WO2022078436A1

WO2022078436A1 - Projection optical system

Info

Publication number: WO2022078436A1
Application number: PCT/CN2021/123772
Authority: WO
Inventors: 李巍; 顾晓强; 田有良
Original assignee: 青岛海信激光显示股份有限公司
Priority date: 2020-10-14
Filing date: 2021-10-14
Publication date: 2022-04-21
Also published as: CN114371587A; CN116391154A

Abstract

A projection optical system, which belongs to the technical field of optoelectronics. A plurality of lasers (101) in a light source assembly correspond to a plurality of light combiner groups (102) on a one-to-one basis; each light combiner group (102) is located on a light-emitting side of the corresponding laser (101); each laser (101) is used for emitting laser to the corresponding light combiner group (102); the light combiner groups (102) are used for mixing incident laser and reflecting same to a beam shrinkage component (103); and the beam shrinkage component (103) is used for performing beam shrinkage on the incident laser and then emitting same, wherein on a reference plane perpendicular to an optical axis (G) of the projection optical system, the laser emitted by each light combiner group (102) forms a light spot, and a plurality of light spots formed by the laser emitted by the plurality of light combiner groups (102) are symmetrically distributed.

Description

Projection Optical System

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of the Chinese patent application filed on October 14, 2020 with the application number 202011094793.X and the title of the invention is projection optical system, the entire contents of which are incorporated into this application by reference.

technical field

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

Background technique

With the development of optoelectronic technology, the requirements for the display effect of the projection screen of the projection device are getting higher and higher. However, the brightness of the projection image formed in the related art is low, and the display effect of the projection image is poor.

SUMMARY OF THE INVENTION

The application provides a projection optical system, and the technical solution is as follows:

A projection optical system is provided, the projection optical system includes: a plurality of lasers, a plurality of light combining lens groups and a beam reducing component;

The multiple lasers are in one-to-one correspondence with the multiple light-combining mirror groups, each of the light-combining mirror groups is located on the light-emitting side of the corresponding laser, and each of the lasers is used to send the corresponding light-combining mirror group to the light-emitting side. emits laser light, and the light combining mirror group is used to mix the incident laser light and reflect it to the beam reduction component, and the beam reduction component is used to reduce the beam of the incident laser light and emit it;

Wherein, on a reference plane perpendicular to the optical axis of the projection optical system, the laser light emitted by each light combining mirror group forms a light spot, and the laser light spots formed by the laser light emitted by the plurality of light combining mirror groups are symmetrically distributed.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the drawings that are used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic structural diagram of a projection optical system in a projection device provided by the related art;

2 is a schematic structural diagram of a projection optical system provided by an embodiment of the present application;

3 is a schematic diagram of a light spot formed on a reference plane provided by an embodiment of the present application;

4 is a schematic diagram of a light spot formed on another reference plane provided by an embodiment of the present application;

5 is a schematic structural diagram of another projection optical system provided by an embodiment of the present application;

6 is a schematic structural diagram of yet another projection optical system provided by an embodiment of the present application;

7 is a schematic structural diagram of yet another projection optical system provided by an embodiment of the present application;

8 is a schematic diagram of the distribution of light spots on a converging lens provided by an embodiment of the present application;

9 is a schematic diagram of the distribution of light spots on another converging lens provided by an embodiment of the present application;

FIG. 10 is a schematic diagram of the distribution of light spots on yet another converging lens provided by an embodiment of the present application;

11 is a schematic diagram of the distribution of light spots on yet another converging lens provided by an embodiment of the present application;

12 is a schematic structural diagram of a projection optical system provided by another embodiment of the present application;

13 is a schematic structural diagram of another projection optical system provided by another embodiment of the present application;

FIG. 14 is a schematic structural diagram of still another projection optical system provided by another embodiment of the present application.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

At present, laser projection equipment is more and more favored by users due to its miniaturization and convenience of use, and the requirements for the display effect of the projection screen of the projection equipment and the size of the projection screen are also higher and higher. However, the brightness of the projection picture of the current laser projection equipment is low, the display effect of the projection picture is poor, and it is difficult to support the normal display of the large-sized projection picture. FIG. 1 is a schematic structural diagram of a projection optical system in a projection device provided by the related art. As shown in FIG. 1, in the related art, the projection optical system includes a laser 001, a combining lens group 002, a beam reducing lens group 003, a condensing lens 004, a light pipe 005, a light valve and a lens. The lens is indicated. The laser 001 can emit laser light to the light combining lens group 002, and the light combining lens 002 mixes the incident laser light and reflects it to the beam reducing mirror group 003 for beam reduction, and then shoots toward the condensing lens 004, and the condensing lens 004 converges the incident laser light. to the light pipe 005, and then the laser light is homogenized by the light pipe 005 and then modulated by a light valve, and then projected through a lens to form a projection image.

The following embodiments of the present application provide a projection optical system, which can improve the display effect of a projection picture of a projection device and increase the size of a projection picture that the projection device can support to display.

