JP2000356981A - Display controller for display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct the display characteristic of a display device. SOLUTION: A display state detecting part 1 detects whether a display device 5 for display is in a display state or not and a display time accumulating part 2 accumulates a display time only when the device is in the display state by a detection signal from the part 1. A display characteristic discriminating part 3 discriminates display characteristics for every an accumulated display time by a display time signal from the part 2 and when a display time becomes the threshold value of a prescribed accumulated display time, it transmits a control signal to a display characteristic correcting part 4. Then, the part 4 corrects the deterioration of luminance of the display device 5 by changing elements being establishment concerning the display to → elements suited to the accumulated display time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects an accumulated display time, performs display control in accordance with the accumulated display time, and corrects or corrects display characteristics such as color temperature characteristics, luminance characteristics, burn-in, and writing characteristics. The present invention relates to a display control device for correcting a deterioration rate of display characteristics.

[0002]

2. Description of the Related Art FIG. 13 shows an example of a method for correcting burn-in of a display device described in Japanese Patent Application Laid-Open No. H4-295887. The timer 10 measures a continuous display time during which display images having the same content are continuously displayed at the same position in the display screen. When this display time exceeds a predetermined time, a part of the display screen is erased,
Alternatively, burn-in is corrected by reducing the display screen and moving the display position within the screen using the resulting empty space in the screen.

FIG. 14 shows an example of a display control device for correcting burn-in of a display screen by screen brightness control described in JP-A-5-61426. The display control unit 17 transmits a display information and a brightness control signal to the display screen 22 and a display that transmits display information from the application program 21 or the keyboard 23 to the display control unit 19. It comprises an access unit 20 and a display display timer 18 for checking the continuous display time of the same screen.

When the display information from the display access unit 20 is interrupted, the display display timer 18 starts counting, and when the specified time is reached, the display control unit 19 sends a control signal to lower the brightness of the display screen 22. . When new display information is transmitted, the display display timer 18 is reset, and the brightness of the display display screen 22 returns to the original.

[0005]

In the above-mentioned conventional display display control device, since the display control is performed by performing a short time measurement from one light-on to a light-off, the display state is temporal. It is possible to cope with the deterioration of display characteristics due to the continuation of the display, but if the display is turned off once and then the display is started again, the past display time information is not taken into account. In addition, correction of display characteristics such as burn-in, change in color temperature, deterioration of luminance, and deterioration of writing characteristics, which occur when the accumulated display time becomes long, or correction of deterioration speed of display characteristics cannot be performed.

In addition, the display time of each partial display area (display area) on the display screen cannot be detected,
When only a specific area is displayed, there is a problem that it is not possible to optimally correct the display characteristics or to control the correction of the deterioration speed of the display characteristics.

Furthermore, the display time of each pattern (display pattern) having a specific property in a displayed image cannot be detected, and if such a display pattern exists, the optimum display characteristics or the deterioration speed of the display characteristics are not determined. There was a problem that correction could not be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and a display capable of correcting display characteristics or correcting the deterioration speed of display characteristics in consideration of the display state history of the display. A first object is to provide a display control device.

It is another object of the present invention to provide a display control device capable of optimally correcting the display characteristics or correcting the deterioration speed of the display characteristics when only a specific area is displayed or when there is a specific display pattern. This is the second purpose.

[0010]

In order to achieve the above-mentioned object, according to the present invention, a display for displaying an image and a display time for obtaining an accumulated display time obtained by accumulating an image display time on the display are provided. An accumulating unit; and a display control unit that controls display of the display according to the accumulated display time.

According to a second aspect of the present invention, there is provided the display control apparatus according to the first aspect, wherein the display control is performed on the display when the accumulated display time exceeds a predetermined accumulated display time threshold. This switches the display control state.

According to a third aspect of the present invention, there is provided the display control device according to the second aspect, wherein the control state after the switching in the display control is larger than the control state before the switching. Are slow in luminance degradation.

