Laser lighting device and lamp

Abstract

The present invention discloses a laser lighting device and a lamp, comprising a laser chip, wherein the laser chip comprises a light-emitting area, the light-emitting area emits laser, the direction of the light-emitting area parallel to the junction plane is a slow axis, the direction perpendicular to the junction plane is a fast axis, the light-emitting angle of the fast axis is greater than the light-emitting angle of the slow axis, and the characteristics are: further comprising a light guide and a wavelength conversion device, the light guide is an inorganic transparent cylinder, the angle α between the axis of the light guide and the junction plane is less than 30°; the length of the refracted light spot in the slow axis direction is L1, the refracted light converges in the fast axis direction, and the length of the refracted light spot in the fast axis direction is L2, #imgabs0#The technical solution utilizes a light guide column to compress and shape the fast axis of the light-emitting area, the laser chip is encapsulated in a tube shell, and the light guide column is fixedly arranged on a light outlet concave in the tube shell. The structure reduces the volume of the laser lighting device and increases the application range of the laser chip.

Description

Technical Field

[0001] The present invention relates to the field of lighting technology, and in particular to a laser lighting device in which a square laser spot emitted by a laser chip forms an approximately circular spot after passing through a light guide. Background Art

[0002] With the development of laser lighting technology, the demand and application of laser devices are becoming more and more extensive. Laser chips have gradually occupied the market of laser light sources with their advantages such as high stability and small size. However, laser chips also have disadvantages in promotion and application due to their own characteristics. For example, the laser emitted by the laser chip is in the slow axis direction in the direction parallel to the junction plane, and in the fast axis direction perpendicular to the junction plane. The luminous angle of the laser emitted by the laser chip in the fast axis direction is different from the luminous angle in the slow axis direction. Usually, the luminous angle in the fast axis direction is greater than the luminous angle in the slow axis direction. The difference in the luminous angles of the fast axis and the slow axis causes the laser emitted by the laser chip to eventually form a long strip of light spot. This characteristic makes the actual application rate of laser chips not high, especially when laser chips are used as light sources in the field of lighting. The angular distribution of the fast axis and the slow axis must be adjusted.

[0003] The technology used by existing laser devices to adjust the above angular distribution is generally complex in structure, large in size, low in yield, and difficult to promote and apply. For example, patent publication number CN104991347A discloses a laser shaping illuminator based on a microlens array, which includes a collimation system, a microlens array group, and a beam expansion system. The patent requires the collimation system, the microlens array group, and the beam expansion system to cooperate. The patent has a complex structure, is difficult to calibrate during the assembly process, and is large in size, making it difficult to promote and apply. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the above-mentioned conventional technology and to invent a laser lighting device for adjusting the angular distribution of the square laser light emitted by a laser chip in view of the deficiencies of the prior art.

[0005] To solve the above problems, the technical solution adopted by the present invention is: a laser lighting device, comprising a laser chip, the laser chip comprising a light-emitting area, the light-emitting area emits laser, the direction of the light-emitting area parallel to the junction plane is a slow axis, the direction perpendicular to the junction plane is a fast axis, the light-emitting angle of the fast axis is greater than the light-emitting angle of the slow axis, characterized in that: it also includes a light guide and a wavelength conversion device, the light guide is an inorganic transparent cylinder, the angle between the axis of the light guide and the junction plane is α, α<30°;

[0006] The laser passes through the side of the light guide and refracts to emit refracted light. The wavelength conversion device is arranged on the optical path of the refracted light. The refracted light forms a refracted light spot on the wavelength conversion device. The refracted light is still divergent in the slow axis direction. The length of the refracted light spot in the slow axis direction is L. 1The refracted light converges in the fast axis direction, and the length of the refracted light spot in the fast axis direction is L 2 ,

[0007] As an improvement of the above technical solution: it also includes a scattering sheet, which is arranged between the wavelength conversion device and the light guide, and the wavelength conversion device is a transmissive fluorescent sheet.

[0008] As an improvement of the above technical solution: it also includes a tube shell, the laser chip is packaged inside the tube shell, a light outlet for emitting laser is set at one end of the tube shell, the light outlet is concave into the tube shell to form a groove, and the light guide is fixedly set in the groove.

