Method for operating display device

Abstract

To provide a display device that can correct the threshold voltage of a driving transistor without a correction of image data.SOLUTION: A display device includes a pixel provided with a driving transistor, a display element, and a memory circuit and a correction data generation circuit. One of a source and a drain of the driving transistor is electrically connected to one electrode of the display element, and a gate of the driving transistor is electrically connected to the memory circuit. In a first period, the correction data generation circuit generates correction data that is data for correcting the threshold voltage of the driving transistor. In a second period, first data is written to the memory circuit. In a third period, second data is supplied to the pixel, whereby third data in which the second data is added to the first data is generated. In a fourth period, an image corresponding to the third data is displayed by the display element.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one aspect of the present invention relates to an article, a method, or a manufacturing method. The aspect may be a process, a machine, a manufacture, or a composition of matter. Therefore, one embodiment of the present invention disclosed in the present specification more specifically relates to a method for producing a medicament for a medical device. The technical fields of the present invention include semiconductor devices, display devices, liquid crystal display devices, light-emitting devices, lighting devices, storage devices, etc. Examples of the present invention include an electronic device, a storage device, an imaging device, a driving method thereof, or a manufacturing method thereof. These can be listed as follows.

[0003] In this specification and the like, a semiconductor device is a device that can function by utilizing semiconductor characteristics. A transistor and a semiconductor circuit are one embodiment of a semiconductor device. A display device, an imaging device, or an electronic device may include a semiconductor device. [Background technology]

[0004] In a display device using a light-emitting element as a display element, image data is supplied to the display element. The threshold voltage of the drive transistor, which controls the current flowing through the This is likely to be reflected in the brightness of the light emitted from the display element. The threshold voltage and mobility of the driving transistor are detected from the source potential of the driving transistor. A display device is described that corrects image data based on a threshold voltage and a mobility determined by the threshold voltage and the mobility. This makes it possible to correct the threshold voltage of the drive transistor. Therefore, the variation in the threshold voltage of the driving transistor from pixel to pixel causes the This can reduce the effect on the brightness of the light being emitted. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-265459 A Summary of the Invention [Problem to be solved by the invention]

[0006] The threshold voltage of the driving transistor is corrected by correcting the image data. and the dynamic range of the image data (the maximum potential that the signal corresponding to the image data can take). This makes it necessary to increase the difference between the maximum and minimum values ​​of the light emitted from the display element. When the brightness of the light being received is increased by one gradation, the increase in the potential of the signal corresponding to the image data is large. In addition, the quality of the displayed image may be degraded due to the lack of a suitable display device. The data driver circuit must be made to withstand high voltages, and the manufacturing costs of the display device are increased. Furthermore, the output potential of the data driver circuit may become large, causing a display device This may increase the power consumption of the device.

[0007] In one embodiment of the present invention, the threshold voltage of a driving transistor is not corrected without correcting image data. It is an object of the present invention to provide a display device capable of correcting the above-mentioned defects. It is an object of the present invention to provide a display device capable of displaying an image at a low cost. One of the objects is to provide a display device. Another object is to provide a display device with low power consumption. Another object of the present invention is to provide a display device capable of displaying a high-brightness image. Another object of the present invention is to provide a small-sized display device. One of the objects of the present invention is to provide a display device having a large display area. One of the objectives of the present invention is to provide a display device with a high image quality. Another object of the present invention is to provide a novel semiconductor device or the like.

[0008] Alternatively, the threshold voltage of the driving transistor may be corrected without correcting the image data. Another object of the present invention is to provide a method for operating a display device capable of displaying a high-quality image. It is an object of the present invention to provide a method for operating a display device capable of displaying low It is one of the objects to provide a method for operating a display device that is inexpensive and consumes low power. One of the objectives is to provide a method for operating the device. Or, to display a high brightness image. It is an object of the present invention to provide a method for operating a display device capable of achieving the above-mentioned object. It is an object of the present invention to provide a method for operating a display device having a large display area. It is an object of the present invention to provide a method for operating a display device having high reliability. Another object of the present invention is to provide a novel display device. Another object of the present invention is to provide a method for operating a novel semiconductor device or the like. do.

[0009] Note that the description of these problems does not preclude the existence of other problems. It is not necessary to solve all of these problems. Problems other than these are described in the specification, This will become apparent from the description in the specification, drawings, claims, etc. It is possible to extract other issues from the description. [Means for solving the problem]

[0010] One embodiment of the present invention is a pixel provided with a transistor, a display element, and a memory circuit, a data generating circuit, and one of a source and a drain of the transistor is connected to a display element. The gate of the transistor is electrically connected to the memory circuit. A method for operating a display device, comprising: A correction data is generated, which is data for correcting the threshold voltage of the transistor, and during a second period In the first period, the first data is written to the memory circuit, and in the third period, the second data is written to the memory circuit. The second data is added to the first data by supplying the second data to the pixel. Third data corresponding to the third data is generated, and in a fourth period, an image corresponding to the third data is displayed. A method of operating a display device displayed by the element.

[0011] Alternatively, in the above aspect, during the first period, the correction data generating circuit generates the correction data. After that, a potential corresponding to the correction data may be supplied to the back gate of the transistor. .

[0012] Alternatively, in the above aspect, a current is passed through the transistor during the first period, and the current The corresponding correction data may be generated by a correction data generation circuit.

[0013] Alternatively, in the above aspect, during the first period, the current flowing through the transistor is equal to or smaller than a certain value. The correction data generating circuit may generate the correction data so that:

[0014] Alternatively, in the above aspect, in the first period, no current is passed through the display element, and in the fourth period, A current may be passed through the display element.

[0015] Alternatively, one embodiment of the present invention is a semiconductor device including a first transistor, a second transistor, a third transistor, a pixel provided with a capacitor, a capacitance element, and a display element; and a correction data generating circuit; One of the source and drain of the transistor is electrically connected to one electrode of the capacitor. One of the source and the drain of the second transistor is electrically connected to the other electrode of the capacitor. the other electrode of the capacitor is electrically connected to the gate of the third transistor. One of the source and drain of the third transistor is electrically connected to one electrode of the display element. A method for operating a display device connected to the display device, comprising: generates correction data for correcting the threshold voltage of the third transistor In the second period, the first potential is supplied to the other electrode of the capacitor. In the third period, In the above, when a second potential is supplied to one electrode of the capacitor, the other electrode of the capacitor is The potential of the electrode becomes a third potential, and in the fourth period, a current corresponding to the third potential is This is a method of operating a display device that is passed to a display element.

[0016] Alternatively, in the above aspect, during the first period, the correction data generating circuit generates the correction data. After that, a potential corresponding to the correction data is supplied to the back gate of the third transistor. Good too.

[0017] Alternatively, in the above aspect, the pixel has a fourth transistor, and the fourth transistor Either the source or the drain of the second transistor is electrically connected to either the source or the drain of the third transistor. A method of operating a connected display device, comprising: By turning on the third transistor, a current flows through the third and fourth transistors. The corresponding correction data may be generated by a correction data generation circuit.

[0018] Alternatively, in the above aspect, the current flowing through the third transistor is constant during the first period. The correction data generating circuit may generate the correction data so that the difference is equal to or smaller than the value.

[0019] Alternatively, in the above embodiment, the fourth transistor may be turned off during the fourth period. stomach.

[0020] Alternatively, in the above embodiment, the second transistor has a metal oxide in a channel formation region. The metal oxides are In, Zn, and M (M is Al, Ti, Ga, Ge, Sn, Y, Zr, La, Ce, Nd or Hf).

[0021] Alternatively, in the above embodiment, the display element may be an organic EL element. Effect of the Invention

[0022] According to one aspect of the present invention, the threshold voltage of the driving transistor can be adjusted without correcting the image data. It is possible to provide a display device capable of correcting the pressure. It is possible to provide a display device capable of displaying the image on a low-cost basis. Alternatively, a display device with low power consumption can be provided. Alternatively, a display device with high brightness can be provided. It is possible to provide a display device capable of displaying an image. Alternatively, it is possible to provide a small display device. Alternatively, a display device having a large display area can be provided. It is possible to provide a highly reliable display device. Alternatively, a novel semiconductor device or the like can be provided.

[0023] Alternatively, the threshold voltage of the driving transistor may be corrected without correcting the image data. It is possible to provide a method for operating a display device capable of displaying high-quality images. It is possible to provide a method for operating a display device that can achieve the above-mentioned object. Alternatively, a method for operating a display device with low power consumption can be provided. Alternatively, a method for operating a display device capable of displaying a high-brightness image can be provided. Alternatively, a method for operating a small-sized display device can be provided. It is possible to provide a method for operating a display device having a large product, or a method for operating a display device having high reliability. It is possible to provide a method for operating a novel display device. Alternatively, a method for operating a novel semiconductor device or the like can be provided.

[0024] The description of these effects does not preclude the existence of other effects. However, it is not necessary to have all of these effects. However, it is possible to extract effects other than these. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a circuit diagram showing an example of the configuration of a pixel. [Diagram 2]FIG. 2 is a timing chart showing an example of a method of operating a pixel. [Diagram 3] 3A and 3B are circuit diagrams showing an example of how a pixel operates. [Figure 4] 4A and 4B are circuit diagrams showing an example of how a pixel operates. [Diagram 5] 5A and 5B are circuit diagrams showing an example of how a pixel operates. [Figure 6] FIG. 6 is a circuit diagram showing an example of a method of operating a pixel. [Figure 7] FIG. 7 is a diagram illustrating an example of the operation of the display device. [Figure 8] 8A and 8B are block diagrams showing configuration examples of a display device. [Figure 9] FIG. 9 is a circuit diagram showing an example of the configuration of a pixel. [Figure 10] 10A and 10B are circuit diagrams showing examples of the configuration of a pixel. [Figure 11] 11A and 11B are circuit diagrams showing examples of the configuration of a pixel. [Figure 12] FIG. 12 is a timing chart showing an example of a method of operating a pixel. [Figure 13] FIG. 13 is a timing chart showing an example of a method of operating a pixel. [Figure 14] 14A and 14B are diagrams showing a configuration example of a display device. [Figure 15] 15A and 15B are diagrams showing a configuration example of a touch panel. [Figure 16] 16A and 16B are diagrams showing a configuration example of a display device. [Figure 17] FIG. 17 is a diagram showing a configuration example of a display device. [Figure 18] FIG. 18 is a diagram showing a configuration example of a display device. [Figure 19] 19A1, 19A2, 19B1, 19B2, 19C1, and 19C2 are diagrams showing examples of the configuration of transistors. [Figure 20]20A1, 20A2, 20A3, 20B1, 20B2, 20C1, and 20C2 are diagrams showing examples of the configuration of transistors. [Figure 21] 21A, 21B, 21C, 21D, 21E, and 21F are diagrams showing an example of an electronic device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The embodiment 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 embodiment, and various changes and modifications may be made in the form and details without departing from the spirit and scope of the present invention. It will be easily understood by those skilled in the art that the above-mentioned invention can be obtained by the following embodiments. It should not be construed as being limited to the contents described.

[0027] In the configuration of the invention described below, the same parts or parts having similar functions are referred to as the same parts. The same reference numerals are used in common among different drawings, and the repeated explanations are omitted. When referring to a function, the same hatch pattern may be used and no particular reference number may be given.

[0028] In addition, the position, size, range, etc. of each component shown in the drawings are not necessarily the same as the actual components for ease of understanding. The position, size, range, etc. may not be shown. Therefore, the disclosed invention may not necessarily be The present invention is not limited to the position, size, range, etc. disclosed in the drawings.

[0029] The terms "film" and "layer" may be interchangeable depending on the circumstances. For example, the term "conductive layer" can be replaced with "conductive film" Alternatively, for example, the term "insulating film" can be changed to "insulating It is possible to change the term to "edge layer."

[0030] In this specification, the term "metal oxide" refers to a metal oxide in a broad sense. Metal oxides are oxide insulators and oxide conductors (including transparent oxide conductors). , oxide semiconductors (also called OS), etc. For example, when a metal oxide is used for the semiconductor layer of a transistor, the metal oxide In other words, when describing an OS FET, In other words, the transistor includes a metal oxide or an oxide semiconductor.

[0031] In the present specification and the like, metal oxides having nitrogen are also referred to as metal oxides. Nitrogen-containing metal oxides are also called metal oxynitrides (met de). It may also be called tetrahydrofuran (tetrahydrofuran) oxynitride.

[0032] (Embodiment 1) In this embodiment, a display device which is one embodiment of the present invention and an operation method thereof will be described with reference to drawings. Please refer to the following for explanation.

[0033] According to one aspect of the present invention, the image data to be supplied to the pixel is not corrected, and the driving transistor is The present invention relates to a method for operating a display device, which can correct a threshold voltage. The dynamic range of the image data (the maximum potential that the signal corresponding to the image data can take) The threshold voltage of the driving transistor can be corrected without increasing the difference between the maximum and minimum values. Therefore, the compensation of the threshold voltage of the driving transistor, for example, from the display element can be achieved. The increase in the potential of the signal corresponding to the image data when increasing the brightness of the light emitted from the This makes it possible to precisely control the brightness of the light emitted from the display element. Since the display device can be controlled precisely, the display device can display high quality images. The data driver circuit does not need to be a high voltage resistant circuit, and the display device can be manufactured at a low price. Furthermore, the output potential of the data driver circuit is prevented from increasing. This allows the power consumption of the display device to be reduced.

[0034] Further, a pixel included in the display device of one embodiment of the present invention is provided with a memory circuit. For example, image correction data for correcting image data can be written into the circuit. This allows image processing such as noise removal to be performed within the pixel. Image processing is performed by directly correcting image data using an external arithmetic circuit, etc. This makes it possible to simplify the calculation process compared to the case where the display device consumes less power. The power consumption can be reduced.

