JP2010097040A - Display element and display device using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display element configured to, when one of light emitting parts does not operate normally, make the other light emitting part that operates normally emit light with luminance higher than the original one. <P>SOLUTION: The display element 110 comprises the first light emitting element 111 and the second light emitting element 111'. The first light emitting element 111 includes the current drive type first light emitting part ELP and a first drive circuit 112 connected to the first light emitting part ELP. The second light emitting element 111' includes a current drive type second light emitting part ELP' and a second drive circuit 112' connected to the second light emitting part ELP'. The display device includes a current increasing means 113 for increasing the current flowing in one of the first light emitting part ELP and the second light emitting part ELP' when the other of the first light emitting part ELP and the second light emitting part ELP' does not operate normally. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display element and a display device using the display element. More specifically, the light-emitting element includes a first light-emitting element and a second light-emitting element. Each light-emitting element is provided for each light-emitting element, and a current-driven light-emitting unit and a drive circuit connected to the light-emitting unit. And a display device including such a display element.

  A display element including a current-driven light emitting unit and a display device including the display element are well known. For example, a display element (hereinafter, abbreviated as an organic EL display element) having an organic electroluminescence light emitting section using electroluminescence (hereinafter abbreviated as EL) of an organic material has high luminance by low-voltage direct current drive. It attracts attention as a display element capable of emitting light.

  Similar to the liquid crystal display device, for example, in a display device using an organic EL display element, a simple matrix method and an active matrix method are well known as driving methods. The active matrix method has the disadvantage that the structure is complicated, but has the advantage that the luminance of the image can be increased. An organic EL display element driven by an active matrix system includes a drive circuit for driving the light emitting unit in addition to the light emitting unit configured by an organic layer including a light emitting layer.

FIG. 25 is a conceptual diagram of an active matrix display device using an organic EL display element including a drive circuit. The display device
(1) Scan circuit 101,
(2) signal output circuit 102,
(3) N in the first direction, M in the second direction different from the first direction (specifically, the direction orthogonal to the first direction), a total of N × M two-dimensional Organic EL display elements 10 arranged in a matrix,
(4) M scanning lines SCL connected to the scanning circuit 101 and extending in the first direction.
(5) N data lines DTL connected to the signal output circuit 102 and extending in the second direction,
(6) Power supply unit 100,
It has. In FIG. 25, 3 × 3 organic EL display elements 10 are shown for convenience, but this is merely an example.

FIG. 26 shows an equivalent circuit diagram of the organic EL display element 10. The organic EL display element 10 includes a light emitting unit ELP and a drive circuit 11 for driving the light emitting unit ELP. In the example illustrated in FIG. 26, the drive circuit 11 includes a write transistor TR _W , a drive transistor TR _D , and a capacitor C ₁ . It is assumed that the write transistor TR _W is an n-channel transistor and the drive transistor TR _D is a p-channel transistor.

In the write transistor TR _W, one of the source / drain regions is connected to the data line DTL, the gate electrode is connected to the scan line SCL. The gate electrode of the drive transistor TR _D is connected to the other source / drain region of the write transistor TR _W and one electrode of the capacitor C ₁ . One source / drain region of the driving transistor TR _D is connected to the other electrode of the power supply line PS1 and the capacitor section C _1. A first voltage V _CC (for example, 20 volts) as a predetermined drive voltage is applied from the power supply unit 100 to the power supply line PS1. The other source / drain region of the driving transistor TR _D is connected to the anode electrode of the light emitting unit ELP. The cathode electrode of the light emitting unit ELP is connected to a power supply line PS2 to which a predetermined voltage V _Cat (for example, 0 volt) is applied. The symbol C _EL represents the capacity of the light emitting unit ELP. In FIG. 25, the illustration of the feeder line PS2 shown in FIG. 26 is omitted.

The basic operation of the organic EL display element 10 will be described. A predetermined video signal V _Sig is applied from the signal output circuit 102 to the gate electrode of the drive transistor TR _D via the write transistor TR _W that is turned on by a signal from the scanning line SCL. Thereafter, even when the write transistor TR _W is turned off, the voltage between the gate electrode and the source region of the drive transistor TR _D is held at a predetermined voltage by the capacitor C ₁ according to the video signal V _Sig. Is done.

The current flowing through the light emitting section ELP is drain current I _ds flowing from the source region of the drive transistor TR _D to the drain region. If the driving transistor TR _D ideally operates in the saturation region, the drain current I _ds can be expressed by the following equation (A). The light emitting unit ELP emits light with a luminance corresponding to the value of the drain current I _ds .

I _ds = k · μ · (V _gs −V _th ) ² (A)
However,
mu: effective mobility L: channel length W: channel width V _gs: voltage V _th between the source region and the gate electrode of the driving transistor TR _D: threshold voltage C _ox :( gate insulating layer of the driving transistor TR _D Relative permittivity) × (vacuum permittivity) / (gate insulating layer thickness)
k≡ (1/2) ・ (W / L) ・ C _ox
And

  By the way, when manufacturing the organic EL display element 10, for example, foreign matter may adhere between the anode electrode and the cathode electrode of the light emitting unit ELP, and the anode electrode and the cathode electrode may be short-circuited. Alternatively, the anode electrode and the cathode electrode may be opened due to, for example, a defect in the organic layer. In such a case, the light emitting unit ELP does not emit light and enters a non-light emitting state. And it will be visually recognized as a dark spot defect of a display apparatus.

For this reason, an organic EL display element having a structure capable of reducing the degree of dark spot defect has been proposed. For example, Japanese Patent Laying-Open No. 2003-280593 (Patent Document 1) discloses a redundant organic EL display element including two light emitting elements each including a light emitting unit and a drive circuit.
JP 2003-280593 A

  Even if the display element is composed of two light emitting elements, if one of the light emitting units does not operate normally, the luminance of the normal display element is approximately half of the original luminance. In this case, it is more difficult to visually recognize the dark spot defect by causing the other light emitting element that operates normally to emit light so as to have a higher luminance than originally intended. For example, a video signal that is adjusted to emit light at a luminance that is approximately twice the original luminance may be sent from a signal output circuit to a normally operating light emitting element, but the configuration of the peripheral circuit of the display device is complicated. There is a problem of becoming.

  Accordingly, an object of the present invention is to make the other light emitting element that operates normally have higher brightness than the original when one light emitting unit does not operate normally without complicating the configuration of the peripheral circuit of the display device. An object of the present invention is to provide a display element that can emit light and a display device including the display element.

In order to achieve the above object, the display device of the present invention comprises:
(1) N display elements arranged in a first direction, M pieces in a second direction different from the first direction, and a total of N × M display elements arranged in a two-dimensional matrix,
(2) M scanning lines extending in the first direction, and
(3) N data lines extending in the second direction;
It is related with the display apparatus provided with.

  The display element of the present invention for achieving the above object and the display element constituting the display device of the present invention for achieving the above object are composed of a first light emitting element and a second light emitting element. The first light emitting element includes a current driven first light emitting unit and a first drive circuit connected to the first light emitting unit, and the second light emitting element is a current driven second light emitting unit. And a second drive circuit connected to the second light emitting unit.

  In the display device of the present invention for achieving the above object, the mth scanning line is included in the first light emitting element and the second light emitting element constituting the display element in the m-th row and the n-th column. And a common scanning signal are applied from the nth data line.

  The display element of the present invention for achieving the above object and the display element constituting the display device of the present invention for achieving the above object are either the first light emitting unit or the second light emitting unit. Current increasing means is provided for increasing the current flowing through the other light emitting unit when one of the devices is not operating normally.

  In the display element of the present invention and the display element constituting the display device of the present invention (hereinafter, these may be simply referred to as the display element of the present invention), the current increasing means is the first light emitting unit. And a first drive circuit and a voltage at a connection portion between the second light emitting portion and the second drive circuit.

And in the display element of the present invention having the preferred configuration described above,
The first drive circuit includes a first drive transistor,
In the first drive transistor, a first voltage is applied to one source / drain region, and the other source / drain region is connected to one end of the first light emitting unit,
The second drive circuit includes a second drive transistor,
In the second drive transistor, the first voltage is applied to one source / drain region, and the other source / drain region is connected to one end of the second light emitting unit,
A second voltage is applied to the other end of the first light emitting unit and the other end of the second light emitting unit,
Current increasing means is
(A) an auxiliary transistor, and
(B) first switching means and second switching means;
Consists of
In the auxiliary transistor,
(A-1) The gate electrode is connected to the gate electrode of the first drive transistor and the gate electrode of the second drive transistor,
(A-2) The first voltage is applied to one source / drain region,
(A-3) The other source / drain region is connected to the connection between the first light emitting unit and the first drive transistor via the first switching means, and the second light emission via the second switching means. Connected to the connecting portion between the second driving transistor and the second driving transistor,
The first switching means operates based on the voltage of the connection portion between the second light emitting unit and the second drive transistor,
The second switching unit may be configured to operate based on a voltage at a connection portion between the first light emitting unit and the first driving transistor.

Here, in the display element of the present invention provided with the first switching means and the second switching means described above,
Each of the first switching means and the second switching means is composed of transistors of the same conductivity type,
The gate electrode of the transistor constituting the first switching means is connected to the connection part between the second light emitting part and the second drive transistor,
The gate electrode of the transistor that constitutes the second switching means may be connected to the connection portion between the first light emitting portion and the first driving transistor.

In the display element of the present invention including the above-described preferable configuration, the first drive circuit includes a first drive transistor, and the second drive circuit includes a second drive transistor.
At least one of the first drive circuit and the second drive circuit further includes a write transistor,
In the writing transistor, a video signal is applied to one source / drain region, a scanning signal is applied to the gate electrode,
The gate electrode of the first driving transistor and the gate electrode of the second transistor can be connected to the other source / drain region of the writing transistor.

  Further, in the display element of the present invention including the various preferable configurations described above, the first drive circuit includes a first drive transistor, and the second drive circuit includes a second drive transistor. A structure may be provided that includes a capacitor for holding the potentials of the gate electrode of the driving transistor and the gate electrode of the second driving transistor.

Further, in the display element of the present invention including the various preferable configurations described above, the first drive circuit includes a first drive transistor, and the second drive circuit includes a second drive transistor.
The current increasing means further includes third switching means,
One end of the third switching means is connected to one source / drain region of the auxiliary transistor, and the first voltage is applied to one source / drain region of the auxiliary transistor via the third switching means. It can be.

  In the display element of the present invention including the above-described various preferred configurations, a current-driven light emitting unit that emits light by passing a current can be widely used as the light emitting unit constituting the light emitting element. Examples of the first light emitting unit and the second light emitting unit include an organic electroluminescence light emitting unit, an inorganic electroluminescence light emitting unit, an LED light emitting unit, and a semiconductor laser light emitting unit. These light emitting portions can be configured using known materials and methods. From the viewpoint of configuring a flat display device for color display, it is particularly preferable that the first light emitting unit and the second light emitting unit are composed of organic electroluminescence light emitting units.

  The arrangement of the light emitting part constituting the first light emitting element and the light emitting part constituting the second light emitting element is not particularly limited. For example, in the configuration in which the light emitting unit is composed of an organic electroluminescence light emitting unit, the first light emitting unit and the second light emitting unit can be arranged in parallel in a planar shape. However, in this case, when any one of the light emitting units is not operating normally, there is a possibility that a part of the light emitting region is visually recognized as missing. On the other hand, in the configuration in which the first light emitting unit and the second light emitting unit are stacked, it is not visually recognized as if a part of the light emitting region is missing, so that the dark spot is less visible. This is preferable.

In the configuration in which the first light emitting part and the second light emitting part are composed of organic electroluminescence light emitting parts, and the first light emitting part and the second light emitting part are laminated,
The first light emitting unit
(D-1) Lower electrode,
(D-2) a first organic layer including a light emitting layer provided on the lower electrode; and
(D-3) a light transmissive intermediate electrode provided on the first organic layer,
Consists of
The second light emitting unit
(E-1) the intermediate electrode,
(E-2) a second organic layer including a light emitting layer provided on the intermediate electrode, and
(E-3) an upper electrode provided on the second organic layer,
Consists of
At least one of the lower electrode and the upper electrode has optical transparency,
The intermediate electrode may constitute an anode electrode of the first light emitting part and the second light emitting part, or alternatively, the intermediate electrode may constitute a cathode electrode of the first light emitting part and the second light emitting part. For convenience, the above-described display element is referred to as a first stacked aspect display element.

  In the display element of the first stacked mode, when the first organic layer is configured so that current flows from the lower electrode to the intermediate electrode, the second organic layer has current flowing from the upper electrode to the intermediate electrode. Configured to flow. On the other hand, when the first organic layer is configured so that a current flows from the intermediate electrode to the lower electrode, the second organic layer is configured so that a current flows from the intermediate electrode to the upper electrode. In addition, the structure provided with another layer between the lower electrode and the first organic layer may be used, or the structure provided with another layer between the first organic layer and the intermediate electrode. Also good. Similarly, a configuration in which another layer is provided between the intermediate electrode and the second organic layer may be used, or a configuration in which another layer is provided between the second organic layer and the upper electrode. May be.

