Laser light source and laser projection equipment

Abstract

The embodiment of the invention belongs to the laser display technology, and provides a laser light source and laser projection equipment, and the laser light source comprises a laser device which comprises a first laser device array, a second laser device array and a third laser device array; the light combining lens group comprises a first light combining lens, a second light combining lens and a third light combining lens; the second light combination lens comprises a first surface and a second surface opposite to the first surface, the first surface is used for transmitting an incident target light beam and changing the phase of the target light beam, and the second surface is used for partially transmitting and partially reflecting the target light beam; the target light beam is laser emitted by the second laser array or laser emitted by the first laser array to the second light combination lens through the first light combination lens. The first surface and the second surface are oppositely arranged, and the times of passing through the first surface by the part of target light beams transmitted or reflected by the second surface are different, so that the phases of the transmitted and reflected parts of target light beams are different, the phase expansion is realized, and the speckle phenomenon is reduced.

Description

Technical Field

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

[0002] Laser light source has the advantages of good monochromaticity, high brightness and long life. It is an ideal light source and is gradually being used in projection equipment.

[0003] In some related technologies, a laser light source that emits red, green and blue lasers is provided. The blue, green and red laser chips are integrated into a laser component. Since the phases of the red, green and blue lasers are relatively single, a certain speckle phenomenon will be generated, thereby affecting the picture display effect. Summary of the Invention

[0004] The embodiments of the present application provide a laser light source and a laser projection device, which can be used to solve the problem in related technologies that, due to the relatively single phase of the red, green and blue lasers emitted by the laser light source, a certain speckle phenomenon will be generated, thereby affecting the image display effect.

[0005] In a first aspect, an embodiment of the present application provides a laser light source, comprising:

[0006] The laser includes a first laser array, a second laser array, and a third laser array, and is configured to emit lasers of different colors;

[0007] a light-combining lens assembly, comprising a first light-combining lens, a second light-combining lens, and a third light-combining lens arranged in sequence, wherein the first light-combining lens, the second light-combining lens, and the third light-combining lens are respectively located on the light-emitting sides of the first laser array, the second laser array, and the third laser array;

[0008] The second light-combining lens includes a first surface and a second surface opposite to the first surface, the first surface is used to transmit the incident target light beam and change the phase of the target light beam, and the second surface is used to partially transmit and partially reflect the incident target light beam; the target light beam is the laser light emitted by the second laser array or the laser light emitted by the first laser array to the second light-combining lens through the first light-combining lens;

[0009] The first light-combining lens is used to reflect the laser light emitted by the first laser array to the second light-combining lens; and reflect the laser light emitted by the second light-combining lens to the first light-combining lens to the third light-combining lens;

[0010] The third light-combining lens is used to reflect the laser light emitted by the third laser array and transmit the laser light emitted by the first light-combining lens and the second light-combining lens to the third light-combining lens.

[0011] In some embodiments of the present application, the second light-combining lens includes a first wave plate and a half-reflecting half-mirror lens, or the second light-combining lens is an integration of the first wave plate and the half-reflecting half-mirror lens;

[0012] The surface of the first wave plate serves as the first surface, and the surface of the half-reflecting half-mirror lens serves as the second surface.

[0013] In some embodiments of the present application, the first wave plate is located on a side close to the first light-combining lens, and the half-reflecting half-mirror lens is located on a side close to the third light-combining lens;

[0014] or,

[0015] The half-reflective half-mirror lens is located on a side close to the first light-combining lens, and the first wave plate is located on a side close to the third light-combining lens.

[0016] In some embodiments of the present application, if the first wave plate is located on a side close to the first light-combining lens and the half-reflecting half-mirror lens is located on a side close to the third light-combining lens, the first wave plate is a 1 / 4 wave plate.

[0017] In some embodiments of the present application, the laser light source further includes a second wave plate, which is located between the laser and the light combining lens group, or on the light output side of the light combining lens group, for changing the phase of the incident laser light.

[0018] In some embodiments of the present application, the second wave plate covers part of the laser light emitted by the first laser array, the second laser array, and the third laser array, or part of the laser light emitted through the light combining lens group, so as to change the phase of the part of the laser light.

[0019] In a second aspect, an embodiment of the present application provides a laser projection device, comprising: a first diffusion element, a homogenization element, a light valve modulation device, a total reflection prism, a projection lens, and the laser light source according to any one of the first aspects;

[0020] Wherein, the first diffusion element is located on the light-emitting side of the laser light source, and is used to diffuse the laser light emitted by the laser light source;

[0021] The homogenizing element is located on the light-emitting side of the first diffusing element and is used to homogenize the laser light emitted by the first diffusing element. The homogenized laser light is reflected by the total reflection prism to the light valve modulation device, so that the light valve modulation device modulates the laser light. The modulated laser light is incident on the projection lens through the total reflection prism.

[0022] In some embodiments of the present application, the homogenizing element is a light pipe or a microlens array.

[0023] In some embodiments of the present application, if the homogenizing element is a light pipe, the laser projection device further includes: a converging lens and a second diffusing element;

[0024] The converging lens is located on the light-emitting side of the first diffusing element and is used to converge the laser light emitted by the first diffusing element;

[0025] The second diffusion element is located between the converging lens and the homogenizing element, and is used to diffuse the converged laser light and transmit the diffused laser light to the homogenizing element.

[0026] In some embodiments of the present application, if the homogenizing element is a microlens array, the laser projection device further includes: an illumination lens assembly;

[0027] The lighting mirror assembly is located between the homogenizing element and the total reflection prism, and is used to adjust the angle at which the laser light emitted from the homogenizing element is incident on the total reflection prism.

