CN111412436A

CN111412436A - Laser lighting device

Info

Publication number: CN111412436A
Application number: CN202010426862.6A
Authority: CN
Inventors: 谢刚; 虞华康
Original assignee: Foshan Yichang Laser Technology Co ltd
Current assignee: Hangzhou Yiquan photoelectric Co.,Ltd.
Priority date: 2020-05-19
Filing date: 2020-05-19
Publication date: 2020-07-14

Abstract

The invention relates to a laser lighting device, which comprises a laser, a focusing lens, a polarization reflecting element, an 1/4 wave plate, a wavelength conversion device, a heat conduction reflecting element, a heat dissipation device and a light distribution device, which are sequentially arranged; laser emitted by the laser passes through the focusing lens, sequentially passes through the polarization reflection element and the 1/4 wave plate, then irradiates the wavelength conversion device, is reflected by the heat conduction reflection element, passes through the 1/4 wave plate and the polarization reflection element again, and enters the light distribution device. The invention combines the advantages of the transmission type and the reflection type fluorescent powder schemes, not only can realize high-power laser white light illumination, but also has good coaxiality of blue light and fluorescence, and reduces the difficulty of application design.

Description

Laser lighting device

Technical Field

The invention relates to a laser lighting device, in particular to the technical field of laser-to-white light lighting.

Background

Laser illumination has received much attention because it enables long-range illumination. The main principle is that a blue semiconductor laser excites yellow fluorescent powder to generate fluorescence, and the fluorescence and residual blue light are synthesized into white light and used for illumination, such as a well-known laser automobile headlamp. The main embodiments today are both transmissive and reflective. For the transmission type fluorescent powder structure, laser needs to penetrate through the fluorescent powder material, and the heat dissipation in the light-transmitting aperture is poor, so that the transmission type fluorescent powder structure is difficult to be used for high-power laser illumination; however, the laser fluorescence has good coaxiality, light distribution is easy to realize, and the structure is relatively simple. For the reflective fluorescent powder structure, the fluorescent powder material can be directly arranged on the heat dissipation structure, so that high-power laser illumination can be realized; however, in order to lead out the illumination light, the reflection light path and the incident light path are generally designed in an off-axis manner, the coaxiality of the laser and the fluorescence is poor, the light distribution structure is complex, and the research and development cost is high.

Disclosure of Invention

The invention provides a laser lighting device aiming at the problems in the prior art.

The invention is realized by the following technical scheme:

the invention provides a laser lighting device, which comprises a laser, a focusing lens, a polarization reflecting element, an 1/4 wave plate, a wavelength conversion device, a heat conduction reflecting element, a heat dissipation device and a light distribution device, which are sequentially arranged; laser emitted by the laser passes through the focusing lens, sequentially passes through the polarization reflecting element and the 1/4 wave plates, then irradiates the wavelength conversion device, is reflected by the heat conduction reflecting element, passes through the 1/4 wave plate again and the fluorescence reflecting film of the polarization reflecting element, and is reflected to enter the light distribution device.

Preferably, the laser is a blue semiconductor laser with the wavelength of 420nm to 480nm, emits linearly polarized light, the polarization degree is greater than 90%, and the collimation angle is less than 5 °.

Preferably, the focusing lens is a positive lens, an optical glass or a quartz material, and is used for converging the laser light on the wavelength conversion device.

Preferably, the polarization reflection element is made of glass or quartz, is placed at an angle of 45 ° or brewster with the incident laser, is coated with a blue light polarization film (p-light high-transmittance, s-light reflection) and a fluorescent light reflection film, and has a polarization direction the same as the polarization direction of the laser (p-light) so that the incident laser can pass through the polarization reflection element.

Preferably, the 1/4 wave plate has the same operating wavelength as the incident laser beam, and is disposed in the optical axis direction thereof such that the incident linearly polarized laser beam is circularly polarized light, and after being reflected by the heat-conducting and light-reflecting member, the circularly polarized light passes through the 1/4 wave plate again, becomes linearly polarized light again, and the polarization direction thereof is rotated by 90 ° (s light) with respect to the incident light (p light), and the reflected light cannot pass through the polarization light-reflecting member and is separated into the incident light path.

Preferably, the wavelength conversion device can emit fluorescent light of 510nm to 610nm after absorbing the laser light source, and the structure of the wavelength conversion device can be a fluorescent powder coating, a fluorescent powder sheet layer, a fluorescent glass sheet and a fluorescent ceramic sheet.

Preferably, the heat-conducting reflecting element is sapphire glass or an aluminum reflecting film. If the glass is sapphire glass, one surface is coated with a reflecting film with the reflectivity of more than 60 percent for incident laser and fluorescence from 510nm to 610 nm. Such as an aluminum reflective film, may be fabricated on the thermally conductive device. For reflecting the laser light and the fluorescent light and conducting the heat generated in the wavelength conversion to the heat sink device.

Preferably, the heat dissipation device is made of a metal material.

The present invention has the following advantageous effects.

The advantages of the transmission type and reflection type fluorescent powder schemes are combined, high-power laser white light illumination can be realized, blue light and fluorescence have good coaxiality, and the application design difficulty is reduced.

Drawings

Fig. 1 is a schematic structural diagram of the laser lighting apparatus of the present invention.

