Display device

Abstract

To provide a display device with reduced power consumption, alternatively, a display device that displays an image in a usable area in a folded state.SOLUTION: There is provided a configuration having an expandable and foldable display unit, a detection unit that detects the folded state, and an image processing unit that generates an image that displays a black image on a part of the display unit according to the folded state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an article, a method, or a manufacturing method. Alternatively, the present invention relates to a process, a machine, relating to the manufacture or composition of matter, especially The present invention is applicable to, for example, a human interface, a semiconductor device, a display device, a light-emitting device, The present invention relates to an electric storage device, a driving method thereof, or a manufacturing method thereof. For example, the present invention relates to a display device. In particular, one aspect of the present invention relates to a foldable display device. . [Background technology]

[0002] The social infrastructure related to information transmission methods has been improved. This allows diverse and abundant information to be shared at work and in the workplace. It is now possible to acquire, process, or send information using information processing devices not only at home but also on the go. are.

[0003] In this context, portable information processing devices have been actively developed.

[0004] For example, portable information processing devices are often used outdoors, and may be subject to unexpected force if dropped. This may be applied to information processing devices and the display devices used therein. As an example of the device, a structure in which the adhesion between the structure separating the light-emitting layer and the second electrode layer is improved is provided. is known (Patent Document 1).

[0005] Also, a first acceleration data is received from a first sensor coupled to the first portion of the electronic device. A multi-panel electronic device is known that includes a function for receiving data from a second panel of the electronic device. and receiving second acceleration data from a second sensor coupled to the portion of the sensor; A multi-panel electronic device is known in which the position of the first portion is movable relative to the position of the second portion. Also, the acceleration data is based at least in part on the first acceleration data and the second acceleration data.

[0005] A multi-panel electronic device is known that further includes a function for determining the configuration of the electronic device based on the It is disclosed in Patent Document 2. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-190794 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-502372 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of one embodiment of the present invention is to provide a display device with reduced power consumption. Alternatively, the object is to provide a display device that displays an image in a usable area in a folded state. Another object of the present invention is to provide a novel display device.

[0008] The description of these problems does not preclude the existence of other problems. It is not necessary for the present invention to solve all of these problems. The above will be made clear from the description, drawings, claims, etc. It is possible to extract other issues from the descriptions in the patent, claims, etc. [Means for solving the problem]

[0009] One aspect of the present invention is a display device comprising: a foldable display unit having a first area and a second area; a detection unit that detects the folded state of the display unit and supplies a folding signal; a control unit which receives the image signal and supplies an image control signal; an image processing unit that generates and supplies an image signal; and a drive circuit that receives the image signal and drives the display unit. The control unit controls the second area of ​​the display unit in the folded state to be black. An image control signal is provided to cause the image processing unit to generate an image to display the image.

[0010] In one aspect of the present invention, the control unit stores a program to be executed by the calculation unit. The program includes a first step of permitting interrupt processing and a display unit If it is unfolded, go to the third step, if it is folded, go to the fourth step. The second step is to move forward and the third step is to generate the images to be displayed in the first and second areas. a fourth step of generating an image that displays a black image in the second area; The fifth step displays the execution status, and the seventh step if an end command is given by the interrupt handler. If no termination command is given, the sixth step goes back to the second step. and a seventh step in which the interrupt process allows the operation. and a ninth step of returning from the interrupt process.

[0011] The display device according to one embodiment of the present invention includes a display unit that can be unfolded and folded, and a display unit that can be folded. The device detects whether the device is folded or not, and displays a black image on part of the display depending on the folded state. The display unit includes an image processing unit that generates an image. This allows a black image to be displayed in the area that is no longer required for display. As a result, power consumption is reduced. This allows for a reduced viewing area, or allows for an image to be displayed in the usable area when folded. It is possible to provide a display device that displays the

[0012] One aspect of the present invention is a display device comprising: a foldable display unit having a first area and a second area; a detection unit that detects the folded state of the display unit and supplies a folding signal; a control unit to which the image control signal is supplied and which supplies an image control signal and a synchronization control signal; an image processing unit configured to generate and supply a first image signal and a second image signal; a synchronization signal supply unit that receives the control signal and supplies a first synchronization signal and a second synchronization signal; a first driving circuit to which the first image signal and the first synchronization signal are supplied and which drives the first region; a second driving circuit to which a second image signal and a second synchronization signal are supplied and which drives a second region; The display device has a second circuit and a control unit. An image control signal for generating an image in which a black image is displayed in the area of ​​the folded state and a display in the folded state a synchronization control signal that stops the selection of scan lines in the second region of the section;

[0013] In one aspect of the present invention, the control unit stores a program to be executed by the calculation unit. The program includes a first step of permitting interrupt processing and a display unit If it is unfolded, go to the third step, if it is folded, go to the fourth step. If there is no change in the deployed state, proceed to the second step and to the fifth step. If the state changes from closed to folded, go to step 6. If there is no change in the folded state, go to the seventh step, and the folded state is unfolded. If the state changes to the one specified, proceed to step 8. Execute step 4 and process 1. The fifth step, the sixth step that executes process 2, and the seventh step that executes process 3. Step 8 executes process 4, and if an end command is given in the interrupt process, If the end command is not given, the ninth step goes to the tenth step and returns to the second step. and a tenth step of terminating the process. and a twelfth step of returning from the interrupt process. The display device is as described above.

[0014] Another aspect of the present invention is the display device described above, which includes the following four processes: Process 1: a first switch for causing the synchronization signal supply unit to supply a synchronization signal to the first drive circuit and the second drive circuit; a second step of causing an image processing unit to generate images to be displayed in the first area and the second area. a third step of displaying an image on the display unit; and a fourth step of returning from process 1. The second process includes a step of supplying a synchronization signal to the synchronization signal supplying unit to the first driving circuit and the second driving circuit. a first step of supplying a black image to a second driving circuit and displaying the black image in the second region in an image processing unit; a second step of generating an image corresponding to the image; and a third step of displaying the image on a display unit. a fourth step of causing the synchronization signal supply unit to stop supplying the synchronization signal to the second drive circuit in sequence; and a fifth step of returning from the process 2. The third process is performed by the synchronization signal supply unit. A first step of supplying a synchronization signal to a first driving circuit, and an image processing unit for displaying an image in a first area. a second step of generating an image showing the image in the first area; and a third step of displaying the image in the first area on the display unit. and a fourth step of returning from process 3. The fourth process is a first step of causing a signal supply unit to sequentially supply a synchronization signal to a second drive circuit; a second step of generating images to be displayed in the first area and the second area; The method includes a third step of displaying the image and a fourth step of returning from the process 4.

[0015] The display device according to one embodiment of the present invention includes a display unit that can be unfolded and folded, and a display unit that can be folded. The device detects whether the device is folded or not, and displays a black image on part of the display depending on the folded state. Stop supplying the synchronization signal used for the image processing unit that generates the image and the part that displays the black image. and a synchronization signal supply unit that can fold a part of the display unit. It is possible to stop displaying areas that are no longer needed for display by folding them. As a result, power consumption Alternatively, it is possible to provide a display device in which the image is reduced in the area that can be used in the folded state. It is possible to provide a display device that displays the above.

[0016] Furthermore, one embodiment of the present invention is a semiconductor device including a first power supply that supplies a power supply potential to a first driver circuit and a second driver circuit. a second power supply that supplies a power supply potential to the operating circuit, and the control unit, in response to a folding signal, A power supply control signal is supplied to the second power supply, and the second power supply controls the supply of a power supply potential in response to the power supply control signal. The display device as described above stops the supply.

[0017] The display device according to one embodiment of the present invention includes a display unit that can be unfolded and folded, and a display unit that displays a black image. a synchronization signal supply unit that can stop the supply of a synchronization signal used for a part that displays a black image; and a power supply that can stop supplying a power supply potential used for the portion that is to be controlled. This allows a part of the display to be folded and the display to be stopped in an area that is no longer required for display. As a result, a display device with reduced power consumption can be provided. It is possible to provide a display device that displays an image in a usable area in a closed state.

[0018] Furthermore, one aspect of the present invention is a method for detecting a magnetic field by using a magnet, the detection unit including a magnetic sensor, and the magnet including a magnetic sensor. The display device is arranged in a position where the sensor can detect whether the display unit is unfolded or folded. It is a location.

[0019] The display device according to one embodiment of the present invention includes a display unit that can be unfolded and folded, and a display unit that can be folded. a detection unit including a magnet and a magnetic sensor arranged to detect a folded state; and an image processing unit that generates an image to display a black image on a part of the display unit according to the state of the display unit. This allows a black image to be displayed in the area that is no longer needed for display because part of the display is folded. The magnetic force of the magnet can be used to keep the folded state. As a result, a display device with reduced power consumption can be provided. It is possible to provide a display device that displays an image in a usable area in any state. [Effects of the Invention]

[0020] According to one embodiment of the present invention, a display device with reduced power consumption can be provided. It is possible to provide a display device that displays an image in a usable area in a closed state. [Brief explanation of the drawings]

[0021] [Figure 1] 1A and 1B are a block diagram and a schematic diagram illustrating a structure of a display device according to an embodiment. [Figure 2] 1A and 1B are a block diagram and a circuit diagram illustrating a configuration of a display portion of a display device according to an embodiment. [Figure 3]FIG. 4 is a flowchart illustrating an operation of a control unit of the display device according to the embodiment. [Figure 4] FIG. 1 is a block diagram illustrating a configuration of a display device according to an embodiment. [Figure 5] FIG. 4 is a flowchart illustrating an operation of a control unit of the display device according to the embodiment. [Figure 6] FIG. 4 is a flowchart illustrating a process performed by a control unit of the display device according to the embodiment. [Figure 7] 1A and 1B are external views illustrating a structure of a display device according to an embodiment. [Figure 8] 1A to 1C illustrate a structure of a display device according to an embodiment. [Figure 9] 1A to 1C illustrate a structure of a display panel that can be applied to a display device according to an embodiment. [Figure 10] 1A to 1C illustrate a structure of a transistor that can be used in a display device according to an embodiment. [Figure 11] 1A to 1C illustrate a structure of a display panel that can be applied to a display device according to an embodiment. [Figure 12] 1A to 1C illustrate a structure of a display panel that can be applied to a display device according to an embodiment. [Figure 13] 1A to 1C illustrate a structure of a display panel that can be applied to a display device according to an embodiment. [Figure 14] FIG. 2 is a block diagram illustrating a configuration of a display portion of a display device according to an embodiment. [Figure 15] 1A and 1B are a block diagram and a circuit diagram illustrating a configuration of a display portion of a display device according to an embodiment. [Figure 16] FIG. 1 is a block diagram illustrating a configuration of a display device according to an embodiment. [Figure 17] FIG. 1 is a block diagram illustrating a configuration of a display device according to an embodiment. [Figure 18] FIG. 1 is a block diagram illustrating a configuration of a display device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. The present invention is not limited to the above embodiments, and various changes and modifications may be made in the form and details thereof without departing from the spirit and scope of the present invention. It will be readily understood by those skilled in the art that the present invention can be achieved by the following embodiments. It should not be construed as being limited to the contents of the description. The same reference numerals are used in different drawings to denote the same parts or parts having similar functions. A repeated explanation will be omitted.

[0023] (Embodiment 1) In this embodiment, a structure of a display device according to one embodiment of the present invention will be described with reference to FIGS. I will explain.

[0024] FIG. 1 is a block diagram and a schematic diagram illustrating a structure of a display device according to one embodiment of the present invention.

[0025] FIG. 2 illustrates a display portion that can be used in a display device of one embodiment of the present invention. FIG. 2(A) is a block diagram illustrating the configuration of the display unit, and FIG. 2(B) is an EL (Electroluminescent) Pixel circuits when a fluoroluminescence element is applied to a display element are explained. FIG.

[0026] 3A is a flowchart illustrating the operation of a control unit in a display device according to one embodiment of the present invention. FIG. 3(B) is a flow chart explaining the main processing, and FIG. 3(C) is a flow chart explaining the interrupt processing. -Figure.

[0027] The display device 200 described in this embodiment is foldable and has a first region 230(1) and a display unit 230 having a second region 230(2), and a display unit 230 in a folded state. a detector 240 that detects the state of the folding mechanism and supplies a folding signal F; a control unit 210 that supplies an image control signal VC; an image processing unit 220 that supplies an image signal VIDEO; and a display unit 230 that receives an image signal VIDEO. and a driving circuit 232 for driving the first region 230(1) (see FIG. 1). The display device 200 can be operated by the user in either the unfolded or folded state. The second area 230(2) is an area that is visible when the display device 200 is folded. This area is inside when the device is closed and is not visible to the user.

[0028] Then, the control unit 210 displays the second area 230(2) of the display unit 230 in the folded state. An image control signal VC is supplied to the image processing unit 220 to generate an image displaying a black image.

[0029] The control unit 210 of the display device 200 described in this embodiment includes a calculation unit and a The program includes a storage unit for storing a program to be executed. The program includes the following steps: It is equipped with a pool.

[0030] In the first step, interrupt processing is enabled (Fig. 3(A)(Q1)). An operation unit that is enabled for interrupt processing can accept an instruction to execute interrupt processing. Then, the processing unit that receives the command to execute the interrupt process stops the main process and executes the interrupt. For example, to handle an event associated with an instruction that handles an interrupt. The supplied arithmetic unit suspends the main processing, executes the interrupt processing, and After that, the calculation unit returns to the main process from the interrupt process and stores the result of the interrupt in the memory unit. Based on the execution result of the reference process, the main process can be resumed.

[0031] In the second step, if the display unit 230 is in an unfolded state, the process advances to the third step. If it is folded, proceed to the fourth step (Fig. 3(A)(Q2)). The folded signal F is acquired, and a judgment is made based on the acquired folded signal F.

[0032] In the third step, the first area 230(1) and the second area 230(2) are displayed. An image is generated (FIG. 3(A)(Q3)). Note that since the display unit 230 is unfolded, the display The entire surface of the display unit 230, in other words, the first area 230(1) and the second area 230(2) can be used to display the image.

[0033] In the fourth step, an image is generated that displays a black image in the second region 230(2) ( 3(A)(Q4)). Note that, since the display unit 230 is folded, one part of the display unit 230 In other words, only the first area 230(1) can be used to display an image. .

[0034] In the fifth step, an image is displayed on the display unit 230 (FIG. 3(A)(Q5)).

[0035] In the sixth step, if an end command is issued by the interrupt process, the process proceeds to the seventh step. If no end command is given, the process returns to the second step (FIG. 3(A)(Q6)).

[0036] In the seventh step, the process ends (FIG. 3(A)(Q7)).

[0037] The interrupt process also has an eighth step that allows the operation and a third step that returns from the interrupt process. 9 steps (Fig. 3(B) (R8) and (R9)). For example, the user of the display device 200 can You can provide commands to select an image to be displayed or to exit the program.

