Indication device

Abstract

To provide a display that prevents a variation in current value caused by a variation in threshold value voltage of a transistor, and reduces deviation from the brightness designated by a video signal.SOLUTION: A display has pixels each including a transistor that controls the value of a current supplied to a load, a first holding capacity, a second holding capacity, and a first switch to a fourth switch, and causes the second holding capacity to hold a threshold value voltage of the transistor and subsequently inputs a potential according to a video signal to the pixel. In this way, the display causes the second holding capacity to hold a voltage obtained by adding a potential capacitively divided with the first holding capacity, of the potential according to the video signal, to the threshold value voltage, to thereby prevent a variation in current value caused by a variation in threshold value voltage of the transistor. A desired current can thus be supplied to loads including a light-emitting device. A display can be provided which reduces deviation from the brightness designated by the video signal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a semiconductor device that has a function to control the current supplied to a load using a transistor. , pixels formed by display elements whose brightness changes according to a signal, and the signals that drive those pixels This relates to a display device including a line drive circuit and a scan line drive circuit. It also relates to a method for driving such a device. Furthermore, this relates to electronic equipment having such a display device as its display unit. [Background technology]

[0002] In recent years, pixels have been using electroluminescence (EL: Electro Luminesce Self-illuminating display devices, or so-called light-emitting devices, that use light-emitting elements such as nce (a type of light source) are attracting attention. There are. As light-emitting elements used in such self-illuminating display devices, organic light-emitting diodes OLED (Organic Light Emitting Diode) and EL These elements are attracting attention and are beginning to be used in EL displays and other applications. Because these light-emitting elements emit light themselves, the pixel visibility is higher compared to liquid crystal displays. It does not require a light bulb. It also has advantages such as a fast response time. Note: The brightness of the light-emitting element... Many of these are controlled by the value of the current flowing through them.

[0003] Furthermore, an active matrix is ​​provided with transistors for controlling the light emission of the light-emitting elements, one for each pixel. Development of RIX-type display devices is underway. Active matrix display devices are passive In addition to enabling high-definition and large-screen displays that are difficult to achieve with matrix-type display devices, Because it operates with lower power consumption than passive matrix display devices, it is expected to be put into practical use. .

[0004] Figure 62 shows the pixel configuration of a conventional active-matrix display device (Patent Document 1). The pixels shown in 62 are thin-film transistors. It has a TFT 11, a TFT 12, a capacitive element 13, a light-emitting element 14, and signal lines 15 and scan lines It is connected to either the source electrode or the drain electrode of TFT12. On one side, the power supply potential Vdd is supplied to one electrode of the capacitive element 13, and the opposite side of the light-emitting element 14 The electrodes are supplied with ground potential.

[0005] At this time, the semiconductor of the TFT12, i.e., the driving TFT, controls the current value supplied to the light-emitting element. When amorphous silicon is used in the body layer, the threshold voltage (Vth) fluctuates due to degradation, etc. This occurs. In this case, even though the same potential is applied to different pixels from the signal line 15, The current flowing through the light-emitting element 14 differs from pixel to pixel, resulting in non-uniform brightness across pixels. Yes. Furthermore, even when polysilicon is used for the semiconductor layer of the driving TFT, the transient The characteristics of the sta can deteriorate or become inconsistent.

[0006] To improve this problem, Patent Document 2 proposes an operation method using the pixels shown in Figure 63. The pixel shown in Figure 63 controls the current value supplied to the transistor 21 and the light-emitting element 24. It has a drive transistor 22, a capacitive element 23, and a light-emitting element 24, and the pixel is connected by a signal line 25 It is connected to scan line 26. The drive transistor 22 is an NMOS transistor. Therefore, either the source electrode or the drain electrode of the drive transistor 22 is A ground potential is supplied, and Vca is supplied to the counter electrode of the light-emitting element 24.

[0007] The timing chart in the operation of this pixel is shown in FIG. 64. In FIG. 64, one frame - period is divided into an initialization period 31, a threshold voltage (Vth) writing period 32, a data writing period 33, and a light emission period 34. Note that one frame period corresponds to the period for displaying one screen of an image, and the initialization period, the threshold voltage (Vth) writing period, and the data writing period are collectively called an address period. First, in the threshold voltage writing period 32, the threshold voltage of the driving transistor 22 is written into the capacitive element. Then, in the data writing period 33, the data voltage (Vdata) indicating the luminance of the pixel is written into the capacitive element, and Vdata + Vth is accumulated in the capacitive element.

[0008] And in the light emission period, the driving transistor 22 is turned on, and by changing Vca , the light emitting element 24 emits light with the luminance specified by the data voltage. By such an operation, the variation in luminance due to the variation in the threshold voltage of the driving transistor is reduced.

[0009] [[ID=3l]]

[0010] [Prior Art Documents] [Patent Documents] [Patent Document 1]

[0011] Japanese Patent Laid-Open No. 8-234683 [Patent Document 2] Japanese Patent Publication No. 2004-295131 [Patent Document 3] Japanese Patent Publication No. 2004-280059 [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] In all cases, the operating methods described in Patent Documents 2 and 3 involve the potential of Vca. By changing this several times per frame period, the initialization and threshold voltage writing described above can be performed. In these pixels, one of the light-emitting elements to which Vca is supplied. Since the opposing electrode is formed across the entire pixel area, the initialization and threshold voltage If even one pixel is performing a data writing operation other than the writing operation, the light-emitting element The child cannot emit light. Therefore, as shown in Figure 65, during one frame period The proportion of the luminescence period (i.e., the duty cycle) becomes smaller.

[0012] A low duty cycle necessitates increasing the current flowing through the light-emitting elements and driving transistors. Because of this, the voltage applied to the light-emitting element increases, and the power consumption increases. Because the drive transistors become more prone to degradation, screen burn-in may occur, or the screen may not function the same as before degradation. Achieving brightness levels such as these would require even greater power.

[0013] Furthermore, since the counter electrodes are connected to all pixels, the light-emitting element functions as a high-capacity element. Therefore, high power consumption is required to change the potential of the counter electrode.

[0014] In view of the above problems, the present invention aims to provide a bright display device with low power consumption. Furthermore, a pixel configuration and semiconductor equipment that minimizes deviation from the brightness specified by the data potential. The objective is to provide a device and a display device. Note that only display devices having light-emitting elements are targeted. Rather, this invention relates to the current value caused by variations in the threshold voltage of the transistor. The challenge is to suppress the variability. [Means for solving the problem]

[0015] One aspect of the present invention is a transistor that controls the current value supplied to a load, and a first retaining capacitor, The pixel includes a second holding capacity and a first to fourth switch, and the second After the threshold voltage of the transistor is held in the retaining capacitance, a potential corresponding to the video signal is applied. The input is given to the pixel. In this way, the second holding capacitance is set to the threshold voltage. The first holding capacitance and the capacitance-divided potentials among the potentials corresponding to the video signal are added together. By maintaining the voltage, variations in the current value caused by variations in the transistor's threshold voltage can be reduced. This suppresses rattling. Therefore, it is possible to supply the desired current to the light-emitting element and other loads. It is possible. Furthermore, it provides a display device with minimal deviation from the brightness specified by the video signal. This becomes possible.

[0016] One aspect of the present invention is a transistor, a retaining capacitor, a first switch, a second switch, It has a third switch and a fourth switch, and the source electrode and drain of the transistor One of the electrodes is electrically connected to the pixel electrode, and the source electrode and the drain electrode of the transistor. The other electrode is electrically connected to the first wiring via the second switch, and the transistor The source electrode and the other drain electrode of the zista are connected via the third switch to the transient The gate electrode of the transistor is electrically connected to the gate electrode of the transistor, and the gate electrode of the transistor is the retaining capacitance. and electrically connected to the second wiring via the fourth switch, and the gate of the transistor The electrode is electrically connected to the third wiring via the holding capacitance and the first switch. It is a semiconductor device.

[0017] One aspect of the present invention is a transistor, a first retaining capacitor, a second retaining capacitor, and a first switch It has a second switch, a third switch, and a fourth switch, and the transistor One of the source and drain electrodes of the transistor is electrically connected to the pixel electrode, and the transistor One of the source electrode and drain electrode of the transistor is connected to the second retaining capacitance via the transistor. It is electrically connected to the gate electrode, and in addition to the source electrode and drain electrode of the transistor, The side is electrically connected to the first wiring via the second switch, and the transistor's The other of the drain electrode and the other of the transistor are connected via the third switch to the gate of the transistor. The electrode is electrically connected to the gate electrode, and the gate electrode of the transistor has the first holding capacitance and The gate of the transistor is electrically connected to the second wiring via the fourth switch. The electrodes are electrically connected to the third wiring via the first retaining capacitor and the first switch. It is a semiconductor device.

[0018] One aspect of the present invention is a transistor, a first retaining capacitor, a second retaining capacitor, and a first switch It has a second switch, a third switch, a fourth switch, and a fifth switch. Furthermore, one of the source electrode and drain electrode of the transistor is electrically connected to the pixel electrode. And one of the source electrode and drain electrode of the transistor is connected via the second retaining capacitance. The gate electrode of the transistor is electrically connected to the source electrode of the transistor and One of the drain electrodes is electrically connected to the fourth wiring via a fifth switch, and the The source electrode and the other drain electrode of the transistor are connected via the second switch to the first distribution The wire is electrically connected, and the source electrode and the other of the drain electrode of the transistor are the The gate electrode of the transistor is electrically connected via switch 3, and the transistor The gate electrode of the sta is connected to the second wiring via the first retaining capacitor and the fourth switch. Electrically connected, the gate electrode of the transistor has the first retaining capacitance and the first This is a semiconductor device that is electrically connected to the third wiring via a switch.

[0019] In the above configuration, the second wiring is identical to the wiring that controls the first switch. It may also be characterized as follows. Furthermore, the second wiring is the first switch or the second switch of the preceding or following row. It may be any of the scan lines that control switch 4.

[0020] One aspect of the present invention is a transistor, a first retaining capacitor, a second retaining capacitor, and a first switch It has a second switch, a third switch, and a fourth switch, and the transistor One of the source and drain electrodes of the transistor is electrically connected to the pixel electrode, and the transistor One of the source electrode and drain electrode of the transistor is connected to the second retaining capacitance via the transistor. It is electrically connected to the gate electrode, and in addition to the source electrode and drain electrode of the transistor, The side is electrically connected to the first wiring via the second switch, and the transistor's The other of the drain electrode and the other of the transistor are connected via the third switch to the gate of the transistor. The electrode is electrically connected to the gate electrode, and the gate electrode of the transistor has the first holding capacitance and The fourth switch is electrically connected to the first wiring, and the transistor's gate The electrode is electrically connected to the third wiring via the first retaining capacitance and the first switch. It is a connected semiconductor device.

[0021] One aspect of the present invention is a transistor, a first retaining capacitor, a second retaining capacitor, and a first switch It has a second switch, a third switch, and a rectifier element, and the transistor's One of the socket electrode and the drain electrode is electrically connected to the pixel electrode, and the socket of the transistor One of the drain electrode and the drain electrode is connected to the gate of the transistor via the second holding capacitance. The source electrode is electrically connected to the drain electrode, and the other of the source electrode and drain electrode of the transistor is in front The first wiring is electrically connected via the second switch, and the source power of the transistor The other electrode, the drain electrode, is connected to the gate electrode of the transistor via the third switch. The gate electrode of the transistor is electrically connected to the first retaining capacitance and the resistor The transistor is electrically connected to the second wiring via a current element, and the gate electrode of the transistor is The first holding capacity and the semiconductor electrically connected to the third wiring via the first switch. It is a conductive device.

[0022] One aspect of the present invention is a transistor, a first retaining capacitor, a second retaining capacitor, and a first switch It has a second switch, a third switch, and a fourth switch, and the transistor One of the source and drain electrodes of the transistor is electrically connected to the pixel electrode, and the transistor One of the source electrode and drain electrode of the transistor is connected to the second retaining capacitance via the transistor. It is electrically connected to the gate electrode, and in addition to the source electrode and drain electrode of the transistor, The side is electrically connected to the first wiring via the second switch, and the transistor's The other of the drain electrode and the other of the transistor are connected via the third switch to the gate of the transistor. The electrode is electrically connected to the gate electrode, and the gate electrode of the transistor has the first holding capacitance and The third wiring is electrically connected via the first switch, and the fourth switch is It is electrically connected in parallel with the first holding capacity and via the first switch This is a semiconductor device electrically connected to wiring 3.

[0023] The transistor may be an N-channel type transistor. The semiconductor layer of the transistor may be characterized by being made of an amorphous semiconductor film. Furthermore, the transistor The semiconductor layer of the inverter may be characterized by being made of amorphous silicon.

[0024] Furthermore, the semiconductor layer of the transistor may be characterized by being made of a crystalline semiconductor film. stomach.

[0025] In the above invention, the potential of the first wiring is the potential of the pixel electrode and the transistor It may also be characterized as being higher than the sum of the threshold voltages.

[0026] Furthermore, the transistor may be a P-channel type transistor. In that case, In the invention described above, the potential of the first wiring is the potential of the transistor, which is the potential of the pixel electrode. It may also be characterized as being lower than the value obtained by subtracting the threshold voltage.

[0027] One aspect of the present invention is a first holding capacity and a state in which one of the source electrode and the drain electrode is electrically connected to the load. The source electrode and the other drain electrode are electrically connected to the first wiring, and the gate A transistor in which the electrode is electrically connected to the second wiring via the first retaining capacitance, A second holding capacitance that maintains the gate-source voltage of the transistor, and the first holding capacitance Means for holding a first voltage in a quantity and a second voltage in the second holding capacity, and the second holding means for discharging the second voltage of the capacitance to the threshold voltage of the transistor, and the second By inputting a potential corresponding to the video signal from the wiring to the first holding capacitor, the traction A semiconductor characterized by having means for supplying a current set in an inverter to the load. It is a device.

[0028] The transistor may be an N-channel type transistor. The semiconductor layer of the transistor may be characterized by being made of an amorphous semiconductor film. Furthermore, the transistor The semiconductor layer of the inverter may be characterized by being made of amorphous silicon.

[0029] Furthermore, the semiconductor layer of the transistor may be characterized by being made of a crystalline semiconductor film. stomach.

[0030] Furthermore, the transistor may be a P-channel type transistor.

[0031] Furthermore, the first aspect of the present invention is a display device having the semiconductor device described above. It is an electronic device that has a display device.

[0032] The switches shown in the specification can be of various forms. For example, These include electrical switches and mechanical switches. In other words, anything that can control the flow of electric current. It is sufficient if it is such that it is not limited to a specific object. For example, a transistor can be used as a switch (example) For example, bipolar transistors, MOS transistors, etc.), diodes (for example, PN Diode, PIN diode, Schottky diode, MIM (Metal Ins Metal Insulator diode, MIS (Metal Insulator S EMI-HEM (diode, diode-connected transistor, etc.), CYRI SATA and other components can be used. Furthermore, logic circuits combining these can be used as switches. It is also possible to use it.

[0033] When a transistor is used as a switch, that transistor is not simply a switch. Because it operates in this manner, the polarity (conductivity type) of the transistor is not particularly limited. However, the off-current It is desirable to use a transistor with the lower polarity. Transistors with low off-current Examples include transistors with an LDD region and transistors with a multi-gate structure. These are some examples. Also, the potential of the source electrode of the transistor that is used as a switch is low. If operating close to the external power supply (Vss, GND, 0V, etc.), use an N-channel type. If the source electrode is operating with a potential close to the high-potential side power supply (such as Vdd), then the P channel... It is preferable to use a transistor of type 1.5. By operating in this manner, the gate saw Because the absolute value of the voltage across the switch can be increased, the switch operation becomes easier. Because it rarely operates as a source follower, the output voltage becomes smaller. This can prevent that.

[0034] Furthermore, using both N-channel and P-channel transistors, CMO An S-type switch may be used as the switch. If a CMOS type switch is used, various Because the output voltage can be easily controlled in relation to the input voltage, it can operate appropriately. Furthermore, Because the voltage amplitude value of the signal used to turn the switch on and off can be reduced, It is also possible to reduce power consumption.

[0035] When using a transistor as a switch, one of the source electrode and the drain electrode The other end of the source electrode and drain electrode serves as the input terminal of the switch, and the other end of the source electrode serves as the output terminal. The electrode functions as a terminal that controls the conductivity of the switch. On the other hand, the diode acts as the switch. When using a code, the switch may not have terminals to control conductivity. Therefore, using a diode as a switch is better than using a transistor for controlling the terminals. Because no wires are needed, the number of wires can be reduced.

[0036] In this invention, "connected" is synonymous with "electrically connected." Therefore, in the configuration disclosed by the present invention, a predetermined connection relationship, for example, in a figure or text, In addition to the shown connection relationships, other elements that enable electrical connections between them (e.g., switches) (Twitch, transistor, capacitance, inductor, resistor, diode, etc.) are arranged. It is also possible that they are placed without other elements in between, and are electrically connected. "Being connected" includes cases where there is a direct connection. Furthermore, the load is not limited to light-emitting elements such as electroluminescent elements, but can also be any element through which current flows. By doing so, it becomes possible to apply display media that change brightness, color tone, polarization, etc. In addition, it is sufficient to supply the desired current to the load, so the load should, for example, be an electron-emitting element Children, liquid crystal elements, electronic ink, electrophoretic elements, grating light bulbs (GLV), Magnetic displays such as PDPs and digital micromirror devices (DMDs) Display media whose contrast changes due to the effect can also be applied. It is also possible to use carbon nanotubes as the output element. As for display devices, EL displays and as for display devices using electron emission elements, field displays. Mission Display (FED) and SED type flat-panel display (SED: Surf ace-conduction Electron-emitter Disply) Examples include liquid crystal displays and transmissive liquid crystal displays. Liquid crystal displays, semi-transmissive liquid crystal displays, and reflective liquid crystal displays use electronic ink. Electronic paper was used as one of the display devices.

[0037] A transistor is defined as a device that includes a gate electrode, a drain region, and a source region, and is less than [number] of the components. Each element has three terminals, and a channel forming region is located between the drain region and the source region. It has the following characteristics. Here, the source region and drain region are defined by the structure and operating conditions of the transistor. Therefore, it is difficult to precisely define the range of the source or drain region, as it changes. Yes. Therefore, when explaining the connection relationship of a transistor, the drain region and the source region are used. For the two terminals, one of the electrodes connected to these regions is the first electrode, and the other is the second electrode. This notation is used in explanations.

[0038] Furthermore, a transistor has at least three terminals, including the base, emitter, and collector. It may be an element having either the emitter or the collector as the first electrode, and the other as the second This corresponds to electrode 2.

[0039] In this invention, various types of transistors can be applied. There are no particular limitations on the type. For example, amorphous silicon, polycrystalline silicon, microcrystalline silicon. Non-single-crystal semiconductor films, such as silicon (also called crystal or semi-amorphous), Thin-film transistors (TFTs) and the like can be used. When using TFTs, various There are several advantages. For example, it can be manufactured at a lower temperature than single-crystal silicon, This allows for reductions in manufacturing costs and the scaling up of manufacturing equipment. This allows for manufacturing on large substrates and simultaneous production of a large number of display devices. Therefore, Furthermore, it becomes possible to manufacture at a lower cost. Also, because the manufacturing temperature is low, heat resistance is weak. A substrate can also be used; for example, a transistor can be placed on a light-transmitting substrate such as a glass substrate. It can be manufactured.

[0040] Furthermore, when manufacturing polycrystalline silicon, the crystallinity can be improved by using a catalyst (such as nickel). This further improves the process, making it possible to manufacture transistors with better electrical characteristics. , gate driver circuits (scan line driving circuits) and source driver circuits (signal line driving circuits), signal The signal processing circuits (signal generation circuit, gamma correction circuit, DA conversion circuit, etc.) are integrally formed on the substrate. This becomes possible. Furthermore, the use of a catalyst is not always necessary.

[0041] Furthermore, when using microcrystalline silicon, gate driver circuits (scan line driving circuits) and saw A portion of the driver circuit (such as an analog switch) can be integrally formed on the circuit board.

[0042] Furthermore, transistors can be formed using semiconductor substrates, SOI substrates, and the like. In this case, MOS transistors, junction transistors, bipolar transistors, etc. It can be used as a transistor. These allow for variations in characteristics, size, and shape. It is possible to manufacture transistors with low power consumption and high current supply capability. Therefore, the circuit This allows for lower power consumption and higher circuit integration.

[0043] Also, ZnO, α-InGaZnO, SiGe, GaAs, IZO, ITO, SnO Which transistors have compound semiconductors or oxide semiconductors, and furthermore, these compound semiconductors Thin-film transistors, which are thin films made of conductors or oxide semiconductors, can be used. This allows for lower manufacturing temperatures, making it possible to manufacture transistors at room temperature, for example. As a result, direct transients are applied to substrates with low heat resistance, such as plastic substrates and film substrates. These compound semiconductors or oxide semiconductors can be transformed into tubular materials. It can be used not only in the channel portion of an inverter, but also in other applications. Example For example, these compound semiconductors or oxide semiconductors can be used as resistive elements, pixel electrodes, and transparent electrodes. It can be used. Furthermore, since these can be deposited or formed simultaneously with the transistor, Costs can be reduced.

[0044] Furthermore, transistors formed using inkjet or printing methods can also be used. This allows for manufacturing at room temperature, at low vacuum levels, or on large substrates. Furthermore, it becomes possible to manufacture without using a mask (reticle), thus enabling the transistor to... The layout can be easily changed. Furthermore, since there is no need to use a registration system, The number of steps is reduced, and manufacturing costs can be lowered. Furthermore, film deposition can be performed only on the necessary areas. Therefore, compared to etching after depositing a film over the entire surface, less material is wasted and production is lower in cost. It becomes possible to manufacture it.

[0045] Furthermore, transistors containing organic semiconductors or carbon nanotubes can be used. Such transistors can be installed on flexible substrates, so impact It has excellent shock resistance. Not limited to these, various other transistors can also be used. .

[0046] Furthermore, various types of substrates can be used on which the transistors are formed. This is possible and is not limited to specific types. As for substrates on which transistors are formed, For example, single crystal substrates, SOI substrates, glass substrates, quartz substrates, plastic substrates, paper substrates, Cellophane substrates, stone substrates, wood substrates, cloth substrates (natural fibers (silk, cotton, linen), synthetic fibers (na) (Iron, polyurethane, polyester) or regenerated fibers (acetate, cupro, rayon) (Including recycled polyester, etc.), rubber substrate, stainless steel substrate, stainless steel A substrate having steel foil can be used. Also, a transient on a certain substrate A transistor is formed, then the transistor is transposed to another substrate, and then the transistor is placed on yet another substrate. They may be arranged as follows. Substrates on which the transistors are transposed include single-crystal substrates, SOI substrates, and gas Lath substrates, quartz substrates, plastic substrates, paper substrates, cellophane substrates, stone substrates, wood substrates Boards, fabric substrates (natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane, polyester) (Includes) or regenerated fibers (acetate, cupro, rayon, recycled polyester), etc. (Mu), leather substrate, rubber substrate, stainless steel substrate, stainless steel foil Substrates such as these can be used. By using these substrates, higher performance can be achieved. This allows for the formation of transistors, improved heat resistance, and weight reduction.

[0047] Furthermore, transistor configurations can take various forms and are not limited to a specific configuration. For example, a multi-gate structure with two or more gate electrodes may be used. When constructed in this way, the channel regions are connected in series, so multiple transistors are connected in series. This results in a multi-gate structure that reduces off-current and transistor By improving the voltage withstand capability, the reliability of the transistor can be made even better. Due to the lutigate structure, even when operating in the saturation region, the drain-source voltage changes. The current between the rain and source does not change much, and a voltage-current characteristic with a flat slope can be obtained. Yes, it is possible. By utilizing a voltage-current characteristic with a flat slope, an ideal current source circuit or a very This makes it possible to realize active loads with high resistance values. As a result, differential circuits and other circuits with good characteristics can be created. A Rent mirror circuit can be realized. Also, gate electrodes are arranged above and below the channel region. The structure can also be as is. By placing gate electrodes above and below the channel region, Because the effective channel region increases, S increases in current and makes it easier for a depletion layer to form. The value can be reduced. Note that if gate electrodes are placed above and below the channel region, This configuration involves connecting multiple transistors in parallel.

[0048] Alternatively, the structure may be such that the gate electrode is placed on top of the channel region, or the channel region A structure in which the gate electrode is located below is also acceptable. Alternatively, a positive staggered structure or an inverse staggered structure may be used. A gal structure is also acceptable. Furthermore, the channel region may be divided into multiple regions, or the channel region may be parallel. They may be connected in a row or in series. Furthermore, in the channel area (or part thereof) The source electrode and drain electrode may overlap. In this way, the channel region (or so By creating a structure in which the source electrode and drain electrode overlap (part of) the channel region, This prevents the accumulation of electric charge in the part, which can lead to unstable operation. Furthermore, an LDD region is provided. It is also acceptable to do so. By providing an LDD region, the off-current is reduced and the transistor's breakdown voltage is improved. The above can make the reliability of the transistor even better. Alternatively, LDD By defining a region, even if the drain-source voltage changes when operating in the saturation region... To obtain a voltage-current characteristic with a flat slope where the drain-source current does not change much. It is possible.

[0049] As mentioned above, the transistor in this invention is a variety of transistors. It can be used and can be formed on various substrates. All the circuits necessary to realize the function may be formed on the same circuit board. For example, all the circuits necessary to achieve a predetermined function are on a glass substrate or plastic substrate. They may be formed on a single crystal substrate or an SOI substrate. In this way, a predetermined function can be achieved. By forming all the necessary circuits on the same board, the number of components is reduced. This allows for cost reduction and improved reliability by reducing the number of connection points with circuit components. Alternatively, a portion of the circuit necessary to achieve a predetermined function is placed on a certain circuit board to achieve the predetermined function. Another part of the circuit necessary to achieve the desired function may be formed on a different board. It is not necessary to form all the circuits required to achieve this on the same circuit board.

[0050] For example, a part of the circuit necessary to achieve a predetermined function is placed on a glass substrate, and another part is placed on a glass substrate. This is formed on a single crystal substrate, and the IC chip is composed of transistors on the single crystal substrate in this way. The chip is connected to the glass substrate using COG (Chip On Glass) and placed on the glass substrate. You may do so. Alternatively, you can use TAB (Tape Automated Board) to store the IC chip. The glass substrate may be connected using a (sanding) or printed circuit board. In this way, the circuit Because some components are formed on the same circuit board, cost reductions are achieved by reducing the number of components and the circuitry. Reliability can be improved by reducing the number of connection points to components. Furthermore, high drive voltage is possible. Because circuits in certain areas or those with high operating frequencies consume a lot of power, these circuits are different from other circuits. By not forming the IC chip on the same substrate as the circuit, for example, by using an IC chip formed on a single-crystal substrate... This can prevent an increase in power consumption. In this specification, one pixel refers to a single element whose brightness can be controlled. For example, one pixel could represent one color element, and brightness could be expressed using that single color element. Therefore, at that time, a color display device consisting of R (red), G (green), and B (blue) color elements In this case, the smallest unit of an image consists of three pixels: a red pixel, a green pixel, and a blue pixel. The color elements are not limited to three colors; more than three colors may be used, and RGB is also acceptable. You can also use other colors. For example, RGBW (where W is white) or RGB with, for example, yellow, sheer These include variations that add one or more colors such as red, magenta, emerald green, and vermilion. You may add a color similar to at least one of the RGB colors to RGB. For example, R, You may also use G, B1, and B2. Both B1 and B2 are blue, but their frequencies are slightly different. Similarly, we can use R1, R2, G, B or R, G1, G2, B. By using color elements, it is possible to display things more closely to reality. By using color elements, power consumption can be reduced. Another example is... When controlling the brightness of a single color element using multiple regions, one of those regions is considered as one They may also be pixels. For example, when performing area gradation or when having sub-pixels (sub-pixels) One example is when there is a region that controls the brightness for each color element. There are multiple, and the whole set expresses the gradation, but one of the areas that controls brightness is It can also be considered as a pixel, in which case a single color element is composed of multiple pixels. Even if there are multiple areas within a single color element that control brightness, they can be combined into a single color. An element may be considered as one pixel. In that case, one color element constitutes one pixel. And so it becomes. Also, when controlling the brightness of a single color element using multiple areas, the picture The size of the area contributing to the display may differ depending on the element. Also, a single color element In each of the multiple brightness control regions, the signals supplied to each are slightly different. You can widen the viewing angle by doing so. In other words, for one color element, there are multiple options. By making the potential of the pixel electrodes in each region different, the voltage applied to the liquid crystal molecules can be varied. This can also improve the field of view.

