Display apparatus and electronic equipment

Abstract

The present invention provides a novel display apparatus. Provided is a display apparatus comprising a plurality of pixels each comprising a light-emitting device, a sensor device, a first circuit device, and a second circuit device, wherein the light-emitting device and the sensor device are provided in a first layer, the first circuit device is provided in a second layer, the second circuit device is provided in a third layer, the light-emitting device comprises a lower electrode, an upper electrode, and a light-emitting layer provided between the lower electrode and the upper electrode, the sensor device has a function of detecting light emitted from the light-emitting device, the first circuit device has a function of driving the light-emitting device or the sensor device, the second circuit device has a function of performing a computation on the basis of information outputted from the first circuit device, the first layer is provided on the second layer, and the second layer is provided on the third layer.

Description

Display devices and electronic devices

[0001] One embodiment of the present invention relates to a display device and an electronic device.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. Examples of the technical field of one embodiment of the present invention disclosed in this specification and the like include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an electronic device, a lighting device, an input device, an input / output device, a driving method thereof, or a manufacturing method thereof.

[0003] In recent years, there has been a demand for higher resolution display devices. Devices requiring high-resolution display devices include, for example, devices for virtual reality (VR), augmented reality (AR), substitutional reality (SR), or mixed reality (MR), and these devices have been actively developed in recent years. Display devices used in these devices are required to be compact as well as high-resolution.

[0004] Representative examples of the display device include a liquid crystal display device, an organic EL (Electro Luminescence) element, a light-emitting device equipped with a light-emitting element (also called a light-emitting device) such as a light-emitting diode (LED: Light Emitting Diode), and electronic paper that displays using an electrophoresis method or the like.

[0005] For example, the basic structure of an organic EL element is a layer containing a light-emitting organic compound sandwiched between a lower electrode and an upper electrode. Light can be emitted from the light-emitting organic compound by applying a voltage to this element. A display device employing such an organic EL element does not require a backlight, which is necessary in liquid crystal display devices and the like, and therefore can realize a thin, lightweight, high-contrast, and low-power display device. For example, Patent Document 1 discloses an example of a display device using an organic EL element. When high display quality is required, such as the display device of Patent Document 1, a display device with a high number of pixels and high resolution may be required.

[0006] International Publication No. 2019 / 220278

[0007] Devices for virtual reality (VR) and augmented reality (AR) require display devices with high display quality, as shown in Patent Document 1. In this case, display is performed in a wearable housing such as glasses or goggles, so miniaturization and weight reduction of the display device are important factors. In a wearable housing, the size of the display device needs to be reduced to, for example, approximately 2 inches or less, 1 inch or less, etc.

[0008] Furthermore, the display device requires a driving circuit such as a gate driver or a source driver for driving the pixels, and a functional circuit such as an application processor for generating control signals for displaying, in order to improve the display quality of the display device.

[0009] In a configuration in which the above-mentioned drive circuit and the above-mentioned function circuit are separately provided in addition to a pixel circuit having a plurality of pixels, there is a problem that the wiring length for electrically connecting each circuit increases, making it difficult to reduce the size and weight of the display device. Furthermore, in a configuration in which the drive circuit and the function circuit are monolithically provided in addition to a pixel circuit having a plurality of pixels, there is a problem that the circuit area increases due to the addition of the drive circuit and the function circuit to the pixel circuit.

[0010] Furthermore, when adding added value such as a sensor to a display device, functional circuits for driving or controlling the sensor are required, which increases the circuit area and makes it difficult to reduce the size and weight of the display device.

[0011] In view of the above problems, an object of one embodiment of the present invention is to provide a display device that is reduced in size.Another object of one embodiment of the present invention is to provide a display device that is reduced in weight.Another object of one embodiment of the present invention is to provide a display device with excellent display quality.Another object of one embodiment of the present invention is to provide a novel display device.

[0012] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these can be extracted from the description of the specification, drawings, claims, etc.

[0013] One embodiment of the present invention is a display device having a plurality of pixels, each of which has a light-emitting device, a sensor device, and a circuit device, wherein the light-emitting device and the sensor device are provided on a first layer, the circuit device is provided on a second layer, the light-emitting device has a lower electrode, an upper electrode, and a light-emitting layer provided between the lower electrode and the upper electrode, the sensor device has a function of detecting light emitted from the light-emitting device, and the first layer is provided on the second layer.

[0014] One embodiment of the present invention is a display device having a plurality of pixels, each of the plurality of pixels having a light-emitting device, a sensor device, a first circuit device, and a second circuit device, the light-emitting device and the sensor device being provided on a first layer, the first circuit device being provided on a second layer, and the second circuit device being provided on a third layer, the light-emitting device having a lower electrode, an upper electrode, and a light-emitting layer provided between the lower electrode and the upper electrode, the sensor device having a function of detecting light emitted from the light-emitting device, the first circuit device having a function of driving the light-emitting device or the sensor device, and the second circuit device having a function of performing calculations based on information output from the first circuit device, the first layer being provided on a second layer, and the second layer being provided on a third layer.

[0015] When the light-emitting device is observed in cross section, it is preferable that the side surface of the lower electrode and the side surface of the light-emitting layer have a region that coincides or approximately coincides with each other.

[0016] It is preferable to have an insulator between the light-emitting device and the adjacent light-emitting device. The insulator preferably contains either or both of an inorganic material and an organic material. The insulator preferably contains a photosensitive organic resin.

[0017] The first circuit device preferably includes a first transistor, and the first transistor preferably includes a metal oxide in a channel forming region.

[0018] The second circuit device preferably includes a second transistor, the second transistor preferably having silicon in a channel forming region.

[0019] The second circuit device preferably has the function of detecting one or more of the user's blinking, movement of the pupil, and movement of the eyelids using either or both of the light-emitting device and the sensor device.

[0020] One embodiment of the present invention is a display device having a plurality of pixels, each of which has a light-emitting device, a sensor device, and a circuit device. The light-emitting device and the sensor device are provided on a first layer, the circuit device is provided on a second layer, the light-emitting device has a lower electrode, an upper electrode, and a light-emitting layer provided between the lower electrode and the upper electrode, the sensor device has a function of detecting light emitted from the light-emitting device, the first layer is provided on the second layer, and each of the plurality of pixels has first to sixth subpixels.

[0021] One embodiment of the present invention is a display device having a plurality of pixels, each of the plurality of pixels having first to sixth subpixels, wherein the first subpixel has a first light-emitting device having a function of emitting red light, the second subpixel has a second light-emitting device having a function of emitting green light, the third subpixel has a third light-emitting device having a function of emitting blue light, at least one of the fourth to sixth subpixels has a first sensor device, and each of the first to sixth subpixels has a circuit device, the first to third light-emitting devices and the first sensor device are provided in a first layer, and the circuit device is provided in a second layer, and the first to third light-emitting devices each have a lower electrode, an upper electrode, and a light-emitting layer provided between the lower electrode and the upper electrode, and the first sensor device has a function of detecting light emitted from the pixel, and the first layer is provided on the second layer.

[0022] In the above configuration, it is preferable that the fourth sub-pixel has a fourth light-emitting device having a function of emitting infrared light, the fifth sub-pixel has a first sensor device, the sixth sub-pixel has a second sensor device, the fifth sub-pixel has a function of detecting visible light, and the sixth sub-pixel has a function of detecting infrared light.

[0023] Each of the first to sixth subpixels preferably has a light-emitting or light-receiving region with a side of 1 μm to 10 μm, and the distance between adjacent subpixels is preferably less than 1 μm.

[0024] One embodiment of the present invention is an electronic device including any of the above display devices, a housing in which the display device is provided, a sensor provided in the housing, and a battery provided in the housing and for supplying power to the display device.

[0025] One aspect of the present invention is an electronic device that includes at least two of the above-described display devices, a housing in which the display devices are provided, a sensor provided in the housing, and a battery provided in the housing and that supplies power to the display devices, wherein the housing has an attachment portion and a pair of lenses, and an image is projected from one of the two display devices onto one of the pair of lenses, and an image is projected from the other of the two display devices onto the other of the pair of lenses.

[0026] Note that other aspects of the present invention will be described in the following embodiments and in the drawings.

[0027] According to one embodiment of the present invention, a display device that is reduced in size can be provided. Alternatively, according to one embodiment of the present invention, a display device that is reduced in weight can be provided. Alternatively, according to one embodiment of the present invention, a display device with excellent display quality can be provided. Alternatively, according to one embodiment of the present invention, a novel display device can be provided.

[0028] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these can be extracted from the description in the specification, drawings, claims, etc.

[0029] FIGS. 1A and 1B are diagrams illustrating a configuration example of a display device. FIGS. 2A and 2B are diagrams illustrating a configuration example of a display device. FIGS. 3A and 3B are diagrams illustrating a configuration example of a display device. FIGS. 4A and 4B are diagrams illustrating a configuration example of a display device. FIG. 5 is a block diagram illustrating a configuration example of a display device. FIG. 6A is a cross-sectional schematic diagram of a display device and a user's eye according to one embodiment of the present invention. FIG. 6B is a schematic diagram illustrating the user's eye and the vicinity of the user's eye. FIG. 6C is a schematic diagram illustrating a retinal pattern of the user's eye. FIGS. 7A to 7D are diagrams illustrating a configuration example of a pixel circuit. FIGS. 8A to 8D are diagrams illustrating a configuration example of a pixel circuit. FIGS. 9A and 9B are diagrams illustrating a configuration example of a display device. FIGS. 10A to 10C are diagrams illustrating a configuration example of a display device. FIG. 11 is a diagram illustrating a configuration example of a display device. FIG. 12 is a diagram illustrating a configuration example of a display device. FIG. 13 is a diagram illustrating a configuration example of a display device. FIG. 14 is a diagram illustrating a configuration example of a display device. 15A to 15F are diagrams illustrating an example of the configuration of a light-emitting device. FIGS. 16A and 16B are diagrams illustrating an example of the configuration of an electronic device. FIG. 16C is a diagram illustrating an example of how the electronic device is used. FIGS. 17A to 17D are diagrams illustrating an example of the configuration of an electronic device. FIGS. 18A and 18B are diagrams illustrating an example of the configuration of an electronic device.

[0030] Hereinafter, embodiments will be described with reference to the drawings. However, it will be readily understood by those skilled in the art that the embodiments can be implemented in many different forms and that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the following description of the embodiments.

[0031] In addition, in the drawings, the size, layer thickness, or area may be exaggerated for clarity, and therefore, are not necessarily limited to the scale. Note that the drawings are schematic illustrations of ideal examples, and are not limited to the shapes, values, etc. shown in the drawings.

[0032] In this specification and the like, unless otherwise specified, the off-state current refers to the drain current when a transistor is in an off state (also referred to as a non-conducting state or a cut-off state). Unless otherwise specified, the off-state current refers to the drain current when a transistor is in an off state (also referred to as a non-conducting state or a cut-off state). ｇｓ is the threshold voltage V ｔｈ (For p-channel transistors, V ｔｈ This refers to a state of being (higher than)

[0033] In this specification and the like, a metal oxide refers to an oxide of a metal in a broad sense. Metal oxides are classified into oxide insulators, oxide conductors (including transparent oxide conductors), oxide semiconductors (also referred to as oxide semiconductors or simply as OSs), and the like. For example, when a metal oxide is used in an active layer of a transistor, the metal oxide may be referred to as an oxide semiconductor. In other words, an OS transistor can be rephrased as a transistor including an oxide or an oxide semiconductor.

[0034] In this specification, etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. In this specification, etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure.

[0035] In this specification and the like, a structure in which different light-emitting layers are formed or different light-emitting layers are painted for each color light-emitting device (here, blue (B), green (G), and red (R)) may be referred to as an SBS (Side By Side) structure. In this specification and the like, a light-emitting device that can emit white light may be referred to as a white light-emitting device. In addition, a white light-emitting device can be combined with a colored layer (for example, a color filter) to realize a full-color display device.

[0036] Light-emitting devices can be broadly divided into single structures and tandem structures. A single-structure device preferably has one light-emitting unit between a pair of electrodes, and the light-emitting unit includes one or more light-emitting layers. To obtain white light emission, when two light-emitting layers are used, light-emitting layers may be selected so that the emission colors of the two light-emitting layers are complementary to each other. For example, by making the emission color of the first light-emitting layer and the emission color of the second light-emitting layer complementary to each other, a configuration in which the entire light-emitting device emits white light can be obtained. When three or more light-emitting layers are used to obtain white light emission, the emission colors of the three or more light-emitting layers may be combined to produce a configuration in which the entire light-emitting device emits white light.

[0037] A tandem-structure device preferably has two or more light-emitting units between a pair of electrodes, and each light-emitting unit preferably includes one or more light-emitting layers. To obtain white light emission, light from the light-emitting layers of the light-emitting units may be combined to obtain white light emission. The configuration for obtaining white light emission is the same as that of the single-structure device. In a tandem-structure device, it is preferable to provide an intermediate layer such as a charge-generating layer between the light-emitting units.

[0038] Furthermore, when comparing the above-described white light-emitting device (single structure or tandem structure) with a light-emitting device having an SBS structure, the light-emitting device having an SBS structure can reduce power consumption compared to the white light-emitting device. If it is desired to reduce power consumption, it is preferable to use a light-emitting device having an SBS structure. On the other hand, the manufacturing process of a white light-emitting device is simpler than that of a light-emitting device having an SBS structure, and therefore the manufacturing cost can be reduced or the manufacturing yield can be increased, making it preferable.

[0039] Embodiment 1 A structural example of a display device according to one embodiment of the present invention will be described below with reference to the drawings.

[0040] <Configuration Example 1 of Display Device> FIGS. 1A and 1B are schematic perspective views of a display device 10. FIG.

[0041] 1A and 1B includes a layer 11 and a layer 12. The display device 10 also includes a display section 15 that is configured with elements provided in the layer 11 and the layer 12. The display section 15 is a region that displays an image in the display device 10. The display section 15 is a region where pixels are provided, each pixel being configured with a pixel circuit and a display element connected to the pixel circuit.

[0042] In this specification and the like, the term "element" may be replaced with "device." For example, a display element, a light-emitting element, and a liquid crystal element may be replaced with, for example, a display device, a light-emitting device, and a liquid crystal device. Furthermore, in this specification and the like, the term "device" may be replaced with "element."

[0043] The display device 10 receives various signals and power supply potentials from the outside via a terminal unit 14, and can display on a display unit 15. The display device is composed of multiple layers, and each layer is provided with transistors for circuit operation or display elements that emit light. The multiple layers are provided with circuit devices such as pixel circuits that have the function of controlling the light emission of the display elements, drive circuits that have the function of controlling the pixel circuits, and functional circuits that have the function of controlling the drive circuits.

[0044] FIG. 1B is a perspective view showing a schematic configuration of the layer 11 and the layer 12. As shown in FIG.

[0045] A plurality of pixel circuits 51 are provided over the layer 12. The layer 12 includes a transistor 52 (also referred to as an OS transistor) having a metal oxide (also referred to as an oxide semiconductor) in a channel formation region 54 or a transistor 21 (also referred to as a Si transistor) having silicon in a channel formation region 22. A silicon substrate is preferably used for the layer 12 because it has higher thermal conductivity than a glass substrate.

[0046] The transistor 21 can be, for example, a transistor having single crystal silicon in a channel formation region. In particular, when a transistor having single crystal silicon in a channel formation region is used as the transistor provided in the layer 12, the on-state current of the transistor can be increased. Therefore, it is preferable because the circuit included in the layer 12 can be driven at high speed. Furthermore, by using microfabrication, the channel length of the Si transistor can be set to, for example, 3 nm to 10 nm. By using a Si transistor, the display device 10 can be provided with an accelerator such as a central processor unit (CPU) or a graphics processing unit (GPU), an application processor, or the like.

