Method and device for generating white in an interferometric modulator display

• US 20060077125A1
• Filed: 07/22/2005
• Published: 04/13/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC LLC A Delaware Limited Liability Company
• Inventors: Floyd, Philip D.
• Granted Patent: US 7,525,730 B2
• Time in Patent Office: Days
• US Class Current: 345/32
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26

Abstract

Various embodiments of the invention relate to methods and systems for generating the color white in displays created from interferometric modulators and more specifically, to the generation of the color white through the use of reflected light at two wavelengths. In one embodiment, a display device displays the color white. The color white is generated by reflecting light from two pluralities of interferometric modulator types. The first modulator type reflects colored light at a specific wavelength. The second modulator type reflects colored light selected to be at a wavelength complementary to the first. The combined light reflected from the two types appears white in the display.

Claims

1. An array of interferometric modulators configured to appear to have a white color, the array comprising:

a first plurality of color interferometric modulators wherein each modulator reflects a first color light;

a second plurality of color interferometric modulators wherein each modulator reflects a second color light; and

wherein the reflected light from the first plurality of color interferometric modulators and the second plurality of color interferometric modulators when combined together appear substantially white.

2. The array of claim 1, wherein the first wavelength and the second wavelength are selected from non-traditional colors.

3. The array of claim 2, wherein the first wavelength is purplish-blue and the second wavelength is greenish-yellow.

4. The array of claim 1, wherein the white color is the color of a blackbody radiator between about 2856K and 6500K.

5. The array of claim 1, wherein the first wavelength of light is within a range of about 470-490 nm and the second wavelength of light is within a range of about 570-600 nm

6. The array of claim 1, wherein the first plurality of interferometric modulators and the second plurality of interferometric modulators are arranged to form at least a portion of a display.

7. A method for selecting wavelengths for a first plurality of interferometric modulators and a second plurality of interferometric modulators so that a combination of the reflected light has the color of white, the method comprising:

selecting a first plurality of interferometric modulator display elements that reflects a first color light; and

selecting a second plurality of interferometric modulator display elements that reflects a second color light, wherein the second color light is complementary to the first color light such that said first color light and said second color light when combined appear substantially white.

8. The method of claim 7, wherein at least one of the first wavelength of light and the second wavelength of light is selected based at least in part on a CIE Chromaticy Diagram.

9. The method of claim 7, wherein the white color is the color of a blackbody radiator between about 2856K and 6500K.

10. A method of displaying a region of an image having a white color, the method comprising:

reflecting a first color light from a first plurality of color interferometric modulators, said first color light having a first center wavelength; and

reflecting a second color light from a second plurality of color interferometric modulators, said second color light having a second center wavelength in the region that is complementary to the first center wavelength.

11. The method of claim 10, wherein at least one of the first center wavelength and the second center wavelength is selected based at least in part on a CEE Chromaticy Diagram.

12. The method of claim 10, wherein the white color is the color of a blackbody radiator between about 2856K and 6500K.

13. An array of light modulators arranged at intersections of rows and columns of first and second electrodes, the array comprising:

a first light modulator forming a first resonant optical cavity at a first intersection of the first and second electrodes, the first resonant optical cavity being configured to reflect light having a first wavelength; and

a second light modulator forming a second resonant optical cavity at a second intersection of the first and second electrodes, the second resonant optical cavity being configured to reflect light having a second wavelength,

wherein the light reflected by the first cavity and the light reflected by the second cavity are complementary and produce a substantially white color when combined together.

14. The array of claim 13, wherein the first electrode and second electrode comprise at least partially reflective metal surfaces.

15. The array of claim 13, wherein the first resonant optical cavity comprises reflective surfaces separated by a first distance and the second resonant optical cavity comprises reflective surfaces separated by a second distance different than the first distance.

16. The array of claim 13, wherein the first wavelength and the second wavelength are selected from non-traditional colors.

17. The array of claim 16, wherein the first wavelength is purplish-blue and the second wavelength is greenish-yellow.

18. The array of claim 13, wherein the white color is the color of a blackbody radiator between about 2856K and 6500K.

19. The array of claim 13, wherein the first wavelength of light is within a range of about 470-490 nm and the second wavelength of light is within a range of about 570-600 nm

20. The array of claim 13, wherein the first plurality of interferometric modulators and the second plurality of interferometric modulators are arranged to form at least a portion of a display.

21. An apparatus for displaying a region of an image having a white color, the apparatus comprising:

means for reflecting light having a first color in the region; and

means for reflecting light at a second color in the region,

wherein said second color is substantially complementary to the first color.

22. The apparatus of claim 21, wherein the first color and the second color are selected from non-traditional colors.

23. The apparatus of claim 22, wherein the first color is purplish-blue and the second color is greenish-yellow.

24. The apparatus of claim 21, wherein the white color is the color of a blackbody radiator between about 2856K and 6500K.

25. The apparatus of claim 21, wherein the first color of light is within a range of about 470-490 nm and the second color of light is within a range of about 570-600 nm

26. The apparatus of claim 21, wherein the means for reflecting light having a first color and the means for reflecting light having a second color are arranged to form at least a portion of a display.