[0035] Also, image data can be written into the memory circuit. After writing the image data, the memory circuit supplies second image data to the pixel in which the memory circuit is provided. By this, the display device displays an image corresponding to the first image data and an image corresponding to the second image data. The brightness of the superimposed image can be adjusted by changing the brightness of the superimposed image. is the sum of the luminance represented by the first image data and the luminance represented by the second image data. Therefore, the data driver circuit can generate a higher potential than the signal represented by the signal. The display device can display an image corresponding to the image data. Brighter than when the image corresponding to only one image data is displayed without overlapping the data. The display device can display a high quality image. Since it is not necessary to use a data driver, the display device can be manufactured at a low price. Since the output potential of the driver circuit can be prevented from increasing, the power consumption of the display device can be reduced. can be reduced.

[0036] <Pixel configuration example 1> FIG. 1 illustrates a configuration example of a pixel 10 that can be used in a display device of one embodiment of the present invention. The pixel 10 includes a transistor 11, a transistor 12, and a transistor 13. 3, a transistor 14, a transistor 15, a display element 20, a capacitive element 21, and a capacitor The transistor 13 has a gate, a capacitance element 22, and a capacitance element 23. It has a back gate.

[0037] One of the source and drain of the transistor 11 is electrically connected to one electrode of the capacitor 21. The source or drain of the transistor 12 is connected to the The gate of the transistor 13 is electrically connected to the other gate of the capacitor 21. The other electrode of the capacitance element 21 is electrically connected to one electrode of the capacitance element 22. The electrode is electrically connected to the

[0038] One of the source or drain of transistor 13 is connected to the source or drain of transistor 14. One of the source and drain of the transistor 14 is electrically connected to The display element 20 is electrically connected to one of the electrodes. The other electrode of the capacitance element 22 is electrically connected to the other electrode of the capacitance element 22. It is electrically connected to one electrode of the element 23 .

[0039] The back gate of the transistor 13 is electrically connected to one of the source and drain of the transistor 15. One of the source and drain of the transistor 15 is electrically connected to the capacitance element 23. The other electrode of the first electrode is electrically connected to the second electrode of the second electrode.

[0040] Here, one of the source and drain of the transistor 11 and one of the electrodes of the capacitor 21 The node to which the source of the transistor 12 is electrically connected is referred to as a node ND1. one of the source and drain of the transistor 13, the other electrode of the capacitance element 21, and the capacitance The node to which one electrode of the capacitance element 22 is electrically connected is referred to as node ND2. One of the source or drain of the transistor 13, and the source or drain of the transistor 14 one electrode of the display element 20, the other electrode of the capacitance element 22, and one electrode of the capacitance element 23. The node to which the electrodes of the transistors are electrically connected is called node ND3. 13, one of the source and drain of the transistor 15, and the capacitance element 23 The node to which the other electrode is electrically connected is designated as node ND4.

[0041] The gate of the transistor 11 and the gate of the transistor 14 are electrically connected to the wiring 31. The gate of the transistor 12 is electrically connected to a wiring 32. The gate of the transistor 15 is electrically connected to the wiring 35. The other of the drain and source terminals is electrically connected to the wiring 41. The other of the drain and source terminals is electrically connected to the wiring 42. The other of the drain and source terminals is electrically connected to the wiring 45. The other of the drain and source terminals is electrically connected to the wiring 53. The other of the drains is electrically connected to the wiring 54. is electrically connected to the wiring 50.

[0042] The wiring 31, the wiring 32, and the wiring 35 function as scan lines. The on / off of the transistor 14 is controlled by the gate of the transistor 11 via the wiring 31. It can be controlled by a signal supplied to the gate of transistor 14. The transistor 12 is turned on and off by a signal supplied to the gate of the transistor 12 via a wiring 32. The on / off of the transistor 15 can be controlled by the transistor 15 via the wiring 35. This can be controlled by a signal supplied to the gate of the gate driver 15.

[0043] The wiring 41, the wiring 42, and the wiring 45 function as data lines. Desired data is supplied via wiring 41, wiring 42, and wiring 45.

[0044] The wiring 50, the wiring 53, and the wiring 54 function as power supply lines. A low potential, for example, can be supplied to the line 54 as a power supply potential. As the potential, for example, a high potential can be supplied.

[0045] The transistor 12 and the capacitor 21 form a memory circuit MEM. The data supplied to the pixel 10 is input to a memory circuit 11 by turning on the transistor 12. The data is written to node ND2 provided in the MEM. The data is held by turning off the transistor 12. may include elements other than the transistor 12 and the capacitive element 21.

[0046] In addition, data supplied to the pixel 10 via the wiring 45 turns on the transistor 15. The data written to node ND4 is The data written to node ND4 is held by turning off register 15. The data may be data for correcting the threshold voltage of the transistor 13.

[0047] In this specification and the like, data for correcting the threshold voltage of a transistor is referred to as a threshold voltage. This is called pressure correction data, or simply correction data.

[0048] Data supplied to the pixel 10 through the wiring 41 turns on the transistor 11. The data written to node ND1 is image data and The image data can be input to the display device 20, and an image corresponding to the image data can be displayed by the display device 20.

[0049] Here, when the potential of the node ND1 is changed by writing data to the node ND1, The potential of the node ND2 changes due to capacitive coupling. Therefore, for example, if image data is input to node ND2, After writing the data for correction, the image data is written to node ND1. As a result, the potential of the node ND2 becomes a potential corresponding to the corrected image data. Image processing such as noise reduction can be performed inside the pixel 10. Compared to image processing, etc., which involves directly correcting image data using an arithmetic circuit, etc. Therefore, the calculation process can be simplified. Power consumption can be reduced.

[0050] In this specification and the like, data for correcting image data is referred to as image correction data.

[0051] Also, image data may be written to the node ND2. For example, the first After writing the image data of the first image data to the node ND1, the second image data is written to the node ND2. An image corresponding to the first image data and an image corresponding to the second image data are superimposed on each other. The superimposed image is displayed by the display element 20. The luminance of the superimposed image is the same as that of the first image data. The brightness represented by the first image data can be the sum of the brightness represented by the second image data. , compared to when the image data are not superimposed and an image corresponding to only one image data is displayed. , a high brightness image can be displayed.

[0052] Note that data written to nodes such as ND2 may be attenuated by factors on the transmission path. Therefore, it is preferable to generate the signal taking this attenuation into consideration.

[0053] The transistor 13 responds to the potential of the gate of the transistor 13, that is, the potential of the node ND2. The transistor functions as a drive transistor that controls the current flowing through the display element 20. That is, the transistor 13 controls the current flowing through the display element 20 when the display element 20 displays an image. The pixel 10 has a function of setting the value of the current to a value corresponding to image data, etc., supplied to the pixel 10.

[0054] By using a transistor with extremely low off-state current as the transistor 12, Since the potential of node ND2 can be held for a long period of time, pixel 10 can In addition, the transistor 15 has an extremely low off-state current. By using a transistor, the potential of the node ND4 can be maintained for a long period of time. Therefore, the pixel 10 can retain the data written to the node ND4 for a long time. As an example of a transistor with low off-state current, a transistor using metal oxide in the channel formation region is An OS transistor can be used.

[0055] In addition to the transistor 12 and the transistor 15, other transistors constituting the pixel 10 The transistor may be an OS transistor. The transistor 15 has a silicon channel region (hereinafter, referred to as a Si transistor). In addition, some of the transistors 11 to 15 may be replaced with O. The remaining transistors may be S transistors. The transistors have amorphous silicon, crystalline silicon (typically low temperature Examples of such transistors include transistors having polysilicon (polysilicon) and transistors having single crystal silicon. can be.

[0056] The semiconductor material used for the OS transistor is preferably a material having an energy gap of 2 eV or more. Alternatively, a metal oxide having a polarization of 2.5 eV or more, more preferably 3 eV or more, can be used. A typical example is an oxide semiconductor containing indium, for example, a CAAC- OS(C-Axis Aligned Crystalline Oxide Semi conductor) or CAC-OS (Cloud-Aligned Composite CAAC-TE Oxide Semiconductor, etc. can be used. The atoms that make up the crystal of OS are stable, making it suitable for transistors and other devices that require high reliability. In addition, CAC-OS exhibits high mobility characteristics, making it suitable for use in transistors that operate at high speed. .

[0057] Since the OS transistor has a large energy gap, it exhibits extremely low off-state current characteristics. In addition, OS transistors have the following problems: impact ionization, avalanche breakdown, and short-channel effect. It has characteristics different from silicon transistors, such as no defects, and forms highly reliable circuits. It is possible.

[0058] The semiconductor layer of the OS transistor may be made of, for example, indium, zinc, and M (aluminum, Titanium, gallium, germanium, yttrium, zirconium, lanthanum, cerium, A film represented by In-M-Zn oxide containing metals such as tin, neodymium, or hafnium It can be said that:

[0059] When the oxide semiconductor constituting the semiconductor layer is an In-M-Zn oxide, The atomic ratio of metal elements in the sputtering target used to form a film of the oxide is In≧ It is preferable that M and Zn satisfy the condition M. The atomic ratio of In:M:Zn is 1:1:1, In:M:Zn is 1:1:1.2, and I n:M:Zn=3:1:2, In:M:Zn=4:2:3, In:M:Zn=4:2:4 .1, In:M:Zn=5:1:6, In:M:Zn=5:1:7, In:M:Zn=5 The atomic ratio of the semiconductor layers to be formed is preferably 1:1:8. The atomic ratio of metal elements contained in the target varies by ±40%. .

[0060] The semiconductor layer is made of an oxide semiconductor having a low carrier density. Carrier density is 1×10 17 / cm 3 Less than or equal to 1×10 15 / cm 3 Further details are below. Preferably 1 x 10 13 / cm 3 Less than or equal to 1×10 11 / cm 3 The following is further Preferably 1 x 10 10 / cm 3 Less than 1 x 10 -9 / cm 3 More than career secrets Such an oxide semiconductor can be a high-purity intrinsic or This is called a qualitatively high-purity intrinsic oxide semiconductor. The oxide semiconductor has a low density of defect states and is stable. It can be said that the oxide semiconductor has excellent characteristics.

[0061] In addition, the semiconductor characteristics and electrical characteristics (field effect The appropriate composition should be used depending on the required properties (mobility, threshold voltage, etc.). In order to obtain the semiconductor characteristics of a transistor, the carrier density, impurity concentration, and defect density of the semiconductor layer are determined. It is preferable to appropriately select the degree, atomic ratio of metal elements to oxygen, interatomic distance, density, etc. .

[0062] In the oxide semiconductor that constitutes the semiconductor layer, silicon and carbon, which are group 14 elements, If oxygen is contained, oxygen vacancies increase and the semiconductor layer becomes n-type. The concentrations of cations and carbon (obtained by secondary ion mass spectrometry) were calculated using a ratio of 2×10 18 atom s / cm 3 Less than or equal to 2×10 17 atoms / cm 3 The following applies.

[0063] In addition, when alkali metals and alkaline earth metals combine with oxide semiconductors, they generate carriers. This may cause the off-state current of the transistor to increase. The concentration of alkali metals or alkaline earth metals in the body layer (obtained by secondary ion mass spectrometry) The concentration at which the 18 atoms / cm 3 Less than or equal to 2×10 16 ato ms / cm 3 To the following:

[0064] In addition, when the oxide semiconductor constituting the semiconductor layer contains nitrogen, the electrons that serve as carriers This increases the carrier density and makes it easier to become n-type. Transistors using conductors tend to be normally-on. The nitrogen concentration (obtained by secondary ion mass spectrometry) was 5×10 18 atoms / cm 3 It is preferable to do the following:

[0065] The semiconductor layer may also have a non-single crystal structure. The non-single crystal structure may have a c-axis oriented structure. CAAC-OS includes CAAC-OS having a crystal structure, a polycrystalline structure, a microcrystalline structure, or an amorphous structure. In single crystal structures, the amorphous structure has the highest density of defect states, and the CAAC-OS has the lowest density of defects. The level density is low.

[0066] An oxide semiconductor film having an amorphous structure has, for example, a disordered atomic arrangement and does not contain a crystalline component. Alternatively, the amorphous oxide film is, for example, a completely amorphous oxide film having no crystalline portion. .

[0067] In addition, the semiconductor layer may have an amorphous structure region, a microcrystalline structure region, a polycrystalline structure region, a CAAC structure region, or a crystalline structure region. The film may be a mixed film having two or more of the -OS region and the single crystal structure region. The film may have a single layer structure or a laminate structure including two or more of the above-mentioned regions. It may have a structure.

[0068] As the display element 20, for example, a light-emitting element can be used. For example, as the light-emitting element, Organic EL (Electro Luminescence) element, inorganic EL element, QDLE D (Quantum Dot Light Emitting Diode) is used. Alternatively, an LED such as a micro LED can be used as the light emitting element.

[0069] By using a micro LED as the display element 20, the power consumption of the display device according to one embodiment of the present invention can be reduced. In addition, the display device according to one embodiment of the present invention can be made thinner and lighter. In addition, the display device using the micro LED as the display element 20 has a high contrast. Since the viewing angle is wide and the viewing angle is high, a high-quality image can be displayed. When using micro LEDs, the area of ​​the light emission region is 10,000 μm 2 The following is preferred: Preferably, 1000 μm 2Less than 700μm is more preferable. 2 The following is even more preferred:

[0070] <One example of pixel operation method 1> FIG. 2 is a timing chart showing an example of a method of operating the pixel 10 having the configuration shown in FIG. In FIG. 2, the operation of the pixel 10 is illustrated in the following periods: T01, T11, T12, T13, 3 to 6 are the same as those shown in FIG. 2. The on / off state of the transistor, the potential of the wiring and the node, and the direction of the current in each period are shown. 2 to 6, "H" indicates a high potential, and "L" indicates a low potential. show.

