Dynamic power and brightness control for a display screen
An image is displayed on an electronic display device at a reduced power level. Power used by the display device is maintained below a predetermined maximum power level by uniformly scaling the initial optical intensity of an image to a lower optical intensity whenever displaying the image at the initial optical intensity would result in power consumption of the display device exceeding the predetermined maximum power level.
1. A method of displaying an image on an electronic display system, comprising:
receiving frames of image data to be displayed, wherein the image data includes an optical output intensity of each pixel and subpixel of a display device of the display system to produce the image or frame and the sub-pixels are red, green, and blue subpixels;
determining an average power level for displaying one or more frames of image data, wherein the average power level is defined as the ratio of the power required by the display device to produce an image at the power required by the display device to produce a fully white screen;
determining an adjusted optical output intensity for each pixel and subpixel as a function of the average power level and the optical output intensity of each subpixel;
adjusting a parameter of the electronic display system in accordance with the average power level, wherein adjusting a parameter comprises scaling the brightness of each pixel and subpixel to the adjusted optical output intensity; and
wherein the electronic display system includes multiple display devices and each display device displays a portion of the image data.
2. The method of claim 1 , wherein the average power level is determined based on a single frame of image data.
3. The method of claim 1 , wherein the average power level is determined based on multiple frames of image data.
4. The method of claim 3 , wherein the parameter is continuously set each time a frame of image data is displayed, based on the average power level that is determined from a running average of the multiple frames of image data.
5. The method of claim 1 , wherein said adjusting includes scaling down a brightness level of the electronic display system.
6. The method of claim 5 , wherein the brightness level of the electronic display system is scaled down in accordance with a function that maps target brightness levels to average power levels.
7. The method of claim 1 , wherein said adjusting includes scaling down a power level of the electronic display system.
8. The method of claim 7 , wherein the power level of the electronic display system is scaled down in accordance with a function that maps target power levels to average power levels.
9. The method of claim 1 , wherein the parameter is adjusted so as to maintain a desired gamma.
10. The method of claim 1 , wherein the average power level is defined by the following equation:
A
P
L
=
∑
i
=
1
i
=
N
I
i
*
1
255
*
N
where N is the total number of subpixels of the display device and I is the intensity of optical output of a subpixel (measured in DAC counts).
11. A method of displaying an image on a laser phosphor display device having a plurality of laser sources, comprising:
receiving frames of image data to be displayed, wherein the image data includes an optical output intensity of each pixel and subpixel of a display device of the display system to produce the image or frame and the sub-pixels are red, green, and blue sub-pixels;
determining an average power level for displaying one or more frames of image data, wherein the average power level is defined as the ratio of the power required by the display device to produce an image at the power required by the display device to produce a fully white screen;
determining an adjusted optical output intensity for each pixel and subpixel as a function of the average power level and the optical output intensity of each subpixel; and
modulating the laser sources in accordance with the average power level, wherein the laser phosphor display device includes two or more distinct display modules and each display module displays a portion of the image data frame, each frame of image data is to be displayed on the distinct display modules simultaneously as a single image.
12. The method of claim 11 , wherein the laser sources are modulated in accordance with a plurality of maximum intensity settings, each of which is set based on the average power level.
13. The method of claim 12 , wherein the maximum intensity settings increase as the average power level decreases.
14. The method of claim 13 , wherein the rates at which the maximum intensity settings increase as the average power level decreases differ, and the highest maximum intensity setting has the highest rate of increase and the lowest maximum intensity setting has the lowest rate of increase.
15. The method of claim 11 , wherein the average power level is determined based on a running average of N frames of image data, N being at least 2.
16. The method of claim 11 , wherein the average power level is defined by the following equation:
A
P
L
=
∑
i
=
1
i
=
N
I
i
*
1
255
*
N
where N is the total number of subpixels of the display device and I is the intensity of optical output of a subpixel (measured in DAC counts).
17. A method of displaying images on a display device, comprising:
receiving an input representing one or more images to be displayed;
determining a display output intensity value based on the input;
comparing the display output intensity value against a maximum allowed brightness value; and
adjusting a parameter of the display device based on said comparing, wherein the display device includes two or more distinct display modules, each display module displays a portion of one image to be displayed, and the input is to be displayed on the distinct display modules simultaneously as a single image, wherein adjusting a parameter comprises scaling a brightness of each pixel and subpixel.
18. The method of claim 17 , wherein the input represents a sequence of images to be displayed.
19. The method of claim 17 , wherein the threshold value varies depending on the display value.
20. An electronic display system having:
multiple display devices, each of which displays a portion of image data;
a processing unit; and
a memory device having instructions stored therein, wherein the processing unit executes the instructions to carry out the steps of:
receiving frames of image data to be displayed, wherein the image data includes an optical output intensity of each pixel and subpixel of a display device of the display system to produce the image or frame and the sub-pixels are red, green, and blue subpixels;
determining an average power level for displaying one or more frames of image data, wherein the average power level is defined as the ratio of the power required by the display device to produce an image at the power required by the display device to produce a fully white screen;
determining an adjusted optical output intensity for each pixel and subpixel as a function of the average power level and the optical output intensity of each subpixel; and
adjusting a parameter of the electronic display system in accordance with the average power level, wherein adjusting a parameter comprises scaling the brightness of each pixel and subpixel to the adjusted optical output intensity.
21. The system of claim 20 , wherein the average power level is determined based on a single frame of image data.
22. The system of claim 20 , wherein the average power level is determined based on multiple frames of image data.
23. The system of claim 22 , wherein the parameter is continuously set each time a frame of image data is displayed, based on the average power level that is determined from a running average of the multiple frames of image data.
24. The system of claim 20 , wherein said adjusting includes scaling down a brightness level of the electronic display system.
25. The system of claim 24 , wherein the brightness level of the electronic display system is scaled down in accordance with a function that maps target brightness levels to average power levels.
26. The system of claim 20 , wherein said adjusting includes scaling down a power level of the electronic display system.
27. The system of claim 26 , wherein the power level of the electronic display system is scaled down in accordance with a function that maps target power levels to average power levels.
28. The system of claim 20 , wherein the parameter is adjusted so as to maintain a desired gamma.
29. The method of claim 20 , wherein the average power level is defined by the following equation:
A
P
L
=
∑
i
=
1
i
=
N
I
i
*
1
255
*
N
where N is the total number of subpixels of the display device and I is the intensity of optical output of a subpixel (measured in DAC counts).
30. A computer-readable storage medium including instructions that, when executed by a processing unit, cause the processing unit to display images on a display device, by performing the steps of:
receiving an input representing one or more images to be displayed on the display device;
determining a display value based on the input;
comparing the display value against a threshold value; and
adjusting a parameter of the display device based on said comparing, wherein the display device includes two or more distinct display modules, each display module displays a portion of one image to be displayed and the input is to be displayed on the distinct display modules simultaneously as a single image, wherein adjusting a parameter comprises scaling a brightness of each pixel and subpixel.
31. The computer-readable storage medium of claim 30 , wherein the display value is a power value and the threshold value is a maximum allowed power value.
32. The computer-readable storage medium of claim 30 , wherein the display value is a display output intensity value and the threshold value is a maximum allowed brightness value.
33. The computer-readable storage medium of claim 30 , wherein the input represents a sequence of images to be displayed.
34. The computer-readable storage medium of claim 30 , wherein the threshold value varies depending on the display value.