Light-emitting device

Abstract

To provide driving method for a semiconductor device capable of reducing variation in threshold voltage and variation of mobility of a transistor.SOLUTION: The semiconductor device includes a transistor and a capacitance element electrically connected to the gate of the transistor, in which variation in current flowing the transistor or variation in mobility of the transistor is reduced by discharging, once through the transistor, charge stored in the capacitance element according to a sum voltage of a voltage according to the threshold voltage of the transistor and a video signal voltage.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a semiconductor device or a method for driving the same. [Background technology]

[0002] In recent years, flat panel displays such as liquid crystal displays (LCDs) have become widely used. However, LCDs have some drawbacks, such as a narrow viewing angle, a narrow color range, and a slow response time. There are various drawbacks to this display, such as: Organic EL (electroluminescence, organic light-emitting diode, OLED, etc.) Research into displays is being actively conducted (Patent Document 1).

[0003] However, organic EL displays require a method to control the current flowing through the organic EL element. The problem was that the current characteristics of the transistors varied from pixel to pixel. If the current flowing through the L element (i.e., the current flowing through the transistor) varies, the OLED element The brightness of the screen also varies, resulting in an uneven display. Methods for correcting the variation in low voltage have been studied (Patent Documents 2 to 6).

[0004] However, even if the variation in the threshold voltage of a transistor is corrected, the mobility of the transistor If there is variation, the current flowing through the organic EL element will also vary, resulting in uneven images. Therefore, a method to correct not only the variation in the threshold voltage of a transistor but also the variation in mobility was investigated. This has been discussed (Patent Documents 7 to 8). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-216110 A [Patent Document 2] JP 2003-202833 A [Patent Document 3] JP 2005-31630 A [Patent Document 4] JP 2005-345722 A [Patent Document 5] JP 2007-148129 A [Patent Document 6] International Publication No. 2006 / 060902 Brochure [Patent Document 7] JP 2007-148128 A (paragraph

[0098] ) [Patent Document 8] JP 2007-310311 A (paragraph

[0026] Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the techniques disclosed in Patent Documents 7 and 8, the image signal (video signal) is input to the pixel while correcting the variation in the mobility of the transistor. , various problems arise.

[0007] For example, in order to correct the variation in mobility while inputting a video signal, a different image may be displayed during that time. It is usually impossible to input a video signal directly. Once the size and other factors are decided, the period during which the video signal is input to each pixel (so-called one gate selection period or The maximum value of the mobility variation during one gate selection period is also determined. The increased period during which correction is performed reduces the time required for other processing (such as inputting video signals and acquiring threshold voltages). Therefore, in a pixel, various processes are performed during one gate selection period. As a result, the processing time is insufficient and accurate processing cannot be performed. Or, the mobility variation correction period cannot be sufficiently secured, so the mobility The correction of the above will be insufficient.

[0008] Furthermore, as the number of pixels and frame frequency increase, or as the screen size increases, The gate selection period per pixel becomes shorter and shorter. It becomes impossible to sufficiently correct the variation in mobility.

[0009] Alternatively, when the mobility variation is corrected while inputting a video signal, the mobility variation is The correction of the image signal waveform is easily affected by distortion of the image signal. When the margin is large or small, the degree of mobility correction varies. , accurate correction is not possible.

[0010] Alternatively, when correcting the variation in mobility while inputting a video signal to the pixel, In point-sequential driving, the video signal is input to the pixels of a certain row. When this is done, the video signal is not input to all the pixels in that row at the same time, but is input one pixel at a time. The video signal is input. Therefore, the length of the period during which the video signal is input is Therefore, when the mobility variation is corrected while inputting the image signal, Since the correction period for the mobility variation differs for each pixel, the amount of correction also differs for each pixel. Therefore, it is not possible to perform the correction correctly. When correcting for variations in pixel density, the signal is sent to all pixels in the row at the same time, rather than being driven point-sequentially. It is necessary to perform line sequential driving to input the signal.

[0011] Furthermore, when line sequential driving is performed, the source signal line driving circuit (also called video signal line driver, source driver, or data driver) has a complex configuration For example, the source signal line driver circuit in line sequential driving is In many cases, circuits such as analog buffers and latch circuits are required. It is often composed of an operational amplifier and a source follower circuit, and the current characteristics of the transistor Therefore, thin film transistors (TFTs) are used to When constructing a transistor, a circuit is required to correct the variation in the current characteristics of the transistor. The scale of the system becomes larger and the power consumption becomes larger. When TFTs are used as the transistors in the pixel area, the pixel area and the signal line drive Therefore, it may be difficult to form the signal line driver circuit and the signal line driver circuit on the same substrate. The path must be created using a method separate from the pixel part, which may increase costs. Furthermore, the pixel area and the signal line driver circuit can be integrated using COG (chip on glass) or or TAB (Tape Automated Bonding) etc. This can cause poor contact and reduce reliability.

[0012] From the above, a device or device having reduced effects of variations in the threshold voltage of a transistor is provided. It is an object of the present invention to provide a driving method for a semiconductor device having a transistor, the driving method being capable of suppressing the influence of the variation in mobility of the transistor. The present invention aims to provide a device and a driving method thereof that reduce noise. The object of the present invention is to provide a device and a driving method thereof that reduce the influence of variations in the current characteristics of the capacitor. Alternatively, the present invention provides a device capable of ensuring a long input period of a video signal or a driving method thereof. Alternatively, the present invention provides a correction period for reducing the effect of variations in threshold voltage. The object of the present invention is to provide a device capable of securing a long mobility and a driving method thereof. A device capable of ensuring a long correction period for reducing the effect of variations in a The object of the present invention is to provide a device that is not easily affected by distortion of the waveform of a video signal. Alternatively, it is an object of the present invention to provide a method for driving the same, in addition to a line sequential driving method. The objective of the present invention is to provide a device that can also use driving, or a driving method thereof. To provide a device capable of forming pixels and a driving circuit on the same substrate, and a driving method thereof Alternatively, the present invention provides a device with low power consumption or a method for driving the device. Another object of the present invention is to provide a low-cost device or a driving method thereof. Or, a device or a driving method thereof that is unlikely to cause contact failure at the connection part of the wiring. It is also an object of the present invention to provide a highly reliable device or a method for driving the same. Another object of the present invention is to provide a device having a large number of pixels and a driving method thereof. Alternatively, the object of the present invention is to provide a device having a high frame frequency or a driving method thereof. Alternatively, the object is to provide a device with a large panel size and a driving method thereof. In addition to these, various other means can be used to provide a better device or a better driving method thereof. The objective of the project is to: [Means for solving the problem]

[0013] A transistor and a capacitor element electrically connected to a gate of the transistor. The voltage stored in the capacitance element corresponds to the sum of the voltage corresponding to the threshold voltage of the transistor and the video signal voltage. The charge is discharged once through the transistor, and the current flowing through the transistor The present invention reduces the variation in the capacitance or mobility of transistors.

[0014] One exemplary embodiment of the present invention is a transistor and a transistor electrically connected to a gate of the transistor. A method for driving a semiconductor device having a capacitor element, comprising: The charge held in the capacitance element is transferred to the transistor in response to the sum of the voltage corresponding to the input voltage and the video signal voltage. This is a method for driving a semiconductor device that causes discharge through a charger.

[0015] In addition, one exemplary embodiment of the present invention is a semiconductor device having a transistor, a display element, and wiring. A method for driving an electric device, comprising: and the gate of the transistor in a conductive state, The other of the transistor and the wiring are electrically connected to each other. and in a non-conducting state, and in a second period, one of the source and drain of the transistor and the gate of the transistor are in a non-conductive state, and the source or drain of the transistor is in a non-conductive state. The display element is connected to the source or drain of the transistor by electrically connecting the source or drain of the transistor to the wiring. This is a method for driving a semiconductor device that is brought into a conductive state.

[0016] In one exemplary embodiment of the present invention, a transistor, a display element, a first wiring, and a second wiring are included. A method for driving a semiconductor device having a wiring, comprising: When either the source or drain of a transistor is electrically connected to the gate of the transistor, The other of the source or drain is electrically connected to the first wiring. The other of the drains is brought into a non-conductive state with the second wiring, and the source or drain of the transistor is In the second period, one of the transistors is turned off from the display element. The source of the transistor is connected to the drain of the transistor. Alternatively, the other of the drains and the first wiring are brought into a conductive state, and the source or drain of the transistor is The other of the inputs and the second wiring are brought into a non-conductive state, and one of the source or drain of the transistor is The present invention relates to a method for driving a semiconductor device that brings a display element into a conductive state.

[0017] In addition, one exemplary embodiment of the present invention is a transistor and a transistor electrically connected to a gate of the transistor. A method for driving a semiconductor device having a capacitor connected to a first period, The capacitance element holds a voltage that is the sum of the voltage corresponding to the threshold voltage of the transistor and the video signal voltage. During the second period, the charge held in the capacitance element during the first period is , and a method for driving a semiconductor device in which a current is discharged through a transistor.

[0018] In addition, one exemplary embodiment of the present invention is a transistor and a transistor electrically connected to a gate of the transistor. A method for driving a semiconductor device having a capacitor element and a display element connected to each other, the method comprising the steps of: In the capacitor, a voltage corresponding to the threshold voltage of the transistor and a video signal voltage are applied to the capacitor. The sum of the voltages is held, and in the second period, the voltage held in the capacitive element in accordance with the voltage in the first period is The charge stored in the transistor is discharged through the transistor during the third period. The present invention is also directed to a method for driving a semiconductor device in which a current is supplied to a display element.

[0019] In addition, one exemplary embodiment of the present invention is a transistor and a transistor electrically connected to a gate of the transistor. A method for driving a semiconductor device having a capacitor connected to a first period, The capacitance element holds a first voltage, and one of the source or drain of the transistor and the display element In the second period, the capacitance element holds a second voltage, and the transistor The display element is electrically connected to the source or drain of the second transistor. This is a method for driving a semiconductor device that uses a voltage higher than the threshold voltage.

[0020] In addition, one exemplary embodiment of the present invention is a semiconductor device including a transistor, a first wiring, and a source of the transistor. A first switch that controls conduction or non-conduction between the first wiring and the drain, and a second wiring and a second transistor for controlling conduction or non-conduction between the source and drain of the transistor. A switch, the other of the source or drain of the transistor, and the gate of the transistor A third switch that controls the conduction or non-conduction of the transistor and a source or drain and a fourth switch for controlling electrical connection or non-conduction between the other and the display element. A driving method for a semiconductor device, the driving method comprising: turning on a first switch and a third switch during a first period. state, and the second switch and the fourth switch are in a non-conducting state, and in a second period The first switch and the fourth switch are in a conductive state, and the second switch and the third switch are in a conductive state. The present invention relates to a method for driving a semiconductor device that turns off a switch.

[0021] In addition, one exemplary embodiment of the present invention is a semiconductor device including a transistor, a first wiring, and a source of the transistor. A first switch that controls conduction or non-conduction between the first wiring and the drain, and a second wiring and a second transistor for controlling conduction or non-conduction between the source and drain of the transistor. A switch, the other of the source or drain of the transistor, and the gate of the transistor A third switch that controls the conduction or non-conduction of the transistor and a source or drain and a fourth switch for controlling electrical connection or non-conduction between the other and the display element. A driving method of a power supply device, comprising: state, and the first switch and the fourth switch are in a non-conducting state, and in a second period The first switch and the third switch are in a conductive state, and the second switch and the fourth switch are in a conductive state. In the third period, the first switch and the fourth switch are turned on. and a driving method of the semiconductor device for turning on the second switch and the third switch - Patent 7233635 It is law.

[0022] The switch may be of various types. For example, an electrical switch may be used. In other words, anything that can control the flow of electric current is acceptable. For example, a transistor (e.g., a bipolar transistor) may be used as a switch. transistors, MOS transistors, etc.), diodes (e.g. PN diodes, PIN diodes, Schottky diodes, MIM (Metal Insulator Metal diode, MIS (Metal Insulator Semiconductor) conductor diodes, diode-connected transistors, etc. Alternatively, a logic circuit that combines these can be used as a switch.

[0023] An example of a mechanical switch is a digital micromirror device (DMD). There are switches that use MEMS (microelectromechanical systems) technology. The switch has an electrode that can be moved mechanically, and the movement of the electrode causes The connection and disconnection are controlled by this.

[0024] When a transistor is used as a switch, the transistor acts simply as a switch. However, the polarity (conductivity type) of the transistor is not particularly limited. To suppress the off-state current, it is desirable to use a transistor with a smaller off-state current. Transistors with low leakage current include transistors with LDD regions and multi-gate There are transistors that operate as switches. The voltage of the source terminal operates at a value close to the voltage of the low-potential power supply (Vss, GND, 0V, etc.) In this case, it is preferable to use an N-channel transistor. If the potential of the transistor is close to the potential of the high-potential power supply (such as Vdd), a P-channel transistor is used. It is preferable to use an N-channel transistor because the source terminal is When operating at a potential close to the low-potential power supply, the source terminal of a P-channel transistor When the transistor is operated close to the potential of the high-potential power supply, the absolute value of the voltage between the gate and source is increased. This is because the switch can operate more accurately because it can detect the force of the current. In addition, the transistor rarely operates as a source follower, so the output voltage is large. This is because there is little risk of the size becoming smaller.

