JP2010203889A - Method and device for measuring luminance of display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure accurately a luminance of each pixel in a display panel only by optical measurement. <P>SOLUTION: Luminance data having luminance values at each imaging point S in a CCD (Charge Coupled Device) 41a of a CCD camera 41 are obtained from an image signal obtained by imaging a display part 30 of an EL display panel 1 by the CCD camera 41 of this luminance measuring device 40, and the obtained luminance data are classified into each pixel corresponding domain Ps and arranged in the order of luminance. Then, a prescribed number (to put it concretely, an equivalent number below an open area ratio of a pixel P to the number of all pixels) of luminance data are extracted from the high luminance side, and a luminance value of each pixel P is calculated based on the extracted luminance data, and thereby a luminance value corresponding to only an outgoing domain R1 in the pixel P including the outgoing domain R1 and a non-outgoing domain R2 can be measured surely. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display panel luminance measurement method and a display panel luminance measurement apparatus.

  An organic EL (Electro Luminescence) element is a light emitting element having a laminated structure in which an electron injection layer, an organic compound layer, and a hole injection layer are interposed between an anode and a cathode. When a forward bias voltage is applied between the anode and the cathode, electrons are injected from the electron injection layer into the organic compound layer, holes are injected from the hole injection layer into the organic compound layer, and electrons are injected into the organic compound layer. The holes cause recombination and the organic compound layer emits light. In addition, an EL display panel that displays images by arranging a plurality of organic EL elements that emit red, green, and blue as subpixels (pixels) on a substrate in a matrix is realized.

  Different organic compound layers can be formed for each red, green, and blue pixel by applying a solution containing different organic compound layer materials to the red, green, and blue pixels in an EL display panel and removing the solvent. . When the organic compound layer is formed by coating, it is difficult to make the thickness of the organic compound layer uniform, and luminance unevenness and chromaticity unevenness due to the difference in layer thickness are likely to occur.

For this reason, a method of acquiring information on luminance unevenness for each pixel in an EL display panel and driving the organic EL element so as to correct the luminance unevenness has been developed.
As a method of acquiring the luminance unevenness information for each pixel, when it is attempted to acquire the luminance unevenness information by optically measuring the EL display panel with a CCD (Charge Coupled Device), each pixel of the EL display panel is obtained. Imaging noise called moire may occur due to the relationship between the arrangement interval and the arrangement interval of each image pickup device of the CCD. Furthermore, moire may be caused by a slight misalignment between each image pickup device of the CCD and each pixel of the EL display panel. Since the state changes, it is difficult to detect accurate luminance unevenness only by optical measurement. Therefore, for example, by combining optical measurement and current measurement, specifying an area with uneven brightness by optical measurement with a CCD, and measuring the current for each pixel in the specified area, accurate brightness unevenness for each pixel can be obtained. There is a technique for acquiring the above information (for example, see Patent Document 1).

JP 2007-18876 A

As described above, since it is difficult to accurately measure the luminance for each pixel in the EL display panel in the conventional optical measurement, in order to accurately measure the luminance unevenness for each pixel, for example, current measurement for each pixel is performed. It was necessary to use together, and it took a lot of labor and time.
In addition, since the current value for each pixel is affected by variations in element characteristics of the transistors and organic EL elements included in the pixel, the current value does not necessarily correspond to the luminance value for each pixel. For this reason, even if current measurement is used in combination with optical measurement, accurate information on luminance unevenness may not be obtained.
In addition, if there is uneven brightness on the entire screen of the display panel, the currents of all the pixels on the display panel must be measured, and there is a problem that the processing may take an enormous amount of time.

  An object of the present invention is to enable accurate measurement of luminance for each pixel in a display panel only by optical measurement.