Alternatively, the first light emitting unit and the second light emitting unit are composed of organic electroluminescence light emitting units, and the first light emitting unit and the second light emitting unit are stacked.
The first light emitting unit
(D-1) Lower electrode,
(D-2) a first organic layer including a light emitting layer provided on the lower electrode; and
(D-3) a first intermediate electrode having optical transparency provided on the first organic layer;
Consists of
The second light emitting unit
(E-1) a second intermediate electrode having light transmittance, provided on the first intermediate electrode through an insulating layer having light transmittance;
(E-2) a second organic layer including a light emitting layer provided on the second intermediate electrode, and
(E-3) Upper electrode,
Consists of
At least one of the lower electrode and the upper electrode may have an optical transparency. For convenience, the above-described display element is referred to as a second stacked aspect display element.

  The display element according to the second lamination mode has an advantage that the polarities of the first organic layer and the second organic layer can be arbitrarily set with respect to the display element according to the first lamination mode. .

  In the display element of the second stacked mode, the lower electrode and the first intermediate electrode constitute the anode electrode and the cathode electrode of the first light emitting part, respectively, and the second intermediate electrode and the upper electrode are respectively The anode electrode and the cathode electrode of the second light emitting unit can be configured. Alternatively, the lower electrode and the first intermediate electrode constitute a cathode electrode and an anode electrode of the first light emitting part, respectively, and the second intermediate electrode and the upper electrode are respectively a cathode electrode and an anode of the second light emitting part. It can be set as the structure which comprises an electrode. For convenience, the display element having the above-described aspect may be referred to as a display element according to the 2A stacking aspect of the present invention.

  In the display element according to the 2A stacking mode, when the first organic layer is configured such that current flows from the lower electrode to the first intermediate electrode, the second organic layer is formed from the second intermediate electrode. An electric current flows through the upper electrode. On the other hand, when the first organic layer is configured such that current flows from the first intermediate electrode to the lower electrode, the second organic layer is configured so that current flows from the upper electrode to the second intermediate electrode. . In other words, the first organic layer and the second organic layer are formed to have the same polarity. Thereby, it has the advantage that the manufacturing process of a 1st organic layer and a 2nd organic layer can be made shared.

  In the display element of the present invention including the various preferable configurations and aspects described above, and the display device of the present invention including the display element of the present invention (hereinafter, these may be simply referred to as the present invention) The element includes current increasing means for increasing a current flowing through the other light emitting unit when one of the first light emitting unit and the second light emitting unit is not operating normally. As a result, when the light emitting unit of one of the light emitting elements is not operating normally, the other light emitting element operating normally operates to emit light with higher luminance. Therefore, without complicating the configuration of the peripheral circuit of the display device, when one light-emitting element does not operate normally, the other light-emitting element that operates normally can emit light so as to have higher luminance than originally intended. it can.

  In the present invention, the first drive circuit and the second drive circuit may each include a write transistor. When the writing transistor is in an off state, the capacitor for holding the potentials of the gate electrode of the first driving transistor and the gate electrode of the second driving transistor basically becomes a source region during light emission. It is attached to hold the voltage between the source / drain region of the driving transistor and the gate of the driving transistor. One capacitor section may be provided in the display element, or each of the first drive circuit and the second drive circuit includes a capacitor section, similarly to the write transistor described above. It may be. The configurations of the first drive circuit and the second drive circuit are not particularly limited. A so-called voltage writing type driving circuit or a current writing type driving circuit may be used. Further, the first drive circuit and the second drive circuit may include a transistor other than the drive transistor and the write transistor.

  The first driving transistor and the second driving transistor constituting the display element of the present invention are basically composed of transistors of the same conductivity type. These may be composed of n-channel transistors or p-channel transistors. The transistor may be a thin film transistor (TFT) or a transistor formed on a semiconductor substrate or the like. The same applies to the write transistor.

  The auxiliary transistor constituting the current amplifying means can basically be constituted by a transistor having the same conductivity type as the first drive transistor and the second drive transistor. Moreover, well-known switching means controlled by voltage can be widely used as the first switching means and the second switching means. The same applies to the third switching means. From the viewpoint of simplifying the manufacturing process of the display element, it is preferable that the first switching means, the second switching means, and the third switching means are composed of transistors having the same configuration as the first drive transistor and the like.

  In this case, the conductivity type of the transistors constituting the first switching means and the second switching means may be the same as or different from the conductivity type of the first drive transistor or the like. By selecting the conductivity type of the transistors constituting the first switching means and the second switching means, the current amplifying means increases the current flowing to the other light emitting section when one light emitting section has a short circuit failure, or It is determined whether the current flowing through the other light-emitting part is increased by the current amplifying means when one light-emitting part has an open failure. What is necessary is just to select suitably the conductivity type of the transistor which comprises the 1st switching means and the 2nd switching means according to the design of a display element. Note that the conductivity type of the transistors constituting the third switching means is not particularly limited. What is necessary is just to select suitably according to the specification of a display apparatus or a display element.

  Similarly to the description of the first drive transistor and the like, the auxiliary transistor constituting the current amplifying means and the transistors constituting the first switching means to the third switching means may be TFTs or formed on a semiconductor substrate or the like. It may be a transistor. The structure of various transistors used in the present invention including the first driving transistor, the second driving transistor, and the writing transistor described above is not particularly limited. In the following description, each transistor is described as an enhancement type, but is not limited thereto. A depletion type transistor may be used. For example, the transistor may be a single gate type or a dual gate type.

  In the present invention, basically, the first light emitting unit and the second light emitting unit are configured to exhibit the same emission color. Note that it is sufficient that the color is determined to be substantially the same color. Therefore, the wavelength of the emitted light of the first light emitting element may be the same as the wavelength of the emitted light of the second light emitting element, or may be different to the extent that they are determined to be the same color.

  The various electrodes and the insulating layer “has light transmittance” means that it has light transmittance at least with respect to light emitted from the first light emitting portion and the second light emitting portion. Therefore, it may be configured to have optical transparency over the entire visible light spectrum, or may be configured to have optical transparency at the wavelength of the emitted light and its nearby wavelengths. Good. Basically, it is preferable to transmit as much light as possible. However, the degree of light transmission is not particularly limited as long as the operation of the display element is not hindered.

  The display device of the present invention may have a so-called monochrome display configuration or a so-called color display configuration. For example, in the case of a monochrome display device, a pixel is constituted by each of the display elements constituting the display device. When the number of display elements constituting the display device is N × M, the number of pixels is (N × M).

  On the other hand, in the case of a color display device, one pixel has three types of sub-pixels, for example, a red light-emitting subpixel that emits red, a green light-emitting subpixel that emits green, and a blue light-emitting subpixel that emits blue. It consists of pixels. Therefore, when the number of display elements constituting the display device is N × M, the number of pixels is (N × M) / 3.

  In the case of color display, one set in which one or more types of subpixels are added to the above-described three types of subpixels (for example, one subpixel that emits white light in order to improve luminance is added). To expand the color reproduction range, one set including sub-pixels that emit complementary colors to expand the color reproduction range, one set including sub-pixels that emit yellow to expand the color reproduction range A pixel can also be configured from a set of subpixels that emit yellow and cyan.

  As values of pixels (pixels) of the display device, VGA (640, 480), S-VGA (800, 600), XGA (1024, 768), APRC (1152, 900), S-XGA (1280, 1024), U-XGA (1600, 1200), HD-TV (1920, 1080), Q-XGA (2048, 1536), (1920, 1035), (720, 480), (1280, 960), etc. Although some of the resolutions can be exemplified, the present invention is not limited to these values.

  When the display element of the first stacked mode is a so-called top emission type, and the lower electrode and the upper electrode constitute an anode electrode, the lower electrode is made of chromium (Cr), iron (Fe), cobalt (Co), nickel ( Ni, copper (Cu), tantalum (Ta), tungsten (W), platinum (Pt), gold (Au), and the like, and a conductive material having a high work function value and high light reflectance. desirable. Furthermore, in the case of a conductive material having a low work function value such as aluminum (Al) and an alloy containing aluminum and having a high light reflectance, an appropriate hole injection layer is provided to improve hole injection properties. By improving, the lower electrode can be used as the anode electrode. Alternatively, a transparent conductive material having excellent hole injection characteristics such as indium and tin oxide (ITO) or indium and zinc oxide (IZO) may be laminated on a highly light reflective conductive material. it can. In addition, it is desirable that the upper electrode is made of a conductive material such as ITO or IZO that transmits luminescent light and has a large work function value.

  The electrode having optical transparency can be composed of a metal compound such as ZnO or MgO in addition to the above-mentioned ITO or IZO, or can be composed of a thin film made of a metal or an alloy. As will be described in detail later, when the display element of the first stacked mode is a top emission type and the upper electrode is used as the cathode electrode, the upper electrode transmits the emitted light, and moreover, the electrons are efficiently used with respect to the organic layer. It is desirable to make it from a conductive material having a small work function value so that it can be injected. In such a case, for example, a conductive film having a high light transmittance (for example, a metal or an alloy having a light transmittance of 30% or more) such as a Mg-Ag alloy thin film having a thickness of several nanometers is placed on the top. It can be used as an electrode. In addition, the structure which provided the auxiliary electrode with good electroconductivity in the part which does not prevent light emission, and this auxiliary electrode and an upper electrode may contact may be sufficient. According to this configuration, the voltage change due to the resistance of the upper electrode is suppressed during the operation of the display device, and the uniformity of the luminance of the displayed image can be improved. The same applies to the display element of the second stacked mode.

  As described above, when the display element according to the first stacking mode is a top emission type and the lower electrode and the upper electrode constitute an anode electrode, the intermediate electrode is the cathode electrode of the first light emitting unit and the second light emitting unit. Configure. The intermediate electrode is preferably made of a conductive material having a small work function value so that the emitted light can be transmitted and electrons can be efficiently injected into the first organic layer and the second organic layer. For example, the intermediate electrode can be composed of a thin film made of Mg, Mg alloy, Al, Al alloy or the like. Or it can also be set as the structure which laminated | stacked the thin film mentioned above on both surfaces of the layer which consists of ITO or IZO.

  On the other hand, when the display element according to the first lamination mode is a top emission type, and the lower electrode and the upper electrode constitute a cathode electrode, the lower electrode has a small work function value such as Al or Al alloy, and It is desirable that the conductive material has a high light reflectance. Note that the lower electrode can be used as the cathode electrode by improving the electron injection property by providing an appropriate electron injection layer on a conductive material having a high light reflectance used as the anode electrode. Further, it is desirable that the upper electrode is made of a conductive material having a small work function value so that the emitted light can be transmitted and electrons can be efficiently injected into the second organic layer. For example, the upper electrode can be composed of a thin film made of Mg, Mg alloy, Al, Al alloy or the like. Alternatively, a configuration in which a layer made of ITO or IZO is laminated on these thin films may be employed. In this case, the intermediate electrode constitutes the anode electrode of the first light emitting unit and the second light emitting unit. The intermediate electrode is preferably made of a conductive material such as ITO or IZO that transmits luminescent light and has a high work function value.

  A case will be described in which the display element of the second stacked mode is a top emission type, the lower electrode and the second intermediate electrode constitute an anode electrode, and the first intermediate electrode and the upper electrode constitute a cathode electrode. In this case, as described above, the lower electrode is made of chromium (Cr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), tantalum (Ta), tungsten (W), platinum ( It is desirable to use a conductive material having a high work function value and high light reflectance such as Pt) or gold (Au). Furthermore, in the case of a conductive material having a low work function value such as aluminum (Al) and an alloy containing aluminum and having a high light reflectance, an appropriate hole injection layer is provided to improve hole injection properties. By improving, the lower electrode can be used as the anode electrode. Alternatively, a transparent conductive material having excellent hole injection characteristics such as ITO and IZO may be stacked on a conductive material having high light reflectivity. The second intermediate electrode is preferably made of a conductive material such as ITO or IZO that transmits luminescent light and has a high work function value. Further, the first intermediate electrode and the upper electrode are made of a conductive material having a small work function value so that the emitted light can be transmitted and electrons can be efficiently injected into the first organic layer and the second organic layer. It is desirable to configure. For example, the first intermediate electrode and the upper electrode can be composed of a thin film made of Mg, Mg alloy, Al, Al alloy or the like. Alternatively, it may be a first intermediate electrode having a structure in which the above-described thin film is laminated on both sides of a layer made of ITO or IZO, or on a thin film made of Mg, Mg alloy, Al, Al alloy or the like. It can also be set as the upper electrode of the structure by which the layer which consists of was laminated | stacked.

  On the other hand, the case where the display element according to the second laminated mode is a top emission type, the lower electrode and the second intermediate electrode constitute a cathode electrode, and the first intermediate electrode and the upper electrode constitute an anode electrode is described. To do. In this case, the lower electrode is preferably made of a conductive material having a small work function value such as Al or an Al alloy and a high light reflectance. Note that the lower electrode can be used as the cathode electrode by improving the electron injection property by providing an appropriate electron injection layer on a conductive material having a high light reflectance used as the anode electrode. Further, it is desirable that the second intermediate electrode is made of a conductive material that transmits emitted light and has a small work function value. For example, the second intermediate electrode can be composed of a thin film made of Mg, Mg alloy, Al, Al alloy or the like. Alternatively, a configuration in which a layer made of ITO or IZO is laminated on these thin films may be employed. Further, the first intermediate electrode and the upper electrode are preferably made of a conductive material such as ITO or IZO that transmits luminescent light and has a large work function value.