[0025] In addition, both N-channel and P-channel transistors are used to realize a CMO An S-type switch may be used as the switch. If a CMOS type switch is used, the P channel Either an N-channel transistor or an N-channel transistor is used. If a current flows through the material, it will function as a switch. Whether the voltage of the input signal is high or low, the voltage can be appropriately output. Furthermore, the voltage amplitude of the signal for turning the switch on or off can be reduced. Therefore, power consumption can be reduced.

[0026] When using a transistor as a switch, the switch is connected to the input terminal (source terminal or drain terminal), and an output terminal (the other of the source terminal or drain terminal); The gate terminal controls the conduction of the transistor. In this case, the switch may not have a terminal for controlling the conduction. Using diodes as switches rather than transistors reduces the wiring required to control the terminals. It is possible to reduce it.

[0027] When it is explicitly stated that A and B are connected, it means that A and B are electrically connected. A and B are connected functionally, A and B are directly connected, Here, A and B are objects (e.g., devices, elements, circuits, etc.). Therefore, a given connection relationship is For example, the present invention is not limited to the connection relationships shown in the drawings or text, and may be modified in any manner without departing from the spirit or scope of the present invention. This also includes things other than relationships.

[0028] For example, if A and B are electrically connected, the following can be considered: The elements that function as One or more diodes (e.g., anode, diode, etc.) may be connected between A and B. Alternatively, When A and B are functionally connected, a circuit (e.g. For example, logic circuits (inverters, NAND circuits, NOR circuits, etc.), signal conversion circuits (DA conversion circuits, AD conversion circuits, gamma correction circuits, etc.), potential level conversion circuits (power supply circuits (boosting circuits , step-down circuits, level shifter circuits that change the potential level of signals, voltage sources, current sources , switching circuits, amplification circuits (circuits that can increase the signal amplitude or current, etc., operational amplifiers , differential amplifier circuits, source follower circuits, buffer circuits, etc.), signal generation circuits, memory circuits, One or more control circuits may be connected between A and B. For example, If the signal output from A is transmitted to B, even if there is another circuit between them, then A and B are considered to be are considered to be functionally connected.

[0029] In addition, when it is explicitly stated that A and B are electrically connected, it means that A and B are electrically When A and B are electrically connected (i.e., when another element or circuit is placed between A and B), A and B are functionally connected (i.e., there is no connection between A and B) and B is functionally connected (i.e., there is no connection between A and B). When A and B are connected directly ( In other words, A and B are connected without any other element or circuit between them. In other words, when it is explicitly stated that something is electrically connected, it should simply be " is the same as if it were expressly stated only that the

[0030] In addition, a display element, a display device which is a device having a display element, a light-emitting element, The light-emitting device can have a variety of configurations and elements. For example, the display element, display device, light-emitting element, or light-emitting device may be an EL (electroluminescent EL elements (EL elements containing organic and inorganic materials, organic EL elements, inorganic EL elements), LE D (white LED, red LED, green LED, blue LED, etc.), transistor (current-dependent transistors that emit light when exposed to light, electron emitters, liquid crystal elements, electronic ink, electrophoretic elements, graphene Rating light bulbs (GLV), plasma displays (PDP), digital microphones Chroma mirror device (DMD), piezoelectric ceramic display, carbon nanotube, Displays whose contrast, brightness, reflectance, transmittance, etc. change due to electromagnetic effects. The display device using the EL element may be an EL display. As a display device using electron emission elements, a field emission display (FED) ) and SED type flat panel displays (SED: Surface-conduction Display devices using liquid crystal elements, such as LC Electron-emitter Displays LCD displays (transmissive LCDs, semi-transmissive LCDs, reflective LCDs) LCD, direct view LCD, projection LCD), electronic ink An example of a display device using an electrophoretic element is electronic paper.

[0031] The EL element has an anode, a cathode, and an EL layer sandwiched between the anode and the cathode. The EL layer is made up of a material that utilizes light emission (fluorescence) from singlet excitons, Those that utilize emission from triplet excitons (phosphorescence) and those that utilize emission from singlet excitons (fluorescence). Some of them use light emitted from triplet excitons (phosphorescence), while others use organic materials. those formed by inorganic matter, those formed by organic matter, Materials formed by inorganic substances, including polymeric materials, low molecular weight materials, polymeric materials However, the present invention is not limited to the above. There can be various types of EL element.

[0032] Note that various types of transistors can be used. There is no limitation on the type of transistor to be used. For example, amorphous silicon, polycrystalline silicon, Microcrystalline (also called microcrystalline, nanocrystalline, or semi-amorphous) silicon The use of thin film transistors (TFTs) having non-single crystal semiconductor films, such as There are various advantages to using TFTs. For example, in the case of single crystal silicon Since it can be manufactured at a lower temperature than conventional methods, it is possible to reduce manufacturing costs or increase the size of manufacturing equipment. Since the manufacturing equipment can be made larger, it is possible to manufacture on large substrates. Since a large number of display devices can be manufactured, the manufacturing cost can be reduced. Therefore, a substrate with low heat resistance can be used. A display element can be manufactured using a transistor on a light-transmitting substrate. It is possible to control the light transmission through the transistor. A part of the film that composes the transistor can transmit light, which improves the aperture ratio. It can be done.

[0033] In addition, by using a catalyst (such as nickel) when producing polycrystalline silicon, It is possible to further improve the crystallinity and manufacture transistors with good electrical characteristics. As a result, the gate driver circuit (scanning line driver circuit) and the source driver circuit (signal line driver circuit ), signal processing circuits (signal generation circuit, gamma correction circuit, DA conversion circuit, etc.) are integrated on the board. It is possible to form.

[0034] In addition, when producing microcrystalline silicon, by using a catalyst (such as nickel), It is possible to further improve the crystallinity and manufacture transistors with good electrical characteristics. In this case, the crystallinity can be improved by simply applying heat treatment without laser irradiation. As a result, the gate driver circuit (scanning line driver circuit) and the source driver circuit It is possible to form a part of the semiconductor device (such as an analog switch) on the substrate. Therefore, if laser irradiation is not performed, the unevenness of the silicon crystallinity can be suppressed. This makes it possible to display images with improved quality.

[0035] However, polycrystalline silicon and microcrystalline silicon can be produced without using a catalyst (such as nickel). It is possible.

[0036] In addition, improving the crystallinity of silicon to polycrystalline or microcrystalline can improve the overall panel quality. It is preferable to perform the process on the whole body, but it is not limited to this. The crystallinity of the silicon may be improved. The crystallinity can be improved by selectively irradiating the silicon with laser light. For example, the peripheral circuit area, which is an area other than the pixels, can be selectively irradiated. Alternatively, the gate driver circuit, the source driver circuit, and the like may be irradiated with laser light only in the region. Alternatively, the laser light may be irradiated only to the area of ​​the source driver circuit. Alternatively, the laser light may be irradiated only to the area of ​​the semiconductor device (e.g., an analog switch). It is possible to improve the crystallization of silicon only in areas where high-speed circuit operation is required. Since there is little need for high-speed operation in the pixel area, the crystallinity is not required to be improved. The pixel circuit can be operated without any problems. The area for improving the crystallinity is small. This allows the manufacturing process to be shortened, improving throughput and reducing manufacturing costs. The number of manufacturing devices required is small, which reduces manufacturing costs. It is possible to do so.

[0037] Alternatively, a transistor can be formed using a semiconductor substrate, an SOI substrate, or the like. This makes it possible to manufacture small-sized transistors with high current supply capacity. By using these transistors, it is possible to reduce the power consumption of a circuit or to increase the integration density of the circuit. This can be done.

[0038] Or ZnO, a-InGaZnO, SiGe, GaAs, IZO, ITO, SnO and transistors having compound semiconductors or oxide semiconductors such as these. A thin film transistor in which a compound semiconductor or an oxide semiconductor is thinned can be used. These features allow the manufacturing temperature to be lowered, making it possible to manufacture transistors at room temperature, for example. As a result, it is difficult to directly transfer the heat to a substrate with low heat resistance, such as a plastic substrate or a film substrate. In addition, these compound semiconductors or oxide semiconductors can be used to form transistors. It can be used not only for the channel part of a transistor but also for other purposes. For example, these compound semiconductors or oxide semiconductors can be used as resistor elements, pixel electrodes, and light-transmitting Furthermore, they can be formed simultaneously with a transistor or as an electrode. Since it is possible to form the semiconductor device, the cost can be reduced.

[0039] Alternatively, transistors formed by inkjet or printing methods can be used. These allow fabrication at room temperature, in a low vacuum, or on large substrates. Since it is possible to manufacture the transistors without using a mask (reticle), The layout can be easily changed. Furthermore, since there is no need to use a resist, This reduces the cost of materials and the number of processes. Furthermore, since the film is applied only to the necessary parts, This method is less wasteful and less costly than the method of etching after forming a film on the entire surface. can be done.

[0040] Alternatively, transistors having organic semiconductors or carbon nanotubes can be used. This makes it possible to form transistors on a flexible substrate. A semiconductor device using such a substrate can be made resistant to shocks.

[0041] Note that the transistor can be formed using various substrates. The substrate is not limited to a specific one. The substrate may be, for example, a single crystal substrate or an SOI substrate. , glass substrate, quartz substrate, plastic substrate, stainless steel substrate, stainless steel A substrate with a foil or other suitable material can be used. A transistor is formed on a substrate, and then the transistor is transferred to another substrate. The substrate on which the transistor is transferred may be a single crystal substrate, an SOI substrate, Glass substrate, quartz substrate, plastic substrate, paper substrate, cellophane substrate, stone substrate, wood substrate Boards, fabric substrates (natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane, polyester) Recycled fibers (acetate, cupra, rayon, recycled polyester) (including leather substrate, rubber substrate, stainless steel substrate, stainless steel foil) Alternatively, the skin (skin surface, dermis) of an animal such as a human or the like may be used. The subcutaneous tissue may be used as a substrate. Alternatively, a substrate may be used to form a transistor, The substrate may be polished to make it thinner. The substrate to be polished may be a single crystal substrate, an SOI substrate, etc. , glass substrate, quartz substrate, plastic substrate, stainless steel substrate, stainless steel Substrates with chill foil and other materials can be used. , formation of transistors with good characteristics, formation of transistors with low power consumption, and durable devices It is possible to facilitate the manufacture of the device, provide heat resistance, and reduce weight or thickness.

[0042] The structure of the transistor can take various forms and is not limited to a specific structure. For example, a multi-gate structure having two or more gate electrodes can be applied. When the gate structure is used, the channel regions are connected in series, so multiple transistors are connected in series. The multi-gate structure reduces the off-state current and improves the transistor durability. Alternatively, the multi-gate structure can improve saturation voltage (improve reliability). When operating in the MOSFET region, the drain-source current remains constant even if the drain-source voltage is changed. The voltage-current characteristic slope does not change much, and the voltage-current characteristic slope can be made flat. By utilizing the flat slope of the current characteristic, ideal current source circuits and very high resistance As a result, it is possible to realize an active load with good characteristics. A mirror circuit can be realized.

[0043] As another example, a structure in which gate electrodes are arranged above and below the channel can be applied. By arranging the gate electrodes above and below the channel, The current value can be increased by increasing the current density. By using a structure in which the MOSFETs are arranged, it becomes easier for a depletion layer to form, and this leads to an improvement in the S value. In addition, by arranging gate electrodes above and below the channel, , a configuration in which a plurality of transistors are connected in parallel.

[0044] A structure in which a gate electrode is disposed above a channel region, and a structure in which a gate electrode is disposed below a channel region The structure in which the channel region is divided into multiple regions is called the normal staggered structure. a structure in which the channel regions are connected in parallel, or a structure in which the channel regions are connected in series In addition, a source electrode and a drain electrode are provided in the channel region (or a part of it). A structure in which the source electrode and drain electrode overlap is also applicable. By using an overlapping structure for the drain electrodes, charges accumulate in part of the channel region. It is possible to prevent the operation from becoming unstable. By providing an LDD region, it is possible to reduce the off-current or to increase the withstand voltage of the transistor. By providing the LDD region, When operating in the saturation region, the drain-source voltage remains constant even if the drain-source voltage changes. The current does not change much and the slope of the voltage-current characteristic can be made flat.

[0045] Note that various types of transistors can be used and can be formed using various substrates. Therefore, all the circuits required to realize a given function can be implemented simultaneously. For example, the circuit required to realize a specific function may be formed on a single substrate. All of the circuits are mounted on various substrates such as glass, plastic, single crystal, or SOI. It is also possible to form the circuit using a substrate that is not suitable for the purpose of realizing a desired function. All components are formed using the same substrate, reducing the number of components and lowering costs. Alternatively, the reliability can be improved by reducing the number of connection points with the circuit components. A part of the circuitry required to realize a certain function is formed on a certain substrate, and the specified function is Other parts of the circuitry required for implementation may be formed on other substrates. In other words, all the circuits required to realize a given function are formed using the same substrate. For example, some of the circuits required to realize a certain function may be mounted on the glass. A separate circuit formed by transistors on a substrate, necessary to realize a specific function. Some of them are formed on single crystal substrates and consist of transistors formed using single crystal substrates. The IC chip is then connected to the glass substrate using COG (Chip On Glass) technology. It is also possible to place the IC chip on the substrate. Alternatively, the IC chip can be mounted on a TA B (Tape Automated Bonding) or printed circuit boards are used to bond glass substrates. In this way, part of the circuit is formed on the same substrate. This reduces the number of components, resulting in lower costs, and reduces the number of connections to circuit components. It is possible to improve reliability. Alternatively, it is possible to improve reliability in areas where the driving voltage is high and where the driving frequency is high. Since the power consumption of the circuits in the parts is large, the circuits in those parts are placed on the same board. Instead, for example, a circuit for that part is formed on a single crystal substrate, and By using an IC chip having such a configuration, it is possible to prevent an increase in power consumption.

