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WO2025189976A1 - Source de lumière laser et dispositif de projection laser - Google Patents

Source de lumière laser et dispositif de projection laser

Info

Publication number
WO2025189976A1
WO2025189976A1 PCT/CN2025/073920 CN2025073920W WO2025189976A1 WO 2025189976 A1 WO2025189976 A1 WO 2025189976A1 CN 2025073920 W CN2025073920 W CN 2025073920W WO 2025189976 A1 WO2025189976 A1 WO 2025189976A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
laser
chip array
combining
mirror
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/CN2025/073920
Other languages
English (en)
Chinese (zh)
Inventor
李巍
田有良
顾晓强
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Qingdao Hisense Laser Display Co Ltd
Original Assignee
Qingdao Hisense Laser Display Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN202410288362.9A external-priority patent/CN120652726A/zh
Priority claimed from CN202410288027.9A external-priority patent/CN120652725A/zh
Application filed by Qingdao Hisense Laser Display Co Ltd filed Critical Qingdao Hisense Laser Display Co Ltd
Publication of WO2025189976A1 publication Critical patent/WO2025189976A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/10—Beam splitting or combining systems
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/28—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details
    • G03B21/20—Lamp housings

Definitions

  • the embodiments of the present application relate to laser display technology, and more specifically, to a laser light source and a laser projection device.
  • a three-color laser light source can be used as a projection light source in high-quality, 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.
  • a laser light source comprising:
  • a laser light emitting assembly includes a plurality of laser chip arrays, wherein the same laser chip array emits laser light of the same color;
  • a light combining component located on the light-emitting side of the light-emitting component, for combining the laser beams emitted by multiple laser chip arrays;
  • the phase modulation element is used to change the phase of the incident target light beam at least once.
  • a second aspect of the embodiments of the present application provides a laser projection device, comprising: a diffusion component, a homogenizing element, a light valve modulation device, a total reflection prism, a projection lens, and any of the above laser light sources;
  • the diffusion component 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 laser light source and is used to homogenize the laser.
  • the homogenized laser is reflected by the total reflection prism to the light valve modulation device, so that the light valve modulation device modulates the laser.
  • the modulated laser is incident on the projection lens through the total reflection prism.
  • FIG1 is a schematic structural diagram of a laser projection device
  • FIG2 is a first structural diagram of a laser light source provided in an embodiment of the present application.
  • FIG3 is a second structural diagram of a laser light source provided in an embodiment of the present application.
  • FIG4 is a third structural diagram of a laser light source provided in an embodiment of the present application.
  • FIG5 is a schematic diagram of the distribution of light spots corresponding to the combined laser beams provided in an embodiment of the present application.
  • FIG6 is a fourth structural diagram of a laser light source provided in an embodiment of the present application.
  • FIG7 is a schematic diagram showing the relationship between a second wave plate and a corresponding light spot of a laser emitted from a light emitting component provided in an embodiment of the present application;
  • FIG8 is 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;
  • FIG9 is a schematic diagram of a curve showing changes in reflectivity of S light and P light as a function of incident angle, provided in an embodiment of the present application;
  • FIG10 is a first structural diagram of a laser projection device provided in an embodiment of the present application.
  • FIG11 is a second structural diagram of a laser projection device provided in an embodiment of the present application.
  • FIG12 is a third structural diagram of a laser projection device provided in an embodiment of the present application.
  • FIG13 is a fourth structural diagram of a laser light source provided in an embodiment of the present application.
  • FIG14 is a schematic diagram of an arrangement of laser chips provided in an embodiment of the present application.
  • FIG15 is a fifth structural diagram of a laser light source provided in an embodiment of the present application.
  • FIG16 is a schematic diagram of an arrangement of first target areas provided in an embodiment of the present application.
  • FIG17 is a first schematic diagram of a target light beam irradiating a phase modulation element according to an embodiment of the present application.
  • FIG18 is a second schematic diagram of a target light beam irradiating a phase modulation element according to an embodiment of the present application.
  • FIG19 is a sixth structural diagram of a laser light source provided in an embodiment of the present application.
  • FIG20 is a seventh structural diagram of a laser light source provided in an embodiment of the present application.
  • FIG21 is a fourth structural diagram of a laser projection device provided in an embodiment of the present application.
  • FIG22 is 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;
  • FIG23 is a fifth structural diagram of a laser projection device provided in an embodiment of the present application.
  • FIG 1 is a schematic diagram of the structure of a laser projection device.
  • the laser light source includes a light-emitting assembly 11 that can emit red, green, and blue laser light.
  • Light-emitting assembly 11 may include laser chip arrays 111, 112, and 113 that emit red, green, and blue laser light, and a collimator.
  • the laser chip arrays that emit red, green, and blue laser light are integrated into a single light-emitting assembly. After emission, the laser light is collimated by the collimator before exiting. The collimator is not shown in Figure 1 .
  • Red laser light is typically P light
  • 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 lights form a uniformly polarized P light.
  • the red, green, and blue laser lights are combined using multiple light-combining mirrors 121, 122, and 123 included in the light-combining assembly 12. After combining, the red, green, and blue laser lights are homogenized by the diffuser 13, then homogenized by the fly-eye lens 14.
  • the combined light is then converged by the first and second illumination lenses 151, 152 included in the illumination lens assembly 15, and incident on the total internal reflection prism 17. After being fully reflected by the total internal reflection prism 17, the light enters the DMD (Digital Micromirror Device) 16. After reflection from the DMD 16, it passes through the total internal reflection prism 17 and is then projected through the projection lens 18 to form an image.
  • DMD
  • each laser chip array includes multiple laser chips.
  • a laser light source includes two laser chip arrays emitting red lasers, meaning two rows of laser chips emitting red lasers, and one laser chip array emitting blue and green lasers, meaning the corresponding laser chips are in one row. This results in poor size consistency for the different color spots, leading to larger and different sizes for the combined red, green, and blue light spots, which can also affect the display quality.
