Luminance control device, display device, luminance control method, luminance control program, and recording medium storing the luminance control program

Abstract

Provided is a display device (100) which predicts a predicted temperature difference between a peripheral display area and an outer peripheral area of a display section (200) based on an input image signal from an image-signal input section (10). When the predicted temperature difference is a set reference value or more, the display device (100) controls luminance of an image displayed on the peripheral display area so as to be lowered. Therefore, the predicted temperature difference is predicted by using only the input image signal, and the luminance of the image displayed on the peripheral display area can be appropriately controlled without performing a calculation using the predicted temperature difference. Hence, such a luminance control for preventing breakage of the display section (200) can be easily performed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a schematic arrangement of a display device according to an embodiment of the present invention;

FIG. 2A is a front view showing a schematic arrangement of a display section according to the embodiment;

FIG. 2B is a side view showing the schematic arrangement of the display section according to the embodiment;

FIG. 3 is a schematic view showing blocks for which peak-detecting APLs and still-image-detecting APLs are to be calculated according to the embodiment;

FIG. 4 is a schematic view showing blocks for which the peak-detecting APLs and the still-image-detecting APLs are to be calculated according to the embodiment;

FIG. 5 is a schematic view showing blocks for which the peak-detecting APLs and the still-image-detecting APLs are to be calculated according to the embodiment;

FIG. 6 is a schematic view showing blocks for which the peak-detecting APLs and the still-image-detecting APLs are to be calculated according to the embodiment;

FIG. 7 is a graph showing relationships between a time and a temperature in a left/right-side peripheral display area and an outer peripheral area at the times of the respective APLs according to the embodiment;

FIG. 8 is a graph showing relationships between a time when images at the times of the respective APLs are displayed and a temperature difference between the left/right-side peripheral display area and the outer peripheral area according to the embodiment;

FIG. 9 is a graph showing a relationship between the APL and a luminance level in a case where a predicted temperature difference is smaller than a set reference value according to the embodiment;

FIG. 10 is a graph showing a relationship between gradation and luminance according to the embodiment;

FIG. 11 is a graph showing a relationship between the APL and the luminance level in a case where the predicted temperature difference is larger than the set reference value according to the embodiment;

FIG. 12 is a flowchart showing a luminance control processing according to the embodiment;

FIG. 13 is a flowchart showing a white image detection processing according to the embodiment;

FIG. 14 is a flowchart showing a still image detection processing according to the embodiment;

FIG. 15 is a flowchart showing a peak luminance detection processing of the peripheral display area according to the embodiment;

FIGS. 16A to 16C are schematic views each showing blocks from which points of the peak-detecting APLs are to be recognized according to another embodiment of the present invention;

FIG. 17 is a schematic view showing blocks from which the points of the peak-detecting APLs are to be recognized according to still another embodiment of the present invention;

FIG. 18 is a schematic view showing blocks from which the points of the peak-detecting APLs are to be recognized according to yet another embodiment of the present invention;

FIG. 19 is a schematic view showing blocks from which the points of the peak-detecting APLs are to be recognized according to further embodiment of the present invention;

FIG. 20 is a graph showing relationships between the APL and the luminance level according to still further embodiment of the present invention; and

FIG. 21 is a block diagram showing a schematic arrangement of a display device according to yet further embodiment of the present invention.

Claims

1. A luminance control device that controls luminance of an image displayed on a display section with luminance according to an input image signal inputted from an outside, the display section including: a display area that can display the image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereon, the outer peripheral area surrounding the display area the luminance control device, comprising: a temperature-difference prediction section that predicts a predicted temperature difference between the peripheral display area and the outer peripheral area based on the input image signal; anda luminance control section that performs a control such that the luminance of the image displayed on the peripheral display area is lowered in accordance with an increase of the predicted temperature difference.

2. The luminance control device according to claim 1, wherein the temperature-difference prediction section includes a motion signal generating section that generates a motion signal indicating a motion amount of the input image signal displayed on the peripheral display area, andthe predicted-temperature-difference calculation section calculates the predicted temperature difference based on the motion signal.