[0028] The present application provides a laser light source and a laser projection device, wherein the laser light source includes a laser and a light combining lens group. The light combining lens group includes a first light combining lens, a second light combining lens and a third light combining lens arranged in sequence. Among them, the second light combining lens includes a first surface and a second surface. The first surface can change the phase of the incident target light beam, and the second surface can partially transmit and partially reflect the incident target light beam. Since the first surface and the second surface are arranged relative to each other, the number of times the partial target light beam transmitted or reflected by the second surface passes through the first surface is different, so the phase of the transmitted partial target light beam and the reflected partial target light beam is different, thereby achieving phase expansion, thereby effectively reducing the speckle phenomenon, and is beneficial to improving the picture display effect. At the same time, since the second light combining lens of the present application can partially transmit and partially reflect the target light beam, the target light beam is changed from one beam to two beams, the optical expansion is increased, which is beneficial to reducing the speckle phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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.

[0030] Figure 1 This is a schematic structural diagram of a laser projection device in a related technology;

[0031] Figure 2 A schematic diagram of the structure of a laser light source provided in an embodiment of the present application Figure 1 ;

[0032] Figure 3 A schematic diagram of the structure of a laser light source provided in an embodiment of the present application Figure 2 ;

[0033] Figure 4 A schematic diagram of the structure of a laser light source provided in an embodiment of the present application Figure 3 ;

[0034] Figure 5 A schematic diagram of the distribution of the corresponding light spots of the combined laser beams provided in an embodiment of the present application;

[0035] Figure 6 A schematic diagram of the structure of a laser light source provided in an embodiment of the present application Figure 4 ;

[0036] Figure 7 A schematic diagram of the relationship between a second wave plate and the corresponding spot of the laser output laser provided in an embodiment of the present application;

[0037] Figure 8 A schematic diagram of the transmission process of laser light emitted by a laser light source in a laser projection device provided in an embodiment of the present application;

[0038] Figure 9 A schematic diagram of a curve showing how the reflectivity of S light and P light varies with the incident angle, provided in an embodiment of the present application;

[0039] Figure 10 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 1 ;

[0040] Figure 11 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 2 ;

[0041] Figure 12 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 3 . DETAILED DESCRIPTION

[0042] 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.

[0043] 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.

[0044] 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.

[0045] In recent years, laser projection has been widely used. As users' requirements for picture color continue to increase, high-quality and high-color gamut laser projection has also begun to be used.

[0046] Figure 1 This is a schematic diagram of the structure of a laser projection device in a related technology, referring to Figure 1 As shown, the laser light source 11 can emit red, green and blue lasers. The laser light source 11 may include laser arrays 111, 112 and 113 that emit red, green and blue lasers and a collimator. The laser arrays that emit red, green and blue lasers are integrated into a laser assembly. After emitting lasers, they are collimated by the collimator and then emitted. Figure 1 The collimating mirror is not shown.

[0047] Red laser light is typically P light, and blue-green laser light is S light. A half-wave plate 19 is placed on the blue-green optical path. After passing through the half-wave plate 19, the blue-green laser light is converted to P light. At this point, the red, green, and blue laser light forms a uniformly polarized P light. The red, green, and blue laser light is combined by the multiple combining lenses 121, 122, and 123 included in the combining lens assembly 12. After combining, the light spot is homogenized by the diffuser 13, then homogenized by the fly-eye lens 14. The light is then converged by the first and second illumination lenses 151, 152 included in the illumination lens assembly 15, and then incident on the total internal reflection prism 17. After being totally reflected by the total internal reflection prism 17, it enters the DMD (Digital Micromirror Device) 16. After reflection from the DMD 16, it is transmitted through the total internal reflection prism 17 and emitted through the projection lens 18 to form an image.

[0048] Since in related technologies, the red, green and blue lasers are all P light, the speckle phenomenon is more serious, thus affecting the image display effect.

[0049] At the same time, because the laser arrays emitting red, green, and blue lasers are integrated into a single laser assembly, each laser array includes multiple laser chips. Typically, a laser light source includes two laser arrays emitting red lasers, meaning there are two rows of laser chips emitting red lasers, and one laser array emitting blue and green lasers, meaning there is one row of corresponding laser chips. This results in poor size consistency of the different color spots, resulting in larger and different sizes of the combined red, green, and blue light spots, which can also affect the image display effect.

[0050] In order to reduce the speckle phenomenon, the phase of the laser can be expanded. Based on this, the present application provides a laser light source and a laser projection device. The laser light source includes a laser and a light combining lens group, wherein the light combining lens group includes a first light combining lens, a second light combining lens and a third light combining lens arranged in sequence. The second light combining lens includes a first surface and a second surface, and the first surface can transmit the incident target light beam and change the phase of the target light beam. The second surface can partially transmit and partially reflect the target light beam. Since the first surface and the second surface are arranged relative to each other, the number of times the transmitted part of the target light beam and the reflected part of the target light beam pass through the first surface is different, that is, the phase is changed differently, and the target light beam is changed from a single phase to a multi-phase beam, achieving phase expansion, which is beneficial to reducing the speckle phenomenon and improving the picture display effect. At the same time, based on the partial transmission and partial reflection of the target light beam by the second surface, the target light beam is changed from one beam to two beams, which increases the optical expansion and is also beneficial to reducing the speckle phenomenon.

[0051] 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.

[0052] Figure 2 A schematic diagram of the structure of a laser light source provided in an embodiment of the present application Figure 1 ,refer to Figure 2 As shown, the laser light source includes:

[0053] The laser 21 includes a first laser array 211, a second laser array 212, and a third laser array 213, and is configured to emit lasers of different colors;

[0054] The light-combining lens group 22 includes a first light-combining lens 221, a second light-combining lens 222, and a third light-combining lens 223 arranged in sequence. The first light-combining lens 221, the second light-combining lens 222, and the third light-combining lens 223 are respectively located on the light-emitting sides of the first laser array 211, the second laser array 212, and the third laser array 213;

[0055] The second light-combining lens 222 includes a first surface S1 and a second surface S2 opposite to the first surface S1. The first surface S1 is used to transmit the incident target light beam and change the phase of the target light beam. The second surface S2 is used to partially transmit and partially reflect the incident target light beam. The target light beam is the laser light emitted by the second laser array 212 or the laser light emitted by the first laser array 211 through the first light-combining lens 221 to the second light-combining lens 222.

