JP2009042486A - Electroluminescence display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correct a change in light emission efficiency for every pixel of an EL display device. <P>SOLUTION: The electroluminescence display device is equipped with a display section, and a data processing section for processing a data signal supplied to the display section, in electroluminescence display device each of a plurality of pixels arranged in matrix in the display section includes a device driving transistor Tr2 for controlling an EL device of a diode structure and the current flowing to the EL device, and a transistor Tr3 for detection connected to an anode electrode of the EL device in order to detect an anode voltage. The data processing section determines the light emission correction value for correcting the data signal to be supplied to the corresponding pixel according to the change in the light emission efficiency in the corresponding electroluminescence device on the basis of the anode voltage obtained via the transistor for detection by supplying the data signal for inspection to each pixel and the initial anode voltage of the corresponding pixel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display device having an electroluminescence element in each pixel, and more particularly to correction of characteristics of the display device according to a change with time.

  An EL display device that employs an electroluminescence element (hereinafter referred to as an EL element), which is a self-luminous element, as a display element of each pixel is expected as a next-generation flat display device, and is researched and developed.

  Among such EL display devices, a so-called active matrix EL display device in which an EL element and a thin film transistor (TFT) for driving the EL element for each pixel are formed in each pixel is accurate in display control for each pixel. Therefore, application to high-definition and large-screen display devices has been attempted.

  However, it is known that the EL element has a light emission efficiency that decreases with the lapse of energization time, resulting in a decrease in light emission luminance. Focusing on the increase in inter-terminal voltage due to a decrease in light emission efficiency, in Patent Document 1, a plurality of dummy EL elements are formed outside a display unit in which pixels are arranged, and terminals of the plurality of dummy EL elements are formed. It is disclosed that when the average value of the inter-voltage increases, the drive current and the power supply voltage supplied to the EL elements of the pixels of the display unit are uniformly increased.

  In addition, when a TFT, particularly a TFT using low-temperature polycrystalline silicon (LTPS), is employed for each pixel, variations in TFT characteristics such as variations in the operation threshold Vth of the TFT may occur. Variation in the threshold value Vth of the TFT causes variation in luminance of the EL element in the corresponding pixel. Therefore, in Patent Document 2, the panel is caused to emit light, the variation in luminance is measured, and the data signal (video signal) supplied to the pixel is corrected. As another method, it has been proposed to incorporate a circuit for correcting variation in Vth of an element driving transistor for controlling a current flowing in an EL element in each pixel.

JP 2002-351403 A JP-A-2005-316408

  However, the decrease in the luminous efficiency of the EL element largely depends on the light emitting material used for the EL element, and even when the same material is used, the driving conditions in each pixel according to the display contents Depending on the difference. Therefore, based on the average value of the inter-terminal voltages of the plurality of dummy EL elements as in Patent Document 1, it is impossible to know the degree of decrease in the light emission efficiency of the EL elements of the individual pixels. Further, if the drive current and the power supply voltage are uniformly adjusted for all the pixels based on the average value of the inter-terminal voltage, there is a possibility that the drive condition is not suitable.

  As in Patent Document 2, the display characteristic value is corrected based on the variation in emission luminance to correct the variation in TFT characteristics for each pixel. However, the variation in TFT characteristics is corrected assuming that the light emission efficiency is constant. .

  However, since the light emission efficiency changes as the energization time elapses as described above, it is necessary to consider the light emission efficiency in order to maintain a high-quality display for a longer period. Moreover, in the said patent document 2, since the correction value obtained by measuring the light emission brightness before shipment is used, it is not possible to perform correction according to the subsequent decrease in light emission efficiency.

  An object of the present invention is to suppress image sticking due to a change in light emission efficiency in an EL display device.

  The present invention is an electroluminescence display device comprising a display unit and a data processing unit for processing a data signal supplied to the display unit, the display unit comprising a plurality of pixels arranged in a matrix, Each of the plurality of pixels is connected to an electroluminescent element having a diode structure, an element driving transistor connected to the electroluminescent element and controlling a current flowing through the electroluminescent element, and an anode electrode of the electroluminescent element A detection transistor for detecting an anode voltage of the electroluminescence element, and the data processing unit supplies an inspection data signal to each pixel and is obtained through the detection transistor Voltage and the initial annotation of the corresponding pixel Based on the de voltage, in accordance with the change in the light emission efficiency of the corresponding electroluminescent element, we obtain the luminous efficiency correction value for correcting the data signal to be supplied to the corresponding pixel.

  In another aspect of the present invention, in the electroluminescence display device, the inspection data signal is corrected by a display unevenness correction value for correcting display unevenness due to characteristic variation of each pixel.

  In another aspect of the present invention, in the electroluminescence display device, the data processing unit corrects display unevenness due to characteristic variation of each pixel with respect to a data signal supplied to the corresponding pixel during normal display. Correction processing is executed based on the display unevenness correction value and the light emission efficiency correction value, and the display unevenness correction value detects the characteristic variation of the corresponding pixel based on the light emission luminance of each pixel of the electroluminescence element. Is required.

  In another aspect of the present invention, in the electroluminescence display device, the data processing unit corrects display unevenness due to characteristic variation of each pixel with respect to a data signal supplied to the corresponding pixel during normal display. Correction processing is executed by the display unevenness correction value and the light emission efficiency correction value, and the display unevenness correction value supplies each pixel with an on-display signal for inspection with the electroluminescence element as a light emission level, and The device driving transistor is operated in the saturation region of the transistor to detect the cathode current of the electroluminescent device, and is obtained based on the value of the cathode current.

  In another aspect of the present invention, in the electroluminescence display device, the data processing unit corrects display unevenness due to characteristic variation of each pixel with respect to a data signal supplied to the corresponding pixel during normal display. Correction processing is executed using the display unevenness correction value and the light emission efficiency correction value, and the display unevenness correction value causes the element driving transistor of each pixel to operate in the saturation region of the transistor and An inspection on-display signal for setting a light emission level, and an inspection off-display signal for setting the electroluminescence element to a non-light emission level, and a cathode current of the electroluminescence element according to the inspection on-display signal; , An on / off current of the electroluminescence element corresponding to the inspection off-display signal Detecting a is determined from comparison with a reference value the OFF current difference.

