Laser projection equipment

Abstract

The embodiment of the invention belongs to the laser display technology, and provides laser projection equipment, which comprises a laser light source, which comprises a plurality of laser arrays, each laser array comprises a plurality of lasers, and the plurality of lasers emit lasers with the same color; the light combining assembly is located on the light emitting side of the laser light source and used for combining laser emitted by the multiple laser arrays; the phase modulation element comprises a plurality of first target areas, the first target areas are used for changing the phases of the target light beams, and different first target areas change different phases of the target light beams; wherein the lasers with the same color in the target light beam cover the multiple first target areas, and the target light beam comprises lasers emitted by at least one of the multiple laser arrays and the light combining assembly. The laser of the same color in the target light beam is changed into the multi-phase light beam after being emitted through the multiple first target areas, so that the speckle phenomenon is effectively reduced, and the display effect of a projection picture is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to laser display technology, and more specifically, to a laser projection device. Background Art

[0002] In recent years, laser projection has been widely used, and users' pursuit of picture color has continued to increase, and high-definition and high-color gamut laser projection has begun to be used.

[0003] In some related technologies, a three-color laser light source can be used as a projection light source in high-quality and high-color gamut laser projection. The three-color laser light source includes a laser that can emit red (R), green (G), and blue (B) lasers.

[0004] However, since the phases of red laser, green laser and blue laser are relatively single and have high coherence, speckle phenomenon occurs, which affects the display effect of the projection image. Summary of the Invention

[0005] The embodiments of the present application provide a laser projection device that can be used to solve the problem in the related art that the phases of red laser, green laser and blue laser are relatively single and have high coherence, thereby generating speckle phenomenon and affecting the display effect of the projected image.

[0006] In a first aspect, an embodiment of the present application provides a laser projection device, comprising:

[0007] A laser light source, comprising a plurality of laser arrays, wherein the laser arrays include a plurality of lasers, and the plurality of lasers emit laser light of the same color;

[0008] A light combining component, located on the light-emitting side of the laser light source, for combining the laser beams emitted by multiple laser arrays;

[0009] A phase modulation element includes a plurality of first target areas, wherein the first target areas are used to change the phase of the target light beam, and different first target areas change the phase of the target light beam differently;

[0010] The lasers of the same color in the target light beam cover a plurality of first target areas, and the target light beam includes lasers emitted by at least one of a plurality of laser arrays and a light combining component.

[0011] In some embodiments of the present application, the phase modulation element is a wave plate or a liquid crystal element.

[0012] In some embodiments of the present application, the multiple laser arrays include a first laser array, a second laser array, and a third laser array; the light combining assembly includes: a reflector, a first light combining mirror, and a second light combining mirror, wherein the reflector is located on the light output side of the first laser array and is used to reflect the laser light emitted by the first laser array;

[0013] The first light combining mirror is located on the light-emitting side of the second laser array and includes: a first surface and a second surface opposite to the first surface; the first surface is a surface close to the reflector, and is used to transmit the laser light emitted by the first laser array and reflect the laser light emitted by the second laser array;

[0014] The second light combining mirror is located on the light-emitting side of the third laser array, and includes: a third surface and a fourth surface opposite to the third surface; the third surface is a surface close to the second surface, and is used to transmit the lasers emitted by the first laser array and the second laser array, and reflect the lasers emitted by the third laser array;

[0015] The second surface includes multiple second target areas, the lasers emitted by the first laser array and the second laser array cover the multiple second target areas, the second target areas are used to change the phases of the lasers emitted by the first laser array and the second laser array, and different second target areas have different phase changes in the lasers, and / or, the fourth surface includes multiple third target areas, the lasers emitted by the first laser array, the second laser array, and the third laser array cover multiple third target areas, the third target areas are used to change the phases of the lasers emitted by the first laser array, the second laser array, and the third laser array, and different third target areas have different phase changes in the lasers.

[0016] In some embodiments of the present application, the first light combining mirror and / or the second light combining mirror is a liquid crystal element.

[0017] In some embodiments of the present application, the first surface of the first light-combining mirror and / or the third surface of the second light-combining mirror are coated with a selective transmission film.

[0018] In some embodiments of the present application, the selective transmission films coated on the first surface and the third surface are both dichroic films, or the selective transmission film coated on one of the first surface and the third surface is a dichroic film, and the selective transmission film coated on the other surface is a polarization selective film.

[0019] In some embodiments of the present application, if the selective transmission film coated on the first surface is a polarization selective film, the laser projection device further includes: a wave plate, which is located between the first laser array and the reflector, or between the second laser array and the first light combining mirror.

[0020] In some embodiments of the present application, the second surface of the first light-combining mirror and / or the fourth surface of the second light-combining mirror are prepared using liquid crystal particles.

