WO2011125108A1

WO2011125108A1 - Method for manufacturing organic el display device, and organic el display device

Info

Publication number: WO2011125108A1
Application number: PCT/JP2010/002473
Authority: WO
Inventors: 中村哲朗; 瀬川泰生
Original assignee: パナソニック株式会社
Priority date: 2010-04-05
Filing date: 2010-04-05
Publication date: 2011-10-13

Abstract

Provided is a method for manufacturing an organic EL display device capable of shortening the measurement time and reducing the luminance unevenness of a display panel. The method for manufacturing the organic EL display device comprises: a first step for acquiring a representative function representing a representative voltage-luminance characteristic (S102); a second step for measuring the luminance at a first signal voltage in a low gradation area (S104); a third step for finding a reference voltage at which the luminance obtained from the representative voltage-luminance characteristic becomes the luminance at the first signal voltage and finding a first correction parameter for making the first signal voltage the reference voltage (S106); a fourth step for finding a predetermined voltage obtained by adding the first correction parameter to a second signal voltage between an intermediate gradation area and a high gradation area (S108); a fifth step for measuring the luminance at the predetermined voltage (S110); and a sixth step for finding a second correction parameter such that the luminance at the predetermined voltage becomes a reference luminance when the second signal voltage is inputted to the representative function (S112).

Description

Method for manufacturing organic EL display device and organic EL display device

The present invention relates to a method for manufacturing an organic EL display device and an organic EL display device, and more particularly, to a method for manufacturing an active matrix organic EL display device and an organic EL display device.

An image display device (organic EL display device) using an organic EL element (OLED: Organic Light Emitting Diode) is known as an image display device using a current-driven light emitting element whose emission intensity is controlled according to the amount of current. It has been. Since this organic EL display device is thin and lightweight and can respond at high speed, it has been attracting attention as a high-quality and high-performance thin display device with good viewing angle characteristics and low power consumption.

In an organic EL display device, organic EL elements constituting pixels are usually arranged in a matrix. An organic EL element is provided at the intersection of a plurality of row electrodes (scanning lines) and a plurality of column electrodes (data lines), and a voltage corresponding to a data signal is applied between the selected row electrodes and the plurality of column electrodes. A device that drives an organic EL element is called a passive matrix organic EL display device.

On the other hand, a thin film transistor (TFT: Thin Film Transistor) is provided at the intersection of a plurality of scanning lines and a plurality of data lines, a gate of a driving transistor is connected to the TFT, and the TFT is turned on through the selected scanning line to thereby turn on the data line. A data signal is input to a drive transistor and an organic EL element is driven by the drive transistor is called an active matrix organic EL display device.

Unlike a passive matrix type organic EL display in which an organic EL element connected to each row electrode (scanning line) emits light only during a period in which each row electrode (scanning line) is selected, the active matrix type organic EL display performs the next scanning (selection). Therefore, even if the duty ratio (the number of scanning lines) is increased, the luminance of the display is not reduced. Accordingly, since it can be driven at a low voltage, it is possible to reduce power consumption. However, in an active matrix organic EL display device, even if the same data signal is given due to variations in characteristics of drive transistors and organic EL elements, the luminance of the organic EL elements differs in each pixel, resulting in uneven brightness. There is a drawback of doing.

Therefore, conventionally, there is a method of measuring the current and luminance with respect to the input signal voltage in multiple stages and correcting the voltage-current characteristic or the voltage-luminance characteristic, thereby uniformizing the luminance of each pixel and reducing luminance unevenness. Proposed. For example, Patent Document 1 discloses a method of correcting the luminance of each pixel by measuring the voltage-current characteristic (characteristic indicating the relationship between the input signal voltage and the current flowing through the organic EL element) for each pixel. . Thereby, luminance unevenness can be reduced and uniform display can be achieved.

JP 2005-284172 A

However, the conventional method for reducing luminance unevenness has a problem that it takes time for measurement because it is necessary to perform measurement many times. That is, since the voltage-current characteristic or the voltage-luminance characteristic is a curve, in the conventional method for reducing the luminance unevenness, it is necessary to measure the current or the luminance with respect to the input signal voltage at least three times, preferably 6 to Eight measurements are required.

Therefore, the present invention has been made in view of such a problem, and provides a method for manufacturing an organic EL display device and an organic EL display device capable of reducing luminance unevenness of a display panel while reducing measurement time. The purpose is to provide.

In order to achieve the above object, a method for manufacturing an organic EL display device according to one embodiment of the present invention includes a plurality of pixels each including a light-emitting element and a voltage-driven drive element that controls supply of current to the light-emitting element. A first step of obtaining a function representing a representative voltage-luminance characteristic common to the display panel; and a first signal voltage corresponding to one gradation belonging to a low gradation region of the representative voltage-luminance characteristic is set to the plurality of pixels. The second step of measuring the luminance emitted from the plurality of pixels using a predetermined measuring device and the luminance obtained from the representative voltage-luminance characteristics are targeted. A reference voltage in the case where the luminance is obtained when the pixel is caused to emit light at the first signal voltage is obtained, and a first correction parameter for setting the first signal voltage to the reference voltage is set for the target pixel. The third to ask A predetermined voltage by adding the first correction parameter to the second signal voltage corresponding to one gradation belonging to any of the intermediate gradation range and the high gradation range of the representative voltage-luminance characteristic. A fourth step of obtaining, and a fifth step of applying the predetermined voltage to a driving element included in the target pixel and measuring the luminance emitted from the target pixel using the predetermined measuring device; The luminance when the target pixel is caused to emit light at the predetermined voltage becomes a reference luminance obtained when the second signal voltage is input to the function representing the representative voltage-luminance characteristic. And a sixth step of obtaining a second correction parameter for the target pixel, wherein the first correction parameter is an offset indicating a difference between the first signal voltage and the reference voltage.

According to the method for manufacturing an organic EL display device according to the present invention, it is possible to manufacture an organic EL display device capable of reducing luminance unevenness of the display panel while shortening the measurement time.

FIG. 1 is a block diagram showing a configuration of an organic EL display device and an organic EL display device manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a circuit configuration of a pixel included in the display unit of the display panel according to the present embodiment and a connection with the peripheral circuit. FIG. 3 is a block diagram showing a functional configuration of the control circuit and the correction parameter determination device according to the present embodiment. FIG. 4 is a diagram for explaining representative voltage-luminance characteristics, a high gradation region, a middle gradation region, and a low gradation region according to the present embodiment. FIG. 5 is a diagram illustrating an example of the correction parameter table according to the present embodiment. FIG. 6 is a flowchart illustrating an example of an operation in which the correction parameter determination device according to the present embodiment determines a correction parameter. FIG. 7 is a flowchart illustrating an example of processing in which the correction parameter calculation unit according to the present embodiment calculates the first correction parameter. FIG. 8 is a diagram for explaining processing in which the correction parameter calculation unit according to the present embodiment calculates the first correction parameter. FIG. 9 is a flowchart illustrating an example of a process in which the correction parameter calculation unit according to the present embodiment calculates the second correction parameter. FIG. 10 is a diagram for explaining processing in which the correction parameter calculation unit according to the present embodiment calculates the second correction parameter. FIG. 11 is a flowchart illustrating an example of processing in which the correction parameter calculation unit according to the first modification of the present embodiment calculates the second correction parameter. FIG. 12 is a diagram for describing processing in which the correction parameter calculation unit according to the first modification of the present embodiment calculates the second correction parameter. FIG. 13 is a block diagram illustrating a functional configuration of a control circuit and a correction parameter determination device according to a second modification of the present embodiment. FIG. 14 is a flowchart illustrating an example of an operation in which the correction parameter determination device according to the second modification example of the present embodiment determines a correction parameter. FIG. 15 is an external view of a thin flat TV incorporating an organic EL display device manufactured by the method for manufacturing an organic EL display device according to the present invention.

