LIGHT-EMITTING DEVICE AND RELATED LIGHT SOURCE SYSTEM

• US 20160085143A1
• Filed: 04/11/2014
• Published: 03/24/2016
• Est. Priority Date: 04/20/2013
• Status: Active Grant

• Current Assignee: Appotronics Corporation Limited
• Original Assignee: Appotronics Corporation Limited
• Inventors: HU, Fei, HOU, Haixiong
• Granted Patent: US 9,904,160 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0057 in the form of a laser diode array, e.g. laser diode bar semiconductor laser arrays with beam combining arrangement H01S5/4012
• CPC Class Codes: G02B 27/0927 Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• CPC Class Codes: G02B 27/0955 Lenses lenses per se G02B3/00
• CPC Class Codes: G02B 27/1013 for colour or multispectral image sensors, e.g. splitting an image into monochromatic image components on respective sensors spectral imaging systems G01J
• CPC Class Codes: G02B 27/123 The splitting element being a lens or a system of lenses, including arrays and surfaces with refractive power
• CPC Class Codes: G02B 27/141 using dichroic mirrors
• CPC Class Codes: G02B 27/30 Collimators
• CPC Class Codes: G02B 3/0006 Arrays G02B3/02, G02B5/188 take precedence
• CPC Class Codes: G02B 6/0006 Coupling light into the fibre in general G02B6/4298
• CPC Class Codes: G03B 21/2013 Plural light sources
• 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: G03B 21/208 Homogenising, shaping of the illumination light

Abstract

A light-emitting device (1) and a related light source system. The light-emitting device (1) comprises a laser light source (11, 21, 31) and a light collecting system (12, 22). The laser light source (11, 21, 31) comprises a first laser array (111, 211, 311) and a second laser array (112, 212, 312) for respectively generating a first light and a second light with different wavelength ranges. The light collecting system (12, 22) is used for collecting the light emitted from the laser light source arrays. The ratio of the divergence angle of the collected second light to that of the first light is less than or equal to a predetermined value. The predetermined value is 0.7. The light-emitting device (1) is capable of generating two kinds of light beams with different etendues.

Claims

1. A light emitting device, comprising:

a laser light source, including a first laser array and a second laser array, for respectively generating a first light and a second light having different wavelength ranges; and

a light collecting system, for collecting the lights generated by the laser arrays, wherein a ratio of a divergence angle of the second light after the collecting system to a divergence angle of the first light after the collecting system is less than a predetermined value, wherein the predetermined value is 0.7.

2. The light emitting device of claim 1,

wherein the light collecting system includes a collecting device and a collimating lens, wherein the collecting device includes at least one condenser lens for condensing light beams from the laser light source, and wherein the collimating lens collimates a light beam from the collecting device;

and

wherein the collecting device includes a first region and a second region, the first region being a region where the first light passes, the second region being a region where the second light passes, wherein a combined focal length of the first region is greater than a combined focal length of the second region, and wherein in output light of the laser light source, a divergence angle of the first light is greater than a divergence angle of the second light, so that a ratio of a divergence angle of the second light after the light collecting system to a divergence angle of the first light after the light collecting system is less than the predetermined value.

3. The light emitting device of claim 1, wherein in output light of the laser light source, divergence angles of the first light and the second light are identical;

wherein the light collecting system includes a collecting device and a collimating lens, wherein the collecting device includes at least one condenser lens for condensing a light beam from the laser light source, and wherein the collimating lens collimates a light beam from the condenser lens; and

wherein the collecting device includes a first region and a second region, the first region being a region where the first light passes, the second region being a region where the second light passes, and wherein a ratio of a combined focal length of the first region is to a combined focal length of the second region is less than or equal to the predetermined value.

4. The light emitting device of claim 2, wherein the first region of the collecting device includes a first collecting lens, disposed on an output light path of the laser light source, wherein a part of the first collecting lens condenses the first light;

wherein the second region of the collecting device includes a second collecting lens, disposed on an output light path of the second light that has passed through the first collecting lens, to condense the second light.

5. The light emitting device of claim 2, wherein the collecting device includes a condenser lens and a reflector cup with an aperture, wherein the condenser lens includes a first surface facing the laser light source and a second surface opposite the first surface, wherein the second surface is provided with a filter film that transmits the second light and reflects the first light;

wherein the reflector cup is disposed on an output light path of the laser light source, and wherein its reflecting surface faces the second surface of the condenser lens;

wherein the first light from the laser light source is directly incident onto the reflector cup, and is reflected by it to the second surface of the condenser lens, and reflected again to the collimating lens; and

wherein the second light from the laser light source is directly incident on the condenser lens, and is collected by it onto the collimating lens; and

wherein an output light of the collimating lens passes through the aperture of the reflecting cup to be output.

6. The light emitting device of claim 2, further comprising a light homogenizing rod, wherein the collecting lens includes a first condenser lens and a second condenser lens, the second condenser lens being disposed between the first condenser lens and a focal point of the first condenser lens, the second condenser lens having a first surface facing the first condenser lens and a second surface opposite the first surface, wherein the second surface is provided with a filter film which transmits the second light and reflects the first light;

wherein the first laser array is disposed on a side of the first condenser lens that faces the second condenser lens, the second laser array is disposed on a side of the second condenser lens that faces away from the first condenser lens, wherein the first laser array and the first condenser lens respectively have apertures at locations corresponding to an optical axis of the collimating lens, wherein the light homogenizing rod is disposed on an output light path of the collimating lens and sequentially penetrates through the apertures of the first condenser lens and the first laser array;

wherein the first light from the first laser array is collected by the first condenser lens to the first surface of the second condenser lens, is reflected by it to the collimating lens, and then enters the light homogenizing rod; and

wherein the second light from the second laser array is collected by the second condenser lens to the collimating lens, is collimated by it and then enters the light homogenizing rod.