[0047] The transistor 52, which is an OS transistor, is preferably a transistor including an oxide containing at least one of indium, an element M (the element M is aluminum, gallium, yttrium, or tin), and zinc in a channel formation region. Such an OS transistor has a characteristic of extremely low off-state current. Therefore, it is preferable to use an OS transistor, particularly as a transistor provided in a pixel circuit, because analog data written to the pixel circuit can be held for a long period of time.

[0048] A layer 11 is provided on the layer 12. A plurality of display elements 61 and a plurality of elements 62 are provided on the layer 11. Pixels 63, each having the display elements 61 and the elements 62, are arranged in a matrix on the layer 11. In this embodiment, a case will be described in which one pixel 63 has six elements (three display elements 61 and three elements 62). In other words, the pixel 63 can be said to have six sub-pixels.

[0049] FIG. 1B shows an example in which one pixel 63 has three display elements 61: a display element 61R, a display element 61G, and a display element 61B.

[0050] The pixel 63 may have a plurality of display elements that emit light of different colors. For example, when the pixel 63 has three color display elements, light-emitting devices of three colors, red (R), green (G), and blue (B), or light-emitting devices of three colors, yellow (Y), cyan (C), and magenta (M), may be used.

[0051] For example, a light emitting device that emits red light can be used for the display element 61R, a light emitting device that emits green light can be used for the display element 61G, and a light emitting device that emits blue light can be used for the display element 61B.

[0052] As the display element 61, it is preferable to use an EL element such as an OLED (organic light-emitting diode) or a QLED (quantum-dot light-emitting diode). Examples of the light-emitting substance (also referred to as a light-emitting material) contained in the display element include a fluorescent substance (fluorescent material), a phosphorescent substance (phosphorescent material), an inorganic compound (such as a quantum dot material), and a substance exhibiting thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material). Note that, as the TADF material, a material in thermal equilibrium between a singlet excited state and a triplet excited state may be used. Such a TADF material has a short emission lifetime (excitation lifetime), which can suppress a decrease in efficiency in a high-brightness region of a light-emitting device.

[0053] Furthermore, an LED such as a micro LED (Light Emitting Diode) can also be used as the display element 61 .

[0054] FIG. 1B shows an example in which the pixel 63 further includes three elements 62: an element 62X_1, an element 62X_2, and an element 62X_3.

[0055] One or more types of elements can be used as the element 62. A light-emitting device or a sensor device (also called a sensor element) such as a light-receiving device (also called a light-receiving element) can be used as the element 62. Specifically, a light-emitting device that emits white light, a light-emitting device that emits yellow light, a light-emitting device that emits infrared light (including near-infrared light), a light-receiving device that detects visible light, and a light-receiving device that detects infrared light can be used as the element 62.

[0056] For example, the display device 10, or an electronic device having the display device 10, can have the function of detecting one or more of the user's blinking, movement of the pupil, and movement of the eyelids using the element 62.

[0057] By using a light-receiving device for the element 62, the display device 10 can capture images of the periphery of the eye, the surface of the eye, or the inside of the eye (such as the fundus). For example, a light-receiving device that detects infrared light can be used to detect one or more of blinking, eyelid movement, and pupil movement. A light-receiving device that detects visible light can be used for fundus diagnosis, eye strain detection, and the like. The amount of hemoglobin can be detected using either or both visible light and infrared light, and the detection accuracy can sometimes be improved by using both visible light and infrared light. These functions will be described in detail in embodiment 2.

[0058] Furthermore, for example, the display device 10 or electronic device can have the function of measuring at least one of force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, magnetism, temperature, chemical substance, time, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, physical condition, pulse, body temperature, oxygen concentration in blood, and arterial blood oxygen saturation using the element 62.

[0059] In addition, the functions possessed by the display device 10 or the electronic device include, for example, a deterioration correction function, an acceleration sensor function, an odor sensor function, a physical condition detection function, a pulse detection function, a body temperature detection function, a pulse oximeter function, or a blood oxygen concentration measurement function.

[0060] The deterioration correction function includes a function to correct deterioration of the display element 61. More specifically, if the reliability of the material used for the display element 61G is low, the element 62 can be configured to have the same structure as the display element 61G, thereby providing two display elements 61G in the pixel 63. This configuration can increase the light-emitting area of ​​the display element 61G. For example, doubling the light-emitting area of ​​the display element 61G can increase the reliability by approximately two times. Alternatively, by providing two display elements 61G in the pixel 63, if one display element 61G becomes non-emitting due to deterioration or the like, the other display element 61G may compensate for the light emission of the first display element 61G.

[0061] Although the above description has been made with respect to the display element 61G, the display element 61B and the display element 61R may also have the same configuration.

[0062] The acceleration sensor function, odor sensor function, physical condition detection function, pulse detection function, body temperature detection function, pulse oximeter function, and blood oxygen concentration measurement function can be realized by providing a sensor device required for each detection as element 62. Furthermore, it can be said that the display device 10 or the electronic device can realize various functions depending on the sensor device provided as element 62.

[0063] As described above, by providing various functions using the elements 62, a display device having the pixels 63 can be called a multi-function display device or a multi-function panel. Note that the number of functions using the elements 62 may be one or more, and the implementer can select the optimum function as appropriate.

[0064] Examples of light-receiving devices that can be used for the element 62 include pn-type and pin-type photodiodes. The light-receiving device functions as a photoelectric conversion device (also called a photoelectric conversion element) that detects light incident on the light-receiving device and generates electric charges. The amount of electric charges generated by the light-receiving device is determined based on the amount of light incident on the light-receiving device.

[0065] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light-receiving device. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of display devices.

[0066] In one embodiment of the present invention, an organic EL device is used as the light-emitting device, and an organic photodiode is used as the light-receiving device. The organic EL device and the organic photodiode can be formed on the same substrate. Therefore, the organic photodiode can be built into a display device using the organic EL device.

[0067] The display device 10 has a light-emitting device and a light-receiving device in each pixel 63. In the display device 10, the pixels 63 have a light-receiving function, so that an object can be imaged or detected while an image is displayed. For example, in addition to displaying an image using all of the display elements 61 of the display device 10, some of the display elements 61 can emit light as a light source, and the remaining display elements 61 can display an image.

[0068] The display device 10 has a display unit 15 in which light-emitting devices are arranged in a matrix, and can display images on the display unit 15. The display unit 15 also has a matrix of light-receiving devices, and the display unit has one or both of an imaging function and a sensing function in addition to an image display function. The display unit 15 can be used as an image sensor. That is, by detecting light with the display unit 15, an image can be captured, or by periodically monitoring the image, movement of an object (movement of the eyes, eyelids, or eyeballs) can be detected. Furthermore, the display device 10 can use the light-emitting devices as a light source for a sensor. Therefore, there is no need to provide a light-receiving unit and a light source separately from the display device 10, and the number of components in the electronic device can be reduced.

[0069] For example, the element 62X_1 may be a light-emitting device that emits infrared light (IR), the element 62X_2 may be a light-receiving device that detects visible light, and the element 62X_3 may be a light-receiving device that detects infrared light.

[0070] In this case, it is preferable that the element 62X_2 be able to detect light emitted by one or more of the display elements 61R, 61G, and 61B.

[0071] Furthermore, it is preferable that the element 62X_3 be able to detect the infrared light emitted by the element 62X_1.

[0072] Note that the pixel 63 is not limited to having six types of elements. For example, the element 62X_1 may be a light receiving device that detects visible light, and the elements 62X_2 and 62X_3 may be light receiving devices that detect infrared light.

[0073] In this case, it is preferable that the element 62X_1 can detect light emitted by one or more of the display elements 61R, 61G, and 61B. Furthermore, the elements 62X_2 and 62X_3 detect infrared light emitted by a light source provided separately from the display device 10.

[0074] Furthermore, the display device of one embodiment of the present invention can have a variable refresh rate. For example, the refresh rate can be adjusted (for example, adjusted within a range of 1 Hz to 240 Hz) depending on the content displayed on the display device, thereby reducing power consumption. Furthermore, the drive frequency of the light-receiving device may be changed depending on the refresh rate. For example, when the refresh rate of the display device is 120 Hz, the drive frequency of the light-receiving device can be configured to be higher than 120 Hz (typically 240 Hz). This configuration enables low power consumption and an increased response speed of the light-receiving device.

[0075] <Configuration Example 2 of Display Device> Figures 2A and 2B are modifications of the display device 10 shown in Figures 1A and 1B. Configurations that differ from the configurations shown in Figures 1A and 1B will be described below.

[0076] 2A and 2B includes a layer 11, a layer 12, and a layer 13. The layer 13 includes a driver circuit 30 and a functional circuit 40. The layer 13 includes a transistor 21 having silicon in a channel formation region 22. The layer 12 includes a transistor 52 having a metal oxide in a channel formation region 54.

[0077] The drive circuit 30 includes, for example, a gate driver circuit, a source driver circuit, etc. In addition, the drive circuit 30 may include one or more of an arithmetic circuit, a memory circuit, a power supply circuit, etc. Since the gate driver circuit, the source driver circuit, and other circuits can be arranged overlapping the display unit 15, the width of the non-display area (also called a frame) around the periphery of the display unit 15 of the display device 10 can be made extremely narrow compared to when these circuits and the display unit 15 are arranged side by side, and a compact display device 10 can be realized.

[0078] The functional circuit 40 has, for example, the function of an application processor for generating signals for controlling each circuit in the display device 10. The functional circuit 40 may also have a circuit for correcting image data, such as an accelerator, such as a CPU or GPU. The functional circuit 40 may also have an LVDS (Low Voltage Differential Signaling) circuit, a MIPI (Mobile Industry Processor Interface) circuit, and / or a D / A (Digital to Analog) conversion circuit, which function as an interface for receiving image data, etc., from outside the display device 10. The functional circuit 40 may also have a circuit for compressing and decompressing image data, and / or a power supply circuit, etc.

[0079] <Configuration Example 3 of Display Device> Figures 3A and 3B are modifications of the display device 10 shown in Figures 2A and 2B. The configurations different from those shown in Figures 2A and 2B will be described below.

[0080] 3A and 3B includes a layer 11, a layer 12, and a layer 13. A driving circuit 30 and a functional circuit 40 are provided in the layer 13. The layer 12 and the layer 13 each include a transistor 21 having silicon in a channel formation region 22.

[0081] By using Si transistors for both layers 12 and 13, it is possible to form them from the same material and in the same manufacturing process, which is preferable. Furthermore, as described above, Si transistors can increase the on-current of the transistor, making it possible to provide a display device that is compatible with high-speed operation.

[0082] <Configuration Example 4 of Display Device> Figures 4A and 4B are modifications of the display device 10 shown in Figures 3A and 3B. Configurations that differ from the configurations shown in Figures 3A and 3B will be described below.

[0083] 4A and 4B includes a layer 11, a layer 12, and a layer 13. The layer 13 includes a driver circuit 30 and a functional circuit 40. The layer 12 and the layer 13 each include a transistor 52 having a metal oxide in a channel formation region 54.

[0084] The use of OS transistors in both the layers 12 and 13 is preferable because they can be formed using the same material and the same manufacturing process. Furthermore, since the off-state current of the OS transistor can be reduced as described above, the OS transistor is preferable for a display device that requires long-term data retention, for example, because power consumption can be reduced.

[0085] Next, a specific configuration example of the drive circuit 30 and the functional circuit 40 described above will be described with reference to Fig. 5. The display device 10 shown in Fig. 5 is a block diagram illustrating pixel circuits 51, a plurality of wirings connecting the drive circuit 30 and the functional circuit 40, buses, etc.

[0086] The display device 10 of one embodiment of the present invention can have a stacked structure including the display element 61, the pixel circuit 51, the driver circuit 30, and the functional circuit 40, thereby enabling an extremely high pixel aperture ratio (effective display area ratio). For example, the pixel aperture ratio can be 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. Furthermore, the pixel circuits 51 can be arranged at extremely high density, enabling extremely high pixel resolution. For example, in the display portion of the display device 10 (a region where the pixel circuits 51 and the display element 61 are stacked), pixels can be arranged with a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and further preferably 6000 ppi or more, and 20,000 ppi or less, or 30,000 ppi or less.

[0087] Because such a display device 10 has extremely high resolution, it can be suitably used in VR devices such as head-mounted displays, or in glasses-type AR devices. For example, even in a configuration in which the display unit of the display device 10 is viewed through lenses, the display device 10 has an extremely high-resolution display unit, so even if the display unit is enlarged with lenses, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display device 10 is not limited to this, and can be suitably used in electronic devices with relatively small display units. For example, it can be suitably used in the display unit of a wearable electronic device such as a smart watch (registered trademark).

[0088] In the display device 10, when single crystal silicon is used as the material of the transistor 21, the size of the display portion 15 can be 0.1 to 5 inches diagonally, preferably 0.5 to 3 inches diagonally, and more preferably 1 to 2 inches diagonally. In the display device 10 of one embodiment of the present invention, the width of the frame can be made extremely narrow. Therefore, for example, when the diagonal size of the layer 12 is 1 inch, about four times the amount of light can be extracted compared to a diagonal size of 0.5 inches, which is preferable.

[0089] In the display device 10 shown in Fig. 5, the layer 12 has a plurality of pixel circuits 51 arranged in a matrix. In the display device 10 shown in Fig. 5, the layer 13 has a drive circuit 30 and a function circuit 40 arranged therein. The drive circuit 30 includes, for example, a source driver circuit 31, a digital-to-analog conversion circuit 32, a gate driver circuit 33, and a level shifter 34. The function circuit 40 includes, for example, a memory device 41, a GPU 42 (AI accelerator), an EL correction circuit 43, a timing controller 44, a CPU 45, a sensor controller 46, and a power supply circuit 47. The function circuit 40 has the function of an application processor.

[0090] In addition, in the display device 10 of FIG. 5, the circuits included in the drive circuit 30 and the circuits included in the function circuit 40 are electrically connected to bus lines BSL, as an example.

[0091] For example, the source driver circuit 31 has a function of transmitting image data to the pixel circuits 51. For this reason, the source driver circuit 31 is electrically connected to the pixel circuits 51 via the wirings SL.

[0092] For example, the digital-analog conversion circuit 32 has a function of converting image data that has been digitally processed by a GPU, a correction circuit, etc. into analog data. The image data converted into analog data is transmitted to the pixel circuits 51 via the source driver circuit 31. Note that the digital-analog conversion circuit 32 may be included in the source driver circuit 31, or the image data may be transmitted in the order of the source driver circuit 31, the digital-analog conversion circuit 32, and the pixel circuits 51.

[0093] For example, the gate driver circuit 33 has a function of selecting a pixel circuit to which image data is to be sent among the pixel circuits 51. Therefore, the gate driver circuit 33 is electrically connected to the pixel circuit 51 via a wiring GL.

[0094] The level shifter 34 has a function of converting signals input to the source driver circuit 31, the digital-to-analog conversion circuit 32, the gate driver circuit 33, etc., to appropriate levels, for example.

[0095] For example, the storage device 41 has a function of storing image data to be displayed on the pixel circuits 51. The storage device 41 can be configured to store the image data as digital data or analog data.

[0096] Furthermore, when image data is stored in the storage device 41, it is preferable to use a nonvolatile memory as the storage device 41. In this case, for example, a NAND type memory or the like can be used as the storage device 41.

[0097] Furthermore, when temporary data generated by the GPU 42, the EL correction circuit 43, the CPU 45, etc. is stored in the storage device 41, it is preferable to use a volatile memory as the storage device 41. In this case, for example, an SRAM (Static Random Access Memory), a DRAM (Dynamic Random Access Memory), etc. can be used as the storage device 41.

[0098] As an example, the GPU 42 has a function of performing processing to output image data read from the storage device 41 to the pixel circuit 51. In particular, the GPU 42 is configured to perform pipeline processing in parallel, and therefore can quickly process image data to be output to the pixel circuit 51. The GPU 42 can also have a function as a decoder for restoring encoded images.