3. The luminance control device according to claim 1, wherein the peripheral display area includes a plurality of peripheral sub-areas along an outer edge of the center display area, andthe temperature-difference prediction section includes: an accumulated-value calculation section that calculates an accumulated value obtained by accumulating signal levels of the input image signals displayed on the peripheral sub-areas for each of the peripheral sub-areas; and a predicted-temperature-difference calculation section that calculates the predicted temperature difference based on a largest accumulated value of the peripheral sub-area among the calculated accumulated values.

4. The luminance control device according to claim 3, wherein more weight is assigned to the peripheral sub-area located on one of a right side and a left side of the center display area than to the peripheral sub-area located on one of an upper side and a lower side of the center display area, andthe accumulated-value calculation section calculates, as the accumulated value of one of the right side and the left side of the peripheral sub-area, the accumulated value being obtained by accumulating the signal levels of the input image signals displayed on the peripheral sub-area while reflecting the assigned weight, and as the accumulated value of one of the upper side and the lower side of the peripheral sub-area, the accumulated value being obtained by accumulating the signal levels of the input image signals displayed on the peripheral sub-area.

5. The luminance control device according to claim 3, wherein the temperature-difference prediction section further includes a motion signal generating section that generates motion signals indicating motion amounts of the input image signals displayed on the peripheral sub-areas for each of the peripheral sub-areas, andthe predicted-temperature-difference calculation section calculates the predicted temperature difference based on the motion signals.

6. The luminance control device according to claim 1, wherein the peripheral display area includes a plurality of peripheral sub-areas along an outer edge of the center display area, andthe temperature-difference prediction section includes: an accumulated-value calculation section that calculates accumulated values obtained by accumulating signal levels of the input image signals displayed on the peripheral sub-areas for each of the peripheral sub-areas; a motion signal generating section that generates motion signals indicating motion amounts of the input image signals displayed on the peripheral sub-areas for each of the peripheral sub-areas; and a predicted-temperature-difference calculation section that calculates predicted candidate temperature differences based on the accumulated values and the motion signals for each of the peripheral sub-areas and sets, as the predicted temperature difference, the predicted candidate temperature difference of which value is the largest among values of the calculated predicted candidate temperature differences.

7. A luminance control device that controls luminance of an image displayed on a display section with luminance according to an input image signal inputted from an outside, the display section including: a display area that can display the image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereon, the outer peripheral area surrounding the display area, the luminance control device comprising: a display-image-signal generating section that generates, based on the input image signal, a display image signal outputted to the display section and allowing the image to be displayed thereon;a temperature-difference prediction section that predicts a predicted temperature difference between the peripheral display area and the outer peripheral area based on the display image signal; anda luminance control section that performs a control such that the luminance of the image displayed on the peripheral display area is lowered in accordance with an increase of the predicted temperature difference.

8. The luminance control device according to claim 7, wherein the temperature-difference prediction section includes a motion signal generating section that generates a motion signal indicating a motion amount of the display image signal displayed on the peripheral display area, andthe predicted-temperature-difference calculation section calculates the predicted temperature difference based on the motion signal.

9. The luminance control device according to claim 7, wherein the peripheral display area includes a plurality of peripheral sub-areas along an outer edge of the center display area, andthe temperature-difference prediction section further includes: an accumulated-value calculation section that calculates an accumulated value obtained by accumulating signal levels of the display image signals displayed on the peripheral sub-areas for each of the peripheral sub-areas; and a predicted-temperature-difference calculation section that calculates the predicted temperature difference based on a largest accumulated value of the peripheral sub-area among the calculated accumulated values.

10. The luminance control device according to claim 9, wherein more weight is assigned to the peripheral sub-area located on one of a right side and a left side of the center display area than to the peripheral sub-area located on one of an upper side and a lower side of the center display area, andthe accumulated-value calculation section calculates, as the accumulated value of one of the right side and the left side of the peripheral sub-area, the accumulated value being obtained by accumulating the signal levels of the display image signals displayed on the peripheral sub-area while reflecting the assigned weight, and as the accumulated value of one of the upper side and the lower side of the peripheral sub-area, the accumulated value being obtained by accumulating the signal levels of the display image signals displayed on the peripheral sub-area.