[0038] The display device 200 according to the embodiment of the present invention includes a display unit 230 that can be unfolded and folded, and a detection unit 240 that detects the folded state of the folding device, and a display unit 230 that displays the folded state of the folding device. It includes an image processing unit 220 that generates an image in which a black image is displayed in a part of the image. As a result, a black image is displayed in the area where a part of the display unit 230 is folded and no longer required for display. As a result, a display device with reduced power consumption can be provided. It is possible to provide a display device that displays an image in a usable area in a closed state.

[0039] In addition, the display device 200 described as an example in this embodiment supplies a power supply potential to the drive circuit 232. a power supply unit 214 that supplies a synchronization signal SYNC to the drive circuit 232; 212 and

[0040] The drive circuit 232 includes a scanning line drive circuit 232G and a signal line drive circuit 232S. 14, the scanning line driving circuit 232G and the signal line driving circuit 23 2S may be arranged in the opposite position. ) means that the scanning line driving circuit 232G and the signal line driving circuit 232S are arranged in reverse positions. In that case, the pixel 631p is also rotated by 90 degrees as shown in FIG. do.

[0041] The detection unit 240 detects the marker 239 to detect whether the display unit 230 is folded.

[0042] The relative positions of the marker 239 and the detection unit 240 change depending on the folded state of the display unit 230. For example, a sign 239 is placed near the display unit 230 so that the detection unit 240 detects the folded state of the display unit 230 and supplies a folding signal F. can.

[0043] The individual elements constituting the display device 200 according to one embodiment of the present invention will be described below.

[0044] Foldable display The foldable display unit 230 is divided into a first area 230(1) and a second area 230(2). The display unit 230 includes a display panel having a display element and a and a supporting housing.

[0045] The display panel has pixel sections in a first region 230(1) and a second region 230(2). The image is displayed in the first area 230(1) and the second area 230(2) consecutively. For example, when the user places the element at the boundary between the first area 230(1) and the second area 230(2), The pixels are spaced at equal intervals from the first region to the second region so that the boundary 230b(1) cannot be identified. (See Figure 1(A)).

[0046] The pixel portion has a plurality of pixels, a plurality of scanning lines, and a plurality of signal lines.

[0047] Each pixel has a pixel circuit electrically connected to one scanning line and one signal line, and a It has a display element electrically connected thereto.

[0048] The display panel applicable to the foldable display unit 230 is, for example, a flexible substrate. For example, a display panel includes a display element on the substrate. Whether the cut surface is facing inward or outward, the curvature radius must be between 1mm and 100mm. Specifically, an inorganic film on which pixels are formed is placed between flexible films. A sandwiched configuration can be applied.

[0049] The foldable display unit 230 may be folded at a boundary 230b(1), for example. It has a hinge that can be folded (see Figure 1(B-1) and Figure 1(B-2)).

[0050] The display unit 230 described in this embodiment can be folded into three, but is not limited to this. Specifically, even if the display unit 230 has a configuration that can be folded into two, it is not possible to fold it into four or more pieces. The more folds that can be made, the easier it is to fold. The external dimensions can be made small when folded, which increases portability.

[0051] The display unit 230 has a boundary 230b(1) between the first area 230(1) and the second area 230(2). ) can be folded.

[0052] FIG. 1(B-1) shows the display unit 230 unfolded and spread out flat.

[0053] The folded state of the display unit 230 is shown in FIG. , mountain fold at boundary 230b(1), valley fold at boundary 230b(2), and third fold. Indicates the status that has been changed.

[0054] In particular, when the display device 200 is folded, the first region 230(1) is 200. This allows the user to use the first The display in the first area 230(1) can be seen.

[0055] An example of the configuration of the foldable display unit 230 will be described in detail in the third embodiment. do.

[0056] <Drive circuit> The drive circuit 232 includes a scanning line drive circuit 232G and a signal line drive circuit 232S. The driving circuit 232 can be configured using various sequential circuits such as a shift register. In addition, when a driver circuit configured with an LSI is arranged on a flexible display unit, The pixel circuit can be formed in the same process as the pixel circuit. The drive circuit can be placed at the bent portion of the flexible display unit. It is preferable to have fewer restrictions on the

[0057] The scanning line driving circuit 232G is supplied with a power supply potential and a synchronization signal SYNC, and supply.

[0058] The signal line driving circuit 232S is supplied with a power supply potential, a synchronization signal SYNC, and an image signal VIDEO. and supplies an image signal.

[0059] The display unit 230 is supplied with a scanning line selection signal, and one scanning line and the pixel connected to it are selected. can be.

[0060] The pixel to which the scanning line selection signal is supplied is supplied with an image signal, and the pixel circuit arranged in that pixel The path stores the image signal. The display element arranged in the pixel displays the image in response to the image signal. do.

[0061] <Synchronization signal supply unit> The synchronization signal supply unit 212 supplies a synchronization signal SYNC. 232 operate in synchronization, for example, vertical synchronization signal and horizontal synchronization signal. In addition to the initial signal, the start pulse signal SP, latch signal LP, pulse width control signal PWC, An example of such a signal is the clock signal CLK.

[0062] 《Power supply section》 The power supply unit 214 supplies a power supply potential. The power supply potential is a high-potential power supply potential ( For example, VDD) and the power supply potential on the low potential side (for example, VSS, GND) It is possible to supply either one or both. In addition, multiple voltages (e.g., VDD1, V DD2) may also be supplied.

[0063] Image Processing Section The image processing unit 220 receives the image control signal VC, generates an image, and outputs the image of the generated image. Provides the signal VIDEO.

[0064] The image signal VIDEO is transmitted to the first area 230(1) and the second area 230(2) of the display unit 230. (2) Contains information about the image to be displayed.

[0065] For example, the image processing unit 220 controls the first area 230(1) and the second area 230(2) in response to the image control signal VC. An image to be displayed in the second area 230(2) can be generated. In response to the signal VC, an image is generated in the second region 230(2), for example, a black image is displayed. For example, the darkest gradation that the display element can display can be The image is called a black image.

[0066] By displaying a black image on the display element, other images (e.g., white image, gray image, etc.) can be displayed. This reduces the power consumption of the display device 200. can.

[0067] Specifically, the second area 230(2) is folded so that the display is not visible. Power consumption can be reduced.

[0068] A display element that consumes less power when displaying a black image than when displaying other images An example of such a display element is a light-emitting element. The power consumption of the display element is lowest at a gray level different from the darkest possible gray level. In this case, an image including that gradation may be displayed instead of the black image.

[0069] <Detection unit and sign> The detector 240 detects the folded state of the display unit 230 and supplies a folding signal F. The folding signal F is information indicating a folded state or information indicating an unfolded state. Includes:

[0070] The detection unit 240 includes a sensor that detects the nearby sign 239. By detecting the sign 239 arranged near the display unit 230, the detection unit 240 A folding signal F can be supplied according to the folded state of the

[0071] The signs 239 can be, for example, the shape and arrangement of objects such as protrusions, light, radio waves, etc. Or, electromagnetic waves such as magnetic force can be mentioned. Specifically, different polarities (for example, the polarity of a magnet) have different signals (e.g. electromagnetic waves modulated in different ways) Examples include:

[0072] The sensor that can be used in the detection unit 240 is selected to be able to identify the sign 239. There are.

[0073] Specifically, when a structure (e.g., a protrusion) with a different shape or arrangement is used for the sign 239, , and switches or the like having different shapes or arrangements are used as sensors so that their structures can be identified. Alternatively, when light is used for the sign 239, a photoelectric conversion element or the like may be used as a sensor. Alternatively, if the sign 239 uses radio waves, an antenna or the like can be used as a sensor. Alternatively, if a magnet is used for the sign 239, a magnetic sensor or the like may be used. can be done.

[0074] In addition to the folding signal F, the detection unit 240 also receives acceleration, orientation, and GPS (Global Positioning System) signals. Positioning System) signals, temperature, humidity, etc. are detected and the information is Information may be provided.

[0075] A configuration in which a magnet is used for the sign 239 and a magnetic sensor that detects the magnetic force of the magnet is used for the detection unit 240 We will explain about this.

[0076] The display device 200 has a magnet as a sign 239, and the detection unit 240 has a magnetic sensor. The stone is placed in a position where the magnetic sensor can detect whether the display unit 230 is unfolded or folded. will be done.

[0077] The display device 200 described in this embodiment includes a display unit 230 that can be unfolded and folded, A magnet (marker 239) and a magnetic sensor arranged to detect the folded state. and a detection unit 240 having a part of the display unit 230 (specifically, the first The image processing unit 220 generates an image that displays a black image in the second area. As a result, a part of the display unit 230 is folded and an area that is no longer required for display (specifically, the second In addition, a black image can be displayed in the folded state using the magnetic force of a magnet. As a result, a display device with reduced power consumption can be provided. Alternatively, it is possible to provide a display device that displays an image in a usable area in a folded state. is a display device that prevents the device from unintentionally changing from a folded state to an unfolded state. We can provide it.

[0078] Control Unit The control unit 210 receives the folding signal F and can provide an image control signal VC. In addition, signals for controlling the power supply unit 214 and the synchronization signal supply unit 212 may be supplied.

[0079] The image control signal VC is a signal for controlling the image processing unit 220. For example, the display unit 2 30 includes a signal that causes the image processor 220 to generate different images depending on the folded state. nothing.

[0080] Timing Generator The timing generator generates and supplies a reference clock signal and other signals required by the display device 200. do.

[0081] Configuration of the display unit 230 The display unit 230 has a plurality of pixels 631p and wiring that connects the plurality of pixels 631p. (See FIG. 2(A) and FIG. 15(A)). The type and number of wirings are determined by the pixel 63. This may be determined appropriately depending on the configuration, number and arrangement of 1p.

[0082] Each pixel 631p is electrically connected to at least one scanning line and one signal line. are.

[0083] For example, when the pixels 631p are arranged in the display unit 230 in a matrix of x columns and y rows, In this case, the signal lines S1 to Sx and the scanning lines G1 to Gy are arranged in the display unit 230. (See FIG. 2(A) and FIG. 15(A)). The scanning lines G1 to Gy are selected by the scanning line selection signals. The signal lines S1 to Sx are connected to the scanning line selection signals. An image signal can be supplied to the pixels.

[0084] 《Pixel 631p Configuration》 The pixel 631p includes a display element and a pixel circuit including the display element.

[0085] The pixel circuit holds the supplied image signal and displays it on the display element. The pixel circuit is configured as follows: The light emitting device is appropriately selected and used depending on the type of display element or the driving method.

[0086] The display element may be an EL element, an electronic ink using electrophoresis, a liquid crystal element, or the like.

[0087] As an example of a pixel circuit, a configuration in which an EL element is used as a display element is shown in FIG. 2(B) and FIG. 15( B).

[0088] The pixel circuit 634EL is electrically connected to the scanning line G, which can supply a scanning line selection signal. and a gate electrode electrically connected to a signal line S for supplying an image signal. and a second electrode electrically connected to the first electrode of the capacitor 634c. The first transistor 634t_1 is connected to the first transistor 634t_2.

[0089] A gate electrode electrically connected to the second electrode of the first transistor 634t_1; a first electrode electrically connected to the second electrode of the capacitor 634c; and a second electrode electrically connected to the first electrode of L; has t_2.

[0090] In addition, the second electrode of the capacitor 634c and the first electrode of the second transistor 634t_2 can supply a power supply potential and a potential required to make the EL element 635EL emit light. The potential of the wiring A may be constant or may be changed for a predetermined period. The second electrode of the EL element 635EL may be supplied with a common potential. The potential difference between the power supply potential and the common potential is This is greater than the light emission start voltage of the EL element 635EL.

[0091] The EL element 635EL has a layer containing a light-emitting organic compound between a pair of electrodes.

[0092] Transistor The second transistor 634t_2 supplies a current according to the potential of the signal line S, and The second transistor 634t_2 controls the light emission of the first transistor 35EL. The region includes silicon, an oxide semiconductor, or the like.

[0093] A transistor suitable for the first transistor 634t_1 and the second transistor 634t_2 may be used. An example of the transistor is a transistor including an oxide semiconductor.

[0094] A transistor using an oxide semiconductor film has a leakage current between the source and drain in an off state. (off-state current) is extremely low compared to conventional silicon transistors. The first transistor 634t_1 and the second transistor 634t_2 are preferably An example of a suitable structure of a transistor will be described in Embodiment 4.

[0095] Note that this embodiment mode can be appropriately combined with other embodiment modes shown in this specification. .

[0096] (Embodiment 2) In this embodiment, the structure of a display device according to one embodiment of the present invention will be described with reference to FIGS. I will explain.

[0097] FIG. 4 is a block diagram illustrating a configuration of a display device according to one embodiment of the present invention.

[0098] 5A is a flowchart illustrating the operation of a control unit in a display device according to one embodiment of the present invention. FIG. 5(B) is a flow chart explaining the main processing, and FIG. 5(C) is a flow chart explaining the interrupt processing. -Figure.

[0099] 6A to 6D show processes 1 to 4 performed by a control unit of a display device according to one embodiment of the present invention. FIG.

[0100] The display device 200B described in this embodiment is foldable and has a first area 230 (1 ) and a second region 230(2), and a display unit 230 folded A detector 240 detects the state and supplies a folding signal F, and a signal F is supplied to the detector 240. , a control unit 210B that supplies an image control signal VC and a synchronization control signal SC; VC is supplied, and the first image signal VIDEO(1) and the second image signal VIDEO(2) are output. ), and an image processing unit 220 that receives a synchronization control signal SC and a first synchronization signal SYN a synchronization signal supply unit 212 that supplies a first synchronization signal SYNC(1) and a second synchronization signal SYNC(2); The image signal VIDEO(1) and the first synchronization signal SYNC(1) are supplied to the first area. a first driving circuit 232(1) for driving the second image signal VIDEO( 2) and a second synchronization signal SYNC(2) are provided to drive the second region 230(2). and a second drive circuit 232(2) that drives the first driving circuit.

[0101] Then, the control unit 210B controls the second area 230(2) of the display unit 230 in the folded state. an image control signal VC for generating an image that displays a black image on the display unit in a folded state; 230(2) provides a synchronization control signal SC that stops the selection of the scan lines in the second region 230(2). do.

[0102] Furthermore, the control unit 210B of the display device 200B described in this embodiment includes a calculation unit and a calculation The program includes a storage unit that stores a program to be executed by the following unit. Equipped with a step.

[0103] In the first step, interrupt processing is permitted (FIG. 5(A)(S1)).

[0104] In the second step, if the display unit 230 is in an unfolded state, the process advances to the third step. If it is in a folded state, proceed to the fourth step (FIG. 5(A)(S2)). The folded signal F is acquired, and a judgment is made based on the acquired folded signal F.

[0105] In the third step, if there is no change in the deployed state of the display unit 230, the fifth step is performed. If the state changes from unfolded to folded, go to step 6 ( (Fig. 5(A)(S3)). Note that the folding signal F obtained in the immediately preceding second step is , and compares the folding signal F stored in the memory unit before that to see if there is a change in state. If there is a change in the unfolded state of the display unit 230, the folding signal F is re-stored and the memory in the memory unit is updated.

