Compact rear projection display

• US 20070153242A1
• Filed: 11/22/2006
• Published: 07/05/2007
• Est. Priority Date: 11/22/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Sokolov, Kirill, Jeong, Tae-hong, Lee, Young-chol, Borodouline, Alexei
• Granted Patent: US 7,922,339 B2
• Time in Patent Office: Days
• US Class Current: 353/119
• CPC Class Codes: G03B 21/62 Translucent screens
• CPC Class Codes: H04N 9/3141 Constructional details thereof details not peculiar to the presence of an electronic spatial light modulator G03B21/14

Abstract

A compact rear projection display which can be used in mobile devices is provided. The compact rear projection display includes a main body unit which generates image signals, an image providing unit which forms and projects an image according to the image signals received from the main body unit, a transparent light guide plate, and a screen disposed at a surface of the transparent light guide plate. The transparent light guide plate guides the image incident from the image providing unit to be displayed on the screen.

Claims

1. A rear projection display comprising:

a main body unit which generates image signals;

an image providing unit which forms and projects an image according to the image signals received from the main body unit; and

a transparent light guide plate, and a screen formed at a side thereof, wherein the image received from the image providing unit is guided to the screen by the transparent light guide plate.

2. The rear projection display of claim 1, wherein the transparent light guide plate comprises:

an image incidence surface through which the image projected by the image providing unit is incident;

a magnifying reflection surface, facing the image incidence surface and, which magnifies and reflects the image incident through the image incidence surface; and

a total reflection surface, facing the screen and parallel to the screen, which totally internally reflects the image reflected by the magnifying reflection surface toward the screen.

3. The rear projection display of claim 2, wherein the image incidence surface and the magnifying reflection surface face each other and are formed at one end of the transparent light guide plate.

4. The rear projection display of claim 3, wherein the image incidence surface is spherical or aspherical.

5. The rear projection display of claim 3, wherein the magnifying reflection surface is aspherical.

6. The rear projection display of claim 2, wherein the screen is formed directly on a surface of the transparent light guide plate or is attached to the surface of the transparent light guide plate with an adhesive member, and

the screen is one of a light diffusion plate, a total internal reflection (TIR) prism array, and a hologram pattern.

7. The rear projection display of claim 2, wherein the image providing unit comprises:

a light source;

a light modulator which modulates light emitted from the light source according to an image signal received from the main body unit to form an image;

an illumination optical system disposed between the light source and the light modulator, which uniformly irradiates the light emitted from the light source to the light modulator; and

a projection optical system which projects the image formed in the light modulator.

8. The rear projection display of claim 7, wherein the image providing unit further comprises a folding mirror which reflects the image projected by the projection optical system to the image incidence surface of the transparent light guide plate.

9. The rear projection display of claim 2, further comprising a connector, which rotatably connects the transparent light guide plate to the main body unit, thereby enabling a first position in which the transparent light guide plate is at a predetermined angle with respect to the main body unit, and a second position in which the transparent light guide plate is folded over a top surface of the main body unit.

10. The rear projection display of claim 9, wherein the main body unit is one of a cell phone, a personal digital assistant (PDA), a laptop computer, or a palmtop computer.

11. A rear projection display comprising:

a main body unit which generates image signals;

an image providing unit, which forms an image according to the image signals received from the main body unit; and

a flat transparent light guide plate,

wherein the transparent light guide plate comprises;

a screen disposed at a surface of the transparent light guide plate,

an image incidence surface, disposed at a first end of the transparent light guide plate, through which the image projected by the image providing unit is incident;

a first reflection surface, facing the incident surface at the first end of the transparent light guide plate, which reflects the image incident through the incidence surface;

a second reflection surface, facing the first reflecting surface and disposed at a second end of the transparent light guide plate, which reflects the image reflected by the first reflection surface; and

a mirror array, facing the screen, which reflects the image reflected by the second reflection surface to the screen, whereby the image is incident on the screen at a right angle thereto.

12. The rear projection display of claim 11, wherein the image incidence surface is spherical or aspherical.

13. The rear projection display of claim 11, wherein the first and second reflection surfaces are aspherical, the first reflection surface is convex, and the second reflection surface is concave.

14. The rear projection display of claim 11, wherein the mirror array facing the screen is one of a saw-like mirror array and a Fresnel lens type mirror array.

15. The rear projection display of claim 11, wherein

the screen is directly formed on a surface of the transparent light guide plate or is attached to the surface of the transparent light guide plate with an adhesive member, and

the screen is one of a light diffusion plate, a TIR prism array, a hologram pattern, a lenticular screen, and a micro lens screen.

16. The rear projection display of claim 11, wherein the image providing unit comprises:

a light source;

a light modulator which modulates light emitted from the light source according to image signals received from the main body unit to form an image;

an illumination optical system disposed between the light source and the light modulator, which uniformly irradiates the light emitted from the light source to the light modulator; and

a projection optical system which projects the image formed in the light modulator.

17. The rear projection display of claim 16, wherein the image providing unit further comprises a folding mirror which reflects the image projected from the projection optical system to the image incidence surface of the transparent light guide plate.

18. The rear projection display of claim 11, further comprising a connector, which rotatably connects the transparent light plate to the main body unit, thereby enabling a first position in which the transparent light guide plate is at a predetermined angle with respect to the main body unit, and a second position in which the transparent light guide plate is folded over a top surface of the main body unit.

19. The rear projection display of claim 18, wherein the main body unit is one of a cell phone, a PDA, a laptop computer, and a palmtop computer.