Emission unit brightness adjustment

• US 10,235,970 B2
• Filed: 05/12/2017
• Issued: 03/19/2019
• Est. Priority Date: 02/13/2015
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Breazile, Jon, Lopez-Barquilla, Ricardo, Huang, Yi-Min
• Primary Examiner(s): Abdin, Shaheda
• Application Number:
  US15/593,730
• Publication Number:
  US 20170249924A1
• Time in Patent Office: 676 Days
• CPC Class Codes: G09G 2320/0653 Controlling or limiting the speed of brightness adjustment of the illumination source
• CPC Class Codes: G09G 2360/141 the light conveying information used for selecting or modulating the light emitting or modulating element
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 5/10 Intensity circuits

Abstract

An electronic device includes a display including an emission unit, a light sensor configured to generate a signal indicative of ambient light level, a memory in which filtering instructions and emission control instructions are stored, and a processor configured to implement the filtering instructions to generate at least one filtered representation of the ambient light level in accordance with the signal. The processor is further configured to implement the emission control instructions to determine whether the ambient light level is increasing or decreasing, and to generate a control signal that, based on the at least one filtered representation, increases a brightness level of the emission unit at a first rate if the ambient light level is increasing and that decreases the brightness level at a second rate if the ambient light level is decreasing. The first rate is greater than the second rate.

Claims

1. An electronic device comprising:

a display comprising an emission unit;

a light sensor configured to generate a signal indicative of ambient light level;

a memory in which filtering instructions and emission control instructions are stored; and

a processor configured to implement the filtering instructions to generate a filtered representation of the ambient light level in accordance with the signal;

wherein the processor is configured to implement the emission control instructions to generate a control signal for adjustment of a brightness level of the emission unit based on the filtered representation; and

wherein the processor is further configured to implement the emission control instructions to delay the adjustment of the brightness level if the brightness level is below a threshold level.

2. The electronic device of claim 1, wherein an extent of a delay of the adjustment is determined via a function of the brightness level.

3. The electronic device of claim 2, wherein the function is a hysteresis function.

4. The electronic device of claim 2, wherein the function comprises a linear function.

5. The electronic device of claim 2, wherein a slope of the function lessens with increasing levels of the brightness level.

6. The electronic device of claim 2, wherein the function is provided via a look-up table.

7. The electronic device of claim 1, wherein the adjustment is delayed for a number of samples of the ambient light level.

8. The electronic device of claim 1, wherein the processor is directed by the emission control instructions, after a delay of the adjustment expires, to adjust the brightness level to a level corresponding with the filtered representation if the ambient light level is increasing.

9. The electronic device of claim 1, wherein the processor is directed by the emission control instructions, after a delay of the adjustment expires, to decrement the brightness level toward a level corresponding with the filtered representation if the ambient light level is decreasing.

10. The electronic device of claim 1, wherein:

the filtering instructions direct the processor to generate a noise-filtered representation of the ambient light level in accordance with the signal, wherein the noise-filtered representation is more responsive to changes in the ambient light level than the filtered representation; and

the emission control instructions direct the processor to boost the adjustment if the brightness level is below a threshold level and if a difference between the noise-filtered representation and the filtered representation exceeds a threshold.

11. The electronic device of claim 10, wherein the emission control instructions direct the processor to boost the adjustment by increasing the filtered representation with each iterative implementation of the emission control instructions.

12. The electronic device of claim 10, wherein a delay procedure of the emission control instructions is not implemented while a boost procedure to boost the adjustment is active.

13. An electronic device comprising:

a display comprising an emission unit;

a light sensor configured to generate a signal indicative of ambient light level;

a memory in which filtering instructions and emission control instructions are stored; and

a processor configured to implement the filtering instructions to generate a filtered representation of the ambient light level in accordance with the signal;

wherein the processor is configured to implement the emission control instructions to generate a control signal for adjustment of a brightness level of the emission unit based on the filtered representation;

wherein the processor, through implementing the filtering instructions, is directed to generate a noise-filtered representation of the ambient light level in accordance with the signal, the noise-filtered representation being more responsive to changes in the ambient light level than the filtered representation; and

wherein the processor, through implementing the emission control instructions, is directed to boost the adjustment if the brightness level is below a threshold level and if a difference between the noise-filtered representation and the filtered representation exceeds a threshold.

14. The electronic device of claim 13, wherein the emission control instructions direct the processor to boost the adjustment by increasing the filtered representation with each iterative implementation of the emission control instructions.

15. The electronic device of claim 13, wherein the adjustment is boosted when the filtered representation and the noise-filtered representation are below an ambient level threshold.

16. The electronic device of claim 13, wherein an extent to which the adjustment is boosted is based on the filtered representation.

17. The electronic device of claim 13, wherein an extent to which the adjustment is boosted is based on the difference between the noise-filtered representation and the filtered representation.

18. A method of controlling an emission unit of a display, the method comprising:

obtaining sensor data acquired by a light sensor responsive to ambient light level;

generating a filtered representation of the ambient light level in accordance with the sensor data;

generating a control signal for adjustment of a brightness level of the emission unit in accordance with the filtered representation;

delaying the adjustment of the brightness level if the brightness level is below a threshold level.

19. The method of claim 18, further comprising determining an extent of a delay of the adjustment via a function of the brightness level.

20. The method of claim 18, further comprising, after a delay of the adjustment expires, adjusting the brightness level to a level corresponding with the filtered representation if the ambient light level is increasing, and decrementing the brightness level toward a level corresponding with the filtered representation if the ambient light level is decreasing.