[0021] In some embodiments of the present application, the laser projection device further includes: a diffusion element, a microlens array, an illumination lens group, a total reflection prism, a light valve modulation device, and a projection lens;

[0022] The diffusion element is located on the light-emitting side of the light-combining component and is used to diffuse the combined laser beams emitted by the light-combining component;

[0023] The microlens array is located on the light-emitting side of the diffusion element, and is used to perform light homogenization on the laser light, and emit the laser light to the illumination mirror group, and then enter the light valve modulation device after passing through the illumination mirror group and the total reflection prism;

[0024] The light valve modulation device modulates the laser, and the modulated laser is incident on the projection lens after passing through the total reflection prism;

[0025] The projection lens is used to image the modulated laser light.

[0026] In some embodiments of the present application, the phase modulation element is located between the laser light source and the light combining component, or between the light combining component and the diffusion element, or between the diffusion element and the microlens array, or between the microlens array and the illumination lens group, or between the total reflection prism and the light valve modulation device, or between the total reflection prism and the projection lens.

[0027] The present application provides a laser projection device, which may include a laser light source, a light combining component and a phase modulation element. The laser light source includes a plurality of laser arrays, the laser array includes a plurality of lasers, and the plurality of lasers emit lasers of the same color, that is, one laser array emits lasers of one color. The light combining component can combine the lasers emitted by the plurality of laser arrays. The phase modulation element includes a plurality of first target areas, the first target areas can change the phase of the target light beam, and different first target areas change the phase of the target light beam differently. The target light beam includes lasers emitted by at least one of the plurality of laser arrays and the light combining component. Since the lasers of the same color in the target light beam cover a plurality of first target areas, and the lasers passing through different first target areas change different phases, the lasers of the same color in the target light beam become multi-phase beams after being emitted through a plurality of first target areas, thereby achieving phase expansion, thereby effectively reducing the speckle phenomenon and improving the display effect of the projection image. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the implementation methods in the embodiments of the present application or related technologies, the following is a brief introduction to the drawings required for use in the embodiments or related technology descriptions. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0029] Figure 1 This is a schematic structural diagram of a laser projection device in a related technology;

[0030] Figure 2 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 1 ;

[0031] Figure 3 A schematic diagram of the arrangement of a laser array provided in an embodiment of the present application;

[0032] Figure 4 A schematic diagram of the structure of a laser light source provided in an embodiment of the present application;

[0033] Figure 5 A schematic diagram of an arrangement of first target areas provided in an embodiment of the present application;

[0034] Figure 6 A schematic diagram of a target light beam irradiating a phase modulation element provided in an embodiment of the present application Figure 1 ;

[0035] Figure 7 A schematic diagram of a target light beam irradiating a phase modulation element provided in an embodiment of the present application Figure 2 ;

[0036] Figure 8 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 2 ;

[0037] Figure 9 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 3 ;

[0038] Figure 10 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 4 ;

[0039] Figure 11 A schematic diagram of a target light beam based on a phase modulation element and a fly-eye lens provided in an embodiment of the present application;

[0040] Figure 12 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 5 . DETAILED DESCRIPTION

[0041] In order to make the purpose, implementation mode and advantages of the present application clearer, the exemplary implementation mode of the present application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0042] It should be noted that the brief descriptions of terms in this application are only for the purpose of facilitating the understanding of the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their ordinary and usual meanings.

[0043] In addition, the terms "comprises" and "comprising" and any variations thereof are intended to cover but not exclude inclusion, for example, a product or device comprising a list of components is not necessarily limited to those components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0044] Due to the characteristics of laser such as coherence, good monochromaticity and good collimation, laser projection has been widely used in recent years.

[0045] Figure 1 This is a schematic diagram of the structure of a laser projection device in a related technology, referring to Figure 1As shown, the laser light source 110 emits red, green, and blue lasers, of which the red laser is P light and the blue and green lasers are S light. A half-wave plate 190 can be placed on the blue and green light paths. The blue and green lasers are converted to P light after passing through the half-wave plate 190. At this time, the red, green, and blue lasers form uniformly polarized P light. The blue, green, and red lasers are combined by the light combining assembly 1201, 1202, and 1203, respectively. After combining, the light spots are homogenized by the diffuser 130, homogenized by the fly-eye lens 140, and then converged by the illumination lens assembly 150. The beams are incident on the DMD 160 through the total internal reflection prism 170, and then transmitted through the total internal reflection prism 170 after reflection, and then emitted through the projection lens 180 to form an image.

[0046] Since the phases of the red laser, green laser and blue laser emitted by the laser light source 110 are relatively single, there is a speckle phenomenon, which affects the display effect of the projection image.

[0047] Since speckle is usually generated based on the interference of the same color light, the speckle can be eliminated for the same color light, that is, the laser of the same color. Specifically, by expanding the phase of the laser of the same color, the laser of the same color can be turned into a multi-phase beam to effectively reduce the speckle phenomenon. Based on this, the present application provides a laser projection device, which may include a laser light source, a light combining component and a phase modulation element. Among them, the phase modulation element may include multiple first target areas, and the first target area is used to change the phase of the target light beam, and different first target areas change the phase of the target light beam differently. The laser of the same color in the target light beam covers multiple first target areas. Since the laser of the same color is a single-phase beam before passing through the multiple first target areas, it changes to different phases after passing through the multiple first target areas. Due to the different phase change amounts, the laser of the same color becomes a multi-phase beam after being emitted by the phase modulation element, achieving phase expansion, thereby effectively reducing the speckle phenomenon and helping to improve the display effect of the projection display picture.