[0106] In the fourth step, if the folded state of the display unit 230 remains unchanged, the seventh step is performed. If the state changes from folded to unfolded in step 8, proceed to step 8. (Fig. 5(A)(S4)). Note that the folded signal F obtained in the immediately preceding second step The folding signal F stored in the memory unit before that is compared to determine whether there is a change in the state. Also, if there is a change in the folded state of the display unit 230, a folding signal is sent. Re-store number F and update the memory unit.

[0107] In the fifth step, process 1 is executed (FIG. 5(A)(S5)).

[0108] In the sixth step, process 2 is executed (FIG. 5(A)(S6)).

[0109] In the seventh step, process 3 is executed (FIG. 5(A)(S7)).

[0110] In the eighth step, the process 4 is executed (FIG. 5(A)(S8)).

[0111] In the ninth step, if an end command is issued by the interrupt process, the tenth step If the end command is not supplied, the process returns to the second step (FIG. 5(A)(S9)).

[0112] In the tenth step, the process ends (FIG. 5(A)(S10)).

[0113] The interrupt process also includes an 11th step that allows the operation and a return step that returns from the interrupt process. and a twelfth step (FIG. 5(B) (T11) and (T12)).

[0114] The control unit 210B of the display device 200B described in this embodiment executes four processes. The program that executes the four processes is , comprising the following steps:

[0115] Process 1 In the first step of the process 1, the first synchronization signal SYNC( 1) to the first driving circuit 232(1), and the second synchronization signal SYNC(2) to the second The drive circuit 232(2) supplies it (FIG. 6(A)(U1)).

[0116] In the second step, the image processor 220 is configured to process the first region 230(1) and the second region 230(2). The image to be displayed is generated in 230(2) (FIG. 6(A)(U2)).

[0117] In the third step, the image is displayed on the display unit 230 (FIG. 6(A)(U3)). .

[0118] In the fourth step, the process returns from process 1 (FIG. 6(A)(U4)).

[0119] Process 2 In the first step of the process 2, the first synchronization signal SYNC( 1) to the first driving circuit 232(1), and the second synchronization signal SYNC(2) to the second The drive circuit 232(2) supplies it (FIG. 6(B)(V1)).

[0120] In the second step, the image processor 220 is instructed to display a black image in the second area 230(2). An image is generated (Fig. 6(B)(V2)).

[0121] In the third step, an image is displayed on the display unit 230 (FIG. 6(B)(V3)).

[0122] In the fourth step, the synchronization signal supply unit 212 supplies the second drive circuit 232(2) with a second The supply of the synchronization signal SYNC(2) to the respective inputs is stopped in sequence (FIG. 6(B)(V4)).

[0123] The order in which the synchronization signal is stopped is, for example, to fix the potential of the start pulse signal to low, The potential of the clock signal is fixed to low, and the power supply potential is fixed to low.

[0124] In the fifth step, the process returns from process 2 (FIG. 6(B)(V5)).

[0125] Process 3 In the first step of the process 3, the first synchronization signal SYNC( 1) is supplied to the first driving circuit 232(1) (FIG. 6(C)(W1)).

[0126] In the second step, the image processor 220 calculates an image to be displayed in the first area 230(1). (Fig. 6(C)(W2)).

[0127] In the third step, the display unit 230 displays an image in the first area 230(1) ( Figure 6(C)(W3)).

[0128] In the fourth step, the process returns from process 3 (FIG. 6C (W4)).

[0129] Process 4 In the first step of the process 4, the second synchronization signal SY NC(2) is supplied in turn to the second driving circuit 232(2) (FIG. 6(D)(X1)).

[0130] The order in which the supply of the synchronization signal is restarted may be, for example, to supply a predetermined power supply potential and then restart the clock signal. A signal is supplied, and a start pulse signal is supplied.

[0131] In the second step, the image processor 220 is configured to process the first region 230(1) and the second region 230(2). The image to be displayed is generated in 230(2) (FIG. 6(D)(X2)).

[0132] In the third step, an image is displayed on the display unit 230 (FIG. 6(D)(X3)).

[0133] In the fourth step, the process returns from process 4 (FIG. 6(D)(X4)).

[0134] The display device 200B according to one embodiment of the present invention includes an expandable and foldable display unit 230 and A detection unit 240 detects the folded state, and a display unit 23 is displayed depending on the folded state. an image processing unit 220 for generating an image in which a black image is displayed in a part of the image area; A synchronization signal supply unit 2 that can stop supplying a second synchronization signal SYNC(2) used for 12. This allows a part of the display unit to be folded and no longer needed for display. As a result, a display device with reduced power consumption can be realized. Alternatively, a display device that displays an image in the usable area in the folded state can be provided. Can be provided.

[0135] The individual elements constituting the display device 200B according to one embodiment of the present invention will be described below. Regarding elements to which the same elements as the display device 200 described in the first embodiment can be applied, The description of the first embodiment is incorporated herein.

[0136] Foldable display The display unit 230 that can be used in the display device 200B has a first region 230(1) The second region 230(2) is driven by the second driving circuit 232(1). 2) The display unit 230 is the same as the display unit 230 described in the first embodiment, except that it is driven by Applicable.

[0137] The scanning lines arranged in the first region 230(1) and the scanning lines arranged in the second region 230(2) are The scan line is located at the boundary 230b(1) between the first region 230(1) and the second region 230(2). As shown in FIG. 16, the scanning line driving circuit 232G is electrically insulated from the In this case, the scan lines are arranged in the first region 230(1) and the second region 230(2). In that case, the scan lines of the second region 230(2) are also selected. Therefore, when it is desired to display black in the second region 230(2), the signal line driving circuit 232S(2) The signal required to display black must be supplied from the Therefore, a constant voltage needs to be supplied, which reduces power consumption. do.

[0138] <Drive circuit> The display device 200B includes a first drive circuit 232(1) and a second drive circuit 232(2). Has.

[0139] The first driving circuit 232(1) includes a scanning line driving circuit 232G(1) and a signal line driving circuit 232G(2). Equipped with 32S(1).

[0140] The second driving circuit 232(2) is a scanning line driving circuit 232G(2) and a signal line driving circuit 232G(3). Equipped with 32S(2).

[0141] 14 and 15, a scanning line driving circuit and a signal line driving circuit are added to FIG. 4. 17 shows the case where the signal is arranged in the first region 230(1). The signal lines arranged in the second region 230(2) are connected to the first region 230(1) and the second region 230(2). The region 230(2) is electrically insulated at the boundary 230b(1). In addition, when the signal line driving circuit 232S is arranged on only one side, the signal lines are arranged in the first region 23 0(1) and the second region 230(2). In that case, the second region Since the image signal is also supplied to the signal line of the second area 230(2), the second area 230(2) is displayed in black. When it is desired to display the pixel, the scanning line driving circuit 232G(2) outputs a signal that does not select the pixel. However, since it is only in the non-selected state, a constant voltage must be supplied. Since it is only necessary to perform the above operation, power consumption can be reduced.

[0142] The scanning line driving circuit 232G(1) is supplied with a power supply potential and a first synchronization signal SYNC(1). and supplies a scanning line selection signal to the scanning lines provided in the first region 230(1).

[0143] The scanning line driving circuit 232G(2) is supplied with a power supply potential and a second synchronization signal SYNC(2). and supplies a scanning line selection signal to the scanning lines provided in the second region 230(2).

[0144] The signal line driving circuit 232S(1) receives the power supply potential, the first synchronization signal SYNC(1), and the first The image signal VIDEO(1) is supplied to the image signal VIDEO(2).

[0145] The signal line driving circuit 232S(2) receives the power supply potential, the second synchronization signal SYNC(2), and the second The image signal VIDEO(2) is supplied to the image signal VIDEO(3).

[0146] A scanning line selection signal is supplied to the first area 230(1) of the display section 230, and one scanning line and its The second region 230(2) of the display unit 230 is connected to the scanning line A selection signal is supplied to select one scan line and the pixels connected to it.

[0147] The pixel to which the scanning line selection signal is supplied is supplied with an image signal, and the pixel circuit arranged in that pixel The path stores the image signal. The display element arranged in the pixel displays the image in response to the image signal. do.

[0148] <Synchronization signal supply unit> The synchronization signal supply unit 212 receives the synchronization control signal SC and generates a first synchronization signal SYNC(1). and supplies a second synchronization signal SYNC(2).

[0149] The first synchronization signal SYNC(1) is used to synchronize the first drive circuit 232(1) with the The second synchronization signal SYNC(2) is a signal used by the second drive circuit 232(2). A synchronization signal is a signal used for synchronized operation. Examples of synchronization signals include vertical synchronization signals and In addition to the horizontal synchronization signal, the start pulse signal SP, latch signal LP, and pulse width control signal P Examples include the WC and the clock signal CLK.

[0150] The synchronization signal supply unit 212 generates a second synchronization signal SYNC in response to the supplied synchronization control signal SC. (2) is supplied or stopped. When the operation is stopped, the operation of the second area 230(2) can be stopped. "Stop" means that the wiring of each part is in a high impedance state (or floating state). It can also refer to the case where a certain potential is applied and the potential does not change, maintaining the same state. It can also refer to the case where something is kept.

[0151] Image Processing Section The image processing unit 220 receives the image control signal VC, generates an image, and outputs the first image of the generated image. The first image signal VIDEO(1) and the second image signal VIDEO(2) are supplied.

[0152] The first image signal VIDEO(1) is displayed in the first area 230(1) of the display unit 230. The second image signal VIDEO(2) includes image information. 0(2) contains information about the image to be displayed.

[0153] For example, the image processing unit 220 controls the first area 230(1) and the second area 230(2) in response to the image control signal VC. An image can be generated to be displayed in the first area 230(1) and the second area 230(2).

[0154] In addition, in response to the image control signal VC, a black image is displayed in the second area 230(2). It is possible to generate an image of

[0155] In addition, only one image to be displayed in the first area 230(1) is generated in response to the image control signal VC. It can be achieved.

[0156] This reduces the power consumed by the display device 200B.

[0157] Specifically, the second area 230(2) is folded so that the display is not visible. Power consumption can be reduced.

[0158] A display element that consumes less power when displaying a black image than when displaying other images An example of such a light-emitting element is a light-emitting element.

[0159] <Detection unit and sign> The detector 240 detects the folded state of the display unit 230 and supplies a folding signal F. The same configuration as in the first embodiment can be applied.

[0160] Control Unit The control unit 210B receives the folding signal F, and outputs the image control signal VC, the synchronization control signal SC, and and a power control signal PC.

[0161] The image control signal VC is a signal for controlling the image processing unit 220. For example, the display unit 2 30 includes a signal that causes the image processor 220 to generate different images depending on the folded state. nothing.

[0162] Timing Generator The timing generator generates and supplies a reference clock signal and the like required by the display device 200B. do.

[0163] 《Power supply section》 The power supply unit 214 receives a power supply control signal PC and supplies a power supply potential.

[0164] The power supply unit 214 supplies or stops the supply of a power supply potential in response to a power supply control signal PC. When the supply of the power supply potential to the second driving circuit 232(2) is stopped, the second The power consumed by the drive circuit 232(2) can be reduced.

[0165] Note that stopping the supply of power supply potential means that the power supply potential on the high potential side (for example, VDD) and the power supply potential on the low potential side (for example, VDD) are disconnected. For at least one of the power supply potentials (e.g., VSS, GND) , in a high impedance state, no energy is supplied, and the other power supply potential is In this case, the driver circuit supplies the other power supply potential As a result, a predetermined voltage is supplied to the wiring of each part connected to the drive circuit. A potential is supplied, and the potential does not change and remains the same.

[0166] For example, when only a non-selection signal is supplied from the scanning line driving circuit 232G(2), Only the power supply potential corresponding to the potential of the selection signal is supplied from the power supply unit 214 to the scanning line driving circuit 232G (2 As a result, almost no current flows in the scanning line driving circuit 232G(2). Therefore, the power consumption can be reduced. When only the potential required for black display is supplied, the voltage corresponding to the potential required for black display is Only the source potential is supplied from the power supply unit 214 to the signal line driving circuit 232S(2). In the signal line driving circuit 232S(2), almost no current flows, so power consumption can be reduced. It is possible to do this.

[0167] Alternatively, stopping the supply of power supply potential means stopping the supply of power supply potential on the high potential side (for example, VDD) and The high-side power supply potential and the low-side power supply potential (e.g., VSS, GND) The impedance state can also refer to the state when no energy is supplied. As a result, no energy is supplied from the drive circuit. The wiring of each part is in a high impedance state (floating state). If the display is currently in progress, that state is maintained, which reduces power consumption. Since no current flows in the drive circuit, power consumption can be reduced.

[0168] The power supply unit 214 has a plurality of power supplies, specifically a first power supply and a second power supply. Good too.

[0169] In the modified example of the display device 200B described in this embodiment, the first drive circuit 232(1) is a first power supply that supplies a power supply potential to the second drive circuit 232(2); In response to the folding signal F, the control unit 210B controls the second power supply The second power supply supplies a power supply potential in response to the power supply control signal PC. Stop.

[0170] The display device according to one embodiment of the present invention includes a display unit that can be unfolded and folded, and a display unit that displays a black image. a synchronization signal supply unit that can stop the supply of a synchronization signal used for a part that displays a black image; and a power supply that can stop supplying a power supply potential used for the portion that is to be controlled. This allows a part of the display to be folded and the display to be stopped in an area that is no longer required for display. As a result, a display device with reduced power consumption can be provided. It is possible to provide a display device that displays an image in a usable area in a closed state.

[0171] <Modification> Regarding the display device 200D exemplified as a modification of this embodiment, the display device 200B in FIG. The display device 200D will be described with reference to FIG.

[0172] A display device 200D described as a modification of this embodiment changes the frequency at which the display unit is rewritten. It is possible.

[0173] Specifically, the scanning line selection signal for selecting pixels is sent at a frequency of 30 Hz (30 times per second) or more. Preferably, the frequency should be between 60Hz (60 times per second) and 960Hz (960 times per second). The first mode outputs at 11.6μHz (once a day) or more, and the second mode outputs at 0.1Hz (0.0 ... Frequency less than 0.1 times per second, preferably 0.28mHz (once per hour) or more and 1Hz (once per second) A display device having a second mode in which the image is output at a frequency of less than once will be described.

[0174] When a still image is displayed using the display device 200D exemplified in the modification of this embodiment, the reflection The flash rate can be set to less than 1 Hz, preferably 0.2 Hz or less, so that it is easy on the user's eyes. It is possible to display images with reduced burden on the display. The display image can be refreshed at an optimal frequency depending on the user's needs. By refreshing the screen less frequently than when the screen is displayed too quickly, flicker is reduced. In addition, this also has the effect of reducing power consumption.

[0175] The display device 200D described in the modification of this embodiment includes a control unit, a drive circuit, and a display The display device 200B has the same configuration as the display device 200B except for the different configuration of the display unit.

