JP2010103472A - Organic el display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display device that is improved in numerical aperture of sub-pixels while increasing the number of elements of G with high visibility. <P>SOLUTION: The organic EL display device comprises a substrate 10 and a plurality of pixels 11 provided on the substrate 10, wherein each pixel 11 comprises a first sub-pixel 11a and a second sub-pixel 11b, the first sub-pixel 11a being formed by laminating an R organic EL element portion 18r and a G1 organic EL element portion 17g and the second sub-pixel 11b being formed by laminating a G2 organic EL element portion 18g and a B organic EL element portion 17b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic EL display device.

  In an organic EL display device composed of R (red), G (green), and B (blue), which are the three primary colors, in order to increase the resolution, the number of G subpixels with high field sensitivity is set to other subpixels ( Conventionally, a configuration in which the number is larger than R and B) has been proposed. For example, Patent Document 1 discloses a configuration in which one pixel is juxtaposed in the order of GRGB. With this configuration, the resolution is improved.

JP 2004-117431 A

  However, by increasing the number of G subpixels with high visibility in order to increase the resolution, for example, one pixel is composed of four subpixels. As a result, the aperture ratio of the sub-pixel itself is reduced as compared with a pixel composed of three conventional sub-pixels. Here, when the aperture ratio of the sub-pixel decreases, the current density flowing through the light-emitting element forming one sub-pixel increases, which causes a problem that the deterioration of the light-emitting element is accelerated.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an organic EL display device in which the total area of the light emitting elements is improved while increasing the number of G light emitting elements having high visibility. It is.

The organic EL display device of the present invention includes a substrate,
A plurality of pixels provided on the substrate,
The pixel is composed of a first subpixel and a second subpixel,
The first subpixel is configured by laminating an R organic EL element part and a G1 organic EL element part,
The second subpixel is formed by stacking a G2 organic EL element part and a B organic EL element part,
The R organic EL element portion includes an anode, a cathode, and an R organic compound layer that is sandwiched between the anode and the cathode and includes at least an R light emitting layer,
The G1 organic EL element part and the G2 organic EL element part have an anode and a cathode, and a G organic compound layer including at least a G light-emitting layer sandwiched between the anode and the cathode,
The B organic EL element portion comprises an anode, a cathode, a B organic compound layer including at least a B light-emitting layer sandwiched between the anode and the cathode;
It is characterized by having.

  ADVANTAGE OF THE INVENTION According to this invention, the organic EL display apparatus which improved the total area of the light emitting element, increasing the number of G light emitting elements with high visibility can be provided.

1 is a schematic cross-sectional view showing a first embodiment of an organic EL display device of the present invention. It is the schematic which shows the layout of the pixel arrangement, the scanning line, and the data line which are provided in the active matrix type organic EL display device which is the first embodiment. FIG. 2 is a circuit diagram illustrating an example of a pixel circuit for driving the organic EL display device of FIG. 1. It is a figure which shows the sequence which drives the pixel circuit of FIG. It is a figure which shows the timing chart which shows operation | movement of a pixel circuit. It is a flowchart which shows an example of the control system of each data line. It is a cross-sectional schematic diagram which shows 2nd embodiment in the organic electroluminescence display of this invention. FIG. 8 is a circuit diagram illustrating an example of a pixel circuit for driving the organic EL display device of FIG. 7.

  Hereinafter, embodiments of a display device according to the present invention will be described with reference to the drawings. Note that well-known or publicly-known techniques in the technical field can be applied to portions that are not particularly illustrated or described in the present specification. The embodiment described below is only one of the embodiments, and the present invention is not limited thereto.

  The organic EL display device of the present invention includes a substrate and a plurality of pixels provided on the substrate.

  In the organic EL display device of the present invention, the pixel includes a first subpixel and a second subpixel.

  Here, the first subpixel constituting the pixel is a member formed by laminating an R organic EL element portion that outputs red light emission and a G1 organic EL element portion that outputs green light emission. However, in the present invention, the lamination type of these two kinds of organic EL element portions is not particularly limited.

  On the other hand, the second subpixel constituting the pixel is a member formed by laminating a G2 organic EL element portion that outputs green light emission and a B organic EL element portion that outputs blue light emission. However, in the present invention, the lamination type of these two kinds of organic EL element portions is not particularly limited.

