Method of imaging using a liquid crystal display device

• US 6,243,149 B1
• Filed: 03/29/1999
• Issued: 06/05/2001
• Est. Priority Date: 10/27/1994
• Status: Expired due to Term

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Gale, Ronald P., Swanson, Gary J.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): NGO, HUYEN LE
• Application Number:
  US09/280,873
• Time in Patent Office: 799 Days
• Field of Search: 349/62, 349/8, 349/84, 349/95, 389/201, 359/224, 359/291, 348/771
• US Class Current: 349/62
• CPC Class Codes: G02B 27/0994 Fibers, light pipes optical fibers per se G02B6/02
• CPC Class Codes: G02B 5/02 Diffusing elements; Afocal elements
• CPC Class Codes: G02B 5/18 Diffraction gratings holographic optical elements G02B5/32, G03H; integrally combined with optical fibres G02B6/02057; for coupling light guides G02B6/34; integrally combined with optical integrated light guides G02B6/12; grating systems G02B27/44
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: H01L 28/55 with a dielectric comprising a perovskite structure material
• CPC Class Codes: H01L 28/60 Electrodes
• CPC Class Codes: H01L 28/75 comprising two or more layers, e.g. comprising a barrier layer and a metal layer
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells
• CPC Class Codes: H04N 9/3108 by using a single electronic spatial light modulator
• CPC Class Codes: H04N 9/315 Modulator illumination systems general applications of lighting devices F21V; general optical systems G02B; lamp houses for projectors not peculiar to the presence of an electronic spatial light modulator G03B21/20
• CPC Class Codes: Y10S 359/90 Methods

Abstract

Binary optics are used in an illumination system to provide a method of imaging for a color projection display. In one embodiment a broad spectrum light source illuminates a multilevel optical phase element which disperses the broad spectrum light from the light source by diffraction. A display having a number of pixel elements, each capable of transmitting a predetermined spectral region, is positioned within the near field region of the multilevel optical phase element so as to receive the light dispersed by the multilevel phase element.

Claims

1. A method of imaging using an active matrix liquid crystal display device comprising:

providing an active matrix array of transistor circuits and pixel electrodes, each pixel electrode being electrically connected to a transistor circuit that actuates a pixel electrode;

providing a layer of liquid crystal material positioned between the pixel electrodes and a counter electrode to form a display structure such that actuation of the pixel electrodes controls transmission of light through a volume of the liquid crystal material;

providing a diffractive optical element optically coupled with the active matrix array to disperse light of different colors through different volumes of the liquid crystal material;

directing light from a light source through the display device while selectively actuating the pixel electrodes to form an image with the display device; and

magnifying the image with a lens.

2. The method of claim 1 further comprising providing a device wherein the diffractive optical element is bonded to the active matrix array.

3. The method of claim 1 further comprising providing a diffractive optical element that includes a light polarizer.

4. The method of claim 1 further comprising providing a housing that forms a direct-view display device.

5. The method of claim 1 further comprising providing a housing that forms a projected-view display device.

6. The method of claim 1 further comprising providing an illumination system that includes a light pipe.

7. The method of claim 6 wherein the step of providing a light pipe further comprises providing a folded light pipe.

8. The method of claim 6 further comprising providing an illumination system that includes a lenslet array, the lenslet array being optically aligned with the diffractive optical element.

9. A method of imaging using an active matrix liquid crystal display device comprising:

providing a light source that emits red, blue and green colors and that is optically coupled to an active matrix array of transistor circuits and pixel electrodes, each pixel electrode being electrically connected to a transistor circuit that actuates a pixel electrode;

providing a layer of liquid crystal material positioned between the pixel electrodes and a counter electrode to form a display structure such that actuation of the pixel electrodes controls transmission of light through a volume of the liquid crystal material;

providing a diffractive optical element optically coupled with the active matrix array to disperse light of different colors through different volumes of the liquid crystal material;

directing light from the light source through the diffractive optical element and the display device while selectively actuating the pixel electrodes to form an image with the display device; and

magnifying the image with a lens.

10. The method of claim 9 further comprising providing a device wherein the diffractive optical element is bonded to the active matrix array.

11. The method of claim 9 further comprising providing a diffractive optical element that includes a light polarizer.

12. The method of claim 9 further comprising providing a housing that forms a direct-view display device.

13. The method of claim 9 further comprising providing a housing that forms a projected-view display device.

14. The method of claim 9 further comprising providing an illumination system that includes a light pipe.

15. The method of claim 14 further comprising providing a light pipe further comprises providing a folded light pipe.

16. The method of claim 14 further comprising providing an illumination system that includes a lenslet array, the lenslet array being optically aligned with the diffractive optical element.

17. A method of imaging using an active matrix liquid crystal display device comprising:

providing a light source that emits red, blue and green colors and that is optically coupled to an active matrix array of transistor circuits and pixel electrodes, each pixel electrode being electrically connected to a transistor circuit that actuates a pixel electrode;

providing a layer of liquid crystal material positioned between the pixel electrodes and a counter electrode to form a display structure such that actuation of the pixel electrodes controls transmission of light through a volume of the liquid crystal material;

providing a diffractive optical element aligned with the active matrix array to disperse light of different colors through different volumes of the liquid crystal material; and

directing light from the light source through the diffractive optical element and the display device while selectively actuating the pixel electrodes to form an image with the display device.

18. The method of claim 17 further comprising providing a device wherein the diffractive optical element is bonded to the active matrix array.

19. The method of claim 17 further comprising providing an illumination system that includes a lenslet array, the lenslet array being optically aligned with the diffractive optical element.