Projection apparatus and projection system

Abstract

A projection apparatus and a projection system are provided. The projection equipment comprises a light source, an optical modulation assembly and a lens. The light source includes at least one laser and at least one optical waveguide. The at least one laser comprises a plurality of first light-emitting chips, a plurality of second light-emitting chips and a plurality of third light-emitting chips. And one of the at least one optical waveguide is positioned on the light emitting side of the plurality of third light emitting chips. Each optical waveguide in the at least one optical waveguide comprises a light incident surface, a light emergent surface, a light incident part and a light emergent part. And the light incident surface and the light emergent surface are oppositely arranged in the thickness direction of the optical waveguide. The light incident part is configured to guide incident laser into the optical waveguide. And the light emitting part is configured to export the laser in the optical waveguide.

Description

Projection equipment and projection systems

[0001] This application claims priority to the Chinese patent application with application number 202222623787.X filed on September 30, 2022; priority to the Chinese patent application with application number 202211208529.3 filed on September 30, 2022; priority to the Chinese patent application with application number 202211216165.3 filed on September 30, 2022, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure relates to the field of laser projection technology, and in particular to a projection device and a projection system. Background Art

[0003] With the development of laser projection technology, projection equipment has gradually entered people's lives and become a common item in people's work and life. The light source in the projection equipment can emit lasers of multiple colors, which are modulated to form a projection image.

[0004] In one aspect, a projection device is provided. The projection device includes a light source, an optical modulation component, and a lens. The light source is configured to emit laser light of multiple colors as an illumination beam. The optical modulation component is configured to modulate the illumination beam to obtain a projection beam. The lens is located on the light-exiting side of the optical modulation component and is configured to project the projection beam to form a projection image. The light source includes at least one laser and at least one optical waveguide. The at least one laser includes a plurality of first light-emitting chips, a plurality of second light-emitting chips, and a plurality of third light-emitting chips. The plurality of first light-emitting chips are configured to emit red laser light. The plurality of second light-emitting chips are configured to emit blue laser light. The plurality of third light-emitting chips are configured to emit green laser light. The number of the plurality of third light-emitting chips and the number of the plurality of second light-emitting chips are each smaller than the number of the plurality of first light-emitting chips. One of the at least one optical waveguide is located on the light-exiting side of the plurality of third light-emitting chips. Each of the at least one optical waveguide includes a light-entry surface, a light-exiting surface, a light-entry portion, and a light-exiting portion. The light-entry surface is the surface of the optical waveguide closest to the laser. The light-exiting surface is parallel to the light-entry surface. The light input surface and the light output surface are arranged opposite each other in the thickness direction of the optical waveguide. The light input portion is configured to guide incident laser light into the optical waveguide. The light output portion is configured to output laser light from the optical waveguide. The light input portion and the light output portion are located between the light input surface and the light output surface. The beam width of the laser light emitted by the light output portion is equal to the beam width of the red laser light emitted by the plurality of first light-emitting chips.

[0005] On the other hand, another projection device is provided. The projection device includes a light source, an optical modulation component, and a lens. The light source is configured to emit laser light of multiple colors as an illumination beam, and the light source includes at least one laser, a light combining component, and a light modulating component. The at least one laser is configured to emit laser light of multiple colors. The light combining component is located on the light output side of the laser, and is configured to combine the laser light of different colors emitted by the at least one laser. The light modulating component is located on the light output side of the light combining component, and is configured to homogenize and shape the laser light after being combined by the light combining component, and the light modulating component includes a first diffractive optical element. The optical modulation component is configured to modulate the illumination beam to obtain a projection beam, and the optical modulation component includes a prism component and a light valve. The prism component is configured to receive the illumination beam emitted by the light modulating component and reflect the illumination beam to the light valve. The light valve is configured to modulate the incident illumination beam into the projection beam according to an image signal. The lens is located at the light-emitting side of the optical modulation component, and is configured to project the projection light beam to form a projection picture.

[0006] In another aspect, a projection system is provided. The projection system includes the above-mentioned projection device and a projection screen. The projection screen is located on the light-emitting side of the projection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] To more clearly illustrate the technical solutions of the present disclosure, the following briefly introduces the drawings required for use in some embodiments of the present disclosure. However, the drawings described below are only drawings of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the products involved in the embodiments of the present disclosure, the actual process of the method, the actual timing of the signals, etc.

[0008] FIG1 is a graph showing energy distribution of a laser in the related art;

[0009] FIG2 is an energy distribution curve diagram of another laser in the related art;

[0010] FIG3 is a structural diagram of a projection system according to some embodiments;

[0011] FIG4 is a structural diagram of a projection device according to some embodiments;

[0012] FIG5 is a light path diagram of a light source, an optical modulation component, and a lens in a projection device according to some embodiments;

[0013] FIG6 is a structural diagram of a light source according to some embodiments;

[0014] FIG7 is a structural diagram of another light source according to some embodiments;

[0015] FIG8 is a graph showing energy distribution of a laser according to some embodiments;

[0016] FIG9 is a structural diagram of another projection device according to some embodiments;

[0017] FIG10 is a cross-sectional view of a diffractive microstructure in a diffractive optical element according to some embodiments;

[0018] FIG11 is a structural diagram of another light source according to some embodiments;

[0019] FIG12 is a structural diagram of another light source according to some embodiments;

[0020] FIG13 is a structural diagram of another light source according to some embodiments;

[0021] FIG14 is a structural diagram of another light source according to some embodiments;

[0022] FIG15 is a structural diagram of another light source according to some embodiments;

[0023] FIG16 is a structural diagram of another light source according to some embodiments;

[0024] FIG17 is a structural diagram of another light source according to some embodiments;

[0025] FIG18 is a structural diagram of another light source according to some embodiments;

[0026] FIG19 is a structural diagram of another light source according to some embodiments;

[0027] FIG20 is a structural diagram of another light source according to some embodiments;

[0028] FIG21 is a structural diagram of another light source according to some embodiments;

[0029] FIG22 is a structural diagram of another light source according to some embodiments;

[0030] FIG23 is a structural diagram of another light source according to some embodiments;

[0031] FIG24 is a structural diagram of another projection device according to some embodiments;

[0032] FIG25 is a diagram of light paths of a light source and a light pipe according to some embodiments;

[0033] FIG26 is a structural diagram of yet another laser according to some embodiments;

[0034] FIG27 is a structural diagram of yet another light source according to some embodiments;

[0035] FIG28 is a schematic diagram of volume grating diffraction according to some embodiments;

[0036] FIG29 is a structural diagram of a volume grating and a light valve according to some embodiments;

[0037] FIG30 is a structural diagram of an optical modulation component in a projection device according to some embodiments;

[0038] FIG31 is a structural diagram of another optical modulation component in a projection device according to some embodiments;

[0039] FIG32 is a structural diagram of yet another projection device according to some embodiments;

[0040] FIG33 is a structural diagram of an arrayed optical waveguide according to some embodiments;

[0041] FIG34 is a structural diagram of a zigzag optical waveguide according to some embodiments;

[0042] FIG35 is a light path diagram of yet another light source according to some embodiments;

[0043] FIG36 is a light path diagram of yet another light source according to some embodiments;

[0044] FIG37 is a structural diagram of yet another projection device according to some embodiments;

[0045] FIG38 is a light path diagram of yet another light source according to some embodiments;

[0046] FIG39 is a light path diagram of yet another light source according to some embodiments;

[0047] FIG40 is a light path diagram of yet another light source according to some embodiments. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe some embodiments of the present disclosure in conjunction with the accompanying drawings. However, the described embodiments are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0049] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0050] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0051] When describing some embodiments, the word "connected" and its derivatives may be used. The term "connected" should be understood broadly. For example, "connected" can mean fixed, removable, or integrated; it can be directly connected or indirectly connected through an intermediary. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0052] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0053] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0054] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0055] Typically, in a projection device, before an illumination beam emitted by a light source enters an optical modulation component, it needs to be homogenized and shaped by a light homogenizing component (such as a light pipe) and a corresponding lens group to improve the display effect of the projected image.

[0056] However, due to the long light pipe and the fact that the lens assembly includes at least two lenses separated by a certain distance, the projection device is relatively large, making it difficult to meet the requirements for miniaturization. Furthermore, although a longer light pipe improves the uniformity of the illumination beam, the requirement for miniaturization limits the length of the light pipe, which in turn limits the upper limit of the projected image quality.

[0057] Figure 1 shows a laser energy distribution curve from a related art technique. As shown in Figure 1 , the horizontal axis (X) represents the position in the laser beam, and the vertical axis (Y) represents the laser energy (e.g., light intensity). The laser energy emitted by each light-emitting chip in laser 101 exhibits a Gaussian distribution, with most of the energy concentrated in the center region of the laser. In this case, the color uniformity of the projected image produced by the laser is poor.

[0058] Figure 2 shows another laser energy distribution curve from related art. In some implementations, a diffuser can be used to diffuse the laser light for uniformity. For example, as shown in Figure 2, after diffusion through the diffuser, the laser energy in the center region remains relatively high, while the energy at the edges remains relatively low, resulting in low laser uniformity. While increasing the diffuser's diffusion angle can improve laser energy uniformity, this also results in a significant loss of edge energy, resulting in low laser utilization.

[0059] In order to solve the above problems, some embodiments of the present disclosure provide a projection system 1 .

[0060] Figure 3 is a block diagram of a projection system according to some embodiments. As shown in Figure 3, projection system 1 includes a projection device 1000 and a projection screen 2000. Projection screen 2000 is located on the light-emitting side of projection device 1000, with the audience facing projection screen 2000. The projection light beam emitted from projection device 1000 is incident on projection screen 2000, then reflected off projection screen 2000 and enters the human eye, allowing the audience to view the projected image.

[0061] FIG4 is a block diagram of a projection device according to some embodiments. As shown in FIG4 , the projection device 1000 includes a housing 40 (only a portion of the housing 40 is shown in FIG4 ), a light source 10 assembled in the housing 40, an optical modulation assembly 20, and a lens 30. The light source 10 is configured to provide an illumination beam (e.g., a laser). The optical modulation assembly 20 is configured to modulate the illumination beam provided by the light source 10 using an image signal to obtain a projection beam. The lens 30 is configured to project the projection beam onto a projection screen 2000 or a wall to form a projection image.

[0062] The light source 10, optical modulation assembly 20, and lens 30 are sequentially connected along the beam propagation direction and each enclosed by a corresponding housing. The housings of the light source 10, optical modulation assembly 20, and lens 30 support the corresponding optical components and ensure that each optical component meets certain sealing or airtight requirements.

[0063] One end of the optical modulation assembly 20 is connected to the light source 10, and the light source 10 and the optical modulation assembly 20 are arranged along the direction of emission of the illumination beam of the projection device 1000 (refer to the M direction in FIG. 4 ). The other end of the optical modulation assembly 20 is connected to the lens 30, and the optical modulation assembly 20 and the lens 30 are arranged along the direction of emission of the projection beam of the projection device 1000 (refer to the N direction in FIG. 4 ). The emission direction M of the illumination beam is approximately perpendicular to the emission direction N of the projection beam. This connection structure not only adapts to the optical path characteristics of the reflective light valve in the optical modulation assembly 20, but also helps shorten the length of the optical path in one dimension, facilitating the overall layout of the device. For example, if the light source 10, the optical modulation assembly 20, and the lens 30 are arranged in one dimension (e.g., the M direction), the optical path length in that dimension will be very long, which is not conducive to the overall layout of the device. The reflective light valve will be described later.

