WO2022017275A1

WO2022017275A1 - Light source system and projection system

Info

Publication number: WO2022017275A1
Application number: PCT/CN2021/106743
Authority: WO
Inventors: 陈晨; 余新; 胡飞; 李屹
Original assignee: 深圳光峰科技股份有限公司
Priority date: 2020-07-22
Filing date: 2021-07-16
Publication date: 2022-01-27
Also published as: CN113970871A

Abstract

Disclosed are an optical system and a projection system. The light source system comprises a first light source, a second light source, a light combining assembly, a compound eye lens set and a collection lens, wherein the first light source is configured to emit a first light beam; the second light source is configured to emit a second light beam, and the optical extension of the first light beam is larger than that of the second light beam; the light combining assembly is configured to combine the first light beam and the second light beam; the compound eye lens set comprises a first compound eye lens and a second compound eye lens, and is configured to homogenize the combined first light beam and second light beam; and the collection lens is located on a side of the compound eye lenses that are far away from the light combining assembly, and is configured to focus the first light beam and the second light beam that are homogenized, wherein the second compound eye lens is located between the first compound eye lens and the collection lens, and is arranged to deviate from the focal point of the collection lens. The present application improves the uniformity of the color and brightness and the safety of the light source system by means of arranging the second compound eye lens to deviate from the focal point of the collection lens.

Description

A light source system and a projection system

technical field

The present application relates to the field of optical technology, and in particular, to a light source system and a projection system.

Background technique

At present, in the field of display (such as projection), the light source of laser plus fluorescence has been widely used. For example, some light sources need to consider the yellow fluorescence (or red fluorescence + green fluorescence) of red, green and blue laser and blue laser. When combining light, the light source also needs to consider uniform light when combining light. In the related art, square rods or fly-eye lenses are often used for uniform light solutions.

In the long-term research and development process, the inventors of the present application found that in the current light source system, when the laser and fluorescence light is homogenized using a fly-eye lens, the laser angle distribution of the homogenized spot will be discretized, which affects the light source. The brightness uniformity of the system, the color uniformity and the safety of the light source.

SUMMARY OF THE INVENTION

The main technical problem to be solved by the present application is to provide a light source system and a projection system, by sacrificing the telecentricity characteristic to weaken the discreteness of the angular distribution of the homogenized light spot, so as to improve the uniformity of the brightness and color of the light source system and the safety of the light source .

In order to solve the above technical problem, a technical solution adopted in the present application is to provide a light source system, the light source system includes: a first light source for emitting a first light beam; a second light source for emitting a second light beam, the first light source The etendue of the light beam is greater than that of the second light beam; the light combining component is used for combining the first light beam and the second light beam; the fly-eye lens group includes a first fly-eye lens and a second fly-eye lens, which is used for combining the light beams The first light beam and the second light beam are homogenized; the collecting lens is located on the side of the fly-eye lens away from the light combining component, and is used for focusing the first and second light beams after the homogenization, wherein the second fly-eye lens is located in the first light beam and the second light beam. A fly-eye lens and the collecting lens are arranged between and offset from the focal point of the collecting lens.

Further, the front focal plane of the collecting lens is located upstream of the optical path of the second fly-eye lens.

Further, the first fly-eye lens includes a first micro-lens unit arranged in an array; the second fly-eye lens includes a second micro-lens unit arranged in an array; the first micro-lens unit is in one-to-one correspondence with the second micro-lens unit, and the The structures of the first microlens unit and the second microlens unit are the same.

Further, the broadening angle δ of the light emitted by the single second microlens unit after passing through the collecting lens satisfies the following formula:

Among them, a is the side length of the longer side of the second micro-lens unit, and f _BFL is the equivalent back focal length of the collecting lens.

Further, the collecting lens is a single lens.

Further, the collecting lens is a combination of at least two lenses.

Further, the light source system also includes a first relay lens, the first relay lens is located between the light combining component and the fly-eye lens group, and is used for collecting the combined first and second light beams to the first fly-eye lens. The first preset area.

Further, the first light source is a fluorescent light source, the second light source is a laser light source, and the laser light source includes at least one green laser emitting green excitation light, at least one red laser emitting red excitation light, and at least one emitting blue excitation light. blue laser.

Further, the light source system further includes a second relay lens, and the relay lens group is located between the second light source and the light combining component, and is used for collecting the second light beam emitted by the second light source to the second preset area of the light combining component. .