[0051] In this specification, semiconductor device refers to a semiconductor element (such as a transistor or diode). This refers to a device having a circuit that includes ). It also refers to all devices that can function by utilizing semiconductor characteristics. General is also acceptable. Furthermore, a display device is defined as a circuit board containing multiple pixels with loads, and the drive of those pixels. Not only the display panel body, which has a peripheral drive circuit formed to enable this, but also a flexible preamplifier to it. This includes those with flexible printed circuits (FPCs) or printed circuit boards (PWBs) attached.

[0052] In this invention, a certain object is formed on top of, or ~formed on As such, the phrases "on top of" or "on top of" mean directly on top of something. It is not limited to being in direct contact. It also applies when they are not in direct contact, that is, when something else is in between. This also includes cases where layer B is on top of layer A (or layer B is on top of layer A). When we say that layer B is formed, it means that layer B is formed in direct contact with layer A, and layer A Another layer (for example, layer C or layer D) is formed on top of it, and layer B is formed on top of that. This includes cases where... Also, the same applies to the description above... This includes not only cases where an object is in direct contact with another object, but also cases where another object is placed in between. Therefore, for example, if layer B is formed above layer A, then on top of layer A When layer B is formed in direct contact with layer A, and when another layer (for example, layer C or layer D) is on top of layer A This includes the case where a layer B is formed on top of it. Furthermore, below ~, Or, in the case of descriptions such as "below ~", similarly, there are cases where it is directly in contact with the object and cases where it is in contact with the object. This includes cases where it has not been done. [Effects of the Invention]

[0053] This invention reduces the variation in current values ​​caused by variations in the threshold voltage of transistors. This can be suppressed. Therefore, it is possible to supply the desired current to the load, including the light-emitting element. This is possible. In particular, when using a light-emitting element as the load, the variation in brightness is small and 1 frame This allows for the provision of a display device with a high proportion of the light emission period within the total time frame. [Brief explanation of the drawing]

[0054] [Figure 1] A diagram illustrating the pixel configuration shown in Embodiment 1. [Figure 2] A timing chart illustrating the operation of the pixels shown in Figure 1. [Figure 3] A diagram illustrating the operation of the pixels shown in Figure 1. [Figure 4] Model diagram of voltage-current characteristics due to channel length modulation. [Figure 5] A diagram illustrating the pixel configuration shown in Embodiment 1. [Figure 6] A diagram illustrating the pixel configuration shown in Embodiment 1. [Figure 7] A diagram illustrating the display device shown in Embodiment 1. [Figure 8] A diagram illustrating the writing operation of the display device shown in Embodiment 1. [Figure 9] A diagram illustrating the pixel configuration shown in Embodiment 2. [Figure 10] A diagram illustrating the pixel configuration shown in Embodiment 3. [Figure 11] A diagram illustrating the pixel configuration shown in Embodiment 3. [Figure 12] A diagram illustrating the pixel configuration shown in Embodiment 3. [Figure 13] A diagram illustrating the pixel configuration shown in Embodiment 4. [Figure 14] A diagram illustrating the pixel configuration shown in Embodiment 4. [Figure 15] A diagram illustrating the pixel configuration shown in Embodiment 4. [Figure 16] A diagram illustrating the pixel configuration shown in Embodiment 4. [Figure 17] A partial cross-sectional view of a pixel shown in Embodiment 9. [Figure 18] A diagram illustrating the light-emitting element shown in Embodiment 9. [Figure 19] A diagram illustrating the direction of light extraction shown in Embodiment 9. [Figure 20] A partial cross-sectional view of a pixel shown in Embodiment 9. [Figure 21] A partial cross-sectional view of a pixel shown in Embodiment 9. [Figure 22] A partial cross-sectional view of a pixel shown in Embodiment 9. [Figure 23] A partial cross-sectional view of a pixel shown in Embodiment 9. [Figure 24] A partial cross-sectional view of a pixel shown in Embodiment 9. [Figure 25] A diagram illustrating the display device shown in Embodiment 11. [Figure 26] A diagram illustrating the display device shown in Embodiment 11. [Figure 27] A diagram illustrating the display device shown in Embodiment 11. [Figure 28] A partial cross-sectional view of a pixel shown in Embodiment 11. [Figure 29] A diagram illustrating the pixel configuration shown in Embodiment 5. [Figure 30] A diagram illustrating the pixel configuration shown in Embodiment 5. [Figure 31] A diagram illustrating the pixel configuration shown in Embodiment 6. [Figure 32] A timing chart illustrating the operation of the pixels shown in Figure 31. [Figure 33] A diagram illustrating an electronic device to which the present invention can be applied. [Figure 34] A diagram showing an example of a mobile phone configuration. [Figure 35] A diagram showing an example of an EL module. [Figure 36] A block diagram showing the main components of an EL television receiver. [Figure 37] A diagram illustrating the pixel configuration shown in Embodiment 6. [Figure 38] A diagram illustrating the pixel configuration shown in Embodiment 7. [Figure 39] A diagram illustrating a driving method that combines digital gradation and time-based gradation. [Figure 40] A diagram illustrating the pixel configuration shown in Embodiment 7. [Figure 41] A diagram illustrating the pixel configuration shown in Embodiment 7. [Figure 42] A diagram illustrating the pixel configuration shown in Embodiment 7. [Figure 43] A diagram illustrating the pixel configuration shown in Embodiment 1. [Figure 44] A top view illustrating the pixel layout shown in Figure 6. [Figure 45] A top view illustrating the pixel layout shown in Figure 6. [Figure 46] A diagram illustrating the pixel configuration shown in Embodiment 8. [Figure 47] A timing chart illustrating the operation of the pixels shown in Figure 46. [Figure 48] A diagram illustrating the operation of the pixels shown in Figure 46. [Figure 49] A diagram illustrating the pixel configuration shown in Embodiment 8. [Figure 50] A diagram illustrating the pixel configuration shown in Embodiment 8. [Figure 51] A diagram illustrating the light-emitting element shown in Embodiment 10. [Figure 52] A diagram illustrating the light-emitting element shown in Embodiment 10. [Figure 53] A diagram illustrating the operation of the pixels shown in Embodiment 1. [Figure 54] A diagram illustrating the pixel configuration shown in Embodiment 1. [Figure 55] A diagram illustrating the pixel configuration shown in Embodiment 1. [Figure 56] A diagram illustrating an example of an application of the display device according to the present invention. [Figure 57] A diagram illustrating an example of an application of the display device according to the present invention. [Figure 58] A diagram illustrating an example of an application of the display device according to the present invention. [Figure 59] A diagram illustrating an example of an application of the display device according to the present invention. [Figure 60] A diagram illustrating an example of an application of the display device according to the present invention. [Figure 61] A diagram illustrating an example of an application of the display device according to the present invention. [Figure 62] A diagram illustrating the pixel configuration of conventional technology. [Figure 63] A diagram illustrating the pixel configuration of conventional technology. [Figure 64] A timing chart for operating pixels as shown in the conventional technology. [Figure 65] A diagram illustrating the ratio of the light emission period within one frame period when using conventional technology. [Modes for carrying out the invention]

[0055] One aspect of the present invention will be described below. However, the present invention can be implemented in many different aspects. It is possible to do so, and without departing from the spirit and scope of the present invention, its form and details may be Those skilled in the art will easily understand that various modifications are possible. Therefore, the contents of this embodiment may be modified in various ways. It is not intended to be interpreted restrictively. Furthermore, in the configuration of the present invention described below, the same applies to The symbols used to indicate this are common across different drawings. (Embodiment 1) The basic configuration of the pixel of the present invention will be explained using Figure 1. The pixel shown in Figure 1 is a transistor Zista 110, first switch 111, second switch 112, third switch 113, Fourth switch 114, first capacitive element 115, second capacitive element 116, light-emitting element 117 It has a signal line 118, a first scan line 119, a second scan line 120, and It is connected to the scan line 121, power line 122, and potential supply line 123 of the 3. In this configuration, transistor 110 is an N-channel transistor, and its gate-source interval The circuit is considered to conduct when the voltage (Vgs) exceeds the threshold voltage (Vth). Furthermore, the pixel electrode of the light-emitting element 117 functions as the anode, and the counter electrode 124 functions as the cathode. The gate-source voltage of a transistor is Vgs, and the drain-source voltage is Vds. The value voltage is Vth, and the voltages stored in the first capacitive element 115 and the second capacitive element 116 are These are denoted as Vc1 and Vc2 respectively, and the power line 122, potential supply line 123, and signal line 118 are as follows: These are also called the first wiring, the second wiring, and the third wiring, respectively. Also, the first scan line 119, the second The second scan line 120 and the third scan line 121 are connected to the fourth wiring, the fifth wiring, and the sixth wiring, respectively. You could also call it wiring.

[0056] The first electrode of transistor 110 (one of the source electrode and the drain electrode) is a light-emitting element. Connected to 117 pixel electrodes, the second electrode (the other of the source electrode and drain electrode) is the second It is connected to the power line 122 via switch 112, and the gate electrode is connected to the third switch 113 And it is connected to the power line 122 via the second switch 112. The 113 is connected between the gate electrode of transistor 110 and the second switch 112. It is.

[0057] Furthermore, the connection point between the gate electrode of transistor 110 and the third switch 113 is a node If it is 130, then node 130 is via the first capacitive element 115 and the first switch 111 It is connected to the signal line 118. In other words, the first electrode of the first capacitive element 115 is the first The second electrode of transistor 110 is connected to the signal line 118 via switch 111, and the gate electrode of transistor 110 is connected to the gate electrode. It is connected to the first electrode of the first capacitive element 115 and the fourth switch 114. It is also connected to the potential supply line 123 via Node 130, which is a second capacitive element 1 It is also connected to the first electrode of transistor 110 via 16. In other words, the second capacitance The first electrode of element 116 is connected to the gate electrode of transistor 110, and the second electrode is connected to the transistor It is connected to the first electrode of the TA110. These capacitive elements are connected by wiring, semiconductor layers and electrodes. This can be formed by sandwiching an insulating film, or in some cases, as shown in Figure 55, a transient It is also possible to omit the second capacitive element 116 by using the gate capacitance of element 110. The means of holding these voltages is called a holding capacitance. Also, node 130 and the first capacitive element 1 Connection between the wiring to which the second electrode of 15 and the first electrode of the second capacitive element 116 are connected. The location is node 131, the first electrode of transistor 110, and the second electrode of second capacitive element 116. The connection point between the electrode and the pixel electrode of the light-emitting element 117 and the wiring to which they are connected is node 132 , and the second electrode of transistor 110, the second switch 112 and the third switch 11 The connection point between the wiring to which point 3 is connected is designated as node 133.

[0058] Furthermore, signals are input to the first scan line 119, the second scan line 120, and the third scan line 121. By doing so, the first switch 111, the second switch 112, and the third switch respectively... The on / off states of switches 113 and 4, 114, are controlled.

[0059] Signal line 118 carries a signal corresponding to the pixel gradation of the video signal, i.e., luminance data. A corresponding electric potential is input.

[0060] Next, the operation of the pixels shown in Figure 1 will be explained using the timing chart in Figure 2 and Figure 3. To clarify, the frame period corresponding to the period for displaying one screen's worth of image in Figure 2 is It is divided into an initialization period, a threshold voltage writing period, a data writing period, and an illumination period. In addition, the initialization period, threshold voltage writing period, and data writing period are combined into one. This is called the response period. There is no particular limit to the duration of one frame, but the flickering (flickering) of the image is what causes the viewer to experience the flickering. It is preferable to keep the time to at least 1 / 60th of a second or less so that you do not feel any discomfort.

[0061] Furthermore, a potential of V1 (V1: any number) is input to the counter electrode 124 of the light-emitting element 117. Furthermore, the potential difference V is the minimum required for the light-emitting element 117 to emit light. EL Let's assume And, power line 122 has V1 + V EL A potential of +Vth+α (α: any positive number) is input. Therefore, power line 122 is V1 + V EL Any potential greater than +Vth+α is acceptable. The potential of the feed line 123 is not particularly limited, but the range of potential input to the panel on which the pixels are formed is It is preferable that it be internal. This eliminates the need to create a separate power supply. Here, we define the potential of the potential supply line 123 as V2.

[0062] First, as shown in Figures 2(A) and 3(A), during the initialization period, the first switch 111 Turn off the second switch 112, the third switch 113, and the fourth switch 114. Turn it on. At this time, transistor 110 is in a conducting state, and the first capacitive element 115 is V1+V EL +Vth+α-V2 is held in the second capacitance element 116, and Vth+α is held in the second capacitance element 116. During the initialization period, a predetermined voltage is applied to the first capacitive element 115, and the second capacitive element 1 At point 16, a voltage at least higher than Vth should be maintained.

[0063] During the threshold voltage writing period shown in Figures 2(B) and 3(B), the second switch 11 Turn 2 off. Therefore, the potential of the first electrode, i.e., the source electrode, of transistor 110 is as follows. First, the gate-source voltage Vgs of transistor 110 rises to the threshold voltage (Vth At this point, transistor 110 becomes non-conductive. Therefore, the second capacitive element 1 The voltage Vc2 held at 16 is approximately equal to Vth.

[0064] During the subsequent data writing period shown in Figures 2(C) and 3(C), the third swim After turning off switch 113 and the fourth switch 114, turn on the first switch 111. Then, a potential (V2 + Vdata) corresponding to the brightness data is input from signal line 118. The voltage Vc2 held by the second capacitive element 116 is the voltage Vc2 held by the first capacitive element 115 and the second capacitive element 116. If the capacitances of the electroluminescent element 116 and the light-emitting element 117 are C1, C2, and C3 respectively, then C3 > >From C1 and C2, it can be expressed as in equation (1).

[0065]

number

[0066] Note that C1 and C2 are necessary when determining the potential supplied from signal line 118, The relationship between them is not particularly limited. Furthermore, in the case where C1 > C2, the Vdata associated with the change in brightness is... Since the amplitude can be reduced, power consumption can be reduced. On the other hand, C2 >In the case of C1, the change in Vc2 due to the on / off state of surrounding switches and off current is suppressed. This is possible. Due to these conflicting effects, C1 and C2 are equal, and the first capacitance element 115 It is preferable that the size of the first and second capacitive elements 116 be the same.

[0067] Furthermore, if you want the light-emitting element 117 to be non-emitting during the next light-emitting period, then Vdata ≤ You just need to input a potential of 0.

[0068] Next, during the light emission period shown in Figures 2(D) and 3(D), the first switch 111 is turned off. After that, the second switch 112 is turned on. At this time, the gate of transistor 110... The source-to-source voltage is Vgs = Vth + Vdata × (C1 / (C1 + C2)), and the luminance data A current corresponding to the light source flows through transistor 110 and light-emitting element 117, and light-emitting element 117 emits light. It lights up. Of course, the potential corresponding to the luminance data input from signal line 118 is the transient The gate-source voltage of the TA110 is Vgs = Vth + Vdata × (C1 / (C1 + C2 Vdata is determined taking into consideration that )) will be the case.

[0069] The current I flowing through the light-emitting element 117 is the current I when the transistor 110 is operating in the saturation region. In this case, it is represented by equation (2).

[0070]

number

[0071] Furthermore, when transistor 110 is operated in the linear region, the current flowing through the light-emitting element 117 I is expressed by equation (3).

[0072]

number

[0073] Here, W is the channel width of transistor 110, L is the channel length, μ is the mobility, and Cox This refers to storage capacity.

[0074] From equations (2) and (3), the operating region of transistor 110 is the saturation region, the linear region, Even in the case of misalignment, the current flowing through the light-emitting element 117 is the threshold value of the transistor 110. It does not depend on the voltage (Vth). Therefore, it does not depend on the variation in the threshold voltage of transistor 110. This suppresses variations in current values ​​caused by the current and supplies the light-emitting element 117 with a current corresponding to the brightness data. It is possible.

[0075] From the above, the variation in brightness is due to variations in the threshold voltage of transistor 110. This can suppress sticking. Also, because it operates with a constant potential at the counter electrode, power consumption is reduced. It becomes possible to reduce the force.

[0076] Furthermore, when transistor 110 is operated in the saturation region, light-emitting element 117 This also suppresses variations in brightness due to degradation. Note that degradation of the light-emitting element is related to its current-voltage characteristics. This is not limited to cases where the value is shifted parallel to the value before degradation. For example, the slope of the characteristic or the characteristic is curved. When expressed, this includes cases where the differential value differs from that before degradation. The light-emitting element 117 has degraded. Then, the V of the light-emitting element 117 EL It increases, and the first electrode of transistor 110, i.e., the thorax, increases. The potential of the source electrode rises. At this time, the source electrode of transistor 110 becomes the second capacitive element. The gate electrode of transistor 110 is connected to the second electrode of 116, and the first electrode of the second capacitive element 116 It is connected to the electrode, and the gate electrode side is floating. Therefore, As the potential rises, the gate potential of transistor 110 also rises by the same amount. Therefore, since the Vgs of transistor 110 does not change, even if the light-emitting element deteriorates, This does not affect the current flowing through the zista 110 and the light-emitting element 117. Furthermore, in equation (2) as well... It can be seen that the current I flowing through the light-emitting element does not depend on the source potential or drain potential.

[0077] Therefore, when transistor 110 is operated in the saturation region, transistor 1 Transistor 110 due to variations in threshold voltage and degradation of light-emitting element 117 This can suppress variations in the current flowing through it.

[0078] Furthermore, when transistor 110 is operated in the saturation region, the shorter the channel length L, the more... If the drain voltage is significantly increased due to the subsidence phenomenon, a large amount of current is likely to flow.

[0079] Furthermore, increasing the drain voltage above the pinch-off voltage shifts the pinch-off point towards the source side. Therefore, the effective channel length that functions as a channel is reduced. As a result, the current value It increases. This phenomenon is called channel length modulation. Note that the pinch-off point is when the channel disappears. This is the boundary point where the channel thickness becomes 0 under a steady gate, and the pinch-off voltage is... This refers to the voltage when the pinch-off point is at the drain terminal. This phenomenon also increases as the channel length L decreases. It is likely to occur. For example, Figure 4 shows a model diagram of the voltage-current characteristics due to channel length modulation. In Figure 4, the channel length L of the transistors is (a)>(b)>(c).

[0080] From the above, when operating transistor 110 in the saturation region, drain source It is preferable that the current I relative to the inter-voltage Vds be as close to constant as possible. Therefore, transistor 11 A longer channel length L is preferable for 0. For example, the channel length L of a transistor is It is preferably larger than the channel width W. Also, the channel length L is 10 μm or more and 50 μm or less, more preferably 15 μm or more and 40 μm or less. However, the channel length L and the channel width W are not limited thereto.

[0081] As described above, since the variation in the current value due to the variation in the threshold voltage of the transistor can be suppressed, in the present invention, the destination of the current controlled by the transistor is not particularly limited. Therefore, the light-emitting element 117 shown in FIG. 1 can typically be an EL element (organic EL element, inorganic EL element, or EL element including an organic substance and an inorganic substance). Further, instead of the light-emitting element 117, an electron-emitting element, a liquid crystal element, an electronic ink, etc. can also be applied. FIG. 5 shows an example in which an EL element 517 is used as the light-emitting element 117. Note that FIG. 5 shows a state where current is flowing from the pixel electrode 511 to the counter electrode 124.

[0082] Also, since the transistor 110 only needs to have a function of controlling the current supplied to the light-emitting element 117, the type of the transistor is not particularly limited, and various types can be used. For example, a thin-film transistor (TFT) using a crystalline semiconductor film, a thin-film transistor using a non-single-crystalline semiconductor film typified by amorphous silicon and polycrystalline silicon, a transistor formed using a semiconductor substrate or an SOI substrate, a MOS transistor, a junction transistor, a bipolar transistor, a transistor using a compound semiconductor such as ZnO or a-InGaZnO, a transistor using an organic semiconductor or a carbon nanotube, and other transistors can be applied to the transistor 110.

[0083] ​The first switch 111 outputs a potential corresponding to the brightness data, i.e., the video signal, via the signal line 118. The timing to input to the pixel is selected, and the voltage held mainly in the first capacitive element 115, and The voltage held by the second capacitive element 116, i.e., the gate-source voltage of transistor 110. This changes the second power of transistor 110. This selects the timing for supplying a predetermined potential to the pole. In some cases, the first The second electrode of the capacitive element 115 and the first electrode of the second capacitive element 116 are also subjected to the predetermined electrical current. The third switch 113 supplies power to the gate electrode and second electrode of transistor 110. This controls the connection to the first capacity for each frame period. The timing for holding a predetermined voltage in element 115 is selected, and the first capacitive element 115 This controls whether or not a predetermined potential is supplied to the electrodes. Therefore, the first switch Switches 111, 112, 113, and 114 are as described above. It is not particularly limited as long as it has a function. For example, it could be a transistor or a diode. A logic circuit combining these components is also acceptable. Note that the first switch 111 and the second switch Switches 112 and 114 supply a signal or potential to the pixel at the above timing. If it is possible to do so, then it is not particularly necessary. Also, the above function can be implemented in the third switch 113 as well. If it can be done, then it's not particularly necessary.

[0084] For example, during the initialization period and the threshold voltage writing period, the first capacitive element 115 It can maintain a constant voltage, and furthermore, it can transmit signals according to the pixel gradation during the data writing period. If input can be made to the pixel, the first switch 111 and the fourth switch are located within the pixel. It is not necessary to provide the 114. Furthermore, V1+V in the initial period and emission period of the pixel EL If it is possible to supply +Vth+α (α>0), then the second S as shown in Figure 43 It is not necessary to provide switch 112 in particular. The pixels shown in Figure 43 are transistor 110, 1 It has a capacitive element 115, a third switch 113, and a pixel electrode 4300. The first electrode of the ZISTA 110 (one of the source electrode and drain electrode) is connected to the pixel electrode 4300. The gate electrode is connected to the second electrode of transistor 110 via the third switch 113. It is connected to the first capacitive element 115. It is also connected to both electrodes. The signal, i.e., the potential corresponding to the brightness data (i.e., V2 + Vdata) and the first capacitive element 1 A potential (i.e., V2) is supplied to 15 for a predetermined period of time to maintain a predetermined voltage. Furthermore, the gate capacitance 4310 of transistor 110 is used as the holding capacitance. Therefore, it is not necessary to provide the second capacitive element 116 in Figure 1. Similarly, the timing chart shown in Figure 2 is used to supply the desired potential to each electrode. Therefore, variations in current values ​​caused by variations in the threshold voltage of transistor 110 are suppressed. This is possible. Therefore, the desired current can be supplied to the pixel electrode 4300. Of course, the gate capacitance of transistor 110 is also the gate capacitance of the second capacitive element 116 in Figure 1. It is possible to use or omit it.

[0085] Next, Figure 6 shows the first switch 111, the second switch 112, the third switch 113 and The case where an N-channel transistor is applied to the fourth switch 114 is shown. Note that the parts common to the configuration of FIG. 1 are denoted by common reference numerals and their description is omitted.

[0086] The first switching transistor 611 corresponds to the first switch 111 in FIG. 1. The second switching transistor 612 corresponds to the second switch 112, the third switching transistor 613 corresponds to the third switch 113, and the fourth switching transistor 614 corresponds to the fourth switch 114. The channel length of the transistor 110 is preferably longer than the channel length of any of the transistors of the first switching transistor 611, the second switching transistor 612, the third switching transistor 613, and the fourth switching transistor 614.

[0087] The gate electrode of the first switching transistor 611 is connected to the first scanning line 119, the first electrode is connected to the signal line 118, and the second electrode is connected to the first electrode of the first capacitive element 115.

[0088] The gate electrode of the second switching transistor 612 is connected to the second scanning line 120, the first electrode is connected to the node 133, and the second electrode is connected to the power supply line 122.

[0089] The gate electrode of the third switching transistor 613 is connected to the third scanning line 121, the first electrode is connected to the node 130, and the second electrode is connected to the

[0090] node 133. The first electrode is connected to the first electrode of the first capacitive element 115, and the second electrode is at a potential It is connected to supply line 123.

[0091] Each switching transistor operates when the signal input to its respective scan line is at a high level. It is sometimes turned on and turns off when the input signal is at a low level.

[0092] Figure 44 shows one configuration of the pixel layout shown in Figure 6, using a top view. The configuration of the zista, capacitive elements, light-emitting elements, etc. will be explained in the embodiments described later, so here we will not go into detail. This section will only describe the layout. Also, the transistor 110 and the first shown in Figure 44 Switching transistors 611 to the fourth switching transistor 614 are semiconductors It uses a bottom-gate type transistor where the gate electrode is located beneath the body layer.

[0093] The conductive layer 4410 shown in Figure 44 is connected to the first scan line 119 and the first switching transistor The conductive layer 4411 includes a portion that functions as the gate electrode of TA 611, and the first It includes a portion that functions as the first electrode of the switching transistor 611. Layer 4412 is the second electrode of the first switching transistor 611 and the first capacitive element It functions as the first electrode of 115 and the first electrode of the fourth switching transistor 614. The conductive layer 4413 includes the second electrode of the first capacitive element 115 and the second capacitance The element 116 includes a first electrode and a portion that functions as the gate electrode of the transistor 110. Furthermore, this conductive layer 4413 is connected to the third switching transistor via wiring 4414. It is connected to a conductive layer 4415 which includes a portion that functions as the first electrode of 613. 4416 is the second electrode of the second capacitive element 116 and the first electrode of the transistor 110. It includes a part that functions as and is connected to the pixel electrode 4455 of the light-emitting element via a contact. Furthermore, the conductive layer 4417 is connected to the second electrode of the transistor 110 and the third switch. The second electrode of transistor 613 and the first electrode of the second switching transistor 612 The conductive layer 4418 includes a portion that functions as an electrode, and connects to the power line 122 and the second switch The conductive layer 4419 includes a portion that functions as the second electrode of transistor 612. The scan line 120 of the second switching transistor 612 functions as the gate electrode. Includes a portion. The conductive layer 4420 is connected to the gate electrode of the third switching transistor 613 and , including a portion that functions as the gate electrode of the fourth switching transistor 614, wiring It is connected to the third scan line 121 via 4421. Also, the fourth switching transistor The conductive layer 4422, which includes the portion that functions as the second electrode of the converter 614, is connected to the wiring 4423 It is connected to the potential supply line 123 via [this].

[0094] Furthermore, among the conductive layers, the gate electrode of the first switching transistor 611, the first The portions that function as the electrode and the second electrode each contain a conductive layer and a semiconductor layer 4431. This is the part formed by the overlapping of the second switching transistor 612. The portions that function as the electrode, the first electrode, and the second electrode each include a conductive layer and a semiconductor layer. This is the part that is formed by overlapping with body layer 4432. Also, among each conductive layer, the third It functions as the gate electrode, first electrode, and second electrode of the switching transistor 613. The portion is formed by overlapping the conductive layer and the semiconductor layer 4433, respectively. The gate electrode, first electrode and second electrode of the fourth switching transistor 614 The functional parts are formed by overlapping conductive layers and semiconductor layers 4434, each containing the respective components. This is the part that is present. Similarly, in transistor 110, the gate electrode, the first electrode and The portion that functions as the second electrode overlaps with the conductive layer and semiconductor layer 4430 that each contains. This is the conductive layer portion that is formed. The first capacitive element 115 is connected to the conductive layer 4412. In the portion where the conductive layer 4413 and the second capacitive element 116 overlap, the conductive layer 4413 and the conductive layer It is formed in the area where it overlaps with 4416.

[0095] Furthermore, conductive layer 4410, conductive layer 4413, conductive layer 4419, conductive layer 4420, and the third running The inspection line 121 and the potential supply line 123 can be fabricated using the same material and the same layer. Semiconductor layer 4430, semiconductor layer 4431, semiconductor layer 4432, semiconductor layer 4433 and semiconductor Layer 4434, conductive layer 4411, conductive layer 4412, conductive layer 4415, conductive layer 4416, conductive The electrical layer 4417, the conductive layer 4418, and the conductive layer 4422 are each made of the same material and the same layer. It can be manufactured using the same material and layer as the pixel electrode 4455. Wiring 414, wiring 4421, and wiring 4423 can be manufactured.

[0096] As shown in Figure 44, each transistor except the first switching transistor 611 In the device, one of the source electrode and the drain electrode is structured to surround the other electrode. This allows for an increase in channel width. Therefore, the semiconductor of the transistors that make up the pixels... This is particularly effective when using an amorphous semiconductor layer with lower mobility than a crystalline semiconductor layer in the body layer. Of course, in the first switching transistor 611 as well, the source electrode and drain The structure may also be such that one electrode surrounds the other electrode.

