Projector based on tunable individually-addressable fabry-perot filters

• US 20070242234A1
• Filed: 04/18/2006
• Published: 10/18/2007
• Est. Priority Date: 04/18/2006
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Lin, Pinyen, Wang, Yao, Mestha, Lalit, Gulvin, Peter
• Granted Patent: US 7,628,493 B2
• Time in Patent Office: Days
• US Class Current: 353/84
• 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 3/0062 Stacked lens arrays, i.e. refractive surfaces arranged in at least two planes, without structurally separate optical elements in-between
• CPC Class Codes: G03B 21/005 Projectors using an electronic spatial light modulator but not peculiar thereto
• CPC Class Codes: G03B 21/14 Details
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

A projection system includes a display apparatus comprising a plurality of tunable Fabry-Perot filters, each of the filters being configured for shifting between a state in which the filter transmits radiation in a bandwidth in the visible range of the electromagnetic spectrum and a state in which the filter transmits radiation in a bandwidth outside the visible range of the electromagnetic spectrum. An illuminator provides light to the plurality of Fabry-Perot filters. A control system receives image data and controls the display apparatus to project an image onto an associated display surface. The control system includes a modulator which provides wavelength modulation signals to the plurality of Fabry-Perot filters to modulate a color of pixels in the image and causes selected ones of the Fabry-Perot filters to shift into the bandwidth outside the visible range to modulate the brightness of pixels in the image.

Claims

1. A projection system, comprising:

a display apparatus comprising a plurality of tunable Fabry-Perot filters, each of the filters being configured for shifting between a state in which the filter transmits radiation in a bandwidth in the visible range of the electromagnetic spectrum and a state in which the filter transmits radiation in a bandwidth outside the visible range of the electromagnetic spectrum;

an illuminator which provides light to the plurality of Fabry-Perot filters;

a control system which receives image data and controls the display apparatus to project an image onto an associated display surface, the control system comprising a modulator which;

provides wavelength modulation signals to the plurality of Fabry-Perot filters to modulate a color of pixels in the image; and

causes selected ones of the Fabry-Perot filters to shift into the bandwidth outside the visible range to modulate the brightness of pixels in the image.

2. The projection system of claim 1, wherein the display apparatus further comprises a projection lens system for magnifying the projected image.

3. The projection system of claim 2, wherein the projection lens system comprises a plurality of microlenses, the projection lens system converging portions of the image received from adjacent filters.

4. The projection system of claim 1, further comprising:

a screen onto which the image is projected by the display apparatus.

5. The projection system of claim 4, wherein the screen is remote from the display apparatus.

6. The projection system of claim 5, wherein the screen is reflective.

7. The projection system of claim 1, wherein the modulator causes selected ones of the Fabry-Perot filters to shift between a bandwidth in the visible range and a bandwidth outside the visible range at a frequency at which the two bandwidths are not separately detectable by the eye.

8. The projection system of claim 1, wherein the brightness modulator causes selected ones of the Fabry-Perot filters to shift between a bandwidth in the visible range and a bandwidth outside the visible range at a frequency of at least 20 Hz.

9. The projection system of claim 8, wherein the frequency is at least 60 Hz.

10. The projection system of claim 1, wherein the brightness modulator causes selected ones of the Fabry-Perot filters to shift between bandwidths using time-division multiplexing.

11. The projection system of claim 1, wherein the display apparatus further comprising a lens intermediate the illuminator and the Fabry-Perot filters.

12. The projection system of claim 1, wherein each of the Fabry-Perot filters is capable of selectively transmitting radiation in any one of a plurality of bandwidths in the visible range of the electromagnetic spectrum.

13. The projection system of claim 1, wherein the each of the Fabry-Perot cavities comprises a pair of mirrors, and the control system adjusts a distance between the pair of mirrors based on the image data.

14. The projection system of claim 13, wherein the mirrors are supported on a transparent substrate.

15. The projection system of claim 1, wherein the filters are arranged in an array.

16. The projection system of claim 1, wherein each of the filters is individually addressable.

18. The method of claim 16, wherein the causing of causing of selected ones of the Fabry-Perot filters to shift into the bandwidth outside the visible range includes causing selected ones of the Fabry-Perot filters to shift between a bandwidth in the visible range and a bandwidth outside the visible range at a frequency of at least 20 Hz.

17. A method of projecting an image comprising:

receiving image data for an image to be projected;

illuminating a plurality of tunable Fabry-Perot filters, each of the filters being configured for shifting between a state in which the filter transmits radiation in a bandwidth in the visible range of the electromagnetic spectrum and a state in which the filter transmits radiation in a bandwidth outside the visible range of the electromagnetic spectrum;

controlling the tunable Fabry-Perot filters to project the image onto an associated display surface including providing wavelength modulation signals to the plurality of Fabry-Perot filters to modulate a color of pixels in the image and causing selected ones of the Fabry-Perot filters to shift into the bandwidth outside the visible range to modulate the brightness of pixels in the image in accordance with the image data.

19. The method of claim 17, wherein the frequency is at least 60 Hz.

20. The method of claim 17, further comprising diverging the image with a lens array comprising a plurality of microlenses.

21. A computer program product including computer-executable instructions for performing the method of claim 17.

22. A projection system comprising:

an image source which supplies image data for an image to be projected;

an array of individually tunable Fabry-Perot filters mounted on a common transparent substrate, each of the filters being configured for transmitting visible light therethrough;

an illuminator which provides light to the plurality of Fabry-Perot filters;

a control system which receives image data and controls the display apparatus to project an image onto an associated display surface, the control system comprising a modulator which provides wavelength modulation signals to the plurality of Fabry-Perot filters to modulate a color of pixels in the image; and

a lens system which includes an array of microlenses intermediate the array of filters and the associated display surface.