Projection device

Abstract

A projection device, comprising: a laser source (100) used for emitting laser, the laser source (100) comprising a plurality of light emitting regions (101, 102, 103, 104) sequentially arranged in a first direction (X), the first direction (X) being parallel to the direction of the fast axis of the laser emitted by the laser source (100); a beam splitting element (200) located on the light emitting side of the laser source (100) and used for splitting the laser beam emitted by each light emitting region (101, 102, 103, 104) into at least two sub-beams in the first direction (X); and a beam combining assembly (300) located on the light emitting side of the beam splitting element (200) and used for combining the sub-beams formed by the beam splitting element (200).

Description

Projection device

[0001] Cross-reference to related applications

[0002] This application claims priority to the Chinese Patent Application No. 202410871317.6, filed on June 29, 2024, entitled “A projection device”, the content of which is incorporated herein by reference in its entirety; this application claims priority to the Chinese Patent Application No. 202422272969.6, filed on September 18, 2024, entitled “A projection device”, the content of which is incorporated herein by reference in its entirety; this application claims priority to the Chinese Patent Application No. 202411328532.8, filed on September 23, 2024, entitled “A projection device”, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the field of projection technology, in particular to a projection device. BACKGROUND

[0004] The projection device is controlled by a planar image information to control a light source, and uses an optical system and a projection space to magnify and display an image on a projection screen. The projection device includes a projection light source, a display element, and a projection lens. The projection light source emits projection light to provide illumination for the display element. The display element modulates the incident light according to the image data of the image to be displayed to form a display image. The projection lens images the display image to the projection screen. Due to the characteristics of monochromaticity and good collimation of laser, a laser light source is used as the projection light source. SUMMARY

[0005] Embodiments of the present application provide a projection device, comprising:

[0006] A laser light source for emitting laser light; the laser light source comprises a plurality of light emitting areas arranged in a first direction in sequence; the first direction is parallel to the fast axis direction of the laser light emitted by the laser light source;

[0007] A beam splitting element located on the light emitting side of the laser light source, for splitting the laser beam emitted by each of the light emitting areas into at least two sub-beams along the first direction;

[0008] A light combining assembly located on the light emitting side of the beam splitting element, for combining each of the sub-beams formed by the beam splitting element. BRIEF DESCRIPTION OF DRAWINGS

[0009] FIG. 1 is a schematic diagram of a projection device according to an embodiment of the present application;

[0010] FIG. 2 is a schematic diagram of a second light combining element according to an embodiment of the present application;

[0011] FIG. 3 is a schematic diagram of a laser receiving region of a first light combining element according to an embodiment of the present application;

[0012] FIG. 4 is a schematic diagram of red laser light combining according to an embodiment of the present application;

[0013] FIG. 5 is a schematic diagram of red laser light combining according to an embodiment of the present application;

[0014] FIG. 6 is a schematic diagram of an out-coupling region according to an embodiment of the present application;

[0015] FIG. 7 is a schematic diagram of a projection device according to an embodiment of the present application;

[0016] FIG. 8 is a schematic diagram of three-color laser light combining according to an embodiment of the present application;

[0017] FIG. 9 is a schematic diagram of a light spot when incident on a beam splitting element according to an embodiment of the present application;

[0018] FIG. 10 is a schematic diagram of a light spot according to an embodiment of the present application;

[0019] FIG. 11 is a schematic diagram of a projection device according to an embodiment of the present application;

[0020] FIG. 12 is a schematic diagram of a projection device according to an embodiment of the present application;

[0021] FIG. 13 is a schematic diagram of a first microlens and a second microlens correspondence according to an embodiment of the present application;

[0022] FIG. 14 is a schematic diagram of an optical shaping element according to an embodiment of the present application;

[0023] FIG. 15 is a schematic diagram of a projection device according to an embodiment of the present application;

[0024] FIG. 16 is a schematic diagram of a projection device according to an embodiment of the present application;

[0025] FIG. 17 is a schematic diagram of an imaging light spot at an aperture according to an embodiment of the present application;

[0026] FIG. 18 is a schematic diagram of a planar structure of a projection light source according to an embodiment of the present application;

[0027] FIG. 19 is a schematic diagram of a light combining spot at a compound eye lens according to an embodiment of the present application;

[0028] FIG. 20 is a structural schematic diagram of a fly-eye lens according to an embodiment of the present application;

[0029] FIG. 21 is a structural schematic diagram of a total reflection prism group according to an embodiment of the present application;

[0030] FIG. 22 is a light path schematic diagram of effective light according to an embodiment of the present application;

[0031] FIG. 23 is a light path schematic diagram of ineffective light according to an embodiment of the present application;

[0032] FIG. 24 is a schematic diagram of a projection device according to an embodiment of the present application;

[0033] FIG. 25 is a schematic diagram of a projection device according to an embodiment of the present application;

[0034] FIG. 26 is a diagram of the variation of the light emitting power of a red laser chip with temperature in a laser according to an embodiment of the present application;

[0035] FIG. 27 is a schematic diagram of a projection device according to an embodiment of the present application;

[0036] FIG. 28 is a schematic diagram of a projection device according to an embodiment of the present application;

[0037] FIG. 29 is a schematic diagram of a projection device according to an embodiment of the present application;

[0038] FIG. 30 is a schematic diagram of a projection device according to an embodiment of the present application;

[0039] FIG. 31 is a schematic diagram of a projection device according to an embodiment of the present application;

[0040] FIG. 32 is a diagram of the light spot formed on the plane of the light emitting surface of a laser emitting first and second types of laser light according to an embodiment of the present application;

[0041] FIG. 33 is a diagram of the light spot formed on the plane parallel to the light emitting surface of a laser emitting first and second types of laser light after the first and second types of laser light pass through third and fourth lenses according to an embodiment of the present application;

[0042] FIG. 34 is a diagram of the light spot formed on the light homogenizing assembly by the first and second types of laser light after the first and second types of laser light are combined according to an embodiment of the present application;

[0043] FIG. 35 is a schematic diagram of a projection device according to an embodiment of the present application;

[0044] FIG. 36 is a structural block diagram of a projection device according to an embodiment of the present application;

[0045] FIG. 37 is a curve diagram of the control component provided by the embodiment of the present application exerting driving current on the first light emitting region in the laser and the LED light emitting unit at different ambient temperatures. DETAILED DESCRIPTION

[0046] In order to make the above objectives, features and advantages of the present application more apparent, comprehensible and easier to understand, the present application will be further described below with reference to the accompanying drawings and embodiments. However, the example embodiments can be implemented in various forms, and should not be understood as being limited to the embodiments set forth herein; on the contrary, these embodiments are provided to make the present application more comprehensive and complete, and to fully convey the ideas of the example embodiments to those skilled in the art. The same reference signs in the drawings represent the same or similar structures, and thus repeated description thereof will be omitted. The expressions of position and direction described in the present application are described with reference to the drawings, but can be changed as needed, and the changes made are included in the scope of protection of the present application. The drawings of the present application are only used to illustrate the relative positional relationship and do not represent the true proportions.

[0047] The projection device is controlled by planar image information to control the light source, and uses an optical system and a projection space to magnify and display the image on a projection surface. As shown in FIG. 1, the embodiment of the present application provides a projection device, which comprises a laser light source 100.

[0048] The laser light source 100 is used for emitting laser light; the laser light source comprises a plurality of light emitting regions arranged in a first direction in sequence, wherein at least two light emitting regions emit laser light of the same color; the first direction is parallel to the fast axis direction of the laser light emitted by the laser light source.

[0049] The light combination component 300 is used for combining the laser light emitted by the laser light source. The display element 400 is located on the light emitting side of the light combination component 300, and is used for modulating the incident laser light according to the driving data of the to-be-displayed image to form a display image.

[0050] The display element 500 can adopt a liquid crystal on silicon (LCoS) or a digital micromirror (DMD).

[0051] The LCoS is based on semiconductor technology to adhere a complementary metal oxide semiconductor (CMOS) substrate to a glass substrate containing a transparent electrode, and then inject liquid crystal for packaging. The LCoS has the characteristics of high aperture ratio of each pixel and high resolution, and can form a high-resolution image.

[0052] The DMD includes a plurality of micro-mirrors, each of which can be driven to deflect individually. By controlling the deflection angle of the DMD, the brightness of the light incident on the projection lens can be controlled.

[0053] In some cases, the light-emitting region of the laser light source emitting the same color of laser light includes at least two, for example, the region emitting red laser light has two, and a half-wave plate needs to be arranged in the propagation direction of one of the light-emitting regions emitting red laser light to change the polarization direction of the red laser light emitted by the light-emitting region, so that the red laser light emitted by the light-emitting region and the red laser light emitted by other light-emitting regions can be polarized combined. In addition, a stationary diffusion sheet and / or a moving diffusion sheet and other optical elements need to be arranged in the optical path to diffuse the laser beam, so that the devices in the projection device are more and the manufacturing is more complicated.

[0054] In view of the above, the projection device of the embodiment of the present application, as shown in FIG. 1, further includes a beam splitting element 200, a light combining assembly 300, and a display element 400. The beam splitting element 200 is used to split the laser beam emitted by each light-emitting region into at least two sub-beams along a first direction. The light combining assembly 300 is located on the light-emitting side of the beam splitting element 200 and includes a first light combining element 301 and at least one second light combining element 302. The first light combining element 301 is arranged corresponding to one light-emitting region emitting the same color of laser light, and the second light combining element 302 is arranged corresponding to the other light-emitting regions one by one. The second light combining element 302 includes alternating reflection regions and transmission regions. The number of reflection regions and transmission regions is equal, and the number of reflection regions is equal to the number of sub-beams split by the beam splitting element. The first light combining element 301 reflects each sub-beam formed after the laser beam emitted by the corresponding light-emitting region passes through the beam splitting element to each transmission region of the second light combining element 302. The second light combining element 302 emits each sub-beam formed after the laser beam emitted by the corresponding light-emitting region passes through the beam splitting element to each reflection region of the second light combining element, so that these sub-beams are reflected, thereby combining the light emitted by the light-emitting region corresponding to the first light combining element 301 and the light-emitting region corresponding to the second light combining element 302.

[0055] For example, as shown in FIG. 1, the light beam splitting element splits the laser beam emitted by each light emitting area into two sub-beams along the first direction when the number of light emitting areas is two. The first light combining element 301 is arranged corresponding to the first light emitting area 101, and the second light combining element 302 is arranged corresponding to the second light emitting area 102. As shown in FIG. 2, the number of reflection regions of the second light combining element is two, and the number of transmission regions of the second light combining element is two. The black regions C1 and C3 are reflection regions, and the blank regions C2 and C4 are transmission regions. As shown in FIG. 3, the area of the projection of the transmission region C2 on the first light combining element 301 along the direction perpendicular to the laser propagation direction of the laser source is area C22, and the area of the projection of the transmission region C4 on the first light combining element 301 along the direction perpendicular to the laser propagation direction of the laser source is area C44.