[0071] In this specification, the high potential indicates a potential higher than the low potential. For example, the high potential is The potential at which a n-channel transistor is turned on is indicated by a low potential. The high potential indicates the potential at which a p-channel transistor is turned off. A low potential indicates the potential at which a p-channel transistor is turned on. For example, a high potential may be a positive potential and a low potential may be a ground potential or It may be a negative potential.

[0072] 2 to 6, a low potential is applied to the wiring 50, a high potential is applied to the wiring 53, and a potential V0 is applied to the wiring 54. The operation method of the pixel 10 will be described assuming that the potential V0 is supplied to the wiring 53. The potential shall be lower than the potential.

[0073] In addition, in FIG. 2 to FIG. 6, the transistors 11 to 15 are all n-channel transistors. The operation of pixel 10 will now be described as a transistor. By appropriately changing the magnitude relationship of the potentials, the transistors 11 to It is also possible to refer to a case where some or all of 15 are p-channel transistors.

[0074] 3 to 6, in order to clarify the on / off state, transistors other than the transistor 13 are not shown. is shown as a switch symbol, and the wiring 31, the wiring 32, and the wiring 35 are omitted. The wirings and nodes whose potentials have changed since the previous period are surrounded by solid lines.

[0075] In a period T01 (see FIG. 2 and FIG. 3A), the potential of the wiring 31, the potential of the wiring 32, and the The potential of the line 35 is set to a high potential, and then the potential of the wiring 42 is set to a potential V0 and the potential of the wiring 45 is set to a potential V 1. As a result, transistors 11, 12, 14, and The transistor 15 is turned on, and the potentials of the nodes ND2 and ND3 are increased to The potential of the node ND4 becomes V1. A current flows through the wiring 54 via the pixel 13. The potential of the wiring 42 is equal to the potential V0 of the wiring 54. The potential of the wiring 41 can be any potential. The explanation will be given assuming it is 0V.

[0076] Here, it is preferable that the potential V0 is set to a potential at which no current flows through the display element 20. For example, the voltage applied to the display element 20 is set to be equal to or lower than the threshold voltage of the display element 20. For example, the potential V0 is set to a value equal to the potential of the wiring 50. It is preferable to set the potential of the transistor 13 to a low potential. In addition, the display of an abnormality can be suppressed.

[0077] In a period T11 (see FIG. 2 and FIG. 3B), the potential of the wiring 45 is detected in the period T01. The potential calculated based on the current thus obtained is called potential Vc. The potential of the back gate of the transistor 13 becomes the potential Vc. For example, when the transistor 14 is turned on, the current c flows through the transistor 13. The potential is set so that the current is equal to or less than a certain value. For example, the threshold voltage of the transistor 13 is , the difference between the potential of the node ND2 and the potential of the node ND3 in the period T11. In the case shown in FIG. 3B, the potential of the node ND2 and the potential of the node ND3 are calculated. Since the difference between the potentials is 0V, for example, the threshold voltage of the transistor 13 is 0V. The potential Vc can be calculated so that

[0078] In this way, the threshold voltage of the transistor 13, which is the driving transistor, is corrected. Therefore, the period T01 and the period T11 can be called a threshold voltage correction period. If the potential V1 is set to the highest possible potential, the current flows through the transistor 13 during the period T01. This is preferable because the current flowing through the transistor becomes large, and therefore the threshold voltage can be corrected with high accuracy.

[0079] In a period T12 (see FIG. 2 and FIG. 4A), the potential of the wiring 35 is set to a low potential. As a result, the transistor 15 is turned off, and the potential of the node ND4 is held at the potential Vc. After that, the potential of the wiring 42 is set to a potential VD1 which corresponds to the first data. As a result, the potential of the node ND2 becomes the potential VD1, and the first data is written to the memory circuit MEM. Here, the first data may be image correction data or image data. Note that the potential of the wiring 45 can be any potential.

[0080] From the above, the period T12 can be said to be a first data writing period.

[0081] In a period T13 (see FIG. 2 and FIG. 4B), the potential of the wiring 32 is set to a low potential. Then, the transistor 12 is turned off, and the potential of the node ND2 is held. If the potential of the line 41 is VD2, which is a potential corresponding to the second data, then the node ND1 The potential of the node ND1 goes from 0V to the potential VD2. In other words, the potential of the node ND1 rises by the potential VD2. Here, since the node ND2 is in a floating state, the capacitive coupling of the node ND2 If the coefficient is set to 1, the potential of the node ND2 becomes the potential "VD1+VD2". The second data is supplied to the pixel 10, and the data held in the memory circuit MEM is converted to the first data. The third data is the data obtained by adding the second data to the second data. The potential of the wiring 42 can be any potential. can.

[0082] In this specification, when the first data and the second data are both image data, The first data is sometimes called first image data, and the second data is sometimes called second image data. be.

[0083] From the above, the period T13 can be said to be a second data writing period.

[0084] In a period T14 (see FIG. 2 and FIG. 5A), the potential of the wiring 31 is set to a low potential. As a result, the transistors 11 and 14 are turned off. In this state, the potential of the node ND1 is maintained. By entering the OFF state, the potential of the node ND3 rises according to the potential of the node ND2. As a result, a current corresponding to the potential difference between the node ND3 and the line 50 flows through the display element 20. Therefore, the image corresponding to the potential of the node ND2, that is, the image corresponding to the third data, is The data corresponding to the potential VD1 is displayed by the display element 20. For example, When the data corresponding to the potential VD2 is image data, the corrected image data An image corresponding to the potential VD1 is displayed by the display element 20. is the first image data, and the data corresponding to the potential VD2 is the second image data. An image corresponding to the first image data and an image corresponding to the second image data are superimposed on each other. The image thus obtained is displayed by the display element 20.

[0085] From the above, the period T14 can be said to be a third data read period.

[0086] In a period T21 (see FIG. 2 and FIG. 5B), the potential of the wiring 31 is set to a high potential. Then, the transistor 11 and the transistor 14 are turned on. The potential VD2′ corresponds to the second data. As a result, the potential of the wiring 41 becomes the potential VD2′, and the capacitive coupling coefficient of the node ND2 If the number is 1, the potential of the node ND2 becomes the potential "VD1+VD2'". The second data is supplied to the pixel 10, and the data held in the memory circuit MEM is converted to the first data. The third data is the data obtained by adding the second data to the potential VD2'. For example, the potential VD1 supplied to the pixel 10 in the period T13 can be a potential different from the potential VD2. The potential can be set to correspond to the image data of the next frame of the image data thus obtained.

[0087] In addition, when the transistor 14 is turned on, the potential of the node ND3 is As a result, no current flows through the display element 20.

[0088] In a period T22 (see FIGS. 2 and 6), the potential of the wiring 31 is set to a low potential. When the transistor 11 is in the off state, the transistor 11 and the transistor 14 are in the off state. In this state, the potential of the node ND1 is maintained. As a result, the potential of the node ND3 rises according to the potential of the node ND2. As a result, a current corresponding to the potential difference between the node ND3 and the wiring 50 flows through the display element 20. Therefore, the image corresponding to the potential of the node ND2, that is, the image corresponding to the third data, is It is displayed by the display element 20.

[0089] From the above, the period T21 can be said to be a second data writing period, and the period T22 In other words, the period T21 is a third data read period. The period T22 is a period in which the same type of operation as that of the period T14 is performed. In addition, the period T13 and the period T14 form one frame. The next frame period is constituted by the period T21 and the period T22. It is possible to do so.

[0090] Here, between the period T14 and the period T21, a potential corresponding to the threshold voltage correction data is supplying a potential Vc corresponding to the first data to the node ND4; and supplying a potential VD1 corresponding to the first data to the node ND5. As described above, the OS transistor 15 is not supplied to the node ND2. By using a transistor, the potential of the node ND4 can be maintained for a long period of time. By using an OS transistor or the like for the resistor 12, the potential of the node ND2 is maintained for a long period of time. Therefore, the supply of the potential Vc to the node ND4 and the supply of the potential VD1 to the node Since it is not necessary to supply the signal to ND2 every frame period, the display device according to one embodiment of the present invention can be operated at high speed.

[0091] As described above, in the display device according to one embodiment of the present invention, image data supplied to the pixel 10 is not corrected. In addition, the threshold voltage of the transistor 13, which is the driving transistor, can be corrected. This allows the dynamic range of the image data (the voltage range that the signal corresponding to the image data can take) to be The threshold voltage of the transistor 13 can be compensated without increasing the difference between the maximum and minimum values ​​of the Therefore, the correction of the threshold voltage of the transistor 13, e.g. The voltage of the signal corresponding to the image data when increasing the brightness of the light emitted from the display element by one gradation. This can suppress the increase in the range of increase in the brightness of the light emitted from the display element. Since the brightness can be precisely controlled, the image displayed by the display element 20 can be of high quality. In addition, a data driver circuit, which is a circuit having a function of generating image data, can be provided. It is not necessary to use high voltage resistance components, and the display device can be manufactured at a low cost. In addition, the output potential of the data driver circuit can be prevented from increasing. The power consumption of the device can be reduced.

[0092] The pixel 10 is provided with a memory circuit MEM, and the memory circuit MEM stores first data. The image correction data can be written as the first data in the memory circuit MEM. After that, the image data is supplied to the pixel 10 as the second data, so that, for example, noise Image processing such as image processing can be performed inside the pixel 10. Image processing, etc. is performed by directly correcting image data using a calculation circuit, etc. Since the calculation process can be simplified, the power consumption of the display device according to one embodiment of the present invention can be reduced. The force can be reduced.

[0093] In addition, after the first image data is written as the first data in the memory circuit MEM, the second image data is written as the first data. By providing the pixel 10 with the second image data as the first data, the display element 20 An image corresponding to the first image data and an image corresponding to the second image data are superimposed on each other to produce an image. The brightness of the superimposed image is a brightness represented by the first image data. The first image data may be a sum of the first and second image data. A data driver circuit, which is a circuit having a function of generating a voltage higher than the voltage that can be generated by the data driver circuit, The image corresponding to the image data represented by the signal of the second position is displayed by the display element 20. This allows you to create an image that corresponds to only one image data without overlapping image data. The display element 20 can display a brighter image than the conventional display. Since the data driver circuit and other circuits do not need to be high voltage resistant, the display device can be made low cost. Furthermore, it is possible to suppress the output potential of the data driver circuit from becoming large. This makes it possible to reduce the power consumption of the display device.

[0094] Here, the image corresponding to the first image data and the image corresponding to the second image data are the same. FIG. 7 shows an image P1 corresponding to the first image data, The image P2 corresponding to the second image data is an image including only text. In this case, the text is displayed by superimposing the image P1 and the image P2. The brightness of the characters can be increased, for example, to emphasize the characters. Image P1 is not limited to an image containing only text, and image P2 is not limited to an image containing both pictures and text. .

[0095] In addition, as shown in FIG. 2, after the potential VD1 is supplied to the node ND2, Since the potential of varies depending on the potential of node ND1, When the first image data, which is the image data, is to be rewritten, the potential of the node ND1 is changed to The image data, the second image data, must also be written to the pixel 10 again. When the second image data is to be rewritten, the charge supplied to the node ND2 is As long as the data is not leaked from 12th, etc. and is retained, there is no need to rewrite the first image data. Therefore, in the case shown in FIG. 7, by adjusting the potential supplied to the node ND1, This allows you to adjust the brightness of the characters.

[0096] Here, as described above, when the first image data is rewritten, the second image data is rewritten. On the other hand, when the second image data is to be rewritten, the first Therefore, image P1 is rewritten more frequently than image P2. It is preferable to use an image with a low degree of contrast.

[0097] <Example of display device configuration> FIG. 8A is a block diagram illustrating a configuration example of a display device 60 which is a display device according to one embodiment of the present invention. The display device 60 includes a display unit 61, a gate driver circuit 62, and a data driver circuit 63. 63, a current detection circuit 64, and a correction data generation circuit 65. In the image forming apparatus 1, pixels 10 are arranged in a matrix.

[0098] The gate driver circuit 62 extends in the row direction (horizontal direction) and functions as a scanning line. The wiring 31, the wiring 32, and the wiring 35 are electrically connected to each other. The line 31, the wiring 32, and the wiring 35 are electrically connected to the pixel 10. The buffer circuit 63 is a plurality of wirings that extend in the column direction (vertical direction) and function as data lines. The current detection circuit 64 is electrically connected to the pixel electrodes 41, the wiring 42, and the wiring 45 in the column direction. As described above, the wiring 41 and the wiring 4 2, the wiring 45, and the wiring 54 are electrically connected to the pixel 10.

[0099] The gate driver circuit 62 controls the on / off of the transistors provided in the pixels 10. For example, transistor 11, transistor 12, The function of generating signals for controlling the on / off of the transistors 14 and 15 is The data driver circuit 63 receives the threshold voltage correction data and the first and second data. It has the function of generating data.

[0100] Here, as mentioned above, the data driver circuit 63 does not need to be a high voltage resistant circuit. This allows the display device 60 to be manufactured at a low cost. Since the increase in the power consumption of the display device 60 can be suppressed, the power consumption of the display device 60 can be reduced. This can be done.

[0101] The current detection circuit 64 detects the current flowing through the wiring 54 and outputs data representing the current value of the detected current. and supplies the generated data to the correction data generation circuit 65. The generating circuit 65 generates a threshold voltage correction data based on the data supplied from the current detection circuit 64. The data driver circuit 63 generates the data Dc and supplies it to the data driver circuit 63. The line 63 changes the potential of the wiring 45 to a potential corresponding to the supplied threshold voltage correction data Dc. The correction data generating circuit 65 can generate a certain potential Vc by using the In addition to the data representing the current value of the current, the data representing the current flow of the transistor 13 when the current flows, , the potential difference between the gate and source (Vgs), and the potential difference between the gate and drain (Vds) Based on the data represented, the threshold voltage correction data Dc can be generated.