As an example of obtaining a gain and an offset that are correction parameters for correcting the luminance corresponding to the video signal supplied to each pixel to a predetermined reference luminance, there is a method using a least square method. In this least square method, the luminance of a plurality of gradations is measured for each pixel, and the gain and the gain are calculated by a predetermined calculation method based on the luminance difference between the luminance of each pixel and the representative voltage-luminance characteristics obtained by each measurement. Find the offset. However, since the least square method has a characteristic that it is necessary to measure the luminance of each pixel with at least three gradations, preferably five gradations or more, the correction parameter is measured after measuring the luminance of each pixel. There is a problem that it takes time to seek.

In addition, the human eye is more likely to recognize the luminance difference on the low gradation side than the luminance difference on the high gradation side, and tends to cause streaky irregularities on the display panel at the low gradation. Therefore, it is desirable that the correction accuracy on the low gradation side is higher than that on the high gradation side. However, normally, the luminance difference between the representative voltage-luminance characteristic and the voltage-luminance characteristic of each pixel increases as it goes to the high gradation side, and the least square method is such that the luminance difference on the high gradation side is minimized. Since the gain and the offset are obtained simultaneously by calculation, the correction error on the high gradation side can be reduced, but the correction error on the low gradation side becomes larger than that on the high gradation side.

Therefore, in this embodiment, first, a first signal voltage corresponding to one gradation belonging to the low gradation region is applied to the driving element included in each of the plurality of pixels, and the first luminance measurement is performed. Then, a reference voltage in a case where the luminance obtained from the representative voltage-luminance characteristic is the luminance when the target pixel emits light with the first signal voltage is obtained, and the first signal voltage is determined as the reference voltage. A first correction parameter for obtaining a voltage is obtained.

Next, a predetermined voltage is obtained by adding the first correction parameter to a second signal voltage corresponding to one gradation belonging to any of the middle gradation range to the high gradation range. Then, the predetermined voltage is applied to the drive element included in the target pixel, and the second luminance measurement is performed.

That is, a first correction parameter for setting the first signal voltage to the reference voltage is obtained, and the predetermined voltage is obtained by adding the first correction parameter to the second signal voltage. The second luminance measurement in the high gradation range can be performed with the reference voltage corresponding to the low gradation range as the base point.

Thereafter, a second correction parameter is obtained such that the measured target pixel has a reference luminance obtained when the second signal voltage is input to the function representing the representative voltage-luminance characteristic.

As described above, the luminance of each pixel in the high gradation region matches the luminance indicated by the representative voltage-luminance characteristic in the state where the reference voltage corresponding to the low gradation region is used as a base point. The accuracy can be increased and the correction accuracy of the high gradation region can be prevented from being lowered. As a result, luminance unevenness of the display panel recognized by human eyes can be suppressed, and luminance unevenness in a high gradation range can also be suppressed.

Moreover, since the first correction parameter and the second correction parameter can be obtained by two luminance measurements, the number of times of luminance measurement required for calculating the conventional correction parameter can be reduced. As a result, the measurement tact from when the luminance of each pixel is measured until the correction parameter is obtained can be shortened.

Thus, it is possible to manufacture an organic EL display device capable of reducing luminance unevenness of the display panel while shortening the measurement time.

Preferably, in the sixth step, the voltage obtained when the luminance when the target pixel is caused to emit light at the predetermined voltage is input to the function representing the representative voltage-luminance characteristic is calculated. The obtained second correction parameter is a gain indicating a ratio between the predetermined voltage and the voltage obtained by the calculation.

According to this aspect, the second correction parameter is a gain indicating a ratio between a predetermined voltage and a voltage obtained by calculation. That is, the second correction parameter can be calculated using the voltage ratio as a gain.

Further, the second correction parameter may be a gain indicating a ratio between the luminance when the target pixel is caused to emit light at the predetermined voltage and the reference luminance.

According to this aspect, the second correction parameter is a gain indicating a ratio between the luminance when the target pixel is caused to emit light at a predetermined voltage and the reference luminance. That is, the second correction parameter can be calculated using the luminance ratio as a gain.

Preferably, the second signal voltage corresponding to one gradation belonging to the high gradation region of the representative voltage-luminance characteristic has a gradation of 20% to 100% of the maximum gradation that can be displayed in each pixel. Corresponding voltage.

According to this aspect, the high gradation area in the display gradation is set to a gradation area corresponding to a gradation of 20% to 100% of the maximum gradation. As a result, the correction parameter can be calculated in a high gradation range suitable for human visibility.

More preferably, the second signal voltage corresponding to one gradation belonging to the high gradation region of the representative voltage-luminance characteristic is a voltage corresponding to a gradation of 30% of the maximum gradation that can be displayed in each pixel. It is.

According to this aspect, a voltage corresponding to the luminance of 30% of the maximum gradation is applied as the second signal voltage corresponding to the high gradation range. In this case, the correction error in the high gradation range can be most suppressed.

Preferably, the first signal voltage corresponding to one gradation belonging to the low gradation region of the representative voltage-luminance characteristic is a gradation of 0% to 10% of the maximum gradation that can be displayed in each pixel. Is a voltage corresponding to.

According to this aspect, the low gradation area in the display gradation is set to a gradation area corresponding to a gradation of 0% to 10% of the maximum gradation. As a result, the correction parameter can be calculated in a low gradation range suitable for human visibility.

More preferably, the first signal voltage corresponding to one gradation belonging to the low gradation part of the representative voltage-luminance characteristic is 0.2% to 10% of the maximum gradation that can be displayed in each pixel. It is a voltage corresponding to the gradation.

The gradation of 0.2% or less of the maximum gradation emitted by each pixel cannot be visually recognized by human eyes. Therefore, in this aspect, a voltage corresponding to a gradation of 0.2% or more of the maximum gradation is applied as the second signal voltage corresponding to the low gradation region. As a result, the correction parameter can be calculated in a low gradation range that matches the human visibility.

Preferably, the second signal voltage corresponding to one gradation belonging to the middle gradation region of the representative voltage-luminance characteristic is a gradation of 10% to 20% of the maximum gradation that can be displayed in each pixel. Is a voltage corresponding to.

According to this aspect, the signal voltage corresponding to one gradation belonging to the middle gradation range of the representative voltage-luminance characteristic corresponds to one gradation belonging to the gradation range of 10% to 20% of the maximum gradation. Apply voltage. As a result, the correction parameter can be calculated in the middle gradation range suitable for human visibility.

Also preferably, the representative voltage-luminance characteristic is a voltage-luminance characteristic for any one of a plurality of pixels included in the display panel.

According to this aspect, the representative voltage-luminance characteristic may be a voltage-luminance characteristic for an arbitrary pixel included in the display panel. As a result, a function representing the representative voltage-luminance characteristic can be easily obtained.

The representative voltage-luminance characteristic is a characteristic that is commonly set for the entire display panel including the plurality of pixels, and is an averaged voltage-luminance characteristic of each pixel included in the display panel. There may be.

According to this aspect, the representative voltage-luminance characteristic is set in common for the entire display panel including the plurality of pixels, and is obtained by averaging the voltage-luminance characteristics of each pixel included in the display panel. Accordingly, the correction parameter is obtained so that the luminance of each pixel included in the display panel has a representative voltage-luminance characteristic common to the entire display panel. When the video signal is corrected using the correction parameter, The brightness of light emitted from each pixel can be made uniform.