1-a laser; 2-a focusing lens; 3-a polarizing reflective element; 4-1/4 wave plates; 5-a wavelength conversion device; 6-thermally conductive reflective elements; 7-a heat sink device; 8-light distribution device.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

As shown in fig. 1, the laser lighting device includes a laser 1, a focusing lens 2, a polarization reflection element 3, an 1/4 wave plate 4, a wavelength conversion device 5, a heat conduction reflection element 6, a heat dissipation device 7 and a light distribution device 8, which are arranged in sequence; laser emitted by the laser 1 passes through the focusing lens 2, then sequentially passes through the polarization reflection element 3 and the 1/4 wave plate 4, then irradiates the wavelength conversion device 5, is reflected by the heat conduction reflection element 6, then passes through the 1/4 wave plate 4 again, and enters the light distribution device 8 through the polarization reflection element 6, so that laser illumination is formed.

The laser 1 is a blue light semiconductor laser with the wavelength of 420nm to 480nm, emits collimated linearly polarized light, and the collimation angle is smaller than 5 degrees and is used for emitting blue light laser.

The focusing lens 2 is a positive lens made of optical glass or quartz and used for converging laser on the wavelength conversion device 5.

The polarization reflection element 3 is made of glass, is placed at an angle of 45 degrees or brewster angle with the incident laser, and is coated with a blue light polarization film and a fluorescent reflection film (not shown in the figure), and the polarization direction is the same as the incident laser direction. For guiding the generated fluorescence out of the incident laser light path; and the light source is matched with an 1/4 wave plate to enable the reflected blue light to be reflected out of an incident laser light path and combined with the fluorescence into white light.

The optical axis direction of the 1/4 wave plate 4 is arranged at 45 degrees to the polarization direction of the incident laser. For rotating the polarization direction of the reflected blue light by 90 degrees with the polarization direction of the incident blue light, and facilitating the light to be guided out from the polarization reflecting element.

The wavelength conversion device 5 can emit fluorescent light of 510nm to 610nm after absorbing the laser light source, and the structure of the wavelength conversion device can be a fluorescent powder coating, a fluorescent powder sheet layer, a fluorescent glass sheet and a fluorescent ceramic sheet.

The heat conduction reflecting element 6 is made of sapphire glass or an aluminum reflecting film. If the glass is sapphire glass, one surface is coated with a reflecting film with the reflectivity of more than 60 percent for incident laser and fluorescence from 510nm to 610 nm. Such as an aluminum reflective film, may be fabricated on the thermally conductive device. For reflecting the laser light and the fluorescent light and conducting the heat generated in the wavelength conversion to the heat sink device.

The heat dissipation device 7 is made of metal and used for dissipating heat.

The light distribution device 8 can be a Fresnel lens, an aspheric lens or a free-form surface lens, and projects the illumination light as required.

It will be appreciated by persons skilled in the art that the embodiments of the invention described above and shown in the drawings are given by way of example only and are not limiting of the invention. The objects of the present invention have been fully and effectively accomplished. The functional and structural principles of the present invention have been shown and described in the examples, and any variations or modifications of the embodiments of the present invention may be made without departing from the principles.

Claims

1. A laser lighting device comprises a laser, a focusing lens, a polarization reflection element, an 1/4 wave plate, a wavelength conversion device, a heat conduction reflection element, a heat dissipation device and a light distribution device which are arranged in sequence; laser emitted by the laser passes through the focusing lens, sequentially passes through the polarization reflecting element and the 1/4 wave plate, then irradiates the wavelength conversion device, is reflected by the heat conduction reflecting element, passes through the 1/4 wave plate and the polarization reflecting element again, and enters the light distribution device.

2. The laser-coupled optical circuit as claimed in claim 1, wherein the laser is a blue semiconductor laser with a wavelength of 420nm to 480nm, emitting linearly polarized light with a polarization degree of more than 90% and a collimation angle of less than 5 °.

3. The laser-coupled optical path of claim 1, wherein the focusing lens is a positive lens and is made of optical glass or quartz.

4. The laser-coupled optical path of claim 1, wherein the polarization-reflective element is made of glass or quartz, is disposed at an angle of 45 ° or brewster with the incident laser, and is coated with a blue-light polarization film and a fluorescent-light reflection film, and has a polarization direction the same as the polarization direction of the laser, so that the incident laser can pass through the polarization-reflective element.

5. The laser coupled optical circuit of claim 1, wherein the 1/4 wave plate has the same operating wavelength as the incident laser, and the direction of the optical axis thereof is set such that the incident linearly polarized laser becomes circularly polarized laser, and after being reflected by the heat-conducting reflective element, the circularly polarized laser passes through the 1/4 wave plate again, the circularly polarized laser becomes linearly polarized laser again, the polarization direction thereof is rotated by 90 ° with respect to the incident laser, and the reflected laser cannot pass through the polarization reflective element and is separated out of the incident optical circuit.

6. The laser-coupled optical circuit of claim 1, wherein the wavelength conversion device emits 510nm to 610nm fluorescence after absorbing the laser light source.

7. The laser-coupled optical circuit according to claim 6, wherein the wavelength conversion device is configured as a phosphor coating, a phosphor sheet, a phosphor glass sheet, or a phosphor ceramic sheet.

8. The laser-coupled optical circuit of claim 1, wherein the thermally conductive reflective element is sapphire glass coated with a reflective film having a reflectance of incident laser light and fluorescence from 510nm to 610nm of greater than 60%.

9. The laser-coupled optical circuit of claim 9, wherein the thermally conductive reflective element is a sapphire glass or aluminum reflective film for reflecting laser light and fluorescence light and conducting heat generated during wavelength conversion to a heat sink device.

10. The laser-coupled optical circuit of claim 1, wherein the heat spreader device is made of metal.