  The R organic EL element portion included in the first subpixel is an organic EL element having an anode, a cathode, and an R organic compound layer that is sandwiched between the anode and the cathode and includes at least an R light emitting layer. is there. The G1 organic EL element portion included in the first sub-pixel includes an anode, a cathode, and a G organic compound layer that is sandwiched between the anode and the cathode and includes at least a G light emitting layer. It is.

  On the other hand, the G2 organic EL element portion included in the second subpixel includes an anode, a cathode, and a G organic compound layer that is sandwiched between the anode and the cathode and includes at least a G light emitting layer. It is an element. Further, the B organic EL element portion included in the second subpixel includes an anode, a cathode, and a B organic compound layer that is sandwiched between the anode and the cathode and includes at least a B light emitting layer. It is.

  Hereinafter, the organic EL display device of the present invention will be described with reference to the drawings.

[First embodiment]
FIG. 1 is a schematic cross-sectional view showing a first embodiment of the organic EL display device of the present invention. The organic EL display device 1 in FIG. 1 includes a substrate 10 and pixels 11 provided on the substrate 10. In FIG. 1, only one pixel 11 is shown, but in an actual organic EL display device, a plurality of pixels 11 are members provided in a matrix.

  The pixel 11 shown in FIG. 1 includes two types of subpixels, that is, a first subpixel 11a and a second subpixel 11b. Each subpixel (11a, 11b) basically includes a lower electrode 12, a first organic compound layer 13, an intermediate electrode layer 14, a second organic compound layer 15 and an upper electrode 16 on the substrate 10. It is a member constructed by laminating in order.

  The first subpixel 11a is a member configured by laminating an R organic EL element portion 18r that outputs red light emission and a G1 organic EL element portion 17g that outputs green light emission in this order. Here, the G1 organic EL element portion 17g is specifically a member formed by laminating the lower electrode 12, the G1 organic compound layer (first organic compound layer) 13g, and the intermediate electrode layer 14a in this order. On the other hand, the R organic EL element portion 18r is a member formed by laminating the intermediate electrode layer 14a, the R organic compound layer (second organic compound layer) 15r, and the upper electrode 16 in this order. The second subpixel 11b is a member configured by laminating a G2 organic EL element portion 18g that outputs green light emission and a B organic EL element portion 17b that outputs blue light emission in this order. Here, the B organic EL element portion 17b is specifically a member formed by laminating the lower electrode 12, the B organic compound layer (first organic compound layer) 13b, and the intermediate electrode layer 14b in this order. On the other hand, the G2 organic EL element portion 18g is a member formed by laminating the intermediate electrode layer 14b, the G2 organic compound layer (second organic compound layer) 15g, and the upper electrode 16 in this order.

  Next, members constituting the organic EL display device will be described.

  The substrate 10 may be composed only of a substrate material such as a glass substrate (hereinafter sometimes referred to as “base material”), but a substrate in which a switching element such as a TFT is formed on the base material is used as the substrate. May be. When a switching element such as a TFT is formed on the substrate, it is desirable to form a planarizing film made of resin on the switching element.

  As described above, when the planarization film is formed, the lower electrode 12 patterned corresponding to each pixel region is formed on the planarization film. Here, the constituent material of the lower electrode 12 is preferably a light reflective material. For example, metal materials such as Cr, Al, Ag, Au, and Pt are preferable. This is because the higher the reflectance (the metal material), the more the light extraction efficiency can be improved. A laminated electrode in which a transparent conductive film such as an ITO film is laminated on a layer made of the above-described light reflective material can also be used as the lower electrode 12. If it is this laminated electrode, the function as an electrode can be ensured with a transparent conductive film such as an ITO film while ensuring the light reflecting function with a light reflective material. For example, the structure which laminated | stacked the ITO electrode on the reflecting film which consists of Ag is mentioned. As described above, since the lower electrode 12 is a light-reflective electrode layer, the organic EL display device of FIG. 1 is a top emission type. The lower electrode 12 may be formed individually for each subpixel or may be formed as an electrode layer common to each subpixel.

