Device having a conductive light absorbing mask and method for fabricating same

• US 20060077516A1
• Filed: 04/29/2005
• Published: 04/13/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Kothari, Manish
• Granted Patent: US 7,420,725 B2
• Time in Patent Office: Days
• US Class Current: 359/290
• CPC Class Codes: G02B 26/00 Optical devices or arrangements for the control of light using movable or deformable optical elements control of light by modification of the optical properties of the media of the elements involved therein G02F1/00
• 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
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

A system and method for an optical component that masks non-active portions of a display and provides an electrical path for one or more display circuits. In one embodiment an optical device includes a substrate, a plurality of optical elements on the substrate, each optical element having an optical characteristic which changes in response to a voltage applied to the optical element, and a light-absorbing, electrically-conductive optical mask disposed on the substrate and offset from the plurality of optical elements, the optical mask electrically coupled to one or more of the optical elements to provide one or more electrical paths for application of voltages to the one or more optical elements. In another embodiment a method of providing an electrical signal to a plurality of optical elements of a display comprises electrically coupling an electrically-conductive light-absorbing mask to one or more optical elements, and applying a voltage to the mask to activate the one or more optical elements.

Claims

1. An optical device comprising:

a substrate;

a light modulating element disposed on the substrate, the modulating element having an optical characteristic which changes in response to a voltage applied to the modulating element; and

an electrically-conductive mask disposed on the substrate and spaced from the modulating element, the mask electrically coupled to the modulating element to provide one or more electrical paths for application of voltages to the modulating element.

2. The device of claim 1, wherein the modulating element comprises an interferometric modulator.

3. The device of claim 1, wherein the optical mask is configured to appear black.

4. The device of claim 1, wherein the optical mask is configured to appear a color other than black.

5. The device of claim 2, further comprising a column electrode electrically coupled to the mask to form an electrically parallel connection.

6. The device of claim 2, further comprising a row electrode electrically coupled to the mask to form an electrically parallel connection.

7. The device of claim 1, wherein the mask comprises a film stack.

8. The device of claim 1, wherein the mask is electrically coupled to the optical element by one or more conductive vias.

9. The device of claim 7, wherein the film stack comprises a first reflective layer and a second reflective layer.

10. The device of claim 9, wherein the first reflective layer is electrically connected to a first electrode and the second reflective layer is electrically connected to a second electrode.

11. The device of claim 9, wherein the first reflective layer and the second reflective layer are electrically connected to the same electrode.

12. A method of providing an electrical signal to a plurality of optical elements of a display, the optical elements individually actuatable by applying a voltage thereto, the method comprising:

electrically coupling an electrically-conductive mask to one or more optical elements; and

applying a voltage to the mask to activate the one or more optical elements.

13. The method of claim 12, wherein the one or more optical elements comprise interferometric modulators.

14. The method of claim 12, wherein the mask comprises a film stack.

15. The method of claim 12, wherein the mask comprises one or more interferometric elements.

16. The method of claim 12, wherein the mask is light-absorbing.

17. The method of claim 14, wherein the film stack comprises a conductive reflective layer to which a voltage is applied to activate the one or more optical elements.

18. A method of fabricating an optical device, the method comprising:

forming an electrically-conductive optical mask on a substrate, wherein the optical mask absorbs light;

forming an optical component on the substrate spaced from the optical mask, wherein the optical component has a driven state and an undriven state, the optical component changing between the driven state and the undriven state in response to an applied voltage, each state having a characteristic optical response to incident light; and

electrically connecting the optical mask to the optical component so at least a portion of the optical mask provides a bus for applying the voltage to the optical component.

19. The method of claim 18, wherein the optical component comprises an interferometric modulator.

20. The method of claim 18, wherein the optical mask comprises one or more interferometric elements.

21. The method of claim 18, wherein the optical mask comprises a film stack.

22. The method of claim 21, wherein the film stack comprises a non-light-absorbing dielectric material sandwiched between two light-reflecting materials.

23. The method of claim 22, wherein one or more of the light-reflecting materials comprises silver, aluminum, or chromium.

24. A method of fabricating an optical device comprising at least one active optical component formed on a transparent substrate, the method comprising:

identifying an area on the substrate that is to be light-absorbing wherein the identified area is laterally offset from the at least one active optical component; and

fabricating a conductive light-absorbing mask on the identified area prior to fabricating the at least one active optical component, wherein the mask is connected to the active optical component.

25. The method of claim 24, wherein the optical component comprises a pixel, the light-absorbing area being an area bordering the pixel.

26. The method of claim 24, wherein the fabricating comprises depositing a first light-reflecting layer on the substrate, depositing a non-light-absorbing dielectric layer on the first light-reflecting layer, and depositing a second light-reflecting layer on the non-light absorbing dielectric layer, wherein one or more of the first or second light-reflecting layer is electrically conductive.

27. The method of claim 26, wherein the first and second light-reflecting layers comprise metallic materials.

28. The method of claim 26, wherein the non-light absorbing dielectric layer comprises an oxide layer.

29. The method of claim 25, wherein the pixel is defined by an interferometric modulator.

30. The method of claim 26, wherein the light-absorbing mask comprises one or more a interferometric elements.

31. An optical device comprising:

means for reflecting incident light from an optical component, wherein the optical component has a driven state and an undriven state, the optical component changing between the driven state and the undriven state in response to an applied voltage, each state having a characteristic optical response to incident light;

means for absorbing light in an electrically-conductive optical mask disposed on the substrate and spaced from optical component; and

means for electrically connecting the optical mask to the optical component so at least a portion of the optical mask provides an electrical bus for a voltage applied to the optical component.

32. An optical device produced by the process comprising:

identifying an area on the substrate that is to be light-absorbing wherein the identified area is laterally offset from the at least one active optical component; and

fabricating a conductive light-absorbing mask on the identified area prior to fabricating the at least one active optical component, wherein the mask is connected to the active optical component.