[0176] <Drive circuit> The scanning line driving circuit 232G(1) and the scanning line driving circuit 232G(2) receive the first The scanning line selection signal SYNC(1) is generated in accordance with the first synchronization signal SYNC(1) and the second synchronization signal SYNC(2). Issues are provided at different frequencies.

[0177] For example, the driving circuit may generate a scanning line selection signal at a frequency of 30 Hz (30 times per second) or more, preferably The frequency is between 60Hz (60 times per second) and 960Hz (960 times per second). The first mode is 11.6μHz (once a day) or more and 0.1Hz (0.1 times per second) Frequency less than 1Hz (once per second) and preferably 0.28mHz (once per hour) or more In a second mode, the scan line selection signals are supplied at full frequency.

[0178] <Synchronization signal supply unit> The synchronization signal supply unit 212 supplies the drive circuit with different frequencies according to the synchronization control signal SC supplied thereto. A first synchronizing signal SYNC(1) and a second synchronizing signal SYNC(2) are used to supply a scanning line selection signal. The signal SYNC(2) is supplied.

[0179] For example, the output frequency of the start pulse signal supplied to the scanning line driving circuit is controlled to select the scanning line. The select signal can be provided at different frequencies.

[0180] Control Unit The control unit 210D supplies a synchronization control signal SC to the synchronization signal supply unit 212, and controls the drive circuit to perform different For example, when displaying a moving image, the scanning line selection signal is supplied at a high frequency. A synchronization control signal SC is supplied to supply a line selection signal. When a still image is displayed, a low frequency A synchronization control signal SC is supplied to cause a scanning line selection signal to be supplied.

[0181] Transistor The second transistor 634t_2 supplies a current according to the potential of the signal line S, and Controls the light emission of 35EL.

[0182] A transistor suitable for the first transistor 634t_1 and the second transistor 634t_2 may be used. An example of the transistor is a transistor including an oxide semiconductor.

[0183] A transistor using an oxide semiconductor film has a leakage current between the source and drain in an off state. (off-state current) is extremely low compared to conventional silicon transistors. It is possible.

[0184] By using a transistor with extremely low off-state current in the pixel portion of the display, flicker can be reduced. The frame frequency can be reduced while suppressing the occurrence of the above problem.

[0185] In addition, in the treatment 2 of this embodiment, a transistor using an oxide semiconductor having an extremely small off-state current was used. The pixels in the second region 230(2) to which the transistor is applied are The image signal for displaying a black image supplied to the transistor was compared with that of a silicon-based transistor. This allows you to stop displaying in areas that are no longer required for display. As a result, a display device with reduced power consumption can be provided. It is possible to provide a display device that displays an image in a usable area in a folded state.

[0186] A transistor suitable for the first transistor 634t_1 and the second transistor 634t_2 may be used. An example of the configuration of the controller will be described in the fourth embodiment.

[0187] Note that this embodiment mode can be appropriately combined with other embodiment modes shown in this specification. .

[0188] (Embodiment 3) In this embodiment, the structure of a display device 200C according to one embodiment of the present invention will be described with reference to FIGS. and explain.

[0189] FIG. 7 is a perspective view illustrating a structure of a display device 200C according to one embodiment of the present invention. 7(A) is a diagram illustrating the display device 200C in an unfolded state, and FIG. 7(B) is a diagram illustrating the display device 200C in a folded state. 7(C) is a diagram illustrating the display device 200C in a folded state, and FIG. 7(D) is a diagram illustrating the display device 200C in a folded state. FIG. 2 is a diagram illustrating a device 200C.

[0190] FIG. 8 is a diagram illustrating the configuration of a display device 200C according to one embodiment of the present invention. 8(A) is a top view of the unfolded display device 200C, and FIG. 8(B) is a top view of the unfolded display device 200C. FIG. 8(C) is a side view of the unfolded display device 200C, and FIG. 8(D) is a bottom view of the unfolded display device 200C. 8(A) is a cross-sectional view taken along the dashed line AB in FIG. 8(A).

[0191] FIG. 9 illustrates the structure of a display panel of a display device 200C according to one embodiment of the present invention. 9(A) is a cross-sectional view of the central part of the display device 200C in the folded state, and FIG. 9(B) is a cross-sectional view of the central part of the display device 200C in the folded state. FIG. 2 is a top view of the display panel in an unfolded state.

[0192] The display device 200C described in this embodiment is foldable and has a first area 230 (1 a display unit including a first region 230(2) and a second region 230(3), a driving circuit for driving the display unit, and a driving circuit for driving the display unit. An image processing unit that supplies image signals to the circuit, and a folding unit that detects the folded state of the display unit The detector 240 supplies a folding signal, and the controller 242 receives a folding signal (see FIG. 7). (A)).

[0193] The control unit then supplies an image control signal in response to the folding signal, and the image processing unit then performs image control. In response to the control signal, an image is generated that displays a black image in the second region 230(2).

[0194] The drive circuit, image processing unit, and control unit are located between the support panel 15a and the support panel 15b. It is set up in.

[0195] The display device 200C has a belt-shaped highly flexible region E1 and a belt-shaped less flexible region E2. In other words, they are arranged in a striped pattern (Fig. 8(A)). This is not limited to the above.

[0196] A part of the connecting member 13a is exposed between the two spaced apart support panels 15a. A part of the member 13b is exposed between the two spaced apart support panels 15b (see FIGS. 8(A) and 8(B)). and Figure 8(B)).

[0197] The display device 200C can be folded by bending it at the highly flexible region E1 ( See Figures 7(B) and 7(C).

[0198] Highly flexible area The highly flexible region E1 functions as a hinge. The highly flexible region E1 has at least The display device has a flexible display panel.

[0199] The highly flexible region E1 is provided with a connecting member 13a on the image display side of the display panel, and The connecting member 13b is provided on the opposite side (see Fig. 8(A) and Fig. 8(B)). 3a and the connecting member 13b sandwich the display panel (see FIGS. 7(A), 8(C) and 8(D)). See D).

[0200] <<Low flexibility area>> The less flexible region E2 is formed by the support panel 15a on the side of the display panel where an image is displayed, and the support panel 15a on the side of the display panel where an image is displayed. The display panel has a support panel 15a and a support panel 15b on the side opposite to the support panel 15a. The wire 15b is sandwiched between the wire 15a and the wire 15b.

[0201] The laminated body in which the support panel 15a and the support panel 15b are stacked is more flexible than the display panel. Low flexibility.

[0202] The support panels 15a and 15b support the display panel to increase its mechanical strength. This can prevent damage to the display panel.

[0203] The support panel 15a and the support panel 15b are connected to the scanning line driving circuit 232G(1) and the scanning The signal line driving circuit 232G(2) and the signal line driving circuit 232S(1) are sandwiched between the two electrodes. This makes it possible to protect the drive circuit from external stress (see Fig. 9(A) and Fig. 9(B)). See B).

[0204] The support panel is disposed only on one of the display surface side and the opposing surface side of the display panel. For example, it is possible to use only the plurality of support panels 15b without using the plurality of support panels 15a. This allows the display device to be made thinner or lighter. .

[0205] <<Connecting member and support panel>> The connecting member 13a, the connecting member 13b, the support panel 15a, and the support panel 15b are connected to the plus Materials such as plastic, metal, alloy and / or rubber can be used.

[0206] By using plastic and rubber, the connection members and support panels are lightweight and resistant to breakage. For example, silicone rubber is used as the connecting member, and the support panel is used Stainless steel or aluminum may be used.

[0207] When a connecting member or a support panel is placed on the display surface side of the display panel, the display on the display panel may be The area overlapping the first area 230(1) and the second area 230(2) is provided with a light-transmitting A material having the formula:

[0208] As a method for fixing two selected from the connecting member, the support panel, and the display panel, for example, For example, adhesives, penetrating screws or pins, clamping clips, etc. can be applied.

[0209] <Detection unit and sign> The indicator 239 and the detection unit 236 are provided so that the folded state of the display unit 230 can be detected. A portion 240 is provided on the support panel 15a (see FIGS. 7(A), 7(B), 8(A) and and Figure 8(C)).

[0210] When the display unit 230 is unfolded, the marker 239 is located at a position away from the detection unit 240. (See FIG. 7(A)).

[0211] When the display unit 230 is bent at the connecting member 13a, the indicator 239 approaches the detection unit 240. (See Figure 7(B)).

[0212] When the display unit 230 is folded at the connecting member 13a, the sign 239 faces the detection unit 240. (See FIG. 7(C)). The detection unit 240 detects the facing markers 239 and detects the folded The controller 10 recognizes the folded state and supplies a folding signal F indicating the folded state.

[0213] Display panel The display panel has a display section, a first driver circuit, and a second driver circuit (see FIG. 9(A)). and Figure 9(B)).

[0214] The display section includes a first area 230(1) and a second area 230(2).

[0215] The first driving circuit is a scanning line driving circuit 232G(1) and a signal line driving circuit 232S(1). The second driving circuit includes a scanning line driving circuit 232G(2) and a signal line driving circuit 232 The signal line driving circuit 232S(2a) and the signal line driving circuit 232S(2b) are provided.

[0216] The first driving circuit drives the first region 230(1). The second driving circuit drives the second region 23 0(2). The signal line driving circuit 232S(2a) and the signal line driving circuit 232S( 2b) supplies an image signal to the pixel to which the scanning line driving circuit 232G(2) supplies a selection signal. do.

[0217] There is a boundary 230b(1) between the first region 230(1) and the second region 230(2). A region 230(1)S is located in the first region 230(1) adjacent to the boundary 230b(1) (see FIG. 9(B)). The area 230(1)S is the area of ​​the display device 200C in the folded state. on the side (see Figure 9(A)).

[0218] The first region 230(1) includes the region 230(1)S. The second region 2 of the display device 200C Even when the driving of the first region 230(2) is stopped in the folded state, By driving the area 230(1)S, an image can be displayed. This allows the display to be made on the side surface of the display device 200C, making it possible to effectively utilize the side surface. .

[0219] The configuration of the flexible display panel will be described in the sixth and seventh embodiments. Reveal.

[0220] The display device 200C is highly portable when folded. 1) can be folded outward, and only the first region 230(1) can be used (see FIG. 7). (See (C)). For example, a touch panel could be installed on the display, allowing the user to check the size of the folded device with one hand. By making it large enough to be supported by the thumb of the supporting hand, the touch panel can be operated with the thumb of the supporting hand. This allows for one-handed operation when the device is folded. It is possible to provide a display device that can

[0221] The second area 230(2) is not visible to the user in the folded state. By not driving the display device 200C in the turned-on state, the power consumed by the display device 200C can be reduced. By folding the area 230(2) inward, it can be prevented from being scratched or stained. It is possible.

[0222] In addition, the display device 200C can display a seamless, wide area when unfolded. This allows for a display that is easy to view.

[0223] Note that this embodiment mode can be appropriately combined with other embodiment modes shown in this specification. .

[0224] (Fourth embodiment) In this embodiment, a transistor 151 that can be used in a display device of one embodiment of the present invention is The structure of this will be explained with reference to FIG.

[0225] 10A to 10C show top views and cross-sectional views of the transistor 151. 10(A) is a top view of the transistor 151, and FIG. 10(B) is a dot-and-dash diagram of FIG. 10(A). 10(C) corresponds to a cross-sectional view of the section between the line AB, and FIG. 10(C) corresponds to a cross-sectional view of the section between the line CD and dashed line in FIG. 10(A). In FIG. 10(A), for clarity, only one of the components is shown. In the figure, some parts are omitted.

[0226] In this embodiment, the first electrode is a source electrode or a drain electrode of a transistor. The term "electrode" refers to one of the poles and the term "second electrode" refers to the other.

[0227] The transistor 151 is a channel-etched transistor and is provided on the substrate 102. a gate electrode 104a formed on the substrate 102 and an insulating film 105 formed on the gate electrode 104a; A first insulating film 108 including the insulating film 106 and the insulating film 107, and a gate electrode 108 The oxide semiconductor film 110 overlaps with the second electrode 104a, and the first electrode 104b contacts the oxide semiconductor film 110. The first insulating film 108, the oxide semiconductor film 109, and the second electrode 112a and the second electrode 112b are also included. On the conductive film 110, the first electrode 112a and the second electrode 112b, insulating films 114 and 116 are formed. , 118, and a second insulating film 120 including the gate electrode 118 formed on the second insulating film 120. The gate electrode 122c is formed by the first insulating film 108 and the second insulating film 120. The gate electrode 104a is connected to the gate electrode 104b through openings 142d and 142e. A conductive film 122a functioning as a pixel electrode is formed over the insulating film 118. In the opening 142a provided in the second insulating film 120, a metal layer connected to the second electrode 112b is formed. do.

[0228] Note that the first insulating film 108 functions as a first gate insulating film of the transistor 151. The second insulating film 120 functions as a second gate insulating film of the transistor 151. The conductive film 122a functions as a pixel electrode.

[0229] The transistor 151 described in this embodiment has a gate electrode 104 a and the gate electrode 122c via the first insulating film 108 and the second insulating film 120. An oxide semiconductor film 110 is provided. The gate electrode 104a is As shown in the top view, the side surface of the oxide semiconductor film 110 is It overlaps with.

[0230] The first insulating film 108 and the second insulating film 120 have a plurality of openings. As shown in FIG. 1(B), the second electrode 112b has an opening 142a through which a part of the second electrode 112b is exposed. 10C, the oxide semiconductor film 110 is sandwiched between the oxide semiconductor film 110 in the channel width direction. The oxide semiconductor film 110 has openings 142d and 142e. 142d and 142e.

[0231] In the opening 142a, the second electrode 112b and the conductive film 122a are connected.

[0232] In addition, the gate electrode 104a and the gate electrode 122c are That is, in the channel width direction, the gate electrode 104a and the gate electrode 12 2c surrounds the oxide semiconductor film 110 via the first insulating film 108 and the second insulating film 120. In addition, the gate electrode 122c is made of an oxide semiconductor on the side surfaces of the openings 142d and 142e. It faces the side of the membrane 110 .

[0233] The gate electrode 104a and the gate electrode 122c are provided. The electrode 122c is set to the same potential, and the side surface of the oxide semiconductor film 110 faces the gate electrode 122c. Furthermore, by orienting the gate electrode 104a and the gate electrode 104b in the channel width direction, The oxide semiconductor film 110 is connected to the first insulating film 108 and the second insulating film 120 via the insulating film 122c. By surrounding the first insulating film 110, the region in which carriers flow in the oxide semiconductor film 110 is The interface between the second insulating film 120 and the oxide semiconductor film 110, and the interface between the second insulating film 120 and the oxide semiconductor film 110 Since carriers flow not only at the interface with the oxide semiconductor film 110 but also in a wide range of the oxide semiconductor film 110, The amount of carrier movement in the transistor 151 increases.

