JP2006201630A - Image persistence phenomenon correcting method, self-luminous device, image persistence phenomenon correcting device and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem in which picture quality is greatly lowered by correction of an image persistence phenomenon. <P>SOLUTION: The image persistence phenomenon correcting method includes: a process in which a deterioration amount difference generated between a correction object pixel and a reference pixel is successively computed according to the input signal related to the driving condition of self-luminous elements; a process in which the computed deterioration amount difference is cumulatively added for every correction object pixel to compute an accumulated deterioration amount difference for each correction object pixel; a process in which judgement is made to judge whether the size of the accumulated deterioration amount difference is updated toward a reducing direction or an enlarging direction due to the emission of the luminous elements by the input signal, a process which instructs an execution stop of the correction operation to the corresponding input signal when it is judged that the size of the accumulated deterioration amount difference is updated to the reducing direction; a process which instructs the computation of the correction amount to reduce the size of the accumulated deterioration amount difference is reduced when it is judged that the size of the accumulated deterioration amount difference is updated to the enlarging direction; and a process which corrects the corresponding input signal by the computed correction amount. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  One embodiment of the present invention relates to a method for correcting a burn-in phenomenon that occurs in a self-luminous device. One embodiment of the present invention relates to a burn-in phenomenon correction apparatus. One embodiment of the present invention relates to a self-luminous device equipped with a burn-in phenomenon correcting device. One embodiment of the present invention relates to a program for causing a computer mounted on a self-luminous device to execute a burn-in correction function.

Flat panel displays are widely used in products such as computer displays, portable terminals, and televisions. Currently, liquid crystal display panels are mainly 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, it is generally known that organic EL elements and other self-light-emitting elements have a characteristic of deteriorating in proportion to the amount of light emission and time.
On the other hand, the content of the image displayed on the display is not uniform. For this reason, the deterioration of the self-luminous element is likely to proceed partially. For example, the self-light-emitting element in the time display area (fixed display area) progresses more rapidly than the self-light-emitting elements 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, the following processing techniques are disclosed.
In this document, input data for each pixel constituting the display panel is integrated for each pixel at a constant period, and the integrated value of each pixel is subtracted from the maximum value of each pixel. A method for setting the correction amount is disclosed. Further, a method is disclosed in which the display characteristics of each pixel are made uniform by emitting each pixel with a constant luminance for a time proportional to the amount of correction in a non-use state. That is, a method is disclosed in which a correction-dedicated pattern is displayed to align the display characteristics of each pixel.

Certainly, the method of displaying the correction-specific pattern is effective in improving the burn-in phenomenon.
However, this method is a correction method that completely ignores the input image. For this reason, there is a problem that the execution of the correction operation is limited to a non-use state. Further, if the non-use state does not exist for a period sufficient for correction, there is a possibility that a correction residue of the burn-in phenomenon occurs. In addition, there is a problem that power is consumed only for correcting the burn-in phenomenon.

The inventors pay attention to the above technical problems and propose the following technical methods.
That is, as a method of correcting the burn-in phenomenon of a self-light-emitting device in which a plurality of self-light-emitting elements are arranged in a matrix, with the self-light-emitting device being used,
(A) processing for sequentially calculating a deterioration amount difference generated between the correction target pixel and the reference pixel based on an input signal related to the driving condition of the self-light-emitting element;
(B) A process of cumulatively adding the calculated deterioration amount difference for each correction target pixel and calculating a cumulative deterioration amount difference for each correction target pixel;
(C) A process of determining whether the magnitude of the cumulative deterioration amount difference is updated in a decreasing direction or an increasing direction due to light emission of the self-luminous element by an input signal;
(D) When it is determined that the magnitude of the cumulative deterioration amount difference is updated in a decreasing direction, a process for instructing to stop execution of the correction operation for the corresponding input signal;
(E) When it is determined that the magnitude of the cumulative deterioration amount difference is updated in an increasing direction, a process for instructing calculation of a correction amount that reduces the magnitude of the cumulative deterioration amount difference;
(F) Proposing a method having a process of correcting the corresponding input signal with the calculated correction amount.
The self-luminous device includes an organic EL (electroluminescence) panel, a PDP (plasma display panel), a CRT (cathode ray tube), an FED (field emission display) panel, an LED panel, and a projector.

The method according to the invention corrects the corresponding input signal when the magnitude of the cumulative deterioration amount difference is updated in the increasing direction, and updates when the magnitude of the cumulative deterioration amount difference is reduced. Stops correction for the corresponding input signal.
That is, pixels that can improve the burn-in phenomenon are displayed as they are, and pixels that do not improve the burn-in phenomenon are displayed as corrected.
As a result, the burn-in phenomenon of the self-light-emitting device can be improved while maintaining the image quality of the original image to some extent even during use of the self-light-emitting device.
Further, since the burn-in phenomenon can be corrected while the self-light-emitting device is in use, it is possible to eliminate the occurrence of correction correction due to insufficient period of non-use.
Further, it is possible to eliminate a situation where power is consumed during the non-use state only for burn-in correction.

Hereinafter, an embodiment example of a burn-in phenomenon correction technique that employs the technical technique 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) Form example 1
(A) Configuration of Burn-in Phenomenon Correction Device FIG. 1 shows a configuration example of a burn-in phenomenon correction device (hereinafter referred to as “correction device”).
Note that the following correction processing is executed for pixels that emit light of the same color. The emission color generally refers to three colors of red, blue, and green. However, white is used when a white light source is used.
Further, it is assumed that the input signal is provided with a gradation value designating luminance, a drive current value applied to the self light emitting element, and other signals relating to the driving conditions of the self light emitting element.