[0048] The following detailed description of the technical solution of the present application is provided in conjunction with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0049] Figure 2 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 1 ,refer to Figure 2 As shown, the laser projection device includes:

[0050] The laser light source 210 includes a plurality of laser arrays, wherein the laser arrays include a plurality of lasers, and the plurality of lasers emit laser light of the same color;

[0051] The light combining component 220 is located on the light output side of the laser light source 210 and is used to combine the laser beams emitted by multiple laser arrays;

[0052] The phase modulation element 230 includes a plurality of first target areas, wherein the first target areas are used to change the phase of the target light beam, and different first target areas change the phase of the target light beam differently;

[0053] The lasers of the same color in the target light beam cover a plurality of first target areas, and the target light beam includes lasers emitted by at least one of a plurality of laser arrays and the light combining component 220 .

[0054] Each laser array includes multiple lasers, and the laser light emitted by the multiple lasers has the same color. That is, a laser array can emit laser light of a single color. For multiple laser arrays, the laser light emitted by different laser arrays can have the same or different colors. In one implementation scenario, the laser light source 210 can also include two or more laser arrays that emit laser light of the same color.

[0055] Take the laser light source 210 as an example of a red, green and blue laser light source. Figure 3 A schematic diagram of the arrangement of a laser array provided in an embodiment of the present application, with reference to Figure 3 As shown, there are four rows and seven columns of lasers, and multiple lasers can be arranged in an array. The first row is the green laser array L G , contains 7 green lasers emitting green lasers, the second row is a blue laser array L B , contains 7 blue lasers emitting blue, and the third and fourth rows are red laser arrays L R , each red laser array includes 7 red lasers emitting red laser light.

[0056] The target beam includes lasers emitted by at least one of the multiple laser arrays and the light combining assembly 220. Taking any laser array as an example, since the laser array includes multiple lasers, the target beam corresponding to the laser array includes lasers emitted by multiple lasers. In this case, the target beam is a single color laser, for example Figure 3 The green laser array L shown G The corresponding target light beam is a light beam containing green lasers emitted by seven green lasers.

[0057] For the light combining assembly 220, the corresponding target beam is the laser light emitted by multiple laser arrays, which is the result of combining the laser light. If the laser light source 210 can emit red, green and blue laser light, the target beam after combining by the light combining assembly 220 will contain three colors of laser light.

[0058] Figure 3 Only one arrangement of lasers is shown as an example. Other numbers of lasers and arrangements may also be used. The embodiments of the present application are only used for illustration and do not limit the lasers, the number of lasers, and the arrangement. The laser light source 210 of the present application may be a monochromatic laser light source, a two-color laser light source, or a three-color laser light source, etc.

[0059] Figure 4 This is a schematic diagram of the structure of a laser light source provided in an embodiment of the present application, refer to Figure 4 As shown, the laser light source 210 may further include a base plate 10 and a tube shell 20. The base plate 10 and the tube shell 20 enclose a receiving space, and the multiple laser arrays of the present application are located in the receiving space.

[0060] The laser light source 210 may also include a collimating lens group 30, which may include an integrally formed convex lens 302. Multiple convex lenses 302 are arranged on the main body 301. The edge of the main body 301 maintains a relatively fixed relationship with the positions of multiple lasers through bonding, so that each convex lens can correspond to a laser respectively.

[0061] Figure 5 A schematic diagram of an arrangement of the first target area provided in an embodiment of the present application is shown. Figure 5 Each small rectangular area shown is a first target area, wherein the multiple first target areas corresponding to A change the phase of the laser in the same way, the multiple first target areas corresponding to B change the phase of the laser in the same way, and the multiple first target areas corresponding to C change the phase of the laser in the same way.

[0062] Figure 5 The multiple first target areas shown are arranged in an array in a certain regular pattern, or they can be arranged randomly. Figure 5 Among the multiple first target areas shown, there are areas with the same laser phase change, such as multiple A areas, multiple B areas, etc. In another implementation scenario, among the multiple first target areas, any two first target areas have different laser phase changes.

[0063] Figure 5 Only the shape and arrangement of a first target area are shown as an example. The shapes and areas of different first target areas may be the same or different, and may be set according to actual needs. This application does not limit the shape, area, number, arrangement of the first target area, and the degree of change in the laser phase.