[0056] The first light-combining lens 221 is used to reflect the laser light emitted by the first laser array 211 to the second light-combining lens 222; and reflect the laser light emitted by the second light-combining lens 222 to the first light-combining lens 221 to the third light-combining lens 223;

[0057] The third light-combining lens 223 is used to reflect the laser light emitted by the third laser array 213 and transmit the laser light emitted by the first light-combining lens 221 and the second light-combining lens 222 to the third light-combining lens 223 .

[0058] The lasers emitted by the first laser array 211, the second laser array 212, and the third laser array 213 are of different colors, and the number of laser arrays emitting lasers of different colors can be one or more. In one implementation scenario, if the laser light source can emit red, green, and blue lasers, the first laser array 211 can emit green laser light, the second laser array 212 can emit blue laser light, and the third laser array 213 can emit red laser light. There can be two third laser arrays 213 emitting red laser light.

[0059] Each laser array may include multiple laser chips that emit laser light. The laser light emitted by the multiple laser chips in the same laser array may have the same color. In one implementation scenario, the multiple laser chips in the multiple laser arrays may be arranged in an array. This application does not limit the number or arrangement of the laser chips.

[0060] The first light-combining lens 221, the second light-combining lens 222 and the third light-combining lens 223 are all used to make a 90-degree turn of the laser light emitted from the corresponding light-emitting area, i.e., the laser array, and then emit it in the direction of the light outlet of the light source. Therefore, the first light-combining lens 221, the second light-combining lens 222 and the third light-combining lens 223 can be arranged in sequence toward the light outlet of the laser light source, and at least one light-combining lens can transmit the laser light of the corresponding color of the other light-emitting areas, and combine it with the laser light reflected by it, and emit it along the light outlet direction of the laser light source.

[0061] In one implementation scenario, the first light-combining lens 221 may be located on the side away from the light exit, the third light-combining lens 223 may be located on the side close to the light exit, and the second light-combining lens 222 may be located between the first light-combining lens 221 and the third light-combining lens 223.

[0062] In one implementation scenario, since the first light-combining lens 221 only reflects the incident laser light, the first light-combining lens 221 can be a reflector.

[0063] Since the third light-combining lens 223 is used to reflect the laser light emitted by the third laser array 213 and transmit the laser light emitted by the first light-combining lens 221 and the second light-combining lens 222 to the third light-combining lens 223, the laser light emitted by the first light-combining lens 221 to the third light-combining lens 223 can be the laser light emitted by the first laser array 211 or the laser light emitted by the second laser array 212. Similarly, the laser light emitted by the second light-combining lens 222 to the third light-combining lens 223 can be the laser light emitted by the first laser array 211 or the laser light emitted by the second laser array 212. Therefore, the laser light emitted by the first light-combining lens 221 and the second light-combining lens 222 to the third light-combining lens 223 is different in color from the laser light emitted by the third laser array 213, that is, the wavelength is different. Therefore, the third light-combining lens 223 can be a dichroic mirror.

[0064] Since the second light-combining lens 222 is located between the first light-combining lens 221 and the third light-combining lens 223, the first surface S1 included in the second light-combining lens 222 can be located on the side close to the first light-combining lens 221, and the second surface S2 is located on the side close to the third light-combining lens 223; or, the second surface S2 is located on the side close to the first light-combining lens 221, and the first surface S1 is located on the side close to the third light-combining lens 223.

[0065] In one implementation scenario, if the first surface S1 is located on a side close to the first light-combining lens 221, and the second surface S2 is located on a side close to the third light-combining lens 223, Figure 2As shown, the laser light emitted by the first laser array is reflected by the first light-combining lens 221 to the first surface S1, and after the phase is changed by the first surface S1, it is transmitted to the second surface S2. The second surface S2 transmits part of the laser light to the third light-combining lens 223 for beam combining before output. The second surface S2 also reflects part of the laser light to the first surface S1, changes the phase by the first surface S1, and then transmits it to the first light-combining lens 221. It is then reflected by the first light-combining lens 221 to the third light-combining lens 223 to be combined with the laser light emitted by the third laser array before output.

[0066] It can be seen from this that for the laser light emitted by the first laser array, based on the second surface S2, part of the reflected laser light passes through the first surface twice, and part of the transmitted laser light passes through the first surface once. Since the first surface S1 can change the phase, the number of times it passes through the first surface S1 is different, that is, the phase changes are different. Therefore, after passing through the second surface S2, the phases of the reflected part of the laser light and the transmitted part of the laser light are different. The laser light emitted by the first laser array is changed from a single-phase beam to a multi-phase beam, achieving phase expansion, which is beneficial to eliminating speckle. At the same time, the laser light is also changed from one beam to two beams, and the optical expansion is increased, which is also beneficial to eliminating speckle.

[0067] Similarly, for the laser emitted by the second laser array, the laser is incident on the second surface S2, and the second surface S2 reflects part of the laser to the third light-combining lens 223. This part of the laser does not change its phase through the first surface S1; part of the laser is transmitted to the first surface S1, and after the phase is changed by the first surface S1, it is transmitted to the first light-combining lens 221, and is reflected by the first light-combining lens 221 to the third light-combining lens 223, so as to be combined with the laser emitted by the third laser array and then emitted.

[0068] It can be seen from this that for the laser emitted by the second laser array, based on the second surface S2, part of the reflected laser does not pass through the first surface S1, and part of the transmitted laser passes through the first surface S1 once. Therefore, the phases of the reflected laser and the transmitted laser are different, so that the laser emitted by the second laser array is changed from a single-phase beam to a multi-phase beam, realizing phase expansion. At the same time, one beam is changed into two beams, which increases the optical expansion and is conducive to eliminating speckle.

