, 606: Video signal reception section, 607: Timing controller, 608: Source driver, 609: Gate driver bar, 620: Display panel, 621: Pixel, 630: System bus, 700: Display panel, 700A: Display panel, 702: Pixel section, 704: Source driver circuit section, 706: Gate driver circuit section, 708: FPC terminal section, 710: Wiring, 716: FPC, 717: I C, 730: Insulating layer, 732: Sealing layer, 736: Coloring layer, 738: Light-shielding layer, 740: Support substrate, 741: Protection layer, 741a: Insulating layer, 741b: Insulating layer, 741c: Insulating layer, 74 2: Adhesive layer, 743: Resin layer, 744: Insulating layer, 745: Support substrate, 746: Insulating layer, 7 47: Adhesive layer, 749: Protection layer, 750: Transistor, 752: Transistor, 760 : Wiring, 761: Conductive layer, 770: Insulating layer, 772: Conductive layer, 780: Anisotropic conductive film, 7 82: Light-emitting device, 786: EL layer, 788: Conductive layer, 790: Capacitor, 1101 : Electrode, 1102: Electrode, 1103: EL layer, 1109: Charge generation layer, 1111: Hole injection layer, 1112: Hole transport layer, 1113: Light-emitting layer, 1114: Electron transport layer, 1115: Electron injection layer, 1120: Light-emitting region, 1123: Light-emitting unit

Claims

1. A display device having a flexible display panel, a hinge, a first housing, and a second housing, wherein the display panel has first to third regions, when the display panel is flattened, the second region is provided between the first region and the third region, at least a part of the first region is fixed to the first housing, at least a part of the third region is fixed to the second housing, the hinge is provided between the first housing and the second housing, the hinge has a first unit, a second unit, and a third unit located between the first unit and the second unit, the first unit and the second unit each have a plurality of columnar bodies having a trapezoidal or substantially trapezoidal cross-section in the short-axis direction of the display panel, the third unit has one columnar body having a flat bottom surface and a side surface perpendicular to the bottom surface, the bottom surface of the columnar body at one end of the first unit is connected so as to be continuous with the first surface of the first housing, the bottom surface of the columnar body at one end of the second unit is connected so as to be continuous with the first surface of the second housing, when the display panel is folded, the side surface of the columnar body at the other end of the first unit contacts one side surface of the third unit, and the side surface of the columnar body at the other end of the second unit contacts the other side surface of the third unit, a display device in which, when the display panel is folded, regions that are substantially arc-shaped are formed in the cross-sections of the plurality of columnar bodies of the first unit and the cross-sections of the plurality of columnar bodies of the second unit, respectively.

2. In claim 1, when the display panel is flattened, the first surface of the first housing, the bottom surfaces of the plurality of columnar bodies of the first unit, the bottom surfaces of the plurality of columnar bodies of the second unit, the bottom surface of the columnar body of the second unit, and the first surface of the second housing are flat and continuous.

Images