Light-emitting device

Abstract

To control a light emission period of a light emitting element to improve visibility.SOLUTION: A display device has a signal line, a first scanning line, a second scanning line, and a pixel circuit. The pixel circuit has a light emitting element, a first transistor, and a second transistor. The second transistor has a back gate, and the second scanning line is electrically connected to the back gate. The second scanning line has a function of controlling a threshold voltage of the second transistor and a function of controlling a light emission period of the light emitting element.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Note that one embodiment of the present invention is not limited to the above technical fields. The technical field of one aspect of the present invention relates to a product, a method, or a manufacturing method. process, machine, manufacture, or composition of matter In particular, one embodiment of the present invention relates to a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, The present invention relates to a device, a driving method thereof, or a manufacturing method thereof. [Background technology]

[0003] Mobile devices such as smartphones and tablets are becoming more and more common. New devices such as displays and digital in-vehicle display devices are being used. Therefore, there is a demand for high visibility and reduced power consumption.

[0004] Active matrix organic EL displays excel in terms of fast response speed and wide viewing angle. This is a hold-type display method (hereinafter referred to as hold-type driving). The light-emitting element emits light during one frame period (one frame is the unit of an image to be displayed). The brightness of the emitted light is controlled by integrating the brightness for one frame period. A display device that displays 60 frames displays an image 60 times per second. The frame period represents a time of approximately 16.67 ms.

[0005] Another driving method is the impulse type display method (hereinafter referred to as impulse type driving). In impulse-type driving, the integrated luminance during the selection period of the pixel circuit is equal to the integrated luminance during one frame period. The light is emitted by controlling the brightness and gradation.

[0006] In the hold type driving or impulse type driving, the light emission brightness is specified by the voltage. In addition to the pressure setting method, a current setting method in which a current is used to specify the pressure is also known.

[0007] Although the responsiveness of organic EL elements is higher than that of liquid crystal elements, the hold-type drive is not very effective in displaying moving images. This causes blurring of the video display, which reduces the video resolution. This refers to the apparent resolution when displayed on a screen, and is the resolution that people perceive when viewing a video. For example, a wedge-shaped figure can be scrolled on the screen, and the image update interval can be identified. This refers to the limit of resolution.

[0008] For example, in Patent Document 1, impulse-type driving and hold-type driving are combined to A control method has been proposed for controlling the gradation and improving visibility.

[0009] For example, in Patent Document 2, a technique for improving the resolution of moving images by inserting black into a display frame is disclosed. A method for reducing the light-emitting period of an organic EL element has been proposed. Methods for preventing the shortening of lifespan are described. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2009-9049 A [Patent Document 2] JP 2011-85768 A Summary of the Invention [Problem to be solved by the invention]

[0011] In the hold-type driving, the active matrix type display is driven in the display area. This can cause video blurring, resulting in problems such as unclear contours when displaying moving images. be.

[0012] In hold-type driving, the display is updated every frame, so integrated luminance is used. Therefore, in order to recognize the change in gray scale, a period of luminance integration is required, and There is a problem with the ending not going up.

[0013] Impulse-type drive by dot sequence suppresses video blurring like hold-type drive, but However, because the light emission period is short, there is a problem of flickering when displaying still images. be.

[0014] In the dot-sequential impulse-type driving, the integrated voltage for one frame period is In order to emit light with the same brightness as the calculated brightness, the driver needs to have a high current supply capacity.

[0015] In view of the above problems, an object of one embodiment of the present invention is to provide a display device having a novel structure. Another embodiment of the present invention is to provide a display device that improves visibility of a display. An object of one embodiment of the present invention is to provide a display device with reduced power consumption. This is one of the topics.

[0016] Note that the problems of one embodiment of the present invention are not limited to the problems listed above. However, this does not preclude the existence of other problems. The other problems are described below. Problems not mentioned in this section are problems that a person skilled in the art would be able to solve by reading the specification or can be derived from drawings and other descriptions, and can be appropriately extracted from these descriptions. In addition, one aspect of the present invention is to achieve at least one of the above-listed and / or other objects. This is to solve one problem. [Means for solving the problem]

[0017] One embodiment of the present invention is a liquid crystal display having a signal line, a first scan line, a second scan line, and a pixel circuit. The pixel circuit includes a light emitting element, a first transistor, and a second transistor. a gate of the first transistor electrically connected to the first scan line; One of the source and the drain of the transistor is electrically connected to the signal line, and the first transistor The other of the source and drain of the transistor is electrically connected to the gate of the second transistor. The second transistor has a back gate and a source or The drain of the first scanning line is electrically connected to one of the electrodes of the light emitting element, and the second scanning line is connected to the A display device electrically connected to a lock gate.

[0018] In the display device, the first or second transistor has an oxide layer in a channel formation region. It is preferable to have a semiconductor.

[0019] In the above display device, the light emitting element preferably has an organic compound layer.

[0020] One embodiment of the present invention is a method for driving a display device including a display portion and a gate driver. The display unit includes a plurality of signal lines, a plurality of first scanning lines, a plurality of second scanning lines, and a first The pixel circuit includes a first pixel circuit and a second pixel circuit, and the first pixel circuit and the second pixel circuit are configured to emit light. The device includes a first transistor and a second transistor, the second transistor being The back gate is electrically connected to the first scanning lines. The gate driver is electrically connected to the plurality of second scan lines, and the first scan lines are connected to the first pixel. The gate of the first transistor of the second pixel circuit and the gate of the first transistor of the second pixel circuit are connected to each other. The second scan line is electrically connected to the gate of the first pixel circuit. A back gate of the transistor and a back gate of the second transistor of the second pixel circuit The gate driver is electrically connected to the first scanning lines and outputs a first scanning signal to the first scanning lines. and the gate driver outputs a second scanning signal to a plurality of second scanning lines. One frame period has a first period and a second period, and the first period In the second period, the light emission and gradation of the light emitting element are controlled, and in the third period, the light emitting element is turned off. A method for driving a display device to be controlled.

[0021] In the above-mentioned configuration, the method for driving a display device includes a second period after the first period. In the first period, the gate driver applies a first scanning signal to the first scanning line, and the signal line A signal is applied to the gate of the second transistor via the first transistor, and a voltage corresponding to the signal is generated. A current is provided to the light emitting element from the second transistor, and a second scanning signal, a second transistor A voltage equal to or higher than the voltage of the source of the first transistor is applied to the back gate of the second transistor. In the case of the MOSFET, the magnitude of the current in the second transistor is controlled by the voltage of the back gate, and the current By controlling the magnitude of the second period, the light emission and the gray scale of the light emitting element are controlled. A scanning signal, a voltage smaller than the voltage of the source of the second transistor, is applied to the second transistor. The second transistor has a threshold voltage Vth1 set by the voltage of the back gate. By controlling the threshold voltage, the light emitting element is turned off to control the light emitting period. It is preferable to provide a method for driving a display device that achieves this.

[0022] In each of the above configurations, a display device and a touch sensor are provided. Joules are preferred. Effect of the Invention

[0023] One embodiment of the present invention can provide a display device having a novel structure. According to one embodiment of the present invention, a display device having improved visibility can be provided. According to the present invention, it is possible to provide a display device that consumes less power.

[0024] Note that the effects of one embodiment of the present invention are not limited to the effects listed above. However, this does not preclude the existence of other effects. Other effects may be affected by this item, as described below. The effects not mentioned in this section are obvious to those skilled in the art. can be derived from drawings and other descriptions, and can be appropriately extracted from these descriptions. In addition, one aspect of the present invention has at least one of the above-listed effects and / or other effects. Therefore, one aspect of the present invention is, in some cases, In some cases, the effect may not be significant. [Brief description of the drawings]

[0025] [Figure 1] FIG. 2 is a diagram illustrating the configuration of a pixel circuit. [Diagram 2] FIG. 1 is a block diagram showing a configuration of a display device. [Diagram 3](A) is a diagram illustrating transistor connections, and (B) is a diagram showing an example of the electrical characteristics of a transistor. [Figure 4] A timing chart showing an example of the operation of a display device. [Diagram 5] (A) is a diagram showing an example of a display, and (B) is a diagram showing an example of a display. [Figure 6] (A)(B)(C)(D): Diagrams explaining the configuration of a pixel circuit. [Figure 7] (A): Flowchart showing an example of a method for manufacturing an electronic component. (B): Top view of a semiconductor wafer. (C): Enlarged view of a portion of a semiconductor wafer. (D): Enlarged view of a chip. (E): Schematic perspective view of an electronic component. [Figure 8] 1A, 1B, and 1C are top views showing examples of the display panel configuration. [Figure 9] 1A, 1B, and 1C are top views showing examples of the display panel configuration. [Figure 10] 1A and 1B are cross-sectional views showing an example of the configuration of a display panel. [Figure 11] 1A and 1B are cross-sectional views showing an example of the configuration of a display panel. [Figure 12] 1A and 1B are cross-sectional views showing an example of the configuration of a display panel. [Figure 13] FIG. 4 is a diagram showing an example of a display module. [Figure 14] (A)(B): Schematic diagrams showing an example of the configuration of a touch panel. [Figure 15] (A)(B)(C): Diagrams showing examples of the configuration of electronic devices. [Figure 16] (A)(B)(C)(D)(E): Diagrams showing examples of electronic device configurations. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, the embodiments will be described with reference to the drawings. It is possible to carry out the present invention in various forms without departing from the spirit and scope of the present invention. It will be readily understood by those skilled in the art that various modifications may be made to the details of the present invention. However, the present invention should not be construed as being limited to the description of the following embodiments.