According to a fourth aspect of the present invention, there is provided the display control apparatus according to the second aspect, wherein the display time accumulating section is configured to output the accumulated display time only when a luminance signal of a predetermined value or more is input to the display. The cumulative display time threshold is a predetermined cumulative display time in which a luminance characteristic is degraded by a predetermined value or more due to display on the display by a luminance signal equal to or more than the predetermined value, and after the switching in the display control. Is such that the life of the display due to burn-in is longer than the control state before the switching.

According to a fifth aspect of the present invention, there is provided the display control apparatus according to the second aspect, wherein the display performs color display by synthesizing a plurality of color components. The threshold is the accumulated display time during which the color temperature characteristic of the display deteriorates to a predetermined value or less, and the control state after the switching in the display control is smaller than the control state before the switching. It would be good.

According to a sixth aspect of the present invention, in the display control apparatus according to the second aspect, the accumulated display time threshold is an accumulated display time in which a writing characteristic of the display deteriorates to a predetermined value or less; The control state after the switching in the display control is such that the writing characteristics on the display are better than the control state before the switching.

According to a seventh aspect of the present invention, there is provided the display control apparatus according to any one of the second to sixth aspects, wherein the display control unit includes a plurality of control states other than the control state in the initial stage. And storing a plurality of accumulated display time thresholds, wherein the display control in the display control unit selectively switches the plurality of control states each time the plurality of accumulated display time thresholds elapses It is.

The invention according to claim 8 is the display display control device according to any one of claims 2 to 6, wherein the display performs display for each of a plurality of divided display areas obtained by dividing a display screen. And the display time can be switched, and the display time accumulating section obtains the accumulated display time for each of the plurality of divided display areas, and the display control in the display control section includes the plurality of divided display areas. The switching of the control state is performed when any one of the cumulative display times for each area exceeds the cumulative display time threshold.

According to a ninth aspect of the present invention, there is provided the display control device according to any one of the second to sixth aspects, wherein the display control unit is configured to control a specific property of an image displayed on the display. Further comprising a pattern detection unit that detects a display pattern that is a pattern having
The display time accumulator accumulates the display time of the display pattern to determine the accumulated display time.

The "image" in the present invention is a concept including both a moving image and a still image.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A display control device according to the present invention will be specifically described below with reference to the drawings.
In the following drawings, the same reference numerals indicate the same or corresponding devices as those in the conventional technology.

(Embodiment 1) FIG. 1 is a block diagram of a display control apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, the display display control device includes a display device 5 (corresponding to a display in the present invention), and a display characteristic using the accumulated display time, specifically, an output luminance value with respect to an input luminance signal in the display device 5. Is a device for correcting the deterioration rate over time with respect to the luminance characteristic corresponding to the ratio, and includes a display state detection unit 1, a display time accumulation unit 2, a display control unit CNT, and a display device 5. .

FIG. 2 is a conceptual diagram of a main part of the display device 5. The display device 5 has a CR for displaying images.
A display 5b comprising a display device such as a T, LCD (liquid crystal display), PDP (plasma display panel), and a signal processing / driving unit 5a for converting an externally applied video signal into a drive signal suitable for display on the display 5b. And

FIG. 3 is a diagram showing the controllability of the display 5b by taking the relationship between the signal level of the video signal and the luminance level of the display 5b as an example. As shown in FIG.
In the display device 5, the brightness of the display 5b can be controlled by adjusting the level of the video signal. Further, the display level can be changed even at the same video signal level by changing elements such as gradation control, contrast control, brightness control, and sustain frequency control included in the signal processing / driving unit 5a. . In the first embodiment and the following embodiments,
Such various controllability in the display 5b is used.

In FIG. 3 and the following description, “elements” refer to the individual control states specified by the various control elements as described above with respect to the display on the display device 5. The difference between the control states is referred to as “element A”, “element B1”, “element B2”, respectively.
… Is distinguished by a symbol.

Returning to FIG. 1, the display control in the display control device will be described below. The display state detection unit 1 detects whether or not the display device 5 is in a display state, and sends a detection signal indicating the detection result to the display time accumulation unit 2. The display time accumulating unit 2 includes a timer 2a and a memory 2b therein, and stores the accumulated display time in the memory 2b. The accumulated display time is initialized at the time of shipment of the display control device. The display time accumulating section 2 cumulatively adds the count of the timer to the accumulated display time only when the sent detection signal indicates the display state. Further, the display time accumulating unit 2 transmits a display time signal indicating the accumulated display time obtained at all times to the display characteristic determining unit 3. Then, the display characteristic determining unit 3 determines the timing of switching the elements based on the accumulated display time indicated by the display time signal so that the display characteristics of the display device 5 are kept good. Specifically, this is performed as follows.

