Projection apparatus using micromirror device

• US 8,238,013 B2
• Filed: 03/12/2009
• Issued: 08/07/2012
• Est. Priority Date: 11/01/2003
• Status: Expired due to Fees

• Current Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Ichikawa, Hirotoshi, Ishii, Fusao
• Primary Examiner(s): Jones, James
• Application Number:
  US12/381,586
• Publication Number:
  US 20090180171A1
• Time in Patent Office: 1,244 Days
• Field of Search: 359/237
• US Class Current: 359/237
• CPC Class Codes: G02B 27/09 Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for adapting the beam shape of a laser diode G02B19/0052; adapting the beam shape of an LED G02B19/0061; coupling into light guides using intermediate optical elements G02B6/4204; beam shaping specially adapted for lasers H01S3/005
• CPC Class Codes: G03B 21/008 using micromirror devices
• CPC Class Codes: G03B 21/2053 Intensity control of illuminating light controlled by video signal processing H04N5/74 or H04N9/31
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/2037 with specific control of sub-frames corresponding to the least significant bits
• CPC Class Codes: G09G 3/2077 by a combination of two or more gradation control methods
• CPC Class Codes: G09G 3/2081 with combination of amplitude modulation and time modulation space and time error diffusion G09G3/2066
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833
• CPC Class Codes: H04N 5/7458 the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]
• CPC Class Codes: H04N 9/3111 for displaying the colours sequentially, e.g. by using sequentially activated light sources sequential projection in colour photography G03B33/08
• CPC Class Codes: H04N 9/317 Convergence or focusing systems electronic adjustment of convergence H04N9/3185; convergence or focusing arrangements for cathode ray tubes H04N9/28; means for automatic focusing of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/53

Abstract

A projection apparatus comprising a micromirror device for reflecting and modulating a light emitted from a light source to project a display an image on a display screen. The projection apparatus further includes a projection optical system comprises an adjustable aperture for adjusting an aperture ratio to control an amount of output light reflected from the micromirror device to the image display screen.

Claims

1. A projection apparatus comprising a micromirror device for reflecting and modulating a light emitted from a light source to project an image on a display screen, the projection apparatus further comprising:

a projection optical system comprising an adjustable aperture for adjusting an aperture ratio to control an amount of output light reflected from said micromirror device to said image display screen;

a controller to control the micromirror device including a plurality of micromirrors to operate in a first state, a second state and a third state as an intermediate state oscillating between the first state and the second state;

said controller further controls and changes the aperture ratio of the projection optical system in a first control time period when at least one of the micromirrors is controlled to operate in the first state and/or a second control time period when at least one of the micromirrors is controlled to operate in the third state; and

the controller further controls and changes the aperture ratio of the projection optical system in one or more of a plurality of divisional control time periods by further dividing the first control time period and/or the second control time period.

2. The projection apparatus according to claim 1, further comprising:

said controller further controls the light source to project the illumination light with an unsymmetrical distribution for reflecting the incident light from the micromirrors with variations of cross sectional shapes for projecting an image light through said adjustable aperture with controllable light intensity.

3. The projection apparatus according to claim 2, further comprising:

said controller further controls the light source to project the illumination light with the unsymmetrical distribution for reflecting the incident light from the micromirrors with an elliptic cross sectional shapes.

4. The projection apparatus according to claim 1, further comprising:

said controller further controls the light source to project the illumination light with the unsymmetrical distribution for reflecting the incident light from the micromirrors with two partially overlapping elliptic cross sectional shapes.

5. The projection apparatus according to claim 1, wherein:

the controller further controls the adjustable aperture ratio of the projection optical system to correspond with a light intensity distribution uniformity in a numeral aperture (NA) of an illumination optical system condensing and orienting the illumination light emitted from the light source.

6. The projection apparatus according to claim 1, wherein:

the controller further controls the adjustable aperture ratio of the projection optical system is adjusted to correspond with a brightness data of a projected image embedded in an input signal.

7. The projection apparatus according to claim 1, further comprising:

the controller further controls the adjustable aperture ratio of the projection optical system to correspond with a brightness data of a project image embedded in an input signal for controlling an amount of light reflected from the micromirrors operating in the third state.

8. The projection apparatus according to claim 1, further comprising:

the controller further controls the adjustable aperture ratio of the projection optical system to correspond with a brightness data of a project image embedded in an input signal and adjusts a light intensity distribution in a numeral aperture (NA) of an illumination optical system condensing and orienting the illumination light emitted from the light source for controlling an amount of light reflected from the micromirrors operating in the third state.

9. The projection apparatus according to claim 1, further comprising:

the micromirrors having a natural oscillation cycle time represented by T where T is substantially in a range between 4 to 30 microseconds.

10. The projection apparatus according to claim 1, further comprising:

the micromirrors are controllable to deflect to a deflection angle approximately equal to or greater than 12 degrees relative to a non-deflectable state.

11. The projection apparatus according to claim 1, wherein:

the light source is an adjustable light source controllable to emit the illumination light with an adjustable light intensity.