[0102] FIG. 8B is a block diagram showing a configuration example of a display device 60, and is a display device having the configuration shown in FIG. The display device 60 shown in FIG. 8B includes a storage device 66 and a storage device The display device 60 differs from the display device 60 having the configuration shown in FIG. 8A in that the display device 67 is provided.

[0103] In the display device 60 having the configuration shown in FIG. 8B, the correction data generated by the correction data generating circuit 65 for each pixel 10 The threshold voltage correction data Dc is written to the storage device 66. The threshold voltage correction data Dc is read out at a predetermined timing and output to the data driver. The circuit 63 is connected to the storage device 66. The storage device 66 is a DRAM (Dynamic Random Access Memory). ccess Memory), SRAM (Static Random Access It is preferable to use a volatile memory such as a volatile memory (e.g., a volatile digital memory (DRAM)). Since the display device 60 can be operated at high speed, the display device 60 can be operated at high speed.

[0104] The threshold voltage correction data Dc written in the memory device 66 is also written in the memory device 67. The storage device 67 is a storage device that has a longer data retention time than the storage device 66. The threshold correction data Dc stored in the memory device 67 is supplied to the memory device 66 as required. The storage device 67 is, for example, a hard disk drive (HDD). Drive), Solid State Drive (SSD) e) It is preferable to use a non-volatile memory such as a flash memory. By using a nonvolatile memory, for example, when the power supply to the display device 60 is cut off, the volatile memory Even if data stored in the storage device 66 is lost, the data can be read from the storage device 67. By supplying the data to the storage device 66, the data can be quickly restored. The storage device 67 receives the threshold voltage correction data Dc directly from the correction data generating circuit 65. The data is not written directly to the memory device 67, but is written directly to the data driver circuit. Therefore, even if the operation speed of the storage device 67 is slow, the display device 60 does not slow down the movement speed significantly.

[0105] As described above, the OS transistor has a feature of having an extremely low off-state current. By configuring the memory device 67 using OS transistors, the memory device 67 can be made nonvolatile. The memory device 67 can be configured with OS transistors. By using non-volatile memory, the configuration of the storage device 67 can be changed to HDD, SSD, flash Therefore, the manufacturing process of the storage device 67 can be simplified. Therefore, the display device 60 can be made inexpensive.

[0106] As described above, by configuring the display device 60 as shown in FIG. 8B, the threshold voltage correction data Dc can be retained for a longer period of time than the period of time that the charge is retained inside the pixel 10. The threshold voltage correction by the correction data generating circuit 65 performed during the period T01 shown in FIG. Since the frequency of generating the correct data Dc can be reduced, the operation of the display device 60 can be made high speed. It can be said that:

[0107] <Pixel configuration example 2> FIG. 9 is a diagram showing an example of the configuration of the pixel 10, which is a modified example of the configuration of the pixel 10 shown in FIG. The pixel 10 having the configuration shown in FIG. 9 is different from the pixel 10 shown in FIG. This differs from the configuration of 10.

[0108] In the pixel 10 having the configuration shown in FIG. 9, the node ND3 is connected to the source or drain of the transistor 13. one of the inputs, one of the source or drain of transistor 14, and the source of transistor 16 Alternatively, one of the drains, the other electrode of the capacitance element 22, and one electrode of the capacitance element 23 are electrically connected to each other. The other of the source and drain of the transistor 16 is connected to the The gate of the transistor 16 is electrically connected to the wiring 36. The wiring 36 functions as a scanning line and is connected to the gate electrode 34 shown in FIGS. 8A and 8B. The input terminal 62 is electrically connected to the input terminal 63 .

[0109] The transistor 16 is in an off state while the transistor 14 is in an on state. In other words, the transistor 1 can be turned on during the period when the transistor 14 is turned off. The gate of transistor 6 is supplied with a complementary signal to the signal supplied to the gate of transistor 14. For example, the potential of the wiring 31 electrically connected to the gate of the transistor 14 can be When the potential of the wiring 36 electrically connected to the gate of the transistor 16 is high, The potential can be a low potential. When the potential of the wiring 31 is a low potential, the potential of the wiring 36 can be at a high potential.

[0110] In the pixel 10 having the configuration shown in FIG. 9, during a period other than the data read period, for example, during the period shown in FIG. A current flows through the display element 20 during periods T01, T11 to T13, and T21. This can prevent the current from flowing to the wiring 54 via the transistor 13. The current can be accurately detected by the current detection circuit 64 shown in Figures 8A and 8B. , abnormal display can be suppressed.

[0111] <Pixel configuration example 3> 10A and 10B are diagrams showing an example of the configuration of a pixel 10. 10 is a pixel 10 having a transistor 11, a transistor 12, and a transistor The transistor 14 and the transistor 15 are provided with back gates. The pixel 10 having the configuration shown in FIG. Transistor 12 and transistors 14 to 16 are provided with back gates. The back gate is electrically connected to the front gate, and the on-state of the transistor is It has the effect of increasing the current. In addition, it is possible to supply a different potential to the back gate than to the front gate. By using this structure, the threshold voltage of the transistor can be controlled. In addition, in FIG. 10A and FIG. 10B, all the transistors are back-gate. However, a transistor without a back gate is used for pixel 1. 0 may have

[0112] <Pixel configuration example 4> FIG. 11A is a diagram showing an example of the configuration of the pixel 10, which is a modified example of the configuration of the pixel 10 shown in FIG. In the pixel 10 having the configuration shown in FIG. The pixel 10 in the configuration shown in FIG. is different.

[0113] The operation method of the pixel 10 having the configuration shown in FIG. 11A can be seen from FIG. 2 to FIG. 6. In the period T01, the potential of the wiring 41 is set to the potential V1, and in the period T11, The potential of the wiring 41 after the period T12 is set to the potential Vc shown in FIG. The potential can be the same as

[0114] The pixel 10 having the configuration shown in FIG. 11B has a transistor 11, transistor 12, transistor 14, and transistor 15 are provided with back gates. In FIG. 11B, all the transistors are provided with back gates. Although the configuration shown in FIG. 1 is a pixel having a transistor that does not have a back gate, It's fine.

[0115] <Example of pixel operation method 2> FIG. 12 is a timing chart showing an example of an operation method of the pixel 10 having the configuration shown in FIG. 12 is a modified example of the operation method shown in FIG. 2. In the operation method shown in FIG. 12, in a period T11, This method differs from the operation method shown in FIG. 2 in that the threshold voltage of the transistor 13 is corrected twice. Specifically, in a period T11-1, the potential of the wiring 45 is adjusted based on the current detected in the period T01. The potential of the node ND4 is Vc1, which is the potential calculated by the above calculation. After that, the current flowing through the wiring 54 via the transistor 13 is detected again, and the period At T11-2, the potential of the wiring 45 is set to a potential calculated based on the detected current. As a result, the potential of the node ND4 becomes the potential Vc1. The threshold voltage may be corrected three or more times.

[0116] By performing the threshold voltage correction multiple times, the threshold voltage can be corrected with high accuracy. Therefore, the image displayed by the display element 20 can be of high quality. .

[0117] <Example of pixel operation method 3> FIG. 13 is a timing chart showing an example of an operation method of the pixel 10 having the configuration shown in FIG. 13 is a modified example of the operation method shown in FIG. 2. In the operation method shown in FIG. The operation shown in period T02 is carried out instead of the operation shown in period T11, which is different from the operation method shown in FIG. different.

[0118] In a period T02, the potentials of the wirings 31, 32, and 35 are set to high potentials. Then, the potential of the wiring 42 is set to potential V0, and the potential of the wiring 45 is set to potential V1. Transistor 11, transistor 12, transistor 14, and transistor 15 are on. The potentials of the nodes ND2 and ND3 are V0 and V4, respectively. As a result, the potential of the wiring 53 is connected to the wiring 5 through the transistor 13. A current flows through the pixel 10. The current is detected by a circuit provided outside the pixel 10. Note that, similarly to the case shown in FIG. 2, the potential of the wiring 42 is equal to the potential V0, which is the potential of the wiring 54. The potential of the wiring 41 can be any potential. The explanation will be given assuming that the voltage is 0V.

[0119] After the potential of the wiring 45 is set to potential V1, the potential of the wiring 45 is swept down. As a result, the potential of the node ND4 also drops, and the threshold voltage of the transistor 13 increases. As a result, the current flowing through the wiring 54 via the transistor 13 becomes smaller. When the current flowing through the wiring 54 via the stator 13 becomes equal to or less than a certain value, the above-mentioned sweep operation is started. The above is the operation in period T02.

[0120] Here, when the sweep operation is completed, the potential of the wiring 45 is Vc, then the node ND The potential of the back gate of the transistor 13 is thus set to the potential Vc. Vc, and the threshold voltage of the transistor 13 is corrected.

[0121] After the end of the period T02, the same operation as that after the period T12 shown in FIG. 2 is performed. The operation method is shown in FIG.

[0122] As shown in FIG. 13, the potential of the wiring 45 is swept to change the threshold voltage of the transistor 13. By performing the above correction, the display device 60 includes a correction data generating circuit 65, a storage device 66, and There is no need to provide the storage device 67. This allows the display device 60 to be made smaller and the display The area of ​​the portion 61 can be increased.

[0123] This embodiment mode can be implemented in appropriate combination with the configurations described in other embodiment modes. It is Noh.

[0124] (Embodiment 2) In this embodiment, a structural example of a display device according to one embodiment of the present invention will be described with reference to drawings. .

[0125] In FIG. 14A, a seal is placed around the display unit 215 provided on the substrate 4001. A sealant 4005 is provided, and the display portion 215 is sealed by the sealant 4005 and the substrate 4006. It has been done.

[0126] The display portion 215 has the pixel described in the first embodiment.

[0127] In FIG. 14A, a gate driver circuit 221, a data driver circuit 231, a data driver The circuit 232 and the power supply circuit 241 are integrated circuits provided on a printed circuit board 4041. The integrated circuit 4042 is formed of a single crystal semiconductor or a polycrystalline semiconductor. The data driver circuit 231 and the data driver circuit 232 are configured as in the embodiment. The gate driver circuit 221 has the function of the data driver circuit shown in FIG. The power supply circuit 241 has the function of the gate driver circuit shown in the first embodiment. The power supply line has a function of generating a specified potential to be supplied to the power supply line.

[0128] A gate driver circuit 221, a power supply circuit 241, a data driver circuit 231, and a data driver Various signals and potentials are supplied to the driver circuit 232 via a flexible printed circuit (FPC). The signal is supplied via a digital signal processor (DPC) 4018.

[0129] The integrated circuit 4042 included in the gate driver circuit 221 and the power supply circuit 241 is The data driver circuit 231 and the data driver 5 have a function of generating a selection signal to be supplied to the data driver circuit 231. The integrated circuit 4042 in the driver circuit 232 generates image data to be supplied to the display unit 215. The integrated circuit 4042 is formed by a sealant 4005 on a substrate 4001. It is implemented in a different area than the area it encloses.

[0130] The method of connecting the integrated circuit 4042 is not particularly limited, and may be wire bonding. COG (Chip On Glass) method, TCP (Tape Carrier The method may be a package method, a COF (Chip On Film) method, or the like.

[0131] FIG. 14B shows an integrated circuit included in the data driver circuit 231 and the data driver circuit 232. In addition, a part or the whole of the driving circuit is It is possible to form a system-on-panel by forming the display unit 215 on the same substrate. .

[0132] In FIG. 14B, the gate driver circuit 221 and the power supply circuit 241 are arranged on the same substrate as the display unit 215. The driving circuit is formed on the substrate at the same time as the pixel circuit in the display unit 215. This makes it possible to reduce the number of parts, thereby improving productivity.

[0133] In FIG. 14B, a display unit 215 and a gate driver circuit are provided on a substrate 4001. A sealant 4005 is provided so as to surround the semiconductor device 221 and the power supply circuit 241 . In addition, a substrate 4006 is provided on the display unit 215, the gate driver circuit 221, and the power supply circuit 241. Therefore, the display unit 215, the gate driver circuit 221, and the power supply circuit 2 41 is a substrate 4001, a sealant 4005, and a substrate 4006, and is sealed together with the display element. It has been stopped.

[0134] In addition, in FIG. 14B, the data driver circuit 231 and the data driver circuit 232 are formed separately. The gate 4001 is mounted on a substrate 4001 as an example, but the present invention is not limited to this configuration. The driver circuit may be formed separately and mounted, or may be a part of the data driver circuit or a gate driver circuit. A part of the driver circuit may be formed separately and mounted.

[0135] The display device includes a panel in which a display element is sealed, and a controller for the panel. The term "IC" may also refer to a module in which an IC or the like including the above is mounted.

[0136] In addition, the display portion and the gate driver circuit provided on the substrate have a plurality of transistors. As the transistor, for example, the following transistors can be used. .

[0137] The structure of the transistors in the peripheral driver circuits and the pixel circuits in the display area is The transistors in the peripheral driver circuit are all the same or different. The pixel structure may be the same or may be a combination of two or more structures. The transistors in the circuit may all have the same structure, or two or more types of structures may be combined. It may be possible to do so.

[0138] An input device can also be provided on the substrate 4006. The display device provided with the input device can function as a touch panel. An input device is not shown in Figures 14A and 14B. The configuration of the input device will be described later. .

[0139] There is no limitation on a detection element (also referred to as a sensor element) included in a touch panel of one embodiment of the present invention. Various sensors that can detect the proximity or contact of a detection target such as a finger or stylus, It can be used as a sensing element.

[0140] The sensor type may be, for example, a capacitance type, a resistive film type, a surface acoustic wave type, or an infrared type. Various methods such as a pressure-sensitive method, an optical method, or a pressure-sensitive method can be used.