  When the display element of the first laminated mode and the display element of the second laminated mode are so-called bottom emission type, the lower electrode is made of a conductive material that transmits the emitted light, and the upper electrode has a light reflectivity, for example. What is necessary is just to comprise from a highly conductive material. These electrodes may be configured using a suitable conductive material as appropriate in accordance with the design of the display element.

  In the display element of the first lamination mode and the display element of the second lamination mode, the lower electrode is formed by, for example, an evaporation method such as an electron beam evaporation method or a hot filament evaporation method, a sputtering method, or a chemical vapor deposition method. (CVD method), ion plating method and etching method combination; various printing methods such as screen printing method, ink jet printing method, metal mask printing method; plating method (electroplating method and electroless plating method); lift-off method; laser It can be formed using an ablation method; a sol-gel method or the like.

In the display element of the second stacked mode, the insulating layer is preferably formed on the basis of a film formation method such as a vacuum evaporation method in which the energy of film formation particles is small, or a film formation method such as an MOCVD method. This is preferable because the influence on the surface can be reduced. Alternatively, the film formation temperature is set to room temperature in order to prevent a decrease in luminance due to the deterioration of the first organic layer, and further, under the condition that the stress of the insulating layer is minimized to prevent the insulating layer from peeling off. It is desirable to form an insulating layer. In addition, the insulating layer is preferably formed without exposing the first organic layer to the atmosphere, whereby the first organic layer can be prevented from being deteriorated by moisture or oxygen in the atmosphere. Furthermore, the insulating layer is preferably made of a material that transmits, for example, 80% or more of the light generated in the first organic layer, and specifically, an inorganic amorphous insulating material such as amorphous silicon (α -Si), amorphous silicon carbide (α-SiC), amorphous silicon nitride (α-Si _1-x N _x ), amorphous silicon oxide (α-Si _1-y O _y ), amorphous carbon (α-C) can do. Since such an inorganic amorphous insulating material does not generate grains, it has low water permeability and constitutes a good insulating layer.

  In the intermediate electrode and the upper electrode constituting the display element according to the first lamination mode, and the first intermediate electrode and the upper electrode constituting the display element according to the second lamination mode, in particular, the vacuum evaporation method is used. From the viewpoint of preventing the occurrence of damage to the first organic layer or the second organic layer, it is preferable to form the film based on a film forming method with a small energy of film forming particles or a film forming method such as MOCVD. The film formation of the second intermediate electrode constituting the display element according to the second lamination mode is basically the same as described above.

  When the first light emitting part and the second light emitting part are composed of organic electroluminescence light emitting parts, the configuration of the organic layer including the light emitting layer is not particularly limited. For example, the organic layer has a stacked structure of a hole transport layer, a light emitting layer, and an electron transport layer, a stacked structure of a hole transport layer and a light emitting layer that also serves as an electron transport layer, a hole injection layer, a hole transport layer, It can be composed of a laminated structure of a light emitting layer, an electron transport layer, and an electron injection layer. As a method for forming an organic layer, a physical vapor deposition method (PVD method) such as a vacuum deposition method; a printing method such as a screen printing method or an ink jet printing method; a lamination of a laser absorption layer and an organic layer formed on a transfer substrate Examples of the laser transfer method and various coating methods include separating the organic layer on the laser absorption layer by irradiating the structure with laser and transferring the organic layer. When the organic layer is formed based on a vacuum evaporation method, for example, a so-called metal mask is used, and the organic layer can be obtained by depositing a material that has passed through an opening provided in the metal mask. The organic layer can be formed using widely known materials.

  The lower electrode, the intermediate electrode, and the upper electrode constituting the display element according to the first stacking mode may have other configurations and materials by using an appropriate electron injection layer or hole injection layer in addition to the above-described configuration. Can also be used. The same applies to the lower electrode, the first intermediate electrode, the second intermediate electrode, and the upper electrode that constitute the display element according to the second stacked mode.

The lower electrode constituting the display element according to the first lamination mode and the lower electrode constituting the display element according to the second lamination mode are provided, for example, on an interlayer insulating layer. The interlayer insulating layer covers a drive circuit formed on the support. The drive circuit is composed of a TFT or the like, and the TFT and the lower electrode are electrically connected via a contact plug provided in the interlayer insulating layer. As a constituent material of the interlayer insulating _{layer, SiO 2, BPSG, PSG,} BSG, AsSG, PbSG, SiON, SOG ( spin on glass), low-melting glass, SiO ₂ based materials such glass paste; SiN-based materials; insulation, such as polyimide Resins can be used alone or in appropriate combination. For the formation of the interlayer insulating layer, known processes such as a CVD method, a coating method, a sputtering method, and various printing methods can be used.

Moisture reaches the first organic layer and the second organic layer on the upper electrode constituting the display element according to the first lamination aspect and the upper electrode constituting the display element according to the second lamination aspect. For the purpose of prevention, it is preferable to provide an insulating protective film. Similar to the insulating layer described above, the protective film can be formed on the basis of a film forming method in which the energy of the film forming particles is small, such as a vacuum evaporation method, or a film forming method such as an MOCVD method. This is preferable because the influence can be reduced. Alternatively, in order to prevent a decrease in luminance due to deterioration of the first organic layer and the second organic layer, the film forming temperature is set to room temperature, and furthermore, the protective film is stressed to prevent the protective film from peeling off. It is desirable to form a protective film under the minimum conditions. In addition, the protective film is preferably formed without exposing the upper electrode to the atmosphere, whereby the deterioration of the organic layer due to moisture and oxygen in the atmosphere can be prevented. Furthermore, when the display device is a top emission type, it is desirable that the protective film is made of a material that transmits, for example, 80% or more of the light generated in the organic layer, and specifically, an inorganic amorphous insulating property. Materials, for example, amorphous silicon (α-Si), amorphous silicon carbide (α-SiC), amorphous silicon nitride (α-Si _1-x N _x ), amorphous silicon oxide (α-Si _1-y O _y ), amorphous Carbon (α-C) can be exemplified. As described in the insulating layer, such an inorganic amorphous insulating material does not generate grains, and thus has a low water permeability and constitutes a good protective film. A substrate is disposed on the protective film, and the protective film and the substrate may be bonded using, for example, an ultraviolet curable adhesive or a thermosetting adhesive. In the case where a common voltage is applied to the upper electrode, the protective film may be formed of a transparent conductive material. For example, the protective film can be made of a transparent conductive material such as ITO or IZO.

High strain point glass, soda glass (Na ₂ O · CaO · SiO ₂ ), borosilicate glass (Na ₂ O · B ₂ O ₃ · SiO ₂ ), forsterite (2MgO · SiO ₂ ) ₂ ), glass materials such as lead glass (Na ₂ O · PbO · SiO ₂ ), and various plastic materials. The constituent materials of the support and the substrate may be the same or different. If a support body and a substrate made of a plastic material having flexibility are used, a flexible display device can be formed.

  In the display element of the present invention and the display device of the present invention including the display element of the present invention, the display element is used when either one of the first light emitting unit and the second light emitting unit is not operating normally. Current increasing means for increasing the current flowing through the other light emitting section is provided. As a result, when the light emitting unit of one of the light emitting elements is not operating normally, the other light emitting element operating normally operates to emit light with higher luminance. Therefore, without complicating the configuration of the peripheral circuit of the display device, when one light-emitting element does not operate normally, the other light-emitting element that operates normally can emit light so as to have higher luminance than originally intended. it can.

  Hereinafter, the present invention will be described based on examples with reference to the drawings.

  Example 1 relates to the display element of the present invention and the display device of the present invention. FIG. 1 shows an equivalent circuit diagram of the display element 110 in the m-th row and the n-th column constituting the display device of the first embodiment. A conceptual diagram of the display device of Example 1 is shown in FIG. A schematic partial cross-sectional view of the display device of Example 1 is shown in FIG.

As shown in FIG. 2, the display device of Example 1 is
(1) N display elements 110 in a first direction, M in a second direction different from the first direction, a total of N × M display elements 110 arranged in a two-dimensional matrix,
(2) M scanning lines SCL extending in the first direction, and
(3) N data lines DTL extending in the second direction,
It has. In FIG. 2, for convenience, 3 × 3 display elements 110 centered on the display element 110 in the m-th row and the n-th column are shown, but this is merely an example.

  The display device of Example 1 is a color display device having a plurality of display elements 110 (for example, N × M = 1920 × 480). One display element 110 constitutes one subpixel. Here, one pixel is arranged in the direction in which the scanning line SCL extends, and includes three types of sub-pixels: a red light-emitting subpixel that emits red light, a green light-emitting subpixel that emits green light, and a blue light-emitting subpixel that emits blue light. It consists of pixels. Therefore, the display device has (N / 3) × M pixels.

  As shown in FIGS. 1 and 2, the display element 110 includes a first light emitting element 111 and a second light emitting element 111 ′. As shown in FIG. 1, the first light emitting element 111 includes a current-driven first light emitting unit ELP and a first drive circuit 112 connected to the first light emitting unit ELP. The second light emitting element 111 'includes a current driven second light emitting unit ELP' and a second drive circuit 112 'connected to the second light emitting unit ELP'.

  The display element 110 increases the current that flows through the light emitting part constituting the other light emitting element when the light emitting part of one of the first light emitting element 111 and the second light emitting element 111 ′ is not operating normally. Current increasing means 113 is provided. The current increasing means 113 operates based on the voltage at the connection between the first light emitting unit ELP and the first drive circuit 112 and the voltage at the connection between the second light emitting unit ELP ′ and the second drive circuit 112 ′. . The current increasing means 113 will be described in detail later.

In Example 1, the first light emitting unit ELP and the second light emitting unit ELP ′ are composed of organic electroluminescent light emitting units. In FIG. 1, the symbol C _EL indicates the capacitance of the first light emitting unit ELP, and the symbol C _EL ′ indicates the capacitance of the second light emitting unit ELP ′. Based on the operation of the scanning circuit 101, the first light emitting element 111 and the second light emitting element 111 ′ constituting the display element 110 in the m-th row and the n-th column are scanned in common from the m-th scanning line SCL _m. A signal is applied, and a common video signal V _Sig is applied from the _nth data line DTL _n based on the operation of the signal output circuit 102.

The first drive circuit 112 includes a first drive transistor TR _{D. In} the first drive transistor TR _D , the first voltage V _CC is applied to one source / drain region, and the other source / drain is provided. The region is connected to one end of the first light emitting unit ELP. In the first embodiment, the first drive transistor TR _D and the second drive transistor TR _D ′ described later are composed of p-channel transistors.

More specifically, one source / drain region of the first drive transistor TR _D is connected to the _mth feeder line PS1 _m . A first voltage V _CC (for example, 20 volts) as a drive voltage is applied to the feeder line PS1 _m according to the operation of the power supply unit 100. The first voltage V _CC is applied to one source / drain region of the first drive transistor TR _D via the feeder line PS1 _m .

The second driving circuit 112 ′ includes a second driving transistor TR _D ′. In the second driving transistor TR _D ′, the first voltage V _CC is applied to one source / drain region, The other source / drain region is connected to one end of the second light emitting unit ELP ′.

More specifically, like the first drive transistor TR _D , one source / drain region of the second drive transistor TR _D ′ is also connected to the _mth power supply line PS1 _m . The first voltage V _CC is also applied to one source / drain region of the second drive transistor TR _D ′ via the feeder line PS1 _m .

A second voltage V _Cat is applied to the other end of the first light emitting unit ELP and the other end of the second light emitting unit ELP ′. More specifically, the other end of the first light emitting unit ELP and the other end of the second light emitting unit ELP ′ are connected to a power supply line PS2 to which a second voltage V _Cat (for example, 0 volts) is applied.

The first drive circuit 112 and the second drive circuit 112 ′ will be further described. At least one of the first drive circuit 112 and the second drive circuit 112 ′ further includes a write transistor. In the first embodiment, the first drive circuit 112 includes a write transistor TR _W , and the second drive circuit 112 ′ includes a write transistor TR _W ′. In addition, each of the first drive circuit 112 and the second drive circuit 112 ′ has a capacitance section C ₁ for holding the potentials of the gate electrode of the first drive transistor TR _{D and} the gate electrode of the second drive transistor TR _D ′. C ₁ 'is provided. In the first embodiment, the write transistors TR _W and TR _W ′ are composed of n-channel transistors.

In the write transistor TR _W, one of the source / drain region is connected to the data line DTL _n, the other source / drain region is connected to the gate electrode of the first driving transistor TR _D, the gate electrode is connected to the scan line SCL _m. A capacitor C ₁ is connected between the gate electrode of the first drive transistor TR _D and one of the source / drain regions.

In the write transistor TR _W ′, one source / drain region is connected to the data line DTL _n , and the other source / drain region is connected to the gate electrode of the second drive transistor TR _D ′. cage, the gate electrode is connected to the scan line SCL _m. A capacitor C ₁ ′ is connected between the gate electrode of the second drive transistor TR _D ′ and one of the source / drain regions.

