System to determine the color of ambient light for adjusting the illumination characteristics of a display

• US 5,726,672 A
• Filed: 07/20/1995
• Issued: 03/10/1998
• Est. Priority Date: 09/20/1994
• Status: Expired due to Term

• Current Assignee: Apple Computer Incorporated (Apple Inc.)
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Hernandez, Mathew W., Cappels, Richard D.
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): KIM, JULIANA
• Application Number:
  US08/504,450
• Time in Patent Office: 964 Days
• Field of Search: 345/22, 345/153, 345/207, 348/184, 348/185, 348/189
• US Class Current: 345/22
• CPC Class Codes: G06F 3/04897 Special input arrangements or commands for improving display capability
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: H04N 5/58 in dependence upon ambient light

Abstract

A system for correcting an output device for the effects of reflected ambient illumination comprises a reflection device of known reflectivity. The color display memory stores a first graphical interface and a second graphical interface. The first graphical interface displays a range of intensities of outputs that the display device can generate. The second graphical interface displays a range of hues that the display device can generate. The reflection device has a target surface which defines an aperture. The ambient light reflecting from the target surface is compared to the first graphical interface and to the second graphical interface by viewing the interfaces through the aperture. The system receives a first input of an intensity of the first graphical interface that appears to match the ambient illumination reflected from the reflection device; the system then receives a second input of a hue of the second graphical interface that appears to match the ambient illumination reflected from the reflection device. The system determines the intensity and hue of the ambient illumination reflected from the output device by matching the intensity and hue of the ambient illumination reflected from the reflection device with the output of the output device. The system then adjusts the outputs of the output device to compensate for the reflected ambient illumination.

Claims

1. A reflection device for adjusting display device output illumination characteristics relative to the color of ambient light, comprising:

a target surface having achromatic and flat reflectivity to ambient light, and defining an aperture through which light output from the display device can be seen by a user and visually compared to the color of ambient light reflected from the target surface.

2. A device as in claim 1 wherein the aperture has a diameter of less than 1/2 inch.

3. A device as in claim 2 wherein aperture diameter is about 0.5 centimeters.

4. A device as in claim 1 wherein the target surface is circular.

5. A device as in claim 4 wherein the target surface has a diameter of between 2 and 4 centimeters.

6. A device as in claim 1 further comprising a handle extending radially from the target surface periphery.

7. A device as in claim 6 wherein the handle comprises a support for attachment to the target surface.

8. A device as in claim 7 wherein the support has a center hole.

9. A device as in claim 8 wherein the center hole is larger than the aperture.

10. A device as in claim 1 wherein display device output illumination is a pre-determined color palette.

11. A reflection device for calibrating display device output illumination characteristics relative to the color of ambient light, comprising:

a target having

an achromatic reflective target surface and

an aperture; and

a handle extending from the target for holding the target parallel and proximal to the display device,

whereby the color of display device output light passing through the aperture can be compared with the adjacent color of ambient light reflected by the target surface surrounding the aperture.

12. A device as in claim 11 wherein the handle is clear.

13. A device as in claim 11 wherein the aperture has a diameter less than 1/2 inch.

14. A device as in claim 13 wherein the aperture has a diameter of about 0.5 centimeters.

15. A device as in claim 11 wherein the target is a circular disk.

16. A device as in claim 15 wherein the target surface has a diameter of between 2 and 4 centimeters.

17. A device as in claim 11 wherein the handle comprises a support for attachment to the target.

18. A device as in claim 17 wherein the support has a center hole.

19. A device as in claim 18 wherein the center hole is larger than the aperture.

20. A device as in claim 11 wherein display device output illumination is a pre-determined color palette.

21. A device as in claim 11 wherein the target surface has spectrally flat reflectivity.

22. A method of making a reflection device for comparing the characteristics of illumination output from a display device with the characteristics of ambient light, comprising the steps of:

providing a target having a target surface with predetermined reflectivity characteristics;

forming an aperture through the target;

providing a handle for holding the target surface parallel and proximal to the display device; and

attaching the target to the handle.

23. A method of making a reflection device as recited in claim 22 wherein the step of providing a handle comprises providing a handle including an annular support which defines a center hole, and the step of attaching the target comprises aligning the center hole with the aperture.

24. A method of making a reflection device as recited in claim 22 wherein the target surface is achromatic and spectrally flat.

25. A method of making a reflection device as recited in claim 22 wherein the aperture has a diameter of less than 1/2 inch.

26. A method of making a reflection device as recited in claim 25 wherein the aperture has a diameter of about 0.5 centimeters.

27. A method of making a reflection device as recited in claim 22 whereto the target is a circular disk.

28. A method of making a reflection device as recited in claim 27 wherein the target has a diameter of between 2 and 4 centimeters.

29. A method of making a reflection device as recited in claim 23 wherein the center hole has a larger diameter than the aperture.

30. A method of making a reflection device as recited in claim 22 wherein display device output illumination includes a pre-determined color palette.