[0234] As a result, the on-current of the transistor 151 increases and the field effect mobility increases. , typically with a field-effect mobility of 10 cm 2 / V·s or more, even 20cm 2 / V·s or later Note that the field-effect mobility here is the mobility as a physical property value of the oxide semiconductor film. It is not an approximate value, but an index of the current driving force in the saturation region of the transistor, and is an apparent The field-effect mobility is shown in Fig. 1. Note that the channel length (also called L length) of the transistor is set to 0.5 μm. 1 μm or more and 6.5 μm or less, preferably more than 1 μm and less than 6 μm, more preferably 1 μm More preferably, it is greater than 1 μm and less than 3.5 μm, and even more preferably By making the thickness larger than 1 μm and equal to or smaller than 2.5 μm, the increase in field effect mobility is remarkable. In addition, the channel length is small, between 0.5 μm and 6.5 μm, so the channel width is also It is possible to make it smaller.

[0235] For this reason, a plurality of regions are provided to serve as connection portions between the gate electrode 104a and the gate electrode 122c. Even if this is the case, the area of ​​the transistor 151 can be reduced.

[0236] In addition, at the end portion of the oxide semiconductor film 110 that has been processed by etching or the like, Damage causes defects and contamination due to impurity adhesion. In the transistor 151, only one of the gate electrode 104a and the gate electrode 122c is formed. In this case, even if the oxide semiconductor film 110 is intrinsic or substantially intrinsic, a switch such as an electric field may be generated. By applying the stress, the edge of the oxide semiconductor film 110 is activated and becomes n-type (low resistance It is likely to become an anti-region.

[0237] Furthermore, when the n-type end portion is provided between the first electrode 112a and the second electrode 112b, As a result, the n-type region becomes a path for carriers, forming a parasitic channel. The drain current rises gradually at the threshold voltage, and the threshold voltage is negative. However, as shown in FIG. 10(C), The gate electrodes 104a and 122c have a potential The gate electrode 122c is formed on the side surface of the second insulating film 120 so as to contact the oxide semiconductor film 110. By facing the side surface, the electric field of the gate electrode 122c is also applied from the side surface of the oxide semiconductor film 110. As a result, the side surface of the oxide semiconductor film 110 or the edge portion including the side surface and its vicinity is affected. As a result, the occurrence of a parasitic channel in the drain current at the threshold voltage is suppressed. The current rise is steep, resulting in a transistor with excellent electrical characteristics.

[0238] Furthermore, by providing the gate electrode 104a and the gate electrode 122c, Since the gate electrode 104a has a function of shielding the electric field of the substrate 102, the gate electrode 104a Charges of charged particles or the like provided on the electrode 122c do not affect the oxide semiconductor film 110. As a result of the stress test (e.g., applying a negative potential to the gate electrode) Deterioration during Bias-Temperature stress testing is suppressed, and Fluctuations in the on-current rise voltage at different drain voltages can be suppressed.

[0239] The BT stress test is a type of accelerated test that measures the transients that occur during long-term use. It is possible to evaluate the change in the characteristics of the BT string (i.e., the change over time) in a short time. The amount of change in the threshold voltage of a transistor before and after the load test is an important factor for examining reliability. The smaller the threshold voltage fluctuation before and after the BT stress test, the better the It can be said that this is a highly reliable transistor.

[0240] The individual elements that make up the transistor 151 will be described below.

[0241] <<Substrate 102>> The substrate 102 may be made of aluminosilicate glass, aluminoborosilicate glass, barium A glass material such as borosilicate glass is used. For mass production, the substrate 102 is an 8th generation (2160mm x 2460mm), 9th generation (2400mm x 2800mm, or 24 Mother glass such as 10th generation (2950mm x 3400mm) It is preferable to use mother glass. If the processing temperature is high and the processing time is long, the glass will be significantly deteriorated. When mass production is carried out using mother glass, heat treatment in the manufacturing process is preferred because of shrinkage. Preferably, the temperature is 600°C or less, more preferably 450°C or less, and even more preferably 350°C or less. It is desirable to do so.

[0242] <Gate electrode 104a> The gate electrode 104a may be made of a material such as aluminum, chromium, copper, tantalum, or titanium. A metal element selected from the group consisting of tungsten, molybdenum, and tungsten, or a metal element selected from the group consisting of the above-mentioned metal elements. The metal layer can be formed by using an alloy of the above metal elements or an alloy combining the above metal elements. The gate electrode 104a may have a single layer structure or a stacked structure of two or more layers. Two-layer structure in which a titanium film is laminated on an aluminum film, and a titanium film is laminated on a titanium nitride film Two-layer structure, two-layer structure in which a tungsten film is laminated on a titanium nitride film, a tantalum nitride film or Two-layer structure in which a tungsten film is laminated on a tungsten nitride film, a titanium film, and There is also a three-layer structure in which an aluminum film is laminated on top and a titanium film is further formed on top of that. In addition to aluminum, titanium, tantalum, tungsten, molybdenum, chromium, and neodymium a film of an element selected from the group consisting of silicon, zinc, and scandium, or an alloy film of a combination of two or more elements, or a nitride film; The gate electrode 104a may be formed by, for example, sputtering. It is possible.

[0243] <<First insulating film 108>> The first insulating film 108 is exemplified by a two-layer laminate structure of an insulating film 106 and an insulating film 107 . The structure of the first insulating film 108 is not limited to this, and may be, for example, a single layer structure or a structure of three or more layers. The laminated structure may be formed as follows.

[0244] The insulating film 106 may be, for example, a silicon nitride oxide film, a silicon nitride film, or an aluminum oxide film. A film such as a rubber film can be used, and it can be formed as a laminate or a single layer using a PE-CVD device. When the insulating film 106 has a laminated structure, a silicon nitride film with few defects is used as the first silicon nitride film. The first silicon nitride film was used as a silicon nitride film, and the second silicon nitride film was used as a silicon nitride film. It is preferable to provide a silicon nitride film that releases less ammonia. The hydrogen and nitrogen contained in the oxide semiconductor film 6 move or diffuse into the oxide semiconductor film 110 to be formed later. This can prevent this from happening.

[0245] The insulating film 107 may be a silicon oxide film, a silicon oxynitride film, or the like. -It is formed in a laminated or single layer using a CVD apparatus.

[0246] The first insulating film 108 is made of, for example, a 400 nm thick nitride film as the insulating film 106. Then, a silicon oxynitride film having a thickness of 50 nm is formed as the insulating film 107. A stacked structure for forming a silicon nitride film and a silicon oxynitride film can be used. It is preferable to form the film continuously in a vacuum, since this prevents the inclusion of impurities. The first insulating film 108 overlapping with the insulating film 104a serves as the gate insulating film of the transistor 151. Silicon nitride oxide is an insulating material with a higher nitrogen content than oxygen content. Silicon oxynitride is an insulating material with a higher oxygen content than nitrogen content. This refers to the edging material.

[0247] <Oxide semiconductor film 110> The oxide semiconductor film 110 is made of at least indium (In), zinc (Zn), and M( In-M- containing metals such as Al, Ga, Ge, Y, Zr, Sn, La, Ce or Hf It is preferable to include a film represented by Zn oxide, or to include both In and Zn. Furthermore, it is preferable to reduce variations in electrical characteristics of transistors using the oxide semiconductor. Therefore, it is preferable to include a stabilizer therewith.

[0248] Stabilizers include gallium (Ga), tin (Sn), hafnium (Hf), and aluminum. Aluminum (Al) or zirconium (Zr). Also, other stabilizers The lanthanides are lanthanum (La), cerium (Ce), and praseodymium (P r), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium ( Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium Er, Thulium, Ytterbium, Lutetium, etc. .

[0249] The oxide semiconductor constituting the oxide semiconductor film 110 is, for example, an In—Ga—Zn-based oxide. In-Al-Zn oxides, In-Sn-Zn oxides, In-Hf-Zn oxides , In-La-Zn oxide, In-Ce-Zn oxide, In-Pr-Zn oxide, In-Nd-Zn oxide, In-Sm-Zn oxide, In-Eu-Zn oxide, I n-Gd-Zn oxide, In-Tb-Zn oxide, In-Dy-Zn oxide, In -Ho-Zn oxide, In-Er-Zn oxide, In-Tm-Zn oxide, In- Yb-Zn oxide, In-Lu-Zn ​​oxide, In-Sn-Ga-Zn oxide, I n-Hf-Ga-Zn oxide, In-Al-Ga-Zn oxide, In-Sn-Al- Zn-based oxide, In-Sn-Hf-Zn-based oxide, In-Hf-Al-Zn-based oxide are used. You can be there.

[0250] Here, the In-Ga-Zn oxide is a material containing In, Ga, and Zn as main components. It means oxide, and the ratio of In, Ga, and Zn does not matter. Other metal elements may also be included.

[0251] The oxide semiconductor film 110 is formed by a sputtering method, an MBE (Molecular Beam Epitaxy) method, or the like. Beam Epitaxy, CVD, pulsed laser deposition, ALD (Atomic Layer Deposition method, etc. can be used as appropriate. When the semiconductor film 110 is formed by sputtering, a dense film is formed. It is suitable.

[0252] When the oxide semiconductor film 110 is formed, it is preferable to include as much of the oxide semiconductor as possible in the film. It is preferable to reduce the hydrogen concentration. In order to reduce the hydrogen concentration, for example, sputtering When forming a film using the sputtering method, not only is the film formation chamber evacuated to a high vacuum, but also the sputtering gas The oxygen gas and argon gas used as sputtering gas have dew points of -40°C or lower, preferably -80°C or lower, more preferably -100°C or lower, and even more preferably By using a gas that has been highly purified to -120°C or lower, moisture and other substances are removed from the oxide semiconductor film. It is possible to prevent intrusion as much as possible.

[0253] In order to remove residual moisture in the film-forming chamber, an adsorption-type vacuum pump, for example, a cryo- It is preferable to use a pump, an ion pump, or a titanium sublimation pump. A cryopump may be a turbomolecular pump with a cold trap added. For example, hydrogen molecules, compounds containing hydrogen atoms such as water (H2O), compounds containing carbon atoms, etc. Because of its high pumping capacity, the film formed in the film-forming chamber is evacuated using a cryopump. The concentration of impurities can be reduced.

[0254] In addition, when the oxide semiconductor film 110 is formed by a sputtering method, The relative density (filling rate) of the metal oxide target used for film formation is 90% or more and 100% or less. Preferably, the density is 95% or more and 100% or less. This allows the deposited film to be a dense film.

[0255] Note that the oxide semiconductor film 110 was formed while the substrate 102 was kept at a high temperature. Forming a film having a thickness of 100 nm or less is also effective in reducing the concentration of impurities that may be contained in the oxide semiconductor film. The temperature to which the substrate 102 is heated may be preferably 150° C. or higher and 450° C. or lower. For example, the substrate temperature may be set to 200° C. or higher and 350° C. or lower.

[0256] Next, a first heat treatment is preferably performed. The first heat treatment is performed at a temperature of 250° C. or higher and 650° C. Preferably, the temperature is 300°C or higher and 500°C or lower, and the inert gas atmosphere and the oxidizing gas atmosphere are used. The first heat treatment may be carried out in an atmosphere containing 10 ppm or more or under reduced pressure. After heat treatment in an inert gas atmosphere, an oxidizing gas is added to replace the oxygen that has been removed. The first heat treatment may be performed in an atmosphere containing 0 ppm or more of fluorine. The crystallinity of the oxide semiconductor used for the first insulating film 108 is increased, and the first insulating film 108 and the oxide semiconductor film Impurities such as hydrogen and water can be removed from the oxide semiconductor film 110. A first heating step may be carried out before processing the particles into islands.

[0257] <<First electrode, second electrode>> Materials of the conductive film 112 that can be used for the first electrode 112a and the second electrode 112b These include aluminum, titanium, chromium, nickel, copper, yttrium, and zirconium. , molybdenum, silver, tantalum, or tungsten, or a metal mainly composed of these. The alloy containing aluminum can be used as a single layer or a laminated structure. One or more selected from aluminum, chromium, copper, tantalum, titanium, molybdenum, and tungsten It is preferable that the above elements are contained. For example, a two-layer structure in which a titanium film is laminated on an aluminum film, Two-layer structure with titanium film laminated on tungsten film, copper-magnesium-aluminum alloy Two-layer structure with copper film laminated on top of titanium film or titanium nitride film and titanium film or nitride film An aluminum film or copper film is laminated on the titanium oxide film, and a titanium film or The three-layer structure is a titanium nitride film, a molybdenum film or a molybdenum nitride film, and the molybdenum film. an aluminum film or a copper film is laminated on the molybdenum film or the molybdenum nitride film, and There is also a three-layer structure in which a molybdenum film or molybdenum nitride film is formed on top of the oxide film. A transparent conductive material containing indium, tin oxide, or zinc oxide may be used. For example, the film can be formed by sputtering.

[0258] <Insulating films 114, 116, 118> The second insulating film 120 is exemplified by a three-layer laminate structure of insulating films 114, 116, and 118. The structure of the second insulating film 120 is not limited to this, and may be, for example, a single-layer structure or a two-layer laminate structure. Alternatively, a laminated structure of four or more layers may be used.

[0259] The insulating films 114 and 116 are formed by interfacing with the oxide semiconductor used as the oxide semiconductor film 110. In order to improve the surface characteristics, inorganic insulating materials containing oxygen can be used. Examples of the insulating material include a silicon oxide film and a silicon oxynitride film. The insulating films 114 and 116 are formed by using, for example, the PE-CVD method. can be done.

[0260] The thickness of the insulating film 114 is 5 nm or more and 150 nm or less, preferably 5 nm or more and 50 nm or less. The thickness of the insulating film 116 can be set to 30 nm or more, preferably 10 nm or more and 30 nm or less. The thickness can be 0 nm or more and 500 nm or less, preferably 150 nm or more and 400 nm or less. do.

[0261] In addition, the insulating films 114 and 116 can be made of the same material. In some cases, the interface between the insulating film 114 and the insulating film 116 cannot be clearly confirmed. In this embodiment, the interface between the insulating film 114 and the insulating film 116 is shown by a broken line. In the embodiment, the two-layer structure of the insulating film 114 and the insulating film 116 has been described. However, the present invention is not limited to this, and examples thereof include a single layer structure of the insulating film 114, a single layer structure of the insulating film 116, and a three-layer structure. A laminated structure of more than one layer may also be used.

[0262] The insulating film 118 is free from external impurities such as water, alkali metals, and alkaline earth metals. The film is formed of a material that prevents diffusion of hydrogen into the oxide semiconductor film 110. nothing.

[0263] An example of the insulating film 118 is a silicon nitride film having a thickness of 150 nm or more and 400 nm or less. In this embodiment, the insulating film 118 may be a silicon oxide film or the like. A silicon nitride film with a thickness of 150 nm is used.

[0264] The silicon nitride film is formed at a high temperature to improve its ability to block impurities. For example, the substrate temperature is preferably 100° C. or higher and lower than the distortion point of the substrate, more preferably 3 It is preferable to form the film by heating at a temperature of 00°C or higher and 400°C or lower. In this case, oxygen is released from the oxide semiconductor used as the oxide semiconductor film 110, and the carrier concentration Since a phenomenon in which the temperature rises may occur, the temperature should be set at a level at which such a phenomenon does not occur.