  In another aspect of the present invention, in the electroluminescence display device, the light emission efficiency correction value includes an anode voltage change rate a corresponding to an initial anode voltage and an anode voltage at the time of measurement, an initial light emission efficiency, and the anode voltage measurement. Based on the relationship between the luminous efficiency change rate b in accordance with the luminous efficiency at the time, the luminous efficiency change rate b calculated from the anode voltage change rate a is used to obtain the initial luminous efficiency for the data signal. It is obtained as a correction amount necessary to obtain the corresponding emission luminance.

  In another aspect of the present invention, in the electroluminescence display device, the anode voltage measurement control unit supplies the inspection data signal to a corresponding pixel when the electroluminescence display device is turned on at a predetermined power supply, and Each detection transistor of the pixel is controlled to measure the anode voltage obtained through the inspection transistor, and the light emission efficiency correction value is stored in advance in the obtained anode voltage and anode voltage storage unit. Calculated based on the initial anode voltage and stored in the light emission efficiency correction value storage unit, and during normal display, the data processing unit is configured to display each pixel based on the light emission efficiency correction value and the display unevenness correction value. Correction processing is performed on the data signal supplied to.

  In the present invention, the anode voltage of the EL element is measured for each pixel through the detection transistor, and the change rate of the light emission efficiency of the electroluminescence (EL) element is obtained based on the anode voltage, and the change rate of the light emission efficiency is determined according to the change rate of the light emission efficiency. Thus, the data signal can be corrected, the occurrence of burn-in for each pixel can be reliably suppressed, and the life of the apparatus for maintaining an appropriate display as the entire display apparatus can be extended.

  In addition, when a threshold deviation of the element driving transistor that controls the current flowing through the EL element occurs, display unevenness may occur due to a difference in the amount of current flowing through the EL element. By performing both corrections based on the measured anode voltage in accordance with the luminous efficiency, high-quality display is achieved with no variation in pixel-to-pixel display over the long term as well as the initial period. can do.

  Furthermore, if a configuration for correcting based on the cathode current of the EL element is built in the display device, it is possible to correct display variations due to subsequent characteristic fluctuations such as an element driving transistor as needed.

  If the anode voltage measurement is performed when the display device is turned on, it is not necessary to perform the measurement at the normal display time, and the measurement time can be afforded.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best embodiment of the present invention (hereinafter referred to as an embodiment) will be described below with reference to the drawings.

  In the present embodiment, the display device is specifically an active matrix organic EL display device, and a display unit including a plurality of pixels is formed on the EL panel 100. FIG. 1 is a diagram showing an example of an equivalent circuit of the active matrix EL display device according to this embodiment. In the display portion of the EL panel 100, a plurality of pixels are arranged in a matrix, and in the horizontal (H) scanning direction (row direction) of the matrix, a selection line (gate line GL) 10 that sequentially outputs selection signals and A capacitance control line 14 (SC) for controlling the potential of the electrode of the storage capacitor Cs and a detection control line 22 (SG) for controlling the detection of the anode voltage of the EL element 18 are provided. In the vertical (V) scanning direction (column direction), a data line 12 (DL) from which a data signal (Vsig) is output and an organic EL element (hereinafter simply referred to as “EL element”) 18 as a driven element are provided. A power supply line 16 (VL) for supplying the drive power supply PVDD and an anode voltage detection line 20 (SL) for detecting the anode voltage of the EL element 18 are formed.

  Each pixel is provided in a region roughly divided by these lines. Each pixel includes an EL element 18 as a driven element, and a selection transistor Tr1 (hereinafter referred to as “hereinafter referred to as“ transistor ”) composed of an n-channel TFT. A selection Tr1 ”), a storage capacitor Cs, an element drive transistor Tr2 (hereinafter referred to as“ element drive Tr2 ”) constituted by a p-channel TFT, and an anode voltage detection transistor (hereinafter referred to as“ detection Tr3 ”).

  The selection Tr1 is connected to the data line 12 (DL) for supplying the data voltage (Vsig) to the pixels whose drains are arranged in the vertical scanning direction, and the gate line for selecting the pixels whose gates are arranged on one horizontal scanning line. 10 (GL), and its source is connected to the gate of the element drive Tr2.

  The element drive Tr2 has a source connected to the power supply line 16 (VL) and a drain connected to the anode of the EL element 18. The cathode of the EL element is formed in common for each pixel and is connected to a cathode power source CV.

  The EL element 18 has a diode structure and includes a light emitting element layer between a lower electrode and an upper electrode. The light-emitting element layer includes, for example, a light-emitting layer containing at least an organic light-emitting material, and can adopt a single-layer structure or a multilayer structure of two layers, three layers, or four layers or more depending on the material characteristics used for the light-emitting element layer. . In the present embodiment, the lower electrode is patterned into individual shapes for each pixel, functions as the anode, and is connected to the element drive Tr2. Further, the upper electrode functions in common with a plurality of pixels as a cathode.

  Furthermore, the source / drain of the detection Tr3 is connected between the anode electrode of the EL element 18 and the anode voltage detection line 20, and the gate of the detection Tr3 is connected to the detection control line 22 (SG).

  In an active matrix EL display device having a circuit configuration as described above for each pixel, when the organic light emitting material used for the EL element deteriorates with the passage of the driving time of the EL element, the initial state of the EL element is the same. The change rate (change amount) of the luminous efficiency may vary from pixel to pixel. For example, when different organic light-emitting materials are used for the EL elements for each of R, G, and B, the rate of deterioration differs depending on the material, and there is a difference in the rate of change in light emission efficiency over time. Even when a common material such as a white light emitting material is used for the R, G, and B pixels, for example, a still image display continues, or only a specific color pixel is driven intensively. A change for each pixel occurs depending on the contents and the like. Although it is difficult to directly measure the change in the luminous efficiency, as shown in FIG. 2, the anode voltage of the EL element and the luminous efficiency change at a constant rate. Specifically, if the initial anode voltage is Vano0 and the initial light emission efficiency is η0, the light emission efficiency decreases as the EL element drive time elapses, and the anode voltage increases. The decrease in luminous efficiency and the increase in anode voltage have a certain relationship as shown by the following formula (i).

  Therefore, in the present embodiment, as described above, each pixel is provided with the detection Tr3 for detecting the anode voltage, and the anode of the corresponding EL element 18 is detected via the detection Tr3 at a predetermined timing after the display device is shipped. The voltage is measured, and a light emission efficiency correction value for correcting the data signal to be supplied to the corresponding pixel is obtained in accordance with the change in the light emission efficiency of the EL element.

