Apparatus for and method of scaling a scanning angle and image projection apparatus incorporating the same

• US 20060007362A1
• Filed: 11/30/2004
• Published: 01/12/2006
• Est. Priority Date: 06/09/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Ju-Hyun, Cho, Jinwoo, Pavel, Serafirnovich, Ko, Youngchul, Ahn, Plisoo
• Granted Patent: US 7,701,412 B2
• Time in Patent Office: Days
• US Class Current: 348/744
• CPC Class Codes: G02B 17/008 Systems specially adapted to form image relays or chained systems
• 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: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161

Abstract

A scalable laser scanning angle apparatus and method of scaling a scanning angle using MEMS devices and elliptical mirrors includes disposing a first scanner at one focal point of an elliptical mirror and scanning the emitted light beam in a first direction at a first scanning angle toward a concave surface of the elliptical mirror such that the scanned light beam is directed toward the second focal point of the elliptical mirror, and scanning the light beam from the concave surface of the elliptical mirror in a second direction at a second scanning angle using a second scanner, wherein the second scanner outputs the light beam across a system scanning angle which corresponds to a combination of the first scanning angle and the second scanning angle. The scanning angle is scalable by repeatedly scanning the light beam at corresponding focal points of a predetermined number of elliptical mirrors, wherein the total scanning angle is scaled by a multiple of a number of times the light beam is scanned.

Claims

1. A laser scanning apparatus, comprising:

a plurality of elliptical mirrors each having first and second focal points disposed so that one of the first and second focal points of each elliptical mirror is shared with another elliptical mirror; and

a plurality of scanners disposed at the first and second focal points of each elliptical mirror and scanning an incident light beam, wherein each of the elliptical mirrors reflects the scanned light from one of the plurality of scanners at the first focal point to another of the plurality of scanners at the second focal point thereby increasing a system scanning angle.

2. The apparatus of claim 1, wherein the one of the plurality of scanners and another of the plurality of scanners scan the incident light beam in opposite directions.

3. The apparatus of claim 1, wherein the one of the plurality of scanners and the another of the plurality of scanners scan the incident light beam across an equal scan angle.

4. The apparatus of claim 1, wherein the plurality of scanners horizontally scan the incident light beam.

5. The apparatus of claim 1, wherein the plurality of scanners vertically scan the incident light beam.

6. The apparatus of claim 1, wherein the scanners are MEMS devices having a movable reflective surface.

7. A scalable laser scanning angle apparatus, comprising:

a light source emitting a light beam;

a first elliptical mirror having first and second focal points;

a first scanner disposed at the first focal point of the first elliptical mirror and scanning the emitted light beam in a first direction at a first scanning angle to a concave surface of the first elliptical mirror such that the scanned light beam passes through the second focal point of the first elliptical mirror; and

a second scanner disposed at the second focal point of the first elliptical mirror scanning the light beam from the concave surface of the first elliptical mirror in a second direction at a second scanning angle, wherein the second scanner outputs the light beam across a system scanning angle which corresponds to a combination of the first scanning angle and the second scanning angle.

8. The apparatus of claim 7, further comprising:

a second elliptical mirror having third and fourth focal points, wherein the second elliptical mirror is disposed such that the third focal point is the same as the second focal point of the first elliptical mirror; and

a third scanner disposed at the fourth focal point of the second elliptical mirror scanning the light beam reflected by the second elliptical mirror output from the second scanner.

9. The apparatus of claim 7, further comprising:

a plurality of elliptical mirrors disposed such that each of the elliptical mirrors shares at least one focal point with another elliptical mirror; and

a plurality of scaling scanners disposed at the foci of each of the elliptical mirrors, the plurality of scaling scanners scanning the light beam output from the second scanner, wherein each of the elliptical mirrors reflects the scanned light from one of the plurality of scaling scanners at one focal point to another of the plurality of scaling scanners at another focal point thereby increasing the system scanning angle.

10. The apparatus of claim 7, wherein the first scanning angle and the second scanning angle are equal.

11. The apparatus of claim 7, wherein the first scanner and the second scanner horizontally scan the light beam.

12. The apparatus of claim 7, wherein the first scanner and the second scanner vertically scan the light beam.

13. The apparatus of claim 7, further comprising:

a first lens disposed between the first scanner and the concave surface of the elliptical mirror directing the scanned light beam reflected from the first scanner to the concave surface of the elliptical mirror; and

a second lens disposed between the concave surface of the elliptical mirror and the second scanner directing the scanned light beam reflected from the concave surface of the elliptical mirror to the second scanner.

14. The apparatus of claim 7, wherein the scanners are MEMS devices having a movable reflective surface.

15. The apparatus of claim 7, wherein the light source emits a single beam.

16. A method of increasing a scanning angle of a scanner, comprising:

scanning an incident light beam at a first focal point of an elliptical mirror within a first scanning angle, the scanned light beam propagating toward the elliptical mirror and reflecting from the elliptical mirror to a second focal point of the elliptical mirror; and

scanning the reflected scanned incident light beam at the second focal point within a second scanning angle resulting in an output light beam within a total scanning angle, wherein the total scanning angle of the scanner is greater than the first scanning angle and the second scanning angle, respectively.