[0064] The laser light emitted by each laser array is a single-phase beam before passing through the phase modulation element 230. Taking any laser array as an example, since the laser array includes multiple lasers, each of which is capable of emitting laser light, the target beam corresponding to the laser array includes laser light emitted by multiple lasers. Figure 6 A schematic diagram of a target light beam irradiating a phase modulation element provided in an embodiment of the present application Figure 1 ,refer to Figure 6 As shown, the laser light emitted by each laser will present an elliptical spot when it is irradiated on the phase modulation element 230. The laser light emitted by different lasers irradiates different positions on the phase modulation element 230, that is, the laser light emitted by different lasers irradiates different first target areas of the phase modulation element 230. At this time, the target light beam corresponding to the laser array covers multiple first target areas. Since different target areas change the phase of the laser light differently, the target light beam emitted after passing through the phase modulation element 230 becomes a multi-phase light beam.

[0065] Specifically, based on one laser included in any laser array, the laser light emitted by one laser corresponds to Figure 6 A light spot is shown in Figure 6 The area of ​​each light spot shown is smaller than the area of ​​its corresponding first target area. Since the phase of the laser light is changed in the same way in the first target area, the phase of the laser light emitted by the laser device remains the same after passing through the first target area, although the phase changes.

[0066] However, for different lasers, since they illuminate different first target areas, the phases of the lasers corresponding to the different lasers are different after they are emitted from different first target areas. For example, the phase of the laser emitted by the first laser changes to P1, the phase of the laser emitted by the second laser changes to P2, and the phase of the laser emitted by the Nth laser changes to PN, where N is a positive integer greater than 2, and P1 ≠ P2 ≠ PN. For a laser array containing these N lasers, the corresponding target beam contains lasers emitted by N lasers. Therefore, after passing through multiple first target areas, the emitted target beam becomes a multi-phase beam, thereby effectively reducing the speckle phenomenon.

[0067] in, Figure 6 The S shown R It can represent the light spot corresponding to the red laser, which is P polarized light, S G Indicates the light spot corresponding to the green laser, S B Indicates the light spot corresponding to the blue laser. Both are S-polarized light, and one light spot corresponds to one laser.

[0068] In another implementation scenario, the description is still based on any laser included in any laser array. Figure 7 A schematic diagram of a target light beam irradiating a phase modulation element provided in an embodiment of the present application Figure 2 ,refer to Figure 7 As shown, a single light spot covers multiple first target areas. That is, after the laser light emitted by a single laser enters the phase modulation element 230, it can cover multiple first target areas and undergo phase modulation by the multiple first target areas. Therefore, the laser light emitted by the laser becomes a multi-phase beam after passing through the phase modulation element 230. Similarly, the laser light emitted by the other lasers included in the laser array also becomes a multi-phase beam after passing through the phase modulation element 230. Therefore, the target beam corresponding to the laser array, which includes laser light emitted by multiple lasers, is also a multi-phase beam. In this case, the phases of the target beam are more diverse, which can effectively reduce the speckle phenomenon.

[0069] In some embodiments, the phase modulation element 230 is a wave plate or a liquid crystal element. The liquid crystal element is made of liquid crystal particles, which can adjust the liquid crystal tilt angle by light exposure to increase the phase of the incident laser. The liquid crystal tilt angles in different first target areas can be different, and different tilt angles change the phase differently. Therefore, when the laser irradiates multiple first target areas, the phase of the incident laser can be expanded.

[0070] In one implementation scenario, the phase modulation element 230 may be located in the optical path following the light combining component 220, that is, Figure 2 As shown, in another implementation scenario, the phase modulation element 230 can also be located between the laser light source 210 and the light combining component 220. At this time, the laser line emitted by the laser light source 210 undergoes phase change through the phase modulation element 230, becoming a multi-phase light beam, and then passes through the light combining component 220 for beam combining.

[0071] An embodiment of the present application provides a laser projection device, which includes a laser light source 210, a light combining component 220, and a phase modulation element 230. The laser light source 210 emits laser light, which can be combined by the light combining component 220. The phase modulation element 230 includes a plurality of first target areas for changing the phase of the target light beam, and different first target areas change the phase of the target light beam differently. Among them, the laser light of the same color in the target light beam can cover multiple first target areas, and the laser light passing through different first target areas changes the phase differently. Therefore, the laser light of the same color after passing through multiple first target areas is a multi-phase beam, which realizes phase expansion, effectively reduces the speckle phenomenon, and is conducive to improving the display effect of the projection picture.

[0072] Figure 8A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 2 ,refer to Figure 8 As shown, in one or more embodiments of the present application, the multiple laser arrays include a first laser array 2101, a second laser array 2102, and a third laser array 2103; the light combining assembly 220 includes: a reflector 2201, a first light combining mirror 2202, and a second light combining mirror 2203, wherein the reflector 2201 is located on the light-emitting side of the first laser array 2101, and is used to reflect the laser light emitted by the first laser array 2101;

[0073] The first light combining mirror 2202 is located on the light-emitting side of the second laser array 2102 and includes a first surface S1 and a second surface S2 opposite to the first surface S1. The first surface S1 is a surface close to the reflector 2201 and is used to transmit the laser light emitted by the first laser array 2101 and reflect the laser light emitted by the second laser array 2102.