In the first step, the display panel is divided into a plurality of divided regions, and the representative voltage-luminance characteristics common to a plurality of pixels included in each of the plurality of divided regions are expressed for each of the divided regions. In the third step, the luminance obtained from the representative voltage-luminance characteristics of the predetermined divided region is the same as the luminance of the pixels included in the predetermined divided region measured in the second step. In this case, the first correction parameter for making the first signal voltage the reference voltage is obtained, and in the sixth step, the predetermined divided region measured in the fifth step is obtained. The second correction so that the luminance of the included pixel becomes the reference luminance obtained when the second signal voltage is input to the function representing the representative voltage-luminance characteristics of the predetermined divided region. Parameters may be possible to find the.

According to this aspect, the display panel including the plurality of pixels is divided into a plurality of divided regions, and the representative voltage-luminance characteristics common to the pixels included in each of the plurality of divided regions are set for each of the divided regions. To do. Then, the first correction parameter and the second correction parameter are obtained so that the luminance of the pixels included in the predetermined divided region has a representative voltage-luminance characteristic of the predetermined divided region.

Thereby, for example, it is possible to obtain a correction parameter that smoothes the luminance change between the adjacent pixels only for the region where the luminance unevenness occurs because the luminance change between the adjacent pixels is intense.

Preferably, the light emitting element included in the pixel emits one of red, green, and blue colors, and in the third step, the first correction is performed for each of the red, green, and blue colors. In the sixth step, the second correction parameter is obtained for each of the red, green, and blue colors.

According to this aspect, the first correction parameter and the second correction parameter are obtained for each color of red, green, and blue. Thereby, it can correct | amend so that a brightness | luminance may become uniform about each color of red, green, and blue.

Preferably, the first correction parameter obtained in the third step and the second correction parameter obtained in the sixth step are further written in a predetermined memory used for the display panel. 7 steps are included.

According to this aspect, the obtained first correction parameter and the second correction parameter are written in a predetermined memory used for the display panel. By correcting the video signal input to each pixel using the first correction parameter and the second correction parameter stored in the predetermined memory, the correction accuracy in the low gradation region can be improved. As a result, luminance unevenness of the display panel recognized by human eyes can be reduced.

The present invention can be realized not only as a method for manufacturing such an organic EL display device, but also as an organic EL display device manufactured using the method for manufacturing the organic EL display device. . In addition, an organic EL display device manufacturing apparatus that realizes the method of manufacturing the organic EL display device, a program that executes processing performed by a processing unit included in the organic EL display device manufacturing apparatus, and a storage medium that stores the program Can be realized. Further, a correction parameter determination method included in the method of manufacturing the organic EL display device, a correction parameter determination device that realizes the correction parameter determination method, and a process performed by a processing unit included in the correction parameter determination device are executed. It can also be realized as a program to be executed and a storage medium for storing the program.

(Embodiment)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an organic EL display device 1 and an organic EL display device manufacturing apparatus 2 according to an embodiment of the present invention.

As shown in the figure, the organic EL display device 1 is a device that displays an image by a light emitting element, and includes a control circuit 10 and a display panel 20.

The control circuit 10 controls the video signal to be displayed on the display panel 20 and displays the video on the display panel 20. A detailed description of the control circuit 10 will be described later.

The display panel 20 includes a display unit 21, a scanning line driving circuit 22, and a data line driving circuit 23, and based on a signal from the control circuit 10 input to the scanning line driving circuit 22 and the data line driving circuit 23, an image is displayed. Is displayed on the display unit 21. Here, the display unit 21 includes a plurality of pixels 100 arranged in a matrix. A detailed description of the display panel 20 will be described later.

The organic EL display device manufacturing apparatus 2 is an apparatus for manufacturing an organic EL display device that can reduce unevenness in luminance of the display panel while shortening the measurement time. The organic EL display device manufacturing apparatus 2 includes a correction parameter determination device 30 and a measurement device 40.

The measuring device 40 is a measuring device that can measure the luminance of light emitted from the plurality of pixels 100 included in the display unit 21. Specifically, the measuring device 40 is an image sensor such as a CCD (Charge Coupled Device) image sensor, and can measure the luminance of all the pixels 100 of the display unit 21 with high accuracy by one imaging. it can. The measuring device 40 is not limited to an image sensor, and any measuring device may be used as long as it can measure the luminance of the pixel 100.

The correction parameter determination device 30 is a device that determines correction parameters for equalizing the luminance of the plurality of pixels 100 included in the display unit 21 based on the luminance of each pixel 100 measured by the measurement device 40. Further, the correction parameter determination device 30 outputs the determined correction parameter to the control circuit 10 of the organic EL display device 1. A detailed description of the correction parameter determination device 30 will be described later.

Next, the detailed configuration of the display panel 20 will be described.

FIG. 2 is a diagram showing a circuit configuration of the pixel 100 included in the display unit 21 of the display panel 20 according to the present embodiment and a connection with peripheral circuits thereof.

The pixel 100 is one pixel included in the display unit 21 and has a function of emitting light by a signal voltage supplied via a data line. As shown in the figure, the pixel 100 includes a light emitting element 110, a driving transistor 120, a switching transistor 130, a storage capacitor 140, a scanning line 24, a data line 25, and a power supply line 151.

The peripheral circuit of the pixel 100 includes a power source 150 and a power source 160 in addition to the scanning line driving circuit 22 and the data line driving circuit 23.

First, the internal circuit configuration of the pixel 100 will be described with reference to FIG.

The light emitting element 110 is an organic EL (electroluminescence) element that emits one of red, green, and blue colors. Specifically, the light emitting element 110 has an anode connected to one of a source and a drain of the driving transistor 120 and a cathode connected to the power source 160. The light emitting element 110 has a function of emitting light when a current driven by the driving transistor 120 flows. That is, current is supplied to the light emitting element 110 through the power supply line 151, and the light emitting element 110 emits light.

The drive transistor 120 is a voltage-driven drive element that controls the supply of current to the light emitting element 110. Specifically, the driving transistor 120 has a gate connected to the data line 25 through the switching transistor 130, one of the source and the drain connected to the light emitting element 110, and the other of the source and the drain connected to the power supply 150. Yes. The drive transistor 120 has a function of converting the signal voltage supplied from the data line 25 into a signal current corresponding to the magnitude thereof.

In the figure, an N-type transistor is illustrated as the drive transistor 120, but the drive transistor 120 is not limited to an N-type transistor, and may be a P-type transistor.

The switching transistor 130 has a gate connected to the scanning line 24, one of the source and the drain connected to the data line 25, and the other of the source and the drain connected to the gate of the driving transistor 120. The switching transistor 130 switches between conduction and non-conduction between the data line 25 and the gate of the driving transistor 120. That is, the switching transistor 130 has a function of supplying the signal voltage value of the data line 25 to the pixel 100 while the scanning line 24 is at a high level.

The holding capacitor 140 is a capacitor that accumulates electric charges. The storage capacitor 140 is connected between one of the source and drain of the driving transistor 120 and the gate of the driving transistor 120. That is, a current corresponding to the charge accumulated in the storage capacitor 140 is caused to flow from the power supply line 151 to the light emitting element 110 by the driving transistor 120.

The power supply 150 is a constant voltage source for the drive transistor 120, and is set to 10 V, for example. The power supply 160 is a constant voltage source of the light emitting element 110 and is grounded, for example. In the present embodiment, the potential of the power source 150 is set higher than the potential of the power source 160.

The scanning line driving circuit 22 supplies a scanning signal to each scanning line 24 of the plurality of pixels 100. That is, the scanning line driving circuit 22 is connected to a plurality of scanning lines 24 for supplying a scanning signal to each of the plurality of pixels 100, and has a function of controlling conduction / non-conduction of the switching transistor 130 of the pixel 100. Have.

