Method for correcting a display device

Abstract

Provided is a new correction method for a display device. One aspect of the present invention is a correction method for a display device, the correction method involving: performing a process in which the voltage for correcting the threshold voltage of a transistor is acquired and the voltage is maintained at a capacity; in a first circuit, performing a process in which electric current flowing to a pixel is measured and a second signal based on the electric current is generated; in a second circuit, performing a process in which a first signal obtained by correcting image data is generated by using the second signal; and performing a process in which the first signal is supplied to the pixel.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a method for correcting a display device.

[0002] It should be noted that one aspect of the present invention is not limited to the above-mentioned technical field. Examples of technical fields of one aspect of the present invention disclosed herein include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting devices, input devices, input / output devices, methods for driving them, or methods for manufacturing them.

[0003] In this specification, a semiconductor device refers to a device that utilizes semiconductor properties, including circuits containing semiconductor elements (transistors, diodes, photodiodes, etc.), devices having such circuits, etc. It also refers to any device that can function by utilizing semiconductor properties. For example, integrated circuits, chips equipped with integrated circuits, and electronic components with chips housed in packages are examples of semiconductor devices. Furthermore, memory devices, display devices, light-emitting devices, lighting devices, and electronic devices are themselves semiconductor devices, and may also contain semiconductor devices. [Background technology]

[0004] In recent years, electronic devices equipped with display devices, such as smartphones and tablet terminals, have become widespread. Typical examples of display devices include liquid crystal displays, organic EL (Electro-Luminescence) elements, light-emitting devices equipped with light-emitting elements such as LEDs, and electronic paper that displays information using electrophoresis.

[0005] For example, the basic structure of an organic EL element consists of a layer containing a light-emitting organic compound sandwiched between a pair of electrodes. By applying a voltage to this element, light can be obtained from the light-emitting organic compound. Display devices using such organic EL elements do not require a backlight, which is necessary for liquid crystal displays, and can therefore be made thin, lightweight, high-contrast, and low-power. In addition, because organic EL elements have a fast response speed, they can be used to create display devices suitable for displaying fast-moving images. For example, an example of a display device using an organic EL element is described in Patent Document 1.

[0006] Furthermore, Patent Document 2 discloses a pixel circuit for controlling the luminescence brightness of an organic EL element, which corrects the threshold voltage variation of transistors for each pixel and improves the display quality of the display device. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2002-324673 [Patent Document 2] Japanese Patent Publication No. 2015-132816 [Overview of the project] [Problems that the invention aims to solve]

[0008] On the other hand, there are problems such as display unevenness due to variations in the characteristics of each individual OLED element. Furthermore, moisture, oxygen, light, and heat accelerate the degradation of the OLED elements' characteristics, leading to a decrease in brightness. In addition, the rate of degradation of OLED elements' characteristics depends on the device structure, material properties, manufacturing process conditions, and the driving method of the display device. For example, in a color display system using three types of OLED elements corresponding to R (red), G (green), and B (blue), the OLED elements may degrade at different rates depending on the corresponding color. In that case, over time, the brightness of the OLED elements will differ for each color, making it impossible to display the desired color on the display device.

[0009] One aspect of the present invention aims to provide a display device with improved display quality. Alternatively, one aspect of the present invention aims to provide a novel display device. Alternatively, one aspect of the present invention aims to provide a novel method for correcting a display device.

[0010] Furthermore, the description of these problems does not preclude the existence of other problems. Moreover, one aspect of the present invention does not need to solve all of these problems. Other problems can be identified from the description in the specification, drawings, claims, etc. [Means for solving the problem]

[0011] (1) One aspect of the present invention is a correction method for a display device, comprising a pixel, a first circuit, and a second circuit, wherein the pixel comprises a light-emitting element, a transistor, and a capacitor, and the transistor has the function of controlling the current supplied to the light-emitting element based on a first signal supplied to the pixel, the method comprising: a first process of acquiring a voltage to correct the threshold voltage of the transistor and holding the voltage in the capacitor; a second process of measuring the current flowing through the pixel in the first circuit after the completion of the first process and generating a second signal based on the current; a third process of generating a first signal in the second circuit after the completion of the second process by correcting the image data using the second signal; and a fourth process of supplying the first signal to the pixel after the completion of the third process.

[0012] (2) One aspect of the present invention is a correction method for a display device, comprising a pixel, a first circuit, and a second circuit, wherein the pixel comprises a light-emitting element, a transistor, and a capacitor, and the transistor has the function of controlling the current supplied to the light-emitting element based on a first signal supplied to the pixel, the correction method for a display device comprising: a second process in the first circuit, which measures the current flowing through the pixel and generates a second signal based on the current; a first process after the completion of the second process, which acquires a voltage to correct the threshold voltage of the transistor and holds the voltage in the capacitor; a third process after the completion of the second process, which generates a first signal in the second circuit that corrects the image data using the second signal; and a fourth process after the completion of the first and third processes, which supplies the first signal to the pixel.

[0013] (3) In addition, in (2) above, the first process and the third process may be performed simultaneously.

[0014] (4) In addition, in any one of the above (1) to (3), the second process may measure the current flowing through the light-emitting element.

[0015] (5) In any one of the above (1) to (4), the transistor includes a back gate, and the transistor has a function of controlling the threshold voltage of the transistor based on the potential supplied to the back gate. The first process may obtain the voltage between the back gate and the source of the transistor.

[0016] (6) In any one of the above (1) to (5), the fourth process may supply the first signal to the gate of the transistor. [Effect of the Invention]

[0017] According to one aspect of the present invention, a display device with improved display quality can be provided. Or, according to one aspect of the present invention, a novel display device can be provided. Or, according to one aspect of the present invention, a correction method for a novel display device can be provided.

[0018] 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 all of these effects. Note that other effects can be extracted from the descriptions in the specification, drawings, claims, etc. [Brief Description of the Drawings]

[0019] FIG. 1 is a diagram for explaining an example of a display device. FIG. 2 is a diagram for explaining an example of a display device. FIG. 3 is a diagram for explaining an example of a display device. FIGS. 4A to 4C are diagrams showing circuit symbols of transistors. FIG. 5 is a flowchart for explaining an example of a correction method for a display device. FIG. 6 is a timing chart for explaining an operation example of a display device. FIG. 7 is a diagram for explaining an operation example of a display device. FIG. 8 is a diagram for explaining an operation example of a display device. FIG. 9 is a diagram for explaining an operation example of a display device. FIG. 10 is a diagram for explaining an operation example of a display device. Figure 11 illustrates an example of the operation of a display device. Figure 12 illustrates an example of the operation of a display device. Figure 13 illustrates an example of the operation of a display device. Figure 14 is a flowchart illustrating an example of a method for correcting a display device. Figure 15 shows an example of a specific configuration of a display device. Figures 16A to 16C show examples of the configuration of a display device. Figures 17A to 17F show examples of pixel configurations. Figure 18 shows an example of a display device configuration. Figures 19A and 19B show examples of the configuration of a display device. Figures 20A to 20F show examples of the configuration of a light-emitting device. Figures 21A to 21F illustrate an example of an electronic device. Figures 22A to 22F illustrate an example of electronic equipment. Figures 23A and 23B illustrate an example of an electronic device. Figure 24 is a diagram illustrating an example of an electronic device. [Modes for carrying out the invention]

[0020] The embodiments will be described below with reference to the drawings. However, the embodiments can be implemented in many different ways. Therefore, it will be easily understood by those skilled in the art that the form and details can be changed in various ways without departing from the spirit and scope. Accordingly, the present invention is not to be construed as being limited to the contents of the following embodiments.

[0021] Furthermore, when it is stated in this specification that X and Y are connected, it is assumed that this specification discloses the cases in which X and Y are electrically connected, functionally connected, and directly connected. Therefore, it is assumed that the disclosed connections are not limited to predetermined connections, such as those shown in the figures or text, but also include connections other than those shown in the figures or text. X and Y are objects (e.g., devices, elements, circuits, wiring, electrodes, terminals, conductive films, layers, etc.).

[0022] One example of a case where X and Y are electrically connected is that one or more elements that enable the electrical connection between X and Y (e.g., switches, transistors, capacitive elements, inductors, resistors, diodes, display devices, light-emitting devices, loads, etc.) can be connected between X and Y.

[0023] One example of a functional connection between X and Y is when one or more circuits that enable the functional connection between X and Y (for example, logic circuits (inverters, NAND gates, NOR gates, etc.), signal conversion circuits (digital-to-analog conversion circuits, analog-to-digital conversion circuits, gamma correction circuits, etc.), potential level conversion circuits (power supply circuits (boost circuits, buck circuits, etc.), level shifter circuits that change the potential level of a signal, etc.), voltage sources, current sources, switching circuits, amplification circuits (circuits that can increase the signal amplitude or current amount, such as operational amplifiers, differential amplifiers, source follower circuits, buffer circuits, etc.), signal generation circuits, memory circuits, control circuits, etc.) can be connected between X and Y.

[0024] Furthermore, when it is explicitly stated that X and Y are electrically connected, this includes both cases where X and Y are electrically connected (i.e., connected with another element or circuit in between) and cases where X and Y are directly connected (i.e., connected without another element or circuit in between).

[0025] Furthermore, for example, it can be expressed as, "X, Y, the source (or first terminal, etc.) and drain (or second terminal, etc.) of the transistor are electrically connected to each other, and the connection is in the order of X, the source (or first terminal, etc.) of the transistor, the drain (or second terminal, etc.) of the transistor, and Y." Alternatively, it can be expressed as, "The source (or first terminal, etc.) of the transistor is electrically connected to X, and the drain (or second terminal, etc.) of the transistor is electrically connected to Y, and X, the source (or first terminal, etc.) of the transistor, the drain (or second terminal, etc.) of the transistor, and Y are electrically connected in this order." Alternatively, it can be expressed as, "X is electrically connected to Y via the source (or first terminal, etc.) and drain (or second terminal, etc.) of the transistor, and X, the source (or first terminal, etc.) of the transistor, the drain (or second terminal, etc.) of the transistor, and Y are provided in this connection order." By using similar notation to these examples to define the order of connections in a circuit configuration, the source (or first terminal, etc.) and drain (or second terminal, etc.) of a transistor can be distinguished and their technical scope determined. Note that these notational methods are examples only and are not limited to them. Here, X and Y are objects (e.g., devices, elements, circuits, wiring, electrodes, terminals, conductive films, layers, etc.).

[0026] Even if independent components are shown as electrically connected in a circuit diagram, a single component may possess the functions of multiple components. For example, if part of a wire also functions as an electrode, a single conductive film possesses the functions of both the wire and the electrode. Therefore, in this specification, "electrically connected" includes cases where a single conductive film possesses the functions of multiple components.

[0027] Furthermore, in this specification, "capacitive element" can refer to, for example, a circuit element having a capacitance value higher than 0F, a region of wiring having a capacitance value higher than 0F, parasitic capacitance, the gate capacitance of a transistor, etc. Therefore, in this specification, "capacitive element" includes not only a circuit element comprising a pair of electrodes and a dielectric material contained between the electrodes, but also parasitic capacitance occurring between wirings, the gate capacitance occurring between one of the sources or drains of a transistor and the gate, etc. Also, terms such as "capacitive element," "parasitic capacitance," and "gate capacitance" can be replaced with terms such as "capacitance," and conversely, the term "capacitance" can be replaced with terms such as "capacitive element," "parasitic capacitance," and "gate capacitance." In addition, the term "a pair of electrodes" in "capacitance" can be replaced with terms such as "a pair of conductors," "a pair of conductive regions," and "a pair of regions." The capacitance value can be, for example, 0.05fF or more and 10pF or less. Alternatively, it may be, for example, 1pF or more and 10μF or less.

[0028] Furthermore, in this specification, a transistor has three terminals called the gate, source, and drain. The gate is a control terminal that controls the amount of current flowing between the source and drain. The two terminals that function as either the source or the drain are the input and output terminals of the transistor. Depending on the conductivity type of the transistor (n-channel or p-channel) and the potential applied to the three terminals of the transistor, one of the two input and output terminals becomes the source and the other becomes the drain. For this reason, in this specification, the terms source and drain can be used interchangeably. Also, in this specification, when describing the connection relationships of a transistor, the notation "one of the source or drain" (or first electrode or first terminal) and "the other of the source or drain" (or second electrode or second terminal) is used. Depending on the structure of the transistor, in addition to the three terminals described above, there may be a back gate. In this case, in this specification, one of the gate or back gate of the transistor may be called the first gate, and the other of the gate or back gate of the transistor may be called the second gate. Furthermore, in the same transistor, the terms "gate" and "back gate" may be interchangeable. Furthermore, if a transistor has three or more gates, in this specification, each gate may be referred to as the first gate, second gate, third gate, and so on.

[0029] Furthermore, in this specification, the term "node" can be replaced with terminals, wiring, electrodes, conductive layers, conductors, impurity regions, etc., depending on the circuit configuration, device structure, etc. Also, terminals, wiring, etc. can be replaced with "node".

[0030] Furthermore, the ordinal numbers "1st," "2nd," and "3rd" in this specification are used to avoid confusion of constituent elements. Therefore, they do not limit the number of constituent elements, nor do they limit the order of the constituent elements. For example, a constituent element referred to as "1st" in one embodiment of this specification may be referred to as "2nd" in another embodiment or in the claims. Also, for example, a constituent element referred to as "1st" in one embodiment of this specification may be omitted in another embodiment or in the claims.

[0031] Furthermore, in this specification, phrases indicating arrangement such as "above," "below," "upward," or "downward" are sometimes used for convenience to explain the positional relationship between components with reference to the drawings. Also, the positional relationship between components changes as appropriate depending on the direction in which each component is depicted. Therefore, the phrases explained in the specification are not limited to those described and can be appropriately rephrased depending on the situation. For example, the expression "insulator located on the upper surface of the conductor" can be rephrased as "insulator located on the lower surface of the conductor" by rotating the orientation of the drawing shown by 180 degrees.

[0032] Furthermore, the terms "above" and "below" do not limit the positional relationship of the components to being directly above or below each other and in direct contact. For example, the expression "electrode B on insulating layer A" does not require electrode B to be formed in direct contact with insulating layer A, and does not exclude cases where other components are included between insulating layer A and electrode B.

[0033] Furthermore, in this specification, terms such as "overlapping" do not limit the state of the stacking order of the components. For example, the expression "electrode B overlapping insulating layer A" does not exclude not only the state in which electrode B is formed on top of insulating layer A, but also the state in which electrode B is formed below insulating layer A or the state in which electrode B is formed to the right (or left) of insulating layer A.

[0034] Furthermore, in this specification, the terms "adjacent" and "proximity" are not limited to direct contact between components. For example, the expression "electrode B adjacent to insulating layer A" does not require that insulating layer A and electrode B be formed in direct contact, and does not exclude cases where other components are included between insulating layer A and electrode B.

[0035] Furthermore, in this specification, terms such as "film" and "layer" can be interchanged as needed. For example, the term "conductive layer" may be changed to the term "conductive film." Or, for example, the term "insulating film" may be changed to the term "insulating layer." Alternatively, depending on the circumstances, terms such as "film" and "layer" can be omitted and replaced with other terms. For example, the term "conductive layer" or "conductive film" may be changed to the term "conductor." Or, the term "conductor" may be changed to the term "conductive layer" or "conductive film." Alternatively, for example, the term "insulating layer" or "insulating film" may be changed to the term "insulator." Or, the term "insulator" may be changed to the term "insulating layer" or "insulating film."