[0069] In another implementation scenario, if the second surface S2 is located on a side close to the first light-combining lens 221, and the first surface S1 is located on a side close to the third light-combining lens 223, then for the laser emitted by the first laser array and the laser emitted by the second laser array, based on the second surface S2, the number of times the transmitted part of the laser and the reflected part of the laser pass through the first surface S1 is also different. Therefore, there is a certain difference in the phases of the two, and the phase expansion can also be achieved, increasing the optical expansion, which is beneficial to eliminating speckle. The specific implementation principle can refer to the above-mentioned principle: the first surface S1 is located on a side close to the first light-combining lens 221, and the second surface S2 is located on a side close to the third light-combining lens 223, which will not be repeated here.

[0070] The present application provides a laser light source, including a laser and a light-combining lens group 22. The light-combining lens group 22 includes a first light-combining lens 221, a second light-combining lens 222, and a third light-combining lens 223 arranged in sequence, which are respectively located on the light-emitting sides of the first laser array 211, the second laser array 212, and the third laser array 213. The second light-combining lens 222 includes a first surface and a second surface. The first surface S1 can transmit the incident target light beam and change the phase of the target light beam. The second surface S2 can partially transmit and partially reflect the target light beam. Since the first surface and the second surface are arranged relative to each other, the number of times the transmitted target light beam and the reflected target light beam pass through the first surface is different, that is, the phase changes are different. The target light beam changes from a single phase to a multi-phase beam, achieving phase expansion, which is beneficial to reducing speckle phenomenon and improving picture display effect. At the same time, based on the partial transmission and partial reflection of the target light beam by the second surface, the target light beam is changed from one beam to two beams, which increases the optical expansion and is also beneficial to reducing speckle phenomenon.

[0071] In one or more embodiments of the present application, the second light-combining lens 222 includes a first wave plate and a half-reflecting half-mirror lens, or the second light-combining lens 222 is an integration of the first wave plate and the half-reflecting half-mirror lens;

[0072] The surface of the first wave plate serves as the first surface, and the surface of the half-reflecting half-mirror lens serves as the second surface.

[0073] In some embodiments, the first wave plate is located on a side close to the first light-combining lens 221, and the half-reflecting half-mirror lens is located on a side close to the third light-combining lens 223;

[0074] or,

[0075] The half-reflecting half-mirror lens is located on a side close to the first light-combining lens 221 , and the first wave plate is located on a side close to the third light-combining lens 223 .

[0076] In one implementation scenario, when the first wave plate and the half-reflecting half-mirror are two independent devices, reference can be made to Figure 3 and Figure 4 shown. Figure 3 A schematic diagram of the structure of a laser light source provided in an embodiment of the present application Figure 2 The second light-combining lens 222 includes a first wave plate 2221 and a half-reflecting half-mirror lens 2222. At this time, the first wave plate 2221 is located on one side of the first light-combining lens 221, and the half-reflecting half-mirror lens 2222 is located on a side close to the third light-combining lens 223. Figure 4 A schematic diagram of the structure of a laser light source provided in an embodiment of the present application Figure 3 At this time, the half-reflecting half-mirror lens 2222 is located on a side close to the first light-combining lens 221, and the first wave plate 2221 is located on a side close to the third light-combining lens 223.

[0077] An example is given in which the first laser array 211 emits green laser light, the second laser array 212 emits blue laser light, and the two third laser arrays 213 emit red laser light. The details are as follows:

[0078] In one implementation scenario, combined with Figure 3 As shown, if the first wave plate 2221 is located on a side close to the first light-combining lens 221, and the semi-reflecting half-mirror 2222 is located on a side close to the third light-combining lens 223, the green laser light emitted by the first laser array 211 is incident on the first light-combining lens 221, reflected by the first light-combining lens 221 to the first wave plate 2221, and after the phase is changed by the first wave plate 2221, it is emitted to the semi-reflecting half-mirror 2222. The semi-reflecting half-mirror 2222 transmits a portion of the green laser light to the third light-combining lens 223, and the transmitted portion of the green laser light is recorded as TG; the semi-reflecting half-mirror 2222 reflects a portion of the green laser light, and the reflected portion of the green laser light is recorded as RG. The reflected portion of the green laser light RG passes through the first wave plate 2221 again, and after the phase is changed by the first wave plate 2221 again, it is emitted to the first light-combining lens 221, and reflected by the first light-combining lens 221 to the third light-combining lens 223.

[0079] From the above, it can be seen that for the green laser, one beam of green laser is converted into two beams based on the half-reflecting half-mirror 2222. At the same time, the part of the green laser RG reflected by the half-reflecting half-mirror 2222 passes through the first wave plate twice, and the phase changes twice. The transmitted part of the green laser TG passes through the first wave plate once, and the phase changes once. Therefore, at this time, the phases of the transmitted part of the green laser TG and the reflected part of the green laser RG are different, and the phase difference between the two is related to the first wave plate 2221.

[0080] Similarly, for the blue laser, the blue laser emitted by the second laser array 212 is incident on the half-reflecting half-mirror 2222, and part of the blue laser is reflected by the half-reflecting half-mirror 2222 to the third light-combining lens 223, and the reflected part of the blue laser is recorded as RB; part of the blue laser is transmitted by the half-reflecting half-mirror 2222 to the first wave plate 2221, and the transmitted part of the blue laser is recorded as TB. After the phase is changed by the first wave plate 2221, it is emitted to the first light-combining lens 221, and is reflected by the first light-combining lens 221 to the third light-combining lens 223.

[0081] From the above, it can be seen that for the blue laser, a beam of blue laser is converted into two beams based on the half-reflecting half-mirror 2222. At the same time, part of the blue laser RB reflected by the half-reflecting half-mirror 2222 does not pass through the first wave plate 2221, so the phase does not change. The transmitted part of the blue laser TB passes through the first wave plate once, and the phase changes once. Therefore, at this time, there is also a difference in phase between the transmitted part of the blue laser TB and the reflected part of the blue laser RB, and the phase difference between the two is also related to the first wave plate 2221.