[0009] As an improvement of the above technical solution: it also includes a window glass, the window glass covers the light outlet, and the light guide is fixed on the window glass.

[0010] As an improvement of the above technical solution: it also includes a substrate, the laser chip is fixed on the surface of the substrate, the laser optical axis extends along the direction of the substrate surface, and the light guide is fixedly arranged on the substrate.

[0011] As an improvement of the above technical solution: it also includes a reflector for changing the direction of the refracted light, the reflector is fixedly arranged on the surface of the substrate, the refracted light reflected by the reflector forms reflected light, and the wavelength conversion device is arranged on the optical path of the reflected light.

[0012] As an improvement of the above technical solution: the axis of the light guide is parallel to the junction plane.

[0013] As an improvement of the above technical solution: the light guide is an optical fiber or a glass column.

[0014] As an improvement of the above technical solution: the full load luminous power of the laser chip is W, Among them, 20<N<100.

[0015] Due to the adoption of the above technical solution, compared with the prior art, the present technical solution utilizes a light guide to compress and shape the fast axis of the light-emitting area, the laser chip is encapsulated in a tube shell, and the light guide is fixedly arranged on the concave light outlet of the tube shell. This structure reduces the volume of the laser lighting device and increases the application range of the laser chip.

[0016] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a cross-sectional view of a laser lighting device.

[0018] Figure 2It is a cross-sectional view of a laser lighting device.

[0019] Figure 3 It is a structural schematic diagram of the light-emitting area and the light guide.

[0020] Figure 4 It is a schematic diagram of the laser lighting device.

[0021] Figure 5 It is a cross-sectional view of another embodiment of the laser lighting device.

[0022] Figure 6 It is a cross-sectional view of another embodiment of the laser lighting device. DETAILED DESCRIPTION

[0023] Embodiment 1:

[0024] Although laser chips have gradually replaced traditional laser diodes in many fields due to their small size and high power conversion rate, in the field of laser display and lighting, the laser emitted by the laser chip has a fast axis with a large light-emitting angle and a slow axis with a small light-emitting angle. The surface distribution of the laser spot formed by the laser chip in the far field is long strips, and the rectangular spot is difficult to be directly used in the field of laser lighting and display. In order to apply laser chips with high energy conversion rate and small size to the field of laser lighting and display. Figure 1-4 As shown, the laser lighting device includes a laser chip 101, and the laser chip 101 includes a light-emitting area 102. The light-emitting area 102 emits laser 121. The direction of the light-emitting area 102 parallel to the junction plane 103 is a slow axis, and the direction perpendicular to the junction plane 103 is a fast axis. The light-emitting angle of the fast axis is greater than the light-emitting angle of the slow axis. It also includes a light guide 104 and a wavelength conversion device 105. The light guide 104 is an inorganic transparent cylinder. When the light guide 104 is a cylinder, when the laser 121 is incident on the inside of the light guide 104 perpendicular to the axial direction of the light guide 104, it will first be refracted due to the difference in propagation media. Secondly, the outer contour of the cylindrical light guide 104 is equivalent to a convex lens, which will collect the incident laser 121. The laser 121 is incident on the light guide 104 along the axial direction of the light guide 104 and is only refracted. According to the above description, in order to reduce the cost, the light guide 104 is preferably implemented as an optical fiber or a glass column on the basis of meeting the above requirements. Optical fibers are easy to obtain and the processing cost of glass columns is low, so optical fibers and glass columns are the light guides 104 we usually use. There are many inorganic transparent cylinders that we are familiar with, not limited to optical fibers and glass columns. All inorganic transparent cylinders are within the protection scope of this patent and will not be listed one by one in this embodiment.

[0025] The fundamental purpose of adding the light guide 104 is to collect the laser light 121 emitted by the laser chip 101 in the fast axis direction, reduce the light emission angle of the laser light 121 in the fast axis direction, and finally the light spot formed by the laser light 121 emitted by the light guide 104 becomes a square or approximately square. A preferred embodiment is that the angle between the axis of the light guide 104 and the junction plane 103 is α, α<30°. When the angle between the axis of the light guide 104 and the junction plane 103 is α<30°, the light guide 104 has a better effect of collecting the laser light 121 emitted by the laser chip 101 in the fast axis direction.