[0036] Furthermore, in this specification, terms such as "electrode," "wiring," or "terminal" do not functionally limit these components. For example, "electrode" may be used as part of "wiring," and vice versa. Moreover, the terms "electrode" or "wiring" also include cases where multiple "electrodes" or "wiring" are formed as a single unit. Similarly, for example, "terminal" may be used as part of "wiring" or "electrode," and vice versa. Furthermore, the term "terminal" also includes cases where multiple "electrodes," "wiring," or "terminals" are formed as a single unit. Therefore, for example, "electrode" can be part of "wiring" or "terminal." Also, for example, "terminal" can be part of "wiring" or "electrode." In addition, terms such as "electrode," "wiring," or "terminal" may be replaced with terms such as "region."

[0037] Furthermore, in this specification, terms such as "wiring," "signal line," and "power line" can be interchanged with each other depending on the circumstances or situation. For example, the term "wiring" may be changed to the term "signal line." Also, for example, the term "wiring" may be changed to the term "power line." Similarly, the reverse is also true; terms such as "signal line" and "power line" may be changed to the term "wiring." Terms such as "power line" may be changed to the term "signal line." Similarly, the reverse is also true; terms such as "signal line" may be changed to the term "power line." In addition, the term "potential" applied to the wiring may be changed to the term "signal," depending on the circumstances or situation. Similarly, the reverse is also true; terms such as "signal" may be changed to the term "potential."

[0038] Furthermore, in this specification, a "switch" is defined as a device having multiple terminals and a function to switch (select) between continuity and non-continuity between the terminals. For example, if a switch has two terminals and there is continuity between both terminals, the switch is said to be in a "conductive state" or "on state." Conversely, if there is no continuity between both terminals, the switch is said to be in a "non-conductive state" or "off state." Note that switching to either a continuative or non-conductive state, or maintaining either a continuative or non-conductive state, may be referred to as "controlling the continuity state."

[0039] In short, a switch is a device that controls whether or not an electric current flows. Alternatively, a switch is a device that selects and switches the path through which an electric current flows. Examples include electrical switches and mechanical switches. In other words, a switch can be anything that can control an electric current, and is not limited to any particular type.

[0040] Examples of switches include transistors (e.g., bipolar transistors, MOS transistors), diodes (e.g., PN diodes, PIN diodes, Schottky diodes, MIM (Metal Insulator Metal) diodes, MIS (Metal Insulator Semiconductor) diodes, diode-connected transistors, etc.), or logic circuits combining these. When a transistor is used as a switch, the "conducting state" or "on state" of the transistor refers to a state in which the source and drain electrodes of the transistor can be considered to be electrically short-circuited. Conversely, the "non-conducting state" or "off state" of the transistor refers to a state in which the source and drain electrodes of the transistor can be considered to be electrically disconnected. When a transistor is used simply as a switch, the polarity (conductivity type) of the transistor is not particularly limited.

[0041] One example of a mechanical switch is a switch using MEMS (Micro-Electro-Mechanical Systems) technology. This switch has mechanically movable electrodes, and the movement of these electrodes selects between a conductive state and a non-conductive state.

[0042] In this specification, "parallel" means that two lines are positioned at an angle of -10° or more and 10° or less. Therefore, the case of -5° or more and 5° or less is also included. "Approximately parallel" or "roughly parallel" means that two lines are positioned at an angle of -30° or more and 30° or less. "Perpendicular" means that two lines are positioned at an angle of 80° or more and 100° or less. Therefore, the case of 85° or more and 95° or less is also included. "Approximately perpendicular" or "roughly perpendicular" means that two lines are positioned at an angle of 60° or more and 120° or less.

[0043] In this specification, when count values ​​and measured values ​​are referred to as "identical," "same," "equal," or "uniform" (including synonyms thereof), unless otherwise explicitly stated, this refers to a margin of error of plus or minus 20%.

[0044] The embodiments described herein will be explained with reference to the drawings. However, the embodiments can be implemented in many different ways. Therefore, it will be easily understood by those skilled in the art that their form and details can be changed in various ways without departing from the spirit and scope. Accordingly, the present invention is not to be interpreted as being limited to the contents described in the embodiments. In the configuration of the invention in the embodiments, the same reference numerals are used in common across different drawings for the same part or part having a similar function, and repeated explanations may be omitted. Also, when referring to similar functions, the hatch patterns may be the same, and no reference numerals may be assigned. Furthermore, in order to make the drawings easier to understand, some components may be omitted in perspective views or top views, etc.

[0045] Furthermore, in the drawings and other illustrations relating to this specification, the size, layer thickness, or area may be exaggerated for clarity. Therefore, it is not necessarily limited to the size or aspect ratio. The drawings are schematic representations of ideal examples and are not limited to the shapes or values ​​shown in the drawings. For example, they may include variations in signals, voltages, or currents due to noise, or variations in signals, voltages, or currents due to timing differences.

[0046] Furthermore, in drawings and other illustrations relating to this specification, arrows indicating the X, Y, and Z directions may be included. In this specification, the "X direction" refers to the direction along the X-axis, and unless explicitly stated, the forward and reverse directions may not be distinguished. The same applies to the "Y direction" and "Z direction." Also, the X, Y, and Z directions are directions that intersect each other. More specifically, the X, Y, and Z directions are directions that are orthogonal to each other. In this specification, one of the X, Y, or Z directions may be referred to as the "first direction" or "first direction." Another may be referred to as the "second direction" or "second direction." The remaining one may be referred to as the "third direction" or "third direction."

[0047] In this specification, when the same symbol is used for multiple elements, and especially when it is necessary to distinguish them, an identifying symbol such as "A", "b", "_1", "[n]", or "[m,n]" may be added to the symbol.

[0048] (Embodiment 1) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention, and a method for correcting the display device.

[0049] <Example of display device configuration> Figure 1 shows an example of the configuration of a display device according to one aspect of the present invention. The display device 10 comprises a pixel 11, a monitor circuit 12, and an image processing circuit 13. The pixel 11 comprises a light-emitting element 61, transistors M1 to M6, and capacitors C1 and C2.

[0050] The monitor circuit 12 has the function of supplying an arbitrary potential to the wiring ML. The monitor circuit 12 also has the function of measuring the current flowing through the wiring ML to the pixel 11. Furthermore, the monitor circuit 12 has the function of generating arbitrary data based on the measured current. For example, current-voltage characteristic data may be generated by acquiring multiple arbitrary potential values ​​supplied to the wiring ML and the current values ​​flowing through the wiring ML at that time, as arbitrary data.

[0051] The image processing circuit 13 has the function of correcting image data using arbitrary data generated by the monitor circuit 12 and generating display data. In this embodiment, the display data refers to the corrected image data. The image processing circuit 13 also has the function of supplying display data or an arbitrary potential to the wiring DL. For example, an arbitrary potential that can turn off transistor M2 may be supplied.

[0052] The gate of transistor M1 is electrically connected to wiring GLa. Either the source or drain of transistor M1 is electrically connected to wiring DL. The other source or drain of transistor M1 is electrically connected to the gate of transistor M2. Transistor M1 has the function of making the connection between the gate of transistor M2 and wiring DL either conductive or nonconductive.

[0053] The gate of transistor M2 is electrically connected to one terminal of capacitor C1. One of the source or drain of transistor M2 is electrically connected to wiring 51. The other of the source or drain of transistor M2 is electrically connected to the other terminal of capacitor C1. Transistor M2 also has a back gate. The back gate of transistor M2 is electrically connected to one terminal of capacitor C2. The other terminal of capacitor C2 is electrically connected to the other of the source or drain of transistor M2.

[0054] The gate of transistor M3 is electrically connected to wiring GLB. One of the source or drain of transistor M3 is electrically connected to one terminal of capacitor C1. The other of the source or drain of transistor M3 is electrically connected to the other terminal of capacitor C1. Transistor M3 has the function of making the connection between the gate of transistor M2 and the other of the source or drain of transistor M2 conductive or non-conductive.

[0055] The gate of transistor M4 is electrically connected to wiring GLB. One of the sources or drains of transistor M4 is electrically connected to wiring 53. The other of the sources or drains of transistor M4 is electrically connected to one terminal of capacitor C2. Transistor M4 has the function of making the connection between wiring 53 and one terminal of capacitor C2 conductive or nonconductive.

[0056] The gate of transistor M5 is electrically connected to the wiring GLc. One of the sources or drains of transistor M5 is electrically connected to the other source or drain of transistor M2. The other source or drain of transistor M5 is electrically connected to one terminal of the light-emitting element 61 (for example, the anode terminal). Transistor M5 has the function of making the other source or drain of transistor M2 and one terminal of the light-emitting element 61 conduct or not conduct.

[0057] The gate of transistor M6 is electrically connected to wiring GLa. One of the sources or drains of transistor M6 is electrically connected to the other source or drain of transistor M2. The other source or drain of transistor M6 is electrically connected to wiring ML. Transistor M6 has the function of making the other source or drain of transistor M2 and wiring ML conduct or not conduct.

[0058] The other terminal of the light-emitting element 61 (for example, the cathode terminal) is electrically connected to the wiring 52.

[0059] The light-emitting element 61 emits light with an intensity corresponding to the amount of current flowing through it. Various display elements can be used as the light-emitting element 61, such as EL elements (EL elements containing organic and inorganic materials, organic EL elements, or inorganic EL elements), LEDs (e.g., white LEDs, red LEDs, green LEDs, or blue LEDs), microLEDs (e.g., LEDs with sides less than 0.1 mm), QLEDs (Quantum-dot Light Emitting Diodes), or electron-emitting elements.

[0060] Furthermore, transistor M2 has the function of controlling the amount of current flowing to the light-emitting element 61. In other words, transistor M2 has the function of controlling the light emission intensity of the light-emitting element 61. Therefore, in this specification, transistor M2 may be referred to as the "driving transistor".

[0061] Furthermore, the region in which the other terminals of capacitors C1 and C2, the other source or drain of transistor M2, the other source or drain of transistor M3, one source or drain of transistor M5, and one source or drain of transistor M6 are electrically connected to each other is also called node ND1.

[0062] Furthermore, the region where one terminal of capacitor C2, the back gate of transistor M2, and the other source or drain of transistor M4 are electrically connected to each other is also called node ND2.

[0063] Furthermore, the region where the other source or drain of transistor M1, the other source or drain of transistor M3, one terminal of capacitor C1, and the gate of transistor M2 are electrically connected to each other is also called node ND3.

[0064] Capacitor C1 has the function of maintaining the potential difference (voltage) between the gate of transistor M2 and the other of the source or drain of transistor M2, for example, when node ND3 is in a floating state.

[0065] Capacitor C2 has the function of maintaining the potential difference (voltage) between the other of the source or drain of transistor M2 and the back gate of transistor M2, for example, when node ND2 is in a floating state.

[0066] In this embodiment, transistors M1 to M6 are enhancement-type (normally-off type) n-channel field-effect transistors unless otherwise specified. Therefore, their threshold voltage (also called "Vth") is greater than 0V.

[0067] In one aspect of the present invention, the pixel 11 can use a transistor containing various semiconductors. For example, the channel formation region can be a transistor containing a single-crystal semiconductor, a polycrystalline semiconductor, a microcrystalline semiconductor, or an amorphous semiconductor. Furthermore, the semiconductor is not limited to a single element whose main component is a single element (e.g., silicon (Si) or germanium (Ge)), but can also be a compound semiconductor (e.g., silicon germanium (SiGe) or gallium arsenide (GaAs)), or an oxide semiconductor.

[0068] Furthermore, while this embodiment and others show an example of configuring the display device 10 using n-channel transistors, the present invention is not limited to this. Some or all of the transistors constituting the display device 10 may be p-channel transistors.

[0069] Furthermore, the pixel 11 according to one aspect of the present invention can use transistors of various structures. For example, planar type, fin type, tri-gate type, top-gate type, bottom-gate type, or dual-gate type (a structure in which gates are arranged above and below the channel) transistors of various configurations can be used. In addition, as the transistor according to one aspect of the present invention, for example, a MOS type transistor, a junction type transistor, or a bipolar transistor can be used.

[0070] For example, an OS transistor (a transistor containing an oxide semiconductor in the semiconductor layer where the channel is formed) may be used as the transistor constituting the pixel 11. Since oxide semiconductors have a bandgap of 2 eV or more, their off-current is extremely low. Therefore, it is preferable to use an OS transistor for a transistor that functions as a switch. For example, OS transistors can be used for transistor M1 and transistors M3 to M6.

[0071] The off-current value of an OS transistor per 1 μm channel width at room temperature is 1 aA (1 × 10⁻¹⁶). -18 A) Below, 1zA(1×10 -21 A) Less than or equal to 1yA(1×10 -24 A) It can be less than or equal to the following. Note that the off-current value of a Si transistor (a transistor in which the semiconductor layer on which the channel is formed contains silicon) per 1 μm of channel width at room temperature is 1 fA (1 × 10⁻¹⁶). -15 A) More than 1pA (1×10 -12 A) The answer is as follows. Therefore, it can be said that the off-current of an OS transistor is about 10 orders of magnitude lower than that of a Si transistor.

[0072] By using OS transistors in the transistors that make up pixel 11, the charge written to each node can be retained for a long period of time. For example, when displaying a still image that does not require rewriting for each frame, it becomes possible to continue displaying the image even if the operation of the peripheral drive circuit is stopped. This method of stopping the operation of the peripheral drive circuit while a still image is being displayed is also called "idle stop drive". By performing idle stop drive, the power consumption of the display device can be reduced.

[0073] Furthermore, OS transistors exhibit almost no increase in off-current even in high-temperature environments. Specifically, OS transistors show almost no increase in off-current even at ambient temperatures between room temperature and 200°C. Additionally, their on-current remains stable even in high-temperature environments. Display devices incorporating OS transistors offer stable operation and high reliability, even in high-temperature environments.

[0074] Furthermore, OS transistors have a high dielectric strength between their source and drain. By using OS transistors in the transistors that make up the pixel 11, operation can be stabilized even when the potential difference (voltage) between the potential supplied to the wiring 51 (also called the anode potential) and the potential supplied to the wiring 52 (also called the cathode potential) is large, resulting in a highly reliable display device. In particular, it is preferable to use OS transistors for one or both of transistors M2 and M5.

[0075] The semiconductor layer of the OS transistor preferably comprises, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium, and tin.

[0076] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also referred to as "IGZO") as the semiconductor layer. Alternatively, an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also referred to as "IAZO") may be used as the semiconductor layer. Alternatively, an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also referred to as "IAGZO") may be used as the semiconductor layer.

[0077] When the semiconductor layer is an In-M-Zn oxide, it is preferable that the atomic ratio of In in the In-M-Zn oxide is greater than or equal to the atomic ratio of M. Examples of such atomic ratios of metal elements in an In-M-Zn oxide include: In:M:Zn=1:1:1 or close to it, In:M:Zn=1:1:1.2 or close to it, In:M:Zn=1:3:2 or close to it, In:M:Zn=1:3:4 or close to it, In:M:Zn=2:1:3 or close to it, In:M:Zn=3:1:2 or close to it, and In:M:Zn=4:2:3 Examples include compositions near the desired atomic ratio, such as In:M:Zn=4:2:4.1 or near the desired ratio, In:M:Zn=5:1:3 or near the desired ratio, In:M:Zn=5:1:6 or near the desired ratio, In:M:Zn=5:1:7 or near the desired ratio, In:M:Zn=5:1:8 or near the desired ratio, In:M:Zn=6:1:6 or near the desired ratio, or In:M:Zn=5:2:5 or near the desired ratio. Note that "nearby composition" includes a range of plus or minus 30% of the desired atomic ratio.