The correction apparatus 1 includes a deterioration amount difference calculation unit 3, a cumulative deterioration amount difference calculation unit 5, a correction effect prediction unit 7, a cumulative deterioration amount difference accumulation unit 9, a correction operation selection unit 11, a correction amount determination unit 13, and a deterioration amount difference correction. The unit 15 is a main component.
The deterioration amount difference calculation unit 3 is a processing device that calculates a deterioration amount difference ΔR between each pixel (correction target pixel) and a reference pixel based on an input signal before correction processing. Any method can be applied to calculate the deterioration amount difference ΔR. For example, a method of calculating the difference between the input signal value corresponding to the correction target pixel and the input signal value corresponding to the reference pixel can be applied.

In the case of this embodiment, when the deterioration of the correction target pixel is advanced with respect to the reference pixel, the deterioration amount difference ΔR is expressed as a plus. On the contrary, when the deterioration of the correction target pixel is delayed with respect to the reference pixel, the deterioration amount difference ΔR is expressed as a minus value. The calculated deterioration amount difference ΔR is given from the deterioration amount difference calculation unit 3 to the cumulative deterioration amount difference calculation unit 5.
Note that the reference pixel may be an actual pixel constituting the self-light-emitting device, or may be set as a virtual pixel. For example, a pixel having the largest cumulative degradation amount and a pixel having the smallest cumulative degradation amount are applied to the actual pixels. In addition, for example, a pixel that gives an average value of the cumulative deterioration amount is applied to the virtual pixel.

The cumulative deterioration amount difference calculation unit 5 is a processing device that calculates a cumulative deterioration amount difference ΣΔR for each pixel. The cumulative deterioration amount difference calculation unit 5 handles the deterioration amount difference calculated based on the input signal as addition information. On the other hand, the cumulative deterioration amount difference calculation unit 5 handles the deterioration amount difference (correction effect) given from the correction effect prediction unit 7 as subtraction information. The cumulative deterioration amount difference calculation unit 5 executes an update process of the cumulative deterioration amount difference ΣΔR by adding or subtracting the deterioration amount difference ΔR.
The correction effect prediction unit 7 is a processing device that predicts the correction effect of the correction amount determined by the correction amount determination unit 13. The correction effect is predicted as a deterioration amount difference ΔR. The correction effect prediction unit 7 is provided to reflect the correction effect on the accumulated deterioration amount difference ΣΔR.

The cumulative deterioration amount difference accumulation unit 9 is a storage device that stores the calculated cumulative deterioration amount difference ΣΔR. The stored cumulative deterioration amount difference ΣΔR is sequentially updated by the cumulative deterioration amount difference calculation unit 5. That is, the cumulative deterioration amount difference ΣΔR is read by the cumulative deterioration amount difference calculation unit 5 and is sequentially updated by the addition / subtraction process described above.
The correction operation selection unit 11 is a processing device that determines whether the magnitude of the cumulative deterioration amount difference ΣΔR is updated in a decreasing direction or an increasing direction according to an input signal of the next light emission period.

In the case of this embodiment, the correction operation selection unit 11 compares the cumulative deterioration amount difference ΣΔRA after the update by the input signal of the next light emission period with the cumulative deterioration amount difference ΣΔRB before the update, and the cumulative deterioration amount according to the magnitude relationship. The update direction of the difference ΣΔR is determined.
The cumulative deterioration amount difference ΣΔRB before the update is read from the cumulative deterioration amount difference accumulation unit 9 to the correction operation selection unit 11. The updated accumulated deterioration amount difference ΣΔRA is read from the accumulated deterioration amount difference calculating unit 5 to the correction operation selecting unit 11.
The correction operation selection unit 11 determines that the cumulative deterioration amount difference after update is ΣΔRA ≧ the cumulative deterioration amount difference before update ΣΔRB, the cumulative deterioration amount difference is updated in an increasing direction, and the updated cumulative deterioration amount difference is updated. When ΣΔRA <cumulative deterioration amount difference before update ΣΔRB, it is determined that the cumulative deterioration amount difference is updated in a decreasing direction.
FIG. 2 shows the relationship between this determination condition and the correction operation. The correction operation selection unit 11 executes functions corresponding to the update direction determination unit and the correction operation instruction unit in the claims.

The correction amount determination unit 13 is a processing device that determines a correction amount for an input signal for each pixel. The correction amount determination unit 13 determines the correction amount in such a direction that the accumulated deterioration amount difference is eliminated within a certain period. The calculation method of the correction amount is arbitrary.
The determined correction amount is given to the correction effect prediction unit 7 and the deterioration amount difference correction unit 15.
The deterioration amount difference correction unit 15 is a processing device that corrects an input signal with a given correction amount. The corrected input signal is output as a drive signal for a display panel in which self-emitting elements are arranged. The correction processing here is realized by addition / subtraction of the correction amount, increase / decrease in the gain of the input signal, replacement with the correction amount, and the like.

(B) Burn-in Correction Processing Example FIG. 3 shows a series of processing operations executed by the correction device 1.
Each time an input signal for the next light emission period is input, the correction operation selection unit 11 checks the cumulative deterioration amount difference ΣΔRB for the previous light emission period (S1).
In parallel with this, the deterioration amount difference calculation unit 3 calculates the deterioration amount difference between the correction target pixel and the reference pixel for the input signal of the next light emission period. Thereafter, the deterioration amount difference calculation unit 3 adds the newly calculated deterioration amount difference to the cumulative deterioration amount difference calculated in the previous light emission period, and calculates a cumulative deterioration amount difference ΣΔRA corresponding to the next light emission period.
This cumulative deterioration amount difference ΣΔRA is confirmed by the correction operation selection unit 11 (S2).

When the cumulative deterioration amount difference before and after the update is confirmed, the correction operation selection unit 11 determines whether or not the cumulative deterioration amount difference ΣΔRA in the next light emission period is smaller than the cumulative deterioration amount difference ΣΔRB in the previous light emission period (S3). ). This determination process is executed for each correction target pixel.
When a positive result is obtained here, the correction operation selection unit 11 instructs the correction amount determination unit 13 to stop the correction process (including an instruction to control the correction amount to zero). The deterioration amount difference correction unit 15 does not correct the input signal corresponding to the next light emission period, and outputs it to the next light emitting device as it is (S4).