FIG. 2 is a schematic structural diagram of a projection optical system provided by an embodiment of the present application. As shown in FIG. 2 , the projection optical system includes: a plurality of lasers 101 , a plurality of light combining lens groups 102 and a beam reducing component 103 . The multiple lasers 101 are in one-to-one correspondence with multiple light combining mirror groups 102, each light combining mirror group 102 is located on the light-emitting side of the corresponding laser 101, and each laser 101 is used to emit laser light to the corresponding light combining mirror group 102, The light combining mirror group 102 is used to mix the incident laser light and reflect it to the beam reducing component 103 , and the beam reducing component 103 is used to reduce the beam of the incident laser light and then emit it.

Wherein, on the reference plane perpendicular to the optical axis G of the projection optical system, the laser light emitted by each light combining mirror group 102 forms a light spot, and the multiple light spots formed by the laser light emitted by the plurality of light combining mirror groups 102 are symmetrically distributed.

To sum up, the projection optical system provided by the embodiments of the present application includes a plurality of lasers, so that the brightness of the laser light used to form the projection image can be relatively high. The laser beams emitted by the multiple light combining mirror groups corresponding to the multiple lasers can form multiple light spots symmetrically distributed on the reference plane, which can ensure that the laser light used by the projection optical system to form the projection image is distributed evenly. Therefore, the laser beam used by the projection optical system of the present application for forming the projection screen has high brightness and high uniformity, and the projection screen formed by the laser has a better display effect.

In one embodiment, the reference plane may be a plane perpendicular to the optical axis of any component of the projection optical system. For example, as shown in FIG. 2 , the beam reducing member 103 includes a convex lens 1031 and a concave lens 1032 . The laser light emitted by the light combining lens group 102 can be directed to the convex lens 1031 first, and then converged by the convex lens 1031 to the concave lens 1032, and the concave lens 1032 can collimate the incident laser light and then emit it to achieve the beam reduction effect of the laser light. The reference plane may be a plane through the center of a convex lens, or a plane through the center of a concave lens. In one embodiment, the reference plane may also be a virtual plane in the laser transmission path of the projection optical system.

In an example, the multiple light spots formed on the reference plane by the laser beams emitted by the multiple light combining lens groups may be symmetrical about the intersection line between the reference plane and the target plane where the optical axis is located, and the target plane may be where the optical axis is located. any plane. The embodiment of the present application takes the projection optical system including two lasers and two light combining lens groups as an example. FIG. 3 is a schematic diagram of a light spot formed on a reference plane provided by the embodiment of the present application. As shown in FIG. 3 , the two light spots G formed by the two light combining lens groups on the reference plane C may be symmetrical about a line S, which is the intersection of the reference plane C and the target plane where the optical axis Z is located.

In another example, the multiple light spots formed on the reference plane by the laser light emitted by the multiple light combining lens groups may be centrally symmetric with respect to the intersection of the reference plane and the optical axis. FIG. 4 is a schematic diagram of a light spot formed on another reference plane provided by an embodiment of the present application. As shown in FIG. 4 , the two light spots G formed by the two light combining lens groups on the reference plane C may be centrally symmetric with respect to the point D, which is the intersection of the reference plane C and the optical axis.

In one embodiment, the multiple light spots formed on the surface of any optical component in the projection optical system by the laser light emitted by the multiple light combining lens groups may be symmetrically distributed, and the surface may or may not be a planar surface. For example, the light spots formed on the light incident surface or light emitting surface of the convex lens by the laser light emitted by the multiple light combining lens groups are symmetrically distributed. Also distributed symmetrically. In one embodiment, both the light incident surface and the light exit surface of the convex lens are convex arc surfaces, and the light entrance surface and the light exit surface of the concave lens are both concave arc surfaces. For example, the multiple light spots formed on the light incident surface or the light exit surface of the convex lens by the laser light emitted by the multiple light combining lens groups can be directly symmetrical with respect to the target plane where the optical axis is located, that is, the multiple light spots can be plane-symmetrical. . The symmetrical distribution of the multiple light spots on the optical component means that the irradiation positions of the laser light emitted by the multiple light combining mirror groups on the optical component are symmetrically distributed, such as symmetrical about the target plane where the optical axis is located.

FIG. 5 is a schematic structural diagram of another projection optical system provided by an embodiment of the present application. As shown in FIG. 5 , the projection optical system may further include: a rectangular light valve 107 . The beam constricting component 103 can condense the incoming laser beam and emit it to the light valve 107 , and the light spot formed by the laser beam on the light valve 107 can be axially symmetrical about the center line of the rectangle. The median line of the rectangle is also the line connecting the midpoints of two opposite sides of the rectangle, and the median line is parallel to the long side or the short side of the rectangle.

In the embodiment of the present application, the light valve 107 may be a liquid crystal on silicon (Liquid Crystal on Silicon, LCOS), a liquid crystal display (Liquid Crystal Display, LCD) or a digital micromirror device (Digital Micromirror Device, DMD). DMD is used as an example to explain. The DMD includes a plurality of tiny reflection sheets arranged in an array, and the plurality of reflection sheets are arranged in a rectangular shape as a whole, so that the light valve is rectangular. In FIG. 5 , only the rectangular outline of the light valve is illustrated, and each reflection sheet in the light valve is not shown. When each reflective sheet is in a natural state, that is, when the projection optical system is not performing image projection, the reflective surfaces of the multiple reflective sheets can be in the same plane, and the reflective surfaces of the multiple reflective sheets can form the light valve surface of the light valve . The light valve described in the embodiments of the present application is rectangular, that is, the light valve surface of the light valve is rectangular as a whole. When the projection optical system performs image projection, the plurality of reflection sheets can be deflected in corresponding directions under the driving of the driving component. The laser light emitted by the beam-shrinking component can be directed to the light valve surface, and then reflected by the reflecting surfaces of the reflective sheets with different deflections in the light valve surface, so as to realize the modulation of the laser light. Projecting based on the modulated laser light can realize Projection of the screen by the projection optical system.