[0141] In this embodiment, a touch panel having a capacitance type sensing element will be described as an example. .

[0142] The capacitive touch sensor includes a surface capacitive touch sensor and a projected capacitive touch sensor. The electrostatic capacitance type includes the self-capacitance type and the mutual capacitance type. This is preferable because it enables simultaneous multi-point detection.

[0143] The touch panel according to one embodiment of the present invention is formed by bonding a display device and a sensing element that are separately manufactured. A structure in which a substrate supporting a display element and an opposing substrate are provided with electrodes constituting a sensing element, or both of the substrate and the opposing substrate are provided with electrodes constituting a sensing element. Various configurations can be applied, such as a configuration in which a pole or the like is provided.

[0144] 15A and 15B show an example of a touch panel. FIG. 15A shows a touch panel 421 FIG. 15B is a perspective schematic diagram of the input device 4200. Note that for clarity, Therefore, only representative components are shown.

[0145] The touch panel 4210 is constructed by bonding a display device and a sensing element that are separately manufactured. be.

[0146] The touch panel 4210 includes an input device 4200 and a display device, which are stacked on top of each other. It is being done.

[0147] The input device 4200 includes a substrate 4263, an electrode 4227, an electrode 4228, and a plurality of wirings 4237. , a plurality of wirings 4238, and a plurality of wirings 4239. For example, the electrode 4227 is The electrode 4228 can be electrically connected to the wiring 4237 or the wiring 4239. The FPC 4272 can be electrically connected to the wiring 4237 and the wiring 4238. The FPC 4272 is electrically connected to each of the plurality of wirings 4238 and the plurality of wirings 4239. can be equipped with IC4273.

[0148] Alternatively, a touch sensor may be provided between the substrate 4001 and the substrate 4006 of the display device. When a touch sensor is provided between the plate 4001 and the substrate 4006, a capacitive touch sensor is used. In addition to the sensor, an optical touch sensor using a photoelectric conversion element may be applied.

[0149] <Example 1 of a cross-sectional configuration of a display device> FIG. 16A is a cross-sectional view of the portion indicated by the chain line N1-N2 in FIG. 14B. FIG. 16A shows an example of the configuration of a light-emitting display device having a top emission structure to which the TFT method is applied. The display device shown has an electrode 4015, which is connected to a terminal of an FPC 4018. 16A, the electrode 401 is electrically connected to the anisotropic conductive layer 4019. 5 is an insulating layer 4112, an insulating layer 4111, and an insulating layer 4110 in an opening formed therein. It is electrically connected to the wiring 4014 .

[0150] The electrode 4015 is formed from the same conductive layer as the electrode layer 4030. The source and drain electrodes of the transistor 4010 and the transistor 4011 are formed in the same conductive layer. has been formed.

[0151] The display unit 215 and the gate driver circuit 221 provided on the substrate 4001 are In FIG. 16A, the display unit 215 includes a transistor 4010. , and a transistor 4011 included in the gate driver circuit 221. In FIG. 16A, a bottom gate type transistor 4010 and a transistor 4011 are used. However, a top-gate transistor may be used.

[0152] In FIG. 16A, an insulating layer 4112 is provided on transistors 4010 and 4011. In addition, a partition wall 4510 is formed over the insulating layer 4112.

[0153] The transistor 4010 and the transistor 4011 are provided over an insulating layer 4102. The transistor 4010 and the transistor 4011 are formed on an insulating layer 4111. The electrode 4017 functions as a back gate electrode. can be done.

[0154] The display device shown in FIG. 16A further includes a capacitor 4020. An electrode 4021 formed in the same process as the gate electrode of the transistor 4010, and a source electrode and The drain electrode is formed in the same process as the gate electrode. They overlap via 103.

[0155] In general, the capacitance of a capacitor provided in a pixel portion of a display device is determined by the capacitance of a transistor disposed in the pixel portion. The capacitance is set so that the charge can be held for a predetermined period of time, taking into consideration the leakage current of the capacitor. The capacitance of the capacitance element may be set in consideration of the off-state current of the transistor and the like.

[0156] The transistor 4010 provided in the display portion 215 is electrically connected to a display element.

[0157] In addition, in the display device shown in FIG. 16A, the insulating layer 4111 and the insulating layer 4103 are formed using an impurity element. The insulating layer 4111 and the insulating layer 4103 are used as the semiconductor layer of the transistor. By sandwiching the body layer, it is possible to prevent impurities from entering from the outside.

[0158] The display device includes a light-emitting element (E The EL element can be applied to a light-emitting device that contains a light-emitting compound between a pair of electrodes. A layer (also called an "EL layer") is provided between a pair of electrodes. When a large potential difference is generated, holes are injected into the EL layer from the anode side and electrons are injected from the cathode side. The injected electrons and holes recombine in the EL layer, and the luminescent material contained in the EL layer will emit light.

[0159] EL elements are also classified according to whether the luminescent material is an organic compound or an inorganic compound. In general, the former is called an organic EL element, and the latter is called an inorganic EL element.

[0160] When a voltage is applied to an organic EL element, electrons are emitted from one electrode and holes are emitted from the other electrode. are injected into the EL layer. Then, the carriers (electrons and holes) recombine. This causes the light-emitting organic compound to form an excited state, and when the excited state returns to the ground state, Due to this mechanism, such a light-emitting element is called a current-excitation type light-emitting element. It is called.

[0161] In addition to the light-emitting compound, the EL layer may be formed by using a material having a high hole-injecting property and a material having a high hole-transporting property. , hole blocking material, material with high electron transporting properties, material with high electron injecting properties, or bipolar material (a substance having high electron-transporting and hole-transporting properties), or the like.

[0162] The EL layer can be produced by deposition (including vacuum deposition), transfer, printing, inkjet, coating, etc. The method can be formed as follows.

[0163] Inorganic EL elements are divided into dispersion-type inorganic EL elements and thin-film-type inorganic EL elements according to their element structure. Dispersion-type inorganic EL elements have a light-emitting layer in which particles of a light-emitting material are dispersed in a binder. The emission mechanism is a donor-acceptor reaction that utilizes the donor and acceptor levels. Thin-film inorganic EL elements are made by sandwiching a light-emitting layer between dielectric layers. The structure is sandwiched between electrodes, and the light emission mechanism utilizes the inner shell electron transition of metal ions. In this example, the light-emitting element is an organic EL element. do.

[0164] In order to extract light emitted from the light-emitting element, at least one of the pair of electrodes must be transparent. A transistor and a light emitting element are formed on the substrate, and light is emitted from the opposite side of the substrate. There are two types of structures: top emission (top emission) where the light is emitted from the top surface of the substrate, and bottom emission ( Bottom emission) structure and dual emission structure that emits light from both sides ) structure, and any light emitting element having any emission structure can be applied.

[0165] FIG. 16A shows a light-emitting display device (also called an "EL display device") that uses light-emitting elements as display elements. The light-emitting element 4513, which is a display element, is a transistor provided in the display portion 215. The light-emitting element 4513 is electrically connected to the transistor 4010. The light-emitting element 4513 includes an electrode layer 4030, a light-emitting layer 4511, The electrode layer 4031 has a laminated structure, but is not limited to this structure. The configuration of the light emitting element 4513 can be changed as appropriate according to the direction of emitted light, etc.

[0166] The partition 4510 is formed using an organic insulating material or an inorganic insulating material, particularly a photosensitive resin. An opening is formed on the electrode layer 4030 using a material, and the side of the opening has a continuous curvature. It is preferable to form the inclined surface so as to have a slope.

[0167] The light-emitting layer 4511 may be composed of a single layer or a plurality of layers may be laminated. It may be possible.

[0168] The light-emitting layer 4511 is made of an inorganic compound such as a quantum dot (QD). For example, the quantum dots may be used in the light-emitting layer to function as a light-emitting material. It is also possible to do so.

[0169] Quantum dots are semiconductor nanocrystals with sizes ranging from a few nm to a few tens of nm, with a size of 1×10 3 1 out of 1 ×10 6 Quantum dots are composed of about 100 atoms. The energy shift depends on the size. Therefore, even quantum dots made of the same material have different emission wavelengths depending on their size. Therefore, by changing the size of the quantum dots used, it is easy to change the emission wavelength. The length can be changed.

[0170] In addition, quantum dots have a narrow emission spectrum peak width, making it possible to obtain emission with good color purity. Furthermore, the theoretical internal quantum efficiency of quantum dots is said to be nearly 100%. This is much higher than the 25% of organic compounds that emit fluorescent light, and the percentage of organic compounds that emit phosphorescent light is This shows that the quantum dots used as luminescent materials can In addition, quantum dots, which are inorganic materials, can be used to obtain a light-emitting device with high luminous efficiency. Since the intrinsic stability is also excellent, it is possible to obtain a light-emitting element that is favorable from the viewpoint of life. can be done.

[0171] The materials that make up quantum dots include elements from Group 14, Group 15, and Group 16, as well as multiple Compounds consisting of group 14 elements, compounds consisting of elements belonging to groups 4 to 14 and group 16 elements compounds of Group 2 elements and Group 16 elements; compounds of Group 13 elements and Group 15 elements; Compounds of Group 13 and Group 17 elements, compounds of Group 14 and Group 15 elements, Compounds of group 1 and group 17 elements, iron oxides, titanium oxides, chalcogenide spinels and various semiconductor clusters.

[0172] Specifically, cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide , zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, arsenide Indium, indium phosphide, gallium arsenide, gallium phosphide, indium nitride, gallium nitride Lithium, indium antimonide, gallium antimonide, aluminum phosphide, arsenide Aluminum, aluminum antimonide, lead selenide, lead telluride, lead sulfide, lead selenide Indium, indium telluride, indium sulfide, gallium selenide, arsenic sulfide, selenium arsenic sulphide, arsenic telluride, antimony sulphide, antimony selenide, antimony telluride, sulphide Bismuth carbide, bismuth selenide, bismuth telluride, silicon, silicon carbide, germanium , tin, selenium, tellurium, boron, carbon, phosphorus, boron nitride, boron phosphide, boron arsenide, Aluminum nitride, aluminum sulfide, barium sulfide, barium selenide, barium telluride Calcium, calcium sulfide, calcium selenide, calcium telluride, beryllium sulfide, selenium Beryllium telluride, beryllium sulfide, magnesium selenide, sulfur Germanium sulphide, germanium selenide, germanium telluride, tin sulfide, tin selenide, Tin telluride, lead oxide, copper fluoride, copper chloride, copper bromide, copper iodide, copper oxide, copper selenide, copper oxide Nickel, cobalt oxide, cobalt sulfide, iron oxide, iron sulfide, manganese oxide, molybdenum sulfide vanadium oxide, tungsten oxide, tantalum oxide, titanium oxide, zirconium oxide , silicon nitride, germanium nitride, aluminum oxide, barium titanate, selenium and zinc and cadmium compounds, indium, arsenic and phosphorus compounds, cadmium, selenium and sulfur compounds Compounds, compounds of cadmium, selenium and tellurium, compounds of indium, gallium and arsenic, Compounds of indium, gallium and selenium, compounds of indium, selenium and sulfur, compounds of copper and indium Examples of suitable materials include, but are not limited to, compounds of tungsten and sulfur, and combinations thereof. In addition, so-called alloy-type quantum dots, whose compositions are expressed in any ratio, are not intended to be used. For example, alloy quantum dots of cadmium, selenium, and sulfur may be used. By changing the rate, the emission wavelength can be changed, making it an effective method for obtaining blue light. It is one of the stages.

[0173] Quantum dot structures include core type, core-shell type, and core-multishell type. Either of these may be used, but it is preferable to cover the core with another inorganic material with a wider band gap. By forming a shell with the material, defects and dangling bonds on the nanocrystal surface can be eliminated. This can reduce the effect of the core It is preferable to use core-shell or core-multishell quantum dots. Examples include zinc sulfide and zinc oxide.

[0174] In addition, quantum dots have a high proportion of surface atoms, making them highly reactive and prone to aggregation. Therefore, a protective agent or a protective group is attached to the surface of the quantum dot. It is preferable that the protecting agent is attached or the protecting group is provided, so that aggregation is prevented. It is possible to prevent the formation of fluorine-containing compounds and increase their solubility in solvents. It also reduces reactivity and improves electrical stability. It is also possible to improve the property of the protective agent (or protective group). Polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene Polyoxyethylene alkyl ethers such as oleyl ether, tripropylphosphine , tributylphosphine, trihexylphosphine, trioctylphosphine, etc. alkylphosphines, polyoxyethylene n-octylphenyl ether, polyoxyethylene Polyoxyethylene alkyl phenyl ethers such as ethylene n-nonylphenyl ether , tri(n-hexyl)amine, tri(n-octyl)amine, tri(n-decyl)amine Tertiary amines such as phosphine oxide, tripropylphosphine oxide, tributylphosphine oxide , trihexylphosphine oxide, trioctylphosphine oxide, tridecylphosphine oxide Sphingoxide and other organic phosphorus compounds, polyethylene glycol dilaurate, polyethylene Polyethylene glycol diesters such as polyethylene glycol distearate, Organic nitrogen compounds such as nitrogen-containing aromatic compounds such as hexafluorophosphate, lutidine, collidine, and quinolines; Cylamine, octylamine, decylamine, dodecylamine, tetradecylamine, heptylamine Aminoalkanes such as xadecylamine and octadecylamine, dibutyl sulfide, etc. Dialkyl sulfides, such as dimethyl sulfoxide and dibutyl sulfoxide Sulfoxides, sulfur-containing aromatic compounds such as thiophene, and other organic sulfur compounds, palmitic acid , higher fatty acids such as stearic acid and oleic acid, alcohols, and sorbitan fatty acid esters fatty acid modified polyesters, tertiary amine modified polyurethanes, polyethyleneimines etc.