[0097] Next, Figure 4 shows a top view of one form of the pixel layout shown in Figure 6, which is different from the layout shown in Figure 44. This is shown in 5. Note that the transistor 110 and the first switching transistor shown in Figure 45 In switching transistors 611 to the fourth 614, the gate electrode is located on the semiconductor layer. It uses top-gate transistors such as sequential staggered transistors.

[0098] In Figure 45, the conductive layer 4510 is connected to the first scan line 119 and the first switching transistor The conductive layer 4511 includes a portion that functions as the gate electrode of the ZISTRA 611, and the signal line 118 and Includes a portion that functions as the first electrode of the first switching transistor 611. The film 4520 serves as the semiconductor layer and second electrode of the first switching transistor 611. The functional part, the first electrode and semiconductor layer of the fourth switching transistor 614 The functional part includes the part that functions as the first electrode of the first capacitive element 115. The conductive film 4520 is connected to the potential supply line 123 via wiring 4512, and wiring 451 2 functions as the second electrode of the fourth switching transistor 614. Also, the conductive layer 4513 is the second electrode of the first capacitive element 115 and the first electrode of the second capacitive element 116. and includes a portion that functions as the gate electrode of transistor 110. Note that the conductive layer 4513 is Through the wiring 4514 which functions as the first electrode of the third switching transistor 613 It is connected to the semiconductor film 4521. This semiconductor film 4521 is a third switching Semiconductor layer of the transistor 613 and portion that functions as a second electrode, second switching The portion of transistor 612 that functions as the first electrode and semiconductor layer, and the portion of transistor 110 The first electrode, the semiconductor and the portion that functions as the second electrode, and the second capacitive element 116 It includes a portion that functions as a second electrode. The conductive layer 4515 has a second scan line 120 and Includes a portion that functions as the gate electrode of the 2 switching transistors 612. Conductive layer 4 516 is the power line 122 and the second electrode of the second switching transistor 612. Includes the functional part. The conductive layer 4517 is the gateway for the third switching transistor 613. The portion that functions as a gate electrode, and the gate electrode of the fourth switching transistor 614 It includes a functional component and is connected to the third scan line 121 via wiring 4518. Furthermore, the pixel electrode 4545 of the light-emitting element is connected to the semiconductor film 4521 via wiring 4519. It is.

[0099] The first capacitive element 115 consists of a semiconductor film 4520 and a conductive layer 4513 that overlap. In this part, the second capacitive element 116 is the part where the semiconductor film 4521 and the conductive layer 4513 overlap. It is formed in minutes.

[0100] Furthermore, conductive layer 4510, conductive layer 4513, conductive layer 4515, conductive layer 4517, and the third running The inspection line 121 and the potential supply line 123 can be fabricated using the same material and the same layer. Semiconductor films 4520 and 4521 can also be fabricated using the same material and the same layers. Furthermore, the same material and layer as the conductive layer 4511 are used for wiring 4512, wiring 4514, and conductive The electrical layer 4516 and wiring 4518 can be manufactured.

[0101] Note that the pixel layout is not limited to the above.

[0102] In the pixel configuration of Figure 6, the threshold of transistor 110 is controlled by the same operating method as in Figure 1. Variations in current values ​​caused by variations in voltage can be suppressed. Therefore, brightness data This allows the light-emitting element 117 to receive a current corresponding to the data, thereby suppressing variations in brightness. This becomes possible. Furthermore, when transistor 110 is operated in the saturation region, This also suppresses variations in brightness caused by the degradation of the light-emitting element 117.

[0103] Furthermore, since pixels can be constructed using only N-channel transistors, the manufacturing process This can be simplified. Also, amorphous semiconductor material can be used in the semiconductor layer of the transistors that make up the pixels. Conductors, semi-amorphous semiconductors, etc., can be used. For example, as an amorphous semiconductor... Amorphous silicon (a-Si:H) is one example. By using these semiconductors... Furthermore, the manufacturing process can be simplified. Therefore, it is possible to reduce manufacturing costs and improve yield. Improvement is possible.

[0104] Note that the first switching transistor 611 and the second switching transistor 61 2. Third switching transistor 613 and fourth switching transistor 614 Therefore, to operate as a simple switch, the polarity (conductivity type) of the transistor is not particularly limited. It is not possible. However, it is desirable to use a transistor with low off-current. Transistors that do not have this feature include those with an LDD region or those with a multi-gate structure. There are things like that. Also, using both N-channel and P-channel types, CMOS type switches You can make it a tweak.

[0105] Furthermore, if the device performs the same operation as shown in Figure 1, the switch connection can take various configurations. This is possible and is not limited to Figure 1. As can be seen from Figure 3, which explains the operation of the pixel configuration in Figure 1, In this invention, the initialization period, threshold voltage writing period, data writing period and light emission period are Each of these should have electrical conductivity as shown by the solid lines in Figures 53(A) to (D). Any configuration that allows switches and other components to be positioned and operated in a way that satisfies this requirement is acceptable.

[0106] Furthermore, during the initialization period, a predetermined voltage is applied to the first capacitive element 115, and the second capacitive element 116 It is sufficient if a voltage at least higher than the threshold voltage Vth of transistor 110 is maintained. Therefore, as shown in Figure 54, node 132 is connected to the potential supply line via the fifth switch 5405. It may be connected to 5401. This fifth switch 5405 is turned on only during the initialization period. Assuming this is the case, in Figure 54, the scan lines that control the on / off state of the fifth switch 5405 are not shown. It is not. Furthermore, the potential of the potential supply line 5401 is V1+V EL A lower potential is better. More preferably, the potential is V1 or less, and by setting the potential to such a degree, the light-emitting element 117 Because a reverse bias voltage can be applied, it is possible to insulate short-circuit points in the light-emitting element, This can suppress the degradation of the light-emitting element. Therefore, the lifespan of the light-emitting element can be extended. .

[0107] Next, the display device having the pixels of the present invention described above will be explained with reference to Figure 7.

[0108] The display device has a signal line drive circuit 711, a scan line drive circuit 712, and a pixel section 713. The pixel section 713 is arranged with multiple signal lines S extending in the column direction from the signal line drive circuit 711. Lines 1 to Sm and power lines P1_1 to Pm_1 extend in the row direction from the scan line drive circuit 712. Multiple first scan lines G1_1~Gn_1, second scan lines G1_2~Gn_2, and Scan lines G1_3~Gn_3 and potential supply lines P1_2~Pn_2, and signal line S1~ It has multiple pixels 714 arranged in a matrix corresponding to Sm. And each pixel 7 14 consists of signal line Sj (one of signal lines S1 to Sm), power line Pj_1, and the first running Scan line Gi_1 (any one of scan lines G1_1 to Gn_1), second scan line Gi_2, It is connected to the third scan line Gi_3 and the potential supply line Pi_2.

[0109] Note that the signal line Sj, power line Pj_1, first scan line Gi_1, second scan line Gi_2, The third scan line Gi_3 and the potential supply line Pi_2 correspond to signal line 118 and power line 1 in Figure 1, respectively. 22, first scan line 119, second scan line 120, third scan line 121, potential supply line 12 It corresponds to 3.

[0110] The signal output from the scan line drive circuit 712 selects the row of pixels to be operated. The operation shown in Figure 2 is performed simultaneously for each pixel belonging to the same row. During the writing period, the pixels of the selected row are output from the signal line drive circuit 711. The video signal is written. At this time, the potential corresponding to the brightness data of each pixel is applied to each signal line. Input is sent to S1~Sm.

[0111] As shown in Figure 8, for example, once the data writing period for row i is complete, it will belong to row i+1. The signal is written to the pixel. Figure 8 shows the data writing period for each row. Therefore, to faithfully represent this, we have extracted and described the operation of the first switch 111 in Figure 2. And, in row i, the pixels that have finished their data writing period move on to the light emission period. It emits light according to the signal written to that pixel.

[0112] Therefore, as long as the data writing periods for each row do not overlap, each row can be initialized independently. The timing can be set. Also, each pixel will emit light except during its own address period. Since it is possible, the ratio of the emission period within one frame period (i.e., the duty cycle) is not It can always be made larger, and it is possible to set it to approximately 100%. Therefore, the variation in brightness is A display device with a low duty cycle and high duty cycle can be obtained.

[0113] Furthermore, it is also possible to set a longer threshold voltage writing period, so the transistor The threshold voltage can be written to the capacitive element more accurately. Therefore, as a display device This can improve the reliability of the system.

[0114] Note that the display device configuration shown in Figure 7 is just one example, and the present invention is not limited thereto. If the potential supply lines P1_2~Pn_2 are arranged parallel to the first scan lines G1_1~Gn_1, It is not necessary for them to be parallel to the signal lines S1~Sm. Also, the power line P1 In _1~Pm_1 as well, it is not necessary to arrange them parallel to the signal lines S1~Sm, the first They may be arranged parallel to scan lines G1_1 to Gn_1.

[0115] In this embodiment, the on / off state of the third switch 113 and the fourth switch 114 is the same. The case shown is when control is performed using a scan line, i.e., the third scan line 121, but each case is different. Alternatively, you may control each switch using the scan lines according to the timing chart in Figure 2. .

[0116] Note that the variation in threshold voltage is due to the threshold voltage of each transistor between pixels. In addition to the differences, when focusing on a single transistor, the change in threshold voltage over time is also... It shall be included. Furthermore, the difference in threshold voltage of each transistor is the manufacturing of the transistor. This also includes differences due to transistor characteristics over time. A transistor refers to a transistor that has the function of supplying current to a load such as a light-emitting element. (Embodiment 2) In this embodiment, a pixel configuration different from that of Embodiment 1 is shown in Figure 9. Items similar to those in item 1 are indicated using the same reference numeral, and are the same part or part having a similar function. I will omit a detailed explanation of the minutes.

[0117] The pixels shown in Figure 9(A) are transistor 110, first switch 111, second switch 112, third switch 113, rectifier element 914, first capacitive element 115, second capacitive It has an element 116 and a light-emitting element 117. The pixels have a signal line 118 and a first scan line 11 9. The second scan line 120, the third scan line 921, the fourth scan line 922 and the power line 122 It is connected. The pixels shown in Figure 9(A) are rectified to the fourth switch 114 in Figure 1. The configuration uses element 914, and the first electrode of the first capacitive element 115 is a rectifier element It is connected to the fourth scan line 922 via 914. In other words, the rectifier element 914 is the first The capacitive element 115 is connected so that current flows from the first electrode to the fourth scan line 922. Of course, as shown in Embodiment 1, the first switch 111, the second switch 11 Switches 2 and 4 114 may use transistors or the like. Also, rectifier element 914 These include the Schottky barrier type 951, PIN type 952, and PN type 953 shown in Figure 9(B). In addition to diodes such as those mentioned above, diode-connected transistors such as transistors 954 and 955 are used. It is possible. However, transistors 954 and 955 are the ones that conduct current. Depending on the direction, the polarity of the transistor needs to be selected appropriately.

[0118] The rectifier element 914 generates current when a high-level signal is input to the fourth scan line 922. When no current flows and an L-level signal is input, current flows through the rectifier element 914. Therefore, When the pixels in Figure 9 operate in the same way as the pixels shown in Figure 1, the initialization period and threshold voltage are as follows: During the writing period, an L-level signal is input to the fourth scan line 922, and during other periods... In this case, an H-level signal is input. For an L-level signal, current simply flows through the rectifier element 914. In addition, similar to Embodiment 1, the potential corresponding to the brightness data input to the pixel is (V2 If we set it to +Vdata, then it is necessary to lower the potential of the first electrode of the second capacitive element 116 to V2. Therefore, the potential obtained by subtracting the forward threshold voltage of the rectifier element 914 from V2 is This shall be done. However, V2 is an arbitrary value, and the light-emitting element 117 shall not emit light during the light-emitting period. If you want it to be light, you should input a potential where Vdata=0. Also, for a high-level signal, As mentioned above, it is sufficient that no current flows through the rectifier element 914, so V2 to the rectifier element 914 It is sufficient if the value is greater than the value obtained by subtracting the forward threshold voltage.

[0119] Considering the above, by operating the pixel configuration in Figure 9 in the same way as in Figure 1, the traction control will be reduced. This suppresses variations in current values ​​caused by variations in the threshold voltage of the converter 110. Yes, it is possible. Therefore, a current corresponding to the brightness data can be supplied to the light-emitting element 117, and the brightness will be increased. This makes it possible to suppress variations in the degree. Also, it allows transistor 110 to operate in the saturation region. In this case, variations in brightness caused by the degradation of the light-emitting element 117 will also be suppressed. It is possible.

[0120] Furthermore, the pixels shown in this embodiment can be applied to the display device shown in Figure 7. Embodiment Similar to point 1, as long as the data writing periods for each row do not overlap, each row can be initialized independently. The timing can be set. Also, each pixel will emit light except during its own address period. Since it is possible, the ratio of the emission period within one frame period (i.e., the duty cycle) is not It can always be made larger, and can be set to approximately 100%. Therefore, there is little variation in brightness. A display device with a high duty cycle can be obtained.

[0121] Furthermore, it is possible to set a longer threshold voltage writing period, which allows current to flow to the light-emitting element. To more accurately write the threshold voltage of the transistor that controls the current value to the capacitive element. This is possible. Therefore, the reliability as a display device is improved.

[0122] This embodiment can be freely combined with the pixel configurations shown in other embodiments, in addition to Figure 1 described above. They can be combined. That is, the rectifier element 914 can also be used in pixels shown in other embodiments. It is possible to use it. (Embodiment 3) In this embodiment, pixels with a configuration different from that of embodiments 1 and 2 are shown in Figures 10 and 11. Specifically, we will describe a pixel configuration in which the potential supply line 123 shown in Figure 1 is replaced with other wiring. Furthermore, it is sufficient to supply an arbitrary potential to the first electrode of the first capacitive element 115. A configuration like the one in Embodiment 1 can be adopted. Similar components to those in Embodiment 1 share the same reference numerals. This is shown using [a specific method / tool], and detailed explanations of identical or similarly functioning parts are omitted.

[0123] The pixels shown in Figure 10(A) are transistor 110, first switch 111, second switch Switch 112, third switch 113, fourth switch 114, first capacitive element 115, second It has a capacitive element 116 and a light-emitting element 117. The pixel has a signal line 118 and a first scanning It is connected to line 119, the second scan line 120, the third scan line 121, and the power line 122. .

[0124] In the pixel shown in Figure 1 of Embodiment 1, the first electrode of the first capacitive element 115 is the fourth switch In contrast to the connection to the potential supply line 123 via switch 114, in Figure 10(A) the power line It can be connected to 122. This is not limited to the potential supply line 123, but also during the initialization period and During the key value voltage writing period, a predetermined voltage is maintained in the first capacitive element 115. This is because it is sufficient to supply potential to the first electrode. Therefore, instead of a potential supply line, a power supply is used. A wire 122 can be used. In this way, a potential is applied to the first electrode of the first capacitive element 115. By replacing the wiring that supplies power with power line 122, the number of wires can be reduced, and the opening The rate can be improved.

[0125] Furthermore, as shown in Figure 10(B), the fourth switch 114 is connected in parallel with the first capacitive element 115. It may also be connected to the fourth switch 114. It is also possible to connect to node 131 via this. During the key value voltage writing period, a predetermined voltage is maintained in the first capacitive element 115. A potential can be supplied to the first electrode.

[0126] Furthermore, as shown in the pixels of Figure 11, the first electrode of the first capacitive element 115 is connected to the light-emitting element 117 A fourth switch is connected to the counter electrode 124 or the wiring supplying a predetermined potential to the counter electrode 124. It may also be connected via switch 114. That is, supplied from the potential supply line 123 in Figure 1. Instead of the potential, a predetermined potential supplied to the counter electrode 124 may be used. This makes it possible to reduce the number of wires and improve the aperture ratio.

[0127] Furthermore, the first electrode of the first capacitive element 115 and the counter electrode 124 of the light-emitting element 117 are connected. The wiring is not only connected to the counter electrode 124, but also in contact with the counter electrode 124 and in parallel. By extending it, it can also be used as auxiliary wiring in the counter electrode. Of course, auxiliary wiring This is not limited to a single pixel, but can extend to adjacent pixels or even the entire pixel region. The auxiliary wiring can be used to reduce the resistance of the counter electrode 124. When the material is made into a thin film, an increase in resistance can be prevented. In particular, when a transparent electrode is used as the counter electrode It is effective in the case of a high resistance of the counter electrode. The variation in brightness of the light-emitting element 117 caused by the non-uniform in-plane potential distribution of the counter electrode is It can be suppressed. Therefore, reliability can be further improved.

[0128] Furthermore, the same operation as in Embodiment 1 is also performed in the pixel configuration shown in Figures 10 and 11. By doing so, variations in current values ​​caused by variations in the threshold voltage of transistor 110 This can suppress the luminance data. Therefore, a current corresponding to the brightness data is supplied to the light-emitting element 117. This allows for the supply of power and suppression of brightness variations. Furthermore, the potential of the counter electrode... By operating with a constant value, it is possible to reduce power consumption. The operating range of 110 is not particularly limited, but when operated in the saturation region, the light-emitting element 11 To suppress variations in the current flowing through transistor 110 caused by the degradation of 7. It is possible.

[0129] Note that the potential supply line in Figure 1 is used during the initialization period and the threshold voltage writing period. A predetermined potential is supplied to the first electrode of the first capacitive element 115. It is sufficient that the voltage is maintained. Therefore, the wiring that substitutes the potential supply line is not limited to the above, and initially Any wiring that does not change potential during the periodization period and threshold voltage writing period is acceptable. For example, As shown in Figure 12, it is also possible to use the first scan line 119 and the third scan line 121. However, when using the third scan line 121, the fourth switch 114 is in the embodiment Note that the switch may function as a rectifier element as shown in point 2, and select the appropriate switch type accordingly. It is necessary.

[0130] Furthermore, the pixels shown in this embodiment can be applied to the display device shown in Figure 7. Similar to state 1, as long as the data writing periods for each row do not overlap, each row can be freely initialized. The start time can be set. Also, each pixel emits light except during its own address period. Because this is possible, the ratio of the emission period within one frame period (i.e., the duty cycle) It can be made very large, and can be set to almost 100%. Therefore, there is little variation in brightness. A display device with a high duty cycle can be obtained.

[0131] Furthermore, it is possible to set a longer threshold voltage writing period, which allows current to flow to the light-emitting element. To more accurately write the threshold voltage of the transistor that controls the current value to the capacitive element. This is possible. Therefore, the reliability as a display device is improved.

[0132] This embodiment is not limited to those described above, and can be freely combined with the pixel configurations shown in other embodiments. It is possible. (Embodiment 4) In this embodiment, pixels with a configuration different from that of embodiments 1 to 3 are shown in Figures 13 to 16. In Embodiment 3, we focused on a single pixel, but the wiring connected to each pixel is By sharing the wiring between pixels, it is also possible to reduce the number of wires. In this case, normally If it works, it can share various wires. For example, it can share a wire with an adjacent pixel. It is possible to have this, and one example of how to do so is described in this embodiment. Those similar to those in state 1 are indicated using the same code, and have the same parts or similar functions. Detailed explanations of the parts will be omitted.

[0133] Pixel 1300 shown in Figure 13 is a transistor 110, a first switch 111, and a second switch. Switch 112, third switch 113, fourth switch 114, first capacitive element 115, It has two capacitive elements 116 and a light-emitting element 117. The pixel has a signal line 118 and a first running line Connected to scan line 119, second scan line 120, third scan line 121, and front row power line 1322. It is being done.

[0134] In the pixel shown in Figure 1 of Embodiment 1, the first electrode of the first capacitive element 115 is the fourth switch In contrast to the power supply line 123 which was connected via switch 114, in Figure 13 the power supply in the front row It can be connected to line 1322. This is not limited to the potential supply line 123, but also during the initialization period and During the threshold voltage writing period, a predetermined voltage is maintained in the first capacitive element 115. This is because it is sufficient to supply potential to the first electrode of the first capacitive element 115. Instead of the potential supply line, the power supply line 1322 in the front row can be used. In this way, the pixels The 1300 model allows for a reduction in the number of wires by sharing wiring with the front row pixels, and the aperture ratio It can improve.

[0135] Furthermore, even with the pixel configuration shown in Figure 13, the operation will be the same as in Embodiment 1. This suppresses variations in current values ​​caused by variations in the threshold voltage of transistor 110. Therefore, it is possible to supply a current corresponding to the brightness data to the light-emitting element 117. This makes it possible to suppress variations in brightness. Also, by keeping the potential of the counter electrode constant Because it operates in this manner, power consumption can be reduced. The operating region is not particularly limited, but if operated in the saturation region, the light-emitting element 117 will degrade. This also suppresses variations in the current flowing through transistor 110 caused by the device.

[0136] Furthermore, as shown in pixel 1400 of Figure 14, the potential supply line 123 in Figure 1 is scanned in the first row. It may be shared with line 1419. The same operation as in Embodiment 1 may also be performed at pixel 1400. This can be done. However, the initialization period and threshold voltage of the row to which pixel 1400 belongs cannot be written. The congestion period must be operated in such a way that it does not overlap with the data writing period of lines that share wiring. be.

[0137] Furthermore, as shown in pixel 1500 of Figure 15, the potential supply line 123 in Figure 1 is scanned in the second row. It may be shared with line 1520. The same operation as in Embodiment 1 may also be performed at pixel 1500. This can be done. However, the initialization period and threshold voltage of the row to which pixel 1500 belongs cannot be written. The congestion period overlaps with the threshold voltage writing period and data writing period of the line sharing the wiring. It needs to be made to operate in a way that either overlaps with these things or not overlaps with them at all. In other words, The potential supplied to the first electrode of the first capacitive element 115 is turned ON or OFF when the second switch 112 is turned ON. Either of the signals that will be turned off will be used.

[0138] In addition to the above, the potential supply line 123 in Figure 1 is the third scan line 1 in the previous row, as shown in Figure 16. It may be shared with 621. However, the initialization period and threshold voltage of the row to which pixel 1600 belongs The voltage write period is the threshold voltage write period and data write period for lines that share wiring. It needs to be operated in a way that does not overlap with other functions.

[0139] In this embodiment, the potential supply line 123 in Figure 1 is the power line in the front row, or the next row or the previous row. The case where the scan lines are shared with the row has been shown, but the initialization period and threshold voltage write period have also been shown. In this configuration, a potential is supplied to the first electrode so that a predetermined voltage is maintained in the first capacitive element 115. Any other wiring method is acceptable as long as it allows for this.

[0140] Furthermore, the pixels shown in this embodiment can be applied to the display device shown in Figure 7. In the display device, the constraints on the operation of each pixel and the data in each row are as described in Figures 13 to 16. Within the range where the data writing periods do not overlap, you can freely set the initialization start time for each line. It is possible. Also, since each pixel can emit light except during its own address period, 1 frame The proportion of the luminescence period within the time period (i.e., the duty cycle) can be made very large, and generally It is also possible to set it to 100%. Therefore, the variation in brightness is small and the duty cycle is High-quality display devices can be obtained.

[0141] Furthermore, it is possible to set a longer threshold voltage writing period, which allows current to flow to the light-emitting element. To more accurately write the threshold voltage of the transistor that controls the current value to the capacitive element. This is possible. Therefore, the reliability as a display device is improved.

[0142] This embodiment is not limited to those described above, and can be freely combined with the pixel configurations shown in other embodiments. It is possible. (Embodiment 5) In this embodiment, Figure 29 shows a pixel with a different configuration from that of Embodiment 1. For those similar to Form 1 of the installation, a common code is used to indicate the same part or similar function. A detailed explanation of the parts it possesses will be omitted.

[0143] The pixels shown in Figure 29 are transistor 2910, first switch 111, and second switch 112, third switch 113, fourth switch 114, first capacitive element 115, second It has a capacitive element 116 and a light-emitting element 117. The pixels have a signal line 118 and a first scan line. 119, second scan line 120, third scan line 121, power line 122, and potential supply line 12 It is connected to 3.

[0144] In this embodiment, transistor 2910 is a multi-transistor connected in series. It is a tigate type transistor and is provided in the same position as transistor 110 in Embodiment 1. However, the number of transistors connected in series is not particularly limited.

[0145] By operating the pixels shown in Figure 29 in the same way as the pixels in Figure 1, transistor 291 This can suppress variations in current values ​​caused by variations in the threshold voltage of 0. This allows the light-emitting element 117 to be supplied with a current corresponding to the brightness data, thus reducing variations in brightness. This makes it possible to suppress [the phenomenon]. Also, since the potential of the counter electrode is kept constant during operation, power consumption is reduced. It is possible to reduce the force. Furthermore, the operating range of transistor 2910 is not particularly limited. However, when operated in the saturation region, the transistor deteriorates due to degradation of the light-emitting element 117. This also suppresses variations in the current flowing through the 2910.

[0146] In this embodiment, the channel length L of the transistor 2910 is the channel length of two transistors connected in series. If the channel widths of the transistors are equal, it acts as the sum of the channel lengths of each transistor. Therefore, in the saturation region, regardless of the drain-source voltage Vds, it becomes more constant. It is easy to obtain a current value close to this. In particular, transistor 2910 has a long channel length L. This is effective when it is difficult to manufacture transistors. Note that the connection point between the two transistors is low It functions as an anti-resistance.

[0147] Furthermore, transistor 2910 has the function of controlling the current value supplied to the light-emitting element 117. As long as it is present, the type of transistor is not particularly limited. Therefore, a crystalline semiconductor film is used. Thin-film transistors (TFTs), such as amorphous silicon and polycrystalline silicon, are non-single-core transistors. Thin-film transistors using crystalline semiconductor films, transistors formed using semiconductor substrates or SOI substrates Transistors, MOS type transistors, junction transistors, bipolar transistors, Zn Transistors using compound semiconductors such as O and α-InGaZnO, organic semiconductors and carbon Transistors using nanotubes and other types of transistors can be applied.

[0148] Furthermore, the pixels shown in Figure 29 are the same as the pixels shown in Figure 1, with the first switch 111 and the second switch 111. Switch 112, the third switch 113, and the fourth switch 114 use transistors, etc. It is possible to be there.

[0149] Furthermore, the pixels shown in this embodiment can be applied to the display device in Figure 7. Similar to state 1, as long as the data writing periods for each row do not overlap, each row can be freely initialized. The start time can be set. Also, each pixel emits light except during its own address period. Because this is possible, the ratio of the emission period within one frame period (i.e., the duty cycle) It can be made very large, and it is possible to make it almost 100%. Therefore, the variation in brightness A display device with low power consumption and a high duty cycle can be obtained.

[0150] Furthermore, it is possible to set a longer threshold voltage writing period, which allows current to flow to the light-emitting element. To more accurately write the threshold voltage of the transistor that controls the current value to the capacitive element. This is possible. Therefore, the reliability as a display device is improved.

[0151] Note that transistor 2910 is not limited to transistors connected in series, but also the transistor shown in Figure 30. A configuration in which transistors are connected in parallel, as shown in transistor 3010, is also acceptable. The transistor 3010 allows a larger current to be supplied to the light-emitting element 117. Furthermore, the characteristics of the two transistors connected in parallel are averaged out. Therefore, the inherent characteristic variations of the transistors that make up transistor 3010 are reduced. Therefore, if the variation is small, the variation in the transistor threshold voltage will be small. This makes it easier to suppress variations in current values ​​caused by the current.

[0152] Furthermore, each of the transistors connected in parallel as shown in transistor 3010 is further shown in Figure They can also be connected in series, as shown in transistor 2910 in section 29.

[0153] This embodiment is not limited to those described above, and can be freely combined with the pixel configurations shown in other embodiments. This means that transistor 2910 or transistor 3010 can do the same as other This can also be applied to the pixel configuration shown in the embodiment. (Embodiment 6) In this embodiment, the transient current value supplied to the light-emitting element in the pixel of the present invention is controlled By switching the transistors periodically, the pixel structure averages out the degradation of transistors over time. The process will be explained using Figure 31.

[0154] The pixels shown in Figure 31 are the first transistor 3101, the second transistor 3102, and the Switch 1 3111, Switch 2 3112, Switch 3113, Switch 4 Switch 3114, fifth switch 3103, sixth switch 3104, first capacitive element 31 15. It has a second capacitive element 3116 and a light-emitting element 3117. The pixels are connected to the signal line 31 18, first scan line 3119, second scan line 3120, third scan line 3121, power line 3 It is connected to 122 and the potential supply line 3123. Furthermore, although not shown in Figure 31, , the fourth and control the on and off of the fifth switch 3103 and the sixth switch 3104. It is also connected to the fifth scan line. In this embodiment, the first transistor 3101 and The second transistor 3102 is an N-channel type transistor, and each transistor The gate-source voltage (Vgs) exceeds the threshold voltage, and the device becomes conductive. This shall be the case. Furthermore, the pixel electrode of the light-emitting element 3117 shall be the anode, and the counter electrode 3124 shall be the cathode. Note that the gate-source voltage of the transistor is Vgs, and the first capacitive element 3115 and the second The voltages stored in the capacitive element 3116 are denoted as Vc1 and Vc2, respectively. Also, the first The threshold voltage of transistor 3101 is Vth1, and the threshold voltage of the second transistor 3102 is Vth1. The voltage is denoted as Vth2, and the power line 3122, the potential supply line 3123, and the signal line 3118 are... These are also called the first wiring, the second wiring, and the third wiring, respectively.