[0078] For example, when describing a composition with an atomic ratio of In:Ga:Zn = 4:2:3 or a similar ratio, it includes cases where, when the atomic ratio of In is 4, the atomic ratio of Ga is between 1 and 3, and the atomic ratio of Zn is between 2 and 4. Also, when describing a composition with an atomic ratio of In:Ga:Zn = 5:1:6 or a similar ratio, it includes cases where, when the atomic ratio of In is 5, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is between 5 and 7. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn = 1:1:1 or a similar ratio, it includes cases where, when the atomic ratio of In is 1, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is greater than 0.1 and 2 or less.

[0079] Furthermore, the pixel 11 may be composed of multiple types of transistors using different semiconductor materials. For example, the pixel 11 may be composed of a transistor having low-temperature polysilicon (LTPS (Low Temperature Poly Silicon)) in its semiconductor layer (hereinafter also referred to as an LTPS transistor) and an OS transistor. LTPS transistors have high field-effect mobility and good frequency characteristics. A configuration combining an LTPS transistor and an OS transistor is sometimes referred to as LTPO.

[0080] For example, among the transistors constituting the pixel 11, it is preferable to use OS transistors for transistors M1 and M3 to M6, and an LTPS transistor for transistor M2. In other words, it is preferable to apply OS transistors to transistors that function as switches to control the conduction or non-conduction state between wiring, and to apply LTPS transistors to transistors that control the current. By using both LTPO, i.e., LTPS transistors and OS transistors in the pixel 11, a display device with low power consumption and high driving capability can be realized. Thus, the correction method for a display device according to one aspect of the present invention is not limited to the transistor configuration, but can be applied to transistors of various configurations.

[0081] When the pixel 11 is composed of multiple types of transistors using different semiconductor materials, the transistors may be placed on different layers for each type of transistor. For example, if the pixel 11 is composed of Si transistors and OS transistors, the layer containing the Si transistors and the layer containing the OS transistors may be stacked on top of each other. This configuration reduces the area occupied by the pixel 11.

[0082] Of the transistors constituting the pixel 11, transistors M1 and M3 to M6 function as switches. Therefore, the display device 10 can be shown as in Figure 2. Transistors M1 and M3 to M6 can be replaced with elements that can realize the function of a switch.

[0083] All or some of the transistors constituting the pixel 11 may be transistors having back gates. By providing a back gate to a transistor, the electric field generated outside the transistor is less likely to act on the channel formation region, thereby stabilizing the operation of the display device and improving the reliability of the display device. In addition, by applying the same potential to the back gate of a transistor as to the gate, the on-resistance of the transistor can be reduced. Furthermore, by controlling the potential of the back gate of a transistor independently of the gate potential, the threshold voltage of the transistor can be changed.

[0084] Figure 3 shows an example of the circuit configuration of the display device 10 in which not only transistor M2, but also transistors M1 and M3 through M6 are composed of transistors with back gates. In Figure 3, an example is shown in which the gate and back gate are electrically connected for each of transistors M1 and M3 through M6. However, it is not necessary to provide back gates for all transistors that make up the display device.

[0085] Furthermore, the gate and back gate may not be electrically connected, and an arbitrary potential may be supplied to the back gate. Note that the potential supplied to the back gate is not limited to a fixed potential. The potential supplied to the back gate of the transistors constituting the display device may be different for each transistor, or it may be the same for each transistor.

[0086] The transistor constituting pixel 11 may be a single-gate transistor with one gate between the source and drain, or a double-gate transistor. Figure 4A shows an example of a circuit symbol for a double-gate transistor 180A.

[0087] Transistor 180A has a configuration in which transistors Tr1 and Tr2 are connected in series. In transistor 180A shown in Figure 4A, one of the source or drain of transistor Tr1 is electrically connected to terminal S. The other of the source or drain of transistor Tr1 is electrically connected to one of the source or drain of transistor Tr2. The other of the source or drain of transistor Tr2 is electrically connected to terminal D. In addition, in transistor 180A shown in Figure 4A, the gates of transistors Tr1 and Tr2 are electrically connected and are also electrically connected to terminal G.

[0088] The transistor 180A shown in Figure 4A has the function of switching between a conductive state and a non-conductive state between terminals S and D by changing the potential of terminal G. Therefore, the double-gate transistor 180A contains transistors Tr1 and Tr2 and functions as a single transistor. In other words, in Figure 4A, one of the source or drain of transistor 180A is electrically connected to terminal S, the other source or drain is electrically connected to terminal D, and the gate is electrically connected to terminal G.

[0089] Furthermore, the transistors constituting pixel 11 may be triple-gate transistors. Figure 4B shows an example of a circuit symbol for a triple-gate transistor 180B.

[0090] Transistor 180B has a configuration in which transistors Tr1, Tr2, and Tr3 are connected in series. In transistor 180B shown in Figure 4B, one source or drain of transistor Tr1 is electrically connected to terminal S. The other source or drain of transistor Tr1 is electrically connected to one source or drain of transistor Tr2. The other source or drain of transistor Tr2 is electrically connected to one source or drain of transistor Tr3. The other source or drain of transistor Tr3 is electrically connected to terminal D. In addition, in transistor 180B shown in Figure 4B, the gates of transistors Tr1, Tr2, and Tr3 are electrically connected and are also electrically connected to terminal G.

[0091] The transistor 180B shown in Figure 4B has the function of switching between a conductive state and a non-conductive state between terminals S and D by changing the potential of terminal G. Therefore, the triple-gate transistor 180B contains transistors Tr1, Tr2, and Tr3 and functions as a single transistor. In other words, in Figure 4B, one of the source or drain of transistor 180B is electrically connected to terminal S, the other source or drain is electrically connected to terminal D, and the gate is electrically connected to terminal G.

[0092] Furthermore, the transistors constituting the pixel 11 may be configured with four or more transistors connected in series. The transistor 180C shown in Figure 4C has a configuration in which six transistors (transistors Tr1 to Tr6) are each connected in series. In addition, in the transistor 180C shown in Figure 4C, the gates of each of the six transistors are electrically connected and are also electrically connected to terminal G.

[0093] The transistor 180C shown in Figure 4C has the function of switching between a conductive state and a non-conductive state between terminals S and D by changing the potential of terminal G. Therefore, transistor 180C contains transistors Tr1 to Tr6 and functions as a single transistor. In other words, in Figure 4C, one of the source or drain of transistor 180C is electrically connected to terminal S, the other of the source or drain is electrically connected to terminal D, and the gate is electrically connected to terminal G.

[0094] Transistors that have multiple gates and whose multiple gates are electrically connected, such as transistors 180A, 180B, and 180C, are sometimes called "multi-gate transistors."

[0095] For example, when operating a transistor in the saturation region, the channel length of the transistor may be increased to improve its electrical characteristics in the saturation region. A multi-gate transistor may be used to realize a transistor with a long channel length.

[0096] <Example of display device calibration operation 1> Figure 5 is a flowchart illustrating an example of a correction method for the display device 10. Figure 5 shows steps S01 to S05. First, step S01 is started. In step S01, the threshold voltage of the drive transistor (transistor M2) is corrected. After step S01 is completed, step S02 is started. In step S02, the current-voltage characteristics of the light-emitting element 61 are acquired. After step S02 is completed, step S03 is started. In step S03, the image data is corrected. After step S03 is completed, step S04 is started. In step S04, the display data (corrected image data) is written. After step S04 is completed, step S05 is started. In step S05, the light-emitting element 61 is made to emit light.

[0097] The specific operation of the display device 10 in each of steps S01 to S05 will be explained below with reference to the drawings. Figure 6 is a timing chart illustrating an example of the operation of the display device 10. Figures 7 to 13 are circuit diagrams illustrating an example of the operation of the display device 10.

[0098] Wiring DL shall be supplied with display data Vdata generated by the image processing circuit 13, or potential V0. Wiring ML shall be supplied with potential V0, or potentials Ve1 to Ve4. Wiring 51 shall be supplied with potential Va, wiring 52 with potential Vc, and wiring 53 with potential V1. Wirings GLa, GLB, and GLC shall each be supplied with either potential H or potential L. Potential H is preferably higher than potential L. In this specification, "potential H" is the potential that, when input to the gate of an n-channel transistor, causes the transistor to turn on. "Potential L" is the potential that, when input to the gate of an n-channel transistor, causes the transistor to turn off.

[0099] Potential Va is the anode potential, and potential Vc is the cathode potential. Furthermore, it is preferable that potential V1 is higher than potential V0. Potential V1 may also be a potential that, when applied to the back gate of transistor M2, can shift the threshold voltage negatively until transistor M2 is in a normally-on state. Furthermore, potential V0 may be a potential that, when applied to the gate of transistor M2, can turn transistor M2 off. For example, potential V0 can be 0V or potential L. Furthermore, it is preferable that potential H is higher than potential V1.

[0100] The light emission intensity of the light-emitting element 61 of the pixel 11 is controlled by the magnitude of the current Ie (see Figure 13) flowing through the light-emitting element 61. The pixel 11 has a function to control the magnitude of the current Ie according to the display data Vdata supplied from the image processing circuit 13 via wiring DL.

[0101] In this embodiment and others, the potential difference (voltage) between the gate and source of a transistor is sometimes referred to as the "gate voltage." That is, "transistor gate voltage" = "transistor gate potential" - "transistor source potential." Also, in this embodiment and others, the potential difference (voltage) between the back gate and source of a transistor is sometimes referred to as the "back gate voltage." That is, "transistor back gate voltage" = "transistor back gate potential" - "transistor source potential."

[0102] In drawings, symbols indicating potential, such as "H," "L," "V0," or "V1" (also called "potential symbols"), may be placed adjacent to terminals or wiring. Furthermore, to make potential changes in terminals or wiring easier to understand, potential symbols indicating potential changes may be enclosed in a box. Additionally, an "×" symbol may be superimposed on an off-state transistor.

[0103] In this specification and other documents, the series of operations that change the conduction or non-conduction state of a transistor, supply charge to a node electrically connected to the transistor, and change the potential of the node may be referred to as "processing."

[0104] [Correction of the threshold voltage of the drive transistor] First, in step S01, a voltage is obtained to correct the threshold voltage of transistor M2, and processing is performed to hold this voltage in capacitor C2.

[0105] The current Ie flowing through the light-emitting element 61 is mainly determined by the display data Vdata and the threshold voltage of transistor M2. Therefore, even if the same display data Vdata is supplied to multiple pixels, if the threshold voltage of transistor M2 in each pixel is different, a different current Ie will flow through each pixel. Thus, variations in the threshold voltage of transistor M2 contribute to a decrease in the display quality of the display device.

[0106] Therefore, by correcting the threshold voltage of transistor M2 to the same value for each pixel, the variation in current Ie can be reduced. In this embodiment, as an example, a method of correcting the threshold voltage of transistor M2 to 0V by changing the potential applied to the back gate of transistor M2 will be described.

[0107] First, during period T11, a reset operation is performed. Specifically, potential H is supplied to wiring GLb and wiring GLc, and potential L is supplied to wiring GLa (see Figure 7).

[0108] Therefore, transistors M3, M4, and M5 are turned ON, while transistors M1 and M6 are turned OFF.

[0109] Furthermore, the potential of node ND1 becomes potential Ve0. In addition, the potential of node ND3 also becomes potential Ve0 via transistor M3. Potential Ve0 is higher than potential Vc by the amount of the voltage drop across the light-emitting element 61. Potential V1 is supplied to node ND2 via transistor M4. It is assumed that transistor M2 becomes normally-on when potential V1 - potential Ve0 is applied as the back gate voltage of transistor M2.

[0110] Next, during period T12, a potential L is supplied to the wiring GLc (see Figure 8). This turns off transistor M5.

[0111] Immediately after transistor M5 turns off, the back gate voltage of transistor M2 is potential V1 - potential Ve0, so transistor M2 is normally on. Therefore, charge is supplied to node ND1 from wiring 51 via transistor M2, and the potential of node ND1 rises over time. Also, since transistor M3 is on, the potential of node ND3 rises similarly. Here, as the potential of node ND1 gradually rises, the back gate voltage of transistor M2 gradually decreases. In other words, the threshold voltage of transistor M2 gradually shifts to positive. Finally, when the threshold voltage of transistor M2 approaches 0V, transistor M2 turns off, and the rise in potential of node ND1 stops. At this time, let Vb be the back gate voltage at which the threshold voltage of transistor M2 becomes 0V. In other words, when the rise in potential of node ND1 stops, the potential of node ND1 is potential V1 - Vb.

[0112] Next, during period T13, a potential L is supplied to the wiring GLb (see Figure 9). This turns off transistors M3 and M4. As a result, nodes ND2 and ND3 become floating, and the charge at each node is retained. In other words, the state in which Vb, acquired during period T12, is applied as the back gate voltage of transistor M2 is maintained.

[0113] By performing the processing during periods T11 to T13, the threshold voltage of transistor M2 is corrected to 0V, and this corrected state can be maintained. In this embodiment, for example, this correction method of the display device is sometimes called "internal correction."

[0114] [Acquisition of current-voltage characteristics of light-emitting elements] Next, in step S02, the monitor circuit 12 measures the current flowing through the light-emitting element 61 and performs processing to obtain the current-voltage characteristics of the light-emitting element 61.

[0115] The light emission intensity of the light-emitting element 61 is determined by the current Ie flowing through it. Furthermore, the current Ie flowing through the light-emitting element 61 is determined by the potential difference (voltage) between the anode terminal and the cathode terminal of the light-emitting element 61. In addition, variations or degradation over time may occur in the characteristics of each pixel's light-emitting element 61. Therefore, even if the threshold voltage of the drive transistor is corrected as described above, variations may occur in the final light emission intensity of the light-emitting element 61, which may lead to a decrease in the display quality of the display device, such as display unevenness.

[0116] Therefore, by acquiring the current-voltage characteristics of the light-emitting element 61 and correcting the image data using the acquired current-voltage characteristics, it is possible to reduce the deterioration of the display quality of the display device due to, for example, variations in the characteristics of the light-emitting element 61 or deterioration in its characteristics.

[0117] An example of a process for obtaining the current-voltage characteristics of the light-emitting element 61 is described below. First, during period T21, a potential H is supplied to wiring GLa and wiring GLc, and a potential L is supplied to wiring GLb (see Figure 10). As a result, transistors M1, M5, and M6 turn on, and transistors M3 and M4 turn off. Also, by supplying a potential V0 to wiring DL, transistor M2 turns off.

[0118] The monitor circuit 12 supplies a potential Ve1 to the wiring ML. Preferably, the potential Ve1 is higher than the potential V0. As a result, the potential Ve1 is supplied to the anode terminal of the light-emitting element 61 via transistors M6 and M5. Then, a voltage of potential Ve1 - potential Vc is applied across both ends of the light-emitting element 61 (between the anode terminal and the cathode terminal), and a current Ie1 corresponding to the applied voltage flows through the light-emitting element 61. The current Ie1 flows from the monitor circuit 12 through the wiring ML, transistor M6, node ND1, and transistor M5 to the light-emitting element 61. Therefore, the current Ie1 can be measured by the monitor circuit 12. In other words, the current Ie1 that flows when a voltage of potential Ve1 - potential Vc is applied across both ends of the light-emitting element 61 can be obtained.

[0119] Next, during period T22, while maintaining the potentials of wirings GLa, GLB, GLC, and DL, the monitor circuit 12 supplies potential Ve2 to wiring ML. Then, similar to period T21, the current Ie2 that flows when a voltage of potential Ve2 - potential Vc is applied across the light-emitting element 61 can be obtained. Similarly, during period T23, by supplying potential Ve3 to wiring ML, the current Ie3 that flows when a voltage of potential Ve3 - potential Vc is applied across the light-emitting element 61 can be obtained. Similarly, during period T24, by supplying potential Ve4 to wiring ML, the current Ie4 that flows when a voltage of potential Ve4 - potential Vc is applied across the light-emitting element 61 can be obtained. After the end of period T24, supplying potential L to wirings GLa and GLC turns off transistors M1, M5, and M6.

