JP5002986B2 - Self-luminous display device, electronic device, burn-in correction device, and program - Google Patents

Description

One embodiment of the present invention relates to a burn-in correction technique for a self-luminous display panel.
The invention proposed by the inventors has aspects such as a self-luminous display device, an electronic device, a burn-in correction device, and a program.

Flat panel displays are widely used in products such as computer displays, portable terminals, and television receivers. Currently, many liquid crystal display panels are used, but the narrow viewing angle and slow response speed continue to be pointed out.
On the other hand, an organic EL display formed of a self-luminous element can overcome the above-mentioned problems of viewing angle and responsiveness, and can achieve a thin form, high brightness, and high contrast that do not require a backlight. Therefore, it is expected as a next-generation display device that replaces the liquid crystal display.

By the way, the organic EL element and other self-light-emitting elements have a characteristic of deteriorating according to the light emission amount and the light emission time.
On the other hand, the content of the image displayed on the self-luminous display device is not uniform. For this reason, the deterioration of the self-luminous element is likely to proceed partially. For example, in the time display area (fixed display area), the luminance degradation proceeds faster than in other display areas (moving image display areas).

The luminance of the self-luminous element that has deteriorated is relatively lowered as compared with the luminance of other display areas. In general, this phenomenon is called “burn-in”. Hereinafter, partial deterioration of the self-luminous element is referred to as “burn-in”.
At present, various methods are being studied for improving the “burn-in” phenomenon.
For example, Patent Document 1 discloses a method of integrating input display data (tone values) and reading a correction value corresponding to the integrated value from a table memory.
JP 2000-132139 A

  However, with this type of correction method, since the calculation and accumulation of the integrated value are executed in real time, a bus width twice as large as the bus width corresponding to the maximum integrated value is required for reading and writing data. Become.

Therefore, the inventors propose a burn-in correction technique that can significantly reduce at least the data width.
That is, as a device for correcting burn-in of a display panel in which a plurality of self-light-emitting elements are arranged in a matrix on a substrate, a correction technique that combines the following functions is proposed.
(A) gradation value / degradation amount conversion unit for converting input gradation value into deterioration amount (b) short period deterioration amount accumulation unit (c) for accumulating the accumulated value of the deterioration amount generated in frame units in a short period unit A deterioration amount difference calculation unit that calculates a deterioration amount difference between the correction target pixel and the reference pixel based on the accumulated value. (D) The accumulated value of the deterioration amount difference calculated in short cycle units is stored in a predetermined long cycle accumulation period. Long-period degradation amount accumulation unit to be accumulated (e) Correction as a future period set to be the same as the long-period accumulation period with a correction amount necessary for eliminating the difference in degradation amount accumulated in the long-period degradation amount accumulation unit Correction amount calculation unit for calculating based on the predicted deterioration amount within the period
(F) Degradation amount difference correction unit that corrects the gradation value of the corresponding pixel with the calculated correction amount. (G) The number of bits is reduced by weighting from the short period deterioration amount accumulation unit to the deterioration amount difference calculation unit. (H) The correction amount calculating unit predicts the deterioration rate β1 of the correction target pixel necessary for eliminating the cumulative value Y of the deterioration amount difference within the correction period t. Is obtained as β1 = β2−Y / t using the degradation rate β2

  In the correction technique proposed by the inventors, calculation of a cumulative value that requires processing in real time is executed only in units of short cycles. In addition to a small memory space used when calculating the accumulated value, it is possible to provide a time margin for calculating the deterioration amount difference and reading / writing data necessary for calculating the accumulated value. As a result, the bus width is only the data to be read and written. For this reason, the bus width constituting the burn-in correction device can be significantly reduced.

Hereinafter, a technique for correcting a burn-in phenomenon using the technical method according to the invention will be described.
In addition, the well-known or well-known technique of the said technical field is applied to the part which is not illustrated or described in particular in this specification.
The embodiment described below is one embodiment of the present invention and is not limited thereto.

(A) Application Example to Organic EL Display (A-1) Overall Configuration FIG. 1 shows a form example of an organic EL display. The organic EL display is an example of the “self-luminous display device” in the claims.
The organic EL display 1 includes a burn-in correction unit 3 and an organic EL panel module 5.

  The burn-in correction unit 3 corresponds to the “burn-in correction device” in the claims. The burn-in correction unit 3 is a processing device that alternately executes a detection process of a deterioration amount difference generated between a correction target pixel and a reference pixel and a correction process that eliminates the deterioration amount difference within a correction period.

The organic EL panel module 5 is a display device that uses an organic EL element as a self-luminous element.
The organic EL panel module 5 includes an effective display area and its drive circuit (data driver, scan driver, etc.).
In the effective display area, organic EL elements are arranged in a matrix. The emission colors are three colors of R (red), G (green), and B (blue). One pixel on the display is formed with these three colors as a set.

(A-2) Basic Configuration of Burn-in Correction Unit 3 FIG. 2 shows a basic configuration example of the burn-in correction unit 3 proposed by the inventors.
The burn-in correction unit 3 includes a gradation value / deterioration amount conversion unit 301, a deterioration amount difference calculation unit 303, a total deterioration amount accumulation unit 305, a correction amount calculation unit 307, and a deterioration amount difference correction unit 309.