[0046] A transistor is defined as a semiconductor device having at least three terminals including a gate, a drain, and a source. A channel region is provided between the drain region and the source region. A current can be passed through the drain region, the channel region, and the source region. The source and drain depend on the transistor structure and operating conditions, so it is unclear which is the source and which is the drain. Therefore, it is difficult to determine whether the source or drain is the same. In some cases, the region that functions as a source or drain is not called a source or drain. In some cases, they are referred to as the first terminal and the second terminal. They may be referred to as the first electrode and the second electrode. Or, they may be referred to as the first region and the second region. There is a match.

[0047] Semiconductor devices include semiconductor elements (transistors, diodes, thyristors, etc.). It also refers to devices that have circuits that can function by utilizing the characteristics of semiconductors. The term "semiconductor device" may generally refer to any device that has semiconductor material. He says.

[0048] Note that the display device refers to a device having a display element. The display device may include a plurality of pixels including a plurality of pixels each including a peripheral circuit. The peripheral driving circuit for driving the plurality of pixels may include a plurality of The display device may be formed on the same substrate as the pixel. Peripheral driving circuits arranged on the substrate by, for example, chip-on-glass (COG) It may include IC chips connected by a wire or IC chips connected by a TAB or the like. The display device may include IC chips, resistor elements, capacitor elements, inductors, transistors, etc. The circuit board may include a flexible printed circuit (FPC) to which a The display device is connected via a flexible printed circuit (FPC) or other device, and the IC chip A printed circuit board on which chips, resistors, capacitors, inductors, transistors, etc. are mounted. The display device may include a polarizing plate or a retardation plate. The display device may include an illumination device, a housing, an audio input / output device, an optical sheet, etc. It may also include an optical sensor.

[0049] Note that it is not explicitly stated that B is formed on A, or that B is formed on A. In the case of the above, it is not limited to B being formed directly on A. This also includes cases where A and B are not in a state where the object is located between them, that is, where there is another object between A and B. Here, A and B are objects (e.g., devices, elements, circuits, wiring, electrodes, terminals, conductive films, layers , etc.).

[0050] Therefore, for example, it is not possible to explicitly state that layer B is formed on top of layer A (or on top of layer A). In the cases listed, layer B is formed directly on layer A, and layer A is formed on layer B. Another layer (such as layer C or layer D) is formed directly on top of it, and layer B is formed directly on top of it. In addition, other layers (such as layers C and D) may be formed as follows: It may be a single layer or a multi-layer.

[0051] Furthermore, the same applies to cases where it is explicitly stated that B is formed above A. It is not limited to B being directly on A, and there is no other object between A and B. This also includes cases where a layer is interposed between layers. For example, if a layer B is formed above a layer A, In this case, layer B is formed directly on layer A, and layer B is formed directly on layer A. Another layer (such as layer C or layer D) is formed on top of it, and layer B is formed directly on top of it. In addition, other layers (such as layers C and D) may be used as single layers. It may be a multi-layer structure.

[0052] In addition, it is explicitly stated that B is formed on A, or B is formed above A. This also includes the case where B is formed diagonally above.

[0053] The same applies to the case where B is below A, or B is below A.

[0054] In addition, where something is explicitly stated as singular, it is preferable to use the singular. However, this is not limited to this, and plurals are also possible. It is preferable that the items described are plural. However, this is not limited to this. , it is also possible that it is singular.

[0055] In the drawings, the size, layer thickness, or area may be exaggerated for clarity. Therefore, it is not necessarily limited to that scale.

[0056] Note that the diagram is a schematic representation of an ideal example, and is not limited to the shapes or values ​​shown in the diagram. For example, there are variations in shape due to manufacturing techniques, variations in shape due to errors, and noise. Variations in signals, voltages, or currents due to timing differences, or variations in signals, voltages, Or, it is possible to include current variation.

[0057] In addition, technical terms may be used for the purpose of describing a specific embodiment or example. Many, but not limited to:

[0058] In addition, undefined terms (including scientific and technical terms such as technical terms or academic terms) are generally It is possible to use the term as meaning equivalent to the general meaning understood by a person skilled in the art. Any words defined herein shall be construed in a manner consistent with the background of the relevant art. is preferred.

[0059] In addition, the terms first, second, third, etc., refer to various elements, members, regions, layers, or sections from one another. Therefore, the words first, second, third, etc. are used to distinguish between elements, parts, etc. The number of materials, regions, layers, areas, etc. is not limited. It is possible to replace "second" or "third" etc. Effect of the Invention

[0060] The effect of variations in the threshold voltage of the transistor can be reduced. The effect of variations in the mobility of the transistor can be reduced. It is possible to reduce the effect of variations in characteristics, or to secure a long input period for the video signal. Alternatively, a correction period for reducing the effect of variations in threshold voltage can be set. Or, the correction period to reduce the effect of the mobility variation can be secured for a long time. It is possible to secure a long period of time. Or, it is possible to make it less susceptible to the distortion of the video signal waveform. Alternatively, not only line sequential driving but also point sequential driving can be used. In this case, the pixel and the driver circuit can be formed on the same substrate. Or, the cost can be reduced. Or, the connection of the wiring part can be improved. It is possible to reduce contact failures, improve reliability, or improve pixel count. You can increase the number of frames, or you can increase the frame frequency, or The panel size can be increased. [Brief description of the drawings]

[0061] [Figure 1] 1A to 1C illustrate a circuit or a driving method described in an embodiment; [Diagram 2] 1A to 1C illustrate a circuit or a driving method described in an embodiment; [Diagram 3] 5A to 5C are diagrams illustrating operations described in an embodiment; [Figure 4] 1A to 1C illustrate a circuit or a driving method described in an embodiment; [Diagram 5] 1A to 1C illustrate a circuit or a driving method described in an embodiment; [Figure 6]1A to 1C illustrate a circuit or a driving method described in an embodiment; [Figure 7] 1A to 1C illustrate a circuit or a driving method described in an embodiment; [Figure 8] 1A to 1C illustrate a circuit or a driving method described in an embodiment; [Figure 9] 1A to 1C illustrate a circuit or a driving method described in an embodiment; [Figure 10] 1A to 1C illustrate a circuit or a driving method described in an embodiment; [Figure 11] 1 is a cross-sectional view illustrating a transistor described in an embodiment. [Figure 12] 1A to 1C are diagrams illustrating electronic devices described in an embodiment. [Figure 13] 1A to 1C are diagrams illustrating electronic devices described in an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0062] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the above-mentioned embodiments, and may be practiced in various different ways without departing from the spirit and scope of the present invention. It will be easily understood by those skilled in the art that the form and details of the present invention may be modified in various ways. The present invention should not be construed as being limited to the description of the present embodiment. In the structure of the invention, the same reference numerals are used in different drawings to indicate similar parts. Detailed descriptions of identical parts or parts having similar functions will be omitted.

[0063] In the following, each embodiment will be described with reference to various figures. In one embodiment, the contents (or even a part of the contents) described in each figure may be the same as those described in another figure. The contents described in (or a part of) are applied, combined, or replaced. Similarly, the contents described in each of the figures of one or more embodiments may be modified without departing from the spirit and scope of the present invention. (or a part of) the contents described in the figures of one or more other embodiments. You can freely apply, combine, or replace the following items (including the content of the do.

[0064] (Embodiment 1) Fig. 1 shows a driving method for correcting the variation in current characteristics such as the mobility of a transistor. An example of the operation timing and the circuit configuration at that time is shown below.

[0065] FIG. 1(a) shows a periodic table for correcting the variation in current characteristics such as the mobility of a transistor 101. The circuit configuration shown in FIG. 1(a) is a transition diagram of the transistor 101. The transistor gate is connected to the MOSFET in order to compensate for variations in current characteristics such as mobility. This is a circuit configuration for discharging the electric charge that is generated by the The connection relationship of the circuit configuration is realized by controlling the ON / OFF state.

[0066] In FIG. 1(a), the source (or drain, first terminal, first The drain (or source electrode) of the transistor 101 is in a conductive state with the wiring 103. The capacitance (second electrode, second terminal, or second electrode) is in a state of electrical continuity with the gate of the transistor 101. A first terminal (or a first electrode) of the element 102 is in electrical communication with the gate of the transistor 101. The second terminal (or the second electrode) of the capacitor 102 is in an electrically connected state with the wiring 103. is located.

[0067] The first terminal (or the first electrode) of the display element 105 is connected to the drain ( or source, second terminal, second electrode) of the transistor 101. A terminal, wiring or electrode other than the drain (or source, second terminal, second electrode) and a surface It is desirable that the first terminal (or the first electrode) of the display element 105 is in a non-conductive state. However, the present invention is not limited to this. The second terminal (or the second electrode) of the display element 105 is connected to the wiring 1. It is preferable that the terminal 104 is in a conductive state with respect to terminal 06, but this is not limited thereto.

[0068] The wiring 104 is connected to the drain (or source, second terminal, second electrode) of the transistor 101. ) of the capacitor 102. The wiring 104 is in a non-conductive state with the first electrode (the first electrode). The drain (or source, second terminal, second electrode) of the transistor 101 and the capacitance element 10 The second terminal (or the first electrode) is not electrically connected to any terminal, wiring, or electrode other than the first terminal (or the first electrode) of the second terminal. It is preferable, but not limited to, that the above-mentioned.

[0069] Note that a video signal or A predetermined voltage may be supplied to the wiring 104. These may be called signal lines or video signal lines.

[0070] Before the connection configuration shown in FIG. 1(a) is established, the mobility of the transistor 101, etc. Before the compensation of the variation in the current characteristic of the transistor 101, the capacitance element 102 is It is desirable that the voltage corresponding to the threshold voltage is maintained. It is preferable that the signal is input to the capacitor 102 via the wiring 104. The capacitor 102 receives a voltage according to the threshold voltage of the transistor 101 and a video signal It is desirable to maintain the sum of the voltages. Therefore, in the state before FIG. 1(a), That is, before compensating for variations in current characteristics such as the mobility of the transistor 101, The wiring 104 is connected to the drain, source, and gate of the transistor 101 and the capacitor 102. At least one of the first terminal (or first electrode), the second terminal (or second electrode), etc. It is desirable that both of them are in a conductive state and that the input operation of the video signal has already been performed.

[0071] Note that the capacitor 102 controls the voltage and It is desirable to hold the sum of the video signal voltages, but this is not limiting. The element 102 does not hold a voltage corresponding to the threshold voltage of the transistor 101. It is also possible that only the video signal voltage is held.

[0072] When a voltage is held by the capacitor 102, a switching noise or the like may cause a However, this is within the range that does not affect the actual operation. Therefore, for example, the threshold voltage of the transistor 101 is When a voltage corresponding to the voltage and the sum of the video signal voltage is input to the capacitance element 102, The voltage held in the capacitance element 102 at this time does not completely match the input voltage. The actual operation may differ slightly due to noise and other factors. It's not a problem if the timing is a little off as long as it doesn't cause any disturbance.

[0073] Next, in FIG. 1(b), a current is supplied to the display element 105 via the transistor 101. The circuit configuration shown in Fig. 1(b) is a transistor. This is a circuit configuration for supplying current from the capacitor 101 to the display element 105. By controlling the on / off of a plurality of switches provided, the connection relationship of the circuit configuration is It is something that will be realized.

[0074] The source (or drain, first terminal, first electrode) of the transistor 101 is connected to the wiring 10 3. The drain (or source, second terminal, second terminal) of transistor 101 The first terminal (or the first electrode) of the display element 105 is in a conductive state. The drain (or source, second terminal, second electrode) of the transistor 101 is The first terminal (or the first electrode) of the capacitor 102 is in a non-conductive state with the gate of the capacitor 101. The second terminal of the capacitor 102 (or The second terminal (or the second electrode) of the display element 105 is in a conductive state with the wiring 103. The second electrode is in electrical communication with the wiring 106 .

[0075] The wiring 104 is connected to the drain (or source, second terminal, second electrode) of the transistor 101. ) of the capacitor 102. The wiring 104 is in a non-conductive state with the first electrode (the first electrode). The drain (or source, second terminal, second electrode) of the transistor 101 and the capacitance element 10 The second terminal (or the first electrode) is not electrically connected to any terminal, wiring, or electrode other than the first terminal (or the first electrode) of the second terminal. It is preferable, but not limited to, that the above-mentioned.

