Light source device, video projector and video projection method

• US 8,403,492 B2
• Filed: 06/28/2010
• Issued: 03/26/2013
• Est. Priority Date: 06/30/2009
• Status: Active Grant

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Shibasaki, Mamoru
• Primary Examiner(s): Epps, Georgia Y
• Assistant Examiner(s): CHOWDHURY, SULTAN U.
• Application Number:
  US12/824,532
• Publication Number:
  US 20100328554A1
• Time in Patent Office: 1,002 Days
• Field of Search: 353/97, 353/20, 353/31, 353/84, 353/98, 353/99, 353/102, 353/34, 353/37, 362/231, 362/293, 362/555, 362/583, 362/284, 362/324, 359/503, 359/640, 359/126, 349/5, 349/7, 349/8, 349/9, 348/742, 348/743, 348/744, 348/745
• US Class Current: 353/31
• CPC Class Codes: G03B 21/204 using secondary light emission, e.g. luminescence or fluorescence using different colours G03B33/00; if related to video signals H04N9/3197
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129

Abstract

A light source device includes: a first light source configured to emit a first source light in a first wavelength range; a source light generator configured to generate, from the first light, a color-varying source light having time varying color; a second light source configured to emit a second source light in a second wavelength range that is different from the first wavelength range; and a light source controller configured to control driving timing for turning on and off each of the first light source and the second light source so as to cyclically select one of the color-varying source light and the second source light to be output as an output source light.

Claims

1. A light source device comprising:

a first light source configured to emit a first source light in a first wavelength range;

a source light modulator comprising a first face, a second face through which the first source light enters the source light modulator, a first area, and a second area, wherein the first area is configured to have the first source light having entered through the second face pass therethrough, and to output a transmitted light from the first face, and wherein the second area comprises a phosphor layer and is configured to reflect a reflected light excited by fluorescence excitation in a wavelength different from the first wavelength range by being irradiated by the first source light having entered through the second face, and to output the reflected light from the second face;

a second light source configured to emit a second source light in a second wavelength range that is different from the first wavelength range;

an integrator configured to uniformalize luminescence distribution of light input through a light incidence face thereof; and

a light guiding optical system configured to guide the transmitted light, the reflected light, and the second source light to the light incidence face of the integrator,

wherein the light guiding optical system comprises;

a first dichroic mirror disposed between the first light source and the source light modulator, the first dichroic mirror being configured to allow the first source light and the second source light to pass therethrough and to reflect the reflected light; and

a second dichroic mirror configured to reflect the second source light and the reflected light and to allow the transmitted light to pass through.

2. The light source device according to claim 1, wherein the first source light and the transmitted light are a blue light.

3. The light source device according to claim 1,

wherein the phosphor layer emits a green light as the reflected light when the first source light is irradiated and excited, and

wherein the second light source is configured to emit a red light as the second source light.

4. The light source device according to claim 1,

wherein the light guiding optical system is configured to share an optical component for the second source light that passed through the first dichroic mirror and the reflected light that is reflected by the first dichroic mirror, and

wherein the optical component comprises a collector lens configured to collect the second source light, the transmitted light, and the reflected light to the light incidence face of the integrator.

5. The light source device according to claim 4, wherein the light guiding optical system is configured such that:

a total magnification of optical components disposed in an optical path of the second source light to the integrator is set to be a magnification for fitting a light emitting area of the second light source to the light incidence face of the integrator; and

a total magnification of optical components disposed in an optical path of the reflected light to the integrator is set to be a magnification for fitting an irradiation area of the first source light on the source light modulator to the light incidence face of the integrator.

6. The light source device according to claim 1,

wherein the light guiding optical system further comprises:

a first lens disposed near the first face of the source light modulator, the first lens being configured to collect the transmitted light output from the first face; and

a second lens disposed near the second face of the source light modulator, the second lens being configured to collect the reflected light output from the second face.

7. The light source device according to claim 6, wherein the first lens is configured to have a size smaller than a size of the second lens.

8. The light source device according to claim 6, wherein the second lens comprises a plurality of lenses.

9. The light source device according to claim 1, further comprising:

a motor configured to rotate the source light modulator,

wherein the motor is attached to the source light modulator on a side of the first face of the source light modulator.

10. A video projector comprising:

a light source device according to claim 1;

a video interface configured to receive a video signal; and

a projector unit configured to generate, from output source light output from the light source device, a color photo image in accordance with the video signal, and to project the color photo image.

11. A light source device comprising:

a first light source configured to emit a first source light in a first wavelength range;

a source light generator configured to generate a source light having time varying color using the first source light;

a second light source configured to emit a second source light in a second wavelength range that is different from the first wavelength range;

a light source controller configured to control the first light source and the second light source to cyclically select one of the source light having time varying color and the second source light to be output as an output source light,

wherein the first light source emits a laser light having a blue wavelength range as the first source light,

wherein the source light generator comprises a color wheel having a green fluorescence reflection portion and a diffusion transmission portion which are arranged in a circumferential direction of the color wheel, the green fluorescence reflection portion comprising a phosphor that emits light having a green wavelength range using the laser light as an excitation light, the diffusion transmission portion diffusing and transmitting the laser light,

wherein the second light source comprises a light emitting diode configured to emit light having a red wavelength range as the second source light, and

wherein the light source device further comprises;

a first dichroic mirror configured to (i) transmit the laser light having the blue wavelength range that is emitted by the first light source, (ii) reflect the light having the green wavelength range that is emitted by the phosphor, and (iii) transmit the light having the red wavelength range that is emitted by the second light source; and

a second dichroic mirror configured to (i) transmit the laser light that is transmitted through the diffusion transmission portion of the color wheel, (ii) reflect the light having the green wavelength range that is reflected by the first dichroic mirror, and (iii) reflect the light having the red wavelength range that is transmitted through the first dichroic mirror.

12. A video projector comprising:

a light source device according to claim 11;

a video interface configured to receive a video signal; and

a projector unit configured to generate, from the output source light, a color photo image in accordance with the video signal and project the color photo image.

13. The video projector according to claim 12,

wherein the light source controller is configured to control a driving timing for turning on and off each of the first light source and the second light source to partially overlap a color-varying source light of at least one color from the source light having time varying color and the second source light so as to generate the output source light, having a mixed color of the color-varying source light and the second source light, and

wherein the projector unit is configured to generate and project the color photo image in accordance with the color of the output source light in synchronization with a timing at which the output source light is turned on.

14. The video projector according to claim 13, wherein the light source controller is configured to control the driving timing so as to temporally separate a first time period during which the second source light is exclusively emitted and a second time period during which both the first source light and the second source light are emitted.

15. The video projector according to claim 13, wherein the light source controller is configured to control the driving timing to overlap the color-varying source light and the second source light in synchronization with a timing at which the color of the color-varying source light is changed so as to generate the output source light having the mixed color.