  The gradation value / degradation amount conversion unit 301 is a processing device that converts a video signal (gradation value) actually supplied to the organic EL panel module 5 into a deterioration amount parameter. The reason why the gradation value is converted into the deterioration amount parameter is that the deterioration amount of the organic EL element currently in practical use is not necessarily proportional to the gradation value. For this reason, the burn-in correction method disclosed in Patent Document 1 that determines the correction value based on the integrated value of the gradation values must be said to have a limited burn-in correction effect at the present time.

Therefore, a gradation value / degradation amount conversion unit 301 is arranged to convert the gradation value of each pixel corresponding to each emission color into a deterioration amount. In this embodiment, the relationship between the gradation value and the deterioration amount of the organic EL element is obtained by experiment, and the correspondence data is stored as a list.
FIG. 3 shows an example of the gradation value / degradation amount conversion table. In the case of the gradation value / deterioration amount conversion table shown in FIG. 3, the deterioration rate and the deterioration amount are stored in association with the gradation value. The deterioration rate means a deterioration amount per unit time. Therefore, the deterioration amount can be obtained by multiplying the deterioration rate by the light emission time t.

The deterioration amount difference calculation unit 303 is a processing device that calculates the deterioration amount difference between each pixel (correction target pixel) constituting the effective display area and the reference pixel. The reference pixel becomes a correction reference when performing burn-in correction. In the case of this embodiment, a pixel that emits light with an average gradation value of all the pixels constituting the effective display area is assumed. The reference pixel may be actually prepared on the display panel, or may be virtually prepared by signal processing.
The deterioration amount difference calculation unit 303 subtracts the deterioration amount of the reference pixel from the deterioration amount of the correction target pixel, and calculates the difference value as a deterioration amount difference.

For example, when the light emission period is t1, the deterioration rate α1 of the correction target pixel, and the deterioration rate α2 of the reference pixel, the theoretical deterioration amount difference Y can be calculated by the following equation.
Y = (α1-α2) · t1
When the deterioration amount difference is a positive value, it means that the deterioration of the correction target pixel is more advanced than the reference pixel. On the other hand, when the deterioration amount difference is a negative value, it means that the deterioration of the correction target pixel is behind the reference pixel.

The total deterioration amount accumulation unit 305 is a storage area or a storage device that stores a cumulative value of the deterioration amount of the reference pixel and a cumulative value of the deterioration amount difference of each pixel (correction target pixel). For example, a semiconductor memory, a hard disk device or other magnetic storage medium, an optical disk or other optical storage medium is used.
The correction amount calculation unit 307 is a processing device that calculates a correction amount necessary for eliminating the deterioration amount difference calculated for each pixel within the correction period (future period) based on the predicted deterioration amount of the reference pixel. .

FIG. 4 shows the calculation principle of the correction amount by the correction amount calculation unit 307. FIG. 4 shows a condition for reducing the deterioration amount difference generated in the immediately preceding period (deterioration amount difference accumulation period) t1 within the correction period t2. In FIG. 4, the transition of the deterioration amount corresponding to the reference pixel is indicated by a broken line, and the transition of the deterioration amount corresponding to the correction target pixel is indicated by a solid line.
When the predicted deterioration rate β2 in the correction period t2 is β2, the predicted deterioration rate β1 of the correction target pixel is expressed by the following equation using the deterioration amount difference Y (= (α1−α2) · t1) generated in the immediately preceding period t1. Is done.
β1 = β2-Y / t2 = β2- (α1-α2) · t1 / t2

The correction amount calculation unit 307 refers to the gradation value / degradation amount conversion table (FIG. 3) and obtains a gradation value corresponding to the calculated deterioration rate β1.
This gradation value is a gradation value required for the corrected video signal. The correction amount calculation unit 307 subtracts a desired gradation value (corresponding to β1) from the predicted gradation value of the correction target pixel so as to satisfy this gradation value, and calculates a correction amount for the correction target pixel.

For example, when the predicted gradation value is larger than a certain gradation value, the correction value becomes a negative value. Further, when the predicted gradation value is smaller than a certain gradation value, the correction value becomes a positive value.
The deterioration amount difference correction unit 309 is a processing device that corrects the gradation value of the corresponding pixel with the calculated correction amount. For example, the deterioration amount difference correction unit 309 executes processing for adding a gradation value to the input video signal.

(A-3) Memory Capacity and Bus Width Required for Realizing the System The memory capacity and bus width required for realizing the burn-in correction unit 3 will be described.
In the following, the half-life of luminance deterioration when the organic EL panel module 5 continuously emits light with 100% luminance is set to 30,000 hours.

