Laser projection system

Abstract

The application discloses a laser projection system, which comprises a laser light source, an illumination system, a light valve and a projection lens. The laser light source is used for emitting laser light. The illumination system is arranged on the light path of the laser light. The illumination system is used for modulating the laser light. The light valve is used for receiving the laser light modulated by the illumination system and emitting the laser light. The projection lens is configured to image the laser light emitted from the light valve. The projection lens comprises a variable light aperture diaphragm. The illumination system comprises a homogenizing element. The homogenizing element has opposite light entrance surfaces and light exit surfaces. The laser light enters the homogenizing element from the light entrance surfaces and is emitted from the light exit surfaces to the light valve. Different spot sizes of the laser light are formed on the light entrance surfaces. The laser light corresponding to different spot sizes is incident on the light aperture of the light aperture diaphragm at different beam divergence angles after being emitted from the light valve. The beam divergence angle is proportional to the spot size, and the beam divergence angle is proportional to the light aperture of the light aperture diaphragm.

Description

Technical Field

[0001] This application relates to the field of projection display technology, and more particularly to a laser projection system. Background Technology

[0002] Laser light sources have advantages such as good monochromaticity, high brightness, and long lifespan, making them a relatively ideal light source. In related technologies, lasers are gradually replacing mercury lamps as the projection light source in projection systems, and compared to LED light sources, lasers are also widely used due to their advantages of small optical spread and high brightness.

[0003] In laser projection systems with related technologies, an adjustable aperture is usually used inside the projection lens to improve image contrast. By reducing the size of the adjustable aperture, stray light entering the projection lens can be reduced, thereby improving image contrast.

[0004] However, while reducing the size of the variable aperture to decrease stray light entering the projection lens, it also directly reduces the effective light passing through the projection lens, resulting in a decrease in the optical efficiency of the laser projection system. This leads to a significant decrease in the overall screen brightness, especially in bright environments or when projecting large images. Insufficient screen brightness will seriously affect the display effect of the laser projection system and impact the viewing experience. Utility Model Content

[0005] This application discloses a laser projection system that can improve image contrast by narrowing the aperture of the projection lens while ensuring the light flux of the laser projection system to avoid a decrease in image brightness.

[0006] To achieve the above objectives, this application discloses a laser projection system, which includes:

[0007] A laser source, wherein the laser source is used to emit laser light;

[0008] An illumination system is disposed in the optical path of the laser, and the illumination system is used to modulate the laser.

[0009] A light valve, the light valve being used to receive the laser light modulated by the illumination system and to emit the laser light; and,

[0010] A projection lens configured to image the laser emitted from the light valve;

[0011] The projection lens includes an aperture stop with a variable light transmission diameter;

[0012] The lighting system includes a homogenizing element having an incident light surface and an exit light surface, wherein the laser light enters the homogenizing element from the incident light surface and exits from the exit light surface to the light valve;

[0013] The laser can form different spot sizes on the incident light surface. The lasers corresponding to different spot sizes are emitted from the light valve and enter the light aperture of the aperture with different beam divergence angles. The beam divergence angle is proportional to the spot size and the aperture diameter of the aperture.

[0014] In the laser projection system provided in this application embodiment, the projection lens includes an aperture stop with a variable aperture. This allows for the reduction of the aperture stop's aperture, enabling the aperture stop to block stray light with large angles and offset propagation paths exceeding the aperture stop's aperture. This reduces stray light entering the projection lens and improves image contrast. Furthermore, this application also enables the laser emitted from the laser source to form different spot sizes on the incident surface of the homogenizing element. Lasers of different spot sizes exiting the light valve and entering the aperture stop's aperture at different beam divergence angles are proportional to the spot size. The aperture of the aperture is directly proportional to the beam size. That is, when the spot size decreases, the beam divergence angle decreases, and the aperture of the aperture decreases, and vice versa. Therefore, by reducing the aperture of the aperture to reduce stray light entering the projection lens, the spot size of the laser on the incident surface of the homogenizing element can be reduced, thereby reducing the beam divergence angle of the laser beam incident on the aperture. Thus, even if the aperture of the aperture is reduced, the obstruction of the effective laser light by the aperture can be reduced or avoided, allowing the effective laser light to still pass smoothly through the aperture. This can improve the contrast of the image while ensuring the light throughput of the projection lens, thus ensuring the brightness of the image. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a structural diagram of the projection lens, reflective components, and light valve in related technologies;

[0017] Figure 2 This is one of the structural schematic diagrams of the laser projection system disclosed in the embodiments of this application;

[0018] Figure 3 This is a schematic diagram of the projection lens structure disclosed in the embodiments of this application;

[0019] Figure 4This is one of the structural schematic diagrams of a laser projection system when the second reflector is moved onto the optical path of the laser, as disclosed in the embodiments of this application;

[0020] Figure 5 yes Figure 2 A schematic diagram of the light spot distribution on the incident light surface of the homogenizing element;

[0021] Figure 6 yes Figure 4 A schematic diagram of the light spot distribution on the incident light surface of the homogenizing element;

[0022] Figure 7 This is a second schematic diagram of the structure of the laser projection system disclosed in the embodiments of this application;

[0023] Figure 8 This is a second schematic diagram of the structure of the laser projection system when the second reflector is moved onto the optical path of the laser, as disclosed in the embodiments of this application;

[0024] Figure 9 This is one of the schematic diagrams of the laser source provided in the embodiments of this application;

[0025] Figure 10 This is a second schematic diagram of the laser source provided in the embodiments of this application;

[0026] Figure 11 This is the third schematic diagram of the structure of the laser projection system disclosed in the embodiments of this application;

[0027] Figure 12 This is the third schematic diagram of the laser projection system when the second reflector is moved onto the optical path of the laser, as disclosed in the embodiments of this application;

[0028] Figure 13 This is the fourth schematic diagram of the structure of the laser projection system when the second reflector is moved into the optical path of the laser, as disclosed in the embodiments of this application;

[0029] Figure 14 This is the fifth schematic diagram of the structure of the laser projection system when the second reflector is moved onto the optical path of the laser, as disclosed in the embodiments of this application.

[0030] Explanation of main figure symbols

[0031] 100 - Laser projection system; 11 - Laser source; 111 - Laser; 1111 - First laser chip; 1112 - Second laser chip; 1113 - Third laser chip; 112 - Lens group; 1121 - First lens; 1122 - Second lens; 1123 - Third lens; 1124 - Fourth lens; 113 - First light steering element; 1131 - Polarizing beam combiner; 1132 - First reflector; 114 - Second light steering element; 1141 - Second reflector; 1142 - Third reflector; 115 - Beam combining assembly; 1151 - Fourth reflector ; 1152-First beam combiner; 1153-Second beam combiner; 12-Illumination system; 121-Homogeneous element; 1211-Incident surface; 1212-Outceasing surface; 122-Relay lens group; 123-Reflection assembly; 13-Light valve; 14-Projection lens; 141-Aperture stop; 142-Lens; 142a-First lens; 142b-Second lens; 142c-Third lens; 142d-Fourth lens; 142e-Fifth lens; 142f-Sixth lens; 142g-Seventh lens; 15-First polarization conversion device; 16-Second polarization conversion device. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the exemplary embodiments of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments. Obviously, the described exemplary embodiments are only some embodiments of this application, and not all embodiments. That is, the specific embodiments described herein are merely used to explain this application and are not intended to limit this application.