The data line driving circuit 23 supplies a signal voltage to each data line 25 of the plurality of pixels 100. That is, the data line driving circuit 23 is connected to a plurality of data lines 25 for supplying a signal voltage to each of the plurality of pixels 100 and has a function of determining a signal current flowing through the driving transistor 120.

Next, detailed configurations of the control circuit 10 and the correction parameter determination device 30 will be described.

FIG. 3 is a block diagram showing a functional configuration of the control circuit 10 and the correction parameter determination device 30 according to the present embodiment.

As shown in the figure, the correction parameter determination device 30 is a device that determines a parameter for correcting the luminance, and includes a measurement control unit 31 and a correction parameter calculation unit 32.

The measurement control unit 31 is a processing unit that measures the luminance of light emitted from the plurality of pixels 100 included in the display panel 20 using the measurement device 40.

Specifically, the measurement control unit 31 first obtains a function representing a representative voltage-luminance characteristic common to the display panel 20. Here, the representative voltage-luminance characteristic is a voltage-luminance characteristic that serves as a reference for making the luminance uniform. The function representing the representative voltage-luminance characteristic is a function representing the relationship between the signal voltage supplied from the data line to the driving transistor 120 and the luminance of the light emitted from the target pixel 100 by the light emitting element 110. . A function representing the representative voltage-luminance characteristic is determined in advance by measurement or the like.

Further, the measurement control unit 31 causes the control circuit 10 to emit the plurality of pixels 100 included in the display panel 20 and causes the measurement device 40 to measure the luminance of light emitted from the plurality of pixels 100. The brightness is acquired.

Specifically, the measurement control unit 31 is a drive element that includes a first signal voltage corresponding to one gradation belonging to the low gradation region of the representative voltage-luminance characteristic in each of the plurality of pixels 100. The luminance applied to the driving transistor 120 and the luminance emitted from the plurality of pixels 100 is measured using the measuring device 40, thereby obtaining the luminance.

In addition, the measurement control unit 31 applies a predetermined voltage calculated by the correction parameter calculation unit 32 to the drive transistor 120 included in the target pixel, and the luminance emitted from the target pixel is measured by the measurement device 40. The brightness is obtained by measuring using

The correction parameter calculation unit 32 calculates the first correction parameter and the second correction parameter for the target pixel using the luminance acquired by the measurement control unit 31 and the function representing the representative voltage-luminance characteristics, and performs control. The calculated correction parameter is output to the circuit 10. Then, the correction parameter calculation unit 32 stores the calculated correction parameter in the memory of the organic EL display device 1.

Specifically, the correction parameter calculation unit 32 obtains a reference voltage when the luminance obtained from the representative voltage-luminance characteristics is the luminance when the target pixel is caused to emit light with the first signal voltage, The first correction parameter for setting the signal voltage of 1 to the reference voltage is obtained for the target pixel.

Here, the first correction parameter is an offset indicating a difference between the first signal voltage and the reference voltage. In addition, the correction parameter calculation unit 32 obtains a first correction parameter for each of red, green, and blue colors emitted from the light emitting element 110.

Further, the correction parameter calculation unit 32 adds the first correction parameter to the second signal voltage corresponding to one gradation belonging to any one of the middle gradation range to the high gradation range of the representative voltage-luminance characteristics. A predetermined voltage is obtained. Here, since the driving transistor 120 is an N-type transistor, the second signal voltage is higher than the first signal voltage. When the driving transistor 120 is a P-type transistor, the second signal voltage is lower than the first signal voltage.

Then, the correction parameter calculation unit 32 uses the reference luminance obtained when the second signal voltage is input to the function representing the representative voltage-luminance characteristics as the luminance when the target pixel emits light at a predetermined voltage. Such a second correction parameter is obtained for the target pixel.

Here, the second correction parameter is a gain indicating the ratio between the luminance when the target pixel is caused to emit light at a predetermined voltage and the reference luminance. Further, the correction parameter calculation unit 32 obtains a second correction parameter for each of red, green, and blue colors emitted from the light emitting element 110.

Here, the representative voltage-luminance characteristics, the high gradation range, the middle gradation range, and the low gradation range will be described.

FIG. 4 is a diagram for explaining representative voltage-luminance characteristics, a high gradation region, a middle gradation region, and a low gradation region according to the present embodiment.

As shown in FIG. 6A, the representative voltage-luminance characteristics indicate that the luminance of light emitted from the pixel 100 is such that the voltage supplied to the driving transistor 120 is γ-th power (for example, γ = 2.2). It is a characteristic indicated by a proportional curve.

Each pixel 100 included in the display panel 20 has different voltage-luminance characteristics. For this reason, in the present embodiment, the representative voltage-luminance characteristic is the voltage-luminance characteristic for any one of the plurality of pixels 100 included in the display panel 20. As a result, a function representing the representative voltage-luminance characteristic can be easily obtained.

The representative voltage-luminance characteristic is a characteristic set in common for the entire display panel 20 including a plurality of pixels 100, and is an averaged characteristic of the voltage-luminance characteristics of each pixel 100 included in the display panel 20. You may decide to be. In this case, since the correction parameter is obtained so that the luminance of each pixel 100 included in the display panel 20 has a representative voltage-luminance characteristic common to the entire display panel 20, the video signal is corrected using this correction parameter. The luminance of the light emitted from each pixel 100 can be made uniform.

Also, (b) in the figure shows a representative voltage-luminance characteristic according to human visibility. That is, since the human eye has a sensitivity close to the LOG function, the representative voltage-luminance characteristic corresponding to the human visual sensitivity is a characteristic whose luminance is indicated by a curve of the LOG function.

For this reason, human eyes are difficult to recognize uneven brightness at high gradations and easy to recognize uneven brightness at low gradations. It is preferable to set the tuning range to be small.

Therefore, the first signal voltage corresponding to one gradation belonging to the high gradation region of the representative voltage-luminance characteristics is preferably a gradation of 20% to 100% of the maximum gradation that can be displayed in each pixel 100. The corresponding voltage, and more preferably the voltage corresponding to the gradation of 30% of the maximum gradation.

Thus, it is preferable that the high gradation area in the display gradation is a gradation area corresponding to a gradation of 20% to 100% of the maximum gradation. As a result, the correction parameter can be calculated in a high gradation range suitable for human visibility. More preferably, a voltage corresponding to a luminance of 30% of the maximum gradation is applied as the second signal voltage corresponding to the high gradation range. In this case, the correction error in the high gradation range can be most suppressed.

The second signal voltage corresponding to one gradation belonging to the middle gradation region of the representative voltage-luminance characteristic is preferably a gradation of 10% or more and 20% or less of the maximum gradation that can be displayed by each pixel 100. Is a voltage corresponding to.

As described above, preferably, the signal voltage corresponding to one gradation belonging to the middle gradation range of the representative voltage-luminance characteristic corresponds to one gradation belonging to the gradation range of 10% to 20% of the maximum gradation. Apply the voltage. As a result, the correction parameter can be calculated in the middle gradation range suitable for human visibility.

The second signal voltage corresponding to one gradation belonging to the low gradation region of the representative voltage-luminance characteristic is preferably a gradation of 0% to 10% of the maximum gradation that can be displayed in each pixel 100. Is a voltage corresponding to.

Thus, it is preferable that the low gradation area in the display gradation is a gradation area corresponding to a gradation of 0% to 10% of the maximum gradation. As a result, the correction parameter can be calculated in a low gradation range suitable for human visibility.

Note that a gradation of 0.2% or less of the maximum gradation emitted by each pixel 100 cannot be visually recognized by human eyes, and therefore the second gradation corresponding to one gradation belonging to the low gradation region of the representative voltage-luminance characteristic. More preferably, the signal voltage is a voltage corresponding to a gradation of 0.2% or more and 10% or less of the maximum gradation.