In this case, the data width necessary for accumulating the total deterioration amount for the half-life can be obtained by the following equation.
First, the number of frames corresponding to the half life is obtained. The number of frames per second is 60 frames.
Number of frames to half-life = 30000 hours x 60 minutes x 60 seconds x 60 frames

Half-life refers to the period required for the luminance level to decrease from 100% to 50%. Accordingly, the luminance level deterioration amount (%) per frame is given by the following equation.
Deterioration amount per frame (%) = 50% ÷ (30000 × 60 × 60 × 60)
= 7.716 × 10 ⁻⁹

However, this value is a value when 100% luminance is continuously output, and an actual video signal takes an arbitrary gradation value. For example, when the gradation resolution is 256 (8 bits), at least the bit width given by the following equation is required to express the deterioration amount (%) per frame.
Deterioration amount per frame (%) = 7.716 × 10 ⁻⁹ ÷ 256
= 3 × 10 ⁻¹¹ (40-bit width)

That is, 40-bit width data processing is required for calculating and accumulating the amount of deterioration that occurs in real time (every frame).
FIG. 5 shows the relationship between the processing device for realizing this processing operation and the bus width.
For example, between the gradation value / deterioration amount conversion unit 301 and the deterioration amount difference calculation unit 303, a data line for 40 bits for each basic light emission color, that is, 120 bits in total is required.

  Further, for example, between the deterioration amount difference calculation unit 303 and the total deterioration amount accumulation unit 305, 40 bits for loading and reading are required for each basic emission color, for a total of 240 bits. The reason why the data width is twice as large is that the stored deterioration amount difference is first loaded in the place where the calculation processing is performed, and the read / write processing for storing the calculated value is executed at the same time. As described above, the longer the period for storing the deterioration amount, or the smaller the gradation resolution, the larger the data width and the larger the system.

(A-4) Improvement Example of System Accordingly, the inventors propose a burn-in correction unit having the following system configuration for the purpose of greatly reducing memory capacity and bus width. Specifically, a method of once calculating the cumulative value in short cycle units prior to the calculation of the total cumulative value is adopted.
FIG. 6 shows a system configuration example of a burn-in correction unit 500 that employs this type of processing method. In FIG. 6, the same reference numerals are given to the portions corresponding to FIG. 2.

  The burn-in correction unit 500 includes a gradation value / deterioration amount conversion unit 301, a deterioration amount difference calculation unit 503, a total deterioration amount accumulation unit 305, a correction amount calculation unit 307, and a deterioration amount difference correction unit 309. That is, the burn-in correction unit 500 has the same system configuration as the burn-in correction unit 3 shown in FIG. 2 except for the deterioration amount difference calculation unit 503.

The deterioration amount difference calculation unit 503 includes a one minute deterioration amount accumulation processing unit 5031, a one minute deterioration amount accumulation memory 5033, and a deterioration amount difference compression unit 5035.
The one-minute deterioration amount accumulation processing unit 5031 is a processing device that cumulatively calculates the deterioration amount generated in units of frames in units of one minute. A one-minute deterioration amount accumulation memory 5033 is used to calculate the cumulative deterioration amount in units of one minute. The bit width can be reduced by executing the cumulative deterioration amount calculation process that requires real-time processing in units of one minute.
The functions of the one-minute deterioration amount accumulation processing unit 5031 and the one-minute deterioration amount accumulation memory 5033 correspond to the “short cycle deterioration amount accumulation unit” in “Claims”.

The deterioration amount difference compression unit 5035 is a processing device that executes a process of calculating a difference between the correction target pixel and the reference pixel with respect to the accumulated deterioration amount difference in units of one minute in which the bit width is compressed.
The deterioration amount difference compression unit 5035 corresponds to the “deterioration amount difference calculation unit” in “Claims”.

The greatest difference between the deterioration amount difference compression unit 5035 and the deterioration amount difference calculation unit 303 shown in FIG. 2 is that the deterioration amount difference is calculated in units of one minute. Further, the deterioration amount difference compression unit 5035 is different from the deterioration amount difference calculation unit 303 in that the deterioration amount difference is calculated based on the deterioration amount whose bit width is compressed by the weighting operation in order to further reduce the bit width.
Incidentally, the total deterioration amount accumulating unit 305 in this embodiment functions as a “long period deterioration amount accumulating unit” in “Claims”.

(A-5) Memory Capacity and Bus Width Required for Realization of System The memory capacity and bus width required for realizing the burn-in correction unit 500 will be described.
Also in this case, the half-life of the luminance deterioration when the organic EL panel module 5 continuously emits light with 100% luminance is set to 30,000 hours.
Accordingly, in this case, the same data width (40 bits) as that for accumulating the total deterioration amount corresponding to the half-life is finally required.

However, from a short-time perspective, only the lower part of this data width has to be calculated in real time.
Therefore, the one-minute deterioration amount storage memory 5033 only needs to have a memory capacity that can store the deterioration amount per frame (3 × 10 ⁻¹¹ (40-bit width)) for one minute.
This memory capacity corresponds to a data width corresponding to a value obtained by multiplying “3”, which is the minimum change unit of the deterioration amount per frame, by one minute, that is, 60 seconds × 60 frames.
Specifically, 3 × 60 seconds × 60 frames = 10800 (14-bit width).