As shown in FIG. 2, the anode voltage change rate a is indicated by a = Vano1 / Vano0, and the luminous efficiency change rate b is indicated by b = η1 / η0. With respect to the initial anode voltage Vano0, the anode voltage when measuring a predetermined anode voltage (predetermined deterioration timing) is Vano1, and with respect to the initial luminous efficiency η0, the luminous efficiency when measuring the anode voltage is η1. The relationship between a and b is given by the following formula (i)
b = a * k (i)
It is a proportional relationship that satisfies In the formula, k is a value specific to the material of the organic EL element.

When the initial luminance of the EL element is represented by L0 and the luminance L1 at the time of the anode voltage measurement (predetermined deterioration timing), each luminance is represented by Expression (ii) and Expression (iii).
L0 = η0 * Ioled
= Η0 * β (Vg1−Vth) ² (ii)
L1 = η1 * Ioled
= Η1 * β (Vg1−Vth) ² (iii)
In the above formulas (2) and (3), β is a characteristic parameter of the element drive Tr2 composed of the Pch type TFT in each pixel, and the following formula (iv)
β = (1/2) * μ * (W / L) * C _ox (iv)
Indicated by Note that C _ox is the gate capacitance of this element driving Tr2.

  In the expressions (ii) and (iii), Vth is an operation threshold value of the element drive Tr2 formed of a Pch TFT, and Vg is a gate source voltage Vgs corresponding to data used for sensing.

If the voltage correction amount required to return to the initial luminance after deterioration is Va,
L0 = η1 * β ((Vg1 + Va) −Vth) ² (v)
It becomes. Furthermore, since formula (i) = formula (v),
b = η0 / η1
= {(Vg1 + Va) −Vth} ² / (Vg1−Vth) ² (vi)
(1 / b) ^1/2 = (Va + Vg1-Vth) / (Vg1-Vth) (vii)
Va = (1 / (b ^1/2 ) −1) (Vg1−Vth) (viii)
Substituting equation (i) into equation (viii) above, the following equation (ix)
Va = (1 / ((a * k) ^1/2 ) -1) (Vg1-Vth) (ix)
Thus, a desired voltage correction amount, that is, a light emission efficiency correction value can be calculated from the measured value of the anode voltage (more precisely, the anode voltage change rate a).

  In the example shown in FIG. 3, the anode voltage is measured by outputting a selection signal for turning on the selection Tr1 to all the gate lines (here, GL1 to GL480) in order to turn on all pixels at the time of measurement. At this time, a predetermined inspection data signal is output to all the data lines DL. Further, an inspection selection signal for selecting the inspection Tr3 is sequentially output to the detection control line SG of the row to be inspected. In all the pixels, the selection Tr1 is turned on and the inspection data signal is held in the holding capacitor Cs, and the element driving Tr2 operates according to the inspection data signal, and the inspection drive is performed from the power supply PVDD to the anode electrode of the EL element 18. A current corresponding to the data signal flows. In this state, when the inspection Tr3 of the row to be measured is turned on, the anode voltage signal of the EL element 18 is output to the corresponding anode voltage detection line 20.

  Here, at the time of normal display, each data line DL of the panel 100 is analogized by a digital-analog converter (DAC) 222 from a display device driving device (IC) 200 as shown in the display device configuration diagram of FIG. A display data signal converted into a signal is output. Each data line DL is provided with a data line switch DSW. During the normal display, the switch DSW is connected to the output terminal of the DAC 222. When the anode voltage is measured, the switch DSW is connected to the data signal output terminal for testing the anode voltage. In this example, a common power supply 412 (Vref) is connected to all data lines DL at the test data signal output terminal. That is, in the example of FIG. 4, the power supply Vref common to all the pixels is used as the inspection data signal. As will be described in detail later, the power supply Vref is set to a desired voltage value necessary for operating the element drive Tr2 in the saturation region. The inspection data signal is output to each data line DL as described above, and an anode voltage signal is output from each pixel in the row where the inspection selection signal is output via the anode voltage detection line 20. The anode voltage signal is sequentially converted into a digital signal in an analog-digital converter (ADC) 420, and an anode voltage value is detected.

  When the common power supply 412 for inspection is not provided, the switch DSW can be omitted, and instead, a data signal for inspection is output from the DAC 222 to each data line DL. As will be described later, when an inspection data signal subjected to individual correction for each pixel is supplied, it is sequentially output from the DAC 222. In this case, in the example of FIG. 3, when the anode voltage is measured, the anode voltage of the row to be inspected is measured with all the pixels turned on. However, as in the normal display, the pixel is turned on for each row. Alternatively, the test data signal may be output to each data line DL to perform anode voltage measurement.

  Between each anode voltage detection line 20 and the ADC 420, a changeover switch SW for selectively supplying an anode voltage signal from the plurality of anode voltage detection lines 20 to the ADC 420 is provided. , Adjacent three rows of R, G, B are switched in order and connected to the ADC 420.

  One switch SW is provided for each of R, G, and B. As shown in FIG. 4, the odd-numbered R, G, and B sets of anode voltage detection lines 20 are SL1, and even-numbered R, G, and B Assuming that the anode voltage detection line 20 of the group B is SL2, SL1R, SL1G, SL1B, SL2R, SL2G, and SL2B are sequentially selected as shown in FIG. 3 by switching the switch SW. A signal is supplied. Further, as shown in an enlarged view in FIG. 3, the SL1R selection period is further selected every six columns as SL1R, SL3R, SL5R... SL639R.

The switching method of the switches SW is not limited to the above example, but by sequentially controlling the switching of the switches SW as described above, even when a single ADC 420 is used, the anodes in all the columns can be reliably and quickly. A voltage signal can be obtained. Assuming that the ADC operating frequency is 1 MHz, in the case of a VGA panel, digital conversion processing of anode voltage signals for all pixels can be executed at (640 × 480 × 3) / 10 ⁶ = 0.46 sec. Thus, for example, if this anode voltage detection is executed when the display device is turned on, the anode voltage of all pixels is read within about 0.5 sec, and the above-described calculation is executed based on the obtained anode voltage. Thus, the light emission efficiency correction value for each pixel can be created. The obtained light emission efficiency correction value is stored in the memory at least until the apparatus power is turned off, and the data signal supplied to each pixel is displayed when the display unit is operated normally. Used for correction.

  The measurement of the anode voltage is not limited to being performed when the power is turned on. For example, the anode voltage may be divided into several lines during vertical and horizontal scanning periods during normal display.