[0064] In some embodiments, light source 10 can sequentially provide three primary colors (or additional colors in addition to the three primary colors). Due to the persistence of vision phenomenon of the human eye, the human eye perceives white light as a mixture of the three primary colors. Alternatively, light source 10 can simultaneously output the three primary colors, continuously emitting white light.

[0065] Figure 5 is a light path diagram of a light source, optical modulation assembly, and lens in a projection device according to some embodiments. As shown in Figure 5, the optical modulation assembly 20 includes a light homogenizing component 210, a lens assembly 220, a light valve 240 (i.e., an optical modulation component), and a prism assembly 250. The light homogenizing component 210 is configured to homogenize the incident illumination beam and emit it to the lens assembly 220. The lens assembly 220 can first collimate the illumination beam and then converge it and emit it to the prism assembly 250. The prism assembly 250 reflects the illumination beam to the light valve 240. The light valve 240 is configured to modulate the incident illumination beam into a projection beam based on an image signal and emit the projection beam to the lens 30.

[0066] In some embodiments, the light homogenizing component 210 may include a light pipe or a fly-eye lens assembly. For example, the light homogenizing component 210 may include a light pipe with a rectangular light inlet. The illumination beam from the light source 10 is incident on the light pipe and reflected within the light pipe for transmission. The reflection angles are random, thereby improving the uniformity of the illumination beam emitted from the light pipe.

[0067] For another example, the light homogenizing component 210 includes a fly-eye lens group, which is composed of two oppositely arranged fly-eye lenses, and the fly-eye lenses are formed by a plurality of microlens arrays. Along the incident direction of the illumination light beam, the focus of the microlens in the first fly-eye lens coincides with the center of the corresponding microlens in the second fly-eye lens, and the optical axes of the microlenses in the two fly-eye lenses are parallel to each other. The light spot of the illumination light beam can be divided by the fly-eye lens group. In addition, the divided light spots can be accumulated by the subsequent lens assembly 220. In this way, the illumination light beam can be homogenized. It should be noted that the light homogenizing component 210 can also be set in the light source 10. For example, the light source 10 includes the light homogenizing component 210. In this case, the light homogenizing component 210 may not be required in the optical modulation component 20.

[0068] The lens assembly 220 may include a convex lens, such as a plano-convex lens, a biconvex lens, or a concave-convex lens (also known as a positive meniscus lens). The convex lens may be a spherical lens or an aspherical lens.

[0069] The prism assembly 250 may be a total internal reflection (TIR) ​​prism assembly or a refractive total internal reflection (RTIR) prism assembly.

[0070] Light valve 240 can be a reflective light valve. It includes multiple reflective sheets, each of which can be used to form a pixel in the projection image. Light valve 240 can adjust the multiple reflective sheets based on the image to be displayed, so that the reflective sheets corresponding to the pixels in the image that need to be bright reflect the light beam toward lens 30. The light beam reflected toward lens 30 is called the projection beam. In this way, light valve 240 can modulate the illumination beam to generate the projection beam, which is then used to display the projected image.

[0071] In some embodiments, the light valve 240 can be a digital micromirror device (DMD). A digital micromirror device includes a plurality of (such as tens of thousands of) tiny reflective lenses that can be driven individually to rotate. These tiny reflective lenses can be arranged in an array. One tiny reflective lens (for example, each tiny reflective lens) corresponds to a pixel in the projection image to be displayed. After processing, the image signal can be converted into digital codes such as 0 and 1. In response to these digital codes, the tiny reflective lenses can swing. The time each tiny reflective lens lasts in the on and off states is controlled to achieve the grayscale of each pixel in a frame of image. In this way, the digital micromirror device can modulate the illumination light beam to achieve the display of the projection image.

[0072] The lens 30 comprises a multi-lens assembly, typically organized into three groups: a front group, a middle group, and a rear group, or a two-group configuration. The front group is the lens group located near the light-emitting side of the projection device 1000, while the rear group is the lens group located near the light-emitting side of the optical modulation assembly 20. The lens 30 can be a zoom lens, a fixed-focus adjustable lens, or a fixed-focus lens. In some embodiments, the projection device 1000 can be an ultra-short-throw projection device, and the lens 30 can be an ultra-short-throw projection lens.

[0073] For ease of description, some embodiments of the present disclosure are mainly described by taking the projection device 1000 adopting a digital light processing (DLP) projection architecture and the light valve 240 being a digital micromirror device as an example. However, this should not be understood as a limitation of the present disclosure.

[0074] The light source 10 in some embodiments of the present disclosure is described in detail below.

[0075] FIG6 is a structural diagram of a light source according to some embodiments. In some embodiments, as shown in FIG6 , the light source 10 includes a laser 101 .

[0076] The laser 101 is configured to emit laser light of multiple colors. For example, the laser 101 includes multiple light emitting areas, each of which can emit laser light of one color, and different light emitting areas can emit laser light of different colors.

[0077] FIG7 is a structural diagram of another light source according to some embodiments. For example, as shown in FIG7 , the laser 101 includes a first light exiting area 1014, a second light exiting area 1015, and a third light exiting area 1016. The first light exiting area 1014, the second light exiting area 1015, and the third light exiting area 1016 are arranged sequentially along the second direction Q, and the three light exiting areas respectively emit three different colors of laser light. For example, the first light exiting area 1014 emits green laser light, the second light exiting area 1015 emits blue laser light, and the third light exiting area 1016 emits red laser light.

[0078] Here, each of the multiple light emitting areas may include multiple light emitting chips, and each of the multiple light emitting chips may be used to emit a beam of laser light. This disclosure does not limit the number of light emitting areas of the laser 101 or the color of the laser light emitted by each light emitting area.

[0079] As shown in Figures 6 and 7, the light source 10 also includes a light combining component 102 and a dimming component 111. The lasers of multiple colors emitted by the laser 101 are directed toward the light combining component 102. The light combining component 102 is located on the light output side of the laser 101 and is configured to combine the lasers of different colors emitted by the laser 101. The laser light emitted from the light combining component 102 is directed toward the dimming component 111. The dimming component 111 is located on the light output side of the light combining component 102 and is configured to homogenize and shape the laser light after being combined by the light combining component 102. For example, the dimming component 111 shapes the received laser light so that the laser light emitted by the dimming component 111 can form a rectangular light spot.

[0080] In some embodiments, the dimming component 111 may be a diffractive optical element (DOE). A diffractive optical element is a two-dimensional diffraction device that can directly adjust the received laser light in two directions. For example, the diffractive optical element diffracts the laser light in the fast and slow axis directions of the incident laser light, so that the laser light emitted from the diffractive optical element can match the desired light spot. Of course, the diffractive optical element can also diffract the incident laser light in two other mutually perpendicular directions, and this disclosure is not limited to this.

[0081] Fig. 8 is a graph showing energy distribution of a laser according to some embodiments. Fig. 9 is a structural diagram of another projection device according to some embodiments.

[0082] When the dimming component 111 is a diffractive optical element, as shown in Figure 8 , after passing through the dimming component 111, the energy distribution of the laser light can be roughly the same at all locations, resulting in a high degree of energy uniformity and utilization. Thus, as shown in Figure 9 , after passing through the dimming component 111, the illumination beam emitted from the light source 10 can be directly incident on the prism assembly 250 and reflected by the prism assembly 250 to the light valve 240, thereby modulating the illumination beam. Therefore, the lens assembly 220 and the light homogenizing component 210, which occupy a large volume, are no longer required, which can reduce the structure of the projection device 1000 and facilitate its miniaturization.

[0083] In some embodiments, the diffractive optical element may include a plurality of diffractive microstructures formed in a two-dimensional distribution using a micro-nano etching process, and the plurality of diffractive microstructures may have different shapes, sizes, and refractive indices to correspond to different wavelengths, different light intensities, or different incident angles of the laser. Fine control of the laser can be achieved through multiple diffractive microstructures. For example, the plurality of diffractive microstructures are respectively rectangular, the size and depth (or height) of the plurality of diffractive microstructures may be different, and the distance between different diffractive microstructures may also be different, thereby achieving targeted adjustment of the incident laser. Of course, the diffractive optical element may also be a multi-layer structure superimposed on each other, in which case the diffractive microstructure may be a two-layer or more layer structure.

[0084] FIG10 is a cross-sectional view of a diffractive microstructure in a diffractive optical element according to some embodiments.

[0085] For example, as shown in FIG10 , FIG10 (A), FIG10 (B), and FIG10 (C) respectively illustrate three types of diffractive microstructures 117. The cross-sectional views of different diffractive microstructures 117 in a diffractive optical element may be any of the three types of diffractive microstructures 117. FIG10 illustrates examples of diffractive microstructures 117 comprising two, three, or four layers. Of course, diffractive microstructures 117 may also comprise other layer structures, for example, eight or sixteen layers.

[0086] It should be noted that as the number of layers of the diffractive microstructures 117 increases, the diffraction efficiency and the ability to homogenize and shape the laser light of the diffractive optical element increase, and the diffractive optical element's ability to improve the uniformity of the laser light energy distribution also increases. However, the more layers of the diffractive microstructures 117, the greater the processing difficulty. Therefore, the number of layers of the diffractive microstructures 117 is within a preset range. For example, the number of layers of the diffractive microstructures 117 is greater than or equal to 8 layers and less than or equal to 16 layers. In addition, the parameters corresponding to the multiple diffractive microstructures 117 in the diffractive optical element (such as shape, size, refractive index, etc.) can be calculated based on the amplitude distribution of the laser light incident on the diffractive optical element, the phase of the incident laser light, and the required amplitude distribution of the laser light through diffraction theory and optimization algorithms (such as the Gale-Shapley algorithm, simulated annealing algorithm, genetic algorithm (GA), etc.).

[0087] In some embodiments, the diffractive optical element includes a transmissive diffractive optical element and a reflective diffractive optical element. The transmissive diffractive optical element can transmit laser light, while the reflective diffractive optical element can reflect laser light.

[0088] For example, as shown in FIG6 , the light-adjusting component 111 includes a first diffractive optical element 1110. The first diffractive optical element 1110 is configured to homogenize and shape incident laser light. For example, as shown in FIG6 , the first diffractive optical element 1110 includes a transmissive diffractive optical element. Of course, in some embodiments, the light-adjusting component 111 may also include a reflective diffractive optical element, which is not limited in this disclosure.

[0089] In some embodiments of the present disclosure, the light source 10 includes a dimming component 111, and after the lasers of multiple colors are combined by the light combining component 102, the dimming component 111 homogenizes and shapes the lasers. There is no need to set a lens group and a light homogenizing component that occupy a large volume, which can reduce the structure in the optical modulation component 20, and the volume of the first diffraction optical element 1110 is small, thereby reducing the volume of the optical modulation component 20, which is beneficial to the miniaturization of the projection equipment 1000 and also beneficial to improving the uniformity of the energy distribution of the laser.

[0090] The light combining component 102 in some embodiments of the present disclosure is described in detail below.

[0091] In some embodiments, the light combining component 102 may be a diffractive optical element configured to adjust the transmission direction of laser light incident at different positions so that laser light of different colors is directed toward the same area, thereby combining the laser light of different colors. It should be noted that light combining may refer to adjusting the laser light of different colors emitted from the light combining component 102 onto the same optical path so that the laser light of different colors is incident upon the same area.

[0092] In some examples, as shown in FIG6 , the light combining component 102 includes a second diffractive optical element 1020. The second diffractive optical element 1020 is configured to adjust the transmission direction of laser light incident at different positions so that laser light of different colors is emitted to the same area. For example, the second diffractive optical element 1020 includes a transmissive diffractive optical element. At this time, the second diffractive optical element 1020 is configured to transmit the incident laser light and combine the incident laser light of multiple colors. Here, the incident direction of the laser light passing through the light combining component 102 is the same as the emission direction. For example, as shown in FIG6 , the laser light emitted by the laser 101 is emitted along the second direction Q toward the second diffractive optical element 1020. After being combined by the second diffractive optical element 1020, the laser light is emitted along the second direction Q.