[0033] It should be noted that the brief descriptions of terminology used in this application are merely for the purpose of facilitating understanding of the embodiments described below, and are not intended to limit the embodiments of this 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 application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0034] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0035] The terms "first," "second," etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this application, a first lens may be referred to as a second lens, and similarly, a second lens may be referred to as a first lens. Both the first lens and the second lens are lenses, but they are not the same lens.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0037] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0038] In the description of this application, it should be noted that the singular forms of "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that terms such as "comprising / including" or "having" specify the presence of the stated features, integrals, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integrals, steps, operations, components, parts, or combinations thereof.

[0039] In addition, the term "and / or" as used in this specification includes any and all combinations of the related listed items. For example, A and / or B can mean: A alone, A and B together, or B alone. That is, the term "and / or" as used in this specification includes any and all combinations of the related listed items.

[0040] Projection display is a method or device that uses a planar image information to control a light source, and utilizes an optical system and projection space to magnify and display the image on a projection screen. With the development of projection display technology, projection displays are gradually being applied to business activities, conferences and exhibitions, scientific education, military command, traffic management, centralized monitoring, and advertising and entertainment. Its advantages, such as large display size and clear display, are also suitable for the requirements of large-screen displays.

[0041] Among them, laser light sources have advantages such as good monochromaticity, high brightness, and long lifespan, making them a relatively ideal light source. In related technologies, lasers have gradually replaced mercury lamps as the projection light source in projection systems, and compared to LED light sources, lasers have also been widely used due to their advantages of small optical spread and high brightness.

[0042] Laser projection display technology, also known as laser projection technology or laser display technology, is a technology that uses lasers as a light source for projection display. Laser projection can realistically reproduce the rich and vibrant colors of the objective world, providing a more stunning expressive effect. Its color gamut coverage can reach more than 90% of the color space that the human eye can perceive, which is more than twice the color gamut coverage of traditional displays.

[0043] Currently, the most common laser projection system is the Digital Light Processing (DLP) architecture, which uses a Digital Micromirror Device (DMD) as the core component. The light emitted from the projection light source is incident on the DMD to generate an image, and then the light emitted from the image generated by the DMD is incident on the projection lens, which forms the image and is finally received by the projection screen.

[0044] In laser projection systems based on relevant technologies, in order to improve image contrast, such as Figure 1 As shown, Figure 1 The dashed arrow roughly illustrates the laser's optical path. Typically, an adjustable aperture 141 is used inside the projection lens 14. By reducing the size of the aperture 141, it can block light beams that exceed its aperture. In this way, stray light with large angles and offset propagation paths can be blocked, thereby reducing stray light entering the projection lens 14 and improving image contrast.

[0045] However, while the variable aperture 141 is reduced in order to reduce stray light entering the projection lens 14, the reduced variable aperture 141 will also block the effective light. This will reduce the effective light passing through the projection lens 14, resulting in a decrease in the optical efficiency of the laser projection system. Consequently, the overall screen brightness will decrease significantly. Especially in bright environments or when projecting large screens, insufficient screen brightness will seriously affect the display effect of the laser projection system and the viewing experience.

[0046] In view of this, the present application provides a laser projection system that can increase the aperture number (F number) of the illumination system while reducing the aperture of the projection lens to improve the image contrast, so that the aperture of the illumination system and the aperture of the projection lens are matched, thereby ensuring the light flux of the laser projection system and avoiding a decrease in image brightness.

[0047] The technical solutions of some embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0048] Please see Figure 2 , Figure 2 The dashed arrows in the diagram roughly indicate the optical path of the laser. This application discloses a laser projection system 100, which includes a laser light source 11, an illumination system 12, a light valve 13, and a projection lens 14.

[0049] The laser source 11 of this application is mainly used to emit lasers.

[0050] The illumination system 12 in this application is disposed in the optical path of the laser. The illumination system 12 is mainly used to modulate the laser. For example, the illumination system 12 is used to homogenize and shape the laser so that the laser spot after passing through the illumination system 12 can be a rectangular spot. The energy distribution of the rectangular spot is more uniform, which can meet the illumination requirements of the laser projection system 100.

[0051] The light valve 13 in this application is used to receive the laser modulated by the illumination system 12 and to emit the laser to the projection lens 14.

[0052] The projection lens 14 in this application is configured to image the laser emitted from the light valve 13. For example, the projection lens 14 is located on the light-emitting side of the lighting system 12. The laser, after being modulated by the lighting system 12 and the light valve 13, needs to be imaged by the projection lens 14 so that the image can be projected onto the projection screen or a set position. The viewer can see the displayed image by viewing the projection screen.

[0053] In some embodiments, the projection lens 14 may include an aperture stop 141 with a variable aperture. This allows stray light with large angles and offset propagation paths that exceeds the aperture stop 141 to be blocked by the aperture stop 141, thereby reducing stray light entering the projection lens 14 and improving image contrast.

[0054] Normally, such as Figure 3As shown, the projection lens 14 also includes one or more lenses 142. When the projection lens 14 has multiple lenses 142, the multiple lenses 142 are arranged sequentially from the object side to the image side along the optical axis. The lens 142 closest to the object side is the first lens 142, and the lens 142 furthest from the object side is the last lens 142. The aperture stop 141 can be located between two adjacent lenses 142, or on the object side of the first lens 142, or on the image side of the last lens 142. This application does not specifically limit the location of the aperture stop 141.

[0055] For example, such as Figure 3 As shown, the projection lens 14 includes seven lenses, which are arranged sequentially from the object side to the image side along the optical axis: a first lens 142a, a second lens 142b, a third lens 142c, a fourth lens 142d, a fifth lens 142e, a sixth lens 142f, and a seventh lens 142g. The aperture stop 141 is located between the fourth lens 142d and the fifth lens 142e.

[0056] In some embodiments, such as Figure 2 As shown, the lighting system 12 includes a homogenizing element 121, which has an incident light surface 1211 and an exit light surface 1212. The laser emitted from the laser source 11 enters the homogenizing element 121 from the incident light surface 1211 and exits from the exit light surface 1212 to the light valve 13. Thus, the laser emitted from the exit light surface 1212 of the homogenizing element 121 enters the light valve 13 to generate an image. The outgoing laser of the image generated by the light valve 13 enters the projection lens 14, which forms an image, and the image is finally received by the projection screen.

[0057] By homogenizing the laser emitted from the laser source 11 using the homogenizing element 121, the phenomenon of excessively high or low local light intensity in the laser can be effectively eliminated, making the light intensity distribution of the laser more uniform. This is beneficial to improving the uniformity of brightness and color accuracy of the projected image. At the same time, the homogenization process can also reduce the spatial coherence of the laser, further reducing speckle problems, and ultimately achieving a clearer, more uniform, and better visually appealing projected image, thus enhancing the user's viewing experience.