11. The luminance control device according to claim 9, wherein the temperature-difference prediction section further includes a motion signal generating section that generates motion signals indicating motion amounts of the display image signals displayed on the peripheral sub-areas for each of the peripheral sub-areas, andthe predicted-temperature-difference calculation section calculates the predicted temperature difference based on the motion signals.

12. The luminance control device according to claim 7, wherein the peripheral display area includes a plurality of peripheral sub-areas along an outer edge of the center display area, andthe temperature-difference prediction section includes: an accumulated-value calculation section that calculates accumulated values obtained by accumulating signal levels of the display image signals displayed on the peripheral sub-areas for each of the peripheral sub-areas; a motion signal generating section that generates motion signals indicating motion amounts of the display image signals displayed on the peripheral sub-areas for each of the peripheral sub-areas; and a predicted-temperature-difference calculation section that calculates predicted candidate temperature differences based on the accumulated values and the motion signals for each of the peripheral sub-areas, and sets, as the predicted temperature difference, the predicted candidate temperature difference of which value is the largest among values of the calculated predicted candidate temperature differences.

13. The luminance control device according to claim 3, further comprising an accumulated-value storing unit that stores the accumulated values in association with the peripheral sub-areas, wherein the accumulated-value calculation section calculates the accumulated values at every predetermined time, andwhen the accumulated values are calculated by the accumulated-value calculation section, the predicted-temperature-difference calculation section accumulates the calculated accumulated values to the accumulated values of the accumulated-value storing unit and calculates the predicted temperature difference based on the largest accumulated value of the peripheral sub-area among the calculated accumulated values.

14. The luminance control device according to claim 9, further comprising an accumulated-value storing unit that stores the accumulated values in association with the peripheral sub-areas, wherein the accumulated-value calculation section calculates the accumulated values at every predetermined time, andwhen the accumulated values are calculated by the accumulated-value calculation section, the predicted-temperature-difference calculation section accumulates the calculated accumulated values to the accumulated values of the accumulated-value storing unit and calculates the predicted temperature difference based on the largest accumulated value of the peripheral sub-area among the calculated accumulated values.

15. The luminance control device according to claim 13, wherein when the accumulated values are calculated in the accumulated-value calculation section, the predicted-temperature-difference calculation section sets priorities of the peripheral sub-areas in a descending order of the accumulated values, accumulates the accumulated values of the peripheral sub-areas of which priorities are higher than a predetermined priority to the accumulated values of the accumulated-value storing unit, and deletes the accumulated values of the peripheral sub-areas of which priorities are lower than the predetermined priority, the accumulated values to be deleted being stored in the accumulated-value storing unit.

16. The luminance control device according to claim 14, wherein when the accumulated values are calculated in the accumulated-value calculation section, the predicted-temperature-difference calculation section sets priorities of the peripheral sub-areas in a descending order of the accumulated values, accumulates the accumulated values of the peripheral sub-areas of which priorities are higher than a predetermined priority to the accumulated values of the accumulated-value storing unit, and deletes the accumulated values of the peripheral sub-areas of which priorities are lower than the predetermined priority, the accumulated values to be deleted being stored in the accumulated-value storing unit.

17. The luminance control device according to claim 1, further comprising a display-image-signal generating section that generates, based on the input image signal, a display image signal outputted to the display section and allowing the image to be displayed thereon, wherein the luminance control section sets maximum luminance of the display image signal based on the predicted temperature difference.

18. The luminance control device according to claim 7, further comprising a display-image-signal generating section that generates, based on the input image signal, a display image signal outputted to the display section and allowing the image to be displayed thereon, wherein the luminance control section sets maximum luminance of the display image signal based on the predicted temperature difference.

19. The luminance control device according to claim 17, further comprising an average-signal-level calculation section that counts signal levels of the input image signals displayed on the display area and calculates an average signal level of the input image signals, wherein the luminance control section controls the maximum luminance to be lowered in accordance with an increase of the average signal level.