[0027] Also, in the drawings, the size, layer thickness, or area are exaggerated for clarity. Therefore, the scale is not necessarily limited to that shown in the drawings. The drawings are merely schematic illustrations and are not limited to the shapes or values ​​shown in the drawings.

[0028] In addition, the ordinal numbers "first," "second," and "third" used in this specification refer to the components of the It should be noted that this is added to avoid confusion and is not intended to limit the numbers.

[0029] In addition, in this specification, the words "above" and "below" indicating the position of the components are used. The positional relationship is used for convenience in describing the drawings. The relationship changes depending on the direction in which each component is depicted. The above words and phrases are not limited to those used above, but can be rephrased appropriately depending on the situation.

[0030] In this specification, a transistor includes a gate, a drain, and a source. The drain terminal is a diode that has at least three terminals. Between the drain region or drain electrode and the source (source terminal, source region or source electrode) A channel region is formed between the source and drain, and a current is applied between the source and drain through the channel region. In this specification and the like, the channel region is a region through which a current can flow. This refers to the region where the current mainly flows.

[0031] In addition, the functions of the source and drain may differ depending on whether transistors of different polarities are used or the circuit In operation, when the direction of the current changes, the positions may be reversed. In the specification, the terms source and drain may be used interchangeably. do.

[0032] In addition, in this specification, "parallel" means that two straight lines are at an angle of -10° or more and 10° or less. Therefore, it includes the case where the angle is between -5° and 5°. "Perpendicular" means that two straight lines are arranged at an angle of 80° or more and 100° or less. Therefore, this also includes cases where the angle is between 85° and 95°.

[0033] In addition, in this specification and the like, the terms "film" and "layer" are interchangeable. For example, the term "conductive layer" can be changed to the term "conductive film." Alternatively, for example, the term "insulating film" may be changed to "insulating layer." It may be possible to change the term to:

[0034] In this specification and the like, unless otherwise specified, the off-state current refers to the current that occurs when a transistor is off. This refers to the drain current when the device is in a non-conducting state (also called a cut-off state). Unless otherwise specified, for n-channel transistors, V is the voltage between the gate and source When gs is lower than the threshold voltage Vth, the gate and This refers to a state in which the voltage Vgs between the n-channel transistors is higher than the threshold voltage Vth. The off-state current of a transistor is the voltage between the gate and source, Vgs, that is, the threshold voltage, Vt This may refer to the drain current when it is lower than h.

[0035] The off-state current of a transistor may depend on Vgs. The off-state current is I or less if there exists a Vgs value at which the off-state current of the transistor is I or less. The off-state current of a transistor is the current that flows through it in the off-state at a given Vgs. , an off-state at Vgs within a given range or a sufficiently reduced off-current is obtained. In some cases, it may refer to the off-state current at Vgs.

[0036] As an example, when the threshold voltage Vth is 0.5V and Vgs is 0.5V, The current is 1×10 -9 A, and the drain current at Vgs of 0.1 V is 1×10 -1 3 A, and the drain current at Vgs -0.5 V is 1×10 -19 A and Vg The drain current at s = -0.8 V is 1 × 10 -22 A n-channel transistor The drain current of the transistor is as follows when Vgs is -0.5V: , or 1×10 when Vgs is in the range of -0.5V to -0.8V -19 After A Therefore, the off-current of the transistor is 1×10 -19 If you say it is less than or equal to A The drain current of the transistor is 1×10 -22 There exists a Vgs below A. Therefore, the off-state current of the transistor is 1×10 -22 It may be said that it is below A. .

[0037] In this specification, the off-state current of a transistor having a channel width W is expressed as It is sometimes expressed as the current value that flows per watt. Also, for a given channel width (for example, 1 μm), In the latter case, the unit of the off-state current is current / length. It may be expressed in units with an element (e.g., A / μm).

[0038] The off-state current of a transistor may depend on temperature. Unless otherwise specified, the operating temperature is room temperature, 60°C, 85°C, 95°C, or 125°C. Or, the reliability of a semiconductor device including the transistor may be guaranteed. The temperature at which the transistor is certified, or the temperature at which a semiconductor device or the like that contains the transistor is used (e.g. For example, the off-state current at a temperature between 5°C and 35°C. The off-state current of the transistor is I or less at room temperature, 60°C, 85°C, 95°C, 125°C, The temperature at which the reliability of a semiconductor device that includes a transistor is guaranteed, or the temperature at which the transistor At temperatures in which semiconductor devices containing the above are used (for example, temperatures between 5°C and 35°C), This may refer to the existence of a Vgs value at which the off-state current of a transistor in a semiconductor device is equal to or less than I. .

[0039] The off-state current of a transistor may depend on the voltage Vds between the drain and source In this specification, unless otherwise specified, the off-state current is measured when Vds is 0.1 V, 0.8 V, 1V, 1.2V, 1.8V, 2.5V, 3V, 3.3V, 10V, 12V, 16V, or In some cases, it indicates the off-state current at 20 V. In other cases, it indicates the off-state current at 20 V. Vds that guarantees the reliability of semiconductor devices, or semiconductor devices including the transistor The term may refer to the off-state current at Vds used in the transistor off-state. The current is equal to or less than I when Vds is 0.1V, 0.8V, 1V, 1.2V, 1.8V, 2.5V, 3V, 3.3V, 10V, 12V, 16V, 20V, transistors included Vds that guarantees the reliability of the semiconductor device, etc., in which the transistor is included, or The off-state current of a transistor at Vds used in semiconductor devices is I or less. This may refer to the existence of a Vgs value.

[0040] In the above description of the off-state current, the drain may be read as the source. The current may also refer to the current through the source when the transistor is in the off state.

[0041] In this specification and the like, the term "leak current" may be used to mean the same thing as the "off current." In this specification, the off-state current refers to, for example, the current flowing when a transistor is in an off state. , may refer to the current flowing between the source and drain.

[0042] Voltage refers to the potential difference between two points, and potential refers to the electrostatic field at a certain point. This refers to the electrostatic energy (electrical potential energy) possessed by a unit charge in a particle. Generally, the potential difference between a potential at a certain point and a reference potential (for example, ground potential) This is simply called potential or voltage, and potential and voltage are often used synonymously. Therefore, in this specification, unless otherwise specified, potential may be read as voltage. In this specification, voltage may be read as potential.

[0043] (Embodiment 1) In this embodiment, a back gate of a transistor included in a pixel circuit is electrically connected to FIG. 1 shows a display device having a function of controlling display by applying a signal from a scanning line. This will be explained with reference to Figures 1 to 6.

[0044] FIG. 1 shows an example of the configuration of a pixel circuit 710C(i,j). FIG. 2 shows a block diagram of one of the pixel circuits of the display unit 120 of the display device 10 shown in FIG. The display unit 120 has m (m is 1 or more) display circuits in the row direction. In the column direction, n (n is an integer greater than or equal to 1) pixel circuits are arranged in a matrix. Here, i is an integer between 1 and m, and j is an integer between 1 and n.

[0045] The pixel circuit 710C(i,j) includes a light-emitting element 710(i,j). As an example, light emitting element 710(i,j) is preferably a light emitting element driven by DC. The gradation of the pixel is controlled by a signal corresponding to a voltage or current.

[0046] The pixel circuit 710C(i,j) includes a transistor SW1, a transistor M, and a capacitance element Cs , and light emitting element 710(i,j).

[0047] The light-emitting element 710(i,j) is made up of a pixel electrode, a counter electrode, and an organic light-emitting device sandwiched between them. A light-emitting element having a compound layer. The pixel electrode is either an anode or a cathode. The counter electrode is either an anode or a cathode. The organic compound layer includes a light-emitting layer.

[0048] The gate of the transistor SW1 of the pixel circuit 710C(i,j) is connected to the scanning line G1(i). Either the source or the drain of the transistor SW1 is electrically connected to the signal line S(j). The other of the source and the drain of the transistor SW1 is electrically connected to a capacitance element One electrode of Cs and the gate of transistor M are electrically connected.

[0049] The drain of the transistor M is electrically connected to a pixel electrode. The source of the transistor M is connected to the counter electrode via the Cat The Cath terminal is electrically connected to the other electrode of the capacitance element Cs. The back gate of the transistor M is electrically connected to the scanning line G2(i). The pair of gates of the transistor M overlap each other with a channel forming region therebetween. It is preferable that the region has the following structure.