[0058] The lighting optical path of the lighting system can be understood as the optical path formed by the path of the laser from the laser source 11 to the homogenizing element 121, or as the optical path formed by the path of the laser from the laser source 11 to the light valve 13.

[0059] Optionally, the homogenizing element 121 can be a double-sided compound eye lens, a light homogenizer, or a diffractive optical element, etc. The type of homogenizing element 121 is flexible and can be selected according to actual needs. This application embodiment does not make specific limitations in this regard.

[0060] Optionally, the light valve 13 can be a digital micromirror device (DMD), a liquid crystal on silicon (LCOS) device, or a liquid crystal display (LCD) device. Among them, DMD and LCOS devices are reflective devices, while LCD devices are transmissive devices.

[0061] When the light valve 13 is a DMD or LCOS device, the laser emitted from the light-emitting surface 1212 of the homogenizing element 121 enters the light valve 13 and is reflected by the light valve 13 to the projection lens 14; when the light valve 13 is an LCD device, the laser emitted from the light-emitting surface 1212 of the homogenizing element 121 enters the light valve 13 and is transmitted through the light valve 13 to the projection lens 14. That is, the laser emitted from the light-emitting surface 1212 of the homogenizing element 121 passes through the light valve 13 and enters the projection lens 14.

[0062] The following will use the optical valve 13 as an example to further explain the technical solution of this application.

[0063] In some embodiments, the laser emitted from the laser source 11 can form different spot sizes on the incident surface 1211 of the homogenizing element 121. Lasers of different spot sizes, after exiting the light valve 13, are incident on the aperture of the aperture 141 at different beam divergence angles. The beam divergence angle is proportional to the spot size and the aperture diameter of the aperture 141. For example, the smaller the spot size, the smaller the beam divergence angle, and the smaller the aperture diameter of the aperture 141. Here, the aperture diameter of the aperture 141 refers to the diameter of the light-transmitting hole of the aperture 141.

[0064] By causing the laser emitted from the laser source 11 to form different spot sizes on the incident surface 1211 of the homogenizing element 121, the lasers corresponding to different spot sizes exit from the light valve 13 and enter the light aperture of the aperture 141 with different beam divergence angles. This beam divergence angle is directly proportional to the spot size and also directly proportional to the light aperture of the aperture 141. That is, when the spot size decreases, the beam divergence angle decreases, and the light aperture of the aperture 141 decreases, and vice versa. Therefore, by reducing the light aperture of the aperture 141... To reduce stray light entering the projection lens 14, the laser spot size on the incident surface 1211 of the homogenizing element 121 can be reduced, thereby reducing the beam divergence angle of the laser incident aperture 141. Thus, even with a smaller aperture, the obstruction of the effective laser light by the aperture 141 can be reduced or avoided, allowing the effective laser light to still pass smoothly through the aperture 141. This improves the image contrast while ensuring the light throughput of the projection lens 14, thus guaranteeing image brightness.

[0065] In other words, the aperture number (i.e., F-number) of the lighting system 12, the focal length f of the lighting system 12, and the spot size D on the incident surface 1211 of the homogenizing element 121 can satisfy the following relationship:

[0066] F_number = f / D.

[0067] When the light spot on the incident surface 1211 of the homogenizing element 121 is a rectangular light spot, the size of the light spot is the length of the diagonal of the rectangular light spot; and when the light spot on the incident surface 1211 of the homogenizing element 121 is a circular light spot, the size of the light spot is the diameter of the circular light spot.

[0068] As can be seen from the above relationship, the aperture number of the lighting system 12 and the spot size on the incident surface 1211 of the homogenizing element 121 are inversely proportional. For example, the smaller the spot size on the incident surface 1211 of the homogenizing element 121, the larger the aperture number of the lighting system 12, and the smaller the aperture of the lighting system 12. Therefore, when reducing the aperture of the projection lens 14 to reduce stray light entering the projection lens 14, by making the spot size of the laser on the incident surface 1211 of the homogenizing element 121 smaller, the aperture number of the lighting system 12 can be increased and the aperture of the lighting system 12 can be reduced, so that the aperture size of the lighting system 12 is the same as or similar to the aperture size of the projection lens 14. This allows the aperture of the lighting system 12 to be matched with the aperture of the projection lens 14, thereby improving the light energy utilization of the lighting system 12, ensuring the light throughput of the projection lens 14, and ensuring the brightness of the image.

[0069] In some embodiments, such as Figure 2 and Figure 4 As shown, Figure 4The dashed arrows in the diagram roughly illustrate the optical path of the laser. The laser source 11 includes a laser 111, a lens group 112, a first light-directing element 113, and a second light-directing element 114.

[0070] The laser 111 in this application is mainly used for emitting laser light. Because MCL lasers (Micro Channel Lasers) have high integration, the laser 111 provided in this embodiment uses an MCL laser, which is beneficial for the miniaturization of the laser source 11. Furthermore, MCL lasers typically include multiple laser chips, and can simultaneously include laser chips for three primary colors of light; therefore, the emission of three primary colors of light can be achieved using a single MCL laser.

[0071] The lens group 112 in this application includes a first lens 1121 and a second lens 1122, wherein the second lens 1122 is not in the optical path of the first lens 1121, and either the first lens 1121 or the second lens 1122 is located in the optical path of the laser. That is, the first lens 1121 and the second lens 1122 are not simultaneously located in the optical path of the laser. For example, when the first lens 1121 is located in the optical path of the laser and the second lens 1122 is not in the optical path of the laser, the laser emitted from the laser 111 passes through the first lens 1121 and enters the light-incident surface 1211 of the homogenizing element 121; when the second lens 1122 is located in the optical path of the laser and the first lens 1121 is not in the optical path of the laser, the laser emitted from the laser 111 passes through the second lens 1122 and enters the light-incident surface 1211 of the homogenizing element 121.

[0072] In this application, the first light-directing element 113 is disposed on the light-emitting side of the second lens 1122 and located in the light path of the second lens 1122. The laser light passing through the second lens 1122 can be incident on the first light-directing element 113, and the direction of the laser light is changed by the first light-directing element 113 so that the laser light passing through the second lens 1122 can be incident on the light-incident surface 1211 of the homogenizing element 121.

[0073] The second light-directing element 114 in this application is movably configured, allowing it to switch between a first state and a second state. For example... Figure 2 As shown, when the second light-directing element 114 is in the first state, the second light-directing element 114 is not in the optical path of the laser. At this time, the laser emitted from the laser 111 passes through the first lens 1121 and enters the light-incident surface 1211 of the homogenizing element 121, forming a first spot size on the light-incident surface 1211 of the homogenizing element 121; as Figure 4As shown, when the second light-directing element 114 is activated to the second state, the second light-directing element 114 is located in the optical path of the laser. The second light-directing element 114 is used to change the propagation direction of the laser emitted from the laser 111 so that the laser passes through the second lens 1122. The laser passing through the second lens 1122 is directed by the first light-directing element 113 to the incident light-incident surface 1211 of the incident homogenizing element 121, and a second light spot size is formed on the incident light-incident surface 1211. The second light spot size is different from the first light spot size. For example, the second light spot size is smaller than the first light spot size, or the second light spot size is larger than the first light spot size.