[0056] As shown in FIGS. 2-4, the laser beam emitted by the first light emitting area 101 is processed by the optical splitting element to split the laser beam emitted by the first light emitting area 101 along the fast axis direction of the laser emitted by the laser source to obtain a first light beam L11 and a second light beam L12. The laser beam emitted by the second light emitting area 102 is processed by the optical splitting element to split the laser beam emitted by the second light emitting area 102 along the fast axis direction of the laser emitted by the laser source to obtain a third light beam L21 and a fourth light beam L22. The first light beam L11 is incident to the area C22 in the first light combining element 301 and is reflected to the transmission region C2 of the second light combining element. The second light beam L12 is incident to the area C44 in the first light combining element 301 and is reflected to the region C4 of the second light combining element. The third light beam L21 is incident to the reflection region C1 in the second light combining element 302, and the fourth light beam L22 is incident to the reflection region C3 in the second light combining element 302. Thus, the second light combining element 302 combines the first light beam L11, the second light beam L12, the third light beam L21, and the fourth light beam L22.

[0057] When the number of the second light combining elements is more than one, the reflection regions and the transmission regions of the plurality of second light combining elements are arranged in a staggered manner. For example, as shown in FIG. 5, if one third light emitting region is added, the number of the second light combining elements 302 needs to be increased to two, i.e., the light combining element 3021 and the light combining element 3022. The first light beam L11 and the second light beam L12 are still incident to the regions C22 and C44 in the light combining element 301 and are reflected to the transmission regions of the light combining element 3021 and the light combining element 3022. The third light beam L21 and the fourth light beam L22 are incident to the reflection region of the light combining element 3021 and are reflected by the light combining element 3021 to the transmission region of the light combining element 3022. The laser beams emitted by the third light emitting region are divided into the fifth light beam L31 and the sixth light beam L32. The fifth light beam L31 and the sixth light beam L32 are incident to the reflection region of the light combining element 3022 and are reflected, so that the first light beam L11, the second light beam L12, the third light beam L21, the fourth light beam L22, the fifth light beam L31 and the sixth light beam L32 are combined by the transmission region of the light combining element 3022.

[0058] The present application divides the laser beams emitted by each light emitting region into at least two sub-beams by using the beam splitting element, and combines the divided sub-beams by using the reflection of the first light combining element and the reflection region and the transmission region of the second light combining element in the light combining assembly. In this way, the light combining process can be completed only by using the optical splitting element and the light combining assembly, the optical path is simplified, and the manufacturing efficiency is improved.

[0059] In some embodiments, the laser light source can use a monochromatic laser, which can emit red laser, green laser or blue laser, etc. The laser light source includes a plurality of light emitting regions, and the light emitting regions emit laser beams of the same color. The optical path is as shown in FIG. 1.

[0060] In some embodiments, the laser light source can use a three-color laser. As shown in FIG. 6, the plurality of light emitting regions in the laser light source include a first light emitting region 101, a second light emitting region 102, a third light emitting region 103 and a fourth light emitting region 104. The first light emitting region 101 and the second light emitting region 102 are used to emit red laser, the third light emitting region 103 is used to emit blue laser, and the fourth light emitting region 104 is used to emit green laser. At this time, as shown in FIG. 7, the light combining assembly includes a first light combining element 301, a second light combining element 302 and a light combining lens group 303. The light combining lens group 303 is used to combine the emitted light of the first light emitting region and the second light emitting region with the emitted light of the third light emitting region and the fourth light emitting region.

[0061] As shown in FIG. 6, the laser light source 100 includes four light emitting areas arranged in the first direction x in turn, the first light emitting area 101 and the second light emitting area 102 are both used for emitting laser light of a first wavelength, the third light emitting area 103 is used for emitting laser light of a second wavelength, and the fourth light emitting area 104 is used for emitting laser light of a third wavelength; wherein the first direction x is parallel to the fast axis direction of the laser light.

[0062] In some embodiments, the first light emitting area 101 and the second light emitting area 102 emit red laser light, the corresponding first wavelength is 620nm-750nm, the third light emitting area 103 emits blue laser light, the corresponding second wavelength is 450nm-495nm, and the fourth light emitting area 104 emits green laser light, the corresponding third wavelength is 495nm-570nm.

[0063] Continuing to refer to FIG. 6, the first light emitting area 101 and the second light emitting area 102 of the laser light source 100 include a plurality of first laser chips arranged in the y direction; the third light emitting area 103 includes a plurality of second laser chips arranged in the y direction; the fourth light emitting area 104 includes a plurality of third laser chips arranged in the y direction; the colors of the laser light emitted by the first laser chips, the second laser chips and the third laser chips are different. The first laser chips can be red laser chips, the second laser chips can be blue laser chips, and the third laser chips can be green laser chips. The red laser chips can emit red laser light, the green laser chips can emit green laser light, and the blue laser chips can emit blue laser light, thereby realizing full-color display.

[0064] In combination with FIGS. 7 and 8, the first light combining member 301 reflects each sub-beam formed by the laser light beam emitted by the first light emitting area 101 after passing through the beam splitting element to the transmission area of the second light combining member; each sub-beam formed by the laser light beam emitted by the second light emitting area 102 after passing through the beam splitting element 200 is emitted to the reflection area of the second light combining member 3012, and the second light combining member 302 combines the emitted light of the first light emitting area and the second light emitting area.

[0065] The light combining lens group 303 is provided corresponding to the third light emitting area 103 and the fourth light emitting area 104, and the light combining lens group 303 is used to combine the emitted light of the first light emitting area 101, the second light emitting area 102 and the emitted light of the third light emitting area 103, the fourth light emitting area 104.

[0066] As shown in FIG. 8, the laser beams emitted by the first light emitting area 101 are processed by the optical splitting element, and the laser beams emitted by the first light emitting area 101 are split along the fast axis direction of the laser to obtain a first red beam L1 and a second red beam L2; the laser beams emitted by the second light emitting area 102 are processed by the optical splitting element, and the laser beams emitted by the second light emitting area 102 are split along the fast axis direction of the laser to obtain a third red beam L3 and a fourth red beam L4; the first red beam L1 and the second red beam L2 are incident to the first light combining element 301 and reflected to the transmission area of the second light combining element; the third red beam L3 and the fourth red beam L4 are incident to the reflection area of the second light combining element 302, so that the second light combining element 302 combines the first red beam L1, the second red beam L2, the third red beam L3, and the fourth red beam L4.

[0067] The red laser emitted by the first light emitting area is incident to the area of the first light combining element corresponding to the transmission area of the second light combining element after the beam splitting element, so that the red laser emitted by the first light emitting area can be fully incident to the transmission area of the second light combining element; and the sub-beams obtained by splitting the red laser emitted by the second light emitting area by the beam splitting element can be fully incident to the reflection area of the second light combining element, thereby improving the beam utilization rate.

[0068] The laser beams emitted by the third light emitting area 103 are processed by the optical splitting element, and the laser beams emitted by the third light emitting area 103 are split along the fast axis direction of the laser to obtain a first blue beam L5 and a second blue beam L6; the laser beams emitted by the fourth light emitting area 104 are processed by the optical splitting element, and the laser beams emitted by the fourth light emitting area 104 are split along the fast axis direction of the laser to obtain a first green beam L7 and a second green beam L8. The light combining lens group 303 combines the first green beam L7 and the second green beam L8, the first blue beam L5 and the second blue beam L6, the first red beam L1, the second red beam L2, the third red beam L3, and the fourth red beam L4.

[0069] Specifically, as shown in FIG. 7, the light combining lens group 303 includes a third light combining element 3031 and a fourth light combining element 3032.

[0070] The third light combining element 3031 is configured to reflect the light emitted by the third light emitting area to the fourth light combining element and transmit the light emitted by the second light combining element 302; and the fourth light combining element 3032 is configured to reflect the light emitted by the fourth light emitting area to the display element 400 and transmit the light emitted by the third light combining element 3031. The center of the laser beams emitted by the light combining lens group 303 is located between the center of the laser beams emitted by the first light combining element 301 and the center of the laser beams emitted by the second light combining element 302.

[0071] Still taking the example that the third light-exit region emits blue laser and the fourth light-exit region emits green laser, the third light-combining component 3031 is configured to reflect the blue laser emitted by the third light-exit region of the light beam splitting component to the fourth light-combining component 3032, and transmit the red laser emitted by the second light-combining component 302; the fourth light-combining component 3032 is configured to reflect the green laser emitted by the fourth light-exit region of the light beam splitting component, and transmit the blue laser and the red laser emitted by the third light-combining component 3031.

[0072] When the light combining is performed by using the light combining assembly, the first green light beam L7 and the second green light beam L8 form two light spots, and the light spots partially overlap; the first blue light beam L5 and the second blue light beam L6 form two light spots, and the light spots partially overlap; the first red light beam L1, the second red light beam L2, the third red light beam L3 and the fourth red light beam L4 form four light spots, and the light spots are arranged along a direction perpendicular to the light propagation direction. Among them, the center of the blue laser emitted by the light-combining lens group and the center of the green laser are located between the center of the laser beam emitted by the first light-combining component and the center of the laser beam emitted by the second light-combining component, the blue laser and the green laser passing through the optical splitting component are divided into at least two sub-beams, which increases the light-emitting range and is similar to the light-emitting range of the red laser emitted by the second light-combining component, so that the beam combining effect is better.

[0073] In some embodiments, the light beam splitting component includes a plurality of first microlenses arranged in an array along a first direction and a second direction; the plurality of first microlenses are arranged into microlens rows along the second direction, and the plurality of microlens rows are arranged in sequence along the first direction; the first direction and the second direction intersect; the plurality of first microlenses constitute a plurality of microlens arrays; wherein the plurality of microlens arrays are arranged one-to-one corresponding to the plurality of light-exit regions; each microlens array includes at least two microlens rows, and each microlens array includes the same number of microlens rows.

[0074] For example, the microlens array can include two microlens rows. In combination with the description of FIG. 9, the plurality of microlens arrays include a first microlens array 201, a second microlens array 202, a third microlens array 203 and a fourth microlens array 204; the first microlens array 201 includes two rows of first microlenses arranged along the second direction y; the two rows of first microlenses correspond to the first light-exit region 101; the second microlens array 202 includes two rows of first microlenses arranged along the second direction y; the two rows of first microlenses correspond to the second light-exit region 102; the third microlens array 203 includes two rows of first microlenses arranged along the second direction y; the two rows of first microlenses correspond to the third light-exit region 103; and the fourth microlens array 204 includes two rows of first microlenses arranged along the second direction y; the two rows of first microlenses correspond to the fourth light-exit region 104.

[0075] The two rows of first microlenses in the first microlens array 201 perform converging processing on the red laser light emitted by the first light-emitting area 101; the two rows of first microlenses in the second microlens array 202 perform converging processing on the red laser light emitted by the second light-emitting area 102; the two rows of first microlenses in the third microlens array 203 perform converging processing on the blue laser light emitted by the third light-emitting area 103; and the two rows of first microlenses in the fourth microlens array 204 perform converging processing on the green laser light emitted by the fourth light-emitting area 104.

[0076] The light beam splitting element performs the same processing on the light beam forming each light spot in each light-emitting area. Taking the converging processing of the light beam forming the red light spot r by the microlens 20111 and the microlens 20112 as an example, the red laser light emitted by the first light-emitting area 101 is incident on the microlens 20111 and the microlens 20112. The converging light beam of the microlens 20111 is a first sub-beam, and the first sub-beam forms a light spot r1. The converging light beam of the microlens 20112 is a second sub-beam, and the second sub-beam forms a light spot r2.

[0077] In some embodiments, as shown in FIG. 11, the projection device further includes: a light homogenizing element 500 located on the light-emitting side of the diffusion sheet 600; the light homogenizing element 500 is used for homogenizing the laser light beam; and the diffusion sheet 600 is located between the light-emitting side of the light combining assembly and the light-emitting side of the light homogenizing element 500. The diffusion sheet 600 can be a moving diffusion sheet.