Thus, more preferably, a voltage corresponding to a gradation of 0.2% or more of the maximum gradation is applied as the second signal voltage corresponding to the low gradation region. As a result, the correction parameter can be calculated in a low gradation range that matches the human visibility.

3, the control circuit 10 is a processing unit for displaying an image on the display panel 20, and includes a control unit 11, a correction unit 12, and a storage unit 13.

The control unit 11 outputs a video signal to the display panel 20 and causes the display panel 20 to display the video. Specifically, the control unit 11 causes the plurality of pixels 100 included in the display panel 20 to emit light according to an instruction from the measurement control unit 31. In addition, the control unit 11 writes the first correction parameter and the second correction parameter for each pixel 100 calculated by the correction parameter calculation unit 32 in the storage unit 13.

The storage unit 13 stores a predetermined correction parameter input from the control unit 11 for each of the plurality of pixels 100. Specifically, the storage unit 13 stores a correction parameter table 13a including a first correction parameter and a second correction parameter for each pixel 100. Details of the correction parameter table 13a will be described later.

The correction unit 12 reads a predetermined correction parameter corresponding to each of the plurality of pixels 100 from the storage unit 13 with respect to the video signal input from the outside, and corrects the video signal corresponding to each of the plurality of pixels 100. . Then, the correction unit 12 outputs the corrected video signal to the control unit 11, and the control unit 11 outputs the corrected video signal to the display panel 20, thereby displaying the video on the display panel 20.

Next, the correction parameter table 13a stored in the storage unit 13 will be described.

FIG. 5 is a diagram showing an example of the correction parameter table 13a according to the present embodiment.

As shown in the figure, the correction parameter table 13a is a data table including a correction parameter composed of a first correction parameter and a second correction parameter for each pixel.

In the figure, the first correction parameter is indicated by offset OS11 to offset OSmn, and the second correction parameter is indicated by gain G11 to gain Gmn. That is, the correction parameter table 13a stores correction parameters configured by (gain, offset) for each pixel 100 corresponding to the matrix of the display unit 21 (m rows × n columns).

Next, the process in which the correction parameter determination device 30 determines the correction parameter will be described.

FIG. 6 is a flowchart showing an example of an operation in which the correction parameter determination device 30 according to the present embodiment determines a correction parameter.

As shown in the figure, first, the measurement control unit 31 obtains a function representing a representative voltage-luminance characteristic (S102).

Then, the measurement control unit 31 measures and acquires the luminance at the first signal voltage of the plurality of pixels 100 included in the display panel 20 (S104). In other words, the measurement control unit 31 causes the control unit 11 of the control circuit 10 to apply the first signal voltage to the driving transistor 120 included in each of the plurality of pixels 100, and the luminance of light emitted from the plurality of pixels 100. Is measured by the measuring device 40 to acquire the brightness.

Next, the correction parameter calculation unit 32 calculates the first correction parameter using the luminance acquired by the measurement control unit 31 and a function representing the representative voltage-luminance characteristics (S106). Details of the process in which the correction parameter calculation unit 32 calculates the first correction parameter will be described later with reference to FIGS.

Then, the correction parameter calculation unit 32 calculates a predetermined voltage obtained by adding the first correction parameter to the second signal voltage (S108).

Next, the measurement control unit 31 causes the control unit 11 of the control circuit 10 to apply a predetermined voltage to the drive transistor 120 included in each of the plurality of pixels 100, thereby increasing the luminance of light emitted from the plurality of pixels 100. The luminance is acquired by causing the measurement device 40 to measure (S110).

Then, the correction parameter calculation unit 32 calculates the second correction parameter using the luminance acquired by the measurement control unit 31 and a function representing the representative voltage-luminance characteristics (S112). Details of the process in which the correction parameter calculation unit 32 calculates the second correction parameter will be described later with reference to FIGS.

Thus, the process of determining the correction parameter by the correction parameter determination device 30 ends.

In addition, the above process is performed about each color of red, green, and blue which the light emitting element 110 light-emits. That is, the measurement control unit 31 measures and acquires the luminance at the first signal voltage and the predetermined voltage of the plurality of pixels 100 for each of the red, green, and blue colors. Then, the correction parameter calculation unit 32 obtains a first correction parameter and a second correction parameter for each of the red, green, and blue colors. Then, the correction parameter calculation unit 32 outputs the calculated correction parameters for the red, green, and blue colors to the control unit 11, and causes the control unit 11 to write the correction parameters in the storage unit 13.

This makes it possible to perform correction so that the luminance is uniform for each color of red, green, and blue.

In the organic EL display device 1 in which the correction parameters are written in the storage unit 13, the correction unit 12 sets correction parameters corresponding to each of the plurality of pixels 100 from the storage unit 13 with respect to the video signal input from the outside. It reads out and correct | amends the video signal corresponding to each of the some pixel 100. FIG. Then, the correction unit 12 outputs the corrected video signal to the control unit 11, and the control unit 11 outputs the corrected video signal to the display panel 20 to display the video on the display panel 20.

Thus, the first correction parameter and the second correction parameter are written in the storage unit 13 which is a predetermined memory used for the display panel 20. By correcting the video signal input to each pixel 100 using the first correction parameter and the second correction parameter stored in the storage unit 13, the correction accuracy in the low gradation region can be improved. . As a result, the luminance unevenness of the display panel 20 recognized by human eyes can be reduced.

Next, details of the process (S106 in FIG. 6) in which the correction parameter calculation unit 32 calculates the first correction parameter will be described with reference to FIGS.

FIG. 7 is a flowchart illustrating an example of a process in which the correction parameter calculation unit 32 according to the present embodiment calculates the first correction parameter.

FIG. 8 is a diagram for explaining a process in which the correction parameter calculation unit 32 according to the present embodiment calculates the first correction parameter. The curve A shown in the figure is a graph showing the representative voltage-luminance characteristics, and the curves B and C are graphs showing the voltage-luminance characteristics of the target pixel.

The correction parameter calculation unit 32 obtains a reference voltage when the luminance obtained from the representative voltage-luminance characteristics is the luminance when the target pixel is caused to emit light with the first signal voltage, and calculates the first signal voltage. A first correction parameter for setting a reference voltage is obtained for a target pixel. That is, as shown in FIG. 8, the correction parameter calculation unit 32 makes a curve so that the curve B or the curve C indicating the voltage-luminance characteristics for the target pixel approaches the curve A indicating the representative voltage-luminance characteristics. An offset, which is a first correction parameter for correcting B or curve C, is calculated.

Specifically, as shown in FIG. 7, the correction parameter calculation unit 32 first determines that the luminance obtained from the representative voltage-luminance characteristics is the luminance when the target pixel emits light with the first signal voltage. In this case, the reference voltage is calculated (S202).

Specifically, as shown in FIG. 8, the correction parameter calculation unit 32 is a reference obtained when the luminance Llow when the target pixel is caused to emit light at the first signal voltage Vlow is input to the curve A. The voltage Vdata (low) is calculated.

7, next, the correction parameter calculation unit 32 calculates an offset as the first correction parameter using the first signal voltage and the reference voltage (S204). Specifically, the correction parameter calculation unit 32 uses the first signal voltage Vlow and the reference voltage Vdata (low) to calculate the offset OS according to the following equation.

OS = Vlow-Vdata (low) (Formula 1)

That is, the offset OS is a numerical value indicating a difference between the first signal voltage and the reference voltage. The correction parameter calculation unit 32 may calculate the offset OS by a method other than the above.