[0175] As quantum dots become smaller, their band gaps become larger, so they can emit light at the desired wavelength. The size of the crystal is adjusted accordingly so that the light emitted by the crystal is as small as possible. The emission of quantum dots is shifted to the blue side, i.e., to higher energy, so quantum dots By changing the size of the The emission wavelength can be adjusted over a wide range. The size (diameter) of the quantum dot is The range of 0.5 nm to 20 nm, preferably 1 nm to 10 nm, is usually used. The narrower the size distribution of quantum dots, the narrower the emission spectrum. The quantum dots can be linearized to obtain light emission with good color purity. However, the quantum dots may be spherical, rod-shaped, disk-shaped, or have other shapes. The quantum rods have the function of emitting directional light, so they can be used as light-emitting materials. By using the same, a light emitting element having better external quantum efficiency can be obtained.

[0176] In most cases, organic EL devices are made by dispersing a light-emitting material in a host material, and then adjusting the concentration of the light-emitting material. The host material is a single layer that is more dense than the emitting material. It is necessary that the material has a single excited energy level or a triplet excited energy level. In particular, when a blue phosphorescent material is used as the light-emitting material, it is necessary to use a material having triplet excitation energy of 100 or more. A host material with high energy level and excellent lifetime is required, and its development is difficult. Here, the quantum dots form an emission layer using only the quantum dots without using a host material. This is also favorable from the viewpoint of life span. When the light-emitting layer is formed only from quantum dots, the quantum dots are A core-shell structure (including a core-multishell structure) is preferred.

[0177] When quantum dots are used as the light-emitting material of the light-emitting layer, the thickness of the light-emitting layer is 3 nm to 100 nm. The thickness of the quantum dots in the light-emitting layer is preferably 10 nm or more and 100 nm or less, and the content of the quantum dots in the light-emitting layer is 1 However, it is preferable to form the light-emitting layer only from quantum dots. In addition, when forming a light-emitting layer in which the quantum dots are dispersed in a host as a light-emitting material, Disperse the quantum dots in the host material, or dissolve the host material and the quantum dots in a suitable liquid medium. Dissolve or disperse it and apply it to wet processes (spin coating, casting, die coating, etc.) Laid coat method, roll coat method, inkjet method, printing method, spray coat method, car The phosphorescent layer can be formed by a method such as the Tencoat method or the Langmuir-Blodgett method. For the light-emitting layer using optical materials, in addition to the above wet process, vacuum deposition method is also suitable. It is possible.

[0178] Examples of liquid media used in wet processes include methyl ethyl ketone, cyclohexane, etc. Ketones such as Sanon, fatty acid esters such as ethyl acetate, halogens such as dichlorobenzene Hydrocarbons, aromatic carbons such as toluene, xylene, mesitylene, and cyclohexylbenzene Hydrogen compounds, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, and dimethylform Organic solvents such as diphenyl ether (DMF) and dimethyl sulfoxide (DMSO) can be used. do.

[0179] In order to prevent oxygen, hydrogen, moisture, carbon dioxide, and the like from entering the light-emitting element 4513, the electrode layer 403 A protective layer may be formed on the substrate 1. The protective layer may be made of silicon nitride, silicon oxynitride, or oxide. Aluminum nitride, aluminum oxide nitride, aluminum oxide nitride, D Diamond-like carbon (LC) can be formed. The space sealed by the plate 4001, the substrate 4006, and the sealant 4005 is filled with a filler 4006. 514 is provided and sealed. In this way, it is airtight so as not to be exposed to the outside air. Protective films with little outgassing (laminated films, UV-cured resin films, etc.) and covers It is preferable to package (enclose) the device in a suitable material.

[0180] Filler 4514 can be inert gas such as nitrogen or argon, or ultraviolet curing resin or heat curing agent. Curable resins can be used, such as PVC (polyvinyl chloride), acrylic resins, and poly Imide, epoxy resin, silicone resin, PVB (polyvinyl butyral), or EV A (ethylene vinyl acetate) or the like can be used. Agents may also be included.

[0181] The sealing material 4005 is made of glass materials such as glass frit and two-liquid mixed resins that can be used at room temperature. Resin materials such as hardening resin, photocurable resin, and thermosetting resin can be used. The sealant 4005 may also contain a desiccant.

[0182] The display device shown in FIG. 16A has a colored layer 4301 and a light-shielding layer 4302. The light-shielding layer 430 has a region overlapping the light-emitting element 4513 via the filler 4514. 2 has an area overlapping with the partition wall 4510 via the filler material 4514 .

[0183] The colored layer 4301 is a colored layer that transmits light of a specific wavelength range. For example, red, green, and blue A color filter that transmits cyan, magenta, or yellow light can be used. Materials that can be used for the colored layer 4301 include metal materials, resin materials, pigments, or Examples of the material include a resin material containing a dye.

[0184] The colored layer 4301 is provided between adjacent light-shielding layers 4302. The light emitted from the light element 4513 is blocked, and color mixing between adjacent light emitting elements 4513 is prevented. Here, the end of the colored layer 4301 is overlapped with the light-shielding layer 4302. By providing the light shielding layer 4302, it is possible to suppress light leakage. A material that blocks light emitted from the element 4513 can be used. For example, a metal material or a pigment or the like can be used. Alternatively, a black matrix can be formed using a resin material containing a dye.

[0185] If necessary, a polarizing plate or a circular polarizing plate (including an elliptical polarizing plate) may be provided on the light-emitting surface of the light-emitting element. A retardation plate (lambda / 4 plate, lambda / 2 plate) may be provided as appropriate. For example, the surface irregularities can be used to diffuse reflected light and reduce glare. Anti-glare treatment can be applied.

[0186] In addition, by making the light-emitting element a microcavity structure, it is possible to extract light with high color purity. can be done.

[0187] The electrode layer 4030 and the electrode layer 4031 are formed in accordance with the direction of the extracted light, the location where the electrode layer is provided, and The light transmitting property or the reflecting property can be selected depending on the pattern structure of the electrode layer.

[0188] The electrode layer 4030 and the electrode layer 4031 are made of indium oxide containing tungsten oxide, oxide Indium zinc oxide with tungsten oxide, indium oxide with titanium oxide, Indium tin oxide, indium tin oxide with titanium oxide, indium zinc oxide, cerium oxide A conductive material having light-transmitting properties, such as indium-tin oxide doped with indium, can be used. .

[0189] The electrode layer 4030 and the electrode layer 4031 are made of tungsten (W) and molybdenum (Mo). , Zirconium (Zr), Hafnium (Hf), Vanadium (V), Niobium (Nb), Ta, Chromium (Cr), Cobalt (Co), Nickel (Ni), Titanium (Ti ), platinum (Pt), aluminum (Al), copper (Cu), silver (Ag), or other metals, The metal layer may be formed using one or more of the alloys or metal nitrides.

[0190] In addition, the electrode layer 4030 and the electrode layer 4031 are made of a conductive polymer. The conductive polymer may be formed by using a conductive composition containing a conductive polymer. Any π-electron conjugated conductive polymer can be used. For example, polyaniline or derivatives thereof, polypyrrole or derivatives thereof, polythiophene or derivatives thereof, or Copolymers of two or more of aniline, pyrrole and thiophene or derivatives thereof Examples include:

[0191] In addition, since transistors are easily damaged by static electricity, etc., a protection circuit for protecting the driver circuit is also provided. It is preferable that the protection circuit is configured using a non-linear element.

[0192] As shown in FIG. 16A, a color filter is formed by combining a light emitting element 4513 having a white light emission color with a colored layer. By applying the filter method, the productivity of the display device of one embodiment of the present invention can be improved. can.

[0193] FIG. 16B is a cross-sectional view of the portion indicated by the chain line N1-N2 in FIG. 14B. The difference from the display device shown in FIG. 16A is that it does not have a color filter and uses a color-coded method. In the color-coded display device, the light-emitting color of the light-emitting element 4513 is formed by the light-emitting layer 4511. Depending on the material, it can be white, red, green, blue, cyan, magenta, or yellow, etc.

[0194] As shown in FIG. 16B, by applying a color-coded method, light with high color purity can be extracted. In addition, even in a display device using a color-coded display, by providing a color filter, Furthermore, light with high color purity can be extracted.

[0195] Note that the display device of one embodiment of the present invention may employ a color conversion method, a quantum dot method, or the like. .

[0196] <Example 2 of a cross-sectional configuration of a display device> FIG. 17 is a cross-sectional view of a portion indicated by a chain line N1-N2 in FIG. 14B. The following shows an example of the configuration of a display device using LEDs, which are light-emitting elements, in particular micro LEDs. 17, etc., the description of the configuration similar to that of the display device shown in FIG. 16A, etc. will be omitted.

[0197] In the display device having the structure shown in FIG. 17, an electrode layer 4031 is provided in the same layer as an electrode layer 4030. In addition, a display element 782 is provided over the insulating layer 4112. The electrode layer 4030 is electrically connected to the electrode layer 4030 via a bump 791, and the electrode layer 4030 is electrically connected to the electrode layer 4030 via a bump 793. 31 is electrically connected to

[0198] A light-shielding layer is provided in the space sealed by the substrate 4001, the substrate 4006, and the sealant 4005. The light-shielding layer 795 is preferably provided between adjacent display elements 782. By providing a light-shielding layer 795 between adjacent display elements 782, light leakage to adjacent pixels is prevented. The light-shielding layer 795 is made of a pigment, a dye, or carbon black. In addition, the side surface of the display element 782 is covered with a light-shielding layer 795. By covering the side surface of the display element 782 with a light-shielding layer 795, In FIG. 17, the upper surface of the light-shielding layer 795 is In the illustrated embodiment, the height of the display element 782 is approximately equal to the height of the upper surface of the display element 782. The embodiment is not limited to this. The height of the upper surface of the light-shielding layer 795 may be lower than the height of the upper surface of the display element 782. The height is approximately the same as or higher than the height of the upper surface of the display element 782, so that the adjacent pixels This effectively suppresses light leakage into the display and color mixing between pixels.

[0199] The display element 782 has a semiconductor layer 781 on a substrate 771. The semiconductor layer 781 is an n-type semiconductor. A conductor layer 775, a light emitting layer 777 on the n-type semiconductor layer 775, and a p-type semiconductor layer on the light emitting layer 777. The p-type semiconductor layer 779 is made of a material having a band gap energy of A material that is larger than the light-emitting layer 777 and can confine carriers to the light-emitting layer 777 is used. This can be done.

[0200] In addition, the display element 782 has an electrode having a function as a cathode on the n-type semiconductor layer 775. a layer 785 and an electrode layer 783 having a function as a contact electrode on the p-type semiconductor layer 779; An electrode layer 787 having a function as an anode is provided on the electrode layer 783. It is preferable that the upper surface and the side surface of the electrode layer 783 are covered with an insulating layer 789. The film functions as a protective film for the display element 782.

[0201] The n-type semiconductor layer 775 is a p-type semiconductor layer, and the p-type semiconductor layer 779 is an n-type semiconductor layer. In this case, the electrode layer 785 functions as an anode, and the electrode layer 787 functions as a cathode. It can also function as a board.

[0202] A bump 791 is provided between the electrode layer 785 and the electrode layer 4030. 85 is electrically connected to the electrode layer 4030. Also, the electrode layer 787 and the electrode layer 4031 A bump 793 is provided between the electrode layer 787 and the electrode layer 4031, so that the electrode layer 787 is electrically connected to the electrode layer 4031. In FIG. 17, the height of the position where the electrode layer 785 is provided and the The height of the layer 787 is different from the height of the bump 791. The height of the electrode layer 785 and the height of the electrode 93 are different. When the height of the position where the layer 787 is provided is the same as the height of the bump 791 and the height of the bump 793, The thickness of the first and second electrodes can be substantially the same.

[0203] The display element 782 can be an LED. In this case, the area of ​​the light emitting region is 1 mm 2 Less than 10000μm, preferably 2 Less than or equal to 3000 μm, more preferably 3000 μm 2 Below, More preferably 700 μm 2 The area of ​​the light emitting region can be reduced. By this, the power consumption of the display device of one embodiment of the present invention can be reduced. The display device according to one embodiment of the present invention can be made thinner and lighter. It can increase the contrast of the display device and widen the viewing angle, allowing it to display high-quality images. It is possible.

[0204] FIG. 18 shows a modified example of the display device shown in FIG. 17, which includes a substrate 4006 and a display element 78. 2 and the light-shielding layer 795, a coloring layer 4301, a light-shielding layer 4302, and a phosphor layer 797 are disposed between the coloring layer 4301 and the light-shielding layer 795. 17 in that the display device shown in FIG.

[0205] The colored layer 4301 has an area overlapping with the display element 782. A light-shielding layer 4302 is provided so that the light-shielding layer 4302 overlaps the end of the colored layer 4301. On top of 4301, a phosphor layer 797 is provided.

[0206] As a result, the phosphor layer 797, the display element 782, and the colored layer 4301 overlap each other. As shown in FIG. 18, the edge of the phosphor layer 797 is located outside the edge of the display element 782. and the end of the colored layer 4301 is preferably positioned outside the end of the phosphor layer 797. This configuration suppresses light leakage to adjacent pixels and color mixing between pixels. can be done.

[0207] The colored layer 4301, the light-shielding layer 4302, and the phosphor layer 797, the display element 782, and the light-shielding layer 7 A filler 4514 is provided between 95 and .