17. The method of claim 16, further comprising:

scaling the scanning angle by repeatedly scanning the light beam at corresponding focal points of a predetermined number of elliptical mirrors, wherein the total scanning angle is scaled by a multiple of a number of times the light beam is scanned.

18. A method of scanning a laser beam, comprising:

scanning a single incident light beam in a first direction to output a first scanned light beam within a first scanning angle; and

scanning the first scanned light beam in a second direction to output a second scanned light beam within a second scanning angle, wherein a system scanning angle corresponds to a combination of the first scanning angle and the second scanning angle.

19. The method of claim 18, further comprising:

reflecting the first scanned light through foci of an elliptical mirror before the scanning the first scanned light beam in the second direction.

20. The method of claim 18, wherein the first direction is opposite to the second direction.

21. The method of claim 18, wherein the first scanning angle is not equivalent to the second scanning angle.

22. A projection TV, comprising:

a modulated light source which emits a light beam;

an elliptical mirror having a first focal point and a second focal point;

a first scanner disposed at the first focal point of the elliptical mirror and scanning the emitted light beam in a first direction along a horizontal axis at a first scanning angle to a concave surface of the first elliptical mirror such that the scanned light beam passes through the second focal point of the first elliptical mirror;

a second scanner disposed at the second focal point of the elliptical mirror scanning the light beam from the concave surface of the elliptical mirror in a second direction along the horizontal axis at a second scanning angle, wherein the second scanner outputs the light beam across a system scanning angle which corresponds to a combination of the first scanning angle and the second scanning angle;

a galvanometer disposed to receive the light beam output from the second scanner and scan the received light beam in a direction substantially orthogonal to the first and second directions; and

a screen disposed to receive the light beam scanned by the galvanometer and the first and second scanners, wherein an image is formed on the screen of the projection TV.

23. The projection TV of claim 22, wherein the first and second scanners are MEMS devices.

24. The projection TV of claim 22, wherein the modulated light source is an RGB laser beam.

25. The projection TV of claim 22, further comprising:

a light source emitting a single laser beam;

a modulator which modulates the laser beam.

26. The projection TV of claim 22, further comprising:

scaling means for increasing the system scanning angle by a multiple of the first scanning angle.

27. The projection TV of claim 26, wherein the scaling means comprises

a plurality of scaling scanners disposed at the foci of scaling elliptical mirrors, such that the light output from the second scanner is repeatedly scanned and reflected from corresponding scaling elliptical mirrors from one scaling scanner to a next scaling scanner until the system scanning angle is scaled to a predetermined magnitude.

28. A projection TV, comprising:

a modulated light source which emits a light beam;

a predetermined number of scanners which reflect the light beam within a scanning angle, the scanners disposed at focal points of elliptical mirrors disposed to overlap such that each elliptical mirror shares at least one focal point with an adjacent elliptical mirror, such that the light beam reflected by one of the scanners is reflected by corresponding elliptical mirrors to another of the scanners until all of the scanners have reflected the light beam within a scanning angle and the light beam is emitted within a total scanning angle which is greater than the scanning angle of the individual scanners;

vertical scanning means for vertically scanning the light beam output from the predetermined number of scanners; and

a screen disposed to receive the light beam scanned by the vertical scanning means and the predetermined number of scanners, wherein an image is formed on the screen of the projection TV.

29. The projection TV of claim 28, wherein the vertical scanning means comprises a galvanometer.

30. The projection TV of claim 28, wherein the vertical scanning means comprises a MEMS device.

31. The projection TV of claim 28, further comprising:

optical means for controlling the light beam reflecting from the scanners and the elliptical mirrors.

32. The projection TV of claim 28, wherein the total scanning angle is a multiple of the number of the scanners and the scanning angle.

33. The projection TV of claim 28, wherein the light source emits a single light beam.

34. The projection TV of claim 28, wherein the scanners reflect the light beam within unequal scanning angles.

35. A projection TV, comprising:

a modulated light source which emits a single light beam;

a horizontal scanning unit, the horizontal scanning unit comprising;

multiple scanners which reflect the light beam within a varying range of a scanning angle and the scanners are driven in alternating positive and negative directions with respect to adjacent scanners to output the light beam within a horizontal scanning unit angle;

vertical scanning means for vertically scanning the light beam output from the horizontal scanning unit; and

a screen disposed to receive the light beam scanned by the vertical scanning means and the predetermined number of scanners, wherein an image is formed on the screen of the projection TV.

36. The projection TV of claim 35, further comprising:

elliptical mirrors disposed to overlap such that each elliptical mirror shares at least one focal point with an adjacent elliptical mirror to reflect light from a first focal point to a second focal point of the elliptical mirror, wherein the multiple scanners are disposed at the focal points of the elliptical mirrors such that the light beam reflected by one of the scanners is reflected by a corresponding elliptical mirror to another of the scanners until all of the scanners and the

elliptical mirrors have reflected the light beam within a scanning angle and the light beam is emitted within a total scanning angle which is greater than the scanning angle of the individual scanners.

37. The projection TV of claim 35, wherein the scanners each reflect the light beam within an equivalent range of the scanning angle.

38. The projection TV of claim 35, wherein the scanners are MEMS devices.

39. The projection TV of claim 35, wherein the horizontal scanning unit comprises a first and a second scanner and a single elliptical mirror.

40. The projection TV of claim 39, wherein the horizontal scanning angle is double the scanning angle.