In order to solve the above technical problem, another technical solution adopted in the present application is to provide a projection system, which includes the light source system of any of the above-mentioned embodiments and a spatial light modulator located on the light exit light path of the light source system. The device is used to modulate the light beam emitted by the light source system into image light carrying image information.

The beneficial effects of the present application are: different from the prior art, the light source system of the present application includes a first light source for emitting a first light beam, a second light source for emitting a second light beam, a light combining component, a fly-eye lens group and a collection lens, the etendue of the first beam is greater than that of the second beam, the light combining component is used to combine the first beam and the second beam to obtain the combined light after the first beam and the second beam are combined, and the fly-eye lens group It is used to homogenize the combined light after the first beam and the second beam are combined, and the collecting lens is used to focus the first beam and the second beam after the homogenization, wherein the second fly-eye lens deviates from the focus of the collecting lens In this way, the first light beam and the second light beam after homogenizing through the fly-eye lens group can still have a certain diffusion angle after passing through the collecting lens, so that the energy of the first light beam and the second light beam after homogenizing The distribution is relatively consistent; that is, the present application reduces the dispersion of the angular distribution of the homogenized second beam spot by sacrificing the high beam characteristics, which is beneficial to improve the uniformity of the brightness and color of the light source system and the safety of the light source system.

Description of drawings

1 is a schematic structural diagram of an embodiment of a light source system provided by the present application;

FIG. 2 is a schematic diagram of the optical path structure of an embodiment of the fly-eye lens group and the collecting lens in FIG. 1;

3 is a schematic view of the optical path structure in the fly-eye lens group in FIG. 1;

4 is a schematic structural diagram of a double-telecentric design fly-eye lens and a collecting lens in the related art;

5 is a schematic diagram of the distribution of an embodiment of the fly-eye lens group and the collecting lens in FIG. 1;

FIG. 6 is a schematic structural diagram of an embodiment of a projection system provided by the present application.

detailed description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

Please refer to FIG. 1. FIG. 1 is a schematic structural diagram of an embodiment of a light source system provided by the present application. The light source system in this embodiment includes at least two light sources, which are a first light source 1 and a second light source 2, respectively. The first light source 1 uses For emitting the first light beam, the second light source 2 is used for emitting a second light beam, wherein the etendue of the first light beam is larger than that of the second light beam.

The first light source 1 refers to a light source with a large etendue of the outgoing light beam, for example, the first light source 1 may be a fluorescent light source, and the first light beam may be a fluorescent light beam; the second light source 2 refers to the optical expansion of the outgoing light beam The light source with a smaller quantity, for example, the second light source 2 may be a laser light source, and the second light beam may be a laser light beam. In a specific embodiment, the first light source 1 may include an excitation light source (not shown) and a fluorescent color wheel (not shown). The excitation light emitted by the excitation light source, such as blue laser, is incident on the fluorescent color wheel, and the fluorescent color The wheel generates corresponding fluorescence under the irradiation of excitation light, for example, the first light beam can be yellow fluorescence, or the first light beam can also be red fluorescence and green fluorescence. The second light source 2 may include a red laser 201 emitting red excitation light, a green laser 202 emitting green excitation light, and a blue laser 203 emitting blue excitation light.

As shown in FIG. 1 , the light source system further includes a light combining component 3 , a fly-eye lens group 4 and a collecting lens 5 .

Specifically, the light combining component 3 is used to combine the first light beam and the second light beam with different etendues, so as to obtain a combined light after the first light beam and the second light beam are combined. As shown in FIG. 1 , for light combining, a reflection film 31 can be arranged on the light combining component 3 by using the idea that the etendue of the second light beam is smaller than that of the first light beam, so as to combine the first light beam and the second light beam. Since the etendue of the second light beam is smaller than that of the first light beam, the second light beam can be incident on the reflective film 31 of the light combining component 3 through beam control, and then exit after being reflected; while the etendue of the first light beam It is relatively large, and the first light beam is incident on the peripheral transmission area of the light combining component 3 through beam control, and then exits after being transmitted. The first light beam incident on the reflective film 31 of the light combining component 3 is reflected, which will reduce the efficiency of the first light beam. Therefore, the area of the reflective film can be designed to be as small as possible.