[0078] Specifically, the combined light beam emitted by the fourth light combining element 3032 is incident on the moving diffusion sheet, the moving diffusion sheet diffuses the combined light beam, so that the combined light beam is uniformly diffused, and the moving diffusion sheet effectively eliminates speckle. The diffused combined light beam is incident on the light homogenizing element 500, and the light homogenizing element 500 homogenizes the diffused combined light beam.

[0079] In some embodiments, as shown in FIG. 12, the projection device further includes: a collimating element 700 located on the light-emitting side of the light combining assembly; and the diffusion sheet 600 is located between the light-emitting side of the light combining assembly and the light-emitting side of the collimating element. The collimating element 700 includes a plurality of second microlenses arranged in an array. Each first microlens corresponds to each second microlens. The diffusion sheet 600 is located at the image-side focal point of the light beam splitting element and the object-side focal point of the collimating element 700. The light homogenizing element 500 is located on the light-emitting side of the collimating element 700. The light homogenizing element 500 is used for homogenizing the laser light beam.

[0080] Specifically, the combined light emitted by the light combining assembly 300 is incident to the diffusion sheet 600. Since the diffusion sheet 600 is located at the image-side focal point of the beam-splitting element and at the object-side focal point of the collimating element 700, the light beam processed by the diffusion sheet 600 passes through the collimating element 700, so that the light emitted by the collimating element 700 is parallel light, which is incident into the light homogenizing element 500, thereby improving the light homogenizing effect of the light homogenizing element 500.

[0081] For example, as shown in FIG. 13, the plurality of second microlenses constitute a fifth microlens array 701, a sixth microlens array 702, a seventh microlens array 703, and an eighth microlens array 704. The second red light beam L2 is incident to the fifth microlens array 701 after passing through the diffusion sheet 600, and the fifth microlens array 701 collimates the second red light beam L2. The fourth red light beam L4 is incident to the sixth microlens array 702 after passing through the diffusion sheet 600, and the sixth microlens array 702 collimates the fourth red light beam L4. The first red light beam L1 is incident to the seventh microlens array 703 after passing through the diffusion sheet 600, and the seventh microlens array 703 collimates the first red light beam L1. The third red light beam L3 is incident to the eighth microlens array 704 after passing through the diffusion sheet 600, and the eighth microlens array 704 collimates the third red light beam L3.

[0082] The first green light beam L7 and the second green light beam L8 are incident to two or three of the four arrays of the collimating element after passing through the diffusion sheet 600. The first blue light beam L5 and the second blue light beam L6 are incident to two or three of the four arrays of the collimating element after passing through the diffusion sheet 600.

[0083] Since the light paths of the first light-emitting area, the second light-emitting area, the third light-emitting area, and the fourth light-emitting area are different after the combined light is incident to the diffusion sheet 600, the spot sizes of the light beams incident to the diffusion sheet 600 are different, which is not conducive to the diffusion effect. In the embodiments of the present application, the focal length of the first microlens in the first microlens array 201 can be greater than the focal length of the first microlens in the second microlens array 202. The focal length of the first microlens in the second microlens array 202 can be greater than the focal length of the first microlens in the third microlens array 203. The focal length of the first microlens in the third microlens array 203 can be greater than the focal length of the first microlens in the fourth microlens array 204.

[0084] The laser light emitted by the first exit area with the longest optical path passes through the first microlens array with the largest focal length, and so on, so that the laser light emitted by the second exit area passes through the second microlens array, the laser light emitted by the third exit area passes through the third microlens array, and the laser light emitted by the fourth exit area with the shortest optical path passes through the fourth microlens array with the smallest focal length, thereby alleviating the problem of different spot sizes on the diffusion sheet caused by the optical path difference.

[0085] In some embodiments, as shown in FIGS. 11 and 12, the light homogenizing element 500 is a compound eye lens including a plurality of third microlenses arranged in an array. The microlens array formed by the third microlenses can have a homogenizing effect on the incident laser beam. Each laser chip emits laser light that forms a laser spot when incident on the microlens array. When one laser spot corresponds to a plurality of third microlenses, the third microlenses can split and homogenize the light spot to form multiple images at a set position, thereby achieving the homogenization effect of the laser.

[0086] Since the red laser, blue laser, and green laser emitted by the laser light source have a greater divergence degree as the optical path increases, in order to improve the beam utilization rate, the numerical aperture of the microlenses in the beam splitting element, the collimating lens group, and the light homogenizing element is limited in the embodiments of the present application. Specifically, the numerical aperture of the first microlens is smaller than that of the second microlens, and the numerical aperture of the second microlens is smaller than that of the third microlens.

[0087] In combination with FIGS. 11 and 12, the projection device further includes a focusing lens group 800 located between the light exit side of the light homogenizing element 500 and the light entrance side of the display element 400, for converging the incident laser beam.

[0088] For example, the focusing lens group 800 includes a first focusing lens 801 and a second focusing lens 802. The laser beam emitted by the light homogenizing element 500 changes the beam propagation direction by the first focusing lens 801, thereby performing the first convergence of the divergent laser beam. The laser beam emitted by the first focusing lens 801 reaches the second focusing lens 802, and the second focusing lens 802 performs the second convergence.

[0089] In some embodiments, as shown in FIGS. 14 and 15, the beam splitting element 200 is a diffractive optical element, and the imaging surface of the diffractive optical element is located on the light entrance surface of the display element.

[0090] The laser light source emits red, green and blue laser light as shown in FIG. 14. The diffractive optical element includes three diffraction regions, namely a first diffraction region 2021, a second diffraction region 2022 and a third diffraction region 2023. The first diffraction region 2021 corresponds to the first light exit region and the second light exit region, the second diffraction region 2022 corresponds to the third light exit region, and the third diffraction region 2023 corresponds to the fourth light exit region.

[0091] As shown in FIGS. 14 and 15, the red laser light emitted by the first light exit region 101 and the second light exit region 102 of the laser light source 100 passes through the first diffraction region 2021. The first diffraction region 2021 can split the incident red laser light into at least two sub-beams. The sub-beams formed by the red laser light emitted by the first light exit region 101 after passing through the first diffraction region 2021 are incident on the first light combination member 301 and are reflected by the first light combination member 301 to the transmission area of the second light combination member. The sub-beams formed by the red laser light emitted by the second light exit region 102 after passing through the first diffraction region 2021 are incident on the reflection area of the second light combination member 302. The transmission area and the reflection area of the second light combination member 302 combine the red laser light and emit it to the third light combination member 3021.

[0092] The blue laser light emitted by the third light exit region 103 passes through the second diffraction region 2022, which splits the laser beam emitted by the third light exit region 103 into at least two sub-beams along the first direction. The blue laser light passing through the second diffraction region 2022 enters the third light combination member 3031, which combines the blue laser light and the red laser light. The green laser light emitted by the fourth light exit region 104 passes through the third diffraction region 2023, which splits the laser beam emitted by the fourth light exit region 104 into at least two sub-beams along the first direction. The green laser light passing through the third diffraction region 2023 enters the fourth light combination member 3032, which combines the blue laser light, the green laser light and the red laser light. The laser beam formed by the laser light emitted by each diffraction region is a uniform light spot. Thus, the combined light beam emitted by the fourth light combination member 3032 is also a uniform light beam, which can be directly incident on the display element 400. The display element 400 converts the combined light beam into a light beam with image information.

[0093] Finally, as shown in FIGS. 11, 12 and 15, the projection device further includes a total reflection prism group 900 and a projection lens 1000. The total reflection prism group 900 is located between the light combination assembly 300 and the display element 400. The total reflection prism group 900 is used to reflect the light emitted by the light combination assembly to the display element 400 and transmit the light modulated by the display element 400 to the projection lens 1000. The addition of a light splitting prism in front of the projection lens can separate the illumination light beam and the imaging light beam to form a color image.

[0094] It should be noted that the laser of FIG. 11, FIG. 12 and FIG. 15 are all three-color laser light path for explaining the light combination. Single-color laser is also applicable, only need to replace the light path before the incident to the diffusion sheet into the form of FIG. 1.

[0095] In some embodiments, since the divergence of the red laser will be greater than the divergence of the green laser and the blue laser, in order to reduce the optical path of the red laser, the laser can also be turned to the structure as shown in FIG. 16, in order to distinguish from the elements of the above-mentioned embodiments, different labels are used, as shown in FIG. 16, the projection device comprises: a projection light source 1, a compound eye lens 2, a display element 3 and a projection lens 4. The projection light source 1 is used to emit projection light; the compound eye lens 2 is located on the light path of the projection light source 1, the display element 3 is located on the light path of the compound eye lens 2, and the projection lens 4 is located on the light path of the display element 3.

[0096] The working principle of the compound eye lens 2 is as follows: the compound eye lens 2 comprises two compound eye lens layers, each compound eye lens layer comprises a plurality of microlenses with the same shape, and the microlenses in the two compound eye lens layers are one-to-one corresponding. The incident light beam is divided into a plurality of sub-beams by the compound eye lens on the light entrance side. Since the microlenses on the light exit side are arranged on the focal plane of the corresponding microlenses on the light entrance side, the sub-beams can be collimated as parallel light exit by the corresponding microlenses on the light exit side. The shape of the sub-beam image is the same as that of the microlenses. The superposition of a plurality of sub-beams can form an imaging spot with better uniformity. The shape of the imaging spot is the same as that of each sub-beam. It can be seen that the shape of the microlenses in the compound eye lens 2 determines the shape of the imaging spot. The shape of the microlenses in the compound eye lens 2 is the same as the shape of the imaging spot of the light beam emitted by the compound eye lens 2.

[0097] The display element 3 is used to modulate the brightness of the incident light according to the image data of the image to be displayed, and forms a display image. The display element 3 does not change the shape of the incident light spot. The projection lens 4 images the display image formed by the display element to a certain distance to form a projection image. Ideally, the light emitted by the projection lens 4 should be the light emitted by the display element 3 for projection display, which is called effective light, and the light not used for projection display is called ineffective light, which needs to be avoided from being emitted from the projection lens 4. In order to intercept the ineffective light emitted by the display element 3, a diaphragm A is arranged in the projection lens 4.

[0098] The projection device in the embodiment of the present application is designed based on the Kohler illumination principle. The light beam emitted by the compound eye lens 2 is imaged at the diaphragm A. FIG. 17 is a schematic diagram of an imaging spot at the diaphragm provided by the embodiment of the present application, which exemplarily shows the shape of the diaphragm A and the imaging spot P at the diaphragm A when the shape of the microlenses in the compound eye lens 2 is rectangular.

[0099] In the embodiment of the present application, the shape of the diaphragm A is designed to be the same as the shape of the microlens in the compound eye lens 2. As shown in FIG. 17, when the shape of the microlens in the compound eye lens 2 is rectangular, the shape of the imaging spot P at the diaphragm A is also rectangular. The shape of the diaphragm A is designed to be rectangular. Therefore, the shape of the diaphragm A is the same as the shape of the imaging spot P at the diaphragm A.

[0100] In order to make the effect of the embodiment of the present application more intuitive and visible, a circular diaphragm A' is also shown by a dashed line in FIG. 17 as a contrast for illustration. As shown in FIG. 17, when the shape of the diaphragm A' is different from the shape of the microlens in the compound eye lens 2, in order to make the effective light emitted by the display element 3 pass through the diaphragm A' and be utilized, the circular diaphragm A' should at least circumscribe the rectangular imaging spot P. Therefore, there is an interval between the edge of the diaphragm A' and the edge of the imaging spot P. Then, the invalid light emitted by the display element 3 can pass through the diaphragm A' from the interval, be imaged by the projection lens 4, and affect the contrast of the projection image. The diaphragm A' with other shapes has the same reason.