[0082] For red lasers, the laser light source includes two third laser arrays 213 emitting red lasers, which can be denoted as 213a and 213b, respectively. The red laser RR1 emitted by the third laser array 213a is reflected by the third light-combining lens 223 before being emitted. Simultaneously, the third light-combining lens 223 transmits a portion of the blue laser RB reflected by the half-reflecting half-mirror and a portion of the green laser TG transmitted by the half-reflecting half-mirror, thereby combining the blue laser RB with the red laser RR1. This combined laser beam can be denoted as the first light beam M.

[0083] Similarly, the red laser RR2 emitted by the third laser array 213b is incident on the third light-combining lens 223, and is emitted after being reflected by the third light-combining lens 223. At the same time, the transmitted part of the blue laser TB and the reflected part of the green laser RG emitted by the first light-combining lens 221 are transmitted to achieve beam combining with the red laser RR2. The combined laser can be referred to as the second light beam N.

[0084] Based on the above, the laser light contained in the first light beam M and the second light beam N and the number of times the laser light passes through the first wave plate 2221 can be referred to as shown in Table 1, which is as follows:

[0085] Table 1: The first wave plate is located on the side close to the first light combining lens, the half-reflective half-mirror is located on the side close to the third light combining lens, the laser light included in the first beam M and the second beam N, and the number of times the laser light passes through the first wave plate

[0086]

[0087] Figure 5A schematic diagram of the distribution of the corresponding light spots of the combined laser beams provided in the embodiment of the present application is provided. Figure 5 As shown, there are two rows of light spots, each row of light spots includes a red light spot S corresponding to the red laser R , Green spot S corresponding to green laser G The blue spot S corresponding to the blue laser B The first row of light spots is the light spot corresponding to the laser contained in the second light beam N, and the second row of light spots is the light spot corresponding to the laser contained in the first light beam M.

[0088] In another implementation scenario, combined with Figure 4 As shown, if the half-reflecting half-mirror 2222 is located on the side close to the first light-combining lens 221, and the first wave plate 2221 is located on the side close to the third light-combining lens 223, then for the green laser, it is reflected to the half-reflecting half-mirror 2222 by the first light-combining lens 221. Based on the half-reflecting half-mirror 2222, part of the green laser RG is reflected back to the first light-combining lens 221, and is reflected again to the third light-combining lens 223 by the first light-combining lens 221; part of the green laser TG is transmitted to the first wave plate 2221, and is incident on the third light-combining lens 223 after the phase is changed by the first wave plate 2221.

[0089] It can be seen from this that the reflected green laser RG does not pass through the first wave plate 2221 and its phase does not change, while the transmitted green laser TG passes through the first wave plate once and its phase changes once, so the phases of the reflected green laser RG and the transmitted green laser TG are different.

[0090] Similarly, for blue laser light, the blue laser light is incident on the first wave plate 2221, and after its phase is changed by the first wave plate 2221, it is emitted to the semi-reflective mirror 2222. Based on the semi-reflective mirror 2222, part of the blue laser light RB is reflected back to the first wave plate 2221, and after its phase is changed by the first wave plate 2221 again, it is emitted to the third light-combining lens 223. Part of the blue laser light TB is transmitted through the first light-combining lens 221 and reflected by the first light-combining lens 221 to the third light-combining lens 223.

[0091] From this, it can be seen that based on the half-reflective half-mirror 2222, the reflected part of the blue laser RB passes through the first wave plate twice, and the phase changes twice, and the transmitted part of the blue laser TB passes through the first wave plate once, and the phase changes once. The phases of the reflected part of the blue laser RB and the transmitted part of the blue laser TB are different.

[0092] The third light-combining lens 223 combines the portion of the green laser light TG and the portion of the blue laser light RB reflected by the semi-reflecting mirror 2222, as well as the red laser light RR1 emitted by the third laser array 213a, to produce a first light beam M. The portion of the green laser light RG and the portion of the blue laser light TB reflected by the first light-combining lens 221, as well as the laser light emitted by the third laser array 213b, are combined to produce a second light beam N.

[0093] Based on the above, the laser light contained in the first light beam M and the second light beam N and the number of times the laser light passes through the first wave plate 2221 can be referred to as shown in Table 2, which is as follows:

[0094] Table 2: The half-mirror mirror is located on the side close to the first light-combining lens, the first wave plate is located on the side close to the third light-combining lens, the laser light contained in the first beam M and the second beam N, and the number of times the laser light passes through the first wave plate

[0095]

[0096] From the above, it can be seen that the first wave plate 2221 is located on the side close to the first light-combining lens 221, and the half-reflective half-mirror 2222 is located on the side close to the third light-combining lens 223, or the first wave plate 2221 is located on the side close to the third light-combining lens 223, and the half-reflective half-mirror 2222 is located on the side close to the first light-combining lens 221. For blue laser and green laser, both are changed from a single light beam to a multi-phase light beam, realizing phase expansion, thereby effectively reducing the speckle phenomenon.

[0097] In both cases, the green laser light emitted by the first laser array 211 and the blue laser light emitted by the second laser array 212 are split into two beams, increasing the etendue. This increase in etendue also helps reduce the energy required for sharp speckle, thereby reducing the speckle effect. Furthermore, when the laser light source includes two third laser arrays 213 emitting red laser light, the difference in size between the green laser light, the blue laser light, and the red laser light is reduced, further improving the display quality.

[0098] In another implementation scenario, if the second light-combining lens 222 is an integration of the first wave plate 2221 and the half-reflective half-mirror 2222, the second light-combining lens 222 has the functions of the first wave plate 2221 and the half-reflective half-mirror 2222. Its implementation principle is basically the same as the principle of the first surface S1 and the second surface S2 included in the second light-combining lens 222 in the above embodiment. Please refer to the above and will not be repeated here.