  • the laser phase can be expanded.
  • the present application provides a laser light source and laser projection device.
  • the laser light source includes a light-emitting component, a light-combining component, and a phase modulation element.
  • the phase modulation element can change the phase of the incident laser beam at least once, thereby changing the target beam from a single phase to a multi-phase beam, achieving phase expansion, which is beneficial for reducing speckle and improving image display effects.
  • FIG2 is a structural schematic diagram of a laser light source provided in an embodiment of the present application.
  • the laser light source includes:
  • the light emitting assembly 21 includes a first laser chip array 211 , a second laser chip array 212 and a third laser chip array 213 , and is configured to emit lasers of different colors.
  • the light combining component 22 is located on the light emitting side of the light emitting component 21 and is used to combine lasers of different colors.
  • the light combining assembly includes multiple light combining mirrors, at least one of which can function as the aforementioned phase modulator, capable of altering the phase of the incident target light beam at least once. This shifts the target light beam from a single phase to a multi-phase beam, achieving phase expansion, which helps reduce speckle and improve image quality.
  • the beam combiner a phase modulator, includes a first surface and a second surface opposite the first.
  • the first surface transmits the incoming target beam and modifies its phase, while the second surface partially transmits and partially reflects the incoming target beam. This allows the combined target beam to shift from a single phase to multiple phases while also increasing its etendue and reducing speckle.
  • the light combining component 22 may include a first light combining mirror 221, a second light combining mirror 222 and a third light combining mirror 223 arranged in sequence.
  • the first light combining mirror 221, the second light combining mirror 222 and the third light combining mirror 223 are respectively located on the light output sides of the first laser chip array 211, the second laser chip array 212 and the third laser chip array 213.
  • the second light-combining mirror 222 serves as a phase modulation element, including 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 emitted by the second laser chip array 212 or the laser emitted by the first laser chip array 211 to the second light-combining mirror 222 through the first light-combining mirror 221.
  • the first light-combining mirror 221 is used to reflect the laser light emitted from the first laser chip array 211 to the second light-combining mirror 222 , and to reflect the laser light emitted from the second light-combining mirror 222 to the first light-combining mirror 221 to the third light-combining mirror 223 .
  • the third light-combining mirror 223 is configured to reflect the laser light emitted from the third laser chip array 213 and transmit the laser light emitted from the first light-combining mirror 221 and the second light-combining mirror 222 to the third light-combining mirror 223 .
  • the lasers emitted by the first laser chip array 211 , the second laser chip array 212 , and the third laser chip array 213 have different colors, and the number of laser chip arrays emitting lasers of different colors may be one or more.
  • the laser light source can emit red, green, and blue lasers.
  • the first laser chip array 211 can emit green laser
  • the second laser chip array 212 can emit blue laser
  • the third laser chip array 213 can emit red laser.
  • Each laser chip array may include multiple laser chips that emit laser light.
  • the laser chips within the same laser chip array may emit laser light of the same color.
  • the laser chips may be arranged in an array; this application does not limit the number or arrangement of the laser chips.
  • the first light-combining mirror 221, the second light-combining mirror 222 and the third light-combining mirror 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 chip array, and then emit it in the direction of the light outlet of the light source. Therefore, the first light-combining mirror 221, the second light-combining mirror 222 and the third light-combining mirror 223 can be arranged in sequence in the direction of the light outlet of the laser light source, and at least one light-combining mirror 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 direction of the light outlet of the laser light source.
  • the first light-combining mirror 221 may be located on a side away from the light outlet
  • the third light-combining mirror 223 may be located on a side close to the light outlet
  • the second light-combining mirror 222 may be located between the first light-combining mirror 221 and the third light-combining mirror 223 .
  • the first light-combining mirror 221 since the first light-combining mirror 221 only reflects the incident laser light, the first light-combining mirror 221 may be a reflective mirror.
  • the laser light emitted by the first light-combining mirror 221 to the third light-combining mirror 223 can be the laser light emitted by the first laser chip array 211 or the laser light emitted by the second laser chip array 212.
  • the laser light emitted by the second light-combining mirror 222 to the third light-combining mirror 223 can be the laser light emitted by the first laser chip array 211 or the laser light emitted by the second laser chip array 212.
  • the laser light emitted by the first and second light-combining mirrors 221 and 222 to the third light-combining mirror 223 has a different color, that is, a different wavelength, than the laser light emitted by the third laser chip array 213. Therefore, the third light-combining mirror 223 can be a dichroic mirror.
  • the first surface S1 included in the second light-combining mirror 222 can be located on the side close to the first light-combining mirror 221, and the second surface S2 is located on the side close to the third light-combining mirror 223; or, the second surface S2 is located on the side close to the first light-combining mirror 221, and the first surface S1 is located on the side close to the third light-combining mirror 223.
  • the laser light emitted by the first laser chip array is reflected by the first light-combining mirror 221 onto the first surface S1, where it undergoes phase change before being transmitted to the second surface S2.
  • the second surface S2 transmits a portion of the laser light to the third light-combining mirror 223 for beam combining before being emitted.
  • the second surface S2 also reflects a portion of the laser light onto the first surface S1, where it undergoes phase change before being transmitted to the first light-combining mirror 221.
  • the portion is then reflected by the first light-combining mirror 221 onto the third light-combining mirror 223 to be combined with the laser light emitted by the third laser chip array before being emitted.
  • the laser emitted by the first laser chip array based on the second surface S2 part of the reflected laser passes through the first surface twice, and part of the transmitted laser 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 changed phase is different. Therefore, after passing through the second surface S2, the phases of the reflected part of the laser and the transmitted part of the laser are different.
  • the laser emitted by the first laser chip array is changed from a single-phase beam to a multi-phase beam, realizing phase expansion, which is conducive to eliminating speckle. At the same time, the laser is also changed from one beam to two beams, and the optical expansion is increased, which is also conducive to eliminating speckle.