[0099] The functional circuit 40 may also include a plurality of circuits capable of improving the display quality of the display device 10. For example, such circuits may include a correction circuit (color adjustment, dimming) that detects color unevenness in the displayed image and corrects the color unevenness to produce an optimal image. Furthermore, when a light-emitting device using an organic EL is used as the display element, the functional circuit 40 may also include an EL correction circuit. As an example, the functional circuit 40 includes an EL correction circuit 43.

[0100] Furthermore, artificial intelligence may be used for the image correction described above. For example, the current flowing through the pixel circuit (or the voltage applied to the pixel circuit) may be monitored and acquired, and the displayed image may be acquired by an image sensor or the like, and the current (or voltage) and the image may be treated as input data for an artificial intelligence calculation (e.g., an artificial neural network), and the output result may be used to determine whether or not the image should be corrected.

[0101] Furthermore, the AI ​​calculations can be applied not only to image correction but also to up-conversion (down-conversion) of image data. As an example, the GPU 42 shown in FIG. 6 is a block for performing various correction calculations (color shading correction 42a, up-conversion 42b, etc.).

[0102] For example, the timing controller 44 has a function of varying the frame rate at which images are displayed. For example, when a still image is displayed on the display device 10, the timing controller 44 can drive the display device 10 at a lower frame rate, and when a moving image is displayed on the display device 10, the timing controller 44 can drive the display device 10 at an increased frame rate.

[0103] The CPU 45 has a function of performing general-purpose processing, such as executing an operating system, controlling data, and executing various calculations and programs. The CPU 45 has a role of issuing commands such as writing or reading image data to or from the storage device 41, correcting image data, and operating a sensor (described later). The CPU 45 may also have a function of transmitting a control signal to at least one of the circuits included in the functional circuit 40.

[0104] The sensor controller 46 has a function of controlling the sensor, for example. In addition, in Fig. 5, a wiring SNCL is illustrated as a wiring for electrically connecting to the sensor.

[0105] The sensor may be, for example, a touch sensor that can be provided in the display unit, or may be, for example, an illuminance sensor.

[0106] For example, the power supply circuit 47 has a function of generating voltages to be supplied to the pixel circuits 51, the drive circuit 30, and the circuits included in the functional circuit 40. The power supply circuit 47 may also have a function of selecting the circuits to which the voltage is supplied. For example, the power supply circuit 47 can reduce the power consumption of the entire display device 10 by stopping the voltage supply to the CPU 45, the GPU 42, etc. during the period when a still image is being displayed.

[0107] As described above, the display device of one embodiment of the present invention can have a stacked structure of a light-emitting device, a sensor device, and circuit devices (such as a pixel circuit, a driver circuit, and a functional circuit). Peripheral circuits, such as a driver circuit and a functional circuit, can be arranged to overlap with the pixel circuit, thereby significantly narrowing the frame width, thereby enabling a miniaturized display device. Furthermore, the display device of one embodiment of the present invention can be lightweight because the wiring connecting the circuits can be shortened by stacking the circuits. Furthermore, the display device of one embodiment of the present invention can have a display portion with improved pixel resolution, thereby enabling a display device with excellent display quality.

[0108] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be appropriately combined with other configuration examples or drawings.

[0109] Embodiment 2 In this embodiment, a display device according to one embodiment of the present invention will be described with reference to drawings.

[0110] 6A is a schematic cross-sectional view showing the positional relationship between the display device 980 and the user's eyes. The display device 980 has a plurality of light-emitting devices and a plurality of sensor devices.

[0111] Light emitted from a light-emitting device included in the display device 980 is irradiated onto the eye via an optical system 950, and the light reflected by the eye is received by a sensor device. The display device 980 can capture images of the periphery of the eye, the surface of the eye, or the inside of the eye (such as the fundus).

[0112] For example, the display device 980 shown in Fig. 6A has a light-emitting device and a sensor device, and therefore can capture an image of the fundus via the optical system 950 to obtain image data of the retinal pattern. However, when the focus is adjusted by the optical system 950, it becomes difficult to capture images of other areas. For example, when the focus is set on the fundus, the periphery of the eye is out of focus, making it almost impossible to capture images of the area.

[0113] A display device according to one embodiment of the present invention includes a light-emitting device and a light-receiving device in each pixel. Since the pixel in the display device according to one embodiment of the present invention has a light-receiving function, it is possible to detect contact or proximity of an object while displaying an image. For example, the display device can not only display an image using subpixels, but also display an image using some of the subpixels that emit light as a light source and other subpixels that detect light.

[0114] Furthermore, in a display device according to one embodiment of the present invention, light-emitting devices are arranged in a matrix in a display portion, and an image can be displayed on the display portion. Furthermore, light-receiving devices are arranged in a matrix in the display portion, and the display portion has one or both of an imaging function and a sensing function in addition to an image display function. The display portion can be used as an image sensor. That is, an image can be captured by detecting light in the display portion, or the movement of an object (movement of an eye, eyelid, or eyeball) can be detected by periodically monitoring the image. Furthermore, the display device according to one embodiment of the present invention can use a light-emitting device as a light source for a sensor. Therefore, a light-receiving portion and a light source are not required separately from the display device, and the number of components in an electronic device can be reduced.

[0115] First, a method for detecting the blinking and eyelid movements of a user will be described below with reference to FIGS. 6A and 6B.

[0116] <Blinking / Eyelid Movement> Near-infrared light is emitted from the display device 980. This near-infrared light is irradiated onto the user's eyes or the vicinity of the user's eyes through the optical system 950. The reflected light passes through the optical system 950 again and is incident on the display device 980. This makes it possible to detect the state of the object.

[0117] 6B is a schematic diagram illustrating the user's eyes and the vicinity of the user's eyes. Fig. 6B shows the user's eyebrows 960, the user's eyelids (upper eyelid 966 and lower eyelid 967), the user's eyelashes 961, the user's pupils 962, the user's cornea 963, and the user's sclera 965. The display device 980 has a function of detecting one or more selected from the user's eyebrows 960, the user's eyelids (upper eyelid 966 and lower eyelid 967), the user's eyelashes 961, the user's pupils 962, the user's cornea 963, and the user's sclera 965 shown in Fig. 6B.

[0118] For example, a display device according to one embodiment of the present invention can detect the state of the user's eyes or the vicinity of the user's eyes shown in FIG. 6B using the display device 980. For example, when the user closes their eyelids (upper eyelid 966 and lower eyelid 967), near-infrared light is irradiated onto the surface of the eyelids, i.e., onto the skin. When the eyelids are open, near-infrared light is irradiated onto the surface of the eyeball. Since the reflectance of the skin and the surface of the eyeball differs, the intensity of the reflected near-infrared light differs. By continuously monitoring this state, the display device 980 can detect either or both of the number of blinks and the time required for one blink.

[0119] When viewing a display for a long period of time, the number of times a person blinks may decrease. Also, when a user becomes tired, the interval between blinks may become longer and the duration of each blink may become longer.

[0120] In the display device of one embodiment of the present invention, the degree of fatigue of a user can be estimated from one or both of the number of blinks of the user per unit time and the time taken for one blink.

[0121] <Movement of the pupil> When a circular spot of infrared light is irradiated onto the boundary region between the cornea (e.g., cornea 963 shown in FIG. 6B ) and the sclera (e.g., sclera 965 shown in FIG. 6B ), the ratio of the area covering the cornea to the area covering the sclera changes as the eyeball moves within the irradiation range of the infrared light spot. Because the reflectance from the area covering the sclera is overwhelmingly greater than that from the area covering the cornea, the amount of reflected light changes as the eyeball moves. By measuring this change, it becomes possible to detect the direction in which the user is looking.

[0122] <Scleral Reflection Method> Next, the scleral reflection method will be described. Near-infrared light is emitted from the display device 980. This near-infrared light is irradiated onto the user's eyes through the optical system 950. The light reflected from the eyes passes through the optical system 950 again and enters the display device 980. This makes it possible to detect the state of an object. When viewing a displayed image, the gaze shifts when viewing a fast-moving object. When the gaze shifts, the eyeball moves. When the eyeball moves, the ratio of the area irradiated with infrared light that covers the cornea to the area that covers the sclera changes, so it is possible to monitor the reflected light component and detect the movement of the eyeball. That is, the display device of one embodiment of the present invention has an eye tracking function.

[0123] By detecting the user's line of sight using eye tracking, it is possible to estimate the area the user is gazing at. Then, by using variable rate shading to reduce the resolution of areas other than the area the user is gazing at, it is possible to reduce the amount of calculations performed by the display device 980 and provide a display device with reduced power consumption.

[0124] In the display device of one embodiment of the present invention, the display device 980 includes both a light-emitting device and a sensor device, which makes it possible to reduce the number of components.

[0125] Next, fundus diagnosis of the user's eye will be described with reference to FIGS. 6A and 6C.

[0126] <Fundus Diagnosis> As shown in FIG. 6A , the user's eye is composed of a lens 942, a retina 941, an optic nerve 943, a vitreous body 947, a choroid 948, and a cornea. Note that the pupil is located between the cornea and the lens, but for simplicity, the cornea and pupil are not shown. The ciliary body is a tissue that continues from the iris, and the choroid 948 is a tissue that continues from the ciliary body. The iris and pupil adjust the light that is irradiated onto the retina 941, like the aperture of a camera. The pattern of the retina 941, known as the retinal pattern, is said to basically remain unchanged from birth to death, and the retinal pattern can be used for personal authentication, etc. The retinal pattern obtained by the display device 980 can be used to perform eye diagnoses even in remote locations.

[0127] By adjusting the optical system 950, the display device 980 has a function of detecting one or more of the user's blinking, movement of the pupil, and movement of the eyelids, without focusing on the fundus. In other words, the display device 980 has a function of detecting eye strain.

[0128] Next, Figure 6C shows an example of a retinal pattern of a right eye obtained by imaging using the display device of one embodiment of the present invention. An optic disc 944, a vein 945, an artery 946, a macula, a fovea, and the like can be observed in the retina 941. Note that in Figure 6C, the vein 945 is indicated by a thicker solid line than the artery 946 to facilitate distinction between the vein 945 and the artery 946. The optic disc 944 refers to the boundary between the optic nerve 943 and the retina 941, and the vein 945 or the artery 946 is disposed so as to extend from the optic disc 944. Note that the fundus refers to the part behind the eyeball and collectively refers to the retina 941, the vitreous body 947, the choroid 948, the optic disc 944, and the like. Note that in the case of the left eye, the optic disc 944 is located on the left side of the retinal pattern, resulting in a retinal pattern that is a mirror image of the retinal pattern of the right eye shown in Figure 6C.

[0129] In order to acquire the retinal pattern of the fundus using the sensor device of the display device 980, the pupil needs to be dilated. In order to dilate the pupil and capture an image of the fundus, the display is changed in the following procedure: The display screen of the display device 980 is gradually darkened to allow the user's eyes to dark adapt; the display screen is brightened for a short period of time, not longer than 16.7 ms, and then the image is captured; after that, the display screen is gradually returned to its original brightness.

[0130] The degree of eye fatigue of the user can also be detected using the display device 980. When the display screen is brightened for a certain period of time and an image is taken, if the user blinks, the eyes cannot be photographed. Therefore, by detecting the number of blinks, the timing, or the length of time the eyes are closed, the degree of eye fatigue can be estimated using a system using AI (Artificial Intelligence) based on the number of blinks, the interval between blinks, the length of time the eyes are closed, etc.

[0131] Additionally, while the display screen of the display device 980 is darkened, multiple images may be taken to detect the user's eye fatigue level. By taking multiple images, the pulsation of retinal blood vessels can be detected, and the user's state of rest or tension can be determined using an AI-based system. Furthermore, various data obtained by the display device 980 can be used to diagnose high blood pressure or diabetes using an AI-based system. When using an AI-based system, a control circuit is installed in the display device 980. The control circuit uses a CPU or GPU. Alternatively, the control circuit can use an APU (Accelerated Processing Unit), which is a chip that integrates a CPU and a GPU. Alternatively, an IC (also called an inference chip) incorporating an AI system may be used. An IC incorporating an AI system is sometimes called a circuit (microprocessor) that performs neural network calculations.

[0132] Furthermore, the orientation of the eyeballs may be controlled by displaying an easily noticeable pattern on the screen of the display device 980 while the display screen of the display device 980 is dark.

[0133] The distance between the display device 980 and the surface of the eye (e.g., the cornea) is preferably 5 cm or less, and more preferably 2 cm or less. To achieve this positional relationship, an optical system 950 with a short focal length is placed between the display device 980 and the eye.

[0134] When the screen is magnified 10 times by the optical system 950, for example, if the display screen of the display device 980 has a diagonal size of about 1 inch and a resolution (definition) of about 2450 ppi, the pitch of the sensor pixels is about 10.4 μm. Since the diameter of each of the retinal veins 945 and arteries 946 is smaller than about 100 μm, they can be imaged using the display device 980.

[0135] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0136] Embodiment Mode 3 In this embodiment mode, a configuration example of a pixel circuit applicable to the pixel circuit 51 and an example of a driving method will be described.

[0137] 7A illustrates a pixel circuit 51A including a transistor 52A, a transistor 52B, and a capacitor 53. 7A also illustrates a display element 61 connected to the pixel circuit 51A. The pixel circuit PIX1 is electrically connected to a wiring SL, a wiring GL, a wiring ANO, and a wiring VCOM.

[0138] The transistor 52A has a gate electrically connected to a wiring GL, one of its source and drain electrically connected to a wiring SL, and the other electrically connected to the gate of the transistor 52B and one electrode of the capacitor C1. The transistor 52B has one of its source and drain electrically connected to a wiring ANO, and the other electrically connected to an anode of the display element 61. The capacitor C1 has the other electrode electrically connected to the anode of the display element 61. The display element 61 has a cathode electrically connected to a wiring VCOM.

[0139] 7B is configured by adding a transistor 52C to the pixel circuit 51A. A wiring V0 is electrically connected to the pixel circuit 51B.

[0140] A pixel circuit 51C shown in FIG. 7C is an example in which transistors having a pair of gates electrically connected are used as the transistors 52A and 52B of the pixel circuit 51A. A pixel circuit 51D shown in FIG. 7D is an example in which the same transistors are used as the pixel circuit 51B. This can increase the current that the transistors can pass. Note that, although transistors having a pair of gates electrically connected are used for all the transistors here, this is not a limitation. Alternatively, a transistor having a pair of gates electrically connected to different wirings may be used. For example, reliability can be improved by using a transistor in which one of the gates is electrically connected to a source.

[0141] 8A has a configuration in which a transistor 52D is added to the pixel circuit 51B. The pixel circuit 51E is electrically connected to three wirings (a wiring GL1, a wiring GL2, and a wiring GL3) that function as gate lines.

[0142] The gate of the transistor 52D is electrically connected to a wiring GL3, one of the source and drain of the transistor 52D is electrically connected to the gate of the transistor 52B, and the other is electrically connected to a wiring V0. The gate of the transistor 52A is electrically connected to a wiring GL1, and the gate of the transistor 52C is electrically connected to a wiring GL2.

[0143] By simultaneously turning on the transistors 52C and 52D, the source and gate of the transistor 52B have the same potential, and the transistor 52B can be turned off. This forcibly cuts off the current flowing through the display element 61. Such a pixel circuit is suitable for use in a display method in which display periods and off periods are alternately provided.

[0144] 8B is an example in which a capacitor 53A is added to the pixel circuit 51E. The capacitor 53A functions as a storage capacitor.

[0145] 8C and 8D are examples in which transistors each having a pair of gates are applied to the pixel circuit 51E or 51F. Transistors 52A, 52C, and 52D have a pair of gates electrically connected to each other, and transistor 52B has one gate electrically connected to its source.

[0146] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0147] Embodiment 4 In this embodiment, a display device according to one embodiment of the present invention will be described with reference to FIGS.

[0148] The display device of the present embodiment can be a high-definition display device, and therefore can be used as a display unit of a wearable device that can be worn on the head, such as a wristwatch-type or bracelet-type information terminal (wearable device), a head-mounted display or other VR device, or a glasses-type AR device.