[0155] The first electrode (one of the source electrode and the drain electrode) of the first transistor 3101 is The fifth switch 3103 is connected to the pixel electrode of the light-emitting element 3117, and the second electrode ( The source electrode and the other drain electrode are connected via the second switch 3112 to the power line 3122 It is connected to the gate electrode of the first transistor 3101 as well as the third switch 3 It is connected to the power line 3122 via 113 and the second switch 3112. Switch 3113 is connected to the gate electrode of the first transistor 3101 and the second switch 3 It is connected between 112 and the second electrode of the first transistor 3101 and the second S The connection point between the wiring connecting switch 3112 and the third switch 3113 is marked with a node. Let's set it to 3133.

[0156] The first electrode (either the source electrode or the drain electrode) of the second transistor 3102 is The sixth switch 3104 is connected to the pixel electrode of the light-emitting element 3117, and the second electrode ( The source electrode and the other drain electrode are connected to the second electrode of the first transistor 3101. It is done. Furthermore, the second electrode of the first transistor 3101 and the second transistor 31 If the connection point between 02 and the second electrode is node 3132, then node 3132 is node 31 It is connected to 33. Also, the gate electrode of the second transistor 3102 is connected to the third switch. It is connected to node 3133 via 3113. Furthermore, the first transistor 310 The gate electrode of transistor 1 is connected to the gate electrode of transistor 3102.

[0157] Furthermore, the gate electrodes of the first transistor 3101 and the second transistor 3102, If the connection point with the third switch 3113 is node 3130, then node 3130 is the first The capacitive element 3115 and the first switch 3111 are connected to the signal line 3118. In other words, the first electrode of the first capacitive element 3115 transmits signals via the first switch 3111. Line 3118 has a second electrode connected to the first transistor 3101 and the second transistor 31 It is connected to the gate electrode of 02. Also, the first electrode of the first capacitive element 3115 is connected to the fourth It is also connected to the potential supply line 3123 via switch 3114. Node 3130 is Furthermore, it is also connected to the pixel electrode of the light-emitting element 3117 via the second capacitive element 3116. In other words, the first electrode of the second capacitive element 3116 is connected to the first transistor 3101 and The gate electrode of transistor 3102 and the second electrode are connected to the fifth switch 3103 or The first transistor 3101 and the second transistor are connected via the sixth switch 3104. It is connected to the first electrode of 3102. These capacitive elements are connected by wiring, semiconductor layers and electrodes. It can also be formed by sandwiching an insulating film, or in some cases, the first transistor 3101 Furthermore, the gate capacitance of the second transistor 3102 is used to omit the second capacitive element 3116. It is also possible to do so.

[0158] Furthermore, signals are sent to the first scan line 3119, the second scan line 3120, and the third scan line 3121. By inputting, the first switch 3111, the second switch 3112, and the third switch are respectively activated. The on / off state of switch 3113 and the fourth switch 3114 is controlled as described above. In Figure 31, the on / off state of the fifth switch 3103 and the sixth switch 3104 is shown. The control scan lines have been omitted.

[0159] Signal line 3118 carries a signal corresponding to the pixel gradation of the video signal, i.e., luminance data. A corresponding electric potential is input.

[0160] Next, the operation of the pixels shown in Figure 31 will be explained using the timing chart in Figure 32. In addition, the frame period corresponding to the period for displaying one screen's worth of image in Figure 32 is: It is divided into an initialization period, a threshold voltage writing period, a data writing period, and an illumination period. .

[0161] Note that a potential of V1 (V1: an arbitrary number) is input to the counter electrode 3124 of the light-emitting element 3117. Also, let V be the potential difference that is at least required for the light-emitting element 3117 to emit light. EL Then, a potential of V1 + V EL + Vth + α (α: an arbitrary positive number) is input to the power supply line 3122. That is, the power supply line 3122 only needs to have a potential of V1 + V EL + Vth + α or higher. Note that Vth is the larger value between Vth1 and Vth2. The potential of the potential supply line 312 3 is not particularly limited, but it is preferably within the range of the potential input to the panel on which the pixels are formed. By doing so, it becomes unnecessary to separately fabricate a power supply. Here, let the potential of the potential supply line 3123 be V2.

[0162] First, as shown in FIG. 32(A), in the initialization period, the first switch 3111 and the sixth switch 3104 are turned off, and the second switch 3112, the third switch 3113, the fourth switch 3114, and the fifth switch 3103 are turned on. At this time, the first transistor 3101 is in a conductive state, and V1 + V + Vth + EL α - V2 is held in the first capacitive element 3115, and Vth + α is held in the second capacitive element 3116. Note that during this initialization period, a predetermined voltage may be held in the first capacitive element 3115, and a voltage higher than at least Vth1 may be held in the second capacitive element 3116.

[0163] In the threshold voltage writing period shown in FIG. 32(B), the second switch 3112 is turned off. Therefore, the potential of the first electrode, that is, the source electrode, of the first transistor 3101 gradually increases, and the gate - source voltage Vgs of the first transistor 3101 becomes the threshold voltage. ​​​​ When Vth1 occurs, the first transistor 3101 becomes non-conductive. Therefore, The voltage Vc2 held by the second capacitive element 3116 is approximately equal to Vth1.

[0164] During the subsequent data writing period shown in Figure 32(C), the third switch 3113 After turning off the fourth switch 3114, turn on the first switch 3111 and the signal The potential (V2 + Vdata) corresponding to the brightness data is input from line 3118. At this time, The voltage Vc2 held by the second capacitance element 3116 is the voltage Vc2 held by the first capacitance element 3115 and the second capacitance element If the capacitances of the capacitance element 3116 and the light-emitting element 3117 are C1, C2, and C3 respectively, then C 3>> From C1 and C2, we get Vth1 + Vdata × (C1 / (C1 + C2)).

[0165] Note that C1 and C2 are necessary when determining the potential supplied from signal line 3118, These relationships are not particularly limited. Furthermore, in the case where C1 > C2, Vdat associated with the change in brightness... Since the amplitude of a can be reduced, power consumption can be reduced. On the other hand, C In the case of 2>C1, changes in Vc2 due to the on / off state of surrounding switches and off currents are suppressed. This is possible. Due to these conflicting effects, C1 and C2 are equal, and the first capacitance element 31 It is preferable that the size of element 15 and the second capacitive element 3116 are the same.

[0166] If you wish to disable the light-emitting element 3117 during the next light-emitting period, please use Vdata You just need to input a potential of ≤0.

[0167] Next, during the light emission period shown in Figure 32(D), after the first switch 3111 is turned off, Turn on switch 3112. At this time, the gate of the first transistor 3101... The source-to-source voltage Vgs is Vth1 + Vdata × (C1 / (C1 + C2)), and the luminance data A current corresponding to the data flows through the first transistor 3101 and the light-emitting element 3117, and the light-emitting element 3117 emits light.

[0168] Due to this operation, the current flowing through the light-emitting element 3117 is through the first transistor 310 In both the case where the operating region of 1 is the saturation region and the linear region, the first transistor 31 It does not depend on the threshold voltage (Vth1) of 01.

[0169] Furthermore, during the initialization period in the following 1 frame period shown in Figure 32(E), the fifth swim Turn off switch 3103, and turn off the third switch 3113, the fourth switch 3114 and the sixth switch Turn on switch 3104. The second transistor 3102 becomes conductive, and the first Capacitive element 3115 has V1 + V EL +Vth+α-V2 is applied to the second capacitance element 3116. Vth+α is maintained. During this initialization period, the first capacitive element 3115 has a predetermined value. If the voltage is such that the second capacitive element 3116 maintains a voltage at least higher than Vth2 good.

[0170] Next, during the threshold voltage writing period shown in Figure 32(F), the second switch 3112 is It is turned off. Therefore, the potential of the first electrode, i.e., the source electrode, of the second transistor 3102 is... The voltage gradually rises, and the gate-source voltage Vgs of the second transistor 3102 reaches the threshold. When the voltage reaches (Vth2), the second transistor 3102 becomes non-conductive. Therefore, the voltage Vc2 held by the second capacitive element 3116 is approximately Vth2.

[0171] During the subsequent data writing period shown in Figure 32(G), the third switch 3113 After turning off the fourth switch 3114, turn on the first switch 3111 and the signal The potential (V2 + Vdata) corresponding to the brightness data is input from line 3118. At this time, The voltage Vc2 held by the second capacitive element 116 is Vth2 + Vdata × (C1 / (C 1 + C2))

[0172] Next, during the light emission period shown in Figure 32(H), after the first switch 3111 is turned off, Turn on switch 3112. At this time, the gate of the second transistor 3102... The source-to-source voltage Vgs is Vth2 + Vdata × (C1 / (C1 + C2)), and the luminance data A current corresponding to the data flows through the second transistor 3102 and the light-emitting element 3117, and the light-emitting element 3117 emits light.

[0173] Furthermore, in the case where the operating region of the second transistor 3102 is either the saturation region or the linear region, Even so, the current flowing through the light-emitting element 3117 does not depend on the threshold voltage (Vth2).

[0174] Therefore, either transistor 3101 or transistor 3102 Even if the current supplied to the light-emitting element is controlled using a zista, the threshold voltage of the transistor will vary. The current value variation caused by the moon is suppressed, and the current value corresponding to the brightness data is set by the light-emitting element 31. It can be supplied to 17. Note that the first transistor 3101 and the second transistor By switching between the 3102 transistors, the load on a single transistor can be reduced. This makes it possible to minimize the change in the transistor's threshold voltage over time.

[0175] From the above, the thresholds for the first transistor 3101 and the second transistor 3102 This can suppress variations in brightness caused by voltage values. Furthermore, the potential of the counter electrode can be kept constant. Therefore, it is possible to reduce power consumption.

[0176] Furthermore, the first transistor 3101 and the second transistor 3102 are operated in the saturation region. In this case, the current flowing through each transistor due to the degradation of the light-emitting element 3117 This also helps to suppress variations.

[0177] Furthermore, the first transistor 3101 and the second transistor 3102 are operated in the saturation region. In this case, a longer channel length L for these transistors is preferable.

[0178] Furthermore, in this invention, variations in current values ​​caused by variations in the threshold voltage of transistors Because it can suppress this, the current controlled by that transistor is particularly targeted to the supply destination. Not limited. Therefore, the light-emitting element 3117 shown in Figure 31 is typically an EL element ( Mechanical EL elements, inorganic EL elements, or EL elements containing organic and inorganic materials can be applied. Furthermore, instead of the light-emitting element 3117, electron-emitting elements, liquid crystal elements, electronic ink, etc., can be applied. It is also possible.

[0179] Furthermore, the first transistor 3101 and the second transistor 3102 are light-emitting elements 3117 As long as it has the function of controlling the current value supplied, the type of transistor is not particularly limited. It is not determined. Therefore, thin-film transistors (TFTs) using crystalline semiconductor films, amorphous semiconductor films Thin-film transistors and semiconductors using non-single-crystal semiconductor films such as polycrystalline silicon. Transistors formed using substrates such as solid substrates or SOI substrates, MOS type transistors, and junction type transistors. transistors, bipolar transistors, and compound semiconductors such as ZnO and α-InGaZnO. Transistors using organic semiconductors and carbon nanotubes, Other transistors can be used.

[0180] The first switch 3111 outputs a potential corresponding to the brightness data, i.e., a signal, via the signal line 3118. The timing of the input is selected, and the voltage held mainly by the first capacitive element 3115, and The voltage held by the second capacitive element 3116, i.e., the first transistor 3101 or the second This changes the gate-source voltage of transistor 3102. Also, the second Switch 3112 is either the first transistor 3101 or the second transistor 3102 This selects the timing for supplying a predetermined potential to the second electrode. In addition, the second electrode of the first capacitive element 3115 and the first electrode of the second capacitive element 3116 also The predetermined potential is supplied. The third switch 3113 also supplies the first transistor 3101. The connection between the gate electrode of the second transistor 3102 and the second electrode of each transistor. The fourth switch 3114 controls the first capacitive element for each frame period. The timing for holding a predetermined voltage in 3115 is selected, and the first capacitive element 3115 This controls whether or not a predetermined potential is supplied to the electrodes. Therefore, the first switch Switch 3111, second switch 3112, third switch 3113, fourth switch 3114 This is not particularly limited as long as it has the above functions. For example, transistors and diodes Alternatively, a logic circuit combining them is also acceptable. Note that the first switch 3111, the Switch 2 3112 and Switch 4 3114 receive signals or electricity at the above timing. It is not particularly necessary if the position can be assigned to the pixel. Also, in the third switch 3113 However, if the above functions can be achieved, there is no particular need for this.

[0181] For example, the first switch 3111, the second switch 3112, the third switch 3113 , the fourth switch 3114, the fifth switch 3103, and the sixth switch 3104 are connected to the N-channel. When using Nell-type transistors, pixels are composed solely of N-channel transistors. This allows for the simplification of the manufacturing process. In addition, the transistors that make up the pixels Amorphous semiconductors and semi-amorphous semiconductors can be used in the semiconductor layer of the ZISTA. For example, amorphous silicon (a-Si:H) is an example of an amorphous semiconductor. By using these semiconductors, the manufacturing process can be further simplified. This can lead to reduced manufacturing costs and improved yield.

[0182] Furthermore, the first switch 3111, the second switch 3112, the third switch 3113, Transition to the 4th switch 3114, the 5th switch 3103, and the 6th switch 3104 When using a transistor, the polarity (conductivity type) of the transistor is not particularly limited. However, when off-voltage... It is desirable to use transistors with low current.

[0183] Also, the first transistor 3101 and the fifth switch 3103 and the second transistor Switches 3102 and the sixth switch 3104 are swapped, as shown in Figure 37. That is also good. In other words, the first transistor 3101 and the first transistor 3102 The electrodes are connected to the first transistor 3101 and the second transistor via the second capacitive element 3116. It is connected to the gate electrode of transistor 3102. Also, the second of the first transistor 3101. The electrodes are connected to node 3132 via the fifth switch 3103, and the second transistor The second electrode of terminal 3102 is connected to node 3132 via the sixth switch 3104. Yes, they are.

[0184] Furthermore, in Figures 31 and 37, the transistor and switch are shown as a set, that is, the first transistor Transistor 3101 and fifth switch 3103, second transistor 3102 and sixth switch The description mentions the case where the number of parallel connections is 2 when using the 3104 set, but the number of parallel connections This is not particularly limited.

[0185] Furthermore, by applying the pixels shown in this embodiment to the display device in Figure 7, the same as in Embodiment 1 can be achieved. As long as the data writing periods for each row do not overlap, you can freely set the initialization start time for each row. It can be configured. Also, each pixel can emit light except during its own address period. Therefore, the proportion of the illumination period within one frame (i.e., the duty cycle) is very large. It can be adjusted to approximately 100%. Therefore, there is little variation in brightness. A display device with a high t-to-touch ratio can be obtained.

[0186] Furthermore, it is possible to set a longer threshold voltage writing period, which allows current to flow to the light-emitting element. To more accurately write the threshold voltage of the transistor that controls the current value to the capacitive element. This is possible. Therefore, the reliability as a display device is improved.

[0187] In this embodiment as well, the potential supply line 3123 is the same as shown in Embodiment 3. Alternatively, the wiring within the pixel may be used as a substitute, or it may be shared with the wiring of other rows as in Embodiment 4. In each of the first transistor 3101 and the second transistor 3102, Multi-gate transistors connected in series or transistors arranged in parallel These may also be used. This embodiment is not limited to these, but the pixel configurations shown in Embodiments 1 to 5 may also be used. It can be applied to [this]. (Embodiment 7) This embodiment shows pixels with a different configuration from Embodiment 1. These are indicated using common symbols, and detailed explanations are provided for parts that are the same or have similar functions. The explanation is omitted. These will be operated in the same manner as in Embodiment 1.

[0188] In this embodiment, regarding the pixel configuration that prevents current from flowing to the light-emitting element 117, Let me explain. In other words, by forcibly creating a non-emitting state, afterimages become less visible, and the video features The objective is to obtain a display device with superior performance.

[0189] One such pixel configuration is shown in Figure 38. The pixel shown in Figure 38 is transistor 110 , first switch 111, second switch 112, third switch 113, fourth switch In addition to the first capacitive element 115, the second capacitive element 116, and the light-emitting element 117, there is a fifth It has a switch 3801. The pixels have a signal line 118, a first scan line 119, and a second In addition to scan line 120, third scan line 121, power line 122, and potential supply line 123, a fourth It is also connected to scan line 3802.

[0190] In Figure 38, the fifth switch 3801 is connected in parallel with the second capacitive element 116. Therefore, when the fifth switch 3801 is turned on, the gate of transistor 110 A short circuit occurs between the electrode and the first electrode. Therefore, the second capacitive element 116 is held. Because the gate-source voltage of transistor 110 can be set to 0V, the transistor The st 110 is turned off, and the light-emitting element 117 can be made non-emitting. Note that the fifth S The on / off control of switch 3801 is controlled by a signal input to the fourth scan line 3802. It scans one pixel row at a time.

[0191] This operation erases the signals written to the pixels. Therefore, the next initialization period A blackout period can be set during which the display is forced to remain in a non-emitting state. In other words, a black display is inserted. This will result in less visible afterimages and improved video characteristics. .

[0192] By the way, there are two types of drive methods for expressing grayscale in display devices: analog grayscale and digital grayscale. There are different methods. Analog grayscale methods include a method that controls the light emission intensity of the light-emitting element in an analog manner, and a method that uses light emission. There is a method of controlling the light emission time of the element using analog controls. In the analog grayscale method, the light-emitting element Analog control of light intensity is commonly used. On the other hand, digital gradation methods are used The light-emitting elements are turned on and off using digital control to express gradation. In the case of digital gradation, It has the advantage of being resistant to noise because it can be processed with digital signals, but it has two states: luminescent and non-luminescent. Since it only has a state, it can only express two tones as is. Therefore, we combine it with another method. Therefore, multi-gradation is being attempted. As a method for multi-gradation, the light-emitting surface of the pixel Area gradation method, which assigns weights to the product and performs gradation display based on the selection of the product, and area gradation method, which assigns weights to the emission time. There are two types of grayscale displays: a time-based grayscale display and a time-based grayscale display.

[0193] When this digital gradation method and time gradation method are combined, as shown in Figure 39, 1f The frame period is divided into multiple subframe periods (SFn). Each subframe period is the first Address period (T) which has a periodization period, threshold voltage writing period and data writing period. a) and the emission period (Ts) are included. The subframe period depends on the number of display bits n. The number of frames is set within one frame period. Also, the ratio of the length of the emission period in each subframe period. 2 (n-1) :2 (n-2) :···:2:1, and the light emission of the light-emitting element during each light emission period, Alternatively, select non-emitting mode and use the difference in total time during the 1-frame period in which the light-emitting element is emitting light. This is how to represent gradation. If the total time of emission is long within one frame period, the brightness will be Higher and shorter durations result in lower brightness. Note that Figure 39 shows an example of 4-bit grayscale. Each frame is divided into four subframe periods, and the combination of emission periods determines the result. , 2 4 =16 gradations can be represented. Note that the ratio of the length of the illumination period is specifically a power of 2. Even without it, gradation expression is possible. Also, even if a certain subframe period is further divided... good.

[0194] Furthermore, when using the time-based gradation method as described above to achieve multi-gradation, the emission period of the lower bits... Because the duration is short, the data writing operation for the next subframe period starts immediately after the end of the emission period. When attempting to start it, it overlaps with the data writing operation of the previous subframe period. This will prevent the system from functioning correctly. Therefore, a data erasure period like the one described above is set within the subframe period. By doing so, it is possible to represent light emission that is shorter than the data writing period required for the entire line. Furthermore, the duration of illumination can be freely set.

[0195] The present invention is particularly effective in analog gradation systems, as well as in digital gradation systems. Even in a system that combines formulas and time-based gradation methods, the emission period can be freely set. Therefore, setting a data erasure period is effective.

[0196] Furthermore, from the power line 122 through the transistor 110 to the pixel electrode of the light-emitting element 117 A cancellation period can be provided by interrupting the current path between them. For example, from power line 122 to the transistor A new switch is added to the current path from the inverter 110 to the pixel electrode of the light-emitting element 117. A mechanism is provided to scan the pixels row by row and turn off the switch, thereby creating an erasure period. It is possible.

[0197] One such configuration is shown in Figure 40. The configuration in Figure 40, in addition to the pixel configuration in Figure 1, has a fifth Switch 4001 is connected between the first electrode of transistor 110 and node 132. And the on / off state of the fifth switch 4001 is input to the fourth scan line 4002. It is controlled by a signal. By turning off this fifth switch 4001, It is possible to set a waiting period.

[0198] Also, between the second electrode of transistor 110 and node 133, and as shown in Figure 41 A fifth switch is connected between the pixel electrode of the light-emitting element 117 and node 132 to erase the period. It is permissible to set one up.

[0199] Of course, in the pixel shown in Figure 1, the second switch 112 is turned off and the power line 122 is turned off. By interrupting the current path to the light-emitting element 117, an erasure period is created without the need for a new switch. You can.

[0200] Furthermore, the erasure period can be forcibly changed by altering the potential of the gate electrode of transistor 110. It is also possible to write it.

[0201] One such configuration is shown in Figure 42. The configuration in Figure 42 is a rectifier element in addition to the pixel configuration in Figure 1. It has a child 4201, and via its rectifier element 4201, it connects the gate electrode of transistor 110 to the It is connected to scan line 4202 of 4. Transistor 110 is an N-channel type transistor. If it is a transistor, the rectifier element 4201 is the fourth from the gate electrode of transistor 110. The scan line 4202 is connected so that current flows through it. The fourth scan line 4202 is connected to the transistor. An L-level signal is input only when the Zista 110 is forcibly turned off; otherwise, an H-level signal is input. The bell signal is input. When the fourth scan line 4202 is at a high level, the rectifier element 4201 No current flows through it, and when it reaches an L level, the fourth scan line is released from the gate electrode of transistor 110. Current flows to 4202. By passing current to the fourth scan line 4202 in this way, The gate-source voltage of transistor 110 is set below the threshold voltage (Vth), and the transistor Turn off transistor 110. Note that the L level potential is the gateway of transistor 110. The threshold voltage in the forward direction of the rectifier element 4201 is added to the potential of the electrode at the L level. The decision must be made considering that the potential will not fall below a certain level.

[0202] The rectifier element 4201 is available in Schottky barrier type and PIN type as shown in Figure 9(B). In addition to PN-type diodes, diode-connected transistors and the like can be used. Cut.

[0203] Furthermore, if the pixel configuration has a means to forcibly make it non-emitting, afterimages can be created by inserting black displays. The above configuration is not particularly limited, as it can make the object less visible.

[0204] The switches and the like for providing the erasure period shown in this embodiment are configured in the pixel configuration of Figure 1 described above. This can also be applied to pixel configurations shown in other embodiments, not limited to this one.

[0205] Furthermore, even without such a switch, by setting a longer initialization period, the initialization period The interval can also serve as an erasure period. Therefore, the pixels described in Embodiments 1 to 6 are operated When doing so, set the length of the initialization period to the duration for which you want the screen to be displayed in black to reduce the visibility of afterimages. This can also improve the video characteristics. Furthermore, as mentioned above, turn on the second switch. It is also possible to set an erasure period by doing so. In addition, during the light emission period, the power line 122 A black indicator may be inserted by making the potential of the black indicator the same as the potential of the counter electrode 124.

[0206] Furthermore, the pixels shown in this embodiment are applicable to the display device shown in Embodiment 1. This is possible. Therefore, a display device with low brightness variation and excellent video characteristics is desirable. You can obtain this. (Embodiment 8) In this embodiment, a P-channel transistor is used to control the current value supplied to the light-emitting element. Figure 46 illustrates the case where a transistor is applied.

[0207] The pixels shown in Figure 46 are transistor 4610, first switch 4611, second switch Switch 4612, third switch 4613, fourth switch 4614, first capacitive element 461 5. It has a second capacitive element 4616 and a light-emitting element 4617. The pixel has a signal line 4618, Scan line 1 4619, scan line 2 4620, scan line 3 4621, power line 4622, and is connected to the potential supply line 4623. In this embodiment, transistor 461 0 is a P-channel transistor, and its absolute gate-source voltage is (|Vgs|). When Vgs exceeds the threshold voltage (|Vth|) (i.e., when Vgs falls below Vth) ), and it shall be assumed that it becomes conductive. Also, the pixel electrode of the light-emitting element 4617 is the cathode, and the counter electrode 4 624 functions as the anode. Note that the absolute value of the gate-source voltage of the transistor is | Vgs|, |Vth| (absolute value of threshold voltage), first capacitance element 4615 and second capacitance The voltages stored in element 4616 are denoted as Vc1 and Vc2, respectively. Also, power line 4622 The potential supply line 4623 and the signal line 4618 are designated as the first wiring, the second wiring, and the third wiring, respectively. Also called wiring. Furthermore, the first scan line 4619, the second scan line 4620 and the third scan line You could also call 4621 the fourth wire, the fifth wire, and the sixth wire, respectively.

[0208] The first electrode of transistor 4610 (one of the source electrode and the drain electrode) is a light-emitting element. The second electrode (the other of the source electrode and drain electrode) is connected to the pixel electrode of sub-4617. The second switch 4612 is connected to the power line 4622, and the gate electrode is connected to the third switch It is connected to the power line 4622 via switch 4613 and the second switch 4612. The third switch 4613 connects the gate electrode of transistor 4610 to the second switch 46 It is connected to 12.

[0209] Furthermore, the connection point between the gate electrode of transistor 4610 and the third switch 4613 is If node 4630 is used, then node 4630 consists of the first capacitive element 4615 and the first switch 4 It is connected to signal line 4618 via 611. In other words, the first capacitive element 4615 Electrode 1 is connected to signal line 4618 via first switch 4611, and electrode 2 is connected to transistor It is connected to the gate electrode of the 4610. Also, the first electrode of the first capacitive element 4615. It is also connected to the potential supply line 4623 via the fourth switch 4614. Node 46 30 is further connected to the first electrode of transistor 4610 via the second capacitive element 4616. They are connected. In other words, the first electrode of the second capacitive element 4616 is connected to the transistor 4610. The gate electrode and the second electrode are connected to the first electrode of transistor 4610. These capacitive elements may be formed by sandwiching an insulating film between wiring, semiconductor layers, and electrodes. In some cases, the gate capacitance of transistor 4610 can be used to omit the second capacitive element 4616. It can also be abbreviated.

[0210] Furthermore, signals are sent to the first scan line 4619, the second scan line 4620, and the third scan line 4621. By inputting, the first switch 4611, the second switch 4612, and the third switch are respectively activated. The on / off state of switch 4613 and the fourth switch 4614 is controlled.

[0211] Signal line 4618 carries a signal corresponding to the pixel gradation of the video signal, i.e., luminance data. A corresponding electric potential is input.

[0212] Next, regarding the operation of the pixels shown in Figure 46, use the timing chart in Figure 47 and Figure 48. Let me explain. Note that in Figure 47, one frame corresponds to the period during which one screen's image is displayed. The time period consists of an initialization period, a threshold voltage writing period, a data writing period, and an illumination period. It is divided. Also, the initialization period, threshold voltage writing period, and data writing period are combined. This is called the address period. There is no particular limit to the duration of one frame, but the image flickers for the viewer. To avoid flicker, it is preferable to set the interval to at least 1 / 60th of a second or less.

[0213] Furthermore, the counter electrode 4624 of the light-emitting element 4617 is input to a potential of V1 (V1: any number). It is done. Also, the potential difference V is the minimum required for the light-emitting element 4617 to emit light. EL Therefore, power line 4622 has V1-V EL -|Vth|-α (α: any positive number) The position is input. In other words, power line 4622 is V1-V EL -|Vth|-α or less It would be good to have one. The potential of the potential supply line 4623 is not particularly limited, but the panel on which the pixels are formed It is preferable that the input potential is within the range of the input voltage. This eliminates the need to manufacture a separate power supply. The need disappears. Note that here we will assume the potential of the potential supply line 4623 is V2.

