Optical projection system and method

• US 7,090,350 B2
• Filed: 02/18/2004
• Issued: 08/15/2006
• Est. Priority Date: 02/05/2004
• Status: Expired due to Fees

• Current Assignee: United Microelectronics Corporation
• Original Assignee: United Microelectronics Corporation
• Inventors: Lu, Ho, Chen, Chung-jung, Yeh, Shih-Po
• Primary Examiner(s): KOVAL, MELISSA J
• Application Number:
  US10/782,574
• Publication Number:
  US 20050174541A1
• Time in Patent Office: 909 Days
• Field of Search: 335/20, 335/31, 335/33, 335/34, 335/37, 335/81, 335/84, 349/5, 349/8, 349/9, 359/486, 358/1.2, 353/34, 353/37, 353/81, 353/84, 353/20, 353/31, 353/33
• US Class Current: 353/20
• CPC Class Codes: G02B 27/1026 for use with reflective spatial light modulators
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G03B 21/14 Details
• CPC Class Codes: G03B 21/2073 Polarisers in the lamp house peculiar to electronic spatial light modulators H04N9/3197
• CPC Class Codes: G03B 33/12 using beam-splitting or beam-combining systems, e.g. dichroic mirrors
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells
• CPC Class Codes: H04N 9/3105 for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10
• CPC Class Codes: H04N 9/3152 for shaping the light beam beam shaping per se G02B27/09
• CPC Class Codes: H04N 9/3167 for polarizing the light beam polarizing optical systems per se G02B27/28

Abstract

An optical projection system can receive a red light beam, green light beam, and blue light beam. The optical projection system includes a color-combination prism, and the light beams respectively enter the color-combination prism from three surfaces and are combined into a mixed light beam, which exits from another surface. A projection lens set receives the mixed light beam to perform the projection. Each of the light beams further includes a liquid crystal reflection panel and a wire grid polarizer (WGP). The liquid crystal reflection panel is parallel to the corresponding surfaces of the color-combination prism. In the design, before the light beam entering the color-combination prism, they are first reflected by the WGP onto the liquid crystal reflection panel, and the liquid crystal reflection panels respectively with a polarizing state reflect the light beams, passing through the WGP and directly propagating toward the color-combination prism.

Claims

1. An optical projection system, capable of receiving a first light beam, a second light beam, and a third light beam, the projection system comprising:

a color-combination prism, having a first surface, a second surface and a third surface, allowing the first, second and third light beams to respectively enter the first, second and third surfaces, so as to form a mixed beam to emit out from another surface;

a projection lens set, for receiving the mixed beam for projection;

a first wire grid polarizer (WGP), a second WGP and a third WGP, for respectively receiving and polarizing the first, second and third light beams and respectively reflecting the polarized beams to a first liquid crystal reflection panel, a second liquid crystal reflection panel and a third liquid crystal panel, wherein the first, second and third liquid crystal reflection panels are respectively positioned substantially parallel to the first, second and third surfaces of the color combination prism, and wherein the first, second and third liquid crystal reflection panels respectively receive the polarized light beams from the first, second and third WGPs and reflect polarized light beams to the first, second and third surfaces of the color combination prism; and

a first polarizer, a second polarizer and a third polarizer, respectively disposed in a light path of each of the first, second and third light beams such that the first, second and third light beams are respectively incident to the first, second and third WGPs and are respectively reflected by the first, second and third WGPs to the first, second and third liquid reflection panels.

2. The optical projection system of claim 1, wherein each of the first, second and third WGPs allows a light component with a first polarization state to pass, and reflects a light component with a second polarization state.

3. The optical projection system of claim 1, wherein each of the first, second and third liquid crystal reflection panels includes a plurality of pixels, whereby an incident polarization state with respect to each of the pixels can be changed to the desired polarization state, so as to transmit the WGPs.

4. The optical projection system of claim 3, wherein the first, second and third liquid crystal reflection panels provide an image pattern by changing the polarization state.

5. The optical projection system of claim 1, wherein the color-combination prism includes an X-cube.

6. The optical projection system of claim 1, further comprising a first color splitter, to split a light source into a first primary color beam and a color mixing beam.

7. The optical projection system of claim 6, further comprising a second color splitter, to split the color mixing beam into a second primary color beam and a third primary color beam.

8. The optical projection system of claim 1, wherein each of the first, second and third liquid crystal reflection panels includes a liquid crystal on silicon (LCOS) panel.

9. The optical projection system of claim 8, wherein the color-combination prism includes an X-cube.

10. An optical projection method, for receiving a first light beam, a second light beam, and a third light beam and projecting, the method comprising:

providing a light source;

splitting the light source into different color light beams;

leading each of the color light beams to respectively enter a wire grid polarizer (WGP), which polarizes the light beam and reflects the polarized light beam to a liquid crystal reflection panel, wherein each of the liquid crystal reflection panels have a plurality of pixels, and wherein the liquid crystal reflection panels includes a liquid crystal on silicon (LCOS) panel;

polarizing each of the color light beams transmitted to the respective WGP such that the WGP reflect the polarized color light beams to the respective liquid crystal reflection panels;

controlling each of the pixels of the liquid crystal reflection panel to have a polarization state with respect to the pixels for the reflection the polarized light beam received from the WGP; and

respectively leading light beams reflected form the liquid crystal reflection panels to directly transmit to the respective WGP and corresponding surfaces of a color combination prism where the light beams are combined into a mixed light beam, wherein each of the liquid crystal reflection panels is positioned substantially parallel to the corresponding surface of the color combination prism.

11. The method of claim 10, wherein the WGP allows a light component with a first polarization state to pass, and reflects a light component with a second polarization state.

12. The method of claim 10, wherein the step of leading the light beams reflected from the liquid crystal reflection panels includes using a color-combination prism to obtain the mixed light beam.

13. The method of claim 12, wherein the color-combination prism includes an X-cube.