In the embodiment of the present application, as shown in FIG. 5 , the light valve surface of the light valve may face the beam reducing component, for example, the light valve may be arranged vertically, and the light valve surface may be perpendicular to the optical axis of the concave lens in the beam reducing component. In one embodiment, FIG. 6 is a schematic structural diagram of still another projection optical system provided by an embodiment of the present application. As shown in FIG. 6 , the projection optical system may further include a total internal reflection (TIR) prism 108 located between the beam reducing member 103 and the light valve 107 . The beam-condensing component 103 can direct the beam-condensed laser light to the total internal reflection prism 108, and the laser light can be totally internally reflected in the total internal reflection prism 108 and then directed to the light valve surface of the light valve 107, at this time, the 107 can be placed horizontally . The light valve surface of the light valve 107 may be parallel to the optical axis of the concave lens in the beam reducing component 103, or may not have a specific relationship with the optical axis of the optical component in the projection optical system, which is not limited in the embodiment of the present application.

Since the divergence angles of the laser light emitted by the laser on the fast axis and the slow axis are different, the size of the light spot formed by the laser light emitted by the laser is different on the fast axis and the size on the slow axis, and the light spot is actually elliptical or rectangular. In the embodiment of the present application, the setting method of the laser needs to match the setting method of the light valve, so as to ensure that the projection optical system has high efficiency. In the embodiment of the present application, the plurality of lasers and light valves in the projection optical system can satisfy the following conditions: when the emitted laser light is directed to the light valve in the shape of a rectangle, the angle range between the fast axis and the long side of the rectangle, and The included angle between the slow axis and the short side of the rectangle is in the range of 80 degrees to 100 degrees. That is, the angle range between the fast axis and the long side of the light valve surface when the laser is directed to the light valve surface is 80 degrees to 100 degrees, and the angle range between the slow axis and the short side of the light valve surface when the laser is directed to the light valve surface. 80 degrees to 100 degrees. For example, the multiple lasers and light valves in the projection optical system can satisfy the conditions: when the laser is directed to the light valve, the fast axis is perpendicular to the long side of the light valve surface, and the slow axis is perpendicular to the short side of the light valve surface, that is, is that the fast axis is parallel to the long side of the light valve face, and the slow axis is parallel to the short side of the light valve face.

The above-mentioned conditions that the laser and the light valve need to meet are also equivalent to: the angle between the fast axis of the laser beam to the light valve and the long side of the light valve surface, and the angle between the slow axis and the short side of the light valve surface are both 90 degrees. , and the error range of this angle is ±10 degrees. In one embodiment, the error range can also be defined by the staff. For example, the error range can also be ±15 degrees. At this time, the condition is: when the laser emitted by the laser is directed to the light valve, the fast axis of the laser is different from that of the light valve. The angle range of the long side of the light valve surface and the angle range between the slow axis of the laser and the short side of the light valve surface are 75 degrees to 105 degrees; the error range can also be other values, such as ±20 degrees, this The application examples are not limited. In one embodiment, in the embodiments of the present application, the position of the light valve may be fixed, and only the lasers may be adjusted so that the laser and the light valve satisfy the above conditions, that is, the plurality of lasers satisfy the above conditions. Alternatively, the position of the laser may be fixed, and only the light valve may be adjusted so that the laser and the light valve satisfy the above conditions.

It should be noted that in the embodiments of the present application, the fast axis direction of the laser at different positions in the projection optical system may be different, and the slow axis direction may also be different. When the laser is reflected, its fast axis is in a mirror image relationship with the fast axis before reflection. , the slow axis is also mirror image relationship with the slow axis before reflection. The fast and slow axes of the laser at a certain position in the projection optical system can be determined based on the fast and slow axes of the laser when it exits the laser and the optical components provided in the laser transmission path between the position and the laser.

FIG. 7 is a schematic structural diagram of another projection optical system provided by an embodiment of the present application, and FIG. 7 is illustrated by taking the vertical placement of the light valve as an example. As shown in FIG. 7 , the projection optical system may further include: a homogenizing part 105 located on the light exit side of the beam reducing part 103 , for example, the homogenizing part may be located between the beam reducing part 103 and the light valve 107 . In one embodiment, please continue to refer to FIG. 7 , the projection optical system may further include: a diffusing sheet 106 and a condensing lens 104 located on the light exit side of the beam reducing component 103 . The beam reducing member 103, the diffusing sheet 106, the condensing lens 104 and the light homogenizing member 105 can be arranged in sequence along one direction (the x direction in the figure), and the diffusing sheet 106 can homogenize the laser beam emitted by the beam reducing member 103 and then shoot toward the direction of the beam. The condensing lens 104 , the condensing lens 104 can condense the incident laser light and then emit it to the light homogenizing part 105 , and the light homogenizing part 105 can further mix and homogenize the incident laser light and then send it to the light valve 107 .