  Next, a configuration example of a connection unit between the display panel 100 and the panel driving unit 200 will be described with reference to FIG. In FIG. 5, in the panel drive unit 200, an output terminal for supplying a data signal during normal display to the data line DL and an input terminal for supplying an anode detection signal from the anode voltage detection line SL to the ADC 420. A common terminal pad 402 is used for the pads. Further, as shown in FIG. 4, a terminal pad 404 for outputting a test data signal common to all the data lines DL when the anode voltage is detected is provided separately from the common terminal pad 402. Is connected to a power source 412. On the panel 100 side, a data line switch DSW is provided for the terminal 404 with respect to the common power supply 412.

  Switching between using the terminal pad 402 as the data signal output terminal or the anode voltage input terminal is switched by a switch 406 for switching between the output path from the DAC 222 that outputs the data signal and the input path to the ADC 420. It has been. The switch 406 is provided corresponding to each terminal pad 402. When connected to the ADC 420 side, the switch 406 is connected to the terminal pad 402 from the anode voltage detection line SL connected via the switch SW. An anode voltage signal is supplied to the ADC 420. When the switch 406 is connected to the output side of the DAC 222, a data signal is supplied from each output stage of the DAC 222 to the corresponding data line DL. In FIG. 5, when the switch 406 is switched to the ADC 420 side and in the anode voltage detection mode, the output unit of the DAC 222 is set to high impedance (HiZ) to prevent noise superposition on the DAC 222.

  Here, in the drive waveform of FIG. 3, when the anode voltage is detected, all the pixels are turned on. When such drive is performed, the gate line GL for selecting the pixels and the detection line are detected. The detection control line SG for selecting Tr3 is provided independently as shown in FIG. When the anode voltage is detected, when selecting a pixel for each row, the gate line GL and the detection control line SG in FIG. 1 can be used in common. That is, the pixel can be selected by the same selection signal, and the detection Tr3 can be selected to detect the anode voltage. When the gate line GL and the detection control line SG are shared, the input / output terminals 402 may not be shared as shown in FIG.

  Next, the relationship between the correction of the light emission efficiency with respect to the data signal supplied to each pixel and the correction of display unevenness will be described with reference to FIGS.

  In the active matrix EL display device, if the operation threshold value Vth of the element drive Tr2 of each pixel varies, even if the same data signal is supplied to each pixel, the same current is supplied to the EL element from the drive power supply PVDD. Not. Such pixel characteristic variations cause luminance variations (display variations), that is, display unevenness. In order to prevent display variation in each pixel over a long period as described above, it is preferable to correct not only the correction according to the light emission efficiency as described above but also the characteristic variation.

  The luminance variation caused by the characteristic variation can be obtained by causing the EL elements of all the pixels to emit light and imaging with a camera as in the above-mentioned Patent Document 2. Further, as will be described later, it can also be obtained by selecting each pixel, passing a current Ioled through the EL element, and sequentially detecting the cathode current. From the thus obtained luminance variation for each pixel, a display unevenness correction value for each pixel is created, and the data signal is corrected (two-dimensional correction), and the amount of current flowing through the EL element as shown in FIG. By adjusting Ioled and further correcting the anode voltage from the detection of the anode voltage according to the light emission efficiency, it is possible to correct variations in initial characteristics and changes over time.

  The method of detecting characteristic variation by imaging with the camera is executed before the display device is shipped. Two-dimensional correction data for correcting variation obtained from the detected luminance is stored in advance in the storage unit 500 of FIG. Further, the method of detecting the characteristic variation by detecting the cathode current may be executed before shipment and stored in the storage unit 500 of FIG. 8, or may be stored in the drive circuit 200 as shown in FIG. By providing the two-dimensional variation detection unit 300, variation can be measured and corrected in real time after the device is shipped.

  When variation in the operation threshold value Vth of the element drive Tr2 occurs, the current Ioled flowing through the EL element and the voltage generated by this current with respect to the gate source voltage Vgs of the element drive Tr2 shown in the equivalent circuit of FIG. Voled has a relationship as shown in FIG. FIG. 6B shows the Vds-ids (Voled-Ioled) characteristics of the element drive Tr2 and the EL element (the same applies to FIGS. 6C and 6D).

  When the operation threshold value Vth of the element drive Tr2 varies, it can be considered that a resistance larger or smaller than normal is connected to the drain side of the element drive Tr2. Although the current-voltage characteristics of the EL element are not different from those of a normal pixel, the voltage applied to the element drive Tr2 satisfies Vgs−Vth <Vds, and the element drive Tr2 is in a saturation region and in an operation region (operation region of Tr2 in a normal display operation). As shown in FIG. 6B, when Vth is smaller than the standard (Vth0), Ioled is larger than the standard, and the light emission luminance is high. Conversely, although not shown, when Vth is higher than the standard Vth0, Ioled is less than the standard, and the light emission luminance of this pixel is lower than the standard light emission luminance.

  Therefore, the data signal supplied to each pixel is operated by operating the element driving Tr2 in the saturation region to supply a display variation inspection signal and observing the light emission luminance or measuring the cathode current Icv corresponding to the EL current Ioled. The display unevenness correction value can be obtained. As shown in FIG. 6B, when the Vth (| Vth |) of the element drive Tr2 is smaller than the standard, the absolute value | Vsig | of the data signal is decreased according to the deviation of the | Vth | This correction corresponds to translating (shifting) the VI characteristic of the EL element as shown in FIG. However, since the inclination and the VI characteristic of the reference EL element are different only by shifting as shown in FIG. 7B, an accurate display is obtained by performing an operation for adjusting the inclination according to the data signal Vsig. Unevenness correction is performed.

  Even when the display unevenness correction is performed as described above, if the light emitting efficiency of the EL element decreases with the lapse of the driving time, the VI characteristic of the EL element changes and the inclination is decreased as shown in FIG. As a result, Voled, that is, the anode voltage increases. Therefore, in the present embodiment, as shown in FIG. 6D, the amount of current is increased by adjusting Vsig so as to compensate for the decrease in light emission efficiency.