[0120] By performing the processing during periods T21 to T24, it is possible to measure the currents Ie1 to Ie4 flowing through the light-emitting element 61 when potentials Ve1 to Ve4 are supplied to the anode terminal of the light-emitting element 61. In other words, the current-voltage characteristics of the light-emitting element 61 can be obtained.

[0121] Here, we have shown an example of acquiring four characteristic data points, where one characteristic data point is defined as a pair of voltage values ​​applied across the light-emitting element 61 and the corresponding current values ​​flowing through the light-emitting element 61. However, this is not limited to this example. The number of characteristic data points acquired can be two, three, or five or more. By acquiring a larger number of characteristic data points, it is possible to obtain a more accurate current-voltage characteristic of the light-emitting element 61.

[0122] [Image data correction] Next, in step S03, the current-voltage characteristics of the light-emitting element 61 acquired in step S02 are used to correct the image data and generate display data Vdata.

[0123] For example, the current-voltage characteristics of the light-emitting element 61 may be acquired for each pixel, and the image data may be corrected to cancel out the variations. For example, the correction amount ΔVthO of the image data can be determined for each pixel, and the image data can be corrected using the formula Vdata = image data + ΔVthO to generate the display data Vdata.

[0124] By performing the processes in steps S02 and S03, the image data can be corrected using the current-voltage characteristics of the light-emitting element 61. In this embodiment, such a correction method for the display device is sometimes referred to as "external correction."

[0125] Furthermore, in this embodiment, an example of correcting image data by acquiring the current-voltage characteristics of the light-emitting element 61 as an external correction is shown, but the embodiment is not limited to this. For example, the image data may be corrected by acquiring the characteristics of the drive transistor, or the image data may be corrected by acquiring the characteristics of both the light-emitting element 61 and the drive transistor.

[0126] [Writing display data] Next, in step S04, processing is performed to write the display data Vdata to the pixel 11.

[0127] During period T31, potential H is supplied to wiring GLa, and potential L is supplied to wirings GLb and GLc (see Figure 11). As a result, transistor M1 turns on, and display data Vdata is supplied to node ND3. Also, transistor M6 turns on, and potential V0 is supplied to node ND1. In other words, the gate voltage of transistor M2 is applied as display data Vdata - potential V0.

[0128] Since nodes ND1 and ND2 are capacitively coupled via capacitor C2, when the potential of node ND1 changes to potential V0, the potential of node ND2 also changes to potential V0+Vb. In other words, Vb is applied to the back gate voltage of transistor M2, and the display data Vdata can be written while maintaining the state in which the threshold voltage of transistor M2 is corrected to 0V.

[0129] Next, during period T32, a potential L is supplied to the wiring GLa (see Figure 12). As a result, transistor M1 turns off, and node ND3 becomes floating. Also, transistor M6 turns off, and charge is supplied from wiring 51 to node ND1 via transistor M2, causing the potential of node ND1 to gradually rise.

[0130] Here, node ND3 is floating, and nodes ND1 and ND3 are capacitively coupled via capacitor C1. Therefore, the potential of node ND3 rises in accordance with the potential rise of node ND1. In other words, the gate voltage of transistor M2 remains at the displayed data Vdata - potential V0. Similarly, node ND2 is floating, and nodes ND1 and ND2 are capacitively coupled via capacitor C2. Therefore, the potential of node ND2 rises in accordance with the potential rise of node ND1. In other words, the back gate voltage of transistor M2 remains at Vb.

[0131] [Light emission from light-emitting elements] Next, during period T33, a potential H is supplied to the wiring GLc (see Figure 13). As a result, transistor M5 turns on, and current flows from wiring 51 to wiring 52. That is, current Ie flows to the light-emitting element 61, and the light-emitting element 61 emits light with an intensity corresponding to the current Ie.

[0132] As current flows from wiring 51 to wiring 52, the potential of node ND1 changes. Similar to the period T32 described above, nodes ND2 and ND3 are in a floating state. Therefore, the gate voltage of transistor M2 remains at the indicated data Vdata - potential V0, and the back gate voltage of transistor M2 remains at Vb.

[0133] Here, the current Ie is determined by the gate voltage and back gate voltage of transistor M2. In other words, the current Ie is proportional to the square of ("gate voltage of transistor M2" - "threshold voltage of transistor M2"). The state in which the displayed data Vdata - potential V0 is applied as the gate voltage of transistor M2 is maintained. Also, the state in which Vb is applied as the back gate voltage of transistor M2 is maintained. In other words, the state in which the threshold voltage of transistor M2 is corrected to 0V is maintained. That is, the current Ie is proportional to the square of (displayed data Vdata - potential V0), and the state in which a current flows that is independent of the threshold voltage of transistor M2 is maintained.

[0134] In one aspect of the present invention, the display quality of the display device 10 can be improved by correcting the threshold voltage of the transistor M2 through internal correction and correcting the current-voltage characteristics of the light-emitting element 61 through external correction.

[0135] <Example of display device calibration operation 2> The correction method for a display device according to one embodiment of the present invention is not limited to the above description. In the correction method for a display device according to one embodiment of the present invention, it is sufficient that both the correction of the threshold voltage of the drive transistor in step S01 and the correction of the image data in step S03 are completed before the writing of the display data in step S04 begins.

[0136] Figure 14 is a flowchart illustrating another example of a method for correcting the display device 10. The method for correcting the display device shown in Figure 14 differs from the method for correcting the display device shown in Figure 5 in the order in which steps S01 to S05 are executed. First, step S02 is started. After step S02 is completed, steps S01 and S03 are started. After steps S01 and S03 are completed, step S04 is started. After step S04 is completed, step S05 is started. The operation of the display device 10 in each of steps S01 to S05 can be understood by referring to the explanation above.

[0137] Step S01 is a process at pixel 11, and step S03 is a process at image processing circuit 13. Therefore, steps S01 and S03 can be performed simultaneously. In other words, steps S01 and S03 may be started simultaneously after step S02 is completed. Performing steps S01 and S03 simultaneously can shorten the time required for correction of the display device 10. In other words, the operating speed of the display device 10 can be increased.

[0138] <Specific example of display device configuration> Next, a more detailed example of the configuration of the display device 10 shown in Figure 1 will be described. Figure 15 shows an example of the configuration of the display device 10 according to one aspect of the present invention in a block diagram. In the block diagram, the components are classified by function and shown as independent blocks, but in reality, it is difficult to completely separate the components by function, and one component may be involved in multiple functions.

[0139] The display device 10 shown in Figure 15 comprises a panel 25 having multiple pixels 11 in a pixel section 24, a controller 26, a CPU 27, an image processing circuit 13, an image memory 28, a memory 29, and a monitor circuit 12. Furthermore, the display device 10 shown in Figure 15 includes a drive circuit 30 and a drive circuit 31 on the panel 25.

[0140] The CPU 27 has the function of decoding instructions input from an external source or instructions stored in memory provided within the CPU 27, and executing those instructions by comprehensively controlling the operation of various circuits of the display device 10.

[0141] The monitor circuit 12 has the function of supplying an arbitrary potential to the pixel 11 and measuring the current flowing through the pixel 11 at that time. It also has the function of generating arbitrary data (for example, the current-voltage characteristics of the light-emitting element 61) based on the measured current. The memory 29 has the function of storing information contained in the signal. The memory 29 may be a volatile memory such as DRAM or SRAM, or a non-volatile memory such as flash memory, MRAM, magnetic memory, magnetic disk, or magneto-optical disk. For example, by using a non-volatile memory as the memory 29, the information of each pixel can be stored even after the power supply is stopped. Therefore, it is not necessary to constantly measure the current flowing through the pixel 11. For example, the operation of measuring the current flowing through the pixel 11 can be performed only before shipping the product, just before stopping the power supply, or just after starting the power supply, and that information can be stored in the memory 29.

[0142] The image memory 28 has the function of storing the image data 32 input to the display device 10. Although Figure 15 illustrates a case where only one image memory 28 is provided in the display device 10, multiple image memories 28 may be provided in the display device 10. For example, if a full-color image is displayed in the pixel section 24 using three image data 32 corresponding to hues such as red, blue, or green, three image memories 28 corresponding to each of the three image data 32 may be provided.

[0143] For example, the image memory 28 can use a memory circuit such as DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory). Alternatively, VRAM (Video RAM) may be used for the image memory 28.

[0144] The image processing circuit 13 has the function of writing image data 32 to the image memory 28 and reading image data 32 from the image memory 28 according to instructions from the CPU 27, and generating display data Vdata from the image data 32. The image processing circuit 13 also has the function of reading information stored in the memory 29 according to instructions from the CPU 27 and correcting the image data using that information. Here, the memory 29 stores arbitrary data generated by the monitor circuit 12 (for example, the current-voltage characteristics of the light-emitting element 61). In other words, for example, the image data 32 can be corrected using the current-voltage characteristics of the light-emitting element 61.

[0145] The controller 26 has the function of, upon receiving display data Vdata containing image information, applying signal processing to the display data Vdata in accordance with the specifications of the panel 25, and then supplying it to the panel 25.

[0146] The drive circuit 31 has the function of selecting multiple pixels 11 of the pixel unit 24 row by row. The drive circuit 30 has the function of supplying display data Vdata provided by the controller 26 to the pixels 11 of the row selected by the drive circuit 31.

[0147] The controller 26 also has the function of supplying various drive signals to the panel 25, for example, to drive the drive circuit 30 or the drive circuit 31. The drive signals include, for example, a start pulse signal SSP, a clock signal SCK, and a latch signal LP that control the operation of the drive circuit 30, and a start pulse signal GSP and a clock signal GCK that control the operation of the drive circuit 31.

[0148] The display device 10 may also have an input device that has the function of providing information or commands to the CPU 27 of the display device 10. For example, a keyboard, pointing device, touch panel, or sensor can be used as the input device.

[0149] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0150] (Embodiment 2) This embodiment describes an example of a display device configuration to which the correction method for a display device according to one aspect of the present invention can be applied. The display device exemplified below can be applied, for example, to the pixel 11 of Embodiment 1 described above.

[0151] One aspect of the present invention is a display device having light-emitting elements (also called light-emitting devices). The display device has two or more light-emitting elements that emit light of different colors. Each light-emitting element has a pair of electrodes and an EL layer between them. The light-emitting elements are preferably organic EL elements (organic electroluminescent elements). The two or more light-emitting elements that emit different colors each have an EL layer containing a different light-emitting material. For example, a full-color display device can be realized by having three types of light-emitting elements that emit red (R), green (G), or blue (B) light.

[0152] When manufacturing a display device with multiple light-emitting elements, each with a different emission color, it is necessary to form separate island-like layers containing light-emitting materials with at least one different emission color (light-emitting layer). When manufacturing part or all of the EL layer separately, a method is known to form island-like organic films using a vapor deposition method with a shadow mask such as a metal mask. However, with this method, deviations from the design occur in the shape and position of the island-like organic films due to various influences, such as the precision of the metal mask, the misalignment between the metal mask and the substrate, the deflection of the metal mask, and the spreading of the contour of the deposited film due to, for example, vapor scattering, making it difficult to achieve high resolution and high aperture ratio. In addition, during vapor deposition, the contour of the layer may become blurred, and the thickness at the edges may become thinner. In other words, the thickness of the island-like light-emitting layers may vary depending on the location. Furthermore, when manufacturing large, high-resolution, or high-definition display devices, there is a concern that the manufacturing yield may be low due to, for example, the low dimensional accuracy of the metal mask and deformation due to heat. Therefore, measures were taken to artificially increase the resolution (also known as pixel density) by employing special pixel arrangement methods, such as the PenTile arrangement.

[0153] In this specification, "island-like" refers to a state in which two or more layers made of the same material and formed in the same process are physically separated. For example, an island-like light-emitting layer refers to a state in which the light-emitting layer and an adjacent light-emitting layer are physically separated.

[0154] One aspect of the present invention involves processing the EL layer into a fine pattern by photolithography without using a shadow mask such as a fine metal mask (FMM). This makes it possible to realize a display device with high resolution and a large aperture ratio, which has been difficult to achieve until now. Furthermore, since the EL layer can be differentiated, it is possible to realize a display device with extremely vivid colors, high contrast, and high display quality. For example, the EL layer may be processed into a fine pattern using both a metal mask and photolithography.

[0155] Furthermore, part or all of the EL layer can be physically separated. This suppresses leakage current between light-emitting elements via a common layer (also called a common layer) used between adjacent light-emitting elements. This prevents crosstalk caused by unintended light emission, enabling the realization of a display device with extremely high contrast. In particular, it enables the realization of a display device with high current efficiency at low brightness levels.

[0156] One aspect of the present invention is a display device that combines a white-emitting light-emitting element and a color filter. In this case, the same configuration of light-emitting elements can be applied to the light-emitting elements provided in pixels (sub-pixels) that emit light of different colors, and all layers can be made into a common layer. Furthermore, part or all of each EL layer is separated by photolithography. This suppresses leakage current through the common layer, enabling the realization of a display device with high contrast. In particular, in an element having a tandem structure in which multiple light-emitting layers are stacked with a highly conductive intermediate layer in between, leakage current through the intermediate layer can be effectively prevented, thus enabling the realization of a display device that combines high brightness, high resolution, and high contrast.

[0157] Furthermore, it is preferable to provide an insulating layer that covers at least the sides of the island-shaped light-emitting layers. The insulating layer may be configured to cover a portion of the upper surface of the island-shaped EL layer. It is preferable to use a material that has barrier properties against water and oxygen as the insulating layer. For example, an inorganic insulating film that does not easily diffuse water or oxygen can be used. This suppresses the degradation of the EL layer and enables the realization of a highly reliable display device.

[0158] Furthermore, between two adjacent light-emitting elements, there is a region (recess) where neither light-emitting element has an EL layer. When a common electrode, or a common electrode and a common layer, is formed to cover this recess, a phenomenon called "step break" may occur where the common electrode is separated by a step at the edge of the EL layer, and the common electrode on the EL layer may become insulated. Therefore, it is preferable to use a configuration (LFP: Local Filling Planarization) in which the local step located between two adjacent light-emitting elements is filled with a resin layer that functions as a planarizing film. This resin layer has the function of a planarizing film. This suppresses step breaks in the common layer or common electrode, and enables the realization of a highly reliable display device.

[0159] In the following section, a more specific configuration example of a display device according to one aspect of the present invention will be described with reference to the drawings.

[0160] [Configuration Example 1] Figure 16A shows a schematic top view of a display device 100 according to one embodiment of the present invention. The display device 100 has multiple red-emitting light-emitting elements 110R, green-emitting light-emitting elements 110G, and blue-emitting light-emitting elements 110B on a substrate 101. In Figure 16A, the designation R, G, or B is added within the light-emitting area of ​​each light-emitting element to simplify the distinction between them.

[0161] The light-emitting elements 110R, 110G, and 110B are each arranged in a matrix. Figure 16A shows a so-called stripe arrangement in which light-emitting elements that emit light of the same color in one direction are arranged. However, the arrangement method of the light-emitting elements is not limited to this, and other arrangement methods such as S-stripe arrangement, delta arrangement, Bayer arrangement, or zigzag arrangement may be applied, or a pentile arrangement or diamond arrangement may be used.

[0162] For the light-emitting elements 110R, 110G, and 110B, it is preferable to use, for example, OLED (Organic Light Emitting Diode) or QLED (Quantum-dot Light Emitting Diode). Examples of light-emitting materials for the EL element include fluorescent materials, phosphorescent materials, inorganic compounds (e.g., quantum dot materials), and thermally activated delayed fluorescence (TADF) materials.