[0101] It can be seen that, in the embodiment of the present application, the diaphragm A and the microlens in the compound eye lens 2 are designed to have the same shape. This facilitates matching the size of the diaphragm A with the size of the imaging spot P, eliminates the interval between the edge of the diaphragm A' and the edge of the imaging spot P, and thus makes the diaphragm A pass the effective light emitted by the display element 3 and intercept the invalid light emitted by the display element 3. This avoids the invalid light mixing with the effective light to form stray light emitted by the projection lens 4, and is beneficial to improving the contrast of the projection image.

[0102] In actual application, the microlens in the compound eye lens 2 and the diaphragm A can also have other shapes, for example, hexagonal, octagonal, or circular, and the like. The imaging spot P at the diaphragm A can also be matched with the shape and size of the diaphragm A in the same way, so as to pass the effective light and intercept the invalid light, and improve the contrast of the projection image.

[0103] Based on the above idea, the specific structure of the projection device is described as follows. As shown in FIG. 16, the projection device comprises, in sequence along the light path propagation direction, a projection light source 1, a light combining lens group 5, a light homogenizing component 6, a compound eye lens 2, an illumination lens group 7, a total reflection prism group 8, a display element 3, and a projection lens 4.

[0104] The projection light source 1 can adopt a laser light source to meet the demand of high brightness. For example, a small laser (Multi Chip Laser, MCL for short) can be adopted, but is not limited thereto. The MCL has the advantages of long service life, high brightness, and high power. In addition, the MCL occupies a small space, which meets the development trend and design requirement of miniaturization of the projection device.

[0105] In the embodiment of the present application, the projection light source 1 adopts a three-color MCL laser, and red laser chips R, green laser chips G and blue laser chips B are arranged in the MCL laser in an array, and are respectively used to emit red laser, green laser and blue laser.

[0106] FIG. 18 is a schematic diagram of a planar structure of the projection light source according to an embodiment of the present application.

[0107] As shown in FIG. 18, the projection light source 1 in the embodiment of the present application has 4 rows and 7 columns of laser chips, including 2 rows and 7 columns of red laser chips R, 1 row and 7 columns of green laser chips G, and 1 row and 7 columns of blue laser chips B, and each laser chip emits an elliptical light spot. In actual application, the projection light source 1 can also adopt other numbers of laser chips arranged in other arrangement manners, and the embodiment of the present application is only exemplary and does not limit the specific number and arrangement manner of the laser chips.

[0108] As shown in FIG. 16, the light exit side of the projection light source 1 is provided with a light combination lens set 5, which is used to combine the red laser, the green laser and the blue laser. The light combination lens set 5 can be composed of a reflecting mirror and a dichroic mirror, and in the embodiment of the present application, the light combination lens set 5 includes a first light combination mirror 51, a second light combination mirror 52 and a third light combination mirror 53.

[0109] The first light combination mirror 51 is located at the light exit side of the green laser chip G, and can adopt a reflecting mirror, which is used to reflect the green laser emitted by the green laser chip G to the second light combination mirror 52.

[0110] The second light combination mirror 52 is located at the intersection of the reflected light path of the first light combination mirror 51 and the light exit path of the blue laser chip B. The second light combination mirror 52 can adopt a dichroic mirror, which is used to transmit the green laser reflected by the first light combination mirror 51 and reflect the blue laser emitted by the blue laser chip B, so as to combine the blue laser and the green laser.

[0111] The third light combination mirror 53 is located at the intersection of the light exit path of the second light combination mirror 52 and the light exit path of the red laser chip R. The third light combination mirror 53 can adopt a dichroic mirror, which is used to transmit the blue laser and the green laser emitted by the second light combination mirror 52 and reflect the red laser emitted by the red laser chip R, so as to combine the blue laser, the green laser and the red laser.

[0112] The light combination optical path of the light combination lens group 5 can also be provided with a diffusion component 6 for homogenizing the light combination beam and improving laser speckle. The diffusion component 6 can be one or more of a static diffusion sheet, a vibrating diffusion wheel, or a rotating diffusion wheel, etc., to change the phase of the incident laser light, thereby destroying the coherence of the laser light and weakening the speckle effect. In actual applications, the number, type, and arrangement order of the diffusion component 6 in the projection device can be designed according to the needs, and the specific design of the diffusion component 6 is only exemplarily described in the embodiments of the present application.

[0113] As shown in FIG. 16, in the embodiments of the present application, the light exit side of the light combination lens group 5 is provided with a first diffusion sheet 61 and a second diffusion sheet 62 as diffusion components, the first diffusion sheet 61 is a static diffusion sheet, and the second diffusion sheet 62 is a vibrating diffusion sheet. The light combination beam emitted by the light combination lens group 5 is projected to the fly-eye lens 2 after passing through the first diffusion sheet 61 and the second diffusion sheet 62, so that the light combination spot projected onto the fly-eye lens 2 has better uniformity.

[0114] FIG. 19 is a schematic diagram of a light combination spot at a fly-eye lens according to an embodiment of the present application.

[0115] As shown in FIG. 19, the red laser spot, the green laser spot, and the blue laser spot projected onto the fly-eye lens 2 are all circular spots, and there is an overlap between the laser spots of different colors, and the overall shape of the light combination spot is approximately rectangular.

[0116] FIG. 20 is a structural schematic diagram of a fly-eye lens according to an embodiment of the present application.

[0117] As shown in FIG. 20, in the embodiments of the present application, the fly-eye lens 2 includes a base material 21, a first fly-eye lens layer 22, and a second fly-eye lens layer 23, and the first fly-eye lens layer 22 and the second fly-eye lens layer 23 are respectively located on the surfaces of the light entrance side and the light exit side of the base material 21. The two fly-eye lens layers are integrated into one, which is conducive to reducing the volume of the projection device and can also reduce the errors generated during assembly.

[0118] Referring to FIGS. 19 and 20, the first fly-eye lens layer 22 and the second fly-eye lens layer 23 each include a plurality of microlenses. For ease of description, the microlenses in the first fly-eye lens layer 22 are referred to as first microlenses 220, and the microlenses in the second fly-eye lens layer 23 are referred to as second microlenses 230. The first microlenses 220 and the second microlenses 230 are correspondingly arranged, and the second microlenses 230 are located on the focal plane of the corresponding first microlenses 220.

[0119] The light beam incident to the compound eye lens 2 can be divided into a plurality of sub-beams by the plurality of first microlenses 220 in the first compound eye lens layer 22, the uniformity of each sub-beam is better than that of the whole light beam, the sub-beams are converged to the center of the corresponding second microlens 230 by the first microlens 220, and the sub-beams can be collimated as parallel light beams by the second microlens 230, and the shape of the sub-beam formed by the sub-beams is the same as that of the second microlens 230. The light beam emitted by the second compound eye lens layer 23 is superimposed by the collimated sub-beams emitted by each second microlens 230, and the light spot formed by the imaging of the light beam is superimposed by a plurality of sub-beams, which can have better uniformity, and the shape of the imaging light spot is the same as that of each sub-beam.

[0120] It can be seen that the light beam emitted by the compound eye lens 2 has better uniformity than the incident light beam, the compound eye lens 2 has the effect of homogenizing the light beam, and at the same time, the compound eye lens 2 can reshape the emitted light spot to the same shape as the microlenses in the compound eye lens 2, so that the shape of the imaging light spot P at the diaphragm A is the same as that of the microlenses in the compound eye lens 2.

[0121] In actual application, a two-piece compound eye lens can also be used, including a first compound eye lens and a second compound eye lens, the first compound eye lens includes a plurality of first microlenses 220, and the second compound eye lens includes a plurality of second microlenses 230. The correspondence and working principle of the first microlenses 220 and the second microlenses 230 can be referred to the above description, which will not be repeated here. The first compound eye lens and the second compound eye lens can be separately arranged, that is, other optical components can be arranged between the two, for example, a diffusion component 6 and a lens can be arranged between the first compound eye lens 2 and the second compound eye lens 2.

[0122] The projection device can also include an illumination lens group 7 located on the optical path between the compound eye lens 2 and the display element 3, for converging or diverging the light beam emitted by the compound eye lens 2, so that the size of the light spot formed by the light beam projected to the display element 3 matches the size of the effective area of the display element 3, thereby fully utilizing the light. The number, spacing, and surface parameters such as curvature radius, optical power, and thickness of each illumination lens in the illumination lens group 7 can be designed according to product requirements, and the embodiments of the present application are not limited herein.

[0123] According to different projection technologies, different types of display elements 3 can be used in the projection device, such as a liquid crystal panel (LCD) or a digital micro device (DMD), etc. Embodiments of the present application can use a digital light processing (DLP) technology, and use a DMD as the display element 3, which has the advantages of high optical efficiency and small size.

[0124] The effective area of the DMD is arranged with thousands of reflective micro-mirrors, which can be driven by a rotating device below the micro-mirror and adjust the angle and direction at a very fast speed under the control of a control signal, and be deflected to an open or closed state. By controlling the deflection state and deflection time of each micro-mirror in the DMD, the brightness and contrast of the display image can be adjusted. The micro-mirror in the open state and the closed state can reflect the incident light to different directions, wherein the light reflected by the micro-mirror in the open state is used to form a display image, which is effective light and needs to be incident into the projection lens 4, and the light reflected by the micro-mirror in the closed state is invalid light and needs to be avoided from entering the projection lens 4.

[0125] As shown in FIG. 16, the projection device further includes a total reflection prism group 8, which is located between the display element 3 and the projection lens 4. The light can be totally reflected in the total reflection prism group 8, so that the optical path inside can be folded, a larger optical path can be achieved in a smaller space volume, which is beneficial to reduce the overall volume of the projection device and meet the design requirement of miniaturization.

[0126] FIG. 21 is a structural schematic diagram of a total reflection prism group provided by an embodiment of the present application.

[0127] The total reflection prism group 8 includes a first prism 81, a second prism 82 and a third prism 83 which are in contact with each other, wherein the first prism 81 includes an incident surface S1, a surface of the first prism 81 adjacent to the second prism 82 and the third prism 83 is a first total reflection interface S2, and a surface of the second prism 82 adjacent to the third prism 83 is a second total reflection interface S3.

[0128] FIG. 22 is a schematic diagram of the optical path of the effective light provided by an embodiment of the present application; and FIG. 23 is a schematic diagram of the optical path of the invalid light provided by an embodiment of the present application.

[0129] Referring to FIGS. 21-23, the light rays emitted by the fly-eye lens 2 first enter the first light-in surface S1 of the first prism 81 and are incident on the first total reflection interface S2, the incident angle of the light rays satisfying the total reflection condition, so the light rays can be totally reflected by the first total reflection interface S2 to the display element 3. The light rays reflected by the display element 3 are incident on the first total reflection interface S2 again, but the incident angle of the light rays no longer satisfies the total reflection condition, so the light rays are transmitted by the first total reflection interface S2 to the second total reflection interface S3.

[0130] Referring to FIGS. 21 and 22, the effective light rays emitted by the display element 3 are transmitted by the first total reflection interface S2 to the second total reflection interface S3, the incident angle of the light rays on the second total reflection interface S3 not satisfying the total reflection condition, so the effective light rays can be transmitted by the second total reflection interface S3 and enter the projection lens 4, and are imaged on the projection screen 9 by the projection lens 4.

