Luminescence shock avoidance in display devices

• US 20080165203A1
• Filed: 05/04/2007
• Published: 07/10/2008
• Est. Priority Date: 01/05/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Pantfoerder, Kai Achim
• Granted Patent: US 8,068,125 B2
• Time in Patent Office: Days
• US Class Current: 345/589
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0653 Controlling or limiting the speed of brightness adjustment of the illumination source
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/10 Intensity circuits

Abstract

A luminescence shock avoidance algorithm is disclosed to selectively limit the brightness level of a display device when the display device is activated in a dark environment to prevent the temporary vision impairment that can occur when a display device is activated in a dark environment. The algorithm receives the state of the display (e.g. on or in standby mode), and can optionally receive an ambient lighting value from an ambient light sensor and a user-selectable manual brightness adjustment setting to determine whether luminescence shock avoidance should even be triggered, and if it is triggered, how much should the brightness level of the display be limited.

Claims

1. A method for avoiding luminescence shock in a display device when a previously dark display device is suddenly illuminated, comprising:

detecting a current ambient light level; and

if the detected ambient light level is below a luminescence shock threshold,

turning on the display device at a reduced brightness level as compared to the brightness level dictated by a brightness function, the brightness function representing a display brightness level for a given ambient light level, and

after a predetermined time interval has elapsed, ramping up the brightness level to the brightness level dictated by the brightness function and the detected ambient light level.

2. The method of claim 1, further comprising:

detecting a current display brightness setting as established by a display brightness control, the current display brightness setting creating an associated modified brightness function; and

after turning on the display device at the reduced brightness level, ramping up the brightness level to the brightness level dictated by the modified brightness function and the detected ambient light level.

3. The method of claim 1, further comprising gamma-shifting the display device to produce light around wavelengths that generate red light when the display device is turned on at the reduced brightness level.

4. The method of claim 1, wherein the reduced brightness level is the same for any detected ambient light level below the luminescence shock threshold.

5. The method of claim 1, further comprising:

determining a current display brightness setting as established by a display brightness control, the current display brightness setting creating an associated modified brightness function; and

modifying the reduced brightness level in accordance with the current display brightness setting;

wherein for any given display brightness setting, the reduced brightness level is the same for any detected ambient light level below the luminescence shock threshold.

6. The method of claim 1, further comprising:

determining a current display brightness setting as established by a display brightness control, the current display brightness setting creating an associated modified brightness function; and

modifying the reduced brightness level in accordance with the current display brightness setting and a reduced brightness function, the reduced brightness function representing a reduced display brightness level for a given ambient light level below the luminescence shock threshold;

wherein the reduced brightness function is the same for any detected ambient light level below the luminescence shock threshold.

7. The method of claim 1, further comprising:

determining a current display brightness setting as established by a display brightness control, the current display brightness setting creating an associated modified brightness function; and

modifying the reduced brightness level in accordance with the current display brightness setting and a reduced brightness function, the reduced brightness function representing a reduced display brightness level for a given ambient light level below the luminescence shock threshold;

wherein the reduced brightness function is dependent on the current display brightness setting.

8. A computer-readable medium comprising program code for avoiding luminescence shock in a display device when a previously dark display device is suddenly illuminated, the program code for causing performance of a method comprising:

detecting a current ambient light level; and

if the detected ambient light level is below a luminescence shock threshold,

turning on the display device at a reduced brightness level as compared to the brightness level dictated by a brightness function, the brightness function representing a display brightness level for a given ambient light level, and

after a predetermined time interval has elapsed, ramping up the brightness level to the brightness level dictated by the brightness function and the detected ambient light level.

9. The computer-readable medium of claim 8, further comprising:

detecting a current display brightness setting as established by a display brightness control, the current display brightness setting creating an associated modified brightness function; and

after turning on the display device at the reduced brightness level, ramping up the brightness level to the brightness level dictated by the modified brightness function and the detected ambient light level.

10. The computer-readable medium of claim 8, further comprising gamma-shifting the display device to produce light around wavelengths that generate red light when the display device is turned on at the reduced brightness level.

11. The computer-readable medium of claim 8, wherein the reduced brightness level is the same for any detected ambient light level below the luminescence shock threshold.

12. The computer-readable medium of claim 8, further comprising:

determining a current display brightness setting as established by a display brightness control, the current display brightness setting creating an associated modified brightness function; and

modifying the reduced brightness level in accordance with the current display brightness setting;

wherein for any given display brightness setting, the reduced brightness level is the same for any detected ambient light level below the luminescence shock threshold.

13. The computer-readable medium of claim 8, further comprising:

determining a current display brightness setting as established by a display brightness control, the current display brightness setting creating an associated modified brightness function; and

modifying the reduced brightness level in accordance with the current display brightness setting and a reduced brightness function, the reduced brightness function representing a reduced display brightness level for a given ambient light level below the luminescence shock threshold;

wherein the reduced brightness function is the same for any detected ambient light level below the luminescence shock threshold.