[0074] The second light-combining mirror 2203 is located on the light-emitting side of the third laser array 2103 and includes a third surface S3 and a fourth surface S4 opposite to the third surface S3; the third surface S3 is a surface close to the second surface S2, and is used to transmit the laser light emitted by the first laser array 2101 and the second laser array 2102, and reflect the laser light emitted by the third laser array 2103;

[0075] The second surface S2 includes multiple second target areas, the lasers emitted by the first laser array 2101 and the second laser array 2102 cover the multiple second target areas, the second target areas are used to change the phases of the lasers emitted by the first laser array 2101 and the second laser array 2102, and different second target areas have different phase changes in the lasers, and / or, the fourth surface S4 includes multiple third target areas, the lasers emitted by the first laser array 2101, the second laser array 2102, and the third laser array 2103 cover multiple third target areas, the third target areas are used to change the phases of the lasers emitted by the first laser array 2101, the second laser array 2102, and the third laser array 2103, and different third target areas have different phase changes in the lasers.

[0076] In one implementation scenario, the light-combining component 220 may only have a light-combining function, and the laser phase may be changed through the phase modulation element 230. The specific principle may refer to the above embodiment. At this time, the first light-combining mirror 2202 and the second light-combining mirror 2203 included in the light-combining component 220 may be dichroic films.

[0077] In another implementation scenario, the light-combining assembly 220 can combine light and also change the phase of the laser light. The light-combining effect can be achieved based on the reflector 2201, the first surface S1 of the first light-combining mirror 2202, and the third surface S3 of the second light-combining mirror 2203. In one implementation scenario, the first surface S1 of the first light-combining mirror 2202 and / or the third surface S3 of the second light-combining mirror 2203 are coated with a selective transmission film.

[0078] In one implementation scenario, the selective transmission films coated on the first surface S1 and the third surface S3 are both dichroic films, or the selective transmission film coated on one of the first surface S1 and the third surface S3 is a dichroic film, and the selective transmission film coated on the other is a polarization selective film.

[0079] Dichroic films transmit and reflect portions of the laser beam based on the wavelength of each color, combining red, green, and blue laser beams. Polarization-selective films transmit and reflect portions of the laser beam based on the polarization direction, combining red, green, and blue laser beams. Green and blue lasers are typically S-light, while red lasers are typically P-light.

[0080] The light combining component 220 can change the phase of the laser based on the second surface S2 of the first light combining mirror 2202 and / or the fourth surface S4 of the second light combining mirror 2203. In one implementation scenario, the first light combining mirror 2202 and / or the second light combining mirror 2203 are liquid crystal elements. Specifically, the second surface S2 of the first light combining mirror 2202 and / or the fourth surface S4 of the second light combining mirror 2203 are prepared using liquid crystal particles. Different phases are changed based on different tilt angles of the liquid crystal particles, thereby achieving modulation of the phase of the incident laser. The light combining component 220 can be used alone or in combination with the phase modulation element 230. When used in combination, the two can change the phase of the laser multiple times, which is conducive to further reducing the speckle phenomenon.

[0081] In one implementation scenario, if both the first light combining mirror 2202 and the second light combining mirror 2203 are capable of changing the phase of the laser light, the following example is provided in which the first laser array 2101 emits green laser light, the second laser array 2102 emits blue laser light, and the third laser array 2103 emits red laser light, and the colors of the laser light emitted by the first laser array 2101, the second laser array 2102, and the third laser array 2103 are not limited.

[0082] Specifically, after being reflected by the reflector 2201, the green laser is incident on the first surface S1 of the first light-combining mirror 2202, is transmitted through the first surface S1, and is emitted to the second surface S2 of the first light-combining mirror 2202. Since the green laser presents multiple corresponding light spots on the second surface S2, the number of light spots is the same as the number of lasers included in the first laser array 2101, that is, one laser corresponds to one light spot. Multiple light spots can cover multiple second target areas, and different second target areas have different abilities to change the laser phase. Therefore, the green laser after being emitted from the second surface S2 becomes a multi-phase beam and is incident on the third surface S3 of the second light-combining mirror 2203.

[0083] Similarly, for the blue laser, the blue laser is incident on the second surface S2 of the first light combining mirror 2202, and after the phase is changed by the multiple second target areas of the second surface S2, it is transmitted to the first surface S1 of the first light combining mirror 2202, reflected by the first surface S1 to the second surface S2, and then the phase is changed again by the multiple second target areas of the second surface S2 before being emitted to the third surface S3 of the second light combining mirror 2203.

[0084] The green laser and the blue laser are transmitted through the third surface S3 of the second light combining mirror 2203 and incident on the fourth surface S4 of the second light combining mirror 2203. After the phases are changed by the multiple third target areas on the fourth surface S4, they are emitted into the subsequent optical path of the laser projection device.

[0085] Similarly, for the red laser, the red laser is incident on the fourth surface S4 of the second light-combining mirror 2203, and after the phase is changed by the multiple third target areas of the fourth surface S4, it is transmitted to the third surface S3 of the second light-combining mirror 2203, reflected by the third surface S3 to the fourth surface S4, and after the phase is changed again by the multiple third target areas of the fourth surface S4, it is emitted into the subsequent optical path of the laser projection device.