[0208] For example, if phosphor layer 797 has a phosphor that emits yellow light and display element 782 emits blue light, By adopting a configuration in which the phosphor layer 797 emits white light, the colored layer If 4301 is a colored layer that transmits red light, the light emitted by the display element 782 passes through the phosphor layer The light is transmitted through the colored layer 797 and the colored layer 736 and emitted to the display surface side as red light. If 4301 is a colored layer that transmits green light, the light emitted by the display element 782 passes through the phosphor layer The light is transmitted through the colored layer 797 and the colored layer 736 and emitted to the display surface side as green light. If 301 is a colored layer that transmits blue light, the light emitted by the display element 782 passes through the phosphor layer 7 The blue light passes through the colored layer 736 and is emitted to the display surface side as blue light. A color display can be performed using a display element 782 of the same type. Since only one type of display element 782 is used, the display device of one embodiment of the present invention can be manufactured by a simple method. As a result, the display device of one embodiment of the present invention can be manufactured at low cost.

[0209] For example, if the phosphor layer 797 has a phosphor that emits red light and the display element 782 has a phosphor that emits blue-green light, By configuring the phosphor layer 797 to emit colored light, white light is emitted from the phosphor layer 797. Alternatively, the phosphor layer 797 may be made of a phosphor that emits red light, a phosphor that emits green light, and a phosphor that emits blue light, and the display element 782 emits near-ultraviolet light or purple light. By configuring the phosphor layer 797 in this manner, white light may be emitted from the phosphor layer 797.

[0210] This embodiment mode can be implemented in appropriate combination with the configurations described in other embodiment modes. It is Noh.

[0211] (Embodiment 3) In this embodiment mode, the transistors described in the above embodiment modes can be replaced with An example of a transistor that can be used will be described with reference to the drawings.

[0212] The display device of one embodiment of the present invention includes a bottom-gate transistor and a top-gate transistor. The present invention can be fabricated using various types of transistors, such as a conventional transistor. The semiconductor layer materials and transistor structures used can be easily replaced to suit the production line. It is possible.

[0213] [Bottom-gate transistor] FIG. 19A1 shows a channel protection transistor, which is a type of bottom gate transistor. In FIG. 19A1, transistor 810 is formed on substrate 771. The transistor 810 is formed on a substrate 771 with an insulating layer 772 interposed therebetween. In addition, a semiconductor layer 742 is provided over the electrode 746 with an insulating layer 726 interposed therebetween. The electrode 746 functions as a gate electrode. The insulating layer 726 functions as a gate insulating layer. Possesses the ability.

[0214] In addition, an insulating layer 741 is provided on a channel formation region of the semiconductor layer 742. Electrode 744a and electrode 744b are provided on insulating layer 726 in contact with a portion of electrode 742. The electrode 744a functions as either a source electrode or a drain electrode. A part of the electrode 744a and the other of the source electrode and the drain electrode A portion of the pole 744 b is formed on the insulating layer 741 .

[0215] The insulating layer 741 functions as a channel protection layer. By providing the insulating film 41, the thickness of the semiconductor layer 742 generated when the electrodes 744a and 744b are formed can be reduced. Therefore, when the electrodes 744a and 744b are formed, the semiconductor layer This can prevent the channel formation region 742 from being etched. According to this, a transistor having good electrical characteristics can be realized.

[0216] The transistor 810 has an insulating layer 741 formed on an electrode 744a, an electrode 744b, and an insulating layer 741. A layer 728 is provided, and an insulating layer 729 is provided on the insulating layer 728 .

[0217] In the case where an oxide semiconductor is used for the semiconductor layer 742, at least the electrode 744a and the electrode 744b In addition, oxygen is taken from a part of the semiconductor layer 742 at the portion in contact with the semiconductor layer 742, and oxygen vacancies are formed. It is preferable to use a material capable of generating oxygen vacancies in the semiconductor layer 742. The carrier concentration in the affected region increases, the region becomes n-type, and the n-type region (n + layer). Therefore, the region can function as a source region or a drain region. When an oxide semiconductor is used for the layer 742, oxygen is taken from the semiconductor layer 742, causing oxygen vacancies. Examples of materials that can be used include tungsten and titanium.

[0218] The source region and the drain region are formed in the semiconductor layer 742, whereby the electrodes 744a and The contact resistance between the electrode 744b and the semiconductor layer 742 can be reduced. The electrical characteristics of the transistor, such as the effective mobility and threshold voltage, can be improved. Cut.

[0219] When a semiconductor such as silicon is used for the semiconductor layer 742, the semiconductor layer 742 and the electrode 744a Between the semiconductor layer 742 and the electrode 744b, a semiconductor functioning as an n-type semiconductor or a p-type semiconductor is provided. The layer functioning as an n-type semiconductor or a p-type semiconductor is preferably provided. The MOS transistor can function as a source or drain region of the MOS transistor.

[0220] The insulating layer 729 has a function of preventing or reducing diffusion of impurities from the outside into the transistor. It is preferable to form the insulating layer 729 using a material having such a property. It is also possible.

[0221] The transistor 811 shown in FIG. 19A2 has a function as a back gate electrode on an insulating layer 729. The transistor 810 differs from the transistor 810 in that it has an electrode 723 having a function. It can be formed from the same materials and by the same method as 746.

[0222] In general, the back gate electrode is formed of a conductive layer, and the gate electrode and the back gate electrode form a semiconductor. The back gate electrode is disposed so as to sandwich the channel forming region of the layer. The back gate electrode can function in the same manner as the gate electrode. Alternatively, the potential may be set to ground potential (GND potential) or any other potential. By changing the potential of the gate electrode independently of the potential of the back electrode, the transistor threshold The voltage can be varied.

[0223] Both the electrode 746 and the electrode 723 can function as a gate electrode. , insulating layer 726, insulating layer 741, insulating layer 728, and insulating layer 729 are gate electrodes. The electrode 723 can function as an insulating layer. It may be provided between.

[0224] When one of the electrodes 746 and 723 is called a "gate electrode," the other is called a "back gate." For example, in the transistor 811, the electrode 723 is called a “gate electrode.” ", the electrode 746 is called a "back gate electrode." When used as a "transistor electrode," the transistor 811 is a type of top-gate transistor. In addition, either the electrode 746 or the electrode 723 can be considered as the "first gate. The first gate electrode may be referred to as the "first gate electrode" and the other as the "second gate electrode."

[0225] The electrode 746 and the electrode 723 are provided with the semiconductor layer 742 interposed therebetween, By setting the electrode 723 at the same potential, the region in which carriers flow in the semiconductor layer 742 is Since the thickness of the film increases, the amount of carrier movement increases. As the on-current of the transistor 811 increases, the field effect mobility increases.

[0226] Therefore, the transistor 811 is a transistor having a high on-current relative to its occupancy area. That is, the area occupied by the transistor 811 is small relative to the required on-current. According to one embodiment of the present invention, the area occupied by a transistor can be reduced. It is possible.

[0227] In addition, since the gate electrode and the back gate electrode are formed of a conductive layer, they can be electrically connected to the outside of the transistor. The function of preventing the electric field generated from acting on the semiconductor layer in which the channel is formed (especially static electricity The back gate electrode is made larger than the semiconductor layer. By forming a back gate electrode and covering the semiconductor layer with the back gate electrode, the electric field shielding function can be improved.

[0228] In addition, by forming the back gate electrode using a conductive film having a light-shielding property, This can prevent light from entering the semiconductor layer from the side. This prevents the semiconductor layer from being deteriorated by light. Therefore, deterioration of electrical characteristics, such as a shift in the threshold voltage of the transistor, can be prevented.

[0229] According to one embodiment of the present invention, a highly reliable transistor can be provided. A highly reliable display device or the like can be realized.

[0230] FIG. 19B1 shows a channel-protected transistor, which is one type of bottom-gate transistor. 8 shows a cross-sectional view of transistor 820. Transistor 820 has a structure similar to that of transistor 810. However, the difference is that an insulating layer 741 covers the end of the semiconductor layer 742. In an opening formed by selectively removing a part of the insulating layer 741 overlapping the semiconductor layer 742, The semiconductor layer 742 and the electrode 744a are electrically connected to each other. In another opening formed by selectively removing a part of the insulating layer 741, the semiconductor layer 742 is The region of the insulating layer 741 that overlaps with the channel forming region is electrically connected to the electrode 744b. The region functions as a channel protection layer.

[0231] The transistor 821 shown in FIG. 19B2 has a function as a back gate electrode on an insulating layer 729. The transistor 820 differs from the transistor 820 in that it has an electrode 723 having a function.

[0232] By providing the insulating layer 729, the semiconductor layer generated when the electrodes 744a and 744b are formed is Therefore, when the electrodes 744a and 744b are formed, the semiconductor device 742 is prevented from being exposed. This can prevent the conductor layer 742 from becoming thin.

[0233] In addition, the transistors 820 and 821 are the transistors 810 and The distance between electrode 744a and electrode 746 and the distance between electrode 744b and electrode 746 are smaller than those of the electrode 811. Therefore, the parasitic capacitance between the electrode 744a and the electrode 746 is reduced. In addition, the parasitic capacitance between the electrode 744b and the electrode 746 can be reduced. According to one embodiment of the present invention, a transistor with favorable electrical characteristics can be provided. do.

[0234] The transistor 825 shown in FIG. 19C1 is a bottom-gate transistor. The transistor 825 is a channel etching type transistor. Therefore, the electrodes 744a and 744b are formed without any need for a metal layer. In some cases, a part of the semiconductor layer 742 exposed during the formation of b may be etched. Since the layer 741 is not provided, productivity of the transistor can be increased.

[0235] A transistor 826 shown in FIG. 19C2 has a function as a back gate electrode on an insulating layer 729. The transistor 825 differs from the transistor 825 in that it has an electrode 723 having a function.

[0236] [Top-gate transistor] The transistor 842 illustrated in FIG. 20A1 is one of the top-gate transistors. The transistor 842 is provided with an electrode 744a and an electrode 744b after the insulating layer 729 is formed. The electrode 744a and the electrode 744b are formed in the insulating layer 728 and the insulating layer 729. The insulating layer 742 is electrically connected to the semiconductor layer 742 in the opening.

[0237] Also, a part of the insulating layer 726 that does not overlap with the electrode 746 is removed, and the electrode 746 is removed as shown in FIG. The electrode 746 and the remaining insulating layer 726 are used as a mask to introduce impurities 755 into the semiconductor. By introducing the ions into the semiconductor layer 742, the ions are self-aligned in the semiconductor layer 742. The transistor 842 has an insulating layer 726 formed on the electrode 746. The semiconductor layer 742 has an area extending beyond the end. The impurity concentration in the region where the impurity 755 is introduced is the same as that in the region where the impurity 755 is introduced without the insulating layer 726. Therefore, the semiconductor layer 742 has an LD in the area that does not overlap with the electrode 746. A D (Lightly Doped Drain) region is formed.

[0238] The transistor 843 shown in FIG. 20A2 is different from the transistor 842 in that it has an electrode 723. The transistor 843 has an electrode 723 formed on a substrate 771. The electrode 723 has a region overlapping with the semiconductor layer 742 with the insulating layer 772 interposed therebetween. It can function as a back gate electrode.

[0239] In addition, the transistor 844 shown in FIG. 20B1 and the transistor 845 shown in FIG. 20B2 As shown in FIG. 1, the insulating layer 726 in the area not overlapping with the electrode 746 may be entirely removed. As shown in FIG. 20C1, transistor 846 and shown in FIG. 20C2, transistor 847 , the insulating layer 726 may remain.

[0240] After forming the electrode 746, the transistors 843 to 847 are also As a result, the semiconductor layer 742 is doped with impurities 755 using the mask. According to one aspect of the present invention, an impurity region can be formed in a self-aligned manner. Therefore, a transistor with good performance can be realized.

[0241] This embodiment mode can be implemented in appropriate combination with the configurations described in other embodiment modes. It is Noh.

[0242] (Embodiment 4) In this embodiment, a CA that can be used for a transistor disclosed in one embodiment of the present invention is described. This section explains the configuration of C-OS.

[0243] CAC-OS is, for example, an oxide semiconductor in which the elements constituting the oxide semiconductor are 0.5 nm to 10 nm. Preferably, the material is unevenly distributed in a size range of 1 nm to 2 nm or less, or in the vicinity thereof. In the following, it is assumed that one or more metal elements are distributed randomly in an oxide semiconductor. The region having the metal element has a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or less. A state in which particles are mixed in sizes of 2 nm or less or close to that size is called a mosaic or patch state. cormorant.

[0244] Note that the oxide semiconductor preferably contains at least indium. In addition to these, aluminum, gallium, yttrium, zinc, etc. are preferably contained. Lithium, Copper, Vanadium, Beryllium, Boron, Silicon, Titanium, Iron, Nickel, Gel Manium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum Contains one or more of the following: tantalum, tungsten, or magnesium. It's fine.

[0245] For example, CAC-OS made of In-Ga-Zn oxide (In-Ga-Zn oxide is one of the CAC-OS) a-Zn oxide may be specifically referred to as CAC-IGZO. (Hereinafter, InO X1 (X1 is a real number greater than 0) or indium zinc oxide Things (hereinafter, In X2 Zinc Y2 O Z2 (X2, Y2, and Z2 are real numbers greater than 0.) ) and gallium oxide (GaO X3 (X3 is a real number greater than 0) . ) or gallium zinc oxide (Ga X4 Zinc Y4 O Z4 (X4, Y4, and Z4 (is a real number greater than 0).) The material is separated into a mosaic shape, Mosaic InO X1 , or In X2 Zinc Y2 O Z2 The structure in which the ions are uniformly distributed in the film ( Hereinafter, this will be referred to as "cloud-like."