[0050] The source of the transistor M is supplied with a cathode voltage via the Cath terminal. An anode voltage is applied to the electrode via the Ano terminal.

[0051] An example is shown in which the other electrode of the capacitance element Cs is electrically connected to the source of the transistor M. However, it may be electrically connected to the drain, or may be electrically connected to a wiring or electrode to which another voltage is applied. The terminating resistor may be connected to the

[0052] The light emitting element 710(i,j) is driven by the voltage of the signal provided from the signal line S(j). The current is controlled. The magnitude of the driving current indicates the gray level of the light emitting element 710(i,j). .

[0053] The display device 10 shown in FIG. 2 includes a gate driver 110 and a display unit 120. The shift driver 110 includes a shift register circuit 111 and a shift register circuit 112. The display unit 120 includes pixel circuits 710C(1,1) to 710C(m,n). do.

[0054] The display unit 120 described in this embodiment includes pixel circuits 710C(1,1) to 7 10C(m,n), the first scanning lines G1(1) to G1(m), and the second scanning line G2(1 ) through G2(m) and signal lines S(1) through S(n).

[0055] FIG. 3A shows a transistor M included in the pixel circuit 710C(i,j). To measure the electrical characteristics of transistor M, the voltage conditions applied to each terminal of transistor M are The conditions are shown in Table 1.

[0056] The VG terminal (hereinafter referred to as VG) is electrically connected to the gate of the transistor M. The VS terminal (hereafter referred to as VS) is electrically connected to the source, and the The VD terminal (hereafter referred to as VD) is connected, and the back gate is electrically connected to This is the VBG terminal (hereinafter referred to as VBG).

[0057] The electrical characteristics of P1 to P4 shown in FIG. 3B were measured by applying different voltages to VBG. The results are shown.

[0058] [Table 1]

[0059] Here, the measurement was performed while changing the gate voltage applied between the gate and source. The current flowing between the drain and the transistor was measured as the drain current ID. This is called DVG measurement or VGID measurement.

[0060] The measured transistor has an oxide semiconductor in the semiconductor layer, a channel length of 4 μm, The channel width is 50 μm.

[0061] P1 is the electrical characteristic when a voltage of 0V is applied to VBG. When VG becomes 0V The drain current ID of the transistor is below the measurement limit. This is because the oxide in the channel of the transistor The characteristics shown are those when a semiconductor is used.

[0062] Here, the measurement lower limit is 1×10 -12 A or less. IDVG measurements are performed using Agilent Semiconductor Parameter Analyzer Analyzer, model: 4155C) was used.

[0063] P2 is the electrical characteristic when a voltage of -5V is applied to VBG. The drain current ID is shifted to the positive side, and the VG voltage at which the drain current ID falls below the measurement limit is shifted to the positive side. This shows that the threshold voltage of the transistor is shifted in the positive direction. This shows that

[0064] P3 is the electrical characteristic when a voltage of 5V is applied to VBG. The electrical characteristic of P1 is negative. The voltage of VG at which the drain current ID falls below the lower limit of measurement is shifted to the negative side. This shows that the threshold voltage of the transistor is shifted to the negative shift. This indicates that the device has been frozen.

[0065] P4 is the electrical characteristic when a voltage of 10V is applied to VBG. Compared to P3, the electrical characteristic The voltage of VG at which the drain current ID falls below the lower limit of measurement is This shows that the voltage is shifting further to the negative side. This indicates that the threshold voltage has further shifted negatively.

[0066] FIG. 4 shows a timing chart of the display device 10 using the transistors described in FIG. The gate driver 110 generates two start pulses: start pulse SP1 and start pulse SP2. The input signal controls pixel circuit 710C(i,j).

[0067] A start pulse SP1 signal is given to a shift register circuit 111. The data circuit 111 outputs a signal to control the scanning line G1(1), and sequentially outputs the scanning lines G1(2) and Select G1(m).

[0068] A start pulse SP2 signal is given to the shift register circuit 112. The timing circuit 112 outputs a signal to control the scanning line G2(1), and sequentially controls the scanning lines G2(2) and Select G2(m).

[0069] The signal of the scanning line G1 selected by the start pulse SP1 is input to the pixel circuit 710C(i, is provided to the gate of transistor SW1 of signal line S(j), The voltage of the signal thus obtained is applied to the gate of transistor M. In response to the voltage applied to the light emitting element 710(i,j), the light emitting element 710(i,j) emits light.

[0070] A voltage equal to or higher than the source voltage of transistor M is applied to the back gate of transistor M. The threshold voltage of the transistor M shifts to the negative side, increasing the current. Therefore, the voltage of the signal applied by the signal line S(j) can be reduced. T1 shown in Fig. 4 indicates a period during which light-emitting element 710(i,j) emits light.

[0071] The signal of the scanning line G2 selected by the start pulse SP2 is input to the pixel circuit 710C(i, j) is applied to the back gate of transistor M, thereby changing the electrical characteristics of transistor M. It can be shifted.

[0072] A voltage smaller than the source voltage of transistor M is applied to the back gate of transistor M. By providing the current, the current flowing through the light emitting element 710(i,j) is reduced to a current value that does not contribute to light emission. Therefore, the light emission period can be controlled by the voltage applied to the back gate. During the period T2, the light emitting element 710(i,j) is turned on by the signal of the scanning line G2. Indicates the period when the light is off.

[0073] The voltage applied to the back gate of the transistor depends on the electrical characteristics of the light emitting element 710(i, j). Therefore, since the voltages differ, an optimum voltage is applied according to the characteristics of the light emitting element.

[0074] 5(A) and 5(B) will be described. FIG. 5(A) shows a start pulse SP1 The following shows an example of the display when a signal with the same pulse width is given to the start pulse SP2 and the G 1(i) updates the display. The same time that the next scan line G1(i+1) is selected At this timing, the signal at G2(i) goes to a voltage that is less than the voltage at the source of transistor M. The area selected in G1(i) that was illuminating is turned off.

[0075] FIG. 5(B) shows the display when driven according to the timing chart shown in FIG. ) is generated in the display area corresponding to the scanning lines G1(i), G1(i-1) and G1(i-2). The light is on during certain periods, and off during other periods. The light is explicitly indicated by hatching. When hold-type driving is performed, the display of the pixel circuit selected by the scanning line is updated. The light emitting element emits light for one frame period. By this, the display can be updated as a line-sequential impulse type drive.

[0076] Therefore, the period during which the light emitting element emits light and displays is controlled by the start pulse SP2. By making the width of the start pulse SP2 signal variable, it is possible to display it like a video. When the movement is fast, the video resolution can be improved by shortening the light emission period. In addition, when there is little movement in the display, such as a still image, the light emission period is extended and the light emission brightness is suppressed. Therefore, the power consumption can be reduced. Line-sequential impulse drive has a longer light emission period than point-sequential impulse drive. This increases the integrated brightness, reducing flickering and improving visibility. .

[0077] In addition, the start pulse SP2 is detected by the battery monitor of the mobile device. The pulse width may be determined according to the state. Figure 5(A) has a longer light emission period than Figure 5(B). Therefore, to achieve the same display quality, the signal line S(j) should be adjusted taking into account the integrated luminance. To reduce power consumption, the signal must be at a low voltage. It is desirable to set the width of the start pulse SP2 signal according to the charging status of the battery. Optimization can reduce power consumption and provide optimal display quality.

[0078] On a display device that displays 60 frames per second, consecutive frames are intentionally displayed black. One method to improve video resolution is to insert a black frame. When inserting a frame, the number of frames displayed per second should be 60 to maintain display quality. It needs to be more than the frame.

[0079] By using the pixel circuit in Figure 1, it is possible to control the light-on and off periods within one frame period. Therefore, the display can be controlled as a line-sequential impulse type drive. By improving the video resolution with impulse-type driving, visibility can be improved. .

[0080] In addition, transistors, capacitance elements, etc. used in the display device 10 described in this embodiment There are no particular restrictions on the device structure of each element. Select a device structure suitable for each function of C(i,j) and the gate driver 110. For example, the device structure of a transistor can be a top gate type, a bottom gate type, or front gate type, dual gate type with both gate (front gate) and bottom gate, and multi-gate types having multiple gate electrodes for one semiconductor layer. The type of semiconductor (composition, crystal structure, etc.) that constitutes the active layer (channel formation region) of the transistor There are no particular restrictions on the type of semiconductor used in the active layer. Non-single crystals include polycrystalline semiconductors, microcrystalline semiconductors, and amorphous semiconductors. Semiconductor materials include semiconductors containing one or more group 14 elements such as Si, Ge, and C. Conductors (e.g., silicon, silicon germanium, silicon carbide, etc.), oxide semiconductors, nitrides Examples of the semiconductor include compound semiconductors such as gallium nitride.