In the write transistors TR _W and TR _W ′, a common video signal V _Sig is applied from the signal output circuit 102 to the one source / drain region via the data line DTL _n , and the scanning electrode SCL is applied to the gate electrode. _A common scanning signal is applied from the scanning circuit 101 via _m . As will be described later, the gate electrode of the first driving transistor TR _{D and} the gate electrode of the second driving transistor TR _D ′ are electrically connected together with the gate electrode of the auxiliary transistor 114 described later. The gate electrode of the first drive transistor TR _{D and} the gate electrode of the second transistor TR _D ′ are connected to the other source / drain region of the write transistors TR _W and TR _W ′.

The current increasing means 113 will be described. The current increasing means 113 is
(A) auxiliary transistor 114, and
(B) first switching means 115 and second switching means 116;
It is composed of

In the auxiliary transistor 114,
(A-1) The gate electrode is connected to the gate electrode of the first drive transistor TR _{D and} the gate electrode of the second drive transistor TR _D ′,
(A-2) The first voltage V _CC is applied to one source / drain region,
(A-3) The other source / drain region is connected to the connection portion between the first light emitting unit ELP and the first drive transistor TR _D via the first switching unit 115 and the second switching unit 116 is connected to the other source / drain region. And is connected to a connection portion between the second light emitting unit ELP ′ and the second driving transistor TR _D ′.

More specifically, like the first drive transistor TR _D and the like, one source / drain region of the auxiliary transistor 114 is also connected to the _mth power supply line PS1 _m . The first voltage V _CC is also applied to one source / drain region of the auxiliary transistor 114 via the feeder line PS1 _m .

The first switching unit 115 operates based on the voltage at the connection between the second light emitting unit ELP ′ and the second driving transistor TR _D ′, and the second switching unit 116 includes the first light emitting unit ELP and the first driving transistor. It operates on the basis of a voltage at the connection of the TR _D.

  In the first embodiment, the first switching means 115 and the second switching means 116 are each composed of transistors of the same conductivity type (p channel type in the first embodiment). Hereinafter, for convenience of explanation, a transistor constituting the first switching means 115 is simply referred to as a transistor 115, and a transistor constituting the second switching means 116 is simply referred to as a transistor 116.

One source / drain region of the transistor 115 and one source / drain region of the transistor 116 are connected to the other source / drain region of the auxiliary transistor 114. The other source / drain region of the transistor 115 is connected to the connection portion between the first light emitting section ELP and the first driving transistor TR _D. The other source / drain region of the transistor 116 is connected to a connection portion between the second light emitting unit ELP ′ and the second drive transistor TR _D ′. The gate electrode of the transistor 115 is connected to a connection portion between the second light emitting unit ELP ′ and the second drive transistor TR _D ′. The gate electrode of the transistor 116 is connected to the connection portion between the first light emitting section ELP and the first driving transistor TR _D.

  The structure of the display element 110 will be described with reference to FIG. In the first embodiment, the first light emitting unit ELP and the second light emitting unit ELP ′ are stacked. The first light emitting unit ELP and the second light emitting unit ELP ′ are both light emitting units that exhibit a predetermined light emission color.

More specifically, the first light emitting unit ELP is:
(D-1) Lower electrode 51,
(D-2) a first organic layer 54 including a light emitting layer provided on the lower electrode 51, and
(D-3) a light transmissive intermediate electrode 55 provided on the first organic layer 54;
Consists of
The second light emitting unit ELP ′
(E-1) Intermediate electrode 55,
(E-2) a second organic layer 57 including a light emitting layer provided on the intermediate electrode 55, and
(E-3) An upper electrode 58 provided on the second organic layer 57,
It is composed of In addition, at least one of the lower electrode 51 and the upper electrode 58 is light transmissive. The display device of Example 1 is a top emission type, and the upper electrode 58 is light transmissive.

  The intermediate electrode 55 constitutes the anode electrode of the first light emitting part ELP and the second light emitting part ELP ′, or the intermediate electrode 55 constitutes the cathode electrode of the first light emitting part ELP and the second light emitting part ELP ′. . As will be described in detail later, in Example 1, the lower electrode 51 constitutes the anode electrode of the first light emitting part ELP, the upper electrode 58 constitutes the anode electrode of the second light emitting part ELP ′, and the intermediate electrode 55 is The cathode electrodes of the first light emitting unit ELP and the second light emitting unit ELP ′ are configured.

The transistors constituting the first drive circuit 112 and the second drive circuit 112 ′ and the capacitors C ₁ and C ₁ ′ and the transistors constituting the current increasing means 113 are formed on the support 20. For example, the first light emitting unit ELP and the second light emitting unit ELP ′ are formed above the transistors and the capacitor units C ₁ and C ₁ ′ with the interlayer insulating layer 41 interposed therebetween. In FIG. 3, the first drive transistor TR _D and the capacitor unit C ₁ constituting the first drive circuit 112 are shown. Other transistors and capacitors are hidden and cannot be seen.

The first drive transistor TR _D includes a gate electrode 31, a gate insulating layer 32, and a semiconductor layer 33. More specifically, the first drive transistor TR _D includes one source / drain region 35 and the other source / drain region 36 provided in the semiconductor layer 33, and one source / drain region 35 and the other source. The portion of the semiconductor layer 33 between the / drain regions 36 includes the corresponding channel forming region 34. Although described later in detail with reference to FIG. 5B described later, the configuration of the second drive transistor TR _D ′ (not shown) is basically the same as described above. Although the conductivity types may be different, other transistors (not shown) basically have the same configuration.

The capacitor portion C ₁ includes an electrode 37, a dielectric layer composed of the extending portion of the gate insulating layer 32, and a wiring 39 (more specifically, a portion of the wiring 39 facing the electrode 37). Although described in detail later with reference to FIGS. 5B and 5C described later, the capacitor C ₁ ′ (not shown) basically has the same configuration as described above. The wiring 39 is connected to one source / drain region 35 of the driving transistor TR _D. The wiring 39 corresponds to the feeder line PS1. The other source / drain region 36 of the drive transistor TR _D is connected to the electrode 38.

Reference numeral 38 ′ is an electrode corresponding to the electrode 38, and the electrode 38 ′ is connected to the other source / drain region of the second drive transistor TR _D ′ (not shown). The wiring 39 is connected to one source / drain region 35 of the drive transistor TR _D as described above, but is further connected to one source / drain region of the second drive transistor TR _D ′ (not shown). ing.

The gate electrode 31, a part of the gate insulating layer 32, and the electrode 37 constituting the capacitor portion C ₁ are formed on the support 20. The electrodes 38, 38 ′, the wiring 39, and the semiconductor layer 33 are formed on the gate insulating layer 32 (including a portion of the dielectric layer composed of the extending portion). Various transistors such as the first drive transistor TR _D and the capacitors C ₁ and C ₁ ′ are covered with an interlayer insulating layer 41. A first light emitting unit ELP is provided on the interlayer insulating layer 41, and a second light emitting unit ELP ′ is provided on the upper side. A wiring 53 corresponding to the power supply line PS2 is provided on the interlayer insulating layer 41. A second interlayer insulating layer 42 is provided on the portion of the interlayer insulating layer 41 where the light emitting portion is not provided. An insulating protective film 43 is provided on the entire surface including the light emitting portion and the second interlayer insulating layer 42. A substrate 60 made of glass, for example, is disposed on the protective film 43. The protective film 43 and the substrate 60 are bonded to each other by an adhesive layer 44 made of an ultraviolet curable adhesive. The emitted light passes through the substrate 60 and is emitted to the outside. The lower electrode 51 constituting the anode electrode of the first light emitting unit ELP is connected to the electrode 38 through a contact plug 52 provided in the interlayer insulating layer 41. The intermediate electrode 55 constituting the cathode electrode of the first light emitting part ELP and the second light emitting part ELP ′ is connected to the wiring 53 constituting the feeder line PS2 through the contact plug 56 provided in the second interlayer insulating layer 42. Has been. The upper electrode 58 constituting the anode electrode of the second light emitting unit ELP ′ is connected to the electrode 38 ′ via a contact plug 59 provided in the second interlayer insulating layer 42 and the interlayer insulating layer 41.

  FIG. 4A shows that in the display element 110 in the m-th row and the n-th column constituting the display device, the first light-emitting element 111 and the second light-emitting element 111 ′ constituting the display element 110 operate normally. It is the figure which showed the state when it is during. In FIG. 4B, in the display element 110 in the m-th row and the n-th column constituting the display device, the first light-emitting element 111 constituting the display element 110 operates normally, but the second light emission It is the figure which showed typically the state when 2nd light emission part ELP 'which comprises element 111' has raise | generated the short circuit defect. For the sake of convenience, in FIGS. 4A and 4B, the capacitances of the light emitting portions ELP and ELP ′ are not shown.

With reference to FIGS. 4A and 4B, the operation of the display element 110 constituting the display device of Example 1 will be described. For the convenience of explanation, in the display element 110, it is assumed that the first light emitting element 111 and the second light emitting element 111 ′ have substantially the same electrical characteristics by design. That is, by design, the electrical characteristics of the first light emitting unit ELP and the electrical characteristics of the second light emitting unit ELP ′ are substantially the same, and the electrical characteristics of the first driving transistor TR _D and the second driving transistor TR _D ′. The electrical characteristics are substantially the same. The same applies to the write transistor TR _W and the write transistor TR _W ′, and the capacitor C ₁ and the capacitor C ₁ ′.

For convenience of explanation, in the current increasing means 113, the auxiliary transistor 114 is designed to have substantially the same electrical characteristics as the first drive transistor TR _D and the second drive transistor TR _D ′ by design. . Further, it is assumed that the transistor 115 and the transistor 116 constituting the current increasing unit 113 have substantially the same electrical characteristics in design.

  With reference to FIG. 4A, the operation when the first light emitting element 111 and the second light emitting element 111 'are operating normally will be described.

A predetermined video signal V _Sig is supplied from the signal output circuit 102 to the gate electrode of the first drive transistor TR _D and the second drive through the write transistors TR _W and TR _W ′ which are turned on by a signal from the scanning line SCL _m. Applied to the gate electrode of the transistor TR _D '. Thereafter, even if the write transistors TR _W and TR _W ′ are turned off, the voltage between the gate electrode and the source region of the first drive transistor TR _D and the second drive are generated by the capacitors C ₁ and C ₁ ′. The voltage between the gate electrode and the source region of the transistor TR _D ′ is held at a predetermined voltage according to the video signal V _Sig .

Current flowing through the first light emitting section ELP through the first driving transistor TR _D is the drain current I _ds flowing from the source region of the first driving transistor TR _D to the drain region. If the first drive transistor TR _D ideally operates in the saturation region, the drain current I _ds can be expressed by the following equation (1).

I _ds = k · μ · (V _gs −V _th ) ² (1)
However,
mu: effective mobility L: channel length W: channel width V _gs: voltage V _th between the source region and the gate electrode of the first driving transistor TR _D: threshold voltage C _ox of the first driving transistor TR _D: (Relative permittivity of gate insulating layer) x (dielectric constant of vacuum) / (thickness of gate insulating layer)
k≡ (1/2) ・ (W / L) ・ C _ox
And The electrical characteristics of the second drive transistor TR _D ′ are the same as the electrical characteristics of the first drive transistor TR _D , and the values of the above equation (1) and various parameters are also applied to the second drive transistor TR _D ′. The same is assumed.

The current flowing through the second light emitting unit ELP ′ via the second drive transistor TR _D ′ is also the drain current I _ds ′ flowing from the source region to the drain region of the second drive transistor TR _D ′. Since the voltage between the source region and the gate electrode of the second drive transistor TR _D ′ is similar to the voltage between the source region and the gate electrode of the first drive transistor TR _D , I _ds ′ = I _ds is there.

In the state shown in FIG. 4A, the voltage at the connecting portion between the first light emitting portion ELP and the first driving transistor TR _D and the connecting portion between the second light emitting portion ELP ′ and the second driving transistor TR _D ′. Is a similar voltage. The transistor 115 operates based on the voltage at the connection between the second light emitting unit ELP ′ applied to the gate electrode and the second driving transistor TR _D ′, and the transistor 116 operates as the first light emitting unit applied to the gate electrode. It operates based on ELP and a voltage at the connection of the first driving transistor TR _D.

That is, one of the source / drain regions of the transistors 115 and 116 is connected to the power supply line PS1 _m to which the voltage V _CC is applied via the auxiliary transistor 114 in the on state. Although depending on characteristics such as the threshold voltage of the first light emitting unit ELP and the second light emitting unit ELP ′, basically, the other source / drain region and the gate electrode of the transistors 115 and 116 are connected to the transistors 115 and 116. A voltage lower than the voltage applied to one of the source / drain regions is applied. The transistor 115 and the transistor 116 are in an on state, and their on resistance values are the same.

