TWI730146B - Optical system - Google Patents

Abstract

An optical system including a first laser light source capable of outputting a first laser light beam, a first optical element and a first material layer is provided. The first optical element is disposed on a light path of the first laser light source. The first optical element is provided with a first surface. A first axis and a second axis perpendicular to each other on the first surface are provided with different radius of curvature. The first material layer is disposed at a light path downstream of the first optical element, and the first material layer has a photoluminescent material. Another optical system is also provided.

Description

Optical system

The present invention relates to an optical system, and particularly relates to an optical system suitable for a projector.

With the development of solid-state light sources and projection technology in recent years, projectors based on solid-state light sources such as Light Emitting Diode (LED) and Laser Diode (LD) have gradually become favored by the market.

In a conventional projector architecture, the excitation light beam emitted by the excitation light source is directly incident on the phosphor wheel (Phosphor Wheel), but this architecture will cause the phosphor wheel to bear too high energy density, which will affect the luminous efficiency of the projector. And reliability (Reliability).

In another conventional projector architecture, the excitation light beam emitted by the excitation light source is incident on the diffuser first and then incident on the fluorescent wheel. The diffuser is used to scatter the excitation beam to make the energy distribution incident on the fluorescent wheel uniform. However, under the structure of this kind of projector, it is necessary to add a diffuser to increase the cost of the overall projector, and the existence of the diffuser also reduces the overall light transmittance. In addition, under the excitation beam with high energy density, there may be a risk of damage to the diffuser.

The present invention provides an optical system, which has good luminous efficiency and reliability, and has a lower cost.

The optical system of the embodiment of the present invention includes a laser light source, an optical element, and a material layer. The laser light source can output a laser beam. The optical element is arranged on the optical path of the laser light source. The optical element is provided with a first surface, and a first axis and a second axis perpendicular to each other on the first surface are provided with different radii of curvature. The first material layer is arranged downstream of the optical path of the optical element. The material layer contains a photoluminescent material.

The optical system of the embodiment of the present invention includes a first laser light source, a phosphor layer, and a first double cone lens. The first laser light source can emit a first laser beam. The phosphor layer is located on the optical path of the first laser beam. The first double cone lens is arranged between the first laser light source and the phosphor layer, and is located on the traveling path of the first laser beam, so that the first laser beam can penetrate the first double cone lens to reach the phosphor powder Floor.

Based on the above, in the optical system of the related embodiment of the present invention, since the first axis and the second axis that are perpendicular to each other on the surface of the optical element in the optical system are provided with different radii of curvature, when the laser beam penetrates the optical When the device is used, the shape of the spot matrix formed by the laser beam can be expanded, and the energy density subsequently projected on the material layer can be reduced. Looking at the optical system of the related embodiment of the present invention from another point of view, since the laser beam penetrates the double cone lens and reaches the phosphor layer in the reaction area of the phosphor wheel, the double cone lens can make the laser beam form The shape of the light spot matrix expands, and the energy density subsequently projected on the phosphor layer is reduced. Therefore, the present invention The optical system of this embodiment can reduce the energy density of the laser beam projected on the material layer (or phosphor layer) without using a diffuser, so that the optical system can have good luminous efficiency and reliability. At the same time, since the optical system of the related embodiment of the present invention does not need to use a diffuser to achieve the effect of diffusing the laser beam, the risk of damage to the diffuser is also avoided.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

1, 1’, 1”: Optical system

10, 10’, 10”: Combining light device

20: imaging device

22: Light valve

24: Projection lens

26: Total reflection

110, 120: Laser light source

130: Synthesizer

141, 142, 143: optical components

150, 170, 180: lens

160: Spectroscopic element

190: Material layer

A1: The first axis

A2: second axis

A3: third axis

A4: Fourth axis

IB: image beam

L, L1, L2: laser beam

L3: Illumination beam

L3R: Red beam

L3B: Blue beam

L3G: Green beam

LD: Packaged blue laser diode chip

PW: Fluorescent wheel

RM1, RM2, RM3: reflector

S1, S2, S3: surface

OEM, OEM’: Optical element matrix

FIG. 1 is a schematic structural diagram of an optical system according to an embodiment of the invention.

FIG. 2 is a schematic top view of the optical elements of the optical system in FIG. 1.

FIG. 3 is a distribution diagram of a matrix of light spots projected on a material layer after a laser beam passes through the optical elements of the optical system of FIG. 1.

FIG. 4 is a schematic structural diagram of an optical system according to another embodiment of the invention.