[0081] The pixel circuit 710C(i,j) in FIG. 1 is an example in which transistors of the same conductivity type are used. Here, the transistor SW1 and the transistor M are n-channel transistors. The transistor is an example in which an oxide semiconductor is used for the semiconductor layer. The transistor SW1 is a bottom-gate transistor, and the transistor M is a back-gate transistor. The transistor is a dual-gate transistor having a gate.

[0082] Note that one aspect of the present invention is not limited to the circuit configuration of the pixel circuit 710C(i,j) in FIG. 6A to 6D show examples of the circuit configuration of a pixel circuit 710C(i,j) different from that shown in FIG. As illustrated in the figure.

[0083] The difference between FIG. 6(A) and FIG. 1 will be described. The source of the transistor M is connected to a pixel electrode. The pixel electrode is electrically connected to the counter electrode via the light emitting element 710(i,j). The drain of the transistor M is electrically connected to the Ano terminal. The other electrode of the capacitance element Cs is electrically connected to the gate of the transistor M. The electrode of the transistor M is electrically connected to the source, but not to the drain. This is also fine.

[0084] The difference between FIG. 6B and FIG. 1 will be described. The active layer of the transistor M1 is of p-type conductivity. It is composed of:

[0085] The difference between FIG. 6C and FIG. 6A is that the active layer of the transistor M1 is a p-type One electrode of the capacitance element Cs is electrically connected to the gate of the transistor M1. The other electrode is electrically connected to the source of the transistor M1. may be electrically connected to the drain. When connected to the source, the transistor M The voltage applied to the source of transistor M1 is applied from the Ano terminal. Therefore, it is easy to control the voltage between the source and gate.

[0086] The pixel circuit 710C(i,j) in FIG. 6D further includes a scanning line G3(i) and a transistor The gate of the transistor SW2 is connected to the scanning line G3 (i ) is electrically connected to

[0087] The voltage applied to the VR terminal is based on the voltage applied to the Cath terminal. It is preferable that the voltage range of transistor SW10(i,j) is such that the transistor SW10(i,j) does not emit light. Before or at the same time that a signal is applied to the gate of transistor M via 1, A voltage is applied from the VR terminal to the source of the transistor M via the switch SW2. The voltage applied to the source of transistor M is given from the VR terminal, so the source of transistor M It is easy to control the voltage between the source and gate.

[0088] The structures and methods described in this embodiment mode may be appropriately combined with the structures and methods described in other embodiment modes. They can be used in combination.

[0089] (Embodiment 2) In this embodiment, as an example of a semiconductor device, an IC chip, an electronic component, an electronic device, etc. I will explain this in more detail.

[0090] <Examples of how to manufacture electronic components> FIG. 7A is a flow chart showing an example of a method for manufacturing an electronic component. This electronic component is also called a body package or an IC package. There are multiple standards and names for terminals depending on their shapes. An example will be described.

[0091] Semiconductor devices made up of transistors are assembled on a printed circuit board through a post-assembly process. The plate is completed by assembling multiple detachable parts. The post-process is shown in Figure 7(A). Specifically, the element substrate obtained in the previous process is After the completion of the step ST61, the back surface of the substrate is ground. This reduces warping of the board during the previous process and allows for the miniaturization of parts. Then, a dicing process is performed to separate the semiconductor device into individual chips (step ST62).

[0092] FIG. 7B is a top view of the semiconductor wafer 6100 before the dicing process is performed. 7C is a partially enlarged view of FIG. 7B. The semiconductor wafer 6100 has a plurality of circuits. A region 6102 is provided. In the circuit region 6102, a semiconductor device according to an embodiment of the present invention is provided. (e.g., memory, timer, CPU, etc.).

[0093] Each of the multiple circuit regions 6102 is surrounded by an isolation region 6104. A separation line (also called a "dicing line") 6106 is set at a position overlapping with 104. In the dicing process (step ST62), the semiconductor wafer 610 is cut along the separation line 6106. 6, a chip 6110 including a circuit region 6102 is cut from the semiconductor wafer 6100. An enlarged view of the chip 6110 is shown in FIG.

[0094] A conductive layer or a semiconductor layer may be provided in the separation region 6104. By providing a conductor layer, ESD that may occur during the dicing process is mitigated, This can prevent the decrease in yield caused by the chips. For the purpose of cooling, removing shavings, preventing static electricity, etc., carbon dioxide gas is dissolved to lower the resistivity. The cutting is performed while supplying the pure water to the cutting part. This reduces the amount of pure water used, thereby reducing the production cost of semiconductor devices. In addition, the productivity of the semiconductor device can be improved.

[0095] After step ST62, the separated chips are picked up individually and then Then, a die bonding process is performed in which the semiconductor device is mounted on a die and bonded to the die (step ST63). The method for bonding the chip to the lead frame in the bonding process should be selected according to the product. For example, the bonding can be performed using resin or tape. The die bonding process is as follows: The chip may be mounted on the interposer and bonded. The leads of the frame and the electrodes on the chip are electrically connected with thin metal wires. Step ST64). Silver wire or gold wire can be used as the thin metal wire. The bonding may be either ball bonding or wedge bonding.

[0096] The wire-bonded chip is sealed with epoxy resin, etc., in a molding process. The molding process is performed (step ST65). The inside of the electronic component is filled with resin. This reduces damage to the built-in circuitry and wires caused by external mechanical forces. This also reduces the deterioration of characteristics due to moisture and dust. The leads are then plated. Then the leads are cut and shaped (step ST66). The plating process prevents the leads from rusting, making it easier to solder when mounting the leads to a printed circuit board later. This can be done reliably. The surface of the package is printed (marked) (step After the inspection process (step ST68), the electronic components are completed (step ST 69) By incorporating the semiconductor device according to the above-mentioned embodiment, a small-sized electronic device with low power consumption can be realized. Parts can be provided.

[0097] A perspective schematic diagram of the completed electronic component is shown in FIG. 7(E). In FIG. 7(E), As an example, a perspective schematic diagram of a QFP (Quad Flat Package) is shown. As shown in FIG. 7(E), the electronic component 6000 has leads 6001 and a chip 6110. do.

[0098] The electronic component 6000 is mounted on, for example, a printed circuit board 6002. 6000 are combined together and each is electrically connected on a printed circuit board 6002. The completed circuit board 6004 can be mounted on an electronic device. By mounting the electronic component 6000, the power consumption of the electronic device can be reduced. Alternatively, it becomes easier to miniaturize electronic devices.

[0099] (Embodiment 3) In this embodiment, a more specific example of a structure of the display panel shown in the above embodiment will be described. The description will be given with reference to FIG. 8 to FIG. 12. In this embodiment, as an example of a display panel, A display panel using a liquid crystal element and a display panel using a light-emitting element will be described.

[0100] 8A to 8C are top views showing configuration examples of a display panel.

[0101] In FIG. 8A, a pixel portion 402 provided on a first substrate 4001 is surrounded by a A sealant 4005 is provided, and the pixel portion 402 is formed by bonding the sealant 4005 and the second substrate 4 8A, the seal on the first substrate 4001 is In a region different from the region surrounded by the material 4005, a single crystal is formed on a separately prepared substrate. A signal line driving circuit 400 and a scanning line driving circuit 40 made of a semiconductor or a polycrystalline semiconductor. 1. Also, a signal line driver circuit 400, a scanning line driver circuit 401, or a pixel Various signals and potentials are applied to the unit 402 via a flexible printed circuit (FPC). The power supply is supplied from FPC4018b and FPC4018c.

[0102] In FIG. 8B and FIG. 8C, the pixel portion 40 is provided on the first substrate 4001. A sealant 4005 is provided so as to surround the gate electrode 2 and the scanning line driver circuit 401 . In addition, a second substrate 4006 is provided on the pixel portion 402 and the scanning line driver circuit 401. Therefore, the pixel portion 402 and the scanning line driver circuit 401 are formed by the first substrate 4001 and the sealant 4002. The display element is sealed by the second substrate 4005 and the second substrate 4006. In FIG. 8C, the first substrate 4001 is surrounded by a sealant 4005. A single crystal semiconductor or polycrystalline semiconductor is formed on a separately prepared substrate in a region different from the region where the In FIG. 8B and FIG. 8C, a signal line driving circuit 400 is provided. are applied to the signal line driver circuit 400, the scanning line driver circuit 401, or the pixel portion 402. The seed signals and potentials are supplied by the FPC4018.

[0103] 8B and 8C show a signal line driving circuit 400 including an IC or the like, This shows an example in which a circuit formed in a process different from that of 402 is provided on a first substrate 4001. However, the present invention is not limited to this configuration. The scanning line driver circuit 401 may be formed of an IC or the like, or may be formed of a signal Only a part of the scanning line driving circuit 400 or a part of the scanning line driving circuit 401 is formed by an IC or the like. It may be provided.