[0086] At this time, the red, green and blue lasers are all multi-phase laser beams, so they can effectively reduce the speckle effect and help improve the display effect.

[0087] Among them, this application limits the shape, area, number, arrangement method and degree of change of laser phase of the second target area and the third target area. Please refer to the arrangement method of the first target area in the above embodiment, and no further details will be given here.

[0088] In another implementation scenario, if only the second light-combining mirror 2203 can change the phase of the laser, the first light-combining mirror 2202 only has a light-combining function, that is, it transmits the green laser emitted by the first laser array 2101 and reflects the blue laser emitted by the second laser array 2102. For green laser and blue laser, the phase cannot be changed after passing through the second surface S2 of the first light-combining mirror 2202, and it is necessary to be incident on the fourth surface S4 of the second light-combining mirror 2203 to achieve phase expansion and become a multi-phase light beam. For red laser, phase expansion can also be achieved through the fourth surface S4 of the second light-combining mirror 2203, so at this time the red and green lasers are also transformed into multi-phase laser beams.

[0089] In another implementation scenario, if only the first beam-combining mirror 2202 can change the phase of the laser beams, and the second beam-combining mirror 2203 only has a beam-combining function, that is, it transmits the green and blue laser beams and reflects the red laser beam, it can be seen from the above that since the green and blue laser beams can change their phases through the second surface S2 of the first beam-combining mirror 2202, the phase of the red laser beam is not expanded. Therefore, the speckle phenomenon of the red laser beam is not effectively reduced in this case, and only the speckle phenomenon of the green and blue laser beams is effectively reduced. For the red laser beam, phase expansion can be achieved by adding a phase modulation element 230.

[0090] Figure 9 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 3 ,refer to Figure 9 As shown, in some embodiments, if the selective transmission film coated on the first surface S1 is a polarization selective film, the laser projection device further includes: a wave plate 300, the wave plate 300 is located between the first laser array 2101 and the reflector 2201, or between the second laser array 2102 and the first light combining mirror 2202. Figure 9 An example is given in which the wave plate 300 is placed between the first laser array 2101 and the reflecting mirror 2201 .

[0091] Still taking the example of the first laser array 2101 emitting green laser, the second laser array 2102 emitting blue laser, and the third laser array 2103 emitting red laser as an example, in one implementation scenario, if the selective transmission film coated on the first surface S1 of the first light combining mirror 2202 is a polarization selective film, the wave plate 300 is arranged between the first laser array 2101 and the reflector 2201. After passing through the wave plate 300, the green laser emitted by the first laser array 2101 is converted from S light to P light, and is incident on the reflector 2201. After being reflected by the reflector 2201, it is directed to the first surface S1 of the first light combining mirror 2202. At this time, the polarization selective film coated on the first surface S1 is used to transmit P light and reflect S light. Therefore, the green laser can pass through the first surface S1 and be incident on the second surface S2. After passing through the second surface S2, it is emitted to the third surface S3. Among them, the wave plate 300 provided can be a half-wave plate.

[0092] For the blue laser, the blue laser is incident on the second surface S2 and emitted to the first surface S1. Since the blue laser is S light, the first surface S1 can reflect the blue laser so that the blue laser is incident on the second surface S2 again and then emitted to the third surface S3 after passing through the second surface S2.

[0093] In one implementation scenario, if the third surface S3 of the second light-combining mirror 2203 is still coated with a polarization-selective film, since the third surface S3 needs to reflect red laser light, which is P light, but the green laser light incident on the third surface S3 is P light, and the blue laser light is S light, the green laser light cannot be transmitted through the third surface S3. At this time, the selective transmission film coated on the third surface S3 of the second light-combining mirror 2203 may be a dichroic film, which realizes partial light beam transmission and partial light beam reflection based on the wavelengths of laser lights of different colors. Therefore, at least one of the first surface S1 and the third surface S3 is coated with a dichroic film, that is, the first surface S1 and the third surface S3 cannot both be coated with polarization-selective films.

[0094] Specifically, the dichroic film can reflect red laser and transmit blue laser and green laser. The specific process of phase change of the red, green and blue lasers through the first light-combining mirror 2202 and the second light-combining mirror 2203 can be referred to as shown above and will not be repeated here.

[0095] It should be noted that since the first surface S1 of the first light-combining mirror 2202 is coated with a polarization-selective film, if the second surface S2 can change the phase of the laser at this time, for the blue laser, after it is incident on the second surface S2 and changes its phase, its polarization direction may include multiple directions. At this time, the polarization-selective film is used to transmit P light and reflect S light. Therefore, after the blue lasers in multiple directions are incident on the polarization-selective film, only S light can be reflected, and the blue lasers in other directions cannot be reflected, resulting in the blue lasers in other directions cannot be effectively utilized. Therefore, the second surface S2 may not have the function of changing the laser phase at this time, and the phases of the red, green and three-color lasers can be changed through the fourth surface S4 of the second light-combining mirror 2203 or the phase modulation element 230 to achieve phase expansion.