[0074] By ensuring that the second lens 1122 is not located in the optical path of the first lens 1121, the laser light transmitted from the first lens 1121 will not enter the second lens 1122. A first light-directing element 113 and a movable second light-directing element 114 are provided. By moving the second light-directing element 114, it can be positioned either in or out of the laser's optical path. When the second light-directing element 114 is not in the laser's optical path, the laser light passes through the first lens 1121 and enters the incident surface 1211 of the homogenizing element 121. A first spot size is formed on the light-incident surface 1211 of the homogenizing element 121. When the second light-directing element 114 is located in the optical path of the laser, the laser is redirected by the second light-directing element 114 and enters the second lens 1122. The laser transmitted through the second lens 1122 is redirected by the first light-directing element 113 and enters the light-incident surface 1211 of the homogenizing element 121, forming a second spot size different from the first spot size on the light-incident surface 1211. This achieves the design objective of forming different spot sizes on the light-incident surface 1211 of the homogenizing element 121.

[0075] Optionally, the second light-directing element 114 can perform linear motion, for example, the second light-directing element 114 can be moved or slidably configured; or, the second light-directing element 114 can also perform rotational motion, for example, the second light-directing element 114 can be rotated. This application does not limit the specific movement mode of the second light-directing element 114, as long as the second light-directing element 114 can switch between a state located on the laser's optical path and a state not located on the laser's optical path.

[0076] It should be noted that when the radius of curvature of the lens (i.e., the first lens 1121 and the second lens 1122) changes, the size of the light spot on the incident surface 1211 of the homogenizing element 121 will change. For example, the larger the radius of curvature of the lens, the smaller the size of the light spot on the incident surface 1211 of the homogenizing element 121. And when the distance between the lens (i.e., the first lens 1121 and the second lens 1122) and the homogenizing element 121 in its optical axis direction changes, the size of the light spot on the incident surface 1211 of the homogenizing element 121 will also change. For example, the smaller the distance between the lens and the homogenizing element 121 in its optical axis direction, the smaller the size of the light spot on the incident surface 1211 of the homogenizing element 121.

[0077] Therefore, by adjusting the radius of curvature of the lens and the distance between the lens and the homogenizing element 121 in the direction of its optical axis, the size of the light spot on the homogenizing element 121 can be adjusted.

[0078] In one exemplary case, the distance between the first lens 1121 and the homogenizing element 121 along the optical axis of the first lens 1121 is not equal to the distance between the second lens 1122 and the homogenizing element 121. This results in a difference between the size of the first light spot formed on the light-incident surface 1211 of the homogenizing element 121 after the laser passes through the first lens 1121 and the size of the second light spot formed on the light-incident surface 1211 of the homogenizing element 121 after the laser passes through the second lens 1122.

[0079] In this exemplary manner, in some embodiments, such as Figure 2 and Figure 4 As shown, in the optical axis direction of the first lens 1121, the distance L1 between the first lens 1121 and the homogenizing element 121 can be greater than the distance L2 between the second lens 1122 and the homogenizing element 121, then as follows Figure 5 and Figure 6 As shown, where, Figure 5 It indicates Figure 2 The size of the first light spot formed on the incident light surface of the homogenizing element in the image. Figure 6 for Figure 4 The second light spot size formed on the incident light surface of the homogenizing element is larger than the first light spot size. Therefore, when the aperture of the aperture stop 141 is reduced to decrease stray light entering the projection lens 14, the second light steering element 114 can be changed from its first state (e.g., ...). Figure 2 The state shown) switches to the second state (such as...). Figure 4(as shown in the diagram) to reduce the size of the laser spot on the incident surface 1211 of the homogenizing element 121, thereby reducing the divergence angle of the laser beam incident on the aperture 141. In this way, even if the aperture 141 is reduced, the obstruction of the effective laser light by the aperture 141 can be reduced or avoided, so that the effective laser light can still pass smoothly through the aperture 141. Thus, while improving the contrast of the image, the light throughput of the projection lens 14 can be guaranteed to ensure the brightness of the image.

[0080] In other embodiments, such as Figure 7 and Figure 8 As shown, Figure 7 and Figure 8 The dashed arrows roughly illustrate the laser's optical path. In the optical axis direction of the first lens 1121, the distance L1 between the first lens 1121 and the homogenizing element 121 can be smaller than the distance L2 between the second lens 1122 and the homogenizing element 121. Therefore, the first light spot size is smaller than the second light spot size. Thus, when the aperture of the aperture stop 141 is reduced to decrease stray light entering the projection lens 14, the second light-directing element 114 can be changed from its second state (e.g., ...). Figure 8 The state shown) switches to the first state (e.g. Figure 7 (as shown in the diagram) to reduce the size of the laser spot on the incident surface 1211 of the homogenizing element 121, thereby reducing the divergence angle of the laser beam incident on the aperture 141. In this way, even if the aperture 141 is reduced, the obstruction of the effective laser light by the aperture 141 can be reduced or avoided, so that the effective laser light can still pass smoothly through the aperture 141. Thus, while improving the contrast of the image, the light throughput of the projection lens 14 can be guaranteed to ensure the brightness of the image.

[0081] Another example is the radius of curvature of the first lens 1121 and the radius of curvature of the second lens 1122. This causes the size of the first spot formed by the laser on the light-incident surface 1211 of the homogenizing element 121 after passing through the first lens 1121 to be different from the size of the second spot formed by the laser on the light-incident surface 1211 of the homogenizing element 121 after passing through the second lens 1122.

[0082] In this exemplary embodiment, in some embodiments, the radius of curvature of the first lens 1121 can be smaller than the radius of curvature of the second lens 1122. Therefore, the size of the first light spot is larger than the size of the second light spot. Thus, when the aperture of the aperture 141 is reduced to decrease stray light entering the projection lens 14, the second light-directing element 114 can be switched from the first state to the second state to reduce the size of the laser spot on the incident surface 1211 of the homogenizing element 121. This reduces the divergence angle of the laser beam incident on the aperture 141. Even with the aperture of the aperture 141 reduced, the obstruction of the effective laser light by the aperture 141 can be reduced or avoided, allowing the effective laser light to still pass smoothly through the aperture of the aperture 141. This ensures that the light throughput of the projection lens 14 is maintained while improving the image contrast, thereby ensuring image brightness.

[0083] In other embodiments, the radius of curvature of the first lens 1121 can be greater than that of the second lens 1122, so the size of the first light spot is smaller than that of the second light spot. Thus, when the aperture of the aperture 141 is reduced to decrease stray light entering the projection lens 14, the second light steering element 114 can be switched from the second state to the first state to reduce the size of the laser spot on the incident surface 1211 of the homogenizing element 121. This reduces the divergence angle of the laser beam incident on the aperture 141. In this way, even if the aperture of the aperture 141 is reduced, the obstruction of the effective laser light by the aperture 141 can be reduced or avoided, so that the effective laser light can still pass smoothly through the aperture of the aperture 141. This can improve the contrast of the image while ensuring the light throughput of the projection lens 14 to ensure the brightness of the image.

