Reflection type annular color wheel for laser display

Abstract

The invention discloses a reflective annular color wheel for laser display. The reflective annular color wheel comprises an outer annular fluorescent material and an inner annular fluorescent material, wherein the bottom of the outer annular fluorescent material and the bottom of the inner annular fluorescent material are connected with the reflecting substrate through the transparent connecting layer. According to the color wheel, the splicing angle does not need to be designed, the production process is simplified, the light spot effect caused by splicing seams is avoided, laser irradiation is more uniform, and therefore the overall color temperature stability is improved; the color wheel can bear blue light excitation power as high as 60W / mm < 2 >, still keeps relatively low color temperature drift, shows good light quenching resistance and thermal stability, overcomes the defects of speckles, poor effect, unstable chromaticity and the like in the prior art, and is suitable for a laser illumination system with high power density.

Description

Technical Field

[0001] The invention relates to the technical field of laser display, and in particular to a reflective annular color wheel for laser display. Background Art

[0002] Laser display technology, that is, image information terminal display technology that uses laser as a light source, has a wider color gamut coverage, better color expression, and more outstanding color reproduction capabilities compared to traditional LED light sources. It is the mainstream technical solution for high-end and smart displays.

[0003] As the heart of laser display technology, the color wheel is one of the core components of the laser light source. Under the excitation of high-energy blue laser, the color wheel rotates at high speed and absorbs blue light to convert it into various colors of fluorescence, such as green light, yellow light, and red light, and then forms an image through the imaging chip. Generally, there are two main types of color wheels, one is a transmissive color wheel and the other is a reflective color wheel. For a transmissive fluorescent color wheel, it is obvious that the color wheel must be located in the center of the entire imaging structure, that is, there are core optical devices in front and behind; in addition, due to the direct transmission of laser blue light for imaging, speckle will appear in the system, which seriously affects the imaging effect. For a reflective fluorescent color wheel, the imaging structure can basically be deployed on one side, which can be located at the edge, corner, or center of the entire optical system, so some compact optical path structures can be designed; in addition, the blue laser in the reflective fluorescent color wheel is scattered light, which has been imaged after being scattered by the fluorescent material, and there will be no laser speckle. Therefore, the performance of the reflective fluorescent color wheel is better. It is worth mentioning that a transmissive fluorescent color wheel is generally a combination of multiple color wheels, such as arc-shaped green fluorescent material + arc-shaped red fluorescent material + blank area. During the laser-excited rotating color wheel, the blue light intermittently excites the fluorescent material, which causes the color temperature of the fluorescent material to drift; when the rotation speed slows down, even "stroboscopic" phenomenon may occur.

[0004] Based on the above problems, it is necessary to design a new reflective color wheel structure to achieve better display quality, such as color temperature uniformity and high blue light resistance power density. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a reflective annular color wheel for laser display, which does not need to design the splicing angle, simplifies the production process, avoids the spot effect caused by the splicing seam, makes the laser irradiation more uniform, and thus improves the overall color temperature stability; the color wheel can withstand up to 60W / mm 2 The blue light excitation power is high, while still maintaining a low color temperature drift, showing good resistance to light quenching and thermal stability, solving the shortcomings of existing technologies such as speckle, poor effect, and unstable color quality, and is suitable for high-power density laser lighting systems.

[0006] The specific scheme includes: a reflective annular color wheel for laser display, including an outer annular fluorescent material and an inner annular fluorescent material; wherein the outer annular fluorescent material and the inner annular fluorescent material are connected to a reflective substrate at the bottom through a transparent connecting layer.

[0007] Furthermore, the outer ring-shaped fluorescent material is a red fluorescent material, and the luminescent matrix is ​​one of CASiN:Eu or KSF:Mn.

[0008] Furthermore, the inner diameter of the outer ring-shaped fluorescent material is 30-40 mm, and the outer diameter is 40-50 mm.

[0009] Furthermore, the inner ring-shaped fluorescent material is a yellow-green fluorescent material, and the luminescent matrix is ​​one of YAG:Ce or LuAG:Ce.

[0010] Furthermore, the inner diameter of the inner ring-shaped fluorescent material is 20 to 30 mm, and the outer diameter is 30 to 40 mm.

[0011] Furthermore, the transparent connecting layer is one of an anhydrous silica inorganic silica gel layer or a borate low-melting-point glass layer.

[0012] Furthermore, the reflective substrate is one of metal aluminum or aluminum oxide ceramics.

[0013] Furthermore, the size of the reflective substrate is the same as that of the color wheel, with an inner diameter of 20 to 30 mm and an outer diameter of 40 to 50 mm.

[0014] Furthermore, the laser spot excited by the reflective annular color wheel is located at the center of the color wheel, and the spot size is 0.785-2.01 mm. 2 .

[0015] The beneficial effects of the present invention are:

[0016] 1. The annular color wheel structure proposed in the present invention enables the laser to continuously irradiate two fluorescent materials. Compared with the traditional separate or segmented excited fluorescent materials, the color temperature drift is smaller and the color quality is more stable. This design effectively reduces the color temperature fluctuation caused by uneven laser irradiation, thereby improving the overall performance of the light source;

[0017] 2. The present invention uses a transparent high thermal conductivity medium of inorganic silica gel and glass powder to encapsulate the fluorescent material and the reflective substrate, which has good connection performance and heat dissipation performance. Compared with traditional silica gel encapsulation materials, the present invention can dissipate heat more efficiently, especially suitable for high power density blue light excitation environment, ensuring long-term stable operation of the system and extending service life;