[0246] In other words, CAC-OS is X3 The region where In is the main component and X2 Zinc Y2 OZ2 , or InO X1 A composite oxide semiconductor having a structure in which a region in which In this specification, for example, the atomic ratio of In to the element M in the first region is The first region has an atomic ratio of In to the element M in the second region that is greater than the atomic ratio of In in the second region. The concentration of In is higher than in the region

[0247] Note that IGZO is a common name and refers to a compound made of In, Ga, Zn, and O. A typical example is InGaO 3 (ZnO) m1 (m1 is a natural number), or In (1+ x0) Ga (1-x0) O 3 (ZnO) m0 (-1≦x0≦1, m0 is an arbitrary number) Examples of such crystalline compounds include

[0248] The crystalline compound has a single crystal structure, a polycrystalline structure, or a CAAC structure. The AAC structure is a structure in which multiple IGZO nanocrystals have a c-axis orientation and It is a non-oriented, connected crystal structure.

[0249] On the other hand, CAC-OS refers to the material composition of oxide semiconductors. In a material composition containing a, Zn, and O, nanoparticles with Ga as the main component were observed in some areas. The regions where the In is mainly contained are observed as nanoparticles, and the regions where the In is mainly contained as nanoparticles are observed. Therefore, in the CAC-OS, the crystal structure is Construction is a secondary element.

[0250] It should be noted that the CAC-OS does not include a laminated structure of two or more films having different compositions. For example, a structure consisting of two layers, a film mainly made of In and a film mainly made of Ga, is not included. do not have.

[0251] In addition, GaO X3 The region where In is the main component and X2 Zinc Y2 O Z2 , or InO X1 Mainly In some cases, no clear boundary between the component regions can be observed.

[0252] Instead of gallium, aluminum, yttrium, copper, vanadium, and beryllium can be used. , boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum , lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium If the product contains one or more of the following, CAC-OS will notify the user of the The area observed is that of nanoparticles mainly composed of metal elements, and in some areas, nanoparticles mainly composed of In. This refers to a structure in which the regions observed as particles are randomly dispersed in a mosaic pattern. .

[0253] CAC-OS is formed by sputtering without intentionally heating the substrate. In addition, when the CAC-OS is formed by a sputtering method, the deposition gas and The gas to be used should be selected from an inert gas (typically argon), oxygen gas, and nitrogen gas. In addition, the ratio of oxygen gas to the total flow rate of the deposition gas during deposition is The lower the flow rate ratio, the more preferable. For example, the flow rate ratio of oxygen gas is set to 0% or more and less than 30%, preferably is preferably set to 0% or more and 10% or less.

[0254] CAC-OS is a type of X-ray diffraction (XRD) measurement method. When measured using the θ / 2θ scan by the out-of-plane method, In other words, no clear peaks are observed from the X-ray diffraction measurement. It can be seen that no orientation in the ab plane direction or the c-axis direction of the region is observed.

[0255] In addition, the CAC-OS uses an electron beam with a probe diameter of 1 nm (also called a nano-beam electron beam). In the electron diffraction pattern obtained by irradiating the sample with electrons, a ring-shaped area of ​​high brightness (ring In the ring region, multiple bright spots are observed. Therefore, from the electron diffraction pattern, The crystal structure of CAC-OS is nc( It can be seen that the material has a nano-crystal structure.

[0256] For example, in the case of CAC-OS made of In-Ga-Zn oxide, energy dispersive X-ray Spectroscopy (EDX: Energy Dispersive X-ray spectroscopy) The EDX mapping obtained using a GaO X3 The region where is the main component and , In X2 Zinc Y2 O Z2 , or InO X1 The areas where the main component is It can be confirmed that the compound has the structure described above.

[0257] CAC-OS has a structure different from that of IGZO compounds in which metal elements are uniformly distributed. It has different properties from ZO compounds. That is, CAC-OS is GaO X3 The main ingredients are In a certain area, X2 Zinc Y2 OZ2 , or InO X1 The area where is the principal component and It has a phase-separated structure with a mosaic of regions each consisting of one element as the main component.

[0258] Here, In X2 Zinc Y2 O Z2 , or InO X1 The area where GaO is the main component X3 N In other words, the In region has a higher electrical conductivity than the region where the main component is In. X2 Zinc Y2 O Z2 , or InO X1 The carriers flow through the region where the oxide semiconductor is the main component. The electrical conductivity of the conductor is expressed. X2 Zinc Y2 O Z2 , or InO X1 Mainly The cloud-like distribution of the oxide semiconductor components in the oxide semiconductor region results in high field-effect mobility. (μ) can be realized.

[0259] On the other hand, GaO X3 The region where the main components are In X2 Zinc Y2 O Z2 , or InO X1 This region has higher insulating properties than the region where GaO is the main component. X3 Mainly The distribution of the oxide semiconductor in the region containing the oxide component suppresses leakage current and provides good switching performance. This allows for switching operations.

[0260] Therefore, when CAC-OS is used in a semiconductor device, GaO X3 Insulation caused by In X2 Zinc Y2 O Z2 , or InO X1The conductivity caused by the This allows for a high on-state current (I on ) and high field effect mobility (μ) can be achieved. do.

[0261] In addition, semiconductor devices using CAC-OS have high reliability. It is ideal for a variety of semiconductor devices, including displays.

[0262] This embodiment mode can be implemented in appropriate combination with the configurations described in other embodiment modes. It is Noh.

[0263] (Embodiment 5) In this embodiment, electronic devices in which the display device of one embodiment of the present invention can be used will be described. This will be explained using the drawings.

[0264] Examples of electronic devices in which the display device of one embodiment of the present invention can be used include display devices, personal computers, and the like. Computers, image storage devices or image playback devices equipped with recording media, mobile phones, portable devices, etc. Game consoles, portable data terminals, e-book terminals, video cameras, digital still cameras, etc. Camera, goggle-type display (head-mounted display), navigation system systems, audio playback devices (car audio, digital audio players, etc.), copiers, Fax machines, printers, multi-function printers, automated teller machines (ATMs), vending machines Specific examples of these electronic devices are shown in Figure 21.

[0265] FIG. 21A shows an example of a television device 910, which includes a housing 911, a display unit 912, and a speaker. FIG. 21A shows a configuration in which a housing 911 is supported by a stand 914. is doing.

[0266] The television device 910 is operated by a switch provided on the housing 911 and a separate remote control. Alternatively, the display unit 912 may be provided with a touch sensor. The remote control 91 may be operated by touching the display unit 912 with a finger or the like. 5 may have a display unit for displaying information output from the remote control unit 915. The channel and sound can be selected by using the operation keys or touch panel of the remote control 915. The amount of data can be manipulated, and the image displayed on the display unit 912 can be manipulated.

[0267] The television device 910 may include a receiver and a modem. The receiver can receive general television broadcasts. It can also be used to receive wired signals via a modem. Or by connecting to a wireless communication network, It is also possible to carry out two-way information communication (between a sender and a receiver, or between receivers, etc.).

[0268] In a television set 910, the display device of one embodiment of the present invention can be used for a display portion 912. This allows a high-quality image to be displayed on the display unit 912.

[0269] FIG. 21B shows an example of a wristwatch-type information terminal 920. The wristwatch-type information terminal 920 has a housing / wristband 921 and a display unit. 922, an operation button 923, an external connection port 924, a camera 925, etc. A touch panel 22 is provided for operating the information terminal 920. The band 921 and the display unit 922 are flexible and have excellent wearability on the body.

[0270] In the information terminal 920, the display device of one embodiment of the present invention can be used for the display portion 922. This allows the display unit 922 to display a high-quality image.

[0271] FIG. 21C shows an example of a digital camera 930, which is equipped with a viewfinder 931. The digital camera 930 includes a housing 932, a display unit 933, an operation button 934, a shutter The digital camera 930 also has a removable lens 936. It should be noted that the lens 936 does not have to be removable.

[0272] The digital camera 930 can capture an image by pressing the shutter button 935. The display portion 933 can also function as a touch panel. In this case, it is also possible to capture an image by touching the display portion 933.

[0273] The housing 932 has a mount having electrodes, and is configured to accommodate the finder 931, a strobe device, etc. can be connected.

[0274] The finder 931 includes a housing 937, a display portion 938, and the like.

[0275] The housing 937 has a mount that engages with the mount of the digital camera 930. The mount 931 can be attached to the digital camera 930. has electrodes and corresponds to image data supplied from the digital camera 930 via the electrodes. The image or the like can be displayed on the display unit 938.

[0276] The display unit 933 of the digital camera 930 and the display unit 938 of the finder 931 are In this way, the display device of the above embodiment can be used. It is possible to display high quality images.

[0277] FIG. 21D is an example of a digital signage 940. A pillar 943 is provided, and a display unit 944 is attached so as to fit along the curved surface of the pillar 943 .

[0278] The larger the display area 944, the more information can be provided at one time. The wider the 944, the more visible it is, which can increase the effectiveness of advertising, for example. .

[0279] When a touch panel is applied to the display unit 944, not only can images be displayed on the display unit 944, This is preferable because the user can operate it intuitively.

[0280] In the digital signage 940, the display device of one embodiment of the present invention is used for the display portion 944. This allows a high-quality image to be displayed on the display unit 944.

[0281] FIG. 21E shows an example of a mobile phone 950, which includes a housing 951, a display unit 952, and an operation button 955. 3. External connection port 954, speaker 955, socket 956, camera 957, earphone socket The mobile phone 950 has a touch sensor on the display unit 952. You can make calls, enter text, or perform any other operation with your finger or a stylus. The user can touch the display unit 952 with a finger. The slot 956 also accepts an SD card. Memory cards, USB memory, SSD (Solid State Drive), etc. Various types of removable storage devices such as USB flash drives can be plugged in.

[0282] In a mobile phone 950, the display device of one embodiment of the present invention can be used for a display portion 952. This allows a high-quality image to be displayed on the display unit 952.

[0283] FIG. 21F shows an example of a portable data terminal 960, which includes a housing 961, a display unit 962, and a speaker 9 The display unit 962 has a touch panel function for inputting information. It can also recognize characters and other information from images captured by the camera 964 and output them to speech. The character can be output as voice by speaker 963.

[0284] In the portable data terminal 960, the display device of one embodiment of the present invention can be used for the display portion 962. This allows a high-quality image to be displayed on the display unit 962.

[0285] This embodiment mode can be implemented in appropriate combination with the configurations described in other embodiment modes. It is Noh. [Explanation of symbols]

[0286] 10: pixel, 11: transistor, 12: transistor, 13: transistor, 14: Transistor, 15: transistor, 16: transistor, 20: display element, 21: capacitance element 22: capacitance element, 23: capacitance element, 31: wiring, 32: wiring, 35: wiring, 36: wiring Line, 41: Wiring, 42: Wiring, 45: Wiring, 50: Wiring, 53: Wiring, 54: Wiring, 60 : display device, 61: display unit, 62: gate driver circuit, 63: data driver circuit, 6 4: current detection circuit, 65: correction data generation circuit, 66: storage device, 67: storage device, 21 5: display unit, 221: gate driver circuit, 231: data driver circuit, 232: data driver circuit, 241: power supply circuit, 723: electrode, 726: insulating layer, 728: insulating layer, 729: insulating layer, 736: coloring layer, 741: insulating layer, 742: semiconductor layer, 744a: electrode , 744b: electrode, 746: electrode, 755: impurity, 771: substrate, 772: insulating layer, 7 75: n-type semiconductor layer, 777: light-emitting layer, 779: p-type semiconductor layer, 781: semiconductor layer, 78 2: display element, 783: electrode layer, 785: electrode layer, 787: electrode layer, 789: insulating layer, 7 91: bump, 793: bump, 795: light shielding layer, 797: phosphor layer, 810: transistor 811: transistor, 820: transistor, 821: transistor, 825: Transistor, 826: transistor, 842: transistor, 843: transistor, 844: transistor, 845: transistor, 846: transistor, 847: trans 910: television device, 911: housing, 912: display unit, 913: speaker 914: Stand, 915: Remote control device, 920: Information terminal, 921: Housing and wristwatch band, 922: display, 923: operation buttons, 924: external connection port, 925: camera camera, 930: digital camera, 931: viewfinder, 932: housing, 933: display , 934: Operation button, 935: Shutter button, 936: Lens, 937: Housing, 9 38: Display unit, 940: Digital signage, 941: Floor, 942: Ceiling, 943: Pillar, 944: display unit, 950: mobile phone, 951: housing, 952: display unit, 953: operation button 954: External connection port, 955: Speaker, 956: Outlet, 957: Camera, 958: earphone jack, 960: portable data terminal, 961: housing, 962: display unit, 9 63: speaker, 964: camera, 4001: circuit board, 4005: sealing material, 4006: base board, 4010: transistor, 4011: transistor, 4014: wiring, 4015: pole, 4017: electrode, 4018: FPC, 4019: anisotropic conductive layer, 4020: capacitance element , 4021: electrode, 4030: electrode layer, 4031: electrode layer, 4041: printed circuit board, 4 042: integrated circuit, 4102: insulating layer, 4103: insulating layer, 4110: insulating layer, 4111 : insulating layer, 4112: insulating layer, 4200: input device, 4210: touch panel, 4227 :Electrode, 4228:Electrode, 4237:Wiring, 4238:Wiring, 4239:Wiring, 4263 : Substrate, 4272: FPC, 4273: IC, 4301: Colored layer, 4302: Light-shielding layer, 4 510: partition wall, 4511: light-emitting layer, 4513: light-emitting element, 4514: filler

Claims

[Claim 1] a pixel including a transistor, a display element, and a memory circuit; and a correction data generating circuit; one of a source and a drain of the transistor is electrically connected to one electrode of the display element; A method of operating a display device, the gate of the transistor being electrically connected to the memory circuit, comprising: In a first period, the correction data generation circuit generates correction data for correcting a threshold voltage of the transistor; In a second period, first data is written to the memory circuit; In a third period, second data is supplied to the pixel to generate third data that is data obtained by adding the second data to the first data; A method of operating a display device, wherein an image corresponding to the third data is displayed by the display element during a fourth period.

Images