The first organic compound layer 13 provided on the lower electrode 12 is not particularly limited as long as it includes at least a light emitting layer that outputs a desired color. Specific examples of the first organic compound layer include those listed below, but the present invention is not limited thereto.
(I) Single layer type (light emitting layer)
(Ii) Two-layer type (light emitting layer / hole injection layer)
(Iii) Three-layer type (electron transport layer / light emitting layer / hole transport layer)
(Iv) 4 layer type (electron injection layer / light emitting layer / hole transport layer / hole injection layer)
(V) An intermediate electrode layer 14 (14a, 14b) provided on the first organic compound layer 13 with any of the five-layer type (electron injection layer / electron transport layer / light emitting layer / hole transport layer / hole injection layer) Is preferably a light-transmissive electrode layer. Examples of the constituent material of the intermediate electrode layer 14 include a transparent conductive film such as ITO and IZO and a metal conductive film that is made of a metal material such as Al, Ag, and Mg and has a thin film thickness until it transmits light. Moreover, you may use what laminated | stacked this transparent conductive film and a metal conductive film. The intermediate electrode layer 14 may be formed individually for each subpixel, or may be formed as an electrode layer common to each subpixel.

  As with the first organic compound layer, the second organic compound layer 15 provided on the intermediate electrode layer 14 has a particularly limited layer structure as long as it includes at least a light emitting layer that outputs a desired color. It is not a thing. Specific examples of the second organic compound layer are the same as those of the first organic compound layer.

  When the lower electrode 12 is a light reflective electrode layer, the upper electrode 16 provided on the second organic compound layer 15 is preferably a light transmissive electrode layer. In this case, as the constituent material of the upper electrode 16, the materials listed as constituent materials of the intermediate electrode layer 14 can be used. The upper electrode 16 may be formed individually for each subpixel, or may be formed as an electrode layer common to each subpixel.

  A specific method for manufacturing the organic EL display device of FIG. 1 will be briefly described. First, a TFT (thin film transistor, not shown) constituting a pixel circuit is formed on an insulating substrate, and an insulating layer (not shown) is formed to protect the TFT (thin film transistor). Subsequently, a flattening layer (not shown) is formed so as to flatten the unevenness generated by the TFT formation. Thus, what formed even the planarization layer on the base material is used at the following processes as the substrate 10.

  Next, after a contact hole for making electrical contact with each drain terminal of the TFT is formed at a predetermined position of the planarizing layer, the lower electrode 12 is manufactured. The lower electrode 12 includes, for example, an Al film (thickness 150 nm) and an ITO film (thickness 10 nm) formed in this order. As a method for forming the lower electrode 12, a wet process or a dry process may be used.

  Next, after UV / ozone cleaning as pretreatment, vacuum baking is performed, and then a first organic compound layer is deposited on the lower electrode 12. Specifically, the B organic compound layer 13b is formed in a region corresponding to the B organic EL element portion, and the G1 organic compound layer 13g is formed in a region corresponding to the G1 organic EL element portion with a desired film thickness.

  Next, the intermediate electrode layer 14a is formed on the B organic compound layer 13b, and the intermediate electrode layer 14b is formed on the G1 organic compound layer 13g. The intermediate electrode layer (14a, 14b) is preferably an electrode made of a transparent conductive material such as ITO or IZO or a semi-transmissive electrode made of Ag, Al or the like. For example, an alloy thin film (MgAg film, film thickness 10 nm) of magnesium and silver is formed. The intermediate electrode layer 14 (14a, 14b) is connected to each drain terminal of the TFT through a contact hole (not shown).

  Next, an R organic compound layer 15r is formed on the intermediate electrode layer 14a, and a G2 organic compound layer 15g is formed on the intermediate electrode layer 14b with a desired film thickness. In addition, a shadow mask corresponding to each arrangement may be used for separately coating each organic light emitting layer, and there is no problem even if another method such as a laser transfer method is used.

  Next, the upper electrode 16 is formed. For example, an alloy thin film (MgAg film, film thickness 10 nm) of magnesium and silver is formed. At this time, the upper electrode 16 is formed so as to be electrically connected to the lower electrode 12. Finally, sealing is performed to obtain an organic EL display device. Here, the film thickness of each member is shown in Table 1, and the front chromaticity of each organic EL element part is shown in Table 2, respectively.