[0093] FIG. 11 is a structural diagram of yet another light source according to some embodiments.

[0094] For another example, as shown in FIG11 , the second diffractive optical element 1020 comprises a reflective diffractive optical element. In this case, the second diffractive optical element 1020 is configured to reflect incident laser light and combine the incident laser light of multiple colors. Here, the incident direction of the laser light passing through the second diffractive optical element 1020 is different from the exit direction.

[0095] For example, as shown in Figure 11, the laser 101 and the second diffractive optical element 1020 are arranged along a first direction P, and the second diffractive optical element 1020 and the dimming component 111 are arranged along a second direction Q. The second diffractive optical element 1020 is tilted relative to the light emitting direction of the laser 101 (such as the first direction P in Figure 11), and the second diffractive optical element 1020 has a first angle α with the first direction P and a second angle β with the second direction Q. For example, the first angle α and the second angle β are 45 degrees respectively. The laser light emitted by the laser 101 is incident on the second diffractive optical element 1020 along the first direction P, and after being combined by the second diffractive optical element 1020, it is reflected along the second direction Q to the dimming component 111. Here, the first direction P can be perpendicular to the second direction Q. Of course, the first direction P and the second direction Q can also be non-perpendicular, and this is not limited in this disclosure.

[0096] As shown in FIG11 , when the second diffractive optical element 1020 includes a reflective diffractive optical element, the second diffractive optical element 1020 includes a diffractive element body 1021 and a reflective film 1022. The reflective film 1022 is located on a side of the diffractive element body 1021 that is away from the laser 101. The diffractive element body 1021 is configured to combine incident laser beams of multiple colors. The reflective film 1022 is configured to reflect the combined laser beams.

[0097] In some embodiments of the present disclosure, the light combining component 102 includes a second diffractive optical element 1020. The second diffractive optical element 1020 can adjust the transmission direction of laser light incident at different positions, so that laser light of different colors is directed to the same area, thereby combining the laser light of different colors. This can improve the light combining effect of the laser light of different colors and also improve the uniformity of the laser energy distribution.

[0098] In other embodiments, the light combining component 102 may include a plurality of light combining mirrors.

[0099] In some examples, as shown in FIG7 , the light-combining component 102 includes a plurality of light-combining mirrors 1023 , which are arranged along a second direction Q. Each of the plurality of light-combining mirrors 1023 is configured to reflect laser light of one color emitted by the laser 101 , so that the plurality of light-combining mirrors 1023 can combine laser light of multiple colors.

[0100] On a plane perpendicular to the second direction Q, the orthographic projections of the multiple light-combining mirrors 1023 at least partially overlap. The multiple light-combining mirrors 1023 include a seventh light-combining mirror 10231, an eighth light-combining mirror 10232, and a ninth light-combining mirror 10233. The seventh light-combining mirror 10231 corresponds to the first light-exiting area 1014, the eighth light-combining mirror 10232 corresponds to the second light-exiting area 1015, and the ninth light-combining mirror 10233 corresponds to the third light-exiting area 1016. For example, each of the three light-combining mirrors 1023 is located on the light-exiting side of the corresponding light-exiting area, and the orthographic projection of each light-combining mirror 1023 on the laser 101 can cover the corresponding light-exiting area.

[0101] The laser beams emitted from the three light-emitting areas are directed toward the corresponding light-combining mirrors 1023 . Each of the three light-combining mirrors 1023 is configured to reflect the laser beams emitted from the corresponding light-emitting area along the second direction Q. For example, the seventh light-combining mirror 10231 reflects the laser beams emitted from the first light-emitting area 1014 along the second direction Q, the eighth light-combining mirror 10232 reflects the laser beams emitted from the second light-emitting area 1015 along the second direction Q, and the ninth light-combining mirror 10233 reflects the laser beams emitted from the third light-emitting area 1016 along the second direction Q.

[0102] At least one of the three light-combining mirrors 1023 is also configured to transmit laser light from other light-combining mirrors 1023 along the second direction Q. For example, the eighth light-combining mirror 10232 can transmit the laser light reflected by the seventh light-combining mirror 10231, and the ninth light-combining mirror 10233 can transmit the laser light reflected by the eighth light-combining mirror 10232, as well as the laser light transmitted by the eighth light-combining mirror 10232. The eighth light-combining mirror 10232 and the ninth light-combining mirror 10233 can be dichroic mirrors, respectively. For example, the eighth light-combining mirror 10232 is a dichroic mirror that transmits green light and reflects blue light, and the ninth light-combining mirror 10233 is a dichroic mirror that transmits blue light and green light and reflects red light. In this way, laser lights of different colors emitted by the laser 101 can be emitted from the ninth light-combining mirror 10233, respectively, to achieve light combining of multiple colors of laser light emitted by the laser 101.

[0103] The above description is made by taking the example that the light source 10 includes the laser 101, the light combining component 102 and the light modulating component 111. Of course, in some embodiments, the light source 10 may further include other components.

[0104] FIG12 is a structural diagram of yet another light source according to some embodiments.

[0105] In some embodiments, as shown in FIG12 , when the light combining component 102 includes a transmissive diffraction optical element, the light source 10 further includes a second reflector 112. The second reflector 112 is located between the light combining component 102 and the dimming component 111, and is configured to reflect the laser light after being combined by the light combining component 102 to the dimming component 111, thereby folding the optical path and avoiding the light source 10 from being too long in a certain direction, which is conducive to the miniaturization of the light source 10. The laser 101, the light combining component 102 and the second reflector 112 are arranged in sequence along the first direction P, and the second reflector 112 and the dimming component 111 are arranged in sequence along the second direction Q. The laser light of multiple colors after being combined by the light combining component 102 can be emitted to the second reflector 112, and the laser light is emitted to the dimming component 111 after changing the transmission direction by the second reflector 112.

[0106] FIG13 is a structural diagram of another light source according to some embodiments. The light source 10 in FIG13 is based on the light source 10 in FIG6 with the addition of a first lens 113. FIG14 is a structural diagram of another light source according to some embodiments. The light source 10 in FIG14 is based on the light source 10 in FIG11 with the addition of a first lens 113. FIG15 is a structural diagram of another light source according to some embodiments. The light source 10 in FIG15 is based on the light source 10 in FIG7 with the addition of a first lens 113.

[0107] In some embodiments, as shown in Figures 13 to 15, the light source 10 further includes a first lens 113, which is located in the optical path between the light combining component 102 and the light modulating component 111. The first lens 113 is configured to collimate the incident laser light so that the light modulating component 111 can receive the collimated laser light. This avoids the poor diffraction processing effect of the diffractive optical element due to the uncertainty of the incident direction of the divergent laser light, thereby improving the homogenization and shaping effect of the light modulating component 111 on the laser light.

[0108] Fig. 16 is a structural diagram of another light source according to some embodiments. In Fig. 16 , the light source 10 is modified from the light source 10 in Fig. 12 with the addition of a first lens 113 .

[0109] In some embodiments, as shown in FIG. 16 , when the light source 10 includes the second reflector 112 , the first lens 113 is located between the second reflector 112 and the dimming component 111 .

[0110] FIG17 is a structural diagram of another light source according to some embodiments. The light source 10 in FIG17 is based on the light source 10 in FIG13 with the addition of a second lens 114. FIG18 is a structural diagram of another light source according to some embodiments. The light source 10 in FIG18 is based on the light source 10 in FIG14 with the addition of a second lens 114. FIG19 is a structural diagram of another light source according to some embodiments. The light source 10 in FIG19 is based on the light source 10 in FIG15 with the addition of a second lens 114. FIG20 is a structural diagram of another light source according to some embodiments. The light source 10 in FIG20 is based on the light source 10 in FIG16 with the addition of a second lens 114.

[0111] In some embodiments, as shown in Figures 17 to 20, the light source 10 further includes a second lens 114. The second lens 114 is located between the laser 101 and the light combining component 102, and is configured to converge the laser light emitted by the laser 101 onto the light combining component 102. In this way, the laser beam in the optical path can be made thinner, thereby reducing the size of the components in the subsequent optical path (e.g., the first lens 113 and the dimming component 111), thereby reducing the volume of the light source 10.

[0112] FIG21 is a structural diagram of another light source according to some embodiments. The light source 10 in FIG21 is based on the light source 10 in FIG14 with the addition of a second lens 114. The principle and effect of adding the second lens 114 to the light sources in FIG6, FIG9, and FIG11 are similar to those in FIG21 and are not further described here.

[0113] It should be noted that, as shown in Figures 13 to 16 , the light source 10 in some embodiments of the present disclosure may include only the first lens 113, or, as shown in Figure 21 , may include only the second lens 114, or, as shown in Figures 17 to 20 , may include both the first lens 113 and the second lens 114. The first lens 113 and the second lens 114 may each be a convex lens, or at least one of the first lens 113 and the second lens 114 may be a Fresnel lens to reduce the size of the lens and improve the collimation and focusing effect of the lens on the laser.

[0114] FIG22 is a structural diagram of another light source according to some embodiments. The light source 10 in FIG22 adds a second light combining mirror group 115 on the basis of the light source 10 in FIG6. In some embodiments, as shown in FIG22, when the light combining component 102 includes a diffractive optical element, the light source 10 further includes a second light combining mirror group 115, and the second light combining mirror group 115 is located between the laser 101 and the light combining component 102. The structure of the second light combining mirror group 115 can refer to the structure of the light combining component 102 in FIG7 and will not be repeated here. The second light combining mirror group 115 is configured to perform a first light combining of the laser lights of multiple colors emitted by the laser 101, and to emit the combined laser lights of multiple colors to the light combining component 102. Afterwards, the light combining component 102 can perform a second light combining of the laser lights of multiple colors that have been preliminarily combined by the second light combining mirror group 115 to improve the light combining effect of the laser lights of different colors.

[0115] In addition, the principle and effect of adding the second light-combining lens group 115 to the light sources 10 of Figures 11 to 14, 16 to 18, 20, and 21 are similar to those of Figure 23 and are not further illustrated here. It should be noted that for the light source 10 including the second lens 114, the second light-combining lens group 115 can be located between the laser 101 and the second lens 114.

[0116] The foregoing description mainly uses the example of the light source 10 including a single laser 101. Of course, in some embodiments, the light source 10 may also include multiple lasers 101. The multiple lasers 101 may be identical. For example, the multiple lasers 101 may emit red laser light, green laser light, and blue laser light. Alternatively, the multiple lasers 101 may be different. For example, one laser 101 among the multiple lasers 101 may emit red laser light, green laser light, and blue laser light, while another laser 101 among the multiple lasers 101 may emit red laser light and blue laser light. Of course, the multiple lasers 101 may also emit laser light of other colors, which is not limited in this disclosure.

[0117] FIG23 is a structural diagram of another light source according to some embodiments. In some embodiments, as shown in FIG23 , the light source 10 includes a third laser 1011 and a fourth laser 1012. The third laser 1011 and the fourth laser 1012 can be the same. For example, the third laser 1011 and the fourth laser 1012 emit red laser light, green laser light, and blue laser light, respectively. The light source 10 also includes a third light combining mirror group 116, which is located on the light output side of the third laser 1011 and the fourth laser 1012, and on the light input side of the light combining component 102. Here, the light combining component 102 includes a diffractive optical element.