In order to solve the above problems, one aspect of the present invention provides:
A display panel having a display area in which a plurality of pixels each having an emission area where light having a luminance corresponding to a gradation value of display data is emitted to a visual field side and a non-emission area where light is not emitted are arranged; A luminance measurement method for measuring the luminance of each pixel by imaging with an imaging device in which a plurality of imaging points are arranged in a matrix at an interval narrower than an arrangement interval of pixels,
By emitting light of luminance according to the gradation value of the display data from the emission area of all the pixels, the entire range of the display area of the display panel is imaged from the visual field side with the imaging device, Obtaining luminance data having a luminance value for each imaging point;
Arranging the luminance data of each imaging point for each pixel corresponding area corresponding to each pixel in the acquired luminance data for each imaging point in ascending or descending order for each luminance value;
Extracting a predetermined number of the luminance data set in advance from the high luminance side of the luminance data arranged for each luminance value for each pixel corresponding region;
Calculating a luminance value of each pixel based on the luminance data on the high luminance side extracted for each pixel corresponding region;
It is characterized by having.
Preferably, in the step of extracting a predetermined number of luminance data from the high luminance side of the luminance data, the predetermined number is a ratio of the predetermined number to the total number of the luminance data for each pixel corresponding region. The number is equal to or less than the ratio of the emission region in the region.
Preferably, the predetermined number is a number at which the ratio of the predetermined number to the total number of the luminance data for each pixel corresponding area is 50% or less of the ratio of the emission area to the entire area of the pixel.
Preferably, the predetermined number is a number obtained by excluding the imaging points arranged at positions adjacent to the non-emission area from the number of imaging points included in the emission area of one pixel.

Another aspect of the present invention is as follows:
A brightness measurement apparatus for a display panel, comprising a display area in which a plurality of pixels each having an emission area where light having a luminance corresponding to a gradation value of display data is emitted to a visual field side and a non-emission area where light is not emitted are arranged. There,
An imaging element that images a whole range of the display area of the display panel, in which a plurality of imaging points are arranged in a matrix at an interval narrower than an arrangement interval of the plurality of pixels;
The imaging element captures the entire range of the display area of the display panel with the imaging element in a state in which light having a luminance corresponding to the gradation value of the display data is emitted from the emission area of all the pixels, and the imaging point A luminance value acquisition control unit for acquiring luminance data having a luminance value for each;
A luminance value permutation control unit that arranges the luminance data of the imaging points for each pixel corresponding region corresponding to each pixel in the acquired luminance data for each imaging point in ascending or descending order for each luminance value;
A luminance value extraction control unit that extracts a predetermined number of the luminance data set in advance from the high luminance side of the luminance data arranged for each luminance value;
A luminance value calculation unit for calculating a luminance value of each pixel based on the luminance data on the high luminance side extracted for each pixel corresponding region;
It is characterized by having.
Preferably, the predetermined number is a number such that a ratio of the predetermined number to a total number of the luminance data for each pixel corresponding area is equal to or less than a ratio of the emission area in the entire area of the pixel.
Preferably, the predetermined number is a number such that a ratio of the predetermined number to a total number of the luminance data for each pixel corresponding region is 50% or less of a ratio of the emission region in the entire region of the pixel. .
Preferably, the predetermined number is a number obtained by excluding the imaging points arranged at positions adjacent to the non-emission area from the number of imaging points included in the emission area of one pixel.

  According to the present invention, the luminance of each pixel in the display panel can be accurately measured only by optical measurement.

It is the schematic which shows EL display panel. It is explanatory drawing which shows the display part of EL display panel. It is a circuit diagram which shows the drive circuit equivalent to one pixel of an EL display panel. It is explanatory drawing which shows a brightness | luminance measuring apparatus. It is explanatory drawing regarding the imaging point of CCD corresponding to each area | region of the display part of EL display panel. FIG. 4 is an enlarged view of a pixel portion in a display unit, and is an explanatory diagram relating to an imaging point on the center side of an opening, corresponding to an emission region in the pixel and excluding an imaging point adjacent to a non-emission region. A state in which “n” imaging points are included in the range of the length “L” is shown (a) when the most imaging points are included in the range, and when the imaging points are the minimum within the range (b). It is explanatory drawing about. It is a figure for demonstrating the effect in this invention in a brightness | luminance measurement. It is the flowchart which showed the flow of the process of the brightness | luminance measurement of EL display panel performed in a brightness | luminance measuring apparatus.

  Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

1 is a schematic diagram showing an EL display panel 1 as a display panel, FIG. 2 is an explanatory diagram showing a display unit 30 of the EL display panel 1, and FIG. 3 shows one pixel (one pixel) of the EL display panel 1. It is a circuit diagram which shows an example of the drive circuit 12 provided in the inside. In practice, pixels corresponding to a larger number of rows and columns are arranged.
The EL display panel 1 is a color display that operates by an active matrix driving method.

For example, as shown in FIG. 1, the EL display panel 1 includes a display unit 30 in which a plurality of pixels are arranged in a matrix, a control unit 20 provided outside the display unit 30, and the display unit 30. A scanning driver 22 provided on the left side, a data driver 23 provided on the upper side of the display unit 30 in the drawing, and a supply driver 24 provided on the right side of the display unit 30 in the drawing are provided.
The control unit 20 includes a memory 21, performs predetermined processing on an externally input video signal, and then outputs a signal to the scanning driver 22, the data driver 23, and the supply driver 24. The memory 21 stores parameters and the like necessary for processing the input signal by the control unit 20.

The display unit 30 of the EL display panel 1 has a plurality of scanning lines 2 drawn from the scanning driver 22, a plurality of signal lines 3 drawn from the data driver 23, and a plurality of supplies drawn from the supply driver 24. Line 4 is arranged.
The scanning lines 2 are arranged to be parallel to each other, the signal lines 3 are arranged to be orthogonal to the scanning lines 2, and the supply lines 4 are arranged to be parallel to the scanning lines 2 between the adjacent scanning lines 2. Yes.

Further, as shown in FIG. 2, the display unit 30 is a display region in which pixels P each having an emission region R1 and a non-emission region R2 surrounding the emission region R1 are arranged in a matrix.
A substantially rectangular region surrounded by the scanning line 2, the signal line 3, and the supply line 4 in FIG. 1 corresponds to the pixel P in FIG. The non-emission region R2 includes a partition wall B provided between the pixels P, a thin film transistor that forms a driving circuit in the pixel, and a wiring region. A substantially rectangular opening surrounded by the partition wall B or the like is the emission region R1. A predetermined light-emitting layer (for example, a laminate including an electron injection layer, an organic compound layer, a hole injection layer, and the like) is formed in the opening to form the emission region R1.
Note that a plurality of pixels P in which light emitting layers of three colors “red, green, and blue” are formed in openings of adjacent pixels P are arranged in a matrix, and the adjacent “red, green, and blue” are arranged. The three color pixels P form a set, which is one unit of display pixels.

  For example, as shown in FIG. 3, the drive circuit 12 includes thin film transistors 5, 6, 7 and a capacitor 8, and drives the organic EL element 10 connected to the circuit. Hereinafter, the thin film transistor 5 is referred to as a switch transistor 5, the thin film transistor 6 is referred to as a holding transistor 6, and the thin film transistor 7 is referred to as a drive transistor 7. The organic EL element 10 is a light emitting element having a laminated structure in which a predetermined light emitting layer is interposed between an anode and a cathode.

  In each pixel P, the gate of the switch transistor 5 is connected to the scanning line 2, one of the drain and source of the switch transistor 5 is connected to the signal line 3, and the other of the drain and source of the switch transistor 5 is The organic EL element 10 is connected to the anode, one electrode 82 of the capacitor 8, and one of the source and drain of the driving transistor 7. The other of the source and drain of the driving transistor 7 is connected to the supply line 4, and the gate of the driving transistor 7 is connected to the other electrode 81 of the capacitor 8 and one of the drain and source of the holding transistor 6. The other of the drain and the source of the holding transistor 6 is connected to the supply line 4, and the gate of the holding transistor 6 is connected to the scanning line 2.

  The organic EL elements 10 in all the pixels P have a cathode as a common electrode, and are kept at a constant voltage Vcom by the cathode being grounded, for example. For example, the organic EL elements 10 in the same row are arranged in the order of red, green, and blue, and the organic EL elements 10 in the same column have the same color.