  In the pixel circuit described above, a p-channel TFT is used as the element driving transistor, but an n-channel TFT may be used. Further, in the above pixel circuit, an example in which a configuration including two transistors, that is, a selection transistor and a drive transistor, is employed as a transistor for one pixel has been described. However, the transistors are not limited to the two types and the circuit configuration described above. . In the above description, the anode voltage of the EL element is detected in order to measure the change in luminous efficiency. However, the change in luminous efficiency may be measured by measuring the cathode voltage. Although the characteristic variation (Vth shift) is detected by measuring the cathode current, the anode current may be measured and detected. For example, when the individual electrode is used as the cathode electrode and the common electrode is used as the anode electrode instead of the configuration in which the individual electrode is used as the anode electrode and the common electrode is used as the cathode electrode for each pixel of the EL element, It is possible to obtain a change in luminous efficiency from the voltage and a characteristic variation from the anode current. In other words, a correction value corresponding to a change in light emission efficiency may be obtained from the voltage of the individual electrode of the EL element. In this case, a correction value corresponding to the threshold variation of the element driving transistor may be obtained from the current of the common electrode.

  FIG. 8 shows data processing of an EL display device that performs correction processing using both display unevenness correction values for correcting display unevenness caused by characteristic variations of pixels stored in advance and light emission efficiency correction values that are obtained as needed. The schematic structure of a part is shown. The storage unit 450 that can employ an EEPROM or the like stores two-dimensional correction data (display unevenness correction value) obtained in advance, and the display unevenness correction value is output to the correction calculation unit 250.

  As described above, the anode voltage signal Vano1 sequentially supplied from the anode voltage detection line to the ADC 420 via the switch SW is digitally converted by the ADC 420 and output to the light emission efficiency correction value creation unit 440. The luminous efficiency correction value creation unit 440 performs the above-described calculation based on the anode voltage Vano1 and the initial anode voltage Vano0 stored in advance (before shipment) in the storage unit 430 that can employ an EEPROM or the like. A light emission efficiency correction value is obtained and output to the correction calculation unit 250. When the initial anode voltage Vano0 is the same for all the EL elements of the pixels, the storage unit 430 may store only the initial anode voltage Vano0 that is common to all pixels, not for each pixel.

  The signal processing unit 230 is a signal processing circuit for converting an external color video signal into a display signal suitable for display on the EL panel 100. The serial / parallel converter 232 converts an externally supplied video signal into parallel data, and the obtained parallel video signal is supplied to the matrix converter 236. When the video signal supplied from the outside is in the YUV format, the matrix conversion unit 236 performs an offset process according to the color tone displayed on the EL panel. Y is the luminance signal, U is the difference between the luminance signal and the blue component, V is the difference between the luminance signal and the red component, and the YUV format represents the color with these three pieces of information. The matrix conversion unit 236 performs conversion processing such as thinning the parallel video signal into a format suitable for the EL panel 100. In addition, color space correction, bright contrast correction, and the like are also executed. Further, the gamma value setting unit 238 performs γ value setting (gamma correction) corresponding to the EL panel 100 for the video signal from the matrix conversion unit 236, and the video signal after gamma correction is used as the display data signal for the above correction calculation. Supplied to the unit 250.

  The correction calculation unit 250 corrects the display data signal to be supplied to each pixel by using both the light emission efficiency correction value and the display unevenness correction value.

  The video signal corrected as described above is supplied to a digital-analog (DA) converter 260, where it is converted into an analog data signal to be supplied to each pixel. This analog data signal is data to be output to the corresponding data line 12 of the display unit, is output to the video line provided in the panel 100, and is supplied to the corresponding data line 12 under the control of the V driver 220V. The correction calculation unit 250 estimates power consumption from the data signal supplied from the signal processing unit 230, generates an ACL signal for optimally controlling the peak current of the EL panel 100, and supplies the ACL signal to the DA conversion unit 260. ing. Thereby, generation | occurrence | production of the excessive consumption current in the panel 100 is suppressed.

  Although not shown, as described above, the luminous efficiency correction value obtained when the display device is turned on as an example is stored in a storage unit such as an EEPROM, and during normal display operation, the processing target is stored in the storage unit. It is preferable to read out the light emission efficiency correction value according to the pixel address and supply it to the correction calculation unit 250.

  Here, from the viewpoint of more accurately measuring the light emission efficiency, it is preferable to perform two-dimensional correction on the inspection data signal supplied to each pixel during the anode voltage measurement. Even when two-dimensional correction is performed on the inspection data signal, the two-dimensional correction data of the corresponding pixel is read from the storage unit 450 shown in FIG. Is output to the display section of the panel. Then, a light emission efficiency correction value may be obtained based on the obtained anode voltage signal. When the two-dimensional correction is performed on the inspection data signal, the inspection data signal is different for each pixel. Therefore, when the anode voltage is measured, a common inspection data signal is supplied to all the pixels on the data line DL. I can't. In applications (including both cases) where the influence of display unevenness is small or the device configuration needs to be simplified, two-dimensional correction is not performed, and the common inspection as shown in FIGS. 4 and 5 is performed. A data signal is supplied to each pixel to perform anode voltage measurement.

  FIG. 9 shows an example of the overall configuration of an electroluminescence display device that executes cathode current detection and anode voltage detection in real time. The display device includes an EL panel 100 in which a display unit including pixels as described above is formed, and a drive unit 200 that controls display and operation in the display unit. Unit 210, variation detector 300, and luminous efficiency change detector 400. As for the detection of the cathode current, the same processing as described below may be executed before shipping the apparatus and stored in the storage unit 450 as shown in FIG.

  The display control unit 210 includes a signal processing unit 230, a variation correction unit 250, a timing signal creation (T / C) unit 240, a driver 220, and the like.

  The signal processing unit 230 has a configuration as shown in FIG. 8 and creates a display data signal suitable for displaying an external color video signal on the EL panel 100. The timing signal creation unit 240 is supplied from the outside. Various timing signals necessary for the display unit such as H and V direction clocks CKH and CKV, horizontal and vertical start signals STH and STV are created based on the dot clock (DOTCLK) and synchronization signals (Hsync and Vsync). To do. The correction calculation unit 250 uses the two-dimensional correction data supplied from the variation detection unit 300 and the light emission efficiency correction value supplied from the light emission efficiency change detection unit 400, and the characteristics of the EL panel that is the target of driving the video signal. Correct according to.

  The driver 220 generates signals for driving the EL panel 100 in the H direction and the V direction based on various timing signals obtained from the timing signal generation unit 240 and supplies the signals to the pixels, and the correction supplied from the variation correction unit 250. The subsequent video signal is supplied as a data signal (Vsig) to each corresponding pixel. The driver 220 includes an H driver 220H that controls driving of the display unit in the H (row) direction and a V driver 220V that controls driving in the V (column) direction, as illustrated in FIG. As shown in FIG. 1, the H driver 220H and the V driver 220V can be built around the display area of the EL panel 100 on the panel substrate in the same manner as the pixel circuit of FIG. Alternatively, it may be configured together with the driving unit 200 or by another integrated circuit (IC).