  • the laser is incident on the second surface S2, and the second surface S2 reflects part of the laser to the third light-combining mirror 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 mirror 221, and is reflected by the first light-combining mirror 221 to the third light-combining mirror 223, so as to be combined with the laser emitted by the third laser chip array and then emitted.
  • the second surface S2 is located on a side close to the first light-combining mirror 221, and the first surface S1 is located on a side close to the third light-combining mirror 223.
  • 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 the side close to the first light-combining mirror 221, and the second surface S2 is located on the side close to the third light-combining mirror 223, which will not be repeated here.
  • the present application provides a laser light source, including a light-emitting component 21 and a light-combining component 22.
  • the light-combining component 22 includes a first light-combining mirror 221, a second light-combining mirror 222, and a third light-combining mirror 223 arranged in sequence, which are respectively located on the light-emitting sides of the first laser chip array 211, the second laser chip array 212, and the third laser chip array 213.
  • the second light-combining mirror 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.
  • 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.
  • 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.
  • the second light-combining mirror 222 includes a first wave plate and a half-reflecting half-mirror, or the second light-combining mirror 222 is an integration of the first wave plate and the half-reflecting half-mirror.
  • the surface of the first wave plate serves as the first surface
  • the surface of the half-reflecting half-mirror lens serves as the second surface
  • the first wave plate is located on a side close to the first light combining mirror 221, and the half-reflective half-mirror is located on a side close to the third light combining mirror 223; or, the half-reflective half-mirror is located on a side close to the first light combining mirror 221, and the first wave plate is located on a side close to the third light combining mirror 223.
  • Figure 3 is a second schematic diagram of the structure of a laser light source provided in an embodiment of the present application.
  • the second light-combining mirror 222 includes a first wave plate 2221 and a half-reflecting half-mirror 2222.
  • the first wave plate 2221 is located on one side of the first light-combining mirror 221, and the half-reflecting half-mirror 2222 is located on the side close to the third light-combining mirror 223.
  • Figure 4 is a third schematic diagram of the structure of a laser light source provided in an embodiment of the present application. At this time, the half-reflecting half-mirror 2222 is located on the side close to the first light-combining mirror 221, and the first wave plate 2221 is located on the side close to the third light-combining mirror 223.
  • the first laser chip array 211 emits green laser light
  • the second laser chip array 212 emits blue laser light
  • the two third laser chip arrays 213 emit red laser light. The details are as follows:
  • the green laser light emitted by the first laser chip array 211 is incident on the first light-combining mirror 221, reflected by the first light-combining mirror 221 to the first wave plate 2221, and then, after its phase is changed by the first wave plate 2221, emitted to the semi-reflecting mirror 2222.
  • the semi-reflecting mirror 2222 transmits a portion of the green laser light to the third light-combining mirror 223, and the transmitted portion of the green laser light is recorded as TG; the semi-reflecting 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 its phase is changed again by the first wave plate 2221, emitted to the first light-combining mirror 221, and reflected by the first light-combining mirror 221 to the third light-combining mirror 223.
  • one beam of green laser is converted into two beams based on the half-reflecting half-mirror 2222.
  • 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.
  • the blue laser emitted by the second laser chip 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 mirror 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.
  • the phase is changed by the first wave plate 2221, it is emitted to the first light-combining mirror 221, and is reflected by the first light-combining mirror 221 to the third light-combining mirror 223.
  • a beam of blue laser is converted into two beams based on the half-reflecting half-mirror 2222.
  • 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.
  • the laser light source includes two third laser chip arrays 213 emitting red laser light, which can be denoted as 213a and 213b, respectively.
  • the red laser light RR1 emitted by the third laser chip array 213a is reflected by the third beam-combining mirror 223 before being emitted.
  • the third beam-combining mirror 223 transmits a portion of the blue laser light RB reflected by the half-reflecting half-mirror lens and a portion of the green laser light TG transmitted therethrough, combining them with the red laser light RR1.
  • This combined laser light can be denoted as the first beam M.
  • the red laser RR2 emitted by the third laser chip array 213b is incident on the third light-combining mirror 223, and is emitted after being reflected by the third light-combining mirror 223.
  • the transmitted portion of the blue laser TB and the reflected portion of the green laser RG emitted by the first light-combining mirror 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.
  • 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:
  • Table 1 shows the laser light contained in the first beam M and the second beam N, as well as the number of times the laser light passes through the first wave plate, when the first wave plate is located on the side close to the first beam combiner and the half-reflecting half-mirror is located on the side close to the third beam combiner.
  • FIG5 is a schematic diagram of the distribution of light spots corresponding to the combined laser beams provided in an embodiment of the present application.
  • two rows of light spots are included, each row of light spots including a red light spot SR corresponding to the red laser, a green light spot SG corresponding to the green laser, and a blue light spot SB corresponding to the blue laser.
  • the first row of light spots corresponds to the laser beams included in the second beam N
  • the second row of light spots corresponds to the laser beams included in the first beam M.
  • the half-reflecting half-mirror 2222 is located on a side close to the first light-combining mirror 221, and the first wave plate 2221 is located on a side close to the third light-combining mirror 223, then for the green laser, it is reflected to the half-reflecting half-mirror 2222 by the first light-combining mirror 221.
  • part of the green laser RG is reflected back to the first light-combining mirror 221, and is reflected again to the third light-combining mirror 223 by the first light-combining mirror 221; part of the green laser TG is transmitted to the first wave plate 2221, and is incident on the third light-combining mirror 223 after the phase is changed by the first wave plate 2221.
  • 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.
  • the blue laser light is incident on the first wave plate 2221, has its phase changed by the first wave plate 2221, and then is emitted to the semi-reflecting mirror 2222.
  • part of the blue laser light RB is reflected back to the first wave plate 2221, has its phase changed again by the first wave plate 2221, and then is emitted to the third light-combining mirror 223.