On the other hand, when a negative result is obtained, the correction operation selection unit 11 instructs the correction amount determination unit 13 to execute the correction process. In response to this instruction, the correction amount determination unit 13 determines the correction amount so that the accumulated deterioration amount difference ΣΔR is corrected within a certain period. Thereafter, the deterioration amount difference correction unit 15 executes the input signal correction process (S5).
Following this process, the correction effect predicting unit 7 converts the correction amount into a deterioration amount difference and gives it to the cumulative deterioration amount difference calculating unit 5. The cumulative deterioration amount difference calculation unit 5 subtracts the converted deterioration amount difference from the cumulative deterioration amount difference, and reflects the correction effect on the cumulative deterioration amount difference (S6).

(C) Effects of Embodiments By performing a series of processes, pixels that can improve the burn-in phenomenon as they are can be displayed on the light-emitting device as they are. For this reason, it is possible to simultaneously execute image quality maintenance and image sticking correction.
Of course, when the original image is displayed on the self-light-emitting device as it is, when the accumulated deterioration amount difference increases (when the burn-in phenomenon becomes noticeable), the correction operation is performed so that the accumulated deterioration amount difference is reduced.
Here, executing the correction operation means changing the input signal value of the correction target pixel. Therefore, the image quality of the pixel for which the correction operation has been performed generally decreases.

However, there is almost no possibility that all the pixels constituting the self-light-emitting device are corrected at the same time from the existence probabilities of the respective states. Therefore, a certain level of image quality is ensured even by partial execution of the correction operation. For example, about half of the pixels can be displayed with the original image quality.
Further, since the burn-in phenomenon correction operation is executed during use (during image display), the correction time in the non-use state can be shortened. That is, even if the non-use state is short, the burn-in correction operation can be completed. In addition, since the correction period in the non-use state can be shortened, useless power consumption can be eliminated.

(B) Embodiment 2
(A) Configuration of Burn-in Phenomenon Correction Device Next, another configuration example of the correction device will be described. In the first embodiment, the case where execution and stop of the correction process are selected according to the change direction before and after the update of the accumulated deterioration amount difference has been described. In this embodiment, another determination method will be described.
Here, a description will be given of a case where the execution or stop of the correction operation is selected based on which of the correction target pixel and the reference pixel is further deteriorated by the previous light emission period and the magnitude relationship of the input signal values in the next light emission period. .
In this embodiment, a description will be given on the assumption that the relationship of deterioration that has occurred until the previous light emission period is determined by the sign (positive value / negative value) of the cumulative deterioration amount difference.

FIG. 4 shows a configuration example of a correction apparatus that employs this method.
The correction device 21 includes a deterioration amount difference calculation unit 3, a cumulative deterioration amount difference calculation unit 5, a correction effect prediction unit 7, a cumulative deterioration amount difference accumulation unit 9, a correction operation selection unit 23, a correction amount determination unit 13, and a deterioration amount difference correction. The unit 15 is a main component.
As shown in FIG. 1, the same reference numerals are assigned to the corresponding parts, and only the correction operation selection unit 23 is different from the first embodiment. Therefore, the description of the same components as those in Embodiment 1 is omitted.
The correction operation selection unit 23 is a processing device that selects execution and stop of the correction operation based on the input signal value and the accumulated deterioration amount difference ΣΔR.
The correction operation selection unit 23 first determines which deterioration of the correction target pixel or the reference pixel is progressing depending on whether the sign of the accumulated deterioration amount difference ΣΔR is a positive value or a negative value.

Next, the change direction of the accumulated deterioration amount difference is determined based on the magnitude relationship of the input signal values in the next light emission period.
For example, when the accumulated deterioration amount difference of the correction target pixel with respect to the reference pixel is positive (meaning that the correction target pixel is relatively deteriorated), the input signal value for the correction target pixel is more When the input signal value is smaller than the reference pixel, the correction operation selection unit 23 determines that the accumulated deterioration amount difference is naturally reduced. In other words, it is determined that the input signal value can naturally improve the burn-in phenomenon.
In addition, for example, when the accumulated deterioration amount difference of the correction target pixel with respect to the reference pixel is positive, the input signal value of the correction target pixel and the reference pixel are the same, or the input signal value for the correction target pixel is the input for the reference pixel. When larger than the signal value, the correction operation selecting unit 23 determines that the accumulated deterioration amount difference is not reduced. That is, it is determined that correction processing is necessary. At this time, the correction amount is determined so that the input signal value corresponding to the correction target pixel is smaller than the input signal value corresponding to the reference pixel.

For example, when the cumulative deterioration amount difference of the correction target pixel with respect to the reference pixel is negative (meaning that the reference pixel is relatively deteriorated), the input signal value with respect to the correction target pixel is greater. When it is larger than the input signal value for the reference pixel, the correction operation selection unit 23 determines that the accumulated deterioration amount difference is naturally reduced. That is, it is determined that the input signal value is a natural improvement in the burn-in phenomenon.
Also, for example, when the accumulated deterioration amount difference of the correction target pixel with respect to the reference pixel is negative, the input signal value of the correction target pixel and the reference pixel are the same, or the input signal value for the correction target pixel is the input for the reference pixel. When the value is smaller than the signal value, the correction operation selecting unit 23 determines that the accumulated deterioration amount difference is not reduced. That is, it is determined that correction processing is necessary. At this time, the correction amount is determined so that the input signal value corresponding to the correction target pixel is larger than the input signal value corresponding to the reference pixel.
FIG. 5 shows the relationship between the determination operation and the correction operation. Again, the correction operation selection unit 23 executes functions corresponding to the update direction determination unit and the correction operation instruction unit in the claims.