The diffusing sheet 106 can diffuse the laser light emitted by the beam reducing member 103 and then shoot it toward the condensing lens 104 to ensure the uniformity of the laser light. Since the diffusing sheet will increase the divergence angle of the laser light in the process of diffusing the laser light, in the embodiment of the present application, the diffusing sheet is arranged between the beam-condensing component and the condensing lens, which can ensure that the divergence angle of the laser beam emitted through the diffusing sheet is relatively large , it can also be effectively converged by the converging lens and then directed to the light guide, avoiding the waste caused by the inability of the laser to enter the light guide due to the increase of the divergence angle of the laser, and ensuring a high utilization rate of the laser. In one embodiment, the position of the diffusing sheet 106 can be fixed, or the diffusing sheet 106 can also be connected with a driving structure, so that the diffusing sheet 106 rotates with the optical axis of the condensing lens as the rotation axis, or the diffusing sheet 106 can also be rotated. It can move back and forth along a direction perpendicular to the arrangement direction of the condensing lenses, which is not limited in the embodiment of the present application.

It should be noted that when a laser is used as a light source of a projection device for projection display, a speckle effect usually occurs. Speckle effect refers to the fact that after two laser beams emitted by a coherent light source are scattered on a rough object (such as the screen of a projection device), the two beams of laser light will interfere in space, and eventually appear granular light and dark on the screen. The effect of alternating spots. The speckle effect makes the display effect of the projected image poor, and these unfocused spots alternate between light and dark are in a flickering state to the human eye, which is prone to dizziness when viewed for a long time, and the user's viewing experience is poor. In the embodiment of the present application, the diffuser of the projection optical system can diffuse the light emitted by the laser, so as to reduce the coherence of the light and reduce the speckle effect. In one embodiment, the diffusing sheet includes microstructures with different diffusion angles arranged according to a certain rule. For example, the microstructures may be structures similar to micro-convex lenses. When the diffuser is moving, it can ensure that the light is directed to different positions of the diffuser at different times, so that the divergence angles of the light at different times are different, and the speckles of different shapes and positions formed by the projection equipment according to the projection of the light can be scattered and superimposed. It can not see obvious speckle, which plays a better role in eliminating speckle.

In one embodiment, the homogenizing member 105 may include a light pipe or a fly-eye lens, and FIG. 6 takes the homogenizing member as a light pipe as an example for illustration. The distribution of the laser spot in the embodiment of the present application is described below by taking the uniform light component including the light guide pipe as an example. In the embodiment of the present application, after the laser light emitted by the light combining lens group 102 corresponding to each laser 101 passes through the beam reducing component 103, a light spot can be formed on the condensing lens 104, so the multiple light combining in the projection optical system The laser light emitted by the mirror group 102 can form a plurality of light spots on the condensing lens 104 . In the embodiment of the present application, the plurality of light spots are located on both sides of the target plane where the optical axis of the projection optical system (eg, the optical axis of the light pipe 105 ) is located. In one embodiment, the difference between the number of light spots on both sides of the target plane may be less than or equal to a number threshold. In one embodiment, the number threshold may be 1, so as to ensure that the light spots are distributed as uniformly as possible.

In one embodiment, the target plane on which the optical axis of the light pipe is located may include the sagittal plane and/or the meridional plane of the light pipe, that is, the target plane may include the sagittal plane of the light pipe, or the meridional plane of the light pipe. , or both the sagittal and meridional planes of the light guide. In this way, the plurality of light spots formed on the condensing lens may be located on both sides of the sagittal plane of the light guide, or on both sides of the meridian plane of the light guide, or on both sides of the sagittal plane of the light guide and on the two sides of the light guide. Both sides of the meridian plane. In the embodiment of the present application, both the sagittal plane and the meridional plane of the light guide may pass through the optical axis of the light guide, and the sagittal plane is perpendicular to the meridional plane.

In the embodiment of the present application, the light entrance of the light guide is rectangular, the sagittal plane of the light guide may be parallel to the long side of the rectangle, and the meridian plane of the light guide is parallel to the short side of the long direction. It should be noted that the divergence angles of the laser light emitted by the laser on the fast axis and the slow axis are different, so the light spot formed by the laser light is actually an ellipse or a rectangle. Therefore, the light entrance of the light guide is rectangular, which can better match the spot shape of the incident laser, ensure that more laser light can be injected into the light guide, improve the utilization rate of the laser, and reduce the area of the light guide without laser light. The volume of the light pipe is wasted.

In one embodiment, the laser light emitted by the multiple lasers in the projection optical system in the embodiment of the present application forms multiple light spots on the condensing lens, which may be symmetrical with respect to at least one of the meridional plane and the sagittal plane of the light guide. It should be noted that the symmetry of the plurality of light spots with respect to the at least one plane may include the case where the plurality of light spots are absolutely symmetrical with respect to the at least one plane, and also include the case where the plurality of light spots are substantially symmetrical with respect to the at least one plane. The embodiment is not limited. The two light spots are roughly symmetrical with respect to one surface, that is, the difference between the surface and the symmetrical area of one of the two light spots and the other light spot is within a set error range, such as the area and the other light spot. The position difference is within the tolerance range or the dimensional difference is within the tolerance range. In one embodiment, the plurality of light spots may be located on both sides of the symmetry plane, or may also be located on both sides of the plane perpendicular to the symmetry plane.