[0265] <Conductive film 122a, gate electrode 122c> The conductive film 122a and the gate electrode 122c can be formed using an indium For example, an oxide containing tungsten oxide, an oxide containing indium oxide, Indium zinc oxide containing tungsten, indium oxide containing titanium oxide, titanium oxide Indium tin oxide containing tin, indium tin oxide (hereinafter referred to as ITO), Conductive materials with transparency such as indium zinc oxide and silicon oxide-doped indium tin oxide In addition, the conductive film 122a and the gate electrode 122c can be made of a material such as The conductive film can be formed by, for example, sputtering.

[0266] Note that the structures and methods described in this embodiment may be different from the structures and methods described in other embodiments. can be used in appropriate combination.

[0267] (Embodiment 5) In this embodiment, one of the oxide semiconductor films applicable to the transistor 151 in Embodiment 4 is An example will be described.

[0268] <Crystallineness of oxide semiconductor film> The structure of the oxide semiconductor film will be described below.

[0269] Oxide semiconductor films are roughly classified into non-single-crystal oxide semiconductor films and single-crystal oxide semiconductor films. The single-crystal oxide semiconductor film is called CAAC-OS (C Axis Aligned Crystal Polycrystalline oxide semiconductor film The oxide semiconductor film includes a microcrystalline oxide semiconductor film, an amorphous oxide semiconductor film, and the like.

[0270] First, the CAAC-OS film will be described.

[0271] The CAAC-OS film is one of the oxide semiconductor films that has multiple crystal parts. The crystal part is so large that it fits inside a cube with a side length of less than 100 nm. The crystals contained in the S film are cubes with sides of less than 10 nm, 5 nm, or 3 nm. This also includes cases where the size fits within the

[0272] The CAAC-OS film was observed under a transmission electron microscope (TEM). When observed under a crystalline microscope, clear boundaries between the crystals, i.e., crystal boundaries, are clearly visible. It is not possible to confirm the grain boundary. It can be said that the AC-OS film is less susceptible to the decrease in electron mobility caused by grain boundaries.

[0273] The CAAC-OS film was observed by TEM from a direction roughly parallel to the sample surface (cross-sectional TEM observation). ) It can be confirmed that the metal atoms are arranged in layers in the crystalline part. Each layer has a surface on which the CAAC-OS film is formed (also referred to as a surface on which the CAAC-OS film is formed) or an uneven surface on which the CAAC-OS film is formed. The shape reflects this and is aligned parallel to the surface on which the CAAC-OS film is formed or the top surface.

[0274] In this specification, "parallel" means that two straight lines are at an angle of -10° or more and 10° or less. Therefore, it includes the case where the angle is between -5° and 5°. "Straight" refers to a state in which two straight lines are arranged at an angle of 80° or more and 100° or less. This also includes cases where the angle is between 85° and 95°.

[0275] On the other hand, the CAAC-OS film was observed by TEM from a direction approximately perpendicular to the sample surface (planar TEM). When observed, it was found that the metal atoms were arranged in triangular or hexagonal shapes in the crystals. However, there is no regularity in the arrangement of metal atoms between different crystal parts. stomach.

[0276] Cross-sectional and planar TEM observations revealed that the crystals in the CAAC-OS film had an orientation. It turns out that there are.

[0277] X-ray diffraction (XRD) was performed on the CAAC-OS film. For example, a CAAC-OS film with InGaZnO4 crystals was found by structural analysis using the device. In the out-of-plane analysis, a peak was observed at a diffraction angle (2θ) of approximately 31°. This peak is attributed to the (009) plane of the InGaZnO4 crystal. This indicates that the crystals of the CAAC-OS film have a c-axis orientation, and the c-axis is approximately aligned on the surface on which the film is formed or on the upper surface. It can be seen that it is oriented in a substantially vertical direction.

[0278] On the other hand, in-pl X-rays are incident on the CAAC-OS film from a direction approximately perpendicular to the c-axis. In the analysis by the ane method, a peak may appear at 2θ around 56°. This is attributed to the (110) plane of the InGaZnO4 crystal. In the case of a semiconductor film, 2θ is fixed at around 56°, and the normal vector of the sample surface is set as the axis (φ axis). When the sample is rotated and analyzed (φ scan), the crystal plane equivalent to the (110) plane is In contrast, in the case of the CAAC-OS film, 2θ is set to 5 Even when the φ is fixed at around 6° and scanned, no clear peak appears.

[0279] From the above, it is concluded that the a-axis and b-axis orientations are inconsistent between different crystal regions in the CAAC-OS film. Although it is regular, it has a c-axis orientation, and the c-axis is parallel to the normal vector of the surface to be formed or the upper surface. Therefore, the layered arrangement confirmed by the cross-sectional TEM observation mentioned above is consistent with the above. Each layer of aligned metal atoms is a plane parallel to the ab plane of the crystal.

[0280] The crystalline part is formed when the CAAC-OS film is formed or when a crystallization process such as a heat treatment is performed. As described above, the c-axis of the crystal is aligned with the surface on which the CAAC-OS film is formed or the surface on which the CAAC-OS film is formed. The orientation of the CAAC-OS film is parallel to the normal vector of the top surface. When the shape is changed by etching, the c-axis of the crystal is aligned with the surface on which the CAAC-OS film is formed. Or it may not be parallel to the normal vector of the upper surface.

[0281] The crystallinity of the CAAC-OS film may not be uniform. When the crystal part of the CAAC-OS film is formed by crystal growth from the vicinity of the top surface, The area near the surface may have a higher degree of crystallinity than the area near the surface to be formed. When impurities are added to a C-OS film, the crystallinity of the region where the impurities are added changes, resulting in partial In some cases, regions of different crystallinity may be formed.

[0282] In addition, the out-of-plane method of CAAC-OS film with InGaZnO4 crystals In the analysis by , in addition to the peak at 2θ around 31°, a peak also appeared at 2θ around 36°. The peak at 2θ around 36° is due to the presence of c-axis orientation in part of the CAAC-OS film. The CAAC-OS film contains crystals that do not have a 2θ of around 31°. It is preferable that the peak is exhibited at 2θ of around 36° and that the peak is not exhibited at 2θ of around 36°.

[0283] In this specification, when the crystal is a trigonal or rhombohedral crystal, it is expressed as a hexagonal crystal system. .

[0284] The CAAC-OS film is an oxide semiconductor film with a low concentration of impurities. These are elements other than the main components of the oxide semiconductor film, such as silicon and transition metal elements. The elements that bond to oxygen more strongly than the metal elements that constitute the oxide semiconductor film, such as fluorine, are oxidized. By removing oxygen from the oxide semiconductor film, the atomic arrangement of the oxide semiconductor film is disrupted, reducing its crystallinity. In addition, heavy metals such as iron and nickel, argon, and carbon dioxide have an atomic radius (or molecular radius) is large, and when it is contained inside the oxide semiconductor film, The impurities contained in the oxide semiconductor film are likely to disturb the atomic arrangement and cause a decrease in crystallinity. Objects can act as carrier traps or carrier sources.

[0285] The CAAC-OS film is an oxide semiconductor film with a low density of defect states.

[0286] In addition, transistors using CAAC-OS films show improved electrical characteristics when irradiated with visible light or ultraviolet light. The fluctuation is small.

[0287] Next, a microcrystalline oxide semiconductor film will be described.

[0288] In the microcrystalline oxide semiconductor film, crystal parts can be clearly seen in the TEM image. The crystal part contained in the microcrystalline oxide semiconductor film may have a size of 1 nm or more and 100 nm or less. , or 1 nm to 10 nm in size. Nanocrystals (nc) are microcrystals of 1 nm or less and 3 nm or less. The oxide semiconductor film having nc-OS (nanocrystalline Oxide Semiconductor Film) The nc-OS film is called a TE film. In the M observation image, the grain boundaries may not be clearly visible.

[0289] The nc-OS film is a microscopic region (e.g., a region of 1 nm to 10 nm, especially a region of 1 nm or more). The nc-OS film has a periodic atomic arrangement in the region of 3 nm or less. There is no regularity in the crystal orientation between the crystal parts. Therefore, no orientation is observed throughout the film. Therefore, depending on the analytical method, the nc-OS film may be indistinguishable from an amorphous oxide semiconductor film. For example, an XRD apparatus using X-rays with a diameter larger than that of the crystals is used for nc-OS films. When performing structural analysis using a certain device, in the analysis by the out-of-plane method, no peaks indicating crystal planes are detected. Also, for the nc-OS film, when performing electron beam diffraction (also referred to as limited field of view electron beam diffraction) using an electron beam with a probe diameter larger than the crystal part (for example, 50 nm or more), a diffraction pattern such as a halo pattern is observed. On the other hand, for the nc-OS film, when performing electron beam diffraction (also referred to as nano-beam electron beam diffraction) using an electron beam with a probe diameter close to or smaller than the size of the crystal part (for example, 1 nm or more and 30 nm or less), spots are observed. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where regions with high brightness are observed in a circular (ring-shaped) manner. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where a plurality of spots are observed within the ring-shaped region. When performing structural analysis using a certain device, in the analysis by the out-of-plane method, no peaks indicating crystal planes are detected. Also, for the nc-OS film, when performing electron beam diffraction (also referred to as limited field of view electron beam diffraction) using an electron beam with a probe diameter larger than the crystal part (for example, 50 nm or more), a diffraction pattern such as a halo pattern is observed. On the other hand, for the nc-OS film, when performing electron beam diffraction (also referred to as nano-beam electron beam diffraction) using an electron beam with a probe diameter close to or smaller than the size of the crystal part (for example, 1 nm or more and 30 nm or less), spots are observed. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where regions with high brightness are observed in a circular (ring-shaped) manner. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where a plurality of spots are observed within the ring-shaped region. For example, when using an electron beam with a probe diameter of 50 nm or more), electron beam diffraction (also referred to as limited field of view electron beam diffraction) is performed. When performing structural analysis using a certain device, in the analysis by the out-of-plane method, no peaks indicating crystal planes are detected. Also, for the nc-OS film, when performing electron beam diffraction (also referred to as limited field of view electron beam diffraction) using an electron beam with a probe diameter larger than the crystal part (for example, 50 nm or more), a diffraction pattern such as a halo pattern is observed. On the other hand, for the nc-OS film, when performing electron beam diffraction (also referred to as nano-beam electron beam diffraction) using an electron beam with a probe diameter close to or smaller than the size of the crystal part (for example, 1 nm or more and 30 nm or less), spots are observed. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where regions with high brightness are observed in a circular (ring-shaped) manner. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where a plurality of spots are observed within the ring-shaped region. For the nc-OS film, when performing electron beam diffraction (also referred to as nano-beam electron beam diffraction) using an electron beam with a probe diameter close to or smaller than the size of the crystal part (for example, 1 nm or more and 30 nm or less), spots are observed. When performing structural analysis using a certain device, in the analysis by the out-of-plane method, no peaks indicating crystal planes are detected. Also, for the nc-OS film, when performing electron beam diffraction (also referred to as limited field of view electron beam diffraction) using an electron beam with a probe diameter larger than the crystal part (for example, 50 nm or more), a diffraction pattern such as a halo pattern is observed. On the other hand, for the nc-OS film, when performing electron beam diffraction (also referred to as nano-beam electron beam diffraction) using an electron beam with a probe diameter close to or smaller than the size of the crystal part (for example, 1 nm or more and 30 nm or less), spots are observed. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where regions with high brightness are observed in a circular (ring-shaped) manner. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where a plurality of spots are observed within the ring-shaped region. When performing structural analysis using a certain device, in the analysis by the out-of-plane method, no peaks indicating crystal planes are detected. Also, for the nc-OS film, when performing electron beam diffraction (also referred to as limited field of view electron beam diffraction) using an electron beam with a probe diameter larger than the crystal part (for example, 50 nm or more), a diffraction pattern such as a halo pattern is observed. On the other hand, for the nc-OS film, when performing electron beam diffraction (also referred to as nano-beam electron beam diffraction) using an electron beam with a probe diameter close to or smaller than the size of the crystal part (for example, 1 nm or more and 30 nm or less), spots are observed. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where regions with high brightness are observed in a circular (ring-shaped) manner. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where a plurality of spots are observed within the ring-shaped region. When performing structural analysis using a certain device, in the analysis by the out-of-plane method, no peaks indicating crystal planes are detected. Also, for the nc-OS film, when performing electron beam diffraction (also referred to as limited field of view electron beam diffraction) using an electron beam with a probe diameter larger than the crystal part (for example, 50 nm or more), a diffraction pattern such as a halo pattern is observed. On the other hand, for the nc-OS film, when performing electron beam diffraction (also referred to as nano-beam electron beam diffraction) using an electron beam with a probe diameter close to or smaller than the size of the crystal part (for example, 1 nm or more and 30 nm or less), spots are observed. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where regions with high brightness are observed in a circular (ring-shaped) manner. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where a plurality of spots are observed within the ring-shaped region. When performing structural analysis using a certain device, in the analysis by the out-of-plane method, no peaks indicating crystal planes are detected. Also, for the nc-OS film, when performing electron beam diffraction (also referred to as limited field of view electron beam diffraction) using an electron beam with a probe diameter larger than the crystal part (for example, 50 nm or more), a diffraction pattern such as a halo pattern is observed. On the other hand, for the nc-OS film, when performing electron beam diffraction (also referred to as nano-beam electron beam diffraction) using an electron beam with a probe diameter close to or smaller than the size of the crystal part (for example, 1 nm or more and 30 nm or less), spots are observed. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where regions with high brightness are observed in a circular (ring-shaped) manner. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where a plurality of spots are observed within the ring-shaped region. When performing structural analysis using a certain device, in the analysis by the out-of-plane method, no peaks indicating crystal planes are detected. Also, for the nc-OS film, when performing electron beam diffraction (also referred to as limited field of view electron beam diffraction) using an electron beam with a probe diameter larger than the crystal part (for example, 50 nm or more), a diffraction pattern such as a halo pattern is observed. On the other hand, for the nc-OS film, when performing electron beam diffraction (also referred to as nano-beam electron beam diffraction) using an electron beam with a probe diameter close to or smaller than the size of the crystal part (for example, 1 nm or more and 30 nm or less), spots are observed. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where regions with high brightness are observed in a circular (ring-shaped) manner. Also, when performing nano-beam electron beam diffraction on the nc-OS film, there may be cases where a plurality of spots are observed within the ring-shaped region.