The fly-eye lens group 4 includes a first fly-eye lens 41 and a second fly-eye lens 42, which are used to uniformize and shape the combined first beam and the second beam, and the shaping can form a predetermined spot shape, such as Rectangle, square, etc. The first fly-eye lens 41 is located between the light combining component 3 and the second fly-eye lens 42 , that is, the combined light after the combining of the first beam and the second beam passes through the first fly-eye lens 41 and the second fly-eye lens 42 in turn for Homogenization and shaping.

The fly-eye lens group 4 may be a single-piece double-fly-eye lens or a double-piece single-fly-eye lens. Specifically, the single-piece double-fly-eye lens refers to that a plurality of microlenses are provided on opposite surfaces of the single-piece lens. Wherein, the two opposite faces may be the first fly-eye lens 41 and the second fly-eye lens 42 in this embodiment, respectively.

Preferably, the fly-eye lens group 4 can also be a double-piece single fly-eye lens, that is, the first fly-eye lens 41 and the second fly-eye lens 42 are arranged in a mirror image. The first fly-eye lens 41 includes first micro-lens units 411 arranged in an array; the second fly-eye lens 42 includes a second micro-lens unit 421 arranged in an array. The first micro-lens unit 411 and the second micro-lens unit 421 are one The first micro-lens unit 411 and the second micro-lens unit 421 corresponding to one another and disposed correspondingly may be convex lenses with exactly the same shape.

More preferably, the distance between the first fly-eye lens 41 and the second fly-eye lens 42 is equal to the focal length of the first microlens unit 411 or the second microlens unit 421 . In this way, the first microlens unit 411 can be imaged on the second microlens unit 421, so as to achieve a uniform output of the light beam.

The collecting lens 5 is located on the side of the fly-eye lens group 4 away from the light combining component 3, and is used for focusing the first beam and the second beam after homogenization. As shown in FIG. 2, FIG. 2 is a schematic diagram of the optical path structure of an embodiment of the fly-eye lens group 4 in FIG. 1. The light beam emitted by the first micro-lens unit 411 propagates parallel to the optical axis after passing through the corresponding second micro-lens unit 421, After passing through the collecting lens 5 , it converges on the back focal plane BFP of the collecting lens 5 . When the collection lens is a double lens group 5, through the beam after _1, from the principal plane of the second lens group PP2 double exit first principal plane PP of the dual focus lens group to the back focal plane BFP two lens groups.

Due to the difference in etendue, the etendue of the first light beam is relatively large, so the spot area of the first light beam in the light combining component 3 is relatively large, in contrast, the etendue of the second light beam is relatively small. As shown in FIG. 3 , after passing through the first fly-eye lens 41 , the first light beam can have a larger expanded light spot on the second fly-eye lens 42 , and the light energy density distribution is relatively uniform; while the second light beam is on the second fly-eye lens 42 The light spot is small and the light energy density distribution is not uniform.

In this embodiment, the second fly-eye lens 42 is located between the first fly-eye lens 41 and the collecting lens 5 and is deviated from the focal point of the collecting lens 5 . That is, adjusting the front focal plane FFP of the collecting lens 5 to the optical path upstream of the second fly-eye lens 42 or adjusting the front focal plane FFP of the collecting lens 5 to the optical path downstream of the second fly-eye lens 42, so that the second fly-eye lens The distance between 42 and the collecting lens 5 is smaller or greater than the focal length of the collecting lens 5 . In this way, the second light beam after the uniform light of the fly-eye lens group 4 can still have a certain diffusion angle after passing through the collecting lens 5, so that the energy distributions of the first light beam and the second light beam after the uniform light are relatively consistent, so that the energy distribution of the uniform light beam is relatively consistent. Improve the brightness and color uniformity of the light source system and improve the safety of the light source.

Specifically, as shown in FIG. 4 , if the distance between the collecting lens 5 and the second fly-eye lens 42 is equal to the focal length of the collecting lens 5 , that is, the front focal plane FFP of the collecting lens 5 and the second fly-eye lens 42 are spatially coincident with each other, then the parallel The light beam incident on the first microlens unit 411 on the optical axis converges on the front focal plane FFP of the collecting lens 5 after the second fly-eye lens 42 , and irradiates on the back focal plane BFP of the collecting lens 5 in a parallel manner. That is to say, the angular distribution of the light beam incident on the first fly-eye lens 41 is mapped to the angular distribution of the back focal plane BFP, and the angular distribution corresponding to the back focal plane BFP of the collecting lens 5 presents a certain separation, and it can be seen that the homogenized light spot 8 The angular distribution is at discrete points and discretization occurs. Specifically, the energy of the second beam in a certain angle range is too concentrated, while the energy distribution at other angles is less, resulting in a ratio of the first beam and the second beam at a certain angle is more than the ideal value, and other At some angles, the ratio of the first light beam and the second light beam is less than the ideal value, so that problems of brightness uniformity and color uniformity occur. This affects the brightness uniformity, color uniformity, and safety of the light source system.