  Then, around the EL display panel 1, the scanning line 2 is connected to the scanning driver 22, the supply line 4 is connected to the supply driver 24, the signal line 3 is connected to the data driver 23, and the EL display panel 1 is connected by these drivers. It is driven by an active matrix driving method.

  Next, a luminance measuring apparatus that measures the luminance of the EL display panel 1 will be described.

  As shown in FIG. 4, the luminance measuring device 40 includes a CCD camera 41 that images the EL display panel 1 and a computer 42 connected to the CCD camera 41. The computer 42 is also connected to the control unit 20 of the EL display panel 1.

  The CCD camera 41 includes a CCD 41a that is an image sensor, and is disposed to face the display unit 30 so as to capture the entire range of the display unit 30 of the EL display panel 1. Output to. A plurality of imaging points S are arranged in a matrix on the CCD 41a of the CCD camera 41. When the entire range of the display unit 30 of the EL display panel 1 is imaged by the CCD camera 41, a plurality of points at the points corresponding to the respective imaging points S over the entire range of the display unit 30, as shown in FIG. Luminance data can be acquired. The interval between the imaging points S of the CCD 41a is shorter than the interval between the pixels P of the display unit 30, and the imaging points S correspond to portions corresponding to the emission region R1 and the non-emission region R2 in the pixel P. The luminance data of each area is acquired.

Here, the CCD camera 41 and the display unit 30 of the EL display panel 1 use, for example, a method in which the CCD camera 41 captures a reference point set in advance on the display unit 30, so that the CCD 41 a of the CCD camera 41 can be used. Each imaging point S and each pixel P of the display unit 30 are positioned so as to have a certain positional relationship. As will be described later, in the luminance measurement method of the present invention, the luminance data group corresponding to one pixel P is used instead of designating the coordinates of each imaging point S of the CCD 41a to obtain the luminance value of each pixel P. Therefore, a predetermined number of luminance data on the high luminance side is extracted from each pixel P. Therefore, even if there is a certain degree of positional deviation between each imaging point S of the CCD 41a and each pixel P of the display unit 30, it is determined for each pixel P. It is possible to accurately measure the luminance value. Therefore, the positioning accuracy between each imaging point S and each pixel P of the CCD 41a may be relatively low.
The computer 42 includes a memory 42a that stores various data and programs, and a control processing unit 42b that executes various processes.

The memory 42 a stores programs for executing various processes in the computer 42 (control processing unit 42 b), and records luminance data (for example, luminance values) based on image signals captured by the CCD camera 41.
The control processing unit 42b executes various processes related to luminance data based on a program stored in the memory 42a.

Specifically, the control processing unit 42b, for example, based on the luminance value acquisition control program, a plurality of imaging points S in the CCD 41a of the CCD camera 41 from the image signal obtained by imaging the display unit 30 by the CCD camera 41. The process of acquiring the luminance data is executed and functions as a luminance value acquisition control unit.
In addition, the control processing unit 42b, for example, based on the luminance value permutation control program, the acquired plurality of luminance data for each imaging point S is an area corresponding to each pixel P of the display unit 30 (hereinafter referred to as a pixel corresponding area Ps). Here, each imaging point S and each pixel P of the CCD 41a are positioned as described above, and the shape and dimensions of one pixel P are known in advance. The luminance data for each imaging point S can be divided for each pixel corresponding region Ps. And the control process part 42b performs the process which arranges the luminance data of the imaging point S for every pixel corresponding | compatible area | region Ps in ascending order or descending order for every luminance value of each luminance data, and functions as a luminance value permutation control part.

  The control processing unit 42b executes a process of extracting a predetermined number of luminance values from the high luminance side of the luminance data arranged in the order of the luminance values for each pixel corresponding region Ps, for example, based on the luminance value extraction control program. And functions as a luminance value extraction control unit. The predetermined number here is a number that is equal to or less than the ratio of the emission region (R1) in the entire region (R1 and R2) of the pixel P to the total number of luminance data divided for each pixel corresponding region Ps. For example, the number is preferably about half of the ratio of the emission region R1 that is the opening to the entire region of the pixel P (that is, the opening ratio of the opening in the partition wall B).

