Monolithic color wheel

• US 5,371,543 A
• Filed: 08/17/1993
• Issued: 12/06/1994
• Est. Priority Date: 03/03/1993
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Anderson, Charles
• Primary Examiner(s): GROODY, JAMES J
• Application Number:
  US08/108,095
• Time in Patent Office: 476 Days
• Field of Search: 358/42, 359/580, 359/583, 359/586, 359/587, 359/589, 359/883, 359/891, 348/268, 348/270, 348/271, 348/742, 348/743
• US Class Current: 348/270
• CPC Class Codes: G02B 26/008 in the form of devices for effecting sequential colour changes, e.g. colour wheels
• CPC Class Codes: H04N 9/30 using solid-state colour display devices
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time

Abstract

A color wheel comprised of two or more interference filters deposited on or bonded to a substrate 30 without the use of a frame or spokes. Filters 32, 34, and 36 preferably abut and are typically made from multiple layers of materials having different indices of refraction. The color wheel does not require extensive machining or balancing, and is very optically efficient because the duration of single color light periods is maximized. The color wheel does not have a frame or spokes and is therefore more aerodynamically efficient resulting in less work required to spin it and less wind noise.

Claims

1. A one-piece color filter wheel comprised of:

a substrate; and

at least two abutting interference filters supported by said substrate, each of said interference filters comprised of a least one optical coating layer.

2. The color wheel of claim 1 wherein said substrate is glass.

3. The color wheel of claim 1 wherein said substrate is plastic.

4. The color wheel of claim 1 wherein said substrate is acrylic.

5. The color wheel of claim 1 wherein said substrate is quartz.

6. The color wheel of claim 1 wherein said interference filters are transmissive.

7. The color wheel of claim 1 wherein said interference filters are reflective.

8. The color wheel of claim 1 having three said interference filters, said interference filters being transmissive and comprised of multiple layers of materials having varying indices of refraction, said materials vacuum deposited on said substrate, wherein said substrate is glass.

9. The color filter wheel of claim 1 wherein said substrate comprises a first side and a second side, said substrate having interference filters deposited on said second side and an anti-reflective coating deposited on said first side.

10. A color filter wheel comprised of:

a primary substrate;

at least two secondary substrates; and

at least two interference filters comprised of at least one optical coating layer deposited on said secondary substrates, said interference filters attached to said primary substrate without the use of a frame or spokes.

11. The color wheel of claim 10 wherein said primary substrate is glass.

12. The color wheel of claim 10 wherein said primary substrate is plastic.

13. The color wheel of claim 10 wherein said primary substrate is acrylic.

14. The color wheel of claim 10 wherein said primary substrate is quartz.

15. The color wheel of claim 10 wherein said interference filters are transmissive.

16. The color wheel of claim 10 wherein said interference filters are reflective.

17. The color wheel of claim 10 wherein said at least two filters are comprised of a red, a green, and a blue filter.

18. The color filter wheel of claim 10 wherein said primary substrate comprises a first side and a second side, said primary substrate having said interference filters attached to said second side and an anti-reflective coating deposited on said first side.

19. A motorized color filter wheel system comprising:

a substrate having a first surface, a second surface, and an axis perpendicular to said first and second surfaces;

a source of light;

at least two interference filters, each of said interference filters having a unique optical transmission bandwidth, wherein said first surface of said substrate is comprised of at least two substantially abutting regions, each of said at least two regions supporting one of said interference filters; and

a motor attached to said substrate for spinning said substrate about its axis, wherein said light is focusable onto a point on said substrate such that each of said interference filters passes through said point during each revolution of said substrate.

20. The color wheel system of claim 19 wherein said at least two filters are comprised of a red, a green, and a blue filter.