The voltage between the source region and the gate electrode of the auxiliary transistor 114 is also similar to the voltage between the source region and the gate electrode of the first driving transistor TR _D. If the auxiliary transistor 114 operates ideally in the saturation region, and the current value is not limited by the transistor 115 and the transistor 116, the drain current I _ad flowing through the auxiliary transistor 114 is equal to I _ds . The drain current I _ad flowing through the auxiliary transistor 114 is shunted by the transistor 115 and the transistor 116. Current I _{AD_B} flowing in the current I _{AD_A} the transistor 116 flowing through the transistor 115 are both a I _ad / 2, further, are both I _ds / 2.

The first light emitting section ELP, the current I _{AD_A} flows in addition to the current I _ds, ', the current I _ds' second light emitting section ELP current flows I _{AD_B} in addition to. As described above, I _ds ′ = I _ds , and I _{ad_A} = I _{ad_B} = I _ds / 2. Accordingly, a current corresponding to 1.5 × _Ids flows through the first light emitting unit ELP and the second light emitting unit ELP ′. Both the first light emitting unit ELP and the second light emitting unit ELP ′ emit light at a luminance corresponding to a current value corresponding to 1.5 × _Ids .

Next, with reference to FIG. 4B, an operation when one of the light emitting units is not operating normally will be described. More specifically, an operation when the second light emitting unit ELP ′ is short-circuited will be described. In FIG. 4B, the drain current flowing through the second drive transistor TR _D ′ is not shown.

As shown in FIG. 4B, in a state where the second light emitting unit ELP ′ has a short circuit failure, both ends of the second light emitting unit ELP ′ are _typically connected by a short circuit resistance R _Srt . Can be expressed as Here, if R _Srt is sufficiently small, the voltage at the connection between the second light emitting unit ELP ′ and the second drive transistor TR _D ′ is approximately V _Cat (= 0 volts). In this state, the voltage of the gate electrode of the transistor 115 is lower than that in the state illustrated in FIG. On the other hand, the voltage of the gate electrode of the transistor 116 basically does not change so much.

Accordingly, the on-resistance value of the transistor 115 is smaller than the on-resistance value of the transistor 116. The relationship between the current I _{ad_A} flowing through the transistor 115 and the current I _{ad_B} flowing through the transistor 116 is I _{ad_A} > I _{ad_B} . Thus, the other light emitting element 111 that operates normally operates to emit light with higher luminance. Depending on the setting of the threshold voltage of the transistor 115 and 116, but for example, the majority of the current in FIG. 4 (B) if through transistor 115, the first light emitting section ELP corresponds to approximately 2 × I _ds Light is emitted at a luminance corresponding to the current value.

  As described above, in the first embodiment, without complicating the configuration of the peripheral circuit of the display device, when one of the light emitting units does not operate normally due to a short circuit failure, the other operates normally. The light emitting element can be made to emit light with higher brightness than originally intended. Even in the case where one light emitting part causes an open failure and does not operate normally, by short-circuiting this light emitting part using a technique such as laser repair, the other light emitting element that operates normally can be made to be Light can be emitted so as to have high luminance.

In addition, by setting the size of the auxiliary transistor 114 to N ₀ times that of the transistors TR _D and TR _D ′, the amount of current flowing through the auxiliary transistor 114 can be appropriately adjusted as the drain current I _ad = N ₀ × I _ds. You can also. The value N ₀ may be set as appropriate according to the design of the display element. The same applies to other embodiments described later.

  Further, the first embodiment includes a first light emitting unit ELP that exhibits a predetermined light emitting color, and a second light emitting unit ELP ′ that is provided above the first light emitting unit ELP and exhibits the predetermined light emitting color. ing. As a result, even if a part of the light-emitting portions is in a non-light-emitting state due to a malfunction, the light-emitting area in the display element is not visually recognized as being missing. Therefore, even if a part of the light emitting portions is in a non-light emitting state due to a malfunction, the light emitting region is not visually recognized as being partly missing.

  The outline of the manufacturing method of the display device and the display element 110 of Example 1 is described below with reference to FIGS. 5A to 5C, FIGS. 6A and 6B, and FIGS. 7A and 7B. ), (A) and (B) in FIG. 8, (A) and (B) in FIG. 9, and (A) and (B) in FIG.

[Step-100] (See FIGS. 5A and 5B)
On the support 20, the TFTs constituting the first drive circuit 112, the second drive circuit 112 ′, and the current increasing means 113 are manufactured by a well-known method for each display element 110 constituting the subpixel. 5A shows only the drive transistor TR _D as in FIG. Other transistors are hidden from view.

FIG. 5B shows a TFT constituting the second drive transistor TR _D ′. Other transistors are hidden from view. Of the drawings referred to in the following description, only FIG. 5B is a schematic partial end view of the support 20 and the like at different locations. Since the configuration of the second drive transistor TR _D ′ is the same as the configuration of the first drive transistor TR _D , description thereof is omitted. In FIG. 5B, the reference numerals of the constituent elements of the second drive transistor TR _D ′ are shown with a dash for distinction. Although the gate electrode 31 of the first drive transistor TR _{D and} the gate electrode 31 ′ of the second drive transistor TR _D ′ are connected, the connection portion is hidden and cannot be seen.

Further, as shown in (A) and (B) in FIG. 5, the electrode 37 constituting the capacitor portion C _1, and a 'electrode 37 constituting the' capacitance section C _1, was formed on the support 20. The electrodes 37 and 37 ′ are formed at the same time in the formation process of the gate electrodes 31 and 31 ′, but the present invention is not limited to this. In the illustrated example, the TFT is a bottom gate type, but may be a top gate type.

[Step-110] (see FIG. 5C)
Next, after a conductive material layer is formed on the entire surface, electrodes 38 and 38 'and wirings 39 are formed based on a photolithography technique and an etching technique. A portion of the wiring 39 that faces the electrode 37 corresponds to the other electrode of the capacitor C ₁ .

Note that the connection between the electrode 38 'and the source / drain region 36' of the second drive transistor TR _D 'is hidden and cannot be seen. Further, the wiring 39 is connected to the source / drain region 35 ′ of the second drive transistor TR _D ′ in addition to the source / drain region 35 of the first drive transistor TR _D , but this connection portion is also hidden and cannot be seen. . Although not shown, the portion of the wiring 39 that faces the electrode 37 ′ corresponds to the other electrode of the capacitor C ₁ ′.

[Step-120] (see (A) and (B) of FIG. 6)
Thereafter, an interlayer insulating layer 41 made of SiO _{2 is} formed on the support 20 by a CVD method so as to cover the TFT, the electrodes 38, 38 ′, and the wiring 39. Next, an opening 52 ′ in which the upper surface of the electrode 38 is exposed at the bottom is formed in the interlayer insulating layer 41 based on the photolithography technique and the etching technique. At the same time, the portion of the interlayer insulating layer 41 corresponding to an opening 59 ′ described later is removed so that the upper surface of the electrode 38 ′ is exposed at the bottom. The interlayer insulating layer 41 may be formed of an organic insulating layer made of polyimide resin or the like, or may be formed of a laminated structure of an inorganic insulating layer such as SiO ₂ and an organic insulating layer such as polyimide resin.

  Thereafter, a lower electrode 51 made of aluminum is formed on the interlayer insulating layer 41 based on a combination of a vacuum deposition method and an etching method, and a wiring 53 is also formed. The lower electrode 51 is electrically connected to the electrode 38 through a contact plug 52 provided in the opening 52 '.

[Step-130] (see FIG. 7A)
Next, a second interlayer insulating layer 42 is formed on the entire surface. Specifically, the second interlayer insulating layer 42 made of polyimide resin having a thickness of 1 μm is formed based on a spin coating method. The second interlayer insulating layer 42 may be composed of an inorganic insulating layer such as SiO ₂ .

[Step-140] (see FIG. 7B and FIG. 8A)
Thereafter, the first organic layer 54 is formed. First, an opening 54 ′ in which the lower electrode 51 is exposed at the bottom is formed based on an etching method. Note that the portion of the second interlayer insulating layer 42 surrounding the opening 54 'preferably forms a gentle slope. At the same time, an opening 56 ′ where the wiring 53 is exposed at the bottom and an opening 59 ′ where the electrode 38 ′ is exposed at the bottom are formed.

  Then, the first organic layer 54 is formed over the portion of the second interlayer insulating layer 42 surrounding the opening 54 ′ from the portion of the lower electrode 51 exposed at the bottom of the opening 54 ′. The first organic layer 54 includes, for example, a hole transport layer made of an organic material and a light emitting layer that also serves as an electron transport layer, which are sequentially stacked. For convenience, the first organic layer 54 is shown as one layer in the figure. The same applies to the drawings referred to in other embodiments.

  Specifically, plasma treatment is performed in order to remove organic deposits on the surface of the lower electrode 51 and improve hole injection properties. Examples of the gas to be introduced include oxygen gas, nitrogen gas, and argon gas. In Example 1, specifically, an oxygen plasma treatment with a treatment power of 100 W and a treatment time of 180 seconds is performed. The surface of the second interlayer insulating layer 42 becomes chemically active by the oxygen plasma treatment.

  Next, an organic material is vacuum-deposited on the basis of resistance heating in a state where a metal mask (not shown) for forming the first organic layer 54 constituting each subpixel is disposed above the second interlayer insulating layer 42. To do. The organic material passes through the opening provided in the metal mask, and from above the portion of the lower electrode 51 exposed at the bottom of the opening 54 ′ constituting the subpixel, the second interlayer insulating layer 42 surrounding the opening 54 ′. It accumulates over the part.

  In the first organic layer 54 in the display element 110 constituting the green light emitting subpixel, for example, m-MTDATA [4,4 ′, 4 ”-tris (3-methylphenylphenylamino) triphenylamine] is used as the hole injection layer. Next, as a hole transport layer, for example, α-NPD [4,4-bis (N-1-naphthyl-N-phenylamino) biphenyl] is deposited to a thickness of 30 nm as a hole transport layer. Next, for example, Alq3 [tris (8-quinolinolato) aluminum (III)] is vapor-deposited with a film thickness of 50 nm as a light-emitting layer that also serves as an electron transport layer, and these layers are continuously formed in the same vacuum vapor deposition apparatus. Evaporate.

  Further, in the first organic layer 54 in the display element 110 constituting the blue light emitting subpixel, for example, m-MTDATA is vapor-deposited with a film thickness of 18 nm as a hole injection layer. Next, for example, α-NPD is deposited in a thickness of 30 nm as the hole transport layer. Further, as a light emitting layer that also serves as a hole blocking layer, for example, after vapor deposition of bathocuproine [2,9-dimethyl-4,7-diphenyl-1,10phenanthroline] with a film thickness of 14 nm, Alq3 is deposited with a film thickness of 30 nm, for example. These layers are successively deposited in the same vacuum deposition apparatus.

  Further, in the first organic layer 54 in the display element 110 constituting the red light emitting subpixel, for example, m-MTDATA is deposited with a film thickness of 55 nm as a hole injection layer. Next, for example, α-NPD is deposited in a thickness of 30 nm as the hole transport layer. Furthermore, as a light emitting layer, for example, after depositing BSB-BCN [2,5-bis {4- (N-methoxyphenyl-N-phenylamino) styryl} benzene-1,4-dicarbonitrile], as an electron transporting layer, For example, Alq3 is deposited with a film thickness of 30 nm. These layers are successively deposited in the same vacuum deposition apparatus.

[Step-150] (see FIG. 8B)
Thereafter, the intermediate electrode 55 is formed. In a state where a metal mask (not shown) for forming the intermediate electrode 55 is disposed above the second interlayer insulating layer 42, the deposited particles are not affected to the extent that the first organic layer 54 is not affected. The intermediate electrode 55 is formed based on a vacuum vapor deposition method that is a film forming method with low energy. By continuously forming the intermediate electrode 55 in the same vacuum deposition apparatus as the formation of the first organic layer 54, the deterioration of the first organic layer 54 and the like due to moisture and oxygen in the atmosphere can be prevented. For example, the intermediate electrode 55 can be obtained by forming a co-deposited film of Mg—Ag (volume ratio 10: 1). The intermediate electrode 55 is electrically connected to the wiring 53 via the contact plug 56.

[Step-160] (see FIG. 9A)
Thereafter, the second organic layer 57 is formed. Specifically, an organic material is formed on the basis of resistance heating in a state where a metal mask (not shown) for forming the second organic layer 57 so as to substantially cover the intermediate electrode 55 is disposed above the intermediate electrode 55. Vacuum deposition. The organic material passes through the opening provided in the metal mask and is deposited on the intermediate electrode 55. The second organic layer 57 is formed on the second interlayer insulating layer 42 so as to cover the edge of the intermediate electrode 55 in the vicinity of the opening 59 ′ so that the upper electrode 58 and the intermediate electrode 55 described later are not in direct contact with each other. It is struck and formed.

  The method for forming the second organic layer 57 in the display element 110 is the same as that described for the first organic layer 54 except that the order of stacking is reversed. For example, in the second organic layer 57 in the display element 110 constituting the green light emitting subpixel, for example, Alq3 is vapor-deposited with a film thickness of 50 nm as a light emitting layer that also serves as an electron transport layer. Next, as a hole transport layer, for example, α-NPD is deposited with a thickness of 30 nm, and then as a hole injection layer, for example, m-MTDATA is deposited with a thickness of 25 nm. These layers are successively deposited in the same vacuum deposition apparatus. For convenience, the second organic layer 57 is shown as one layer in the figure. The same applies to the drawings referred to in other embodiments. The method of forming the second organic layer 57 in the display element 110 constituting the blue light emitting subpixel and the second organic layer 57 in the display element 110 constituting the red light emitting subpixel is also the same as that of the first embodiment except that the order of stacking is reversed. Since it is the same as that described in the organic layer 54, the description is omitted.