  • Part of the blue laser light TB is transmitted through the first light-combining mirror 221 and reflected by the first light-combining mirror 221 to the third light-combining mirror 223.
  • 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.
  • the third light-combining mirror 223 combines the portion of green laser light TG transmitted by the semi-reflecting mirror 2222 and the portion of blue laser light RB reflected by the semi-reflecting mirror 2222, as well as the red laser light RR1 emitted by the third laser chip array 213a, to produce a first light beam M.
  • the portion of green laser light RG reflected by the first light-combining mirror 221 and the portion of blue laser light TB transmitted by the first light-combining mirror 221, as well as the laser light emitted by the third laser chip array 213b, are combined to produce a second light beam N.
  • 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:
  • Table 2 shows 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, when the half-reflecting half-mirror is located on the side close to the first beam combiner and the first wave plate is located on the side close to the third beam combiner:
  • the first wave plate 2221 is located on the side close to the first light combining mirror 221, and the half-reflective half-mirror 2222 is located on the side close to the third light combining mirror 223, or the first wave plate 2221 is located on the side close to the third light combining mirror 223, and the half-reflective half-mirror 2222 is located on the side close to the first light combining mirror 221.
  • the blue laser and the green laser a single light beam is changed into a multi-phase light beam, achieving phase expansion, thereby effectively reducing the speckle phenomenon.
  • the green laser light emitted by the first laser chip array 211 and the blue laser light emitted by the second laser chip array 212 are split into two beams, increasing the etendue. This increase in etendue also helps reduce the energy of sharp speckle, thereby reducing the speckle effect. Furthermore, when the laser light source includes two third laser chip arrays 213 emitting red laser light, the difference in size between the green, blue, and red laser light spots is reduced, further improving the display quality.
  • the second light-combining mirror 222 is an integration of the first wave plate 2221 and the half-reflective half-mirror 2222. At this time, the second light-combining mirror 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 mirror 222 in the above embodiment. Please refer to the above and will not be repeated here.
  • FIG 6 is a fourth structural schematic diagram of a laser light source provided in an embodiment of the present application.
  • the laser light source also includes a second wave plate 23, which is located between the light-emitting component and the light-combining component 22, or on the light-emitting side of the light-combining component 22, and is used to change the phase of the incident laser.
  • the second wave plate 23 covers part of the laser light emitted by the first laser chip array 211 , the second laser chip array 212 and the third laser chip array 213 or part of the laser light emitted by the light combining component 22 to change the phase of part of the laser light.
  • FIG7 is a schematic diagram showing the relationship between a second wave plate and the corresponding light spot of the laser emitted from the light-emitting component, provided in an embodiment of the present application.
  • part of the laser light emitted from the light-emitting component can pass through the second wave plate 23, while part of the laser light does not pass through the second wave plate 23.
  • the phase of the part of the laser light passing through the second wave plate 23 is different from that of the part of the laser light not passing through the second wave plate 23, thereby achieving the diversity of the laser phase, which is beneficial to reducing the speckle phenomenon and improving the picture display effect.
  • the second light combining mirror 222 may include a first wave plate 2221 and a half-reflective half-mirror 2222, or the second light combining mirror 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.
  • 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.
  • 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.
  • the first wave plate 2221 when the first wave plate 2221 is located on a side close to the first light combining mirror 221 and the half-reflecting half-mirror 2222 is located on a side close to the third light combining mirror 223 , the first wave plate 2221 is a 1/4 wave plate.
  • FIG8 is a 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.
  • 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.
  • the 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.
  • the laser light can be reflected to the third surface P3, and is transmitted to the fifth surface P5 through the third surface P3, the second surface P2, and the fourth surface P4 in sequence, and then is emitted to the projection lens 26 through the fifth surface P5.
  • 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.
  • the green laser light emitted by the first laser chip array 211 and the blue laser light emitted by the second laser chip array 212 are S light
  • the red laser light emitted by the third laser chip array 213 is P light.
  • FIG9 is a schematic diagram of a curve showing the change in reflectivity of S light and P light with the incident angle according to an embodiment of the present application.
  • the incident angle increases, the reflectivity of both S light and P light gradually increases.
  • the difference in reflectivity between S light and P light is small.
  • the difference in reflectivity between S light and P light becomes larger, and the reflectivity of S light is significantly greater than that of P light.
  • the transmittance of S light is less than that of P light.
  • 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. This can reduce the speckle phenomenon while ensuring a higher laser utilization rate.
  • 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.
  • 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.
  • the present application can set most of the laser light included in the second light beam N as P light.
  • 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.
  • both the first light beam M and the second light beam N contain red, green, and blue laser light.
  • 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
  • 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.
  • 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.
  • 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.
  • 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 ⁇ /4.
  • 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 ⁇ /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.
  • the red laser light in the first light beam M and the second light beam N are both P light.
  • 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.
  • 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.
  • 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.
  • 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.
  • the first wave plate 2221 can be a quarter wave plate or other wave plates, and can be set according to actual needs.
  • the first wave plate 2221 can be a 1/4 wave plate, which can effectively ensure a high laser utilization rate and is also beneficial to reduce speckle phenomenon and improve display effect.
  • FIG 10 is a structural schematic diagram of a laser projection device provided in an embodiment of the present application.
  • the laser projection device includes: a diffusion component, a homogenization element 28, a light valve modulation device 25, a total reflection prism 24, a projection lens 26 and a laser light source of any one of the above embodiments.
  • the diffusion assembly includes a first diffusion element 27 located at 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 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.
  • 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.
  • the homogenizing element 28 is a light pipe or a micro-lens array, wherein the micro-lens array can be a fly-eye lens.
  • FIG11 is a second structural diagram of a laser projection device provided in an embodiment of the present application.