[0076] In other words, the period during which the variation in current characteristics such as the mobility of the transistor 101 is corrected (FIG. 1(a)) supplies current to the display element 105 via the transistor 101. When the period (FIG. 1(b)) begins, at least the drain ( or a source, second terminal, or second electrode) and the gate of the transistor 101. , the drain (or source, second terminal, second electrode) of the transistor 101 and the display element The state of conduction between the first terminal (or the first electrode) of 105 and the first terminal (or the first electrode) of 105 changes. The conductive state of other parts may also change. Arrange elements such as switches, transistors, or diodes so that their state can be controlled It is desirable to use the element to control the conduction state, as shown in FIG. 1(a) and FIG. 1(b). Therefore, it is possible to realize a circuit configuration that realizes the connection state shown in FIG. If the connection situation like 1(b) can be realized, a switch, transistor, or diode can be used. Elements such as electrodes can be freely arranged, and there are no limitations on the number or connection structure.

[0077] As an example, as shown in FIG. 2(a), a first terminal of a switch 201 is connected to a transistor 1 The second terminal is electrically connected to the gate of transistor 101, and the second terminal is electrically connected to the drain (or source) of transistor 101. The first terminal of the switch 202 is electrically connected to the first electrode of the switch 202. The terminal is electrically connected to the drain (or source, second terminal, second electrode) of the transistor 101. The first terminal is electrically connected to the display element 105. By arranging the switches, a circuit configuration that realizes the connection situation of Figure 1(a) and Figure 1(b) can be created. It is possible to achieve this.

[0078] Another example different from that shown in FIG. 2(a) is shown in FIG. 2(b) and FIG. 2(c). In FIG. 2(b), The position of the switch 202 in FIG. 2(b) was changed to the position of the switch 205 in FIG. In FIG. 2(c), the switch 202 in FIG. 2(a) is deleted. Instead, for example, By changing the potential of the wiring 106, the display element 105 is brought into a non-conducting state, as shown in FIG. It is possible to realize the same operation as (a). And it is also possible to realize switches and transistors. If necessary, they will be arranged accordingly.

[0079] Although it is stated that A is in a conductive state with B, in that case, there are various It is possible for various elements to be connected. For example, resistors, capacitors, transistors, etc. , diodes, etc. are connected in series or parallel between A and B. Similarly, it is stated that A is in a non-conducting state with B, but in that case, A and B It is possible that various elements are connected between A and B. It is possible for various elements to be connected in other parts. For example, resistors, capacitors, transistors, diodes, and other elements are connected in series. Alternatively, they may be connected in a parallel connection.

[0080] Therefore, for example, in the circuit of FIG. 2(a), the circuit 2(d), the circuit with switch 204 added is shown in FIG. 2(e), and the circuit with switch 206 added is shown in FIG. The circuit with the addition is shown in Figure 2(f).

[0081] In this way, during the period in which the variation in current characteristics such as the mobility of the transistor 101 is corrected, In FIG. 1(a), the variation in current characteristics such as the mobility of the transistor 101 is reduced. Therefore, during the period when a current is supplied to the display element 105 (FIG. 1(b)), The variation in the current supplied to the display element 105 is also reduced. The variation in state is also reduced, making it possible to perform display with high display quality.

[0082] The circuit configurations shown in FIGS. 2(a) to 2(f) described above are the same as those shown in FIGS. 1(a) and 1(b). This is an example of the circuit configuration shown in Fig. 2(a). In addition to the multiple switches shown in FIG. 2(f), multiple switches provided between the wirings are turned on. Alternatively, the connection relationship of the circuit configuration is realized by controlling the on / off state.

[0083] During the period when a current is supplied to the display element 105 (FIG. 1(b)), the transistor 10 The period in which the variation in the current characteristics such as the mobility of 1 is corrected (Fig. 1(a)) appears immediately after the period in which the variation in the current characteristics such as the mobility of 1 is corrected (Fig. 1(a)). This is because during the period when a current is supplied to the display element 105 (FIG. 1(b) )) is obtained by dividing the gate potential of the transistor 101 (the potential held in the capacitor 102) During the period when a current is supplied to the display element 105 (FIG. 1(b)), However, the current characteristics of the transistor 101, such as its mobility, A current is supplied to the display element 105 immediately after the period in which the fluctuation is corrected (FIG. 1(a)). The present invention is not limited to the above-mentioned period (FIG. 1(b)). During which period the variation in the current characteristics is being corrected, the charge amount of the capacitance element 102 changes. Then, the charge amount of the capacitance element 102 determined at the end of the period is used as a current to be supplied to the display element 105. If there is no significant change during the period when the current is supplied (Figure 1(b)), the transistor The period in which the variation in the current characteristics such as the mobility of the MOSFET 101 is corrected (FIG. 1(a)) and the period in which the variation in the current characteristics such as the mobility of the MOSFET 101 is corrected (FIG. 1(b)). During the period in which a current is supplied to the display element 105 (FIG. 1(b)), another process is performed. A period may be set.

[0084] Therefore, during the period during which the variation in current characteristics such as the mobility of the transistor 101 is corrected, When the charge held in the capacitor 102 at the time of the completion of the discharge, a current is supplied to the display element 105. The charge held in the capacitor 102 at the time the period in which the current is applied starts is approximately the same as that held in the capacitor 102 at the time the current is applied. However, due to the effects of noise, etc., the charge amounts of both may differ slightly. Specifically, the difference between the charge amounts of both should be within 10%, and more preferably If the difference in charge amount is within 3%, the display element will reflect that difference. This is more preferable because the difference is not visible to the human eye.

[0085] Therefore, the period during which the variation in the current characteristics such as the mobility of the transistor 101 is corrected (FIG. FIG. 3(a) shows how the voltage-current characteristics change in the case of FIG. 1(a). The charge stored in the capacitor 102 is converted into current characteristics such as the mobility of the transistor 101. During the period when the variation is being corrected (FIG. 1(a)), the source and drain of the transistor 101 As a result, the charge held in the capacitance element 102 is discharged through the drain. The amount of current flowing through the capacitor 102 decreases, and the voltage held by the capacitor 102 also decreases. The absolute value of the voltage between the gate and source of the transistor 101 also decreases. The stored charge is discharged through the transistor 101, so the amount of discharged charge is depends on the current characteristics of the transistor 101. That is, the mobility of the transistor 101 is If the channel width W of the transistor 101 is higher, more charge is discharged. If the ratio of the channel length L (W / L) is large, more charge is discharged. If the absolute value of the voltage between the gate and source of the transistor 101 is large (i.e., the capacitance element 1 The greater the absolute value of the voltage held at 02, the more charge is discharged. Or, If the parasitic resistance in the source and drain regions of the transistor 101 is small, Alternatively, if the resistance in the LDD region of the transistor 101 is small, the charge is discharged. Alternatively, the capacitor electrically connected to the transistor 101 is discharged. If the contact resistance at the contact hole is small, more charge can be discharged.

[0086] Therefore, before discharging, that is, to compensate for the variation in current characteristics such as the mobility of the transistor 101, The voltage-current characteristic graph for the period before the corrective period (Figure 1(a)) shows that the During the period when the variation in the current characteristics such as the mobility of the transistor 101 is being corrected (Fig. 1(a)), As a result of a part of the charge stored in the capacitance element 102 being discharged, a curve with a small slope is formed. The graph changes to the following. For example, the difference between the voltage-current characteristic graphs before and after discharge is The mobility of the transistor 101 is larger. Therefore, the mobility of the transistor 101 is larger. When the mobility of is high (i.e., when the slope of the graph is steep), the change in slope after discharge is When the amount of charge is large and the mobility of the transistor 101 is low (i.e., the slope of the graph is small), In the case where the transistor is not discharged, the change in the slope becomes smaller after the discharge. The difference in the voltage-current characteristic graphs becomes smaller when the mobility of stadium 101 is high and when it is low. In this way, the influence of the mobility variation can be reduced. If the absolute value of the voltage between the gate and source is large (i.e., the voltage held by the capacitance element 102 The greater the absolute value of , the more charge is discharged and the If the absolute value of the voltage between the input and output terminals is small (i.e., the absolute value of the voltage held by the capacitance element 102 is small), value), less charge is discharged, so the mobility dispersion is more appropriately It is possible to reduce the

[0087] The graph in Figure 3(a) shows the results after the effect of threshold voltage variations has already been reduced. Therefore, as shown in FIG. 3(b), the mobility of the transistor 101 is Before the compensation period (Fig. 1(a)), the influence of the threshold voltage variation is The effect of the threshold voltage is reduced. is translated by the threshold voltage. In other words, The voltage supplied is the sum of the video signal voltage and the threshold voltage. The effect of voltage variation is reduced. After reducing the threshold voltage variation, ) by reducing the mobility variation, the transistor 101 This can significantly reduce the variation in current characteristics.

[0088] The current characteristic of the transistor 101 that can correct the variation is Not only mobility, but also threshold voltage, parasitic resistance in the source (drain) part, LDD region the resistance at the contact hole electrically connected to the transistor 101; The current characteristics of these are also shown in Fig. 1. Therefore, as in the case of the mobility, the variation can be reduced.

[0089] Therefore, before discharging, the variation in the current characteristics such as the mobility of the transistor 101 is corrected. The charge amount of the capacitance element 102 in the period before the transition period (FIG. 1(a)) is At the end of the period (Fig. 1(a)) during which the variation in the current characteristics such as the mobility of the transistor 101 is corrected, This is because the charge amount of the capacitor 102 at the time of the transfer of the transistor 101 is larger than that of the capacitor 102 at the time of the transfer of the transistor 101. During the period when the variation in current characteristics such as mobility is being corrected (FIG. 1(a)), the capacitance element 102 Since the charge of the capacitor 102 is discharged, the charge stored in the capacitor 102 decreases. It is.

[0090] In addition, when the charge held in the capacitance element 102 is partially discharged, the discharge stops immediately. If the battery is completely discharged, that is, if the current stops flowing, If the discharge is complete, most of the video signal information will be lost. It is desirable to stop the discharge before the current flows through transistor 101. It is desirable to stop the discharge while the current is flowing.

[0091] Therefore, one gate selection period (or one horizontal period, or one frame period) is divided by the number of pixel rows. The calculated value is used to correct the variation in the current characteristics such as the mobility of the transistor 101. When comparing the length of one gate selection period (or one horizontal period, 1 It is desirable to have a longer period (e.g., frame period divided by the number of pixel rows) because This is because discharging for longer than one gate selection period can result in over-discharging. However, this is not limited to this.

[0092] Alternatively, the period during which a video signal is input to the pixel and the current such as the mobility of the transistor 101 are Comparing the period during which the characteristic variations are corrected (Fig. 1(a)), the pixel receives the image signal It is desirable that the period during which the image signal is input is longer than the period during which the image signal is input to the pixel. If the battery is discharged for longer than the specified period, it may be over-discharged. , but is not limited to this.

[0093] Alternatively, the period during which the threshold voltage of the transistor is acquired and the movement of the transistor 101 When comparing the length of the period during which the variation in current characteristics such as the degree of current flow is corrected (Fig. 1(a)), It is desirable to have a longer period for acquiring the threshold voltage of the transistor. This is because If the discharge is continued for a period longer than the period during which the transistor threshold voltage is acquired, the transistor will be discharged too much. However, the present invention is not limited to this.

[0094] In addition, during the period in which the variation in current characteristics such as the mobility of the transistor 101 is corrected (FIG. 1 In (a), the length of the period during which the charge held in the capacitance element 102 is discharged is, for example, For example, the amount of variation in the mobility of the transistor 101, the size of the capacitance element 102, It is desirable to determine this based on factors such as W / L of 101.

[0095] For example, consider the case where there are multiple circuits as shown in Figures 1 and 2. For example, a first pixel for displaying a first color and a second pixel for displaying a second color, Each pixel corresponds to transistor 101, and the first pixel corresponds to transistor The first pixel has a transistor 101A and the second pixel has a transistor 101B. The first pixel uses a capacitive element 102A as a capacitive element corresponding to the capacitive element 102, and the second pixel uses a capacitive element 102B as a capacitive element corresponding to the capacitive element 102. It is assumed that the element has a capacitance element 102B.

[0096] And, the W / L of the transistor 101A is larger than the W / L of the transistor 101B. In this case, the capacitance value of the capacitive element 102A is larger than the capacitance value of the capacitive element 102B. is desirable because the transistor 101A discharges more charge and therefore The voltage of the capacitor 102A also changes more significantly. It is desirable that the capacitance value of element 102A is large. When the channel width W of the transistor 101B is larger than the channel width W of the capacitor 102A, It is desirable that the capacitance value of the capacitance element 102B is larger than the capacitance value of the capacitance element 102B. The channel length L of the transistor 101A is smaller than the channel length L of the transistor 101B. In this case, the capacitance value of the capacitive element 102A is larger than the capacitance value of the capacitive element 102B. is desirable.

[0097] In order to control the amount of charge discharged from the capacitance element 102, a capacitance element For example, for Fig. 1(a) and Fig. 1(b), the capacitance element can be An example of the case where the above is added is shown in Fig. 4(a) and Fig. 4(b). The circuit configuration described below is an example of the circuit configuration shown in FIG. 1(a) and FIG. 1(b). In reality, the multiple switches shown in Figs. 4(a) to 4(f) are In addition to the capacitance element, a plurality of switches provided between the wirings are controlled to be turned on or off. In this way, the connection relationship of the circuit configuration is realized.

