Projector and method for controlling projector

• US 9,154,754 B2
• Filed: 07/18/2013
• Issued: 10/06/2015
• Est. Priority Date: 07/23/2012
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Narimatsu, Shuji, Iisaka, Hidehito
• Primary Examiner(s): CHOWDHURY, SULTAN U.
• Application Number:
  US13/945,058
• Publication Number:
  US 20140022514A1
• Time in Patent Office: 810 Days
• Field of Search: 353/31, 353/37, 353/85, 353/94, 353/121, 345204-207, 362/20, 362157-208, 362/276, 348743-747, 348/E9.027
• US Class Current: 1/1
• CPC Class Codes: G03B 21/14 Details
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 33/06 by additive-colour projection apparatus
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 3/36 using liquid crystals
• 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 9/3155 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
• CPC Class Codes: H04N 9/3197 using light modulating optical valves

Abstract

A projector including a first light source, a second light source that emits light having a color different from the first light source, a light modulator that modulates the light emitted from each of the first and the second light sources, and a controller that controls a first operation state in which the first and the second light sources are driven based on time division driving to perform image display and a second operation state in which the first and the second light sources are driven based on time division driving to perform illumination, wherein in the second operation state, a switching frequency at which the first and the second light sources are switched from one to the other is higher than a switching frequency at which the first and the second light sources are switched from one to the other in the first operation state.

Claims

1. A projector comprising:

a first light source that is a solid-state light source;

a second light source that is a solid-state light source and emits light having a color different from the color of light emitted from the first light source;

a light modulator that modulates the light emitted from each of the first light source and the second light source; and

a controller that controls a first operation state in which the first light source and the second light source are driven based on time division driving to perform image display and a second operation state in which the first light source and the second light source are driven based on time division driving to perform illumination,

wherein in the second operation state, a switching frequency at which the first light source and the second light source are switched from one to the other in the time division drive operation is higher than the switching frequency at which the first light source and the second light source are switched from one to the other in the first operation state.

2. The projector according to claim 1,

wherein the controller includes a common drive circuit that controls the first light source and the second light source together.

3. The projector according to claim 1,

wherein in the second operation state, the action of the light modulator is so locked that the light modulator performs white display.

4. The projector according to claim 3,

wherein the light modulator is a normally white liquid crystal light valve.

5. The projector according to claim 1,

wherein the switching frequency at which the first light source and the second light source are switched from one to the other in the second operation state is set at an integer multiple of the switching frequency at which the first light source and the second light source are switched from one to the other in the first operation state.

7. The projector according to claim 1,

wherein a single light modulator modulates the light emitted from both the first and second light sources.

8. The projector according to claim 1,

wherein in the second operation state, the light modulator is driven at a constant grayscale other than a black display, whereas in the first operation state the light modulator is driven at multiple different grayscales while the first and second light sources are driven.

6. A method for controlling a projector including:

a first light source that is a solid-state light source,

a second light source that is a solid-state light source and emits light having a color different from the color of light emitted from the first light source,

a light modulator that modulates the light emitted from each of the first light source and the second light source, and

a controller that controls a first operation state in which the first light source and the second light source are driven based on time division driving to perform image display and a second operation state in which the first light source and the second light source are driven based on time division driving to perform illumination,

wherein in the second operation state, a switching frequency at which the first light source and the second light source are switched from one to the other in the time division drive operation is higher than the switching frequency at which the first light source and the second light source are switched from one to the other in the first operation state.

9. The method according to claim 6,

wherein a single light modulator modulates the light emitted from both the first and second light sources.

10. The method according to claim 6,

wherein in the second operation state, the light modulator is driven at a constant grayscale other than a black display, whereas in the first operation state the light modulator is driven at multiple different grayscales while the first and second light sources are driven.