Holographic illumination system

• US 6,646,772 B1
• Filed: 11/13/2001
• Issued: 11/11/2003
• Est. Priority Date: 09/14/1999
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: DigiLens Inc
• Inventors: Waldern, Jonathan D., Popovich, Milan M., Storey, John J.
• Primary Examiner(s): Juba, John
• Assistant Examiner(s): BOUTSIKARIS, LEONIDAS
• Application Number:
  US10/054,319
• Time in Patent Office: 728 Days
• Field of Search: 359/15, 359/22, 359/24, 359/13, 353/30, 353/31, 353/74, 349/201, 349/202
• US Class Current: 359/15
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G02F 1/13342 Holographic polymer dispersed liquid crystals
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence

Abstract

Disclosed is an apparatus and method of illuminating an image display via an electrically switchable holographic optical element. The method includes a first electrically switchable holographic optical element (ESHOE) receiving illumination light. The first ESHOE comprises oppositely facing front and back surfaces. The first ESHOE focuses a first component (e.g., p-polarized blue light) of the illumination light while transmitting the remaining components of the illumination light without substantial alteration. An image display is provided and receives the focused first component. In response to receiving the focused first component, the image display emits image light. The first ESHOE receives and transmits this image light without substantial alteration. In one embodiment, the focused first component emerges from the first ESHOE at the back surface thereof, and the first ESHOE receives the image light at the back surface.

Claims

1. A method comprising:

a first electrically switchable holographic optical element (ESHOE) receiving illumination light;

the first ESHOE focusing a first component of the illumination light onto an image display while transmitting the remaining components of the illumination light without substantial alteration;

the image display receiving the focused first component light;

image light emitting from the image display in response to the image display receiving the focused first component;

the first ESHOE receiving and transmitting the image light without substantial alteration.

2. The method of claim 1 wherein the first ESHOE comprises oppositely facing front and back surfaces, wherein the focused first component light emerges from the first ESHOE at the back surface thereof, wherein the first ESHOE receives the image light at the back surface thereof, and wherein the first ESHOE transmits the received image light without substantial alteration.

3. The method of claim 1, wherein the first ESHOE operates between an active state and an inactive state, wherein the first ESHOE, when operating in the active state, focuses the first component of the illumination light by diffraction while transmitting the remaining components of the illumination light without substantial alteration, wherein the first ESHOE, when active, transmits the image light without substantial alteration, and wherein the first ESHOE, when operating in the inactive state, transmits the illumination light including the first component thereof without substantial alteration.

4. The method of claim 1 wherein the image display modulates the focused first component light in accordance with image information provided to the image display to produce the image light.

5. The method of claim 1 wherein the image light has a polarization state that is orthogonal to the polarization state of the focused first component light.

6. The method of claim 1 wherein the first ESHOE comprises a holographic recording medium that records a hologram, wherein the holographic recording medium comprises:

a monomer dipentaerythritol hydroxypentaacrylate;

a liquid crystal;

a cross-linking monomer;

a coinitiator; and

a photoinitiator dye.

7. The method of claim 1 wherein the first ESHOE comprises a hologram made by exposing an interference pattern inside a polymer-dispersed liquid crystal material, the polymer-dispersed liquid crystal material comprising, before exposure:

a polymerizable monomer;

a liquid crystal;

a cross-linking monomer;

a coinitiator; and

a photoinitiator dye.

8. An apparatus comprising:

a first electrically switchable holographic optical element (ESHOE) for receiving illumination light, wherein the first ESHOE is configured to focus a first component of the illumination light while transmitting the remaining components of the illumination light without substantial alteration;

an image display for receiving the focused first component, wherein the image display is configured to emit image light in response to the image display receiving the focused first component;

wherein the first ESHOE is configured to receive and transmit the image light without substantial alteration.

9. The apparatus of claim 8 wherein the first ESHOE comprises oppositely facing front and back surfaces, wherein the focused first component emerges from the first ESHOE at the back surface thereof, wherein the first ESHOE is configured to receive the image light at the back surface thereof, and wherein the first ESHOE transmits the image light without substantial alteration.

10. The apparatus of claim 8 wherein the first ESHOE operates between an active state and an inactive state, wherein the first ESHOE, when operating in the active state, focuses the first component of the illumination light by diffraction while transmitting the remaining components of the illumination light without substantial alteration, wherein the first ESHOE, when active, transmits the image light without substantial alteration, and wherein the first ESHOE, when operating in the inactive state, transmits the illumination light including the first component thereof without substantial alteration.

11. The apparatus of claim 8 wherein the image display is configured to modulate the focused first component in accordance with image information provided to the image display.

12. The apparatus of claim 8 wherein the image light has a polarization state that is orthogonal to the polarization state of the first focused component.

13. The apparatus of claim 8 wherein the first ESHOE comprises a holographic recording medium that records a hologram, wherein the holographic recording medium comprises:

a monomer dipentaerythritol hydroxypentaacrylate;

a liquid crystal;

a cross-linking monomer;

a coinitiator; and

a photoinitiator dye.

14. The apparatus of claim 8 wherein the first ESHOE comprises a hologram made by exposing an interference pattern inside a polymer-dispersed liquid crystal material, the polymer-dispersed liquid crystal material comprising, before exposure:

a polymerizable monomer;

a liquid crystal;

a cross-linking monomer;

a coinitiator; and

a photoinitiator dye.