Projection apparatus using variable light source

• US 8,282,221 B2
• Filed: 08/14/2008
• Issued: 10/09/2012
• Est. Priority Date: 11/01/2003
• Status: Active Grant

• Current Assignee: Ignite USA (Ignite), Olympus Corporation
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Arai, Kazuma, Ishii, Fusao
• Primary Examiner(s): Dowling, William C
• Application Number:
  US12/228,728
• Publication Number:
  US 20090051712A1
• Time in Patent Office: 1,517 Days
• Field of Search: 353/85, 353/121, 353/122, 348/742, 348/743, 348/771
• US Class Current: 353/85
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0237 Switching ON and OFF the backlight within one frame
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• 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 3/2029 the sub-frames having non-binary weights
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• 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 9/3123 using pulse width modulation
• CPC Class Codes: H04N 9/3155 for controlling the light source light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406

Abstract

A projection apparatus using a spatial light modulator (SLM), comprising the following: at least one variable light source, at least one spatial light modulator for modulating the illumination light emitted from the variable light source in accordance with the modulation state of arrayed pixel elements, a variable light source controller for controlling modulation of the variable light source, and a spatial light modulator controller for controlling modulation of each pixel element of the spatial light modulator, wherein the variable light source controller controls the variable light source so as to reduce the period in which the modulation states of the pixel element are in transition on a display image.

Claims

1. A projection apparatus using a spatial light modulator (SLM), comprising:

a variable light source;

at least one spatial light modulator for modulating an illumination light emitted from the variable light source in accordance with the modulation state of arrayed pixel elements;

a variable light source controller for controlling modulation of the variable light source; and

a spatial light modulator controller for controlling modulation of each pixel element of the spatial light modulator, wherein the variable light source controller controls the variable light source for emitting the illumination light as pulse emissions in a pulse width less than or equal to 12.2 microseconds, wherein the variable light source is controlled to operate at a normal state in at least 50% of the emission pulses for emitting the illumination light at a predefined normal emission intensity.

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

the variable light source controller further controls the variable light to operate in a non-emission state during a period when at least one of the pixel elements is in operated in a transition state.

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

the variable light source controller changes the emission states of the variable light source during a period when the pixel element is maintained at a fixed modulation state to correct a loss in brightness due to the pixel element is previously controlled to operate in transition state.

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

the variable light source controller changes the emission intensities of the variable light source during a period when the pixel element is maintained at a fixed modulation state.

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

the variable light source controller controls the variable light source to emit the illumination light to superimpose a predetermined emission pulse on the illumination light projected from variable light source during a period when the pixel element is maintained at a fixed modulation state.

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

the variable light source controller controls the variable light source during a period when the pixel element is operated in a transition state for correcting a loss in brightness, the loss occurring during a previously period when the pixel element is operated in a transition state.

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

the variable light source is controlled by the variable light source controller for emitting the illumination light as the pulse emission having a pulse width smaller than or equal to a period of controlling the pixel element to operate in transition state.

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

the variable light source is controlled by the variable light source controller for emitting the illumination light as the pulse emission having a pulse width smaller than or equal to a period of controlling the pixel element to operate in a transition state.

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

the pixel element further comprises a micromirror and at least one electrode for controlling the micromirror, and

the spatial light modulator controller controls and deflects the micromirror for reflecting the illumination light emitted from the variable light source in accordance with a deflection state the micromirror.

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

the spatial light modulator controller converts at least a part of an input image signal corresponding to the pixel element into non-binary data and controls the pixel element in accordance with the non-binary data.

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

the pixel element further comprises a micromirror and at least one electrode for controlling the micromirror, and

the spatial light modulator controller controls and deflects the micromirror for reflecting the illumination light emitted from the variable light source in accordance with a deflection state the micromirror.

13. The projection apparatus according to claim 12, wherein:

the micromirror is controlled to deflect between a minimum and maximum deflection angle having an angular range no larger than 16 degrees.

10. A projection apparatus using a spatial light modulator (SLM), comprising:

a variable light source;

at least one spatial light modulator for modulating an illumination light emitted from the variable light source in accordance with the modulation state of arrayed pixel elements;

a variable light source controller for controlling modulation of the variable light source; and

the variable light source is controlled by the variable light source controller for emitting the illumination light as pulse emissions in a pulse width no more than 4.07 microseconds wherein the variable light source is controlled to operate at a normal state in at least 50% of the emission pulses for emitting the illumination light at a predefined normal emission intensity.

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

the variable light source controller further controls the variable light to operate in a non-emission state during a period when at least one of the pixel elements is in operated in a transition state.

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

the variable light source controller changes the emission states of the variable light source during a period when the pixel element is maintained at a fixed modulation state to correct a loss in brightness due to the pixel element is previously controlled to operate in transition state.

16. The projection apparatus according to claim 15, wherein:

the variable light source controller changes the emission intensities of the variable light source during a period when the pixel element is maintained at a fixed modulation state.

17. The projection apparatus according to claim 15, wherein:

the variable light source controller controls the variable light source to emit the illumination light to superimpose a predetermined emission pulse on the illumination light projected from variable light source during a period when the pixel element is maintained at a fixed modulation state.

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

the variable light source controller controls the variable light source during a period when the pixel element is operated in a transition state for correcting a loss in brightness, the loss occurring during a previously period-when the pixel element is operated in a transition state.

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

the spatial light modulator controller converts at least a part of an input image signal corresponding to the pixel element into non-binary data and controls the pixel element in accordance with the non-binary data.