Camera module with ambient light detection

• US 20050218303A1
• Filed: 03/30/2004
• Published: 10/06/2005
• Est. Priority Date: 03/30/2004
• Status: Active Grant

• Current Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Original Assignee: Micron Technology, Inc.
• Inventors: Poplin, Dwight D.
• Granted Patent: US 7,071,456 B2
• Time in Patent Office: Days
• US Class Current: 250/214.AL
• CPC Class Codes: G01J 1/42 using electric radiation detectors optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10
• CPC Class Codes: G01J 1/4204 with determination of ambient light solar light G01J2001/4266
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3271 Power saving in keyboard
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: H04N 5/58 in dependence upon ambient light
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A camera module forms digital images and measures an ambient light level. A device such as a digital camera, a telephone, or a PDA containing the camera module can set lighting levels of I/O systems such as keypads or displays according to the ambient light level to thereby save power or optimize functionality of the I/O systems. A dedicated sensor in the camera module or one or more selected sensors in the imaging array of the camera module can measure the ambient light level.

Claims

1. A device comprising:

a camera module;

an I/O system; and

a controller connected to the camera module and the I/O system, wherein the controller sets lighting of the I/O system in response to a signal from the camera module indicating an ambient light level.

2. The device of claim 1, wherein the I/O system comprises a lighted keypad, and the controller sets the lighting of the lighted keypad in response to the signal from the camera module.

3. The device of claim 1, wherein the I/O system comprises a display, and the controller sets the lighting of the display in response to the signal from the camera module.

4. The device of claim 1, wherein the controller turns off the lighting in response to the signal from the camera module indicating that the ambient light level is high.

5. The device of claim 1, wherein the camera module comprises an array of pixel sensors, and the signal from the camera module indicates an intensity measured by a selected one of the pixel sensors in the array.

6. The device of claim 5, wherein the pixel sensors in the array have associated color filters, and the selected one of the pixel sensors has a green color filter.

7. The device of claim 1, wherein the camera module comprises an array of pixel sensors, and the signal from the camera module corresponds to a transform of intensities measured by selected red, green, and blue pixel sensors in the array.

8. The device of claim 1, wherein the camera module comprises a dedicated ambient light sensor, and the signal from the camera module indicates an intensity that the dedicated ambient light sensor measures.

9. The device of claim 8, wherein the dedicated ambient light sensor comprises a photodiode covered by a green filter material that is used for green pixel sensors in the array.

10. The device of claim 9, wherein the dedicated ambient light sensor further comprises:

a second photodiode covered by a red filter material that is used for red pixel sensors in the array; and

a third photodiode covered by a blue filter material that is used for blue pixel sensors in the array.

11. A method for operating a device, comprising:

operating a camera module to measure an ambient light level; and

adjusting lighting of an I/O system according to the ambient level measured by the camera module.

12. The method of claim 11, wherein adjusting the lighting comprises adjusting the lighting of a lighted keypad according to the ambient level measured by the camera module.

13. The method of claim 11, wherein adjusting the lighting comprises adjusting the lighting of a display according to the ambient level measured by the camera module.

14. The method of claim 13, further comprising:

operating the camera module to create a digital image; and

displaying the digital image on the display.

15. The method of claim 11, further comprising operating the camera module to create a digital image.

16. The method of claim 11, wherein operating the camera module comprises:

activating a pixel sensor in an imaging array of the camera module; and

measuring the ambient light using the pixel sensor activated.

17. The method of claim 16, wherein pixel sensors in the array have associated color filters, and the pixel sensor activated has a green filter.

18. A camera module comprising:

an array of pixel sensors; and

a dedicated ambient light sensor.

19. The camera module of claim 18, wherein the array of pixel sensors and the dedicated ambient light sensor are integrated into a single semiconductor chip.

20. The camera module of claim 18, wherein the dedicated ambient light sensor comprises:

a first photodiode covered by a green filter material that is used for green pixel sensors in the array;

a second photodiode covered by a red filter material that is used for red pixel sensors in the array; and

a third photodiode covered by a blue filter material that is used for blue pixel sensors in the array.