(B) Burn-in Correction Processing Example FIG. 6 shows a series of processing operations executed by the correction device 21.
Each time an input signal for the next light emission period is input, the correction operation selection unit 23 checks the cumulative deterioration amount difference ΣΔRB for the previous light emission period (S11).
The correction operation selection unit 23 checks the input signal value of the next light emission period for each of the correction target pixel and the reference pixel (S12).
Next, the correction operation selection unit 23 determines whether or not the cumulative deterioration amount difference ΣΔRB in the previous light emission period is non-zero (S13).
When a negative result is obtained in step S13 (that is, when the cumulative deterioration amount difference ΣΔRB = 0), the correction operation selection unit 23 instructs to output the input signal without correction (S14).

On the other hand, when a positive result is obtained, the correction operation selection unit 23 determines whether or not the cumulative deterioration amount difference ΣΔRB is negative (S15).
If a positive result is obtained in step S15, the correction operation selection unit 23 determines whether or not the input signal value of the correction target pixel is equal to or less than the reference pixel (S16).
If a negative result is obtained in this step S16, this means that the cumulative deterioration amount difference ΣΔRA is reduced. Accordingly, the correction operation selection unit 23 instructs to output the input signal without correction (S14).
On the other hand, if a positive result is obtained in step S16, this means that the cumulative deterioration amount difference ΣΔRA is enlarged. Accordingly, the correction operation selection unit 23 instructs the execution of the correction process so that the input signal value of the correction target pixel is changed to a value larger than the reference pixel so that the cumulative deterioration amount difference ΣΔRA is reduced (S17). Then, the correction of the input signal is executed with the calculated correction amount.

If a negative result is obtained in step S15, the correction operation selection unit 23 determines whether the input signal value of the correction target pixel is equal to or higher than the reference pixel (S18).
If a negative result is obtained in step S18, this means that the cumulative deterioration amount difference ΣΔR1 is reduced. Accordingly, the correction operation selection unit 23 instructs to output the input signal without correction (S14).
On the other hand, if a positive result is obtained in step S18, this means that the cumulative deterioration amount difference ΣΔR1 is enlarged. Accordingly, the correction operation selection unit 23 instructs the execution of the correction process so that the input signal value of the correction target pixel is changed to a value smaller than the reference pixel so that the cumulative deterioration amount difference ΣΔR1 is reduced (S19). Then, the correction of the input signal is executed with the calculated correction amount.
Thereafter, the correction effect prediction unit 7 converts the correction amount into a deterioration amount difference, and gives it to the cumulative deterioration amount difference calculation unit 5. The cumulative deterioration amount difference calculation unit 5 subtracts the converted deterioration amount difference from the cumulative deterioration amount difference, and reflects the correction effect on the cumulative deterioration amount difference (S20).

(C) Effects of Embodiments When such a processing method is employed, an image (or pixel) that can improve the burn-in phenomenon even if it is used can be displayed on the self-luminous device as it is. For this reason, it is possible to simultaneously execute image quality maintenance and image sticking correction.
Of course, when the original image is displayed on the self-luminous device as it is, if the accumulated deterioration amount difference increases (the burn-in phenomenon becomes more conspicuous), the correction operation is executed so that the accumulated deterioration amount difference is reduced.
Further, since the burn-in phenomenon correction operation is executed during use (during image display), the correction time in the non-use state can be shortened. That is, even if the non-use state is short, the burn-in correction operation can be completed. In addition, since the correction period in the non-use state can be shortened, useless power consumption can be eliminated.

(C) Embodiment 3
(A) Configuration of Burn-in Phenomenon Correction Device In this embodiment, the correction processing selection operation will be described in the case where the deterioration rate is used for calculating the deterioration amount difference.
The deterioration rate refers to a value obtained by converting a decrease in light emission amount per unit time, and is obtained from an actual measurement value of light emission characteristics. For example, it is given as a value obtained by converting the actually measured amount of decrease in luminance when light emission by individual gradation values continues for a certain period.
The deterioration rate (deterioration ratio per unit time) has a characteristic that the light emission luminance (for example, drive current amount) of each pixel and the heat generation temperature at that time have an influence.
This is a very effective processing technique when the deterioration of the light emission characteristics does not proceed in proportion to the input signal value, and is a calculation technique proposed by the inventors.

(A) Configuration of Burn-in Phenomenon Correction Device FIG. 7 shows another example of the correction device. 7 includes a gradation value-deterioration rate conversion table 33, a deterioration amount difference calculation unit 35, a cumulative deterioration amount difference calculation unit 5, a correction effect prediction unit 7, a cumulative deterioration amount difference accumulation unit 9, and a correction operation. The selection unit 37, the correction amount determination unit 39, and the deterioration amount difference correction unit 15 are main components.
(A-1) Tone value-deterioration rate conversion table Among these, the tone value-deterioration rate conversion table 33, the deterioration amount difference calculation unit 35, and the correction operation selection unit 37 are the components that are unique to this embodiment. is there. In the following, these components will be mainly described. Since other configurations are the same as those of the first embodiment, the description thereof is omitted.

The gradation value-deterioration rate conversion table 33 (hereinafter referred to as “conversion table 33”) is a lookup table for converting an input signal into a deterioration rate when given as a gradation value.
Here, the table information is set based on the correspondence relationship between the gradation value and the deterioration rate acquired in the previous experiment. The inventors propose the following method as an example of an experiment for determining table information. For example, when the self-luminous device is turned on for a certain period at a certain fixed gradation value, how much the actually measured luminance is reduced with respect to the initial luminance of the maximum gradation value (255 for 8-bit) The operation of actually measuring (that is, the luminance reduction rate) is repeated for all gradation values.
When the number of gradations is large, a method of sampling an appropriate gradation value and calculating using a relational expression obtained from the result is also conceivable.

FIG. 8 shows the correspondence between the gradation value and the deterioration rate. For example, the deterioration rate corresponding to the gradation value “n” is set to “X _n
Note that, since FIG. 8 is a case of 8 bits, n is given as a value from 0 to 255.
FIG. 9 shows a specific example. In this example, the deterioration rate of the large gradation value (255) is 0.03%, and the deterioration rate of the intermediate gradation value (127) is 0.01%. Further, the degradation amounts when the light emission period is 1 are 300 × 10 ⁻⁴ % and 100 × 10 ⁻⁴ %, respectively.
In this conversion table, the deterioration rate can be read from the gradation value, or the gradation value can be read from the deterioration rate.