[Step-170] (see FIG. 9B)
Next, with respect to the second organic layer 57 in a state where a metal mask (not shown) for forming the upper electrode 58 is disposed above the second organic layer 57 for each display element 110 constituting the subpixel. The upper electrode 58 is formed for each display element 110 constituting the sub-pixel based on a vacuum deposition method, which is a film-forming method in which the energy of film-forming particles is small enough to have no influence. By continuously forming the upper electrode 58 in the same vacuum deposition apparatus as the formation of the second organic layer 57 without exposing the second organic layer 57 to the atmosphere, the second organic layer 57 is formed by the moisture and oxygen in the atmosphere. Deterioration of the organic layer 57 and the like can be prevented. Specifically, the upper electrode 58 can be obtained by forming a deposited film of ITO. The upper electrode is electrically connected to the electrode 38 ′ via the contact plug 59.

[Step-180] (see FIG. 10A)
Next, an insulating protective film 43 made of silicon nitride (Si _1-x N _x ) is formed on the entire surface based on the CVD method. By forming the protective film 43 continuously without exposing the upper electrode 58 to the atmosphere, it is possible to prevent deterioration of the second organic layer 57 and the like due to moisture and oxygen in the atmosphere. Moreover, you may form the protective film which consists of organic materials based on a vacuum evaporation method.

[Step-190] (see FIG. 10B)
Thereafter, the protective film 43 and the substrate 60 are bonded by an adhesive layer 44 made of an ultraviolet curable adhesive. Finally, the display device can be completed by connecting to an external circuit. In addition, it is good also as a structure which filled the space which covers a display area | region in the state which has arrange | positioned the transparent substrate on the protective film 43, and sealed the outer peripheral part with the adhesive agent etc. Alternatively, an inert gas such as nitrogen gas may be sealed in the space, and a desiccant may be sealed in a region communicating with the space. The same applies to other embodiments described later.

  The second embodiment is a modification of the first embodiment. Example 2 also relates to the display element of the present invention and the display device of the present invention. FIG. 11 shows an equivalent circuit diagram of the display element 210 in the m-th row and the n-th column constituting the display device according to the second embodiment. In the second embodiment, when one light-emitting unit does not operate normally due to an open failure, the other light-emitting element that operates normally can emit light so as to have a higher luminance than originally intended.

  As shown in FIG. 11, the display element 210 according to the second embodiment also includes a current increasing unit 213. In the first embodiment, the first switching means 115 and the second switching means 116 constituting the current increasing means 113 are composed of p-channel transistors. On the other hand, in the second embodiment, the first switching means 215 and the second switching means 216 constituting the current increasing means 213 are composed of n-channel transistors. In addition to the differences described above, the configuration of the display element 210 of the second embodiment is the same as that described in the display element 110 of the first embodiment. Since the auxiliary transistor 214 shown in FIG. 11 has the same configuration as the auxiliary transistor 114 described in the first embodiment, description thereof is omitted.

  As described above, the configurations of the first light emitting element 211 and the first drive circuit 212 shown in FIG. 11 are the same as those of the first light emitting element 111 and the first drive circuit 112 described in the first embodiment. Similarly, the configurations of the second light emitting element 211 ′ and the second drive circuit 212 ′ shown in FIG. 11 are the same as those of the second light emitting element 111 ′ and the second drive circuit 112 ′ described in the first embodiment. Description of these will be omitted.

  The conceptual diagram of the display device of Example 2 including the display element 210 is the same as that of FIG. 2 referred to in Example 1, in which the display element 110 is the display element 210, the first light emitting element 111 is the first light emitting element 211, The second light emitting element 111 ′ is replaced with the second light emitting element 211 ′, and the current increasing means 113 is replaced with the current increasing means 213. A conceptual diagram of the display device of Example 2 is omitted. The schematic partial cross-sectional view of the display device according to the second embodiment is the same as that shown in FIG. 3 referred to in the first embodiment except that the reference numerals are replaced as described above. A schematic partial cross-sectional view of the display device of Example 2 is omitted.

  FIG. 12A shows that in the display element 210 in the m-th row and the n-th column constituting the display device, the first light-emitting element 211 and the second light-emitting element 211 ′ constituting the display element 210 operate normally. It is the figure which showed the state when it is during. FIG. 12B shows the display element 210 in the m-th row and the n-th column that constitutes the display device, but the first light-emitting element 211 that constitutes the display element 210 is operating normally, but the second light emission. It is the figure which showed typically the state when 2nd light emission part ELP 'which comprises element 211' has raise | generated the open defect. For convenience, in FIG. 12A and FIG. 12B, illustration of the capacities of the light emitting portions ELP and ELP ′ is omitted.

  With reference to FIGS. 12A and 12B, the operation of the display element 210 constituting the display device of Example 2 will be described. For convenience of explanation, it is assumed that the transistor 215 and the transistor 216 constituting the current increasing unit 213 have substantially the same electrical characteristics in design as in the first embodiment.

  With reference to FIG. 12A, an operation when the first light emitting element 211 and the second light emitting element 211 'are operating normally will be described.

As described in the first embodiment, the predetermined video signal V _Sig is supplied from the signal output circuit 102 to the first drive transistor via the write transistors TR _W and TR _W ′ which are turned on by the signal from the scanning line SCL _m. It is applied to the gate electrode of the gate electrode and the second driving transistor TR _D 'of the TR _D. Thereafter, even if the write transistors TR _W and TR _W ′ are turned off, the voltage between the gate electrode and the source region of the first drive transistor TR _D and the second drive are generated by the capacitors C ₁ and C ₁ ′. The voltage between the gate electrode and the source region of the transistor TR _D ′ is held at a predetermined voltage according to the video signal V _Sig .

Further, as described in Example 1, the current flowing through the first light emitting section ELP through the first driving transistor TR _D is the drain current I _ds from the drain region of the first driving transistor TR _D flows into the source region is there. If the first drive transistor TR _D ideally operates in the saturation region, the drain current I _ds can be expressed by the above-described equation (1). Since the voltage between the source region and the gate electrode of the second drive transistor TR _D ′ is similar to the voltage between the source region and the gate electrode of the first drive transistor TR _D , I _ds ′ = I _ds is there.

As described in the first embodiment, the auxiliary transistor 214 operates ideally in the saturation region, and if the current value is not limited by the transistors 215 and 216, the drain current I _ad flowing through the auxiliary transistor 214 = I _ds .

However, in the second embodiment, the transistors 215 and 216 are n-channel transistors. One source / drain region of the transistors 215 and 216 is in a state of being connected to the power supply line PS1 _m to which the voltage V _CC is applied via the auxiliary transistor 214 in the on state. Basically, the transistors 215 and 216 are connected. A voltage lower than the voltage applied to one of the source / drain regions of the transistors 215 and 216 is applied to the other source / drain region and the gate electrode. Accordingly, the transistor 215 and the transistor 216 are in an off state, and the values of the off resistance are the same. A current I _ad whose value is limited to a leakage current flows through the auxiliary transistor 214. Current I _{AD_B} flowing in the current I _{AD_A} the transistor 216 flowing through the transistor 215 are both I _ad / 2.

The first light emitting section ELP, the current I _{AD_A} flows in addition to the current I _ds, ', the current I _ds' second light emitting section ELP current flows I _{AD_B} in addition to. If the value of the current I _ad shown in FIG. 12A is sufficiently small, currents corresponding to I _ds flow in the first light emitting unit ELP and the second light emitting unit ELP ′, respectively. Both the first light emitting unit ELP and the second light emitting unit ELP ′ emit light at a luminance corresponding to a current value corresponding to I _ds .

Next, with reference to FIG. 12B, an operation when one of the light emitting units is not operating normally will be described. More specifically, the operation when the second light emitting unit ELP ′ has an open defect will be described. In FIG. 12B, the drain current flowing through the second drive transistor TR _D ′ is not shown.

As shown in FIG. 12B, the state in which the second light emitting unit ELP ′ is defective in opening is typically connected in series with the open resistance R _Opn . Can be expressed as Here, if R _Opn is sufficiently large, the voltage at the connection between the second light emitting unit ELP ′ and the second drive transistor TR _D ′ is approximately V _CC (= 20 volts). In this state, the voltage of the gate electrode of the transistor 215 is higher than that in the state illustrated in FIG. On the other hand, the voltage of the gate electrode of the transistor 216 basically does not change so much.

Accordingly, the transistor 215 is turned on. If the value of the current flowing through the auxiliary transistor 214 is not limited by the transistors 215 and 216, the drain current I _ad = I _ds flowing through the auxiliary transistor 214, most of which flows through the transistor 215. Thereby, the other light emitting element 211 that operates normally operates to emit light with higher luminance. Although depending on the threshold voltage setting of the transistors 215 and 216, etc., for example, in FIG. 12B, if most of the current flows through the transistor 215, the first light emitting unit ELP corresponds to approximately 2 × _Ids . Light is emitted at a luminance corresponding to the current value.

  As described above, in the second embodiment, without complicating the configuration of the peripheral circuit of the display device, when one light emitting unit does not operate normally due to an open failure, the other operates normally. The light emitting element can be made to emit light with higher brightness than originally intended. Even when one of the first light emitting unit ELP and the second light emitting unit ELP ′ is in a short-circuited state and the light-emitting unit in a short-circuited state and the drive circuit are separated by a known technique such as laser repair, the above-mentioned Works as it did.

  In Example 2, even if some of the light emitting portions are in a non-light emitting state due to malfunction, the light emitting region in the display element is not visually recognized as being missing. Therefore, even if a part of the light emitting portions is in a non-light emitting state due to a malfunction, the light emitting region is not visually recognized as being partly missing.

  The third embodiment is also a modification of the first embodiment. Example 3 also relates to the display element of the present invention and the display device of the present invention. The display element of Example 3 is mainly different from the display element of Example 1 in that the current increasing means includes third switching means.

  FIG. 13 shows an equivalent circuit diagram of the display element 310 in the m-th row and the n-th column constituting the display device according to the third embodiment. FIG. 14 shows a conceptual diagram of the display device of Example 3 including the display element 310.

  As shown in FIG. 13, the display element 310 according to the third embodiment also includes a current increasing unit 313. The configuration of the auxiliary transistor 314 illustrated in FIG. 13 is the same as the configuration of the auxiliary transistor 114 described in the first embodiment. The configurations of the first switching means 315 and the second switching means 316 are the same as the configurations of the first switching means 115 and the second switching means 116 described in the first embodiment. Description of these will be omitted.

As described with reference to FIG. 1 in the first embodiment, in the display element 110 of the first embodiment, one source / drain region of the auxiliary transistor 114 constituting the current increasing means 113 is directly connected to the feed line PS1 _m. It is connected to the. On the other hand, in the third embodiment, the current increasing unit 313 further includes a third switching unit 317. The third switching means 317 is connected between one source / drain region of the auxiliary transistor 314 and the power supply line PS1 _m to which the first voltage V _CC is applied.

That is, in the display element 310 according to the third embodiment, one end of the third switching unit 317 is connected to one source / drain region of the auxiliary transistor 314, and the first voltage V _CC is the third switching. Applied to one source / drain region of the auxiliary transistor 314 via the means 317. In the third embodiment, the third switching means 317 is composed of an n-channel transistor, like the write transistors TR _W and TR _W ′. Hereinafter, for convenience of description, a transistor constituting the third switching unit 317 is simply referred to as a transistor 317. A gate electrode of the transistor 317 is connected to a control line CL _m connected to the second scanning circuit 300. In addition to the differences described above, the configuration of the display element 310 of the third embodiment is the same as that described in the display element 110 of the first embodiment.

  As described above, the configurations of the first light emitting element 311 and the first drive circuit 312 shown in FIG. 13 are the same as those of the first light emitting element 111 and the first drive circuit 112 described in the first embodiment. Similarly, the configurations of the second light emitting element 311 'and the second drive circuit 312' shown in FIG. 13 are the same as those of the second light emitting element 111 'and the second drive circuit 112' described in the first embodiment. Description of these will be omitted.

If current increasing means 313 and the control line CL _m and the like are hidden in the sectional view, schematic partial cross-sectional view of a display device of Example 3 is also similar to FIG. 3 referred to in Example 1. That is, in FIG. 3, the display element 110 is the display element 310, the first light emitting element 111 is the first light emitting element 311, the second light emitting element 111 ′ is the second light emitting element 311 ′, and the current increasing means 113 is the current increasing means. This is the same as replacing the means 313. A schematic partial cross-sectional view of the display device of Example 3 is omitted.