[0118] The structure of the third light-combining mirror group 116 can be different from that of the second light-combining mirror group 115. The third light-combining mirror group 116 can be plate-shaped, and the third laser 1011 and the fourth laser 1012 are located on opposite sides of the third light-combining mirror group 116. For example, the side of the third light-combining mirror group 116 away from the light-combining component 102 faces the third laser 1011, and the side of the third light-combining mirror group 116 close to the light-combining component 102 faces the fourth laser 1012.

[0119] The third light-combining mirror assembly 116 may be a dichroic mirror, and different regions of the third light-combining mirror assembly 116 may have different dichroic properties. For example, as shown in FIG23 , the third light-combining mirror assembly 116 includes a first region 1161 and a second region 1162. The first region 1161 is closer to the third laser 1011 than the second region 1162. The first region 1161 is configured to reflect blue and green laser light and transmit red laser light, while the second region 1162 is configured to reflect red laser light and transmit blue and green laser light.

[0120] Here, the light emitting area 1031 of the third laser 1011 that emits red laser corresponds to the first area 1161, and the light emitting area 1032 of the third laser 1011 that emits blue laser and the light emitting area 1033 of the green laser 1033 correspond to the second area 1162 respectively; the light emitting area 1034 of the fourth laser 1012 that emits red laser corresponds to the second area 1162, and the light emitting area 1035 of the fourth laser 1012 that emits blue laser and the light emitting area 1036 of the green laser correspond to the first area 1161 respectively. In this way, the red laser emitted by the third laser 1011 and the blue laser and green laser emitted by the fourth laser 1012 can be emitted from the first area 1161 respectively, and the blue laser and green laser emitted by the third laser 1011 and the red laser emitted by the fourth laser 1012 can be emitted from the second area 1162 respectively, thereby realizing the first light combination of the multiple colors of lasers emitted by the third laser 1011 and the fourth laser 1012 by the third light combining mirror group 116.

[0121] It should be noted that the schematic diagram of the distinction between different colors of laser light in Figure 23 is only used to indicate the color of the laser light emitted by each component, and the position of each color laser light in Figure 23 does not represent the actual distribution position of the laser light. For example, the laser light emitted from the light combining component 102 includes red laser light, green laser light, and blue laser light. Figure 23 uses the example of the red laser light being located in the middle area of ​​the light combining component 102, and the blue laser light and the green laser light being located on either side of the light combining component 102. This schematic diagram is only used to distinguish between the three colors of laser light. In actual practice, multiple areas of the light combining component 102 can respectively emit red laser light, green laser light, and blue laser light, and these three colors of laser light can be emitted to the same area on the dimming component 111.

[0122] It should be noted that, in some embodiments of the present disclosure, the description that a certain component is located between two components refers to the positional relationship of the components on the transmission path of the laser, and is not an intuitive positional relationship in space.

[0123] The foregoing description primarily uses the example of light source 10 including a diffractive optical element, thereby omitting light homogenizing component 210 and lens assembly 220. Of course, in some embodiments, optical modulation assembly 20 may include a volume grating to modulate the illumination beam, thereby omitting lens assembly 220 and prism assembly 250, thereby facilitating miniaturization of projection device 1000.

[0124] Figure 24 is a structural diagram of another projection device according to some embodiments. Figure 25 is a light path diagram of a light source and a light pipe according to some embodiments, and Figure 25 includes a side view of the light pipe.

[0125] As shown in Figure 24, the projection device 1000 includes a light source 10, an optical modulation component 20, and a lens 30. The optical modulation component 20 includes a light homogenizing component 210, a volume grating 230, and a light valve 240 (eg, a DMD).

[0126] As shown in FIG25 , the light homogenizing component 210 includes a wedge-shaped light pipe 2100. The cross-sectional area of ​​the light pipe 2100 decreases along the propagation direction of the illumination beam (e.g., direction K in FIG25 ). For example, as shown in FIG25 , the light pipe 2100 includes a first end 211 and a second end 212. The first end 211 is located closer to the light source 10 and serves as the incident end, receiving the illumination beam from the light source 10. The second end 212 is located further away from the light source 10 and serves as the exit end, from which the illumination beam homogenized by the light pipe 2100 is emitted. The cross-sectional area of ​​the first end 211 is greater than that of the second end 212. Here, the cross-sectional area of ​​the light pipe 2100 may refer to a cross-sectional area of ​​the light pipe 2100 taken on a plane perpendicular to the propagation direction of the illumination beam (the target plane).

[0127] The wedge-shaped light pipe 2100 can directly receive the illumination light beam from the light source 10 , and the illumination light beam does not need to be converged by a converging lens or other structure, which is beneficial to simplifying the structure of the projection device 1000 and facilitating the miniaturization of the projection device 1000 .

[0128] The light homogenizing component 210 can utilize the aforementioned wedge-shaped light guide 2100. The illumination beam from the light source 10 enters the light guide 2100 through the first end 211 thereof, where it is homogenized. After homogenization, the light guide 2100 exits the second end 212 thereof toward the volume grating 230. The light valve 240 is located on the light-emitting side of the volume grating 230 and is configured to receive the illumination beam from the volume grating 230 and modulate it to produce a projection beam. It should be noted that the details regarding the light homogenizing component 210 and the light valve 240 can be found above and will not be further elaborated here.

[0129] FIG26 is a structural diagram of yet another laser according to some embodiments.

[0130] The following describes the structure of the light source 10 using the laser 101 shown in FIG26 as an example. It should be noted that the laser 101 in FIG26 includes multiple light-emitting chips 1013 arranged in a 4×7 matrix array. The multiple light-emitting chips 1013 include multiple first light-emitting chips 1013A, multiple second light-emitting chips 1013B, and multiple third light-emitting chips 1013C. The multiple first light-emitting chips 1013A emit red laser light and are arranged in a 2×7 matrix array. The multiple second light-emitting chips 1013B emit blue laser light, and the multiple third light-emitting chips 1013C emit green laser light. The multiple second light-emitting chips 1013B and the multiple third light-emitting chips 1013C are each arranged in a 1×7 matrix array. Of course, the number and arrangement of the laser 101 and the multiple light-emitting chips 1013 are not limited to this. For example, the positions of the multiple second light-emitting chips 1013B and the multiple third light-emitting chips 1013C in FIG26 are interchanged.

[0131] FIG. 27 is a structural diagram of yet another light source according to some embodiments.

[0132] In some embodiments, as shown in FIG27 , the light source 10 further includes a first light-combining lens assembly 104. The first light-combining lens assembly 104 is located on the light-emitting side of the plurality of first light-emitting chips 1013A, the plurality of second light-emitting chips 1013B, and the plurality of third light-emitting chips 1013C, and is configured to combine red laser light, green laser light, and blue laser light. A light pipe 2100 (light homogenizing component 210) is located on the light-emitting side of the first light-combining lens assembly 104. Here, the light pipe 2100 can be a light pipe with a uniform cross-sectional area.

[0133] The first light-combining mirror group 104 may include a first light-combining mirror 1041, a second light-combining mirror 1042, and a third light-combining mirror 1043. The third light-combining mirror 1043 is located on the light-emitting side of the plurality of third light-emitting chips 1013C. The third light-combining mirror 1043 may be a reflector and is configured to reflect the green laser light emitted by the plurality of third light-emitting chips 1013C toward the second light-combining mirror 1042.

[0134] The second light-combining mirror 1042 is located on the light-emitting side of the plurality of second light-emitting chips 1013B and on the light-emitting side of the third light-combining mirror 1043. For example, the second light-combining mirror 1042 is located at the intersection of the light reflected by the third light-combining mirror 1043 and the light emitted by the plurality of second light-emitting chips 1013B. The second light-combining mirror 1042 can be a dichroic mirror and is configured to transmit the green laser light reflected by the third light-combining mirror 1043 and reflect the blue laser light emitted by the plurality of second light-emitting chips 1013B, thereby combining the blue and green laser light beams.

[0135] The first light-combining mirror 1041 is located on the light-emitting side of the plurality of first light-emitting chips 1013A, and on the light-emitting side of the second light-combining mirror 1042. For example, the first light-combining mirror 1041 is located at the intersection of the light emitted by the plurality of first light-emitting chips 1013A and the light emitted by the second light-combining mirror 1042. The first light-combining mirror 1041 can be a dichroic mirror, and is configured to transmit the blue laser and green laser emitted by the second light-combining mirror 1042, and reflect the red laser emitted by the plurality of first light-emitting chips 1013A, thereby combining the blue laser, green laser and red laser. It should be noted that the functions of the plurality of light-combining mirrors are not limited to this. For example, when the positions of the plurality of second light-emitting chips 1013B and the plurality of third light-emitting chips 1013C in FIG. 19 are interchanged, the third light-combining mirror 1043 can be configured to reflect the blue laser, and the second light-combining mirror 1042 can be configured to reflect the green laser and transmit the blue laser.

[0136] In some embodiments, as shown in FIG27 , the light source 10 further includes a diffuser 105 and a converging lens 103. The diffuser 105 and converging lens 103 are located between the first light combining lens assembly 104 and the light pipe 2100. Furthermore, the diffuser 105 is located on the light-exiting side of the first light combining lens assembly 104, and the converging lens 103 is located on the light-exiting side of the diffuser 105. The diffuser 105 is configured to homogenize the incident light beam, thereby eliminating speckle. The converging lens 103 is configured to converge the laser light, allowing more laser light to enter the light homogenizing component 210, thereby improving the utilization rate of the laser light.

[0137] The volume grating 230 in some embodiments of the present disclosure is described in detail below.

[0138] As shown in FIG. 24 , the volume grating 230 is located on the light-emitting side of the light-homogenizing component 210 and is configured to diffract incident light (eg, an illumination light beam).

[0139] Volume grating 230, also known as a volume grating, refers to a diffraction element formed by the entire volume of an element. This diffraction element can modulate incident light by periodically varying its refractive index or periodically absorbing light of specific wavelengths. For example, volume grating 230 is a grating with a periodic refractive index, also known as a volume phase grating, where the refractive index varies periodically at different locations on the volume grating 230.

[0140] It should be noted that, typically, a light beam incident on a thin diffraction grating can be diffracted, forming two light beams (i.e., a transmitted light beam and a diffracted light beam). However, when a light beam is incident on a volume grating 230 and diffracted, only one light beam is formed. FIG28 is a schematic diagram of volume grating diffraction according to some embodiments. For example, as shown in FIG28 , a first light beam A1 is diffracted upon incident on the volume grating 230, forming a first diffracted light beam A11. A second light beam A2 is diffracted upon incident on the volume grating 230, forming a second diffracted light beam A22.

[0141] Diffraction efficiency is the ratio of the optical power of the diffracted light to the optical power of the incident light. A diffraction efficiency of 100% indicates that all incident light is diffracted and emitted. Ideally, diffraction efficiency reaches 100% only when light of a predetermined wavelength is incident on the volume grating 230 at the Bragg angle. Deviations in the incident angle or wavelength will result in a decrease in diffraction efficiency or even zero diffraction efficiency.

[0142] Therefore, the volume grating 230 can be designed based on the above-mentioned properties to achieve a high diffraction efficiency. Generally, the incident angle of the light beam incident on the volume grating 230 is deterministic. This angle is related to the structure of the projection device 1000 and the divergence angle of the light emitted by the light pipe 2100. The laser light incident on the volume grating 230 can have three wavelength bands (e.g., wavelengths corresponding to red, green, and blue laser light). Therefore, when designing the volume grating 230, an appropriate refractive index variation, thickness, and period can be selected based on the wavelength of the incident laser light and the incident angle of the incident laser light at different locations on the volume grating 230. This ensures that the three-color laser light is completely diffracted (i.e., the diffraction efficiency corresponding to all incident light is 100%) after entering the volume grating 230. This avoids crosstalk between light beams of different angles and wavelengths and reduces the generation of unnecessary diffraction. Here, the period of the volume grating 230 refers to the length from one refractive index change point to the adjacent refractive index change point in the volume grating 230.