[0104] The method of connecting the drive circuit formed by ICs, etc. is not particularly limited, and may be wired. Yarbonding, COG (Chip On Glass), TCP (Tape Car Rier Package), COF (Chip On Film), etc. can be used. FIG. 8A shows a signal line driving circuit 400 and a scanning line driving circuit 401 that are set up using COG. FIG. 8B is an example in which a signal line driver circuit 400 is provided by a COG. FIG. 8C shows an example in which a signal line driving circuit 400 is provided using TCP.

[0105] When the signal line driving circuit 400 is formed by ICs, the number of ICs is not limited to one, but may be multiple ICs. The signal line driver circuit 400 may be formed by an IC. In this case, the number of ICs is not limited to one, and the scanning line driving circuit 401 may be configured with multiple ICs. In Fig. 9A, as an example, the signal line driver circuit 400 is configured with six ICs. By configuring a signal line driver circuit with multiple ICs, it is possible to respond to high-definition of the pixel portion 402. can be done.

[0106] The scanning line driver circuit 401 may be provided on both the left and right ends of the pixel portion 402. When the scanning line driving circuit 401a and the scanning line driving circuit 401b are provided on both ends of the element portion 402 This is a configuration example.

[0107] The signal line driver circuit 400 may be provided on both the upper and lower ends of the pixel portion 402. A signal line driver circuit 400a and a signal line driver circuit 400b are provided at both the upper and lower ends of the pixel section 402. This is a configuration example for the case where each signal line driver circuit is composed of six ICs. FIG. 10(A) and FIG. 10(B) are cross-sectional views of the area indicated by the dashed line N1-N2 in FIG. 8(B). FIG.

[0108] The display panel shown in FIG. 10(A) and FIG. 10(B) has an electrode 4015. 4015 is electrically connected to the terminal of FPC 4018 via anisotropic conductive layer 4019. The electrode 4015 is also formed by insulating layers 4110, 4111, and 4112. The electrode 4015 is electrically connected to the wiring 4014 through an opening formed in the electrode 4015. is formed from the same conductive layer as the first electrode layer 4030.

[0109] The pixel portion 402 and the scanning line driver circuit 401 provided on the first substrate 4001 are In FIG. 10(A) and FIG. 10(B), the pixel portion 402 includes a a transistor 4010 included in the scanning line driver circuit 401; In FIG. 10A, a transistor 4010 and a transistor 4011 are illustrated. In FIG. 10B, an insulating layer 4112 is provided on the insulating layer 4112. 0 is formed.

[0110] The transistor 4010 and the transistor 4011 are provided over an insulating layer 4102. The transistor 4010 and the transistor 4011 are formed by insulating layers 410. 2, and an insulating layer 4103 is formed on the electrode 517. A semiconductor layer 512 is formed on the insulating layer 4103. An electrode 510 and a and an electrode 511 are formed, and an insulating layer 4110 and an insulating A layer 4111 is formed, and an electrode 516 is formed on the insulating layer 4110 and the insulating layer 4111. The electrode 510 and the electrode 511 are formed from the same conductive layer as the wiring 4014.

[0111] In the transistor 4010 and the transistor 4011, the electrode 517 is a gate electrode. The electrode 510 functions as either a source electrode or a drain electrode. The electrode 511 serves as the other of the source electrode and the drain electrode, and the electrode 51 The reference numeral 6 functions as a back gate electrode.

[0112] The transistor 4010 and the transistor 4011 are bottom gate structures, and By providing a back gate, the on-state current can be increased. The threshold value can be controlled.

[0113] In the transistor 4010 and the transistor 4011, the semiconductor layer 512 is a channel The semiconductor layer 512 has a function as a region for forming a hole. Silicon, amorphous silicon, oxide semiconductors, organic semiconductors, etc. may be used. In order to increase the conductivity of the semiconductor layer 512 or to control the threshold voltage of a transistor, For this purpose, an impurity may be introduced into the semiconductor layer 512.

[0114] When an oxide semiconductor is used as the semiconductor layer 512, the semiconductor layer 512 is formed of indium (In When the semiconductor layer 512 is an oxide semiconductor containing indium, The layer 512 has high carrier mobility (electron mobility).

[0115] However, the semiconductor layer 512 is not limited to an oxide semiconductor containing indium. 512 does not contain indium, such as zinc tin oxide, gallium tin oxide, etc. Oxide semiconductors containing zinc, oxide semiconductors containing gallium, oxide semiconductors containing tin, etc. An example of the oxide semiconductor will be described in detail in Embodiment 6. do.

[0116] The display panel shown in FIG. 10(A) and FIG. 10(B) includes a capacitor 4020. The capacitor 4020 is formed in a region where the electrode 511 and the electrode 4021 overlap with each other with the insulating layer 4103 interposed therebetween. The electrode 4021 is formed of the same conductive layer as the electrode 517.

[0117] FIG. 10A shows an example of a liquid crystal display panel using liquid crystal elements as display elements. In FIG. 1(A), a liquid crystal element 4013 which is a display element has a first electrode layer 4030 and a second The liquid crystal layer 4008 is sandwiched between an electrode layer 4031 and a liquid crystal layer 4008. An insulating layer 4032 and an insulating layer 4033 functioning as an alignment film are provided. 4031 is provided on the second substrate 4006 side, and the first electrode layer 4030 and the second electrode layer 40 31 is superimposed via a liquid crystal layer 4008.

[0118] The spacer 4035 is a columnar spacer obtained by selectively etching an insulating layer. The distance (cell gap) between the first electrode layer 4030 and the second electrode layer 4031 is controlled. A spherical spacer may also be used.

[0119] When liquid crystal elements are used as display elements, thermotropic liquid crystal, low molecular weight liquid crystal, high molecular weight liquid crystal, etc. Liquid crystal, polymer dispersed liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, etc. can be used. These liquid crystal materials can exhibit cholesteric, smectic, cubic, and chromatic phases depending on the conditions. It shows an isotropic phase, an isotropic phase, etc.

[0120] Also, liquid crystals exhibiting a blue phase without using an alignment film may be used. The blue phase is one of the liquid crystal phases. When the temperature of a cholesteric liquid crystal is increased, the cholesteric The blue phase appears just before the transition from the crystalline phase to the isotropic phase. In order to improve the temperature range, a liquid crystal composition containing 5% by weight or more of chiral agent is used. The liquid crystal composition containing the liquid crystal exhibiting the blue phase and the chiral agent has a high response speed. The time required for alignment is as short as 1 msec or less, and since the liquid crystal display is optically isotropic, alignment treatment is not required. The viewing angle dependency is small. In addition, since there is no need to provide an alignment film, rubbing treatment is also unnecessary. Therefore, electrostatic damage caused by the rubbing process can be prevented, and This reduces defects and damage to the liquid crystal display panel, thereby improving the productivity of the liquid crystal display panel. It is possible to improve it.

[0121] In addition, a pixel is divided into several regions (subpixels), each of which is illuminated in a different direction. This is called multi-domain or multi-domain design, which is designed to defeat molecules in a complex manner. The following method can be used.

[0122] The specific resistance of the liquid crystal material is 1×109 Ω cm or more, preferably 1×10 1 1 Ω cm or more, and more preferably 1×10 12 Ω·cm or more. The specific resistance values ​​specified in the specification are those measured at 20°C.

[0123] When an oxide semiconductor transistor is used as the transistor 4010, the transistor 401 0 can reduce the current value in the off state (off current value). This allows the retention time of electrical signals such as the EEPROM to be extended, and the write interval can be extended when the power is on. This allows the frequency of refresh operations to be reduced, resulting in reduced power consumption. This has the effect of suppressing the above.

[0124] In addition, in the display panel, a black matrix (light-shielding layer), a polarizing member, a retardation member, An optical member (optical substrate) such as an anti-reflection member may be provided as appropriate. For example, a polarizing substrate and A circularly polarized light by a retardation substrate may be used. Alternatively, threads or the like may be used.

[0125] FIG. 10B shows an example of a display panel using light-emitting elements such as EL elements as display elements. EL elements are divided into organic EL elements and inorganic EL elements.

[0126] When a voltage is applied to an organic EL element, electrons flow from one electrode and positive electrons flow from the other electrode. The holes are injected into the EL layer, respectively. Then, the carriers (electrons and holes) recombine. By this, the light-emitting organic compound forms an excited state, and the excited state returns to the ground state. Due to this mechanism, this type of light-emitting device is a current-excited type of light-emitting device. In addition to the light-emitting compound, the EL layer also contains a material with high hole injection properties, A material with high transport properties, a hole blocking material, a material with high electron transport properties, a material with high electron injecting properties, or bipolar substances (substances with high electron transport and hole transport properties) The EL layer may be formed by deposition (including vacuum deposition), transfer, printing, inkjet, or the like. It can be formed by a coating method or the like.

[0127] Inorganic EL elements are classified into dispersion type inorganic EL elements and thin film type inorganic EL elements depending on the element structure. Dispersion-type inorganic EL elements have a light-emitting layer in which particles of light-emitting material are dispersed in a binder. The emission mechanism is a donor-based ion exchange reaction that utilizes the donor and acceptor levels. This is an acceptor recombination type emission. Thin-film inorganic EL elements sandwich the light-emitting layer between dielectric layers. The structure is sandwiched between electrodes, and the light emission mechanism is the inner shell electron transition of metal ions. It is a localized emission that is utilized.