(A-2) Degradation Amount Difference Calculation Unit The degradation amount calculation unit 35 is a processing device that calculates a deterioration amount in each light emission period from an input signal value (gradation value) corresponding to each pixel.
The deterioration amount calculation unit 35 reads out the deterioration rate corresponding to the gradation value with reference to the gradation value-deterioration rate conversion table 33, and multiplies the read out deterioration rate by the light emission time t. A processing device that calculates the difference in quantity.
FIG. 10 shows an example of signal processing executed by the deterioration amount difference calculation unit 35. The correction target pixel will be described as pixel 1, and the reference pixel will be described as pixel 2.
First, the deterioration amount calculation unit 35 detects each gradation value and the light emission period t1 for each of the pixels 1 and 2 (S21).

Next, the deterioration amount difference calculation unit 35 derives a deterioration rate corresponding to each detected gradation value (S22). Here, the deterioration rate corresponding to the pixel 1 is denoted by α1, and the deterioration rate corresponding to the pixel 2 is denoted by α2.
The deterioration amount difference calculation unit 35 multiplies the derived deterioration rates α1 and α2 by the light emission period t1 to calculate the deterioration amount R (α1) of the pixel 1 and the deterioration amount R (α2) of the pixel 2 (S23). ).
Thereafter, the deterioration amount difference calculation unit 35 executes a calculation process given by R (α1) −R (α2), and calculates a deterioration amount difference ΔR between the two pixels of the pixel 1 and the pixel 2 (S24).
The deterioration amount difference ΔR calculated in this way is given to the cumulative deterioration amount difference calculation unit 5 and used for updating the cumulative deterioration amount difference ΣΔR.

(A-3) Correction Operation Selection Unit The correction operation selection unit 37 executes the correction operation based on the accumulated deterioration amount difference ΔR until the previous light emission period and the deterioration rates α1 and α2 corresponding to the gradation values of the next light emission period. A processing device that selects a stop.
First, a correction condition that gives a criterion for executing and stopping the correction operation will be described.
11 and 12 explain the selection principle of the correction operation. Similar to the case of FIG. 10, the correction target pixel will be described as pixel 1, and the reference pixel will be described as pixel 2. Also, the current light emission period is assumed to be t1, and the next light emission period is assumed to be t2. When the following conditions are satisfied, the light emission period t2 is a period for correcting the accumulated deterioration amount difference generated up to the light emission period t1.

In the following description, it is assumed that the light emission periods t1 and t2 have an arbitrary length. However, t1 and t2 may be the same one frame period. Again, the deterioration rate corresponding to the pixel 1 is α1, and the deterioration rate corresponding to the pixel 2 is α2.
In this case, the deterioration amount R (α1) of the pixel 1 in the light emission period t1 is given by α1 × t1, and the deterioration amount R (α2) of the pixel 2 in the light emission period t1 is given by α2 × t2. Accordingly, the deterioration amount difference ΔR1 of the pixel 1 with respect to the pixel 2 is given by R (α1) −R (α2) (= (α1−α2) × t1).

FIG. 11 shows a change in characteristics when the deterioration rate α1 of the light emission period t1 is larger than α2 (that is, when the deterioration of the pixel 1 is more advanced than the pixel 2). In this case, the deterioration amount difference ΔR1 is a positive value. Note that FIG. 11 shows that the deterioration amounts of the pixel 1 and the pixel 2 are the same at the start of the light emission period t1.
FIG. 12 shows a characteristic change when the deterioration rate α1 of the light emission period t1 is smaller than α2 (that is, when the deterioration of the pixel 1 is delayed from the pixel 2). In this case, the deterioration amount difference ΔR1 is a negative value. FIG. 12 also shows that the deterioration amounts of the pixel 1 and the pixel 2 are the same at the start of the light emission period t1.

The deterioration amount difference ΔR2 in the light emission period t2 can be similarly expressed. That is, ΔR2 can be expressed as R (β1) −R (β2) (= (β1−β2) × t2) using the deterioration rate β1 corresponding to the pixel 1 and the deterioration rate β2 corresponding to the pixel 2.
As can be seen from FIG. 11 and FIG. 12, in order to improve the burn-in phenomenon, update is performed so that the difference in deterioration amount that is the cause is smaller, that is, | ΔR1 + ΔR2 | is smaller than | ΔR1 |. Needs to be updated.
This condition is given by | ΔR1 |> | ΔR1 + ΔR2 |.
If this conditional expression is satisfied, it is possible to reduce the deterioration amount difference between pixels only by displaying the original image as it is without performing any correction operation.
Therefore, execution of the correction operation and selection of stop can be determined by whether or not this conditional expression is satisfied.

Hereinafter, a specific example of the processing operation executed by the correction operation selection unit 37 will be shown.
First, the correction operation selection unit 37 determines whether the accumulated deterioration amount difference ΣΔRB of the correction target pixel in the current light emission period (in this case, the light emission period t1) is a positive value or a negative value. That is, it is determined whether the deterioration of the correction target pixel is advanced or delayed with respect to the reference pixel.
Next, the correction operation selection unit 37 determines the magnitude relationship between the deterioration rate of the correction target pixel and the deterioration rate of the reference pixel in the next light emission period (in this case, the light emission period t2).
For example, when the accumulated deterioration amount difference is a positive value, if the deterioration rate β1 of the correction target pixel is lower than the deterioration rate of the reference pixel β2, the deterioration amount difference ΔR is reduced.
Therefore, the correction operation selection unit 37 determines that a correction operation that causes a deterioration in image quality is unnecessary for pixels that satisfy this condition in the original image signal.