FIG. 7 shows the relationship between the processing device for realizing this processing operation and the bus width.
For example, between the one-minute deterioration amount accumulation processing unit 5031 and the one-minute deterioration amount accumulation memory 5033, data lines for 14 bits for loading and reading for each basic light emission color, a total of 84 bits, are required.

The one-minute deterioration amount accumulation processing unit 5031 outputs the accumulated deterioration amount (short-period deterioration amount) calculated for each pixel to the deterioration amount difference compression unit 5035 every time one minute elapses. In this example, in order to further reduce the number of bits, the number of bits per basic emission color is reduced from 14 bits to 10 bits by weighting processing.
However, an error naturally occurs due to the reduction of the data amount. However, the error amount for one minute is much shorter than the total deterioration amount (30000 hours) to be managed, and the error due to the reduction of the data amount can be ignored.

Further, the deterioration amount difference compression unit 5035 adds the 10-bit width deterioration amount difference calculated every minute to the total deterioration amount (34-bit width) read from the total deterioration amount accumulation unit 305, and again adds the total deterioration amount. A process of writing in the storage unit 305 is executed.
Here, the reading and writing of data executed between the deterioration amount difference compression unit 5035 and the total deterioration amount accumulation unit 305 are executed in a time division manner within one minute. Therefore, as shown in FIG. 7, the bit width is not twice the bit width corresponding to the total deterioration amount.
As a result, the bit width between the deterioration amount difference compression unit 5035 and the total deterioration amount accumulation unit 305 may be 34 bits wide × 102 bits for three colors.

As described above, the memory capacity of the total deterioration amount accumulation unit 305 is 34 bits wide, which is smaller than the 40-bit width of each pixel in the case of FIG.
In addition, the bit width used for connection between the total deterioration amount accumulation unit 305 and the deterioration amount difference compression unit 5035 is also greatly reduced from the 240 bit width to the 102 bit width.

(A-6) Burn-in Correction Operation Next, the burn-in correction operation realized by the burn-in correction unit 500 will be described.
FIG. 8 shows an example of the processing procedure of the correction operation by the burn-in correction value 500. The burn-in correction operation is performed by alternately repeating a period in which a difference in deterioration amount between pixels is accumulated and a period in which the difference is corrected.
First, the gradation value / degradation amount conversion unit 301 detects a gradation value for each of the correction target pixel and the reference pixel (S1).

  Next, the gradation value / degradation amount conversion unit 301 derives the deterioration rate corresponding to each of the correction target pixel and the reference pixel using the gradation value / degradation amount conversion table shown in FIG. That is, the deterioration rate α1 of the correction target pixel and the deterioration rate α2 of the reference pixel are derived (S2). In addition, as the correction target pixel, all the pixels constituting the effective display area are designated in order or in parallel.

When the deterioration amount of each pixel is derived in units of frames, the one-minute deterioration amount accumulation processing unit 5031 calculates the accumulated value of the deterioration amount corresponding to each pixel in real time every one minute (S3). For the calculation of the accumulated value, a one-minute deterioration amount accumulation memory 5033 is used.
When the accumulated value in units of 1 minute is obtained, the 1-minute degradation amount accumulation processing unit 5031 weights and compresses the degradation amount of 14-bit width, and outputs it to the degradation amount difference compression unit 5035 as the degradation amount of 10-bit width. The degradation amount difference compression unit 5035 calculates a difference between the degradation amount of the correction target pixel and the degradation amount of the reference pixel, and calculates a degradation amount difference in units of 1 minute (S4).

  Further, the deterioration amount difference compression unit 5035 adds the deterioration amount difference accumulated up to the previous period and the newly calculated deterioration amount difference in units of one minute for the correction target pixel, and the total deterioration amount within the measurement period. (Cumulative deterioration amount difference) is calculated (S5). For the reference pixel, the amount of deterioration accumulated up to the previous period and the newly calculated amount of deterioration in increments of one minute are added to calculate the total amount of deterioration within the measurement period.

  When the accumulation period t1 ends, the correction amount calculation unit 307 determines a light emission period t2 as a correction period (S6). An arbitrary value can be set for the light emission period t2. However, if it is too short, the amount of correction within a unit time becomes large and the image quality is degraded. Therefore, it is desirable that the correction amount be in an allowable range. For example, the light emission period t2 is set to be the same as the accumulation period t1.

Thereafter, the correction amount calculation unit 307 derives the deterioration rate β2 based on the predicted gradation value of the reference pixel that will be input during the light emission period t2 (S7).
By deriving the deterioration rate β2, all values (deterioration amount differences Y, β2, light emission period t2) necessary for calculating the deterioration rate β1 of the correction target pixel are determined.

Thereafter, the correction amount calculation unit 307 obtains a deterioration rate β1 necessary to eliminate the deterioration amount difference in accordance with the correction condition equation described above (S8). That is, the deterioration rate β1 is calculated using β1 = β2-Y / t2.
Further, the correction amount calculation unit 307 obtains a gradation value corresponding to the derived deterioration rate β1 (S9).

