Light shielding member for a micro-mirror projection system

• US 7,708,412 B2
• Filed: 08/10/2006
• Issued: 05/04/2010
• 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 Ki
• Primary Examiner(s): Epps; Georgia Y
• Assistant Examiner(s): Owens; Danell L
• Application Number:
  US11/501,884
• Publication Number:
  US 20070035701A1
• Time in Patent Office: 1,363 Days
• Field of Search: 353/30, 353/81, 353/87, 348/771, 348/842
• US Class Current: 353/81
• 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 micro-mirror projection system, comprising:

an optical engine unit including;

optical parts configured to convert incident light into an image signal,

a primary lens configured to transmit the image signal, and

an engine cover configured to cover the optical parts and the primary lens;

a DMD (digital micro mirror device) configured to reflect the image signal transmitted from the primary lens;

a prism formed closely to the DMD and configured to adjust a path of light;

a projection lens configured to project an on-beam of light from the prism toward a screen; and

a light-blocking part provided on an incident side of the projection lens and configured to shield at least light of a flat state region located between the on-beam and an off-beam reflected from the DMD, such that only the on-beam passes through the projection lens,

wherein the light-blocking part is formed by bending a part of the engine cover such that the light-blocking part is interposed between the prism and the projection lens.

2. The micro-mirror projection system according to claim 1, wherein the engine cover comprises a light absorption part configured to absorb the off-beam.

3. The micro-mirror projection system according to claim 1, wherein the engine cover is manufactured by processing a metal plate.

4. The micro-mirror projection 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.

5. The micro-mirror projection system according to claim 4, wherein the light-blocking part has a triangular shape.

6. The micro-mirror projection 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.

7. The micro-mirror projection system of claim 1, further comprising:

an engine body configured to receive the engine cover on an upper side thereof, and to accommodate at least the prism.

8. The micro-mirror projection system according to claim 7, wherein the engine body is a single part and receives the optical engine unit and the prism.

9. A micro-mirror projection system, comprising:

an optical engine unit including;

optical parts configured to convert incident light into an image signal therein,

a primary lens configured to transmit the image signal, and

an engine cover configured to cover the optical parts and the primary lens;

a DMD (digital micro mirror device) configured to reflect the image signal transmitted from the primary lens;

a prism formed closely to the DMD and configured to adjust a path of light;

a projection lens configured to project an on-beam of light from the prism towards a screen;

light absorption parts provided on an inner surface of at least the engine cover and configured to absorb an off-beam reflected from the DMD; and

a light-blocking part provided on an incident side of the projection lens, such that only the on-beam passes through the projection lens by shielding at least light of a flat state region which is located between the on-beam and the off-beam reflected from the DMD,

wherein the light-blocking part is integrally provided to the engine cover, the engine cover being formed by processing a metal plate.

10. The micro-mirror projection system according to claim 9, wherein one side of the light-blocking part passes through a boundary point between an on-beam region and the flat state region.

11. The micro-mirror projection system according to claim 10, wherein the light blocking part has a triangular shape.

12. A micro-mirror projection system, comprising:

an optical engine unit including;

optical parts configured to convert incident light into an image signal therein,

a primary lens configured to transmit the image signal,

an engine body on which the optical parts and the primary lens are mounted, and

an engine cover coupled to the engine body and configured to cover the optical parts and the primary lens;

a DMD (digital micro mirror device) configured to reflect the image signal transmitted from the primary lens;

a prism formed closely to the DMD and configured to adjust a path of light;

a projection lens configured to project an on-beam of light from the prism towards a screen;

light absorption parts provided on an inner surface of at least the engine cover and configured to absorb an off-beam reflected by the DMD; and

a light-blocking part integrally and vertically provided to the engine body at an incident side of the projection lens, such that only the on-beam passes through the projection lens by shielding at least light of a flat state region which is defined between the on-beam and the off-beam reflected from the DMD.