[0096] In another implementation scenario, if the selective transmission film coated on the third surface S3 of the second light-combining mirror 2203 is a polarization-selective film, the polarization-selective film is used to reflect P light and transmit S light. Since the blue laser light emitted by the second laser array 2102 and the green laser light emitted by the first laser array 2101 are both S light, there is no need to set the wave plate 300 between the first laser array 2101 and the reflector 2201, and between the second laser array 2102 and the first light-combining mirror 2202. For the first light-combining mirror 2202, since the blue laser light and the green laser light are both S light and have the same polarization direction, the selective transmission film coated on its first surface S1 can be a dichroic film, which can achieve transmission of the green laser light and reflection of the blue laser light based on wavelength.

[0097] In summary, the present application provides a light-combining assembly 220, comprising a reflector 2201, a first light-combining mirror 2202, and a second light-combining mirror 2203. The second surface S2 of the first light-combining mirror 2202 and / or the fourth surface S4 of the second light-combining mirror 2203 can change the phase of the incident laser light, thereby modulating the phase of the incident laser light and converting the combined laser light into a multi-phase beam, thereby effectively reducing speckle and improving the display effect.

[0098] Figure 10 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 4 ,refer to Figure 10 As shown, in addition to the laser light source 210, the light combining component 220 and the phase modulation element 230, the laser projection device also includes: a diffusion element 240, a microlens array 250, an illumination lens group 260, a total reflection prism 270, a light valve modulation device 280 and a projection lens 290;

[0099] The diffusion element 240 is located on the light-emitting side of the light-combining component 220 and is used to diffuse the combined laser beams emitted by the light-combining component 220;

[0100] The microlens array 250 is located on the light-emitting side of the diffusion element 240 and is used to homogenize the laser light and emit it to the lighting lens group 260 , and then enter the light valve modulation device 280 after passing through the lighting lens group 260 and the total reflection prism 270 ;

[0101] The light valve modulation device 280 modulates the laser light, and the modulated laser light passes through the total reflection prism 270 and is incident on the projection lens 290;

[0102] The projection lens 290 is used to image the modulated laser light.

[0103] The diffusion element 240 may be a diffusion sheet or a diffusion wheel, etc., which diffuses and homogenizes the incident laser light to reduce the speckle phenomenon.

[0104] The microlens array 250 may be a fly-eye lens. After the laser light emitted from the fly-eye lens passes through the illumination lens assembly 260 , the laser light conforms to the size and incident angle required by the light valve modulation device 280 . Figure 11 A schematic diagram of a target beam based on a phase modulation element and a fly-eye lens provided in an embodiment of the present application, with reference to Figure 11 As shown, each light spot not only corresponds to and covers multiple first target areas, but also corresponds to multiple fly-eye lenses.

[0105] The lighting lens assembly 260 may include a first lighting lens 2601 and a second lighting lens 2602 .

[0106] Light valve modulation device 280 can be a DMD (Digital Micromirror Device). The surface of a DMD comprises thousands of tiny mirrors, each of which can be individually driven to deflect, for example, by ±12 degrees or ±17 degrees. Light reflected at a positive deflection angle is called "ON" light, the effective beam incident on projection lens 290 for projection imaging. Light reflected at a negative deflection angle is called "OFF" light, the ineffective light that reaches the housing or is absorbed by a light-absorbing device.

[0107] In some embodiments, the phase modulation element 230 is located between the laser light source 210 and the light combining component 220, or between the light combining component 220 and the diffusion element 240, or between the diffusion element 240 and the microlens array 250, or between the microlens array 250 and the illumination lens group 260, or between the total reflection prism 270 and the light valve modulation device 280, or between the total reflection prism 270 and the projection lens 290.

[0108] If the phase modulation element 230 is located in the optical path following the light combining component 220, for example Figure 10 The phase modulation element 230 shown in the figure is located between the light combining component 220 and the diffusion element 240. At this time, the selective transmission film coated on the first surface S1 of the first light combining mirror 2202 or the third surface S3 of the second light combining mirror 2203 can be a dichroic film or a polarization selective film.

[0109] Figure 12 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 5 , Figure 12 The phase modulation element 230 shown in the figure is located between the laser light source 210 and the light combining component 220. Since the phase modulation element 230 can phase-modulate the red, green and blue lasers, when the red, green and blue lasers are emitted after passing through the phase modulation element 230, the red, green and blue lasers are all multi-phase light beams with multiple polarization directions. Therefore, the selective transmission film coated on the first surface S1 of the first light combining mirror 2202 and the third surface S3 of the second light combining mirror 2203 in the light combining component 220 can be a dichroic film.

[0110] The embodiment of the present application is only an example to illustrate the position of the phase modulation element 230. In actual applications, the position of the phase modulation element 230 can be set according to actual needs, and the present application does not limit this.