[0131] Specifically, the third prism 83 includes a first light-out surface S4, the effective light rays transmitted by the second total reflection interface S3 enter the third prism 83 and are incident on the projection lens 4 through the first light-out surface S4. The light spot formed on the first light-out surface S4 by the effective light rays emitted by the display element 3 should fall within the range of the first light-out surface S4, so as to ensure that all the effective light rays can enter the projection lens 4 and be utilized, avoiding loss of the effective light rays.

[0132] Referring to FIGS. 21 and 23, the ineffective light rays emitted by the display element 3 are transmitted by the first total reflection interface S2 to the second total reflection interface S3, the incident angle of the light rays on the second total reflection interface S3 satisfying the total reflection condition, so the ineffective light rays can be totally reflected by the second total reflection interface S3. In this way, the effective light rays and the ineffective light rays can be separated by the second total reflection interface S3, avoiding the ineffective light rays affecting the imaging quality of the projection image.

[0133] Specifically, the second prism 82 includes a second light-out surface S5, the ineffective light rays reflected by the second total reflection interface S3 are emitted through the second light-out surface S5. The second light-out surface S5 and the first light-out surface S4 are arranged at a set angle, so the light rays emitted by the first light-out surface S4 and the second light-out surface S5 do not intersect, so as to ensure that the ineffective light rays will not mix with the effective light rays.

[0134] FIG. 24 is a structural schematic diagram of another projection device provided by an embodiment of the present application.

[0135] As shown in FIG. 24, in the embodiment of the present application, the projection device can further include a light receiver 10, the light receiver 10 being located on the light-out side of the second light-out surface S5. The light receiver 10 can receive the ineffective light rays totally reflected by the second total reflection interface S3, avoiding the ineffective light rays propagating inside the projection device and interfering with the light ray propagation in other optical components.

[0136] Referring to FIG. 23 and FIG. 24, in the total reflection prism group 8, the second light exit surface S5 is connected with the first total reflection interface S2. On the premise that the areas of the first total reflection interface S2 and the second total reflection interface S3 are large enough, the size of the second prism 82 can be appropriately reduced, so that the position where the second light exit surface S5 is connected with the first total reflection interface S2 has a spacing from the edge of the first total reflection interface S2, thereby providing a space for arranging the light receiver 10, improving the utilization rate of the internal space of the projection device, and being conducive to improving the integration of the projection device and further realizing miniaturization.

[0137] Referring to FIG. 21, the first light exit surface S4 is connected with the first total reflection interface S2 and the second total reflection interface S3 respectively. In order to ensure that the areas of the first total reflection interface S2 and the second total reflection interface S3 are large enough and avoid light loss, the position where the first light exit surface S4 is connected with the first total reflection interface S2 can coincide with the edge of the first total reflection interface S2, and the position where the first light exit surface S4 is connected with the second total reflection interface S3 can coincide with the edge of the second total reflection interface S3.

[0138] FIG. 25 is a structural schematic diagram of another projection device provided by an embodiment of the present application.

[0139] As shown in FIG. 25, in the embodiment of the present application, the total reflection prism group 8 can include a first prism 81 and a second prism 82. The surface of the first prism 81 adjacent to the second prism 82 is the first total reflection interface S2. The light emitted by the compound eye lens 2 is incident on the first total reflection interface S2, is totally reflected by the first total reflection interface S2 to the display element 3, is reflected by the display element 3 to the first total reflection interface S2, is transmitted by the first total reflection interface S2 and is incident in the projection lens 4, and is imaged on the projection screen 9 by the projection lens 4.

[0140] In the embodiment of the present application, even if part of the invalid light may be mixed into the valid light incident on the projection lens 4, the diaphragm A in the projection lens 4 can block the invalid light so that it cannot be emitted from the projection lens 4 to affect the quality of the projection image. The design of the diaphragm A can refer to the corresponding description of FIG. 16 and FIG. 17, which will not be repeated here. The structure of the total reflection prism group 8 in the embodiment of the present application is relatively simple, and the design difficulty and process difficulty are low, which can be applied to products with low cost requirements.

[0141] The projection device provided by the embodiment of the present application can be applied to a vehicle. Due to the small internal space of the vehicle and unstable air flow, the environmental temperature of the environment where the projection device is located changes greatly.

[0142] When the ambient temperature of the projection device is high, the heat dissipation component arranged in the projection device is more difficult to effectively dissipate the heat emitted by the laser, resulting in a high working temperature of the laser. Please refer to FIG. 26, which is a schematic view of the variation of the luminous power of a red light-emitting unit in a laser with temperature. After a certain fixed driving current is provided to the red light-emitting unit in the laser, as the working temperature of the laser gradually increases, the luminous power of the red light-emitting unit in the laser gradually decreases.

[0143] Therefore, when the working temperature of the laser is high, the luminous power of the red light-emitting unit in the laser for emitting red laser is low, resulting in that the laser can no longer provide stable three-color light, and further resulting in that the display effect of the projection picture projected through the projection lens in the projection device is poor.

[0144] Therefore, when the working temperature of the laser is high, the luminous power of the red light-emitting unit in the laser for emitting red laser is low, resulting in that the laser can no longer provide stable three-color light, and further resulting in that the display effect of the projection picture projected through the projection lens in the projection device is poor.

[0145] The laser light source 100 in the projection device 000 is configured to emit laser light towards the light combination component 300. The laser light emitted by the laser light source 100 can include first laser light s1 and second laser light s2. In a possible implementation, the first laser light s1 emitted by the laser 101 can be red laser light, and the second laser light s2 emitted by the laser 101 can include green laser light and blue laser light. The laser 101 can include a red laser chip for emitting red laser light, and a green laser chip for emitting green laser light and a blue laser chip for emitting blue laser light. The number of red laser chips can be multiple, and the multiple red laser chips can be arranged in a row; the number of green laser chips and blue laser chips can also be multiple, and the multiple green laser chips and the multiple blue laser chips can be arranged in a row. In this way, the red laser chips arranged in a row in the laser 101 can be used to emit the first laser light s1, and the green laser chips and the blue laser chips arranged in a row in the laser 101 can be used to emit the second laser light s2.

[0146] The LED light source 200 in the projection device 000 is used to emit LED light rays s3 towards the light combination assembly 300, and the color of the LED light rays s3 emitted by the LED light source 200 can be the same as the color of the first type of laser s1. For example, since the first type of laser s1 can be red laser, the color of the LED light rays s3 emitted by the LED light source 200 is also red. In this embodiment, the wavelength of the first type of laser s1 emitted by the laser light source 100 is different from the wavelength of the LED light rays s3 emitted by the LED light source 200. The first type of laser s1 emitted by the laser light source 100 and the LED light rays s3 emitted by the LED light source 200 are two types of light rays with the same color but different wavelengths. For example, the wavelength of the first type of laser s1 emitted by the laser light source 100 ranges from 635 nm to 651 nm; and the wavelength of the LED light rays s3 emitted by the LED light source 200 ranges from 609 nm to 625 nm.

[0147] In this application, the light emitting direction of the laser light source 100 in the projection device 000 intersects with the light emitting direction of the LED light source 200, but both the laser emitted by the laser light source 100 and the LED light rays s3 emitted by the LED light source 200 can be directed to the light combination assembly 300. The light combination assembly 300 can be used to combine the laser emitted by the laser light source 100 and the LED light rays s3 emitted by the LED light source 200, and the combined light beam can be guided to the optical engine device 400 by the light combination assembly 300.

[0148] It should be noted that, since the first type of laser s1 emitted by the laser light source 100 and the LED light rays s3 emitted by the LED light source 200 are two types of light rays with the same color but different wavelengths, after the light combination assembly 300 receives the first type of laser s1 emitted by the laser light source 100 and the LED light rays s3 emitted by the LED light source 200, the light combination assembly 300 can transmit one of the first type of laser s1 emitted by the laser light source 100 and the LED light rays s3 emitted by the LED light source 200, and reflect the other one of the first type of laser s1 emitted by the laser light source 100 and the LED light rays s3 emitted by the LED light source 200, so that the first type of laser s1 emitted by the laser light source 100 and the LED light rays s3 emitted by the LED light source 200 can be combined.

[0149] The optical engine device 400 in the projection device 000 is used to modulate the combined light beam to obtain an image light beam, and the image light beam can be guided to the projection lens 500 by the optical engine device 400.

[0150] The projection lens 500 in the projection device 000 can image the image light beam after receiving the image light beam, so that a corresponding projection picture can be transmitted.

[0151] In the embodiment of the present application, after the projection device 000 is applied in the vehicle, the color of the first laser s1 emitted by the laser light source 100 is red laser, so that in the case that the ambient temperature of the projection device 000 is high, the light emitting power of the laser chip for emitting the first laser s1 in the laser light source 100 is low, and the efficiency of the first laser s1 emitted by the laser light source 100 is low. The color of the LED light s3 emitted by the LED light source 200 in the projection device 000 is the same as that of the first laser s1 emitted by the laser light source 100, and the light emitting power of the LED light source 200 is less affected by the ambient temperature. Therefore, by setting the LED light source 200, the first laser s1 emitted by the laser light source 100 can be compensated, so that the cooperation of the laser light source 100 and the LED light source 200 can provide more stable three-color light source for the optical engine 400, and then the display effect of the projection picture transmitted by the projection lens 500 is better.

[0152] In the embodiment of the present application, the type of the light combination assembly 300 in the projection device 000 is various, and the embodiment of the present application is illustratively described by taking the following two optional implementation manners as examples:

[0153] The first optional implementation manner is shown in FIG. 28, the light combination assembly 300 can include the first light combination lens 301 and the second light combination lens 302 arranged in parallel. The first light combination lens 301 and the second light combination lens 302 can be arranged in the first direction X in sequence. Here, the LED light source 200 in the projection device 000 can be distributed on the side of the first light combination lens 301 away from the second light combination lens 302. Therefore, the second light combination lens 302, the first light combination lens 301 and the LED light source 200 can be arranged in the first direction X in sequence, and the optical axis of the LED light s3 emitted by the LED light source 200 can be parallel to the first direction X.

[0154] The laser light source 100 in the projection device 000 is used for emitting the first laser s1 towards the first light combination lens 301, and emitting the second laser s2 towards the second light combination lens 302.

[0155] In the present application, the first laser light s1 emitted by the laser light source 100 and the LED light s3 emitted by the LED light source 200 can both be directed to the first light-combining lens 301. Since the first laser light s1 emitted by the laser light source 100 and the LED light s3 emitted by the LED light source 200 are two light rays of the same color but different wavelengths. Therefore, the first light-combining lens 301 can be a lens that transmits one wavelength of light and reflects another wavelength of light. For example, the first light-combining lens 301 can be used to transmit the LED light s3 emitted by the LED light source 200 and reflect the first laser light s1 emitted by the laser light source 100. The LED light s3 emitted by the LED light source 200 can be combined with the first laser light s1 emitted by the laser light source 100, and the combined light can be directed to the second light-combining lens 302.