[0149] 9A shows a perspective view of a display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, and may be any of the display devices 100B to 100E described below.

[0150] The display module 280 has a substrate 291 and a substrate 292. The display module 280 has a display unit 281. The display unit 281 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in a pixel unit 284 (described later) can be viewed.

[0151] 9B is a perspective view schematically illustrating the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 for connecting to the FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0152] The pixel section 284 has a plurality of periodically arranged pixels 284a. An enlarged view of one pixel 284a is shown on the right side of FIG. 9B . The pixel 284a has six elements. The pixel 284a has light-emitting devices 130a, 130b, and 130c that emit light of different colors. The pixel 284a further has elements 130d, 130e, and 130f. The elements 130d, 130e, and 130f correspond to the element 62 described in the first embodiment, and may be, for example, a light-emitting device or a sensor device. Note that the number of elements included in one pixel and the arrangement method thereof are not particularly limited.

[0153] Note that pixel 284a is composed of six subpixels. It is extremely difficult to achieve a high aperture ratio in a pixel having many subpixels. It is also difficult to realize a high-resolution display device using a pixel having many subpixels. Therefore, in a manufacturing method of a display device according to one embodiment of the present invention, the island-shaped EL layer is formed by forming the EL layer on the entire surface and then processing it, rather than by using a metal mask having a fine pattern. This makes it possible to realize a high-resolution display device or a display device with a high aperture ratio, which has been difficult to achieve until now. Furthermore, since the EL layer can be formed separately for each color, a display device with extremely vivid images, high contrast, and high display quality can be realized. Furthermore, a high-resolution display device or a display device with a high aperture ratio that has a built-in light-receiving device and a light detection function can be realized.

[0154] For example, island-shaped light-emitting layers can be formed by vacuum deposition using a metal mask (also called a shadow mask). However, with this method, deviations in the shape and position of the island-shaped light-emitting layers from the design occur due to various factors, such as the accuracy of the metal mask, misalignment between the metal mask and the substrate, deflection of the metal mask, and the spread of the contours of the formed film due to vapor scattering, making it difficult to achieve high-definition displays and high aperture ratios.

[0155] In a manufacturing method of a display device according to one embodiment of the present invention, an island-shaped pixel electrode (which can also be referred to as a lower electrode) is formed, a first layer (which can be referred to as an EL layer or a part of an EL layer) including a light-emitting layer that emits light of a first color is formed on the entire surface, and then the first layer is processed to form the island-shaped first layer. Subsequently, a second layer (which can be referred to as an EL layer or a part of an EL layer) including a light-emitting layer that emits light of a second color is formed on the entire surface in the same manner as the first layer, and the second layer is processed to form the island-shaped second layer.

[0156] Regarding the spacing between adjacent light-emitting devices, it is difficult to make it less than 10 μm using a formation method that uses a metal mask, for example, but with the above method, it is possible to narrow it to 3 μm or less, 2 μm or less, or even 1 μm or less.

[0157] Furthermore, the pattern of the EL layer itself (also known as the processing size) can be made much smaller than when a metal mask is used. Furthermore, for example, when a metal mask is used to separately fabricate an EL layer, thickness variations occur between the center and edges of the EL layer, resulting in a smaller effective area that can be used as a light-emitting region relative to the area of ​​the EL layer. On the other hand, with the above-described fabrication method, the EL layer is formed by processing a film formed to a uniform thickness, so the thickness can be made uniform within the EL layer, and even with a fine pattern, almost the entire area can be used as a light-emitting region. Therefore, a display device that combines high definition and a high aperture ratio can be fabricated.

[0158] Here, the first layer and the second layer each include at least a light-emitting layer, and preferably consist of multiple layers. Specifically, it is preferable to have one or more layers on the light-emitting layer. By having another layer between the light-emitting layer and the sacrificial layer, it is possible to prevent the light-emitting layer from being exposed to the outermost surface during the manufacturing process of the display device, thereby reducing damage to the light-emitting layer. This can improve the reliability of the light-emitting device.

[0159] In the light-emitting devices emitting light of different colors, it is not necessary to separately form all layers constituting the EL layer, and some layers can be formed in the same process. In a manufacturing method of a display device according to one embodiment of the present invention, some layers constituting the EL layer are formed in an island shape for each color, and then the remaining layers constituting the EL layer (for example, a carrier injection layer) and a common electrode (which can also be referred to as an upper electrode) are formed in common to the light-emitting devices of each color.

[0160] The same manufacturing method as for light-emitting devices can be applied to sensor devices such as light-receiving devices. The island-shaped active layer (also called photoelectric conversion layer) of a light-receiving device is formed by depositing a film that will become the active layer on the entire surface and then processing it, rather than by using a metal mask with a fine pattern, so that the island-shaped active layer can be formed with a uniform thickness.

[0161] In the pixel of the display device of this embodiment, the subpixel having the light-emitting device or the light-receiving device may have a light-emitting region or a light-receiving region each having a side of 1 μm to 10 μm, and the pixel may have a region in which the distance between two adjacent subpixels is less than 1 μm.

[0162] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0163] One pixel circuit 283a controls the driving of multiple elements included in one pixel 284a. One pixel circuit 283a may be configured to have six circuits for controlling the driving of elements. For example, the pixel circuit 283a may be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitor element per light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to either the source or the drain. This realizes an active matrix display device.

[0164] The circuit portion 282 includes a circuit for driving each pixel circuit 283 a of the pixel circuit portion 283. For example, it is preferable that the circuit portion 282 includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0165] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit portion 282. An IC may be mounted on the FPC 290.

[0166] The display module 280 can be configured such that one or both of the pixel circuit unit 283 and the circuit unit 282 are provided overlapping the pixel unit 284, thereby enabling the aperture ratio (effective display area ratio) of the display unit 281 to be extremely high. For example, the aperture ratio of the display unit 281 can be 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. Furthermore, the pixels 284a can be arranged at an extremely high density, enabling the resolution of the display unit 281 to be extremely high. For example, it is preferable that the pixels 284a be arranged in the display unit 281 at a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and 20,000 ppi or less, or 30,000 ppi or less.

[0167] Because such a display module 280 has extremely high resolution, it can be suitably used in VR devices such as head-mounted displays, or in glasses-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display unit 281, so even when the display unit is enlarged with lenses, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display units. For example, it can be suitably used in the display unit of a wearable electronic device such as a wristwatch.

[0168] [Display Device 100A] A display device 100A shown in FIG. 10A includes a substrate 301, light-emitting devices 130a, 130b, and 130c, a capacitor 240, and a transistor 310.

[0169] Substrate 301 corresponds to substrate 291 in FIGS. 9A and 9B.

[0170] The transistor 310 has a channel formation region in a substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single crystal silicon substrate. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as one of a source and a drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311.

[0171] An element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0172] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided over the insulating layer 261 .

[0173] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located therebetween.

[0174] The conductive layer 241 is provided over the insulating layer 261 and is buried in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain of the transistor 310 by a plug 271 buried in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0175] An insulating layer 255a is provided to cover the capacitor 240, and an insulating layer 255b is provided on the insulating layer 255a.

[0176] The insulating layer 255a and the insulating layer 255b can be formed using various inorganic insulating films such as an insulating oxide film, an insulating nitride film, an oxynitride insulating film, and an insulating nitride oxide film. The insulating layer 255a is preferably formed using an oxide insulating film or an oxynitride insulating film such as a silicon oxide film, a silicon oxynitride film, or an aluminum oxide film. The insulating layer 255b is preferably formed using a nitride insulating film or a nitride oxide insulating film such as a silicon nitride film or a silicon nitride oxide film. More specifically, the insulating layer 255a is preferably formed using a silicon oxide film, and the insulating layer 255b is preferably formed using a silicon nitride film. The insulating layer 255b preferably functions as an etching protective film. Alternatively, the insulating layer 255a may be formed using a nitride insulating film or a nitride oxide insulating film, and the insulating layer 255b may be formed using an oxide insulating film or an oxynitride insulating film. Although this embodiment shows an example in which a recess is provided in the insulating layer 255b, the insulating layer 255b does not necessarily have a recess.

[0177] Light-emitting devices 130a, 130b, and 130c are provided on insulating layer 255b. An insulator is provided in the region between adjacent light-emitting devices. In Fig. 10A and other figures, insulating layer 125 and insulating layer 127 on insulating layer 125 are provided in this region.

[0178] In this embodiment, an example is shown in which the display device is a top emission type that emits light in a direction opposite to the substrate on which the light emitting device is formed. Note that the display device may be a bottom emission type that emits light toward the substrate on which the light emitting device is formed, or a dual emission type that emits light from both sides.

[0179] The light-emitting devices 130a, 130b, and 130c each emit light of a different color. In this embodiment, an example is shown in which the light-emitting devices 130a, 130b, and 130c emit light of three colors: red (R), green (G), and blue (B).

[0180] A light-emitting device has an EL layer between a pair of electrodes. In this specification and the like, one of the pair of electrodes may be referred to as a pixel electrode, and the other as a common electrode. Of the pair of electrodes that a light-emitting device has, one electrode functions as an anode, and the other electrode functions as a cathode. In the following, an example will be described in which the pixel electrode functions as an anode and the common electrode functions as a cathode.

[0181] The light-emitting device 130a has a pixel electrode 111a on an insulating layer 255b, an island-shaped first layer 113a on the pixel electrode 111a, a fourth layer 114 on the island-shaped first layer 113a, and a common electrode 115 on the fourth layer 114. In the light-emitting device 130a, the first layer 113a and the fourth layer 114 can be collectively referred to as an EL layer.

[0182] The light-emitting device 130b includes a pixel electrode 111b, a second layer 113b, a fourth layer 114, and a common electrode 115. The light-emitting device 130c includes a pixel electrode 111c, a third layer 113c, a fourth layer 114, and a common electrode 115.

[0183] When the light-emitting device is observed in cross section, the side surface of the lower electrode (pixel electrode) and the side surface of the light-emitting layer have a region where they coincide or approximately coincide. In addition, when viewed from above, it can also be said that the top surface shape of the lower electrode and the top surface shape of the light-emitting layer coincide or approximately coincide.

[0184] In this specification, the phrase "top surface shapes generally match" refers to the overlap of at least a portion of the contours between stacked layers. For example, this includes cases where the upper and lower layers are processed using the same mask pattern or a portion of the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or outside the lower layer. In these cases, the phrase "top surface shapes generally match" also applies.

[0185] The light-emitting devices of each color share the same film as a common electrode. The common electrode 115 shared by the light-emitting devices of each color is electrically connected to a conductive layer 123 provided in the connection portion 140 shown in Fig. 10B. The conductive layer 123 is electrically connected to wiring provided below it via a plug 256.

[0186] The pixel electrode of the light-emitting device is electrically connected to one of the source and drain of the transistor 310 via a plug 256 embedded in the insulating layers 255a and 255b, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. The height of the top surface of the insulating layer 255b and the height of the top surface of the plug 256 are the same or approximately the same. Various conductive materials can be used for the plug.

[0187] In this specification, the phrase "the height of A and the height of B are the same or approximately the same" includes the case where the height of A and the height of B are the same, and also the case where a difference occurs between the height of A and the height of B due to a manufacturing error when the heights of A and B are made to be the same.

[0188] For example, an insulating layer 261 is formed, an opening is provided in the insulating layer 261, a conductive layer that will become the plug 271 is formed so as to fill the opening, and then a planarization process is performed using a chemical mechanical polishing (CMP) method or the like. This makes it possible to realize a configuration in which the height of the upper surface of the plug 271 and the height of the upper surface of the insulating layer 261 are the same or approximately the same.

[0189] Of the pixel electrode and common electrode, the electrode from which light is extracted uses a conductive film that transmits visible light. It is preferable to use a conductive film that reflects visible light for the electrode from which light is not extracted. It is preferable to apply a micro-optical resonator (microcavity) structure by using an electrode (semi-transmissive / semi-reflective electrode) that is transparent and reflective to visible light for the electrode from which light is extracted. This allows the light emitted from the light-emitting layer to resonate between the two electrodes, thereby intensifying the light emitted from the light-emitting device. The semi-transmissive / semi-reflective electrode can have a laminated structure of a reflective electrode and an electrode (also called a transparent electrode) that is transparent to visible light.

[0190] The first layer 113a, the second layer 113b, and the third layer 113c are preferably each provided in an island shape and each have a light-emitting layer that emits light of a different color. The light-emitting layer can contain one or more light-emitting substances. Examples of the light-emitting substance include substances that emit visible light such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red, and substances that emit invisible light such as near-infrared light.

[0191] Examples of the light-emitting material include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0192] The first layer 113 a, the second layer 113 b, and the third layer 113 c may further include, as a layer other than the light-emitting layer, a layer containing a substance with high hole-injection properties, a substance with high hole-transport properties (also referred to as a hole-transport material), a hole-blocking material, a substance with high electron-transport properties (also referred to as an electron-transport material), a substance with high electron-injection properties, an electron-blocking material, a bipolar substance (a substance with high electron-transport properties and high hole-transport properties, also referred to as a bipolar material), or the like.

[0193] The light-emitting device can be made of either a low-molecular-weight compound or a high-molecular-weight compound, and may contain an inorganic compound. The layers constituting the light-emitting device can be formed by a method such as vapor deposition (including vacuum vapor deposition), transfer, printing, inkjet printing, or coating.

[0194] For example, the first layer 113a, the second layer 113b, and the third layer 113c may each have one or more of 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.

[0195] The EL layer may include one or more of 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, as layers commonly formed in the light-emitting devices of each color. For example, a carrier injection layer (hole injection layer or electron injection layer) may be formed as the fourth layer 114. It is also possible to form all layers of the EL layer separately for each color. In other words, the EL layer does not need to include a layer commonly formed in the light-emitting devices of each color.

[0196] Each of the first layer 113a, the second layer 113b, and the third layer 113c preferably includes a light-emitting layer and a carrier transport layer on the light-emitting layer. This prevents the light-emitting layer from being exposed to the outermost surface during the manufacturing process of the display device, thereby reducing damage to the light-emitting layer. This improves the reliability of the light-emitting device.

[0197] In addition, when a light-emitting device with a tandem structure is fabricated, an intermediate layer is provided between the two light-emitting units. The intermediate layer has the function of injecting electrons into one of the two light-emitting units and holes into the other when a voltage is applied between a pair of electrodes. The intermediate layer can also be called a charge-generating layer.

[0198] The side surfaces of the pixel electrodes 111a, 111b, and 111c, the first layer 113a, the second layer 113b, and the third layer 113c are respectively covered with insulating layers 125 and 127. A fourth layer 114 is provided on the first layer 113a, the second layer 113b, the third layer 113c, and the insulating layers 125 and 127, and a common electrode 115 is provided on the fourth layer 114.

[0199] This prevents the fourth layer 114 (or the common electrode 115) from coming into contact with any of the side surfaces of the pixel electrodes 111a, 111b, 111c, the first layer 113a, the second layer 113b, and the third layer 113c, thereby preventing short circuits in the light-emitting device.

[0200] The insulating layer 125 preferably covers at least the side surfaces of the pixel electrodes 111a, 111b, and 111c. Furthermore, the insulating layer 125 preferably covers the side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c. The insulating layer 125 can be configured to be in contact with the side surfaces of the pixel electrodes 111a, 111b, and 111c, the first layer 113a, the second layer 113b, and the third layer 113c.

[0201] The insulating layer 127 is provided on the insulating layer 125 so as to fill recesses formed in the insulating layer 125. The insulating layer 127 can be configured to overlap with the side surfaces of the pixel electrodes 111a, 111b, and 111c, the first layer 113a, the second layer 113b, and the third layer 113c, with the insulating layer 125 interposed therebetween.