[0163] Figure 16A also shows a connecting electrode 111C that is electrically connected to the common electrode 113. The connecting electrode 111C is supplied with a potential (for example, the anode potential or cathode potential) to the common electrode 113. The connecting electrode 111C is located outside the display area where, for example, the light-emitting elements 110R are arranged.

[0164] The connecting electrode 111C can be provided along the outer perimeter of the display area. For example, it may be provided along one side of the outer perimeter of the display area, or it may be provided across two or more sides of the outer perimeter of the display area. That is, if the top surface shape of the display area is rectangular, the top surface shape of the connecting electrode 111C can be, for example, a strip (rectangle), L-shape, U-shape (square bracket shape), or quadrilateral.

[0165] Figures 16B and 16C are schematic cross-sectional views corresponding to the dashed-dotted lines A1-A2 and A3-A4 in Figure 16A, respectively. Figure 16B shows schematic cross-sectional views of the light-emitting element 110R, light-emitting element 110G, and light-emitting element 110B, while Figure 16C shows schematic cross-sectional views of the connection portion 140 to which the connecting electrode 111C and the common electrode 113 are connected.

[0166] The light-emitting element 110R has a pixel electrode 111R, an organic layer 112R, a common layer 114, and a common electrode 113. The light-emitting element 110G has a pixel electrode 111G, an organic layer 112G, a common layer 114, and a common electrode 113. The light-emitting element 110B has a pixel electrode 111B, an organic layer 112B, a common layer 114, and a common electrode 113. The common layer 114 and the common electrode 113 are provided in common to the light-emitting elements 110R, 110G, and 110B.

[0167] The organic layer 112R of the light-emitting element 110R contains a luminescent organic compound that emits light with intensity in at least the red wavelength range. The organic layer 112G of the light-emitting element 110G contains a luminescent organic compound that emits light with intensity in at least the green wavelength range. The organic layer 112B of the light-emitting element 110B contains a luminescent organic compound that emits light with intensity in at least the blue wavelength range. The organic layers 112R, 112G, and 112B can each also be called EL layers and each contains a layer (luminescent layer) that contains at least a luminescent organic compound.

[0168] In the following, when describing matters common to the light-emitting element 110R, light-emitting element 110G, and light-emitting element 110B, they may be referred to simply as light-emitting element 110. Similarly, for components distinguished by letters, such as organic layer 112R, organic layer 112G, and organic layer 112B, when describing matters common to these components, the letters may be omitted and symbols used.

[0169] The organic layer 112 and the common layer 114 can each independently have one or more of the following: an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer. For example, the organic layer 112 may have a stacked structure of a hole injection layer, a hole transport layer, an emissive layer, and an electron transport layer, in that order from the pixel electrode 111 side, and the common layer 114 may have an electron injection layer.

[0170] Pixel electrodes 111R, 111G, and 111B are provided for each light-emitting element. A common layer 114 and a common electrode 113 are provided as a continuous layer common to each light-emitting element. A conductive film that is transparent to visible light is used on either each pixel electrode or the common electrode 113, while a conductive film that is reflective is used on the other. By making each pixel electrode transparent and the common electrode 113 reflective, a bottom-emission type display device can be created. Conversely, by making each pixel electrode reflective and the common electrode 113 transparent, a top-emission type display device can be created. Furthermore, by making both each pixel electrode and the common electrode 113 transparent, a dual-emission type display device can be created.

[0171] A protective layer 121 is provided on the common electrode 113, covering the light-emitting elements 110R, 110G, and 110B. The protective layer 121 has the function of preventing impurities, such as water, from diffusing to each light-emitting element from above.

[0172] It is preferable that the end of the pixel electrode 111 has a tapered shape. When the end of the pixel electrode has a tapered shape, the organic layer 112 provided along the side surface of the pixel electrode also has a tapered shape. By making the side surface of the pixel electrode tapered, the coverage of the EL layer provided along the side surface of the pixel electrode can be improved. Furthermore, by making the side surface of the pixel electrode tapered, it becomes easier to remove foreign matter (for example, dust or particles) during the manufacturing process through processes such as washing, which is preferable.

[0173] In this specification, a tapered shape refers to a shape in which at least a portion of the side surface of a structure is inclined with respect to the substrate surface. For example, it is preferable to have a region in which the angle between the inclined side surface and the substrate surface (also called the taper angle) is less than 90°.

[0174] The organic layer 112 is processed into an island shape by photolithography. As a result, at its edges, the organic layer 112 has a shape where the angle between the top surface and the side surface is close to 90 degrees. On the other hand, an organic film formed using, for example, an FMM (Fine Metal Mask) tends to gradually become thinner towards the edges, and for example, in the range of 1 μm to 10 μm, the top surface is formed in a slope shape, making it difficult to distinguish between the top surface and the side surface.

[0175] Between two adjacent light-emitting elements, there is an insulating layer 125, a resin layer 126, and a layer 128.

[0176] Between two adjacent light-emitting elements, the sides of the organic layers 112 of each element face each other with a resin layer 126 in between. The resin layer 126 is located between the two adjacent light-emitting elements and is provided to fill the edges of each organic layer 112 and the region between the two organic layers 112. The resin layer 126 has a smooth, convex upper surface shape, and a common layer 114 and a common electrode 113 are provided covering the upper surface of the resin layer 126.

[0177] The resin layer 126 functions as a planarizing film that fills the step between two adjacent light-emitting elements. By providing the resin layer 126, it is possible to prevent the common electrode 113 from being separated by the step at the edge of the organic layer 112 (also called step breakage), and to prevent the common electrode on the organic layer 112 from becoming insulated. The resin layer 126 can also be called LFP (Local Filling Planarization).

[0178] As the resin layer 126, an insulating layer having an organic material can be suitably used. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, or precursors of these resins can be used as the resin layer 126. Alternatively, as the resin layer 126, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used.

[0179] Furthermore, a photosensitive resin can be used as the resin layer 126. A photoresist may be used as the photosensitive resin. The photosensitive resin can be a positive-type material or a negative-type material.

[0180] The resin layer 126 may contain a material that absorbs visible light. For example, the resin layer 126 itself may be composed of a material that absorbs visible light, or the resin layer 126 may contain a pigment that absorbs visible light. As the resin layer 126, for example, a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light, or a resin that contains carbon black as a pigment and functions as a black matrix can be used.

[0181] The insulating layer 125 is provided in contact with the side surface of the organic layer 112. Furthermore, the insulating layer 125 covers the upper end of the organic layer 112. Additionally, a portion of the insulating layer 125 is provided in contact with the upper surface of the substrate 101.

[0182] The insulating layer 125 is located between the resin layer 126 and the organic layer 112 and functions as a protective film to prevent the resin layer 126 from coming into contact with the organic layer 112. If the organic layer 112 and the resin layer 126 come into contact, the organic layer 112 may dissolve due to organic solvents used during the formation of the resin layer 126. Therefore, as shown in this embodiment, by providing an insulating layer 125 between the organic layer 112 and the resin layer 126, it is possible to protect the sides of the organic layer.

[0183] The insulating layer 125 can be an insulating layer having an inorganic material. For example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxidative nitride insulating film, or an oxidative nitride insulating film can be used for the insulating layer 125. The insulating layer 125 may be a single layer structure or a laminated structure. Examples of oxide insulating films include silicon oxide film, aluminum oxide film, magnesium oxide film, indium gallium zinc oxide film, gallium oxide film, germanium oxide film, yttrium oxide film, zirconium oxide film, lanthanum oxide film, neodymium oxide film, hafnium oxide film, or tantalum oxide film. Examples of nitride insulating films include silicon nitride film or aluminum nitride film. Examples of oxidative nitride insulating films include silicon oxidative nitride film or aluminum oxidative nitride film. Examples of oxidative nitride insulating films include silicon oxidative nitride film or aluminum oxidative nitride film. In particular, by applying an insulating layer 125 formed by the ALD method, such as an aluminum oxide film, a metal oxide film such as a hafnium oxide film, or an inorganic insulating film such as a silicon oxide film, an insulating layer 125 with fewer pinholes and excellent protection for the EL layer can be formed.

[0184] In this specification, the term "oxide-nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and the term "nitride oxide" refers to a material in which the nitrogen content is greater than the oxygen content. For example, when "silicon oxynitride" is written, it refers to a material in which the oxygen content is greater than the nitrogen content, and when "silicon nitride oxide" is written, it refers to a material in which the nitrogen content is greater than the oxygen content.

[0185] The insulating layer 125 can be formed using methods such as sputtering, CVD, PLD, or ALD. It is preferable to form the insulating layer 125 using the ALD method, which provides good coverage.

[0186] Alternatively, a reflective film (for example, a metal film containing one or more selected from silver, palladium, copper, titanium, and aluminum) may be provided between the insulating layer 125 and the resin layer 126, and the light emitted from the light-emitting layer may be reflected by the reflective film. This can improve the light extraction efficiency.

[0187] Layer 128 is a portion of the protective layer (also called a mask layer or sacrificial layer) that remains after etching the organic layer 112. The material used for layer 128 can be the same material used for the insulating layer 125. Using the same material for both layer 128 and the insulating layer 125 is preferable, as it allows for the use of common processing equipment, for example.

[0188] In particular, metal oxide films such as aluminum oxide films or hafnium oxide films, or inorganic insulating films such as silicon oxide films, formed by the ALD method, have fewer pinholes and therefore offer excellent protection for the EL layer, making them suitable for use in insulating layers 125 and 128.

[0189] A protective layer 121 is provided covering the common electrode 113.

[0190] The protective layer 121 can be, for example, a single-layer structure or a multilayer structure including at least an inorganic insulating film. Examples of inorganic insulating films include oxide films or nitride films such as silicon oxide film, silicon oxide nitride film, silicon oxide nitride film, silicon nitride film, aluminum oxide film, aluminum oxide nitride film, or hafnium oxide film. Alternatively, the protective layer 121 may be a semiconductor material or conductive material such as indium gallium oxide, indium zinc oxide, indium tin oxide, or indium gallium zinc oxide.

[0191] As the protective layer 121, a laminated film of an inorganic insulating film and an organic insulating film can also be used. For example, it is preferable to have a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films. Furthermore, it is preferable that the organic insulating film functions as a planarizing film. This makes the upper surface of the organic insulating film flat, thereby improving the coverage of the inorganic insulating film on top of it and enhancing its barrier properties. Also, since the upper surface of the protective layer 121 is flat, it is preferable because it reduces the influence of uneven shapes caused by the structure below when a structure (e.g., a color filter, touch sensor electrodes, or lens array) is provided above the protective layer 121.

[0192] Figure 16C shows a connection portion 140 in which the connecting electrode 111C and the common electrode 113 are electrically connected. In the connection portion 140, openings are provided in the insulating layer 125 and the resin layer 126 on the connecting electrode 111C. The connecting electrode 111C and the common electrode 113 are electrically connected at these openings.

[0193] Figure 16C shows a connection portion 140 where the connecting electrode 111C and the common electrode 113 are electrically connected. However, the common electrode 113 may be provided on the connecting electrode 111C via a common layer 114. In particular, when a carrier-injected layer is used for the common layer 114, the electrical resistivity of the material used for the common layer 114 can be sufficiently low and it can be formed with a thin thickness. Therefore, even if the common layer 114 is located at the connection portion 140, no problems often occur. As a result, the common electrode 113 and the common layer 114 can be formed using the same shielding mask, thereby reducing manufacturing costs.

[0194] The above is a description of an example of a display device configuration.

[0195] [Pixel layout] The following section primarily describes a pixel layout different from that shown in Figure 16A. There are no particular limitations on the arrangement of light-emitting elements (sub-pixels), and various methods can be applied.

[0196] Furthermore, the top surface shape of the sub-pixel can be, for example, a triangle, a quadrilateral (including rectangles or squares), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, or a circle. Here, the top surface shape of the sub-pixel corresponds to the top surface shape of the light-emitting region of the light-emitting element.

[0197] The pixel 150 shown in Figure 17A has an S-stripe array applied to it. The pixel 150 shown in Figure 17A is composed of three subpixels: light-emitting element 110a, light-emitting element 110b, and light-emitting element 110c. For example, light-emitting element 110a may be a light-emitting element that emits blue light, light-emitting element 110b may be a light-emitting element that emits red light, and light-emitting element 110c may be a light-emitting element that emits green light.

[0198] The pixel 150 shown in Figure 17B has a light-emitting element 110a with a roughly trapezoidal top surface shape with rounded corners, a light-emitting element 110b with a roughly triangular top surface shape with rounded corners, and a light-emitting element 110c with a roughly square or roughly hexagonal top surface shape with rounded corners. Furthermore, the light-emitting element 110a has a larger light-emitting area than the light-emitting element 110b. Thus, the shape and size of each light-emitting element can be determined independently. For example, the more reliable the light-emitting element, the smaller its size can be. For example, light-emitting element 110a may be a light-emitting element that emits green light, light-emitting element 110b may be a light-emitting element that emits red light, and light-emitting element 110c may be a light-emitting element that emits blue light.

[0199] A Pentile array is applied to pixels 124a and 124b shown in Figure 17C. Figure 17C shows an example in which pixels 124a having light-emitting elements 110a and 110b, and pixels 124b having light-emitting elements 110b and 110c are arranged alternately. For example, light-emitting element 110a may be a light-emitting element that emits red light, light-emitting element 110b may be a light-emitting element that emits green light, and light-emitting element 110c may be a light-emitting element that emits blue light.

[0200] Pixels 124a and 124b shown in Figures 17D and 17E utilize a delta array. Pixel 124a has two light-emitting elements (element 110a and 110b) in the top row (1st row) and one light-emitting element (element 110c) in the bottom row (2nd row). Pixel 124b has one light-emitting element (element 110c) in the top row (1st row) and two light-emitting elements (element 110a and 110b) in the bottom row (2nd row). For example, element 110a may be an element that emits red light, element 110b may be an element that emits green light, and element 110c may be an element that emits blue light.

[0201] Figure 17D shows an example where each light-emitting element has a roughly rectangular top shape with rounded corners, and Figure 17E shows an example where each light-emitting element has a circular top shape.

[0202] Figure 17F shows an example in which light-emitting elements of different colors are arranged in a zigzag pattern. Specifically, in a top view, the upper edges of two light-emitting elements arranged in a row (for example, light-emitting elements 110a and 110b, or light-emitting elements 110b and 110c) are offset. For example, light-emitting element 110a may be a light-emitting element that emits red light, light-emitting element 110b may be a light-emitting element that emits green light, and light-emitting element 110c may be a light-emitting element that emits blue light.

[0203] In photolithography, the finer the pattern to be processed, the more significant the effects of light diffraction become. This compromises the fidelity of transferring the pattern to the photomask through exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, patterns with rounded corners are likely to form. Consequently, the top surface shape of the light-emitting element may be, for example, a polygon with rounded corners, an ellipse, or a circle.

[0204] Furthermore, in a method for manufacturing a display panel according to one embodiment of the present invention, the EL layer is processed into an island shape using a resist mask. The resist film formed on the EL layer needs to be cured at a temperature lower than the heat resistance temperature of the EL layer. Therefore, depending on the heat resistance temperature of the EL layer material and the curing temperature of the resist material, the curing of the resist film may be insufficient. A resist film that is not sufficiently cured may take a shape that deviates from the desired shape during processing. As a result, the top surface shape of the EL layer may become, for example, a polygon with rounded corners, an ellipse, or a circle. For example, if an attempt is made to form a resist mask with a square top surface, a resist mask with a circular top surface may be formed, resulting in a circular top surface shape for the EL layer.

[0205] Furthermore, in order to achieve the desired shape of the upper surface of the EL layer, a technique (OPC (Optical Proximity Correction) technique) may be used to pre-correct the mask pattern so that the design pattern and the transferred pattern match. Specifically, in the OPC technique, for example, a correction pattern is added to the corners of the shape on the mask pattern.