  • the laser projection device further includes: a converging lens and a second diffusion element;
  • 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 from the first diffusion element 27;
  • the second diffusion element is located between the converging lens and the homogenizing element 28 , and is used to diffuse the converged laser light and transmit the diffused laser light to the homogenizing element 28 .
  • the laser light emitted by the laser light source is combined by the light combining assembly 22, and after its phase is changed, it is emitted to the second wave plate 23.
  • the second wave plate 23 changes the phase of a portion of the laser light, it is emitted to the first diffusion element 27.
  • the light guide After diffusion by the first diffusion element 27, convergence by the converging lens, and diffusion by the second diffusion element, it is incident on the light guide for homogenization.
  • the total reflection prism 24, DMD, and projection lens 26 for projection.
  • Figure 11 does not show the total reflection prism, DMD, and projection lens 26. Their positional relationship can be seen in Figure 10.
  • 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.
  • 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.
  • FIG12 is a third structural diagram of a laser projection device provided in an embodiment of the present application.
  • the laser projection device further includes: an illumination lens group 31 .
  • the illumination lens 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 .
  • the lighting mirror group may include one or more lighting lenses.
  • the lighting mirror group shown in Figure 12 includes a first lighting lens 311 and a second lighting lens 312, which adjust the angle of the laser incident on the total reflection prism 24 so that the laser incident on the DMD meets the angle and size required by the DMD.
  • the laser light emitted by the laser light source has its phase changed by the light combining component 22, and is then combined and emitted to the first diffusion element 27. After passing through the first diffusion element 27, the homogenizing element 28, and the total reflection prism 24, it is incident on the light valve modulator 25. After being modulated by the light valve modulator 25, the modulated laser light is incident on the projection lens 26 through the total reflection prism 24 to realize image display.
  • speckle is typically generated by the interference of homochromatic light
  • speckle reduction can be performed on homochromatic light, i.e., laser light of the same color.
  • homochromatic light i.e., laser light of the same color.
  • the laser light of the same color becomes a multi-phase beam, effectively reducing the speckle phenomenon.
  • the phase modulation element may include multiple first target areas, and the first target areas are used to change the phase of the target light beam. 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 beam of single phase before passing through multiple first target areas, it changes to different phases after passing through 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 from the phase modulation element, achieving phase expansion, thereby effectively reducing the speckle phenomenon, and is beneficial to improving the display effect of the projection display screen.
  • FIG13 is a fourth structural diagram of a laser light source provided in an embodiment of the present application.
  • the laser light source includes:
  • the light emitting assembly 21 includes a plurality of laser chip arrays.
  • Each laser chip array includes a plurality of laser chips.
  • the plurality of laser chips in the same laser chip array emit laser light of the same color.
  • the light combining component 22 is located on the light emitting side of the light emitting component 21 and is used to combine the laser beams emitted by multiple laser chip arrays.
  • the phase modulation element 29 includes a plurality of first target areas, each of which 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 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 chip arrays and a light combining component 22 .
  • Each laser chip array includes multiple laser chips.
  • the laser light emitted by the multiple laser chips in the same laser chip array is the same color, meaning that a single laser chip array can emit laser light of a single color.
  • the laser light emitted by different laser chip arrays can be the same or different in color.
  • the light-emitting assembly 21 can include two or more laser chip arrays that emit laser light of the same color.
  • FIG14 is a schematic diagram of a laser chip arrangement according to an embodiment of the present application. Referring to FIG14 , four rows and seven columns of laser chips are shown. Multiple laser chips can be arranged in an array.
  • the first row is a green laser chip array LG , comprising seven green laser chips emitting green laser light.
  • the second row is a blue laser chip array LB , comprising seven blue laser chips emitting blue light.
  • the third and fourth rows are both red laser chip arrays LR , each comprising seven red laser chips emitting red laser light.
  • the target beam includes laser light emitted by at least one of the multiple laser chip arrays and the light combining assembly 22.
  • the target beam corresponding to the laser chip array includes laser light emitted by multiple laser chips.
  • the target beam is laser light of a single color.
  • the target beam corresponding to the green laser chip array LG shown in FIG14 is a beam of green laser light emitted by seven green laser chips.
  • the corresponding target beam is the laser light emitted by the multiple laser chip arrays, which is the laser light after being combined. If the light emitting component 21 can emit red, green and blue laser light, the target beam after being combined by the light combining component 22 contains three colors of laser light.
  • Figure 14 only shows an exemplary arrangement of lasers. Other numbers of lasers and arrangements may also be used. The embodiments of this application are only used for illustration and do not limit the laser chips, the number of laser chips, and the arrangement.
  • the light-emitting component 21 of this application may be a monochromatic laser, a two-color laser, or a three-color laser, etc.
  • Figure 15 is a fifth structural schematic diagram of a laser light source provided in an embodiment of the present application.
  • the light-emitting component 21 may also 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 chip arrays of the present application are located in the receiving space.
  • the light-emitting component 21 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.
  • Figure 16 is a schematic diagram of an arrangement of first target areas provided in an embodiment of the present application.
  • Each small rectangular area shown in Figure 16 is a first target area, wherein the multiple first target areas corresponding to A change the phase of the laser at the same time, the multiple first target areas corresponding to B change the phase of the laser at the same time, and the multiple first target areas corresponding to C change the phase of the laser at the same time.
  • the multiple first target areas shown in FIG16 are arranged in an array in a certain regular pattern, or they can be arranged randomly. At the same time, the multiple first target areas shown in FIG16 include areas with the same laser phase change, such as multiple areas A, multiple areas B, etc. In another implementation scenario, among the multiple first target areas, the laser phase changes of any two first target areas are different.
  • Figure 16 only shows an example of the shape and arrangement of a first target area.
  • the shapes and areas of different first target areas can be the same or different, and can 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.
  • each laser chip array is a single-phase beam before passing through the phase modulation element 29.
  • each laser chip can emit laser light, so the target beam corresponding to the laser chip array contains laser light emitted by multiple laser chips.