[0202] Note that either the insulating layer 125 or the insulating layer 127 may not be provided. FIG. 10C shows an example in which the insulating layer 125 is not provided. When the insulating layer 125 is not provided, the insulating layer 127 may be in contact with the side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c. The display device may also have an insulating layer that covers an edge of the pixel electrode. In this case, one or both of the insulating layer 125 and the insulating layer 127 may be provided on the insulating layer.

[0203] The fourth layer 114 and the common electrode 115 are provided over the first layer 113a, the second layer 113b, the third layer 113c, the insulating layer 125, and the insulating layer 127. Before the insulating layer 125 and the insulating layer 127 are provided, a step is generated between a region where the pixel electrode and the EL layer are provided and a region where the pixel electrode and the EL layer are not provided (a region between light-emitting devices). In the display device of one embodiment of the present invention, the insulating layer 125 and the insulating layer 127 can flatten the step, thereby improving the coverage of the fourth layer 114 and the common electrode 115. Therefore, poor connection due to a step can be suppressed. Alternatively, an increase in electrical resistance caused by a local thinning of the common electrode 115 due to the step can be suppressed.

[0204] In order to improve the flatness of the surfaces on which the fourth layer 114 and the common electrode 115 are formed, it is preferable that the heights of the upper surfaces of the insulating layers 125 and 127 are the same or approximately the same as the heights of the upper surfaces of at least one of the first layer 113a, the second layer 113b, and the third layer 113c. The upper surface of the insulating layer 127 preferably has a flat shape, and may have protrusions or recesses.

[0205] The insulating layer 125 has regions in contact with side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c, and functions as a protective insulating layer for the first layer 113a, the second layer 113b, and the third layer 113c. By providing the insulating layer 125, impurities (oxygen, moisture, and the like) can be prevented from entering the inside from the side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c, thereby providing a highly reliable display device.

[0206] If the width (thickness) of the insulating layer 125 in the region in contact with the side surfaces of the first layer 113 a, the second layer 113 b, and the third layer 113 c is large in a cross-sectional view, the distance between the first layer 113 a, the second layer 113 b, and the third layer 113 c may become large, resulting in a low aperture ratio. Also, if the width (thickness) of the insulating layer 125 is small, the effect of suppressing impurities from penetrating into the interior from the side surfaces of the first layer 113 a, the second layer 113 b, and the third layer 113 c may become small. The width (thickness) of the insulating layer 125 in regions in contact with the side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c is preferably 3 nm to 200 nm, more preferably 3 nm to 150 nm, further preferably 5 nm to 150 nm, further preferably 5 nm to 100 nm, further preferably 10 nm to 100 nm, and further preferably 10 nm to 50 nm. By setting the width (thickness) of the insulating layer 125 in the above range, a display device having a high aperture ratio and high reliability can be obtained.

[0207] The insulating layer 125 can be an insulating layer containing an inorganic material. For example, an inorganic insulating film such as an insulating oxide film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film can be used for the insulating layer 125. The insulating layer 125 may have a single-layer structure or a stacked-layer structure. Examples of oxide insulating films include a silicon oxide film, an aluminum oxide film, a magnesium oxide film, an indium gallium zinc oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of nitride insulating films include a silicon nitride film and an aluminum nitride film. Examples of oxynitride insulating films include a silicon oxynitride film and an aluminum oxynitride film. Examples of nitride oxide insulating films include a silicon nitride oxide film and an aluminum nitride oxide film. In particular, aluminum oxide is preferable because it has a high etching selectivity with respect to the EL layer and functions to protect the EL layer in the formation of the insulating layer 127 described below. In particular, by using an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by the ALD method as the insulating layer 125, it is possible to form an insulating layer 125 with few pinholes and excellent function of protecting the EL layer.

[0208] In this specification and elsewhere, an oxynitride refers to a material whose composition contains more oxygen than nitrogen, and a nitride oxide refers to a material whose composition contains more nitrogen than oxygen. For example, silicon oxynitride refers to a material whose composition contains more oxygen than nitrogen, and silicon nitride oxide refers to a material whose composition contains more nitrogen than oxygen.

[0209] The insulating layer 125 can be formed by a sputtering method, a CVD method, a PLD method, an ALD method, or the like. The insulating layer 125 is preferably formed by an ALD method because it has good coverage.

[0210] The insulating layer 127 provided on the insulating layer 125 has the function of planarizing recesses formed in the insulating layer 125 between adjacent light-emitting devices. In other words, the insulating layer 127 improves the flatness of the surface on which the common electrode 115 is formed. An insulating layer containing an organic material can be suitably used as the insulating layer 127. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, and precursors of these resins can be used as the insulating layer 127. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used as the insulating layer 127. Alternatively, a photosensitive resin (also referred to as an organic resin) can be used as the photosensitive resin. Photoresist may be used as the photosensitive resin. The photosensitive resin may be a positive type material or a negative type material.

[0211] The difference in height between the top surface of the insulating layer 127 and the top surface of any of the first layer 113a, the second layer 113b, and the third layer 113c is, for example, preferably 0.5 times or less, more preferably 0.3 times or less, the thickness of the insulating layer 127. For example, the insulating layer 127 may be provided so that the top surface of any of the first layer 113a, the second layer 113b, and the third layer 113c is higher than the top surface of the insulating layer 127. For example, the insulating layer 127 may be provided so that the top surface of the insulating layer 127 is higher than the top surface of the light-emitting layer included in the first layer 113a, the second layer 113b, or the third layer 113c.

[0212] Furthermore, protective layers 131 and 132 are laminated on the light-emitting devices 130a, 130b, and 130c. The substrate 120 is attached to the protective layer 132 via a resin layer 122. The conductivity of the protective layers 131 and 132 does not matter. The protective layers 131 and 132 can be at least one of an insulating film, a semiconductor film, and a conductive film.

[0213] The protective layers 131 and 132 have inorganic films, which can prevent oxidation of the common electrode 115 and prevent impurities (moisture, oxygen, etc.) from entering the light-emitting devices 130a, 130b, and 130c, thereby suppressing deterioration of the light-emitting devices and improving the reliability of the display device.

[0214] Furthermore, the protective layers 131 and 132 may include an organic film. For example, the protective layer 132 may include both an organic film and an inorganic film.

[0215] The upper end portions of the pixel electrodes 111a, 111b, and 111c are not covered with an insulating layer, which allows the distance between adjacent light-emitting devices to be extremely narrow, thereby enabling a high-definition or high-resolution display device.

[0216] The display device of this embodiment can reduce the distance between light-emitting devices. Specifically, the distance between light-emitting devices, the distance between EL layers, or the distance between pixel electrodes can be less than 10 μm, 5 μm or less, 3 μm or less, 2 μm or less, 1 μm or less, 500 nm or less, 200 nm or less, 100 nm or less, 90 nm or less, 70 nm or less, 50 nm or less, 30 nm or less, 20 nm or less, 15 nm or less, or 10 nm or less. In other words, the distance between the side surface of the first layer 113 a and the side surface of the second layer 113 b or the distance between the side surface of the second layer 113 b and the side surface of the third layer 113 c has a region of 1 μm or less, preferably a region of 0.5 μm (500 nm) or less, and more preferably a region of 100 nm or less.

[0217] A light-shielding layer, a color filter, etc. may be provided on the surface of the substrate 120 facing the resin layer 122. Various optical members may be disposed on the outside of the substrate 120. Examples of optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an anti-reflection layer, and a light-collecting film. The outside of the substrate 120 may also be provided with an anti-static film that suppresses the adhesion of dust, a water-repellent film that makes it difficult for dirt to adhere, a hard coat film that suppresses scratches that occur during use, an impact absorbing layer, etc.

[0218] The substrate 120 can be made of glass, quartz, ceramic, sapphire, resin, metal, alloy, semiconductor, or the like. A material that transmits light is used for the substrate on the side from which light from the light-emitting device is extracted. Using a flexible material for the substrate 120 can increase the flexibility of the display device and realize a flexible display. A polarizing plate may also be used as the substrate 120.

[0219] The resin layer 122 may be made of various curable adhesives such as a photo-curable adhesive such as an ultraviolet curable adhesive, a reaction-curable adhesive, a thermosetting adhesive, or an anaerobic adhesive.

[0220] Materials that can be used for the gate, source, and drain of a transistor as well as conductive layers such as various wirings and electrodes that constitute a display device include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, as well as alloys containing these metals as main components, etc. Films containing these materials can be used as a single layer or a stacked layer structure.

[0221] Examples of light-transmitting conductive materials include conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metal materials, can be used. Alternatively, nitrides of such metal materials (e.g., titanium nitride) can be used. When using metal materials or alloy materials (or their nitrides), it is preferable to thin them sufficiently to ensure light-transmitting properties. A stacked film of the above materials can also be used as a conductive layer. For example, a stacked film of an alloy of silver and magnesium and indium tin oxide is preferable because it can enhance conductivity. These materials can also be used for conductive layers such as various wirings and electrodes constituting display devices, and conductive layers (conductive layers functioning as pixel electrodes or common electrodes) in light-emitting devices.

[0222] 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 oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

[0223] 11 is different from the display device 100A mainly in the configuration of the transistors. Note that descriptions of parts that are the same as those of the display device 100A may be omitted.

[0224] The transistor 320 is a transistor (OS transistor) in which a metal oxide (also referred to as an oxide semiconductor) is used for a semiconductor layer in which a channel is formed.

[0225] The transistor 320 includes a semiconductor layer 321 , an insulating layer 323 , a conductive layer 324 , a pair of conductive layers 325 , an insulating layer 326 , and a conductive layer 327 .

[0226] Substrate 331 corresponds to substrate 291 in FIGS. 9A and 9B.

[0227] An insulating layer 332 is provided over a substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320 and prevents oxygen from being released from the semiconductor layer 321 toward the insulating layer 332. The insulating layer 332 can be, for example, a film through which hydrogen or oxygen is less likely to diffuse than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0228] A conductive layer 327 is provided over the insulating layer 332, and an insulating layer 326 is provided to cover the conductive layer 327. The conductive layer 327 functions as a first gate electrode of the transistor 320, and part of the insulating layer 326 functions as a first gate insulating layer. An oxide insulating film such as a silicon oxide film is preferably used for at least a portion of the insulating layer 326 that is in contact with the semiconductor layer 321. The top surface of the insulating layer 326 is preferably planarized.

[0229] The semiconductor layer 321 is provided over the insulating layer 326. The semiconductor layer 321 preferably includes a metal oxide (also referred to as an oxide semiconductor) film having semiconductor properties. A pair of conductive layers 325 is provided over and in contact with the semiconductor layer 321 and functions as a source electrode and a drain electrode.

[0230] An insulating layer 328 is provided to cover top surfaces and side surfaces of the pair of conductive layers 325 and side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided over the insulating layer 328. The insulating layer 328 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 264 or the like into the semiconductor layer 321 and prevents oxygen from being released from the semiconductor layer 321. The insulating layer 328 can be an insulating film similar to the insulating layer 332.

[0231] Openings reaching the semiconductor layer 321 are provided in the insulating layer 328 and the insulating layer 264. Inside the openings, an insulating layer 323 and a conductive layer 324 are buried, the insulating layer 323 being in contact with side surfaces of the insulating layer 264, the insulating layer 328, and the conductive layer 325 and the top surface of the semiconductor layer 321. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0232] The upper surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are planarized so that their heights are the same or approximately the same, and insulating layers 329 and 265 are provided to cover them.

[0233] The insulating layer 264 and the insulating layer 265 function as interlayer insulating layers. The insulating layer 329 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 265 or the like to the transistor 320. The insulating layer 329 can be formed using an insulating film similar to the insulating layer 328 and the insulating layer 332.

[0234] A plug 274 electrically connected to one of the pair of conductive layers 325 is provided so as to be embedded in the insulating layer 265, the insulating layer 329, and the insulating layer 264. Here, the plug 274 preferably has a conductive layer 274a covering the side surfaces of the openings of the insulating layer 265, the insulating layer 329, the insulating layer 264, and the insulating layer 328 and a part of the upper surface of the conductive layer 325, and a conductive layer 274b in contact with the upper surface of the conductive layer 274a. In this case, it is preferable to use a conductive material through which hydrogen and oxygen do not easily diffuse as the conductive layer 274a.

[0235] 12 has a stacked structure of a transistor 310 in which a channel is formed in a substrate 301 and a transistor 320 in which a channel is formed and a semiconductor layer containing a metal oxide. Note that descriptions of parts that are the same as those of the display devices 100A and 100B may be omitted.

[0236] An insulating layer 261 is provided to cover the transistor 310, and a conductive layer 251 is provided over the insulating layer 261. An insulating layer 262 is provided to cover the conductive layer 251, and a conductive layer 252 is provided over the insulating layer 262. The conductive layers 251 and 252 each function as wirings. An insulating layer 263 and an insulating layer 332 are provided to cover the conductive layer 252, and the transistor 320 is provided over the insulating layer 332. An insulating layer 265 is provided to cover the transistor 320, and a capacitor 240 is provided over the insulating layer 265. The capacitor 240 and the transistor 320 are electrically connected by a plug 274.

[0237] The transistor 320 can be used as a transistor that forms a pixel circuit. The transistor 310 can be used as a transistor that forms a pixel circuit or a driver circuit (gate line driver circuit, source line driver circuit) that drives the pixel circuit. The transistors 310 and 320 can be used as transistors that form various circuits such as an arithmetic circuit or a memory circuit.

[0238] By using this configuration, not only pixel circuits but also driving circuits etc. can be formed directly below the light-emitting device, making it possible to make the display device smaller than when driving circuits are provided around the periphery of the display area.

[0239] Display Device 100D A display device 100D shown in FIG. 13 has a stacked structure of a transistor 310A and a transistor 310B, each of which has a channel formed in a semiconductor substrate.

[0240] The display device 100D has a configuration in which a substrate 301B on which a transistor 310B, a capacitor 240, and each light-emitting device are provided and a substrate 301A on which a transistor 310A is provided are bonded together.

[0241] The substrate 301B is provided with a plug 343 penetrating the substrate 301B. The plug 343 is electrically connected to a conductive layer 342 provided on the back surface of the substrate 301 (the surface opposite to the substrate 120 side). On the other hand, the substrate 301A has a conductive layer 341 provided on the insulating layer 261.

[0242] The conductive layer 341 and the conductive layer 342 are joined together, thereby electrically connecting the substrate 301A and the substrate 301B.

[0243] It is preferable to use the same conductive material for the conductive layers 341 and 342. For example, a metal film containing an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or a metal nitride film containing the above elements (titanium nitride film, molybdenum nitride film, tungsten nitride film), etc., can be used. In particular, it is preferable to use copper for the conductive layers 341 and 342. This allows for the application of Cu-Cu (copper-copper) direct bonding technology (a technology that achieves electrical conductivity by connecting Cu (copper) pads together). Note that the conductive layers 341 and 342 may be bonded via bumps.

[0244] [Display Device 100E] A display device 100E illustrated in FIG. 14 has a stacked structure of a transistor 320A and a transistor 320B each including an oxide semiconductor as a semiconductor in which a channel is formed.

[0245] The transistor 320A, the transistor 320B, and the peripheral configuration thereof can be adapted from the display device 100B.

[0246] Although two transistors including an oxide semiconductor are stacked here, the present invention is not limited to this structure, and for example, three or more transistors may be stacked.

[0247] This embodiment mode can be combined with other embodiment modes as appropriate.

[0248] Embodiment 5 In this embodiment, a light-emitting device that can be used for a display device according to one embodiment of the present invention will be described.

[0249] 15A , the light-emitting device has an EL layer 786 between a pair of electrodes (a lower electrode 772 and an upper electrode 788). The EL layer 786 can be composed of multiple layers such as a layer 4420, a light-emitting layer 4411, and a layer 4430. The layer 4420 can have, for example, a layer containing a substance with high electron-injection properties (electron-injection layer) and a layer containing a substance with high electron-transport properties (electron-transport layer). The light-emitting layer 4411 contains, for example, a light-emitting compound. The layer 4430 can have, for example, a layer containing a substance with high hole-injection properties (hole-injection layer) and a layer containing a substance with high hole-transport properties (hole-transport layer).