As shown in FIG. 5 , in this embodiment, by adjusting the position of the second fly-eye lens 42 to a position deviating from the focal point of the collecting lens 5 , the chief ray incident on the back focal plane BFP of the collecting lens 5 is no longer parallel to the optical axis It has a certain diffusion angle, so that the discreteness of the angular distribution of the homogenized light spot 8 can be better solved.

Preferably, the front focal plane FFP of the collecting lens 5 is adjusted to the upstream direction of the optical path of the second fly-eye lens 42, so that the distance between the second fly-eye lens 42 and the collecting lens 5 is smaller than the focal length of the collecting lens 5, so that the The split light spot on the second fly-eye lens 42 is within one focal length of the collecting lens 5 , and then passes through the collecting lens 5 for imaging, which can better homogenize the angular distribution of the light beam on the back focal plane BFP of the collecting lens 5 .

Specifically, in this embodiment, the broadening angle δ of the light beam emitted by the single second micro-lens unit 421 after passing through the collecting lens 5 is related to the equivalent front focal length of the collecting lens 5 and the front focal plane FFP of the collecting lens 5 and the first _{The function of the distance d 1} of the two fly-eye lens arrays, preferably, δ satisfies the following formula:

Wherein, a is the side length of the longer side of the second micro-lens unit 421 , and f _BFL is the equivalent back focal length of the collecting lens 5 . In this way, the light spot 8 on the rear focal plane of the collecting lens 5 can exhibit a relatively uniform angular distribution.

Optionally, the collecting lens 5 can be a single lens, and when the collecting lens 5 is a single lens, the structure of the entire light source system can be simpler, the design is convenient, and the cost is saved.

In other embodiments, the collecting lens 5 may also be a combination of at least two lenses. When the collecting lens 5 is a combination of at least two lenses, it can also be equivalent to a single lens. In a specific embodiment, the collecting lens 5 can be a simple double-thin lens group, the first principal plane PP1 of the collecting lens 5 is coincident with the first lens, and the second principal plane PP2 of the collecting lens 5 is coincident with the second lens where the focal length of the first lens is f1, the focal length of the second lens is f2, and the distance between the first principal plane PP1 and the second principal plane PP2 is d, then the equivalent focal length of the collecting lens 5 The formula for calculating fEFL is:

The calculation formula of the equivalent back focal length f _{BFL of the collecting lens 5 is:}

The equivalent front focal length fFEL of the collecting lens 5 is:

When the collecting lens 5 is a combination of multiple lenses, the distance between the collecting lens 5 and the second fly-eye lens 42 is relatively short, and the volume of the entire light source system can be reduced.

In this embodiment, setting the second fly-eye lens 42 at a position deviating from the focal point of the collecting lens 5 can make the second light beam homogenized by the fly-eye lens group 4 still have a certain diffusion angle after passing through the collecting lens 5, so that the The energy distributions of the first beam and the second beam after homogenization are relatively consistent; the present application sacrifices the characteristics of the high beam to a certain extent to weaken the discreteness of the angular distribution of the homogenized spot of the second beam, which is beneficial to improve the brightness and brightness of the light source system. The uniformity of color and the improvement of the safety threshold of the light source system make the light source system more applicable.

Optionally, as shown in FIG. 1 , the light source system further includes a first relay lens 6, and the first relay lens 6 is located between the light combining component 3 and the fly-eye lens group 4, and is used to make the combined first light beam. and the second light beam are concentrated to the first preset area of the first fly-eye lens 41 . In this embodiment, the first relay lens 6 straightens the first light beam and the second light beam and then enters the fly-eye lens group 4 . Both the first light beam and the second light beam combined by the light combining component 3 are focused by the first relay lens 6 and then emitted, so as to improve the utilization rate of the light beam by the subsequent optical path system. That is to say, after the combined first beam and the second beam pass through the first relay lens 6, the optical axes of the two beams are approximately coincident, and the divergence angles of the combined two beams also become smaller, so that This is beneficial to the subsequent uniform light treatment of the fly-eye lens group 4 .