Next, the correction amount calculation unit 307 calculates a correction amount for the predicted gradation value of the correction target pixel so as to satisfy the obtained gradation value (S10). That is, the correction amount is determined relative to the predicted gradation value.
The deterioration amount difference correction unit 309 corrects the gradation value of the corresponding correction target pixel with the correction amount determined in this way.

(A-7) Effect of Embodiment As described above, in the case of the organic EL display described in this embodiment, the deterioration amount of each pixel is determined using a deterioration rate that is a parameter reflecting a decrease in light emission luminance. Therefore, it is possible to accurately measure the deterioration amount of the light emission characteristics and accurately determine the correction value as compared with the prior art.

In addition, by adopting a method of calculating the degradation amount of each pixel for each emission color in units of 1 minute, it is possible to realize a reduction in data width and a reduction in memory capacity of a signal processing portion that requires real-time processing.
In addition, when the deterioration amount is given from the deterioration amount accumulation processing unit 5031 to the deterioration amount difference compression unit 5035, the deterioration is finally stored by weighting the deterioration amount of 14-bit width and compressing it to the 10-bit width. The amount can be reduced to 34 bits. That is, the memory capacity can be reduced.

Further, reading and writing of 34-bit width data necessary for the calculation processing of the total deterioration amount necessary for calculating the correction value may be executed in a time-sharing manner at intervals of one minute as shown in FIG. For this reason, the bit width between the deterioration amount difference compression unit 5035 and the total deterioration amount accumulation unit 305 does not have to be twice the deterioration amount. As a result, a significant reduction in bit width can be realized.
Note that the processing method for calculating the deterioration amount in two stages of a short cycle and a long cycle as in this embodiment can be realized by simple signal processing. Therefore, even when the screen size is increased, the production difficulty of the display panel itself is not increased, and the cost is hardly increased. Thus, it is also effective in terms of manufacturing technology.

(B) Other Embodiments (a) In the above embodiment, a case has been described in which the deterioration amount for 34 bits is read / written at once from the deterioration amount difference compression unit 5035 to the total deterioration amount accumulation unit 305.
However, a method may be employed in which the degradation amount of 34-bit width is divided into smaller data units and transmitted in multiple times, and the degradation amount for 34 bits is reconstructed on the receiver side.
For example, as shown in FIG. 10, a 34-bit width degradation amount may be divided into 8-bit units, transmitted in five times, and reconstructed on the receiver side.

In this case, the number of bits of the data line necessary for connection from the deterioration amount difference compression unit 5035 to the total deterioration amount storage unit 305 may be 24 bits in total for 8 bits × 3 colors as shown in FIG. In the above example, since the number of bits at the same location is 102 bits, it can be reduced to a quarter or less.
FIG. 12 shows an example of data read / write timing between the deterioration amount difference compression unit 5035 and the total deterioration amount storage unit 305.

(B) In the above-described embodiment, the case where the bit width is compressed by weighting the accumulated value of the deterioration amount calculated in units of one minute has been described.
However, even when the deterioration amount difference is calculated without compressing the bit width, the effect of reducing the bit width can be realized.
FIG. 13 shows a basic configuration example of the burn-in correction unit 700. The burn-in correction unit 700 includes a gradation value / deterioration amount conversion unit 301, a deterioration amount difference calculation unit 703, a total deterioration amount accumulation unit 305, a correction amount calculation unit 307, and a deterioration amount difference correction unit 309.

In FIG. 13, the same reference numerals are given to the portions corresponding to FIG. 6. The difference is that a deterioration amount difference compression unit 5035, which is a component of the deterioration amount difference calculation processing unit 703, is replaced with a deterioration amount difference calculation unit 7031.
FIG. 14 shows a connection state between the one-minute deterioration amount accumulation processing unit 5031 and the deterioration amount difference calculation processing unit 7031 and a connection state between the deterioration amount difference calculation processing unit 7031 and the total deterioration amount accumulation processing unit 305.

In this case, since the deterioration amount difference is not compressed, 14-bit data is read and written. However, since data can be read and written in a time-sharing manner, even for three colors, 42 bits and 120 bits are used. That's it.
In particular, the bit width for connecting the deterioration amount difference calculation processing unit 7031 and the total deterioration amount accumulation unit 305 is halved compared to the system configuration of FIG.
As described above, the memory capacity cannot be reduced, but a very effective reduction in the bit width can be expected.

(C) In the above-described embodiment, the period in which the deterioration amount is temporarily accumulated (that is, the short period) is described as 1 minute.
However, the period for accumulating the deterioration amount in the short term may be in seconds or in units of several minutes. During this period, it is desirable to determine an optimum value through the relationship with the memory capacity of the short period deterioration amount accumulation unit that accumulates the deterioration amount.

For example, when the memory capacity is small, the accumulation period is shortened, and when the memory capacity is large, the accumulation period is lengthened. The short-term accumulation period may be shortened when the deterioration amount detection accuracy is increased, and the short-term accumulation period may be lengthened when there is a margin in the deterioration amount detection accuracy.
In addition, it is desirable that this period is ensured for a time sufficient to read and write the deterioration amount and the deterioration amount difference in a time-sharing manner. As a result of reading and writing being performed in a time-sharing manner, the number of bit lines can be reduced.