8 to 11 are schematic diagrams of the distribution of light spots on the condensing lens provided by the embodiments of the present application, and FIGS. 8 to 11 may be right views of the condensing lens and the light guide shown in FIG. 7 . As shown in FIG. 8 , when the projection optical system includes two lasers, the laser light emitted by the two lasers can respectively form two light spots G on the condensing lens 104 , and the two light spots G are respectively located on the sagittal plane M1 of the light pipe 105 . Both sides, and at the same time, are symmetrical about the sagittal plane M1 and the meridional plane M2 of the light pipe 105 . In one embodiment, the two light spots may also be located on both sides of the meridian plane M2 of the light guide, which is not limited in the embodiment of the present application. As shown in FIG. 9 , when the projection optical system includes three lasers, the laser light emitted by the three lasers can respectively form three light spots G on the condensing lens 104, and the three light spots G are respectively located on the meridian plane M2 of the light pipe. For example, there are two light spots on the left side of the meridian plane M2 and one light spot on the right side; the three light spots are symmetrical with respect to the sagittal plane M1 of the light guide 105 . In one embodiment, the three light spots may also be symmetrical with respect to both sides of the sagittal plane M1 of the light pipe 105 and with respect to the meridional plane M2, which is not limited in the embodiment of the present application. As shown in FIG. 10 , when the projection optical system includes four lasers, the laser light emitted by the four lasers can respectively form four light spots G on the condensing lens 104, and the four light spots G are located on both sides of the sagittal plane M1 of the light guide , and are located on both sides of the meridian plane M2 of the light pipe, and the four light spots are symmetrical about the sagittal plane M1 and the meridian plane M2 of the light pipe 105 at the same time. As shown in FIG. 11 , when the projection optical system includes five lasers, the laser light emitted by the five lasers can respectively form five light spots G on the condensing lens 104, and the five light spots G are respectively located on the meridian plane M2 of the light pipe. For example, there are two light spots on the left side of the meridian plane M2 and three light spots on the right side; the five light spots are symmetrical with respect to the sagittal plane M1 of the light guide 105 . In one embodiment, the five light spots may also be symmetrical with respect to both sides of the sagittal plane M1 of the light pipe 105 and with respect to the meridional plane M2, which is not limited in the embodiment of the present application.

It should be noted that the embodiments of the present application only describe the distribution of the plurality of light spots in the case that the projection optical system includes two, three, four and five lasers. The projection optical system may also include other numbers of lasers, and the light spot distribution at this time can be deduced by analogy, which is not repeated in this embodiment of the present application. In one embodiment, when the number of lasers included in the projection optical system in the embodiment of the present application is an even number, the multiple light spots formed by the laser light emitted by the multiple lasers on the condensing lens may be related to the sagittal plane of the light pipe at the same time. Symmetrical to the meridian plane to further improve the uniformity of the laser light directed to the light guide.

In the embodiment of the present application, the light outlet of the light pipe is also rectangular, the light outlet of the light pipe and the light valve surface are in a conjugated object-image relationship, and the laser light emitted from the light outlet of the light pipe and the laser light directed to the light valve surface are in the same shape. The object-image relationship of the yoke. Corresponding to the conditions that the laser and the light valve in the projection optical system need to meet, the setting method of the light pipe also needs to match the setting method of the laser, so as to ensure that the projection optical system has a high luminous efficiency. In the embodiment of the present application, the plurality of lasers and the light guide in the projection optical system may satisfy the following conditions: when the laser light emitted by the laser is directed towards the light guide, the angle range between the fast axis of the laser and the sagittal plane of the light guide, and The included angle between the slow axis of the laser and the meridian plane of the light guide is in the range of 80 degrees to 100 degrees. For example, when the laser emitted by the laser is directed to the light guide, the fast axis of the laser is perpendicular to the sagittal plane of the light guide, and the slow axis of the laser is perpendicular to the meridian plane of the light guide; that is, the fast axis of the laser is parallel to the meridional plane of the light guide. , the slow axis is parallel to the sagittal plane of the light pipe. For example, the light entrance of the light guide is rectangular, and when the laser light emitted from the laser is directed to the light guide, the fast axis is parallel to the short side of the rectangle, and the slow axis is parallel to the long side of the rectangle.

It should be noted that this condition is also equivalent to that the laser and the light guide need to satisfy: the angle between the fast axis of the laser beam directed to the light guide and the sagittal plane of the light guide, and the angle between the slow axis and the meridian plane of the light guide are both 90°. degrees, and the error range of this angle is ±10 degrees. In one embodiment, the error range can also be defined by the staff. For example, the error range can also be ±15 degrees. At this time, the condition is: when the laser emitted by the laser is directed to the light guide, the fast axis of the laser is different from the speed of the laser. The included angle range of the sagittal plane of the light guide and the included angle range of the slow axis of the laser and the meridional plane of the light guide are both 75 degrees to 105 degrees; the error range can also be other values, such as ±20 degrees, which is implemented in this application. Examples are not limited. In one embodiment, in the examples of the present application, the position of the light pipe may be fixed, and only the lasers may be adjusted so that the laser and the light pipe meet the above conditions, that is, the plurality of lasers satisfy the above conditions.