  • Figure 17 is a schematic diagram of a target beam irradiated onto a phase modulation element provided by an embodiment of the present application. Referring to Figure 17, the laser light emitted by each laser chip will present an elliptical light spot when irradiated onto the phase modulation element 29.
  • the laser light emitted by different laser chips irradiates different positions on the phase modulation element 29, that is, the laser light emitted by different laser chips irradiates different first target areas of the phase modulation element 29.
  • the target beam corresponding to the laser chip array covers multiple first target areas. Since different target areas change the phase of the laser light differently, the target beam emitted after passing through the phase modulation element 29 becomes a multi-phase beam.
  • the explanation is based on a laser chip included in any laser chip array.
  • the laser emitted by a laser chip corresponds to a light spot shown in Figure 17.
  • the area of each light spot shown in Figure 17 is smaller than the area of its corresponding first target area. Since the phase of the laser is changed in a first target area, for the laser emitted by the laser chip, after passing through the first target area, although the phase changes, the phase of the emitted laser remains the same.
  • the phases of the lasers corresponding to the different laser chips differ after exiting from the different first target areas.
  • the phase of the laser emitted by the first laser chip changes to P1
  • the phase of the laser emitted by the second laser chip changes to P2
  • the phase of the laser emitted by the Nth laser chip changes to PN, where N is a positive integer greater than 2 and P1 ⁇ P2 ⁇ PN.
  • the corresponding target beam contains lasers emitted by N lasers. Therefore, after passing through multiple first target areas, the target beam becomes a multi-phase beam, effectively reducing the speckle phenomenon.
  • SR shown in FIG17 represents the light spot corresponding to the red laser, which is P-polarized light
  • SG represents the light spot corresponding to the green laser
  • SB represents the light spot corresponding to the blue laser, both of which are S-polarized light.
  • One light spot corresponds to one laser chip.
  • FIG18 is a second schematic diagram of a target beam irradiating a phase modulation element according to an embodiment of the present application.
  • a single light spot covers multiple first target areas. That is, after the laser light emitted by a laser chip is incident on the phase modulation element 29, 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 chip becomes a multi-phase beam after passing through the phase modulation element 29. Similarly, the laser light emitted by the other laser chips included in the laser chip array also becomes a multi-phase beam after passing through the phase modulation element 29. Therefore, the target beam corresponding to the laser chip array, which includes laser light emitted by multiple laser chips, is also a multi-phase beam. In this case, the phases of the target beam are more diverse, effectively reducing speckle.
  • the phase modulation element 29 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.
  • the phase modulation element 29 can be located in the subsequent optical path of the light combining component 22, as shown in Figure 13. In some embodiments, the phase modulation element 29 can also be located between the light emitting component 21 and the light combining component 22. At this time, the laser emitted by the light emitting component 21 is phase-changed by the phase modulation element 29 and becomes a multi-phase light beam, and then is combined by the light combining component 22.
  • the embodiment of the present application provides a laser light source including a light-emitting component 21, a light-combining component 22 and a phase modulation element 29.
  • the light-emitting component 21 emits laser light, which can be combined by the light-combining component 22.
  • the phase modulation element 29 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.
  • laser light of the same color in the target light beam can cover multiple first target areas, and laser light passing through different first target areas changes different phases. Therefore, the light beam of laser light of the same color after being emitted through multiple first target areas is a multi-phase light beam, which realizes phase expansion, effectively reduces the speckle phenomenon, and is conducive to improving the display effect of the projection picture.
  • FIG 19 is a fifth structural schematic diagram of a laser light source provided in an embodiment of the present application.
  • multiple laser chip arrays are divided into a first laser chip array 211, a second laser chip array 212, and a third laser chip array 213;
  • the light combining component 22 includes: a first light combining mirror 221, a second light combining mirror 222, and a third light combining mirror 223.
  • the first light-combining mirror 221 is located on the light-emitting side of the first laser chip array 211 and is used to reflect the laser light emitted by the first laser chip array 211.
  • the second light-combining mirror 222 is located on the light-emitting side of the second laser chip array 212 and includes a first surface S1 and a second surface S2 opposite to the first surface S1.
  • the first surface S1 is the surface closest to the first light-combining mirror 221 and is used to transmit the laser light emitted by the first laser chip array 211 and reflect the laser light emitted by the second laser chip array 212.
  • the third light-combining mirror 223 is located on the light-emitting side of the third laser chip array 213 and includes a third surface S3 and a fourth surface S4 opposite to the third surface S3.
  • the third surface S3 is the surface closest to the second surface S2 and is used to transmit the laser light emitted by the first laser chip array 211 and the second laser chip array 212 and reflect the laser light emitted by the third laser chip array 213.
  • the second surface S2 includes multiple second target areas, the lasers emitted by the first laser chip array 211 and the second laser chip array 212 cover the multiple second target areas, the second target areas are used to change the phases of the lasers emitted by the first laser chip array 211 and the second laser chip array 212, and different second target areas change the phases of the lasers differently, and/or, the fourth surface S4 includes multiple third target areas, the lasers emitted by the first laser chip array 211, the second laser chip array 212, and the third laser chip array 213 cover the multiple third target areas, the third target areas are used to change the phases of the lasers emitted by the first laser chip array 211, the second laser chip array 212, and the third laser chip array 213, and different third target areas change the phases of the lasers differently.
  • the light-combining component 22 may only have a light-combining function, and the laser phase may be changed by the phase modulation element 29.
  • the specific principle may refer to the above embodiment.
  • the second light-combining mirror 222 and the third light-combining mirror 223 included in the light-combining component 22 may be dichroic films.
  • the light-combining assembly 22 can combine light and also change the phase of the laser beam.
  • the light-combining function can be achieved based on the first surface S1 of the first light-combining mirror 221, the second light-combining mirror 222, and the third surface S3 of the third light-combining mirror 223.