In addition, the control processing unit 42b executes, for example, a process of calculating an average value of luminance values of luminance data on the high luminance side extracted for each pixel P based on a luminance average calculation control program, and functions as a luminance calculation unit. To do.
Then, the average value of the luminance values of the luminance data calculated by the control processing unit 42b as the luminance calculating unit is set as the luminance value of each pixel P. Thus, the luminance of all the pixels P of the EL display panel 1 (display unit 30) is measured.
In the above description, the control processing unit 42b obtains a plurality of luminance data for each imaging point S in the CCD 41a of the CCD camera 41, and then classifies the obtained plurality of luminance data for each imaging point S for each pixel corresponding region Ps. However, the processing order is not limited to this. For example, when acquiring a plurality of luminance data for each imaging point S, the luminance data is acquired while dividing the luminance data for each pixel corresponding region Ps. There may be.
In the above description, the control processing unit 42b calculates the average value of the luminance values of the luminance data on the high luminance side extracted for each pixel P, and sets this as the luminance value of each pixel P. The luminance value of each pixel P is not limited to the average value of the luminance values of the luminance data. For example, when the variation of the luminance value of each luminance data is large, the median value (median) of the luminance value of each luminance data may be used, and further, a value calculated by a calculation method based on another statistical processing method May be used.

  Here, the control processor 42b as a luminance value extraction controller controls the predetermined number of luminance values extracted from the high luminance side of all luminance values arranged for each pixel P to the entire region (R1 and R2) of the pixel P. Consider a number that is equal to or less than the ratio (aperture ratio) of the emission area (R1) in the inside, particularly about half the ratio (aperture ratio) of the emission area R1 that is an opening to the entire area of the pixel P. .

Since the imaging point S in the CCD 41a corresponds to a portion corresponding to the emission region R1 and the non-emission region R2 in the pixel P, there is a high luminance side in the luminance data arranged in order of luminance value for each pixel corresponding region Ps. The luminance data having a relatively high luminance value obtained by the imaging point S corresponding to the emission region R1 is selectively arranged.
Therefore, it can be said that the luminance data corresponding to the emission region R1 can be selectively obtained by extracting the number of luminance data equal to or less than the ratio (aperture ratio) of the emission region R1 from the high luminance side of the total luminance value. Specifically, for example, when the total luminance data is 100 and the aperture ratio is 40%, if 40 or less luminance data are extracted from the high luminance side, the extracted luminance data is theoretically stored in the emission region R1. Corresponding.
However, if there is a deviation in the imaging range of the display unit 30 by the CCD camera 41, or there is an error when the luminance data for each imaging point S of the CCD 41a is divided for each pixel corresponding region Ps, for example, the emission region R1 In some cases, the luminance data obtained by the imaging point S straddling the non-exiting region R2 may be included on the high luminance side, and as a result, a luminance value corresponding only to the emitting region R1 cannot be obtained reliably. Therefore, in order to reliably obtain the luminance value corresponding only to the emission region R1, it is preferable to exclude the luminance value corresponding to the imaging point S corresponding to the vicinity of the boundary between the emission region R1 and the non-emission region R2.

  For example, as shown in FIG. 6, the size of the entire region of the pixel P is “X × Y”, the size of the emission region R1 of the pixel P is “A × B”, and the interval between the imaging points S of the CCD 41a. Is “d”.

For example, when “n” imaging points S are included in the range of the length “L”, as shown in FIG. 7A, when the most imaging points S are included in the range, Equations (1) and (2) are established.
(N−1) × d <L (1)
n <(L + d) / d (2)
Further, as shown in FIG. 7B, when the imaging point S is the smallest in the range, the following expressions (3) and (4) are established.
L <(n + 1) × d (3)
(Ld) / d <n Formula (4)

Based on the equations (2) and (4), the imaging point S (the imaging indicated by the white circles in FIG. 6) corresponds to the emission region R1 in the pixel P and excludes the imaging point S adjacent to the non-emission region R2. The number “N” of points S) can be expressed by the following equations (5) and (6).
{[(A−d) / d] −2} × {[(B−d) / d] −2} <N (5)
N <{[(A + d) / d] −2} × {[(B + d) / d] −2} Expression (6)

