Emission unit brightness adjustment

• US 9,679,534 B2
• Filed: 02/13/2015
• Issued: 06/13/2017
• 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, Huang, Yi-Min, Lopez-Barquilla, Ricardo
• Primary Examiner(s): ABDIN, SHAHEDA A
• Application Number:
  US14/622,500
• Publication Number:
  US 20160240167A1
• Time in Patent Office: 851 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 first and second filtered representations of the ambient light level in accordance with the signal, the first and second filtered representations being based on respective filters defined via the filtering instructions;

wherein 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 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;

wherein the first rate is greater than the second rate;

wherein the first and second rates are based on the first and second filtered representations, respectively; and

wherein the respective filters for the first and second filtered representations have first and second sampling periods, respectively, the first sampling period being shorter than the second sampling period.

2. The electronic device of claim 1, wherein the emission control instructions direct the processor to generate the control signal such that the brightness level increases in accordance with the first filtered representation if the ambient light level is increasing and such that the brightness level decreases in accordance with the second filtered representation if the ambient light level is decreasing.

3. The electronic device of claim 1, wherein the filtering instructions direct the processor to reset the second filtered representation based on the first filtered representation if the ambient light level is increasing.

4. The electronic device of claim 1, wherein the emission control instructions direct the processor to determine whether the ambient light level is increasing or decreasing based on a comparison of the first and second filtered representations.

5. The electronic device of claim 1, wherein the filtering instructions direct the processor to adjust the first and second rates based on the ambient light level.

6. The electronic device of claim 1, wherein:

the filtering instructions define first and second sets of rates for the first and second rates, respectively; and

the filtering instructions direct the processor to select a respective rate from the first set or the second set based on the ambient light level.

7. 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 at least one filtered representation of the ambient light level in accordance with the signal;

wherein 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; and

wherein the first rate is greater than the second rate; and

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 at least one filtered representation; and

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

8. The electronic device of claim 7, wherein the emission control instructions direct the processor to boost the first rate by increasing the at least one filtered representation with each iterative implementation of the emission control instructions.

9. An electronic device of 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 at least one filtered representation of the ambient light level in accordance with the signal;

wherein 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; and

wherein the first rate is greater than the second rate; and

wherein the emission control instructions direct the processor to delay a change in the brightness level if the brightness level is below a threshold level.

10. The electronic device of claim 9, wherein an extent to which the change is delayed is a function of the brightness level.

11. 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 at least one filtered representation of the ambient light level in accordance with the signal;

wherein 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; and

wherein the first rate is greater than the second rate; and

wherein;

the display further comprises a touch sensor unit; and

the emission control instructions direct the processor to prevent a change in the brightness level if a stylus is detected by the touch sensor unit.

12. 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 first and second filtered representations of the ambient light level in accordance with the signal, the first and second filtered representations using first and second sampling periods, respectively, the first sampling period being shorter than the second sampling period;

wherein the processor is further configured to implement the emission control instructions to determine a direction in which the ambient light level is trending, and to generate a control signal that, based on the direction, increases a brightness level of the emission unit in accordance with the first filtered representation or decreases the brightness level in accordance with the second filtered representation.

13. The electronic device of claim 12, wherein the emission control instructions direct the processor to increase the brightness level in accordance with the first filtered representation if the direction is positive and to decrease the brightness level in accordance with the second filtered representation if the direction is negative.

14. The electronic device of claim 12, wherein the filtering instructions direct the processor to determine the direction based on a comparison of the first and second filtered representations.

15. The electronic device of claim 12, wherein the filtering instructions direct the processor to adjust the first and second sampling periods based on the ambient light level.

16. The electronic device of claim 12, 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 first and second filtered representations;

the emission control instructions direct the processor to boost the first filtered representation with each iterative implementation of the emission control instructions if the brightness level is below a threshold level and if a difference between the noise-filtered representation and the first filtered representation exceeds a threshold.

17. 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 first and second filtered representations of the ambient light level in accordance with the sensor data, the first and second filtered representations using first and second sampling periods, respectively, the first sampling period being shorter than the second sampling period;

determining a direction in which the ambient light level is trending; and

generating a control signal that, based on the direction in which the ambient light level is trending, increases a brightness level of the emission unit in accordance with the first filtered representation or decreases the brightness level in accordance with the second filtered representation.

18. The method of claim 17, further comprising delaying a change in the brightness level if the brightness level is below a threshold level.

19. The method of claim 17, further comprising preventing a change in the brightness level if a stylus is detected by a touch sensor unit.

20. The method of claim 17, further comprising:

generating a noise-filtered representation of the ambient light level in accordance with the signal; and

boosting the first filtered representation if the brightness level is below a threshold level and if a difference between the noise-filtered representation and the first filtered representation exceeds a threshold.