Optical scanner, laser image projector adopting the optical scanner, and method of driving the laser image projector

• US 6,636,339 B2
• Filed: 05/04/2001
• Issued: 10/21/2003
• Est. Priority Date: 11/03/2000
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Jin-ho
• Primary Examiner(s): Phan, James
• Application Number:
  US09/848,332
• Publication Number:
  US 20020054415A1
• Time in Patent Office: 900 Days
• Field of Search: 359/196-202, 359/212-221, 359/223-226, 359/900, 348/754, 348/756, 348/757, 347/232, 347/239, 347/243
• US Class Current: 359/201.2
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• 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

An optical scanner, a laser image projector using the optical scanner, and a method of driving the laser image projector are provided. The optical scanner includes: a base substrate; a plurality of parallel stationary comb electrodes arranged on the base substrate extending upwards at right angle; a stage having a mirror side at its top side, being separated a predetermined distance above the base substrate; a plurality of parallel driving comb electrodes arranged on the bottom of the stage extending at right angle interdigitated with the stationary comb electrodes; torsion bars formed at both side edges of the stage with a predetermined length to support such that the stage pivots; and supports for supporting the torsion bars such that the stage is suspended above the base substrate. The laser image projector includes the optical scanners using micro mirrors, instead of a horizontal scanning rotating polygonal mirror and a vertical scanning galvanometer, and is driven such that a single horizontal left-to-right scanning is followed by another right-to-left horizontal scanning without redundant flyback interval. Therefore, comparing with a driving method which needs quick returning 5-10 times faster than horizontal scanning rate, the driving speed can be markedly reduced, so that high-speed driving limitations of optical scanner for high-resolution image display can be overcome.

Claims

1. A laser image projector comprising:

a light source for emitting a white light beam;

a beam separating unit for separating the white light beam into three main monochromic beams;

an acousto-optic modulating unit for modulating the three main monochromic beams based on color signals;

a beam combining unit for combining the monochromic beams modulated by the acousto-optic modulating unit into a single combined beam; and

a laser scanning unit for scanning the single beam combined with the monochromic beams to form an image,

wherein the laser scanning unit comprises a horizontal scanning mirror for horizontally scanning the single combined beam, and a vertical scanning mirror for vertically scanning a beam incident from the horizontal scanning mirror and,

wherein the laser scanning unit further comprises a memory for temporarily storing an image information horizontally scanned from the right to the left.

2. A laser image projector comprising:

a light source for emitting a white light beam;

a beam separating unit for separating the white light beam into three main monochromic beams;

an acousto-optic modulating unit for modulating the three main monochromic beams based on color signals;

a beam combining unit for combining the monochromic beams modulated by the acousto-optic modulating unit into single combined beam; and

a laser scanning unit for scanning the single beam combined with the monochromic beams to form an image,

wherein the laser scanning unit comprises a first optical scanner having the horizontal scanning mirror and a second optical scanner having the vertical scanning mirror,

wherein each of the first and second optical scanners comprises;

a base substrate;

a plurality of parallel stationary comb electrodes arranged on the base substrate extending upwards at right angle;

a stage having a mirror side at its top side, being separated a predetermined distance above the base substrate;

a plurality of parallel driving comb electrodes arranged on the bottom of the stage extending at right angle interdigitated with the stationary comb electrodes;

torsion bars formed at both side edges of the stage with a predetermined length to support such that the stage pivots; and

supports for supporting the torsion bars such that the stage is suspended above the base substrate.

4. The laser image projector of any of claims 2 and 3, wherein the laser scanning unit further comprises a memory for temporarily storing an image information horizontally scanned from the right to the left.

5. The laser image projector of claim 4, wherein the three monochromic beams have a wavelength of 450-470 nm, a wavelength of 530-535 nm, and a wavelength of 630-650 nm, respectively.

6. The laser image projector of claim 5, wherein the three monochromic beams have a wavelength of 457 nm, a wavelength of 532 nm, and a wavelength of 635 nm, respectively.

7. The laser image projector of any of claims 2 and 3, wherein the three monochromic beams have a wavelength of 450-470 nm, a wavelength of 530-535 nm, and a wavelength of 630-650 nm, respectively.

3. A laser image projector comprising:

a light source for emitting a white light beam;

a beam separating unit for separating the white light beam into three main monochromic beams;

an acousto-optic modulating unit for modulating the three main monochromic beams based on color signals;

a beam combining unit for combing the monochromic beams modulated by the acousto-optic modulating unit into a single combined beam; and

a laser scanning unit for scanning the single beam combined with the monochromic beams to form an image,

wherein the laser scanning unit comprises a horizontal scanning mirror for horizontally scanning the single combined beam, and a vertical scanning mirror for vertically scanning a beam incident from the horizontal scanning mirror, and

wherein the horizontal scanning mirror horizontally scans the single beam combined with the monochromic beams alternately from the left to the right and from the right to the left.

8. A laser image projector comprising:

a light source for emitting a white light beam;

a beam separating unit for separating the white light beam into three main monochromic beams;

an acousto-optic modulating unit for modulating the three main monochromic beams based on color signals;

a beam combining unit for combing the monoebromic beams modulated by the acousto-optic modulating unit into a single combined beam; and

a laser scanning unit for scanning the single beam combined with the monochromic beams to form an image,

wherein the laser scanning unit comprises a horizontal scanning mirror for horizontally scanning the single combined beam, and a vertical scanning mirror for vertically scanning a beam incident from the horizontal scanning mirror, and

wherein the three monochromic beams have a wavelength of 457 nm, a wavelength of 532 nm, and a wavelength of 635 nm, respectively.

9. A method of driving a laser image projector including:

a light source for emitting a white light beam;

a beam separating unit for separating the white light beam into three main monochromic beams;

an acousto-optic modulating unit for modulating the three main monochromic beams based on color signals;

a beam combining unit for combining the monochromic beams modulated by the acousto-optic modulating unit into a single combined beam; and

a laser scanning unit for scanning the single beam combined with the monochromic beams to form an image, the method comprising alternately horizontally scanning the single beam combined with the modulated monochromic beams from the left to the right and from the right to the left.

10. The method of claim 9, wherein an image signal scanned in opposite directions to an input image signal in the alternate horizontal scanning from the left to the right and from the right to the left is temporarily stored in a memory and is output in the reverse order such that a correct image can be displayed.