  The variation detection unit 300 operates to detect a display variation and obtain a correction value during the blanking period of the EL panel 100 under a normal use environment. In the example of FIG. 9, the inspection control for controlling the variation inspection is performed. 310, a test signal generating circuit 320 for generating a test signal and supplying it to the pixels in the test row of the EL panel, a cathode current detection for detecting a cathode current obtained from the cathode electrode when the test signal is supplied A unit 330, a memory 340 for storing a cathode current detection result, a correction data generation unit 350 for generating correction data based on the detected cathode current, and the like. In addition, a control signal generation circuit for generating a selection signal necessary for selecting and inspecting a pixel in an inspection row and controlling a potential of a predetermined line as described later is incorporated in the driver 220 at the time of inspection. It can be executed according to the control of the inspection control unit 310. This configuration may be executed by a dedicated inspection control signal generation circuit, or may be executed by the inspection control unit 310.

  The light emission efficiency change detection unit 400 performs an operation for executing an anode voltage test to obtain a light emission efficiency correction value. The anode voltage test control unit 410, the anode voltage detection unit 420, the initial anode voltage memory 430, and the light emission efficiency. A correction value creation unit 440 is provided. At the time of inspection, the anode voltage inspection control unit 410 selects each pixel and supplies an inspection data signal to the driver 220, for example, and generates a control signal necessary for obtaining an anode voltage. As shown in FIG. 8, the anode voltage detection unit 420 includes an ADC connected to each anode voltage detection line 20 through a switch SW, and converts the anode voltage Vano1 obtained from each line 20 into a digital signal to obtain luminous efficiency. This is supplied to the correction value creation unit 440. The light emission efficiency correction value creation unit 440 creates a correction value based on the initial anode voltage read from the memory 430 and the measured anode voltage Vano1, and supplies the correction value to the correction calculation unit 250, as described with reference to FIG. To do.

  The cathode current detection unit 330 includes an ADC that converts the cathode current Icv obtained from the cathode electrode terminal Tcv into a digital signal as needed. In the cathode current detection process, during one blanking period of the video signal, a predetermined one row of the display unit is selected as an inspection row, an inspection signal is supplied to the corresponding pixel, and the cathode electrode of the EL element of the pixel The cathode current Icv flowing out from the cathode terminal to the cathode terminal is detected. The blanking period is a vertical blanking period or a horizontal blanking period. As a driving method for detecting the cathode current, the following method can be adopted.

(Driving method 1) When the cathode electrode is a common electrode common to all the pixels and the cathode current detection is executed during the horizontal blanking period For the EL panel 100 in the y row x column matrix, a predetermined 1 is set in one horizontal blanking period. An inspection row (n-th row) is selected, and an inspection signal is supplied to a predetermined pixel (k-th column) to detect a cathode current at that time. By repeating this operation by sequentially changing the selected row, it is possible to execute cathode current detection for all the pixels in the k-th column in one frame (one vertical (V) scan) period. By executing this process for all the columns, the detection process for all the pixels of the EL panel 100 is completed. When the EL panel 100 has a VGA type size, there are 480 rows × 640 columns of pixels. In the above method, one frame is 60 Hz, and the total is about 10.7 seconds (= 1/60 seconds × 640 columns). Cathode current detection for the pixel can be performed.

(Driving method 2) Cathode electrode is common to all pixels, and cathode current detection is executed during the vertical blanking period. During one vertical blanking period, all pixels belonging to a predetermined one inspection row (the nth row) are sequentially The inspection signal is supplied and the cathode current at that time is detected. This procedure is executed for all rows by changing the inspection row every vertical blanking period to obtain the cathode current of all the pixels. In this method, in the case of a VGA panel similar to the above, cathode current detection can be performed for all pixels in a total of about 8 seconds (= 1/60 seconds × 480 rows). A timing chart for executing this driving method 2 is as shown in FIG. 10, and in the period from the rising edge of the vertical start signal (STV) to the next rising edge, the cathode current is inspected for the nth row. Yes.

(Driving method 3) When the cathode electrode is divided for each column and the detection of the cathode current is performed during the vertical blanking period, all pixels in a predetermined one inspection row (n-th row) during one vertical blanking period Each of the test signals is supplied, and the cathode current in each column is detected. This procedure is executed for all rows by changing the inspection row every vertical blanking period to obtain the cathode current of all the pixels. In this method, in the case of a VGA panel similar to the above, cathode current detection can be performed for all pixels in a total of about 8 seconds (= 1/60 seconds × 480 rows).

As an inspection signal for the cathode current, by supplying an on-display signal for inspection with the light emission level of the EL element as a light emission level, it is possible in principle to detect display unevenness in accordance with the threshold variation of the element drive Tr2. it can. However, as the inspection signal, as shown in FIG. 7B and FIG. 10 showing the operation of the driving method 2 (see Vsig during the blanking period), the above-described on-display signal for inspection and the EL element are not light-emitted. And supply an inspection off display signal as a level to the pixels in the inspection row, and detect an on cathode current when the inspection on display signal is applied and an off cathode current when the inspection off display signal is applied. By obtaining the difference ΔIcv, it is possible to increase the inspection speed and the accuracy of the inspection. It measures the off-cathode current Icv _off, this Icv _off because it can relatively grasped on cathode current Icv _on when the ON display signal as a reference, to determine exactly the absolute value of the ON cathode current Icv _on This is because it is not necessary and it is not necessary to measure the off-cathode current Icv _off which is a separate reference. That is, by using the difference (cathode current difference) between the on-cathode current and the off-cathode current, the influence of the characteristic variation of the current detection amplifier 332 can be canceled from the cathode current difference, and the on-cathode current. This is because a reference value for determining the absolute value of the value is not required. Specifically, Vref + Icv _on * R and Vref + Icv _off * R are respectively read, converted into digital data by the AD conversion unit of the cathode current detection unit 330, and supplied to the memory unit 340. By subtraction, (Icv _on -Icv _off ) * R is finally obtained, and ΔIcv = Icv _on -Icv _off can be obtained.