[0099] Figure 6 A schematic diagram of the structure of a laser light source provided in an embodiment of the present application Figure 4 ,refer to Figure 6 As shown, in some embodiments, the laser light source further includes a second wave plate 23, which is located between the laser and the light combining lens group 22, or located on the light output side of the light combining lens group 22, for changing the phase of the incident laser light.

[0100] In one implementation scenario, the second wave plate 23 covers part of the laser light emitted by the first laser array 211 , the second laser array 212 , and the third laser array 213 or part of the laser light emitted through the light combining lens group 22 to change the phase of the part of the laser light.

[0101] Figure 7 A schematic diagram of the relationship between a second wave plate and the corresponding spot of the laser output laser provided in the embodiment of the present application, with reference to Figure 7 As shown, by reasonably setting the size and position of the second wave plate 23, part of the laser light emitted by the laser can pass through the second wave plate 23, and part of the laser light does not pass through the second wave plate 23. Based on the phase modulation of the second wave plate 23, the phase of the part of the laser light passing through the second wave plate 23 and the part of the laser light not passing through the second wave plate 23 are different, thereby achieving the diversity of the laser phase, which is beneficial to reducing the speckle phenomenon and improving the picture display effect.

[0102] In summary, the second light-combining lens 222 may include a first wave plate 2221 and a half-reflective half-mirror 2222, or the second light-combining lens 222 is an integration of the first wave plate 2221 and the half-reflective half-mirror 2222, wherein the first wave plate 2221 serves as the first surface S1, transmits the incident laser and changes the phase of the laser, and the half-reflective half-mirror 2222 is used to partially transmit and partially reflect part of the incident laser. Due to the half-reflective half-mirror 2222, the transmitted part of the laser and the reflected part of the laser pass through the first wave plate 2221 for different numbers of times, so the phases of the two are different, so that the incident laser changes from a single phase to a multi-phase, achieving phase expansion, which is beneficial to reducing the speckle phenomenon and thus improving the picture display effect. At the same time, based on the half-reflective half-mirror 2222, one laser beam is converted into two laser beams, which increases the optical expansion. The setting 23 of the second wave plate further increases the diversity of the laser phase, which is also beneficial to reducing the speckle phenomenon.

[0103] In one or more embodiments of the present application, if the first wave plate 2221 is located on a side close to the first light-combining lens 221 and the half-reflective half-mirror lens 2222 is located on a side close to the third light-combining lens 223, the first wave plate 2221 is a 1 / 4 wave plate.

[0104] In one implementation scenario, if the laser light source of the present application is used in a projection device, Figure 8A schematic diagram of the transmission process of the laser light emitted by the laser light source in a laser projection device provided in an embodiment of the present application, with reference to Figure 8 As shown, in addition to the laser light source, a laser projection device may also include multiple components, such as a total reflection prism 24, a light valve modulation device 25 as a core component, and a projection lens 26. Laser light emitted by the laser light source is incident on the first surface P1 of the total reflection prism 24, is transmitted through the first surface P1, is incident on the second surface P2 of the total reflection prism 24, is totally reflected by the second surface P2, and is incident on the light valve modulation device 25 through the third surface P3. After the light valve modulation device 25 modulates the laser light, the laser light is reflected to the third surface P3, and is sequentially transmitted through the third surface P3, the second surface P2, and the fourth surface P4 to the fifth surface P5, and then is emitted to the projection lens 26 through the fifth surface P5.

[0105] As can be seen from the above, the laser light needs to be transmitted multiple times from the time it enters the total reflection prism 24 to the time it enters the projection lens 26. A total of six transmissions are shown above. Therefore, when the transmittance of the laser light entering the total reflection prism 24 is high, the laser light utilization rate can be effectively improved.

[0106] Still taking the example of the first laser array 211 emitting green laser, the second laser array 212 emitting blue laser, and the two third laser arrays 213 emitting red laser, normally, the green laser emitted by the first laser array 211 and the blue laser emitted by the second laser array 212 are S light, and the red laser emitted by the third laser array 213 is P light.

[0107] Figure 9 A schematic diagram of a curve showing the change of the reflectivity of S light and P light with the incident angle provided in an embodiment of the present application, with reference to Figure 9 As shown in the figure, as the incident angle increases, the reflectivity of both S and P light gradually increases. When the incident angle is small, the difference in reflectivity between S and P light is small. As the incident angle gradually increases, the difference in reflectivity between S and P light becomes larger, and the reflectivity of S light is significantly greater than that of P light. Correspondingly, the transmittance of S light is less than that of P light.

[0108] Therefore, to ensure high laser utilization, the laser light incident on total reflection prism 24 is preferably P-light. For example, in related art, a half-wave plate is placed on the blue-green optical path to convert the blue and green lasers from S-light to P-light. Simultaneously, the red laser light is also P-light, resulting in high laser utilization. However, since the red, green, and blue lasers are all P-light and have the same polarization direction, speckle is more severe.

[0109] Depend on Figure 9It can be seen that when the incident angle is large, the reflectivity difference between S light and P light is large, and when the incident angle is small, the reflectivity difference between the two is small. In order to reduce the speckle phenomenon, the laser with a larger incident angle can be set as P light, and the laser with a smaller incident angle can be set as S light. While reducing the speckle phenomenon, it can also ensure a higher laser utilization rate.

[0110] Based on the first light beam M and the second light beam N shown in the above embodiment, compared with the case where both the first light beam M is P light and both the second light beam N is S light, the corresponding laser utilization rate is higher when both the first light beam M is S light and both the second light beam N is P light.

[0111] Since the laser light needs to pass through multiple transmissions before entering the total reflection prism 24 and then the projection lens 26, it can be understood that during these multiple transmissions, the comprehensive incident angle corresponding to the second light beam N is greater than the comprehensive incident angle corresponding to the first light beam M. To ensure laser utilization, the present application can set most of the laser light included in the second light beam N as P light.

[0112] In one implementation scenario, the laser utilization rate can be calculated and determined based on the laser light incident on the total reflection prism 24 and the laser light incident on the projection lens 26 , without calculating the utilization rate of each transmission.