Specifically, if X = Y = 150 μm, A = B = 100 μm, and d = 10 μm, the number (N) of the imaging points S is 49 <N <81.
Similarly, the total number (Np) of the imaging points S included in the pixel P is
{[(X−d) / d]} × {[(Y−d) / d]} <Np <{[(X + d) / d]} × {[(Y + d) / d], 196 <Np <256.
That is, the imaging points corresponding to the emission area R1 but excluding the imaging points S adjacent to the non-emission area R2 with respect to the 196 imaging points S having the minimum number (Np) of the pixels P in the entire area. The ratio of the number “N” of S corresponds to 25% when N = 49 and 41% when N = 81.
In addition, the imaging points corresponding to the emission region R1 but excluding the imaging points S adjacent to the non-emission region R2 with respect to the maximum 256 imaging points S (Np) entering the entire region of the pixel P. The ratio of the number “N” of S corresponds to 19% when N = 49 and 32% when N = 81.
Since the aperture ratio ((A × B) × 100 / (X × Y)) of the pixel P is 44.4%, the number (Np) of the imaging points S entering the entire region of the pixel P is If the number is equal to or less than the aperture ratio, it can be said that luminance data corresponding to the emission region R1 can be selectively obtained.
Furthermore, if the number is about half of the aperture ratio, it can be said that luminance data corresponding only to the emission region R1 can be obtained more reliably.

Next, the effect by this invention is demonstrated. FIG. 8 is a diagram for explaining the effect of the present invention in luminance measurement. FIG. 8A shows the relationship between one pixel P and the one-pixel corresponding area Ps set in the CCD 41a in the case of the present invention, and FIG. 8B shows the setting in the CCD in the conventional optical measurement. The relationship between the 1-pixel luminance detection area Px and the 1-pixel P is shown. In the present invention, the one-pixel corresponding area Ps set in the CCD 41a is set to the same size as the one pixel P. As shown in FIG. 8A, even when the one-pixel corresponding region Ps is shifted by Xa in the horizontal direction and by Ya in the vertical direction, the emission region R1 is present in the one-pixel corresponding region Ps. If included, the luminance data corresponding to the emission region R1 can be extracted.
On the other hand, the luminance detection region Px of one pixel set in the CCD in the conventional optical measurement is set to a size smaller than the size of the emission region R1 in order to measure the luminance of the light emitted from the emission region R1. In this case, as in the case shown in FIG. 8A, when the horizontal direction is shifted by Xa and the vertical direction is shifted by Ya, a part of the luminance detection region Px is located in the non-exit region R2 outside the output region R1. It will take. In this case, a value obtained by averaging the luminance values measured by the CCD in the luminance detection region Px is lower than the luminance of the original emission region R1.

  As described above, since the influence of the positional deviation between the CCD and the pixel P is relatively large in the configuration in the conventional optical measurement, in order to accurately measure the luminance of each pixel P, the positioning of the CCD and the pixel P is strictly performed. There was a need. In addition, since this is difficult, it is necessary to use, for example, current measurement together in order to measure accurate luminance unevenness. On the other hand, in the configuration of the present invention, as described above, the allowable range for positional deviation is relatively large as compared with the conventional configuration. Therefore, in the present invention, the positioning accuracy between the CCD and the pixel P may be relatively low, and the configuration related to positioning can be simplified. Furthermore, in the present invention, since it is possible to measure the exact brightness of each pixel P only by optical measurement with the CCD, it is not necessary to use current measurement together, and brightness unevenness on the entire surface of the display panel is measured. Even in this case, the time required for the measurement can be shortened as compared with the prior art.

  Next, a method for measuring the luminance of the EL display panel 1 using the above-described luminance measuring device 40 will be described. FIG. 9 is a flowchart showing a flow of luminance measurement processing of the EL display panel 1 performed in the luminance measurement device 40.