  For example, the cathode current detection data for all the pixels is accumulated in the memory 340 in about 10 seconds. The memory 340 stores the cathode current detection data for all the pixels until at least the next time new cathode current detection data is obtained for all the pixels. Keep it.

  The memory 340 includes a volatile primary memory and a nonvolatile secondary memory. In addition, a selector is provided for selecting whether the data (ΔIcv data) supplied to the primary memory is data obtained in real time from the current detection unit 330 or data stored in the secondary memory.

  As the primary memory, a volatile memory capable of writing and reading data at high speed is used (for example, SRAM). On the other hand, as the secondary memory, a non-volatile memory such as an EEPROM that can retain data even when the apparatus power is turned off and is rewritable is used. Accordingly, when a high-speed memory is used as the primary memory, the cathode current detection data can be stored and the detection data can be supplied to the correction data creation unit 350 at a high speed. However, a high-speed memory such as SRAM is volatile, and data is lost when the apparatus power is turned off. However, by adopting a non-volatile EEPROM or the like as the secondary memory, the cathode current detection data for each pixel stored in advance in the secondary memory is read and supplied to the primary memory when the power is turned on. In this case, correction can be performed using the cathode current detection data stored in the secondary memory immediately after the power is turned on until the real-time cathode current detection data is obtained.

  The correction data creation unit 350 reads the cathode current detection data for each pixel stored in the primary memory 342 in the memory 340 as needed, and based on this data, changes in the characteristics of the element drive Tr2 of each pixel with respect to the video signal. Correction data for correcting the resulting display variation is created as follows.

  Next, the creation of correction data according to the threshold deviation of the element drive Tr2 will be described more specifically. As shown in FIG. 7B, when the same inspection signal that causes the EL element to emit light is applied, the threshold value Vth of the element drive Tr2 of the pixel to be measured is normal. When shifting to a higher voltage side than Vth (the one-dot chain line in the figure), the obtained cathode current is Icv for the normal pixel, whereas it is Icvb for the shifted pixel.

  Accordingly, as shown in FIG. 7B, the correction data creation unit 350, when the operation threshold value Vth of the element drive Tr2 is deviated from a normal TFT, is determined from the cathode current detection data as the operation threshold value Vth. Correction data that compensates for the deviation is obtained. Conceptually, with this correction data, the voltage of the data signal supplied to each pixel is shifted according to the deviation of the operation threshold value Vth as shown by the dotted line in FIG.

  An example of a method of creating correction data for shifting the voltage of the data signal will be specifically described as follows. First, the deviation of the operation threshold value of each pixel from the reference can be obtained by the following equation (1).

  In formula (1), Vth (i), V (Icv), Vsigon and γ are defined as follows.

Vth (i): Operation threshold deviation of the pixel to be inspected V (ΔIcv): On / off cathode current value (voltage data) of the pixel to be inspected
V (ΔIcvref): reference on / off cathode current value (voltage data)
Vsigon: gradation level of on-display signal for inspection γ: luminous efficiency characteristic of display panel (constant value)
When the gradation level [Vsignon] of the on-display signal for inspection is set to 240 (0 to 255), for example, the gradation level 240, the on / off cathode current value [V (ΔIcv)] of the pixel to be inspected, and the reference on / off Based on the cathode current value [V (ΔIcvref)] and the constant luminous efficiency characteristic γ, the operation threshold value deviation Vth (i) with respect to the reference of each pixel can be obtained from the above equation (1). For example, it is assumed that the threshold deviation amount Vth (i) from the reference is obtained for each of the pixels A to E as follows.

Vth (A) = 0
Vth (B) = 13.4
Vth (C) = 17.0
Vth (D) = 3.2
Vth (E) = 20.7
In the above example, the threshold value Vth shift of the pixel E is the maximum, and when the data signal of the same gradation level is supplied to each pixel, the pixel E emits light with the lowest luminance in the display portion. On the other hand, there is a limit to the maximum value of the data signal that can be supplied to each pixel. Therefore, the maximum value Vsig _max of the data signal is determined based on the pixel E of Vth (i) _max . That is, the maximum value Vth (i) _max is obtained from the obtained Vth (i) of each pixel, and the difference ΔVth (i) of Vth of other pixels with respect to this Vth (i) _max is obtained. Further, the maximum value Vsig _max (i) of the data signal to be supplied to the pixel is subtracted from the obtained ΔVth (i) from Vsig _max to obtain [Vsig _max −ΔVth (i)]. The initial correction data RSFT (init) reflecting the correction value of (2) is supplied to the correction calculation unit 250.

  The correction data of each pixel created by the correction data creation unit 350 as described above can be stored in, for example, the correction value storage unit 280 shown in FIG. This correction data is preferably stored until the correction data for all the pixels is next obtained.

  The correction calculation unit 250 executes variation correction for each pixel on the video signal supplied from the signal processing unit 230 using the stored correction data until new display unevenness correction data is obtained. (Two-dimensional display unevenness correction). The correction data creation unit 350 may create correction data and supply the correction data to the correction calculation unit 250 at a timing necessary for the correction calculation in the correction calculation unit 250 (according to the timing of the video signal).

Here, in the variation correction unit 250, the following formula (2) is given as an example.

  2D display unevenness correction is executed using. In Formula (2), RSFT (init) is initial correction data reflecting the correction value obtained by the correction data creation unit 350 (if correction data for each pixel exists before factory shipment, the correction is performed). The value also reflects the data). Rin is an input video signal supplied from the signal processing unit 230, and is 9-bit data here and has any value of 0 to 511. ADJ_SFT is a correction value adjustment (weighting) parameter, and R_SFT is display data after two-dimensional display unevenness correction.

  As can be understood from FIG. 7B, when a deviation occurs in the operation threshold value Vth of the element drive Tr2, the slope β of the characteristic curve of this TFT is different from the slope of the normal TFT characteristic curve. Accordingly, the correction calculation unit 250 uses the above equation (2) and the like to perform the optimum correction according to the value (luminance level) of the actual video signal in consideration of the slope β, that is, the weighting parameter of the above equation (2). Is adjusted so that a cathode current suitable for normal TFT characteristics flows to the EL element. By such correction, it is possible to surely prevent white gradation on the low gradation side (shift to the high gradation side) or the like caused by a difference in the inclination of the TFT characteristics when only simple ΔVth shift correction is performed.

  As described above, the display unevenness correction by detecting the cathode current as described above can be performed more accurately on the anode voltage test data signal when the anode voltage is measured. Become. Of course, as shown in FIGS. 4 and 5 described above, the common inspection data signal may be output without performing the display unevenness correction on the inspection data signal when the anode voltage is measured.