[0084] In another exemplary case, the distance between the first lens 1121 and the homogenizing element 121 in the optical axis direction of the first lens 1121 is not equal to the distance between the second lens 1122 and the homogenizing element 121, and the radius of curvature of the first lens 1121 and the second lens 1122 are different.

[0085] In this exemplary manner, in some embodiments, the distance L1 between the first lens 1121 and the homogenizing element 121 in the optical axis direction of the first lens 1121 can be greater than the distance L2 between the second lens 1122 and the homogenizing element 121, and the radius of curvature of the first lens 1121 can be smaller than the second radius of curvature. Thus, the size of the first light spot is larger than the size of the second light spot. Therefore, when the aperture of the aperture 141 is reduced to decrease stray light entering the projection lens 14, the second light steering element 114 can be switched from the first state to the second state to reduce the size of the laser spot on the incident surface 1211 of the homogenizing element 121. This reduces the divergence angle of the laser beam incident on the aperture 141. In this way, even if the aperture of the aperture 141 is reduced, the obstruction of the effective laser light by the aperture 141 can be reduced or avoided, so that the effective laser light can still pass smoothly through the aperture of the aperture 141. This can improve the contrast of the image while ensuring the light throughput of the projection lens 14 to ensure the brightness of the image.

[0086] When the distance L1 between the first lens 1121 and the homogenizing element 121 is less than the distance L2 between the second lens 1122 and the homogenizing element 121 in the optical axis direction of the first lens 1121, and the radius of curvature of the first lens 1121 is greater than the radius of curvature of the second lens 1121, the size of the first light spot is smaller than the size of the second light spot. Thus, when the aperture of the aperture 141 is reduced to decrease stray light entering the projection lens 14, the second light steering element 114 can be switched from the second state to the first state to reduce the size of the laser spot on the incident surface 1211 of the homogenizing element 121. This reduces the divergence angle of the laser beam incident on the aperture 141. In this way, even if the aperture of the aperture 141 is reduced, the obstruction of the effective laser light by the aperture 141 can be reduced or avoided, so that the effective laser light can still pass smoothly through the aperture of the aperture 141. This can improve the contrast of the image while ensuring the light throughput of the projection lens 14 to ensure the brightness of the image.

[0087] As an optional embodiment, the first lens 1121 is movably disposed, and the first lens 1121 can move along its optical axis to approach or move away from the homogenizing element 121, thereby adjusting the distance between the first lens 1121 and the homogenizing element 121 in its optical axis direction, and adjusting the size of the first light spot, so that the first light spot size is not unique, that is, the first light spot size can include at least two different light spot sizes, and thus at least three different light spot sizes can be formed on the light incident surface 1211 of the homogenizing element 121. This allows the illumination system 12 to be adapted not only to projection lenses 14 with two different aperture sizes, but also to projection lenses 14 with three or more aperture sizes, improving the compatibility of the illumination system 12 and the projection lens 14.

[0088] As another optional implementation, the second lens 1122 is movably disposed and can move along its optical axis to approach or move away from the homogenizing element 121. This allows adjustment of the distance between the second lens 1122 and the homogenizing element 121 along its optical axis, thereby adjusting the size of the second light spot. The second light spot size can be non-unique, meaning it can include at least two different light spot sizes. Consequently, at least three different light spot sizes can be formed on the light incident surface 1211 of the homogenizing element 121. This allows the illumination system 12 to be adapted not only to projection lenses 14 with two different aperture sizes, but also to projection lenses 14 with three or more aperture sizes, improving the compatibility of the illumination system 12 and the projection lens 14.

[0089] As another alternative implementation, the first lens 1121 is movably disposed and can move along its optical axis to approach or move away from the homogenizing element 121, and the second lens 1122 is movably disposed and can move along its optical axis to approach or move away from the homogenizing element 121. In this way, the distance between the first lens 1121 and the homogenizing element 121 in its optical axis direction can be adjusted to form a non-unique first spot size on the light-incident surface 1211 of the homogenizing element 121. The distance between the second lens 1122 and the homogenizing element 121 in its optical axis direction can also be adjusted to form a non-unique second spot size on the light-incident surface 1211 of the homogenizing element 121. Thus, at least four different spot sizes can be formed on the light-incident surface 1211 of the homogenizing element 121. This allows the illumination system 12 to be adapted not only to projection lenses 14 with two or three different aperture sizes, but also to projection lenses 14 with four or more aperture sizes, further improving the compatibility of the illumination system 12 and the projection lens 14.

[0090] In some embodiments, such as Figure 7 and Figure 8 As shown, the first light-directing element 113 may include a polarizing beam combiner 1131 and a first reflector 1132. The polarizing beam combiner 1131 is disposed on the light-emitting side of the first lens 1121. When the second light-directing element 114 is in a first state, the polarizing beam combiner 1131 transmits the laser light transmitted from the first lens 1121 to the light-incident surface 1211 of the homogenizing element 121. Alternatively, when the second light-directing element 114 is in a second state, the polarizing beam combiner 1131 reflects the laser light transmitted from the second lens 1122 to the light-incident surface 1211 of the homogenizing element 121. The first reflector 1132 is disposed on the light-emitting side of the second lens 1122 and reflects the laser light transmitted from the second lens 1122 to the polarizing beam combiner 1131.

[0091] Specifically, when the second light-directing element 114 is in the first state, it is not in the optical path of the laser. The laser light transmitted from the first lens 1121 passes through the polarizing beam combiner 1131 and enters the light-incident surface 1211 of the homogenizing element 121. When the second light-directing element 114 is in the second state, it is in the optical path of the laser. The laser light is directed by the second light-directing element 114 and enters the second lens 1122. The laser light transmitted from the second lens 1122 is reflected by the first reflector 1132 to the polarizing beam combiner 1131 and then reflected by the polarizing beam combiner 1131 to the light-incident surface 1211 of the homogenizing element 121.

[0092] The first light steering element 113 adopts the above structure, which enables the laser light transmitted from the first lens 1121 and the laser light transmitted from the second lens 1122 to be transmitted to the light incident surface 1211 of the homogenizing element 121. Moreover, the structure of the first light steering element 113 is relatively simple, easy to implement, and cost-saving.

[0093] Optionally, the first reflector 1132 may be a reflector or a reflective prism, etc.

[0094] In some embodiments, the second light steering element 114 may include a second reflector 1141 and a third reflector 1142. The second reflector 1141 is movably configured to switch between a first state and a second state. The third reflector 1142 is disposed on the light-emitting side of the second reflector 1141 and is used to reflect the laser emitted through the second reflector 1141 toward the second lens 1122. Thus, when the second reflector 1141 is in the first state, it is not in the optical path of the laser, and the laser emitted from the laser 111 passes through the first lens 1121 and enters the light-incident surface 1211 of the homogenizing element 121. Specifically, the laser emitted from the laser 111 passes sequentially through the first lens 1121 and the polarizing combiner 1131 and enters the light-incident surface 1211 of the homogenizing element 121.