Then, the correction parameter calculation unit 32 stores the first correction parameter in the memory of the organic EL display device 1 (S206). Specifically, the correction parameter calculation unit 32 outputs the first correction parameter to the control unit 11 to cause the control unit 11 to write the first correction parameter to the storage unit 13 and update the correction parameter table 13a. Let

Thus, the process in which the correction parameter calculation unit 32 calculates the first correction parameter (S106 in FIG. 6) ends.

Next, details of the process (S112 in FIG. 6) in which the correction parameter calculation unit 32 calculates the second correction parameter will be described with reference to FIGS.

FIG. 9 is a flowchart illustrating an example of processing in which the correction parameter calculation unit 32 according to the present embodiment calculates the second correction parameter.

FIG. 10 is a diagram for explaining a process in which the correction parameter calculation unit 32 according to the present embodiment calculates the second correction parameter. The curve A shown in the figure is a graph showing the representative voltage-luminance characteristics, and the curves B and C are curves indicating the voltage-luminance characteristics of the target pixel, which are corrected by the first correction parameter. 6 is a graph showing the voltage-luminance characteristics after exposure. That is, the curve B and the curve C are curves after the curve B and the curve C illustrated in FIG. 8 are corrected by the first correction parameter.

The correction parameter calculation unit 32 causes the luminance when the target pixel emits light at a predetermined voltage to be the reference luminance obtained when the second signal voltage is input to the function representing the representative voltage-luminance characteristics. The second correction parameter is obtained for the target pixel. That is, as shown in FIG. 10, the correction parameter calculation unit 32 corrects the curve B and the curve C so that the curve B and the curve C approach the curve A indicating the representative voltage-luminance characteristics. The gain which is is calculated.

Specifically, as shown in FIG. 9, first, the correction parameter calculation unit 32 calculates the reference luminance obtained when the second signal voltage is input to the function representing the representative voltage-luminance characteristics (S302). . That is, as shown in FIG. 10A, the correction parameter calculation unit 32 calculates the reference luminance Ldata (high) by inputting the second signal voltage to the function of the curve A representing the representative voltage-luminance characteristics. .

Returning to FIG. 9, next, the correction parameter calculation unit 32 calculates the gain as the second correction parameter using the luminance when the target pixel is caused to emit light at a predetermined voltage and the reference luminance (S304). ). Specifically, as shown in FIG. 10A, the correction parameter calculation unit 32 calculates the luminance Lhigh when the target pixel is made to emit light at a predetermined voltage Vhigh and the reference luminance Ldata (high). The gain G is calculated by the following formula.

G = Lhigh / Ldata (high) (Formula 2)

That is, the gain G is a numerical value indicating the ratio between the luminance when the target pixel is caused to emit light at a predetermined voltage and the reference luminance. Thus, the second correction parameter can be calculated using the luminance ratio as a gain.

The correction parameter calculation unit 32 may calculate the gain G by a method other than the above. Accordingly, as shown in FIG. 10B, the curve B and the curve C can be brought close to the curve A by correcting the curve B and the curve C with the second correction parameter.

Then, the correction parameter calculation unit 32 stores the second correction parameter in the memory of the organic EL display device 1 (S306). Specifically, the correction parameter calculation unit 32 outputs the second correction parameter to the control unit 11 so that the control unit 11 writes the second correction parameter in the storage unit 13 and updates the correction parameter table 13a. Let

Thus, the process in which the correction parameter calculation unit 32 calculates the second correction parameter (S112 in FIG. 6) ends.

As described above, the correction parameter determination device 30 determines the first correction parameter and the second correction parameter for all the pixels 100 included in the display panel 20.

As described above, according to the method of manufacturing the organic EL display device 1 by the organic EL display device manufacturing apparatus 2 according to the present invention, the first correction parameter for setting the first signal voltage to the reference voltage is obtained. Since the predetermined voltage is obtained by adding the correction parameter of 1 to the second signal voltage, the second luminance measurement in the high gradation range can be performed with the reference voltage corresponding to the low gradation range as the base point. . Then, a second correction parameter is obtained such that the measured pixel 100 has a reference luminance obtained when the second signal voltage is input to the function representing the representative voltage-luminance characteristics. As described above, since the luminance of each pixel 100 in the high gradation region matches the luminance indicated by the representative voltage-luminance characteristics with the reference voltage corresponding to the low gradation region as the base point, the correction accuracy in the low gradation region As well as a reduction in correction accuracy in the high gradation range. As a result, luminance unevenness of the display panel 20 recognized by human eyes can be suppressed, and luminance unevenness in a high gradation range can also be suppressed. In addition, since the first correction parameter and the second correction parameter can be obtained by two luminance measurements, the number of times of luminance measurement required for calculating the conventional correction parameter can be reduced. As a result, the measurement tact from when the luminance of each pixel 100 is measured until the correction parameter is obtained can be shortened.

(First modification)
In the above embodiment, the correction parameter calculation unit 32 calculates the gain indicating the luminance ratio as the second correction parameter. However, in the first modification, the correction parameter calculation unit 32 calculates a gain indicating a voltage ratio as the second correction parameter.

FIG. 11 is a flowchart illustrating an example of processing in which the correction parameter calculation unit 32 according to the first modification of the present embodiment calculates the second correction parameter. That is, this figure is a flowchart showing details of the process (S112 in FIG. 6) in which the correction parameter calculation unit 32 shown in FIG. 6 calculates the second correction parameter.

FIG. 12 is a diagram for describing processing in which the correction parameter calculation unit 32 according to the first modification of the present embodiment calculates the second correction parameter. The curve A shown in the figure is a graph showing the representative voltage-luminance characteristics, and the curves B and C are curves indicating the voltage-luminance characteristics of the target pixel, which are corrected by the first correction parameter. 6 is a graph showing the voltage-luminance characteristics after exposure. That is, the curve B and the curve C are curves after the curve B and the curve C illustrated in FIG. 8 are corrected by the first correction parameter.

The correction parameter calculation unit 32 is a second correction parameter for correcting the curve B and the curve C so that the curve B and the curve C approach the curve A indicating the representative voltage-luminance characteristics, as shown in FIG. Calculate the gain.

Specifically, as shown in FIG. 11, first, the correction parameter calculation unit 32 inputs the luminance when the target pixel emits light at a predetermined voltage into a function representing the representative voltage-luminance characteristics. A gain calculation voltage, which is a voltage obtained in step S402, is calculated (S402). That is, as shown in FIG. 12A, the correction parameter calculation unit 32 inputs the luminance Lhigh when the target pixel emits light at the predetermined voltage Vhigh into a function representing the representative voltage-luminance characteristics. The gain calculation voltage Vdata (high) obtained in this case is calculated.

11, next, the correction parameter calculation unit 32 calculates a gain as a second correction parameter using a predetermined voltage and a gain calculation voltage (S404). Specifically, as shown in FIG. 12A, the correction parameter calculation unit 32 calculates the gain G by the following equation using a predetermined voltage Vhigh and a gain calculation voltage Vdata (high). To do.

G = Vhigh / Vdata (high) (Formula 3)

That is, the gain G is a numerical value indicating a ratio between a predetermined voltage and a gain calculation voltage. That is, the second correction parameter can be calculated using the voltage ratio as a gain. Accordingly, as shown in FIG. 12B, the curve B and the curve C can be brought close to the curve A by correcting the curve B and the curve C with the second correction parameter.

Then, the correction parameter calculation unit 32 stores the second correction parameter in the memory of the organic EL display device 1 (S406).

As described above, the process (S112 in FIG. 6) in which the correction parameter calculation unit 32 according to the first modification of the present embodiment calculates the second correction parameter ends.