[0214] First, as shown in Figures 47(A) and 48(A), during the initialization period, the first switch 4 Turn off 611, and turn off the second switch 4612, the third switch 4613 and the fourth switch Turn on transistor 4614. At this time, transistor 4610 is in a conducting state, and the first capacity The quantitative element 4615 has V1-V EL -|Vth|-α-V2 is applied to the second capacitance element 4616. |Vth|+α is maintained. During the initialization period, the first capacitive element 4615 is A constant voltage is present, and the second capacitive element 4616 has a voltage with an absolute value at least higher than |Vth|. It's fine as long as it's retained.

[0215] During the threshold voltage writing period shown in Figures 47(B) and 48(B), the second switch Turn off 4612. Therefore, the gate electrode of transistor 4610 gradually rises. The gate-source voltage Vgs of transistor 4610 has reached the threshold voltage |Vth|. By the way, transistor 4610 becomes non-conductive. Therefore, the second capacitive element 4616 The sustained voltage Vc2 is approximately |Vth|.

[0216] During the subsequent data writing period shown in Figures 2(C) and 3(C), the third swim After turning off switch 4613 and the fourth switch 4614, turn on the first switch 4611. Then, a potential (V2-Vdata) corresponding to the brightness data is input via signal line 4618. At this time, the voltage Vc2 held by the second capacitive element 4616 is equal to the voltage Vc2 held by the first capacitive element 461 5. The capacitances of the second capacitive element 4616 and the light-emitting element 4617 are C1, C2, and C2, respectively. If we set it to 3, then C3 >> C1, and since C2, it can be expressed as in equation (4).

[0217]

number

[0218] Note that C1 and C2 are necessary when determining the potential supplied from signal line 4618, These relationships are not particularly limited. Furthermore, in the case where C1 > C2, Vdat associated with the change in brightness... Since the amplitude of a can be reduced, power consumption can be reduced. On the other hand, C In the case of 2>C1, changes in Vc2 due to the on / off state of surrounding switches and off currents are suppressed. This is possible. Due to these conflicting effects, C1 and C2 are equal, and the first capacitance element 46 It is preferable that the size of element 15 and the second capacitive element 4616 are the same.

[0219] If you wish to disable the light-emitting element 4617 during the next light-emitting period, please use Vdata You just need to input a potential of ≤0.

[0220] Next, during the light emission period shown in Figures 47(D) and 48(D), the first switch 4611 is activated. After turning it off, turn on the second switch 4612. At this time, transistor 4610 The gate-source voltage is Vgs = -|Vth| -Vdata × (C1 / (C1+C2) ) and current flows to transistor 4610 and light-emitting element 4617 according to the brightness data. Then, the light-emitting element 4617 emits light. Of course, the brightness data input from the signal line 4618 The corresponding potential is the gate-source voltage of transistor 4610, Vgs = -|Vth|- When determining Vdata, it is necessary to consider that Vdata × (C1 / (C1+C2)). There is.

[0221] The current I flowing through the light-emitting element 4617 is used to operate the transistor 4610 in the saturation region. In that case, it is expressed by equation (5).

[0222]

number

[0223] Since transistor 4610 is a P-channel transistor, Vth < 0. Therefore, equation (5) can be transformed into equation (6).

[0224]

number

[0225] Furthermore, when transistor 4610 is operated in the linear region, the current I flowing through the light-emitting element is It is represented by equation (7).

[0226]

number

[0227] Since Vth < 0, equation (7) can be transformed into equation (8).

[0228]

number

[0229] Here, W is the channel width of transistor 4610, L is the channel length, μ is the mobility, and Co x represents the storage capacity.

[0230] From equations (6) and (8), the operating region of transistor 4610 is the saturation region and the linear region. In either case, the current flowing through the light-emitting element 4617 is the same as that of the transistor 4610. It does not depend on the threshold voltage (Vth). Therefore, the variation in the threshold voltage of transistor 4610 This suppresses variations in current values ​​caused by the light source 461 and generates a current corresponding to the brightness data. It can be supplied to 7.

[0231] From the above, it can be concluded that the variation in brightness caused by the threshold voltage of transistor 4610 is This can suppress rattling. Also, because it operates with a constant potential at the counter electrode, energy consumption is reduced. This makes it possible to reduce power consumption.

[0232] Furthermore, when transistor 4610 is operated in the saturation region, light-emitting element 46 17 The variation in brightness due to degradation can also be suppressed. When the light-emitting element 4617 degrades, Child 4617 V EL The voltage increases, and the voltage of the first electrode of transistor 4610, i.e., the source electrode, increases. The position decreases. At this time, the source electrode of transistor 4610 is the second capacitive element 4616 The gate electrode of transistor 4610 is connected to the second electrode of the first capacitive element 4616. It is connected to an electrode, and the gate electrode side is floating. Therefore, As the gate potential decreases, the gate potential of transistor 4610 also decreases by the same amount. Therefore, since the Vgs of transistor 4610 does not change, even if the light-emitting element deteriorates, the transistor will still function. This does not affect the current flowing through the inverter 4610 and the light-emitting element 4617. Note that in equation (6) However, it can be seen that the current I flowing through the light-emitting element does not depend on the source potential or drain potential.

[0233] Therefore, when transistor 4610 is operated in the saturation region, The transistor malfunction was caused by variations in the threshold voltage of 4610 and degradation of the light-emitting element 4617. This can suppress variations in the current flowing through the 4610.

[0234] Furthermore, when transistor 4610 is operated in the saturation region, breakdown phenomena and channel length modulation may occur. To suppress the increase in current, the channel length L of transistor 4610 should be longer. More preferable.

[0235] As described above, variations in current values ​​caused by variations in the transistor threshold voltage can be suppressed. Because it can be controlled, the current controlled by the transistor in this invention The destination is not particularly limited. Therefore, the light-emitting element 4617 shown in Figure 46 is typically E Applying L elements (organic EL elements, inorganic EL elements, or EL elements containing organic and inorganic materials) It is possible to replace the light-emitting element 4617 with an electron-emitting element, a liquid crystal element, or an electronic ink. Other applications are also possible. Figure 49 shows an example in which the light-emitting element 4617 is replaced with an EL element 4917. This is shown. Figure 49 shows the current flowing from the counter electrode 4624 to the pixel electrode 4911. This indicates that.

[0236] Furthermore, transistor 4610 has the function of controlling the current value supplied to light-emitting element 4617. As long as it does so, the type is not particularly limited and various types can be used. For example For example, thin-film transistors (TFTs) using crystalline semiconductor films, amorphous silicon and polycrystalline silicon Thin-film transistors using non-single-crystal semiconductor films, such as those represented by CON, semiconductor substrates, and SOI substrates. Transistors formed using MOS type transistors, junction type transistors, bipods Transistors using compound semiconductors such as ZnO and α-InGaZnO Transistors using organic semiconductors and carbon nanotubes, and other types of transistors. It can be applied to transistor 4610.

[0237] The first switch 4611 outputs a potential corresponding to the brightness data, i.e., a signal, via the signal line 4618. The timing of the input is selected, and the voltage held mainly by the first capacitive element 4615, The voltage held by the second capacitive element 4616, i.e., the gate-source voltage of transistor 4610. It changes the voltage. Also, the second switch 4612 controls the transistor 4610. This selects the timing for supplying a predetermined potential to the second electrode. In addition, the second electrode of the first capacitive element 4615 and the first electrode of the second capacitive element 4616 also The predetermined potential is supplied. The third switch 4613 controls the gate voltage of transistor 4610. This controls the connection between the pole and the second electrode, and the fourth switch 4614 controls each frame period. A timing is selected to maintain a predetermined voltage in the first capacitive element 4615 at each interval, and the first capacitor This controls whether or not a predetermined potential is supplied to the first electrode of the quantitative element 4615. Therefore, the first switch 4611, the second switch 4612, the third switch 4613, Switch 4614 is not particularly limited as long as it has the above functions. For example, It can be a diode or a diode, or a logic circuit combining them. Switch 4611, the second switch 4612, and the fourth switch 4614 are controlled by the above timing It is not particularly necessary if a signal or potential can be applied to the pixel by a serration. Also, the third serration If the above functions can be achieved with the Itch 4613, then there is no particular need for this.

[0238] Furthermore, when using a transistor, the polarity (conductivity type) of the transistor is not particularly limited. However, it is desirable to use a transistor with low off-current. As for the transistors, there are those that have an LDD area or a multi-gate structure. There are also other options. Furthermore, both N-channel and P-channel types can be used in CMOS switches. You may do so.

[0239] For example, the first switch 4611, the second switch 4612, and the third switch 461 3. When a P-channel transistor is applied to the fourth switch 4614, each The scan line that controls the on / off state of a switch receives a low-level signal when you want to turn it on, and a low-level signal when you want to turn it off. When you want to do this, an H-level signal is input. In this case, a P-channel transistor is used. Since pixels can be composed of only these elements, the manufacturing process can be simplified.

[0240] Furthermore, the pixels shown in this embodiment can be applied to the display device in Figure 7, and Embodiment 1 Similarly, as long as the data writing periods for each row do not overlap, each row can be initialized at any time. The period can be set. Also, each pixel can emit light except during its own address period. Because it is possible, the ratio of the illumination period within one frame (i.e., the duty cycle) is very It can be increased to approximately 100%. Therefore, there is less variation in brightness. A display device with a high duty cycle can be obtained.

[0241] Furthermore, it is possible to set a longer threshold voltage writing period, which allows current to flow to the light-emitting element. To more accurately write the threshold voltage of the transistor that controls the current value to the capacitive element. This is possible. Therefore, the reliability as a display device is improved.

[0242] Furthermore, this embodiment can be freely combined with the pixel configurations shown in other embodiments. This can be done. For example, similar to Embodiment 2, a rectifier element can be used in the fourth switch 4614. Alternatively, as in embodiments 3 and 4, the potential supply line 4623 may be replaced with other wiring. Furthermore, the transistor 4610 is configured to have the transistor configuration shown in Embodiments 5 and 6. It is also possible to apply the configuration and operation shown in Embodiment 7. The transistor 4610 described in this embodiment is not limited to these, but may be used in other embodiments. It can also be applied to the pixels shown.

[0243] However, the polarity of the transistor that controls the current flowing through the light-emitting element affects the current flowing through the rectifier element. It is necessary to change the direction of the current. For example, a rectifier element is used to create an erasure period. Figure 50 illustrates the case where this is the case.

[0244] If transistor 4610 is a P-channel type transistor, then rectifier element 5001 It is connected so that current flows from the fourth scan line 5002 to node 4630. The scan line 5002 is a high-level signal only when transistor 4610 is forced off. A signal is input, and otherwise an L-level signal is input. The fourth scan line 5002 is L-level. In this case, no current flows through the rectifier element 5001, and when it reaches the H level, the fourth scan line 500 Current flows from node 2 to node 4630. By flowing current to node 4630 in this way, The gate potential of transistor 4610 is increased, and the gate-source interval of transistor 4610 is increased. The voltage is set below the threshold voltage (|Vth|) to forcibly turn off transistor 4610. This action inserts black frames, making afterimages less noticeable and improving video characteristics. It can be done. (Embodiment 9) In this embodiment, one form of a partial cross-sectional view of a pixel of the present invention will be explained with reference to Figure 17. The transistor shown in the partial cross-sectional view in this embodiment supplies power to the light-emitting element. This is a transistor that has the function of controlling the current value.

[0245] First, an underlayer film 1712 is formed on a substrate 1711 having an insulating surface. The substrate 1711 can be a glass substrate, a quartz substrate, or a plastic substrate (polyimide, acrylic). Polyethylene terephthalate, polycarbonate, polyarylate, polyether In addition to insulating substrates such as sulfones and ceramic substrates, metal substrates (tantalum, tungsten) are also used. Materials such as semiconductor substrates (e.g., cellulose, molybdenum) or those with an insulating film formed on their surface can also be used. However, it is necessary to use a substrate that can withstand the heat generated during the process.

[0246] The base film 1712 may be a silicon oxide film, a silicon nitride film, or a silicon oxide-nitride film (SiO2). x N y Using insulating films such as ), these insulating films are formed as a single layer or two or more layers. The film 1712 may be formed using sputtering, CVD, or the like. In this embodiment, the base film While 1712 is used as a single layer, it is of course possible to use two or more layers.

[0247] Next, a transistor 1713 is formed on the undercoat 1712. Transistor 1713 is , at least a semiconductor layer 1714 and a gate insulating film 171 formed on the semiconductor layer 1714 5 and a gate electrode 171 formed on the semiconductor layer 1714 via a gate insulating film 1715 It consists of 6, and the semiconductor layer 1714 has a source region and a drain region.

[0248] The semiconductor layer 1714 is made of amorphous silicon (a-Si:H), as well as silicon, silicone Amorphous semiconductors mainly composed of crystalline and amorphous germanium (SiGe), amorphous and crystalline states Semi-amorphous semiconductors and amorphous semiconductors containing a mixture of crystalline grains ranging from 0.5 nm to 20 nm. Observable microcrystalline semiconductors and crystalline semiconductors such as polysilicon (p-Si:H) A film can be used. Furthermore, crystal grains ranging from 0.5 nm to 20 nm can be observed. The microcrystalline state is what is commonly called a microcrystal. For example, in semiconductor layer 1714 When using amorphous semiconductor films, they can be formed using methods such as sputtering or CVD. When using a crystalline semiconductor film, for example, if an amorphous semiconductor film is formed and then further crystallized... Good. Also, if necessary, in addition to the above main components, to control the threshold voltage of the transistor It may contain trace amounts of impurity elements (such as phosphorus, arsenic, and boron).

[0249] Next, a gate insulating film 1715 is formed by covering the semiconductor layer 1714. 15 uses, for example, silicon oxide, silicon nitride, or silicon oxide nitride to form a single or multiple film. It is formed by layering. The film deposition method can include CVD, sputtering, etc. Cut.

[0250] Next, gate electrodes are connected to the semiconductor layer 1714 via the gate insulating film 1715. Form 1716. The gate electrode 1716 may be formed as a single layer, or multiple metal films may be stacked. It may be formed in layers. The gate electrode may be made of tantalum (Ta), tungsten (W), Titanium (Ti), molybdenum (Mo), aluminum (Al), copper (Cu), chromium (C) r), niobium (Nb), etc., selected elements or alloy materials mainly composed of these elements Alternatively, it can be formed from compound materials. For example, tantalum nitride can be used as the first conductive layer. Using a first conductive film and a second conductive film, tungsten (W) was used as the second conductive layer. It may also be used as a gate electrode.

[0251] Next, the gate electrode 1716 or the resist formed into the desired shape is used as a mask. This method is used to selectively add impurities that impart n-type or p-type conductivity to the semiconductor layer 1714. In this way, the semiconductor layer 1714 has channel formation regions and impurity regions (source A region (including a drain region, a gold region, and an LDD region) is formed. Also, when added... Depending on the conductivity type of the impurity element, it can be an N-channel transistor or a P-channel transistor. It is possible to manufacture them while distinguishing between T and other elements.

[0252] Figure 17 shows the gate electrode 17 in order to fabricate the LDD region 1720 in a self-aligned manner. A silicon compound, such as a silicon oxide film, a silicon nitride film, or an acid, is used to cover 16. After forming the silicon nitride film, the sidewall 1717 is formed by etching back. Subsequently, by adding impurities that impart conductivity to the semiconductor layer 1714, the source region 1718, drain region 1719 and LDD region 1720 can be formed. Therefore, the LDD area 1720 is located below the sidewall 1717. Wall 1717 is provided in order to form the LDD region 1720 in a self-aligned manner. It is not necessarily required to provide it. Note that impurities that impart conductivity include phosphorus, arsenic, and boro. "n" and similar terms are used.

[0253] Next, the gate electrode 1716 is covered with the first insulating film 1730 as the first interlayer insulating film 1 721, a second insulating film 1722 is laminated and formed. 1722 refers to silicon oxide film, silicon nitride film, or silicon oxide-nitride film (SiO x N y ) etc. Inorganic insulating films or low dielectric constant organic resin films (photosensitive or non-photosensitive organic resin films) are used. This is possible. Alternatively, a membrane containing siloxane may be used. Note that siloxane is silico This material has a skeletal structure formed by the bonding of silicon (Si) and oxygen (O), and the substituents are: Organic groups (e.g., alkyl groups, aromatic hydrocarbons) are used. Additionally, fluoro groups are used as substituents. It may include [something].

[0254] Furthermore, the first insulating film 1721 and the second insulating film 1722 may be made of the same insulating film material. In this embodiment, the first interlayer insulating film 1730 is configured as a two-layer laminated structure, but it can also be used as a single layer. It's good, and it's also good as a laminated structure with three or more layers.

[0255] The first insulating film 1721 and the second insulating film 1722 were manufactured using sputtering, CVD, and spi It can be formed using a coating method, and an organic resin film or a film containing siloxane can be used. In some cases, it may be formed using a coating method.

[0256] Subsequently, a source electrode and a drain electrode 1723 are formed on the first interlayer insulating film 1730. The source electrode and drain electrode 1723 are connected via contact holes. It is connected to source area 1718 and drain area 1719.

[0257] The source electrode and drain electrode 1723 are made of silver (Ag), gold (Au), and copper (Cu). Nickel (Ni), platinum (Pt), palladium (Pd), iridium (Ir), rhodium Rh (metal), tungsten (W), aluminum (Al), tantalum (Ta), molybdenum Iron (Mo), cadmium (Cd), zinc (Zn), iron (Fe), titanium (Ti), silicon ( Si), germanium (Ge), zirconium (Zr), barium (Ba), neodymium ( Using metals such as Nd or their alloys, or metal nitrides thereof, or multilayer films thereof. It is possible.

[0258] Next, a second interlayer insulating film 1731 is formed covering the source electrode and drain electrode 1723. The second interlayer insulating film 1731 may be an inorganic insulating film, a resin film, or a laminate thereof. It can be used. As an inorganic insulating film, silicon nitride film, silicon oxide film, silicon oxide nitride film or These can be used as laminated films. Examples of resin films include polyimide and polyamide. Acrylic, polyimideamide, epoxy, and the like can be used.

[0259] Next, pixel electrodes 172 An insulator 1725 is formed to cover the end of 4. The insulator 1725 will be formed later In order to ensure good film formation of the light-emitting material layer 1726, the upper end of the insulator 1725 or It is preferable that the lower end be formed to have a curved surface with curvature. For example, insulator 172 When positive-type photosensitive acrylic is used as the material for 5, the curve is only at the upper end of the insulator 1725. It is preferable to have a curved surface with a radius of error (0.2 μm to 3 μm). Also, insulating material 1 As 725, a negative type that becomes insoluble in etchant when exposed to light, or light Therefore, any positive type that is soluble in etchant can be used. Furthermore, Insulator 1725 can be made not only from organic materials but also from inorganic materials such as silicon oxide and silicon oxynitride. It can be done.

[0260] Next, a layer 1726 containing light-emitting material and a counter electrode are placed on the pixel electrode 1724 and the insulator 1725. It forms pole 1727.

[0261] Furthermore, the layer 1726 containing the light-emitting material is sandwiched between the pixel electrode 1724 and the counter electrode 1727. In the region, a light-emitting element 1728 is formed.

[0262] Next, the details of the light-emitting element 1728 will be explained using Figure 18. Note that in Figure 17... The pixel electrode 1724 and the counter electrode 1727 are, respectively, the pixel electrode 1801 and the counter electrode 1727 in Figure 18. This corresponds to electrode 1802. Also, in Figure 18(a), the pixel electrode is the anode, and the counter electrode is This will be used as the cathode.

[0263] As shown in Figure 18(a), there is an emissive layer between the pixel electrode 1801 and the counter electrode 1802. In addition to 1813, there are hole injection layer 1811, hole transport layer 1812, electron transport layer 1814, and electron injection layer 1813. Inlet layers 1815, etc., are also provided. These layers have a potential at the pixel electrode 1801 that is equal to the potential at the counter electrode 1 When a voltage is applied to be higher than the potential of 802, a hole is released from the pixel electrode 1801 side. The layers are stacked so that electrons are injected from the counter electrode 1802 side.

[0264] In such a light-emitting element, a hole injected from the pixel electrode 1801 and the counter electrode 18 The electrons injected from 02 recombine in the light-emitting layer 1813, exciting the light-emitting material. Then, the luminescent substance in the excited state emits light when it returns to the ground state. Any substance that exhibits luminescence (electroluminescence) will suffice.

[0265] There are no particular limitations on the material that forms the light-emitting layer 1813; it can be formed solely from light-emitting material. It can be a layer, but if density quenching occurs, the energy gap of the light-emitting material is A light-emitting substance is dispersed in a layer consisting of a substance (host) that has a larger energy gap. It is preferable that the layers are mixed in such a way. This prevents concentration quenching of the luminescent material. This is possible. Note that the energy gap refers to the lowest molecular orbital (LUMO). Unoccupied Molecular Orbital) levels and highest occupied molecular orbital Road(HOMO:Highest Occupied Molecular Orbita l) This refers to the energy difference with respect to the energy level.

[0266] Furthermore, there are no particular limitations on the luminescent material; any material capable of emitting light at a desired wavelength can be used. For example, if you want to obtain red luminescence, use 4-dicyanomethylene-2-isopropyl alcohol. Ropyru-6-[2-(1,1,7,7-tetramethylderoridine-9-yl)ethenyl ]-4H-pyran (abbreviation: DCJTI), 4-dicyanomethylene-2-methyl-6-[2 -(1,1,7,7-tetramethyljurolidine-9-yl)ethenyl]-4H-pyran (Abbreviation: DCJT), 4-dicyanomethylene-2-tert-butyl-6-[2-(1, 1,7,7-Tetramethyljurolidine-9-yl)ethenyl]-4H-pyran (abbreviation: DCJTB) and perifrantene, 2,5-dicyano-1,4-bis[2-(10-methoxy C-1,1,7,7-tetramethylderoridine-9-yl)ethenyl]benzene, etc., 6 By using a material that exhibits emission with a peak in its emission spectrum from 00 nm to 680 nm. This can be done. Also, if you want to obtain green light emission, use N,N'-dimethylquinacridone (abbreviated). Names: DMQd), Coumarin-6, Coumarin-545T, Tris(8-quinolinolato)aluminium Um (abbreviation: Alq), N,N'-diphenylquinacridone (abbreviation: DPQd), etc., 50 Use a material that exhibits emission with a peak in its emission spectrum from 0 nm to 550 nm. This can be done. Also, if you want to obtain blue light emission, use 9,10-bis(2-naphthyl)-te rt-butylanthracene (abbreviation: t-BuDNA), 9,9'-biantryl, 9,1 0-Diphenylanthracene (abbreviated as DPA) and 9,10-bis(2-naphthyl)ant Helical (abbreviation: DNA), bis(2-methyl-8-quinolinolato)-4-phenylpheno Lato-gallium (BGaq), bis(2-methyl-8-quinolinolato)-4-phenyl Enolato-aluminum (BAlq), etc., with emission spectra from 420 nm to 500 nm. A substance that exhibits luminescence with a peak can be used.

[0267] There are no particular limitations on the materials used to disperse the luminescent material; for example, 9, 10-di(2-naphthyl)-2-tert-butylanthracene (abbreviation: t-BuDNA) Anthracene derivatives such as ) or 4,4'-bis(N-carbazolyl)biphenyl (abbreviated) In addition to carbazole derivatives such as CBP, bis[2-(2-hydroxyphenyl)pyri] [zinc dinato] (abbreviation: Znpp2), bis[2-(2-hydroxyphenyl)benzox Metal complexes such as sazolatozinc (abbreviated as ZnBOX) can be used.

[0268] The anode material forming the pixel electrode 1801 is not particularly limited, but a material with a large work function is preferred. (Function 4.0 eV or higher) Using metals, alloys, electrically conductive compounds, and mixtures thereof It is preferable to do so. Specific examples of such anode materials include, as an oxide of a metal material, ITO (abbreviated as ITO), ITO containing silicon oxide (abbreviated as ITSO), acid Using a target prepared by mixing indium oxide with 2-20 wt% zinc oxide (ZnO) In addition to the indium zinc oxide (abbreviated as IZO) that is formed, gold (Au), platinum (Pt), and nitrile are also produced. Ni (Ni), Tungsten (W), Chromium (Cr), Molybdenum (Mo), Iron (Fe ), cobalt (Co), copper (Cu), palladium (Pd), or nitrides of metallic materials (e.g.) Examples include titanium nitride.

[0269] On the other hand, the material used to form the counter electrode 1802 is one with a small work function (work function 3.8 Metals, alloys, electrically conductive compounds, and mixtures thereof (with an electrical conductivity of less than eV) can be used. . Specific examples of such cathode materials include elements belonging to Group 1 or Group 2 of the periodic table, that is, Alkali metals such as lithium (Li) and cesium (Cs), or magnesium (Mg) , alkaline earth metals such as calcium (Ca) and strontium (Sr), and those containing these Examples include alloys (Mg:Ag, Al:Li). Also, the counter electrode 1802 and the light-emitting layer 18 Between 13 and the counter electrode, a layer with excellent electron injection properties is laminated and provided, thereby working Regardless of the size of the function, pixel electrodes such as Al, Ag, ITO, and ITO containing silicon dioxide 1 Various conductive materials, including those listed as materials for 801, can be used as counter electrodes 1802. It is possible to do so. Furthermore, the electron injection layer 1815, which will be described later, is particularly excellent in its function of injecting electrons. The same effect can be achieved by using the same materials.

[0270] Furthermore, in order to extract the emitted light to the outside, the pixel electrode 1801 and the counter electrode 1802 Either one or both are transparent electrodes such as ITO, or several to several dozen electrodes that allow visible light to pass through. It is preferable that the electrode is formed with a thickness of nm.

[0271] Between the pixel electrode 1801 and the light-emitting layer 1813, there is a hole transport layer as shown in Figure 18(a). It has 1812. The hole transport layer is a layer that transports holes injected from the pixel electrode 1801 to the light-emitting layer 18 This layer has the function of transporting to 13. In this way, a hole transport layer 1812 is provided, and the pixel electricity By separating the pole 1801 and the light-emitting layer 1813, the light emission is extinguished due to the metal. This can prevent it.

[0272] Furthermore, it is preferable to form the hole transport layer 1812 using a material with high hole transport properties. Especially 1 x 10 -6 cm 2 Formed using a material with a hole mobility of / Vs or higher. This is preferable. A substance with high hole transport is a substance in which the mobility of holes is higher than that of electrons. . Specific examples of materials that can be used to form the hole transport layer 1812 include 4, 4'-Bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB) , 4,4'-bis[N-(3-methylphenyl)-N-phenylamino]biphenyl (abbreviated) Name: TPD), 4,4',4''-Tris(N,N-diphenylamino)triphenyl Min (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)- N-phenylamino]triphenylamine (abbreviation: MTDATA), 4,4'-bis{N -[4-(N,N-di-m-tolylamino)phenyl]-N-phenylamino}biphenyl Tris(N,N-di(m-tril)amino)ben (abbreviation: DNTPD), 1,3,5-tris[N,N-di(m-tril)amino]ben Zen (abbreviation: m-MTDAB), 4,4',4''-tris(N-carbazolyl) truffle Phenylamine (abbreviation: TCTA), phthalocyanine (abbreviation: H2Pc), copper phthalocyanine Examples include nitrate (abbreviated as CuPc), vanadylphthalocyanine (abbreviated as VOPc), etc. Furthermore, the hole transport layer 1812 was formed by combining two or more layers made of the materials described above. It may also be a multi-layered structure.

[0273] Furthermore, between the counter electrode 1802 and the light-emitting layer 1813, as shown in Figure 18(a), electrons It may have a transport layer 1814. Here, the electron transport layer is defined as the electrons that are released from the counter electrode 1802. This layer has the function of transporting incoming electrons to the light-emitting layer 1813. By providing layer 1814 and separating the counter electrode 1802 and the light-emitting layer 1813, light emission is reduced. This prevents quenching caused by the metal material of the electrode.

[0274] There are no particular limitations regarding the electron transport layer 1814, and Tris(8-kinolinorat)alminiu Alq (abbreviation), Tris(4-methyl-8-quinolinolato)aluminum (abbreviation: A lmq3), bis(10-hydroxybenzo[h]-quinolinato)beryllium (abbreviation: B eBq2), bis(2-methyl-8-quinolinolato)-4-phenylphenolato-aluminum Metal complexes containing a quinoline or benzoquinoline skeleton, such as nium (abbreviated as BAlq). Substances formed by the body, etc., can be used. In addition, bis[2-(2-hydroxy [Ciphenyl)-benzoxazolato]zinc (abbreviation: Zn(BOX)2), bis[2-(2 -hydroxyphenyl)-benzothiazolat]zinc (abbreviation: Zn(BTZ)2), etc. Formed by metal complexes having xazole-based or thiazole-based ligands, etc. Also, 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1 ,3,4-oxadiazole (abbreviation: PBD) and 1,3-bis[5-(p-tert- Butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviation: OXD) -7), 3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenyl (Lu)-1,2,4-triazole (abbreviation: TAZ), 3-(4-tert-butylphenicol) (L)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazo β-EtTAZ (abbreviation: p-EtTAZ), β-phenanthroline (abbreviation: BPhen), β-Cu It may also be formed using prion (abbreviated as BCP), etc. Electron transport layer 181 4 is formed using a material in which the electron mobility is higher than the hole mobility as described above. It is preferable that the electron transport layer 1814 is 10 -6 cm 2 Electron movement of / Vs or greater It is more preferable to form it using a material having a degree. Furthermore, the electron transport layer 1814 is A multilayer structure may be formed by combining two or more layers made of the materials described above.