FIG. 5 is a schematic top view of another optical element of the optical system in FIG. 4.

FIG. 6 is a distribution diagram of the light spot matrix projected on the material layer after the laser beam passes through the two optical elements of the optical system of FIG. 4.

FIG. 7 is a schematic structural diagram of an optical system according to still another embodiment of the present invention.

FIG. 8 is a diagram showing the distribution of light spots projected on the material layer after the laser beam passes through the diffuser.

FIG. 9 is a diagram showing the distribution of light spots projected on the material layer after the laser beam passes through the optical element matrix of the optical system of FIG. 7.

FIG. 1 is a schematic structural diagram of an optical system according to an embodiment of the invention. FIG. 2 is a top view of optical elements of the optical system in FIG. 1. FIG. 3 is a distribution diagram of a matrix of light spots projected on a material layer after a laser beam passes through the optical elements of the optical system of FIG. 1.

The optical element referred to in the present invention refers to an optical element composed of a part or all of reflective or penetrable materials, usually including glass or plastic.

Please refer to FIG. 1. In this embodiment, the optical system 1 is a projector. The optical system 1 includes a light combining device 10 and an imaging device 20. The light combining device 10 includes a laser light source 110, a laser light source 120, a light combining element 130, an optical element 141, a lens group 150, a light splitting element 160, a lens group 170, a lens group 180, and a fluorescent wheel PW including a material layer 190 ( Phosphor Wheel), mirror RM1, mirror RM2, mirror RM3. The imaging device 20 includes a light valve 22, a projection lens 24, and a total reflection prism 26 (Total Reflection Prism). It is worth mentioning that in the aforementioned optical system, there is no need to provide a diffuser in order to have a corresponding effect. Each element in the optical system 1 will be described in the following paragraphs.

The laser light source 110 and the laser light source 120 referred to in the present invention respectively refer to a single packaged laser diode module or a matrix composed of a plurality of the aforementioned laser diode modules. The aforementioned packaged laser diode module includes a Laser Diode (LD). In this embodiment, the laser light source 110 and the laser light source 120 are respectively a plurality of packaged blue laser diode modules arranged in a matrix. The laser light source 110 can output a laser beam L1. The laser light source 120 can output a laser beam L2. The colors of the laser beam L1 and the laser beam L2 are substantially blue. The laser beam L1 and the laser beam L2 each have a spectrum. Spectrum is widely used to record the properties of light. For example, the spectrum refers to a pattern formed by light beams arranged in sequence according to the wavelength or frequency of light. The peak wavelengths (Peak Wavelength) of these spectra of laser beam L1 and laser beam L2 are between 400 nm and 470 nm, respectively. The peak wavelengths of these spectra of laser beam L1 and laser beam L2 are light intensity. The wavelength corresponding to the largest location. More specifically, the laser beam L1 and the laser beam L2 each have a corresponding Spectral Energy Distribution Curve in a spectral energy distribution map, and the peak of this distribution curve falls on the blue In the wavelength range (for example, 400 nm to 470 nm).

The light combining element 130 referred to in the present invention refers to an optical element that can combine more than one light beam to output a light beam, such as a striped mirror, a dichroic filter, a lens, or a total reflection mirror. Please refer to FIG. 1, in this embodiment, the light combining element 130 is a stripe mirror. Because the striped mirror has been widely used in the field of light combining light. In short, the light combining element 130 has a plurality of light-transmitting parts (not shown) and reflective parts (not shown) that are alternately arranged. In this embodiment, the light beam can penetrate the light combining element 130 through the light-transmitting part of the light combining element 130, and the light beam can be reflected by the reflective part of the light combining element 130.

The optical element 141 referred to in the present invention is a biconical lens (Biconic lens) or a free form lens with a positive refractive power (Positive Refractive Power). In this embodiment, the surface S1 of the optical element 141 serves as the light incident surface of the light beam. The first axis A1 and the second axis A2 perpendicular to each other on the surface S1 are provided with different radii of curvature (Radius of Curvature). In other embodiments, the optical element 141 is a free-form lens, the free-form lens is a lens with a free-form surface, and the free-form surface is not axisymmetric. The refractive power of the optical element 141 can be positive or negative. In this example, the refractive power of the optical element 141 is positive.

In this embodiment, the lens group 150 has a negative refractive power (Negative Refractive Power). Both the lens group 170 and the lens group 180 have positive refractive power. Each lens group 150, 170, 180 includes one or two or more lenses with refractive power.