7. The light emitting device of claim 1, wherein

different regions of the light collecting system through which the first light and the second light of output light of the laser light source pass respectively have identical focal lengths;

and

wherein in the output light of the laser light source, a ratio of a divergence angle of the second light to a divergence angle of the first light is less than or equal to the predetermined value.

8. The light emitting device of claim 2, wherein the laser light source further includes a first collimating lens array and a second collimating lens array, wherein collimating lenses in the first and second collimating lens arrays respectively correspond one to one with laser elements of the first and second laser arrays, for collimating light emitted by the corresponding laser elements;

and

wherein a focal length of the collimating lenses of the second collimating lens array is grater than a focal length of the collimating lenses of the first collimating lens array, so that a ratio of a divergence angle of the collimated second light to a divergence angle of the collimated first light is less than or equal to the predetermined value;

or,

a degree of off-focus of the laser elements of the first laser array and their corresponding collimating lenses is greater than a degree of off-focus of the laser elements of the second laser array and their corresponding collimating lenses, so that a ratio of a divergence angle of the collimated second light to a divergence angle of the collimated first light is less than or equal to the predetermined value, or,

a divergence angle of light emitted by the laser elements of the first laser array is greater than a divergence angle of light emitted by the laser elements of the second laser array, so that a ratio of a divergence angle of the collimated second light to a divergence angle of the collimated first light is less than or equal to a predetermined value.

9. The light emitting device of claim 2, further comprising a scattering plate or a fly-eye lens pair disposed on a propagation path of the first light within the laser light source, wherein the scattering plate or the fly-eye lens pair avoids a propagation path of the second light.

10. The light emitting device of claim 2, further comprising a light homogenizing rod, for homogenizing a light from the light collecting system, wherein all cross sections of the light homogenizing rod in a direction perpendicular to the light homogenizing rod are identical;

wherein the laser light source includes an emitting region a non-emitting region, wherein the first and second laser arrays are located in the emitting region;

wherein the light collecting system includes a reflective focusing device and a collimating lens, wherein the reflective focusing device includes a focusing region and a non-focusing regions, wherein the focusing region focuses output light from the laser light source and reflects it to the collimating lens, wherein the collimating lens collimates the light from the reflective focusing device and outputs it to the light homogenizing rod; and

wherein non-emitting region of the laser light source and the non-focusing region are located on a same straight line parallel to an output optical axis of the laser light source, and the light homogenizing rod penetrates through the non-emitting region and/or the non-focusing region.

11. The light emitting device of claim 10, wherein the reflective focusing device includes a condenser lens with an aperture and a reflecting element, wherein the aperture of the condenser lens is the non-focusing region, and wherein regions of the condenser lens other than the aperture and the reflecting element are the focusing region;

wherein the region of the condenser lens other than the aperture condenses output light from the laser light source, and the reflecting element reflects a light from the condenser lens to the collimating lens; and

wherein the light homogenizing rod penetrates through the aperture of the condenser lens and the non-emitting region of the laser light source.

12. The light emitting device of claim 10, wherein the reflective focusing device is a reflecting cup, wherein a center region of the reflecting cup is the non-focusing region, and a region other than the center region is the focusing region, and wherein the light homogenizing rod penetrates through the non-emitting region of the laser light source.

13. The light emitting device of claim 10, wherein the reflective focusing device includes a reflecting element and a reflecting cup with an aperture, wherein the aperture of the reflecting cup is the non-focusing region, and regions other than the aperture and the reflecting element are the focusing region;

and

wherein the light homogenizing rod penetrates through the aperture of the reflecting cup.

14. The light emitting device of claim 13, further comprising a third reflecting element mounted in the non-emitting region of the laser light source.

15. The light emitting device of claim 1, further comprising a light homogenizing rod for homogenizing a light from the light collecting system, wherein all cross sections of the light homogenizing rod in a direction perpendicular to the light homogenizing rod are identical.

16. The light emitting device of claim 1, wherein the predetermined value is 0.3.

17. A light source system, comprising:

the light emitting device of claim 1;

a wavelength conversion device, having a wavelength conversion layer which absorbs the first light from the light emitting device to generate a converted light;

wherein one surface of the wavelength conversion layer receives the first light, and outputs from the same surface at least a part of the first light, and at least a part of the converted light or at least a part of a mixed light of the converted light and unabsorbed first light;

a scattering device, including a scattering layer which scatters the second light from the light emitting device;

wherein the scattering layer receives the second light on one surface, and outputs on the same surface at least a part of the second light; and

a light guidance device, including a first region, wherein the second light and the first light from the light emitting device are incident on the light guidance device from a first light path, wherein at least a part of the second light is incident on the first region, and at least a part of the first light is incident on a region of the light guidance device other than the first region;

wherein the light incident on the region of the light guidance device other than the first region is guided to the wavelength conversion device, and the light incident on the first region of the light guidance device is guided to the scattering device;

wherein the region of the light guidance device other than the first region further guides the converted light from the wavelength conversion device and the second light from the scattering device to a second light path to be output.