FIG. 4 is a conceptual diagram showing the temporal change of the luminance characteristic and the correction of the luminance characteristic when displaying an image by the elements A and B1. In FIG. 4, the luminance aging curves BL1 and BL2 show the temporal change of the luminance characteristic when the display is continued by the element A and the element B1, respectively. FIG.
As can be understood from the above, in the initial stage, the display is performed by the element A in which the display quality of the display device 5 is the highest, but after the display is performed to some extent, the luminance characteristic is more than a certain level for a long time than the image quality is prioritized. It is better to continue the display with the element B1 that is maintained at For this reason, in the first embodiment, the display characteristic determination unit 3 has a previously determined accumulated display time in which the luminance characteristic of the display device 5 becomes worse than a predetermined luminance characteristic threshold when the display is continued with the element A. When it is determined that the accumulated display time threshold value t1 has been reached, the control signal is changed to the display characteristic correction unit 4 so as to change the display on the display device 5 from the element A to the element B1.
Send to Then, the display characteristic correction unit 4 switches the display on the display device 5 from the element A to the element B1 according to the control signal.

The factor B1 that slows down the rate of deterioration of the luminance characteristic may be a factor that suppresses the brightness of the display screen of the display device 5. As specific control, the brightness of the display screen is suppressed by adjusting the video signal level by adjusting the contrast and brightness. In particular, in the case of a PDP, it can also be realized by suppressing the maintenance frequency.

By switching the elements of the display device 5 in this manner, the speed of deterioration of the luminance characteristic is reduced,
It is possible to control the display device 5 to maintain a somewhat good luminance characteristic even when a long-time display is performed.

(Embodiment 2) The display control device according to the second embodiment has almost the same configuration as the display control device according to the first embodiment. However, there are three embodiments in which the life correction, the color temperature characteristic correction, and the writing characteristic correction are performed by burn-in. Hereinafter, each embodiment will be described in detail.

<Embodiment 1> When a region having a high luminance level exists in the display screen when the display device 5 is performing display, only the region causes a significant deterioration in luminance in a very short time. Causes burn-in. Therefore, in the first embodiment, when such a region having a high luminance level is displayed for a predetermined time on the display device 5, the entire screen is delayed from the display by the element A in which the display quality is prioritized, due to burn-in. Element B2 like
(Not shown). Specifically, the display state detection unit 1 has a function of monitoring whether or not a luminance signal having a predetermined value or more (hereinafter, referred to as a “high luminance signal”) is included in the display image signal. While displaying, it is always monitored. Then, when it is detected that such a high luminance signal has been input, the information to that effect is also included in the detection signal and sent to the display time accumulating unit 2.

In the display time accumulating section 2, only when the information in the detection signal indicates the input of a high luminance signal, the timer 2a
Is cumulatively added to the cumulative display time. The accumulated display time is also initialized at the time of shipping the display control device. Then, the display time accumulating unit 2
Transmits a display time signal representing the accumulated display time obtained all the time to the display characteristic determination unit 3. Then, when the display is continued with the element A, the cumulative display time threshold value t2 (not shown), which is a previously determined cumulative display time such that the luminance characteristic of the display device 5 becomes worse than the predetermined luminance characteristic threshold value, is obtained. If it is determined that the
Thus, the element B2 is changed to the element B2 having a slower deterioration rate of the luminance characteristic so that the life due to the burn-in of the display device 5 is longer than when the display by the element A is continued.

The element B2 that extends the life due to burn-in may be a display control element that suppresses the brightness of the display screen of the display device 5, similarly to the element B1 in the first embodiment. The specific control is the same as in the first embodiment. The switching process from element A to element B2 is performed in the same manner as the switching process from element A to element B1 in the first embodiment. This makes it possible to reduce the luminance deterioration rate of the display device 5 and prolong the life due to burn-in.