[0143] In some embodiments, the volume grating 230 can be made of a photopolymer film. For example, polypropylene (PP) film can be used. Photopolymers undergo polymerization under illumination, causing the refractive index of the resulting material to change. In this way, depending on the design requirements of the volume grating 230, different locations on the photopolymer film can be illuminated to varying degrees to create a gradient refractive index variation, thereby achieving higher diffraction efficiency for the incident three-color laser beam.

[0144] In some embodiments, the thickness of the volume grating 230 is on the order of a wavelength. For example, the thickness of the volume grating 230 is an integer multiple of the wavelength of the laser light of the corresponding color. After the light beam emitted by the light homogenizing component 210 is incident on the volume grating 230, the volume grating 230 can deflect, homogenize, and amplify the light beam, so that the light beam becomes a large surface light source. The diffracted light emitted by the volume grating 230 is approximately parallel light and can be directly incident on the light valve 240. Therefore, compared to the projection device 1000 shown in Figure 5, the use of the volume grating 230 can greatly reduce the size of the illumination system in the projection device 1000, reduce the volume of the projection device 1000, and facilitate the miniaturization of the projection device 1000. Here, the illumination system can refer to the relevant optical components in the optical modulation component 20 used to shape the illumination beam to match the light valve 240.

[0145] In some embodiments, the volume grating 230 is disposed on one side of the light valve 240, with the light-emitting surface of the volume grating 230 forming a predetermined angle with the light-entering surface of the light valve 240. Since digital micromirror devices are typically square, and laser light from a light source must be incident on the DMD at a predetermined angle, the light-emitting surface of the volume grating 230 and the light-entering surface of the DMD can be arranged at a predetermined angle.

[0146] Figure 29 illustrates the structure of a volume grating and a light valve according to some embodiments. For example, as shown in Figure 29 , a predetermined angle β is formed between the light-emitting surface 2300 of the volume grating 230 and the light-incident surface 2400 of the light valve 240. Because different DMDs have different requirements for the incident angle of light, the angle between the volume grating 230 and the DMD must be set based on the DMD's requirements.

[0147] Figure 30 is a structural diagram of an optical modulation assembly in a projection device according to some embodiments. In some embodiments, as shown in Figure 30 , the volume grating 230 is located on the side of the light valve 240. The light pipe 2100 is located on the side of the volume grating 230 away from the light valve 240, and the extension direction of the light pipe 2100 is parallel to the side of the light valve 240. In this case, the optical modulation assembly 20 also includes a reflector assembly 260. The reflector assembly 260 is disposed on the light output side of the light pipe 2100 and is configured to reflect the illumination light beam emitted by the light pipe 2100 toward the volume grating 230.

[0148] Reflector assembly 260 may include one or more first reflectors (reflectors) capable of reflecting red, green, and blue laser light. For example, as shown in FIG22 , reflector assembly 260 includes two reflectors 261 and 262 positioned at a predetermined angle. It should be noted that one, two, or more reflectors may be provided on the light-emitting side of light pipe 2100, depending on practical circumstances, and this disclosure is not limited thereto.

[0149] It should be noted that the size, position, and tilt angle of the reflector assembly 260 relative to the illumination beam emitted from the light pipe 2100 must satisfy the conditions for reflecting the illumination beam emitted from the light pipe 2100 onto the light incident surface of the volume grating 230. Therefore, parameters such as the period, thickness, and refractive index variation of the volume grating 230 can be designed based on the incident angle when the reflector assembly 260 reflects the illumination beam onto the volume grating 230.

[0150] FIG31 is a structural diagram of another optical modulation component in a projection device according to some embodiments. In some embodiments, as shown in FIG31 , the optical modulation component 20 further includes one or more collimating lenses 270. The collimating lenses 270 are positioned between the light pipe 2100 and the reflector assembly 260 and are configured to collimate an incident light beam. For example, the collimating lenses 270 are positioned proximate to the light outlet of the light pipe 2100. After being collimated by the collimating lenses 270, the illumination beam emitted from the light pipe 2100 is incident on the reflector assembly 260. The incident angle of the illumination beam incident on the reflector assembly 260 can be fixed, so that the incident angle of the illumination beam when reflected by the reflector assembly 260 to the volume grating 230 can also be fixed, which helps simplify the design of the volume grating 230.

[0151] When the optical modulation assembly 20 includes a collimating lens 270, the structure of the optical modulation assembly 20 is simple, facilitating miniaturization of the projection device 1000. Furthermore, by providing the collimating lens 270 at the light outlet of the light pipe 2100, the divergence angle of the illumination beam emitted from the light pipe 2100 can be reduced, facilitating determination of the incident angle of the illumination beam when it enters the volume grating 230.

[0152] It should be noted that the solution of using the volume grating 230 to achieve light uniformity in some embodiments of the present disclosure can also be applied to liquid crystal display devices. For example, this solution can be used as the backlight of a liquid crystal display panel.

[0153] The above mainly uses the example of adjusting the uniformity of the light spot using a diffractive optical element or a volume grating to illustrate. Of course, in some embodiments, the projection device 1000 can also use an optical waveguide (such as an arrayed optical waveguide or a zigzag optical waveguide) to adjust the uniformity of the light spot of multiple colors of laser light. Here, the arrayed optical waveguide or the zigzag optical waveguide can be in the form of a sheet. For example, the arrayed optical waveguide or the zigzag optical waveguide is a transparent substrate with a high refractive index. The illumination beam emitted by the light source is coupled into one side of the substrate through a specific structure. The illumination beam is totally reflected and propagates within the substrate. After propagating to a certain position, it is coupled out through another specific structure.

[0154] The light source 10 with an optical waveguide in some embodiments of the present disclosure is described in detail below.

[0155] In some embodiments, the light source 10 may include a laser 101 and one or more optical waveguides 108. The following description will take the laser 101 shown in FIG26 as an example.

[0156] The optical waveguide 108 may be located on the light-emitting side of the third light-emitting chip 1013C. The optical waveguide 108 may include a light input portion 1081 and a light output portion 1082. The light input portion 1081 is configured to direct incident laser light (e.g., at least one of a blue laser or a green laser) into the optical waveguide 108. The light output portion 1082 is configured to output the laser light within the optical waveguide 108. Furthermore, the beam width of at least one of the blue laser light or the green laser light emitted by the light output portion 1082 is equal to the beam width of the red laser light emitted by the first light-emitting chip 1013A. Here, the beam width may refer to the size of the light beam on a plane perpendicular to the direction of the beam axis.

[0157] The optical waveguide 108 can be made of a material with optical transparency and low transmission loss, such as glass, silicon dioxide, or lithium niobate. Furthermore, the light input portion 1081 and the light output portion 1082 of the optical waveguide 108 have reflective or transmissive coatings to ensure that light incident on the optical waveguide 108 propagates along a predetermined path within the optical waveguide 108.

[0158] FIG32 is a structural diagram of another projection device according to some embodiments. In some examples, as shown in FIG32 , the optical waveguide 108 includes a parallel light entrance surface 1080A and a light exit surface 1080B, and the light entrance surface 1080A and the light exit surface 1080B are arranged relative to each other in the thickness direction of the optical waveguide 108 (such as the PL direction in FIG32 ). The light entrance portion 1081 and the light exit portion 1082 of the optical waveguide 108 are respectively located between the light entrance surface 1080A and the light exit surface 1080B. The light entrance surface 1080A of the optical waveguide 108 faces the laser 101. It should be noted that the optical modulation component 20 in FIG32 can be replaced by the above-mentioned optical modulation component 20 having a volume grating.

[0159] In some embodiments, the optical waveguide 108 may include an arrayed optical waveguide 106 or a zigzag optical waveguide 107 .

[0160] FIG33 is a structural diagram of an arrayed optical waveguide according to some embodiments. For example, as shown in FIG33 , the arrayed optical waveguide 106 includes a first body 1061, a first reflective film 1062, one or more first transflective films 1063, and a second reflective film 1064. The first reflective film 1062, the first transflective film 1063, and the second reflective film 1064 are disposed within the first body 1061. The first reflective film 1062 is located at one end of the first body 1061, serving as the light entrance portion of the arrayed optical waveguide 106 (i.e., the light entrance portion 1081 of the optical waveguide 108). The first transflective film 1063 and the second reflective film 1064 are located at the other end of the first body 1061, serving as the light exit portion of the arrayed optical waveguide 106 (i.e., the light exit portion 1082 of the optical waveguide 108). The first transflective film 1063 is located between the first reflective film 1062 and the second reflective film 1064.

[0161] The first reflective film 1062, the first transflective film 1063, and the second reflective film 1064 are arranged parallel to each other and tilted at a set angle γ relative to the light incident surface 1080A of the optical waveguide 108. The set angle γ satisfies the conditions for reflecting the incident laser light and causing the laser light to be totally reflected in the first body 1061.

[0162] A light beam incident on the light entrance portion of the arrayed optical waveguide 106 is reflected by the first reflective film 1062 and then undergoes multiple total reflections within the first body 1061 before propagating. When the light beam passes through the first transflective film 1063, the first transflective film 1063 can reflect a first portion of the light beam out of the arrayed optical waveguide 106 and transmit a second portion of the light beam to the next first transflective film 1063. When the light beam propagates to the second reflective film 1064, the second reflective film 1064 reflects the entire remaining light beam out of the arrayed optical waveguide 106. It should be noted that coating the first transflective film 1063 can change its transmittance and reflectivity of incident light, while coating the second reflective film 1064 can change the light beams that can be transmitted and reflected.

[0163] By providing multiple film layers within the arrayed optical waveguide 106, the light beam within the arrayed optical waveguide 106 can be split into different exiting portions, thereby expanding the light beam. Furthermore, by adjusting the number and position of the first transflective films 1063 within the arrayed optical waveguide 106, the size (e.g., beam width) of the light beam exiting the arrayed optical waveguide 106 can be adjusted. Furthermore, if the arrayed optical waveguide 106 includes multiple first transflective films 1063, adjusting the reflectivity and transmittance of the multiple first transflective films 1063 can cause the light beam to be reflected multiple times within the arrayed optical waveguide 106, thereby improving the uniformity of the light beam exiting the arrayed optical waveguide 106.

[0164] FIG34 illustrates the structure of a zigzag optical waveguide according to some embodiments. For example, as shown in FIG34 , the zigzag optical waveguide 107 includes a second body 1071, a third reflective film 1072, and a prism portion 1073. The third reflective film 1072 and the prism portion 1073 are disposed within the second body 1071. The third reflective film 1072 is located at one end of the second body 1071, serving as the light entrance portion of the zigzag optical waveguide 107 (i.e., the light entrance portion 1081 of the optical waveguide 108). The prism portion 1073 is located at the other end of the second body 1071, serving as the light exit portion of the zigzag optical waveguide 107 (i.e., the light exit portion 1082 of the optical waveguide 108).

[0165] The third reflective film 1072 is positioned at a predetermined distance from the prism portion 1073 to ensure that the prism portion 1073 transmits and reflects laser light of a corresponding wavelength. The third reflective film 1072 is tilted at a predetermined angle γ relative to the light incident surface 1080A of the optical waveguide 108. This predetermined angle γ satisfies the conditions for reflecting the incident laser light and causing it to undergo total internal reflection within the second body 1071.