[0156] The second laser light s2 emitted by the laser light source 100 can also be directed to the second light-combining lens 302. Similarly, since the color of the second laser light s2 emitted by the laser light source 100 is different from the color of the first laser light s1, the wavelength of the second laser light s2 is necessarily different from the wavelength of the first laser light s1, and also different from the wavelength of the LED light s3 emitted by the LED light source 200. Therefore, the second light-combining lens 302 can also be a lens that transmits one wavelength of light and reflects another wavelength of light. For example, the second light-combining lens 302 can be used to reflect the second laser light s2 emitted by the laser light source 100 and transmit the first laser light s1 and the LED light s3 combined by the first light-combining lens 301.

[0157] In this case, the first laser light s1 emitted by the laser light source 100 and the LED light s3 emitted by the LED light source 200 can be combined by the first light-combining lens 301 and then directed to the second light-combining lens 302, so that the second light-combining lens 302 can combine the second laser light s2 emitted by the laser light source 200 and the first laser light s1 and the LED light s3 emitted by the first light-combining lens 301. In this way, it can be ensured that the light beam subsequently directed to the optical engine device 400 is a three-color light beam after combination.

[0158] In one possible implementation, as shown in FIG. 28, the arrangement direction of the laser light source 100 and the light-combining assembly 100 can be parallel to the second direction Y, which can be perpendicular to the first direction X. The optical axis of the laser light emitted by the laser light source 100 can be parallel to the second direction Y. Therefore, the optical axis of the laser light emitted by the laser light source 100 can be perpendicular to the optical axis of the LED light s3 emitted by the LED light source 200.

[0159] In this case, in order to ensure that the first laser s1 emitted by the laser light source 100 can be successfully combined with the LED light s3 emitted by the LED light source 200, it is required that the angle between the first laser s1 emitted by the laser light source 100 and the normal line of the first combining lens 301 is 45°. That is, the angle between the first combining lens 301 and the plane perpendicular to the optical axis of the LED light s3 is 45°.

[0160] In another possible implementation, as shown in FIG. 29, which is a structural schematic diagram of another projection device provided by the embodiment of the present application. The angle between the optical axis of the first laser s1 emitted by the laser light source 100 and the normal line of the first combining lens 301 is less than 45°. That is, the laser light source 100 can be incident on the first combining lens 301 in an inclined manner. That is, the optical axis of the laser emitted by the laser light source 100 and the second direction Y are not parallel to each other but intersect with each other.

[0161] In this case, in order to ensure that the first laser s1 emitted by the laser light source 100 can be successfully combined with the LED light s3 emitted by the LED light source 200, it is required that the angle between the first laser s1 emitted by the laser light source 100 and the normal line of the first combining lens 301 is 45°. That is, the angle between the first combining lens 301 and the plane perpendicular to the optical axis of the LED light s3 is 45°.

[0162] Thus, the angle between the first combining lens 301 and the plane perpendicular to the optical axis of the LED light s3 is also less than 45°. Since the LED light s3 emitted by the LED light source 200 forms a large spot area, when the angle between the first combining lens 301 and the plane perpendicular to the optical axis of the LED light s3 is less than 45°, the angle between the optical axis of the LED light s3 emitted by the LED light source 200 and the first combining lens 301 is also less than 45°. Compared with the scheme shown in FIG. 28, the spot size of the LED light s3 emitted by the LED light source 200 on the first combining lens 301 can be reduced. Therefore, without increasing the size of the first combining lens 301, the first combining lens 301 can receive as much LED light s3 as possible, and thus the first combining lens 301 can occupy less space in the projection device 000 while ensuring a high utilization rate of the LED light s3.

[0163] In the embodiment of the present application, since the first laser s1 is red laser, the red laser emitted by the laser 101 in the laser light source 100 belongs to P-polarized light, and the first light-combining lens 301 has poor reflection effect on P-polarized light, but has good reflection effect on S-polarized light. Therefore, in order to ensure that the first light-combining lens 301 can better reflect the first laser s1 towards the first light-combining lens 301, it is necessary to convert the polarization state of the red laser emitted by the laser 101.

[0164] For example, as shown in FIGS. 28 and 29, the laser 101 in the laser light source 100 can include a first light-emitting area 101a for emitting the first laser s1, and a second light-emitting area 101b for emitting the second laser s2. The laser light source 100 can further include a half-wave plate 102 covering the first light-emitting area 101a. Here, the first light-emitting area 101a includes a plurality of red laser chips for emitting red laser; the second light-emitting area 101b includes a plurality of green laser chips for emitting green laser and a plurality of blue laser chips for emitting blue laser.

[0165] In this case, even if the first laser s1 directly emitted by the first light-emitting area 101a in the laser 101 is P-polarized light, it can be ensured that the first laser s1 is converted into S-polarized light after passing through the half-wave plate 102. In this way, it can be ensured that the first laser s1 subsequently towards the first light-combining lens 301 is S-polarized light, so that the first light-combining lens 301 has good reflection effect on the first laser s1.

[0166] Optionally, as shown in FIGS. 28 and 29, the laser light source 100 can further include a diffusion sheet 106 located at the light-emitting side of the laser 101. The first laser s1 and the second laser s2 emitted by the laser 101 will pass through the diffusion sheet 106 and then be respectively emitted towards the first light-combining lens 301 and the second light-combining lens 302. Here, the diffusion sheet 106 can be rotated or vibrated during the light-emitting process of the laser 101, so as to achieve the effect of eliminating speckle.

[0167] The second optional implementation manner is shown in FIG. 30, which is a structural schematic diagram of still another projection device provided by the embodiment of the present application. The light-combining assembly 300 in the projection device 000 can include a third light-combining lens 303. The third light-combining lens 303 is used for transmitting the combined light beam of the first laser s1 and the second laser s2 emitted by the laser light source 100, and reflecting the LED light s3 emitted by the LED light source 200.

[0168] It should be noted that, since the first laser s1 emitted by the laser 101 in the laser light source 100 is incident on the third light combination lens 303, even if the first laser s1 is P-polarized light, the third light combination lens 303 can ensure good transmission effect of the first laser s1. Therefore, it is not necessary to arrange a half-wave plate on the light-emitting side of the first laser s1 in the laser light source 100, thereby effectively simplifying the structure of the laser light source 100.

[0169] In the embodiment of the present application, the first laser s1 and the second laser s2 emitted by the laser light source 100 in the projection device 000 can be combined first, and then incident on the third light combination lens 303. The third light combination lens 303 can be a lens that reflects light of one wavelength and transmits light of another wavelength. In this way, after the third light combination lens 303 transmits the combined first laser s1 and second laser s2 emitted by the laser light source 100 and reflects the LED light s3 emitted by the LED light source 200, the LED light s3 can be combined with the combined first laser s1 and second laser s2.

[0170] For example, the laser light source 100 can include a laser 101, a first lens 103, a second lens 104, and a first reflecting mirror 105.

[0171] The laser 101 can be used to emit the first laser s1 and the second laser s2. For example, the laser 101 in the laser light source 100 can include a first light-emitting region 101a and a second light-emitting region 101b. The first light-emitting region 101a is used to emit the first laser s1, and the second light-emitting region 101b is used to emit the second laser s2.

[0172] The first lens 103 in the laser light source 100 can be located on the emission side of the first laser s1. For example, the first lens 103 can cover each laser chip in the first light-emitting region 101a of the laser 101, so that the first laser s1 emitted by each laser chip can be incident on the first lens 103.

[0173] The second lens 104 in the laser light source 100 can be located on the emission side of the second laser s2. For example, the second lens 104 can cover each laser chip in the second light-emitting region 101b of the laser 101, so that the second laser s2 emitted by each laser chip can be incident on the second lens 104.

[0174] The second lens 104 can be arranged in parallel with the first lens 103, and the first reflecting mirror 105 can be located on the side of the first lens 103 away from the second lens 104.

[0175] The second mirror 104 is configured to reflect the second laser s2, and the first mirror 103 is configured to reflect the first laser s1 and transmit the second laser s2. In this way, the second laser s2 emitted by each second light emitting unit 101b in the laser 101 can be reflected by the second mirror 104 to the first mirror 103 after being emitted to the second mirror 104, the first mirror 103 can reflect the first laser s1 after being emitted to the first mirror 103, and the first mirror 103 can also transmit the second laser s2 reflected by the second mirror 104. The first laser s1 reflected by the first mirror 103 and the second laser s2 transmitted by the first mirror 103 can be combined, and the combined light beams can be emitted to the first mirror 105, so that the first mirror 105 can reflect the combined first laser s1 and second laser s2 emitted by the first mirror 103 to the third combining mirror 303.

[0176] In a possible implementation, as shown in FIG. 30, the arrangement direction of the first mirror 103, the second mirror 104, and the first mirror 105 in the laser light source 100 can be parallel to the second direction Y, which can be perpendicular to the first direction X. That is, the optical axis of the combined first laser s1 and second laser s2 emitted by the laser light source 100 can be parallel to the second direction Y after being combined by the first mirror 103 and the second mirror 105. The arrangement direction of the LED light source 200 and the third combining mirror 303 can also be parallel to the second direction Y, that is, the optical axis of the LED light s3 emitted by the LED light source 200 can also be parallel to the second direction Y.

[0177] In this case, in order to ensure that the combined first laser s1 and second laser s2 emitted by the laser light source 100 and the LED light s3 emitted by the LED light source 200 can be successfully combined in the first direction X, it is necessary to ensure that the angle between the LED light s3 emitted to the third combining mirror 301 and the normal line of the third combining mirror 301 is 45°. That is, the angle between the third combining mirror 303 and the plane perpendicular to the optical axis of the LED light s3 is 45°.

[0178] In another possible implementation, as shown in FIG. 31, which is a structural schematic diagram of a projection device provided by another embodiment of the present application, the angle between the optical axis of the LED light s3 emitted by the LED light source 200 and the normal line of the third combining mirror 303 can be less than 45°. That is, the LED light source 200 can emit the LED light s3 to the third combining mirror 303 in an inclined manner. That is, the optical axis of the LED light s3 emitted by the LED light source 200 is not parallel to the second direction Y, but intersects with the second direction Y.

[0179] In this case, since the light spot area formed by the LED light rays s3 emitted by the LED light source 200 is large, when the included angle between the optical axis of the LED light rays s3 emitted by the LED light source 200 and the normal line of the third light combination lens 303 is less than 45°, the light spot size of the LED light rays s3 emitted by the LED light source 200 on the third light combination lens 301 can be reduced relative to the scheme shown in FIG. 30. Therefore, without increasing the size of the third light combination lens 301, the third light combination lens 303 can receive as much LED light rays s3 as possible, and the occupied space of the third light combination lens 303 in the projection device 000 can be reduced under the premise of ensuring high utilization of the LED light rays s3.

[0180] It should be noted that since the LED light rays s3 reflected by the third light combination lens 303 need to be parallel to the first direction X, the included angle between the third light combination lens 303 and the plane perpendicular to the first direction X needs to be equal to the included angle between the optical axis of the LED light rays s3 emitted by the LED light source 200 and the normal line of the third light combination lens 303.

[0181] Here, in order to ensure that the third light combination lens 303 can better combine the LED light rays s3 and the combined first laser s1 and second laser s2 emitted by the laser light source 100, the first reflecting mirror 105 and the third light combination lens 303 need to be arranged in parallel. Therefore, the included angle between the first reflecting mirror 105 and the plane perpendicular to the first direction X is also equal to the included angle between the optical axis of the LED light rays s3 emitted by the LED light source 200 and the normal line of the third light combination lens 303. In this way, the included angle between the optical axis of the combined first laser s1 and second laser s2 incident on the first reflecting mirror 105 and the normal line of the first reflecting mirror 105 also needs to be equal to the included angle between the optical axis of the LED light rays s3 emitted by the LED light source 200 and the normal line of the third light combination lens 303. That is, the optical axis of the combined first laser s1 and second laser s2 of the first reflecting mirror 105 is parallel to the optical axis of the LED light rays s3 incident on the third light combination lens 303. Therefore, the optical axis of the LED light rays s3 emitted by the LED light source 200 needs to be parallel to the arrangement direction of the first lens 103 and the second lens 104 in the laser light source 100.