<Embodiment 2> In Embodiment 2 of Embodiment 2, the display device 5 capable of displaying a color image is provided, and the luminance characteristic of each color component is renormalized to thereby improve the color temperature characteristic. Correction has been performed. FIG. 5 is a conceptual diagram showing how the luminance characteristic of each color component changes over time and how the color temperature characteristic is corrected in the display device 5. As shown in FIG. 5, not all the color components are continuously displayed on the display device 5, so that three color components (for example, R (red), G (green),
B (blue)) Normally, the temporal changes of the respective luminance characteristics are different from each other. Therefore, as shown in FIG. 5, even if the luminance characteristic of the display device 5 is normalized in the initial stage (the luminance characteristic of each color component is coincident with the accumulated display time of “0” in FIG. 5), it gradually increases as the display is performed. Differences occur in the luminance characteristics between the respective color components. Therefore, when the accumulated display time becomes longer, the color temperature characteristic deteriorates as compared with the initial stage, and this phenomenon becomes remarkable as time elapses.

Therefore, in the device of the second embodiment, as shown in FIG. 5, during the cumulative display time, the color temperature characteristics previously obtained by experiments or the like are deteriorated below a predetermined value (the luminance characteristics of the respective color components are higher than a predetermined value). The color temperature characteristic is corrected by re-adjusting the luminance balance (normalizing the luminance characteristic) when the accumulated display time threshold t3, which is the accumulated display time that differs (ie, the luminance balance deteriorates), has elapsed. ing. Specifically, the accumulated display time of the display device 5 is obtained in substantially the same manner as in the first embodiment, and when the accumulated display time reaches the accumulated display time threshold t3, the display of the display device 5 is changed from the element A to the element B3 (not shown). ). However, the element B3 here is set as follows. That is, from the time-dependent change DG of the luminance characteristic of each color component as shown in FIG.
The element B3 is set such that the luminance characteristic of the other color component matches the color component (color C3 in FIG. 5) indicating the lowest luminance characteristic at the cumulative display time threshold value t3 (matches the brightness). The specific control can be realized by adjusting the video signal level by adjusting the contrast and brightness.

As a result, as shown in FIG. 5, when the elements are switched, the color temperature characteristics are kept good even after a long time as compared with the case where the elements are not switched (indicated by the alternate long and short dash line in FIG. 5). The difference in luminance characteristics of each color component is kept small), and the display quality is significantly improved.

<Embodiment 3> Further, in Embodiment 3, the display 5b is a PDP, and the deterioration rate of the writing characteristic in the display device 5 having such a display 5b is corrected. Here, the write characteristic is a characteristic as to whether or not a write operation (address operation), a sustain operation (sustain), and an erase operation are normally performed in the PDP, and more specifically, a specific drive voltage. This is a characteristic indicating whether or not all the pixels to be turned on are turned on.

FIG. 6 is a diagram showing an example of a temporal change of a threshold value (lowest drive voltage) of a drive voltage for displaying the display device 5. In FIG. 6, the threshold voltage curve T
L1 and TL2 are the driving voltage when the display is continued by the element A in the initial stage and the display voltage threshold value is low even after a long time as shown in FIG. This indicates a change with time of the threshold value. In an arbitrary accumulated display time, display is not properly performed by the display device 5 below the threshold voltage curves TL1 and TL2 (abnormal range), and is performed properly at voltages higher than these (normal range). ).

The element B4 having good writing characteristics even after such a long time includes, specifically,
What is necessary is just to adjust the video signal level by adjusting the brightness or lower the maintenance frequency.

Then, in FIG. 6, the threshold voltage curve TL1
Is curved upward as the cumulative display time increases, and if the display is performed by the element A at the predetermined drive voltage V1, the display shifts to an abnormal range where the display is not performed properly at an early time (T). . On the other hand, when the display is performed by the element B4, the threshold voltage curve TL2 has a linear characteristic with a small slope, so that the accumulated display time does not shift to the abnormal range until after a long time. Therefore, in the third embodiment, when the accumulated display time threshold t4, which is the accumulated display time in which the display voltage threshold of the element A obtained in advance by experiment or the like becomes equal to or more than the predetermined value, elapses, the display by the element A is changed to the display by the element B4. Switch. Specifically, the accumulated display time of the display device 5 is obtained in substantially the same manner as in the first embodiment,
When it reaches the cumulative display time threshold t4, the display on the display device 5 is switched from element A to element B4.