In this embodiment of the present application, the laser may include a collimating lens group, and the collimating lens group may include a plurality of collimating lenses (for example, please refer to the collimating lens T in FIG. 1 ) corresponding to the plurality of light-emitting chips in the laser. ), the laser light emitted by each light-emitting chip can pass through the corresponding collimating lens, and then emit the laser after being collimated by the collimating lens. It should be noted that collimating the light means converging the light, so that the divergence angle of the light becomes smaller and closer to parallel light. The divergence angle of the laser light emitted by the light-emitting chip on the fast axis is greater than the divergence angle on the slow axis, and the spot size on the fast axis is larger than that on the slow axis. After the laser is collimated by the collimating lens, the divergence angle on the fast axis can be smaller than the divergence angle on the slow axis. For example, the divergence angle on the fast axis can be adjusted to be close to 0 degrees by the collimating lens, and the divergence angle on the slow axis It can be adjusted to 0.5 degrees to 0.7 degrees by the collimating lens. Therefore, the divergence angle on the fast axis of the laser light emitted by the laser is smaller than the divergence angle on the slow axis. Then, after the laser beam is reflected by the light combining lens group and sent to the condensing lens through the beam reducing component, the spot size on the fast axis can be smaller than the spot size on the slow axis.

In the embodiments of the present application, the laser and the light guide are made to satisfy the above conditions, that is, when the laser emitted by the laser is directed to the light guide, the angle range between the fast axis of the laser and the sagittal plane of the light guide, and the slow axis of the laser and the light guide The included angles of the meridional planes of the conduits are in the range of 80 degrees to 100 degrees. In this way, it can ensure that the shape of the light spot of the laser light directed to the light guide on the condensing lens is highly matched with the shape of the light guide, and it can ensure that the laser passing through the converging lens can enter the light guide more and improve the utilization rate of the laser. Avoid wasting lasers. When the fast axis of the laser directed to the light guide (that is, the laser on the converging lens) is parallel to the short side of the light entrance of the light guide, and the slow axis is parallel to the long side of the light entrance of the light guide, the light spot on the converging lens is The shape has the highest matching degree with the shape of the light entrance of the light guide, which can further improve the utilization rate of the laser and avoid the waste of the laser.

The various optical components in the projection optical system will be introduced below in conjunction with the accompanying drawings:

It should be noted that, in FIGS. 2 and 5 to 7, the projection optical system includes two lasers 101, and the two lasers 101 are arranged along the x-direction, and the two lasers are in the same direction (as shown in FIG. 2 and FIG. 2 ). The y direction in 5 to 7) is illuminated as an example for illustration. In one embodiment, FIG. 12 is a receiving schematic diagram of a projection optical system provided by another embodiment of the present application. As shown in FIG. 12 , the two lasers may also be arranged along the y direction, and the two lasers One laser emits light in the y direction, and the other laser emits light in the opposite direction of the y direction. This embodiment of the present application does not limit the setting method of the lasers in the projection optical system. It is only necessary to ensure that the multiple light spots formed by the laser light emitted by the plurality of lasers on the condensing lens meet the requirements for the light spot distribution in the embodiment of the present application. For example, it is ensured that the multiple light spots are located on both sides of the target plane where the optical axis of the light guide is located.

In one embodiment, each laser 101 in this embodiment of the present application can emit laser light of at least two colors. For example, each laser 101 may include multiple light-emitting regions, each light-emitting region may be used to emit laser light of one color, and the colors of laser light emitted by different light-emitting regions may be different, and the plurality of light-emitting regions may be sequentially arranged in a certain direction. The laser may include at least two types of light-emitting chips, different types of light-emitting chips are used to emit lasers of different colors, and the area where each type of light-emitting chip is located may be a light-emitting area in the laser. For example, the laser in the embodiment of the present application may be a multi-chip Laser Diode (MCL) type laser, and the laser may include a plurality of light-emitting chips arranged in multiple rows and columns. For example, the laser includes four rows of light-emitting chips, wherein the first row of light-emitting chips is used to emit green light, the second row of light-emitting chips is used to emit blue light, and the third and fourth rows of light-emitting chips are used to emit red light. The area where the light-emitting chips in the row are located may be one light-emitting area, the area where the light-emitting chips in the second row are located may also be another light-emitting area, and the areas where the light-emitting chips in the third and fourth rows are located may be another light-emitting area.

