Optical projection system and image display device having the same

• US 20050174545A1
• Filed: 01/14/2005
• Published: 08/11/2005
• Est. Priority Date: 02/09/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Jong-soo
• Granted Patent: US 7,370,977 B2
• Time in Patent Office: Days
• US Class Current: 353/69
• CPC Class Codes: G02B 17/08 Catadioptric systems used in non-imaging applications G02B19/00
• CPC Class Codes: G02B 17/0852 having a field corrector only
• CPC Class Codes: G03B 21/147 Optical correction of image distortions, e.g. keystone
• CPC Class Codes: G03B 21/28 Reflectors in projection beam in illumination beam G03B21/2066

Abstract

An optical projection system and an image display device having the same include a refraction part to create pincushion distortion in an image, and a reflection part to create barrel distortion in the pincushion-distorted image to compensate for the pincushion distortion and to project an enlarged image without distortion onto an image display surface. The refraction part includes a first cylinder symmetrical optic system having a first group of lenses including at least one aspheric lens, a second cylinder symmetrical optic system having a second group of lenses including at least one aspheric lens, a first planar reflecting optic system to bend the image that passes through the first cylinder symmetrical optic system by a first predetermined angle, and a second planar reflecting optic system to reflect the image that passes through the second cylinder symmetrical optic system to the reflection part. The reflection part includes a reflecting mirror inclinedly disposed at a predetermined angle and having an XY polynomial surface.

Claims

1. An optical projection system to enlarge an image in an image display device, the optical projection system comprising:

a series of lenses and reflectors to refract light beams of an image by converging and diverging the light beams of the image and by bending the light beams of the image, respectively; and

a polynomial reflector to receive the image from the series of lenses and reflectors, to compensate for distortion introduced by the series of lenses and reflectors, to enlarge the image, and to project the enlarged image toward a screen.

2. The optical projection system according to claim 1, wherein the series of lenses and reflectors distorts the image to have a pin cushion-like shape and the polynomial reflector expands and distorts the image having the pin cushion-like shape to have a barrel-like shape to compensate for the distortion introduced by the series of lenses and reflectors.

3. The optical projection system according to claim 2, wherein the series of lenses and reflectors includes at least one aspheric lens that prevents unwanted image distortion from being introduced to the light beams of the image.

4. The optical projection system according to claim 1, wherein the series of lenses comprises:

a first one or more lenses to converge the light beams of the image;

a second one or more lenses to diverge the light beams received from the first one or more lenses;

a first reflector to reflect the light beams of the image received from the second one or more lenses from a first direction to a second direction substantially perpendicular to the first direction;

a third one or more lenses to converge the light beams of the image received from the first reflector;

a fourth one or more lenses to diverge the light beams of the image received from the third one or more lenses; and

a second reflector to reflect the light beams of the image received from the fourth one or more lenses to the reflection part in a third direction opposite to the first direction.

5. The optical projection system according to claim 4, wherein the first and third one or more lenses each include at least one positive power lens and the second and the fourth one or more lenses each include at least one negative power lens.

6. An optical projection system to enlarge an image in an image display device, the optical projection system comprising:

a refraction part to introduce a first distortion to an image received from a lighting system; and

a reflection part to receive the image from the refraction part and to introduce a second distortion to the image that compensates for the first distortion while expanding the image.

7. The optical projection system according to claim 6, wherein the first and second distortions are desired distortions.

8. The optical projection system according to claim 6, wherein the refraction part comprises at least a first group of lenses to converge and then diverge light beams of the image.

9. The optical projection system according to claim 8, wherein the at the least first group of lenses includes at least one lens of positive power, at least one lens of negative power, and at least one aspheric lens.

10. The optical projection system according to claim 6, wherein the at least the first group of lenses further includes a second group of lenses perpendicular to the first group of lenses.

11. The optical projection system according to claim 10, wherein the refraction part further comprises

a first reflector to reflect the light beams of the image received from the first group of lenses to the second group of lenses, and

a second reflector to reflect the light beams of the image received from the second group of lenses to the reflection part.

12. The optical projection system according to claim 11, wherein the first group of lenses passes the light beams of the image horizontally from a front side of the image display device to a rear side of the image display device, the first reflector reflects the light beams of the image received from the first group of lenses vertically to the second group of lenses at a first predetermined angle, the second group of lenses passes the light-beams of the image vertically from a bottom side of the image display device to a top side of the image display device, the second reflector reflects the light beams of the image received from the second group of lenses to the reflection part at the front side of the image display device, and the reflection part reflects the light beams of the image toward a screen of the image display device.

13. An image display device, comprising:

a lighting system to provide light beams;

a micro display part to modulate the light beams provided by the lighting system to create an image;

a series of lenses and reflectors to introduce a first distortion by, respectively, refracting and bending the light beams of the image received from the micro display part;

a polynomial reflector to receive the light beams of the image from the series of lenses and reflectors and to introduce a second distortion that compensates for the first distortion while expanding the image; and

a screen to receive the expanded image substantially without distortion.

14. The image display device according to claim 13, further comprising:

a third planar reflector disposed parallel to the screen to reflect the expanded image from the polynomial reflector to the screen at a wide angle of view.

15. The image display device according to claim 14, wherein the wide angle of view corresponds to an angle at which the expanded image is incident on the third planar reflector.

16. The image display device according to claim 13, wherein the first distortion comprises a pincushion distortion and the second distortion comprises a barrel distortion.

17. The image display device according to claim 13, wherein the series of lenses and reflectors includes at least one aspheric lens that prevents a third distortion from being introduced to the light beams of the image.

18. A method of projecting an image onto a screen in an image display device with an optical projection system, the method comprising:

receiving an image from an image forming part;

creating pincushion distortion in the image in a refraction part; and

expanding the image while compensating for the pincushion distortion by creating a barrel distortion in the pincushion distorted image and projecting the expanded image toward the screen with a reflection part.

19. The method according to claim 18, further comprising:

generating light beams with a lighting system;

modulating the light beams to form the image with a micro display part; and

directing the light beams of the image to the optical projection system.

20. The method according to claim 18, wherein creating the pincushion distortion in the image in the refraction part comprises alternately converging, diverging, and reflecting, light beams of the image with lenses of positive power, lenses of negative power, and reflectors respectively.

21. The method according to claim 18, wherein creating the pincushion distortion in the image in the refraction part further comprises passing the light beams of the image through a horizontal group of lenses, reflecting the light beams of the image from the horizontal group of lenses to a vertical group of lenses, and reflecting the light beams of the image from the vertical group of lenses to the reflection part.

22. The method according to claim 18, wherein creating the pincushion distortion in the image in the refraction part further comprises compensating for unwanted distortion with an aspheric lens.

23. The method according to claim 18, wherein the reflection part is a polynomial surface.

24. The method according to claim 18, further comprising:

receiving the expanded image from the reflection part and reflecting the expanded image onto the screen using a third reflector parallel to the screen.