As described above, at the cumulative display time threshold value t4, the element A is switched from the element A to the element B4 in which the degradation rate of the writing characteristic in the display device 5 is slow (good even after a long time). Can be kept in
The display operation in the normal driving range of the display device 5 can be performed for a long time.

As described above, according to the second embodiment, the cumulative display time is measured, and the correction of the display characteristics such as the color temperature characteristic, the burn-in and the writing characteristic, or the correction of the deterioration speed of the display characteristic according to the cumulative display time is performed. Therefore, it is possible to realize a display control device in which the display characteristics of the display device 5 do not deteriorate even after a long time.

As described above, in the first embodiment and the second embodiment, the case where the cumulative display time threshold is one has been described. However, a plurality of cumulative display time thresholds can be used. FIG. 7 is a diagram showing a temporal change of the luminance characteristic in an example having two cumulative display time thresholds t5 and t6 (where t5 <t6). In this case, the display characteristic correction unit 4 holds the settings corresponding to the plurality of elements B5 and B6, and when the accumulated display time exceeds the accumulated display time threshold t5 as shown in FIG. When the threshold value t6 is exceeded, switching is performed from element A to element B5 and from element B5 to element B6, respectively. And the elements B5, B5
No. 6 has the same tendency as each of the elements B1 to B4 in each embodiment of the first and second embodiments (a slow deterioration rate of the luminance characteristic, a long life due to image sticking, a good color temperature characteristic, In particular, the element B6 is an element whose tendency is stronger than that of the element B5.

By switching the elements in two stages as described above, the correction of the display characteristics or the correction of the deterioration speed of the display characteristics can be finely performed according to each stage of the accumulated display time.

Further, three or more elements are prepared,
The element may be switched each time three or more accumulated display time thresholds elapse.

(Embodiment 3) In the first and second embodiments, the case where the display operation time of the entire display screen of the display device 5 is accumulated has been described. 5, the effective screen area is divided into n × m (n and m are natural numbers), and the accumulated display time for each divided display area is determined in the display time accumulating unit. The accumulated display time threshold value is set in any one of the divided display areas. When the time has elapsed, the element is switched. Thus, by managing the accumulated display time for each divided display area, it is possible to correct burn-in occurring locally.

FIG. 8 shows the display device 5 at the time of 2 × 3 division.
FIG. 6 is a diagram illustrating an example of an effective screen area in FIG. FIG. 9 is a diagram showing the accumulated display time for each divided display area. As shown in FIG. 8, each divided display area is represented by i × j (i
= 1, 2, j = 1 to 3), the divided display area 1 ×
Consider a case in which the display (lighting) state continues intermittently in 1, 1 × 3, 2 × 2 and the non-display (non-lighting) state in the other divided display areas 1 × 2, 2 × 1, 2 × 2. When,
As shown in FIG. 9, the divided display areas 1 × 1, 1 × 3, 2 × 2
Only the display time is accumulated and added in the display time accumulation unit 2.

FIG. 10 is a diagram showing a temporal change of the luminance characteristic in the divided display areas. In FIG. 10, the horizontal axis does not indicate the accumulated display time but indicates a continuous normal time. As shown in FIG. 10, in the non-lit divided display areas 1 × 2, 2 × 1, and 2 × 2, the luminance characteristics hardly change with time, but the lit divided display areas 1 × 1 and 2 × 2
In 1 × 3, 2 × 2, the deterioration continues as time advances.