[0098] In FIG. 4(a) and FIG. 4(b), the first terminal (or the first electrode) of the capacitive element 402A is in a conductive state with the drain (or source, second terminal, second electrode) of the transistor 101. The second terminal (or the second electrode) of the capacitor 402A is in an electrically conductive state with the wiring 103. In FIG. 4(b), the conductive state of each terminal of the capacitive element 402A is the same as that in FIG. However, it is not limited to this. A part of the wiring may be in a non-conducting state. .

[0099] Similarly, another example in which a capacitive element is added to Fig. 1(a) and Fig. 1(b) is shown in Fig. 4(c). 4(d). The first terminal (or the first electrode) of the capacitor element 402B is a transistor. The drain (or source, second terminal, second electrode) of the capacitor 101 is in a conductive state. The second terminal (or second electrode) of the capacitor 402B is in a conductive state with the wiring 106. In FIG. 4(d), the conduction state of each terminal of the capacitive element 402B is the same as that in FIG. 4(c). However, it is preferable that the conductive layer is in a non-conductive state.

[0100] For example, consider a case where there are multiple circuits such as those shown in FIG. a first pixel for displaying a first color and a second pixel for displaying a second color, The second pixel corresponds to the transistor 101, and the second pixel corresponds to the transistor The first pixel has a transistor 101A and the second pixel has a transistor 101B. As a capacitive element corresponding to the element 102, the first pixel uses a capacitive element 102A, and the second pixel uses Furthermore, the capacitance elements 402A to 402B are included. As a capacitive element corresponding to at least one of the capacitance elements 40 and 2C, the first pixel Let the second pixel have a capacitance element 402AB and the second pixel have a capacitance element 402AA.

[0101] And, the W / L of the transistor 101A is larger than the W / L of the transistor 101B. In this case, the capacitance value of the capacitive element 102A is larger than the capacitance value of the capacitive element 102B. Alternatively, it is preferable that the capacitance value of the capacitance element 402AA is smaller than that of the capacitance element 402AB. It is preferable that the total capacitance of the capacitance element 102A and the capacitance element 402AA is larger than the total capacitance of the capacitance element 102A and the capacitance element 402AA. The capacitance value is greater than the total capacitance value of the capacitive element 102B and the capacitive element 402AB. This is because the transistor 101A discharges more charge and therefore the potential is Alternatively, the channel width W of the transistor 101A is set to be smaller than that of the transistor 101A. When the channel width W of the capacitance element 102A is larger than that of the capacitance element 101B, the capacitance value of the capacitance element 102A is larger than that of the capacitance element 102B. It is preferable that the capacitance value of the capacitance element 402AA is larger than that of the capacitance element 402B. It is preferable that the capacitance value of the capacitance element 102AB is larger than that of the capacitance element 402AB. The total capacitance of the capacitive element 102A and the capacitive element 402AA is smaller than that of the capacitive element 102B and the capacitive element 402A. It is desirable that the capacitance of the transistor 101A is larger than the total capacitance of the transistors B. When the channel length L of the transistor 101B is smaller than the channel length L of the capacitor 102A, It is desirable that the capacitance value of the capacitance element 102B is larger than the capacitance value of the capacitance element 102B. It is desirable that the capacitance value of element 402AA is larger than the capacitance value of capacitive element 402AB. Alternatively, the total capacitance of the capacitive element 102A and the capacitive element 402AA may be smaller than that of the capacitive element 102A. It is desirable that the capacitance value of capacitance element 402B and capacitance element 402AB be larger than the total capacitance value of capacitance element 402A.

[0102] The capacitance values ​​of the capacitive elements 402AA and 402AB are different. It is also possible that the capacitance values ​​of 2A and capacitive element 102B are approximately equal. In other words, the capacitance value is adjusted not between the capacitive element 102A and the capacitive element 102B but between the capacitive element It is also possible to use the capacitor 402AA and the capacitive element 402AB. When the sizes of capacitor 102A and capacitor 102B are different, a difference occurs in the size of the video signal. Therefore, the capacitance element 402A may have a large effect on other elements. It is desirable to adjust the capacitance value using A and the capacitive element 402AB.

[0103] The circuit connection structure is not limited to that shown in FIG. 1(a) and FIG. 1(b). For example, FIG. In FIG. 1B, the second terminal (or the second electrode) of the capacitor 102 is connected to the wiring 103. A constant potential is maintained for at least a predetermined period of time. For example, the second wiring of the capacitor 102 may be in electrical continuity with the wiring having a function of supplying the An example in which the terminal (or the second electrode) is connected to the wiring 107 is shown in FIG. Similarly, the second terminal (or the second electrode) of the capacitor 102 is connected to the wiring 10 An example of the case where the MOSFET is connected to 6 is shown in FIG. 1(e) and FIG. 1(f).

[0104] In addition, in Figs. 1(c) to 1(f), as in Figs. 4(a) to 4(d), As an example, the capacitance element can be arranged as shown in Fig. 1(c) and Fig. 1(d). 4(e) and 4(f) show the case where an additional capacitive element 402C is provided.

[0105] In addition, in Figs. 1(c) to 1(f), as in Figs. 2(a) to 2(f), A switch can be placed.

[0106] In addition, Figs. 1(a) to 1(f), Figs. 2(a) to 2(f), Figs. 4(a) to 4(f) ) and the like, the capacitor element 102 has been described as a single element, but this is not limiting. A plurality of capacitance elements can be arranged by series connection or parallel connection. For example, in FIG. 1(a) and FIG. 1(b), two capacitance elements 102A and 102B are connected in series. Examples of the case where they are connected are shown in Figure 1(g) and Figure 1(h).

[0107] In addition, in FIG. 1, FIG. 3, FIG. 4, etc., when the transistor 101 is a P-channel type, However, the present invention is not limited to this. As shown in FIG. 5, an N-channel type may be used. As an example, in comparison with FIG. 1(a) to FIG. 1(d), the case where an N-channel type is used is shown in FIG. 5(a) to 5(d). In other cases, the same procedure can be carried out. The circuit configurations described in FIG. 5(a) to FIG. 5(d) are the same as those shown in FIG. 1(a) and FIG. 1(b). This is an example of a circuit configuration that can be realized. In addition to the multiple switches and capacitance elements shown in FIG. 5(d), multiple switches are provided between the wirings. The connection relationship of the circuit configuration is realized by controlling the on / off of the switches.

[0108] The transistor 101 controls the amount of current flowing through the display element 105. 105, but is not limited thereto.

[0109] In addition, the wiring 103 often has a capability of supplying power to the display element 105. Alternatively, the wiring 103 may have a capability of supplying a current to the transistor 101. This is often the case, but is not limited to this.

[0110] Note that the wiring 107 often has a capability of supplying a voltage to the capacitor 102. Alternatively, in order to make the gate potential of the transistor 101 less likely to fluctuate due to noise, etc. In many cases, the function of the ion exchange is, but not limited to, that of the ion exchange.

[0111] Note that the voltage according to the threshold voltage of the transistor 101 is A voltage as high as the low voltage or close to the threshold voltage of transistor 101. For example, when the threshold voltage of the transistor 101 is large, , the voltage according to the threshold voltage is also large, and when the threshold voltage of the transistor 101 is small, In this way, the magnitude is determined according to the threshold voltage. The voltage that is waiting is called the voltage according to the threshold voltage. Voltages that are slightly different due to the effects of the above are also called voltages according to the threshold voltage. It is possible.

[0112] The display element 105 has a function of changing the luminance, brightness, reflectance, transmittance, etc. Therefore, examples of the display element 105 include a liquid crystal element, a light emitting element, A display device such as a display element, an organic electroluminescence element, or an electrophoretic element can be used.

[0113] In this embodiment, the contents described in each figure may be the same as those described in another embodiment. However, they can be freely combined or replaced as appropriate.

[0114] (Embodiment 2) In this embodiment mode, a specific example of the circuit and the driving method described in Embodiment Mode 1 will be described.

[0115] FIG. 6(a) shows specific examples of FIG. 1(a), FIG. 1(b), FIG. 2(a), and FIG. 2(d). A first terminal of the switch 601 is connected to the wiring 104, and a second terminal of the switch 601 is connected to the transistor The first terminal of the switch 203 is connected to the source (or drain) of the transistor 101. The second terminal is connected to the wiring 103, and the second terminal is connected to the source (or drain) of the transistor 101. The first terminal of the capacitor 102 is connected to the gate of the transistor 101. The first terminal of the switch 201 is connected to the line 103, and the second terminal of the switch 201 is connected to the line 103. The first terminal is connected to the gate of the transistor 101, and the second terminal is connected to the drain of the transistor 101 ( The first terminal of the switch 202 is connected to the transistor 101 (or the source). The second terminal is connected to the first terminal of the display element 105. A second terminal of the display element 105 is connected to a wiring 106.

[0116] Note that the potential of the drain (or source) or gate of the transistor 101 is controlled by In order to achieve this, it is desirable to add a switch, but this is not limited to this. Examples of adding a switch 602 are shown in FIG. 6(b) and FIG. 6(c). In FIG. 6(b), a switch 602 is added. A first terminal of the transistor 101 is connected to the gate of the transistor 101, and a second terminal of the transistor 102 is connected to the wiring 60. 6. In FIG. 6(c), a switch 603 is added, the first terminal of which is connected to the The second terminal is connected to the drain (or source) of the transistor 101, and the second terminal is connected to the wiring 606. is connected.

[0117] It should be noted that the wiring 606 can be shared with other wiring to reduce the number of wirings. For example, In FIG. 6(d), the wiring 106 and the wiring 606 are shared, and an example in which the wiring 106 is used alone is shown. The first terminal of the switch 602 is connected to the gate of the transistor 101, and the second terminal of the switch 602 is connected to the gate of the transistor 101. The second terminal of the switch 602 is connected to the wiring 106. The connection destination is not limited, and it is possible to connect to various wirings. By having such a configuration, the number of wirings can be reduced.

[0118] The circuit connection configuration is not limited to this. If it is placed in various places, by placing switches and transistors, Circuits of various configurations can be realized.

[0119] In this way, the example of the configuration described in the first embodiment can take various configurations. Furthermore, specific examples of Fig. 1(a), Fig. 1(b), Fig. 2(a), and Fig. 2(d) have been shown. Similarly, specific examples can be constructed in FIGS. 1, 2, 4, and 5.

[0120] As an example, an example of Fig. 1(c) and Fig. 1(d) is shown in Fig. 6(e). In this case, the second terminal of the switch 603 and the second terminal (or the second electrode) of the capacitor 102 are ) are both connected to the wiring 107 and share the wiring. do not have.

[0121] Further, an example of FIG. 4(c) and FIG. 4(d) is shown in FIG. 6(f). The first terminal is connected to the drain (or source) of the transistor 101, and the second terminal is connected to wiring 106.

[0122] In this way, FIG. 6 shows a part of the configuration example described in the first embodiment. Other examples can be configured in a similar manner.

[0123] Next, the operation method will be described. Here, the circuit in Figure 6(b) will be used. A similar method of operation can be used for other circuits.

[0124] First, as shown in FIG. 7(a), initialization is performed. This is performed by setting the gate of the transistor 101, Or, it is an operation of setting the drain (or source) potential to a predetermined potential. As a result, the transistor 101 can be turned on. A predetermined voltage is supplied to the capacitor 102. Therefore, a charge is held in the capacitor 102. The switch 602 is in a conductive state and is turned on. Switch 201, switch 202, and switch 203 are in a non-conducting state and are turned off. However, it is preferable that the display element 105 is a Since it is desirable for there to be no current, it is desirable to be in a state where this can be achieved. Therefore, at least one of the switches 202 and 203 It is preferably in a non-conducting state and turned off.

[0125] Note that the potential of the wiring 606 is desirably lower than that of the wiring 104. It is desirable that the position of the wiring 106 is approximately the same as that of the wiring 106. Here, approximately means that the position is equal within the margin of error. This refers to a state where the electrical characteristics are equal within a range of ±10%. In addition, these potentials are set when the transistor 101 is a P-channel type. Therefore, when the polarity of the transistor 101 is an N-channel type, the potential Preferably the relationship is reversed.

[0126] Next, as shown in FIG. 7(b), a video signal is input. The threshold voltage of the transistor 101 is also acquired. Switch 202, switch 203, and switch 1 are in a conductive state and are turned on. 602 is in a non-conducting state and is preferably turned off. At this time, the capacitive element 102 is supplied with a video signal during the period shown in FIG. Since there is an accumulated charge, the charge is discharged. Therefore, the transistor 101 The potential of the gate of the transistor 101 is determined by a video signal supplied from a wiring 104. In other words, the potential supplied from the wiring 104 approaches the potential obtained by adding the low-value voltage (negative value) and the low-value voltage (negative value). The potential of the image signal is lower than the potential of the image signal by the absolute value of the threshold voltage of the transistor 101. At this time, the voltage between the gate and source of the transistor 101 is These operations cause the input of a video signal and the threshold voltage of the In addition, the charge of the capacitance element 102 can be discharged. In this case, the transistor 101 is almost completely discharged. With almost no current flowing, the voltage between the gate and source of transistor 101 is , which is very close to the threshold voltage of transistor 101. It is also possible to stop the discharge before it occurs.

