MULTI-WAVELENGTH LIGHT SOURCE DEVICE

• US 20090122531A1
• Filed: 08/29/2008
• Published: 05/14/2009
• Est. Priority Date: 11/13/2007
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: SUMIYAMA, Fumika, KAMIJIMA, Shunji
• Granted Patent: US 7,780,311 B2
• Time in Patent Office: Days
• US Class Current: 362/231
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G02B 5/1828 having means for producing variable diffraction controlling the direction of light by means of one or more diffracting elements G02B26/0808; acousto-optical elements G02F1/11, G02F1/33; electro- or magneto-optical diffraction G02F1/292, G02F1/2955
• CPC Class Codes: G02B 5/203 having holographic or diffractive elements diffraction gratings per se G02B5/18; holographic elements per se G02B5/32; generating the spectrum using diffraction elements G01J3/18
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129
• CPC Class Codes: H04N 9/3164 using multiple light sources

Abstract

A multi-wavelength light source device includes three light source devices. The light source device includes a plurality of light emitting elements, and a dispersing section making wavelengths of light beams emitted from the respective light emitting elements different from each other, a spectral line width of the emitted light beam in each of the light source devices is equal to or greater than 0.2 nm, a wavelength of the red light beam in the light source device for emitting the red light beam is greater than 612 nm, a wavelength of the green light beam in the light source device for emitting the green light beam is greater than 525 nm and smaller than 538 nm, and a wavelength of the blue light beam in the light source device for emitting the blue light beam is greater than 465 nm and smaller than 468 nm.

Claims

1. A multi-wavelength light source device comprising:

three light source devices for respectively emitting a red light beam, a green light beam, and a blue light beam,

wherein the light source device includes

a plurality of light emitting elements, and

a dispersing section making wavelengths of light beams emitted from the respective light emitting elements different from each other,

a spectral line width of the emitted light beam in each of the light source devices is equal to or greater than 0.2 nm,

a wavelength of the red light beam in the light source device for emitting the red light beam is greater than 612 nm,

a wavelength of the green light beam in the light source device for emitting the green light beam is greater than 525 nm and smaller than 538 nm, and

a wavelength of the blue light beam in the light source device for emitting the blue light beam is greater than 465 nm and smaller than 468 nm.

2. The multi-wavelength light source device according to claim 1,

wherein the spectral line width of the emitted light beam in each of the light source devices is equal to or greater than 0.5 nm.

3. The multi-wavelength light source device according to claim 2,

wherein the spectral line width of the emitted light beam in each of the light source devices is equal to or greater than 1.0 nm.

4. The multi-wavelength light source device according to claim 1,

wherein the wavelength of the red light beam in the light source device for emitting the red light beam is greater than 612 nm and smaller than 658.5 nm.

5. The multi-wavelength light source device according to claim 1,

wherein the dispersing section includes a wavelength selection element having a plurality of light entrance areas where the light beams emitted from the light emitting elements enter respectively, and for selectively reflecting a part of a light beam with a predetermined selection wavelength out of each of the light beams, which are emitted from the respective light emitting elements, towards the respective light emitting elements, and transmitting the rest of each of the light beams, which are emitted from the respective light emitting elements, and

the selection wavelengths in the respective light entrance areas are different from each other.

6. The multi-wavelength light source device according to claim 5,

wherein the dispersing section includes a state changing section making the selection wavelengths different from each other.

7. The multi-wavelength light source device according to claim 5,

wherein the wavelength selection element has a wavelength selection film different in film thickness between the light entrance areas.

8. The multi-wavelength light source device according to claim 1,

wherein the dispersing section includes

a wavelength conversion element having a plurality of light entrance areas where the light beams emitted from the light emitting elements enter respectively, and for converting a certain wavelength of each of the light beams, which are emitted from the respective light emitting elements, into a predetermined conversion wavelength, and emitting a light beam with the conversion wavelength together with the light beam with the rest of the wavelengths, and

a wavelength selection element for selectively reflecting a part of the light beam with the conversion wavelength out of the light beam, which is emitted from the wavelength conversion element, towards the respective light emitting elements, and transmitting the rest of the light beam, which is emitted from the wavelength conversion element, and

the conversion wavelengths in the respective light entrance areas are different from each other.

9. The multi-wavelength light source device according to claim 8,

wherein the wavelength conversion element has repeated structures of domains with polarization inverted to each other along optical axes of the light beams emitted from the respective light emitting elements, and

the widths of the domains in the optical axis direction are different between the light entrance areas from each other.

10. The multi-wavelength light source device according to claim 8,

wherein the dispersing section includes a state changing section that makes the conversion wavelengths different from each other.

11. The multi-wavelength light source device according to claim 10,

wherein the wavelength conversion element has repeated structures of domains with polarization inverted to each other along optical axes of the light beams emitted from the respective light emitting elements, and

the widths of the domains in the optical axis direction in the respective light entrance areas are identical to each other.