[0275] Furthermore, between the pixel electrode 1801 and the hole transport layer 1812, as shown in Figure 18(a) It may also have a hole injection layer 1811. Here, the hole injection layer functions as an anode. This layer has the function of promoting the injection of holes from the electrode into the hole transport layer 1812.

[0276] There are no particular limitations on the hole injection layer 1811; molybdenum oxide, vanadium oxide, etc. Formed by metal oxides such as ruthenium oxide, tungsten oxide, and manganese oxide. These can be used. In addition, phthalocyanine (abbreviation: H2Pc) and copper phthalocyanine can be used. Phthalocyanine compounds such as cyanine (CuPc), 4,4-bis(N-(4-(N, N-di-m-tolylamino)phenyl)-N-phenylamino)biphenyl (abbreviation: DN) Aromatic amine compounds such as TPD, or poly(ethylenedioxythiophene) / Possible hole injection is also possible with polymers such as styrene sulfonic acid aqueous solution (PEDOT / PSS). An infill layer 1811 can be formed.

[0277] Furthermore, a mixture of the aforementioned metal oxide and a substance with high hole transport properties is used for the pixel electrode 180. It may also be provided between 1 and the hole transport layer 1812. Even if such a layer is made thick, the driving voltage Because it does not involve an increase in density, the microcavity effect and optical interference effect can be achieved by adjusting the thickness of the layer. Optical design can be performed using the effect. Therefore, it has excellent color purity and is dependent on the viewing angle. High-quality light-emitting elements with minimal color changes can be fabricated. Furthermore, pixel electrode 1801 The pixel electrode 1801 is affected by the irregularities that occur on the surface during film formation and the minute residues remaining on the electrode surface. A film thickness can be selected to prevent a short circuit between the counter electrode 1802 and the film.

[0278] Furthermore, between the counter electrode 1802 and the electron transport layer 1814, as shown in Figure 18(a), It may also have an electron injection layer 1815. Here, the electron injection layer is a layer that functions as a cathode. This layer has the function of promoting electron injection from the electrode to the electron transport layer 1814. If no electron injection layer is provided, an electron injection layer is provided between the electrode that functions as the cathode and the light-emitting layer. The injection of electrons into the light-emitting layer may be assisted.

[0279] There are no particular limitations on the electron injection layer 1815; lithium fluoride (LiF), cesium fluoride, etc. Alkali metals or alkaline earth elements such as um (CsF) and calcium fluoride (CaF2) Compounds formed using metal-like compounds can be used. In addition, Alq or 4 , such as 4-bis(5-methylbenzoxazol-2-yl)stilbene (BzOs) In addition to materials with high electron transport properties, alkali metals or aluminium such as magnesium or lithium. A mixture with earth metals can also be used as the electron injection layer 1815.

[0280] Note that the hole injection layer 1811, hole transport layer 1812, light-emitting layer 1813, and electron transport layer 181 4. The electron injection layer 1815 is produced by methods such as vapor deposition, inkjet printing, or coating. It may also be formed by a misalignment method. Also, regarding the pixel electrode 1801 or the counter electrode 1802 Even if present, it can be formed using either sputtering or vapor deposition methods.

[0281] Furthermore, the layer structure of the light-emitting element is not limited to that shown in Figure 18(a), but also as shown in Figure 18(b). As shown, the electrodes may be fabricated in order, starting with the one that functions as the cathode. That is, pixel electrode 180 With 1 as the cathode, an electron injection layer 1815, an electron transport layer 1814, and an emissive layer are placed on the pixel electrode 1801. The layers are stacked in the following order: 1813, hole transport layer 1812, hole injection layer 1811, and counter electrode 1802. That's also good. Note that the opposing electrode 1802 functions as the anode.

[0282] Note that the description of the light-emitting element refers to one with a single light-emitting layer, but there are also examples of light-emitting elements having multiple light-emitting layers. This may also be the case. By providing multiple light-emitting layers and mixing the light emitted from each light-emitting layer... White light can be obtained. For example, in the case of a light-emitting element having two light-emitting layers, the first light Between the light layer and the second light-emitting layer, there are spacing layers, a hole-generating layer and an electron-generating layer. It is preferable to do so. With this configuration, each light emitted to the outside is visually It is mixed with other elements and is visible as white light. Therefore, white light can be obtained.

[0283] Furthermore, in Figure 17, light emission occurs from either the pixel electrode 1724 or the counter electrode 1727. It is extracted to the outside through one or both of the pixel electrodes 1724 or the counter electrode 1 Either or both of 727 are made of a translucent material.

[0284] When only the counter electrode 1727 is made of a translucent material, as shown in Figure 19(a) The light emitted passes through the counter electrode 1727 and is extracted from the side opposite the substrate. Also, the pixel electrode 1724 If only the material is translucent, the light emission will be as shown in Figure 19(b) by the pixel electrode 17 It is removed from the substrate side through 24. The pixel electrode 1724 and the counter electrode 1727 are If both are made of a light-transmitting material, the light emission is as shown in Figure 19(c) by the pixels. Taken through electrode 1724 and counter electrode 1727 from both the substrate side and the side opposite the substrate. It will be released.

[0285] Wiring and electrodes are not limited to the materials mentioned above, but can also be made from aluminum (Al), tantalum (Ta), and other materials. Tungsten (Ti), Molybdenum (Mo), Tungsten (W), Neodymium (Nd), Chromium ( Cr), nickel (Ni), platinum (Pt), gold (Au), silver (Ag), copper (Cu), magnesium Magnesium (Mg), Scandium (Sc), Cobalt (Co), Zinc (Zn), Niobium ( Nb), silicon (Si), phosphorus (P), boron (B), arsenic (As), gallium (Ga ), one or more elements selected from the group including indium (In), tin (Sn), or Compounds and alloy materials comprising one or more elements selected from the aforementioned group (for example, indi ITO containing tin oxide (ITO), indium zinc oxide (IZO), and silicon oxide. (ITSO), zinc oxide (ZnO), aluminum neodymium (Al-Nd), magnesium silver ( Formed using substances such as Mg-Ag, or combinations of these compounds. This can be done. Also, compounds of these elements with silicon (silicides) (for example, aluminum silicides) (e.g., nitriding, molybdenum silicon, nickel silicide, etc.) and nitrogen compounds (e.g., nitriding) It may also be formed using titanium, tantalum nitride, molybdenum nitride, etc. Note that silicon ( Even if silicon contains many n-type impurities (such as phosphorus) and p-type impurities (such as boron), Good. The inclusion of these impurities improves conductivity, making it easier to use as wiring or electrodes. Furthermore, silicon comes in various forms: single crystal, polycrystalline (polysilicon), and amorphous (amorphous silicon). Either of the following may be used. When using single-crystal silicon or polycrystalline silicon, reduce the resistance. It can be cut, and in the case of amorphous silicon, it can be manufactured using a simple manufacturing process.

[0286] When using aluminum or silver, it is possible to reduce signal delay due to their high conductivity. It is possible. Also, because etching is easy, patterning is easy and microfabrication can be performed. Yes, it is possible. Furthermore, copper, due to its high conductivity, can also reduce signal delay. Butene does not cause material defects even when it comes into contact with oxide semiconductors such as ITO and IZO or silicon. It can be manufactured without causing problems such as patterning and etching. It is desirable because it is easy to perform and has excellent heat resistance. In the case of titanium, ITO and IZO are also desirable. It can be manufactured without causing material defects or other problems when in contact with any oxide semiconductor or silicon. It is desirable because it can be manufactured and has excellent heat resistance. Also, tungsten and neodymium are excellent It is desirable because it has good heat resistance. Furthermore, when neodymium is alloyed with aluminum, it has good heat resistance. The properties are improved and aluminum hillocks can be suppressed. Silicon is a transient It can be formed simultaneously with the semiconductor layer that the material possesses, and has high heat resistance. I contain indium tin oxide (ITO), indium zinc oxide (IZO), and silicon oxide. TO (ITSO), zinc oxide (ZnO), and silicon (Si) are translucent, so they allow light to pass through. These are particularly desirable when used in areas where transparency is required, such as pixel electrodes and common electrodes. It can be used as such.

[0287] Furthermore, the wiring and electrodes are not limited to a single-layer structure formed using the above materials, but can also be multi-layer structures. This is also possible. For example, if it is formed as a single-layer structure, the manufacturing process can be simplified, This can reduce stress. Furthermore, a multi-layer structure can leverage the advantages of each material. Therefore, it is possible to reduce the disadvantages and form high-performance wiring and electrodes. This is possible. For example, a structure that includes a low-resistance material (such as aluminum) as part of a multilayer structure. By using this method, the resistance of the wiring can be reduced. In addition, by including materials with high heat resistance... Eel structure (for example, sandwiching a material with low heat resistance but other advantages between materials with high heat resistance) By using a laminated structure like this, it has high heat resistance and advantages that could not be utilized with a single layer. This makes it possible to utilize the material. For example, a layer containing aluminum can be made with molybdenum or titanium. It is desirable to use wiring or electrodes that are sandwiched between layers containing [the specified element].

[0288] Furthermore, if there are parts where wiring or electrodes come into direct contact with wiring or electrodes of other materials, This can have adverse effects on the material. For example, if one material is mixed into another material, each material It alters the properties of the material, preventing it from fulfilling its original purpose, or causing problems during manufacturing. Sometimes, manufacturing may not be possible. In such cases, one layer is sandwiched between other layers. This can be solved by covering or concealing the problem. For example, indium tin oxide (IT If you want to bring O) and aluminum into contact, you can interpose titanium or molybdenum in between. It is desirable. Similarly, if you want to bring silicon and aluminum into contact, you can use titanium or aluminum in between. It is desirable to use ribden as an intermediary.

[0289] Next, transistor 1713 uses an amorphous semiconductor film as the semiconductor layer in a forward staggered structure. Let's explain the inverter. A partial cross-sectional view of a pixel is shown in Figure 20. Note that in Figure 20, the forward stroke is shown. This section describes a transistor with a hoop structure, along with an explanation of the capacitive elements present in pixels. ru.

[0290] As shown in Figure 20, a base film 2012 is formed on the substrate 2011. A pixel electrode 2013 is formed on the film 2012. Also, the same layer as the pixel electrode 2013 A first electrode 2014 made of the same material is formed.

[0291] Furthermore, wiring 2015 and wiring 2016 are formed on the undercoat 2012, and the pixel electrode 20 End 13 is covered with wiring 2015. An N-type is placed on top of wiring 2015 and wiring 2016. N-type semiconductor layers 2017 and 2018 having the conductivity type are formed. Furthermore, between wiring 2015 and wiring 2016, the semiconductor layer 2019 is on the underlayer 2012. It is formed. And a part of the semiconductor layer 2019 is the N-type semiconductor layer 2017 and the N-type semiconductor layer. It extends to the 2018 layer. This semiconductor layer is amorphous silicon (a-Si It is formed from amorphous semiconductors such as :H). Note that it is not limited to amorphous semiconductors, but also semiamorphs. It may be a crystalline semiconductor, microcrystalline semiconductor, etc. Furthermore, a gate insulating film may be placed on the semiconductor layer 2019. 2020 is formed. Also, an insulating layer made of the same material as the gate insulating film 2020 is formed in the same layer. The film 2021 is also formed on the first electrode 2014.

[0292] Furthermore, a gate electrode 2022 is formed on the gate insulating film 2020, and transistor 2 025 is formed. Also, a second electrode made of the same material is formed in the same layer as the gate electrode 2022. 2023 is formed on the first electrode 2014 via an insulating film 2021, and the insulating film 2021 A capacitive element 2024 is formed, sandwiched between the first electrode 2014 and the second electrode 2023. Furthermore, the ends of the pixel electrode 2013, transistor 2025 and capacitive element 2024 An interlayer insulating film 2026 is formed covering it.

[0293] A layer containing light-emitting material is placed on the interlayer insulating film 2026 and the pixel electrode 2013 located at its opening. Layer 2027 and the counter electrode 2028 are formed, and the layer 2027 containing the light-emitting material is the pixel electrode 201 The light-emitting element 2029 is formed in the region sandwiched between element 3 and the counter electrode 2028.

[0294] Furthermore, the first electrode 2014 shown in Figure 20(a) is connected to the wiring 201 shown in Figure 20(b). Formed from the same material as 5 and 2016, the insulating film 2021 is formed from the first electrode 2030 and the second The capacitive element 2031 may be configured to be sandwiched between electrodes 2023. Also, in Figure 20 So, an N-channel transistor was used for transistor 2025, but a P-channel transistor was used. Zista is fine too.

[0295] Substrate 2011, undercoat 2012, pixel electrode 2013, gate insulating film 2020, gate electrode Used in electrode 2022, interlayer insulating film 2026, layer 2027 containing light-emitting material and counter electrode 2028 The materials used are the substrate 1711, the undercoat 1712, and the pixel electrode 17, as explained in Figure 17. 24, gate insulating film 1715, gate electrode 1716, interlayer insulating films 1730 and 1731, The same materials as those used for the light-emitting layer 1726 and the counter electrode 1727 can be used, respectively. Also, wiring 2015 and wiring 2016 are the source electrode and drain electrode in Figure 17. The same materials as those used for Extreme 1723 should be used.

[0296] Next, as another configuration of a transistor using an amorphous semiconductor film as the semiconductor layer, we have a substrate and a semiconductor A structure in which a gate electrode is sandwiched between body layers, that is, a gate electrode located below the semiconductor layer. Figure 21 shows a partial cross-sectional view of a pixel having a luminous gate-type transistor.

[0297] An undercoat 2112 is formed on the substrate 2111. Furthermore, a gate is formed on the undercoat 2112. Electrode 2113 is formed. Also, in the same layer as gate electrode 2113, a second electrode made of the same material is formed. Electrode 2114 is formed. The material of gate electrode 2113 is the same as shown in Figure 17. In addition to the materials used in electrode 1716, there are also phosphorus-added polycrystalline silicon and metal-silicone materials. A silicide, which is a compound of 2, may also be used.

[0298] Furthermore, a gate insulating film 2115 covers the gate electrode 2113 and the first electrode 2114. It is formed.

[0299] A semiconductor layer 2116 is formed on the gate insulating film 2115. A semiconductor layer 2117 made of the same material as 16 is formed on the first electrode 2114 in the same layer. Furthermore, this semiconductor layer is made from amorphous semiconductors such as amorphous silicon (a-Si:H). It is formed. Furthermore, it is not limited to this, but also includes semi-amorphous semiconductors, microcrystalline semiconductors, etc. That's good too.

[0300] On the semiconductor layer 2116 are an N-type semiconductor layer 2118 and an N-type semiconductor layer having an N-type conductivity. Layer 2119 is formed, and an N-type semiconductor layer 2120 is formed on semiconductor layer 2117.

[0301] Wirings 2121 and 2121, respectively, are located on the N-type semiconductor layer 2118 and the N-type semiconductor layer 2119. 122 is formed, and transistor 2129 is formed. Also, N-type semiconductor layer 212 A conductive layer 2123 made of the same material and layer as wiring 2121 and wiring 2122 is formed on top of 0. Then, the conductive layer 2123, the N-type semiconductor layer 2120, and the semiconductor layer 2117 form a second electrical It forms an electrode. Furthermore, the gate insulating film 211 is formed by this second electrode and the first electrode 2114. A capacitive element 2130 is formed with a configuration in which 5 is sandwiched.

[0302] Furthermore, one end of the wiring 2121 extends, and the upper part of the extended wiring 2121 is adjacent to the diagram. A primary electrode 2124 is formed.

[0303] Furthermore, the ends of the pixel electrode 2124, the transistor 2129 and the capacitive element 2130 are covered. A sea urchin-shaped insulator 2125 is formed.

[0304] A layer 2126 containing light-emitting material and a counter electrode 2 are placed on the pixel electrode 2124 and the insulator 2125. 127 is formed, and a layer 2126 containing light-emitting material is formed between the pixel electrode 2124 and the counter electrode 2127. In the region between them, a light-emitting element 2128 is formed.

[0305] Semiconductor layer 2117 and N-type semiconductor layer 212 which form part of the second electrode of the capacitive element 2130 0 does not necessarily need to be provided. In other words, the second electrode is the conductive layer 2123, and the first electrode 21 A capacitive element with a structure in which the gate insulating film 2115 is sandwiched between 14 and the conductive layer 2123 may also be used. .

[0306] Furthermore, although an N-channel transistor was used for transistor 2129, a P-channel transistor was used. Ranjista would be fine too.

[0307] Note that in Figure 21(a), the pixel electrode 2124 is formed before the wiring 2121 is formed. By doing so, a second pixel electrode made of the same material and layer as the pixel electrode 2124, as shown in Figure 21(b), is created. A capacitive element in which a gate insulating film 2115 is sandwiched between electrode 2131 and the first electrode 2114. It is also acceptable to form 2132.

[0308] We have shown a transistor with an inverse staggered channel etch structure, but of course the channel A transistor with a protection structure is also acceptable. Next, regarding the case of a transistor with a channel protection structure... This will be explained using Figure 22. Note that in Figure 22, elements similar to those in Figure 21 are common. This is indicated using the sign.

[0309] The channel-protected transistor 2201 shown in Figure 22(a) is shown in Figure 21(a). The channel etch structure transistor 2129 is such that the channel is in the semiconductor layer 2116. It differs in that an insulator 2202, which serves as an etching mask, is provided on the region to be formed. ru.

[0310] Similarly, the channel-protected transistor 2201 shown in Figure 22(b) is shown in Figure 21( The channel etch structure transistor 2129 shown in b) is located in the semiconductor layer 2116. An insulator 2202, which serves as an etching mask, is provided over the region where the channel is formed. They differ in that respect.

[0311] By using an amorphous semiconductor film in the semiconductor layer of the transistor constituting the pixel of the present invention, Manufacturing costs can be reduced. The materials used are those explained in Figure 17. It is possible.

[0312] Furthermore, the structure of transistors and the configuration of capacitive elements are not limited to those described above, and various configurations are possible. Transistors and capacitive elements can be used, either in their construction or configuration.

[0313] Furthermore, the semiconductor layer of the transistor is made of amorphous silicon (a-Si:H) and other amorphous materials. In addition to semiconductor films consisting of semiconductors, semi-amorphous semiconductors, and microcrystalline semiconductors, polysilicon ( Crystalline semiconductor films such as p-Si:H may also be used.

[0314] Figure 23 shows a partial cross-sectional view of a pixel having a transistor with a crystalline semiconductor film as the semiconductor layer. This is shown and explained below. Note that transistor 2318 shown in Figure 23 is the same as shown in Figure 29. It is a multi-gate transistor.

[0315] As shown in Figure 23, a base film 2302 is formed on the substrate 2301, and a semiconductor layer is placed thereon. 2303 is formed. The semiconductor layer 2303 is formed by shaping a crystalline semiconductor film into a desired form. Pattern and shape.

[0316] An example of a method for fabricating a crystalline semiconductor film is described below. First, the substrate 2301 is subjected to sputtering. Amorphous silicon films are deposited using methods such as CVD. Then, the deposited amorphous silicon... The recon film is subjected to thermal crystallization, laser crystallization, or thermal crystallization using a catalytic element such as nickel. Crystallization is performed using crystallization methods to obtain a crystalline semiconductor film. Furthermore, these crystallization methods can be combined. They can also be crystallized together.

[0317] Furthermore, the films to be crystallized are not limited to amorphous semiconductor films, including amorphous silicon films. It does not need to be specified; semiconductor films such as semi-amorphous semiconductors and microcrystalline semiconductors are also acceptable. Alternatively, compound semiconductor films containing amorphous structures, such as amorphous silicon germanium films, may be used. stomach.

[0318] When forming a crystalline semiconductor film by thermal crystallization, a heating furnace, laser irradiation, or RTA (Rapid Thermal Annealing), or a combination of these. It can be used.

[0319] Furthermore, when forming a crystalline semiconductor film by laser crystallization, a continuous-wave type laser is used. The beam (CW laser beam) and pulsed laser beam (pulsed laser beam) It can be used. The laser beams that can be used here are Ar lasers and Kr lasers. Gas lasers such as excimer lasers, single crystal YAG, YVO4, forsterite ( Mg2SiO4), YAlO3, GdVO4, or polycrystalline (ceramic) YAG, Y2O3, YVO4, YAlO3, GdVO4, Nd, Yb, Cr as dopants. The medium contains one or more of the following: Ti, Ho, Er, Tm, and Ta. Laser, glass laser, ruby ​​laser, alexandrite laser, Ti:sapphire This uses one or more of the following: a laser, a copper vapor laser, or a gold vapor laser. It is possible to have the fundamental wave of such a laser beam, and the second harmonic of these fundamental waves. By irradiating with a laser beam of the fourth harmonic, large-grained crystals can be obtained. Example For example, the second harmonic (532nm) and third harmonic of the Nd:YVO4 laser (fundamental wave 1064nm) It is possible to use harmonics (355 nm). In this case, the laser energy density is 0.0 1-100 MW / cm² 2 Degree (preferably 0.1 to 10 MW / cm²) 2 ) is necessary. The light is then irradiated at a scanning speed of approximately 10 to 2000 cm / sec.

[0320] Note that single crystals of YAG, YVO4, forsterite (Mg2SiO4), and YAlO3 are also included. GdVO4, or polycrystalline (ceramic) YAG, Y2O3, YVO4, YAlO 3. GdVO4 is given dopants Nd, Yb, Cr, Ti, Ho, Er, Tm, and Ta. Lasers using a medium containing one or more of the following additives, Ar ion lasers, Furthermore, Ti:sapphire lasers can be made to oscillate continuously, and Q-switched operation and By performing mode synchronization, etc., pulse oscillation can be made at an oscillation frequency of 10 MHz or higher. It is also possible. When a laser beam is oscillated at an oscillation frequency of 10 MHz or higher, the semiconductor film While the semiconductor film is melting and solidifying due to the laser, the next pulse is irradiated onto the semiconductor film. Therefore, unlike when using a pulsed laser with a low oscillation frequency, solids are formed in the semiconductor film. Because the liquid interface can be moved continuously, the bonds grow continuously in the scanning direction. Crystal grains can be obtained.

[0321] Furthermore, in the field where crystalline semiconductor films are formed by thermal crystallization using catalytic elements such as nickel, In some cases, it is preferable to perform a gettering treatment after crystallization to remove catalytic elements such as nickel. It seems so.

[0322] As described above, the crystallization process creates partially crystalline regions in the amorphous semiconductor film. This partially crystallized crystalline semiconductor film is patterned into a desired shape to form island-shaped semiconductors. A film is formed. This semiconductor film is used as the semiconductor layer 2303 of the transistor.

[0323] Furthermore, the crystalline semiconductor layer is the channel formation region 2304 and the saw of transistor 2318. In addition to being used in the impurity region 2305 which becomes the drain region or the drain region, it is also used in the capacitive element 2319 It is also used in the semiconductor layer 2306 and impurity region 2308, which form the lower electrode. Region 2308 does not need to be provided in particular. Also, channel formation region 2304 and semiconductor layer 2 Channel doping may be performed on port 306.

[0324] Next, a gate insulating film 2309 is applied to the lower electrode of the semiconductor layer 2303 and the capacitive element 2319. Furthermore, a gate insulating film 2309 is formed on the semiconductor layer 2303. The gate electrode 2310 has a gate insulating film 2309 on the semiconductor layer 2306 of the capacitive element 2319. An upper electrode 2311 made of the same material as the gate electrode 2310 is formed in the same layer via this connection. In this way, the transistor 2318 and the capacitive element 2319 are fabricated.

[0325] Next, an interlayer insulating film 2312 is formed covering the transistor 2318 and the capacitive element 2319. Furthermore, the interlayer insulating film 2312 is in contact with the impurity region 2305 via a contact hole. Wiring 2313 is formed. And, adjacent to the wiring 2313, on the interlayer insulating film 2312 Pixel electrodes 2314 are formed there, and the ends of the pixel electrodes 2314 and the wiring 2313 are covered and insulated. Material 2315 is formed. Furthermore, a layer 2316 containing light-emitting material is placed on the pixel electrode 2314. And a counter electrode 2317 is formed, and the light-emitting material is emitted between the pixel electrode 2314 and the counter electrode 2317. In the region where the containing layer 2316 is sandwiched, the light-emitting element 2320 is formed.

[0326] Furthermore, a bottom gate using a crystalline semiconductor film such as polysilicon (p-Si:H) as the semiconductor layer. A partial cross-section of a pixel having a tetrahedron transistor is shown in Figure 24.

[0327] A base film 2402 is formed on the substrate 2401, and a gate electrode 2403 is formed thereon. Furthermore, the first capacitive element 2423, made of the same material as the gate electrode 2403, is located in the same layer as the gate electrode 2403. Electrode 2404 is formed.

[0328] Furthermore, the gate insulating film 2405 covers the gate electrode 2403 and the first electrode 2404. It is formed.

[0329] A semiconductor layer is formed on the gate insulating film 2405. The semiconductor film is amorphous. Semiconductor films such as solid semiconductors, semi-amorphous semiconductors, and microcrystalline semiconductors are subjected to thermal crystallization, laser crystallization, etc. Crystallization is performed using a crystallization method, or a thermal crystallization method using a catalytic element such as nickel, and the desired The semiconductor layer is formed by patterning it into the desired shape.

[0330] Using such a semiconductor layer, the channel formation region 2406 of transistor 2422, LD D region 2407 and impurity region 2408 which becomes the source region or drain region, and capacity Region 2409, impurity region 2410, and impurity region 24 of element 2423 which will become the second electrode 11 is formed. Note that impurity regions 2410 and 2411 do not need to be provided. This is also good. Furthermore, impurities are added to channel-forming regions 2406 and 2409. That's good too.

[0331] Furthermore, the capacitive element 2423 has a gate insulating film 2405 which is the first electrode 2404 and a semiconductor layer It is a configuration sandwiched between second electrodes, which consist of regions 2409 and the like formed from the above.

[0332] Next, a first interlayer insulating film 2412 is formed covering the semiconductor layer, and the first interlayer insulating film 24 A wiring 2413 is formed on 12, in contact with the impurity region 2408 via a contact hole. It is.

[0333] Furthermore, an opening 2415 is formed in the first interlayer insulating film 2412. A second interlayer insulating film 2416 covers 2422, the capacitive element 2423, and the opening 2415. A second interlayer insulating film 2416 is formed, and wiring 2413 and A connected pixel electrode 2417 is formed. Also, the end of the pixel electrode 2417 is covered An insulator 2418 is formed. Then, a layer 24 containing light-emitting material is placed on the pixel electrode 2417. 19 and the counter electrode 2420 are formed, and light-emitting material is formed between the pixel electrode 2417 and the counter electrode 2420. In the region where the layer 2419 containing the material is sandwiched, the light-emitting element 2421 is formed. An opening 2415 is located at the bottom of element 2421. In other words, from the light-emitting element 2421 When light is extracted from the substrate side, the first interlayer insulating film 2412 has an opening 2415. Therefore, the light transmittance can be increased.

[0334] By using a crystalline semiconductor film in the semiconductor layer of the transistor constituting the pixel of the present invention, For example, the scan line drive circuit 712 and signal line drive circuit 711 in Figure 7 are connected to the pixel section 713 This makes it easier to form an integrated structure with it.

[0335] Furthermore, the structure of transistors using a crystalline semiconductor film as the semiconductor layer is the same as described above. It is not limited to this, and various structures can be adopted. The same applies to capacitive elements. Furthermore, in this embodiment, unless otherwise specified, the materials shown in Figure 17 may be used as appropriate. It is possible.

[0336] The transistor shown in this embodiment emits light in the pixels described in Embodiments 1 to 8. It can be used as a transistor to control the current value supplied to the element. By operating the pixels as described in the embodiments 1 to 8, the threshold voltage of the transistor is controlled. This can suppress variations in current values ​​caused by pressure variations. Therefore, luminance data This allows for the supply of a corresponding current to the light-emitting element, thereby suppressing variations in brightness. This is the result. Furthermore, because the potential of the counter electrode is kept constant during operation, power consumption can be reduced. It is Noh.