[0250] A structure having the layer 4420, the light-emitting layer 4411, and the layer 4430 provided between a pair of electrodes can function as a single light-emitting unit, and the structure of FIG. 15A is referred to as a single structure in this specification.

[0251] 15B shows a modified example of the EL layer 786 included in the light-emitting device shown in Fig. 15A. Specifically, the light-emitting device shown in Fig. 15B includes a layer 4431 on a lower electrode 772, a layer 4432 on the layer 4431, a light-emitting layer 4411 on the layer 4432, a layer 4421 on the light-emitting layer 4411, a layer 4422 on the layer 4421, and an upper electrode 788 on the layer 4422. For example, when the lower electrode 772 is an anode and the upper electrode 788 is a cathode, the layer 4431 functions as a hole injection layer, the layer 4432 functions as a hole transport layer, the layer 4421 functions as an electron transport layer, and the layer 4422 functions as an electron injection layer. Alternatively, when the lower electrode 772 is a cathode and the upper electrode 788 is an anode, the layer 4431 functions as an electron injection layer, the layer 4432 functions as an electron transport layer, the layer 4421 functions as a hole transport layer, and the layer 4422 functions as a hole injection layer. With such a layer structure, carriers can be efficiently injected into the light-emitting layer 4411, and the efficiency of carrier recombination in the light-emitting layer 4411 can be increased.

[0252] As shown in FIGS. 15C and 15D, a configuration in which a plurality of light-emitting layers (light-emitting layers 4411, 4412, and 4413) are provided between the layer 4420 and the layer 4430 is also a variation of the single structure.

[0253] 15E and 15F, a configuration in which a plurality of light-emitting units (EL layer 786a, EL layer 786b) are connected in series via an intermediate layer (charge generating layer) 4440 is referred to as a tandem structure in this specification. Note that, although the configuration shown in FIGS. 15E and 15F is referred to as a tandem structure in this specification and the like, this is not limiting, and for example, the tandem structure may also be referred to as a stack structure. Note that by using a tandem structure, a light-emitting device capable of emitting light with high brightness can be obtained.

[0254] In FIG. 15C, light-emitting layers 4411, 4412, and 4413 may be made of light-emitting materials that emit light of the same color.

[0255] Furthermore, different light-emitting materials may be used for the light-emitting layer 4411, the light-emitting layer 4412, and the light-emitting layer 4413. When the light emitted from the light-emitting layer 4411, the light-emitting layer 4412, and the light-emitting layer 4413 has a complementary color relationship, white light can be obtained. Fig. 15D shows an example in which a colored layer 785 that functions as a color filter is provided. When white light passes through the color filter, light of a desired color can be obtained.

[0256] 15E, the light-emitting layer 4411 and the light-emitting layer 4412 may be made of the same light-emitting material. Alternatively, the light-emitting layer 4411 and the light-emitting layer 4412 may be made of light-emitting materials that emit light of different colors. When the light emitted by the light-emitting layer 4411 and the light emitted by the light-emitting layer 4412 are complementary colors, white light emission is obtained. FIG. 15F shows an example in which a coloring layer 785 is further provided.

[0257] 15C, 15D, 15E, and 15F, the layer 4420 and the layer 4430 may have a laminated structure consisting of two or more layers, as shown in FIG. 15B.

[0258] A structure that produces different luminescent colors (here, blue (B), green (G), and red (R)) for each light-emitting device is sometimes called an SBS (Side By Side) structure.

[0259] The light-emitting device can emit light of red, green, blue, cyan, magenta, yellow, or white, depending on the material of the EL layer 786. Furthermore, the color purity can be further improved by providing the light-emitting device with a microcavity structure.

[0260] A light-emitting device that emits white light preferably has a configuration in which two or more types of light-emitting materials are contained in the light-emitting layer. To obtain white light emission, light-emitting materials can be selected such that the respective emissions of the two or more light-emitting materials have a complementary color relationship. For example, by making the emission color of the first light-emitting layer and the emission color of the second light-emitting layer complementary to each other, a light-emitting device that emits white light as a whole can be obtained. The same applies to light-emitting devices having three or more light-emitting layers.

[0261] The light-emitting layer preferably contains two or more light-emitting materials that emit light of R (red), G (green), B (blue), Y (yellow), O (orange), etc. Alternatively, it is preferable that the light-emitting layer contains two or more light-emitting materials, and the light emitted by each of the light-emitting materials contains spectral components of two or more colors of R, G, and B.

[0262] Here, a specific example of the configuration of the light-emitting device will be described.

[0263] The light-emitting device has at least a light-emitting layer. The light-emitting device may further have, as a layer other than the light-emitting layer, a layer containing a substance with high hole-injection properties, a substance with high hole-transport properties, a hole-blocking material, a substance with high electron-transport properties, an electron-blocking material, a substance with high electron-injection properties, a bipolar substance (a substance with high electron-transport properties and high hole-transport properties), or the like.

[0264] The light-emitting device can be made of either a low-molecular-weight compound or a high-molecular-weight compound, and may contain an inorganic compound. The layers constituting the light-emitting device can be formed by a method such as vapor deposition (including vacuum vapor deposition), transfer, printing, inkjet printing, or coating.

[0265] For example, a light emitting device can include one or more of 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.

[0266] The hole injection layer is a layer that injects holes from the anode into the hole transport layer and contains a substance with high hole injection properties, such as an aromatic amine compound and a composite material containing a hole transport material and an acceptor material (electron acceptor material).

[0267] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light emitting layer. The hole transport layer is a layer that contains a hole transporting material. The hole transporting material is a material having a concentration of 1×10 −６ cm ２A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher hole transporting property than electron transporting property. As the hole transporting material, a substance having a high hole transporting property, such as a π-electron-rich heteroaromatic compound (e.g., a carbazole derivative, a thiophene derivative, a furan derivative, etc.) or an aromatic amine (a compound having an aromatic amine skeleton), is preferred.

[0268] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light emitting layer. The electron transport layer is a layer that contains an electron transporting material. The electron transporting material is a material having a concentration of 1×10 −６ cm ２ / Vs or more is preferred. Note that other substances can also be used as long as they have a higher electron transporting property than holes. Examples of electron-transporting materials that can be used include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, and metal complexes having a thiazole skeleton, as well 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, and other π-electron-deficient heteroaromatic compounds including nitrogen-containing heteroaromatic compounds.

[0269] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer and contains a substance with high electron injection properties. Examples of the substance with high electron injection properties include alkali metals, alkaline earth metals, and compounds thereof. Examples of the substance with high electron injection properties include a composite material containing an electron transport material and a donor material (electron donor material).

[0270] The electron injection layer may be formed of, for example, lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ２), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatolithium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatolithium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatolithium (abbreviation: LiPPP), lithium oxide (LiO ｘ ), alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used.

[0271] Alternatively, the electron injection layer may be formed using a material having electron transport properties. For example, a compound having an unshared electron pair and an electron-deficient heteroaromatic ring may be used as the material having electron transport properties. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and a triazine ring may be used.

[0272] The organic compound having an unshared electron pair preferably has a lowest unoccupied molecular orbital (LUMO) of -3.6 eV to -2.3 eV. Generally, the highest occupied molecular orbital (HOMO) level and the LUMO level of an organic compound can be estimated by CV (cyclic voltammetry), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, or the like.

[0273] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used as the organic compound having an unshared electron pair. Note that NBPhen has a higher glass transition point (Tg) and is superior in heat resistance compared to BPhen.

[0274] The light-emitting layer is a layer containing a light-emitting substance. The light-emitting layer can contain one or more light-emitting substances. As the light-emitting substance, a substance that emits light of a color such as blue, purple, blue-purple, green, yellow-green, yellow, orange, or red is appropriately used. Furthermore, a substance that emits near-infrared light can also be used as the light-emitting substance.

[0275] Examples of the light-emitting material include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0276] 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, and naphthalene derivatives.

[0277] Examples of phosphorescent materials include organometallic complexes (particularly iridium complexes) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton; organometallic complexes (particularly iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand; platinum complexes; and rare earth metal complexes.

[0278] The light-emitting layer may contain one or more organic compounds (host materials, assist materials, etc.) in addition to a light-emitting substance (guest material). One or more organic compounds may be a hole-transporting material or an electron-transporting material. Alternatively, a bipolar material or a TADF material may be used as the one or more organic compounds.

[0279] The light-emitting layer preferably includes, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material that are a combination that easily forms an exciplex. This configuration allows for efficient emission using Exciplex-Triple Energy Transfer (ExTET), which is energy transfer from the exciplex to the light-emitting material (phosphorescent material). By selecting a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest-energy absorption band of the light-emitting material, energy transfer becomes smooth, allowing for efficient emission. This configuration simultaneously enables high efficiency, low-voltage operation, and long life of the light-emitting device.

[0280] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0281] Embodiment 6 In this embodiment, a metal oxide (also referred to as an oxide semiconductor) that can be used for the OS transistor described in the above embodiment will be described.

[0282] The metal oxide preferably contains at least indium or zinc. It is particularly preferable that it contains indium and zinc. It is also preferable that it contains aluminum, gallium, yttrium, tin, or the like in addition to these. It may also contain one or more elements selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, and the like.

[0283] The metal oxide can be formed by a sputtering method, a chemical vapor deposition (CVD) method such as a metal organic chemical vapor deposition (MOCVD) method, or an atomic layer deposition (ALD) method.

[0284] <Classification of Crystal Structure> Examples of the crystal structure of an oxide semiconductor include amorphous (including completely amorphous), c-axis-aligned crystalline line (CAAC), nanocrystalline line (nc), cloud-aligned composite (CAC), single crystal, and polycrystalline.

[0285] The crystalline structure of the film or substrate can be evaluated using an X-ray diffraction (XRD) spectrum. For example, it can be evaluated using an XRD spectrum obtained by a GIXD (Grazing-Incident XRD) measurement. The GIXD method is also called the thin film method or the Seemann-Bohlin method.

[0286] For example, in the case of a quartz glass substrate, the shape of the peak in the XRD spectrum is almost symmetrical. On the other hand, in the case of an IGZO film having a crystalline structure, the shape of the peak in the XRD spectrum is asymmetrical. The asymmetrical shape of the peak in the XRD spectrum clearly indicates the presence of crystals in the film or substrate. In other words, if the shape of the peak in the XRD spectrum is not symmetrical, the film or substrate cannot be said to be in an amorphous state.

[0287] The crystalline structure of the film or substrate can be evaluated by a diffraction pattern (also referred to as a nanobeam electron diffraction pattern) observed by nanobeam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, and it can be confirmed that the quartz glass is in an amorphous state. Furthermore, a spot-like pattern is observed in the diffraction pattern of an IGZO film formed at room temperature, rather than a halo. For this reason, it is estimated that the IGZO film formed at room temperature is neither crystalline nor amorphous, but is in an intermediate state, and it cannot be concluded that it is in an amorphous state.

[0288] <<Structure of Oxide Semiconductor>> Note that oxide semiconductors may be classified differently from the above when focusing on their structures. For example, oxide semiconductors are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the above-mentioned CAAC-OS and nc-OS. Non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, pseudo-amorphous-like oxide semiconductors (a-like OSs), amorphous oxide semiconductors, and the like.

[0289] Here, the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described in detail.

[0290] [CAAC-OS] A CAAC-OS is an oxide semiconductor having multiple crystalline regions, each with its c-axis aligned in a specific direction. The specific direction refers to the thickness direction of the CAAC-OS film, the normal direction to the surface where the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region having periodic atomic arrangement. If the atomic arrangement is considered as a lattice arrangement, a crystalline region is also a region with a uniform lattice arrangement. Furthermore, a CAAC-OS has a region where multiple crystalline regions are connected in the a-b plane direction, and the region may have distortion. Note that distortion refers to a portion where the lattice arrangement changes between a region with a uniform lattice arrangement and a region with another uniform lattice arrangement in a region where multiple crystalline regions are connected. In other words, a CAAC-OS is an oxide semiconductor whose c-axes are aligned and whose orientation is not clearly aligned in the a-b plane direction.

[0291] Each of the multiple crystalline regions is composed of one or more minute crystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of a single minute crystal, the maximum diameter of the crystalline region is less than 10 nm. When a crystalline region is composed of many minute crystals, the size of the crystalline region may be several tens of nanometers.

[0292] In an In-M-Zn oxide (wherein the element M is one or more elements selected from aluminum, gallium, yttrium, tin, titanium, and the like), the CAAC-OS tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium (In) and oxygen (hereinafter referred to as an In layer) and a layer containing the element M, zinc (Zn), and oxygen (hereinafter referred to as an (M, Zn) layer) are stacked. Note that indium and the element M are mutually substituted. Therefore, the (M, Zn) layer may contain indium. The In layer may contain the element M. The In layer may contain Zn. The layered structure is observed as a lattice image in a high-resolution transmission electron microscope (TEM) image, for example.

[0293] When a CAAC-OS film is subjected to structural analysis using an XRD apparatus, for example, a peak indicating c-axis orientation is detected at or near 2θ = 31° in out-of-plane XRD measurement using θ / 2θ scanning. Note that the position of the peak indicating c-axis orientation (the value of 2θ) may vary depending on the type and composition of the metal elements constituting the CAAC-OS.

[0294] For example, multiple bright spots are observed in the electron diffraction pattern of a CAAC-OS film, and the spots are observed at positions that are point-symmetric with respect to a spot of an incident electron beam that has passed through the sample (also referred to as a direct spot).

[0295] When a crystalline region is observed from the specific direction, the lattice arrangement in the crystalline region is basically a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be a non-regular hexagon. The distortion may have a pentagonal, heptagonal, or other lattice arrangement. In the CAAC-OS, no clear grain boundary can be identified even near the distortion. This indicates that the distortion in the lattice arrangement suppresses the formation of grain boundaries. This is thought to be because the CAAC-OS can tolerate distortion due to the lack of close-packed arrangement of oxygen atoms in the a-b plane and the change in interatomic bond distance caused by metal atom substitution.

[0296] Note that a crystal structure in which clear grain boundaries are observed is called polycrystalline. The grain boundaries act as recombination centers, and are likely to trap carriers, resulting in a decrease in the on-state current of a transistor and a decrease in field-effect mobility. Therefore, CAAC-OS, in which clear grain boundaries are not observed, is one of the crystalline oxides having a crystal structure suitable for a semiconductor layer of a transistor. Note that a structure containing Zn is preferable for forming a CAAC-OS. For example, In—Zn oxide and In—Ga—Zn oxide are suitable because they can suppress the generation of grain boundaries more effectively than In oxide.

[0297] CAAC-OS is an oxide semiconductor with high crystallinity and no clear crystal grain boundaries. Therefore, it can be said that the CAAC-OS is less susceptible to a decrease in electron mobility due to crystal grain boundaries. Furthermore, since the crystallinity of an oxide semiconductor can be reduced by the inclusion of impurities, the formation of defects, or the like, the CAAC-OS can also be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, an oxide semiconductor having a CAAC-OS has stable physical properties. Therefore, an oxide semiconductor having a CAAC-OS is heat-resistant and highly reliable. Furthermore, the CAAC-OS is stable even against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, the use of a CAAC-OS in an OS transistor can increase the flexibility of the manufacturing process.