20. The luminance control device according to claim 18, further comprising an average-signal-level calculation section that counts signal levels of the input image signals displayed on the display area and calculates an average signal level of the input image signals, wherein the luminance control section controls the maximum luminance to be lowered in accordance with an increase of the average signal level.

21. The luminance control device according to claim 19, wherein the luminance control section uniquely determines a relationship between the input image signals and the display image signals upon setting the maximum luminance.

22. The luminance control device according to claim 20, wherein the luminance control section uniquely determines a relationship between the input image signals and the display image signals upon setting the maximum luminance.

23. A display device, comprising: a display section including: a display area that can display an image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereon, the outer peripheral area surrounding the display area, the display section displaying the image with luminance according to an input image signal inputted from an outside; anda luminance control device that controls the luminance of the image displayed on the display section, whereinthe luminance control device includes:a temperature-difference prediction section that predicts a predicted temperature difference between the peripheral display area and the outer peripheral area based on the input image signal; anda luminance control section that performs a control such that the luminance of the image displayed on the peripheral display area is lowered in accordance with an increase of the predicted temperature difference.

24. A display device, comprising: a display section including: a display area that can display an image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereon, the outer peripheral area surrounding the display area, the display section displaying the image with luminance according to an input image signal inputted from an outside; anda luminance control device that controls the luminance of the image displayed on the display section, whereinthe luminance control device includes:a display-image-signal generating section that generates, based on the input image signal, a display image signal outputted to the display section and allowing the image to be displayed thereon;a temperature-difference prediction section that predicts a predicted temperature difference between the peripheral display area and the outer peripheral area based on the display image signal; anda luminance control section that performs a control such that the luminance of the image displayed on the peripheral display area is lowered in accordance with an increase of the predicted temperature difference.

25. The display device according to claim 23, further comprising a heat-radiating member provided on back surfaces of the display area and the outer peripheral area.

26. The display device according to claim 24, further comprising a heat-radiating member provided on back surfaces of the display area and the outer peripheral area.

27. A luminance control method of controlling luminance of an image displayed on a display section with luminance according to an input image signal inputted from an outside, the display section including: a display area that can display the image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereon, the outer peripheral area surrounding the display area, the luminance control method performed by a computing unit and comprising: predicting a predicted temperature difference between the peripheral display area and the outer peripheral area based on the input image signal; andcontrolling the luminance of the image displayed on the peripheral display area so as to be lowered in accordance with an increase of the predicted temperature difference.

28. A luminance control method of controlling luminance of an image displayed on a display section with luminance according to an input image signal inputted from an outside, the display section including: a display area that can display the image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereon, the outer peripheral area surrounding the display area, the luminance control method performed by a computing unit and comprising: generating a display image signal outputted to the display section and allowing the image to be displayed thereon, based on the input image signal;predicting a predicted temperature difference between the peripheral display area and the outer peripheral area based on the display image signal; andcontrolling the luminance of the image displayed on the peripheral display area so as to be lowered in accordance with an increase of the predicted temperature difference.

29. A luminance control program that operates a computing unit to function as a luminance control device that controls luminance of an image displayed on a display section with luminance according to an input image signal inputted from an outside, the program being readable by the computing unit, wherein the display section includes: a display area that can display the image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereof, the outer peripheral area surrounding the display area,the computing unit functions as:a temperature-difference prediction section that predicts a predicted temperature difference between the peripheral display area and the outer peripheral area based on the input image signal; anda luminance control section that controls the luminance of the image displayed on the peripheral display area so as to be lowered in accordance with an increase of the predicted temperature difference.

30. A luminance control program that operates a computing unit to function as a luminance control device that controls luminance of an image displayed on a display section with luminance according to an input image signal inputted from an outside, the program being readable by the computing unit, wherein the display section includes: a display area that can display the image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereof, the outer peripheral area surrounding the display area,the computing unit functions as:a display-image-signal generating section that generates, based on the input image signal, a display image signal outputted to the display section and allowing the image to be displayed thereon;a temperature-difference prediction section that predicts a predicted temperature difference between the peripheral display area and the outer peripheral area based on the display image signal; anda luminance control section that controls the luminance of the image displayed on the peripheral display area so as to be lowered in accordance with an increase of the predicted temperature difference.