  According to Table 2, the G1 organic EL element part and the G2 organic EL element part have different chromaticity and light emission efficiency because the interference effect is different between G1 and G2. Therefore, in this embodiment, the design is performed so that the chromaticity difference between G1 and G2 is small. For this reason, the chromaticity difference is such that it cannot be seen by human eyes. On the other hand, if there is a difference in light emission luminance between the G1 organic EL element part and the G2 organic EL element part, when displaying a green image on the entire surface, only one sub-pixel becomes bright, which is a problem. Therefore, when displaying a green image on the entire surface, it is necessary to devise a technique for making the emission luminance uniform between the G1 organic EL element unit and the G2 organic EL element unit. Here, as a method for adjusting the light emission luminance, adjustment of the amount of current and the light emission period is effective. In addition, it is preferable that the two organic EL element portions stacked are arranged on the light extraction side with the longer PL peak wavelength because the design becomes easy. If the longer PL peak wavelength is arranged on the light extraction side, the distance from the reflective lower electrode to the light emitting layer included in each organic EL element can be adjusted to be proportional to the PL peak wavelength. It is. This is also because the light emission efficiency is improved by making good use of the interference between the light directly extracted from the light emitting layer and the light reflected by the lower electrode.

  FIG. 2 is a schematic diagram showing a pixel array, a scanning line, and a data line laying form provided in the active matrix organic EL display device according to the first embodiment.

  In FIG. 2, the plurality of pixels 11 provided in the organic EL display device are arranged in a matrix of n rows in the row direction and m columns in the column direction. On the other hand, in FIG. 2, n scanning lines R1, R2,..., Rn (hereinafter, representatively referred to as “R”) are arranged in the row direction of the pixels and are selected as the desired pixel 11. It is provided for applying a signal. On the other hand, in FIG. 2, m data lines D1, D2,..., Dm (hereinafter referred to as “D” representatively) are arranged in the pixel column direction and are displayed on a desired pixel 11. It is provided for applying a signal.

A pixel circuit (not shown) is provided at the intersection of the scanning line R and the data line D corresponding to each pixel 11. This pixel circuit has a known programming configuration such as a current programming method and a voltage programming method. Here, programming refers to a processing method for performing the following processes (A) to (C).
(A) A selection signal is sequentially applied to the scanning line R. (B) A video signal is supplied from the data line D to each pixel 11 in the selected row. (C) Depending on the capacitance such as a capacitor provided in the pixel 11. In the above process of holding the video signal, the period during which the selection signal is applied to the scanning line R of each row is a programming period. This period is shifted in time by one programming period for each row.

  The row in which the programming period has ended moves to the light emission period next. Specifically, a current corresponding to the video signal held in the holding capacitor of each pixel circuit is generated and supplied to the light emitting element. The light emitting element emits light with a luminance corresponding to the current.

  The organic EL display device of the present invention is configured to sequentially emit a plurality of colors with a time difference. One frame period is divided into a v programming period (one time) and a light emission period (a plurality of times). During the programming period, all the video signals of different colors are programmed in the pixel circuit of the selected row, and then light emission is performed. Light emission by color is sequentially performed during the period. By performing light emission with luminance according to the video signal in each light emission period, a temporally synthesized color image is obtained.

  Each pixel circuit is provided with a switching TFT and a current control TFT in addition to the above-mentioned storage capacitor. Further, a plurality of data lines for each column for supplying a video signal to the pixel circuit are provided for each color as shown in the following specific example. As another method, a single data line may be used and a color-specific signal may be supplied by time division (a format using pulse time modulation driving).

(Operation of pixel circuit)
FIG. 3 is a circuit diagram showing an example of a pixel circuit for driving the organic EL display device of FIG. In FIG. 3, light emitting elements 31a, 31b, 31c, and 31d are the R organic EL element part 18r, the G1 organic EL element part 17g, the B organic EL element part 17b, and the G2 organic EL element part 18g shown in FIG. . The R organic EL element portion 18r and the G1 organic EL element portion 17g are connected to a common pixel TFT. Specifically, the common terminals of the light emitting elements 31a and 31b corresponding to the R organic EL element unit 18r and the G1 organic EL element unit 17g are connected to the switch Q3R of the pixel circuit 33a and the switch Q3G1 of the pixel circuit 33b through the tap 32a. ing. On the other hand, the G2 organic EL element part 18g and the B organic EL element part 17b are connected to a common pixel TFT. Specifically, the common terminals of the light emitting elements 31c and 31d corresponding to the G2 organic EL element unit 18g and the B organic EL element unit 17b are connected to the switch Q3B of the pixel circuit 33c and the switch Q3G2 of the pixel circuit 33d through the tap 32b. ing.

  FIG. 4 is a diagram showing a sequence for driving the pixel circuit of FIG. In other words, the temporal order of programming display of each pixel in the organic EL display device 1 of the present embodiment shown in FIG. 1 is shown.