In one embodiment, please continue to refer to FIG. 2 , FIGS. 5 to 7 and FIG. 12 , the light combining mirror group 102 corresponding to each laser 101 may include a plurality of light combining mirrors J, and each light combining mirror J may be combined with the laser 101 . One of the light-emitting regions in the laser 101 corresponds to one of the light-emitting regions, and is used to reflect the laser light emitted from the light-emitting region, and then the plurality of light combining mirrors J can be arranged along the arrangement direction of each light-emitting region in the laser 101 (as shown in FIG. 2 , FIGS. 5 to 7 and FIG. 12 ). in the x direction) are arranged in order. The plurality of light combining mirrors J in each light combining mirror group 102 can be inclined relative to the light-emitting surface of the laser 101 (that is, the included angle between the light-combining mirror and the light-emitting surface is an acute angle or an obtuse angle). The light mirror J can reflect the incident laser light toward a target direction, and the target direction can be parallel to the arrangement direction of the plurality of light combining mirrors J. In this way, some of the light-combining mirrors in the light-combining mirror group 102 reflect the laser light to other light-combining mirrors, and the other light-combining mirrors may be dichroic mirrors, which are used to reflect the laser light emitted from the corresponding light-emitting area, and transmit the laser light to other light-combining mirrors. Laser light emitted from the light-emitting area. For example, the light-emitting area corresponding to the red laser beam can reflect the red laser beam and transmit the blue laser beam and the green laser beam. Furthermore, the laser light emitted by the light combining mirror group 102 may be the laser light after the laser light reflected by each light combining mirror is mixed, and the light combining mirror group 102 has the effect of mixing the laser light emitted by the corresponding laser 101 . For example, the light emitted by the light combining lens group 102 may be white light obtained by mixing red laser, green laser and blue laser. The light spot formed by the laser light on any optical component in the subsequent laser transmission path may be a white light spot, for example, the light spot formed by the laser light on the condensing lens is a white light spot.

In one embodiment, the polarization direction of the red laser light emitted by the laser 101 is different from the polarization directions of the green laser light and the blue laser light. Half wave plate P. In this way, the green laser and blue laser emitted by the laser can be adjusted to have the same polarization direction as that of the red laser through the half-wave plate, and then be directed to the light combiner to ensure that the polarization directions of the lasers emitted by the light combiner are consistent. .

In the embodiment of the present application, since the beam of the laser light emitted by the light combining lens group 102 is relatively thick, and the light entrance of the light pipe 105 is small, the laser cannot be directly injected into the light pipe 105, so each light combining lens group 102 The incident laser light can be first reflected to the beam reducing component 103 to narrow the laser beam through the beam reducing component 103 , and then further converge the laser beam through the condensing lens 104 to enter the light pipe 105 . The beam reduction component may also be referred to as a telescope system. In one embodiment, the multiple beams of laser light respectively emitted by the multiple light combining lens groups 102 may still be multiple beams after passing through the beam reducing component 103 , so the multiple laser beams directed to the condensing lens 104 may be formed on the condensing lens 104 . For multiple light spots, the condensing lens 104 can condense the multiple laser beams into one laser beam, and then enter the light guide 105 .

In the embodiments of the present application, there are various implementation manners of the beam reducing component, and the above embodiments are all illustrated by taking one implementation manner of the beam reducing component as an example. In this implementation manner, as shown in FIG. 2 , FIGS. 5 to 7 and FIG. 12 , the beam reducing component 103 may only include a convex lens 1031 and a concave lens 1032 , and a plurality of light combining lenses and convex lenses 1031 in the light combining lens group 102 , the concave lens 1032 , the condensing lens 104 and the light pipe 105 can be arranged in sequence, for example, arranged in sequence along the x direction. The laser light emitted by the light combining lens group 102 can be directed to the convex lens 1031 first, and then converged by the convex lens 1031 to the concave lens 1032, and the concave lens 1032 can collimate the incident laser light and then emit it to reduce the beam of the laser light.

In the second implementation manner of the beam reducing component, as shown in FIG. 13 , the beam reducing component 103 may include a convex lens 1031 , a reflecting mirror 1033 and a concave lens 1032 , a plurality of light combining mirrors and a convex lens 1031 in the light combining lens group 102 The reflector 1033 and the reflector 1033 may be sequentially arranged along the first direction (eg, the x-direction), and the reflector 1033, the concave lens 1032, the condensing lens 104 and the light pipe 105 may be sequentially arranged along the second direction (eg, the y-direction). The second direction intersects, eg, the first direction may be perpendicular to the second direction. The laser light emitted by the light combining lens group 102 can be directed to the convex lens 1031 first, and then converged by the convex lens 1031 to the reflector 1033, and the reflector 1033 can reflect the incident laser light to the concave lens 1032, so as to adjust the transmission direction of the laser light, that is, to adjust the transmission direction of the laser light. The transmission direction is adjusted from the first direction to the second direction. The concave lens 1032 can collimate the incoming laser light and then emit it, so as to reduce the beam of the laser light.

For the above-mentioned second implementation manner, each optical element in the projection optical system can be arranged in two directions, and the arrangement of each element can be more compact, so the overall length of the projection optical system can be reduced, which is convenient for the projection equipment. miniaturization. And FIG. 13 takes the order of the laser and the corresponding light combining mirror group arranged in the x direction as an example, in one embodiment, the laser and the corresponding light combining mirror group can also be arranged in turn in the opposite direction of the x direction, that is, 13, the laser can be arranged on the right side of the combining lens group, such as below the condensing lens, so that each optical element in the projection optical system can be made more compact, and the miniaturization of the projection optical system can be further improved.

In the embodiment of the present application, the optical axis of the light pipe 105 , the optical axis of the condensing lens 104 , and the optical axis of the concave lens 1032 in the beam reducing component 103 may all be collinear. If the beam reducing component 103 is the first implementation manner, the optical axis of the light pipe 105 , the optical axis of the condensing lens 104 , the optical axis of the concave lens 1032 and the optical axis of the convex lens 1031 in the beam reducing component 103 may all be collinear. It should be noted that the optical axis of the light guide is also the central axis of the light guide, the light guide may be in the shape of a long strip, and the optical axis of the light guide may be perpendicular to its length direction.