The beam splitter 160 referred to in the present invention refers to a beam splitter, a polarizer, a mirror, a lens, a plate glass, a scallop, an integrating rod, a light guide rod, or a combination including at least one of the foregoing. A light beam is divided into several light beam output components. In detail, the light splitting element 160 generally refers to an optical element with a light splitting function, such as half mirrors, polarizers that use P polarity and S polarity to split light, various wave plates, various beams that use incident angles to split light, and use wavelengths. Spectroscopic splitter and so on. In this embodiment, the dichroic element 160 is a dichroic mirror (DM), which has wavelength selectivity, and is a dichroic plate that uses wavelength (color) to perform light splitting. In related embodiments, the light splitting element 160 may be an optical element with a color separation function, and for example It is a dichroic film or coating that is plated on other components. In this embodiment, the light splitting element 160 has, for example, a light splitting function that allows blue light beams to pass through and reflects yellow, red, and green light beams. Or, in this example, the light splitting element 160 can reflect blue light. Light outside the wavelength range.

The fluorescent wheel PW referred to in the present invention refers to a Reflective Phosphor Wheel, a Transmissive Phosphor Wheel, or a Transmissive Phosphor Wheel. In this embodiment, the fluorescent wheel PW is a half-through and half-trans fluorescent wheel. A light-transmitting area and a reaction area are provided on the round substrate of the semi-transmitting and semi-transmitting fluorescent wheel PW. The reaction zone of the phosphor wheel PW includes a material layer 190 and a reflective layer disposed between the material layer 190 and the substrate. The light-transmitting area and the reaction area together form a ring pattern. The material layer 190 referred to in the present invention is mixed with photoluminescent materials. More specifically, in this example, the photoluminescent material is phosphor, and the material layer 190 has to be mixed with red phosphor and green phosphor in the reaction zone according to different colors. The material layer 190 can receive the excitation light beam and generate a converted light beam with a corresponding wavelength according to the characteristics of the phosphor included in the photoluminescence phenomenon. The light-transmitting area on the fluorescent wheel PW allows the light beam to penetrate the fluorescent wheel PW. The light-transmitting layer can be a transparent material or a hollow area without material. In this example, the light-transmitting layer refers to transparent glass.

The term light valve in the present invention has been widely used in the industry. Generally speaking, it is an exponential micro-mirror device (DMD), a liquid-crystal-on-silicon panel , LCOS Panel) or any one of spatial light modulators such as transmissive LCD panels. In this embodiment, the light valve It is a digital micromirror component.

The projection lens 24 referred to in the present invention is composed of at least one lens. The projection lens 24 may be provided with an aperture diaphragm (or called an aperture), and at least one lens is provided at the front and rear of the aperture diaphragm to adjust the shape and aberration of the image beam IB. In this example, the projection lens 24 includes 10 lenses with diopters and an aperture (Aperture Stop). In another example, the projection lens 24 includes less than or equal to 20 lenses with diopters. In another example, the projection lens 24 includes less than or equal to 8 lenses with diopters.

The reflecting mirrors RM1, RM2, RM3 referred to in the present invention can be optical elements such as lenses, mirrors, convex mirrors, concave mirrors or flat mirrors for reflecting light beams. In this embodiment, the mirror RM1, the mirror RM2, and the mirror RM3 are plane mirrors, respectively.

In the following paragraphs, the arrangement of the components in the optical system 1 and the transmission process of the light beam will be exemplified.

First, the arrangement of the components in the optical system 1 of this embodiment will be explained. In this embodiment, the optical path of the laser light source 110 and the optical path of the laser light source 120 are perpendicular to each other and intersect the light combining element 130. The light emitting position of the laser light source 110 corresponds to the transparent part of the light combining element 130, and the light emitting position of the laser light source 120 corresponds to the reflecting part of the light combining element 130. The optical element 141 (double cone lens) is arranged on the optical path of the laser light source 110 and the optical path of the laser light source 120, and the optical element 141 is arranged between the laser light source 110 and the material layer 190 (phosphor layer). The lens group 150, the lens group 170, and the lens group 180 are disposed between the optical element 141 and the material layer 190 between. The lens group 150, the dichroic element 160, the lens group 170, the lens group 180, the material layer 190, the fluorescent wheel PW, the reflecting mirror RM1, the reflecting mirror RM2, and the reflecting mirror RM3 are arranged downstream of the optical path of the optical element 141 (Downstream). In the present invention, element A is downstream of the optical path of element B, which means that the light beam will pass through element B before reaching element A. The total reflection beam 26 of the imaging device 20 is disposed between the light valve 22 and the projection lens 24.