  The sequence in FIG. 4 is for an organic EL display device of n rows, and each row is sequentially selected from row (1) to row (n), and each row is programmed in the program period. At this time, two types of video signals are programmed corresponding to light emission in an A light emission period and a B light emission period described later. Thereafter, in the A light emission period and the subsequent B light emission period, one of the two types of organic EL element portions constituting the sub-pixel emits light. In the case of this embodiment, in the A light emission period, the R organic EL element unit 18r included in the first subpixel 11a and the B organic EL element unit 17b included in the second subpixel 11b emit light. On the other hand, in the B light emission period, the G1 organic EL element portion 17g included in the first subpixel 11a and the G2 organic EL element portion 18g included in the second subpixel 11b emit light.

  The drive sequence of one frame is in the order of the program period programmed in each row (row (1) to row (n)), the A emission period after the end of each row program period, and the B emission period, and this sequence is repeated in units of frames. .

  In the sequence shown in FIG. 4, the light emission unit for the A light emission period and the B light emission period is one time. However, the A light emission period and the B light emission period may be shortened and repeated alternately until the next program period. Good.

  FIG. 5 is a timing chart showing the operation of the pixel circuit. In FIG. 5, Pa, Pb, and P1 represent the drive timing of each control line shown in FIG. In FIG. 5, Vc indicates the drive timing of the power supply line in FIG. At this time, Va is a power source (VCC, a positive potential for driving the light emitting elements 31b and 31d), and Vb is a ground (GND, a ground potential for turning off the light emitting elements 31b and 31d).

  In the period from t1 to t2 (program period shown in FIG. 4), the switches Q2R, Q2B, Q2G1, and Q2G2 of the pixel circuits 33a, 33b, 33c, and 33d are turned on. At this time, video signals are charged to the storage capacitors C1R, C1B, C1G1, and C1G2 from the data lines data_r, data_b, data_g1, and data_g2. Each data line data_r, data_b, data_g1, and data_g2 generates a voltage corresponding to the programming of the next row in FIG.

  In the period from t2 to t3 (A light emission period shown in FIG. 4), Q3R and Q3B are turned on by the control line Pa, and signal currents flow from the drive transistors Q1R and Q1B to the light emitting elements 31a and 31c, respectively. . In the period from t1 to t3, Vc is the ground. Then, after the drive timing P1 elapses during the period from t1 to t3, the light emitting elements 31a and 31c enter the light emitting state.

  In the period from t3 to t4, Q3G1 and Q3G2 are turned on by the control line Pb, and signal currents flow from the driving transistors Q1G1 and Q1G2 to the light emitting elements 31b and 31d, respectively. In the period from t3 to t4, Vc is VCC, so that the light emitting elements 31b and 31d are in a light emitting state.

  As described above, each light emitting element (31a, 31b, 31c, 31d) is independently controlled based on the input data signal.

(Description of data line control block)
FIG. 6 is a flowchart illustrating an example of a control system for each data line (data_r, data_b, data_g1, and data_g2).

  First, N-bit serial data input to the display system in the order of RGB is input to the parallel data separation unit. Next, the serial data is separated into N-bit digital data indicated by R data, G data, and B data and output.

  The R data and B data output from the parallel data separation unit are respectively input from the γ correction unit to the contrast adjustment unit, and white balance adjustment is performed for each color. Then, the D / A unit converts the digital data into analog data. The analog data is appropriately amplified in accordance with the output gain of each driving transistor in the AMP unit, and then an analog voltage is supplied to the data line.

  On the other hand, the G data output from the parallel data separation unit is input to the G1, G2 data conversion unit after the white balance is adjusted by the contrast adjustment unit from the γ correction unit. In the G1 and G2 data conversion units, ½ luminance data of the G data output from the contrast unit is output to the D / A unit as G1 and G2 data, respectively.

  Note that the G1 and G2 data output by the G1 and G2 data converters do not necessarily have the same value. For example, when the areas of the light emitting elements 31b and 31d are different, or when the light emission efficiency is different due to a difference in interference effect, the G1 and G2 data are adjusted so as to be inversely proportional to the area ratio. Specifically, the G1 and G2 data converters adjust the output G1 and G2 data, respectively, and adjust the amount of current so that the light emission luminances of the light emitting elements 31b and 31d become substantially equal values.

  By driving in this way, the G organic EL element portion with high visibility has double the number of light emitting elements as the number of light emitting elements of the R organic EL element portion and the B organic EL element portion, so that the resolution is improved. Increase. Furthermore, in this embodiment, since two types of light emitting elements are laminated, the substantial aperture ratio is improved. Therefore, the organic EL display device has a long life and a high resolution.