[0095] When the second reflector 1141 is in the second state, it is located in the optical path of the laser. The second reflector 1141 reflects the laser emitted from the laser generator 111 to the third reflector 1142. The third reflector 1142 reflects the laser emitted through the second reflector 1141 to the second lens 1122. The laser passing through the second lens 1122 is then redirected by the first light-directing element 113 to the incident light-incident surface 1211 of the homogenizing element 121. Specifically, the laser emitted from the laser generator 111 is reflected by the second reflector 1141 to the third reflector 1142, and then by the third reflector 1142 to the second lens 1122. The laser then passes through the second lens 1122, and is reflected by the first reflector 1132 to the polarizing beam combiner 1131, and then by the polarizing beam combiner 1131 to the incident light-incident surface 1211 of the homogenizing element 121.

[0096] The second light steering element 114 adopts the above structure, which can change the propagation direction of the laser emitted from the laser 111, so that the laser can pass through the first lens 1121 or the second lens 1122. Moreover, the structure of the second light steering element 114 is relatively simple, easy to implement, and cost-saving.

[0097] Optionally, the second reflector 1141 may be a mirror or a prism. The third reflector 1142 may also be a mirror or a prism.

[0098] To achieve full-color display, the laser 111 includes at least two types of laser chips; wherein the two types of laser chips have different emission wavelengths.

[0099] In some embodiments, such as Figure 9 and Figure 10 As shown, the laser 111 may include a first laser chip 1111, a second laser chip 1112 and a third laser chip 1113, wherein there may be multiple first laser chips 1111, multiple second laser chips 1112 and multiple third laser chips 1113, and the multiple first laser chips 1111, multiple second laser chips 1112 and multiple third laser chips 1113 are arranged in an array.

[0100] In practical implementation, the positions of the first laser chip 1111, the second laser chip 1112, and the third laser chip 1113 can be set according to actual needs. For example, Figure 9 As shown, multiple first laser chips 1111 can form a row of first laser chips 1111, multiple second laser chips 1112 can form a row of second laser chips 1112, and multiple third laser chips 1113 can form a row of third laser chips 1113, thus forming a row of first laser chips 1111, a row of second laser chips 1112, and a row of third laser chips 1113 arranged sequentially; for example, as... Figure 10 As shown, the first laser chip 1111 and the second laser chip 1112 are arranged side by side and alternately to form a row of first laser chips 1111, and multiple third laser chips 1113 can form an array of third laser chips 1113, thus forming a row of first laser chips 1111 and a row of third laser chips 1113 arranged in sequence.

[0101] In addition, other arrangement methods can be used to arrange various laser chips. The embodiments in this application are only for illustrative purposes and do not specifically limit the arrangement method of laser chips.

[0102] In practical applications, the first laser chip 1111 can be a green laser chip, the second laser chip 1112 can be a blue laser chip, and the third laser chip 1113 can be a red laser chip.

[0103] All three types of laser chips emit linearly polarized light. However, the lasers emitted by the first laser chip 1111 and the second laser chip 1112 are first linearly polarized light, while the laser emitted by the third laser chip 1113 is second linearly polarized light. The polarization directions of the first and second linearly polarized light are perpendicular to each other. For example, since the first laser chip 1111 is a green laser chip and the second laser chip 1112 is a blue laser chip, the lasers emitted by the first and second laser chips 1111 and 1112 are typically S-polarized light. Since the third laser chip 1113 is a red laser chip, the laser emitted by the third laser chip 1113 is typically P-polarized light.

[0104] In some embodiments, the lasers of different colors emitted by the laser 111 can be combined first, and then the combined laser beam can be shaped.

[0105] In some embodiments, such as Figure 7 and Figure 8 As shown, the laser source 11 also includes a beam combining component 115, which is located on the light-emitting side of the laser 111 and is used to combine at least two laser beams of different colors emitted by the laser 111. The illumination system 12 is located on the light-emitting side of the beam combining component 115.

[0106] The laser 111 is still used as an example, which includes a first laser chip 1111, a second laser chip 1112, and a third laser chip 1113.

[0107] like Figure 7 and Figure 8As shown, in some embodiments, when multiple first laser chips 1111 are arranged in an m*n array, multiple second laser chips 1112 are arranged in an m*n array, and multiple third laser chips 1113 are arranged in an m*n array, the light combining component 115 includes a fourth reflector 1151, a first light combining mirror 1152, and a second light combining mirror 1153; wherein, the fourth reflector 1151 is located on the light-emitting side of the first laser chip 1111; the first light combining mirror 1152 is located at the intersection of the emitted light from the fourth reflector 1151 and the emitted light from the second laser chip 1112; and the second light combining mirror 1153 is located at the intersection of the emitted light from the first light combining mirror 1152 and the emitted light from the third laser chip 1113. Here, m and n are both natural numbers greater than zero.

[0108] The fourth reflector 1151 is used to reflect the emitted light of the first laser chip 1111 towards the first beam combiner 1152; the first beam combiner 1152 is used to transmit the emitted light of the first laser chip 1111 and reflect the emitted light of the second laser chip 1112; the second beam combiner 1153 is used to transmit the emitted light of the first laser chip 1111 and the second laser chip 1112 and reflect the emitted light of the third laser chip 1113.

[0109] The first laser chip 1111 can be a green laser chip, the second laser chip 1112 can be a blue laser chip, and the third laser chip 1113 can be a red laser chip. The fourth reflector 1151 reflects the green laser towards the first beam combiner 1152; the first beam combiner 1152 transmits the green laser and reflects the blue laser, thus combining the blue and green lasers and outputting them towards the second beam combiner 1153; the second beam combiner 1153 transmits the combined blue and green lasers while reflecting the red laser. The illumination system 12 is located on the output side of the second beam combiner 1153 and is used to shape the combined laser beam.

[0110] Optionally, the fourth reflector 1151 may be a reflector or a reflective prism, etc.

[0111] In other embodiments, such as Figure 11 and Figure 12 As shown, Figure 11 and Figure 12The dashed arrows roughly illustrate the optical path of the laser. When the first laser chip 1111 and the second laser chip 1112 are arranged side-by-side alternately in an m*n array, and multiple third laser chips 1113 are arranged in an m*n array, the light combining component 115 includes a first light combining mirror 1152 and a second light combining mirror 1153; wherein, the first light combining mirror 1152 is located on the light-emitting side of the first laser chip 1111 and the second laser chip 1112; the second light combining mirror 1153 is located at the intersection of the emitted light from the first light combining mirror 1152 and the emitted light from the third laser chip 1113. Here, m and n are both natural numbers greater than zero.

[0112] The first beam combiner 1152 is used to combine the first laser chip 1111 and the second laser chip 1112 into a beam, and to reflect the beam-combined outgoing light to the second beam combiner 1153; the second beam combiner 1153 is used to transmit the beam-combined outgoing light of the first laser chip 1111 and the second laser chip 1112, and to reflect the outgoing light of the third laser chip 1113.

[0113] The first laser chip 1111 can be a green laser chip, the second laser chip 1112 can be a blue laser chip, and the third laser chip 1113 can be a red laser chip. The fourth reflector 1151 can reflect both the green and blue lasers, and then combine them into a beam before reflecting it towards the first beam combiner 1152. The first beam combiner 1152 transmits the combined blue and green lasers while reflecting the red laser. The illumination system 12 is located on the light-emitting side of the second beam combiner 1153 and is used to shape the combined laser beam.