[0113] As can be seen from the above embodiment, both the first light beam M and the second light beam N contain red, green, and blue laser light. In one implementation scenario, if the first wave plate 2221 is located near the first light-combining lens 221 and the half-reflecting mirror 2222 is located near the third light-combining lens 223, the green laser light contained in the second light beam N is the portion of green laser light RG reflected by the half-reflecting mirror 2222, and the blue laser light contained in the second light beam N is the portion of blue laser light TB transmitted by the half-reflecting mirror 2222.

[0114] It can be seen from the above embodiment that the reflected part of the green laser RG passes through the first wave plate twice, and the transmitted part of the blue laser TB passes through the first wave plate once. Since the green laser and the blue laser are both S light before passing through the first wave plate 2221, and compared with the blue laser, the green laser has a greater impact on the brightness. Therefore, the reflected part of the green laser RG contained in the second light beam N can be set to P light, so the first wave plate 2221 can be a 1 / 4 wave plate.

[0115] When first wave plate 2221 is a quarter-wave plate, the transmitted portion of blue laser light TB passes through the first wave plate only once. Therefore, the transmitted portion of blue laser light TB is converted from linearly polarized light to circularly polarized light after passing through first wave plate 2221. Circularly polarized light has a higher transmittance than S-light, which also helps improve laser utilization.

[0116] When first wave plate 2221 is a quarter-wave plate, the green laser light contained in first beam M is the portion of green laser light TG transmitted by half-reflecting mirror 2222. Because the transmitted portion of green laser light TG has passed through the first wave plate once, it is converted from linearly polarized light to circularly polarized light after passing through first wave plate 2221. The phase difference between the transmitted portion of green laser light TG and the portion of green laser light RG reflected by half-reflecting mirror 2222, contained in second combined light N, is π / 4.

[0117] Similarly, when first wave plate 2221 is a quarter-wave plate, the blue laser light contained in first light beam M is the portion of blue laser light RB reflected by half-reflecting mirror 2222. Because the reflected portion of blue laser light RB does not pass through the wave plate, the blue laser light in first light beam M remains S light. The phase of the reflected portion of blue laser light RB also differs by π / 4 from the phase of the portion of blue laser light TB in second light beam N that is transmitted by half-reflecting mirror 2222.

[0118] It should be noted that, since the red laser light does not pass through the first wave plate 2221 , the red laser light in the first light beam M and the second light beam N are both P light.

[0119] In one implementation scenario, the first wave plate 2221 is a 1 / 4 wave plate, or it can be a wave plate within a certain range, such as a wave plate within 1 / 4±1 / 8, so that in the laser incident on the total reflection prism 24, the P light distribution is better than the S light distribution, so as to ensure a higher transmittance and thus ensure a higher laser utilization rate.

[0120] In another implementation scenario, it can be seen from the above embodiment that when the half-reflecting half-mirror 2222 is located on the side close to the first light-combining mirror and the first wave plate 2221 is close to the side of the third light-combining mirror, please refer to Table 2 for details. For the second light beam N, the reflected part of the green laser RG does not pass through the first wave plate 2221. Therefore, the reflected part of the green laser RG contained in the second light beam N is still S light. At this time, a third wave plate can be set on the transmission light path of the reflected part of the green laser RG. The third wave plate can be a 1 / 2 wave plate to convert the reflected part of the green laser RG into P light to improve its transmittance.

[0121] At this time, the first wave plate 2221 can be a quarter wave plate or other wave plates, and can be set according to actual needs.

[0122] In summary, if the first wave plate 2221 is located on the side close to the first light-combining lens 221, and the half-reflective half-mirror lens 2222 is located on the side close to the third light-combining lens 223, the first wave plate 2221 can be a 1 / 4 wave plate, which can effectively ensure a higher laser utilization rate and is also beneficial to reduce speckle phenomenon and improve display effect.

[0123] Figure 10 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 1 ,refer to Figure 10 As shown, the laser projection device includes: a first diffusion element 27, a homogenization element 28, a light valve modulation device 25, a total reflection prism 24, a projection lens 26 and the laser light source described in any one of the above embodiments;

[0124] The first diffusion element 27 is located on the light-emitting side of the laser light source and is used to diffuse the laser light emitted by the laser light source.

[0125] The homogenizing element 28 is located on the light-emitting side of the first diffusing element 27 and is used to homogenize the laser light emitted by the first diffusing element 27. The homogenized laser light is reflected by the total reflection prism 24 to the light valve modulator 25, so that the light valve modulator 25 modulates the laser light. The modulated laser light is incident on the projection lens 26 through the total reflection prism 24.

[0126] In one implementation scenario, the light valve modulation device 25 may be a DMD, which includes thousands of tiny mirrors. Each tiny mirror can be flipped at a certain angle to achieve modulation of the laser.

[0127] In one implementation scenario, the homogenizing element 28 is a light pipe or a microlens array, wherein the microlens array can be a fly-eye lens.

[0128] Figure 11 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 2 , in some embodiments, if the homogenizing element 28 is a light pipe, the laser projection device further includes: a converging lens and a second diffusing element;

[0129] The converging lens is located on the light-emitting side of the first diffusion element 27 and is used to converge the laser light emitted by the first diffusion element 27;

[0130] The second diffusion element is located between the converging lens and the homogenizing element 28 , and is configured to diffuse the converged laser light and transmit the diffused laser light to the homogenizing element 28 .

[0131] Specifically, the laser light emitted by the laser light source is combined by the light combining lens assembly 22 and has its phase changed before being emitted to the second wave plate 23. After the second wave plate 23 changes the phase of a portion of the laser light, it is emitted to the first diffuser 27. After being diffused by the first diffuser 27, converged by the converging lens, and diffused by the second diffuser, it is incident on the light guide for homogenization. After being homogenized by the light guide, it is incident on the total internal reflection prism 24, the DMD, and the projection lens 26 for projection. Figure 11 The full-emission prism, DMD and projection lens 26 are not shown in the figure. The positional relationship between the three can be referred to in FIG. Figure 10 shown.