[0166] The prism portion 1073 is located on the light incident surface 1080A of the optical waveguide 108. The prism portion 1073 may include a plurality of parallel sub-prisms 1074, each of which is in a strip shape. In two or more sub-prisms 1074 located near the third reflective film 1072, a second transflective film 1075 is provided on the surface of the sub-prism 1074 facing the third reflective film 1072. In one or more sub-prisms 1074 located away from the third reflective film 1072, a fourth reflective film 1076 is provided on the surface of the sub-prism 1074 facing the third reflective film 1072. The number of second transflective films 1075 and fourth reflective films 1076 can be set according to actual needs.

[0167] A light beam incident on the light entrance portion of the zigzag optical waveguide 107 is reflected by the third reflective film 1072 and then undergoes multiple total reflections within the second body 1071 before propagating. When the light beam passes through the second transflective film 1075 within the prism portion 1073, the second transflective film 1075 reflects the first portion of the light beam out of the zigzag optical waveguide 107 and transmits the second portion of the light beam to the next second transflective film 1075. The light beam then propagates to the fourth reflective film 1076, where it is reflected out of the zigzag optical waveguide 107.

[0168] By providing a plurality of film layers in the zigzag optical waveguide 107 , the spot of the light beam emitted from the zigzag optical waveguide 107 can be expanded to the same width as the prism portion 1073 , and the light beam can be homogenized.

[0169] Applying the arrayed optical waveguide 106 and the zigzag optical waveguide 107 to the projection device 1000 can make the distribution of laser beams of different colors emitted by the light source 10 uniform, thereby improving the display effect of the projection image.

[0170] In some embodiments, light source 10 may include a light waveguide 108 located on the light-emitting side of the plurality of third light-emitting chips 1013C. Light waveguide 108 is configured to expand the beam width of the green laser light emitted by the third light-emitting chip 1013C, so that the beam width of the green laser light emitted from the light-emitting portion 1082 of light waveguide 108 is equal to the beam width of the red laser light emitted by the plurality of first light-emitting chips 1013A.

[0171] The product of a laser's spot size and divergence angle determines its etendue. For example, the smaller the laser beam width, the smaller its etendue. A small etendue can lead to severe laser speckle. In three-color laser projection systems, the etendue of the red laser is typically greater than that of the blue and green lasers. Therefore, the speckle effect of blue and green lasers is more pronounced than that of red lasers.

[0172] In some embodiments of the present disclosure, because the human eye is less sensitive to blue light, uniform light can be achieved by making the beam widths of green and red lasers the same. Furthermore, increasing the beam width of the green laser increases its etendue, making it equal to that of the red laser, thereby reducing speckle. This allows for better display quality with fewer optical components and facilitates miniaturization of the projection device 1000.

[0173] In some embodiments, as shown in FIG32 , the light source 10 further includes a fourth beam-combining mirror group 109 . The fourth beam-combining mirror group 109 is located on the light-emitting side of the laser 101 and the optical waveguide 108 and is configured to combine the red laser, the green laser, and the blue laser. The combined beam can have good uniformity. For example, the fourth beam-combining mirror group 109 may be composed of one or more reflective mirrors and one or more dichroic mirrors. Of course, the fourth beam-combining mirror group 109 may also be configured according to specific light-combining requirements.

[0174] In some embodiments, as shown in FIG32 , the light source 10 further includes a light homogenizing component 210 . The light homogenizing component 210 may be located on the light-emitting side of the fourth beam-combining lens group 109 and configured to homogenize the laser beams combined by the fourth beam-combining lens group 109 to uniformly distribute the laser energy and reduce speckle. The details of the light homogenizing component 210 can be found above and are not further described here.

[0175] In some embodiments, as shown in FIG32 , the light source 10 further includes a converging lens 103 , which is disposed on the light-emitting side of the fourth light-combining lens group 109 and configured to converge the incident light beam. The relevant contents of the converging lens 103 can be found in the previous text and will not be repeated here.

[0176] The following describes in detail several examples in which the light source 10 includes a light waveguide 108 in some embodiments of the present disclosure.

[0177] FIG35 is a light path diagram of another light source according to some embodiments. In some examples, as shown in FIG35 , when the optical waveguide 108 includes an arrayed optical waveguide 106, the first reflective film 1062 is located on the light-emitting side of the third light-emitting chip 1013C, and the first transflective film 1063 and the second reflective film 1064 are located on the light-emitting side of the first light-emitting chip 1013A. The first transflective film 1063 is configured to reflect a first portion of green laser light and transmit a second portion of green laser light and red laser light. The second reflective film 1064 is configured to reflect green laser light and transmit red laser light. Here, the second reflective film 1064 functions as a dichroic mirror. Furthermore, the spacing W1 between the first transflective film 1063 and the second reflective film 1064 is equal to the beam width of the red laser light emitted by the multiple first light-emitting chips 1013A. Here, the beam width of the red laser light equal to the spacing W1 can be understood as the corresponding dimension of the red laser light in the same direction as the spacing W1. However, the present disclosure is not limited to this.

[0178] As shown in FIG35 , the green laser light emitted by the third light-emitting chip 1013C is incident on the first reflective film 1062. Because the inclination angle of the first reflective film 1062 relative to the light incident surface 1080A satisfies the total reflection condition, after reflecting the green laser light onto the light incident surface 1080A, the green laser light undergoes multiple total reflections within the first body 1061 between the light incident surface 1080A and the light emitting surface 1080B before being incident on the first transflective film 1063. A first portion of the green laser light is reflected by the first transflective film 1063 and exits the arrayed optical waveguide 106. A second portion of the green laser light is transmitted through the transflective film 1063 and continues to propagate within the first body 1061 until it enters the second reflective film 1064. The second reflective film 1064 reflects all of the incident green laser light out of the arrayed optical waveguide 106.

[0179] In this case, the fourth light-combining mirror group 109 may include a fourth light-combining mirror 1091 and a fifth light-combining mirror 1092. The fourth light-combining mirror 1091 is located on the light-emitting side of the plurality of second light-emitting chips 1013B and is configured to reflect blue laser light. The fifth light-combining mirror 1092 is located on the light-emitting side of the array optical waveguide 106 and is configured to reflect red laser light and green laser light and transmit blue laser light. The fourth light-combining mirror 1091 and the fifth light-combining mirror 1092 are arranged in parallel, and both can be tilted at a preset angle relative to the plane where the optical waveguide 108 is located.

[0180] In this way, after emitting from the arrayed optical waveguide 106, the green laser light can be reflected by the fifth light-combining mirror 1092 to the converging lens 103. The blue laser light emitted by the plurality of second light-emitting chips 1013B can be directly transmitted by the arrayed optical waveguide 106 and then incident on the fourth light-combining mirror 1091, where it is reflected by the fourth light-combining mirror 1091 to the fifth light-combining mirror 1092. The blue laser light reflected by the fifth light-combining mirror 1092 is then transmitted by the fifth light-combining mirror 1092 to the converging lens 103. The red laser light emitted by the plurality of first light-emitting chips 1013A is transmitted by the arrayed optical waveguide 106 to the fifth light-combining mirror 1092, where it is reflected by the fifth light-combining mirror 1092 to the converging lens 103. The red, green, and blue laser light incident on the converging lens 103 is converged by the converging lens 103 to the light homogenizing component 210.

[0181] In some embodiments of the present disclosure, since the first transflective film 1063 and the second reflective film 1064 are respectively disposed on the light-emitting sides of the two rows of first light-emitting chips 1013A, and the green laser light is split into two parts by the first transflective film 1063 and the second reflective film 1064 before being emitted from the arrayed optical waveguide 106, the beam width of the green laser light emitted from the arrayed optical waveguide 106 can be increased and can be equal to the spacing W1 between the first transflective film 1063 and the second reflective film 1064. Furthermore, since the first transflective film 1063 and the second reflective film 1064 can transmit red laser light, the beam width of the red laser light emitted by the plurality of first light-emitting chips 1013A can also be equal to the spacing W1 between the first transflective film 1063 and the second reflective film 1064. Therefore, the beam width of the green laser light can be equal to the beam width of the red laser light. In this way, the light beam emitted from the light source 10 is more uniform, and the etendue of the green laser light can be expanded to be equal to that of the red laser light, thereby reducing the speckle phenomenon of the green laser light.

[0182] It should be noted that the transmittance and reflectance of the first transflective film 1063 can be changed according to the design requirements of the projection device 1000. In some embodiments, the transmittance of the first transflective film 1063 can be 50%, and the reflectance of the first transflective film 1063 can be 50%. This ensures that the energy of the green laser beam emitted from the first transflective film 1063 and the second reflective film 1064 is equal, thereby improving the uniformity of the light intensity distribution of the emitted green laser.

[0183] FIG36 is a light path diagram of another light source according to some embodiments. In other examples, as shown in FIG36 , when the optical waveguide 108 includes a zigzag optical waveguide 107, a third reflective film 1072 is located on the light-emitting side of the plurality of third light-emitting chips 1013C, and a prism portion 1073 is located on the light-emitting side of the first light-emitting chip 1013A. The second transflective film 1075 is configured to reflect a first portion of the green laser light and transmit a second portion of the green laser light and red laser light. A fourth reflective film 1076 is provided on the surface of the sub-prism 1074, which is farthest from the third reflective film 1072 and faces the third reflective film 1072. This fourth reflective film 1076 is configured to reflect the green laser light and transmit the red laser light. Here, the fourth reflective film 1076 functions as a dichroic mirror. This fourth reflective film 1076 can reflect all light beams propagating from the zigzag optical waveguide 107 to this point out of the zigzag optical waveguide 107, thereby expanding the beam and preventing beam loss. Furthermore, the width of the prism portion 1073 is equal to the beam width of the red laser light emitted by the plurality of first light emitting chips 1013A.

[0184] As shown in FIG36 , green laser light emitted from multiple third light-emitting chips 1013C is incident on the third reflective film 1072. Because the inclination angle of the third reflective film 1072 relative to the light incident surface 1080A satisfies the total reflection condition, after reflecting the green laser light onto the light incident surface 1080A, the green laser light undergoes multiple total reflections within the second body 1071 between the light incident surface 1080A and the light exiting surface 1080B before entering the prism portion 1073. When the green laser light passes through the second transflective film 1075 on the sub-prism 1074, a first portion of the green laser light is reflected out of the zigzag optical waveguide 107, while a second portion of the green laser light is transmitted and continues to propagate through the next sub-prism 1074. After repeating this process multiple times, the remaining green laser light is completely reflected out of the zigzag optical waveguide 107 by the fourth reflective film 1076.

[0185] In this case, the fourth light combining mirror group 109 may include a fourth light combining mirror 1091 and a fifth light combining mirror 1092. The structure and function of the fourth light combining mirror group 109 are similar to those of the fourth light combining mirror group 109 in FIG28 and are not described again.

[0186] Because the green laser light emitted from the plurality of third light-emitting chips 1013C is split into multiple portions within the zigzag optical waveguide 107 and then emitted from the zigzag optical waveguide 107, the beam width of the green laser light emitted from the zigzag optical waveguide 107 is increased and can be equal to the width W2 of the prism portion 1073. Since the width of the prism portion 1073 is equal to the beam width of the red laser light emitted from the plurality of first light-emitting chips 1013A, the beam widths of the green laser light and the red laser light can be equal. As a result, the emitted light after the two beams are combined by the fourth light-combining lens assembly 109 is more uniform, and the etendue of the green laser light can be expanded to the same as that of the red laser light, thereby reducing speckle in the green laser light.

[0187] In some embodiments, the light source 10 may also include two light waveguides 108 .