[0114] In some embodiments, such as Figure 11 and Figure 12 As shown, the laser projection system 100 also includes a first polarization conversion device 15 and a second polarization conversion device 16.

[0115] The first polarization conversion device 15 in this application can be located on the light-emitting side of the first laser chip 1111 and the second laser chip 1112, so that the laser emitted by the first laser chip 1111 and the second laser chip 1112 is converted from first linearly polarized light to second linearly polarized light after passing through the first polarization conversion device 15, and the polarization direction is the same as that of the laser emitted by the first laser chip 1111. This allows the laser emitted by the first laser chip 1111, the second laser chip 1112 and the third laser chip 1113 to be transmitted through the polarization combining plate 1131 after passing through the first lens 1121. Alternatively, the first polarization conversion device 15 is located on the light-emitting side of the third laser chip 1113, so that the laser emitted from the third laser chip 1113 is converted from second linearly polarized light to first linearly polarized light after passing through the first polarization conversion device 15, and the polarization direction is the same as that of the laser emitted from the first laser chip 1111 and the second laser chip 1112. This allows the lasers emitted from the first laser chip 1111, the second laser chip 1112 and the third laser chip 1113 to pass through the polarization combiner 1131 after passing through the first lens 1121 and be incident on the homogenizing element 121.

[0116] The second polarization conversion device 16 in this application is used to perform polarization conversion on the laser light that has been turned by the second light-directing element 114 and has not been incident on the polarization combiner 1131, so that the polarization direction of the laser light incident on the polarization combiner 1131 when the second light-directing element 114 is in the first state is different from the polarization direction of the laser light incident on the polarization combiner 1131 when the second light-directing element 114 is in the second state. This allows the laser light to pass through the polarization combiner 1131 and be incident on the homogenizing element 121 when the second light-directing element 114 is in the first state, and the laser light to be reflected by the polarization combiner 1131 to the homogenizing element 121 when the second light-directing element 114 is in the second state.

[0117] In some embodiments, such as Figure 12 As shown, the second polarization conversion device 16 can be disposed between the second reflector 1141 and the third reflector 1142. At this time, the second polarization conversion device 16 is used to polarize the laser reflected by the second reflector 1141. The polarization-reversed laser is reflected by the third reflector 1142, passes through the second lens 1122, and is reflected by the first reflector 1132 to the polarization combiner 1131.

[0118] In other embodiments, such as Figure 13 As shown, Figure 13The dashed arrows roughly indicate the optical path of the laser. The second polarization conversion device 16 can be disposed between the third reflector 1142 and the second lens 1122. In this case, the second polarization conversion device 16 is used to polarize the laser reflected by the third reflector 1142. The polarization-reversed laser passes through the second lens 1122 and is reflected by the first reflector 1132 to the polarization combiner 1131.

[0119] In some other embodiments, such as Figure 14 As shown, Figure 14 The dashed arrows roughly indicate the optical path of the laser. The second polarization conversion device 16 can be disposed between the second reflector 1141 and the third reflector 1142. In this case, the second polarization conversion device 16 is used to polarize the laser light that has been reflected sequentially by the second reflector 1141 and the third reflector 1142 and then reflected by the first reflector 1132 through the second lens 1122. The polarized laser light is then incident on the polarization combiner 1131.

[0120] For example, the first polarization conversion device 15 is disposed on the light-emitting side of the first laser chip 1111 and the second laser chip 1112, converting the laser light from the first laser chip 1111 and the second laser chip 1112 from first linearly polarized light to second linearly polarized light; the second polarization conversion device 16 is disposed between the second reflector 1141 and the third reflector 1142, converting the laser light reflected and redirected by the second reflector 1141 from second linearly polarized light to first linearly polarized light.

[0121] When the second reflector 1141 is in the first state, the lasers from the first laser chip 1111, the second laser chip 1112, and the third laser chip 1113 are all incident on the homogenizing element 121 as second linearly polarized light through the first lens 1121 and the polarizing beam combiner 1131. When the second reflector 1141 is in the first state, the lasers from the first laser chip 1111, the second laser chip 1112, and the third laser chip 1113 are all incident on the second reflector 1141 as second linearly polarized light. The laser emitted from the second reflector 1141 is converted from second linearly polarized light to first linearly polarized light after passing through the second polarization conversion device 16. This causes the laser emitted from the second reflector 1141 to be reflected by the third reflector 1142, transmitted through the second lens 1122, reflected by the first reflector 1132 to the polarizing beam combiner 1131, and reflected by the polarizing beam combiner 1131 to the homogenizing element 121.

[0122] Optionally, the first polarization conversion device 15 may include, but is not limited to, waveplates, birefringent crystals, liquid crystals, diffraction devices, and metasurfaces. The type of the first polarization conversion device 15 is flexible and can be selected according to actual needs. This application embodiment does not impose specific limitations on this.

[0123] Similarly, the second polarization conversion device 16 may include, but is not limited to, waveplates, birefringent crystals, liquid crystals, diffraction devices, and metasurfaces. The type of the second polarization conversion device 16 is flexible and can be selected according to actual needs. This application embodiment does not make specific limitations in this regard.

[0124] In some embodiments, such as Figure 14 As shown, the lens group 112 further includes a third lens 1123 and a fourth lens 1124. The first lens 1121, the third lens 1123, and the fourth lens 1124 are arranged sequentially along the optical axis of the first lens 1121. The first light-directing element 113 is located between the first lens 1121 and the third lens 1123. When the second light-directing element 114 is in the first state, the laser light passes through the first lens 1121, the third lens 1123, and the fourth lens 1124 and is incident on the light-incident surface 1211 of the homogenizing element 121. When the second light-directing element 114 is in the second state, the laser light is redirected by the second light-directing element 114 and passes through the second lens 1122, and then redirected by the first light-directing element 113 and passes through the third lens 1123 and the fourth lens 1124 and is incident on the light-incident surface 1211 of the homogenizing element 121.

[0125] This configuration allows for further modulation of the laser through the synergistic effect of the first lens 1121 with the third lens 1123 and the fourth lens 1124, or through the synergistic effect of the second lens 1122 with the third lens 1123 and the fourth lens 1124. This ensures that the light spot on the homogenizing element 121 has uniform light intensity and uniform energy distribution at all positions, which better meets the illumination requirements of the laser projection system 100.

[0126] In some embodiments, such as Figure 14 As shown, the lighting system 12 also includes a relay lens group 122, which is disposed on the light-emitting side of the homogenizing element 121 and located between the homogenizing element 121 and the light valve 13. The laser emitted from the homogenizing element 121 passes through the relay lens group 122 and enters the light valve 13.

[0127] Since the laser beam homogenized by the homogenizing element 121 is prone to divergence or optical path deviation during transmission to the optical valve 13, affecting the imaging effect, the relay lens group 122 can readjust the propagation direction and convergence of the laser beam, and scale the irradiation range of the laser beam, thereby ensuring that the laser beam enters the optical valve 13 in a more ideal state, so that the laser beam can irradiate more areas on the optical valve 13.