[0132] The first diffusion element 27 may be a diffusion sheet for diffusing the laser light so as to increase the spot size of the laser light emitted by each laser chip in the laser light source, thereby improving the homogenization effect through the light pipe.

[0133] The second diffusion element may be a diffusion wheel, which can achieve a uniform speckle dispersion effect based on rapid rotation of the diffusion wheel.

[0134] By changing the phase of the laser light based on the light combining lens group 22 and the second wave plate, the laser light incident on the total reflection prism 24 is a multi-phase beam, which can eliminate speckles and effectively improve the transmittance of the laser light, thereby improving the laser utilization rate.

[0135] Figure 12 A schematic diagram of the structure of a laser projection device provided in an embodiment of the present application Figure 3 , in some embodiments, if the homogenizing element 28 is a microlens array, the laser projection device further includes: an illumination lens assembly;

[0136] The lighting mirror assembly is located between the homogenizing element 28 and the total reflection prism 24 and is used to adjust the angle at which the laser light emitted from the homogenizing element 28 is incident on the total reflection prism 24 .

[0137] In one implementation scenario, the lighting lens assembly may include one or more lighting lenses. Figure 12 The lighting lens assembly shown in FIG. 3 includes a first lighting lens 311 and a second lighting lens 312 , which adjust the angle at which the laser is incident on the total reflection prism 24 so that the laser incident on the DMD meets the angle and size required by the DMD.

[0138] An embodiment of the present application provides a laser projection device, in which the laser light emitted by the laser light source has its phase changed by the light combining lens group 22, and is emitted to the first diffusion element 27 after being combined, and is incident on the light valve modulation device 25 after passing through the first diffusion element 27, the homogenization element 28, and the total reflection prism 24. After being modulated by the light valve modulation device 25, the modulated laser light is incident on the projection lens 26 through the total reflection prism 24 to realize image display.

[0139] 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.

[0140] 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 light source, characterized in that: The laser light source comprises: The laser includes a first laser array, a second laser array, and a third laser array, and is configured to emit lasers of different colors; a light-combining lens assembly, comprising a first light-combining lens, a second light-combining lens, and a third light-combining lens arranged in sequence, wherein the first light-combining lens, the second light-combining lens, and the third light-combining lens are respectively located on the light-emitting sides of the first laser array, the second laser array, and the third laser array; The second light-combining lens includes a first surface and a second surface opposite to the first surface, the first surface is used to transmit the incident target light beam and change the phase of the target light beam, and the second surface is used to partially transmit and partially reflect the incident target light beam; the target light beam is the laser light emitted by the second laser array or the laser light emitted by the first laser array to the second light-combining lens through the first light-combining lens; The first light-combining lens is used to reflect the laser light emitted by the first laser array to the second light-combining lens; and reflect the laser light emitted by the second light-combining lens to the first light-combining lens to the third light-combining lens; The third light-combining lens is used to reflect the laser light emitted by the third laser array and transmit the laser light emitted by the first light-combining lens and the second light-combining lens to the third light-combining lens.

2. The laser light source according to claim 1, wherein: The second light combining lens includes a first wave plate and a half-reflecting half-mirror lens, or the second light combining lens is an integration of the first wave plate and the half-reflecting half-mirror lens; The surface of the first wave plate serves as the first surface, and the surface of the half-reflecting half-mirror lens serves as the second surface.

3. The laser light source according to claim 2, wherein: The first wave plate is located on a side close to the first light-combining lens, and the half-reflecting half-mirror lens is located on a side close to the third light-combining lens; or, The half-reflective half-mirror lens is located on a side close to the first light-combining lens, and the first wave plate is located on a side close to the third light-combining lens.

4. The laser light source according to claim 3, characterized in that If the first wave plate is located on a side close to the first light-combining lens, and the half-reflecting half-mirror lens is located on a side close to the third light-combining lens, the first wave plate is a 1 / 4 wave plate.

5. The laser light source according to claim 1, wherein: The laser light source further includes a second wave plate, which is located between the laser and the light combining lens group, or located on the light output side of the light combining lens group, and is used to change the phase of the incident laser light.

6. The laser light source according to claim 5, characterized in that The second wave plate covers part of the laser light emitted by the first laser array, the second laser array and the third laser array or part of the laser light emitted through the light combining lens group, so as to change the phase of the part of the laser light.

7. A laser projection device, characterized in that: The laser projection device comprises: a first diffusion element, a homogenization element, a light valve modulation device, a total reflection prism, a projection lens, and the laser light source according to any one of claims 1 to 6; Wherein, the first diffusion element is located on the light-emitting side of the laser light source, and is used to diffuse the laser light emitted by the laser light source; The homogenizing element is located on the light-emitting side of the first diffusing element and is used to homogenize the laser light emitted by the first diffusing element. The homogenized laser light is reflected by the total reflection prism to the light valve modulation device, so that the light valve modulation device modulates the laser light. The modulated laser light is incident on the projection lens through the total reflection prism.

8. The laser projection device according to claim 7, characterized in that: The homogenizing element is a light pipe or a micro lens array.

9. The laser projection device according to claim 8, characterized in that: If the homogenizing element is a light pipe, the laser projection device further comprises: a converging lens and a second diffusing element; The converging lens is located on the light-emitting side of the first diffusing element and is used to converge the laser light emitted by the first diffusing element; The second diffusion element is located between the converging lens and the homogenizing element, and is used to diffuse the converged laser light and transmit the diffused laser light to the homogenizing element.

10. The laser projection device according to claim 8, characterized in that: If the homogenizing element is a microlens array, the laser projection device further comprises: an illumination lens assembly; The lighting mirror assembly is located between the homogenizing element and the total reflection prism, and is used to adjust the angle at which the laser light emitted from the homogenizing element is incident on the total reflection prism.

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