Next, the transmission process of the light beam in the optical system 1 of this embodiment will be explained again. The laser light beams L1 and L2 emitted by the laser light sources 110 and 120 are combined by the light combining element 130 and output the laser light beam L. After the laser beam L passes through the optical element 141, the lens group 150, the beam splitting element 160, the lens group 170, and the lens group 180 in sequence, it is finally transmitted to the material layer 190 or the light-transmitting layer (not shown) on the phosphor wheel PW. The motor (not shown) on the fluorescent wheel PW will rotate, and when the light beam irradiates the photoluminescent material in the material layer 190 of the fluorescent wheel PW, the material layer and the light-transmitting layer will be irradiated by the laser beam L in sequence. When the laser beam L is transmitted to the material layer 190, the material layer 190 is sequentially excited to emit a red light beam L3R and a green light beam L3G and is reflected by the reflective layer behind the material layer 190, and then passes through the lens group 180 and the lens group in sequence. 170. The beam splitting element 160 enters the imaging device 20. When the laser beam L is transmitted to the light-transmitting layer on the fluorescent wheel PW, the laser beam L will penetrate the fluorescent wheel PW and then be sequentially reflected by the mirror RM1, the mirror RM2, and the mirror RM3 and pass through the light splitting element. 160 enters the imaging device 20, as shown by the red light beam L3R, the green light beam L3G, and the blue light beam L3B in the figure, and each of the aforementioned light beams has a spectrum, and the peak wavelength of this spectrum is between 625 nm and 740. Nanometers, between 495 nanometers and 570 nanometers, and 400 Between nanometers and 475 nanometers.

Then, the illuminating light beam L3 is first transmitted to the total reflection beam 26 in the imaging device 20 and is totally reflected toward the light valve 22. After the light valve 22 converts the parts of the illumination light beam L3 into the image light beam IB according to the time sequence, the image light beam IB penetrates the total reflection beam 26 and is received by the projection lens 24. The projection lens 24 projects the image beam IB onto an imaging plane (Imaging Plane) or a screen to form an image frame.

It is worth mentioning that in this embodiment, the aspect ratio of the shape of the spot matrix formed by the laser beam L before passing through the optical element 141 is, for example, 1:1. In other words, the laser beam L The shape of the spot matrix formed by L before passing through the optical element 141 is similar to a square. The aspect ratio of the laser surface excited by the laser beam L on the material layer 190 (for example, 16:9), the laser surface is usually designed to have the aspect ratio of the light valve 22 (for example, 16 : 10) Close. In this embodiment, since the first axis A1 and the second axis A2 perpendicular to each other on the surface S1 of the optical element 141 are provided with different radii of curvature, the laser beam L can be projected to the spot matrix on the material layer 190 The shape is expanded (for example, 16:9) to conform to the aspect ratio of the laser surface of the material layer 190, and at the same time, the energy density of the laser beam L on the material layer 190 is dispersed.

It must be noted that the following embodiments follow part of the content of the previous embodiment, and for the same component names, you can refer to the part of the content of the previous embodiment.

FIG. 4 is a schematic structural diagram of an optical system according to another embodiment of the invention. FIG. 5 is a schematic top view of another optical element of the optical system in FIG. 4. Figure 6 is the projection of the laser beam after passing through the two optical elements of the optical system of Figure 4 Schematic diagram of the matrix of light spots on the material layer.

Please refer to FIG. 4, the optical system 1'of FIG. 4 is roughly similar to the optical system 1 of FIG. In this embodiment, the light combining device 10' in the optical system 1'further includes a plurality of optical elements 142 and optical elements 143. The optical elements 142 and 143 referred to in the present invention may be double cone lenses or free-form surface lenses. In this embodiment, the optical elements 142 and 143 are double cone lenses, respectively. Please refer to FIG. 5, the optical element 142 is provided with a surface S2. The third axis A3 and the fourth axis A4 perpendicular to each other on the surface S2 are provided with different radii of curvature. The optical element 143 is the same as the optical element 142. The same reference numerals and component names are similar to the description of each component of the optical system 1 in FIG. 1.

In the following paragraphs, the difference between the arrangement of the components of the optical system 1'and the optical system 1 and the transmission process of the light beam is exemplified.