[0026] In order to give full play to the light-collecting ability of the light guide 104 in the fast axis direction for the laser 121 emitted by the laser chip 101, a preferred embodiment is that the axis of the light guide 104 is parallel to the junction plane 103. When the axis of the light guide 104 is parallel to the junction plane 103, the light-collecting ability of the light guide 104 in the fast axis direction for the laser 121 emitted by the laser chip 101 reaches the limit, and the light-collecting effect is optimal at this time.

[0027] According to the above description, the light guide 104 adjusts the light emitting angle of the laser 121 emitted by the laser chip 101 in the fast axis direction. The purpose of the adjustment is to make the length of the spot formed by the laser 121 in the fast axis direction and the slow axis direction equal or approximately equal. The laser 121 passes through the side of the light guide 104 and refracts to emit refracted light 122. The wavelength conversion device 105 is arranged on the optical path of the refracted light 122. The refracted light 122 forms a refracted light spot on the wavelength conversion device 105. Because the light guide 104 is not a curved surface in the slow axis direction, the light guide 104 has no effect of gathering or converging the laser 121 in this direction. Therefore, the refracted light 122 is still divergent in the slow axis direction, and the length of the refracted light spot in the slow axis direction is L. 1 Because the light guide 104 is an arc surface convex outward in the fast axis direction, the refracted light 122 converges in the fast axis direction, and the length of the refracted light spot in the fast axis direction is L 2 , Since the refracted light 122 is divergent in the slow axis direction and convergent in the fast axis direction, the wavelength conversion device 105 is placed in an appropriate position so that the length L of the refracted light spot in the slow axis direction is 1 and the length L in the fast axis direction 2 The value range of the ratio is within the specified range. Figure 4 As shown, when the wavelength conversion device 105 moves in the area B, 1 and L 2 The ratio range between is within the specified range, and the wavelength conversion device 105 is located in the ideal range. It can be imagined that when the wavelength conversion device 105 moves to area C, the length of the refracted light spot in the slow axis direction will be less than L1 , the length of the refracted light spot in the fast axis direction will be greater than L 2 , at this time L 1 and L 2 The ratio between them is not within the range we need; it can be imagined that when the wavelength conversion device 105 moves to area A, the length of the refracted light spot in the slow axis direction will be greater than L 1 , the length of the refracted light spot in the fast axis direction will be smaller than L 2 , at this time L 1 and L 2 The ratio between them is not within the range we need. Through analysis, we can know that L 1 and L 2 The ratio range between them defines the distance range between the wavelength conversion device 105 and the light-emitting area 103.

[0028] When the luminous power W of the laser chip 101 is known, the energy density N at this time can be obtained according to the area of ​​the refracted light spot formed on the wavelength conversion device 105 after the laser 121 passes through the light guide 104. The full load luminous power of the laser chip 101 is W. Where 20<N<100. When N exceeds 100, the energy density is too high, which will cause the wavelength conversion device 105 to be saturated or burned. When N is less than 20, the laser lighting device cannot meet the use requirements. Usually, the full load luminous power W of the laser chip 101 is used, and because 20<N<100, 0.04<L 1 *L 2 <0.2.

[0029] In summary, the technical characteristics of 20<N<100 deduce L 1 *L 2 The value range of is the area of ​​the refracted light spot. From the derivation process of the technical solution, we can know that the decision of L 1 With L 2 The determining factors of the product and the ratio are both the distance between the light emitting area 103 and the wavelength conversion device 105, so the distance between the light emitting area 103 and the wavelength conversion device 105 is the core of this embodiment.

[0030] According to the above analysis of energy density N, it can be known that the energy density is relatively large at this time. Secondly, the laser light 121 after passing through the light guide 104 is still rectangular, which is still not ideal in laser lighting and display. A preferred embodiment is to further include a scattering plate 106, which is arranged between the wavelength conversion device 105 and the light guide 104, and the wavelength conversion device 105 is a transmissive fluorescent plate. The scattering plate 106 is arranged between the wavelength conversion device 105 and the light guide 104, and the scattering plate 106 scatters the refracted light 122 emitted from the light guide 104, so as to avoid the refracted light spot formed on the wavelength conversion device 105 due to excessive energy density and damage to the wavelength conversion device 105. Secondly, the refracted light spot formed on the wavelength conversion device 105 by the refracted light 122 after being scattered by the scattering plate 106 is closer to a circle, which is more suitable for applications in the field of laser lighting and display.