[0337] Furthermore, by applying such pixels to the display device in Figure 7, each pixel has its own advantage. Since it is possible to emit light except during the response period, the ratio of the emission period within one frame period The duty cycle (i.e., the ratio) can be made very large, and can even be set to approximately 100%. Therefore, a display device with less variation in brightness and a high duty cycle can be obtained.

[0338] Furthermore, it is possible to set a longer threshold voltage writing period, which allows current to flow to the light-emitting element. To more accurately write the threshold voltage of the transistor that controls the current value to the capacitive element. This is possible. Therefore, the reliability as a display device is improved. (Embodiment 10) In this embodiment, regarding an element having a different configuration from the light-emitting element shown in Embodiment 9, explain.

[0339] Light-emitting devices that utilize electroluminescence use organic or inorganic luminescent materials. They are distinguished by whether they are a hybrid or organic; generally, the former are called organic EL elements, and the latter are called inorganic EL elements. It is.

[0340] Inorganic EL elements are classified into dispersed inorganic EL elements and thin-film inorganic EL elements depending on their element configuration. They are classified as follows: The former has a light-emitting layer in which particles of light-emitting material are dispersed in a binder, while the latter has a light-emitting layer in which particles of light-emitting material are dispersed in a binder. Although it differs in that it has a light-emitting layer made of a thin film of light-emitting material, electrons accelerated by a high electric field They are similar in that they require [something]. Furthermore, the mechanism of the resulting luminescence involves the donor level This involves donor-acceptor recombination luminescence utilizing acceptor levels, and the inner shell of metal ions. There is localized light emission that utilizes electron transitions. Generally, in dispersed inorganic EL elements, donor- In contrast to receptor recombination type luminescence, localized luminescence is often observed in thin-film inorganic EL elements.

[0341] The luminescent material used in this embodiment consists of at least a matrix material and impurity elements that serve as luminescent centers. It is composed of (also called luminescent material). By changing the impurity elements it contains, various It is possible to obtain luminescence of various colors. Methods for producing luminescent materials include solid-phase methods and liquid-phase methods (coprecipitation method). Various methods can be used, such as spray pyrolysis, double decomposition, and precursor. - Methods involving thermal decomposition reactions, reverse micelles, and methods combining these with high-temperature firing, Liquid-phase methods such as freeze-drying can also be used.

[0342] The solid-phase method involves weighing the base material and impurity elements or compounds containing impurity elements, and mixing them in a mortar. This method involves heating and firing the material in an electric furnace to induce a reaction and incorporate impurity elements into the base material. The firing temperature is preferably 700-1500°C. If the temperature is too low, the solid-phase reaction will not proceed. This is because if the temperature is too high, the base material will decompose. Note that firing is performed in powder form. While this is also possible, it is preferable to perform the firing in pellet form. This does not require firing at a relatively high temperature. However, because it is a simple method, it is highly productive and suitable for mass production.

[0343] The liquid phase method (coprecipitation method) involves a matrix material or a compound containing the matrix material and impurity elements or impurity components. This method involves reacting a compound containing an element in a solution, drying it, and then firing it. The particles are uniformly distributed, and the reaction can proceed even at low firing temperatures due to the small particle size.

[0344] Sulfides, oxides, and nitrides can be used as the base material for the luminescent material. Examples of sulfides include zinc sulfide (ZnS), cadmium sulfide (CdS), and calcium sulfide. Calcium (CaS), yttrium sulfide (Y2S3), gallium sulfide (Ga2S3), sulfide Throntium (SrS), barium sulfide (BaS), etc. can be used. For example, zinc oxide (ZnO), yttrium oxide (Y2O3), etc. can be used. This can be done. Also, examples of nitrides include aluminum nitride (AlN) and gallium nitride. Materials such as GaN (GaN) and indium nitride (InN) can be used. Furthermore, selenium sulfate can be used. Lead (ZnSe), zinc telluride (ZnTe), etc. can also be used, and calcium sulfide- Strontium (CaGa2S4), strontium-gallium sulfide (SrGa2S4), strontium sulfide It may also be a ternary mixed crystal such as lium-gallium (BaGa2S4).

[0345] Manganese (Mn), copper (Cu), samarium (Sm), and other elements serve as the emission centers for localized luminescence. Terbium (Tb), Erbium (Er), Thulium (Tm), Europium (Eu), Cerium (Ce), praseodymium (Pr), etc., can be used. Note that charge compensation is also available. For example, halogen elements such as fluorine (F) and chlorine (Cl) may be added.

[0346] On the other hand, as the emission center of donor-acceptor recombination type emission, the second that forms the donor level Using a light-emitting material containing one impurity element and a second impurity element that forms an acceptor level. This is possible. The first impurity element is, for example, fluorine (F), chlorine (Cl), aluminum. Aluminum (Al) and the like can be used. A second impurity element could be, for example, copper (Cu). Silver (Ag), etc., can be used.

[0347] When synthesizing donor-acceptor recombination type luminescent materials using a solid-phase method, the matrix material A material, a first impurity element or a compound containing the first impurity element, and a second impurity element or The compounds containing the two impurity elements were weighed separately, mixed in a mortar, and then heated and fired in an electric furnace. This is performed. The above-mentioned matrix material can be used as the matrix material, and the first impurity element or Examples of compounds containing the first impurity element include fluorine (F), chlorine (Cl), and sulfide. Aluminum (Al2S3), etc., can be used, and a second impurity element or a second impurity Examples of element-containing compounds include copper (Cu), silver (Ag), copper sulfide (Cu2S), and sulfur Silver oxide (Ag2S), etc., can be used. The firing temperature is preferably 700 to 1500°C. If the temperature is too low, the solid-phase reaction will not proceed, and if the temperature is too high, the base material will decompose. This is because... Furthermore, while firing can be performed in powder form, firing in pellet form is also possible. This is preferable.

[0348] Furthermore, when utilizing solid-phase reactions, the impurity elements are the first impurity element and the second impurity Compounds composed of elements may be used in combination. In this case, impurity elements are diffused. Because the solid-phase reaction proceeds easily, a uniform luminescent material can be obtained. Furthermore, Because no extraneous impurity elements are included, a highly pure luminescent material can be obtained. The first impurity Examples of compounds composed of a monoatomic element and a second impurity element include copper chloride (CuCl), Silver chloride (AgCl) or similar substances can be used.

[0349] Furthermore, the concentrations of these impurity elements are 0.01 to 10 atom% relative to the base material. It is sufficient if the amount is within the range of 0.05 to 5 atom%.

[0350] In the case of thin-film inorganic EL elements, the light-emitting layer is a layer containing the above-mentioned light-emitting material, and is produced by resistance heating deposition. Vacuum deposition methods such as electron beam deposition (EB deposition), physical vapor deposition methods such as sputtering Chemical vapor deposition (PVD), organometallic CVD, hydride transport vacuum CVD, etc. It can be formed using methods such as VD (Volatile Deposition), atomic layer epitaxy (ALE), etc.

[0351] Figures 51(A) to (C) show one of the thin-film inorganic EL elements that can be used as a light-emitting element. An example is shown. In Figures 51(A) to (C), the light-emitting element is the first electrode 5101, the light-emitting layer Includes 5102 and a second electrode 5103.

[0352] The light-emitting element shown in Figures 51(B) and 51(C) is the same as the light-emitting element in Figure 51(A), The structure has an insulating layer between the electrode and the light-emitting layer. The light-emitting element shown in Figure 51(B) is the first An insulating layer 5104 is provided between the electrode 5101 and the light-emitting layer 5102, as shown in Figure 51(C). The optical element has an insulating layer 5104a between the first electrode 5101 and the light-emitting layer 5102, and a second electrode An insulating layer 5104b is provided between the electrode 5103 and the light-emitting layer 5102. It may be provided only between one of the pair of electrodes that sandwich the light-emitting layer and the light-emitting layer, or both It may be placed between them. The insulating layer may be a single layer or a laminate consisting of multiple layers.

[0353] Furthermore, in Figure 51(B), an insulating layer 5104 is provided so as to be in contact with the first electrode 5101. However, by reversing the order of the insulating layer and the light-emitting layer, the insulating layer is placed in contact with the second electrode 5103. 5104 may be provided.

[0354] In the case of dispersed inorganic EL elements, particulate light-emitting material is dispersed in a binder to form a film-like light-emitting layer. Form. If the desired particle size cannot be obtained sufficiently by the method for producing the luminescent material, The material can be processed into particles by crushing it in a mortar and pestle or similar. A binder is a binder made from granular luminescent material. This is a substance used to fix materials in a dispersed state and maintain them in the shape of a light-emitting layer. The light-emitting material is, The binder uniformly disperses and fixes the material within the light-emitting layer.

[0355] In the case of dispersed inorganic EL elements, the method for forming the light-emitting layer is droplet ejection, which can selectively form the light-emitting layer. Printing methods (such as screen printing and offset printing), coating methods such as spin coating The dipping method and the dispenser method can also be used. The film thickness is not particularly limited. Although not specified, it is preferably in the range of 10 to 1000 nm. Also, the light-emitting material and the binder In the light-emitting layer containing DA, the proportion of the light-emitting material should be 50 wt% or more and 80 wt% or less.

[0356] Figures 52(A) to (C) show one of the dispersed inorganic EL elements that can be used as a light-emitting element. An example is shown. The light-emitting element in Figure 52(A) consists of a first electrode 5101, a light-emitting layer 5202, and a second electrode 5101. It has a stacked structure of two electrodes 5103, and the light is held in the light-emitting layer 5202 by a binder. Contains optical material 5201.

[0357] Binders that can be used in this embodiment include insulating organic materials and inorganic materials. Any materials can be used. Furthermore, a mixture of organic and inorganic materials may be used. As an insulating material, a relatively high dielectric constant polymer such as cyanoethylcellulose resin is used. Polyethylene, polypropylene, polystyrene resin, silicone resin, epoxy Resins such as polyvinylidene fluoride can be used. Aromatic polyamides can also be used. Heat-resistant polymers such as polybenzimidazole, Alternatively, siloxane resin may be used. Note that siloxane resin refers to a resin with Si-O-Si bonds. It corresponds to the resin it contains. Siloxane has a skeletal structure formed by the bonding of silicon (Si) and oxygen (O). This is formed. The substituent is an organic group containing at least hydrogen (e.g., alkyl group, alkyl group). A fluoro group is used as a substituent. Alternatively, a fluoro group may be used as a substituent. For example, an organic group containing at least hydrogen and a fluoro group may be used. Also, organic materials In addition to the above, it also includes vinyl resins such as polyvinyl alcohol and polyvinyl butyral, and phenoxyethanol. Acrylic resin, novolac resin, acrylic resin, melamine resin, urethane resin, oxazole resin Resin materials such as lipids (polybenzoxazole) may also be used. Titanic acid may be used in these resins. High dielectric constant materials such as barium (BaTiO3) and strontium titanate (SrTiO3) The dielectric constant can also be adjusted by appropriately mixing fine particles.

[0358] Furthermore, the inorganic insulating material included in the binder is silicon dioxide (SiO₂). x ), silicon nitride ( SiN x ), silicon containing oxygen and nitrogen, aluminum nitride (AlN), oxygen and nitrogen Aluminum or aluminum oxide (Al2O3), titanium oxide (TiO2), Ba TiO3, SrTiO3, lead titanate (PbTiO3), potassium niobate (KNbO3) ), lead niobate (PbNbO3), tantalum oxide (Ta2O5), barium tantalate ( BaTa2O6), lithium tantalate (LiTaO3), yttrium oxide (Y2O3) ), zirconium oxide (ZrO2), zinc sulfide (ZnS), and other inorganic materials are included in this substance. It can be formed from materials selected from the above. By adding an inorganic material with a high dielectric constant to the organic material. By adding (or otherwise), the dielectric constant of the light-emitting layer, which consists of a light-emitting material and a binder, is changed. This allows for greater control and a higher dielectric constant.

[0359] In the manufacturing process, the luminescent material is dispersed in a solution containing a binder, but in this embodiment... As a solvent for a binder-containing solution that can contain the binder material, the solvent is such that the binder material dissolves and the luminescent layer is formed. Methods for forming the film (various wet processes) and solutions with viscosity suitable for the desired film thickness can be prepared. A suitable solvent can be selected. Organic solvents can be used, for example, as a binder. When using siloxane resin, propylene glycol monomethyl ether, propylene Glycol monomethyl ether acetate (also known as PGMEA), 3-methyl-3 Methyl-1-butanol (also known as MMB) can be used.

[0360] The light-emitting element shown in Figures 52(B) and 52(C) is the same as the light-emitting element in Figure 52(A), The structure has an insulating layer between the electrode and the light-emitting layer. The light-emitting element shown in Figure 52(B) is a first electric An insulating layer 5104 is provided between the electrode 5101 and the light-emitting layer 5202, and the light-emitting element shown in Figure 52(C) The child has an insulating layer 5104a between the first electrode 5101 and the light-emitting layer 5202, and a second electrode 51 An insulating layer 5104b is provided between 03 and the light-emitting layer 5202. In this way, the insulating layer is It may be provided only between one of the pair of electrodes that sandwich the light layer and the light-emitting layer, or between both. It may be provided. The insulating layer may be a single layer or a laminate consisting of multiple layers.

[0361] Furthermore, in Figure 52(B), an insulating layer 5104 is provided so as to be in contact with the first electrode 5101. However, by reversing the order of the insulating layer and the light-emitting layer, the insulating layer is placed in contact with the second electrode 5103. 5104 may be provided.

[0362] The insulating layers 5104, 5104a, and 5104b in Figures 51 and 52 are not particularly limited. Although this does not occur, it is preferable that the film has high dielectric strength and a dense film quality, and furthermore, the dielectric constant A high value is preferable. For example, silicon oxide (SiO2), yttrium oxide (Y2O 3) Titanium oxide (TiO2), aluminum oxide (Al2O3), hafnium oxide (H fO2), tantalum oxide (Ta2O5), barium titanate (BaTiO3), titanic acid Strontium (SrTiO3), lead titanate (PbTiO3), silicon nitride (Si3 Using N4), zirconium oxide (ZrO2), etc., or a mixture of these, or a multilayer film of two or more types These insulating films can be formed by sputtering, deposition, CVD, etc. This can be done. Furthermore, the insulating layer can be formed by dispersing particles of these insulating materials in a binder. The binder material can be formed using the same materials and methods as the binder contained in the light-emitting layer. Good. The film thickness is not particularly limited, but is preferably in the range of 10 to 1000 nm. .

[0363] Furthermore, the first electrode 5101 and the second electrode 5103 are made of metal, alloy, conductive compound, And mixtures thereof can be used. For example, the pixel electricity described in Embodiment 9 The materials used for the electrode 1801 and the counter electrode 1802 can be appropriately selected and used.

[0364] In this embodiment, the light-emitting element is located between a pair of electrodes that sandwich the light-emitting layer, i.e., the first Light emission is obtained by applying a voltage to the first electrode 5101 and the second electrode 5103.

[0365] The inorganic EL element obtained as described above is used as the light-emitting element in Embodiment 9. In addition to being able to do so, it can also be freely combined with other embodiments. (Embodiment 11) In this embodiment, one form of the display device of the present invention will be described with reference to Figure 25.

[0366] Figure 25(a) is a top view showing the display device, and Figure 25(b) is a section of the line A-A' in Figure 25(a). This is a top view (cross-sectional view taken along line A-A'). The display device is located on the substrate 2510 as shown in the figure. The dotted lines indicate the signal line driving circuit 2501, the pixel section 2502, and the first scan line driving circuit 250. 3. It has a second scan line drive circuit 2506. These are the sealing substrate 2504, seal It is sealed using material 2505.

[0367] Furthermore, 2508 refers to the first scan line drive circuit 2503, the second scan line drive circuit 2506 and This is wiring for transmitting signals input to the signal line drive circuit 2501, and is connected to the external input terminal. The video signal is transmitted from the FPC (Flexible Printed Circuit) 2509 to the crossover. It receives signals such as the start signal and start signal. An IC chip is located on the connection point between the FPC2509 and the display device. 2518 and 251 (semiconductor chips with memory circuits, buffer circuits, etc. formed on them) 9 is implemented using COG (Chip On Glass), etc. Note that here we are using FPC. Although only shown in the diagram, a printed circuit board (PWB) is attached to this FPC. The present invention may include not only the display device body but also an FPC or PWB. This includes the state in which it is attached. It also includes those with IC chips or other components mounted on them. Let's assume that.

[0368] The cross-sectional structure will be explained using Figure 25(b). On the substrate 2510, there is a pixel section 2502 and its peripheral drive circuits (first scan line drive circuit 2503, second scan line drive circuit 2506 and A signal line drive circuit 2501 is formed, but here the signal line drive circuit 2501 and Pixel section 2502 is shown.

[0369] The signal line drive circuit 2501 is an N-channel transistor 2520, 2521. It is composed of transistors of the same conductivity type. Of course, P-channel transistors and CMOS circuits can be constructed using not only transistors of the same conductivity type but also P-channel transistors. It may be formed. In this embodiment, a display panel in which peripheral drive circuits are integrally formed on the substrate. Although it indicates this, it is not necessarily required, and all or part of the peripheral drive circuitry can be IC-based. It can be formed into a chip or similar and then implemented using a COG (Center of Graving).

[0370] The pixel section 2502 uses the pixels described in Embodiments 1 to 8. (See Figure 2) 5(b) contains transistor 2511 which functions as a switch and current supplied to the light-emitting element. The transistor 2512 that controls the value and the light-emitting element 2528 are shown. The first electrode of the zistor 2512 is connected to the pixel electrode 2513 of the light-emitting element 2528. Furthermore, an insulator 2514 is formed covering the end of the pixel electrode 2513. The border material 2514 is formed by using a positive-type photosensitive acrylic resin film.

[0371] Furthermore, in order to ensure good coverage, the upper or lower end of the insulator 2514 is cut off. To form a curved surface having curvature on the surface. For example, the material of the insulator 2514 and When a positive-type photosensitive acrylic is used, the radius of curvature (0) is only at the upper end of the insulator 2514. It is preferable to have a curved surface with a thickness of 0.2 μm to 3 μm. Also, the insulating material 2514 is used. Therefore, a negative type that becomes insoluble in etchant by light, or etchant by light. Any positive-type solvent that dissolves in the cant can be used. Furthermore, insulating material 251 As material 4, not only organic materials but also inorganic materials such as silicon oxide and silicon oxynitride can be used.

[0372] Furthermore, on the pixel electrode 2513, there is a layer 2516 containing light-emitting material and a counter electrode 2517. Formed. If the layer 2516 containing the light-emitting material has at least a light-emitting layer, Other layers are not particularly limited and can be selected as appropriate.

[0373] Furthermore, the sealing substrate 2504 and the substrate 2510 are bonded together using the sealing material 2505. As a result, the space 2 enclosed by the substrate 2510, the sealing substrate 2504, and the sealing material 2505 The structure is such that a light-emitting element 2528 is provided in 507. In addition to cases where an active gas (such as nitrogen or argon) is used for filling, the structure is also filled with sealing material 2505. This includes the term "to become."

[0374] Furthermore, it is preferable to use an epoxy resin for the sealing material 2505. The material should preferably be as impermeable to moisture and oxygen as possible. (Sealing substrate 2504) Materials used include glass substrates and quartz substrates, as well as FRP (Fiberglass-R reinforced plastics, PVF (polyvinyl fluoride), polyester A plastic substrate made of tel or acrylic can be used.

[0375] Furthermore, by using the pixels described in Embodiments 1 to 8 in the pixel unit 2502, This can suppress variations in brightness between pixels or within pixels over time, and furthermore, A high-quality display device with a high t-to-t ratio can be obtained. Furthermore, in this invention, the counter electrode By maintaining a constant electrical potential during operation, power consumption can be reduced.

[0376] As shown in Figure 25, the signal line drive circuit 2501, the pixel unit 2502, and the first scan line drive circuit By integrating the line 2503 and the second scan line drive circuit 2506, the cost of the display device is reduced. This allows for streamlining. Furthermore, the signal line drive circuit 2501, the pixel section 2502, and the first drive The transistors used in the scan line drive circuit 2503 and the second scan line drive circuit 2506 are the same By adopting a single-conductivity type, the manufacturing process can be simplified, leading to further cost reductions. It is possible.

[0377] As described above, the display device of the present invention can be obtained. Note that the above configuration is just one example. The configuration of the display device of the present invention is not limited thereto.

[0378] Furthermore, the configuration of the display device is as shown in Figure 26(a), with the signal line drive circuit 2601 being... It may also be configured by forming it on an IC chip and mounting it on a display device using a COG or similar. (See Figure 2) In 6(a), the substrate 2600, the pixel section 2602, the first scan line drive circuit 2603, and the second Scan line drive circuit 2604, FPC 2605, IC chip 2606, IC chip 2607 The sealing substrate 2608 and the sealing material 2609 are respectively the substrate 2510 in Figure 25(a). Pixel section 2502, first scan line drive circuit 2503, second scan line drive circuit 2506, FP C2509, IC chip 2518, IC chip 2519, encapsulation substrate 2504, sealing material 2 It corresponds to 505.

[0379] In other words, only the signal line drive circuit, which requires high-speed operation of the drive circuit, uses CMOS, etc. The IC chip is formed on a semiconductor wafer such as silicon wafer to reduce power consumption. By using a single chip, it is possible to achieve faster operation and lower power consumption.

[0380] Furthermore, the first scan line drive circuit 2603 and the second scan line drive circuit 2604 are connected to the pixel section 260 By forming it as an integral part of 2, cost reduction can be achieved. Furthermore, this first scan line drive circuit 26 03. The second scan line driving circuit 2604 and the pixel section 2602 use transistors of the same conductivity type. This configuration allows for further cost reduction. At this time, the first scan line drive cycle By using a boot trap circuit in path 2603 and the second scan line drive circuit 2604, This prevents the output potential from becoming too low. Also, the first scan line drive circuit Amorphous material is present in the semiconductor layer of transistors constituting 2603 and the second scan line drive circuit 2604. When using fast silicon, the threshold voltage fluctuates due to degradation, so this needs to be corrected. It is preferable that it has a function.

[0381] Furthermore, the pixel unit 2602 also operates using the pixels described in Embodiments 1 to 8. This makes it possible to suppress variations in brightness between pixels or within pixels over time, Furthermore, a high-quality display device with a high duty cycle can be obtained. In addition, in the present invention, By keeping the potential of the direct electrode constant during operation, it is possible to reduce power consumption. Also, F Functional circuits (memory and buffers) are formed at the connection point between PC2605 and board 2600. By mounting IC chips, the substrate area can be used more effectively.

[0382] Furthermore, the signal line drive circuit 2501, the first scan line drive circuit 2503 and Signal line drive circuit 2611 corresponding to scan line drive circuit 2506, first scan line drive circuit 2613 and the second scan line drive circuit 2614 are each IC as shown in Figure 26(b). It may also be configured by forming it on a chip and mounting it on a display panel using COG, etc. (See Figure 26) b) Substrate 2610, pixel unit 2612, FPC 2615, IC chip 2616, I The C chip 2617, the encapsulation substrate 2618, and the sealing material 2619 are shown in Figure 25(a). Substrate 2510, pixel section 2502, FPC 2509, IC chip 2518, IC chip 2 519 corresponds to the encapsulation substrate 2504 and the sealing material 2505.

[0383] Furthermore, an amorphous semiconductor, for example, amorphous semiconductor, is used in the semiconductor layer of the transistor in the pixel section 2612. By using silicon (a-Si:H), costs can be reduced. Furthermore, It will also be possible to manufacture large display panels.

[0384] Furthermore, a signal line drive circuit, a first scan line drive circuit, and a first scan line drive circuit are provided in the row and column directions of the pixels, respectively. It is not necessary to provide a second scan line driving circuit. For example, as shown in Figure 27(a), an IC chip The peripheral drive circuit 2701 formed on the board is the first scan line drive circuit 26 shown in Figure 26(b). 13. Having the functions of a second scan line drive circuit 2614 and a signal line drive circuit 2611. It is permissible to do so. Note that in Figure 27(a), the substrate 2700, pixel unit 2702, and FPC 270 4. IC chip 2705, IC chip 2706, encapsulation substrate 2707, and sealing material 2708 are These are the substrate 2510, pixel unit 2502, FPC 2509, and IC chip 2, respectively, as shown in Figure 25(a). This corresponds to 518, IC chip 2519, encapsulation substrate 2504, and sealing material 2505.

[0385] Figure 27(b) shows a schematic diagram illustrating the wiring connections of the display device shown in Figure 27(a). Figure 27(b) shows the substrate 2710, peripheral drive circuit 2711, pixel unit 2712, and FPC2 713 and FPC2714 are shown in the diagram.

[0386] FPC2713 and FPC2714 receive external signals and power from the peripheral drive circuit 2711. A potential is input. The output from the peripheral drive circuit 2711 is the output of the pixel unit 2712. The input is provided to the row-direction and column-direction wiring connected to the pixels.

[0387] Furthermore, when using a white light-emitting element, a color filter is provided on the encapsulation substrate. This enables full-color display. The present invention can also be applied to such display devices. This is possible. Figure 28 shows an example of a partial cross-sectional view of a pixel area.

[0388] As shown in Figure 28, a base film 2802 is formed on the substrate 2800, and a light-emitting element is placed thereon. A transistor 2801 is formed to control the current value supplied to it, and transistor 2801 A pixel electrode 2803 is formed in contact with the first electrode, and a layer 2804 containing a light-emitting material is placed on top of it. A counter electrode 2805 is formed.

[0389] Furthermore, the layer 2804 containing the light-emitting material is sandwiched between the pixel electrode 2803 and the counter electrode 2805. The part that is there becomes the light-emitting element. In Figure 28, it is assumed to emit white light. Then, a red color filter 2806R and a green color filter are placed on top of the light-emitting element. The 2806G and the blue color filter 2806B are provided, enabling full-color display. This can be done. Additionally, a black matrix can be used to isolate these color filters. (Also known as BM) 2807 is provided.

[0390] The display device of this embodiment is not limited to embodiments 1 to 8, but also to embodiments 9 or 10. The configurations described can be combined as appropriate. Furthermore, the configuration of the display device is not limited to those described above. Furthermore, the present invention can also be applied to display devices with other configurations. (Embodiment 12) The display device of the present invention can be applied to various electronic devices. Specifically, the display device of an electronic device It can be applied to the display unit. Furthermore, as an electronic device, it can be used with video cameras and digital cameras. Cameras, goggle-type displays, navigation systems, sound playback devices (car audio) Audio equipment, audio components, computers, game consoles, mobile devices (mobile devices) Image playback devices equipped with recording media (computers, mobile phones, portable game consoles, or e-books, etc.) Device (specifically, recording media such as Digital Versatile Disc (DVD)) Examples include devices that can regenerate the body and have a display capable of showing the resulting image.

[0391] Figure 33(A) shows a display, consisting of a housing 3301, a support base 3302, and a display unit 3303. This includes a speaker unit 3304, a video input terminal 3305, etc.

[0392] Furthermore, the display unit 3303 uses the pixels described in Embodiments 1 to 8. By increasing brightness, variations in brightness between pixels or within pixels over time can be suppressed. Furthermore, it is possible to obtain a display with a high-quality display unit that has an even higher duty cycle. Furthermore, in this invention, power consumption is reduced because the potential of the counter electrode is kept constant during operation. Yes, it is possible. Note that the display is for personal computers and television broadcast reception. This includes all information display devices, such as those for advertising and other purposes.

[0393] Furthermore, in recent years, there has been a growing need for larger displays. The rise in cost due to standardization is becoming a problem. Therefore, the question is how to reduce manufacturing costs. The challenge lies in producing high-quality products at the lowest possible price.

[0394] Since the pixels of the present invention can be fabricated using transistors of the same conductivity type, the number of manufacturing steps can be reduced. This can reduce manufacturing costs. Also, the semiconductor layer of the transistors that make up the pixels. By using an amorphous semiconductor, such as amorphous silicon (a-Si:H), the process can be simplified. This simplifies the process and further reduces costs. In this case, the drive circuit around the pixel area is an IC. When formed on a chip and mounted on a display panel using COG (Chip On Glass), etc. Good. Furthermore, the high-speed signal line drive circuit is formed on the IC chip, and the relatively high-speed operation... The low scan line drive circuit is an integrated circuit composed of transistors of the same conductivity type as the pixel section. You can do it.

[0395] Figure 33(B) is a camera, consisting of the main unit 3311, the display unit 3312, the image receiving unit 3313, and the operation unit. Includes key 3314, external connection port 3315, shutter button 3316, etc.