In this example, the optical elements 142 and 143 are arranged on the optical paths of the laser light sources 110 and 120 and between the laser light sources 110 and 120 and the light combining element 130. In this example, a plurality of optical elements 142 and 143 are respectively arranged in front of the laser light sources 110 and 120, and the optical elements 142 and 143 are arranged in a matrix to form an optical element matrix OEM. Each optical element 142, 143 corresponds to a laser diode module in the laser light source 110, 120, and is arranged coaxially. Through the above configuration, the laser beams L1 and L2 can respectively penetrate the optical elements 142 and 143 and the optical element 141 to reach the material layer 190 in sequence. In this example, the optical element 141 is a double cone lens.

Please refer to FIG. 6 for the above, in the optical system 1'of the present embodiment, the optical element 141 expands the shape of the spot matrix formed by the laser beam L, and the optical element 142 is more sensitive to the laser beam L1 and The laser beam L2 is in the spot matrix Each light spot formed separately adjusts its shape individually. That is to say, the optical system 1'of the present embodiment can be individually expanded through the arrangement of the optical element 142 to project each light spot in the matrix of the laser beam L onto the material layer 190 (or phosphor layer). The size of the dots further reduces the energy density on the material layer 190 (or phosphor layer).

FIG. 7 is a schematic structural diagram of an optical system according to still another embodiment of the present invention. FIG. 8 is a schematic diagram of the light spot projected on the material layer after the laser beam passes through the diffuser in the prior art. FIG. 9 is a schematic diagram of the light spots projected on the material layer after the laser beam passes through the optical element matrix of the optical system of FIG. 7.

Please refer to FIG. 7. The optical system 1" of FIG. 7 is roughly similar to the optical system 1 of FIG. 1, and the differences are briefly described as follows. In this embodiment, the light combining device 10" in the optical system 1" It does not have the laser light source 120, the optical element 142, the light combining element 130, and the lens group 1506. The same reference numerals and element names are similar to the description of each element of the optical system 1 in FIG. 1 and the optical system 1" in FIG. No longer. However, in another example, the laser light source 120 and the light combining element 130 can be selectively added by referring to other embodiments to increase the intensity of the laser beam.

The arrangement of the optical system 1" and the transmission process of the light beam are exemplarily described in the following paragraphs. The plurality of optical elements 141 of the optical system 1" are arranged in a matrix and closely arranged to form an optical element matrix OEM'. Each optical element 141 corresponds to a laser diode module in the laser light source 110 and is arranged coaxially, and the surface S1 of the optical element 141 serves as the light exit surface of the light beam.

Then, the laser beam L1 sequentially penetrates the optical element 141 and the beam splitting element 160, the lens group 170, and the lens group 180 are finally transferred to the material layer 190 on the phosphor wheel PW, and the transmission process is similar to that of the optical system 1.

Please refer to Figure 8 and Figure 9. After comparing Figure 8 with Figure 9, it can be seen that the laser beam L1 passes through the optical element matrix OEM' and then projects on the material layer 190 to diffuse the light spots (as shown in Figure 9). It is obvious that the light spot projected on the material layer 190 through the diffusion sheet diffuses the effect (as shown in FIG. 8). In other words, the diffusion effect of the optical system 1" of the present embodiment on the laser beam L is better than the diffusion effect of the method of using a diffusion sheet in the prior art.

In summary, in the optical system of the related embodiment of the present invention, since the first axis and the second axis that are perpendicular to each other on the surface of the optical element in the optical system are provided with different radii of curvature, when the laser beam penetrates With this optical element, the shape of the spot matrix formed by the laser beam can be expanded, and the energy density subsequently projected on the material layer can be reduced. Looking at the optical system of the related embodiment of the present invention from another point of view, since the laser beam penetrates the double cone lens and reaches the phosphor layer in the reaction zone of the phosphor wheel, the double cone lens can make the light formed by the laser beam The shape of the dot matrix expands and reduces the energy density subsequently projected on the phosphor layer. Therefore, the optical system of the related embodiment of the present invention can reduce the energy density of the laser beam projected on the material layer (or phosphor layer) without using a diffuser, thereby enabling the optical system to have good luminous efficiency. And reliability. At the same time, since the optical system of the related embodiment of the present invention does not need to use a diffuser to achieve the effect of diffusing the laser beam, the risk of damage to the diffuser is also avoided.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Inventions, any person with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be defined as the scope of the appended patent application. quasi.