FIG. 14 is a schematic structural diagram of still another projection optical system provided by another embodiment of the present application. As shown in FIG. 9 , the projection optical system may include: a light source assembly 10 , an optical machine 20 and a lens 30 . The light source assembly 10 is used for emitting light to the optical machine 20, and the optical machine 20 is used for modulating the incoming light and then sending it to the lens 30, and the lens 30 is used for projecting the incoming light. The light source assembly 10 may include the above-mentioned laser 101 , a combining lens group 102 , a beam reducing component 103 , a diffusing sheet 105 and a condensing lens 104 . In the embodiment of the present application, the uniformity of the laser light emitted by the light source assembly 10 is relatively high, so a projection device using the light source assembly can form a projection image with better display effect according to the laser beam with relatively high uniformity. In one embodiment, the optomechanical may include the above-mentioned uniform light component, total internal reflection (TIR) prism group and light valve.

The term "and/or" in this application is only an association relationship to describe associated objects, which means that there can be three kinds of relationships, for example, A and/or B, which can mean that A exists alone, A and B exist at the same time, independently There are three cases of B. In addition, the character "/" in this document generally indicates that the related objects are an "or" relationship. In this application, the term "at least one of A, B and C" means that seven relationships can exist, which can mean: A alone exists, B alone exists, C alone exists, A and B exist simultaneously, A and C exist simultaneously, and There are C and B, and there are seven cases of A, B, and C at the same time. In the embodiments of the present application, the terms "first" and "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance. The term "plurality" refers to two or more, unless expressly limited otherwise. "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range, and basically achieve the technical effect.

The above descriptions are only examples of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application. Inside.

Claims

A projection optical system, characterized in that the projection optical system comprises: a plurality of lasers, a plurality of light combining lens groups and a beam reducing component;

The multiple lasers are in one-to-one correspondence with the multiple light-combining mirror groups, each of the light-combining mirror groups is located on the light-emitting side of the corresponding laser, and each of the lasers is used to send the corresponding light-combining mirror group to the light-emitting side. emits laser light, and the light combining mirror group is used to mix the incident laser light and reflect it to the beam reduction component, and the beam reduction component is used to reduce the beam of the incident laser light and emit it;

Wherein, on a reference plane perpendicular to the optical axis of the projection optical system, the laser light emitted by each light combining mirror group forms a light spot, and the laser light spots formed by the laser light emitted by the plurality of light combining mirror groups are symmetrically distributed.
The projection optical system according to claim 1, wherein, on the reference plane, the plurality of light spots are axis-symmetrical about an intersection line of the reference plane and a target plane where the optical axis is located.
The projection optical system according to claim 2, wherein the projection optical system further comprises: a rectangular light valve, and the beam reducing component is used for emitting laser light to the light valve, where the laser light is located. The light spot formed on the light valve is axially symmetrical about the median line of the rectangle.
The projection optical system according to claim 3, wherein the plurality of lasers satisfy: when the emitted laser light is directed to the rectangular light valve, the angle range between the fast axis and the long side of the rectangle , and the included angle between the slow axis and the short side of the rectangle is in the range of 80 degrees to 100 degrees.
The projection optical system according to claim 4, wherein the plurality of lasers further satisfy: when the emitted laser light is directed to the rectangular light valve, the fast axis is perpendicular to the long side of the rectangle, and the slow axis is perpendicular to the long side of the rectangle. The axis is perpendicular to the short side of the rectangle.
The projection optical system according to any one of claims 1 to 5, characterized in that, the projection optical system further comprises: a light homogenizing part located on the light exit side of the beam reducing part, the light homogenizing part comprising a light pipe or Fly eye lens.
The projection optical system according to claim 6, wherein the uniform light component comprises the light guide, and the target plane comprises a sagittal plane and/or a meridional plane of the light guide.
The projection optical system according to claim 7, wherein the plurality of lasers satisfy: the angle range between the fast axis and the sagittal plane of the light guide when the emitted laser light is directed to the light guide, and The included angle between the slow axis and the meridian plane of the light guide is in the range of 80 degrees to 100 degrees.
The projection optical system according to any one of claims 1 to 5, wherein each of the lasers is used to emit laser light of at least two colors.
The projection optical system according to any one of claims 1 to 5, wherein the beam reducing component comprises a convex lens, a reflecting mirror and a concave lens;

The convex lens is used for receiving the laser light emitted by the plurality of light combining lens groups and condensing the laser light to the reflecting mirror, and the reflecting mirror is used for reflecting the incident laser light to the concave lens, and the concave lens is used for It is emitted after collimating the incoming laser light.
The projection optical system according to any one of claims 1 to 5, characterized in that, the projection optical system further comprises a diffusing sheet located on the light exit side of the beam condensing component, and the diffusing sheet is used for reducing the beam The laser light emitted from the part is homogenized and emitted.
The projection optical system according to claim 11, wherein the projection optical system further comprises a condensing lens located on the light-emitting side of the diffusing sheet, and the diffusing sheet is used for evenly distributing the laser light emitted by the beam reducing member. After the laser beam is laserized, it is emitted to the condensing lens, and the condensing lens is used for condensing the incident laser light and then emitting it.