[0298] [nc-OS] The nc-OS has periodic atomic arrangement in a microscopic region (e.g., a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In other words, the nc-OS has microcrystals. Note that the size of the microcrystals is, for example, 1 nm to 10 nm, particularly 1 nm to 3 nm, and therefore the microcrystals are also called nanocrystals. Furthermore, the nc-OS does not exhibit regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is observed throughout the film. Therefore, depending on the analysis method, the nc-OS may be indistinguishable from an a-like OS or an amorphous oxide semiconductor. For example, when a structural analysis of an nc-OS film is performed using an XRD apparatus, no peak indicating crystallinity is detected in out-of-plane XRD measurement using θ / 2θ scanning. When an nc-OS film is subjected to electron diffraction (also referred to as selected-area electron diffraction) using an electron beam with a probe diameter larger than that of a nanocrystal (e.g., 50 nm or more), a diffraction pattern resembling a halo pattern is observed. On the other hand, when an nc-OS film is subjected to electron diffraction (also referred to as nanobeam electron diffraction) using an electron beam with a probe diameter close to or smaller than that of a nanocrystal (e.g., 1 nm to 30 nm), an electron diffraction pattern in which multiple spots are observed within a ring-shaped region centered on a direct spot may be obtained.

[0299] [a-Like OS] The a-like OS is an oxide semiconductor having a structure between the nc-OS and an amorphous oxide semiconductor. The a-like OS has pores or low-density regions. That is, the a-like OS has lower crystallinity than the nc-OS and CAAC-OS. Furthermore, the a-like OS has a higher hydrogen concentration in the film than the nc-OS and CAAC-OS.

[0300] <<Structure of Oxide Semiconductor>> Next, the above-described CAC-OS will be described in detail. Note that the CAC-OS relates to a material structure.

[0301] [CAC-OS] CAC-OS is, for example, a material in which elements constituting a metal oxide are unevenly distributed in a size of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof. Note that hereinafter, a state in which one or more metal elements are unevenly distributed in a metal oxide and regions containing the metal elements are mixed in a size of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof, is also referred to as a mosaic or patch state.

[0302] Furthermore, the CAC-OS has a mosaic structure in which a material is separated into a first region and a second region, and the first region is distributed throughout the film (hereinafter also referred to as a cloud structure). That is, the CAC-OS is a composite metal oxide having a structure in which the first region and the second region are mixed.

[0303] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in the In—Ga—Zn oxide are denoted as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS in the In—Ga—Zn oxide, the first region is a region where [In] is larger than [In] in the CAC-OS composition. The second region is a region where [Ga] is larger than [Ga] in the CAC-OS composition. Alternatively, for example, the first region is a region where [In] is larger than [In] in the second region and [Ga] is smaller than [Ga] in the second region. The second region is a region where [Ga] is larger than [Ga] in the first region and [In] is smaller than [In] in the first region.

[0304] Specifically, the first region is a region whose main component is indium oxide, indium zinc oxide, or the like. The second region is a region whose main component is gallium oxide, gallium zinc oxide, or the like. In other words, the first region can be referred to as a region whose main component is In. The second region can be referred to as a region whose main component is Ga.

[0305] It should be noted that there are cases where a clear boundary between the first region and the second region cannot be observed.

[0306] Furthermore, CAC-OS in In—Ga—Zn oxide refers to a structure in which a mosaic of regions containing Ga as the main component and regions containing In as the main component are randomly arranged in a material composition containing In, Ga, Zn, and O. Therefore, it is presumed that CAC-OS has a structure in which metal elements are distributed nonuniformly.

[0307] The CAC-OS can be formed by sputtering without heating the substrate. When the CAC-OS is formed by sputtering, one or more of an inert gas (typically argon), oxygen gas, and nitrogen gas may be used as the deposition gas. The lower the flow rate of oxygen gas relative to the total flow rate of deposition gas during deposition, the more preferable it is. For example, the flow rate of oxygen gas relative to the total flow rate of deposition gas during deposition is preferably 0% or more and less than 30%, and more preferably 0% or more and 10% or less.

[0308] Furthermore, for example, in the case of CAC-OS in an In—Ga—Zn oxide, EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) can confirm that the CAC-OS has a structure in which a region containing In as a main component (first region) and a region containing Ga as a main component (second region) are unevenly distributed and mixed.

[0309] Here, the first region has higher conductivity than the second region. That is, the flow of carriers through the first region causes the metal oxide to exhibit conductivity. Therefore, the first region is distributed in a cloud-like manner in the metal oxide, thereby achieving a high field-effect mobility (μ).

[0310] On the other hand, the second region has higher insulating properties than the first region. That is, the second region is distributed in the metal oxide, thereby suppressing leakage current.

[0311] Therefore, when a CAC-OS is used in a transistor, the conductivity due to the first region and the insulating property due to the second region act complementarily, thereby providing the CAC-OS with a switching function (a function of turning on / off). In other words, a CAC-OS has a conductive function in a part of the material and an insulating function in a part of the material, and the entire material functions as a semiconductor. By separating the conductive function and the insulating function, both functions can be maximized. Therefore, by using a CAC-OS in a transistor, a high on-current (I ｏｎ ), high field-effect mobility (μ), and good switching behavior can be achieved.

[0312] Furthermore, a transistor using the CAC-OS has high reliability, and therefore, the CAC-OS is ideal for various semiconductor devices such as display devices.

[0313] Oxide semiconductors have a variety of structures, each of which has different characteristics. The oxide semiconductor of one embodiment of the present invention may include two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, a CAC-OS, an nc-OS, and a CAAC-OS.

[0314] <Transistor Having Oxide Semiconductor> Next, a case where the oxide semiconductor is used for a transistor will be described.

[0315] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility and high reliability can be realized.

[0316] For the transistor, an oxide semiconductor having a low carrier concentration is preferably used. For example, the carrier concentration of the oxide semiconductor is 1×10 １７ cm −３ Below 1 × 10, preferably １５ cm −３ More preferably, 1×10 １３ cm −３ or less, more preferably 1 × 10 １１ cm −３ More preferably, 1×10１０ cm −３ is less than 1×10 −９ cm −３ That is all. Note that in order to reduce the carrier concentration of an oxide semiconductor film, the impurity concentration in the oxide semiconductor film may be reduced to reduce the density of defect states. In this specification and the like, a semiconductor having a low impurity concentration and a low density of defect states is referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor. Note that an oxide semiconductor having a low carrier concentration may also be referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor.

[0317] Furthermore, a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has a low density of defect states, and therefore the density of trap states may also be low.

[0318] Furthermore, charges trapped in the trap states of an oxide semiconductor take a long time to disappear and may behave like fixed charges. Therefore, a transistor in which a channel formation region is formed in an oxide semiconductor with a high density of trap states may have unstable electrical characteristics.

[0319] Therefore, in order to stabilize the electrical characteristics of a transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. Furthermore, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in the adjacent film. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, and silicon.

[0320] <Impurities> Here, the influence of each impurity in an oxide semiconductor will be described.

[0321] When an oxide semiconductor contains silicon or carbon, which is one of Group 14 elements, defect levels are formed in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon near the interface with the oxide semiconductor (concentration obtained by secondary ion mass spectrometry (SIMS)) are set to 2×10 １８ atoms / cm ３ Below 2 × 10, preferably １７ atoms / cm３ The following applies.

[0322] Furthermore, when an oxide semiconductor contains an alkali metal or an alkaline earth metal, defect levels are formed and carriers are generated in some cases. Therefore, a transistor using an oxide semiconductor containing an alkali metal or an alkaline earth metal is likely to have normally-on characteristics. For this reason, when the concentration of the alkali metal or the alkaline earth metal in the oxide semiconductor obtained by SIMS is 1×10 １８ atoms / cm ３ Below 2 × 10, preferably １６ atoms / cm ３ Do the following:

[0323] Furthermore, when nitrogen is contained in an oxide semiconductor, electrons serving as carriers are generated, the carrier concentration increases, and the semiconductor is likely to become n-type. As a result, a transistor using an oxide semiconductor containing nitrogen as a semiconductor tends to have normally-on characteristics. Alternatively, when nitrogen is contained in an oxide semiconductor, trap states may be formed. As a result, the electrical characteristics of the transistor may become unstable. For this reason, the nitrogen concentration in the oxide semiconductor obtained by SIMS is set to 5×10 １９ atoms / cm ３ Less than 5×10 １８ atoms / cm ３ or less, more preferably 1 × 10 １８ atoms / cm ３ or less, more preferably 5 × 10 １７ atoms / cm ３ Do the following:

[0324] Furthermore, hydrogen contained in an oxide semiconductor may react with oxygen bonded to a metal atom to form water, which may form an oxygen vacancy. Hydrogen entering the oxygen vacancy may generate electrons as carriers. Furthermore, some of the hydrogen may bond with oxygen bonded to a metal atom to generate electrons as carriers. Therefore, a transistor using an oxide semiconductor containing hydrogen is likely to have normally-on characteristics. Therefore, it is preferable to reduce hydrogen in the oxide semiconductor as much as possible. Specifically, the hydrogen concentration in the oxide semiconductor measured by SIMS is 1×10 ２０ atoms / cm ３ less than 1×10 １９ atoms / cm ３ less than 5×10 １８ atoms / cm ３ less than 1×10 １８ atoms / cm ３ Make it less than.

[0325] When an oxide semiconductor with sufficiently reduced impurities is used for a channel formation region of a transistor, stable electrical characteristics can be obtained.

[0326] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0327] Embodiment 7 In this embodiment, electronic devices to which a display device according to one embodiment of the present invention can be applied will be described.

[0328] The electronic devices of this embodiment include the display device of one embodiment of the present invention in their display portions. The display device of one embodiment of the present invention can easily achieve high definition and high resolution. Therefore, the display device of one embodiment of the present invention can be used in the display portions of various electronic devices.

[0329] In particular, the display device of one embodiment of the present invention can be suitably used in electronic devices having a relatively small display area because it can increase the resolution. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), and head-mounted wearable devices such as VR devices (e.g., head-mounted displays), AR glasses-type devices, and MR devices.

[0330] The display device of one embodiment of the present invention preferably has an extremely high resolution such as HD (1280 × 720 pixels), FHD (1920 × 1080 pixels), WQHD (2560 × 1440 pixels), WQXGA (2560 × 1600 pixels), 4K (3840 × 2160 pixels), or 8K (7680 × 4320 pixels). A resolution of 4K, 8K, or higher is particularly preferable. Furthermore, the pixel density (resolution) of the display device of one embodiment of the present invention is preferably 100 ppi or higher, more preferably 300 ppi or higher, more preferably 500 ppi or higher, more preferably 1000 ppi or higher, more preferably 2000 ppi or higher, more preferably 3000 ppi or higher, more preferably 5000 ppi or higher, and even more preferably 7000 ppi or higher. By using a display device having either or both of high resolution and high definition, it is possible to further enhance the sense of realism and depth in electronic devices for personal use, such as portable or home use. Furthermore, the screen ratio (aspect ratio) of the display device of one embodiment of the present invention is not particularly limited. For example, the display device can accommodate various screen ratios, such as 1:1 (square), 4:3, 16:9, and 16:10. In particular, for AR applications, a horizontally elongated screen with an aspect ratio of, for example, 16:9 is preferable to a square screen.

[0331] The electronic device of this embodiment may have a sensor (including a function to measure force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0332] The electronic device of the present embodiment can have various functions, such as a function to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date, time, etc., a function to execute various software (programs), a wireless communication function, a function to read out programs or data recorded on a recording medium, etc.

[0333] An example of a wearable device that can be worn on the head will be described with reference to FIG. 16A . The wearable device of this embodiment has functions for displaying various information depending on the application, such as a function for displaying captured video in real time and a function for displaying an operation screen. Furthermore, the wearable device may have one or both of a function for displaying AR content and a function for displaying VR content. Note that the wearable device may also have a function for displaying SR or MR content in addition to AR and VR. Having a wearable device with a function for displaying AR, VR, SR, MR, or other content can enhance the user's sense of immersion.

[0334] The electronic device 700 shown in Figure 16A each has a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0335] The display device of one embodiment of the present invention can be applied to the display panel 751. Therefore, the electronic device can provide an extremely high-definition display.

[0336] The electronic device 700 can project an image displayed on the display panel 751 onto a display area 756 of the optical member 753. Because the optical member 753 is translucent, the user can see the image displayed in the display area superimposed on a transmitted image visually recognized through the optical member 753. Therefore, the electronic device 700 is an electronic device capable of AR display.

[0337] A camera capable of capturing an image in front of the electronic device 700 may be provided as an imaging unit in the electronic device 700. In addition, the electronic device 700 may be provided with an acceleration sensor such as a gyro sensor, thereby detecting the orientation of the user's head and displaying an image corresponding to the orientation in the display area 756.

[0338] Each of the pair of mounting parts 723 is provided with a vibration module 725 as an audio output means. The vibration module 725 allows a part of the mounting part 723 to function as a speaker using bone conduction. By using bone conduction, audio can be heard without worrying about sound leaking to the surroundings. Note that earphones may also be used as the audio output means.

[0339] The communication unit has a wireless communication device, and can supply a video signal, etc. Instead of or in addition to the wireless communication device, a connector to which a cable through which a video signal and a power supply potential are supplied may be provided.

[0340] The electronic device 700 is also provided with a battery, which can be charged wirelessly and / or wired.

[0341] The housing 721 may be provided with a touch sensor module. The touch sensor module has a function of detecting a touch on the outer surface of the housing 721. The touch sensor module can detect a tap operation or a slide operation by the user and perform various processes. For example, a tap operation can perform a process such as pausing or resuming a video, and a slide operation can perform a process such as fast-forwarding or fast-rewinding. Furthermore, providing a touch sensor module on each of the two housings 721 can expand the range of operations.

[0342] Various touch sensors can be used as the touch sensor module. For example, various types of touch sensors can be used, such as a capacitance type, a resistive film type, an infrared type, an electromagnetic induction type, a surface acoustic wave type, and an optical type. In particular, it is preferable to use a capacitance type or an optical type sensor in the touch sensor module.

[0343] When an optical touch sensor is used, a photoelectric conversion device (also called a photoelectric conversion element) can be used as the light receiving device. The active layer of the photoelectric conversion device can be made of either or both of an inorganic semiconductor and an organic semiconductor.

[0344] 16A , a display panel 751 is provided on a housing 721, and an image is projected from the side onto an optical member 753. However, the present invention is not limited to this, and the display panel 751 may be configured to project an image onto the optical member 753 from above or below.

[0345] 16B shows an example in which an image is projected onto optical member 753 from above. Display panel 751 is disposed, for example, on frame 757 so as to output an image to the lower side. A portion of the light emitted from display panel 751 is reflected by optical member 752 toward optical member 753 and projected onto optical member 753. A portion of the light reflected by optical member 753 (light 763) passes through optical member 752 and reaches user's eye 765. Meanwhile, external light 761 passes through optical member 753 and optical member 752 and reaches user's eye 765. This allows the image on display panel 751 to be superimposed on an actual background.

[0346] A lens 754 may be provided on the display surface side of the display panel 751. Furthermore, a microlens array may be provided between the display panel 751 and the lens 754.

[0347] The optical members 752 and 753 may each include a polarizing plate, a circular polarizing plate, a lens, a half mirror, etc. For example, the optical member 752 functions as a beam splitter, transmitting light of a predetermined polarization and reflecting light of other polarizations. The optical member 753 collects and reflects the light incident from the optical member 752, and polarizes the light so that it can pass through the optical member 752.

[0348] An example of using the electronic device 700 in a medical setting will be described with reference to Fig. 16C. Fig. 16C shows a state in which medical treatment is being performed using an endoscope device 710.

[0349] A doctor 712 operates an endoscope device 710 to observe the inside of a patient 715 and administer appropriate treatment. The doctor 712 wears an electronic device 700. Images captured by the endoscope device 710 are displayed in real time on the display unit of the electronic device 700, and the doctor 712 can administer treatment while viewing the images.

[0350] In addition, the image captured by the endoscope device 710 can also be displayed on a separately installed monitor device 711. This allows other doctors 713, 714, etc. to watch the procedure being performed by the doctor 712 in real time without disturbing the doctor 712. Here, an example is shown in which the monitor device 711 is installed inside the operating room, but it can also be viewed in a separate room. For example, a trainee doctor or the like can get a realistic feel for the atmosphere at the treatment site by watching the procedure being performed by the doctor 712 on a monitor device installed in the operating room.