Further, for example, when the accumulated deterioration amount difference is a positive value, when the deterioration rate β1 of the correction target pixel is larger than the deterioration rate of the reference pixel β2 or when both gradation values are the same, the deterioration amount difference ΔR is increased or It remains.
In this case, the correction operation selection unit 37 instructs the correction operation so that the deterioration rate β1 of the correction target pixel is lower than the deterioration rate of the reference pixel β2.
Further, for example, when the cumulative deterioration amount difference is a negative value, if the deterioration rate β1 of the correction target pixel is larger than the deterioration rate of the reference pixel β2, the deterioration amount difference ΔR is reduced.
Therefore, the correction operation selection unit 37 determines that a correction operation that causes a deterioration in image quality is unnecessary for pixels that satisfy this condition in the original image signal.

In addition, for example, when the cumulative deterioration amount difference is a negative value, when the deterioration rate β1 of the correction target pixel is smaller than the deterioration rate of the reference pixel β2 or when both gradation values are the same, the deterioration amount difference ΔR increases or It remains.
In this case, the correction operation selection unit 37 instructs the correction operation so that the deterioration rate β1 of the correction target pixel is larger than the deterioration rate of the reference pixel β2.
FIG. 13 shows the relationship between the determination operation and the correction operation. Again, the correction operation selection unit 37 executes functions corresponding to the update direction determination unit and the correction operation instruction unit in the claims.

(A-4) Correction Amount Determination Unit When the correction amount determination unit 39 is instructed to perform a correction operation, the deterioration rate β1 so that the accumulated deterioration amount difference ΣΔR read from the accumulated deterioration amount difference accumulation unit 9 is eliminated. Is a processing device for calculating
The correction amount determination unit 39 determines a gradation value (correction amount) corresponding to the correction deterioration rate β1 with reference to the gradation value-deterioration rate conversion table 33. In other words, the gradation value corresponding to the deterioration rate is derived by reversely converting the conversion table.
The derived gradation value is given to the deterioration amount difference correction unit 15 as a correction amount.

(B) Burn-in Correction Processing Example FIG. 14 shows a series of processing operations executed by the correction device 31.
Each time an input signal for the next light emission period is input, the correction operation selection unit 37 checks the cumulative deterioration amount difference ΣΔRB for the previous light emission period (S31).
In addition, the correction operation selection unit 37 checks the deterioration rate corresponding to the gradation value of the next light emission period for each of the correction target pixel and the reference pixel (S32).
Next, the correction operation selection unit 37 determines whether or not the cumulative deterioration amount difference ΣΔRB in the previous light emission period is non-zero (S33).
When a negative result is obtained in step S33 (that is, when the cumulative deterioration amount difference ΣΔR1 = 0), the correction operation selection unit 37 instructs to output the input signal without correction (S34).

On the other hand, when a positive result is obtained, the correction operation selection unit 37 determines whether or not the cumulative deterioration amount difference ΣΔR1 is negative (S35).
When a positive result is obtained in step S35, the correction operation selection unit 37 determines whether or not the deterioration rate β1 of the correction target pixel is equal to or higher than the deterioration rate β2 of the reference pixel (S36).
If a negative result is obtained in this step S36, this means that the cumulative deterioration amount difference ΣΔRA is reduced. Therefore, the correction operation selection unit 37 instructs to output the input signal without correction (S34).
On the other hand, if a positive result is obtained in step S36, this means that the cumulative deterioration amount difference ΣΔRA is enlarged. Accordingly, the correction operation selection unit 23 instructs the execution of the correction process so that the deterioration rate of the correction target pixel is changed to a value larger than the reference pixel so that the cumulative deterioration amount difference ΣΔRA is reduced (S37). Then, the input signal is corrected using the correction amount derived for the deterioration rate.

If a negative result is obtained in step S35, the correction operation selecting unit 23 determines whether or not the deterioration rate β1 of the correction target pixel is equal to or higher than the deterioration rate β2 of the reference pixel (S38).
If a negative result is obtained in this step S38, this means that the cumulative deterioration amount difference ΣΔRA is reduced. Therefore, the correction operation selection unit 37 instructs to output the input signal without correction (S34).
On the other hand, if a positive result is obtained in step S38, this means that the cumulative deterioration amount difference ΣΔRA is increased. Therefore, the correction operation selection unit 37 instructs the execution of the correction process so that the deterioration rate of the correction target pixel is changed to a value smaller than the reference pixel so that the cumulative deterioration amount difference ΣΔRA is reduced (S39). Then, the correction of the input signal is executed with the calculated correction amount.
Thereafter, the correction effect prediction unit 7 converts the correction amount into a deterioration amount difference, and gives it to the cumulative deterioration amount difference calculation unit 5. The cumulative deterioration amount difference calculation unit 5 subtracts the converted deterioration amount difference from the cumulative deterioration amount difference, and reflects the correction effect on the cumulative deterioration amount difference (S40).

(D) Example of mounting on self-luminous device FIG. 15 shows an example of mounting the burn-in phenomenon correcting device on the self-luminous device.
The self-light-emitting device 41 includes a burn-in phenomenon correction device 45 and a display device 47 mounted on a housing 43.
Here, the burn-in phenomenon correction device 45 corresponds to any of the correction devices 1, 21, and 31 described above. The burn-in phenomenon correction device 45 inputs an image signal generated at an external terminal or inside, and executes an input signal correction operation so that a deterioration amount difference does not occur between the correction target pixel and the reference pixel.

The display device 47 is assumed to be composed of a display device and its drive circuit. As the display device, an organic EL (electroluminescence) panel, a PDP (plasma display panel), an FED (field emission display) panel, an LED panel, or a CRT is used.
In the case of FIG. 14, the self-light-emitting device 41 is illustrated as having a burn-in phenomenon correction device 45, which is a dedicated processing device for correcting the burn-in phenomenon. However, when all the functions are executed in software. These functions are realized by a computer mounted on the self-luminous device.