First, the entire range of the display unit 30 of the EL display panel 1 in which all the pixels P emit light at a predetermined reference gradation is imaged by the CCD camera 41 of the luminance measuring device 40, and each imaging point S in the CCD 41 a of the CCD camera 41 is captured. Luminance data is acquired by the control processing unit 42b and recorded in the memory 42a (step S101). Here, the reference gradation may be, for example, the highest gradation or an intermediate gradation.
Next, the control processing unit 42b classifies the luminance data for each imaging point S acquired and recorded in the memory 42a for each pixel corresponding region Ps (step S102).
Then, the control processing unit 42b arranges the luminance data for each imaging point S for each pixel corresponding region Ps in ascending order or descending order for each luminance value (step S103).
Next, the control processing unit 42b obtains a predetermined number (for example, the total number of pixels P (Np) from the high luminance side from the luminance data for each imaging point S arranged in the order of luminance values for each pixel corresponding region Ps. ) Of luminance data corresponding to the aperture ratio of the pixel P or less (N)) is extracted (step S104). The luminance data extracted here is obtained by the imaging point S corresponding to the emission region R1 in the pixel P, and the imaging point S straddling the emission region R1 and the non-emission region R2 or the non-emission region The thing by the imaging point S corresponding to R2 is excluded.
Next, the control processing unit 42b sets the average value of the luminance values of the luminance data on the high luminance side extracted for each pixel corresponding region Ps as the luminance value of each pixel P (step S105).
In this way, it is possible to reliably measure and obtain the luminance value for every pixel P and corresponding only to the emission region R1 in the pixel P.

  That is, the luminance data for each imaging point S in the CCD 41a of the CCD camera 41 is acquired from the image signal obtained by imaging the display unit 30 of the EL display panel 1 with the CCD camera 41 of the luminance measuring device 40, and the acquisition is performed. The luminance data is divided for each pixel corresponding area Ps and arranged in the order of luminance for each pixel corresponding area Ps, and then a predetermined number (specifically, for the total number of pixels) from the high luminance side of the luminance data for each pixel corresponding area Ps. Luminance data of a number equal to or less than the aperture ratio of the pixel P), and the average value of the luminance values of the extracted luminance data is calculated, whereby the emission region in the pixel P composed of the emission region R1 and the non-emission region R2 The luminance value corresponding to R1 can be accurately measured.

  As described above, according to the luminance measuring method according to the present invention, the luminance measuring device 40 is used, and the display unit 30 of the EL display panel 1 is imaged by the CCD camera 41, so that only the inside of the emission region R1 in the pixel P is supported. Thus, it is possible to easily extract the luminance data to be obtained and to obtain an accurate luminance value for each pixel P.

When the control processing unit 42b of the computer 42 of the luminance measuring device 40 determines that the luminance value for each pixel P is uneven based on the obtained luminance value, the control processing unit 42b Correction data for making the display luminance on the display unit 30 of the panel 1 uniform is created, and the created correction data is output to the control unit 20 of the EL display panel 1 and stored in the memory 21 of the EL display panel 1. Execute the process.
The EL display panel 1 drives the organic EL element 10 of the display unit 30 so as to correct the luminance unevenness according to the correction data stored in the memory 21.

  In the above embodiment, the case where the emission region R1 that is the opening is rectangular has been described as an example. However, the present invention is not limited to this, and the emission region R1 may have other shapes. However, a luminance value corresponding only to the emission region R1 may be obtained by appropriately setting a predetermined number of luminance values extracted from the high luminance side of all luminance values arranged for each pixel P.

Further, the luminance unevenness may be determined for each color of “red, green, blue” with respect to the luminance value for each pixel P obtained by the measurement by the luminance measuring device 40.
Furthermore, although the case where the present invention is applied to the EL display panel 1 has been described in the above embodiment, the present invention is not limited to this, and display data from the emission region R1 of each pixel P in the display unit 30 is displayed. The present invention can be applied to a device that emits light having a luminance corresponding to the gradation value of the light source. For example, it can be suitably applied to a transmissive liquid crystal display panel that controls the transmittance of light from the backlight can do.

  In addition, it is needless to say that other specific detailed structures can be appropriately changed.