[0351] The display device of one embodiment of the present invention can be applied not only to the display portion of the electronic device 700 but also to the display portion of the monitor device 711. Therefore, doctors 713, 714, and the like can make highly accurate medical decisions using images with extremely high resolution and can share the decisions with the doctor 712 who is performing the treatment.

[0352] FIG. 17A is a diagram showing the appearance of the head-mounted display 8200.

[0353] The head-mounted display 8200 includes a mounting portion 8201, a lens 8202, a main body 8203, a display portion 8204, and a cable 8205. The mounting portion 8201 has a built-in battery 8206.

[0354] A cable 8205 supplies power from a battery 8206 to the main body 8203. The main body 8203 is provided with a wireless receiver or the like, and can display an image corresponding to received image data or the like on a display portion 8204. In addition, a camera provided in the main body 8203 captures the movement of the user's eyeball or eyelid, and calculates the coordinates of the user's line of sight based on the information, thereby allowing the user's line of sight to be used as an input means.

[0355] The attachment unit 8201 may be provided with a plurality of electrodes at positions that come into contact with the user. The main body 8203 may have a function of recognizing the user's line of sight by detecting a current flowing through the electrodes in accordance with the movement of the user's eyeballs. The main body 8203 may also have a function of monitoring the user's pulse by detecting the current flowing through the electrodes. The attachment unit 8201 may also have various sensors such as a temperature sensor, a pressure sensor, and an acceleration sensor, and may have a function of displaying biological information of the user on the display unit 8204. The attachment unit 8201 may also detect the movement of the user's head, and change the image displayed on the display unit 8204 in accordance with the movement.

[0356] The display device of one embodiment of the present invention can be applied to the display portion 8204. This allows the power consumption of the head-mounted display 8200 to be reduced, and therefore the head-mounted display 8200 can be used continuously for a long period of time. Furthermore, by reducing the power consumption of the head-mounted display 8200, the battery 8206 can be made smaller and lighter, and therefore the head-mounted display 8200 can be made smaller and lighter. This reduces the burden on a user of the head-mounted display 8200, and the user can feel less fatigued.

[0357] 17B, ​​17C, and 17D are diagrams showing the external appearance of a head-mounted display 8300. The head-mounted display 8300 includes a housing 8301, a display portion 8302, a band-shaped fixture 8304, and a pair of lenses 8305. A battery 8306 is built into the housing 8301, and power can be supplied from the battery 8306 to the display portion 8302 and the like.

[0358] A user can view the display on the display portion 8302 through the lens 8305. Note that it is preferable to arrange the display portion 8302 in a curved manner. By arranging the display portion 8302 in a curved manner, a user can feel a high sense of presence. Note that although the configuration in which one display portion 8302 is provided has been illustrated in this embodiment, the present invention is not limited thereto. For example, two display portions 8302 may be provided. In this case, if one display portion is provided for one eye of the user, three-dimensional display using parallax or the like can be performed.

[0359] Note that the above-described display device can be applied to the display portion 8302. This allows the power consumption of the head-mounted display 8300 to be reduced, and therefore the head-mounted display 8300 can be used continuously for a long period of time. Furthermore, by reducing the power consumption of the head-mounted display 8300, the battery 8306 can be made smaller and lighter, and therefore the head-mounted display 8300 can be made smaller and lighter. This reduces the burden on the user of the head-mounted display 8300, and the user can be less likely to feel fatigued.

[0360] Next, an example of an electronic device different from the electronic device shown in FIGS. 17A to 17D is shown in FIGS. 18A and 18B.

[0361] The electronic device shown in Figures 18A and 18B has a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (including a function to measure force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays), and a battery 9009.

[0362] The electronic device shown in FIGS. 18A and 18B has various functions. For example, it may have a function to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date, or time, a function to control processing using various software (programs), a wireless communication function, a function to connect to various computer networks using the wireless communication function, a function to send or receive various data using the wireless communication function, a function to read programs or data recorded on a recording medium and display them on the display unit, etc. Note that the functions that the electronic device shown in FIGS. 18A and 18B can have are not limited to these, and it may have various other functions. Also, although not shown in FIGS. 18A and 18B , the electronic device may be configured to have multiple display units. Furthermore, the electronic device may be equipped with a camera or the like, and may have functions such as taking still images, taking videos, saving the captured images to a recording medium (external or built-in to the camera), and displaying the captured images on the display unit.

[0363] The electronic device shown in FIGS. 18A and 18B will be described in detail below.

[0364] FIG. 18A is a perspective view showing a mobile information terminal 9101. The mobile information terminal 9101 has one or more functions selected from, for example, a telephone, a notebook, an information viewing device, and the like. Specifically, it can be used as a smartphone. The mobile information terminal 9101 can display text or images on multiple surfaces. For example, three operation buttons 9050 (also referred to as operation icons or simply icons) can be displayed on one surface of the display unit 9001. Information 9051, indicated by a dashed rectangle, can be displayed on the other surface of the display unit 9001. Examples of the information 9051 include an indication of an incoming email, SNS (social networking service), or phone call, the title of the email or SNS message, the name of the sender of the email or SNS message, the date and time, the remaining battery level, and signal strength. Alternatively, the operation buttons 9050 or the like may be displayed in place of the information 9051.

[0365] The above-described display device can be applied to the portable information terminal 9101. This allows the power consumption of the portable information terminal 9101 to be reduced, and the portable information terminal 9101 can be used continuously for a long period of time. Furthermore, by reducing the power consumption of the portable information terminal 9101, the battery 9009 can be made smaller and lighter, and the portable information terminal 9101 can be made smaller and lighter. This allows the portable information terminal 9101 to be more portable.

[0366] FIG. 18B is a perspective view showing a wristwatch-type portable information terminal 9200. The portable information terminal 9200 can execute various applications such as mobile phone calls, e-mail, document browsing and creation, music playback, Internet communication, and computer games. The display surface of the display unit 9001 is curved, and a display can be performed along the curved display surface. FIG. 18B shows an example in which time 9251, operation buttons 9252 (also referred to as operation icons or simply icons), and content 9253 are displayed on the display unit 9001. The content 9253 can be, for example, a video.

[0367] The portable information terminal 9200 can also perform short-range wireless communication according to a communication standard. For example, hands-free conversation is also possible by mutual communication with a wirelessly enabled headset. The portable information terminal 9200 also has a connection terminal 9006, and can directly exchange data with another information terminal via a connector. Charging can also be performed via the connection terminal 9006. Note that charging may be performed by wireless power supply without using the connection terminal 9006.

[0368] The above-described display device can be applied to the portable information terminal 9200. This allows the power consumption of the portable information terminal 9200 to be reduced, and the portable information terminal 9200 can be used continuously for a long period of time. Furthermore, by reducing the power consumption of the portable information terminal 9200, the battery 9009 can be made smaller and lighter, and the portable information terminal 9200 can be made smaller and lighter. This allows the portable information terminal 9200 to be more portable.

[0369] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0370] ANO: wiring, BSL: bus wiring, GL: wiring, SL: wiring, SNCL: wiring, VCOM: wiring, 10: display device, 11: layer, 12: layer, 13: layer, 14: terminal section, 15: display section, 21: transistor, 22: channel formation region, 30: drive circuit, 31: source driver circuit, 32: digital-to-analog conversion circuit, 33: gate driver circuit, 34: level shifter, 40: functional circuit, 41: storage device, 42a: color unevenness correction, 42b: up-conversion, 42: GPU, 43: EL correction circuit, 44: timing controller, 45: CPU, 46: sensor controller controller, 47: power supply circuit, 51A: pixel circuit, 51B: pixel circuit, 51C: pixel circuit, 51D: pixel circuit, 51E: pixel circuit, 51F: pixel circuit, 51G: pixel circuit, 51H: pixel circuit, 51: pixel circuit, 52A: transistor, 52B: transistor, 52C: transistor, 52D: transistor, 52: transistor, 53A: capacitor, 53: capacitor, 54: channel formation region, 61B: display element, 61G: display element, 61R: display element, 61: display element, 62X_1: element, 62X_2: element, 62X_3: element, 62: element, 63: pixel, 100 A: display device, 100B: display device, 100C: display device, 100D: display device, 100E: display device, 111a: pixel electrode, 111b: pixel electrode, 111c: pixel electrode, 113a: first layer, 113b: second layer, 113c: third layer, 114: fourth layer, 115: common electrode, 120: substrate, 122: resin layer, 123: conductive layer, 125: insulating layer, 127: insulating layer, 130a: light-emitting device, 130b: light-emitting device, 130c: light-emitting device, 130d: element, 130e: element, 130f: element, 131: protective layer, 132: protective layer, 140: connection portion, 2 40: Capacitor, 241: Conductive layer, 243: Insulating layer, 245: Conductive layer, 251: Conductive layer, 252: Conductive layer, 254: Insulating layer, 255a: Insulating layer, 255b: Insulating layer, 256: Plug, 261: Insulating layer, 262: Insulating layer, 263: Insulating layer, 264: Insulating layer, 265: Insulating layer, 271: Plug, 274a: Conductive layer, 274b: Conductive layer, 274: Plug, 280: Display module, 281: Display section, 282: Circuit section, 283a: Pixel circuit, 283: Pixel circuit section, 284a: Pixel, 284: Pixel section, 285: Terminal section, 286: Wiring section, 290: FPC, 291: Substrate,292: substrate, 301A: substrate, 301B: substrate, 301: substrate, 310A: transistor, 310B: transistor, 310: transistor, 311: conductive layer, 312: low resistance region, 313: insulating layer, 314: insulating layer, 315: element isolation layer, 320A: transistor, 320B: transistor, 320: transistor, 321: semiconductor layer, 323: insulating layer, 324: conductive layer, 325: conductive layer, 326: insulating layer, 327: conductive layer, 328: insulating layer, 329: insulating layer, 331: substrate, 332: insulating layer, 341: conductive layer, 342: conductive electrical layer, 343: plug, 700: electronic device, 710: endoscope device, 711: monitor device, 712: doctor, 713: doctor, 714: doctor, 715: patient, 721: housing, 723: wearing part, 725: vibration module, 751: display panel, 752: optical member, 753: optical member, 754: lens, 756: display area, 757: frame, 758: nose pad, 761: external light, 763: light, 765: eye, 772: lower electrode, 785: colored layer, 786a: EL layer, 786b: EL layer, 786: EL layer, 788: upper electrode, 941: retina, 94 2: lens, 943: optic nerve, 944: optic disc, 945: vein, 946: artery, 947: vitreous body, 948: choroid, 950: optical system, 951: light emission, 960: eyebrow, 961: eyelash, 962: pupil, 963: cornea, 965: sclera, 966: upper eyelid, 967: lower eyelid, 980: display device, 4411: light-emitting layer, 4412: light-emitting layer, 4413: light-emitting layer, 4420: layer, 4421: layer, 4422: layer, 4430: layer, 4431: layer, 4432: layer, 8200: head-mounted display, 8201: mounting part, 8202: lens, 82 03: main body, 8204: display unit, 8205: cable, 8206: battery, 8300: head-mounted display, 8301: housing, 8302: display unit, 8304: fixture, 8305: lens, 8306: battery, 9000: housing, 9001: display unit, 9003: speaker, 9005: operation keys, 9006: connection terminal, 9007: sensor, 9009: battery, 9050: operation button, 9051: information, 9101: mobile information terminal, 9200: mobile information terminal, 9251: time, 9252: operation button, 9253: content,

Claims

1. A display device having a plurality of pixels for detecting fatigue of a user, Each of the plurality of pixels includes a light emitting device, a sensor device, and a circuit device; the light emitting device and the sensor device are provided on a first layer; the circuit device is disposed on a second layer; The light emitting device includes a lower electrode, an upper electrode, and a light emitting layer disposed between the lower electrode and the upper electrode; the sensor device has a function of detecting light emitted from the light-emitting device, the first layer is disposed on the second layer; the light emitting device emits near infrared light; When the user closes his / her eyelids, the near-infrared light is reflected by the surface of the eyelid and detected by the sensor device; When the user has his / her eyelids open, the near-infrared light is reflected by the surface of the user's eyeball and detected by the sensor device; Detecting one or both of the number of blinks of the user and the time taken for one blink. Display device.

2. A display device having a plurality of pixels for detecting fatigue of a user, each of the plurality of pixels includes a light emitting device, a sensor device, a first circuit device, and a second circuit device; the light emitting device and the sensor device are provided on a first layer; the first circuit device is disposed on a second layer; the second circuit device is disposed on a third layer; The light emitting device includes a lower electrode, an upper electrode, and a light emitting layer disposed between the lower electrode and the upper electrode; the sensor device has a function of detecting light emitted from the light-emitting device, the first circuit device has a function of driving the light-emitting device or the sensor device; the second circuit device has a function of performing a calculation based on information output from the first circuit device; the first layer is disposed on the second layer; the second layer is disposed on the third layer; the light emitting device emits near infrared light; When the user closes his / her eyelids, the near-infrared light is reflected by the surface of the eyelid and detected by the sensor device; When the user has his / her eyelids open, the near-infrared light is reflected by the surface of the user's eyeball and detected by the sensor device; Detecting one or both of the number of blinks of the user and the time taken for one blink. Display device.

3. In claim 1 or 2, When the cross section of the light-emitting device was observed, A side surface of the lower electrode and a side surface of the light emitting layer have a region that coincides or approximately coincides with each other. Display device.

4. In any one of claims 1 to 3, an insulator is provided between the light emitting device and an adjacent light emitting device; The insulator includes either an inorganic material or an organic material, or both of them. Display device.

5. In claim 4, The insulator includes a photosensitive organic resin. Display device.

6. In claim 2, the first circuit device includes a first transistor; the first transistor has a metal oxide in a channel formation region; Display device.

7. In claim 2, the second circuit device includes a second transistor; the second transistor has silicon in a channel formation region; Display device.

8. A display device having a plurality of pixels for detecting fatigue of a user, Each of the plurality of pixels includes a first sub-pixel to a sixth sub-pixel, the first subpixel has a first light-emitting device capable of emitting red light; the second subpixel has a second light-emitting device operable to emit green light; the third subpixel has a third light-emitting device capable of emitting blue light; At least one of the fourth subpixel to the sixth subpixel has a first sensor device; each of the first subpixel to the sixth subpixel includes a circuit device; the first light emitting device, the second light emitting device, and the first sensor device are provided on a first layer; the circuit device is disposed on a second layer; each of the first light emitting device to the third light emitting device includes a lower electrode, an upper electrode, and a light emitting layer provided between the lower electrode and the upper electrode; the first sensor device has a function of detecting light emitted from the pixel; the first layer is disposed on the second layer; the fourth subpixel has a fourth light emitting device having a function of emitting infrared light; the fifth sub-pixel has the first sensor device; the sixth sub-pixel has a second sensor device; the fifth subpixel has a function of detecting visible light, the sixth subpixel has a function of detecting infrared light, When the user closes his / her eyelids, the infrared light is reflected by the surface of the eyelid and detected by the sensor device; When the user has his / her eyelids open, the infrared light is reflected by the surface of the user's eyeball and detected by the sensor device; Detecting one or both of the number of blinks of the user and the time taken for one blink. Display device.

9. In claim 8, Each of the first subpixel to the sixth subpixel is A light-emitting region or a light-receiving region having a side of 1 μm or more and 10 μm or less, The distance between adjacent subpixels is less than 1 μm. Display device.

10. A display device according to any one of claims 1 to 9, A housing in which the display device is provided; A sensor provided in the housing; A battery provided in the housing and supplying power to the display device. electronic equipment.

11. At least two display devices according to any one of claims 1 to 10; A housing in which the display device is provided; A sensor provided in the housing; a battery provided in the housing and configured to supply power to the display device; The housing has a mounting portion and a pair of lenses, an image is projected onto one of the pair of lenses from one of the two display devices; An image is projected onto the other of the pair of lenses from the other of the two display devices. electronic equipment.