1‧‧‧Optical system

10‧‧‧Combined light device

20‧‧‧Imaging device

22‧‧‧Light valve

24‧‧‧Projection lens

26‧‧‧Total reflection

110、120‧‧‧Laser light source

130‧‧‧Combined light element

141‧‧‧Optical components

150、170、180‧‧‧lens

160‧‧‧Splitter element

190‧‧‧Material layer

IB‧‧‧Image beam

L, L1, L2‧‧‧Laser beam

L3‧‧‧Illumination beam

L3R‧‧‧Red beam

L3B‧‧‧Blue beam

L3G‧‧‧Green beam

LD‧‧‧Packed blue laser diode chip

PW‧‧‧Fluorescent Wheel

RM1, RM2, RM3‧‧‧Mirror

S1‧‧‧surface

Claims (10)

An optical system, comprising: a first laser light source capable of outputting a first laser beam; a first optical element arranged on the optical path of the first laser light source, and the first optical element is provided with a first surface , A first axis and a second axis perpendicular to each other on the first surface are provided with different radii of curvature; a lens matrix is arranged on the optical path of the first laser light source and located between the first laser light source and the Between the first optical elements; and a first material layer arranged at the downstream of the optical path of the first optical element, the first material layer containing a photoluminescent material. According to the optical system described in claim 1, wherein the first optical element is a double cone lens or a free-form surface lens, and the refractive power of the first optical element is positive. The optical system described in item 2 of the scope of patent application, wherein the lens matrix includes a second optical element, the second optical element is provided with a second surface, a third axis and a first axis perpendicular to each other on the second surface Four axes are provided with different radii of curvature, and the first optical element and the first material layer are arranged downstream of the optical path of the second optical element. The second optical element is a double cone lens or a free-form surface lens. The diopter of the second optical element is positive. The optical system described in item 3 of the scope of patent application further includes: a second laser light source capable of outputting a second laser beam; A third optical element is arranged on the optical path of the second laser light source, the third optical element is provided with a third surface, and a fifth axis and a sixth axis perpendicular to each other on the third surface are provided with different The radius of curvature, and the first optical element and the first material layer are arranged downstream of the optical path of the third optical element, the third optical element is a double cone lens or a free-form surface lens, and the refractive power of the third optical element is positive. For example, the optical system described in item 4 of the scope of patent application further includes: a light combining element disposed on the optical path of the first laser light source and the second laser light source, and the light combining element can reflect the first laser light source. Either one of the beam and the second laser beam is penetrated by the other; and a lens having a positive refractive power, the lens being arranged between the first optical element and the first material layer. The optical system described in the first item of the scope of patent application, wherein the lens matrix includes a second optical element, and the optical system further includes: a second laser light source capable of outputting a second laser beam; and a third An optical element is arranged on the optical path of the second laser light source, and the third optical element is arranged between the second laser light source and the first optical element; a lens having a positive refractive power, and the lens is arranged on the first optical element. Between an optical element and the first material layer; and a light combining element disposed on the optical path of the first laser light source and the second laser light source, the light combining element can reflect the first laser beam and Any one of the second laser beams, and make the other penetrate; Wherein, the first optical element, the second optical element and the third optical element are respectively a double cone lens or a free-form surface lens, and the refractive power of the first optical element, the second optical element and the third optical element The diopter of the element is positive, the first material layer is a fluorescent wheel, and the light combining element is a striped mirror. An optical system comprising: a first laser light source capable of emitting a first laser beam; a phosphor layer located on the optical path of the first laser beam; and a first double cone lens arranged on the first laser beam Between a laser light source and the phosphor layer and located on the traveling path of the first laser beam, so that the first laser beam can penetrate the first biconical lens to reach the phosphor layer; and A lens matrix is arranged on the optical path of the first laser light source and located between the first laser light source and the first biconical lens. The optical system according to claim 7, wherein the lens matrix includes a second double cone lens, and the first laser beam can sequentially penetrate the second double cone lens and the first double cone lens. When reaching the phosphor layer, the refractive powers of the first biconical lens and the second biconical lens are respectively positive. For example, the optical system described in item 8 of the scope of patent application further includes a second laser light source capable of emitting a second laser beam, and a third laser light source is provided between the second laser light source and the first biconical lens. A double cone lens, the second laser beam can sequentially penetrate the third double cone lens and the first double cone lens to reach the phosphor layer, wherein the refractive power of the third double cone lens is positive. For example, the optical system described in claim 7 further includes a fluorescent wheel including the reaction zone and a light-transmitting zone, and the reaction zone is provided with the phosphor layer.

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