As shown in equation (1) described in Example 1, the drain current flowing through the first driving transistor TR _D, the value of the voltage V _gs between the source region and the gate electrode of the first driving transistor TR _D, and , _{Determined by} the value of the threshold voltage V _th . The same applies to the second drive transistor TR _D ′. Therefore, even if the value of the voltage V _gs between the source region and the gate electrode is the same, if the threshold voltage V _th of the transistor TR _{D and the} like varies, the luminance of the display element also varies. Thereby, the uniformity of the brightness | luminance of the image displayed on a display apparatus deteriorates. When the transistor TR _D or the like is composed of TFTs, it is difficult to avoid that the threshold voltage varies to some extent.

For this reason, various driving methods for driving the display element so that variations in the threshold voltage of the transistor do not affect the drain current have been proposed. In such a display element driving method, for example, a step of applying an initialization voltage or the like having a value different from the value of the first voltage V _{CC to} one source / drain region of the transistors TR _D and TR _D ′. Is required. However, in performing such a process, if the initialization voltage or the like is still applied to the auxiliary transistor 314, the operation may be inconvenient.

In the third embodiment, the transistor 317 constituting the third switching means is connected between one source / drain region of the auxiliary transistor 314 and the power supply line PS1 _m to which the first voltage V _CC is applied. . Therefore, for example, when the above-described initialization voltage or the like is applied to the power supply line PS1 _m , the signal from the second scanning circuit 300 is applied to the gate electrode of the transistor 317 via the control line CL _m , and the transistor 317 is Turn off. On the other hand, when the first voltage V _CC is applied to the feeder line PS1 _m , the transistor 317 is turned on. Accordingly, the display element can be driven without causing any particular inconvenience so that the variation in the threshold voltage V _th of the transistor does not affect the drain current. The timing at which the third switching means 317 is controlled may be appropriately set according to the specifications of the display element and the display device and the driving method.

  The fourth embodiment is also a modification of the first embodiment. Example 4 also relates to the display element of the present invention and the display device of the present invention. The display element according to the fourth embodiment is the same as the display element according to the first embodiment except that the stacked structure of the first light emitting unit ELP and the second light emitting unit ELP ′ is different from the display element according to the first embodiment.

  FIG. 15 is a schematic partial cross-sectional view of the display device according to the fourth embodiment. The equivalent circuit diagram of the display element 410 in the m-th row and the n-th column constituting the display device of Example 4 is the same as FIG. 1 referred to in Example 1, except that the display element 110 is the display element 410 and the first light emitting element. 111, the first light emitting element 411, the second light emitting element 111 ′, the second light emitting element 411 ′, the first drive circuit 112, the first drive circuit 412, and the second drive circuit 112 ′, the second drive circuit 412 ′. This is the same as replacing the current increasing means 113 with the current increasing means 413. An equivalent circuit diagram of the display element 410 of Example 4 is omitted. Further, the conceptual diagram of the display device according to the fourth embodiment is the same as that in which the reference numbers are replaced as described above. The conceptual diagram of the display device of Example 4 is also omitted.

  The configurations of the first drive circuit 412 and the second drive circuit 412 'are the same as the configurations of the first drive circuit 112 and the second drive circuit 112' described in the first embodiment. The configuration of the current increasing unit 413 is the same as the configuration of the current increasing unit 113 described in the first embodiment. Description of these will be omitted. Further, the operation of the display device 410 is the same as the operation of the display element 110 described in the first embodiment, and thus the description thereof is omitted.

  As will be described later, the first intermediate electrode constituting the display element 410 of Example 4 has the same configuration as the intermediate electrode 55 described in Example 1. For convenience of explanation, in the fourth embodiment, the first intermediate electrode is also described with reference numeral 55.

As shown in FIG. 15, the first light emitting unit ELP
(D-1) Lower electrode 51,
(D-2) a first organic layer 54 including a light emitting layer provided on the lower electrode 51, and
(D-3) a first intermediate electrode 55 having optical transparency provided on the first organic layer 54;
Consists of
The second light emitting unit ELP ′
(E-1) A second intermediate electrode 455 having light transmittance, which is provided on the first intermediate electrode 55 via an insulating layer 445 having light transmittance.
(E-2) a second organic layer 457 including a light emitting layer provided on the second intermediate electrode 455, and
(E-3) Upper electrode 458,
It is composed of In addition, at least one of the lower electrode 51 and the upper electrode 458 has light transmittance. The display device of Example 4 is also a top emission type, and the upper electrode 458 is light transmissive.

The transistors constituting the first drive circuit 412 and the second drive circuit 412 ′, the capacitors C ₁ and C ₁ ′, and the transistors constituting the current increasing means 413 are formed on the support 20. For example, the first light emitting unit ELP and the second light emitting unit ELP ′ are formed above the transistors and the capacitor units C ₁ and C ₁ ′ with the interlayer insulating layer 41 interposed therebetween. In FIG. 15, the first drive transistor TR _D and the capacitor unit C ₁ constituting the first drive circuit 412 are shown. Other transistors and capacitors are hidden and cannot be seen.

  In the fourth embodiment, the lower electrode 51 and the first intermediate electrode 55 constitute an anode electrode and a cathode electrode of the first light emitting unit ELP, respectively, and the second intermediate electrode 455 and the upper electrode 458 are respectively A description will be given assuming that the anode electrode and the cathode electrode of the second light emitting unit ELP ′ are configured. In addition, by changing the polarity of the organic layer, the lower electrode 51 and the first intermediate electrode 55 constitute a cathode electrode and an anode electrode of the first light emitting part ELP, respectively, and the second intermediate electrode 455 and the upper electrode 458 The cathode electrode and the anode electrode of the second light emitting unit ELP ′ can be respectively configured.

This will be described with reference to FIG. As in the first embodiment, the driving transistor TR _D , the capacitor C _1, etc. are covered with the interlayer insulating layer 41. A first light emitting unit ELP is provided on the interlayer insulating layer 41. A wiring 53 corresponding to the power supply line PS2 is provided on the interlayer insulating layer 41. A second interlayer insulating layer 42 is provided on the portion of the interlayer insulating layer 41 where the first light emitting unit ELP is not provided. The lower electrode 51 constituting the anode electrode of the first light emitting unit ELP is connected to the electrode 38 through a contact plug 52 provided in the interlayer insulating layer 41. The first intermediate electrode 55 constituting the cathode electrode of the first light emitting unit ELP is connected to the wiring 53 constituting the feeder line PS2 through the contact plug 56 provided in the second interlayer insulating layer 42. The above structure is the same as that described in the first embodiment.

  In Example 4, a light-transmitting insulating layer 445 is formed on the entire surface including the first light emitting unit ELP. Further, a second intermediate electrode 455, a second organic layer 457, and an upper electrode 458 are stacked thereon to constitute a second light emitting unit ELP '. A third interlayer insulating layer 446 is provided on the portion of the insulating layer 445 where the second light emitting unit ELP 'is not provided. The second intermediate electrode 455 constituting the anode electrode of the second light emitting unit ELP ′ is connected to the electrode 38 ′ via the insulating layer 445, the second interlayer insulating layer 42, and the contact plug 456 provided in the interlayer insulating layer 41. It is connected. The upper electrode 458 constituting the cathode electrode of the second light emitting unit ELP ′ is connected to the third interlayer insulating layer 446, the insulating layer 445, and the contact plug 459 provided in the second interlayer insulating layer 42 (shown in the figure). In the example, it is further connected via a contact plug 56) to the wiring 53 constituting the feeder line PS2. An insulating protective film 447 is provided on the entire surface including the second light emitting unit ELP ′ and the third interlayer insulating layer 446. A substrate 60 made of, for example, glass is disposed on the protective film 447. The protective film 447 and the substrate 60 are bonded to each other by an adhesive layer 44 made of an ultraviolet curable adhesive. The emitted light passes through the substrate 60 and is emitted to the outside.

  Unlike the first embodiment, in the display element 410 of the fourth embodiment, the first organic layer 54 and the second organic layer 457 have the same polarity. Thereby, there is an advantage that the manufacturing process of the first organic layer 54 and the second organic layer 457 can be made common.

  The outline of the manufacturing method of the display device and the display element 410 of Example 4 will be described below with reference to FIGS. 16 (A) and 16 (B), FIGS. 17 (A) and 17 (B), and FIGS. ), (A) and (B) in FIG. 19, and (A) and (B) in FIG.

[Step-400]
First, similarly to [Step-100] to [Step-130] of the first embodiment, the structure shown in FIG. 7A referred to in the first embodiment is obtained.

[Step-410] (see (A) and (B) of FIG. 16)
Next, the first organic layer 54 and the first intermediate electrode 55 are formed. First, basically the same process as [Process-140] of Example 1 is performed to form the first organic layer 54. The opening 56 ′ described in the first embodiment is formed, and the second interlayer insulating layer 42 corresponding to the opening 456 ′ described later is removed. Thereafter, the same process as [Process-150] in Example 1 is performed to form the first intermediate electrode 55. That is, in a state where a metal mask (not shown) for forming the first intermediate electrode 55 is disposed above the second interlayer insulating layer 42, the first organic layer 54 is not affected. The first intermediate electrode 55 is formed on the basis of a vacuum deposition method, which is a film forming method in which the energy of the film forming particles is small. The first intermediate electrode 55 is electrically connected to the wiring 53 via the contact plug 56.

[Step-420] (see FIG. 17A)
Next, the light-transmitting insulating layer 445 is formed over the entire surface. In the fourth embodiment, the insulating layer 445 made of silicon nitride (Si _1-x N _x ) is formed based on the CVD method. The formation of the insulating layer 445 is continuously performed without exposing the first intermediate electrode 55 to the atmosphere, so that deterioration of the first organic layer 54 and the like due to moisture and oxygen in the atmosphere can be prevented. In the case where damage due to CVD becomes a problem, the insulating layer 445 may be formed by, for example, a vacuum evaporation method.

[Step-430] (see FIG. 17B and FIG. 18A)
Thereafter, the second intermediate electrode 455 is formed. First, an opening 456 ′ with an electrode 38 ′ exposed at the bottom is formed by an etching method. In addition, a portion of the insulating layer 445 corresponding to an opening 459 ′ described later is removed. Next, a second intermediate electrode 455 made of ITO is formed on the insulating layer 445 based on a combination of vacuum deposition and etching. The second intermediate electrode 455 is electrically connected to the electrode 38 ′ via a contact plug 456 provided in the opening 456 ′. Note that the opening 456 ′ may be formed by forming the insulating layer 445 using a mask in order to avoid damage due to etching. Similarly, the second intermediate electrode 455 may be formed using a mask.

[Step-440] (see FIG. 18B)
Thereafter, a third interlayer insulating layer 446 is formed on the entire surface. Specifically, a third interlayer insulating layer 446 made of polyimide resin having a thickness of 1 μm is formed based on the spin coating method in the same manner as in [Step-130] of Example 1.

[Step-450] (see FIGS. 19A and 19B)
Next, an opening 457 ′ in which the second intermediate electrode 455 is exposed at the bottom is formed by an etching method in the same process as [Step-140] in the first embodiment. At the same time, an opening 459 ′ with the contact plug 56 exposed at the bottom is formed by etching. Note that the wiring 53 may be exposed at the bottom of the opening 459 ′.

  In [Step-440], the opening 457 'or the like may be formed by forming the third interlayer insulating layer 446 using, for example, a vacuum evaporation method using a mask. In this case, [Step-450] is not necessary.

  The portion of the third interlayer insulating layer 446 surrounding the opening 457 'preferably forms a gentle slope. Thereafter, the second organic layer 457 is formed over the portion of the third interlayer insulating layer 446 surrounding the opening 457 ′ from the portion of the second intermediate electrode 455 exposed at the bottom of the opening 457 ′.

  In Example 1, when the second organic layer was formed, the order of stacking the first organic layer was reversed. On the other hand, in Example 4, the second organic layer is laminated in the same manner as the first organic layer. Therefore, the formation process of the first organic layer and the second organic layer can be shared.

[Step-460] (see FIG. 20A)
Next, the upper electrode 458 is formed. In the same manner as in [Step-170] in Example 1, with respect to the second organic layer 457, a metal mask (not shown) for forming the upper electrode 458 is disposed above the second organic layer 457. The upper electrode 458 is formed for each display element 410 constituting the sub-pixel based on a vacuum deposition method, which is a film forming method in which the energy of the film forming particles is small enough to prevent the influence of the above. By continuously forming the upper electrode 458 in the same vacuum deposition apparatus as the formation of the second organic layer 457 without exposing the second organic layer 457 to the atmosphere, the second organic layer 457 is formed by the moisture and oxygen in the atmosphere. Deterioration of the organic layer 457 and the like can be prevented. Specifically, the upper electrode 458 can be obtained by forming a vapor deposition film similar to the first intermediate electrode 55. The upper electrode 458 is electrically connected to the wiring 53 through a contact plug 459. Note that the upper electrode 458 may be provided as an electrode common to the plurality of display elements 410.

[Step-470] (see FIG. 20B)
Thereafter, in the same manner as in [Step-180] in Example 1, an insulating protective film 447 made of silicon nitride (Si _1-x N _x ) is formed on the entire surface based on a vacuum deposition method. The formation of the protective film 447 is continuously performed in the same vacuum deposition apparatus as the formation of the upper electrode 458 without exposing the upper electrode 458 to the atmosphere, whereby the second organic layer 457 due to moisture and oxygen in the atmosphere. Etc. can be prevented.

