Gamma correction for adjustable light source

• US 7,826,126 B2
• Filed: 09/05/2008
• Issued: 11/02/2010
• Est. Priority Date: 11/01/2003
• Status: Expired due to Fees

• Current Assignee: Ignite USA (Ignite)
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Shiral, Akira, Nishino, Hirokazu, Ishii, Fusao, Horikawa, Yoshiaki
• Primary Examiner(s): Choi; William C
• Application Number:
  US12/231,962
• Publication Number:
  US 20100128225A1
• Time in Patent Office: 788 Days
• Field of Search: 359/198.1, 359/221.2, 359/290, 359/291, 359/292
• US Class Current: 359/290
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 3/2011 by amplitude modulation
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833

Abstract

The present invention provides a projection apparatus comprising: a light source, a light source control unit for controlling the output of the light source; at least one spatial light modulator for modulating the illumination light from the light source by multiple pixel elements; and an optical system for projecting, onto a screen, the illumination light deflected by the spatial light modulator, wherein: the light source control unit 1) modulates the output of the illumination light from the light source during a modulation period of the spatial light modulator, and 2) non-linearly controls the gray scale of an image projected onto the screen.

Claims

1. A projection apparatus, comprising:

a light source;

a light source control unit for controlling output of the light source;

at least one spatial light modulator for modulating illumination light from the light source by multiple pixel elements; and

an optical system for projecting, onto a screen, the illumination light deflected by the spatial light modulator, wherein the light source control unit modulates the output of the illumination light from the light source during a modulation period of the spatial light modulator, and non-linearly controls gray scale of an image projected onto the screen.

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

the light source control unit modulates output of the illumination light by making the intensity of the illumination light variable.

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

the light source control unit modulates output of the illumination light by making the emission interval cycle of the pulse emission of the light source variable.

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

the light source control unit modulates output of the illumination light by making the emission interval cycle of that pulse emission of the light source constant and by making the emission pulse time variable.

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

the light source control unit modulates output of the illumination light by making the emission interval cycle and the emission pulse time of pulse emission of the light source variable.

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

the light source control unit modulates output of the illumination light by making at least one of the emission interval cycles, the emission pulse time, or the emission pulse intensity of pulse emission of the light source variable.

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

the light source control unit modulates output of the illumination light by input image data.

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

the light source control unit increases the maximum brightness of the light source by making the emission interval cycle of the pulse emission variable within a particular time of one frame, when output of the illumination light is modulated by making the emission interval cycle of the pulse emission of the light source variable.

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

the spatial light modulator comprises a micromirror device in which multiple mirror elements for deflecting light from the light source are arranged.

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

the light source is a light emitting diode (LED) or a laser device.