[0188] FIG37 is a block diagram of another projection device according to some embodiments. For example, as shown in FIG37 , light source 10 includes a first optical waveguide 108A and a second optical waveguide 108B. First optical waveguide 108A is located on the light-emitting side of multiple third light-emitting chips 1013C, and second optical waveguide 108B is located on the light-emitting side of multiple second light-emitting chips 1013B. First optical waveguide 108A is configured to expand the beam width of green laser light emitted by multiple third light-emitting chips 1013C, while second optical waveguide 108B is configured to expand the beam width of blue laser light emitted by multiple second light-emitting chips 1013B. This ensures that the beam widths of the green laser light emitted by the first optical waveguide 108A and the blue laser light emitted by the second optical waveguide 108B are equal to the beam width of the red laser light emitted by the multiple first light-emitting chips 1013A.

[0189] The arrangement of two optical waveguides 108 in projection device 1000 can be used when the number of second light-emitting chips 1013B (e.g., blue light-emitting chips) in laser 101 is small. This increases the beam widths of the blue and green lasers to be the same as the beam width of the red laser. This ensures a uniform distribution of the output beam from light source 10 and avoids issues with abnormal color temperature and color in the projected image caused by the smaller beam width of the blue laser. Furthermore, the etendues of the blue and green lasers can be increased to be the same as that of the red laser, thereby reducing speckle.

[0190] The first optical waveguide 108A and the second optical waveguide 108B can each use an arrayed optical waveguide 106; alternatively, the first optical waveguide 108A and the second optical waveguide 108B can each use a zigzag optical waveguide 107; alternatively, the first optical waveguide 108A uses an arrayed optical waveguide 106 and the second optical waveguide 108B uses a zigzag optical waveguide 107; alternatively, the first optical waveguide 108A uses a zigzag optical waveguide 107 and the second optical waveguide 108B uses an arrayed optical waveguide 106. The above four methods can expand the beam width of blue and green laser light. The following description uses the example of using the arrayed optical waveguide 106 as the first optical waveguide 108A and the second optical waveguide 108B as the example.

[0191] FIG38 is a light path diagram of another light source according to some embodiments. In some examples, as shown in FIG38 , the first reflective film 1062 of the first light waveguide 108A is located on the light-emitting side of the plurality of third light-emitting chips 1013C, while the first transflective film 1063 and the second reflective film 1064 of the first light waveguide 108A are located on the light-emitting side of the plurality of first light-emitting chips 1013A. The structure and function of the multiple film layers in the first light waveguide 108A can be found in the relevant information regarding the arrayed light waveguide 106 in FIG28 and will not be further described here.

[0192] The first reflective film 1062 of the second optical waveguide 108B is located on the light-emitting side of the plurality of second light-emitting chips 1013B. This film is configured to reflect the blue laser light emitted by the plurality of second light-emitting chips 1013B. The first transflective film 1063 and the second reflective film 1064 of the second optical waveguide 108B are located on the light-emitting side of the plurality of first light-emitting chips 1013A. The first transflective film 1063 of the second optical waveguide 108B is configured to reflect a first portion of the blue laser light and transmit a second portion of the blue laser light, the green laser light, and the red laser light. The second reflective film 1064 of the second optical waveguide 108B is configured to reflect the blue laser light and transmit the green laser light and the red laser light.

[0193] Here, the first transflective film 1063 and the second reflective film 1064 of the second optical waveguide 108B can be equivalent to a dichroic mirror. The arrangement angles of the multiple film layers in the second optical waveguide 108B can refer to the relevant description above and will not be repeated here.

[0194] The spacing between the first transflective film 1063 and the second reflective film 1064 in the first optical waveguide 108A, and the spacing between the first transflective film 1063 and the second reflective film 1064 in the second optical waveguide 108B, are both equal to the beam width of the red laser light emitted by the plurality of first light-emitting chips 1013A. Furthermore, the first transflective film 1063 in the first optical waveguide 108A can be arranged parallel to the first transflective film 1063 in the second optical waveguide 108B, and the second reflective film 1064 in the first optical waveguide 108A can be arranged parallel to the second reflective film 1064 in the second optical waveguide 108B.

[0195] Green laser light emitted by the plurality of third light-emitting chips 1013C is incident on the first reflective film 1062 in the first optical waveguide 108A and is reflected by the first reflective film 1062. The green laser light reflected by the first reflective film 1062 undergoes multiple total reflections in the first optical waveguide 108A and is incident on the first transflective film 1063 in the first optical waveguide 108A. A first portion of the green laser light is reflected by the first transflective film 1063 and exits the first optical waveguide 108A. A second portion of the green laser light is transmitted by the first transflective film 1063 and continues to propagate in the first optical waveguide 108A until it enters the second reflective film 1064 in the first optical waveguide 108A. The green laser light that enters the second reflective film 1064 is completely reflected by the second reflective film 1064 and exits the first optical waveguide 108A. The beam width of the green laser light emitted from the first optical waveguide 108A is equal to the beam width of the red laser light.

[0196] The blue laser light emitted by the plurality of second light-emitting chips 1013B passes through the first optical waveguide 108A and enters the first reflective film 1062 in the second optical waveguide 108B, where it is reflected by the first reflective film 1062. The blue laser light reflected by the first reflective film 1062 undergoes multiple total reflections in the second optical waveguide 108B and enters the first transflective film 1063 in the second optical waveguide 108B. A first portion of the blue laser light is reflected by the first transflective film 1063 and exits the second optical waveguide 108B. A second portion of the blue laser light is transmitted by the first transflective film 1063 and continues to propagate in the second optical waveguide 108B until it enters the second reflective film 1064 in the second optical waveguide 108B. The blue laser light entering the second reflective film 1064 is completely reflected by the second reflective film 1064 and exits the second optical waveguide 108B. The beam width of the blue laser light emitted from the second optical waveguide 108B is equal to the beam width of the red laser light.

[0197] The green laser light and the red laser light emitted from the first optical waveguide 108A may pass through the second optical waveguide 108B and enter the focusing lens 103 , and the blue laser light and the red laser light emitted from the second optical waveguide 108B may directly enter the focusing lens 103 .

[0198] Thus, by providing two optical waveguides 108 in the projection device 1000, the beam widths of the red, green, and blue lasers can be made equal, resulting in a uniform color distribution of the light beam emitted by the light source 10. Furthermore, there is no need to provide a fourth beam combining lens group 109 for beam combining, and the light beams can be directly converged by a single converging lens 103, which helps simplify the internal structure of the projection device 1000 and achieve a low-cost and lightweight design.

[0199] FIG39 is a light path diagram of another light source according to some embodiments. In other examples, the light source 10 in FIG38 may also include a fourth beam-combining mirror group 109. For example, as shown in FIG39 , the light source 10 further includes a fourth beam-combining mirror group 109, which includes a sixth beam-combining mirror 1093. The sixth beam-combining mirror 1093 is configured to reflect the green and red laser light emitted from the first optical waveguide 108A and the blue and red laser light emitted from the second optical waveguide 108B in the same direction to achieve beam combining. For example, the sixth beam-combining mirror 1093 reflects the incident three-color laser light toward the converging lens 103. By providing the sixth beam-combining mirror 1093, the laser light in the light source 10 can be redirected, facilitating the display of the projected image, thereby making the projection device 1000 applicable to a wider range of real-world scenarios.

[0200] The structures and functions of the laser 101, the first optical waveguide 108A, and the second optical waveguide 108B can be found in the relevant description in FIG38 and will not be repeated here.

[0201] The foregoing description mainly uses the example of a light source 10 including a laser 101, wherein the laser 101 includes a plurality of first light-emitting chips 1013A, a plurality of second light-emitting chips 1013B, and a plurality of third light-emitting chips 1013C, and one or more optical waveguides 108 are located on the light-emitting side of the laser 101. Of course, in some embodiments, the light source 10 may also include multiple lasers 101.

[0202] FIG40 is a light path diagram of another light source according to some embodiments. In some examples, as shown in FIG40 , multiple lasers 101 include a first laser 101A and a second laser 101B. The first laser 101A includes one or more first light-emitting chips 1013A, and the second laser 101B includes one or more second light-emitting chips 1013B and one or more third light-emitting chips 1013C. A first optical waveguide 108A and a second optical waveguide 108B are located on the light-emitting side of the second laser 101B, with the second optical waveguide 108B located on the side of the first optical waveguide 108A away from the second laser 101B. For example, as shown in FIG33 , the first optical waveguide 108A is located on the light-emitting side of the plurality of third light-emitting chips 1013C, and the second optical waveguide 108B is located on the light-emitting side of the plurality of second light-emitting chips 1013B. The first optical waveguide 108A is configured to expand the beam width of green laser light emitted by the plurality of third light-emitting chips 1013C, while the second optical waveguide 108B is configured to expand the beam width of blue laser light emitted by the plurality of second light-emitting chips 1013B. Furthermore, in the first optical waveguide 108A, the spacing between the first transflective film 1063 and the second reflective film 1064 is equal to the beam width of red laser light emitted by the plurality of first light-emitting chips 1013A in the first laser 101A. In the second optical waveguide 108B, the spacing between the first transflective film 1063 and the second reflective film 1064 is equal to the beam width of red laser light emitted by the plurality of first light-emitting chips 1013A in the first laser 101A.

[0203] In this case, the light source 10 further includes a fourth light-combining mirror group 109 , and the fourth light-combining mirror group 109 includes a sixth light-combining mirror 1093 . The sixth light-combining mirror 1093 is configured to reflect the blue laser and the green laser and transmit the red laser.

[0204] The red laser light emitted by the multiple first light-emitting chips 1013A in the first laser 101A is transmitted through the sixth light-combining mirror 1093 to the converging lens 103. The green laser light emitted by the multiple third light-emitting chips 1013C in the second laser 101B is expanded through the first optical waveguide 108A to the same beam width as the red laser light. The blue laser light emitted by the multiple second light-emitting chips 1013B in the second laser 101B is expanded through the second optical waveguide 108B to the same beam width as the red laser light. The green laser light and the blue laser light are respectively reflected by the sixth light-combining mirror 1093 to the converging lens 103, which converges the red, green, and blue laser light.

[0205] Furthermore, the solution in which the light source 10 includes two lasers 101 can also be used in the laser 101 shown in FIG26 . Thus, the solution in which the light source 10 includes two lasers 101 can be applied to situations in which the ratio of the number of three-color light-emitting chips included in the laser 101 varies. It should be noted that the solution in FIG33 in which two lasers 101 are used can also use only one optical waveguide 108. The structure and function of the optical waveguide 108 can be found in the relevant description above and will not be repeated here.

[0206] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0207] Those skilled in the art will understand that the scope of the present disclosure is not limited to the above specific embodiments, and that certain elements of the embodiments may be modified and replaced without departing from the spirit of the present disclosure. The scope of the present disclosure is limited by the appended claims.

Claims

1. A projection device, comprising: a light source configured to emit laser light of multiple colors as an illumination beam; an optical modulation component configured to modulate the illumination light beam to obtain a projection light beam; as well as a lens, located on a light-emitting side of the optical modulation component, the lens being configured to project the projection light beam to form a projection image; The light source comprises: at least one laser, the at least one laser comprising: a plurality of first light-emitting chips configured to emit red laser light; a plurality of second light-emitting chips configured to emit blue laser light; and a plurality of third light-emitting chips configured to emit green laser light, wherein the number of the plurality of third light-emitting chips and the number of the plurality of second light-emitting chips are respectively smaller than the number of the plurality of first light-emitting chips; and At least one optical waveguide, one optical waveguide of the at least one optical waveguide being located on a light-emitting side of the plurality of third light-emitting chips; each optical waveguide of the at least one optical waveguide comprising: The light incident surface is the surface of the optical waveguide close to the laser; a light emitting surface arranged parallel to the light incident surface, wherein the light incident surface and the light emitting surface are arranged opposite to each other in the thickness direction of the optical waveguide; a light input portion configured to guide incident laser light into the optical waveguide; and The light output portion is configured to output the laser light in the optical waveguide, and the light input portion and the light output portion are located between the light input surface and the light output surface; the beam width of the laser light emitted by the light output portion is equal to the beam width of the red laser light emitted by the multiple first light-emitting chips.