[0128] FIG. 10B illustrates an example in which an organic EL element is used as the light-emitting element 4513.

[0129] In FIG. 10B, a light-emitting element 4513 is a transistor provided in the pixel portion 402. The light-emitting element 4513 is electrically connected to the first electrode layer 403. 0, a light-emitting layer 4511, and a second electrode layer 4031. However, the present invention is not limited to this structure. The structure of the light emitting element 4513 is determined according to the direction of light extracted from the light emitting element 4513. It can be changed as appropriate.

[0130] The partition 4510 is formed using an organic insulating material or an inorganic insulating material. An opening is formed on the first electrode layer 4030 using a resin material, and the side of the opening is continuous. It is preferable to form the inclined surface so as to have a curvature.

[0131] The light-emitting layer 4511 may be composed of a single layer or a plurality of layers may be laminated. It doesn't matter whether it's

[0132] In order to prevent oxygen, hydrogen, moisture, carbon dioxide, and the like from entering the light-emitting element 4513, the second electrode A protective layer may be formed on the layer 4031 and the partition wall 4510. The protective layer may be silicon nitride. Con, silicon oxynitride, aluminum oxide, aluminum nitride, aluminum oxynitride , aluminum oxide nitride, DLC (Diamond-Like Carbon), etc. In addition, the first substrate 4001, the second substrate 4006, and the sealing material The space sealed by 4005 is sealed with a filler 4514. In order to prevent exposure to the outside air, a protective film (lamination) with high airtightness and low outgassing is used. It is possible to package (enclose) the product using a cover material (film, UV-curable resin film, etc.) preferable.

[0133] Filler 4514 can be inert gas such as nitrogen or argon, or ultraviolet curing resin. Or thermosetting resin can be used, such as PVC (polyvinyl chloride), acrylic resin, Polyimide, epoxy resin, silicone resin, PVB (polyvinyl butyral) or EV A (ethylene vinyl acetate) can be used. Also, the filler 4514 can be dried. A desiccant may also be included.

[0134] The sealing material 4005 is made of glass materials such as glass frit and two-liquid mixed resin. Use resin materials such as room temperature curing resin, photocuring resin, and thermosetting resin. Furthermore, the sealant 4005 may contain a desiccant.

[0135] 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. Optical films such as retardation plates (λ / 4 plates, λ / 2 plates), color filters, etc. may be installed as appropriate. In addition, the polarizing plate or the circular polarizing plate may be provided with an anti-reflection film. It is possible to apply an anti-glare treatment that can diffuse reflected light and reduce glare.

[0136] In addition, by making the light-emitting element a microcavity structure, it is possible to extract light with high color purity. In addition, by combining a microcavity structure with a color filter, This reduces interference and improves the visibility of the displayed image.

[0137] The first electrode layer 4030 and the second electrode layer 4031 are made of indium tungsten oxide. Oxide, indium zinc oxide with tungsten oxide, indium oxide with titanium oxide oxide, indium tin oxide, indium tin oxide with titanium oxide, indium zinc oxide A conductive material with light-transmitting properties, such as indium tin oxide doped with silicon oxide, is used. It is possible.

[0138] The first electrode layer 4030 and the second electrode layer 4031 are made of tungsten (W) and molybdenum (Mo). Mo, Zirconium (Zr), Hafnium (Hf), Vanadium (V), Niobium ( Nb), Tantalum (Ta), Chromium (Cr), Cobalt (Co), Nickel (Ni), Titanium (Ti), platinum (Pt), aluminum (Al), copper (Cu), silver (Ag) and other metals The metal may be formed by using one or more of the following metals: do.

[0139] The first electrode layer 4030 and the second electrode layer 4031 are made of a conductive polymer (conductive polymer). The conductive polymer may be a conductive composition containing a conductive polymer. For this purpose, a so-called π-electron conjugated conductive polymer can be used. For example, polyaniline or a derivative thereof, polypyrrole or a derivative thereof, polythiophene or a derivative thereof, Alternatively, a copolymer of two or more of aniline, pyrrole and thiophene or Derivatives and the like are included.

[0140] In order for the light emitting element 4513 to emit light to the outside, at least the first electrode layer 4030 or It is sufficient that one of the second electrode layers 4031 is transparent. There are two types of structures: top emission and bottom emission. The top emission structure is classified as a dual emission structure. This refers to the case where light is extracted from the surface (upper surface) opposite to the substrate on which the light emitting element is formed. The emission structure extracts light from the surface (bottom surface) of the substrate on which the transistors and light-emitting elements are formed. A double-sided emission structure is one in which light is emitted from both the top and bottom. For example, In the case of a top emission structure, the second electrode layer 4031 may be made transparent. In the case of a dual-side emission structure, the first electrode layer 4030 may be made transparent. The first electrode layer 4030 and the second electrode layer 4031 may be made transparent.

[0141] FIG. 11A shows a top view of the transistors 4011 and 4010 shown in FIG. FIG. 11B is a cross-sectional view showing a case where a gate-type transistor is provided. The transistors 4011 and 4010 shown in FIG. 10B are top-gate transistors. 13 shows a cross-sectional view in the case where a star is provided.

[0142] In the transistors 4010 and 4011 in FIG. 11(A) and (B), the electrode 517 is a gate. The electrode 510 functions as either a source electrode or a drain electrode. The electrode 511 functions as the other of the source electrode and the drain electrode.

[0143] For details of other components in Figs. 11(A) and (B), please refer to Figs. 10(A) and (B). Please refer to the description.

[0144] FIG. 12A illustrates the transistor 4011 and the transistor 401 shown in FIG. FIG. 10 is a cross-sectional view of the case where an electrode 516 functioning as a back gate is provided. 12B shows a transistor 4011 and a transistor 4021 shown in FIG. 10 shows a cross-sectional view in the case where an electrode 516 functioning as a back gate is provided.

[0145] The transistor 4010 and the transistor 4011 are top-gate and back-gate By having the above, the on-current can be increased. It is possible.

[0146] For details of other components in Figs. 12(A) and (B), please refer to Figs. 10(A) and (B). Please refer to the description.

[0147] (Embodiment 4) Next, application examples of a display module using the display panel shown in the above embodiment will be described. 13 will be used for explanation.

[0148] The display module 800 shown in FIG. 13 is provided between an upper cover 801 and a lower cover 802. , a touch panel 804 connected to an FPC 803, and a display panel connected to an FPC 805 806, a frame 809, a printed circuit board 810, and a battery 811. In some cases, the input / output terminal 811, the touch panel 804, etc. may not be provided.

[0149] The display panel described in the above embodiment can be used as the display panel 806 in FIG. This can be done.

[0150] The upper cover 801 and the lower cover 802 are connected to the touch panel 804 and the display panel 8 The shape and dimensions can be changed as appropriate to fit the size of 06.

[0151] The touch panel 804 is a resistive or capacitive touch panel. In addition, the display panel 806 may be used by overlapping it with the opposing substrate (sealing substrate). It is also possible to provide a touch panel function. It is also possible to provide an optical sensor in each pixel to make an optical touch panel. A touch sensor electrode is provided in each pixel of the display panel 806, forming a capacitive touch panel. In this case, the touch panel 804 may be omitted.

[0152] The top cover 801 may have a light path. The light emitted from the light source module passes through an optical path provided in the upper cover 801 and is Light is irradiated from one side of the cover and enters the optical path on another side different from the side that irradiates the light. The presence or absence of the light is detected by an optical sensor or an optical sensor module mounted on a printed circuit board 810. By making this judgment, it is also possible to detect whether the screen is being touched by a finger or pen. In this case, a touch panel is provided on the display panel 806 or on the opposing substrate of the display panel 806. It is also possible to omit the touch panel 804.

[0153] FIG. 14A shows a touch panel 804 using a mutual capacitance type touch sensor as an example. In FIG. 14(A), as an example, a pulse voltage is The given wiring CLx is six wirings X1-X6, and the wiring CLy that detects the change in current is Y The number of wires is not limited to six. FIG. 14A shows that the wiring CLx and the wiring CLy overlap each other, or Illustrated is a capacitive element 854 formed by arranging a line CLy and a wiring CLy in close proximity to each other.

[0154] The wiring CLx and the wiring CLy are electrically connected to the IC850. It includes a drive circuit 851 and a detection circuit 852 .

[0155] As an example, the driving circuit 851 applies a pulse voltage to the wirings X1 to X6 in order. When a pulse voltage is applied to the wirings X1 to X6, the capacitance element 854 An electric field is generated between the wiring CLx and the wiring CLy that form the A current flows through the capacitor 854. The electric field generated between these wirings is generated by touching with a finger or a pen. In other words, the capacitance of the capacitive element 854 changes depending on the touch of a finger or a pen. The capacitance value changes. In this way, the capacitance value changes when a finger or pen touches the By utilizing this, the proximity or contact of a detection object can be detected.