[0031] The laser chip 101 needs to be protected from collision or extrusion during use. Secondly, the laser 121 emitted by the laser chip 101 has a high energy density, and it is easy to be ignited by the laser 121 when encountering small particles such as dust, thereby damaging the laser chip 101. A preferred embodiment is to further include a tube shell 107, wherein the laser chip 101 is encapsulated inside the tube shell 107, and a light outlet 108 for emitting laser light is provided at one end of the tube shell 107, and the light outlet 108 is concave toward the tube shell 107 to form a groove 109, and the light guide 104 is fixedly disposed in the groove 109. In order to protect the laser chip 101, the laser chip 101 is encapsulated in the tube shell 107 by means of TO encapsulation to prevent the laser chip 101 from being damaged by collision and extrusion. The light guide 104 is fixedly arranged at the light outlet 108 which is concave into the tube shell 107 to form a groove 109. This structure makes the light guide 104 closer to the laser chip 101, reduces the divergence of the laser 121 emitted by the laser chip 101, and reduces the diameter of the light guide 104, thereby reducing the cost. Secondly, the light guide 104 is arranged in the groove 109, which reduces the volume of the laser lighting device and facilitates application.

[0032] The laser chip 101 is sealed in the tube shell 107. In order to make the laser 121 emitted by the laser chip 101 to be emitted outside the tube shell 107, a light outlet 108 is provided on the tube shell 107. The light outlet 108 provided on the tube shell 107 increases the risk of small particles and dust entering the tube shell 107. In order to prevent dust and small particles from entering the tube shell 107. A preferred embodiment is to further include a window glass 110, the window glass 110 covers the light outlet 108, and the light guide 104 is fixed on the window glass 110. The window glass 110 prevents small particles and dust from entering the tube shell 107, and the window glass 110 can also fix the light guide 104, so as to prevent the light guide 104 from affecting the shape of the refraction spot formed by the refracted light 122 on the wavelength conversion device 105 due to the light guide 104 being not firmly fixed.

[0033] Embodiment 2:

[0034] According to the structure of the laser chip, it can be known that the heat is dissipated through the side surface parallel to the junction plane. In Example 1, the laser chip is packaged inside the tube shell in the TO packaging method. The TO packaging method is to stand the laser chip upright, and the heat dissipation surface of the laser chip conducts heat with the substrate through the heat-conducting column. This structure makes the heat dissipation performance of the TO-packaged laser chip poor, and it cannot be used for a long time, and the service life of the laser chip is significantly reduced. Secondly, in order to avoid the influence of dust and small particles on the laser chip, Example 1 uses a tube shell to encapsulate the laser chip inside the tube shell. However, the laser emitted from the light outlet of the tube shell is still a laser with a relatively high energy density. Once there are flammable materials such as dust or small particles in this space, they will also burn, affecting the life of the laser chip.

[0035] This embodiment discloses a new packaging method to avoid the chance of laser contact with dust, small particles and other objects. Figure 5 and 6 As shown, the laser lighting device is different from Example 1 in that it further includes a substrate 211, the laser chip 201 is fixed to the substrate surface 212, the laser optical axis extends along the direction of the substrate surface 212, and the light guide 204 is fixed on the substrate 211. The side where the laser chip 201 is fixed to the substrate surface 212 is the side where the laser chip 201 dissipates heat. The heat generated by the laser chip 201 is directly transferred to the substrate 211. Without increasing the product cost, the thermal conductivity is better and the service life of the laser chip 201 is longer.

[0036] The fundamental purpose of using TO packaging for the laser chip 201 in Example 1 is to make the optical axis of the laser 221 emitted by the laser chip 201 perpendicular to the substrate surface 212, in order to twist the laser 221 emitted by the laser chip 201. A preferred implementation is to further include a reflector 213 for changing the direction of the refracted light 222, the reflector 213 is fixedly arranged on the substrate surface 212, the refracted light 222 reflected by the reflector 213 forms the reflected light 223, and the wavelength conversion device 205 is arranged on the optical path of the reflected light 223. In this technical solution, the reflector 213 twists the emission direction of the refracted light 222 by 90°, and the emission direction of the refracted light 222 can also be changed by changing the angle between the reflector 213 and the substrate surface 212 as needed.

