Rear surface projection type screen that diffracts and diffuses high luminance projection light from a projector including first and second polarizing plates

• US 8,337,022 B2
• Filed: 09/10/2010
• Issued: 12/25/2012
• Est. Priority Date: 10/24/2005
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kondo, Tetsujiro, Kokubo, Tetsushi, Mukai, Hitoshi, Hibi, Hirofumi, Tanaka, Kazumasa, Tanaka, Kenji, Morisaki, Hiroyuki
• Primary Examiner(s): Le, Que T
• Assistant Examiner(s): BENNETT, JENNIFER D
• Application Number:
  US12/879,196
• Publication Number:
  US 20100328618A1
• Time in Patent Office: 837 Days
• Field of Search: 353/20, 353/97, 353 30- 31, 353/122, 359/443, 359/450, 359/452, 359/453, 359454-460, 359738-740, 250/208.1, 250/225, 250/216
• US Class Current: 353/20
• CPC Class Codes: G03B 21/62 Translucent screens
• CPC Class Codes: G03B 37/04 with cameras or projectors providing touching or overlapping fields of view
• CPC Class Codes: H04N 9/3167 for polarizing the light beam polarizing optical systems per se G02B27/28

Abstract

A rear projection image display apparatus that includes one or more projectors that project an image having a high luminance, a first screen having a fibrous texture and that diffracts light incident from the one or more projectors in accordance with a fiber roughness of the fibrous texture, and a second screen attached to the first screen on a side of the first screen opposite the one or more projectors and that diffuses light incident from the first screen and outputs the diffused light.

Claims

1. A rear projection image display apparatus comprising:

a projector configured to project an image having a high luminance;

a transmission type screen including a first screen having a fibrous texture and configured to diffract light incident from the projector in accordance with a fiber roughness of the fibrous texture, and a second screen comprising diffusing particles in a vinyl chloride resin attached to the first screen on a side of the first screen opposite the projector and configured to diffuse light incident from the first screen and output the diffused light;

a first polarizing plate having a first polarization direction, the first polarizing plate disposed in front of an exit pupil of the projector and at a first distance from the transmission type screen; and

a second polarizing plate having a second polarizing direction that is substantially orthogonal to the first polarizing direction, the second polarizing plate being disposed near a rear surface side opposite to an irradiation surface of the transmission type screen and at a second distance from the transmission type screen, which is smaller than the first distance, wherein

only the first polarizing plate and the second polarizing plate are configured to polarize the image projected from the projector.

2. The rear projection image display apparatus according to claim 1, wherein the first screen is made of cotton.

3. The rear projection image display apparatus according to claim 1, wherein the first screen is made of silk.

4. The rear projection image display apparatus according to claim 1, wherein the first screen is made of pongee.

5. The rear projection image display apparatus of claim 1, wherein a gain characteristic of the diffused light output from the second screen is greater than 0.9 for light incident on the first screen at an angle of 15 degrees.

6. The rear projection image display apparatus of claim 1, wherein a gain characteristic of the diffused light output from the second screen is approximately 0.8 for light incident on the first screen at an angle of 30 degrees.

7. The rear projection image display apparatus of claim 1, wherein a gain characteristic of the diffused light output from the second screen is greater than 0.6 for light incident on the first screen at an angle of 45 degrees.

8. The rear projection image display apparatus of claim 1, wherein a gain characteristic of the diffused light output from the second screen is greater than 0.5 for light incident on the first screen at an angle of 60 degrees.

9. The rear projection image display apparatus of claim 1, wherein a gain characteristic of the diffused light output from the second screen is greater than 0.4 for light incident on the first screen at an angle of 75 degrees.

10. The rear projection image display apparatus according to claim 1, wherein

in the projection light from the projector, color components are respectively polarized in predetermined directions, and

the first and second polarization directions are configured to be nonparallel to a polarization direction of any of the color components of the projection light.

11. The rear projection image display apparatus according to claim 10, wherein

the projector is a 3LCD projector that separates an illumination light from a high luminance, single light source into color components of three primary colors of RGB, combines the light controlled by LCDs respectively corresponding to the colors, and then projects the light, a polarization direction of the light of R and B projected from the exit pupil and a polarization direction of the light of G defining 90 degrees, and

the polarization direction of the second polarizing plate is arranged so as to define about 45 degrees with respect to the polarization directions of the light of R, B and G.

12. The rear projection image display apparatus according to claim 1, wherein a surface area of the first polarizing plate is less than a surface area of the second polarizing plate.

13. The rear projection image display apparatus according to claim 1, wherein the first polarizing plate is disposed closer to the front exit of the pupil of the projector than the transmission type screen.

14. The rear projection image display apparatus according to claim 1, wherein the first polarizing plate is a heat-resistant polarizing plate.