[0018] 3. Compared with the existing segmented color wheel, the color wheel of the present invention has a simplified structure, does not require the design of complex splicing angles, has a simpler manufacturing process, significantly reduces production costs, and is suitable for large-scale industrial applications, and can meet the market demand for high-performance light sources; at the same time, it avoids the spot effect caused by splicing seams, making laser irradiation more uniform, thereby improving the overall color temperature stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a top view of the structure of the reflective annular color wheel of Example 1;

[0021] Figure 2 It is a structural plan view of the reflective annular color wheel of Example 1;

[0022] Figure 3 The blue laser excitation area (static) of the reflective annular color wheel of Example 1;

[0023] Figure 4 The color temperature of the reflective annular color wheel of Example 1 under the excitation of blue lasers with different power densities;

[0024] Among them, 1. inner ring fluorescent material; 2. outer ring fluorescent material; 3. transparent connecting layer; 4. reflective substrate. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] A reflective annular color wheel for laser display, as shown in the attached Figure 1 As shown, it includes an outer ring-shaped fluorescent material 1 and an inner ring-shaped fluorescent material 2, which are in contact with each other. Figure 2As shown, the bottom of the annular color wheel is connected to the reflective substrate 4 through a transparent connecting layer 3. The outer annular fluorescent material 1 is a red fluorescent material, and the luminescent matrix is ​​KSF:Mn. The inner diameter is 30mm and the outer diameter is 40mm. The inner annular fluorescent material 2 is a yellow fluorescent material, and the luminescent matrix is ​​YAG:Ce. The inner diameter is 20mm and the outer diameter is 30mm. The transparent connecting layer 3 is a borate low-melting-point glass layer. The reflective substrate 4 is alumina ceramic, and its size is the same as that of the color wheel, with an inner diameter of 20mm and an outer diameter of 40mm.

[0028] The reflective fluorescent color wheel was placed in a high-energy blue laser excitation system, and the color wheel speed was 3000 rpm. Figure 3 As shown, the laser spot excited to the annular color wheel is located at the center of the annular color wheel, and the spot size is 0.785~2.01mm 2 When the power density is increased from 10W / mm 2 Increased to 60 / mm 2 , the color temperature increased from 3570K to 3826K; when the power density increased further, the color wheel showed color temperature drift. This is mainly because the blue light power density is too high, and the Mn ions in the red fluorescent material are quenched, resulting in less red light and higher color temperature. This reflective fluorescent color wheel can handle 60W / mm 2 Blue light excitation.

[0029] Example 2

[0030] A reflective annular color wheel for laser display, as shown in the attached Figure 1 As shown, it includes an outer ring-shaped fluorescent material 1 and an inner ring-shaped fluorescent material 2, which are in contact with each other. Figure 2 As shown, the bottom of the annular color wheel is connected to the reflective substrate 4 through a transparent connecting layer 3. The outer annular fluorescent material 1 is a red fluorescent material, and the luminescent matrix is ​​CASiN:Eu. The inner diameter is 40mm and the outer diameter is 50mm. The inner annular fluorescent material 2 is a green fluorescent material, and the luminescent matrix is ​​LuAG:Ce. The inner diameter is 30mm and the outer diameter is 40mm. The transparent connecting layer 3 is an anhydrous silica inorganic silica gel layer. The reflective substrate 4 is metal aluminum, and its size is the same as that of the color wheel, with an inner diameter of 30mm and an outer diameter of 50mm.

[0031] The reflective fluorescent color wheel was placed in a high-energy blue laser excitation system, and the color wheel speed was 3000 rpm. Figure 3 As shown, the laser spot excited to the annular color wheel is located at the center of the annular color wheel, and the spot size is 0.785~2.01mm 2 When the power density is increased from 10W / mm 2 Increased to 100 / mm 2, the color temperature increased from 5685K to 5888K. At such a high power density, the color temperature only increased by 203K, and the luminous stability was excellent, which was suitable for blue light excitation with different power densities, even up to 100W / mm 2 .

[0032] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A reflective annular color wheel for laser display, characterized in that: It comprises an outer annular fluorescent material and an inner annular fluorescent material which are in contact with each other; wherein the bottoms of the outer annular fluorescent material and the inner annular fluorescent material are connected to a reflective substrate via a transparent connecting layer.

2. A reflective annular color wheel for laser display as claimed in claim 1, characterized in that: The outer ring fluorescent material is a red fluorescent material, and the luminescent matrix is ​​one of CASiN:Eu or KSF:Mn.

3. A reflective annular color wheel for laser display as claimed in claim 1, characterized in that: The inner diameter of the outer ring-shaped fluorescent material is 30-40 mm, and the outer diameter is 40-50 mm.

4. A reflective annular color wheel for laser display as claimed in claim 1, characterized in that: The inner ring fluorescent material is a yellow-green fluorescent material, and the luminescent matrix is ​​one of YAG:Ce and LuAG:Ce.

5. A reflective annular color wheel for laser display as claimed in claim 1, characterized in that: The inner diameter of the inner ring-shaped fluorescent material is 20-30 mm, and the outer diameter is 30-40 mm.

6. A reflective annular color wheel for laser display as claimed in claim 1, characterized in that: The transparent connecting layer is one of an anhydrous silicon dioxide inorganic silica gel layer or a borate low melting point glass layer.

7. A reflective annular color wheel for laser display as claimed in claim 1, characterized in that: The reflective substrate is one of metal aluminum or aluminum oxide ceramics.

8. A reflective annular color wheel for laser display as claimed in claim 1, characterized in that: The size of the reflective substrate is the same as that of the inner and outer annular fluorescent materials, with an inner diameter of 20 to 30 mm and an outer diameter of 40 to 50 mm.

9. A reflective annular color wheel for laser display as claimed in claim 1, characterized in that: The laser spot excited by the reflective annular color wheel is located at the center of the color wheel, and the spot size is 0.785-2.01 mm 2 .

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