[0156] The detection circuit 852 detects the capacitance change in the capacitance element 854 and detects the capacitance change in the wirings Y1 to Y6. This is a circuit for detecting changes in current. The wiring from Y1 to Y6 detects the proximity or When there is no contact, the detected current value does not change, but when the object to be detected approaches or comes into contact with the object, When the capacitance value decreases, the change in the current value is detected. The total flow rate may be detected. In that case, an integrating circuit or the like may be used for detection. Alternatively, the peak value of the current may be detected. In that case, the current is converted into a voltage and the voltage value is The peak value of may be detected.

[0157] In FIG. 14A, a driving circuit 851 and a detection circuit 852 are formed in the same IC. However, each circuit may be formed in a different IC. On the other hand, the driving circuit 851 can be a source of noise. By forming the detection circuit 851 and the detection circuit 852 with different ICs, the malfunction of the detection circuit 852 is prevented. It is possible.

[0158] In addition, the driving circuit 851, the detection circuit 852, and the driving circuit of the display panel 806 are integrated into one I In that case, the cost of the IC in the entire display module can be reduced. It is possible.

[0159] In FIG. 14A, the IC 850 is disposed on the touch panel 804. 0 may be placed on the FPC 803. A schematic diagram of this case is shown in FIG.

[0160] Returning again to FIG.

[0161] The frame 809 has a function of protecting the display panel 806 and also a function of preventing the display panel 806 from being damaged by the operation of the printed circuit board 810. The frame also functions as an electromagnetic shield to block electromagnetic waves generated by the 09 may also function as a heat sink.

[0162] The printed circuit board 810 includes a power supply circuit, a signal circuit for outputting a video signal, and a clock signal. The touch panel may further include a light source and a light sensor for touch detection. The wavelength range of the light source is preferably greater than 780 nm, and greater than 1.6 μm. The optical sensor has a function of detecting light in the wavelength range of the light source. The power source for supplying the power may be an external commercial power source or a separately provided battery 81. The power source may be a commercial power source. The battery 811 may be omitted if a commercial power source is used. It is.

[0163] In addition, the display module 800 may include components such as a polarizing plate, a retardation plate, and a prism sheet. It may be added.

[0164] (Embodiment 5) In this embodiment, an electronic device and a lighting device according to one embodiment of the present invention will be described with reference to drawings. explain.

[0165] 15(A)-16(E) show examples of the configuration of electronic devices. The display unit of the electronic device of 16(C) may be a touch panel having a touch sensor. By using a touch panel, the display unit can also function as an input unit for electronic devices. Cut.

[0166] The information terminal 2010 shown in FIG. 15A includes a display unit 2012 incorporated in a housing 2011. In addition, operation buttons 2013, external connection port 2014, speaker 2015, microphone In this embodiment, the display area of ​​the display unit 2012 is curved. 2010 is a battery-powered portable information terminal, also known as a tablet information terminal or The information terminal 2010 can be used as a smartphone. It has functions such as a notebook, Internet connection, and music playback. You can also make calls, enter text, and display information. Various operations such as screen switching on the display unit 2012 can be performed by touching the display unit 2012 with a finger or the like. Also, by inputting a voice from the microphone 2016, the information terminal 20 The operation button 2013 can be used to turn the power on and off. Also, various operations such as screen switching on the display unit 2012 can be performed.

[0167] FIG. 15B shows an example of a wristwatch-type information terminal. The information terminal 2030 has a housing 2031. The watch has a display unit 2032, a crown 2033, a belt 2034, and a detection unit 2035. The information terminal 2030 can be operated by rotating the display unit 2033. By touching 2 with a finger, the information terminal 2030 can be operated.

[0168] The detection unit 2035 has a function of acquiring, for example, information on the usage environment and biological information. Microphone, image sensor, acceleration sensor, direction sensor, pressure sensor, temperature sensor, humidity sensor A detection unit 20 includes a sensor, an illumination sensor, a positioning sensor (for example, a GPS (Global Positioning System)), etc. It may also be provided at 35.

[0169] The information terminal 2010 and the information terminal 2030 are equipped with wireless communication devices of the same standard. Bidirectional communication may be performed by a signal 2020. For example, an information terminal 2010 may When an e-mail, a phone call, etc. arrives, the display unit 2032 of the information terminal 2030 notifies the user of the arrival of the e-mail, a phone call, etc. The information is displayed.

[0170] FIG. 15C shows an example of a glasses-type information terminal. The information terminal 2040 has a mounting part 2041. The battery 2046 includes a housing 2042, a cable 2045, a battery 2046, and a display unit 2047. The terminal 2046 is housed in the mounting portion 2041. The display portion 2047 is provided in the housing 2042. The housing 2042 contains a processor, a wireless communication device, a storage device, and various electronic components. The display unit 20 in the housing 2042 is connected to the battery 2046 via a cable 2045. Power is supplied to the display unit 2047 and electronic components. Various information such as images is displayed. The impulse driving by line sequence shown in the first embodiment is used. This provides improved video resolution and reduced power consumption while reducing flicker. It is possible.

[0171] Information terminals that communicate using wireless signals are subject to electromagnetic coupling due to the antennas used for communication. It has the function of generating energy using either the combined method, the electromagnetic induction method, or the radio wave method. It is possible.

[0172] A camera may be provided in the housing 2042. The camera can be used to record the movements of the user's eyes and eyelids. By detecting this, the information terminal 2040 can be operated.

[0173] The mounting part 2041 is equipped with various sensors such as a temperature sensor, a pressure sensor, an acceleration sensor, and a biosensor. For example, a biosensor may be provided to acquire biometric information of the user. For example, the information terminal 2010 may store the information in a storage device in the information terminal 2010 by a wireless signal 2021. The information terminal 2040 can perform two-way communication between the The biometric information is then transmitted to the information terminal 2010. The information terminal 2010 uses the received biometric information to Calculates the person's fatigue level, activity level, etc.

[0174] The notebook PC (personal computer) 2050 shown in FIG. 1, a display unit 2052, a keyboard 2053, and a pointing device 2054. The notebook PC 2050 can be operated by touching the display unit 2052 .

[0175] The video camera 2070 shown in FIG. 16B includes a housing 2071, a display unit 2072, and a housing 20 73, operation keys 2074, a lens 2075, and a connection part 2076. The display part 2072 is The operation keys 2074 and the lens 2075 are provided in the housing 2073. The housing 2071 and the housing 2073 are connected by a connection part 2076. The angle between the housing 2071 and the housing 2073 can be changed by the connection part 2076. The image of the display unit 2072 is changed according to the angle between the housing 2071 and the housing 2073 in the display unit 2076. The display unit 2072 may be configured to switch between different images. It is possible to perform various operations such as call and stop operations, zoom magnification adjustment, and change of shooting range.

[0176] The portable game machine 2110 shown in Fig. 16(C) includes a housing 2111, a display unit 2112, a speaker 2113, an LED lamp 2114, operation key buttons 2115, connection terminals 2116, a camera 2117, a microphone 2118, and a recording medium reading unit 2119.

[0177] The electric refrigerator 2150 shown in Fig. 16(D) includes a housing 2151, a refrigerator door 2152, and a freezer door 2153, etc.

[0178] The automobile 2170 shown in Fig. 16(E) includes a vehicle body 2171, wheels 2172, a dashboard 2173, and lights 2174, etc. The processor of Embodiment 2 is used for various processors in the automobile 21 70.

[0179] (Embodiment 6) <Configuration of CAC-OS> Hereinafter, the configuration of CAC (Charge-Aligned Composite)-OS that can be used for the transistor disclosed in one aspect of the present invention will be described.

[0180] CAC-OS is, for example, a structure in which the elements constituting the oxide semiconductor are unevenly distributed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 2 nm or less, or in the vicinity thereof. Hereinafter, in the oxide semiconductor, one or more metal elements are unevenly distributed, and the region having the metal element is mixed in a state of 0.5 nm or more and 10 nm or less, preferably 1 n m or more and 2 nm or less, or in the vicinity thereof, and this state is also referred to as a mosaic state or a patch state.

[0181] Note that the oxide semiconductor preferably contains at least indium. In addition to these, aluminum, gallium, iridium, and zinc are preferably included. tritium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, Germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium , tantalum, tungsten, magnesium, etc. It may be included.

[0182] For example, CAC-OS in In-Ga-Zn oxide (In- Ga-Zn oxide (which may be specifically referred to as CAC-IGZO) is an indium oxide (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 ) 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 are The material is separated into two parts, resulting in a mosaic-like shape, and the mosaic is a real number greater than 0. InO X1 , or In X2 Zinc Y2 O Z2 The structure in which the ions are uniformly distributed in the film (see below) (also called cloud-like).

