COLOR CORRECTING FOR AMBIENT LIGHT

• US 20080303918A1
• Filed: 06/11/2007
• Published: 12/11/2008
• Est. Priority Date: 06/11/2007
• Status: Abandoned Application

• Current Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Original Assignee: Micron Technology, Inc.
• Inventors: Keithley, Douglas Gene
• Application Number:
  US11/760,990
• Publication Number:
  US 20080303918A1
• Time in Patent Office: Days
• US Class Current: 348/223.1
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• 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 3/3413 Details of control of colour illumination sources

Abstract

An apparatus and method are described for adjusting the color balance of a display. According to the method, a sensor of the apparatus detects the color temperature of ambient light. A controller of the apparatus adjusts the color balance of the emissive display based on the detected color temperature of ambient light.

Claims

1. Apparatus for adjusting an image displayed on a display comprising:

a display unit configured to emit light;

a color sensor configured to detect a color temperature of ambient light; and

a controller configured to control the display unit to adjust a color balance of the light emitted by the display unit based on at least the color temperature of ambient light detected by the color sensor.

2. The apparatus of claim 1,

wherein the display unit is a lighted display and the apparatus further includes a lighting unit having a plurality of component color light sources,

wherein the controller is configured to adjust separately at least one of the respective component color light sources.

3. The apparatus of claim 2,

wherein the lighted display is selected from the group consisting of a reflective display and a transmissive display.

4. The apparatus of claim 1,

wherein the display unit is an emissive display unit.

5. The apparatus of claim 1 further comprising:

drive circuitry for outputting a drive signal containing information for adjusting the light emitted from the display unit,

wherein the display unit is configured to receive an image signal containing information about an image to be displayed and the drive signal,

and wherein the display unit comprises a plurality of individual color components.

6. The apparatus of claim 5,

wherein the controller is configured to control the display unit via the drive circuitry by adjusting an intensity of at least one of the plurality of individual color components.

7. The apparatus of claim 1 further comprising:

a drive unit configured to control the display unit to display the image,

wherein the display unit is configured to receive the image signal and a drive signal containing information for adjusting the light emitted from the display unit,

and wherein the controller is configured to cause the drive unit to adjust a color balance of the light emitted from the lighting unit by adjusting the image signal.

8. The apparatus of claim 1,

wherein the color sensor is an imager.

9. A method of adjusting an image displayed on a display unit comprising the steps of:

detecting a color temperature of ambient light;

processing an image for display on the display unit including adjusting a color balance of light emitted from the display unit based on, at least, the color temperature of ambient light detected by the color sensor; and

displaying the processed image on the display unit.

10. The method of claim 9,

further comprising the step of calculating at least one adjustment ratio for adjusting the color balance of the light emitted from the display unit.

11. The method of claim 10,

wherein the calculating step includes the steps of:

comparing the color temperature of the detected ambient light with at least one adjustment value;

selecting at least one of the adjustment values as an at least one selected adjustment value; and

calculating the at least one adjustment ratio using the at least one selected adjustment value.

12. The method of claim 10,

wherein the calculating step includes the steps of:

comparing the color temperature of the detected ambient light with at least two adjustment values;

interpolating between at least two of the adjustment values to determine at least one interpolated reference value; and

calculating the at least one adjustment ratio using the at least one interpolated reference value.

13. The method of claim 9,

wherein the calculating step includes calculating a color ratio of different colors making up the detected ambient light,

and wherein the adjusting step includes setting a color ratio of the display unit to match the calculated color ratio.

14. The method of claim 9,

wherein the detecting step includes continually sampling the ambient light to obtain a plurality of color temperature samples.

15. The method of claim 14,

wherein the detecting step further includes selecting a maximum color temperature from among the plurality of color temperature samples as the color temperature as the ambient color temperature value.

16. The method of claim 14,

wherein the detecting step further includes averaging the plurality of color temperature samples to obtain an averaged color temperature and selecting the averaged color temperature as the ambient color temperature.

17. The method of claim 13,

wherein the detecting step includes sampling the ambient light once to obtain the ambient color temperature.

18. The method of claim 9, further including the steps of:

determining a lighting level of the ambient light; and

adjusting the color balance of light emitted from the display unit when the lighting level of the ambient light is greater than a predetermined threshold value and not adjusting the color balance of light emitted from the display unit when the lighting level of the ambient light is not greater than the predetermined threshold value.

19. Image display apparatus for storing and displaying image data comprising:

a memory for storing captured image data;

an image processor for processing the captured image data to produce image display signals;

a display device, responsive to the image display signals, for displaying an image representing the scene;

an ambient light sensor for sensing at least first and second color components representing a color temperature of light which is ambient to the image display apparatus;

color temperature correcting circuitry, responsive to the sensed first and second color components, to control at least one of the image processor and the display device to match the color temperature of the displayed image to the color temperature of the light ambient to the image display apparatus.

20. The image display apparatus of claim 19, wherein the color correcting circuitry is configured to:

convert the image display signals from an image color space to a linear color space;

multiply each component of the converted image display signals by a ratio of an ambient light value, corresponding to the component, to a respective reference light value, corresponding to the component, in the linear color space to determine a plurality of converted color signals; and

convert the plurality of converted color signals back to the image color space.

21. The image display apparatus of claim 19, wherein the display device includes a lighted display panel and a light source for providing light to the lighted display panel and the color temperature correcting circuit adjusts the light provided by the light source to match the color temperature of the light ambient to the display device.

22. The image display apparatus of claim 19, further comprising:

a second ambient light sensor disposed such that a light sensitive region of the second ambient light sensor is adjacent a display region of the display device, wherein;

the second ambient light sensor is configured to provide a signal representing an intensity of light emitted from at least a portion of the display region of the display device; and

the color correcting circuitry is configured to adjust at least one of the image display signals responsive to the intensity signal provided by the second ambient light sensor;

23. The image display apparatus of claim 19, further comprising:

a housing,

wherein the display device and the ambient light sensor are disposed on a front surface of the housing.

24. The image display apparatus of claim 19, further comprising:

a housing,

wherein the display device is disposed on a front surface of the housing and the ambient light sensor is disposed on a back surface of the housing.

25. The image display apparatus of claim 22,

further comprising a button configured such that when the button is depressed, the ambient light sensor begins sensing the at least first and second color components.

26. The image display apparatus of claim 19, further comprising a fish eye lens disposed over the ambient light sensor.

27. The image display apparatus of claim 19 further comprising a diffusion lens disposed over the ambient light sensor.