FIG. 11 is a block diagram of a display control device according to the third embodiment. In the third embodiment, the display device 5 performs the above-described divided display by the element A in the initial stage. Then, in the display position detecting section 6 for detecting the divided area on the display screen, a detection signal representing the displayed (lit) divided display area is input to the display time accumulating section 2. The memory 2b in the display time accumulating section 2 has a storage area for the accumulated display time corresponding to each of the plurality of divided display areas, and each divided area is based on a detection signal from the display position detecting section 6. The display time for each display area is accumulated, and a display time signal indicating the accumulated display time for each divided display area obtained at all times is transmitted to the display characteristic determination unit 3. Then, based on the display time signal, the display characteristic determining unit 3 selects the maximum cumulative display time among the cumulative display times for each divided display area, and determines the maximum cumulative display time and the same as in the first embodiment. Is compared with a cumulative display time threshold value t1, which is a previously determined cumulative display time that is worse than the predetermined luminance characteristic, and when the cumulative display time of any of the divided display areas exceeds the cumulative display time threshold value t1, the display device 5 is changed from the element A to the element B as in the first embodiment.
A control signal is sent to the display characteristic correction unit 4 so as to switch to 1. Then, the display characteristic correction unit 4 switches the display on the display device 5 from the element A to the element B1. This allows
The deterioration speed of the luminance characteristic is corrected so as to suppress the luminance deterioration of the divided display area (the divided positions 1 × 1, 1 × 3, 2 × 2 in the case of FIG. 10) having the maximum accumulated display time.

As described above, according to the third embodiment, by performing display control on the basis of the divided display area in which the luminance characteristic deteriorates quickly, the luminance characteristic of the entire display screen can be kept good for a long time. As a result, display quality and reliability can be improved.

Further, in the third embodiment, description has been made of luminance degradation as an example. However, the present invention is not limited to this. For example, life correction due to burn-in, color temperature characteristic correction, writing The characteristic correction may be performed based on the accumulated display time of each of the plurality of divided display regions as in the third embodiment. In this case, it is possible to configure a life correction, a color temperature characteristic correction, and a writing characteristic correction device by burning.
"Even if there is a divided display area with high brightness, the life due to burn-in of the entire screen can be prolonged.""Even if there is a divided area where the color temperature deteriorates quickly, the color temperature characteristics of the entire screen can be kept good." In addition, there is an effect that "the writing characteristics of the entire screen can be kept good even if there is a divided region where the writing characteristics deteriorate quickly".

(Embodiment 4) In the above-described Embodiment 3, the case where the display operation time of the divided display area of the display screen is accumulated has been described. In Embodiment 4, the display by the input signal to the display device 5 is performed. The accumulated display time for each pattern is obtained, and display control is performed based on the accumulated display time.

FIG. 12 is a block diagram of a display control device according to the fourth embodiment. In FIG. 12, when the display pattern detecting unit 7 detects a display pattern in which image sticking such as a still image is likely to occur from the input image signal,
The detection signal is output to the display time accumulating unit 2. As a still image detection method, an input image signal is compared with an input image signal before a predetermined time, and if there is no difference between them, it is determined that the image is a still image.

The display time accumulating section 2 obtains the accumulated display time for the display pattern based on such a detection signal, and transmits a display time signal indicating the accumulated display time of the display pattern to the display characteristic determining section 3. Then, the display characteristic determining unit 3 compares the accumulated display time with an accumulated display time threshold t7 (not shown), which is a previously determined accumulated display time that is worse than a predetermined luminance characteristic, and calculates the accumulated display time. Is longer than the accumulated display time threshold t7, a control signal is sent to the display characteristic correction unit 4 to switch the display element of the display device 5 from the element A to the element B7 (not shown), and the display characteristic correction unit 4 Controls the display by the display device 5. Here, the element B7 may have the same tendency as the element B2 in the first embodiment of the second embodiment.

As a result, it is possible to extend the life of the entire display screen due to the display of a specific display pattern.

Here, an example in which there is a still image at one place in the display image has been mainly described. However, such a display pattern may be divided into a plurality of places on the display screen of the display device 5 or a moving image may be displayed. In the case where an image that moves on the screen regularly or an image that periodically changes the screen is included, the display pattern detection unit 7 sets each display pattern (for a moving or changing image, It is sufficient to output a detection signal for each of the above (display at each position). In that case, the display time accumulating unit 2 calculates the accumulated display time of each display pattern accordingly,
The display characteristic discriminating unit 3 determines that the maximum accumulated display time is
A similar effect can be obtained by comparing with the accumulated display time threshold value t7.