(D) In the above-described embodiment, the case where the data width is reduced by weighting when reading the short-term deterioration amount from the one-minute deterioration amount accumulation processing unit 5031 to the deterioration amount difference compression unit 5035 has been described.
However, a method of reducing the data width by weighting when the deterioration amount is stored in the one-minute deterioration amount storage memory 5033 may be employed.
FIG. 15 shows the relationship between the bit widths of the data lines in this case. In this case, a small memory capacity of the one-minute deterioration amount storage memory 5033 can be substituted.

(E) In the above-described embodiment, the case where the deterioration amount difference for each pixel and the average gradation value of the entire screen are calculated in units of emission colors has been described.
However, it is also applicable to the case where the gradation value for each luminescent color is converted to the gradation value on the gray scale, and the deterioration amount difference corresponding to the gradation value on the gray scale or the average gradation value of the entire screen is calculated. it can.

(F) In the above-described embodiment, only one gradation value / deterioration amount conversion table is prepared, and the case where mutual conversion between the deterioration amount (rate) and the gradation value is realized has been described.
However, if there is a possibility that the gradation value and the deterioration rate (amount) change over time due to the influence of the usage environment, material characteristics, etc., a plurality of gradation value / degradation amount conversion tables that are optimal for each condition. You may employ | adopt the method of using selectively. In this case, a temperature sensor, a usage time timer, and other detection devices may be arranged, and the gradation value / degradation amount conversion table referred to by each processing unit may be switched according to the detection result.

(G) In the above-described embodiment, only one gradation value / deterioration amount conversion table is prepared and mutual conversion between the deterioration amount (rate) and the gradation value is realized.
However, a mechanism that corrects the input / output relationship by arranging dummy pixels in the display panel to detect changes over time in the light emission characteristics of the organic EL element and detecting changes over time in the light emission characteristics through a luminance detection sensor. May be adopted.
For example, a method may be employed in which all or part of the deterioration rate for each gradation value is detected, and the deterioration rate (amount) associated with each gradation value is calculated according to the detection result.

(H) In the above-described embodiment, the case where the basic primary colors are three colors of RGB has been described. However, the basic primary colors can also be applied when there are four or more colors including complementary colors. In this case, it is only necessary to prepare as many dummy pixels as the number of these basic primary colors.
(I) In the above-described embodiment, the basic primary color development mode has not been described. However, an organic EL element having a different light emitting element material for each basic primary color may be prepared, or a color filter method or a color conversion method may be used. A basic primary color may be generated.

(J) Although the organic EL display panel is illustrated as an example of the self-luminous display device in the above-described embodiment, the present invention can also be applied to other self-luminous display devices. For example, the present invention can be applied to FED (field emission display), inorganic EL display panel, LED panel, and the like.

(K) In the above-described embodiment, as a method for correcting the burn-in correction amount, the case where the gradation value is converted into the deterioration amount parameter and the burn-in correction value is determined so as to eliminate the difference in the deterioration amount from the reference pixel has been described.
However, any method including a known processing technique can be adopted for the burn-in correction value calculation process.

(L) In the above-described embodiment, the case where the video signal supplied to the organic EL panel module 5 is fed back to the gradation value / degradation amount conversion unit 301 and the degradation amount corresponding to each correction target pixel is calculated has been described. .
However, the degradation amount may be calculated by giving the video signal input to the degradation amount difference correction unit 309 or the video signal corrected by the degradation amount difference correction unit 309 to the gradation value / degradation amount conversion unit 301.

(M) In the above-described embodiment, a case has been described in which a pixel that emits light with an average luminance value of all the pixels constituting the effective display area is used as the reference pixel.
However, the reference pixel for which the deterioration amount is converged is not limited to the average luminance value. For example, a method may be adopted in which the pixel having the smallest deterioration amount accumulated in pixel units or the pixel having the largest deterioration amount is used as the reference pixel. Which pixel or gradation value is used as the reference value when determining the correction value depends on the mounting system.

(N) In the above-described embodiment, the case where the burn-in correction units 500 and 700 are mounted on the organic EL display 1 has been described.
However, the burn-in correction units 500 and 700 can be mounted on various electronic devices that mount or control the self-luminous display measures.
For example, a computer, a printing device, a video camera, a digital camera, a game device, a portable information terminal (a portable computer, a mobile phone, a portable game machine, an electronic book, etc.), a clock, an image reproducing device (for example, an optical disc device, a home) Server).

In any electronic device, the casing, the signal processing unit (MPU), and the external interface are configured in common, and the peripheral devices according to the product form are combined.
For example, an electronic device having a communication function such as a cellular phone has a transmission / reception circuit and an antenna in addition to the above-described structure. FIG. 15A shows a schematic configuration example of this type of electronic apparatus. In this example, the electronic device 1001 includes a signal processing unit 1003, an operation unit 1005, a communication unit 1007, and a display panel 1009.

