Luminescence shock avoidance in display devices
A luminescence shock avoidance algorithm selectively limits 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.
1. An electronic device, comprising:
a display;
an ambient light sensor that detects an ambient light level while the display is in a standby mode, wherein the display is at a first brightness level while the display is in the standby mode; and
control circuitry that increases a brightness of the display from the first brightness level based on the detected ambient light level when the display is turned on.
2. The electronic device defined in claim 1 , wherein the control circuitry is configured to increase the brightness of the display from the first brightness level to a second brightness level when the detected ambient light level is below a threshold.
3. The electronic device defined in claim 2 , wherein the control circuitry is configured to increase the brightness of the display from the first brightness level to a third brightness level when the detected ambient light level is above the threshold.
4. The electronic device defined in claim 3 , wherein the third brightness level is greater than the second brightness level.
5. The electronic device defined in claim 3 , wherein the control circuitry is configured to increase the brightness of the display based on a brightness adjustment function, and wherein the third brightness level is equal to a first normal brightness level determined by the brightness adjustment function for the detected ambient light level that is above the threshold.
6. The electronic device defined in claim 5 , wherein the brightness adjustment function is selected by a user of the electronic device.
7. The electronic device defined in claim 1 , wherein the control circuitry increases the brightness of the display from the first brightness level based on a comparison between the detected ambient light level and a threshold.
8. A method of operating an electronic device having a display, the method comprising:
with an ambient light sensor, producing ambient light data while the display is in standby mode; and
with control circuitry, activating the display by adjusting a brightness level of the display from a first brightness level while the display is in standby mode to a second brightness level while the display is activated based on the ambient light data.
9. The method defined in claim 8 , wherein the ambient light data is based on a detected ambient light level and wherein activating the display further comprises:
increasing the brightness level of the display from the first brightness level to the second brightness level when the detected ambient light level is below a threshold.
10. The method defined in claim 9 , wherein activating the display further comprises:
increasing the brightness of the display from the first brightness level to a third brightness level when the detected ambient light level is above the threshold.
11. The method defined in claim 10 , wherein the third brightness level is greater than the second brightness level.
12. The method defined in claim 11 , wherein activating the display further comprises:
increasing the brightness of the display based on a brightness adjustment function, wherein the third brightness level is equal to a first normal brightness level determined by the brightness adjustment function for the detected ambient light level that is above the threshold.
13. The method defined in claim 12 , wherein the brightness adjustment function is selected by a user of the electronic device.
14. The method defined in claim 13 , wherein the second brightness level is less than a second normal brightness level determined by the brightness adjustment function for the detected ambient light level that is below the threshold.
15. The method defined in claim 14 , further comprising:
increasing the brightness of the display from the second brightness level to the second normal brightness level after a predetermined period of time.
16. The method defined in claim 8 , wherein activating the display comprises activating the display in response to reception of a telephone call.
17. The method defined in claim 8 , wherein activating the display comprises activating the display in response to reception of a text message.
18. The method defined in claim 8 , wherein activating the display comprises activating the display in response to reception of an e-mail.
19. An electronic device, comprising:
a display;
an ambient light sensor that detects an ambient light level while the display is in a standby mode, wherein the display is at a first brightness level while the display is in the standby mode; and
control circuitry configured to turn on the display by adjusting a brightness level of the display from the first brightness level to a second brightness level based on a comparison between the ambient light level and a threshold, wherein the second brightness level is greater than the first brightness level.
20. The electronic device defined in claim 19 , wherein the control circuitry is configured to turn on the display in response to a stimulus and wherein the stimulus is selected from the group consisting of: reception of a telephone call, reception of a text message, and reception of an e-mail.