(C) Effects of Embodiments Even when such a processing method is employed, image quality maintenance and burn-in correction can be performed simultaneously.
Furthermore, in the case of this embodiment, the deterioration amount of each light emission period can be accurately calculated using the deterioration rate. That is, even when the deterioration of the light emission characteristics does not proceed in proportion to the input signal value, the correction amount can be determined with high accuracy, and the burn-in phenomenon can be eliminated.
Of course, the correction operation for the burn-in phenomenon is performed even during use (during image display), so that the correction time in the non-use state can be shortened. In addition, since the correction period in the non-use state can be shortened, useless power consumption can be eliminated.

(F) Other Embodiments (a) In the above-described embodiments, the case where the light emission period t1 and the correction period t2 are arbitrary lengths has been described.
However, the light emission period t1 and the correction period t2 may be the same. For example, a unit field or a unit frame may be used. In this case, the deterioration amount can be calculated by each input signal value or its converted value (for example, deterioration rate).
(B) In the above-described embodiment, the method of determining the interpolation amount is selected so as to store the accumulated deterioration amount difference ΣΔR.
However, in order to eliminate the deterioration amount difference generated in the previous light emission period in each light emission period, a mechanism using the deterioration amount difference in the previous light emission period instead of the cumulative deterioration amount difference may be employed. That is, the mechanism for managing the difference in deterioration amount can be eliminated.

(C) In the above-described third embodiment, the case where the correspondence relationship between the gradation value of the unit frame and the deterioration rate is stored as the conversion table has been described.
However, the correspondence between the integrated value of gradation values corresponding to a plurality of frames and the deterioration rate may be stored. In this case, it is effective when the light emission period t1 and the correction period t2 are each given by a plurality of frames.
(D) 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 example of a form of the burn-in phenomenon correction apparatus. The relationship between determination conditions and correction | amendment operation | movement is shown. 5 is a flowchart illustrating an example of a burn-in correction process. It is a figure which shows the other example of a burn-in phenomenon correction apparatus. The relationship between determination conditions and correction | amendment operation | movement is shown. 5 is a flowchart illustrating an example of a burn-in correction process. It is a figure which shows the other example of a burn-in phenomenon correction apparatus. It is a figure which shows a cumulative deterioration amount-correction value conversion table. It is a figure which shows the specific example of a cumulative deterioration amount-correction value conversion table. It is a flowchart which shows the calculation process example of deterioration amount difference. It is a figure explaining generation | occurrence | production and reduction | decrease of a deterioration amount difference in case deterioration of a correction object pixel is advanced with respect to a reference pixel. It is a figure explaining generation | occurrence | production and reduction | decrease of a degradation amount difference in case degradation of a reference pixel is advanced with respect to a reference pixel. The relationship between determination conditions and correction | amendment operation | movement is shown. 5 is a flowchart illustrating an example of a burn-in correction process. It is a figure which shows the structural example of a self-light-emitting device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Burn-in phenomenon correction device 3 Deterioration amount difference calculation unit 5 Cumulative deterioration amount difference calculation unit 7 Correction effect prediction unit 9 Cumulative deterioration amount difference accumulation unit 11 Correction operation selection unit 13 Correction amount determination unit 15 Degradation amount difference correction unit 21 Burn-in phenomenon correction Device 23 Correction operation selection unit 31 Burn-in phenomenon correction device 33 Gradation value-deterioration rate conversion table 35 Deterioration amount difference calculation unit 37 Correction operation selection unit 39 Correction amount determination unit

Claims (11)