[0290] The nc-OS film is an oxide semiconductor film with higher regularity than the amorphous oxide semiconductor film. Therefore, the nc-OS film has a lower density of defect energy levels than the amorphous oxide semiconductor film. However, in the nc-OS film, no regularity is observed in the crystal orientation between different crystal parts. Therefore, the nc-OS film has a higher density of defect energy levels than the CAAC-OS film. The nc-OS film is an oxide semiconductor film with higher regularity than the amorphous oxide semiconductor film. Therefore, the nc-OS film has a lower density of defect energy levels than the amorphous oxide semiconductor film. However, in the nc-OS film, no regularity is observed in the crystal orientation between different crystal parts. Therefore, the nc-OS film has a higher density of defect energy levels than the CAAC-OS film. The nc-OS film is an oxide semiconductor film with higher regularity than the amorphous oxide semiconductor film. Therefore, the nc-OS film has a lower density of defect energy levels than the amorphous oxide semiconductor film. However, in the nc-OS film, no regularity is observed in the crystal orientation between different crystal parts. Therefore, the nc-OS film has a higher density of defect energy levels than the CAAC-OS film. The nc-OS film is an oxide semiconductor film with higher regularity than the amorphous oxide semiconductor film. Therefore, the nc-OS film has a lower density of defect energy levels than the amorphous oxide semiconductor film. However, in the nc-OS film, no regularity is observed in the crystal orientation between different crystal parts. Therefore, the nc-OS film has a higher density of defect energy levels than the CAAC-OS film. <000176​​​​​​​​​​​​ Upon impact, the crystalline regions contained in the sputtering target cleave from the ab plane, forming a -b Peels off as flat or pellet-shaped sputtered particles with surfaces parallel to the plane In this case, the plate-shaped or pellet-shaped sputtered particles may be in a crystalline state. By reaching the substrate while maintaining this state, a CAAC-OS film can be formed.

[0293] A plate-shaped or pellet-shaped sputtering particle has a circular equivalent of a plane parallel to the ab plane. Diameter is 3 nm or more and 10 nm or less, and thickness (length perpendicular to the ab plane) is 0.7 nm or more. The sputtered particles in the form of plates or pellets are flat on the ab plane. The face may be an equilateral triangle or a regular hexagon. Here, the circle-equivalent diameter of the face is the area of ​​the face. The diameter of a perfect circle is equal to

[0294] In addition, the following conditions are preferably applied to form the CAAC-OS film.

[0295] By increasing the substrate temperature during film formation, migration of sputtered particles after reaching the substrate is suppressed. Specifically, the substrate temperature is set to 100°C or higher and 740°C or lower, preferably 200°C or higher. The film is formed at 500℃ or less. By increasing the substrate temperature during film formation, it is possible to form a flat or pellet-shaped film. When sputtered particles reach the substrate, migration occurs on the substrate, The flat surface of the sputtering particles adheres to the substrate. By using an electric current, the sputtering particles repel each other while adhering to the substrate. The CAAC-OS film is formed with uniform thickness without unevenly overlapping the coating particles. It is possible.

[0296] By reducing the amount of impurities mixed in during film formation, it is possible to prevent the crystal state from being destroyed by impurities. For example, the concentration of impurities (hydrogen, water, carbon dioxide, nitrogen, etc.) present in the film formation chamber can be reduced. In addition, the impurity concentration in the deposition gas can be reduced. A deposition gas having a temperature of 80° C. or less, preferably −100° C. or less, is used.

[0297] In addition, increasing the oxygen ratio in the deposition gas and optimizing the power reduces plasma damage during deposition. The oxygen ratio in the deposition gas is preferably 30% by volume or more, and more preferably 100% by volume or more. The product is %.

[0298] Alternatively, the CAAC-OS film is formed by the following method.

[0299] First, a first oxide semiconductor film is formed to a thickness of 1 nm or more and less than 10 nm. The semiconductor film is formed by sputtering. Specifically, the substrate temperature is set to 100°C or higher for 5 00℃ or less, preferably 150℃ or more and 450℃ or less, and the oxygen ratio in the deposition gas is 30 The film is formed at a volume percentage of at least 100%, preferably 100%.

[0300] Next, heat treatment is performed to convert the first oxide semiconductor film into a first CAAC-OS film with high crystallinity. The temperature of the heat treatment is 350°C or higher and 740°C or lower, preferably 450°C or higher and 650°C or lower. The heat treatment time is 1 minute to 24 hours, preferably 6 minutes to 4 hours. The heat treatment may be carried out in an inert atmosphere or an oxidizing atmosphere. Or, after heat treatment in an inert atmosphere, heat treatment is performed in an oxidizing atmosphere. By the heat treatment in air, the impurity concentration of the first oxide semiconductor film can be reduced in a short time. On the other hand, oxygen vacancies are generated in the first oxide semiconductor film by heat treatment in an inert atmosphere. In this case, the oxygen deficiency can be reduced by heat treatment in an oxidizing atmosphere. Heat treatment can be carried out at a pressure of 1000 Pa or less, 100 Pa or less, 10 Pa or less, or The treatment may be performed under reduced pressure of 1 Pa or less. Under reduced pressure, the impurity concentration of the first oxide semiconductor film can be reduced to It can be reduced in an even shorter time.

[0301] The first oxide semiconductor film has a thickness of 1 nm or more and less than 10 nm. Compared with nanometers or larger, it can be easily crystallized by heat treatment.

[0302] Next, a second oxide semiconductor film having the same composition as the first oxide semiconductor film is formed to a thickness of 10 nm or more and 50 nm or more. The second oxide semiconductor film is deposited to a thickness of 100 nm or less by sputtering. Specifically, the substrate temperature is set to 100°C or higher and 500°C or lower, preferably 150°C or higher and 450°C or lower. The oxygen ratio in the deposition gas is set to 30% by volume or more, preferably 100% by volume. do.

[0303] Next, heat treatment is performed to form a second oxide semiconductor film by solid-phase growth from the first CAAC-OS film. The heat treatment temperature was 350°C. The temperature is set to 450°C or higher and 740°C or lower, preferably 450°C or higher and 650°C or lower. The heating time is from 1 minute to 24 hours, preferably from 6 minutes to 4 hours. The heat treatment may be carried out in an active atmosphere or an oxidizing atmosphere. Preferably, the heat treatment is carried out in an inert atmosphere. After that, heat treatment is performed in an oxidizing atmosphere. The impurity concentration of the semiconductor film can be reduced in a short time. Oxygen vacancies may be generated in the second oxide semiconductor film by the treatment. The oxygen deficiency can be reduced by heat treatment in a 10 atmosphere. The pressure may be reduced to 00 Pa or less, 100 Pa or less, 10 Pa or less, or 1 Pa or less. Under reduced pressure, the impurity concentration of the second oxide semiconductor film can be reduced in a shorter time. do.

[0304] In this manner, a CAAC-OS film having a total thickness of 10 nm or more can be formed. The CAAC-OS film can be suitably used as an oxide semiconductor film in an oxide stack. It is possible.

[0305] Next, for example, the substrate is not heated, so that the surface to be formed is kept at a low temperature (for example, less than 130°C, Oxide film at temperatures below 100°C, below 70°C, or room temperature (20°C to 25°C) The formation method will be described.

[0306] When the surface to be formed is at a low temperature, the sputtered particles rain down irregularly on the surface to be formed. For example, since migration does not occur, it is possible to include areas where other sputter particles have already accumulated. That is, the oxide film obtained by deposition has a uniform thickness, for example. The oxide film obtained in this way is not uniform, and the crystal orientation may be disordered. It has crystalline parts (nanocrystals) to maintain the crystallinity of the carbon particles to a certain extent.

[0307] In addition, for example, when the pressure during film formation is high, the flying sputtered particles may be mixed with other gases such as argon. The frequency of collisions with particles (atoms, molecules, ions, radicals, etc.) increases. Sputtered particles are Collisions with other particles during flight (resputtering) can cause the crystal structure to collapse. For example, sputtered particles collide with other particles and form into flat or pellet-like shapes. It may not be possible to maintain the same state, and the molecule may be fragmented (e.g., divided into individual atoms). At this time, atoms separated from the sputtered particles are deposited on the surface to be formed, forming an amorphous oxide. A film may form.

[0308] In addition, instead of a sputtering method using a target having a polycrystalline oxide as a starting point, In the case of a method of forming a film using a solid, or by gasifying a solid such as a target, In the case of the method using the ion beam, the atoms fly in a separated state and deposit on the surface to be formed, resulting in an amorphous oxide. In laser ablation, for example, a thin film may be formed from the target. Atoms, molecules, ions, radicals, clusters, etc. emitted from the surface fly and deposit on the surface. Therefore, an amorphous oxide film may be formed.

[0309] The oxide semiconductor film included in the resistor and the transistor of one embodiment of the present invention may be any of the above-described oxide semiconductor films. In addition, an oxide semiconductor film having a stacked structure may be used. In this case, the crystal states of the oxide semiconductor films may be different from each other. It is preferable to use a CAAC-OS film as the oxide semiconductor film functioning as a filter. In addition, the oxide semiconductor film included in the resistor element has a higher resistance than the oxide semiconductor film included in the transistor. However, the impurity concentration is high, so the crystallinity may be reduced.

[0310] As described above, the structures, methods, etc. described in this embodiment are applicable to the structures, methods, etc. described in other embodiments. They can be used in any suitable combination.

[0311] (Sixth embodiment) In this embodiment, a structure of a display panel that can be applied to the display device of one embodiment of the present invention will be described. This will be described with reference to FIG. 11. The display panel described in this embodiment is The touch sensor (contact detection device) is placed on top of the display, making it a touch panel (input / output device). It can be said that this is the position.

[0312] FIG. 11A is a top view illustrating a structure of a display panel that can be applied to a display device of one embodiment of the present invention. Figure.

[0313] FIG. 11(B) is a cross-sectional view taken along the cutting lines AB and CD in FIG. 11(A).

[0314] FIG. 11C is a cross-sectional view taken along the line EF in FIG. 11A.

[0315] <Explanation of top view> The input / output device 300 illustrated in this embodiment includes a display portion 301 (see FIG. 11A). .

[0316] The display unit 301 includes a plurality of pixels 302 and a plurality of imaging pixels 308. The imaging pixels 308 are It is possible to detect a finger or the like touching the display unit 301. A touch sensor can be configured using the above.

[0317] The pixel 302 includes a plurality of sub-pixels (for example, the sub-pixel 302R), each of which includes a light-emitting element and a The pixel circuit is capable of supplying power to drive the light emitting element.

[0318] The pixel circuit includes wiring that can supply a selection signal and wiring that can supply an image signal. The wiring is electrically connected to the wiring.

[0319] The input / output device 300 also includes a scanning line driver circuit that can supply a selection signal to the pixel 302. 303g(1), and an image signal line driver circuit 303 that can supply image signals to the pixels 302. 03s(1). In addition, the image signal line driver circuit 303s is provided to avoid the bent portion. By placing (1), the occurrence of malfunctions can be reduced.

[0320] The imaging pixel 308 includes a photoelectric conversion element and an imaging pixel circuit that drives the photoelectric conversion element.

[0321] The imaging pixel circuit has wiring that can supply a control signal and a power supply potential. It is electrically connected to the wiring that can be used.

[0322] The control signal may be, for example, a pixel circuit for reading out a recorded image signal. a signal that can initialize the imaging pixel circuit; and a signal that can initialize the imaging pixel circuit. Examples of such signals include signals that can determine the time at which the signal is detected.

[0323] The input / output device 300 includes an imaging pixel drive circuit that can provide control signals to the imaging pixels 308. 303g(2) and an imaging signal line drive circuit 303s(2) that reads out imaging signals. If the imaging signal line driving circuit 303s(2) is arranged to avoid the bent portion, a malfunction may occur. This can reduce the occurrence of collisions.

[0324] <Explanation of the cross-sectional view> The input / output device 300 includes a substrate 310 and an opposing substrate 370 facing the substrate 310 ( See Figure 11(B)).

[0325] The substrate 310 is made of a flexible substrate 310b, which prevents unintended diffusion of impurities into the light emitting element. The barrier film 310a and the adhesive layer 310b bond the barrier film 310a to the substrate 310b. c is a laminated body.

[0326] The opposing substrate 370 is a flexible substrate 370b, which prevents unintended impurities from diffusing into the light emitting element. A barrier film 370a for preventing the occurrence of heat and an adhesive layer 3 for bonding the barrier film 370a to the substrate 370b. 70c (see FIG. 11(B)).

[0327] The sealing material 360 bonds the opposing substrate 370 and the substrate 310 together. It has a refractive index higher than that of air and also serves as an optical bonding layer. 1 light-emitting element 350R) and an imaging pixel circuit and a photoelectric conversion element (for example, photoelectric conversion element 3 08p) is located between the substrate 310 and the opposing substrate 370.

[0328] 《Pixel configuration》 The pixel 302 includes a subpixel 302R, a subpixel 302G, and a subpixel 302B (FIG. 11 Also, the subpixel 302R includes a light-emitting module 380R, and the subpixel 302G The subpixel 302B includes a light-emitting module 380G, and the subpixel 302B includes a light-emitting module 380B.

[0329] For example, the subpixel 302R provides power to the first light-emitting element 350R and the second light-emitting element 350R. The pixel circuit includes a transistor 302t that can supply The light emitting module 380R includes a first light emitting element 350R and an optical element (for example, The first colored layer 367R is provided.

[0330] The first light emitting element 350R includes a first lower electrode 351R, an upper electrode 352, a first lower electrode Between 351R and the upper electrode 352, there is a layer 353 containing a light-emitting organic compound (FIG. 11( See C).

[0331] The layer 353 containing a light-emitting organic compound includes a light-emitting unit 353a, a light-emitting unit 353b, and a light-emitting layer 353c. An intermediate layer 354 is provided between the light-emitting unit 353a and the light-emitting unit 353b.

[0332] The light emitting module 380R has a first colored layer 367R on the counter substrate 370. The colored layer Any material may be used as long as it transmits light having a specific wavelength, such as red, green, or blue. Alternatively, a material that selectively transmits light emitted by a light-emitting element can be used. Alternatively, a region that is transparent as it is may be provided.

[0333] For example, the light emitting module 380R includes a first light emitting element 350R and a first color layer 367R. It has a sealant 360 in contact with it.

[0334] The first colored layer 367R is located so as to overlap the first light emitting element 350R. A part of the light emitted by the light emitting element 350R is absorbed by the sealing material 360, which also serves as an optical bonding layer, and the first The light passes through the colored layer 367R and is emitted to the outside of the light emitting module 380R as shown by the arrow in the figure. It is served.

[0335] <<Configuration of input / output devices>> The input / output device 300 has a light-shielding layer 367BM on the opposing substrate 370. The light-shielding layer 367BM , and is provided so as to surround the colored layer (for example, the first colored layer 367R).

[0336] The input / output device 300 includes an anti-reflection layer 367p at a position overlapping the display unit 301. The stop layer 367p may be, for example, a circular polarizer.

[0337] The input / output device 300 includes an insulating film 321. The insulating film 321 covers the transistor 302t. The insulating film 321 is used as a layer for flattening unevenness caused by the pixel circuit. In addition, the diffusion of impurities into the transistor 302t and the like can be suppressed. The insulating film 321 can be formed by stacking layers that can be used for the insulating film.

[0338] The input / output device 300 has a light emitting element (for example, a first light emitting element 350R) on an insulating film 321. do.

[0339] The input / output device 300 has a partition wall 328 overlapping the end of the first lower electrode 351R, and the partition wall 328 is formed on the insulating film 321. (See FIG. 11C). In addition, the distance between the substrate 310 and the counter substrate 370 is controlled. Spacers 329 are provided on the partition walls 328 .

