DLP optical system

• US 20070035701A1
• Filed: 08/10/2006
• Published: 02/15/2007
• Est. Priority Date: 08/12/2005
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Hyun
• Granted Patent: US 7,708,412 B2
• Time in Patent Office: Days
• US Class Current: 353/33
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time
• 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

Abstract

A DLP optical system is provided. The DLP optical system includes a lamp unit, an optical engine unit, a DMD, a prism, a projection lens, and a light-blocking part. The lamp unit provides light, and the optical engine unit is optically connected with the lamp unit, has optical parts for converting light incident from the lamp unit into an image signal therein, and includes a primary lens for transmitting the image signal. The DMD reflects the image signal transmitted from the primary lens, and the prism is formed closely to the DMD to adjust a path of light. The projection lens projects an on-beam of light from the prism that contributes to forming of an image onto a screen. The light-blocking part is provided on an incident side of the projection lens to transmit only the on-beam and shields light of a flat state region located between an on-beam and an off-beam.

Claims

1. A DLP (digital light processing) optical system comprising:

a lamp unit for providing light;

an optical engine unit optically connected with the lamp unit, having optical parts for converting light incident from the lamp unit into an image signal therein, and including a primary lens for transmitting the image signal;

a DMD (digital micro mirror device) for reflecting the image signal transmitted from the primary lens;

a prism formed closely to the DMD, for adjusting a path of light;

a projection lens for projecting an on-beam of light from the prism that contributes to image forming onto a screen; and

a light-blocking part provided on an incident side of the projection lens, for transmitting only the on-beam and shielding at least light of a flat state region located between the on-beam and an off-beam.

2. The DLP optical system according to claim 1, wherein the light-blocking part is formed in an engine cover covering at least the prism.

3. The DLP optical system according to claim 2, wherein the engine cover comprises a light absorption part for absorbing the off-beam.

4. The DLP optical system according to claim 2, wherein the light-blocking part is integrally formed with the engine cover.

5. The DLP optical system according to claim 2, wherein the engine cover is manufactured by molding a metal plate, and the light-blocking part is formed by bending part of the engine cover such that the light-block part is interposed between the prism and the projection lens.

6. The DLP optical system according to claim 1, wherein one side of the light-blocking part passes through a boundary point between a region of the on-beam and the flat state region.

7. The DLP optical system according to claim 6, wherein the light-blocking part has a triangular shape including the one side of the light-blocking part.

8. The DLP optical system according to claim 1, wherein the light-blocking part is formed on one side of the prism.

9. The DLP optical system according to claim 8, wherein the light-blocking part is formed on a light-emitting surface of the prism.

10. The DLP optical system according to claim 1, wherein the light-blocking part is formed in an interval part between a light-emitting part of the prism and a light-incident part of the projection lens.

11. The DLP optical system according to claim 1, wherein the light-emitting part is formed in an engine body receiving at least the prism.

12. A DLP optical system comprising:

a lamp unit for providing light;

an optical engine unit for converting light incident from the lamp unit into an image signal;

a DMD for selectively reflecting an image signal incident from the optical engine unit to an on-beam region;

a prism for adjusting a path of light incident from the DMD;

a projection lens for projecting light from the prism onto a screen;

an engine body for receiving at least the prism;

an engine cover provided on an upper side of the engine body, for protecting parts contained inside the engine cover; and

a light-blocking part provided in an interval part between a light-emitting part of the prism and a light-incident part of the projection lens, for shielding at least light of a flat state region to improve a contrast of an image.

13. The DLP optical system according to claim 12, wherein the light-blocking part is formed in the engine cover.

14. The DLP optical system according to claim 12, wherein the light-blocking part is formed in the engine body.

15. The DLP optical system according to claim 12, wherein the light-blocking part is formed on one side of the prism.

16. The DLP optical system according to claim 12, wherein the light-blocking part has one side crossing one corner portion of the on-beam region.

17. The DLP optical system according to claim 12, wherein the engine body is a single part and receives the optical engine unit and the prism.

18. A DLP optical system comprising:

a lamp unit;

an optical engine unit for converting light incident from the lamp unit into an image signal;

a DMD for selectively reflecting an image signal incident from the optical engine unit to an on-beam region, an off-beam region, a flat state region formed between the on-beam region and the off-beam region; and

a light-blocking part for blocking light of the flat state region among light reflected by the DMD.