[0127] By such an operation, the capacitance element 102 receives a voltage according to the threshold voltage and a video signal voltage A voltage obtained by adding up these is supplied, and an electric charge according to that voltage is accumulated.

[0128] During this period, when the charge of the capacitance element 102 is discharged, the period may differ. However, this is not a big problem because after a certain amount of time has passed, the battery will be almost completely discharged. Therefore, even if the period is different in length, the effect on the operation is small. This operation can be driven using dot sequence rather than line sequence. The configuration of the driving circuit can be simplified. Therefore, the circuit shown in Figure 6 can be used for one screen. When the pixel is arranged in a matrix, the pixel section has a signal supply circuit for supplying the pixel section with a signal. The driver circuit section and the driver circuit section are configured using the same type of transistors, or However, this is not limited to this, and it is also possible to use line sequential driving. It is also possible to form the pixel portion and the driver circuit portion on different substrates.

[0129] Next, as shown in FIG. 7(c), the variation in current characteristics such as the mobility of the transistor 101 This corresponds to the periods shown in Fig. 1(a) and Fig. 1(c). Then, the switch Switch 201 and switch 203 are in a conductive state and are turned on. In this case, the switch 202 and the switch 602 are preferably in a non-conducting state and turned off. By setting the capacitor 102 in this state, the charge stored in the capacitor 102 is In this way, a small amount of discharge is made through transistor 101. By applying the current to the transistor 101, the effect of variations in the current can be reduced. do.

[0130] Next, as shown in FIG. 7(d), a current is applied to the display element 105 via the transistor 101. This corresponds to the periods shown in Fig. 1(b) and Fig. 1(d). Then, switch 2 Switch 201, switch 202, switch 203 are in a conductive state and are turned on. Switch 601 and switch 602 are in a non-conducting state and are preferably off. At this time, the voltage between the gate and source of the transistor 101 is a voltage according to the threshold voltage. A voltage according to the current characteristic of the transistor 101 is subtracted from the sum of the voltage of the image signal and the image signal voltage. Therefore, the influence of the variation in the current characteristic of the transistor 101 is Therefore, the display element 105 can be supplied with a current of an appropriate magnitude. do.

[0131] In the case of the circuit configuration of FIG. 6(a), during the initialization period shown in FIG. 7(a), As shown in (a), the gate or drain of the transistor 101 is connected to the display element 105. The potential of the input (or source) of the switch 201 can be controlled. It is desirable that switch 202 is in a conductive state and is turned on. The switch 203 is preferably in a non-conducting state and turned off. The present invention is not limited to this. The operations in FIG. 7(b) and subsequent figures may be performed in the same manner.

[0132] In the case of the circuit configuration of FIG. 6(c), during the initialization period shown in FIG. 7(a), As shown in FIG. 8(b), the gate or drain of transistor 101 is connected to a switch 603. The potential of the drain (or source) of the switch 201 can be controlled. It is desirable that switch 603 is in a conductive state and is turned on. The switches 202 and 203 are in a non-conducting state and are turned off. It is preferable, but not limited to, to operate in the same manner as in FIG. 7(b) and subsequent figures. good.

[0133] In addition, in Figure 7, when switching to each action, other actions or For example, the state shown in FIG. 7(a) and 7(b). There is no problem with providing such a period. , there is no problem.

[0134] In this embodiment, the contents described in each figure may be the same as those described in another embodiment. However, they can be freely combined or replaced as appropriate.

[0135] (Embodiment 3) In this embodiment mode, another specific example of the circuit and the driving method described in Embodiment Mode 1 will be described. .

[0136] FIG. 9(a) shows a specific example of FIG. 1(a), FIG. 1(b), and FIG. 2(a). A first terminal of the transistor 101 is connected to the wiring 104, and a second terminal of the transistor 101 is connected to the gate A first terminal of the capacitor 102 is connected to the gate of the transistor 101. The first terminal of the switch 201 is connected to the wiring 102, and the second terminal is connected to the wiring 103. The second terminal is connected to the gate of the transistor 101, and the second terminal is connected to the drain of the transistor 101. The first terminal of the switch 202 is connected to the transistor 10 (or the source). The second terminal is connected to the drain (or source) of the display element 105. A second terminal of the display element 105 is connected to a wiring 106. The source (or drain) of the transistor 101 is connected to a wiring 103 .

[0137] The circuit connection configuration is not limited to this. If it is placed in various places, by placing switches and transistors, Circuits of various configurations can be realized.

[0138] For example, it is possible to change the connection of the switch 901 as shown in FIG. In FIG. 9(e), the first terminal of the switch 901 is connected to the wire 104, and the second terminal is , is connected to the drain (or source) of the transistor 101 .

[0139] In this way, the example of the configuration described in the first embodiment can take various configurations. Furthermore, specific examples of Figs. 1(a), 1(b), and 2(a) have been shown, but Figs. 1 and 2 Specific examples can be similarly constructed in FIGS.

[0140] Next, the method of operation will be described.

[0141] First, as shown in FIG. 9B, a video signal is input. The switch 901 is in a conductive state. The switches 201 and 202 are in a non-conducting state and are turned off. It is preferable that the wiring 104 is a capacitor. An electric charge is stored in element 102 .

[0142] Next, as shown in FIG. 9(c), the variation in current characteristics such as the mobility of the transistor 101 This corresponds to the periods shown in Fig. 1(a) and Fig. 1(c). Then, the switch Switch 901 and switch 202 are in a non-conducting state. In this state, it is desirable that the capacitor element is turned off. The charge stored in the transistor 102 is discharged through the transistor 101. By discharging a small amount through transistor 101, The effect of current variations can be reduced.

[0143] Next, as shown in FIG. 9(d), a current is applied to the display element 105 via the transistor 101. This corresponds to the periods shown in Fig. 1(b) and Fig. 1(d). Then, switch 2 Switch 201 and switch 901 are in a non-conducting state. At this time, the gate and source of the transistor 101 are in an off state. The voltage between the transistors is determined by subtracting a voltage according to the current characteristics of the transistor 101 from the video signal voltage. Therefore, the influence of the variation in the current characteristics of the transistor 101 is eliminated. The influence of the light can be reduced, and a current of an appropriate magnitude can be supplied to the display element 105. come.

[0144] In the case of the circuit configuration of FIG. 9(e), during the period of FIG. 9(b), the switch 201 and the switch It is desirable that the switch 901 is in a conductive state and is turned on. ) and onwards, the same operation can be performed.

[0145] In addition, in Figure 9, when switching to each action, other actions or It is also possible that a period of time is provided.

[0146] In this embodiment, the contents described in each figure may be the same as those described in another embodiment. However, they can be freely combined or replaced as appropriate.

[0147] (Embodiment 4) In this embodiment mode, specific examples of the circuits described in the first to third embodiments will be described. .

[0148] For example, the circuit shown in FIG. 6(b) constitutes one pixel, and the pixels are arranged in a matrix. FIG. 10 shows the case where the switch is a P-channel type. However, this is not limited to this, and transistors of other polarities may also be used. Use transistors of both polarities, diodes or diode-connected transistors. It is also possible to use a transistor connected to the input terminal of the input terminal.

[0149] The circuit shown in FIG. 6(b) constitutes one pixel, pixel 1000M. Pixels with the same configuration as 00M are pixel 1000N, pixel 1000P, and pixel 1000Q. , arranged in a matrix. Each pixel is connected to the same wiring according to its top / bottom and left / right arrangement. It may be connected.

[0150] Next, the correspondence between each element in FIG. 6(b) and each element in pixel 1000M is shown below. The wiring 104 corresponds to the wiring 104M, the wiring 103 corresponds to the wiring 103M, and the switch 601 corresponds to transistor 601M, and switch 203 corresponds to transistor 203M. The transistor 101 corresponds to a transistor 101M, and the capacitive element 102 corresponds to a capacitor. Switch 201 corresponds to transistor 201M, and switch 2 02 corresponds to transistor 202M, and switch 602 corresponds to transistor 602M. Correspondingly, the display element 105 corresponds to a light emitting element 105M, and the wiring 106 corresponds to a wiring 106M. Correspondingly, the wiring 606 corresponds to the wiring 606M.

[0151] The gate of the transistor 601M is connected to the wiring 1002M. The gate of transistor 3M is connected to wiring 1001M. The gate of transistor 202M is The gate of the transistor 201M is connected to the wiring 1004M. The gate of the transistor 602M is connected to a wiring 1005M.

[0152] The wiring connected to the gate of each transistor is a wiring of another pixel or the same It is possible that the gate of the transistor 602M is connected to another wiring of the pixel. The port can be connected to a wiring 1002N that is a wiring of the pixel 1000N. In this case, the wiring 1005M and the wiring 1002N are shared, and the wiring 1005M is deleted. It is possible.

[0153] As the switch 602, a transistor 602M having three or four terminals is used. However, the case where a two-terminal diode or a diode-connected transistor is used is also shown. When they are used, the transistor 602M can be turned on or off. The wiring 1005M that controlled the above can be deleted.

[0154] The wiring 606M is connected to the wiring 606P, the wiring 606N, the wiring 606Q, and the wiring 106M. Alternatively, the wiring 606M may be connected to a wiring of another pixel. It is possible.

[0155] As with FIG. 10, various circuits can be configured.

[0156] In this embodiment, the contents described in each figure may be the same as those described in another embodiment. However, they can be freely combined or replaced as appropriate.

[0157] (Embodiment 5) In this embodiment, a structure and a manufacturing method of a transistor will be described.

[0158] 11A to 11G are diagrams illustrating examples of a structure and a manufacturing method of a transistor. 1(A) is a diagram showing an example of a transistor structure. 1A to 1C are diagrams illustrating an example of a method for manufacturing a transistor.

[0159] Note that the structure and manufacturing method of the transistor are not limited to those shown in FIGS. Various structures and fabrication methods can be used.

[0160] First, an example of a transistor structure will be described with reference to FIG. 11A is a cross-sectional view of a transistor having a plurality of different structures. In the figure, transistors having different structures are shown side by side. This is an expression used to explain the structure of a transistor. They do not need to be arranged side by side, and can be created separately as needed.

[0161] Next, the characteristics of each layer constituting the transistor will be described.

[0162] The substrate 7011 is a glass substrate such as barium borosilicate glass or aluminoborosilicate glass. Plates, quartz substrates, ceramic substrates, or metal substrates including stainless steel, etc., can be used. Other examples include polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). Flexibility of plastics such as polyethersulfone (PES) or acrylic It is also possible to use a substrate made of a synthetic resin having the above properties. By this, it is possible to manufacture a semiconductor device that can be bent. As long as the substrate has the above structure, there is no significant restriction on the area and shape of the substrate. For example, if a rectangular shape with one side longer than 1 meter is used, productivity will be significantly improved. This advantage is much greater than that of using a circular silicon substrate. So that's a big advantage.

[0163] The insulating film 7012 functions as a base film. The purpose of the insulation is to prevent alkaline earth metals from adversely affecting the characteristics of semiconductor elements. The film 7012 is made of silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (S iO x N y )(x>y), silicon oxynitride (SiN x O y ) (x>y) etc. The insulating film may have a single layer structure or a laminate structure of these insulating films. When the film 7012 is provided in a two-layer structure, a silicon nitride oxide film is provided as the first insulating film, and a silicon nitride oxide film is provided as the second insulating film. As another example, the insulating film 7012 may be a three-layer film. In the case of a structure, a silicon oxynitride film is provided as the first insulating film, and a silicon nitride film is provided as the second insulating film. It is preferable to provide a silicon nitride oxide film and then provide a silicon oxynitride film as a third insulating film.

[0164] The semiconductor layer 7013, the semiconductor layer 7014, and the semiconductor layer 7015 are made of amorphous semiconductor. Conductor, microcrystalline semiconductor, or semi-amorphous semiconductor (SAS) Alternatively, a polycrystalline semiconductor layer may be used. It has an intermediate structure between crystal structures (including single crystals and polycrystals) and is stable in terms of free energy. A semiconductor having three states, which has short-range order and contains crystalline regions with lattice distortion. At least in some areas of the film, crystalline regions of 0.5 to 20 nm were observed. When the main component is silicon, the Raman spectrum has a peak at 520 cm -1 Lower wave number than X-ray diffraction shows that the (111) and (22) structures are derived from the silicon crystal lattice. 0) diffraction peak is observed. It contains at least 1 atomic % or more of hydrogen or halogen. SAS is a material gas. The material gas is SiH4, Other examples include Si2H6, SiH2Cl2, SiHCl3, SiCl4, and SiF4. Alternatively, GeF4 may be mixed. or diluted with H2 and one or more rare gas elements selected from He, Ar, Kr, and Ne. The dilution ratio is in the range of 2 to 1000 times, the pressure is in the range of approximately 0.1 Pa to 133 Pa, The power supply frequency is 1 MHz to 120 MHz, preferably 13 MHz to 60 MHz, and the substrate heating temperature is The temperature can be 300°C or less. The impurity elements in the film are oxygen, nitrogen, carbon, and other atmospheric components. Impurities are 1×10 20 cm -1 It is preferable that the oxygen concentration is 5×10 or less. 1 9 / cm 3 Less than or equal to 1×10 19 / cm 3 Here, the sputtering method is Using LPCVD, plasma CVD, etc., materials mainly composed of silicon (Si) (e.g. BaSi x Ge 1-x An amorphous semiconductor layer is formed by laser crystallization of the amorphous semiconductor layer. The thermal crystallization method using an RTA or furnace annealing furnace, and the method using a metal element that promotes crystallization The crystallization is carried out by a crystallization method such as a thermal crystallization method.