[0206] The above is an explanation of pixel layout.

[0207] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0208] (Embodiment 3) This embodiment describes an example of a display device configuration that can be applied to a correction method for a display device according to one aspect of the present invention.

[0209] The display device of this embodiment can be used in electronic devices with relatively large screens, such as television sets, desktop or notebook personal computers, monitors for computers, digital signage, or large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, smartphones, smartwatches, tablet devices, personal information terminals, or audio playback devices.

[0210] [Display device 400] Figure 18 shows a perspective view of the display device 400, and Figure 19A shows a cross-sectional view of the display device 400.

[0211] The display device 400 has a configuration in which substrate 452 and substrate 451 are bonded together. In Figure 18, substrate 452 is clearly indicated by a dashed line.

[0212] The display device 400 includes, for example, a display unit 462, a circuit 464, and wiring 465. Figure 18 shows an example in which IC 473 and FPC 472 are mounted on the display device 400. Therefore, the configuration shown in Figure 18 can also be described as a display module having the display device 400, an IC (integrated circuit), and an FPC.

[0213] For example, a scan line drive circuit can be used as circuit 464.

[0214] The wiring 465 has the function of supplying signals and power to the display unit 462 and the circuit 464. These signals and power are input to the wiring 465 from outside the display device 400 via the FPC 472, or from the IC 473.

[0215] Figure 18 shows an example in which IC 473 is provided on the substrate 451 using, for example, the COG (Chip On Glass) method or the COF (Chip On Film) method. IC 473 can be an IC having, for example, a scan line drive circuit or a signal line drive circuit. Note that the display device 400 or display module may be configured without an IC. Alternatively, the IC may be mounted on an FPC using, for example, the COF method.

[0216] Figure 19A shows an example of a cross-section when a portion of the display device 400 is cut, including a part of the area containing the FPC 472, a part of the circuit 464, a part of the display unit 462, and a part of the area containing the connection part. In Figure 19A, an example of a cross-section is shown when a portion of the display unit 462 is cut, specifically including the area containing the green light-emitting element 430b and the blue light-emitting element 430c.

[0217] The display device 400 shown in Figure 19A has, for example, a transistor 202, a transistor 210, a light-emitting element 430b, and a light-emitting element 430c between substrates 453 and 454.

[0218] The light-emitting elements 430b and 430c can be the light-emitting elements exemplified in Embodiment 1.

[0219] Here, if the pixels of the display device have three types of subpixels that have light-emitting elements that emit different colors from each other, the three subpixels could be, for example, subpixels that emit red (R), green (G), and blue (B) light, or subpixels that emit yellow (Y), cyan (C), and magenta (M) light. If there are four such subpixels, the four subpixels could be subpixels that emit four colors of light, such as R, G, B, and white (W), or subpixels that emit four colors of light, such as R, G, B, and Y.

[0220] The substrate 454 and the protective layer 416 are bonded together via an adhesive layer 442. The adhesive layer 442 is provided in overlap with the respective light-emitting elements 430b and 430c, and a solid encapsulation structure is applied to the display device 400.

[0221] The light-emitting element 430b and the light-emitting element 430c have conductive layers 411a, 411b, and 411c as pixel electrodes. Conductive layer 411b is reflective to visible light and functions as a reflective electrode. Conductive layer 411c is transparent to visible light and functions as an optical adjustment layer.

[0222] The conductive layer 411a is connected to the conductive layer 222b of the transistor 210 through an opening provided in the insulating layer 214. The transistor 210 has the function of controlling the driving of the light-emitting element.

[0223] An EL layer 412G or EL layer 412B is provided covering the pixel electrode. An insulating layer 421 is provided in contact with the side surfaces of the EL layer 412G and the EL layer 412B, and a resin layer 422 is provided to fill the recesses of the insulating layer 421. A layer 424 is provided between the EL layer 412G and the insulating layer 421, and between the EL layer 412B and the insulating layer 421, respectively. A common layer 414, a common electrode 413, and a protective layer 416 are provided covering the EL layer 412G and the EL layer 412B.

[0224] The light emitted by the light-emitting element is directed towards the substrate 452. It is preferable to use a material with high transmittance to visible light for the substrate 452.

[0225] Both transistors 202 and 210 are formed on the substrate 451. These transistors can be manufactured using the same materials and the same process.

[0226] The substrate 453 and the insulating layer 212 are bonded together by an adhesive layer 455.

[0227] The method for manufacturing the display device 400 involves first bonding a fabricated substrate, on which an insulating layer 212, transistors, and light-emitting elements are provided, to a substrate 454 using an adhesive layer 442. Then, the fabricated substrate is peeled off, and the substrate 453 is attached to the exposed surface, thereby transferring the components formed on the fabricated substrate to the substrate 453. It is preferable that both the substrate 453 and the substrate 454 are flexible. This enhances the flexibility of the display device 400.

[0228] The insulating layer 212 can be made of an inorganic insulating film that can be used for the insulating layer 211 and the insulating layer 215, respectively.

[0229] A connection portion 204 is provided in the region of substrate 453 that does not overlap with substrate 454. At the connection portion 204, wiring 465 is electrically connected to FPC 472 via a conductive layer 466 and a connecting layer 242. The conductive layer 466 can be obtained by processing the same conductive film as the pixel electrode. This allows the connection portion 204 and FPC 472 to be electrically connected via the connecting layer 242.

[0230] Transistors 202 and 210 each have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer 231 having a channel forming region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 that functions as a gate insulating layer, a conductive layer 223 that functions as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel forming region 231i. The insulating layer 225 is located between the conductive layer 223 and the channel forming region 231i.

[0231] The conductive layer 222a and the conductive layer 222b are each connected to the low-resistance region 231n via openings provided in the insulating layer 215. Of the conductive layer 222a and the conductive layer 222b, one functions as a source and the other functions as a drain.

[0232] Figure 19A shows an example in which the insulating layer 225 covers the top and sides of the semiconductor layer. The conductive layer 222a and conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and insulating layer 215, respectively.

[0233] On the other hand, in the transistor 209 shown in Figure 19B, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231, but does not overlap with the low-resistance region 231n. For example, the structure shown in Figure 19B can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 19B, an insulating layer 215 is provided covering the insulating layer 225 and the conductive layer 223, and the conductive layers 222a and 222b are connected to the low-resistance region 231n, respectively, through openings in the insulating layer 215. Furthermore, an insulating layer 218 covering the transistor 209 may also be provided.

[0234] The transistor structure of the display device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, or an inverse staggered transistor can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0235] Transistors 202 and 210 are configured in which a semiconductor layer on which a channel is formed is sandwiched between two gates. The transistor may be driven by connecting two gates to the transistor and supplying the same signal to these two gates. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential to control the threshold voltage to one of the two gates and a potential to drive the other gate.

[0236] The crystallinity of the semiconductor material used in the semiconductor layer of the transistor is not particularly limited; amorphous semiconductors, single-crystal semiconductors, or semiconductors with crystalline properties other than single crystals (microcrystalline semiconductors, polycrystalline semiconductors, or semiconductors with crystalline regions in part) may be used. Using a single-crystal semiconductor or a semiconductor with crystalline properties is preferable because it suppresses the degradation of transistor characteristics.

[0237] The semiconductor layer of the transistor preferably has a metal oxide (also called an oxide semiconductor). In other words, the display device of this embodiment preferably uses a transistor (hereinafter referred to as an OS transistor) that uses a metal oxide in the channel formation region.

[0238] The band gap of the metal oxide used in the semiconductor layer of the transistor is preferably 2 eV or more, and more preferably 2.5 eV or more. By using a metal oxide with a large band gap, the off-current of the OS transistor can be reduced.

[0239] The metal oxide preferably contains at least indium or zinc, and more preferably indium and zinc. For example, the metal oxide preferably contains indium, M (where M is one or more selected from gallium, aluminum, yttrium, tin, silicon, boron, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt), and zinc.

[0240] Alternatively, the semiconductor layer of the transistor may contain silicon. Examples of silicon include amorphous silicon or crystalline silicon (e.g., low-temperature polysilicon or single-crystal silicon).

[0241] The transistors in circuit 464 and the transistors in display unit 462 may have the same structure or different structures. The structures of the multiple transistors in circuit 464 may all be the same or there may be two or more different structures. Similarly, the structures of the multiple transistors in display unit 462 may all be the same or there may be two or more different structures.

[0242] It is preferable to use a material that does not easily allow impurities such as water and hydrogen to diffuse into at least one layer of the insulating layer covering the transistor. This allows the insulating layer to function as a barrier layer. With such a configuration, the diffusion of impurities from the outside into the transistor can be effectively suppressed, and the reliability of the display device can be improved.

[0243] It is preferable to use an inorganic insulating film for insulating layers 211, 212, 215, 218, and 225. Examples of inorganic insulating films that can be used include silicon nitride, silicon oxynitride, silicon oxide, silicon nitride, aluminum oxide, or aluminum nitride. Alternatively, hafnium oxide, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, or neodymium oxide may be used. Furthermore, two or more of the above-mentioned inorganic insulating films may be laminated together.

[0244] An organic insulating film is preferred for the insulating layer 214, which functions as a planarizing layer. Examples of materials that can be used as the organic insulating film include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimidoamide resins, siloxane resins, benzocyclobutene resins, phenolic resins, or precursors of these resins.

[0245] Various optical components can be arranged along the inner or outer surface of the substrate 454. Examples of optical components include light-shielding layers, polarizing plates, phase difference plates, light-diffusing layers (e.g., diffusion films), anti-reflective layers, microlens arrays, or light-gathering films. Furthermore, on the outer surface of the substrate 454, for example, an antistatic film to suppress the adhesion of dust, a water-repellent film to make it difficult for dirt to adhere, a hard coat film to suppress the occurrence of scratches during use, or an impact-absorbing layer may be arranged.

[0246] By providing a protective layer 416 that covers the light-emitting element, it is possible to suppress the entry of impurities such as water into the light-emitting element and improve the reliability of the light-emitting element.

[0247] Figure 19A shows the connection section 228. At the connection section 228, the common electrode 413 and the wiring are electrically connected. Figure 19A shows an example where the same stacked structure as the pixel electrode is applied as the wiring.

[0248] Substrates 453 and 454 can be made of, for example, glass, quartz, ceramics, sapphire, resin, metal, alloy, or semiconductor, respectively. The substrate on the side that extracts light from the light-emitting element should be made of a material that transmits the light. Using flexible materials for substrates 453 and 454 can increase the flexibility of the display device. Alternatively, a polarizing plate may be used as substrate 453 or substrate 454.

[0249] For substrates 453 and 454, for example, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (e.g., nylon or aramid), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamide-imide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, or cellulose nanofiber can be used, respectively. Glass of a thickness sufficient to provide flexibility may be used for one or both of substrates 453 and 454.

[0250] As the adhesive layer, various types of curing adhesives can be used, such as UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, or anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, or EVA (ethylene vinyl acetate) resins. Materials with low moisture permeability, such as epoxy resins, are particularly preferred. Two-component mixed resins may also be used. Furthermore, adhesive sheets may be used, for example.

[0251] For the connecting layer 242, for example, an anisotropic conductive film (ACF) or an anisotropic conductive paste (ACP) can be used.

[0252] Materials that can be used for conductive layers in transistor gates, sources, and drains, as well as in various wiring and electrodes that constitute display devices, include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, as well as alloys mainly composed of such metals. Films containing these materials can be used as single-layer or multilayer structures.

[0253] Furthermore, as a light-transmitting conductive material, for example, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, or zinc oxide containing gallium, or graphene can be used. Alternatively, for example, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, or alloy materials containing such metallic materials, can be used. Alternatively, for example, nitrides of such metallic materials (e.g., titanium nitride) may be used. When using metallic materials or alloy materials (or their nitrides), it is preferable to make them thin enough to be light-transmitting. In addition, a laminated film of the above materials can be used as a conductive layer. For example, using a laminated film of an alloy of silver and magnesium and indium tin oxide is preferable because it can enhance conductivity. These can also be used in conductive layers of various wirings and electrodes that constitute a display device, and in conductive layers of light-emitting elements (conductive layers that function as pixel electrodes or common electrodes).

[0254] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxide nitride, silicon nitride, silicon nitride, or aluminum oxide.

[0255] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0256] (Embodiment 4) This embodiment describes a light-emitting element (also called a light-emitting device) that can be used in a display device according to one aspect of the present invention.

[0257] In this specification, devices fabricated using a metal mask or FMM (Fine Metal Mask, or High-Resolution Metal Mask) may be referred to as MM (Metal Mask) structured devices. Furthermore, in this specification, devices fabricated without using a metal mask or FMM may be referred to as MML (Metal Maskless) structured devices.

[0258] In this specification, a structure in which light-emitting devices that emit light of each color (here, blue (B), green (G), and red (R)) create separate light-emitting layers, or a structure in which light-emitting layers are painted separately, may be referred to as an SBS (Side By Side) structure. Also, in this specification, a light-emitting device capable of emitting white light may be referred to as a white light-emitting device. A white light-emitting device can be combined with a colored layer (for example, a color filter) to realize a full-color display device.

[0259] [Light-emitting devices] Light-emitting devices can be broadly classified into single-structure and tandem-structure devices. A single-structure device has one light-emitting unit between a pair of electrodes. This light-emitting unit has a configuration that includes one or more light-emitting layers. To obtain white light emission in a single-structure device, one should select two light-emitting layers such that the colors of the light emitted by each layer are complementary colors. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary colors, a configuration that emits white light as a whole can be obtained. Also, when obtaining white light emission using three or more light-emitting layers, the combination of the colors of the light emitted by each of the three or more light-emitting layers should result in a configuration that emits white light as a whole.

[0260] A tandem device has multiple light-emitting units between a pair of electrodes. Each light-emitting unit includes one or more light-emitting layers. By using light-emitting layers that emit light of the same color in each light-emitting unit, the brightness per given current can be increased, and a more reliable light-emitting device can be achieved compared to a single structure. To obtain white light emission in a tandem structure, the light from the light-emitting layers of multiple light-emitting units should be combined to produce white light emission. The combination of light-emitting colors that produces white light emission is the same as that for a single structure. In a tandem device, it is preferable to provide an intermediate layer, such as a charge-generating layer, between the multiple light-emitting units.

[0261] When comparing white light-emitting devices with SBS structure light-emitting devices, SBS structure light-emitting devices can consume less power than white light-emitting devices. On the other hand, white light-emitting devices have a simpler manufacturing process than SBS structure light-emitting devices, resulting in lower manufacturing costs and higher manufacturing yields.

[0262] <Example of light-emitting device configuration> As shown in Figure 20A, the light-emitting device has an EL layer 790 between a pair of electrodes (lower electrode 791 and upper electrode 792). The EL layer 790 can be composed of multiple layers, such as layer 720, light-emitting layer 711, and layer 730. Layer 720 may include, for example, a layer containing a material with high electron injection properties (electron injection layer) and a layer containing a material with high electron transport properties (electron transport layer). The light-emitting layer 711 may contain, for example, a light-emitting compound. Layer 730 may include, for example, a layer containing a material with high hole injection properties (hole injection layer) and a layer containing a material with high hole transport properties (hole transport layer).

[0263] A configuration having a layer 720, a light-emitting layer 711, and a layer 730 provided between a pair of electrodes can function as a single light-emitting unit. In this specification, the configuration shown in Figure 20A is referred to as a single structure.

