Active matrix liquid crystal display device

• US 6,449,023 B2
• Filed: 04/09/2001
• Issued: 09/10/2002
• Est. Priority Date: 10/27/1994
• Status: Expired due to Term

• Current Assignee: Kopin Corporation, Massachusetts Institute of Technology
• Original Assignee: Kopin Corporation, Massachusetts Institute of Technology
• Inventors: Gale, Ronald P., Swanson, Gary J.
• Primary Examiner(s): Sikes, William
• Assistant Examiner(s): Ngo, Julie
• Application Number:
  US09/829,102
• Publication Number:
  US 20010048493A1
• Time in Patent Office: 519 Days
• Field of Search: 349/62, 349/8, 349/124, 349/84, 349/95
• 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

A transmissive active matrix liquid crystal display device has a multievel optical phase element that sepaeates each color component of light into a plurality of diffraction orders. The multilevel optical phase element is aligned with a an active matrix array and directs light of different colors through different pixels of a liquid crystal material. The transmission of light through the liquid crystal material is controlled by an array of transistor circuits that actuate pixel electrodes.

Claims

1. A transmissive active matrix liquid crystal display device comprising:

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

an optically transmissive substrate attached to the active matrix array;

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

a multilevel optical phase element that separates each color component of light into a plurality of diffraction orders, wherein said multilevel optical phase element is aligned with the active matrix array and directs light of different colors through different volumes of the liquid crystal material; and

a housing that contains the transmissive display structure and the multilevel optical phase element.

2. The display device of claim 1 wherein the diffractive optical phase element is bonded to a transfer substrate, and wherein the transfer substrate is bonded to the active matrix array.

3. The display device of claim 1 further comprising a light polarizer that polarizes light before the light is incident upon the multilevel optical phase element.

4. The display device of claim 1 wherein the housing forms a direct-view display device aligned with the transmissive display.

5. The display device of claim 1 further comprising one or more projection lenses aligned with the transmissive display or a mirror reflection of the transmissive display.

6. The display device of claim 1 further comprising an illumination system in alignment with the multilevel optical phase element.

7. The display device of claim 6 wherein the illumination system includes a light pipe.

8. The display device of claim 7 wherein the light pipe is a folded light pipe.

9. The display device of claim 6 wherein the illumination system includes a reflective box light source.

10. The display device of claim 6 wherein the illumination system includes a lenslet array, the lenslet array being optically aligned with the multilevel optical phase element.

11. The display device of claim 1 further comprising a viewing optic.

12. The display device of claim 11 wherein the viewing optic includes a cholesteric liquid crystal (CLC) element.