[Second Embodiment]
FIG. 7 is a schematic cross-sectional view showing a second embodiment of the organic EL display device of the present invention. The basic configuration of the second embodiment is the same as that of the first embodiment, and members that are the same as those of the first embodiment have the same reference numerals.

  The organic EL display device 7 of FIG. 7 is the first embodiment except that the configuration of the second subpixel 11b is stacked in the order of the G2 organic EL element unit 71 and the B organic EL element unit 72. It is the same composition as. In the organic EL display device 7 of FIG. 7, the G2 organic EL element unit 71 is specifically a member formed by laminating the lower electrode 12b, the G2 organic compound layer 73, and the intermediate electrode layer 14 in this order. On the other hand, the B organic EL element portion 72b is a member formed by laminating the intermediate electrode layer 14, the B organic compound layer 74b, and the upper electrode 16b in this order.

  FIG. 8 is a circuit diagram showing an example of a pixel circuit for driving the organic EL display device of FIG. In FIG. 8, light emitting elements 81a, 81b, 81c and 81d are the R organic EL element part 18r, the G1 organic EL element part 17g, the B organic EL element part 71 and the G2 organic EL element part 72 shown in FIG. . Each terminal is connected to the drive transistors Q1R, Q1G1, Q1B, and Q1G2 through electrodes 82a, 82b, 82c, and 82d, respectively. Note that the organic EL display device of this embodiment does not require a switch as in the first embodiment, and each element is independently connected to a drive transistor.

  In this embodiment, the basic driving method may be the same as that of the first embodiment, and other known methods can be used. Also in this embodiment, since the number of G organic EL elements having high visibility is twice as large as the number of R organic EL elements and the number of B organic EL elements as in the first embodiment, the resolution is increased. . Furthermore, in this embodiment, since two types of light emitting elements are laminated, the substantial aperture ratio is improved. Therefore, as in the first embodiment, the organic EL display device has a long life and a high resolution.

  1 (7): Organic EL display device, 10: Substrate, 11: Pixel, 11a: First subpixel, 11b: Second subpixel, 17g: G1 organic EL element part, 17b (72): B organic EL element part , 18r: R organic EL element part, 18g (71): G2 organic EL element part

Claims (8)

A substrate,
A plurality of pixels provided on the substrate,
The pixel is composed of a first subpixel and a second subpixel,
The first subpixel is configured by laminating an R organic EL element part and a G1 organic EL element part,
The second subpixel is formed by stacking a G2 organic EL element part and a B organic EL element part,
The R organic EL element portion includes an anode, a cathode, and an R organic compound layer that is sandwiched between the anode and the cathode and includes at least an R light emitting layer,
The G1 organic EL element part and the G2 organic EL element part have an anode and a cathode, and a G organic compound layer including at least a G light-emitting layer sandwiched between the anode and the cathode,
An organic EL display device, wherein the B organic EL element portion includes an anode, a cathode, and a B organic compound layer including at least a B light emitting layer sandwiched between the anode and the cathode.   2. The organic EL display device according to claim 1, wherein when displaying a green image on the entire surface, the light emission luminance of the G1 organic EL element portion is equal to the light emission luminance of the G2 organic EL element portion.   Among the G1 organic EL element part and the G2 organic EL element part, the light emission period of the organic EL element part with low emission efficiency is lengthened, and the light emission luminance of the G1 organic EL element part and the light emission of the G2 organic EL element part The organic EL display device according to claim 2, wherein the brightness is made equal.   Among the G1 organic EL element part and the G2 organic EL element part, a large amount of current is passed through the organic EL element part having low light emission efficiency to emit light from the G1 organic EL element part and light emission from the G2 organic EL element part. The organic EL display device according to claim 2, wherein the brightness is made equal.   5. The organic EL display device according to claim 1, wherein at least one of the organic EL element units is controlled by pulse time modulation driving. 6.   The organic EL display device according to any one of claims 1 to 5, wherein the R organic EL element part and the G1 organic EL element part are connected to a common pixel TFT.   The organic EL display device according to claim 1, wherein the G2 organic EL element part and the B organic EL element part are connected to a common pixel TFT.   The organic EL display device according to any one of claims 1 to 7, wherein the longer one of the two organic EL element portions stacked, the longer PL peak wavelength is disposed on the light extraction side.

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