[0264] Specifically, the light-emitting device shown in Figure 20B has layers 730-1, 730-2, a light-emitting layer 711, 720-1, 720-2, and an upper electrode 792 on the lower electrode 791. For example, the lower electrode 791 is the anode and the upper electrode 792 is the cathode. In this case, layer 730-1 functions as a hole injection layer, layer 730-2 as a hole transport layer, layer 720-1 as an electron transport layer, and layer 720-2 as an electron injection layer. On the other hand, when the lower electrode 791 is the cathode and the upper electrode 792 is the anode, layer 730-1 functions as an electron injection layer, layer 730-2 as an electron transport layer, layer 720-1 as a hole transport layer, and layer 720-2 as a hole injection layer. By using such a layer structure, it is possible to efficiently inject carriers into the light-emitting layer 711 and increase the efficiency of carrier recombination within the light-emitting layer 711.

[0265] Furthermore, as shown in Figures 20C and 20D, a configuration in which multiple light-emitting layers (light-emitting layer 711, light-emitting layer 712, and light-emitting layer 713) are provided between layer 720 and layer 730 is also a variation of the single structure.

[0266] As shown in Figures 20E and 20F, a configuration in which multiple light-emitting units (EL layers 790a and EL layers 790b) are connected in series via an intermediate layer (charge generation layer) 740 is referred to as a tandem structure in this specification. The tandem structure may also be called a stack structure. By using a tandem structure, a light-emitting device capable of high-brightness light emission can be made.

[0267] In Figure 20C, the light-emitting layers 711, 712, and 713 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material. By stacking the light-emitting layers, the luminescence brightness can be increased.

[0268] Furthermore, different light-emitting materials may be used for the light-emitting layers 711, 712, and 713. Light-emitting materials may also be used such that the combined colors of the light emitted by each of the light-emitting layers 711, 712, and 713 result in white light emission. Figure 20D shows an example where a colored layer 795, which functions as a color filter, is provided. By passing white light through the color filter, light of the desired color can be obtained.

[0269] Furthermore, in Figure 20E, the light-emitting layer 711 and the light-emitting layer 712 may be made of light-emitting materials that emit light of the same color. Alternatively, the light-emitting layer 711 and the light-emitting layer 712 may be made of light-emitting materials that emit light of different colors. When the color of the light emitted by the light-emitting layer 711 and the color of the light emitted by the light-emitting layer 712 are complementary colors, white light emission is obtained. Figure 20F shows an example in which a colored layer 795 is further provided.

[0270] Furthermore, in Figures 20C, 20D, 20E, and 20F, as shown in Figure 20B, layer 720 and layer 730 may be a laminated structure consisting of two or more layers.

[0271] Also, in FIG. 20D, light-emitting materials that emit light of the same color may be used for the light-emitting layer 711, the light-emitting layer 712, and the light-emitting layer 713. Similarly, in FIG. 20F, light-emitting materials that emit light of the same color may be used for the light-emitting layer 711 and the light-emitting layer 712. At this time, by applying a color conversion layer instead of the coloring layer 795, light of a desired color different from the color of the light emitted by the light-emitting material can be obtained. For example, by using light-emitting materials that emit blue light for each light-emitting layer and allowing the blue light to pass through the color conversion layer, light having a longer wavelength than blue (e.g., red or green) can be obtained. As the color conversion layer, for example, a fluorescent material, a phosphorescent material, or a quantum dot can be used.

[0272] The emission color of the light-emitting device can be, for example, red, green, blue, cyan, magenta, yellow, or white depending on the materials constituting the EL layer 790. Further, by providing a microcavity structure to the light-emitting device, the color purity can be further enhanced.

[0273] A light-emitting device that emits white light may be configured to include two or more light-emitting substances in the light-emitting layer, or two or more light-emitting layers having different light-emitting substances may be stacked. At this time, light-emitting substances can be selected such that the colors of the light emitted by each of the light-emitting substances combine to emit white light as the entire light-emitting device.

[0274] [Light-emitting device] Here, a specific configuration example of the light-emitting device will be described.

[0275] The light-emitting device has at least a light-emitting layer. Further, as layers other than the light-emitting layer, the light-emitting device may further have layers containing, for example, substances with high hole injection properties, substances with high hole transport properties, hole blocking materials, substances with high electron transport properties, electron blocking materials, substances with high electron injection properties, electron blocking materials, or bipolar substances (substances with high electron transport properties and high hole transport properties).

[0276] For the light-emitting device, either a low-molecular compound or a high-molecular compound can be used. Further, the light-emitting device may contain an inorganic compound. Each layer constituting the light-emitting device can be formed by a method such as, for example, a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an inkjet method, or a coating method.

[0277] For example, the light-emitting device can be configured to have one or more layers selected from a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0278] The hole injection layer is a layer that injects holes from the anode into the hole transport layer and is a layer containing a material with high hole injection properties. Examples of materials with high hole injection properties include aromatic amine compounds and composite materials containing a hole transport material and an acceptor material (electron-accepting material).

[0279] The hole transport layer is a layer that transports the holes injected from the anode by the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole transport material. As the hole transport material, a substance having a hole mobility of 1×10 -6 cm 2 / Vs or more is preferable. As long as the substance has higher hole transportability than electrons, other substances can also be used. Examples of hole transport materials include hole transport materials with high hole transportability such as π-electron-excessive heteroaromatic compounds (for example, carbazole derivatives, thiophene derivatives, or furan derivatives) or aromatic amines (compounds having an aromatic amine skeleton).

[0280] The electron transport layer is a layer that transports the electrons injected from the cathode by the electron injection layer to the light-emitting layer. The electron transport layer is a layer containing an electron transport material. As the electron transport material, a substance having an electron mobility of 1×10 -6 cm 2Materials having an electron mobility of 1 / Vs or higher are preferred. However, other materials can also be used as long as they have higher electron transport capabilities than holes. Examples of electron-transporting materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, or metal complexes having a thiazole skeleton, as well as other highly electron-transporting materials such as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, or other π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds.

[0281] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer, and is a layer containing a material with high electron injection capabilities. Alkali metals, alkaline earth metals, or compounds thereof can be used as materials with high electron injection capabilities. Composite materials containing both electron transport materials and donor materials (electron-donating materials) can also be used as materials with high electron injection capabilities.

[0282] Examples of electron injection layers include lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-(quinolinolato)lithium (abbreviated as Liq), 2-(2-pyridyl)phenolate (abbreviated as LiPP), 2-(2-pyridyl)-3-pyridinolatritium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl)phenolate (abbreviated as LiPPP), and lithium oxide (LiO2). x Alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. Furthermore, the electron injection layer may be a multilayer structure of two or more layers. For example, this multilayer structure may consist of lithium fluoride as the first layer and ytterbium as the second layer.

[0283] Alternatively, an electron-transporting material may be used as the electron injection layer described above. For example, a compound having a lone pair of electrons and an electron-deficient heteroaromatic ring can be used as the electron-transporting material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, or pyridazine ring), and a triazine ring can be used.

[0284] Furthermore, it is preferable that the lowest unoccupied molecular orbital (LUMO) level of the organic compound having a lone pair of electrons is between -3.6 eV and -2.3 eV. Generally, the highest occupied molecular orbital (HOMO) level and LUMO level of the organic compound can be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, or inverse photoelectron spectroscopy.

[0285] Examples of organic compounds containing lone pairs of electrons include 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), or 2,4,6-tris[3'-(pyridine-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz). NBPhen has a higher glass transition temperature (Tg) and superior heat resistance compared to BPhen.

[0286] The luminescent layer is a layer containing a luminescent material. The luminescent layer may contain one or more types of luminescent materials. As the luminescent material, for example, materials that exhibit luminescent colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red may be used as appropriate. In addition, materials that emit near-infrared light may also be used as the luminescent material.

[0287] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0288] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, or naphthalene derivatives.

[0289] Examples of phosphorescent materials include organometallic complexes (especially iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or pyridine skeleton; organometallic complexes (especially iridium complexes) using phenylpyridine derivatives having electron-withdrawing groups as ligands; platinum complexes; or rare earth metal complexes.

[0290] The light-emitting layer may contain one or more types of organic compounds (e.g., a host material or an assist material) in addition to the light-emitting substance (guest material). One or more of the organic compounds may be hole-transporting materials and electron-transporting materials, or both. Alternatively, one or more of the organic compounds may be bipolar materials or TADF materials.

[0291] The light-emitting layer preferably comprises, for example, a phosphorescent material and a combination of a hole-transporting material and an electron-transporting material that readily forms an excitation complex. This configuration allows for efficient emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the excitation complex to the light-emitting substance (phosphorescent material). By selecting a combination that forms an excitation complex that exhibits emission overlapping with the wavelength of the lowest-energy absorption band of the light-emitting substance, energy transfer becomes smoother, and light emission can be obtained efficiently. This configuration simultaneously achieves high efficiency, low-voltage operation, and a long lifespan for the light-emitting device.

[0292] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0293] (Embodiment 5) This embodiment describes electronic equipment to which a display device according to one aspect of the present invention can be applied.

[0294] A display device according to one aspect of the present invention can be applied to the display unit of an electronic device. Therefore, one aspect of the present invention can realize an electronic device with high display quality. Alternatively, one aspect of the present invention can realize an electronic device with extremely high resolution. Alternatively, one aspect of the present invention can realize an electronic device with high reliability.

[0295] Examples of electronic devices using a display device or the like according to an aspect of the present invention include, for example, display devices such as televisions and monitors, lighting devices, desktop or notebook personal computers, word processors, image playback devices that play back still images or moving images stored on recording media such as DVDs (Digital Versatile Discs), portable CD players, radios, tape recorders, headphone stereos, stereos, table clocks, wall clocks, cordless telephone handsets, transceivers, car phones, mobile phones, portable information terminals, tablet terminals, portable game machines, stationary game machines such as pachinko machines, calculators, electronic notebooks, e-book terminals, electronic translators, voice input devices, video cameras, digital still cameras, high-frequency heating devices such as electric shavers and microwave ovens, electric rice cookers, washing machines, vacuum cleaners, water heaters, fans, hair dryers, air conditioners, humidifiers, dehumidifiers, and other air-conditioning equipment, dishwashers, dish dryers, clothes dryers, futon dryers, electric refrigerators, freezers, refrigerator-freezers, DNA storage freezers, flashlights, tools such as chain saws, smoke detectors, or medical devices such as dialysis devices. Further, for example, industrial devices such as induction lamps, signal lights, belt conveyors, elevators, escalators, industrial robots, power storage systems, or power storage devices for power leveling and smart grids can be mentioned. Also, for example, a moving body propelled by an engine using fuel or an electric motor using power from a power storage body may be included in the category of electronic devices. Examples of the moving body include, for example, electric vehicles (EVs), hybrid vehicles (HV) having both an internal combustion engine and an electric motor, plug-in hybrid vehicles (PHVs), tracked vehicles obtained by changing the tire wheels of these into endless tracks, motorized bicycles including electric assist bicycles, motorcycles, electric wheelchairs, golf carts, small or large ships, submarines, helicopters, airplanes, rockets, artificial satellites, space exploration vehicles, planetary exploration vehicles, or spacecraft.

[0296] An electronic device according to an aspect of the present invention may have a secondary battery (battery). Further, it is preferable that the secondary battery can be charged using non-contact power transmission.

[0297] Examples of secondary batteries include lithium-ion secondary batteries, nickel-metal hydride batteries, nickel-cadmium batteries, organic radical batteries, lead-acid batteries, air secondary batteries, nickel-zinc batteries, and silver-zinc batteries.

[0298] An electronic device according to one aspect of the present invention may have an antenna. By receiving signals with the antenna, the display unit can display images and information. Furthermore, if the electronic device has an antenna and a secondary battery, the antenna may be used for contactless power transmission.

[0299] An electronic device according to one aspect of the present invention may have sensors (including, for example, those with functions to measure force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation).

[0300] An electronic device according to one aspect of the present invention can have various functions. For example, it can have a function to display various information (e.g., still images, videos, or text images) on a display unit, a touch panel function, a function to display a calendar, date, or time, a function to execute various software (programs), a wireless communication function, or a function to read programs or data recorded on a recording medium.

[0301] Furthermore, electronic devices having multiple display units may have functions such as displaying image information primarily on one part of the display unit and text information primarily on another part, or displaying a three-dimensional image by displaying images that take parallax into account on multiple display units. Furthermore, electronic devices having an image receiving unit may have functions such as capturing still images or moving images, automatically or manually correcting captured images, saving captured images to a recording medium (external or built into the electronic device), or displaying captured images on a display unit. However, the functions of an electronic device according to one aspect of the present invention are not limited to these. An electronic device according to one aspect of the present invention may have a variety of functions.

[0302] A display device according to one aspect of the present invention can display high-definition images. Therefore, it can be suitably used in portable electronic devices, wearable electronic devices, or e-book readers. For example, it can be suitably used in xR devices such as VR devices or AR devices.

[0303] Figure 21A shows the external appearance of the camera 8000 with the viewfinder 8100 attached.

[0304] The camera 8000 includes a housing 8001, a display unit 8002, operation buttons 8003, and a shutter button 8004, etc. A detachable lens 8006 is also attached to the camera 8000. The lens 8006 and the housing of the camera 8000 may be integrated into a single unit.

[0305] Camera 8000 can take an image by pressing the shutter button 8004 or by touching the display unit 8002, which functions as a touch panel.

[0306] The housing 8001 has a mount with electrodes, and in addition to the viewfinder 8100, it can be connected to, for example, a strobe device or the like.

[0307] The viewfinder 8100 includes a housing 8101, a display unit 8102, and buttons 8103, etc.

[0308] The housing 8101 is attached to the camera 8000 by a mount that engages with the camera 8000's mount. The viewfinder 8100 can, for example, display images or other data received from the camera 8000 on the display unit 8102.

[0309] Button 8103 has a function such as a power button.

[0310] A display device according to one aspect of the present invention can be applied to the display unit 8002 of a camera 8000 and the display unit 8102 of a viewfinder 8100. The viewfinder 8100 may be built into the camera 8000.

[0311] Figure 21B shows the external appearance of the head-mounted display 8200.

[0312] The head-mounted display 8200 includes a mounting section 8201, lenses 8202, a main unit 8203, a display unit 8204, and a cable 8205, among other components. The mounting section 8201 also has a built-in battery 8206.

[0313] Cable 8205 has the function of supplying power from battery 8206 to main unit 8203. Main unit 8203 is equipped with, for example, a wireless receiver and can display received video information on display unit 8204. In addition, main unit 8203 is equipped with, for example, a camera and can use information of the user's eyeball or eyelid movements as an input means.

[0314] Furthermore, the attachment unit 8201 may have a function to recognize gaze, for example, by providing a plurality of electrodes at a position that touches the user and is capable of detecting the current flowing in accordance with the user's eye movements. It may also have a function to monitor the user's pulse rate based on the current flowing through the electrodes. The attachment unit 8201 may also have various sensors, for example, a temperature sensor, a pressure sensor, or an acceleration sensor. The head-mounted display 8200 may have a function to display the user's biometric information on the display unit 8204, or a function to change the image displayed on the display unit 8204 in accordance with the user's head movements.

[0315] A display device according to one aspect of the present invention can be applied to a display unit 8204.

[0316] Figures 21C to 21E show the external appearance of the head-mounted display 8300. The head-mounted display 8300 includes a housing 8301, a display unit 8302, a band-shaped fixing device 8304, and a pair of lenses 8305.

[0317] The user can view the display on the display unit 8302 through the lens 8305. It is preferable that the head-mounted display 8300 has the display unit 8302 positioned in a curved shape, for example, as this allows the user to experience a greater sense of presence. Furthermore, by viewing different images displayed in different areas of the display unit 8302 through the lens 8305, it is possible to perform, for example, a three-dimensional display using parallax. The configuration is not limited to having only one display unit 8302; for example, two display units 8302 may be provided, with one display unit for each of the user's eyes.