[0182] Optionally, as shown in FIG. 30 and FIG. 31, the laser light source 100 can further include a diffusion sheet 106 between the first mirror 105 and the third light-combining lens 303. The first type of laser light s1 and the second type of laser light s2 after being reflected by the first mirror 105 can be emitted to the third light-combining lens 303 after passing through the diffusion sheet 106. Here, the diffusion sheet 106 can be rotated or vibrated during the light emission of the laser 101, so as to achieve the effect of eliminating speckle. It should be noted that, since the first mirror 105 and the third light-combining lens 303 are distributed in the first direction X, and the space between the first mirror 105 and the third light-combining lens 303 is relatively large relative to the space near the light emission side of the laser 101. Therefore, after the diffusion sheet 106 is placed between the first mirror 105 and the third light-combining lens 303, the placement of the diffusion sheet 106 can be more favorable.

[0183] In the embodiments of the present application, as shown in FIG. 28, FIG. 29, FIG. 30 and FIG. 31, the projection device 000 can further include a light homogenizing assembly 600 located at the light emission side of the light-combining assembly 300, and a second mirror 700 located between the light homogenizing assembly 600 and the optical engine 400. Here, the LED light s3 emitted by the LED light source 200 and the laser light after being combined by the light-combining assembly 300 can be emitted to the light homogenizing assembly 600. The light homogenizing assembly 600 can perform light homogenizing processing on the combined LED light s3 and laser light, and then emit the light to the second mirror 700. The second mirror can reflect the light homogenized by the light homogenizing assembly 600 to the optical engine 400.

[0184] For example, the light homogenizing assembly 600 can include one or more compound eye lenses, which can also include light pipes. The embodiments of the present application do not limit this.

[0185] Optionally, as shown in FIG. 28, FIG. 29, FIG. 30 and FIG. 31, the projection device 000 can further include a first converging lens 801 located between the light homogenizing assembly 600 and the second mirror 700, and a second converging lens 802 located between the second mirror 700 and the optical engine 600. Here, the first converging lens 801 is used to perform first converging on the light homogenized by the light homogenizing assembly 600, so that the light after the first converging can be better emitted to the second mirror 700; the second converging lens 802 is used to perform second converging on the light reflected by the second mirror 700, so that the light after the second converging can be better emitted to the optical engine 600.

[0186] In the present application, as shown in FIG. 28, FIG. 29, FIG. 30 and FIG. 31, the LED light source 200 in the projection device 000 can include: an LED light emitting unit 201, and a collimating lens group 202 located at the light emitting side of the LED light emitting unit 201. Here, the LED light rays s3 emitted by the LED light emitting unit 201 are divergent light rays, which can be converted into collimated light rays after passing through the collimating lens group 202, so as to ensure that the LED light rays s3 emitted by the LED light source 200 are collimated light rays, so that they can be better combined with the laser light emitted by the laser light source 100 subsequently.

[0187] In the embodiment of the present application, the laser 101 in the laser light source 100 emits the first type of laser and the second type of laser, and the light spots formed by the laser 101 in the plane parallel to the light emitting surface of the laser 101 can refer to FIG. 32. As shown in FIG. 32, the first type of laser emitted by the first light emitting area in the laser 101 can form a row of red light spots R in this plane; the second type of laser emitted by the second light emitting area in the laser 101 can form another row of light spots in this plane, part of the light spots in this row of light spots are green light spots G, and the other part of the light spots are blue light spots B. In this row of light spots, two blue light spots B can be continuously distributed on one side, and three green light spots G can be continuously distributed on the other side.

[0188] In order to ensure that the green laser and the blue laser in the second type of laser emitted by the laser 100 can be better combined, it is necessary to convert the distribution position of the two blue light spots B. For example, as shown in FIG. 28, FIG. 29, FIG. 30 and FIG. 21, the laser light source 100 in the projection device 000 can include: a third lens 107 and a fourth lens 108 distributed at the light emitting side of the laser 101. The cooperation of the third lens 107 and the fourth lens 108 can convert the distribution position of the two blue light spots B. Wherein, the laser 101 in the laser light source 100 emits the first type of laser and the second type of laser, and the light spots formed by the laser 101 in the plane parallel to the light emitting surface of the laser 101 after passing through the third lens 107 and the fourth lens 108 can refer to FIG. 33, and through the cooperation of the third lens 107 and the fourth lens 108, the blue light spot B distributed at the leftmost side in FIG. 32 can be converted to the right side of the three green light spots G. That is, the three green light spots G can be distributed between the two blue light spots B.

[0189] In this case, the light spots of the first type of laser (i.e., red laser) and the second type of laser (i.e., green laser and blue laser) after being combined can be formed on the light homogenizing assembly 600, which can be referred to FIG. 34. As shown in FIG. 34, after the first type of laser and the second type of laser are combined, four red light spots R, three green light spots G, and two blue light spots B can be uniformly arranged in the transverse direction, thereby ensuring that the light combination effect of the first type of laser and the second type of laser is good.

[0190] In the embodiments of the present application, as shown in FIGS. 28, 29, 30, and 31, the light engine device 400 in the projection device 000 can include a total reflection prism group 401. The total reflection prism group 401 generally includes two connected three prisms. The light engine device 400 in the projection device 000 can generally further include a display element 402.

[0191] The combined light beam reflected by the second mirror 700 can be incident on the total reflection prism group 401, which can reflect the combined light beam to the display element 402. The display element 402 can modulate the combined light beam into an image light beam, and the image light beam can be reflected to the total reflection prism group 401 again. The image light beam 401 can be transmitted through the total reflection prism group 401 and then be incident on the projection lens 500. The projection lens 500 can image the image light beam and then transmit the corresponding projection image.

[0192] In the present application, as shown in FIG. 35, FIG. 35 is a structural schematic diagram of another projection device provided by another embodiment of the present application. In the light path between the light combination assembly 300 and the total reflection prism group 401, the optical axis of the LED light ray s3 emitted from the LED light source 200 does not coincide with the optical axis of the first type of laser s1 emitted from the laser light source 100.

[0193] The optical axis of the LED light ray s3 emitted from the LED light source 200 can coincide with the optical axis of the light path between the light combination assembly 300 and the total reflection prism group 401; and the optical axis of the first type of laser s1 emitted from the laser light source 100 can be offset outward relative to the optical axis of the light path between the light combination assembly 300 and the total reflection prism group 401.

[0194] In this case, since the first laser s1 emitted by the laser light source 100 is red laser light with a wavelength range of 635 nm to 651 nm, and the LED light s3 emitted by the LED light source 200 is red LED light s3 with a wavelength range of 609 nm to 625 nm, the refractive index of the red laser light with a larger wavelength in the total reflection prism group 401 is smaller than the refractive index of the red LED light s3 with a smaller wavelength in the total reflection prism group 401. Therefore, in order to ensure that the red laser light with a larger wavelength in the total reflection prism group 401 occurs total internal reflection in the total reflection prism group 401, the optical axis of the first laser s1 emitted from the laser light source 100 needs to be offset outward relative to the optical axis of the light path between the light combination assembly 300 and the total reflection prism group 401, so that the incidence angle of the red laser light with a larger wavelength to the total reflection prism group 401 can be increased, and thus the total reflection prism group 401 can more easily occur total internal reflection inside the total reflection prism group 401 without changing the size of the total reflection prism group 401.

[0195] It should be noted that, in order to ensure that the first laser s1 and the second laser s2 emitted from the laser light source 100 can be better combined in the light path between the light combination assembly 300 and the total reflection prism group 401, the optical axis of the first laser s1 emitted from the laser light source 100 and the optical axis of the second laser s2 emitted from the laser light source 100 need to coincide in the light path between the light combination assembly 300 and the total reflection prism group 401.

[0196] In the embodiment of the present application, as shown in FIG. 36, FIG. 36 is a structural block diagram of a projection device provided by another embodiment of the present application. The projection device 100 can further include a control assembly 900. The control assembly 900 can be electrically connected with the laser 101 in the laser light source 100 and electrically connected with the LED light emitting unit 201 in the LED light source 200.

[0197] Here, the control assembly 900 can be configured to: after obtaining that the environment temperature of the environment where the projection device 000 is located is in a first temperature range, control the driving current of the first light emitting area 101a for emitting the first laser in the laser 101 to be a first current, and control the driving current of the LED light emitting unit 201 to be a second current; after obtaining that the environment temperature of the environment where the projection device 000 is located is in a second temperature range, control the driving current of the first light emitting area 101a for emitting the first laser in the laser 101 to be a third current, and control the driving current of the LED light emitting unit 201 to be a fourth current. Wherein, the maximum temperature in the first temperature range is less than the minimum temperature in the second temperature range, and the third current is less than the first current, and the fourth current is greater than the second current.

[0198] That is, in the case that the ambient temperature of the environment where the projection device 000 is located is detected to be high, the drive current for driving the first light emitting region 101a in the laser 101 to emit light can be reduced, so that the power consumption of the laser 101 can be reduced, and the drive current for driving the LED light emitting unit 201 to emit light can be increased, so that the red laser light emitted by the laser 101 can be compensated by the red LED light emitted by the LED light emitting unit 201.

[0199] In the embodiment of the present application, please refer to FIG. 37, which is a curve diagram of the drive current applied by the control component to the first light emitting region in the laser and the LED light emitting unit at different ambient temperatures. In FIG. 37, the horizontal coordinate represents the ambient temperature of the environment where the projection device 000 is located; the vertical coordinate represents the percentage of the drive current applied by the control component 900 to the maximum constant current. Here, curve a in FIG. 37 represents the percentage of the drive current applied by the control component 900 to the first light emitting region 101a in the laser 101 to the maximum constant current of the first light emitting region 101a, and the change curve of the ambient temperature of the environment where the projection device 000 is located; curve b in FIG. 37 represents the percentage of the drive current applied by the control component 900 to the LED light emitting unit 201 to the maximum constant current of the LED light emitting unit 201, and the change curve of the ambient temperature of the environment where the projection device 000 is located.

[0200] According to FIG. 37, the lower the ambient temperature of the environment where the projection device 000 is located, the greater the drive current applied by the control component 900 to the first light emitting region 101a in the laser 101, and the smaller the drive current applied by the control component 900 to the LED light emitting unit 201; on the contrary, the higher the ambient temperature of the environment where the projection device 000 is located, the smaller the drive current applied by the control component 900 to the first light emitting region 101a in the laser 101, and the greater the drive current applied by the control component 900 to the LED light emitting unit 201.

[0201] Optionally, as shown in FIG. 36, the projection device 000 can further include a first temperature sensor 1000 fixed at the shell of the projection device 000. The first temperature sensor 1000 can be electrically connected with the control component 900, and the first temperature sensor 1000 can be used to acquire the ambient temperature of the environment where the projection device 000 is located, and after acquiring the ambient temperature, the temperature information representing the ambient temperature can be sent to the control component 900, so that the control component 900 can acquire the ambient temperature of the environment where the projection device 000 is located through the first temperature sensor 1000.

