Light source employing a wavelength conversion device with a light introducing device and a light collecting device

Patent metadata

Field	Value
Publication number	US-9851071-B2
Application number	US-201113992144-A
Country	US
Kind code	B2
Filing date	Dec 7, 2011
Priority date	Dec 8, 2010
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A light source comprising an excitation light source for providing excitation light, and an optical wavelength conversion member disposed at a distance from the excitation light source. The optical wavelength conversion member comprises an optical wavelength conversion material for converting the excitation light into stimulated light. The light source also comprises an optical-guiding member that allows the excitation light to be incident on the optical wavelength conversion material, and an optical-collecting member for collecting converted light originating from the optical wavelength conversion material. To separate the paths of the converted light and the excitation light, the etendue of the optical-guiding member is less than or equal to ¼ of the etendue of the optical-collecting member. This allows the optical-guiding member to draw in the excitation light while preventing the excessive escape of the converted light through the optical-guiding member.

First claim

What is claimed is:

1. A light source device, comprising:
an excitation light source providing an excitation light;
a wavelength conversion device located remotely from the excitation light source, including a wavelength conversion material for converting the excitation light into a converted light;
a light introducing device for directing the excitation light onto the wavelength conversion material; and
a light collecting device for collecting the converted light from the wavelength conversion material, wherein the light collecting device includes a first reflecting device for changing a traveling direction of the converted light toward an output port,
wherein the light introducing device is an area surrounded by the first reflecting device which has different transmission and reflection properties than the first reflecting device, the area of the light introducing device being different from the output port,
wherein an etendue of the light introducing device is less than or equal to ¼ of an etendue of the light collecting device.

2. The light source device of claim 1 , wherein the light collecting devices further collects an un-absorbed portion of the excitation light from the wavelength conversion material.

3. The light source device of claim 1 , wherein the excitation light is a blue light, and the wavelength conversion material includes a yellow phosphor for converting the blue light into a yellow light.

4. The light source device of claim 1 , wherein the excitation light source includes a laser or a light emitting diode.

5. The light source device of claim 1 , wherein the wavelength conversion device further includes a substrate having a reflective surface, and wherein the wavelength conversion material is disposed on the reflective surface.

6. The light source device of claim 5 ,
wherein the wavelength conversion material is disposed between the reflective surface of the substrate and the first reflecting device;
wherein the light introducing device is an aperture in the first reflecting device, wherein the excitation light from the excitation light source passes through the aperture to illuminate the wavelength conversion material; and
wherein a size of the aperture is less than or equal to ¼ of a size of a reflective surface of the first reflecting device.

7. The light source device of claim 6 ,
wherein the first reflecting device is a reflector plate having the aperture;
wherein the light collecting device further includes a lens set, and wherein the converted light from the wavelength conversion material is collected by the lens set into a near parallel light toward the reflector plate.

8. The light source device of claim 6 ,
wherein the first reflecting device has a hemispherical or semi-ellipsoidal shape with an inward-facing reflective surface and having the aperture;
wherein when the first reflecting device has a semi-ellipsoidal shape, a light entrance port of the light collecting device is located near a focal point of the first reflecting device, and the wavelength conversion device is disposed such that an illumination point of the excitation light on the wavelength conversion material is located near another focal point of the first reflecting device; and
wherein when the first reflecting device has a hemispherical shape, a light entrance port of the light collecting device is located near a spherical center of the first reflecting device, and the wavelength conversion device is either disposed such that the illumination point of the excitation light on the wavelength conversion material is located near the spherical center of the first reflecting device and aligned with the light entrance port, or disposed such that the wavelength conversion material at the illumination point of the excitation light is located at a position symmetrical to the light entrance port with respect to the spherical center.

9. The light source device of claim 8 , wherein the first reflecting device is a hollow structure coated with a reflective film on its interior surface, and wherein the aperture is an opening in the reflective surface of the hollow structure.

10. The light source device of claim 8 , wherein the first reflecting device is a solid transparent body coated with a reflective film on its exterior surface, wherein the aperture is an opening in the reflective film.

11. The light source device of claim 10 , wherein an air gap is provided between the wavelength conversion material at the illumination point of the excitation light and the transparent body, the air gap having a thickness less than 1% of a longest semi-principal axis of the semi-ellipsoidal reflector or a radius of the hemispherical reflector.

12. The light source device of claim 8 , wherein the aperture is located at an off-centered location of the first reflecting device to allow the excitation light to be perpendicularly incident on the wavelength conversion material.

13. The light source device of claim 6 , wherein the first reflecting device is a serrated reflecting device having the aperture.

14. The light source device of claim 5 ,
wherein the light collecting device directs the converted light to an output of the light source device via an output path;
wherein the light introducing device is a second reflecting device disposed in the output path, the second reflecting device having a reflective surface for reflecting the excitation light from the excitation light source toward the wavelength conversion material;
wherein the wavelength conversion material is disposed between the reflective surface of the substrate and the second reflecting device; and
wherein an output light spot size of the converted light is 4 times or more of a size of the second reflecting device projected at a location of the output light spot.

15. The light source device of claim 1 ,
wherein the light collecting device includes a first reflecting device for changing a traveling direction of the converted light;
wherein the light introducing device is an aperture of the first reflecting device, wherein the excitation light from the excitation light source passes through the aperture to illuminate the wavelength conversion material;
wherein a backward traveling converted light from the wavelength conversion material is reflected by the first reflecting device back to the wavelength conversion material, and passes through the wavelength conversion material; and
wherein a size of the aperture is less than or equal to ¼ of a size of a reflective surface of the first reflecting device.

16. The light source device of claim 15 ,
wherein the first reflecting device is a hemispherical reflector,
wherein the light collecting devices includes a tapered rectangular light rod; and
wherein the backward traveling converted light from the wavelength conversion material is reflected by the hemispherical reflector back to the wavelength conversion material, passes through the wavelength conversion material, and is collected by the tapered rectangular light rod.

17. The light source device of claim 15 , wherein the aperture is covered by a dielectric film that transmits the excitation light and reflects the converted light.

18. The light source device of claim 1 , further comprising a filter plate disposed between the excitation light and the wavelength conversion material, which transmits the converted light, transmits the excitation light with an incident angle between 0 to 15 degrees, and reflects the excitation light having an incident angle greater than 15 degrees.

19. The l

Assignees

• Hu Fei
• Li Yi
• Yang Yi
• Appotronics China Corp

Inventors

• Hu Fei
• Li Yi
• Yang Yi

Classifications

• G03B21/2066

  Reflectors in illumination beam (in projection beam G03B21/28) · CPC title

• G02B26/008

  in the form of devices for effecting sequential colour changes, e.g. colour wheels · CPC title

• F21K9/64

  using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer · CPC title

• F21V13/08

  the elements being filters or photoluminescent elements and reflectors · CPC title

• H04N9/315

  Modulator illumination systems (general applications of lighting devices F21V; general optical systems G02B; lamp houses for projectors not peculiar to the presence of an electronic spatial light modulator G03B21/20) · CPC title