[0183] In other words, CAC-OS is X3 The region where In is the main component and X2 Zinc Y2O Z2 , or InO X1 A composite oxide semiconductor having a structure in which a region in which In this specification, for example, the number of In atoms relative to the element M in the first region is The first region has a ratio of In to the element M that is greater than the atomic ratio of In to the element M in the second region. It is assumed that the concentration of In is higher than that of the second region.

[0184] IGZO is a common name and refers to a compound made of In, Ga, Zn, and O. A typical example is InGaO3(ZnO). m1 (m1 is a natural number), or In (1+x0) Ga (1-x0) O3(ZnO) m0 (-1≦x0≦1, m0 is an arbitrary number) Examples of the crystalline compound include those represented by the following formula:

[0185] The crystalline compound has a single crystal structure, a polycrystalline structure, or a CAAC structure. The CAAC structure is a structure in which multiple IGZO nanocrystals have a c-axis orientation and are aligned on the ab plane. In the case of ZnO, the crystal structure is non-oriented and connected.

[0186] On the other hand, CAC-OS refers to the material composition of an oxide semiconductor. In a material composition containing Ga, Zn, and O, some of the nanoparticles are mainly composed of Ga. The region where In is observed as a nanoparticle and the region where In is observed as a nanoparticle are mainly composed of In are shown in Fig. Therefore, in CAC-OS, The crystal structure is a secondary factor.

[0187] Note that CAC-OS does not include a laminated structure of two or more films with different compositions. For example, a structure consisting of two layers, one containing In as the main component and the other containing Ga as the main component, Not at all.

[0188] In addition, GaO X3 The region where In is the main component and X2 Zinc Y2 O Z2 , or InO X1 In some cases, it may be difficult to observe a clear boundary between the region in which the main component is

[0189] Instead of gallium, aluminum, yttrium, copper, vanadium, and beryllium are used. Aluminum, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium If it contains one or more metal elements selected from the group consisting of cadmium, ruthenium, etc., it is classified as CAC- The OS is observed to have nanoparticles in some areas mainly composed of the metal element, and in other areas containing In. The main component, nanoparticle-like regions, are randomly distributed in a mosaic pattern. This refers to a configuration in which

[0190] 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 The gas is selected from an inert gas (typically argon), oxygen gas, and nitrogen gas. One or more of these may be used. The lower the flow rate ratio of the gas, the more preferable. For example, the flow rate ratio of oxygen gas is preferably 0% or more and less than 30%. Or, it is preferable to set it to 0% or more and 10% or less.

[0191] CAC-OS is a method for measuring X-ray diffraction (XRD). When measured using the out-of-plane θ / 2θ scan, In other words, no clear peaks are observed in the measurement area from the X-ray diffraction. It can be seen that the orientation of the regions in the ab plane direction and the c-axis direction is not observed.

[0192] In addition, the CAC-OS uses an electron beam with a probe diameter of 1 nm (also called a nanobeam electron beam). In the electron beam diffraction pattern obtained by irradiating the sample with electrons, a ring-shaped region of high brightness and the Therefore, the electron diffraction pattern indicates that the CAC-OS The crystal structure has no orientation in the planar and cross-sectional directions. It can be seen that it has a crystal structure.

[0193] For example, in the CAC-OS of In-Ga-Zn oxide, the energy dispersive X Energy Dispersive X-ray spectroscopy (EDX) The EDX mapping obtained using scopy revealed that GaO X3 The area 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 a structure similar to that shown in FIG.

[0194] CAC-OS has a structure different from that of IGZO compounds in which metal elements are uniformly distributed. It has different properties from GZO compounds. That is, CAC-OS is GaO X3 The main components are and the region where In X2 Zinc Y2 O Z2 , or InOX1 The region where is the main component and the region where is The phase is gradually separated, and the regions each consisting of one element as a main component are arranged in a mosaic pattern.

[0195] Here, In X2 Zinc Y2 O Z2 , or InO X1 The area where GaO is the main component X This is a region with high conductivity compared to the region where In 3 is the main component. X2 Zinc Y2 O Z2 , or InO X1 The carriers flow through the area where the main component is oxygen. Therefore, the conductivity of In is expressed as a semiconductor. X2 Zinc Y2 O Z2 , or InO X1 The region where the main component is a metal is distributed in a cloud-like shape in the oxide semiconductor, which results in a high electric field efficiency. As a result, a high mobility (μ) can be achieved.

[0196] 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 etc. By distributing the region in which the main component is Switching operation can be achieved.

[0197] Therefore, when CAC-OS is used in a semiconductor device, GaO X3 Insulation and , In X2 Zinc Y2 O Z2 , or InO X1 The conductivity caused by the This results in a high on-state current (I on ), and high field-effect mobility (μ) can be done.

[0198] In addition, semiconductor devices using CAC-OS have high reliability. It is ideal for a variety of semiconductor devices including displays.

[0199] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination. [Explanation of symbols]

[0200] G1 scan line G2 scan line G3 scan line M1 Transistor S signal line SP1 Start pulse SP2 Start pulse SW1 Transistor SW2 transistor 10 Display device 110 Gate Driver 111 Shift register circuit 112 Shift Register Circuit 120 Display section 400 Signal line driver circuit 400a Signal line driver circuit 400b Signal line driver circuit 401 Scanning line driver circuit 401a Scanning line driving circuit 401b Scanning line driving circuit 402 Pixel section 510 electrode 511 Electrode 512 Semiconductor layer 516 Electrode 517 Electrode 710 Light emitting element 710C Pixel circuit 800 Display Module 801 Top cover 802 Lower cover 803 FPC 804 Touch Panel 805 FPC 806 Display Panel 809 Frames 810 Printed Circuit Board 811 Battery 850 IC 851 Drive circuit 852 Detection circuit 854 Capacitive element 2010 Information terminal 2011 Case 2012 Display section 2013 Operation button 2014 External connection port 2015 Speaker 2016 Microphone 2020 Wireless Signal 2021 Radio Signal 2030 Information terminal 2031 Case 2032 Display section 2033 Crown 2034 Belt 2035 Detection unit 2040 Information terminal 2041 Mounting part 2042 Case 2045 Cable 2046 Battery 2047 Display section 2051 Case 2052 Display section 2053 Keyboard 2054 Pointing Device 2070 Video Camera 2071 Case 2072 Display section 2073 Case 2074 Operation key 2075 Lens 2076 Connection 2110 Portable gaming machines 2111 Case 2112 Display section 2113 Speaker 2114 LED Lamp 2115 Operation key button 2116 Connection terminal 2117 Camera 2118 Microphone 2119 Recording medium reading unit 2150 Electric refrigerator-freezer 2151 Case 2152 Refrigerator door 2153 Freezer door 2170 Automobiles 2171 Body 2172 Wheel 2173 Dashboard 2174 Light 2050 Notebook PC 4001 Substrate 4005 Sealing material 4006 Substrate 4008 Liquid crystal layer 4010 Transistor 4011 Transistor 4013 Liquid crystal element 4014 Wiring 4015 Electrode 4018 FPC 4018b FPC 4019 Anisotropic conductive layer 4020 Capacitive element 4021 Electrode 4030 Electrode layer 4031 Electrode layer 4032 Insulation layer 4033 Insulation layer 4035 Spacer 4102 Insulating layer 4103 Insulating layer 4110 Insulating layer 4111 Insulating layer 4112 Insulating layer 4510 Bulkhead 4511 Light-emitting layer 4513 Light emitting element 4514 Filling material 6000 Electronic Components 6001 Lead 6002 Printed circuit board 6004 Circuit Board 6100 Semiconductor Wafers 6102 Circuit area 6104 Separation area 6106 Separation line 6110 Chip

Claims

[Claim 1] A plurality of pixels arranged in a matrix form, The pixel includes a first transistor, a second transistor, and a light-emitting element, one of a source and a drain of the first transistor is electrically connected to a signal line; the other of the source and the drain of the first transistor is electrically connected to a first gate of the second transistor; a gate of the first transistor electrically connected to a first scan line; one of a source and a drain of the second transistor is electrically connected to a first terminal; the other of the source and the drain of the second transistor is electrically connected to the light emitting element; a second gate of the second transistor is electrically connected to a second scan line; The plurality of pixels have a light emitting period during which the light emitting element emits light and a light-off period during which the light emitting element is turned off in one frame period, the off period is longer than the light-emitting period, a function of controlling lengths of the light-emitting period and the light-off period in a plurality of pixels included in any one row among the plurality of pixels by a potential applied to a second gate of the second transistor, during the light emission period, when an image signal is input to a first gate of the second transistor via the first transistor, a voltage higher than that of the first terminal is applied to the second scanning line, thereby shifting a threshold voltage of the second transistor in a direction in which a current flowing through the second transistor increases; A light-emitting device in which, when displaying a moving image, a first scanning line electrically connected to the one row is selected, and then, at the same timing as when another first scanning line is selected following the one first scanning line, a voltage lower than that of the first terminal is applied to a second scanning line electrically connected to the one row, thereby turning off a plurality of pixels included in the one row.

Images