31. A luminance control program that operates a computing unit to execute a luminance control method of controlling luminance of an image displayed on a display section with luminance according to an input image signal inputted from an outside, wherein the display section includes: a display area that can display the image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereon, the outer peripheral area surrounding the display area,the computing unit executes the luminance control method including:predicting a predicted temperature difference between the peripheral display area and the outer peripheral area based on the input image signal; andcontrolling the luminance of the image displayed on the peripheral display area so as to be lowered in accordance with an increase of the predicted temperature difference.

32. A luminance control program that operates a computing unit to execute a luminance control method of controlling luminance of an image displayed on a display section with luminance according to an input image signal inputted from an outside, wherein the display section includes: a display area that can display the image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereon, the outer peripheral area surrounding the display area,the computing unit executes the luminance control method including:generating, based on the input image signal, a display image signal outputted to the display section and allowing the image to be displayed thereon;predicting a predicted temperature difference between the peripheral display area and the outer peripheral area based on the display image signal; andcontrolling the luminance of the image displayed on the peripheral display area so as to be lowered in accordance with an increase of the predicted temperature difference.

33. A recording medium storing a luminance control program in a manner readable by a computing unit, the luminance control program operating the computing unit to function as a luminance control device that controls luminance of an image displayed on a display section with luminance according to an input image signal inputted from an outside, wherein the display section includes: a display area that can display the image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereof, the outer peripheral area surrounding the display area,the computing unit functions as:a temperature-difference prediction section that predicts a predicted temperature difference between the peripheral display area and the outer peripheral area based on the input image signal; anda luminance control section that controls the luminance of the image displayed on the peripheral display area so as to be lowered in accordance with an increase of the predicted temperature difference.

34. A recording medium storing a luminance control program in a manner readable by a computing unit, the luminance control program operating the computing unit to function as a luminance control device that controls luminance of an image displayed on a display section with luminance according to an input image signal inputted from an outside, wherein the display section includes: a display area that can display the image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereof, the outer peripheral area surrounding the display area,the computing unit functions as:a display-image-signal generating section that generates, based on the input image signal, a display image signal outputted to the display section and allowing the image to be displayed thereon;a temperature-difference prediction section that predicts a predicted temperature difference between the peripheral display area and the outer peripheral area based on the display image signal; anda luminance control section that controls the luminance of the image displayed on the peripheral display area so as to be lowered in accordance with an increase of the predicted temperature difference.

35. A recording medium storing a luminance control program in a manner readable by a computing unit, the luminance control program operating the computing unit to execute a luminance control method of controlling luminance of an image displayed on a display section with luminance according to an input image signal inputted from an outside, wherein the display section includes: a display area that can display the image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereon, the outer peripheral area surrounding the display area,the computing unit executes the luminance control method including:predicting a predicted temperature difference between the peripheral display area and the outer peripheral area based on the input image signal; andcontrolling the luminance of the image displayed on the peripheral display area so as to be lowered in accordance with an increase of the predicted temperature difference.

36. A recording medium storing a luminance control program in a manner readable by a computing unit, the luminance control program operating the computing unit to execute a luminance control method of controlling luminance of an image displayed on a display section with luminance according to an input image signal inputted from an outside, wherein the display section includes: a display area that can display the image thereon, the display area having a center display area and a peripheral display area surrounding the center display area; and an outer peripheral area that cannot display the image thereon, the outer peripheral area surrounding the display area,the computing unit executes the luminance control method including:generating, based on the input image signal, a display image signal outputted to the display section and allowing the image to be displayed thereon;predicting a predicted temperature difference between the peripheral display area and the outer peripheral area based on the display image signal; anda controlling the luminance of the image displayed on the peripheral display area so as to be lowered in accordance with an increase of the predicted temperature difference.