[0165] The insulating film 7016 is made of silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (Si O x N y )(x>y), silicon oxynitride (SiN xO y ) (x>y) etc. The insulating film may have a single layer structure or a laminate structure of these insulating films.

[0166] The gate electrode 7017 can be formed of a single-layer conductive film or a stacked structure of two or three conductive films. The gate electrode 7017 can be formed using a conductive film. For example, Tantalum (Ta), Titanium (Ti), Molybdenum (Mo), Tungsten (W), Chromium (Cr), silicon (Si), or other elements, or nitride films of the above elements (typically tantalum nitride film, tungsten nitride film, titanium nitride film), or a combination of the above elements. The alloy film made of the above elements (typically Mo-W alloy, Mo-Ta alloy) or Silicide films (typically tungsten silicide films and titanium silicide films) are used. The above-mentioned single film, nitride film, alloy film, silicide film, etc. can be used as a single layer. They may be used alone or in a laminated state.

[0167] The insulating film 7018 is formed by depositing silicon oxide (SiO x ) , silicon nitride (SiN x ), silicon oxynitride (SiO x N y )(x>y), silicon oxynitride (S iN x O y ) (x>y) and other insulating films containing oxygen or nitrogen, and DLC (Diamond-Like Carbon) The carbon-containing film may have a single layer structure, or a laminate structure. do.

[0168] The insulating film 7019 is made of siloxane resin or silicon oxide (SiO x ), silicon nitride (Si N x), silicon oxynitride (SiO x N y )(x>y), silicon oxynitride (SiN x O y )(x >y) and other insulating films containing oxygen or nitrogen, and carbon such as DLC (diamond-like carbon). Films containing epoxy, polyimide, polyamide, polyvinylphenol, phenylene, etc. The insulating layer is made of a single layer or a laminated structure of organic materials such as benzocyclobutene and acrylic. It is possible to form a siloxane resin. The skeleton of xane is composed of bonds between silicon (Si) and oxygen (O). For this purpose, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group may also be used as the substituent. Alternatively, at least one of the following may be used as the substituent: An organic group containing hydrogen and a fluoro group may be used. It is also possible to provide an insulating film 7019 directly so as to cover the port electrode 7017 .

[0169] The conductive film 7023 is made of Al, Ni, C, W, Mo, Ti, Pt, Cu, Ta, Au, Mn, etc. A single film of any element, a nitride film of any of the elements, or a composite film of any of the elements A gold film or a silicide film of the above element can be used. For example, As alloys containing multiple elements, Al alloys containing C and Ti, Al alloys containing Ni, and Al alloys containing C and Examples of usable alloys include Al alloys containing Ni and C and Al alloys containing Mn and C. For example, when a laminated structure is used, Al can be sandwiched between Mo or Ti. This improves the resistance of Al to heat and chemical reactions.

[0170] Next, referring to the cross-sectional views of transistors having different structures shown in FIG. The features of each structure will be explained below.

[0171] The transistor 7001 is a single drain transistor and can be manufactured by a simple method. Therefore, there is an advantage that the manufacturing cost is low and the yield can be high. The taper angle is 45° or more and less than 95°, and more preferably 60° or more and less than 95°. It is also possible to set the angle to less than 45°. Here, the semiconductor layer 7013 and the semiconductor layer 7015 are The semiconductor layer 7013 is a channel region, and the semiconductor layer 7015 is a semiconductor layer having a different impurity concentration. are used as the source and drain regions. In this way, by controlling the amount of impurities, The resistivity of the semiconductor layer can be controlled by controlling the electrical connection state between the semiconductor layer and the conductive film 7023. It is possible to achieve an ohmic contact. As a method for this, impurities are doped into the semiconductor layer using the gate electrode 7017 as a mask. The method can be used.

[0172] The transistor 7002 is a transistor having a gate electrode 7017 with a taper angle of at least a certain value. Since the material is a photoresist and can be manufactured by a simple method, the manufacturing cost is low and the yield is high. Here, the semiconductor layer 7013, the semiconductor layer 7014, and the semiconductor layer 7015 are The impurity concentrations are different. The semiconductor layer 7013 is a channel region, and the semiconductor layer 7014 is a low-concentration Drain (Lightly Doped Drain: LDD) region, semiconductor layer 7015 are used as the source and drain regions. In this way, by controlling the amount of impurities, The resistivity of the semiconductor layer can be controlled by controlling the electrical connection state between the semiconductor layer and the conductive film 7023. It is possible to approach ohmic contact. Since it has an LDD region, A high electric field is unlikely to be applied, and deterioration of the element due to hot carriers can be suppressed. As a method for forming semiconductor layers having different amounts of impurities, the gate electrode 7017 is masked A method of doping impurities into a semiconductor layer can be used as the transistor 70. In the case of 02, the gate electrode 7017 has a taper angle of at least a certain value. It is possible to provide a gradient in the concentration of impurities doped into the semiconductor layer through the electrode 7017. The taper angle is between 45° and 95°. More preferably, the taper angle is 60° or more and less than 95°. Alternatively, the taper angle is less than 45°. It is also possible.

[0173] The transistor 7003 has a gate electrode 7017 that is made up of at least two layers. In this specification, the upper electrode of the transistor is longer than the upper gate electrode. In this case, the shape of the upper gate electrode and the lower gate electrode is called a hat type. The hat-shaped 017 allows the LDD area to be expanded without the need for an additional photomask. As in the transistor 7003, the LDD region can be formed as a gate. The structure overlapping the electrode 7017 is particularly called the GOLD structure (Gate Overlap). The gate electrode 7017 can be formed into a hat shape by the following method. A method such as the following may also be used.

[0174] First, when patterning the gate electrode 7017, the lower gate The upper gate electrode and the upper gate electrode are etched to give them a tapered shape. Next, the inclination of the upper gate electrode is processed to be nearly vertical by anisotropic etching. This forms a gate electrode with a hat-shaped cross section. By doping an element, the semiconductor layer 7013 used as a channel region, LD A semiconductor layer 7014 used as the D region, a semiconductor layer 7015 used as the source region and the drain region A layer 7015 is formed.

[0175] The LDD region overlapping the gate electrode 7017 is called the Lov region. The LDD region that does not overlap with is called the Loff region. Here, the Loff region is Although it is highly effective in suppressing the off-state current, it also reduces the electric field near the drain and reduces the damage caused by hot carriers. The effect of preventing the deterioration of the on-current value is low. On the other hand, the Lov region relaxes the electric field near the drain, Although it is effective in preventing the deterioration of the on-state current, it is not very effective in suppressing the off-state current. It is preferable to fabricate transistors having structures according to the characteristics required for each circuit. For example, when the semiconductor device is used as a display device, the pixel transistor has an off-state current value In order to suppress this, it is preferable to use a transistor having a Loff region. The transistors in the side circuits reduce the electric field near the drain and prevent the degradation of the on-current value. In order to achieve this, it is preferable to use a transistor having a Lov region.

[0176] The transistor 7004 has a sidewall 7021 in contact with the side surface of the gate electrode 7017. By providing the sidewall 7021, The area overlapping with the hole 7021 can be the LDD area.

[0177] The transistor 7005 is formed by doping the semiconductor layer using a mask 7022. , LDD (Loff) region is formed in the transistor. An LDD region can be formed, and the off-current value of the transistor can be reduced.

[0178] The transistor 7006 is formed by doping the semiconductor layer using a mask. This is a transistor in which the LDD region is formed. This can reduce the electric field near the drain of the transistor and reduce the deterioration of the on-current value. can be reduced.

[0179] Next, an example of a method for manufacturing a transistor is shown in FIGS.

[0180] Note that the structure and manufacturing method of the transistor are not limited to those shown in FIGS. Various structures and fabrication methods can be used.

[0181] In this embodiment, a semiconductor layer 7012 is formed on the surface of a substrate 7011 and on the surface of an insulating film 7012. 7013, the surface of the semiconductor layer 7014, the surface of the semiconductor layer 7015, and the insulating film 701 6, the surface of the insulating film 7018, or the surface of the insulating film 7019 is subjected to plasma treatment. By performing oxidation or nitridation on the insulating film, the semiconductor layer or the insulating film can be oxidized or nitridized. In this way, by oxidizing or nitriding the semiconductor layer or the insulating film using the plasma treatment, The surface of the semiconductor layer or the insulating film is modified by the CVD method or the sputtering method. This allows the formation of a denser insulating film compared to conventional insulating films, and therefore reduces defects such as pinholes. It is possible to suppress the above-mentioned problems and improve the characteristics of the semiconductor device. The insulating film 7024 thus formed is called a plasma-treated insulating film.

[0182] The sidewall 7021 is made of silicon oxide (SiO x ) or silicon nitride (SiN x ) A method for forming a sidewall 7021 on the side of a gate electrode 7017 For example, after the gate electrode 7017 is formed, silicon oxide (SiO x ) or nitrogen Silicon nitride (SiN x After forming a film of silicon oxide (SiO x )also is silicon nitride (SiN x ) film can be etched. , silicon oxide (SiO x ) or silicon nitride (SiN x ) membrane Since the gate electrode 7017 can be left unremoved, a sidewall 7021 is formed on the side of the gate electrode 7017. It is possible.

[0183] The structure of a transistor and a method for manufacturing a transistor have been described above. Wiring, electrodes, conductive layers, conductive films, terminals, vias, plugs, etc. are made of aluminum (Al), tin (Tin), Ta (Ta), titanium (Ti), molybdenum (Mo), tungsten (W), neodymium ( Nd), Chromium (Cr), Nickel (Ni), Platinum (Pt), Gold (Au), Silver (Ag), Copper (Cu), magnesium (Mg), scandium (Sc), cobalt (Co), zinc ( Zn), Niobium (Nb), Silicon (Si), Phosphorus (P), Boron (B), Arsenic (As) From the group consisting of gallium (Ga), indium (In), tin (Sn), and oxygen (O) One or more elements selected, or one or more elements selected from the above group Compounds and alloy materials containing indium (e.g., indium tin oxide (ITO), indium zinc) Lead oxide (IZO), indium tin oxide with silicon oxide (ITSO), zinc oxide (Zn O), tin oxide (SnO), cadmium tin oxide (CTO), aluminum neodymium (Al-Nd) , magnesium silver (Mg-Ag), molybdenum niobium (Mo-Nb), etc. Alternatively, wiring, electrodes, conductive layers, conductive films, terminals, etc., may contain these compounds. It is preferable that the material is formed of a combination of materials selected from the above group. Compounds of silicon with one or more other elements (silicides) (e.g., aluminum silicon , molybdenum silicon, nickel silicide, etc.), one or more selected from the above group It contains compounds of nitrogen with several elements (e.g. titanium nitride, tantalum nitride, molybdenum nitride, etc.). It is preferable that the above-mentioned method is used.

[0184] Silicon (Si) can contain n-type impurities (such as phosphorus) or p-type impurities (such as boron). The inclusion of impurities in silicon can improve electrical conductivity or reduce the electrical conductivity of the silicon. Therefore, it is possible to use it as wiring, electrodes, etc. It becomes.

[0185] Silicon can be classified into single crystal, polycrystalline (polysilicon), and microcrystalline (microcrystalline silicon). Silicon with various crystallinity can be used. It is possible to use silicon that does not have crystallinity, such as amorphous silicon. By using single crystal silicon or polycrystalline silicon, wiring, electrodes, conductive layers, conductors, etc. It is possible to reduce the resistance of conductive films, terminals, etc. Amorphous silicon or microcrystalline silicon By using this, wiring and the like can be formed in a simple process.

[0186] Incidentally, aluminum or silver has high electrical conductivity, and therefore can reduce signal delay. Furthermore, it is easy to etch, making it easy to pattern and enabling fine processing. .

[0187] In addition, because copper has high conductivity, it is possible to reduce signal delay. When using copper, In order to improve adhesion, a laminated structure is preferable.

[0188] Molybdenum or titanium is used in oxide semiconductors (ITO, IZO, etc.) or silicon It has the advantages of not causing defects even when in contact with metals, being easy to etch, and having high heat resistance. This is desirable.

[0189] Tungsten is preferable since it has an advantage such as high heat resistance.

[0190] Neodymium is preferable because it has the advantage of being highly heat resistant. When alloyed with aluminum, heat resistance improves and aluminum is less likely to cause hillocks. It becomes.

[0191] Silicon has high heat resistance and can be formed simultaneously with the semiconductor layer of the transistor. This is desirable because of the advantages it offers.

[0192] In addition, ITO, IZO, ITSO, zinc oxide (ZnO), silicon (Si), tin oxide (S Cadmium tin oxide (CTO) and cadmium tin oxide (CTO) are transparent, so they are used in areas where light can pass through. For example, it can be used as a pixel electrode or a common electrode.