[0111] In summary, the present application provides a laser projection device. The laser light emitted by the laser light source 210 is combined by the light combining assembly 220 and then incident on the phase modulation element 230. After phase modulation by the phase modulation element 230, the emitted laser light is a multi-phase beam. After being diffused by the diffusion element 240, homogenized by the microlens array 250, and converged by the illumination lens assembly 260, the beam is incident on the total reflection prism 270. The total reflection prism 270 can reflect the laser light to the light valve modulation device 280. After being modulated by the light valve modulation device 280, the laser light is incident on the projection lens 290 through the total reflection prism 270 to generate a projection image.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0113] For ease of explanation, the above description has been made with reference to specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations are possible. The above embodiments are selected and described to better explain the principles and practical applications, so that those skilled in the art can better utilize the embodiments and various different variations of the embodiments suitable for specific use considerations.

Claims

1. A laser projection device, characterized in that: The laser projection device comprises: A laser light source, comprising a plurality of laser arrays, wherein the laser arrays include a plurality of lasers, and the plurality of lasers emit laser light of the same color; A light combining component, located on the light-emitting side of the laser light source, for combining the laser beams emitted by multiple laser arrays; A phase modulation element includes a plurality of first target areas, wherein the first target areas are used to change the phase of the target light beam, and different first target areas change the phase of the target light beam differently; The lasers of the same color in the target light beam cover a plurality of first target areas, and the target light beam includes lasers emitted by at least one of a plurality of laser arrays and a light combining component.

2. The laser projection device according to claim 1, characterized in that: The phase modulation element is a wave plate or a liquid crystal element.

3. The laser projection device according to claim 1, characterized in that: The multiple laser arrays include a first laser array, a second laser array, and a third laser array; the light combining assembly includes: a reflector, a first light combining mirror, and a second light combining mirror, wherein the reflector is located on the light output side of the first laser array and is used to reflect the laser light emitted by the first laser array; The first light combining mirror is located on the light-emitting side of the second laser array and includes: a first surface and a second surface opposite to the first surface; the first surface is a surface close to the reflector, and is used to transmit the laser light emitted by the first laser array and reflect the laser light emitted by the second laser array; The second light combining mirror is located on the light-emitting side of the third laser array, and includes: a third surface and a fourth surface opposite to the third surface; the third surface is a surface close to the second surface, and is used to transmit the lasers emitted by the first laser array and the second laser array, and reflect the lasers emitted by the third laser array; The second surface includes multiple second target areas, the lasers emitted by the first laser array and the second laser array cover the multiple second target areas, the second target areas are used to change the phases of the lasers emitted by the first laser array and the second laser array, and different second target areas have different phase changes in the lasers, and / or, the fourth surface includes multiple third target areas, the lasers emitted by the first laser array, the second laser array, and the third laser array cover multiple third target areas, the third target areas are used to change the phases of the lasers emitted by the first laser array, the second laser array, and the third laser array, and different third target areas have different phase changes in the lasers.

4. The laser projection device according to claim 3, characterized in that: The first light combining mirror and / or the second light combining mirror is a liquid crystal element.

5. The laser projection device according to claim 4, characterized in that: The first surface of the first light-combining mirror and / or the third surface of the second light-combining mirror are coated with a selective transmission film.

6. The laser projection device according to claim 5, characterized in that: The selective transmission films coated on the first surface and the third surface are both dichroic films, or the selective transmission film coated on one of the first surface and the third surface is a dichroic film, and the selective transmission film coated on the other surface is a polarization selective film.

7. The laser projection device according to claim 6, characterized in that: If the selective transmission film coated on the first surface is a polarization selective film, the laser projection device further includes: a wave plate, which is located between the first laser array and the reflector, or between the second laser array and the first light combining mirror.

8. The laser projection device according to claim 4, characterized in that: The second surface of the first light-combining mirror and / or the fourth surface of the second light-combining mirror are prepared using liquid crystal particles.

9. The laser projection device according to any one of claims 1 to 8, characterized in that: The laser projection device further comprises: a diffusion element, a microlens array, an illumination lens group, a total reflection prism, a light valve modulation device and a projection lens; The diffusion element is located on the light-emitting side of the light-combining component and is used to diffuse the combined laser beams emitted by the light-combining component; The microlens array is located on the light-emitting side of the diffusion element, and is used to perform light homogenization on the laser light, and emit the laser light to the illumination mirror group, and then enter the light valve modulation device after passing through the illumination mirror group and the total reflection prism; The light valve modulation device modulates the laser, and the modulated laser is incident on the projection lens after passing through the total reflection prism; The projection lens is used to image the modulated laser light.

10. The laser projection device according to claim 9, characterized in that: The phase modulation element is located between the laser light source and the light combining component, or between the light combining component and the diffusion element, or between the diffusion element and the microlens array, or between the microlens array and the illumination lens group, or between the total reflection prism and the light valve modulation device, or between the total reflection prism and the projection lens.

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