14. The computer-readable medium of claim 8, further comprising:

determining a current display brightness setting as established by a display brightness control, the current display brightness setting creating an associated modified brightness function; and

modifying the reduced brightness level in accordance with the current display brightness setting and a reduced brightness function, the reduced brightness function representing a reduced display brightness level for a given ambient light level below the luminescence shock threshold;

wherein the reduced brightness function is dependent on the current display brightness setting.

15. The computer-readable medium of claim 8, further comprising a computing system including a processor for reading the computer-readable medium.

16. The computer-readable medium of claim 15, further comprising a mobile telephone that incorporates the computing system.

17. The computer-readable medium of claim 15, further comprising a digital audio player that incorporates the computing system.

18. A system for avoiding luminescence shock in a display device when a previously dark display device is suddenly illuminated, comprising:

an ambient light sensor configured for detecting a current ambient light level; and

a processor coupled to the ambient light sensor and programmed for, if the detected ambient light level is below a luminescence shock threshold,

turning on the display device at a reduced brightness level as compared to the brightness level dictated by a brightness function, the brightness function representing a display brightness level for a given ambient light level, and

after a predetermined time interval has elapsed, ramping up the brightness level to the brightness level dictated by the brightness function and the detected ambient light level.

19. The system of claim 18, further comprising memory coupled to the processor for storing the brightness function in the form of a look-up table.

20. The system of claim 18, the processor further programmed for:

detecting a current display brightness setting as established by a display brightness control, the current display brightness setting creating an associated modified brightness function; and

after turning on the display device at the reduced brightness level, ramping up the brightness level to the brightness level dictated by the modified brightness function and the detected ambient light level.

21. The system of claim 20, further comprising memory coupled to the processor for storing the modified brightness functions in the form of a look-up table.

22. The system of claim 18, the processor further programmed for gamma-shifting the display device to produce light around wavelengths that generate red light when the display device is turned on at the reduced brightness level.

23. The system of claim 18, wherein the reduced brightness level is the same for any detected ambient light level below the luminescence shock threshold.

24. The system of claim 18, the processor further programmed for:

determining a current display brightness setting as established by a display brightness control, the current display brightness setting creating an associated modified brightness function; and

modifying the reduced brightness level in accordance with the current display brightness setting;

wherein for any given display brightness setting, the reduced brightness level is the same for any detected ambient light level below the luminescence shock threshold.

25. The system of claim 18, the processor further programmed for:

determining a current display brightness setting as established by a display brightness control, the current display brightness setting creating an associated modified brightness function; and

modifying the reduced brightness level in accordance with the current display brightness setting and a reduced brightness function, the reduced brightness function representing a reduced display brightness level for a given ambient light level below the luminescence shock threshold;

wherein the reduced brightness function is the same for any detected ambient light level below the luminescence shock threshold.

26. The system of claim 18, the processor further programmed for:

determining a current display brightness setting as established by a display brightness control, the current display brightness setting creating an associated modified brightness function; and

modifying the reduced brightness level in accordance with the current display brightness setting and a reduced brightness function, the reduced brightness function representing a reduced display brightness level for a given ambient light level below the luminescence shock threshold;

wherein the reduced brightness function is dependent on the current display brightness setting.

27. The system of claim 18, further comprising a mobile telephone that incorporates the system.

28. The system of claim 18, further comprising a digital audio player that incorporates the system.

29. An apparatus for avoiding luminescence shock in a display device when a previously dark display device is suddenly illuminated, comprising:

means for detecting a current ambient light level; and

means for, if the detected ambient light level is below a luminescence shock threshold,

turning on the display device at a reduced brightness level as compared to the brightness level dictated by a brightness function, the brightness function representing a display brightness level for a given ambient light level, and

after a predetermined time interval has elapsed, ramping up the brightness level to the brightness level dictated by the brightness function and the detected ambient light level.

30. A mobile telephone including a computer-readable medium comprising program code for avoiding luminescence shock in a display device when a previously dark display device is suddenly illuminated, the program code for causing performance of a method comprising:

detecting a current ambient light level; and

.

if the detected ambient light level is below a luminescence shock threshold,

turning on the display device at a reduced brightness level as compared to the brightness level dictated by a brightness function, the brightness function representing a display brightness level for a given ambient light level, and

after a predetermined time interval has elapsed, ramping up the brightness level to the brightness level dictated by the brightness function and the detected ambient light level.

31. A digital audio player including a computer-readable medium comprising program code for avoiding luminescence shock in. a display device when a previously dark display device is suddenly illuminated, the program code for causing performance of a method comprising:

detecting a current ambient light level; and

if the detected ambient light level is below a luminescence shock threshold,

turning on the display device at a reduced brightness level as compared to the brightness level dictated by a brightness function, the brightness function representing a display brightness level for a given ambient light level, and

after a predetermined time interval has elapsed, ramping up the brightness level to the brightness level dictated by the brightness function and the detected ambient light level.