Further, in the fourth embodiment, an example of correction of burn-in by a display pattern has been described. However, the present invention is not limited to this. The color temperature characteristic correction and the write characteristic correction as in the second embodiment can be performed based on the accumulated display time for each display pattern as in the fourth embodiment. In these cases, if the element B7 has the same tendency as the element B1 in the first embodiment, the element B3 in the second embodiment of the second embodiment, and the element B4 in the third embodiment of the second embodiment, respectively. Good.

According to these, a luminance characteristic deterioration correction, a color temperature characteristic correction, and a writing characteristic correction device can be constructed, respectively. Good luminance characteristics can be maintained even when display is performed. "" Even if there is a display pattern with rapid degradation of color temperature, the color temperature characteristics of the entire screen can be kept good. " Even if there is a display pattern whose deterioration is fast, the writing characteristics of the entire screen can be kept good. "

(Modification) In each of the above embodiments, examples of the display control device and the display control by the display control device have been described, but the present invention is not limited to this.

For example, in each of the above embodiments, color display is performed only in the second embodiment of the second embodiment. In the other embodiments, description has been made assuming a single color (monochrome) display. Also, in the case of performing color display, by detecting the accumulated time of each color component of a plurality of color components (for example, RGB), it can be applied to correction of various characteristics such as luminance characteristics of each color component.

In each of the above-described embodiments, the cumulative display time threshold value at which the luminance characteristics and the like deteriorate to a predetermined value or less is determined in advance, and the cumulative display time is compared with the threshold value to correct each characteristic. In addition, a table representing each display characteristic with respect to the accumulated display time obtained in advance by an experiment or the like is held, and a value of the display characteristic corresponding to the accumulated display time is obtained from the table, and the value is deteriorated to a predetermined value or less. The characteristic may be corrected (switching the element) at the stage when this is detected.

[0061]

Since the present invention is configured as described above, it has the following effects.

According to the first to ninth aspects of the present invention, display control is performed in accordance with the accumulated display time obtained by accumulating the image display time on the display. And the deterioration rate of the display characteristics can be corrected.

According to the present invention, the display control switches the display control state on the display when the accumulated display time exceeds a predetermined accumulated display time threshold value. In addition, it is possible to easily correct the display characteristics of the display and to correct the deterioration speed of the display characteristics.

According to the third aspect of the present invention, the control state after the switching is smaller than the control state before the switching.
Since the speed of the luminance deterioration in the display is slow, the speed of the luminance deterioration can be reduced.

According to the fourth aspect of the present invention, the cumulative display time is added only when the luminance signal having a predetermined value or more is input to the display. This is a predetermined accumulated display time in which the luminance characteristic is degraded by a predetermined amount or more by display, such that the control state after switching in the display control has a longer life due to burn-in of the display than the control state before switching. Therefore, the life of the display due to burn-in can be extended.

According to the present invention, the cumulative display time threshold is the cumulative display time during which the color temperature characteristic of the display deteriorates to a predetermined value or less, and the control state after switching is the control state before switching. Since the color temperature characteristics of the display are better than those of the display, the color temperature characteristics can be improved.

According to the present invention, the cumulative display time threshold value is the cumulative display time during which the writing characteristic of the display deteriorates to a predetermined value or less, and the control state after the switching is compared with the control state before the switching. Thus, since the writing characteristics of the display are improved, the writing characteristics can be improved.

According to the present invention, a plurality of control states are stored in addition to the control state in the initial stage, and a plurality of accumulated display time thresholds are stored. Since the plurality of control states are selectively switched each time the accumulated display time threshold value elapses, finer display control can be performed.

According to the invention of claim 8, the display can switch between display and non-display for each of a plurality of divided display areas obtained by dividing the display screen. Since the control state is switched when any one of the accumulated display times of the divided display regions exceeds the accumulated display time threshold, the display characteristics such as the luminance characteristic, the color temperature characteristic, and the writing characteristic are rapidly deteriorated. By performing the display control based on the area, the display characteristics of the entire display screen can be kept good, and the display quality and the reliability can be improved.