  Further, for example, an electronic device having a storage device such as a game machine, an electronic book, or the like has a drive circuit for the storage medium in addition to the above structure. FIG. 15B illustrates a schematic configuration example of this type of electronic device. In this example, the electronic device 1101 includes a signal processing unit 1103, an operation unit 1105, a medium driving unit 1107, and a display panel 1109.

  For example, in the case of a printing apparatus, a printing unit is mounted in addition to the above-described configuration. The optimum printing unit is installed according to the printing method. Examples of the printing method include a laser method and an ink jet method. FIG. 16A illustrates a schematic configuration example of this type of electronic device. In this example, the electronic device 1201 includes a signal processing unit 1203, an operation unit 1205, a printing unit 1207, and a display panel 1209.

  For example, in the case of a video camera or a digital camera, in addition to the above-described configuration, a camera unit and a writing circuit for storing captured video data in a storage medium are mounted. FIG. 16B illustrates a schematic configuration example of this type of electronic device. In this example, the electronic device 1301 includes a signal processing unit 1303, an operation unit 1305, an imaging unit 1307, and a display panel 1309.

(O) In the above-described embodiment, the burn-in correction function has been described from the functional aspect, but it goes without saying that an equivalent function can be realized as hardware or software.
Further, not only all of these processing functions are realized by hardware or software, but some of them may be realized by using hardware or software. That is, a combination of hardware and software may be used.
(P) Various modifications can be considered for the above-described embodiments within the scope of the gist of the invention. Various modifications and application examples created based on the description of the present specification are also conceivable.

It is a figure which shows the schematic structural example of an organic electroluminescent display. It is a figure which shows the internal structural example of a burn-in correction | amendment part. It is a figure which shows the example of a conversion table holding the correspondence of a gradation value and a deterioration rate. It is a figure explaining the correction process principle of a burn-in phenomenon. It is a figure which shows the bit width which connects between each signal processing parts. It is a figure which shows the internal structural example of a burn-in correction | amendment part. It is a figure which shows the bit width which connects between each signal processing parts. It is a figure which shows the example of a process sequence of the burn-in correction operation. It is a figure explaining the reading / writing timing of deterioration amount. It is a figure which shows the bit width which connects between each signal processing parts. It is a figure explaining the relationship between the bit width and number used for reading / writing of the deterioration amount. It is a figure explaining the reading / writing timing of deterioration amount. It is a figure which shows the internal structural example of a burn-in correction | amendment part. It is a figure which shows the bit width which connects between each signal processing parts. It is a figure which shows the bit width which connects between each signal processing parts. It is a figure explaining the application example to another electronic device. It is a figure explaining the application example to another electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic EL display 3 Image sticking correction | amendment part 5 Organic EL panel module 301 Gradation value / deterioration amount conversion part 303 Deterioration amount difference calculation part 305 Total deterioration amount accumulation | storage part 307 Correction amount calculation part 309 Deterioration amount difference correction part 500 Burn-in correction part 503 Deterioration amount difference calculation unit 5031 1 minute deterioration amount accumulation processing unit 5033 1 minute deterioration amount accumulation memory 5035 Degradation amount difference compression unit 700 Burn-in correction unit 703 Degradation amount difference calculation unit 7031 Degradation amount difference calculation processing unit

Claims (15)