(Second modification)
In the embodiment and the first modification example, the first correction parameter and the second correction parameter are determined for the plurality of pixels 100 included in the display panel 20. However, in this modification, the display panel 20 is divided into a plurality of divided areas, and the first correction parameter and the second correction parameter are determined for each of the divided areas.

FIG. 13 is a block diagram illustrating functional configurations of the control circuit 10 and the correction parameter determination device 50 according to a modification of the present embodiment. Note that the control circuit 10, the display panel 20, and the measuring device 40 have the same functions as the control circuit 10, the display panel 20, and the measuring device 40 shown in FIG.

Further, the correction parameter determination device 50 includes an area dividing unit 51 in addition to the measurement control unit 31 and the correction parameter calculation unit 32. The measurement control unit 31 and the correction parameter calculation unit 32 have the same functions as the measurement control unit 31 and the correction parameter calculation unit 32 shown in FIG.

The area dividing unit 51 gives an instruction to the measurement control unit 31 and the correction parameter calculating unit 32 so as to divide the display panel 20 into a plurality of divided areas and perform processing for each divided area.

The measurement control unit 31 acquires a function representing a representative voltage-luminance characteristic common to the plurality of pixels 100 included in each of the plurality of divided regions for each divided region in accordance with the instruction of the region dividing unit 51.

The correction parameter calculation unit 32 follows the instruction of the region dividing unit 51, and the luminance obtained from the representative voltage-luminance characteristics of the predetermined divided region is the same as the luminance of the pixels included in the predetermined divided region measured by the measurement control unit 31. The first correction parameter for obtaining the first signal voltage as the reference voltage is obtained.

In addition, the correction parameter calculation unit 32 converts the luminance of the pixels included in the predetermined divided area measured by the measurement control unit 31 into a function representing the representative voltage-luminance characteristics of the predetermined divided area in accordance with an instruction from the area dividing unit 51. A second correction parameter is obtained such that the reference luminance obtained when the second signal voltage is input is obtained.

Next, the process in which the correction parameter determination device 50 determines the correction parameter will be described.

FIG. 14 is a flowchart illustrating an example of an operation in which the correction parameter determination device 50 according to the modification of the present embodiment determines a correction parameter.

As shown in the figure, the area dividing unit 51 first divides the display panel 20 into a plurality of divided areas (S502). The number of divided regions divided by the region dividing unit 51 is not particularly limited. For example, the region dividing unit 51 divides the display panel 20 into 16 divided regions × 26 divided regions.

Next, the measurement control unit 31 acquires a function representing the representative voltage-luminance characteristics for each divided region (S504).

Further, the measurement control unit 31 measures and acquires the luminance at the first signal voltage of the plurality of pixels 100 included in all the divided regions (S506). Here, the measurement control unit 31 simultaneously obtains the luminance of the plurality of pixels 100 by causing the plurality of pixels 100 included in all the divided regions to emit light simultaneously with the first signal voltage.

Then, the correction parameter calculation unit 32 calculates the first correction parameter for the plurality of pixels 100 included in all the divided regions (S508).

The correction parameter calculation unit 32 calculates a predetermined voltage obtained by adding the first correction parameter to the second signal voltage for the plurality of pixels 100 included in all the divided regions (S510).

Then, the measurement control unit 31 measures and acquires the luminance at the predetermined voltage for the plurality of pixels 100 included in all the divided regions (S512). That is, the measurement control unit 31 simultaneously acquires the luminance of the plurality of pixels 100 by causing the plurality of pixels 100 included in all the divided regions to simultaneously emit light at the predetermined voltage.

Next, the correction parameter calculation unit 32 calculates the second correction parameter for the plurality of pixels 100 included in all the divided regions (S514).

Note that details of the processing (S504 to S514) in which the measurement control unit 31 and the correction parameter calculation unit 32 calculate the first correction parameter and the second correction parameter will be described with reference to the measurement control unit 31 and the correction control unit 31 shown in FIG. Since the correction parameter calculation unit 32 is the same as the process (S102 to S112) for calculating the first correction parameter and the second correction parameter, detailed description thereof is omitted.

As described above, the processing for determining the correction parameter by the correction parameter determination device 50 ends.

Thus, according to an embodiment of the present invention, the display panel 20 including a plurality of pixels 100 is divided into a plurality of divided regions, and each divided region is divided into the pixels 100 included in each of the plurality of divided regions. A common representative voltage-luminance characteristic may be set. Then, the first correction parameter and the second correction parameter are obtained so that the luminance of the pixel 100 included in the predetermined divided region becomes the representative voltage-luminance characteristic of the predetermined divided region. Thereby, for example, it is possible to obtain a correction parameter that smoothes the luminance change between the adjacent pixels 100 only for the region where the luminance unevenness occurs because the luminance change between the adjacent pixels 100 is severe.

From the above, it is possible to manufacture the organic EL display device 1 that can reduce the luminance unevenness of the display panel 20 while shortening the measurement time.

For example, the organic EL display device 1 is incorporated in a thin flat TV as shown in FIG. By the manufacturing method of the organic EL display device 1 according to the present invention, a thin flat TV including the organic EL display device 1 capable of reducing the luminance unevenness of the display panel 20 while shortening the measurement time is realized.

As mentioned above, although the manufacturing method of the organic EL display device 1 according to the present invention has been described using the above-described embodiment and its modifications, the present invention is not limited to this.

That is, the embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

For example, in the present embodiment and its modifications, the correction parameter determination device 30 determines the first correction parameter and the second correction parameter for all the pixels 100 included in the display panel 20. However, the correction parameter determination device 30 may determine the first correction parameter and the second correction parameter for only some of the pixels 100 included in the display panel 20.

Further, in the second modification of the present embodiment, the correction parameter determination device 30 determines the first correction parameter and the second correction parameter for all the divided areas included in the display panel 20. However, the correction parameter determination device 30 may determine the first correction parameter and the second correction parameter for only some of the divided areas included in the display panel 20.

Further, in the present embodiment and the modification thereof, the correction parameter calculation unit 32 obtains the first correction parameter and the second correction parameter for each of red, green, and blue colors emitted from the light emitting element 110. did. However, the correction parameter calculation unit 32 may obtain the first correction parameter and the second correction parameter only for any one of red, green, and blue, or only for two colors. .

Further, in the present embodiment and its modification, the correction parameter calculation unit 32 stores the calculated first correction parameter and second correction parameter in the storage unit 13. However, the correction parameter calculation unit 32 may end the process without causing the storage unit 13 to store the first correction parameter and the second correction parameter.

Further, in the present embodiment and its modification, the correction parameter is determined from the relationship between the voltage and the luminance in each pixel by using the voltage-luminance characteristics in each pixel. However, the correction parameter is determined from the relationship between the voltage and current in each pixel by using the voltage-current characteristics of each pixel using the value of the current flowing through the light emitting element 110 instead of the luminance. It may be. Since the luminance and the current are in a proportional relationship, the correction parameter can be determined by a similar method by replacing the luminance in the present embodiment and its modification with the current.

INDUSTRIAL APPLICABILITY The present invention is particularly useful for a method for manufacturing an organic EL flat panel display incorporating an organic EL display device, and a method for manufacturing an organic EL display device capable of reducing luminance unevenness of the display panel while shortening the measurement time. And so on.