[0396] Furthermore, the display unit 3312 uses the pixels described in Embodiments 1 to 8. By increasing brightness, variations in brightness between pixels or within pixels over time can be suppressed. Furthermore, it is possible to obtain a camera with a high-quality display unit that has an even higher duty cycle. In this invention, power consumption can be reduced because the potential of the counter electrode is kept constant during operation. be.

[0397] Furthermore, in recent years, with the increasing performance of digital cameras and other devices, production competition has intensified. Therefore, the key is how to keep the price low while still providing high performance.

[0398] Since the pixels of the present invention can be fabricated using transistors of the same conductivity type, the number of manufacturing steps can be reduced. This can reduce manufacturing costs. Also, the semiconductor layer of the transistors that make up the pixels. By using an amorphous semiconductor, such as amorphous silicon (a-Si:H), the process can be simplified. This simplifies the process and further reduces costs. In this case, the drive circuit around the pixel area is an IC. It is best to form it on a chip and mount it on a display panel using COG or similar. Note that this is for high-speed signals. The line drive circuit is formed on an IC chip, and the scan line drive circuit, which has a relatively low operating speed, is shared with the pixel section. It may also be formed as a single circuit composed of transistors of the same conductivity type.

[0399] Figure 33(C) shows a computer, consisting of a main unit 3321, a casing 3322, a display unit 3323, Includes keyboard 3324, external connection port 3325, pointing device 3326, etc. The display unit 3323 uses the pixels described in Embodiments 1 to 8. The invention makes it possible to suppress variations in brightness between pixels or within pixels over time. Furthermore, it is possible to obtain a computer with a high-quality display unit that has a higher duty cycle. Furthermore, in this invention, power consumption is reduced in order to operate while keeping the potential of the counter electrode constant. This is possible. Furthermore, transistors of the same conductivity type or transistors can be used to make up the pixel section. Cost reduction can be achieved by using an amorphous semiconductor film for the semiconductor layer of the inverter.

[0400] Figure 33(D) shows a mobile computer, consisting of a main unit 3331, a display unit 3332, and a switch. Includes the control panel 3333, operation keys 3334, infrared port 3335, etc. Also includes the display unit 3332. The pixels described in Embodiments 1 to 8 are used. The present invention allows for inter-pixel or This can suppress variations in brightness over time in pixels, and furthermore, the duty cycle is A mobile computer with a high-quality display unit can be obtained. This allows for lower power consumption by maintaining a constant potential at the counter electrode during operation. Furthermore, transistors of the same conductivity type or transistor semiconductors are used to make up the pixel area. Cost reduction can be achieved by using layered amorphous semiconductor films.

[0401] Figure 33(E) shows a portable image playback device (specifically, a DVD player) equipped with a recording medium. The main unit 3341, the housing 3342, the display unit A3343, the display unit B3344, and the recording medium. Includes a DVD / Blu-ray reader 3345, operation keys 3346, speaker unit 3347, etc. Display unit A3343 primarily displays image information, while display unit B3344 primarily displays text information. It can be displayed. Note that display units A3343 and B3344 are of Embodiment 1. The pixels described in section 8 are used. The present invention provides information on the time interval between pixels or within pixels. It can suppress variations in brightness and also provides a high-quality display with a high duty cycle. An image reproduction device having the following characteristics can be obtained. In this invention, the potential of the counter electrode is kept constant. In order to operate it, power consumption can be reduced. Also, the transistors that make up the pixel part The transistor uses the same conductivity type, or an amorphous semiconductor film is used for the semiconductor layer of the transistor. This allows for cost reduction.

[0402] Figure 33(F) shows a goggle-type display, consisting of a main unit 3351, a display unit 3352, and an arm. It includes the 3353 section. The display section 3352 uses the pixels described in Embodiments 1 to 8. This invention suppresses variations in brightness between pixels or within pixels over time. It can be controlled and also has a high-quality display unit with a high duty cycle, a goggle-type display. A spray can be obtained. In this invention, the potential of the counter electrode is kept constant during operation. Therefore, it is possible to reduce power consumption. Also, the same transistors that make up the pixel section By using conductive transistors and amorphous semiconductor films in the semiconductor layers of transistors, low cost It is possible to achieve a more streamlined design.

[0403] Figure 33(G) shows a video camera, consisting of a main unit 3361, a display unit 3362, a housing 3363, External connection port 3364, remote control receiver 3365, image receiver 3366, battery 336 7. Includes the voice input unit 3368, operation keys 3369, eyepiece unit 3360, etc. Note that the display unit 3 Pixel 362 uses the pixels described in Embodiments 1 to 8. According to the present invention, between pixels Alternatively, it can suppress variations in brightness over time in pixels, and furthermore, duty cycle - A video camera with a high-quality display unit and a high ratio can be obtained. By maintaining a constant potential at the counter electrode during operation, power consumption can be reduced. The transistors that make up the pixel area are transistors of the same conductivity type or the semiconductor layer of the transistors Cost reduction can be achieved by using amorphous semiconductor films.

[0404] Figure 33(H) shows a mobile phone, consisting of the main unit 3371, the casing 3372, the display unit 3373, and sound. Voice input unit 3374, voice output unit 3375, operation keys 3376, external connection port 3377, This includes the antenna 3378, etc. The display unit 3373 is shown in the image described in Embodiments 1 to 8. The element is used. According to the present invention, the variation in brightness between pixels or within pixels over time is A mobile phone that can suppress noise and has a high-quality display with a high duty cycle. This allows for the creation of a mechanism. Furthermore, in this invention, the potential of the counter electrode is kept constant for operation, thus eliminating the need for electricity. It is possible to reduce power consumption. Also, the transistors constituting the pixel section are of the same conductivity type. By using amorphous semiconductor films in transistors and the semiconductor layers of transistors, costs can be reduced. It can be measured.

[0405] Thus, the present invention can be applied to any electronic device. (Embodiment 13) In this embodiment, an example of the configuration of a mobile phone having the display device of the present invention as its display unit is shown in Figure I will explain using 34.

[0406] The display panel 3410 is detachably incorporated into the housing 3400. The shape and dimensions of 00 can be appropriately changed to match the size of the display panel 3410. The housing 3400, which secures the display panel 3410, is fitted onto the printed circuit board 3401. It can be assembled as a module.

[0407] The display panel 3410 is connected to the printed circuit board 3401 via the FPC 3411. The lint circuit board 3401 contains a speaker 3402, a microphone 3403, and a transmitting / receiving circuit 3 404, a signal processing circuit 3405 including a CPU and controller is formed. A module like this is combined with an input means 3406 and a battery 3407, and the housing 340 9 and housing 3412. Note that the pixel portion of the display panel 3410 is shaped within housing 3412. It is positioned so that it can be seen through the opening window.

[0408] The display panel 3410 consists of a pixel section and some peripheral drive circuits (among multiple drive circuits, the operating frequency A small number of drive circuits are integrally formed on the substrate using transistors, and other peripheral drive circuits (multiple The drive circuits with the highest operating frequency among the numerous drive circuits are formed on the IC chip, and the IC chip The chip can also be implemented on the display panel 3410 using COG (Chip On Glass). Rui then uses TAB (Tape Automated Bonding) to connect the IC chip to... A printed circuit board may be used to connect to the glass substrate. Furthermore, all peripheral drive circuits may be connected to ICs. The IC chip may be formed on a surface and then mounted on a display panel using a COG or similar device.

[0409] Furthermore, the pixels used in the pixel section are those described in Embodiments 1 to 8. According to the present invention, It is possible to suppress variations in brightness over time between pixels or within pixels, and furthermore, duty cycle A display panel 3410 having a high-quality display unit with a high image-to-image ratio can be obtained. The invention allows for lower power consumption by maintaining a constant potential at the counter electrode during operation. Furthermore, the transistors constituting the pixel section may be transistors of the same conductivity type or transistors with half-conductors. Cost reduction can be achieved by using an amorphous semiconductor film for the conductive layer.

[0410] Furthermore, the configuration shown in this embodiment is just one example of a mobile phone, and a mobile phone with such a configuration is also available. It is not limited to this and can be applied to mobile phones with various configurations. (Embodiment 14) In this embodiment, Figure 3 shows an EL module that combines a display panel and a circuit board. This will be explained using Figure 5 and Figure 36.

[0411] As shown in Figure 35, the display panel 3501 consists of a pixel section 3503 and a scan line driving circuit 3504. and has a signal line drive circuit 3505. The circuit board 3502 has, for example, a controller The signal splitting circuit 3506 and signal division circuit 3507 are formed. 1 and circuit board 3502 are connected by connecting wire 3508. FPCs, etc., can be used.

[0412] The display panel 3501 consists of a pixel section and some peripheral drive circuits (among multiple drive circuits, the operating frequency A small number of drive circuits are integrally formed on the substrate using transistors, and other peripheral drive circuits (multiple The drive circuits with the highest operating frequency among the numerous drive circuits are formed on the IC chip, and the IC chip The chip can also be implemented on the display panel 3501 using COG (Chip On Glass). Rui then uses TAB (Tape Automated Bonding) to connect the IC chip to... A printed circuit board may be used to connect to the glass substrate. Furthermore, all peripheral drive circuits may be connected to ICs. The IC chip may be formed on a surface and then mounted on a display panel using a COG or similar device.

[0413] Furthermore, the pixels used in the pixel section are those described in Embodiments 1 to 8. According to the present invention, It is possible to suppress variations in brightness over time between pixels or within pixels, and furthermore, duty cycle A high-quality display panel 3501 with a high IF ratio can be obtained. By keeping the pole potential constant during operation, power consumption can be reduced. Also, the pixel section The transistors that make up the structure include transistors of the same conductivity type and amorphous materials in the semiconductor layer of the transistors. Cost reduction can be achieved by using semiconductor films.

[0414] Such EL modules can be used to complete an EL television receiver. (Figure 36) This is a block diagram showing the main components of an EL television receiver. The tuner 3601 is for video signals. It receives the number and audio signals. The video signal is amplified by the video signal amplification circuit 3602 and output from there. A video signal processing circuit 3603 converts the signal into color signals corresponding to red, green, and blue, and The video signal is processed by control circuit 3506, which converts it to the input specifications of the drive circuit. The control circuit 3506 outputs signals to the scan line side and the signal line side, respectively. When using digital drive, a signal splitting circuit 3507 is provided on the signal line side, and the input digital signal Alternatively, the system may be configured to supply the product in m separate portions.

[0415] Of the signals received by tuner 3601, the audio signal is sent to audio signal amplification circuit 3604. The output is then supplied to the speaker 3606 via the audio signal processing circuit 3605. Circuit 3607 receives control information for the receiving station (receiving frequency) and volume from input unit 3608, and It sends signals to the 3601 and the audio signal processing circuit 3605.

[0416] For example, the housing 3301 in Figure 33(A) described in Embodiment 12, the EL module in Figure 35 By assembling the chutes, you can complete the television receiver.

[0417] Of course, the present invention is not limited to television receivers, but also applies to personal computer monitors. Initially, large-scale displays such as information boards in train stations and airports, and advertising boards on the streets are particularly important. It can be applied to various uses as a display medium for products. (Embodiment 15) In this embodiment, an example of an application of the display device according to the present invention will be described.

[0418] Figure 56 shows an example in which the display device according to the present invention is installed as an integral part of a building. This refers to a structure including the enclosure 5600, display panel 5601, speaker unit 5602, etc. Yes, it is. Furthermore, 5603 is a remote control device for operating the display panel 5601.

[0419] The display panel 5601 uses the pixels described in Embodiments 1 to 8. This makes it possible to suppress variations in brightness between pixels or within pixels over time, Furthermore, a high-quality display panel with a high duty cycle can be obtained. By maintaining a constant potential at the counter electrode during operation, power consumption can be reduced. The transistors that make up the pixel area are transistors of the same conductivity type or the semiconductor layer of the transistors Cost reduction can be achieved by using amorphous semiconductor films.

[0420] The display device shown in Figure 56 is integrated with the structure, thus requiring a large space. It can be installed without requiring any special equipment.

[0421] Figure 57 shows another example in which the display device according to the present invention is installed as an integral part of a building. The display panel 5701 is installed as an integral part of the unit bath 5702, and the bather It becomes possible to view the display panel 5701 while bathing. The display panel 5701 shows the bather Information can be displayed by interacting with it. Therefore, it can be used as an advertising or entertainment tool. It has the function of [doing something].

[0422] The display panel 5701 uses the pixels described in Embodiments 1 to 8. This makes it possible to suppress variations in brightness between pixels or within pixels over time, Furthermore, a high-quality display panel with a high duty cycle can be obtained. By maintaining a constant potential at the counter electrode during operation, power consumption can be reduced. The transistors that make up the pixel area are transistors of the same conductivity type or the semiconductor layer of the transistors Cost reduction can be achieved by using amorphous semiconductor films.

[0423] Furthermore, the display device according to the present invention is not limited to the side wall of the unit bath 5702 shown in Figure 57. It can be integrated with various locations. For example, it can be integrated with part of a mirror surface or the bathtub itself. It may also be installed in [location]. Furthermore, the shape of the display device may be matched to the shape of the mirror or the bathtub. It's okay if it is.

[0424] Figure 58 shows another example in which the display device according to the present invention is installed as an integral part of a building. In Figure 58, the display panel 5802 is curved to match the curved surface of the columnar body 5801. Here, the columnar structure 5801 will be described as a utility pole.

[0425] The display panel 5802 shown in Figure 58 is installed at a position higher than the human eye level. By installing the display panel 5802 on structures that are repeatedly erected outdoors, as shown above, Information can be provided to a specific number of viewers via the display panel 5802. Therefore, it is suitable to use the display panel as an advertisement. Also, the display panel 5802 is It is possible to display the same image through external control, and to switch images instantly. Because it is easy to use, it can be expected to provide extremely efficient information display and advertising effects. Also, display panel 5 By providing a self-illuminating display element in 802, a display medium with high visibility even at night is created. It can be said to be useful. Also, by installing the display panel 5802 on a utility pole, the display panel 5 Securing a power supply for 802 is easy. Also, in the event of an emergency such as a disaster, It can also serve as a means of quickly and accurately conveying information to disaster victims.

[0426] The display panel 5802 uses the pixels described in Embodiments 1 to 8. This makes it possible to suppress variations in brightness between pixels or within pixels over time, Furthermore, a high-quality display panel with a high duty cycle can be obtained. By maintaining a constant potential at the counter electrode during operation, power consumption can be reduced. The transistors that make up the pixel area are transistors of the same conductivity type or the semiconductor layer of the transistors Cost reduction can be achieved by using amorphous semiconductor films. Furthermore, film-like substrates are also available. Organic transistors provided in this location may also be used.

[0427] In this embodiment, the building integrated with the display device of the present invention includes walls, a unit bathroom, Although a columnar structure was used as an example, it is possible to install them in various other types of buildings as well.

[0428] Next, an example in which the display device according to the present invention is installed integrally with a moving object will be shown.

[0429] Figure 59 shows an example in which the display device according to the present invention is integrated with an automobile. The display panel 5902 is installed integrally with the vehicle body 5901, and the vehicle body It can display information on operation and input from inside and outside the vehicle on demand. Panel 5902 may have a navigation function.

[0430] The display panel 5902 uses the pixels described in Embodiments 1 to 8. This makes it possible to suppress variations in brightness between pixels or within pixels over time, Furthermore, a high-quality display panel with a high duty cycle can be obtained. By maintaining a constant potential at the counter electrode during operation, power consumption can be reduced. The transistors that make up the pixel area are transistors of the same conductivity type or the semiconductor layer of the transistors Cost reduction can be achieved by using amorphous semiconductor films.

[0431] Furthermore, the display device according to the present invention can be used not only on the vehicle body 5901 shown in Figure 59, but also in various other applications. They can be installed in places such as glass windows, doors, steering wheels, shift levers, and seat cuffs. It may be installed as an integral part of the rearview mirror, etc. In this case, the shape of the display panel 5902 It is acceptable for it to be shaped to match the form of the object being installed.

[0432] Figure 60 shows an example in which the display device according to the present invention is installed integrally with a train vehicle. be.

[0433] Figure 60(a) shows an example in which a display panel 6002 is installed on the glass of a train car door 6001. This is a diagram illustrating the difference in the amount of manpower required when switching advertisements compared to traditional paper advertisements. It has the advantage of being cost-effective. Also, the display panel 6002 receives signals from an external source. Because it is possible to switch the images displayed on the display unit instantly, for example, train The display panel image can be switched according to the time of day when the types of passengers getting on and off the train change. By switching images instantly in this way, a more effective advertising effect can be expected.

[0434] Figure 60(b) shows the glass of the train car door 6001, as well as the glass window 6003 and the ceiling. This figure shows an example in which a display panel 6002 is provided on 6004. Thus, the present invention The display device can be easily installed in locations where installation was previously difficult. Therefore, effective advertising effects can be obtained. In addition, the display device according to the present invention is from the outside Because the image displayed on the display unit can be switched instantly by signal, This reduces the costs and time incurred when switching advertising campaigns, allowing for more flexible advertising operations and information dissemination. This becomes possible.

[0435] Furthermore, the display panel 6002 shown in Figure 60 uses the pixels described in Embodiments 1 to 8. This invention suppresses variations in brightness between pixels or within pixels over time. This allows for the creation of high-quality display panels with even higher duty cycles. Furthermore, in this invention, power consumption is reduced because the potential of the counter electrode is kept constant during operation. It is possible. Furthermore, transistors of the same conductivity type or transistors can be used to make up the pixel area. Cost reduction can be achieved by using an amorphous semiconductor film for the semiconductor layer of the ZISTA.

[0436] Furthermore, the display device according to the present invention is not limited to the above and can be installed in various locations. For example, the display device according to the present invention is integrated with the handrails, seats, railings, floors, etc. This is also acceptable. In this case, the shape of the display panel 6002 should be matched to the shape of the object it is installed on. It's okay if it is.

[0437] Figure 61 shows an example in which the display device according to the present invention is installed integrally with a passenger aircraft. This is the diagram.

[0438] Figure 61(a) shows a display panel 6102 installed on the ceiling 6101 above the seats of a passenger aircraft. This diagram shows the shape when in use. The display panel 6102 has a hinge portion 610 It is installed integrally with the ceiling 6101 via 3, and is mounted by the extension and retraction of the hinge portion 6103. Passengers can view the display panel 6102 at their desired position. The display panel 6102 is for passengers Information can be displayed by operating it. Therefore, it can be used as an advertising or entertainment tool. It has the function of being able to be folded. Also, as shown in Figure 61(b), the hinge part can be folded to the ceiling 610 By storing it in position 1, safety during takeoff and landing can be ensured. Note that it will not be displayed in emergencies. By illuminating the display elements of panel 6102, it can also be used as a means of information transmission and as an emergency light. It is possible.

[0439] Furthermore, the display panel 6102 shown in Figure 61 uses the pixels described in Embodiments 1 to 8. This invention suppresses variations in brightness between pixels or within pixels over time. This allows for the creation of high-quality display panels with even higher duty cycles. Furthermore, in this invention, power consumption is reduced because the potential of the counter electrode is kept constant during operation. It is possible. Furthermore, transistors of the same conductivity type or transistors can be used to make up the pixel area. Cost reduction can be achieved by using an amorphous semiconductor film for the semiconductor layer of the ZISTA.

[0440] Furthermore, the display device according to the present invention can be used not only on the ceiling 6101 shown in Figure 61, but also in various other locations. It can be installed as an integral part of a place. For example, together with a seat, seat table, armrest, window, etc. It may also be installed on the body. In addition, a large display panel that can be viewed by many people simultaneously may be installed on the aircraft. It may be mounted on a wall. In this case, the shape of the display panel 6102 should match the shape of the object on which it is mounted. It's fine if it's a combination of both.

[0441] In this embodiment, the mobile body is a train car body, an automobile body, an airplane body. The examples given are not limited to these, but also include motorcycles and automobiles (including cars, buses, etc.). This can be applied to various things such as trains (including monorails and railways), ships, etc. The display device according to the invention instantly displays the display panel inside a mobile vehicle based on an external signal. Since it can be switched at any time, the display device according to the present invention can be installed on a mobile body. More mobile devices can be used as advertising boards targeting a large number of customers, information boards during disasters, etc. It can be used for various purposes.

[0442] The display device of this embodiment is not limited to embodiments 1 to 8, but also to embodiments 9 or 10. The configurations described can also be combined as appropriate. The configuration of the display device is as described above. It's not limited to things. [Explanation of Symbols]

[0443] 110 transistors 111 First switch 112 Second switch 113 The third switch 114 The fourth switch 115 First capacitive element 116 Second capacitive element 117 Light-emitting element 118 signal line 119 First scan line 120 Second scan line 121 Third scan line 122 Power line 123 Potential supply line 124 Counter electrode 611 First switching transistor 612 Second switching transistor 613 Third switching transistor 614 Fourth switching transistor 2910 Transistors 3010 Transistor 3101 First transistor 3102 Second transistor 3103 The fifth switch 3104 The sixth switch 3111 First switch 3112 Second switch 3113 The third switch 3114 The fourth switch 3115 First capacitive element 3116 Second capacitive element 3117 Light-emitting element 3118 Signal Line 3119 First scan line 3120 Second scan line 3121 Third scan line 3122 Power line 3123 Potential supply line 3124 Counter electrode 3801 The fifth switch 3802 Fourth scan line 4001 The fifth switch 4002 Fourth scan line 4201 Rectifier element 4202 Fourth scan line 4610 Transistor 4611 First switch 4612 Second switch 4613 The third switch 4614 The fourth switch 4615 First capacitive element 4616 Second capacitive element 4617 Light-emitting element 4618 Signal Line 4619 First scan line 4620 Second scan line 4621 Third scan line 4622 Power line 4623 Potential supply line 4624 Counter electrode 5001 Rectifier element 5002 Fourth scan line

Claims

1. It comprises a first transistor, a second transistor, a third transistor, a switch, a capacitive element, a light-emitting element, and a power line extending in a first direction. The source or drain of the first transistor is electrically connected to the source or drain of the second transistor. The source or drain of the second transistor, the other of which is electrically connected to the power line, The gate of the second transistor is electrically connected to the first scan line. Either the source or the drain of the third transistor is electrically connected to the gate of the first transistor. The source or drain of the third transistor is electrically connected to the source or drain of the first transistor. The gate of the third transistor is electrically connected to the second scan line. The first terminal of the switch is electrically connected to the light-emitting element. The second terminal of the switch is electrically connected to the potential supply line. The first terminal of the capacitive element is electrically connected to the gate of the first transistor. The second terminal of the capacitive element is electrically connected to the light-emitting element. The light-emitting element is electrically connected to the other of the source or drain of the first transistor. In a plan view, the channel length direction of the second transistor is aligned with the direction of the first transistor. In a plan view, the channel length direction of the third transistor is aligned in a direction different from the first direction. The first transistor has a first region in the semiconductor layer that functions as a channel formation region, The semiconductor layer has a second region that functions as a channel formation region for the second transistor, and a third region that connects the first region and the second region. The power line has a fourth region that overlaps with the third region, and a fifth region that is wider than the fourth region. The power line has a region that overlaps with the first conductive layer which has a region that functions as the gate electrode of the second transistor. The power line has a region that overlaps with the second conductive layer which has a region that functions as the gate electrode of the third transistor. The power line has a region that is in contact with the semiconductor layer through an opening. The fifth region is a display device having a region that overlaps with the opening.

2. It comprises a first transistor, a second transistor, a third transistor, a capacitive element, a switch, a light-emitting element, and a power line extending in a first direction. The source or drain of the first transistor is always in electrical contact with the source or drain of the second transistor. The source or drain of the second transistor is always in electrical contact with the power line. The gate of the second transistor is always in contact with the first scan line. Either the source or drain of the third transistor is always in contact with the gate of the first transistor. The source or drain of the third transistor is always in electrical contact with the source or drain of the first transistor. The gate of the third transistor is always in contact with the second scan line. The first terminal of the switch is always in electrical contact with the light-emitting element. The second terminal of the switch is always in electrical contact with the potential supply line. The first terminal of the capacitive element is always in electrical contact with the gate of the first transistor. The second terminal of the capacitive element is always in electrical contact with the light-emitting element. When the power line is in a conductive state with the light-emitting element via at least the channel formation region of the first transistor and the channel formation region of the second transistor, the current of the power line is input to the light-emitting element via at least the channel formation region of the first transistor and the channel formation region of the second transistor. In a plan view, the channel length direction of the second transistor is aligned with the direction of the first transistor. In a plan view, the channel length direction of the third transistor is aligned in a direction different from the first direction. The first transistor has a first region in the semiconductor layer that functions as a channel formation region, The semiconductor layer has a second region that functions as a channel formation region for the second transistor, and a third region that connects the first region and the second region. The power line has a fourth region that overlaps with the third region, and a fifth region that is wider than the fourth region. The power line has a region that overlaps with the first conductive layer which has a region that functions as the gate electrode of the second transistor. The power line has a region that overlaps with the second conductive layer which has a region that functions as the gate electrode of the third transistor. The power line has a region that is in contact with the semiconductor layer through an opening. The fifth region is a display device having a region that overlaps with the opening.

3. It comprises a first transistor, a second transistor, a third transistor, a capacitive element, a switch, a light-emitting element, and a power line extending in a first direction. The third transistor has an oxide semiconductor in the channel formation region, The source or drain of the first transistor is electrically connected to the source or drain of the second transistor. The source or drain of the second transistor, the other of which is electrically connected to the power line, The gate of the second transistor is electrically connected to the first scan line. Either the source or the drain of the third transistor is electrically connected to the gate of the first transistor. The source or drain of the third transistor is electrically connected to the source or drain of the first transistor. The gate of the third transistor is electrically connected to the second scan line. The first terminal of the switch is electrically connected to the light-emitting element. The second terminal of the switch is electrically connected to the potential supply line. The first terminal of the capacitive element is electrically connected to the gate of the first transistor. The second terminal of the capacitive element is electrically connected to the light-emitting element. The light-emitting element is electrically connected to the other of the source or drain of the first transistor. In a plan view, the channel length direction of the second transistor is aligned with the direction of the first transistor. In a plan view, the channel length direction of the third transistor is aligned in a direction different from the first direction. The first transistor has a first region in the semiconductor layer that functions as a channel formation region, The semiconductor layer has a second region that functions as a channel formation region for the second transistor, and a third region that connects the first region and the second region. The power line has a fourth region that overlaps with the third region, and a fifth region that is wider than the fourth region. The power line has a region that overlaps with the first conductive layer which has a region that functions as the gate electrode of the second transistor. The power line has a region that overlaps with the second conductive layer which has a region that functions as the gate electrode of the third transistor. The power line has a region that is in contact with the semiconductor layer through an opening. The fifth region is a display device having a region that overlaps with the opening.

4. It comprises a first transistor, a second transistor, a third transistor, a capacitive element, a switch, a light-emitting element, and a power line extending in a first direction. The third transistor has an oxide semiconductor in the channel formation region, The source or drain of the first transistor is always in electrical contact with the source or drain of the second transistor. The source or drain of the second transistor is always in electrical contact with the power line. The gate of the second transistor is always in contact with the first scan line. Either the source or drain of the third transistor is always in contact with the gate of the first transistor. The source or drain of the third transistor is always in electrical contact with the source or drain of the first transistor. The gate of the third transistor is always in contact with the second scan line. The first terminal of the switch is always in electrical contact with the light-emitting element. The second terminal of the switch is always in electrical contact with the potential supply line. The first terminal of the capacitive element is always in electrical contact with the gate of the first transistor. The second terminal of the capacitive element is always in electrical contact with the light-emitting element. When the power line is in a conductive state with the light-emitting element via at least the channel formation region of the first transistor and the channel formation region of the second transistor, the current of the power line is input to the light-emitting element via at least the channel formation region of the first transistor and the channel formation region of the second transistor. In a plan view, the channel length direction of the second transistor is aligned with the direction of the first transistor. In a plan view, the channel length direction of the third transistor is aligned in a direction different from the first direction. The first transistor has a first region in the semiconductor layer that functions as a channel formation region, The semiconductor layer has a second region that functions as a channel formation region for the second transistor, and a third region that connects the first region and the second region. The power line has a fourth region that overlaps with the third region, and a fifth region that is wider than the fourth region. The power line has a region that overlaps with the first conductive layer which has a region that functions as the gate electrode of the second transistor. The power line has a region that overlaps with the second conductive layer which has a region that functions as the gate electrode of the third transistor. The power line has a region that is in contact with the semiconductor layer through an opening. The fifth region is a display device having a region that overlaps with the opening.

5. In any one of claims 1 to 4, Each of the first to third transistors is an n-channel type transistor in the display device.

Images