[0340] <Configuration of Image Signal Line Driving Circuit> The image signal line driver circuit 303s(1) includes a transistor 303t and a capacitor 303c. The image signal line driver circuit 303s(1) is formed on the same substrate as the pixel circuit in the same process. It is possible.

[0341] <<Image pixel configuration>> The imaging pixel 308 converts light incident on the photoelectric conversion element 308p and the photoelectric conversion element 308p into a The imaging pixel circuit includes a transistor 308t. include.

[0342] For example, a pin-type photodiode can be used as the photoelectric conversion element 308p.

[0343] Other Configurations The input / output device 300 includes a wiring 311 through which a signal can be supplied, and a terminal 319 311. In addition, signals such as image signals and synchronization signals can be supplied. The FPC 309(1) is electrically connected to the terminal 319. The FPC 309(1) is arranged to avoid the bending portion of the power supply device 300. The folded side (long side in the figure) is selected from the area surrounding the portion 301. It is preferable to place the FPC 309(1) in the center. The distance of the external circuit that drives the device 300 can be shortened, making connection easier. The center of gravity of the external circuit can be approximately aligned with the center of gravity of the input / output device 300. This makes it easier to handle information processing devices, and prevents accidental dropping and other malfunctions. It is possible.

[0344] In addition, a printed wiring board (PWB) may be attached to the FPC309(1). .

[0345] Note that this embodiment mode can be appropriately combined with other embodiment modes shown in this specification. .

[0346] (Embodiment 7) In this embodiment, a structure of a display panel that can be applied to the display device of one embodiment of the present invention will be described. This will be described with reference to FIGS. 12 and 13. The display panel has a touch sensor (touch detection device) on top of the display. It can be called an input / output device.

[0347] 12A is a schematic perspective view of a touch panel 500 exemplified in this embodiment. For clarity, representative components are shown in Figure 12. Figure 12(B) shows a touch panel 500 FIG.

[0348] FIG. 13 is a cross-sectional view of the touch panel 500 taken along line X1-X2 of FIG. 12(A).

[0349] The touch panel 500 includes a display unit 501 and a touch sensor 595 (see FIG. 12(B)). The touch panel 500 also includes a substrate 510, a substrate 570, and a substrate 590. It should be noted that the substrates 510, 570 and 590 are all flexible.

[0350] The display unit 501 includes a substrate 510, a plurality of pixels on the substrate 510, and a display device for supplying signals to the pixels. The plurality of wirings 511 are arranged to extend to the outer periphery of the substrate 510. The terminal 519 is connected to the FPC 509(1). Make an electrical connection.

[0351] <Touch sensor> The substrate 590 includes a touch sensor 595 and a plurality of electrodes electrically connected to the touch sensor 595. The wiring 598 is arranged around the periphery of the substrate 590, and some of the wiring 598 is It forms a terminal for electrical connection with FPC 509(2). For clarity, the touch sensor 595 provided on the back side of the substrate 590 (the back side of the paper) Electrodes, wiring, etc. are indicated by solid lines.

[0352] The touch sensor used for the touch sensor 595 is preferably a capacitance type touch sensor. There are two types of capacitive touch panels: surface capacitive touch panels and projected capacitive touch panels. There are two types of capacitance type sensors, self-capacitance type and mutual capacitance type, which mainly differ in the driving method. The mutual capacitance method is preferable because it allows simultaneous multi-point detection.

[0353] In the following, when a projected capacitive touch sensor is applied, Fig. 12(B) is used. The following description will be given using various sensors that can detect the proximity or contact of a detection target such as a finger. A sensor can be applied.

[0354] The projected capacitive touch sensor 595 has an electrode 591 and an electrode 592. 91 is electrically connected to one of the plurality of wirings 598, and the electrode 592 is electrically connect to one of the others.

[0355] As shown in FIGS. 12(A) and 12(B), the electrode 592 has a shape in which multiple quadrilaterals are connected in one direction. The electrode 591 has a quadrilateral shape. The wiring 594 extends in the direction in which the electrode 592 extends. Two electrodes 591 arranged in a direction intersecting the direction of the electrode 5 are electrically connected. It is preferable that the area of ​​the intersection of the wiring 594 with the wiring 92 be as small as possible. The area of ​​the region where no electrodes are provided can be reduced, and unevenness in transmittance can be reduced. The unevenness in brightness of light passing through the touch sensor 595 can be reduced.

[0356] The shapes of the electrodes 591 and 592 are not limited to this, and various shapes are possible. For example, The electrodes 591 are arranged so that there are as few gaps as possible between them, and the electrodes 59 are connected to each other via an insulating layer. 2 may be provided at intervals so as to leave an area that does not overlap with the electrode 591. At this time, a dummy electrode electrically isolated from the two adjacent electrodes 592 is placed between them. Providing a pole is preferable because it can reduce the area of ​​the region with different transmittance.

[0357] The configuration of the touch panel 500 will be described with reference to FIG.

[0358] The touch sensor 595 includes a substrate 590, electrodes 591 arranged in a staggered pattern on the substrate 590, and The electrode 592, the electrode 591, and the insulating layer 593 covering the electrode 592, and the adjacent electrode 591 are Electrically connecting wiring 594 is provided.

[0359] The adhesive layer 597 is formed between the substrate 590 and the substrate 501 so that the touch sensor 595 and the display unit 501 overlap each other. 70 are pasted together.

[0360] The electrode 591 and the electrode 592 are formed using a light-transmitting conductive material. Conductive materials that can be used include indium oxide, indium tin oxide, indium zinc oxide, Conductive oxides such as zinc oxide and zinc oxide doped with gallium can be used.

[0361] After forming a film of a light-transmitting conductive material on a substrate 590 by a sputtering method, By using various patterning techniques such as lithography, unnecessary parts are removed to form the electrode 591. and electrode 592 can be formed.

[0362] The insulating layer 593 covers the electrode 591 and the electrode 592. Examples of suitable resins include acrylic and epoxy resins, resins with siloxane bonds, and oxidized resins. Inorganic insulating materials such as silicon, silicon oxynitride, and aluminum oxide can also be used. do.

[0363] An opening reaching the electrode 591 is provided in the insulating layer 593, and a wiring 594 is formed on the adjacent electrode 5 The wiring 594 formed using a light-transmitting conductive material is electrically connected to the touch panel 91. This is preferable because it can increase the aperture ratio of the panel. It is preferable to use a material with higher conductivity for the wiring 594 .

[0364] One electrode 592 extends in one direction, and a plurality of electrodes 592 are provided in a stripe pattern.

[0365] The wiring 594 is provided to intersect with the electrodes 592 .

[0366] A pair of electrodes 591 are provided with one electrode 592 sandwiched therebetween and are electrically connected to a wiring 594. There are.

[0367] The plurality of electrodes 591 do not necessarily need to be arranged in a direction perpendicular to one electrode 592. The angle between the first and second electrodes may be less than 90 degrees.

[0368] One wiring 598 is electrically connected to the electrode 591 or the electrode 592. The wiring 598 may be made of, for example, aluminum, gold, platinum, silver, Nickel, titanium, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium Metallic materials such as aluminum and alloy materials containing such metallic materials can be used.

[0369] Note that an insulating layer is provided to cover the insulating layer 593 and the wiring 594 to protect the touch sensor 595. It is possible.

[0370] Furthermore, the connection layer 599 electrically connects the wiring 598 and the FPC 509(2).

[0371] The connection layer 599 may be made of various anisotropic conductive films (ACFs). Conductive Film) and Anisotropic Conductive Paste (ACP) Pic Conductive Paste) can be used.

[0372] The adhesive layer 597 is transparent. For example, a thermosetting resin or an ultraviolet curing resin may be used. Specifically, resins having acrylic, urethane, epoxy, or siloxane bonds can be used. Resins such as fats can be used.

[0373] <Display section> The touch panel 500 includes a plurality of pixels arranged in a matrix. and a pixel circuit that drives the display element.

[0374] In this embodiment, when a white organic electroluminescence element is applied to a display element, However, the display element is not limited to this.

[0375] For example, as display elements, in addition to organic electroluminescence elements, electrophoretic and electronic Display elements that display using a powder liquid method (also called electronic ink), shutter-type M Various display elements can be used, such as EMS display elements and optical interference type MEMS display elements. It is possible to select and use a configuration suitable for the display element to be applied from various pixel circuits. can be done.

[0376] The substrate 510 is made of a flexible substrate 510b, which prevents unintended diffusion of impurities into the light emitting element. A barrier film 510a and an adhesive layer 510b are bonded to the barrier film 510a. c is a laminated body.

[0377] The substrate 570 is made of a flexible substrate 570b, which prevents unintended diffusion of impurities into the light emitting element. A barrier film 570a and an adhesive layer 570b are bonded to the barrier film 570a. c laminate.

[0378] The sealing material 560 bonds the substrate 570 and the substrate 510 together. The first layer has a larger refractive index and also serves as an optical bonding layer. Light emitting element 550R is located between substrate 510 and substrate 570.

[0379] 《Pixel configuration》 The pixel includes a sub-pixel 502R, which comprises a light-emitting module 580R.

[0380] The subpixel 502R supplies power to the first light-emitting element 550R and the second light-emitting element 550R. The light emitting module further includes a pixel circuit including a transistor 502t. 580R includes a first light emitting element 550R and an optical element (for example, a first color layer 567R). can.

[0381] The first light emitting element 550R includes a lower electrode, an upper electrode, and a light emitting active layer between the lower electrode and the upper electrode. The layer includes an organic compound.

[0382] The light emitting module 580R has a first color layer 567R on the substrate 570. Any material that transmits light having a wavelength of, for example, red, green, or blue, may be used. Alternatively, the light emitted by the light emitting element can be directly transmitted through the light emitting element. Alternatively, a transparent region may be provided.

[0383] The light emitting module 580R includes a first light emitting element 550R and an encapsulant in contact with the first colored layer 567R. It has a stopper 560.

[0384] The first colored layer 567R is located so as to overlap the first light emitting element 550R. A part of the light emitted by the light emitting element 550R is absorbed by the sealing material 560, which also serves as an optical bonding layer, and the first The light is transmitted through the colored layer 567R and emitted to the outside of the light emitting module 580R as shown by the arrow in the figure. It is served.

[0385] <<Display Configuration>> The display unit 501 has a light-shielding layer 567BM on a substrate 570. The light-shielding layer 567BM is a colored layer (for example, the first colored layer 567R) is provided so as to surround the first colored layer 567R.

[0386] The display unit 501 includes an anti-reflection layer 567p at a position overlapping the pixels. As the polarizer, for example, a circular polarizer can be used.

[0387] The display portion 501 includes an insulating film 521. The insulating film 521 covers the transistor 502t. The insulating film 521 is used as a layer for flattening unevenness caused by the pixel circuit. In addition, the diffusion of impurities into the transistor 502t and the like can be suppressed. A stacked insulating film can be used as the insulating film 521.

[0388] The display unit 501 has a light-emitting element (for example, a first light-emitting element 550R) on an insulating film 521. .

[0389] The display portion 501 has a partition wall 528 on the insulating film 521, which overlaps with an edge of the lower electrode. A spacer for controlling the distance between the substrate 510 and the substrate 570 is provided on the partition wall 528 .

[0390] <Configuration of Image Signal Line Driving Circuit> The image signal line driver circuit 503s(1) includes a transistor 503t and a capacitor 503c. The image signal line driver circuit 503s(1) is formed on the same substrate as the pixel circuit in the same process. It is possible.

[0391] Other Configurations The display unit 501 includes a wiring 511 capable of supplying a signal, and a terminal 519 is connected to the wiring 511. 1. In addition, F PC 509(1) is electrically connected to terminal 519.

[0392] In addition, a printed wiring board (PWB) may be attached to the FPC509(1). .

[0393] Note that this embodiment mode can be appropriately combined with other embodiment modes shown in this specification. . [Explanation of symbols]

[0394] 13a Connecting member 13b Connecting member 15a Support Panel 15b Support panel 102 Circuit Board 104a gate electrode 106 insulating film 107 Insulating film 108 insulating film 110 Oxide semiconductor film 112 Conductive film 112a first electrode 112b second electrode 114 insulating film 116 Insulating film 118 insulating film 120 insulating film 122a Conductive film 122b Conductive film 122c gate electrode 142a aperture 142d aperture 142e aperture 151 transistors 200 Display device 200B display device 200C display device 200D display device 210 Control Unit 210B Control section 212 Synchronization signal supply unit 214 Power supply section 220 Image Processing Unit 230 Display section 230(1) First Area 230(2) Second Area 230(1)S area 230b(1) Boundary 230b(2) Boundary 232 Drive Circuit 232G scanning line driver circuit 232S signal line driver circuit 239 signs 240 Detection unit 300 I / O devices 301 Display section 302 pixels 302B subpixel 302G subpixel 302R subpixel 302t transistor 303c capacity 303g(1) Scanning line driver circuit 303g(2) Imaging pixel drive circuit 303s(1) Image signal line driver circuit 303s(2) Image signal line driver circuit 303t transistor 308 imaging pixels 308p photoelectric conversion element 308t transistor 309 FPC 310 Substrate 310a Barrier film 310b board 310c adhesive layer 311 Wiring 319 terminal 321 Insulating Film 328 Bulkhead 329 Spacer 350R light emitting element 351R lower electrode 352 Upper electrode 353 layers 353a Light Emitting Unit 353b Lighting unit 354 Middle Class 360 Encapsulating material 367BM light shielding layer 367p anti-reflection layer 367R colored layer 370 Opposing substrate 370a Barrier film 370b board 370c adhesive layer 380B Light Emitting Module 380G light emitting module 380R Light Emitting Module 500 touch panel 501 Display section 502R subpixel 502t transistor 503c capacity 503s Image signal line driver circuit 503t transistor 509 FPC 510 board 510a Barrier film 510b board 510c adhesive layer 511 Wiring 519 terminal 521 Insulating film 528 Bulkhead 550R light emitting element 560 Encapsulating material 567BM light shielding layer 567p anti-reflection layer 567R colored layer 570 PCB 570a Barrier film 570b board 570c ​​adhesive layer 580R Light Emitting Module 590 PCB 591 Electrode 592 Electrode 593 Insulating Layer 594 Wiring 595 Touch Sensor 597 Adhesive layer 598 Wiring 599 Connection Layer 631p pixels 634c Capacitor 634EL pixel circuit 634t transistor 634t_1 Transistor 634t_2 transistor 635EL EL element E1 Highly flexible area E2 Low flexibility area

Claims

[Claim 1] a foldable display unit having a first area and a second area; a detection unit that detects a folded state of the display unit and supplies a folding signal; a control unit to which the folding signal is supplied and which supplies an image control signal; an image processing unit to which the image control signal is supplied and which generates and supplies an image signal; a drive circuit to which the image signal is supplied and which drives the display unit; The control unit supplies the image control signal to the image processing unit to generate an image that displays a black image in the second area of ​​the display unit in a folded state.

Images