Optionally, as shown in FIG. 1 , the light source system may further include a second relay lens 7 , which is located between the second light source 2 and the light combining component 3 and is used to transmit the light emitted by the second light source 2 . The second light beam is collected to the second predetermined area of the light combining component 3 . In this embodiment, the second light beam can be incident on the reflective film 31 of the light combining component 3 through the beam control of the second relay lens 7 .

The light source system of this embodiment can effectively improve the problem of discretization of the angular distribution after combining the first light beam and the second light beam due to different etendues. It is beneficial to improve the uniformity of brightness and color of the light source system, improve the safety threshold of the light source system, and enhance the applicability of the light source system.

As shown in FIG. 6 , the present application further provides a projection system, which includes the light source system 61 of any of the above embodiments and a spatial light modulator 62 located on the light exit path of the light source system 61 .

The spatial light modulator 62 is used to modulate the light beam emitted by the light source system 61 into image light carrying image information. Spatial light modulator 62 may be a single-chip or multi-chip spatial light modulator.

The spatial light modulator 62 may be a reflective display element, for example, the spatial light modulator 62 may be a DMD (Digital Micro mirror Device, digital micro mirror device). In other alternative embodiments, the spatial light modulator 62 may also be LCOS (Liquid Crystal On Silicon, liquid crystal display on silicon), LCD (Liquid Crystal Display, liquid crystal display), and the like.

For the specific structure of the light source system 61 , please refer to the text of the above-mentioned embodiments and the related descriptions of the drawings, which will not be repeated here.

In the projection system of the present embodiment, the second fly-eye lens of the light source system 61 is deviated from the focal point of the collecting lens, and the telecentricity characteristic is sacrificed to improve the combined effect of the first beam and the second beam due to the difference in etendue. The problem of discretization of the light beam homogenization spot angle distribution can improve the brightness and color uniformity of the light source system 61, thereby improving the effect of the projection system.

The above description is only an embodiment of the present application, and is not intended to limit the scope of the patent of the present application. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present application, or directly or indirectly applied to other related technologies Fields are similarly included within the scope of patent protection of this application.

Claims

A light source system, characterized in that the light source system comprises:

a first light source for emitting a first light beam;

a second light source, configured to emit a second light beam, the etendue of the first light beam is greater than that of the second light beam;

a light combining component for combining the first light beam and the second light beam;

A fly-eye lens group, comprising a first fly-eye lens and a second fly-eye lens, used for homogenizing the combined first light beam and the second light beam;

a collecting lens, located on the side of the fly-eye lens away from the light combining component, used for focusing the first beam and the second beam after uniform light,

Wherein, the second fly-eye lens is located between the first fly-eye lens and the collecting lens, and is deviated from the focal point of the collecting lens.
The light source system according to claim 1, wherein the front focal plane of the collecting lens is located upstream of the optical path of the second fly-eye lens.
The light source system according to claim 2, wherein,

The first fly-eye lens includes first microlens units arranged in an array;

The second fly-eye lens includes second microlens units arranged in an array;

The first microlens unit corresponds to the second microlens unit one-to-one, and the structures of the first microlens unit and the second microlens unit are the same.
The light source system according to claim 3, wherein the broadening angle δ of the light emitted by the single second microlens unit after passing through the collecting lens satisfies the following formula:

Where, a is the side length of the longer side of the second microlens unit, and f BFL is the equivalent back focal length of the collecting lens.
The light source system according to claim 1, wherein the collecting lens is a single lens.
The light source system according to claim 1, wherein the collecting lens is a combination of at least two lenses.
The light source system according to claim 1, wherein the light source system further comprises a first relay lens, the first relay lens is located between the light combining component and the fly-eye lens group, and is used for The combined first light beam and the second light beam are collected to a first preset area of the first fly-eye lens.
The light source system according to claim 1, wherein the first light source is a fluorescent light source, the second light source is a laser light source, and the laser light source comprises at least one green laser emitting green excitation light, at least one A red laser emitting red excitation light and at least one blue laser emitting blue excitation light.
The light source system according to claim 8, wherein the light source system further comprises a second relay lens, and the relay lens group is located between the second light source and the light combining component, and is used for combining The second light beam emitted by the second light source is collected to a second preset area of the light combining component.
A projection system, characterized in that the projection system comprises the light source system according to any one of claims 1-9 and a spatial light modulator located on the light exit light path of the light source system, and the spatial light modulator is used for converting The light beam emitted by the light source system is modulated into image light carrying image information.