1 EL display panel (display panel)
30 Display Unit 40 Luminance Measuring Device 41 CCD Camera 41a CCD (Imaging Device)
42 Computer 42a Memory 42b Control processing unit (luminance value acquisition control unit, luminance value permutation control unit, luminance value extraction control unit, luminance calculation unit)
B Partition P Pixel R1 Emission area R2 Non-emission area S Imaging point

Claims (8)

A display panel having a display area in which a plurality of pixels each having an emission area where light having a luminance corresponding to a gradation value of display data is emitted to a visual field side and a non-emission area where light is not emitted are arranged; A luminance measurement method for measuring the luminance of each pixel by imaging with an imaging device in which a plurality of imaging points are arranged in a matrix at an interval narrower than an arrangement interval of pixels,
By emitting light of luminance according to the gradation value of the display data from the emission area of all the pixels, the entire range of the display area of the display panel is imaged from the visual field side with the imaging device, Obtaining luminance data having a luminance value for each imaging point;
Arranging the luminance data of each imaging point for each pixel corresponding area corresponding to each pixel in the acquired luminance data for each imaging point in ascending or descending order for each luminance value;
Extracting a predetermined number of the luminance data set in advance from the high luminance side of the luminance data arranged for each luminance value for each pixel corresponding region;
Calculating a luminance value of each pixel based on the luminance data on the high luminance side extracted for each pixel corresponding region;
A method for measuring the brightness of a display panel, comprising:   In the step of extracting the predetermined number of luminance data from the high luminance side of the luminance data, the predetermined number is a ratio of the predetermined number to the total number of the luminance data for each of the pixel corresponding regions in the entire region of the pixel. The display panel luminance measurement method according to claim 1, wherein the number is equal to or less than a ratio of the emission region.   The predetermined number is a number such that a ratio of the predetermined number to a total number of the luminance data for each pixel corresponding region is 50% or less of a ratio of the emission region to the total region of the pixel. Item 3. A method for measuring the luminance of a display panel according to Item 2.   The predetermined number is a number obtained by excluding the imaging points arranged at positions adjacent to the non-emission area from the number of imaging points included in the emission area of one pixel. 2. A method for measuring the luminance of a display panel according to 1. A brightness measurement apparatus for a display panel, comprising a display area in which a plurality of pixels each having an emission area where light having a luminance corresponding to a gradation value of display data is emitted to a visual field side and a non-emission area where light is not emitted are arranged. There,
An imaging element that images a whole range of the display area of the display panel, in which a plurality of imaging points are arranged in a matrix at an interval narrower than an arrangement interval of the plurality of pixels;
The imaging element captures the entire range of the display area of the display panel with the imaging element in a state in which light having a luminance corresponding to the gradation value of the display data is emitted from the emission area of all the pixels, and the imaging point A luminance value acquisition control unit for acquiring luminance data having a luminance value for each;
A luminance value permutation control unit that arranges the luminance data of the imaging points for each pixel corresponding region corresponding to each pixel in the acquired luminance data for each imaging point in ascending or descending order for each luminance value;
A luminance value extraction control unit that extracts a predetermined number of the luminance data set in advance from the high luminance side of the luminance data arranged for each luminance value;
A luminance value calculation unit for calculating a luminance value of each pixel based on the luminance data on the high luminance side extracted for each pixel corresponding region;
A brightness measuring apparatus for a display panel, comprising:   6. The predetermined number is a number such that a ratio of the predetermined number to a total number of the luminance data for each pixel corresponding area is equal to or less than a ratio of the emission area in the entire area of the pixel. 4. A display panel luminance measuring device according to 1.   The predetermined number is a number such that a ratio of the predetermined number to a total number of the luminance data for each pixel corresponding region is equal to or less than 50% of a ratio of the emission region in the entire region of the pixel. The brightness | luminance measuring apparatus of the display panel of Claim 6.   The predetermined number is a number obtained by excluding the imaging points arranged at positions adjacent to the non-emission area from the number of imaging points included in the emission area of one pixel. 5. The display panel brightness measuring apparatus according to 5.

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