  • the first surface S1 of the second light-combining mirror 222 and/or the third surface S3 of the third light-combining mirror 223 are coated with a selective transmission film.
  • 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.
  • 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.
  • the light combining component 22 can change the phase of the laser based on the second surface S2 of the second light combining mirror 222 and/or the fourth surface S4 of the third light combining mirror 223.
  • the second light combining mirror 222 and/or the third light combining mirror 223 are liquid crystal elements. Specifically, the second surface S2 of the second light combining mirror 222 and/or the fourth surface S4 of the third light combining mirror 223 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 22 can be used alone or in combination with the phase modulation element 29. When the two are used in combination, the phase of the laser can be changed multiple times, which is conducive to further reducing the speckle phenomenon.
  • the following example uses the first laser chip array 211 emitting green laser light, the second laser chip array 212 emitting blue laser light, and the third laser chip array 213 emitting red laser light.
  • the colors of the laser light emitted by the first laser chip array 211 , the second laser chip array 212 , and the third laser chip array 213 are not limited.
  • the green laser light after being reflected by the first light-combining mirror 221, the green laser light is incident on the first surface S1 of the second light-combining mirror 222. It is then transmitted through the first surface S1 and emitted onto the second surface S2 of the second light-combining mirror 222. Since the green laser light irradiates the second surface S2, it presents multiple corresponding light spots. The number of light spots is the same as the number of laser chips included in the first laser chip array 211, i.e., one light spot for each laser chip. These multiple light spots can cover multiple second target areas. Different second target areas have different abilities to change the laser phase. Therefore, after emitting from the second surface S2, the green laser light becomes a multi-phase beam and is incident on the third surface S3 of the third light-combining mirror 223.
  • the blue laser is incident on the second surface S2 of the second light-combining mirror 222, 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 second light-combining mirror 222, 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 third light-combining mirror 223.
  • the green laser and the blue laser are transmitted through the third surface S3 of the third light combining mirror 223 and incident on the fourth surface S4 of the third light combining mirror 223. 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.
  • the red laser is incident on the fourth surface S4 of the third light-combining mirror 223, and after the phase is changed by multiple third target areas of the fourth surface S4, it is transmitted to the third surface S3 of the third light-combining mirror 223, reflected by the third surface S3 to the fourth surface S4, and after the phase is changed again by multiple third target areas of the fourth surface S4, it is emitted into the subsequent optical path of the laser projection device.
  • 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.
  • 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.
  • the second light-combining mirror 222 only has a light-combining function, that is, it transmits the green laser light emitted by the first laser chip array 211 and reflects the blue laser light emitted by the second laser chip array 212.
  • the phase cannot be changed after passing through the second surface S2 of the second light-combining mirror 222. Instead, the green and blue laser light must be incident on the fourth surface S4 of the third light-combining mirror 223 to achieve phase expansion, thus becoming a multi-phase beam.
  • the fourth surface S4 of the third light-combining mirror 223 can also achieve phase expansion, so at this time, the red and green laser light also become multi-phase laser beams.
  • the third light-combining mirror 223 merely performs a light-combining function, namely transmitting the green and blue laser beams and reflecting the red laser beam, then, as can be seen above, since the green and blue laser beams can be phase-modulated by the second surface S2 of the second light-combining mirror 222, the phase of the red laser beam is not expanded. Therefore, speckle reduction for the red laser beam is not effectively achieved, and only that for the green and blue laser beams is effectively reduced. For the red laser beam, phase expansion can be achieved by adding a phase modulating element 29.
  • FIG20 is a seventh structural diagram of a laser light source provided in an embodiment of the present application.
  • the laser projection device further includes: a wave plate (23), the wave plate being located between the first laser chip array 211 and the first light combining mirror 221, or between the second laser chip array 212 and the second light combining mirror 222.
  • FIG20 illustrates an example of placing the wave plate between the first laser chip array 211 and the first light combining mirror 221.
  • the first laser chip array 211 emitting green laser
  • the second laser chip array 212 emitting blue laser
  • the third laser chip array 213 emitting red laser
  • the selective transmission film coated on the first surface S1 of the second light-combining mirror 222 is a polarization selective film
  • the wave plate is arranged between the first laser chip array 211 and the first light-combining mirror 221.
  • the green laser emitted by the first laser chip array 211 is converted from S light to P light after passing through the wave plate, and is incident on the first light-combining mirror 221. After being reflected by the first light-combining mirror 221, it is reflected to the first surface S1 of the second light-combining mirror 222.
  • 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.
  • the wave plate arranged can be a half-wave plate.
  • 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.
  • the selective transmission film coated on the third surface S3 of the third light-combining mirror 223 can be a dichroic film, which realizes partial light beam transmission and partial light beam reflection based on the wavelengths of different color lasers. Therefore, the selective transmission film coated on at least one of the first surface S1 and the third surface S3 is a dichroic film, that is, the first surface S1 and the third surface S3 cannot both be coated with polarization-selective films.
  • 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 second light-combining mirror 222 and the third light-combining mirror 223 can be referred to as shown above and will not be repeated here.
  • 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.
  • 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.
  • the second surface S2 may not have the function of changing the laser phase, and the phases of the red, green and three-color lasers can be changed through the fourth surface S4 of the third light-combining mirror 223 or the phase modulation element 29 to achieve phase expansion.
  • the selective transmission film coated on the third surface S3 of the third light-combining mirror 223 is a polarization-selective film, which reflects P light and transmits S light, and since both the blue laser light emitted by the second laser chip array 212 and the green laser light emitted by the first laser chip array 211 are S light, there is no need to install wave plates between the first laser chip array 211 and the first light-combining mirror 221, or between the second laser chip array 212 and the second light-combining mirror 222.
  • the selective transmission film coated on its first surface S1 can be a dichroic film, which transmits the green laser light and reflects the blue laser light based on wavelength.
  • the present application provides a light-combining assembly 22, comprising a first light-combining mirror 221, a second light-combining mirror 222, and a third light-combining mirror 223.