DESCRIPTION OF SYMBOLS 1 Organic EL display apparatus 2 Organic EL display apparatus manufacturing apparatus 10 Control circuit 11 Control part 12 Correction | amendment part 13 Memory | storage part 13a Correction | amendment parameter table 20 Display panel 21 Display part 22 Scan line drive circuit 23 Data line drive circuit 24 Scan line 25

Data line

30, 50 Correction Parameter Determination Device 31 Measurement Control Unit 32 Correction Parameter Calculation Unit 40 Measurement Device 51 Area Division Unit 100 Pixel 110 Light Emitting Element 120 Drive Transistor 130 Switching Transistor 140

Retention Capacitor

150, 160 Power Supply 151 Power Supply Line

Claims

A first step of obtaining a function representing a representative voltage-luminance characteristic common to a display panel including a plurality of pixels including a light-emitting element and a voltage-driven drive element that controls supply of current to the light-emitting element;
A first signal voltage corresponding to one gradation belonging to the low gradation region of the representative voltage-luminance characteristic is applied to a driving element included in each of the plurality of pixels, and luminance emitted from the plurality of pixels is increased. A second step of measuring using a predetermined measuring device;
A reference voltage is obtained when the luminance obtained from the representative voltage-luminance characteristics is the luminance when the target pixel emits light with the first signal voltage, and the first signal voltage is used as the reference voltage. A third step for obtaining a first correction parameter for the target pixel;
A fourth voltage for obtaining a predetermined voltage by adding the first correction parameter to a second signal voltage corresponding to one gradation belonging to any of the middle gradation range to the high gradation range in the representative voltage-luminance characteristic. Steps,
A fifth step of applying the predetermined voltage to a drive element included in the target pixel and measuring the luminance emitted from the target pixel using the predetermined measuring device;
The second luminance is such that the luminance when the target pixel emits light at the predetermined voltage becomes a reference luminance obtained when the second signal voltage is input to the function representing the representative voltage-luminance characteristic. A sixth step of determining a correction parameter of the target pixel,
The first correction parameter is an offset indicating a difference between the first signal voltage and the reference voltage.
A method for manufacturing an organic EL display device.
In the sixth step, a voltage obtained when the luminance when the target pixel is caused to emit light at the predetermined voltage is input to the function representing the representative voltage-luminance characteristic is obtained by calculation,
The second correction parameter is a gain indicating a ratio between the predetermined voltage and the voltage obtained by the calculation.
A method for producing an organic EL display device according to claim 1.
The second correction parameter is a gain indicating a ratio between luminance when the target pixel is caused to emit light at the predetermined voltage and the reference luminance.
A method for producing an organic EL display device according to claim 1.
The second signal voltage corresponding to one gradation belonging to the high gradation region of the representative voltage-luminance characteristic is a voltage corresponding to a gradation of 20% to 100% of the maximum gradation that can be displayed in each pixel. ,
The manufacturing method of the organic electroluminescence display of any one of Claim 1 thru | or 3.
The second signal voltage corresponding to one gradation belonging to the high gradation region of the representative voltage-luminance characteristic is a voltage corresponding to a gradation of 30% of the maximum gradation that can be displayed in each pixel.
The manufacturing method of the organic electroluminescence display of Claim 4.
The first signal voltage corresponding to one gradation belonging to the low gradation region of the representative voltage-luminance characteristic is a voltage corresponding to a gradation of 0% to 10% of the maximum gradation that can be displayed in each pixel. is there,
The manufacturing method of the organic electroluminescence display of any one of Claim 1 thru | or 5.
The first signal voltage corresponding to one gradation belonging to the low gradation portion of the representative voltage-luminance characteristic corresponds to a gradation of 0.2% to 10% of the maximum gradation that can be displayed in each pixel. Voltage,
The manufacturing method of the organic electroluminescence display of Claim 6.
The second signal voltage corresponding to one gradation belonging to the middle gradation range of the representative voltage-luminance characteristic is a voltage corresponding to a gradation of 10% to 20% of the maximum gradation that can be displayed in each pixel. is there,
The manufacturing method of the organic electroluminescence display of any one of Claim 1 thru | or 7.
The representative voltage-luminance characteristic is a voltage-luminance characteristic for any one of a plurality of pixels included in the display panel.
The manufacturing method of the organic electroluminescence display of any one of Claim 1 thru | or 8.
The representative voltage-luminance characteristic is a characteristic set in common for the entire display panel including the plurality of pixels, and is an averaged voltage-luminance characteristic of each pixel included in the display panel.
The manufacturing method of the organic electroluminescence display of any one of Claim 1 thru | or 8.
In the first step, the display panel is divided into a plurality of divided regions, and for each of the divided regions, a function that represents the representative voltage-luminance characteristics common to a plurality of pixels included in each of the plurality of divided regions. Acquired,
In the third step, a reference voltage when the luminance obtained from the representative voltage-luminance characteristics of the predetermined divided region is the same as the luminance of the pixels included in the predetermined divided region measured in the second step is Determining the first correction parameter for making the first signal voltage the reference voltage,
In the sixth step, the luminance of the pixels included in the predetermined divided region measured in the fifth step is input to the function representing the representative voltage-luminance characteristics of the predetermined divided region. Determining the second correction parameter so as to be the reference luminance obtained in the case of
The manufacturing method of the organic electroluminescence display of any one of Claim 1 thru | or 8.
The light emitting element included in the pixel emits one of red, green, and blue colors,
In the third step, the first correction parameter is obtained for each of the red, green, and blue colors,
In the sixth step, the second correction parameter is obtained for each of the red, green, and blue colors.
The manufacturing method of the organic electroluminescence display of any one of Claim 1 thru | or 11.
further,
A seventh step of writing the first correction parameter obtained in the third step and the second correction parameter obtained in the sixth step into a predetermined memory used in the display panel;
The manufacturing method of the organic electroluminescence display of any one of Claims 1 thru | or 12.
The second signal voltage is higher than the first signal voltage.
The manufacturing method of the organic electroluminescence display of any one of Claims 1 thru | or 13.
The predetermined measuring device is an image sensor;
The manufacturing method of the organic electroluminescence display of any one of Claims 1 thru | or 14.
A plurality of pixels including a light-emitting element and a voltage-driven drive element that controls supply of current to the light-emitting element;
A plurality of data lines for supplying a signal voltage to each of the plurality of pixels;
A plurality of scanning lines for supplying a scanning signal to each of the plurality of pixels;
A data line driving circuit for supplying the signal voltage to the plurality of data lines;
A scanning line driving circuit for supplying the scanning signal to the plurality of scanning lines;
A storage unit for storing predetermined correction parameters for each of the plurality of pixels;
A correction unit that reads out the predetermined correction parameter corresponding to each of the plurality of pixels from the storage unit with respect to a video signal input from the outside, and corrects the video signal corresponding to each of the plurality of pixels; With
The predetermined correction parameter is:
A first step of obtaining a function representing a representative voltage-luminance characteristic common to the plurality of pixels;
A first signal voltage corresponding to one gradation belonging to the low gradation region of the representative voltage-luminance characteristic is applied to a driving element included in each of the plurality of pixels, and luminance emitted from the plurality of pixels is increased. A second step of measuring using a predetermined measuring device;
A reference voltage is obtained when the luminance indicated by the representative voltage-luminance characteristic is the luminance when the target pixel emits light with the first signal voltage, and the first signal voltage is used as the reference voltage. A third step for obtaining a first correction parameter for the target pixel;
A fourth step of obtaining a predetermined voltage by adding the first correction parameter to a second signal voltage corresponding to one gradation belonging to any one of a middle gradation region to a high gradation region of the representative voltage-luminance characteristic; When,
A fifth step of applying the predetermined voltage to a drive element included in the target pixel and measuring the luminance emitted from the target pixel using the predetermined measuring device;
The second luminance is such that the luminance when the target pixel emits light at the predetermined voltage becomes a reference luminance obtained when the second signal voltage is input to the function representing the representative voltage-luminance characteristic. A correction parameter for the target pixel is generated by a sixth step,
The first correction parameter is an offset indicating a difference between the first signal voltage and the reference voltage.
Organic EL display device.