According to the ninth aspect of the present invention, the display time accumulating section accumulates the display time of the display pattern to obtain the accumulated display time. The deterioration rate can be corrected, and the display quality and the reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment.

FIG. 2 is a conceptual diagram of a display device.

FIG. 3 is a diagram illustrating a display level with respect to a video signal level of a display device.

FIG. 4 is a conceptual diagram of luminance characteristic degradation when an element is changed and luminance characteristic correction.

FIG. 5 is a conceptual diagram of a temporal change of luminance characteristics for each color component and color temperature control.

FIG. 6 is a conceptual diagram of a change over time in write characteristics and correction of write characteristics.

FIG. 7 is a diagram illustrating an example of a display correction method when two time change points are provided.

FIG. 8 is a diagram showing an example of a display screen in 2 × 3 division.

FIG. 9 is a diagram illustrating an accumulated display time for each 2 × 3 divided display area.

FIG. 10 is a diagram showing a change over time in luminance characteristics for each 2 × 3 divided display area.

FIG. 11 is a block diagram showing a configuration of a third embodiment.

FIG. 12 is a block diagram showing a configuration of a fourth embodiment.

FIG. 13 is a diagram illustrating an example of a conventional burn-in correction method.

FIG. 14 is a diagram illustrating an example of a conventional burn-in correction by controlling the brightness of a display screen.

[Explanation of symbols]

1 display state detecting section, 2 display time accumulating section, 3 display characteristic determining section, 4 display characteristic correcting section, 5 display device, 6 display position detecting section, 7 display pattern detecting section.

Claims (9)

[Claims] A display for displaying an image; a display time accumulating unit for obtaining an accumulated display time obtained by accumulating an image display time on the display; and a display for controlling display of the display according to the accumulated display time. A display display control device, comprising: a control unit. 2. The display display control device according to claim 1, wherein the display control switches a display control state of the display when the cumulative display time exceeds a predetermined cumulative display time threshold. A display display control device, characterized in that: 3. The display display control device according to claim 2, wherein the control state after the switching in the display control is slower in luminance degradation in the display than the control state before the switching. A display display control device, characterized in that: 4. The display control device according to claim 2, wherein the display time accumulating section adds the accumulated display time only when a luminance signal having a predetermined value or more is input to the display. The cumulative display time threshold is a predetermined cumulative display time in which a luminance characteristic is deteriorated by a predetermined value or more due to display on the display by a luminance signal equal to or more than the predetermined value, and the control state after the switching in the display control is the switching. A display display control device characterized in that the life of the display due to burn-in is longer than in the previous control state. 5. The display display control device according to claim 2, wherein the display performs color display by synthesizing a plurality of color components, and wherein the cumulative display time threshold is a color in the display. The accumulated display time in which the temperature characteristic is deteriorated to a predetermined value or less, and the control state after the switching in the display control is such that the color temperature characteristic in the display is better than the control state before the switching. A display display control device, comprising: 6. The display display control device according to claim 2, wherein the accumulated display time threshold is an accumulated display time in which a writing characteristic of the display deteriorates to a predetermined value or less, and after the switching in the display control. Wherein the control state is such that the writing characteristics on the display are better than the control state before the switching. 7. The display display control device according to claim 2, wherein the display control unit stores a plurality of control states other than a control state in an initial stage and a plurality of control states. Storing a cumulative display time threshold, wherein the display control in the display controller selectively switches the plurality of control states each time the plurality of cumulative display time thresholds elapses. Display control unit. 8. The display display control device according to claim 2, wherein the display is switchable between display and non-display for each of a plurality of divided display areas obtained by dividing a display screen. Wherein the display time accumulating section calculates the accumulated display time for each of the plurality of divided display areas, and wherein the display control in the display control section performs the accumulated display time for each of the divided display areas. Wherein the switching of the control state is performed when any one of the thresholds exceeds the cumulative display time threshold. 9. The display display control device according to claim 2, wherein the display control unit is a pattern having a specific property in an image displayed on the display. The display display control device, further comprising: a pattern detection unit for detecting the display time, wherein the display time accumulation unit accumulates the display time of the display pattern to obtain the accumulated display time.