[0037] The laser 221 emitted by the laser chip 201 is divergent. When the laser chip 201 is fixed on the substrate surface 212, the substrate surface 212 will block part of the laser 221 emitted by the laser chip 201, affecting the use effect. A preferred embodiment is to add a pad 215 between the laser chip 201 and the substrate surface 212. The pad 215 is made of a material with a high thermal conductivity, such as metallic copper. One end of the laser chip 201 where the light-emitting area 102 is set extends outside the pad 215. After the pad 215 raises the laser chip 201, the laser 221 emitted by the laser chip 201 can be completely incident on the light guide 204.

[0038] The device further comprises a packaging shell 214, which is fixedly arranged on the substrate 211, wherein the laser chip 201 and the reflector 213 are packaged inside the packaging shell 214. The packaging shell 214 is provided with a light outlet 208, and the reflected light 223 formed after being reflected by the reflector 213 is emitted from the light outlet 208, and the wavelength conversion device 205 and the scattering sheet 206 are both fixedly arranged at the light outlet 208. The wavelength conversion device 205 is fixedly arranged on the outside of the packaging shell 214, and the scattering sheet 206 is fixedly arranged inside the packaging shell 214.

[0039] The specific embodiments of the present invention are described in detail above, and the contents are the best embodiments of the present invention and cannot be used to limit the protection scope of the present invention. For those skilled in the art, any equivalent modifications and substitutions made to the invention are also within the scope of the present invention.

Claims

1. A laser lighting device, comprising a laser chip, wherein the laser chip comprises a light-emitting region, the light-emitting region emits laser light, the direction of the light-emitting region parallel to the junction plane is a slow axis, the direction of the light-emitting region perpendicular to the junction plane is a fast axis, the light-emitting angle of the fast axis is greater than the light-emitting angle of the slow axis, and the device is characterized in that: It also includes a light guide and a wavelength conversion device, wherein the light guide is an inorganic transparent cylinder, and the angle between the axis of the light guide and the junction plane is α, α<30°; The laser passes through the side of the light guide and refracts to emit refracted light. The wavelength conversion device is arranged on the optical path of the refracted light. The refracted light forms a refracted light spot on the wavelength conversion device. The refracted light is still divergent in the slow axis direction, and the length of the refracted light spot in the slow axis direction is L1. The refracted light converges in the fast axis direction, and the length of the refracted light spot in the fast axis direction is L2.

2. The laser lighting device according to claim 1, characterized in that: It also includes a scattering sheet, which is arranged between the wavelength conversion device and the light guide, and the wavelength conversion device is a transmissive fluorescent sheet.

3. The laser lighting device according to claim 1 or 2, characterized in that: It also includes a tube shell, the laser chip is packaged inside the tube shell, a light outlet for emitting laser is arranged at one end of the tube shell, the light outlet is concave toward the tube shell to form a groove, and the light guide is fixedly arranged in the groove.

4. The laser lighting device according to claim 3, characterized in that: It also includes a window glass, which covers the light outlet, and the light guide is fixed on the window glass.

5. The laser lighting device according to claim 1 or 2, characterized in that: It also includes a substrate, the laser chip is fixed on the surface of the substrate, the laser optical axis extends along the direction of the substrate surface, and the light guide is fixedly arranged on the substrate.

6. The laser lighting device according to claim 5, characterized in that: It also includes a reflector for changing the direction of the refracted light. The reflector is fixedly arranged on the surface of the substrate. The refracted light reflected by the reflector forms reflected light. The wavelength conversion device is arranged on the optical path of the reflected light.

7. The laser lighting device according to claim 1, characterized in that: The axis of the light guide is parallel to the junction plane.

8. The laser lighting device according to claim 1, characterized in that: The light guide is an optical fiber or a glass column.

9. The laser lighting device according to claim 1, characterized in that: The full load luminous power of the laser chip is W. Among them, 20<N<100.

10. A lamp, characterized in that: A laser lighting device comprising any one of claims 1-9.

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