[0193] IZO is preferable because it is easy to etch and process. It is also unlikely that residue will remain when cleaning the pixel. If IZO is used as the electrode, it may cause problems (short circuit, alignment disorder, etc.) in the liquid crystal element or light emitting element. This can reduce the impact of

[0194] In addition, wiring, electrodes, conductive layers, conductive films, terminals, vias, plugs, etc. may have a single-layer structure. A multi-layer structure may be used. By making it a single-layer structure, wiring, electrodes, conductive layers, conductive films This simplifies the manufacturing process for terminals, etc., shortens the number of days required for the process, and reduces costs. Alternatively, by using a multi-layer structure, it is possible to utilize the advantages of each material. It is possible to form wiring, electrodes, etc. with good performance while reducing the disadvantages. For example, by including a low-resistance material (such as aluminum) in the multi-layer structure, the As another example, a low heat-resistant material can be sandwiched between high heat-resistant materials. By using a layered structure, it is possible to utilize the advantages of low heat resistance materials while also reducing wiring, electrodes, etc. For example, the layer containing aluminum can be made of molybdenum, titanium, It is preferable to use a laminated structure in which the material is sandwiched between layers containing tungsten, neodymium, etc.

[0195] Here, if wiring, electrodes, etc. are in direct contact with each other, they may adversely affect each other. For example, For example, one wiring or electrode may penetrate into the material of the other wiring or electrode and change its properties. As another example, the formation or manufacture of a high resistance portion When doing so, problems may occur and normal production may not be possible. In this case, if a highly reactive material is sandwiched or covered by a less reactive material in a laminated structure, For example, when connecting ITO and aluminum, It is preferable to sandwich a titanium, molybdenum, or neodymium alloy between the two. When connecting silicon and aluminum, titanium and molybdenum are placed between the silicon and aluminum. It is preferable to sandwich a lithium-ion or neodymium alloy.

[0196] The wiring means a conductive material arranged thereon. The wiring may be linear or may be The electrodes do not have to be linear but may be short. Therefore, the electrodes are included in the wiring.

[0197] In this embodiment, the contents described in each figure may be the same as those described in another embodiment. However, they can be freely combined or replaced as appropriate.

[0198] (Embodiment 6) In this embodiment, an example of an electronic device will be described.

[0199] 12(A) to 12(H) and 13(A) to 13(D) are diagrams showing electronic devices. These electronic devices include a housing 9630, a display unit 9631, a speaker 9633, and an LED. Lamp 9634, operation key 9635, connection terminal 9636, sensor 9637 (force, displacement, position Position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemicals, sound, time , hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared rays 9638, a microphone 9639, etc.

[0200] FIG. 12A shows a mobile computer, which includes, in addition to the above, a switch 9670, The portable terminal 9671 may have an infrared port 9672, etc. A type of image reproducing device (for example, a DVD reproducing device) that, in addition to the above, also has a second display 12C shows a GOG. In addition to the above, the display includes a second display unit 9632, a support unit 9673, 12(D) is a portable game machine, and In addition to the above, a recording medium reading unit 9672 and the like can be provided. This is a digital camera with a TV receiving function. In addition to the above, it also has an antenna 9675, a shutter The mobile phone may have a touch button 9676, an image receiving unit 9677, etc. In addition to the above, the second display unit 9632, the recording medium reading unit 9672, FIG. 12(G) shows a television receiver, which, in addition to the above, has a FIG. 12(H) shows a portable television receiver. In addition to the above, the device may have a charger 9678 capable of transmitting and receiving signals, etc. FIG. 13(A) shows a display, which includes, in addition to the above, a support base 9679, etc. FIG. 13B shows a camera, which, in addition to the above, can also have an external connection port. It may have a port 9680, a shutter button 9676, an image receiving unit 9677, etc. FIG. 13C shows a computer that, in addition to the above, includes a pointing device 96 81, an external connection port 9680, a reader / writer 9682, etc. 13(D) is a mobile phone, which, in addition to the above, includes a transmitting unit, a receiving unit, a mobile phone / mobile a tuner for one segment partial reception service for a terminal, and so on.

[0201] The electronic devices shown in FIGS. 12(A) to 12(H) and 13(A) to 13(D) are For example, various information (still images, videos, text images, etc.) Function to display on the display unit, touch panel function, calendar, date or time display, etc. Functions, functions to control processing by various software (programs), wireless communication functions, A function to connect to various computer networks using wireless communication functions, A function to transmit or receive various data using a program recorded on a recording medium The data can be read out and displayed on the display unit. In electronic devices with displays, one display unit is used primarily to display image information, and another A function that mainly displays text information on one display unit, or a function that takes parallax into account on multiple displays By displaying an image, it is possible to have a function of displaying a stereoscopic image. In electronic devices having an image receiving unit, the functions of taking still images, taking videos, and The function to automatically or manually correct the captured image, and to store the captured image on a recording medium (external or in the camera) It can have functions such as storing the captured image on a built-in memory and displaying the captured image on the display unit. Note that the electronic devices shown in FIGS. The functions that can be possessed by the are not limited to these, and the function can have various functions.

[0202] The electronic device described in this embodiment has a display unit for displaying some information. The electronic device is characterized in that the influence of the characteristic variation of the transistor is small in the display section. This reduces the amount of interference that can be seen, resulting in a very uniform image.

[0203] Next, application examples of the semiconductor device will be described.

[0204] FIG. 13(E) shows an example in which a semiconductor device is integrated with a building. ) includes a housing 9730, a display unit 9731, a remote control device 9732 which is an operation unit, and a speaker 9 Semiconductor devices are wall-mounted and integrated with buildings, and the space required for installation is limited. It can be installed without requiring a large space.

[0205] FIG. 13(F) shows another example in which a semiconductor device is provided inside a building as an integral part of the building. The display panel 9741 is attached to the unit bath 9742 and is This allows viewing of the display panel 9741.

[0206] In this embodiment, a wall and a unit bath are used as examples of structures. The manner in which the semiconductor device is installed is not limited to this, and the semiconductor device can be installed in various structures.

[0207] Next, an example in which the semiconductor device is integrated with a moving object will be described.

[0208] FIG. 13G is a diagram showing an example in which the semiconductor device is provided in an automobile. The device 9761 is attached to the vehicle body 9762 and is adapted to detect the movement of the vehicle body or the movement from inside or outside the vehicle. The information entered can be displayed on demand. It is okay to do so.

[0209] FIG. 13(H) is a diagram showing an example in which a semiconductor device is integrated with a passenger airplane. FIG. 13(H) shows a display panel 9782 attached to a ceiling 9781 above the seats of a passenger airplane. The display panel 9782 is attached to the ceiling 97. 81 and the hinge part 9783 are attached together, and the extension and contraction of the hinge part 9783 This allows passengers to view the display panel 9782. The display panel 9782 is operated by passengers. It has the function of displaying information by

[0210] In this embodiment, an automobile body and an airplane body are exemplified as moving bodies. However, this is not limited to motorcycles, four-wheeled vehicles (including cars, buses, etc.), trains (monorail, etc.) They can be installed on a variety of things, including buildings, railways, ships, etc.

[0211] In this embodiment, the contents described in each figure may be the same as those described in another embodiment. However, they can be freely combined or replaced as appropriate. [Explanation of symbols]

[0212] 101 Transistor 102 Capacitive element 103 Wiring 104 Wiring 105 Display element 106 Wiring 107 Wiring 201 Switch 202 Switch 203 Switch 204 Switch 205 Switch 206 Switch 601 Switch 602 Switch 603 Switch 606 Wiring 901 Switch 101A Transistor 101B Transistor 101M Transistor 102A Capacitive Element 102B Capacitive element 102M Capacitive Element 103M Wiring 104M Wiring 105M Light emitting element 106M Wiring 201M Transistor 202M transistor 203M Transistor 402A Capacitive Element 402B Capacitive element 402C A to Capacitive element 601M Transistor 602M Transistor 606M Wiring 606N Wiring 606P Wiring 606Q Wiring 7001 Transistor 7002 Transistor 7003 Transistor 7004 Transistor 7005 Transistor 7006 Transistor 7011 Substrate 7012 Insulating film 7013 Semiconductor layer 7014 Semiconductor layer 7015 Semiconductor layer 7016 Insulating film 7017 Gate electrode 7018 Insulating film 7019 Insulating film 7021 Sidewall 7022 Mask 7023 Conductive film 7024 Insulating film 8601 Anode 8602 Cathode 8603 Hole transport region 8604 Electron transport area 8605 Mixed area 8606 area 8607 area 8608 area 8609 area 9601 Display Panel 9602 Pixel section 9603 Scanning line driver circuit 9604 Signal line driver circuit 9605 Circuit Board 9606 Control Circuit 9607 Signal splitting circuit 9608 Connection Wiring 9611 Tuner 9612 Video signal amplifier circuit 9613 Video signal processing circuit 9614 Signal line driver circuit 9615 Audio signal amplifier circuit 9616 Audio signal processing circuit 9617 Speaker 9618 Control circuit 9619 Input section 9621 Display Panel 9622 Control Circuit 9623 Signal splitting circuit 9624 Scanning line driver circuit 9630 Case 9631 Display section 9632 Display section 9633 Speaker 9634 LED Lamp 9635 Operation Key 9636 Connection terminal 9637 Sensor 9638 Microphone 9670 Switch 9671 Infrared port 9672 Recording medium reading unit 9673 Support part 9674 Earphones 9675 Antenna 9676 Shutter button 9677 Image receiving unit 9678 charger 9679 Support stand 9680 External connection port 9681 Pointing Device 9682 Reader / Writer 9730 Chassis 9731 Display section 9732 Remote control device 9733 Speaker 9741 Display Panel 9742 Unit Bath 9761 Display Panel 9762 Body 9781 Ceiling 9782 Display Panel 9783 Hinge part 1000M pixels 1000N pixels 1000P pixels 1000Q pixels 1001M Wiring 1002M Wiring 1002N Wiring 1003M Wiring 1004M Wiring 1005M Wiring 1005N Wiring 402AA Capacitive element 402AB Capacitive element

Claims

1. A pixel includes first to sixth transistors, a light-emitting element, a first capacitor, and first to third wirings, The first wiring has a function of supplying a video signal to the pixel, the third wiring has a function of supplying a first potential to the pixel; the first transistor has a function of controlling a magnitude of a current flowing between the second wiring and the light-emitting element in accordance with a potential corresponding to the video signal; Each of the second transistor to the sixth transistor has a function as a switch, one of a source and a drain of the second transistor is always electrically connected to the first wiring, the other of the source and the drain of the second transistor is always electrically connected to one of the source and the drain of the first transistor; one of the source and the drain of the third transistor is always electrically connected to the second wiring; the other of the source and the drain of the third transistor is always electrically connected to one of the source and the drain of the first transistor; one of the source and the drain of the fourth transistor is always electrically connected to the gate of the first transistor; the other of the source and the drain of the fourth transistor is always electrically connected to the other of the source and the drain of the first transistor; one of the source and the drain of the fifth transistor is always electrically connected to the other of the source and the drain of the first transistor; the other of the source and the drain of the fifth transistor is always electrically connected to a pixel electrode of the light-emitting element; one of the source and the drain of the sixth transistor is always electrically connected to the other of the source and the drain of the first transistor; the other of the source and the drain of the sixth transistor is always electrically connected to the third wiring; one electrode of the first capacitance element is always electrically connected to a gate of the first transistor; the other electrode of the first capacitance element is always electrically connected to the second wiring; a period during which the second transistor is in a non-conductive state and the sixth transistor is in a conductive state; Light emitting device.

2. A pixel includes first to sixth transistors, a light-emitting element, a first capacitor, and first to third wirings, The first wiring has a function of supplying a video signal to the pixel, the third wiring has a function of supplying a first potential to the pixel; the first transistor has a function of controlling a magnitude of a current flowing between the second wiring and the light-emitting element in accordance with a potential corresponding to the video signal; Each of the second transistor to the sixth transistor has a function as a switch, one of a source and a drain of the second transistor is always electrically connected to the first wiring, the other of the source and the drain of the second transistor is always electrically connected to one of the source and the drain of the first transistor; one of the source and the drain of the third transistor is always electrically connected to the second wiring; the other of the source and the drain of the third transistor is always electrically connected to one of the source and the drain of the first transistor; one of the source and the drain of the fourth transistor is always electrically connected to the gate of the first transistor; the other of the source and the drain of the fourth transistor is always electrically connected to the other of the source and the drain of the first transistor; one of the source and the drain of the fifth transistor is always electrically connected to the other of the source and the drain of the first transistor; the other of the source and the drain of the fifth transistor is always electrically connected to a pixel electrode of the light-emitting element; one of the source and the drain of the sixth transistor is always electrically connected to the other of the source and the drain of the first transistor; the other of the source and the drain of the sixth transistor is always electrically connected to the third wiring; one electrode of the first capacitance element is always electrically connected to a gate of the first transistor; the other electrode of the first capacitance element is always electrically connected to the second wiring; a period during which the second transistor is in a non-conductive state and the sixth transistor is in a conductive state; the sixth transistor is not turned on during a period in which the video signal is input to the pixel via the second transistor; Light emitting device.

3. In claim 1 or 2, The first transistor is a p-channel transistor. Light emitting device.

4. In any one of claims 1 to 3, the first capacitance element has a plurality of second capacitance elements connected in parallel; Light emitting device.

Images