[0318] A display device according to one aspect of the present invention can be applied to the display unit 8302. The display device according to one aspect of the present invention can also achieve extremely high resolution. For example, even when the display is magnified and viewed using the lens 8305 as shown in Figure 21E, the pixels are difficult for the user to see. In other words, the display unit 8302 can be used to allow the user to view highly realistic images.

[0319] Figure 21F shows the external appearance of a goggle-type head-mounted display 8400. The head-mounted display 8400 has a pair of housings 8401, a mounting part 8402, and a cushioning member 8403. A display unit 8404 and a lens 8405 are provided inside each of the pair of housings 8401. The pair of display units 8404 can display different images from each other to perform a three-dimensional display using parallax.

[0320] The user can view the display on the display unit 8404 through the lens 8405. The lens 8405 has a focus adjustment mechanism and its position can be adjusted according to the user's eyesight. The display unit 8404 is preferably square or a horizontally elongated rectangle. This can enhance the sense of realism.

[0321] The mounting portion 8402 is preferably adjustable to the size of the user's face and has plasticity and elasticity to prevent it from slipping off. Furthermore, it is preferable that a part of the mounting portion 8402 has a vibration mechanism that functions as, for example, a bone conduction earphone. This eliminates the need for separate earphones or speakers, allowing users to enjoy video and audio simply by wearing the device. The housing 8401 may also have a function to output audio data via, for example, wireless communication.

[0322] The mounting portion 8402 and the cushioning member 8403 are parts that come into contact with the user's face (forehead, cheeks, etc.). By ensuring that the cushioning member 8403 is in close contact with the user's face, light leakage can be prevented, thereby enhancing the sense of immersion. It is preferable to use a soft material for the cushioning member 8403 so that it adheres closely to the user's face when the user wears the head-mounted display 8400. For example, materials such as rubber, silicone rubber, urethane, or sponge can be used. Furthermore, if a material such as sponge is covered with cloth or leather (genuine leather or synthetic leather), gaps are less likely to form between the user's face and the cushioning member 8403, effectively preventing light leakage. In addition, using such materials is preferable because it feels good against the skin and, for example, prevents the user from feeling cold when wearing it in cold weather. It is preferable that the components that come into contact with the user's skin, such as the cushioning member 8403 or the mounting portion 8402, are removable, as this facilitates cleaning or replacement.

[0323] Figure 22A shows an example of a television system. The television system 7100 has a display unit 7000 incorporated into a housing 7101. Here, the housing 7101 is shown supported by a stand 7103.

[0324] In Figure 22A, a display device according to one aspect of the present invention can be applied to the display unit 7000.

[0325] The television device 7100 shown in Figure 22A can be operated by operating switches on the housing 7101 or by a separate remote control unit 7111. Alternatively, the display unit 7000 may be equipped with a touch sensor, allowing the television device 7100 to be operated by, for example, touching the display unit 7000 with a finger. The remote control unit 7111 may have a display unit that displays information output from the remote control unit 7111. The television device 7100 can operate channels or volume using the operation keys or touch panel on the remote control unit 7111. It can also operate the image displayed on the display unit 7000.

[0326] The television system 7100 can be configured to include, for example, a receiver and a modem. The receiver can receive general television broadcasts. Furthermore, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (from sender to receiver) or two-way (for example, between sender and receiver, or between receivers) information communication.

[0327] Figure 22B shows an example of a notebook personal computer. The notebook personal computer 7200 has a casing 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214, etc. A display unit 7000 is incorporated into the casing 7211.

[0328] In Figure 22B, a display device according to one aspect of the present invention can be applied to the display unit 7000.

[0329] Figures 22C and 22D show examples of digital signage.

[0330] The digital signage 7300 shown in Figure 22C includes a housing 7301, a display unit 7000, and a speaker 7303, etc. Furthermore, it may include LED lamps, operation keys (including a power switch or operation switch), connection terminals, various sensors, or a microphone, etc.

[0331] Figure 22D shows a digital signage system mounted on a cylindrical column. The digital signage system 7400 has a display unit 7000 that is provided along the curved surface of the column 7401.

[0332] In Figures 22C and 22D, a display device according to one aspect of the present invention can be applied to the display unit 7000.

[0333] The larger the display area of ​​the Digital Signage 7300 or Digital Signage 7400, the more information can be displayed at once. Furthermore, a larger display area makes it more eye-catching, which can, for example, enhance the effectiveness of advertisements.

[0334] Furthermore, it is preferable to apply a touch panel to the display unit 7000 of the digital signage 7300 or digital signage 7400. This allows not only images or videos to be displayed on the display unit 7000, but also to be operated intuitively by the user. In addition, when used for purposes such as providing route information or traffic information, intuitive operation can enhance usability.

[0335] Furthermore, as shown in Figures 22C and 22D, it is preferable that the digital signage 7300 or digital signage 7400 can be linked wirelessly with an information terminal 7311 or information terminal 7411, such as a smartphone owned by the user. For example, the advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or information terminal 7411. Also, the display on the display unit 7000 can be switched by operating the information terminal 7311 or information terminal 7411.

[0336] Furthermore, the digital signage 7300 or digital signage 7400 can also run games using the screen of the information terminal 7311 or information terminal 7411 as the control device (controller). This allows a large number of users to participate in and enjoy the game simultaneously.

[0337] Figure 22E shows an example of an information terminal. The information terminal 7550 includes a housing 7551, a display unit 7552, a microphone 7557, a speaker unit 7554, a camera 7553, and an operation switch 7555. A display device according to one aspect of the present invention can be applied to the display unit 7552. The display unit 7552 can also function as a touch panel. Furthermore, the information terminal 7550 can be equipped with an antenna and a battery inside the housing 7551. The information terminal 7550 can be used, for example, as a smartphone, a mobile phone, a tablet information terminal, a tablet personal computer, or an e-book reader.

[0338] Figure 22F shows an example of a wristwatch-type information terminal. The information terminal 7660 includes a housing 7661, a display unit 7662, a band 7663, a buckle 7664, an operation switch 7665, and input / output terminals 7666. The information terminal 7660 may also include, for example, an antenna and a battery inside the housing 7661. The information terminal 7660 can run various applications, such as mobile phone calls, email, document viewing and creation, music playback, internet communication, or computer games.

[0339] Furthermore, the information terminal 7660 is equipped with a touch sensor on the display unit 7662, allowing it to be operated by touching the screen with a finger or stylus, for example. For example, touching the icon 7667 displayed on the display unit 7662 can launch an application. The operation switch 7665 can have various functions, such as setting the time, turning the power on or off, turning wireless communication on or off, activating or deactivating silent mode, or activating or deactivating power saving mode. For example, the functions of the operation switch 7665 can also be configured by the operating system built into the information terminal 7660.

[0340] Furthermore, the information terminal 7660 is capable of performing standardized short-range wireless communication. For example, it can communicate with a wireless communication-enabled headset to make hands-free calls. The information terminal 7660 can also send and receive data with other information terminals via the input / output terminal 7666. It can also be charged via the input / output terminal 7666. Note that charging may be performed by wireless power supply without using the input / output terminal 7666.

[0341] Figure 23A shows the exterior of the automobile 9700. Figure 23B shows the driver's seat of the automobile 9700. The automobile 9700 includes a body 9701, wheels 9702, a dashboard 9703, and lights 9704, etc. A display device according to one aspect of the present invention can be used, for example, in the display unit of the automobile 9700. For example, a display device according to one aspect of the present invention can be applied to each of the display units 9710 to 9715 shown in Figure 23B.

[0342] Display units 9710 and 9711 are display devices installed on the windshield of an automobile. In one aspect of the present invention, the electrodes of the display device are made of a light-transmitting conductive material, thereby creating a so-called see-through display device that allows the other side to be seen through. A see-through display device does not obstruct the driver's view when the automobile 9700 is in operation. Therefore, the display device according to one aspect of the present invention can be installed on the windshield of the automobile 9700. If the display device is equipped with, for example, a transistor for driving the display device, it is preferable to use a light-transmitting transistor, such as an organic transistor using an organic semiconductor material or a transistor using an oxide semiconductor.

[0343] The display unit 9712 is a display device installed on the pillar. For example, by displaying images from an imaging device installed on the vehicle body 9701 on the display unit 9712, the field of view obstructed by the pillar can be compensated for. The display unit 9713 is a display device installed on the dashboard 9703. For example, by displaying images from an imaging device installed on the vehicle body 9701 on the display unit 9713, the field of view obstructed by the dashboard 9703 can be compensated for. In other words, the automobile 9700 can compensate for blind spots and enhance safety by displaying images from an imaging device installed on the vehicle body 9701 on the display units 9712 and 9713. Furthermore, by displaying images that compensate for the parts that are not visible, safety checks can be performed more naturally and without discomfort.

[0344] Figure 24 shows the interior of automobile 9700, which employs bench seats for the driver and passenger. Display unit 9721 is a display device provided in the door. For example, by displaying images from an imaging means provided in the vehicle body 9701 on display unit 9721, the view obstructed by the door can be compensated for. Display unit 9722 is a display device provided in the steering wheel. Display unit 9723 is a display device provided in the center of the seat surface of the bench seat.

[0345] Display units 9714, 9715, or 9722 can provide the user with various information by displaying, for example, navigation information, driving speed, engine RPM, mileage, fuel level, gear status, or air conditioning settings. The display items and layout displayed on the display units can be changed as appropriate to suit the user's preferences. The above information can also be displayed on one or more of the display units 9710 to 9713, 9721, and 9723. In addition, one or more of the display units 9710 to 9715 and 9721 to 9723 can also be used as lighting devices.

[0346] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments. [Explanation of symbols]

[0347] 10: Display device, 11: Pixel, 12: Monitor circuit, 13: Image processing circuit, 51: Wiring, 52: Wiring, 53: Wiring, 61: Light-emitting element, 180A: Transistor, 180B: Transistor, 180C: Transistor, M1: Transistor, M2: Transistor, M3: Transistor, M4: Transistor, M5: Transistor, M6: Transistor, C1: Capacitor, C2: Capacitor, DL: Wiring, ML: Wiring, GLa: Wiring, GLB: Wiring, GLC: Wiring, ND1: Node, ND2: Node, ND3: Node, Vdata: Display data, V0: Potential, V1: Potential, Va: Potential, Vc: Potential, Ve0: Potential, Ve1: Potential, Ve2: Potential, Ve3: Potential, Ve4: Potential, T11: Period, T12: Period, T13: Period, T21: Period, T22: Period, T23: Period, T24: Period, T31: Period, T32: Period, T33: Period, S01: Step, S02: Step, S03: Step, S04: Step, S05: Step

Claims

1. It comprises a pixel, a first circuit, and a second circuit, The aforementioned pixel comprises a light-emitting element, a first transistor, and a first capacitor. A correction method for a display device, wherein the first transistor has the function of controlling the current supplied to the light-emitting element based on a first signal supplied to the pixel, A first process is performed in which a voltage is obtained to correct the threshold voltage of the first transistor, and the voltage is held in the first capacitor. After the completion of the first process, the second circuit performs a second process in which it supplies a potential to the gate of the first transistor that can turn off the first transistor, measures the current flowing through the light-emitting element, and generates a second signal based on the current. After the completion of the second process, the second circuit performs a third process in which it generates the first signal obtained by correcting the image data using the second signal. After the completion of the third process, a fourth process is performed in which the first signal is supplied to the pixel. A method for correcting a display device.

2. It comprises a pixel, a first circuit, and a second circuit, The aforementioned pixel comprises a light-emitting element, a first transistor, and a first capacitor. A correction method for a display device, wherein the first transistor has the function of controlling the current supplied to the light-emitting element based on a first signal supplied to the pixel, In the second circuit, a potential is supplied to the gate of the first transistor that can turn off the first transistor, and in the first circuit, a second process is performed in which the current flowing through the light-emitting element is measured and a second signal is generated based on the current. After the completion of the second process, the first process is performed to obtain a voltage for correcting the threshold voltage of the first transistor and to hold the voltage in the first capacitor. After the completion of the second process, the second circuit performs a third process in which it generates the first signal obtained by correcting the image data using the second signal. After the completion of the first and third processes, a fourth process is performed in which the first signal is supplied to the pixel. A method for correcting a display device.

3. In claim 2, The first process and the third process are performed simultaneously. A method for correcting a display device.

4. In any one of claims 1 to 3, The first transistor is equipped with a back gate, The first transistor has the function of controlling the threshold voltage of the first transistor based on the potential supplied to the back gate. The first process involves obtaining the voltage between the back gate and the source of the first transistor. A method for correcting a display device.

5. In any one of claims 1 to 3, The fourth process involves supplying the first signal to the gate of the first transistor. A method for correcting a display device.

6. In any one of Claims 1 to 3, The display device comprises a second transistor, a third transistor, a fourth transistor, a first wire, a second wire, a third wire, a fourth wire, a fifth wire, and a sixth wire. Either the source or the drain of the second transistor is electrically connected to the gate of the first transistor. The source or drain of the second transistor, the other of which is electrically connected to the first wiring, The gate of the second transistor is electrically connected to the second wiring, Either the source or drain of the third transistor is electrically connected to either the source or drain of the first transistor. The source or drain of the third transistor is electrically connected to one terminal of the light-emitting element. The gate of the third transistor is electrically connected to the third wiring, Either the source or drain of the fourth transistor is electrically connected to either the source or drain of the first transistor. The source or drain of the fourth transistor, the other of which is electrically connected to the fourth wiring, The gate of the fourth transistor is electrically connected to the second wiring, The source or drain of the first transistor, the other of which is electrically connected to the fifth wiring, The other terminal of the light-emitting element is electrically connected to the sixth wiring, The first circuit has the function of measuring the current flowing to the light-emitting element via the fourth wiring, The second circuit has the function of supplying the first wiring with a potential that can turn off the first signal or the first transistor. A method for correcting a display device.

7. In claim 4, The display device comprises a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a second capacitor, a first wiring, a second wiring, a third wiring, a fourth wiring, a fifth wiring, a sixth wiring, a seventh wiring, and an eighth wiring. Either the source or the drain of the second transistor is electrically connected to the gate of the first transistor. The source or drain of the second transistor, the other of which is electrically connected to the first wiring, The gate of the second transistor is electrically connected to the second wiring, Either the source or drain of the third transistor is electrically connected to either the source or drain of the first transistor. The source or drain of the third transistor is electrically connected to one terminal of the light-emitting element. The gate of the third transistor is electrically connected to the third wiring, Either the source or drain of the fourth transistor is electrically connected to either the source or drain of the first transistor. The source or drain of the fourth transistor, the other of which is electrically connected to the fourth wiring, The gate of the fourth transistor is electrically connected to the second wiring, Either the source or drain of the fifth transistor is electrically connected to the gate of the first transistor. The source or drain of the fifth transistor is electrically connected to the source or drain of the first transistor. The gate of the fifth transistor is electrically connected to the seventh wiring, Either the source or drain of the sixth transistor is electrically connected to the back gate of the first transistor. The source or drain of the sixth transistor, the other of which is electrically connected to the eighth wiring, The gate of the sixth transistor is electrically connected to the seventh wiring, One terminal of the first capacitor is electrically connected to the back gate of the first transistor. The other terminal of the first capacitance is electrically connected to either the source or the drain of the first transistor. One terminal of the second capacitor is electrically connected to the gate of the first transistor. The other terminal of the second capacitance is electrically connected to either the source or the drain of the first transistor. The source or drain of the first transistor, the other of which is electrically connected to the fifth wiring, The other terminal of the light-emitting element is electrically connected to the sixth wiring, The first circuit has the function of measuring the current flowing to the light-emitting element via the fourth wiring, The second circuit has the function of supplying the first wiring with a potential that can turn off the first signal or the first transistor. A method for correcting a display device.

Images