  In the case of calculating the display unevenness correction value by imaging the light emission luminance with the camera as described above, in the above equation (1), instead of Vsigon and Vsigoff, for example, the obtained luminance levels Lon and Loff are respectively used. Can be used to calculate.

1 is an equivalent circuit diagram for explaining an example of a schematic circuit configuration of an EL display device according to an embodiment of the present invention. It is a figure explaining the relationship between the anode voltage and luminous efficiency which concern on embodiment of this invention. It is a figure which shows the operation | movement waveform at the time of the anode voltage measurement which concerns on embodiment of this invention. It is a figure which shows schematic structure of the EL display panel which concerns on embodiment of this invention, and the drive device which drives this panel. It is a figure which shows the structural example of the connection part of the EL display panel which concerns on embodiment of this invention, and the drive device which drives a panel. It is a figure explaining the correction principle of the characteristic variation of the element drive transistor which concerns on embodiment of this invention, and the correction principle of light emission efficiency reduction | decrease. It is another figure explaining the correction principle of the characteristic variation of the element drive transistor which concerns on embodiment of this invention, and the correction principle of light emission efficiency reduction | decrease. It is a figure which shows the structural example of EL display apparatus provided with the correction function which concerns on embodiment of this invention. It is a schematic circuit diagram explaining an example different from FIG. 1 of the schematic circuit configuration of the EL display device according to the embodiment of the present invention. It is a timing chart explaining the drive system 2 for the detection of the cathode current which concerns on embodiment of this invention.

Explanation of symbols

  10 gate lines (GL), 12 data lines (DL), 14 capacitance control lines (SC), 16 power supply lines (VL), 18 EL elements, 20 anode voltage detection lines (SL), 22 detection control lines (SG), 100 EL panel, 200 drive unit (panel drive device), 220 driver, 222 inspection control signal generation circuit, 230 signal processing unit, 240 timing signal creation (T / C) unit, 250 correction calculation unit, 280 correction parameter setting unit (Correction value storage unit), 300 variation detection unit, 310 inspection control unit, 320 inspection signal generation circuit, 330 cathode current detection unit, 340 memory, 350 correction data creation unit, 400 luminous efficiency change detection unit, 410 anode voltage detection Control unit, 420 anode voltage inspection unit, 430 memory (initial annotator) Voltage storage unit), 440 luminous efficiency correction value creation section 450 the two-dimensional correction data storage unit, 500 storage unit.

Claims (7)

An electroluminescence display device comprising: a display unit; and a data processing unit for processing a data signal supplied to the display unit,
The display unit includes a plurality of pixels arranged in a matrix.
Each of the plurality of pixels is
An electroluminescent element having a diode structure;
An element driving transistor connected to the electroluminescent element for controlling a current flowing through the electroluminescent element;
A detection transistor connected to the anode electrode of the electroluminescence element for detecting the anode voltage of the electroluminescence element,
The data processing unit supplies an inspection data signal to each pixel and based on the anode voltage obtained through the detection transistor and the initial anode voltage of the corresponding pixel, in the corresponding electroluminescence element An electroluminescence display device characterized by obtaining a light emission efficiency correction value for correcting a data signal to be supplied to a corresponding pixel in accordance with a change in light emission efficiency. The electroluminescent display device according to claim 1,
The electroluminescence display device, wherein the inspection data signal is corrected by a display unevenness correction value for correcting display unevenness caused by characteristic variation of each pixel. The electroluminescence display device according to claim 1 or 2,
The data processing unit
During normal display, a correction process is performed on the data signal supplied to the corresponding pixel by using the display unevenness correction value for correcting display unevenness due to the characteristic variation of each pixel and the light emission efficiency correction value.
The display unevenness correction value is
An electroluminescence display device characterized in that it is obtained by detecting a characteristic variation of a corresponding pixel based on a light emission luminance of each pixel of the electroluminescence element. The electroluminescence display device according to claim 1 or 2,
The data processing unit
During normal display, a correction process is performed on the data signal supplied to the corresponding pixel by using the display unevenness correction value for correcting display unevenness due to the characteristic variation of each pixel and the light emission efficiency correction value.
The display unevenness correction value is
An on-display signal for inspection with the electroluminescence element as a light emission level is supplied to each pixel, and the element driving transistor is operated in a saturation region of the transistor to detect a cathode current of the electroluminescence element, An electroluminescence display device characterized by being obtained based on a value of a cathode current. The electroluminescence display device according to claim 1 or 2,
The data processing unit
During normal display, a correction process is performed on the data signal supplied to the corresponding pixel by using the display unevenness correction value for correcting display unevenness due to the characteristic variation of each pixel and the light emission efficiency correction value.
The display unevenness correction value is
An on-display signal for inspection that causes the element driving transistor of each pixel to operate in a saturation region of the transistor and that causes the pixel to emit light, and an off-display signal for inspection that causes the electroluminescent element to emit light at a non-emission level Supply, and
Detecting the on / off current difference between the cathode current of the electroluminescence element according to the on-display signal for inspection and the cathode current of the electroluminescence element according to the off-display signal for inspection;
The electroluminescence display device characterized in that the on / off current difference is obtained from a comparison with a reference value. The electroluminescence display device according to any one of claims 1 to 5,
The luminous efficiency correction value is
Based on the relationship between the anode voltage change rate a according to the initial anode voltage and the anode voltage at the time of measurement, and the light emission efficiency change rate b according to the initial light emission efficiency and the light emission efficiency at the time of the anode voltage measurement, The electroluminescence obtained by using the light emission efficiency change rate b calculated from the anode voltage change rate a and obtaining the data signal as a correction amount necessary for obtaining light emission luminance corresponding to the initial light emission efficiency. Display device. The electroluminescence display device according to any one of claims 1 to 6,
The anode voltage measurement control unit supplies the inspection data signal to a corresponding pixel when a predetermined power source of the electroluminescence display device is turned on, controls each detection transistor of the plurality of pixels, and the inspection transistor Measure the anode voltage obtained through
The luminous efficiency correction value is calculated based on the obtained anode voltage and the initial anode voltage held in advance in the anode voltage storage unit, and stored in the luminous efficiency correction value storage unit,
In normal display, the data processing unit executes correction processing on a data signal supplied to each pixel based on the light emission efficiency correction value and display unevenness correction value.

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