A method of correcting the burn-in phenomenon of a self-light-emitting device in which a plurality of self-light-emitting elements are arranged in a matrix while the self-light-emitting device is in use,
A process of sequentially calculating a deterioration amount difference generated between the correction target pixel and the reference pixel based on an input signal related to a driving condition of the self-light emitting element;
A process of cumulatively adding the calculated deterioration amount difference for each correction target pixel and calculating a cumulative deterioration amount difference for each correction target pixel;
A process of determining whether the magnitude of the cumulative deterioration amount difference is updated in a direction of reduction or update in a direction of enlargement due to light emission of the self-luminous element by the input signal;
When it is determined that the magnitude of the cumulative deterioration amount difference is updated in a decreasing direction, a process for instructing execution stop of the correction operation for the corresponding input signal;
When it is determined that the magnitude of the cumulative deterioration amount difference is updated in an increasing direction, a process for instructing calculation of a correction amount that reduces the magnitude of the cumulative deterioration amount difference;
And a process of correcting a corresponding input signal with the calculated correction amount. In the burn-in phenomenon correction method according to claim 1,
According to the input signal corresponding to the next light emission period, the process of determining whether the magnitude of the cumulative deterioration amount difference is updated in the direction of reducing or updated in the direction of increasing,
A process of comparing the accumulated deterioration amount difference before update with the accumulated deterioration amount difference after update;
When the cumulative deterioration amount difference after update is smaller, a process of determining that the cumulative deterioration amount difference is updated in a direction in which the magnitude of the cumulative deterioration amount difference is reduced;
And determining that the cumulative deterioration amount difference is updated in an increasing direction when the cumulative deterioration amount difference after the update is larger or the cumulative deterioration amount difference before and after the update is the same. Burn-in correction method. In the burn-in phenomenon correction method according to claim 1,
According to the input signal corresponding to the next light emission period, the process of determining whether the magnitude of the cumulative deterioration amount difference is updated in the direction of reducing or updated in the direction of increasing,
A process of determining whether the cumulative deterioration amount difference before update is a positive value or a negative value;
A direction in which the magnitude of the cumulative deterioration amount difference increases when the input signal value of the correction target pixel is equal to or greater than the input signal value of the reference pixel when it is determined that the cumulative deterioration amount difference before update is a positive value. A process for determining that it is updated to
When it is determined that the accumulated deterioration amount difference before update is a positive value, and the input signal value of the pixel to be corrected is smaller than the input signal value of the reference pixel, the accumulated deterioration amount difference is updated in a direction to reduce. A process for determining that
When it is determined that the accumulated deterioration amount difference before update is a negative value, and the input signal value of the correction target pixel is larger than the input signal value of the reference pixel, the accumulated deterioration amount difference is updated in the direction of reducing. A process for determining that
A direction in which the magnitude of the cumulative degradation amount difference increases when the input signal value of the correction target pixel is the same as or smaller than the input signal value of the reference pixel when it is determined that the cumulative degradation amount difference before update is a negative value A process for determining that it is updated to
A burn-in phenomenon correction method comprising: In the burn-in phenomenon correction method according to claim 1,
According to the input signal corresponding to the next light emission period, the process of determining whether the magnitude of the cumulative deterioration amount difference is updated in the direction of reducing or updated in the direction of increasing,
A process of determining whether the cumulative deterioration amount difference before update is a positive value or a negative value;
The deterioration rate derived from the input signal value of the pixel to be corrected is equal to or greater than the deterioration rate derived from the input signal value of the reference pixel when it is determined that the cumulative deterioration amount difference before update is a positive value. , Processing for determining that the magnitude of the cumulative deterioration amount difference is updated in an increasing direction;
When it is determined that the accumulated deterioration amount difference before update is a positive value, accumulation is performed when the deterioration rate derived from the input signal value of the correction target pixel is smaller than the deterioration rate derived from the input signal value of the reference pixel. A process for determining that the magnitude of the deterioration amount difference is updated in a decreasing direction;
Accumulated when the deterioration rate derived from the input signal value of the correction target pixel is larger than the deterioration rate derived from the input signal value of the reference pixel when it is determined that the accumulated deterioration amount difference before update is a negative value. A process for determining that the magnitude of the deterioration amount difference is updated in a decreasing direction;
The deterioration rate derived from the input signal value of the pixel to be corrected is equal to or smaller than the deterioration rate derived from the input signal value of the reference pixel when it is determined that the cumulative deterioration amount difference before update is a negative value , Processing for determining that the magnitude of the cumulative deterioration amount difference is updated in an increasing direction;
A burn-in phenomenon correction method comprising: In the burn-in phenomenon correction method according to claim 1,
The burn-in phenomenon correction method, wherein the reference pixel is set for each of a plurality of self-light-emitting elements that emit light of the same color. In the burn-in phenomenon correction method according to claim 1,
The burn-in phenomenon correction method, wherein the reference pixel is a pixel virtually set for calculating a correction amount. In the burn-in phenomenon correction method according to claim 1,
The burn-in phenomenon correction method, wherein the input signal is a gradation value for designating luminance. In the burn-in phenomenon correction method according to claim 1,
The burn-in phenomenon correction method, wherein the input signal is a drive current value applied to a self-luminous element. A self-light-emitting device in which a plurality of self-light-emitting elements are arranged in a matrix on a substrate,
A deterioration amount difference calculation unit that sequentially calculates a deterioration amount difference generated between the correction target pixel and the reference pixel, based on an input signal related to a driving condition of the self-light emitting element;
A cumulative deterioration amount difference calculating unit that cumulatively adds the calculated deterioration amount difference for each correction target pixel and calculates a cumulative deterioration amount difference for each correction target pixel;
An update direction determination unit that determines whether the magnitude of the cumulative deterioration amount difference is updated in the direction of reduction or update in the direction of enlargement due to light emission of the self-light-emitting element by the input signal;
When it is determined that the magnitude of the cumulative deterioration amount difference is updated in a decreasing direction, an instruction to stop execution of the correction operation for the corresponding input signal is issued, and the cumulative deterioration amount difference is updated in the increasing direction. A correction operation instruction unit that instructs calculation of a correction amount that reduces the magnitude of the cumulative deterioration amount difference,
A self-luminous device comprising: a deterioration amount difference correction unit that corrects a corresponding input signal with a determined correction amount. A self-light-emitting device burn-in phenomenon correcting device in which a plurality of self-light-emitting elements are arranged in a matrix on a substrate,
A deterioration amount difference calculation unit that sequentially calculates a deterioration amount difference generated between the correction target pixel and the reference pixel, based on an input signal related to a driving condition of the self-light emitting element;
A cumulative deterioration amount difference calculating unit that cumulatively adds the calculated deterioration amount difference for each correction target pixel and calculates a cumulative deterioration amount difference for each correction target pixel;
An update direction determination unit that determines whether the magnitude of the cumulative deterioration amount difference is updated in the direction of reduction or update in the direction of enlargement due to light emission of the self-light-emitting element by the input signal;
When it is determined that the magnitude of the cumulative deterioration amount difference is updated in a decreasing direction, an instruction to stop execution of the correction operation for the corresponding input signal is issued, and the cumulative deterioration amount difference is updated in the increasing direction. A correction operation instruction unit that instructs calculation of a correction amount that reduces the magnitude of the cumulative deterioration amount difference,
A burn-in phenomenon correction device, comprising: a deterioration amount difference correction unit that corrects a corresponding input signal with a determined correction amount. In a computer mounted on a self-luminous device in which a plurality of self-luminous elements are arranged in a matrix,
A process of sequentially calculating a deterioration amount difference generated between the correction target pixel and the reference pixel based on an input signal related to a driving condition of the self-light emitting element;
A process of cumulatively adding the calculated deterioration amount difference for each correction target pixel and calculating a cumulative deterioration amount difference for each correction target pixel;
A process of determining whether the magnitude of the cumulative deterioration amount difference is updated in a direction of reduction or update in a direction of enlargement due to light emission of the self-luminous element by the input signal;
When it is determined that the magnitude of the cumulative deterioration amount difference is updated in a decreasing direction, a process for instructing execution stop of the correction operation for the corresponding input signal;
When it is determined that the magnitude of the cumulative deterioration amount difference is updated in an increasing direction, a process for instructing calculation of a correction amount that reduces the magnitude of the cumulative deterioration amount difference;
And a process for correcting a corresponding input signal with the calculated correction amount.

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