[Step-480]
Next, in the same manner as in [Step-190] in Example 1, the protective film 447 and the substrate 60 are bonded by the adhesive layer 44 made of an ultraviolet curable adhesive. Finally, the display device shown in FIG. 15 can be completed by connecting to an external circuit.

  As mentioned above, although this invention was demonstrated based on the preferable Example, this invention is not limited to this Example. The configurations, structures, manufacturing methods, materials constituting the display device and the display element, and the like of the display device and the display element in the embodiments are examples and can be changed as appropriate.

  For example, the display elements shown in Examples 1 to 4 may have a configuration in which the relationship between the cathode electrode and the anode electrode is changed by changing the polarity of the organic layer.

In the first embodiment, each of the first drive circuit 112 and the second drive circuit 112 ′ includes the write transistor and the capacitor, but the present invention is not limited to this. The structure with which either one is provided may be sufficient. For example, as shown in FIG. 21, only the first drive circuit 112 may include a write transistor TR _W and a capacitor C ₁ . The same applies to the second to fourth embodiments.

In the first to fourth embodiments, the first drive transistor TR _D and the second drive transistor TR _D ′ are p-channel transistors. However, the present invention is not limited to this. The first drive transistor TR _D and the second drive transistor TR _D ′ may be composed of n-channel transistors. In this case, the auxiliary transistor constituting the current increasing means is also composed of an n-channel transistor. FIG. 22 is an equivalent circuit diagram of the display element of Example 1 when the first drive transistor TR _D and the second drive transistor TR _D ′ are configured by n-channel transistors. FIG. 23 is an equivalent circuit diagram of the display element of Example 2 in the case where the first drive transistor TR _D and the second drive transistor TR _D ′ are composed of n-channel transistors. FIG. 24 is an equivalent circuit diagram of the display element of Example 3 in the case where the first drive transistor TR _D and the second drive transistor TR _D ′ are configured by n-channel transistors. In these configurations, the other electrodes of the capacitors C ₁ and C ₁ ′ are connected to the other source / drain regions of the transistors TR _D and TR _D ′, respectively.

FIG. 1 is an equivalent circuit diagram of the display element in the m-th row and the n-th column constituting the display device of the first embodiment. FIG. 2 is a conceptual diagram of the display device according to the first embodiment. FIG. 3 is a schematic partial cross-sectional view of the display device according to the first embodiment. FIG. 4A shows a state in which the first light-emitting element and the second light-emitting element constituting the display element are operating normally in the m-th row and n-th column display element constituting the display device. FIG. FIG. 4B shows a display element of the m-th row and the n-th column that constitutes the display device, but the first light-emitting element that constitutes the display element is operating normally, but the second light-emitting element is constituted. It is the figure which showed typically the state when the 2nd light emission part to raise | generate has produced the short circuit defect. 5A to 5C are schematic partial end views of a support and the like for explaining the method for manufacturing the display device of Example 1. FIG. 6A and 6B are schematic partial end views of a support and the like for explaining the manufacturing method of the display device of Example 1 following FIG. 5C. 7A and 7B are schematic partial end views of a support and the like for explaining the manufacturing method of the display device of Example 1 following FIG. 6B. FIGS. 8A and 8B are schematic partial end views of a support and the like for explaining the manufacturing method of the display device of Example 1 following FIG. 7B. FIGS. 9A and 9B are schematic partial end views of a support and the like for explaining the manufacturing method of the display device of Example 1 following FIG. 8B. FIGS. 10A and 10B are schematic partial end views of a support and the like for explaining the manufacturing method of the display device of Example 1 following FIG. 9B. FIG. 11 is an equivalent circuit diagram of the display element in the m-th row and the n-th column constituting the display device of the second embodiment. FIG. 12A shows a state in which the first light-emitting element and the second light-emitting element constituting the display element are operating normally in the m-th row and n-th column display element constituting the display device. FIG. FIG. 12B shows a display element in the m-th row and the n-th column that constitutes the display device, but the first light-emitting element that constitutes the display element is operating normally, but the second light-emitting element is constituted. It is the figure which showed typically the state when the 2nd light emission part to raise | generate has produced the open defect. FIG. 13 is an equivalent circuit diagram of the display element in the m-th row and the n-th column constituting the display device according to the third embodiment. FIG. 14 is a conceptual diagram of a display device according to the third embodiment. FIG. 15 is a schematic partial cross-sectional view of the display device according to the fourth embodiment. FIGS. 16A and 16B are schematic partial end views of a support and the like for explaining the manufacturing method of the display device of Example 4. FIGS. 17A and 17B are schematic partial end views of a support and the like for explaining the manufacturing method of the display device of Example 4 following FIG. 16B. 18A and 18B are schematic partial end views of a support and the like for explaining the manufacturing method of the display device of Example 4 following FIG. 17B. FIGS. 19A and 19B are schematic partial end views of a support and the like for explaining the manufacturing method of the display device of Example 4 following FIG. 18B. 20A and 20B are schematic partial end views of a support and the like for explaining the manufacturing method of the display device of Example 4 following FIG. 19B. FIG. 21 is an equivalent circuit diagram of the display element of Example 1 in which only the first drive circuit includes the write transistor and the capacitor. FIG. 22 is an equivalent circuit diagram of the display element of Example 1 in which the first drive transistor and the second drive transistor are composed of n-channel transistors. FIG. 23 is an equivalent circuit diagram of the display element of Example 2 in which the first drive transistor and the second drive transistor are composed of n-channel transistors. FIG. 24 is an equivalent circuit diagram of the display element of Example 3 in which the first drive transistor and the second drive transistor are composed of n-channel transistors. FIG. 25 is a conceptual diagram of an active matrix display device using an organic EL display element including a drive circuit. FIG. 26 is an equivalent circuit diagram of the organic EL display element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Organic EL display element, 11 ... Drive circuit, 20 ... Support body, 31 ... Gate electrode, 32, 32 '... Gate insulating layer, 33, 33' ... Semiconductor layer , 34, 34 '... channel formation region, 35, 35' ... source / drain region, 36, 36 '... source / drain region, 37, 37' ... electrode, 38, 38 '. ..Electrode, 39... Wiring, 41 .. interlayer insulating layer, 42... Second interlayer insulating layer, 43 .. protective film, 44 .. adhesive layer, 51. Contact plug, 52 '... opening, 53 ... wiring, 54 ... first organic layer, 54' ... opening, 55 ... intermediate electrode (first intermediate electrode), 56 ... contact plug, 56 '... opening, 57 ... second organic layer, 58 ... upper electrode, 59 ... contour Plug, 59 '... opening, 60 ... substrate, 445 ... insulating layer, 446 ... third interlayer insulating layer, 447 ... protective film, 455 ... second intermediate electrode, 456 ... Contact plug, 456 '... Opening portion, 457 ... Second organic layer, 457' ... Opening portion, 458 ... Upper electrode, 459 ... Contact plug, 459 '... Opening part, 100 ... Power supply part, 101 ... Scanning circuit, 102 ... Signal output circuit, 300 ... Second scanning circuit, 110,210,310,410 ... Display element, 111,211 , 311, 411... 1st light emitting element, 111 ′, 211 ′, 311 ′, 411 ′... Second light emitting element, 112, 212, 312, 412. ', 312', 412 '... 2nd drive circuit, 113, 21 , 313, 413 ... current increasing means, 114, 214, 314 ... auxiliary transistors, 115, 215, 315 ... first switching means (transistors), 116, 216, 316 ... second switching means. (Transistor), 317 ... third switching means (transistor), SCL ... scanning line, DTL ... data line, PS1 ... feed line, PS2 ... feed line, CL ... control line , ELP: light emitting unit (first light emitting unit), ELP ′: second light emitting unit, C _EL : capacity of light emitting unit (first light emitting unit), C _EL ′: second light emitting unit Capacitance, C ₁ , C ₁ ′, capacitance, TR _W , TR _W ′, write transistor, TR _D, drive transistor (first drive transistor), TR _D ′, second drive transistor

Claims (12)

A first light-emitting element and a second light-emitting element;
The first light emitting element includes a current-driven first light emitting unit and a first drive circuit connected to the first light emitting unit,
The second light emitting element includes a current-driven second light emitting unit and a second drive circuit connected to the second light emitting unit,
A display element comprising current increasing means for increasing a current flowing through the other light emitting unit when one of the first light emitting unit and the second light emitting unit is not operating normally.   2. The display according to claim 1, wherein the current increasing unit operates based on a voltage at a connection portion between the first light emitting portion and the first drive circuit and a voltage at a connection portion between the second light emission portion and the second drive circuit. element. The first drive circuit includes a first drive transistor,
In the first drive transistor, a first voltage is applied to one source / drain region, and the other source / drain region is connected to one end of the first light emitting unit,
The second drive circuit includes a second drive transistor,
In the second drive transistor, the first voltage is applied to one source / drain region, and the other source / drain region is connected to one end of the second light emitting unit,
A second voltage is applied to the other end of the first light emitting unit and the other end of the second light emitting unit,
Current increasing means is
(A) an auxiliary transistor, and
(B) first switching means and second switching means;
Consists of
In the auxiliary transistor,
(A-1) The gate electrode is connected to the gate electrode of the first drive transistor and the gate electrode of the second drive transistor,
(A-2) The first voltage is applied to one source / drain region,
(A-3) The other source / drain region is connected to the connection between the first light emitting unit and the first drive transistor via the first switching means, and the second light emission via the second switching means. Connected to the connecting portion between the second driving transistor and the second driving transistor,
The first switching means operates based on the voltage of the connection portion between the second light emitting unit and the second drive transistor,
The display element according to claim 2, wherein the second switching unit operates based on a voltage at a connection portion between the first light emitting unit and the first drive transistor. Each of the first switching means and the second switching means is composed of transistors of the same conductivity type,
The gate electrode of the transistor constituting the first switching means is connected to the connection part between the second light emitting part and the second drive transistor,
4. The display element according to claim 3, wherein the gate electrode of the transistor constituting the second switching means is connected to a connection portion between the first light emitting portion and the first drive transistor. At least one of the first drive circuit and the second drive circuit further includes a write transistor,
In the writing transistor, a video signal is applied to one source / drain region, a scanning signal is applied to the gate electrode,
5. The display element according to claim 3, wherein the gate electrode of the first drive transistor and the gate electrode of the second drive transistor are connected to the other source / drain region of the write transistor.   6. The display element according to claim 3, further comprising a capacitor for holding the potentials of the gate electrode of the first drive transistor and the gate electrode of the second drive transistor. 7. The current increasing means further includes third switching means,
One end of the third switching means is connected to one source / drain region of the auxiliary transistor, and the first voltage is applied to one source / drain region of the auxiliary transistor via the third switching means. The display element according to any one of claims 3 to 6.   The display element according to claim 1, wherein the first light emitting unit and the second light emitting unit are organic electroluminescent light emitting units.   The display element according to claim 8, wherein the first light emitting unit and the second light emitting unit are stacked. The first light emitting unit
(D-1) Lower electrode,
(D-2) a first organic layer including a light emitting layer provided on the lower electrode; and
(D-3) a light transmissive intermediate electrode provided on the first organic layer,
Consists of
The second light emitting unit
(E-1) the intermediate electrode,
(E-2) a second organic layer including a light emitting layer provided on the intermediate electrode, and
(E-3) an upper electrode provided on the second organic layer,
Consists of
At least one of the lower electrode and the upper electrode has optical transparency,
The display element according to claim 9, wherein the intermediate electrode constitutes an anode electrode of the first light emitting part and the second light emitting part, or alternatively, the intermediate electrode constitutes a cathode electrode of the first light emitting part and the second light emitting part. . The first light emitting unit
(D-1) Lower electrode,
(D-2) a first organic layer including a light emitting layer provided on the lower electrode; and
(D-3) a first intermediate electrode having optical transparency provided on the first organic layer;
Consists of
The second light emitting unit
(E-1) a second intermediate electrode having light transmittance, provided on the first intermediate electrode through an insulating layer having light transmittance;
(E-2) a second organic layer including a light emitting layer provided on the second intermediate electrode, and
(E-3) Upper electrode,
Consists of
The display element according to claim 9, wherein at least one of the lower electrode and the upper electrode has light transmittance. (1) N display elements arranged in a first direction, M pieces in a second direction different from the first direction, and a total of N × M display elements arranged in a two-dimensional matrix,
(2) M scanning lines extending in the first direction, and
(3) N data lines extending in the second direction;
With
The display element is composed of a first light emitting element and a second light emitting element,
The first light emitting element includes a current-driven first light emitting unit and a first drive circuit connected to the first light emitting unit,
The second light emitting element includes a current-driven second light emitting unit and a second drive circuit connected to the second light emitting unit,
A common scanning signal is applied from the mth scanning line to the first light emitting element and the second light emitting element constituting the display element in the mth row and the nth column, and from the nth data line. A common video signal is applied,
The display element includes a current increasing unit that increases a current flowing through the light emitting unit constituting the other light emitting element when the light emitting unit of one of the first light emitting element and the second light emitting element is not operating normally. A display device comprising:

Images