[0128] Optionally, the relay lens group 122 may include two relay lenses, thereby further compensating for aberrations and distortions in the optical path through the synergistic effect of the two relay lenses, improving the clarity and uniformity of the projected image, reducing image blurring and edge distortion caused by laser transmission problems, and ultimately achieving a high-quality and highly stable projection effect, bringing users a better visual experience.

[0129] Understandably, in other embodiments, the relay lens group 122 may also include three relay lenses, four relay lenses, or more relay lenses.

[0130] In some embodiments, such as Figure 14 As shown, the lighting system 12 also includes a reflector 123, which is disposed on the light-emitting side of the homogenizing element 121 and located between the light valve 13 and the projection lens 14. The reflector 123 is used to reflect the laser emitted from the homogenizing element 121 toward the light valve 13 at a set angle.

[0131] By setting the reflector component 123 to deflect the laser emitted from the homogenizing element 121, the direction of the optical path can be changed so that the laser emitted from the homogenizing element 121 can be incident on the optical valve 13 at a suitable angle. This allows for more precise coverage of the effective area of ​​the optical valve 13, forming a uniform diffraction image and providing a good basis for the modulation of the optical valve 13. The optical valve 13 then performs amplitude modulation based on this uniform image, enabling fine control of the intensity distribution of the combined laser beam and accurate encoding of image information, thereby forming a high-quality image beam.

[0132] In specific implementation, the reflective component 123 may be a total internal reflection prism (TIR) ​​or simply a reflector; no limitation is made here.

[0133] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0134] Furthermore, the embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the content of this specification should not be construed as a limitation of this application, and the protection scope of this application should be determined by the appended claims.

Claims

1. A laser projection system, characterized in that, The laser projection system includes: A laser source, wherein the laser source is used to emit laser light; An illumination system is disposed in the optical path of the laser, and the illumination system is used to modulate the laser; A light valve, the light valve being used to receive the laser light modulated by the illumination system and to emit the laser light; and, A projection lens configured to image the laser emitted from the light valve; The projection lens includes an aperture stop with a variable light transmission diameter; The lighting system includes a homogenizing element having an incident light surface and an exit light surface, wherein the laser light enters the homogenizing element from the incident light surface and exits from the exit light surface to the light valve; The laser can form different spot sizes on the incident light surface. The lasers corresponding to different spot sizes are emitted from the light valve and enter the light aperture of the aperture with different beam divergence angles. The beam divergence angle is proportional to the spot size and the aperture diameter of the aperture.

2. The laser projection system according to claim 1, characterized in that, The laser source includes: A laser, the laser being used to emit the laser beam; The lens group includes a first lens and a second lens, wherein the second lens is not in the optical path of the first lens, and either the first lens or the second lens is in the optical path of the laser. A first light-directing element is disposed on the light-emitting side of the second lens and located in the optical path of the second lens; A second light steering element is movably configured and can switch between a first state and a second state. When the second light-directing element is activated to the first state, the second light-directing element is not in the optical path of the laser. The laser emitted from the laser passes through the first lens and enters the incident surface of the homogenizing element, forming a first spot size on the incident surface. When the second light-directing element is activated to the second state, the second light-directing element is located in the optical path of the laser. The second light-directing element is used to change the propagation direction of the laser emitted from the laser so that the laser passes through the second lens. The laser that passes through the second lens is redirected by the first light-directing element to the incident surface of the homogenizing element and forms a second spot size on the incident surface. The second spot size is different from the first spot size.

3. The laser projection system according to claim 2, characterized in that, In the optical axis direction of the first lens, the distance between the first lens and the homogenizing element is not equal to the distance between the second lens and the homogenizing element; And / or, The radius of curvature of the first lens is different from that of the second lens.

4. The laser projection system according to claim 2, characterized in that, The first light steering element includes: A polarizing beam combiner is disposed on the light-emitting side of the first lens. The polarizing beam combiner is configured to, when the second light-directing element is activated to the first state, transmit the laser light emitted from the first lens to the light-incident surface; or, the polarizing beam combiner is configured to, when the second light-directing element is activated to the second state, reflect the laser light emitted from the second lens to the light-incident surface. A first reflector is disposed on the light-emitting side of the second lens, and the first reflector is used to reflect the laser light transmitted from the second lens to the polarizing beam combiner.

5. The laser projection system according to claim 4, characterized in that, The laser includes a first laser chip, a second laser chip, and a third laser chip. The laser emitted by the first laser chip and the second laser chip is first linearly polarized light, and the laser emitted by the third laser chip is second linearly polarized light. The polarization directions of the first linearly polarized light and the second linearly polarized light are perpendicular to each other. The laser projection system also includes: A first polarization conversion device is located on the light-emitting side of the first laser chip and the second laser chip, or on the light-emitting side of the third laser chip. The first polarization conversion device is used to make the polarization direction of the laser light from the first laser chip, the second laser chip and the third laser chip the same. The second polarization conversion device is used to perform polarization conversion on the laser light that has been deflected by the second optical steering element and has not been incident on the polarization combiner.

6. The laser projection system according to claim 2, characterized in that, The second light steering element includes: A second reflector, movably configured to switch between the first state and the second state; and... A third reflector is disposed on the light-emitting side of the second reflector, and the third reflector is used to reflect the laser emitted by the second reflector toward the second lens; When the second reflector is moved to the first state, the second reflector is not in the optical path of the laser, and the laser emitted from the laser passes through the first lens and enters the incident surface of the homogenizing element; When the second reflector is moved to the second state, the second reflector is located in the optical path of the laser. The second reflector is used to reflect the laser emitted from the laser to the third reflector. The third reflector is used to reflect the laser emitted through the second reflector to the second lens. The laser transmitted through the second lens is directed by the first light-directing element to the incident light surface of the homogenizing element.

7. The laser projection system according to claim 2, characterized in that, The lens group further includes a third lens and a fourth lens. The first lens, the third lens, and the fourth lens are arranged sequentially along the optical axis of the first lens, and the first light steering element is located between the first lens and the third lens. When the second light-directing element is activated to the first state, the laser light passes through the first lens, the third lens, and the fourth lens and enters the incident surface of the homogenizing element; When the second light-directing element is activated to the second state, the laser light is directed by the second light-directing element to pass through the second lens, and then directed by the first light-directing element to pass through the third lens and the fourth lens and enter the incident surface of the homogenizing element.

8. The laser projection system according to claim 2, characterized in that, The first lens is movably disposed and can move along its optical axis to approach or move away from the homogenizing element; And / or, The second lens is movably disposed and can move along its optical axis to approach or move away from the homogenizing element.

9. The laser projection system according to any one of claims 1-8, characterized in that, The lighting system further includes a relay lens group, which is disposed on the light-emitting side of the homogenizing element and located between the homogenizing element and the light valve. The laser emitted from the homogenizing element passes through the relay lens group and enters the light valve.

10. The laser projection system according to any one of claims 1-8, characterized in that, The lighting system further includes a reflective component, which is disposed on the light-emitting side of the homogenizing element and located between the light valve and the projection lens. The reflective component is used to reflect the laser emitted by the homogenizing element toward the light valve at a set angle.

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