2. The projection device according to claim 1, wherein: The optical waveguide satisfies one of the following conditions: The optical waveguide includes an arrayed optical waveguide, and the arrayed optical waveguide includes: first ontology; a first reflective film disposed in the first body and located at one end of the first body, the first reflective film being configured to reflect laser light incident on the first reflective film; a first transflective film disposed in the first body and located at the other end of the first body, the first transflective film being configured to reflect a first portion of the laser light from the first reflective film and transmit a second portion of the laser light from the first reflective film; and a second reflective film disposed in the first body and located at the other end of the first body, the first transflective film being located between the first reflective film and the second reflective film, the second reflective film being configured to at least reflect laser light transmitted by the first transflective film; The light incident portion is the first reflective film, and the light exit portion is the first transflective film and the second reflective film. The first reflective film, the first transflective film, and the second reflective film are arranged parallel to each other and tilted at a set angle relative to the light incident surface of the optical waveguide. The set angle satisfies a condition that the incident laser light is totally reflected in the optical waveguide. The spacing between the first transflective film and the second reflective film is equal to the beam width of the red laser light emitted by the plurality of first light-emitting chips. as well as, The optical waveguide comprises a zigzag optical waveguide, wherein the zigzag optical waveguide comprises: Second ontology; a third reflective film disposed in the second body; and a prism portion disposed within the second body and located on the light incident surface of the optical waveguide, the prism portion comprising a plurality of sub-prisms arranged in parallel, each of the sub-prisms being in a strip shape; in two or more sub-prisms close to the third reflective film, a second transflective film is disposed on surfaces of the two or more sub-prisms facing the third reflective film; and in at least one sub-prism away from the third reflective film, a fourth reflective film is disposed on a surface of the at least one sub-prism facing the third reflective film; The light incident portion is the third reflective film, the light emitting portion is the prism portion, the third reflective film and the prism portion are at a set distance from each other; the width of the prism portion is equal to the beam width of the red laser emitted by the multiple first light-emitting chips.

3. The projection device according to claim 2, wherein: The reflectivity of the first transflective film is 50%, and the transmittance of the first transflective film is 50%.

4. The projection device according to claim 2 or 3, wherein: The at least one optical waveguide satisfies one of the following: The at least one optical waveguide includes an optical waveguide, the first reflective film is located on the light-emitting side of the plurality of third light-emitting chips and is configured to reflect the green laser; the first transflective film is configured to reflect a first portion of the green laser from the first reflective film and transmit the green laser. emitting a second portion of the green laser light from the first reflective film; the second reflective film being located on the light-emitting side of the plurality of first light-emitting chips and being configured to reflect the green laser light and transmit the red laser light; as well as, The at least one optical waveguide includes one optical waveguide, the third reflective film is located on a light-emitting side of the plurality of third light-emitting chips and is configured to reflect green laser light; the prism portion is located on a light-emitting side of the plurality of first light-emitting chips, and the second transflective film in the two or more sub-prisms is configured to reflect a first portion of the green laser light from the third reflective film and transmit a second portion of the green laser light from the third reflective film; The fourth reflective film in the at least one sub-prism is configured to reflect green laser light and transmit red laser light; as well as, The at least one optical waveguide comprises: a first optical waveguide located on a light-emitting side of the plurality of third light-emitting chips, the first optical waveguide being configured to expand a beam width of green laser light emitted by the plurality of third light-emitting chips so that the beam width of the green laser light emitted from the first optical waveguide is equal to the beam width of the red laser light emitted by the plurality of first light-emitting chips; as well as a second optical waveguide located on a light-emitting side of the plurality of second light-emitting chips, the second optical waveguide being configured to expand a beam width of the blue laser light emitted by the plurality of second light-emitting chips so that the beam width of the blue laser light emitted from the second optical waveguide is equal to the beam width of the red laser light emitted by the plurality of first light-emitting chips.

5. The projection device according to any one of claims 2 to 4, wherein: The at least one laser satisfies one of the following: The at least one laser includes a laser, the laser includes the plurality of first light-emitting chips, the plurality of second light-emitting chips, and the plurality of third light-emitting chips; the at least one optical waveguide is located on the light-emitting side of the laser; as well as, The at least one laser comprises: A first laser comprising the plurality of first light-emitting chips; and The second laser includes the plurality of second light-emitting chips and the plurality of third light-emitting chips; and the at least one optical waveguide is located at a light-emitting side of the second laser.

6. The projection device according to claim 5, wherein: The light source further includes a first light combining lens group, which is located on the light output side of the at least one laser and is configured to combine the red laser, the green laser and the blue laser.

7. The projection device according to any one of claims 1 to 6, wherein: The optical modulation component comprises: a light homogenizing component, located on the light-emitting side of the light source, configured to homogenize the incident illumination light beam; a volume grating located on the light-emitting side of the light-homogenizing component, the volume grating being configured to diffract the illumination beam from the light-homogenizing component so that the spot size and exit angle of the laser light diffracted by the volume grating meet the incident conditions of the optical modulation component; the spot size and exit angle of the laser light diffracted by the volume grating are related to the thickness, period, and refractive index variation of the volume grating; a set angle is formed between the light-emitting surface of the volume grating and the light-entering surface of the optical modulation component, and the set angle meets the incident angle condition when the laser light enters the optical modulation component; and The optical modulation component is located at the light-emitting side of the volume grating, and is configured to modulate the illumination light beam emitted from the volume grating to obtain the projection light beam.

8. The projection device according to claim 7, wherein: The volume grating is located on the side of the optical modulation component; the light uniforming component is located on the side of the volume grating away from the optical modulation component; The optical modulation component also includes a reflector group, which is located on the light-emitting side of the light-evening component. The reflector group is configured to reflect the illumination light beam emitted from the light-evening component to the volume grating, so that the illumination light beam reflected by the reflector group is incident on the volume grating at a Bragg angle; the reflector group includes a first reflector.

9. The projection device according to claim 8, wherein: The optical modulation component also includes a collimating lens group, which is located between the light uniformity component and the reflector group. The collimating lens group is configured to collimate the illumination light beam emitted from the light uniformity component, and the illumination light beam collimated by the collimating lens group is incident on the reflector group.

10. The projection device according to claim 9, wherein: The light uniforming component includes a light pipe, and an extension direction of the light pipe is parallel to the side of the optical modulation component.

11. The projection device according to claim 10, wherein: The light guide is wedge-shaped, and along the transmission direction of the illumination light beam, the cross-sectional area of ​​the light guide on a target plane perpendicular to the transmission direction of the illumination light beam decreases; the light guide comprises: a first end, proximate to the light source, the first end being configured to receive an illumination beam from the light source; and The second end is away from the light source, the cross-sectional area of ​​the first end on the target plane is larger than the cross-sectional area of ​​the second end on the target plane, and the illumination light beam homogenized by the light pipe is emitted from the second end.

12. A projection device comprising: A light source configured to emit laser light of multiple colors as an illumination beam, the light source comprising: at least one laser configured to emit laser light of multiple colors; and a light combining component, located on the light-emitting side of the laser, configured to combine laser lights of different colors emitted by the at least one laser; and a light-adjusting component located at the light-emitting side of the light-combining component, the light-adjusting component being configured to homogenize and shape the laser light after being combined by the light-combining component, the light-adjusting component comprising a first diffractive optical element; an optical modulation component configured to modulate the illumination light beam to obtain a projection light beam, the optical modulation component comprising: a prism assembly configured to receive the illumination light beam emitted by the dimming component and reflect the illumination light beam to the light valve; and The light valve is configured to modulate the incident illumination light beam into the projection light beam according to the image signal; and A lens is located at the light-emitting side of the optical modulation component, and the lens is configured to project the projection light beam to form a projection picture.

13. The projection device according to claim 12, wherein: The light combining component includes a second diffractive optical element, which is configured to adjust the transmission direction of laser light incident at different positions so that laser light of different colors is emitted to the same area, and the second diffractive optical element satisfies one of the following conditions: The second diffractive optical element includes a transmissive diffractive optical element, and the second diffractive optical element is configured to transmit incident laser light and combine incident laser light of multiple colors; and The second diffractive optical element includes a reflective diffractive optical element and is arranged at an angle relative to the light output direction of the laser. The second diffractive optical element is configured to reflect the incident laser light and combine the incident laser light of multiple colors.

14. The projection device according to claim 13, wherein: The second diffractive optical element includes: a diffraction element body configured to combine incident laser beams of multiple colors; and The reflective film is located on a side of the diffraction element body away from the at least one laser and is configured to reflect the combined laser light.

15. The projection device according to claim 13, wherein: The second diffractive optical element includes a transmissive diffractive optical element, and the light source further includes a second reflector, which is located between the light combining component and the dimming component and is configured to reflect the laser light combined by the light combining component to the dimming component.

16. The projection device according to any one of claims 12 to 15, wherein: The light source also includes a second light-combining mirror group, which is located between the laser and the light-combining component. The second light-combining mirror group is configured to perform a first light combination on the laser lights of multiple colors emitted by the laser and emit the combined laser lights of multiple colors toward the light-combining component.

17. The projection device according to claim 12, wherein: The at least one laser includes a plurality of light emitting areas, each of the plurality of light emitting areas is configured to emit laser light of one color; the laser and the light combining component are arranged along a first direction, the light combining component and the light modulating component are arranged along a second direction, and the first direction is perpendicular to the second direction; The light-combining component includes a plurality of light-combining mirrors, and the plurality of light-combining mirrors are arranged in sequence along the second direction. On a plane perpendicular to the second direction, the orthographic projections of the plurality of light-combining mirrors at least partially overlap; the plurality of light-combining mirrors correspond to the plurality of light-emitting areas, and the light-combining mirrors are at least configured to reflect the laser light emitted by the corresponding light-emitting areas along the second direction.

18. The projection device according to any one of claims 12 to 17, wherein: The light source satisfies at least one of the following: The light source further includes a first lens, the first lens is located on the optical path between the light combining component and the light adjusting component, and the first lens is configured to collimate the incident laser light; or The light source further includes a second lens, which is located between the laser and the light combining component, and is configured to converge the laser light emitted by the laser onto the light combining component.

19. The projection device according to claim 12, wherein: The at least one laser includes a third laser and a fourth laser, wherein the third laser and the fourth laser are configured to emit blue laser, green laser, and red laser, respectively; the light source further includes a third light combining mirror group, which is located on the light output side of the third laser and the fourth laser, and includes: The first region is located at the light-emitting area of ​​the third laser emitting red laser light and the light-emitting area of ​​the fourth laser emitting blue laser light and green laser light, and the first region is configured to reflect the blue laser light and the green laser light and transmit the red laser light. light; and The second region is located on the light-emitting side of the light-emitting area of ​​the fourth laser that emits red laser light, and the light-emitting area of ​​the third laser that emits blue laser light and green laser light, and the second region is configured to reflect the red laser light and transmit the blue laser light and the green laser light.

20. A projection system comprising: A projection device, wherein the projection device is the projection device according to any one of claims 1 to 19; as well as The projection screen is located at the light-emitting side of the projection device, and is configured to receive the projection light beam from the projection device to form a projection picture.

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