Projector

Patent metadata

Field	Value
Publication number	US-9798224-B2
Application number	US-201614997589-A
Country	US
Kind code	B2
Filing date	Jan 18, 2016
Priority date	Jan 23, 2015
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A projector includes a light source, a digital micro-mirror device (DMD), a first prism, a second prism, and a lens. The light source is used for emitting an incident light. The DMD is used for receiving and reflecting the incident light as an image light. The first prism is disposed between the light source and the DMD. The second prism is disposed between the first prism and the DMD. The first prism includes a first plane, a second plane, and an intermediate portion. The intermediate portion adjoins the first plane and includes a reflecting portion. The incident light from the second plane is reflected by the reflecting portion and then passes through the second plane. The second prism includes a fourth plane, a fifth plane, and a sixth plane. When the DMD is operated in an on-state, the image light passes through the sixth plane.

First claim

What is claimed is:

1. A projector comprising:
a light source for emitting an incident light;
a digital micro-mirror device having a first side in a first direction and a second side in a second direction perpendicular to the first direction, wherein the first side is longer than the second side, the digital micro-mirror device receives and reflects the incident light as an image light;
a first prism disposed between the light source and the digital micro-mirror device for receiving and transmitting the incident light, the first prism comprising:
a first plane faced to the light source for receiving the incident light;
a second plane adjoined to the first plane; and
an intermediate portion adjoined to the first plane and comprising a reflecting portion and a third plane, wherein the reflecting portion is a plano-convex lens, and the reflecting portion comprises:
a seventh plane adjoined to the third plane; and
an eighth surface opposite to the seventh plane and comprising a mirror coating for reflecting the incident light;

wherein the incident light is transmitted to the reflecting portion and is reflected by the reflecting portion, then, the incident light passes through the second plane;

a second prism disposed between the first prism and the digital micro-mirror device for receiving and transmitting the incident light and the image light, the second prism comprising:
a fourth plane paralleled to the second plane for receiving the incident light;
a fifth plane adjoined to the fourth plane and paralleled to the digital micro-mirror device, wherein the fifth plane comprises an adjoining side paralleled to the first side; and
a sixth plane adjoined to the fourth plane and the fifth plane; and

a lens faced to the sixth plane for receiving and projecting the image light;
wherein the incident light is transmitted to the digital micro-mirror device through the fourth plane and the fifth plane, the image light passes through the fifth plane and is reflected by the fourth plane, when the digital micro-mirror device operates in an ON-state, the image light passes through the sixth plane.

2. The projector of claim 1 , wherein the digital micro-mirror device is a two-axis tilting digital micro-mirror device.

3. The projector of claim 1 , wherein the fifth plane is perpendicular to the sixth plane.

4. The projector of claim 1 , wherein the sixth plane is parallel to the first plane.

5. The projector of claim 1 , further comprising:
a first angle located between the first plane and the second plane;
a second angle located between the second plane and the third plane; and
a third angle located between the intermediate portion and the first plane;
wherein the third angle is greater than the first angle and the second angle.

6. The projector of claim 1 , wherein an angle of incidence of the incident light transmitted to the first plane is a right angle.

7. The projector of claim 1 , wherein a space exists between the second plane and the fourth plane.

8. The projector of claim 1 , wherein a space exists between the digital micro-mirror device and the fifth plane.

9. The projector of claim 1 , further comprising:
a lens module disposed between the light source and the first plane.

10. The projector of claim 9 , wherein an equivalent focal length of the lens module is 80 mm-82 mm.

11. The projector of claim 9 , further comprising:
a light pipe disposed between the light source and the lens module for receiving and transmitting the incident light.

12. The projector of claim 11 , wherein the light pipe is a wedge-shaped light pipe.

13. The projector of claim 11 , wherein the light pipe, the lens module, the prisms, and the digital micro-mirror device form an optical mechanical system with the magnification of the optical mechanical system being 1.7˜1.9.

Assignees

• Qisda Optronics (Suzhou) Co Ltd
• Qisda Corp

Inventors

• Chien Chih-Shiung

Classifications

• G03B21/008

  using micromirror devices · CPC title

• G02B17/08

  Catadioptric systems {(used in non-imaging applications G02B19/00)} · CPC title

• G03B21/2066 Primary

  Reflectors in illumination beam (in projection beam G03B21/28) · CPC title

• G03B21/28

  Reflectors in projection beam {(in illumination beam G03B21/2066)} · CPC title

• G03B21/208

  Homogenising, shaping of the illumination light · CPC title