In a self-luminous display device having a display panel in which a plurality of self-luminous elements are arranged in a matrix on a substrate,
A gradation value / degradation amount conversion unit for converting an input gradation value into a deterioration amount;
A short period deterioration amount accumulating unit for accumulating a cumulative value of a short period unit of the deterioration amount generated in frame units;
A deterioration amount difference calculation unit that calculates a deterioration amount difference between the correction target pixel and the reference pixel based on the accumulated value;
A long-period deterioration amount accumulation unit that accumulates a cumulative value of deterioration amount differences calculated in short-cycle units and accumulates a predetermined long-cycle accumulation period;
A correction amount necessary for eliminating the difference in deterioration amount accumulated in the long-period deterioration amount accumulation unit is calculated based on a predicted deterioration amount within a correction period as a future period set to be the same as the long-period accumulation period. A correction amount calculation unit to perform,
A deterioration amount difference correction unit that corrects the gradation value of the corresponding pixel with the calculated correction amount, and
From the short period deterioration amount accumulation unit to the deterioration amount difference calculation unit, a cumulative value in which the number of bits is reduced by weighting is output ,
The correction amount calculation unit uses the deterioration rate β1 of the correction target pixel necessary to eliminate the accumulated value Y of the deterioration amount difference, and the deterioration rate β2 of the reference pixel predicted within the correction period t. A self-luminous display device determined as β2-Y / t . The self-luminous display device according to claim 1,
The self-luminous display device in which the short period unit is a minute unit. The self-luminous display device according to claim 1,
The short cycle unit is a self-luminous display device that secures a time sufficient to read and write data in a time-sharing manner when calculating a cumulative value of deterioration amount differences. The self-luminous display device according to claim 1,
The short cycle unit is a self-luminous display device set in accordance with a storage capacity used for accumulation of deterioration amount. The self-luminous display device according to claim 1,
The short-period deterioration amount accumulation unit is a self-luminous display device that accumulates accumulated values in which the number of bits is reduced by weighting. The self-luminous display device according to claim 1,
The self-luminous display device in which the deterioration amount difference calculation unit and the long-period deterioration amount accumulation unit execute reading and writing of data in a time division manner when calculating a cumulative value of the deterioration amount difference. The self-luminous display device according to claim 1,
The self-luminous display device, wherein the reference pixel is a pixel that emits light at an average gradation value of all the pixels constituting the effective display area. The self-luminous display device according to claim 1,
The reference pixel is a self-luminous display device set for each self-luminous element that emits light of the same color. The self-luminous display device according to claim 1,
The self-luminous display device in which the deterioration amount corresponding to each gradation value is given as a value obtained by converting the actually measured amount of decrease in luminance when light emission by each gradation value continues for a certain period. In an electronic device including a display panel and a computer system in which a plurality of self-luminous elements are arranged in a matrix on a substrate,
A gradation value / degradation amount conversion unit for converting an input gradation value into a deterioration amount;
A short period deterioration amount accumulating unit for accumulating a cumulative value of a short period unit of the deterioration amount generated in frame units;
A deterioration amount difference calculation unit that calculates a deterioration amount difference between the correction target pixel and the reference pixel based on the accumulated value;
A long-period deterioration amount accumulation unit that accumulates a cumulative value of deterioration amount differences calculated in short-cycle units and accumulates a predetermined long-cycle accumulation period;
A correction amount necessary for eliminating the difference in deterioration amount accumulated in the long-period deterioration amount accumulation unit is calculated based on a predicted deterioration amount within a correction period as a future period set to be the same as the long-period accumulation period. A correction amount calculation unit to perform,
A deterioration amount difference correction unit that corrects the gradation value of the corresponding pixel with the calculated correction amount, and
From the short period deterioration amount accumulation unit to the deterioration amount difference calculation unit, a cumulative value in which the number of bits is reduced by weighting is output ,
The correction amount calculation unit uses the deterioration rate β1 of the correction target pixel necessary to eliminate the accumulated value Y of the deterioration amount difference, and the deterioration rate β2 of the reference pixel predicted within the correction period t. Electronic equipment calculated as β2-Y / t . The electronic device according to claim 10 ,
The electronic device is an electronic device that is a portable terminal device. The electronic device according to claim 10 ,
The electronic apparatus is an electronic apparatus that is a printing apparatus equipped with a printing unit. The electronic device according to claim 10 ,
The electronic device is an electronic device that is an image pickup apparatus equipped with an image pickup device. In a burn-in correction apparatus that corrects burn-in of a display panel in which a plurality of self-luminous elements are arranged in a matrix on a substrate,
A gradation value / degradation amount conversion unit for converting an input gradation value into a deterioration amount;
A short period deterioration amount accumulating unit for accumulating a cumulative value of a short period unit of the deterioration amount generated in frame units;
A deterioration amount difference calculation unit that calculates a deterioration amount difference between the correction target pixel and the reference pixel based on the accumulated value;
A long-period deterioration amount accumulation unit that accumulates a cumulative value of deterioration amount differences calculated in short-cycle units and accumulates a predetermined long-cycle accumulation period;
A correction amount necessary for eliminating the difference in deterioration amount accumulated in the long-period deterioration amount accumulation unit is calculated based on a predicted deterioration amount within a correction period as a future period set to be the same as the long-period accumulation period. A correction amount calculation unit to perform,
A deterioration amount difference correction unit that corrects the gradation value of the corresponding pixel with the calculated correction amount, and
From the short period deterioration amount accumulation unit to the deterioration amount difference calculation unit, a cumulative value in which the number of bits is reduced by weighting is output ,
The correction amount calculation unit uses the deterioration rate β1 of the correction target pixel necessary to eliminate the accumulated value Y of the deterioration amount difference, and the deterioration rate β2 of the reference pixel predicted within the correction period t. Burn-in correction device calculated as β2-Y / t . As a process for correcting burn-in of a display panel in which a plurality of self-luminous elements are arranged in a matrix on a substrate,
A process of converting the input tone value into a deterioration amount;
A process of accumulating a cumulative value of short-period units of deterioration amount generated in frame units;
A process of calculating a deterioration amount difference between the correction target pixel and the reference pixel based on the accumulated value;
A process of accumulating a cumulative value of the deterioration amount difference calculated in short cycle units for a predetermined long cycle accumulation period;
A process of calculating a correction amount necessary for eliminating the deterioration amount difference accumulated in the processing based on a predicted deterioration amount within a correction period as a future period set to be the same as the long-period accumulation period;
Processing to correct the gradation value of the corresponding pixel with the calculated correction amount,
In the process of calculating the deterioration amount difference from the process of accumulating the short cycle unit accumulated value, the accumulated value in which the number of bits is reduced by weighting is output ,
The process of calculating the correction amount uses the deterioration rate β1 of the correction target pixel necessary to eliminate the accumulated value Y of the deterioration amount difference, and the deterioration rate β2 of the reference pixel predicted within the correction period t, Program obtained as β1 = β2−Y / t .

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