[0202] In the embodiments of the present application, as shown in FIG. 36, the projection device 000 can further include a heat dissipation assembly 1100, which can be connected with the control assembly 900. The heat dissipation assembly 1100 can be used at least for dissipating heat of the laser 101. In other possible implementation manners, the heat dissipation assembly 1100 can also be used for dissipating heat of the key devices in the projection device 000, such as the LED light unit 201 and the display element 401.

[0203] The control assembly 900 can be further configured to: after obtaining the environment temperature of the environment where the projection device 000 is located and determining that the environment temperature is less than or equal to a preset temperature threshold, control the heat dissipation power of the heat dissipation assembly 1100 to be a target heat dissipation power, the target heat dissipation power being negatively correlated with the working temperature of the laser 201; and after obtaining the environment temperature of the environment where the projection device 000 is located and determining that the environment temperature is greater than the preset temperature threshold, lower the driving current of the first light emitting area 101a and increase the driving current of the LED light unit 201.

[0204] For example, the laser light source 100 can further include a second temperature sensor 109 arranged at the position of the laser 101. The second temperature sensor 109 can be electrically connected with the control assembly 900, and can be used to obtain the working temperature of the laser 101. After obtaining the working temperature of the laser 101, the second temperature sensor 109 can send temperature information representing the working temperature to the control assembly 900, so that the control assembly 900 can obtain the working temperature of the laser 101 through the second temperature sensor 109. In this way, the control assembly 900 can control the heat dissipation power of the heat dissipation assembly 1100 according to the working temperature of the laser 101, so that the heat dissipation power can be negatively correlated with the working temperature of the laser 201. That is, in the case that the environment temperature of the environment where the projection device 000 is located is less than or equal to a preset temperature threshold, the higher the working temperature of the laser 101 is, the higher the heat dissipation power of the heat dissipation assembly 1100 is, so as to improve the heat dissipation efficiency of the laser 101 and ensure that the working temperature of the laser 101 is low in general.

[0205] In a possible implementation manner, as shown in FIG. 36, the heat dissipation assembly 1100 can include a heat sink body (not shown in the figure) based on the laser 101, and a heat dissipation fan 1101 used for dissipating heat of the heat sink body. The heat dissipation fan 1101 can be electrically connected with the control assembly 900. The heat dissipation power of the heat dissipation assembly 1100 can be represented by the rotating speed of the heat dissipation fan 1101. That is, the higher the heat dissipation power of the heat dissipation assembly 1100 is, the higher the rotating speed of the heat dissipation fan 1101 is.

[0206] To this end, in the embodiments of the present application, in the case that the ambient temperature of the environment where the projection device 000 is located is less than or equal to the preset temperature threshold (i.e., the ambient temperature of the environment where the projection device 000 is located is relatively low), the overall working temperature of the laser 101 can be relatively low by controlling the heat dissipation power of the heat dissipation assembly 1100, so as to ensure that the light emitting efficiency of the red laser emitted by the laser 101 is relatively high.

[0207] In the case that the ambient temperature of the environment where the projection device 000 is located is greater than the preset temperature threshold (i.e., the ambient temperature of the environment where the projection device 000 is located is relatively high), it is difficult for the heat dissipation assembly 1100 to effectively dissipate the heat emitted by the laser 101, resulting in that the working temperature of the laser 101 is relatively high, and further resulting in that the power of the red laser emitted by the laser 101 decreases obviously. In this case, the driving current for driving the first light emitting region 101a in the laser 101 to emit light can be reduced, so as to reduce the power consumption of the laser 101, and the driving current for driving the LED light emitting unit 201 to emit light can be increased, so that the proportion of the red LED light emitted by the LED light emitting unit 201 is relatively high, and thus the red laser emitted by the laser 101 can be compensated by the red LED light emitted by the LED light emitting unit 201.

[0208] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A projection device, comprising: a laser light source configured to emit laser light; the laser light source comprising a plurality of light emitting areas arranged in a first direction in sequence; the first direction being parallel to a fast axis direction of the laser light emitted by the laser light source; a beam splitting element located on a light emitting side of the laser light source and configured to split the laser light emitted by each of the light emitting areas into at least two sub-beams in the first direction; a light combining assembly located on a light emitting side of the beam splitting element and configured to combine the sub-beams formed by the beam splitting element.

2. The projection apparatus of claim 1, wherein, the at least two light emitting areas emit laser light of the same color; the first direction is parallel to a fast axis direction of the laser light emitted by the laser light source; the light combining assembly comprises: a first light combining element corresponding to one of the light emitting areas emitting laser light of the same color; at least one second light combining element corresponding to the other light emitting areas; the second light combining element comprising alternating reflection regions and transmission regions; the number of the reflection regions and the transmission regions is equal, and the number of the reflection regions is equal to the number of the sub-beams formed by the beam splitting element; the first light combining element reflects the sub-beams formed by the laser light emitted by the corresponding light emitting area via the beam splitting element to the transmission regions of the second light combining element respectively; the second light combining element emits the sub-beams formed by the laser light emitted by the corresponding light emitting area via the beam splitting element to the reflection regions of the second light combining element respectively.

3. The projection apparatus according to claim 1 or 2, wherein, the beam splitting element comprises a plurality of first microlenses arranged in an array in the first direction and the second direction; the plurality of first microlenses are arranged into microlens rows in the second direction, and the plurality of microlens rows are arranged in sequence in the first direction; the first direction and the second direction intersect; the plurality of first microlenses form a plurality of microlens arrays; the microlens arrays correspond to the light emitting areas one by one; each microlens array comprises at least two microlens rows, and the number of the microlens rows comprised by each microlens array is the same. 4.The projection device of claim 3, further comprising: a collimating element located on a light emitting side of the light combining assembly; a diffusion sheet located between a light emitting side of the light combining assembly and a light entering side of the collimating element; wherein the collimating element comprises a plurality of second microlenses arranged in an array; each of the first microlenses and each of the second microlenses are arranged one by one; the diffusion sheet is located at an image side focal point of the beam splitting element, and the diffusion sheet is located at an object side focal point of the collimating element. 5.The projection device of claim 4, further comprising: a light homogenizing element located on a light emitting side of the collimating element; the light homogenizing element is configured to homogenize the laser light; 6. The projection apparatus of claim 5, wherein, the light homogenizing element is a compound eye lens, and the compound eye lens comprises a plurality of third microlenses arranged in an array; a numerical aperture of the first microlenses is smaller than a numerical aperture of the second microlenses, and the numerical aperture of the second microlenses is smaller than a numerical aperture of the third microlenses. 7.The projection device of claim 5 or 6, further comprising: A focusing lens group is located between the light-exiting side of the light homogenizing element and the light-entering side of the display element, and is used for converging the incident laser beam.

8. The projection apparatus as claimed in claim 1 or 2, wherein, The light beam splitting element is a diffractive optical element, and an imaging surface of the diffractive optical element is located on the light-entering surface of the display element.

9. The projection apparatus according to any of claims 2 to 8, wherein, The plurality of light-exiting regions include a first light-exiting region, a second light-exiting region, a third light-exiting region, and a fourth light-exiting region; the first light-exiting region and the second light-exiting region are both used for exiting red laser light, the third light-exiting region is used for exiting blue laser light, and the fourth light-exiting region is used for exiting green laser light. The light combining assembly further includes a light combining mirror group, which is used for combining the laser light exited by the first light-exiting region and the second light-exiting region with the laser light exited by the third light-exiting region and the fourth light-exiting region. The center of the blue laser light and the center of the green laser light exited by the light combining mirror group are both located between the center of the laser light beam exited by the first light combining element and the center of the laser light beam exited by the second light combining element.

10. The projection apparatus of claim 9, wherein, The diffractive optical element includes three diffractive regions, i.e., a first diffractive region, a second diffractive region, and a third diffractive region; the first diffractive region corresponds to the first light-exiting region and the second light-exiting region, the second diffractive region corresponds to the third light-exiting region, and the third diffractive region corresponds to the fourth light-exiting region.

11. The projection device according to any one of claims 6-10, further comprising: an illumination lens group located on the light-exiting side of the light combining assembly; a display element located on the light-exiting side of the illumination lens group, and used for modulating the incident laser beam to form a display image according to driving data of the image to be displayed; a projection lens located on the light path of the display element, and used for projecting and imaging the light beam exited by the display element.

12. The projection apparatus of claim 11, wherein, The light homogenizing element is a compound eye lens, and the compound eye lens includes a plurality of third microlenses with the same shape. The projection lens includes a diaphragm, and the shape of the diaphragm is the same as the shape of the third microlenses in the compound eye lens.

13. The projection apparatus of claim 12, wherein, The shape of the third microlenses and the diaphragm is rectangular.

14. The projection device according to claim 12, further comprising: a total reflection prism group located between the display element and the projection lens; the total reflection prism group includes a first prism, a second prism, and a third prism in contact with each other; the first prism includes a light-entering surface, a surface of the first prism adjacent to the second prism and the third prism is a first total reflection interface, and a surface of the second prism adjacent to the third prism is a second total reflection interface. The light rays emitted by the fly-eye lens are incident to the first total reflection interface from the light-incident surface of the first prism, are totally reflected by the first total reflection interface to the display element, the light rays emitted by the display element include effective light rays and ineffective light rays, the effective light rays are used for projection display, the effective light rays emitted by the display element are transmitted to the second total reflection interface from the first total reflection interface, are transmitted by the second total reflection interface and are incident to the projection lens, and the ineffective light rays emitted by the display element are totally reflected by the second total reflection interface from the first total reflection interface.

15. The projection apparatus of claim 14, wherein, The third prism includes a first light-incident surface, the effective light rays transmitted by the second total reflection interface are incident to the projection lens from the first light-incident surface, and the light spot formed by the effective light rays emitted by the display element on the first light-incident surface falls within the range of the first light-incident surface.

16. The projection apparatus according to claim 14 or 15, wherein, The second prism includes a second light-incident surface, the ineffective light rays reflected by the second total reflection interface are emitted from the second light-incident surface; The second light-incident surface and the first light-incident surface are arranged at a set angle, and the light rays emitted by the first light-incident surface and the second light-incident surface do not intersect.

17. The projection apparatus of claim 16, wherein, The second light-incident surface is connected to the first total reflection interface, and the position where the second light-incident surface is connected to the first total reflection interface is spaced from the edge of the first total reflection interface. The projection device further includes a light receiver, and the light receiver is located on the light-emitting side of the second light-incident surface.

18. The projection apparatus according to any one of claims 15 to 17, wherein, The first light-incident surface is connected to the first total reflection interface and the second total reflection interface, the position where the first light-incident surface is connected to the first total reflection interface coincides with the edge of the first total reflection interface, and the position where the first light-incident surface is connected to the second total reflection interface coincides with the edge of the second total reflection interface.

19. The projection device of claim 12, further comprising: a total reflection prism group, the total reflection prism group including a first prism and a second prism, and a surface of the first prism adjacent to the second prism being a first total reflection interface; the light rays emitted by the fly-eye lens are incident to the first total reflection interface, are totally reflected by the first total reflection interface to the display element, are reflected by the display element to the first total reflection interface, are transmitted by the first total reflection interface and are incident to the projection lens.

20. The projection apparatus of any of claims 12-19, wherein, The fly-eye lens includes a base material, a first fly-eye lens layer and a second fly-eye lens layer, and the first fly-eye lens layer and the second fly-eye lens layer are respectively located on the surfaces of the light-incident side and the light-emitting side of the base material.

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