  • the second surface S2 of the second light-combining mirror 222 and/or the fourth surface S4 of the third light-combining mirror 223 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.
  • Figure 21 is a fourth structural schematic diagram of a laser projection device provided in an embodiment of the present application.
  • the laser projection device in addition to the light-emitting component 21, the light-combining component 22 and the phase modulation element 29, the laser projection device also includes: a diffusion component, a homogenization element 28, a light valve modulation device 25, a total reflection prism 24, and a projection lens 26.
  • the homogenizing element 28 may be a microlens array.
  • the laser projection device further includes an illumination lens assembly 31 .
  • the diffusion component can be a first diffusion element 27 located on the light-emitting side of the light-combining component 22 , and is used to diffuse the combined laser beams emitted by the light-combining component 22 .
  • the micro lens array (28) is located on the light output side of the diffusion component and is used to perform light homogenization on the laser light, and emit the laser light to the lighting mirror group 31, and then enter the light valve modulation device 25 after passing through the lighting mirror group 31 and the total reflection prism 24.
  • the light valve modulation device 25 modulates the laser light, and the modulated laser light passes through the total reflection prism 24 and is incident on the projection lens 26 .
  • the projection lens 26 is used to form an image of the modulated laser light.
  • the diffusion element in the diffusion assembly may be a diffusion sheet or a diffusion wheel, etc., which diffuses and homogenizes the incident laser light to reduce the speckle phenomenon.
  • the microlens array can be a fly-eye lens. After the laser light emitted by the fly-eye lens passes through the illumination lens assembly 31, it conforms to the size and incident angle required by the light valve modulation device 25.
  • Figure 22 is a schematic diagram of a target light beam based on a phase modulation element and a fly-eye lens according to an embodiment of the present application. Referring to Figure 22, each light spot not only corresponds to multiple first target areas, but also corresponds to multiple fly-eye lenses.
  • the lighting lens assembly 31 may include a first lighting lens 311 and a second lighting lens 312 .
  • the light valve modulation device 25 can be a DMD (Digital Micromirror Device).
  • the surface of the DMD includes thousands of tiny mirrors, each of which can be individually driven to deflect, for example, by plus or minus 12 degrees or plus or minus 17 degrees.
  • the light reflected at a positive deflection angle is ON light, which is the effective light beam that enters the projection lens 290 and is used for projection imaging.
  • the light reflected at a negative deflection angle is OFF light, which is the ineffective light that reaches the housing or is absorbed by a light absorption device.
  • the phase modulation element 29 is located between the light-emitting component 21 and the light-combining component 22, or between the light-combining component 22 and the diffusion component, or between the diffusion component and the microlens array, or between the microlens array and the illumination lens group 31, or between the total reflection prism 24 and the light valve modulation device 25, or between the total reflection prism 24 and the projection lens 26.
  • the selective transmission film coated on the first surface S1 of the second light combining mirror 222 or the third surface S3 of the third light combining mirror 223 can be a dichroic film or a polarization selective film.
  • Figure 23 is a structural schematic diagram five of a laser projection device provided in an embodiment of the present application.
  • the phase modulation element 29 shown in Figure 23 is located between the light-emitting component 21 and the light-combining component 22. Since the phase modulation element 29 can phase-modulate the red, green and blue lasers at this time, when the red, green and blue lasers are emitted after passing through the phase modulation element 29, 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 second light-combining mirror 222 and the third surface S3 of the third light-combining mirror 223 in the light-combining component 22 can be a dichroic film.
  • the embodiment of the present application is only an example to illustrate the position of the phase modulation element 29.
  • the position of the phase modulation element 29 can be set according to actual needs, and the present application does not limit this.
  • the present application provides a laser projection device.
  • the laser light emitted by the light-emitting component 21 is combined by the light-combining component 22 and then incident on the phase modulation element 29.
  • the emitted laser light is a multi-phase beam.
  • the total reflection prism 24 can reflect the laser light to the light valve modulation device 25.
  • the laser light is incident on the projection lens 26 through the total reflection prism 24 to generate a projection image.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Semiconductor Lasers (AREA)

Abstract

L'invention concerne une source de lumière laser et un dispositif de projection laser. La source de lumière laser comprend : un ensemble d'émission de lumière (21) comprenant un premier réseau de puces laser (211), un deuxième réseau de puces laser (212) et un troisième réseau de puces laser (213) qui sont utilisés pour émettre de la lumière laser de différentes couleurs ; un ensemble de combinaison de lumière (22) situé sur le côté de sortie de lumière de l'ensemble d'émission de lumière (21) et utilisé pour combiner la lumière laser émise par la pluralité de réseaux de puces laser (211, 212, 213) ; et un élément de modulation de phase (222) utilisé pour modifier au moins une fois la phase d'un faisceau lumineux cible incident.
PCT/CN2025/073920 2024-03-13 2025-01-22 Source de lumière laser et dispositif de projection laser Pending WO2025189976A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN202410288362.9A CN120652726A (zh) 2024-03-13 2024-03-13 激光光源及激光投影设备
CN202410288027.9 2024-03-13
CN202410288027.9A CN120652725A (zh) 2024-03-13 2024-03-13 一种激光投影设备
CN202410288362.9 2024-03-13

Publications (1)

Publication Number Publication Date
WO2025189976A1 true WO2025189976A1 (fr) 2025-09-18

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Application Number Title Priority Date Filing Date
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060221429A1 (en) * 2005-03-31 2006-10-05 Evans & Sutherland Computer Corporation Reduction of speckle and interference patterns for laser projectors
JP2012073477A (ja) * 2010-09-29 2012-04-12 Nikon Corp スペックル低減装置およびプロジェクタ
CN110082928A (zh) * 2019-04-30 2019-08-02 中北大学 一种基于偏振多样性与角度多样性结合的激光消散斑装置
CN113900342A (zh) * 2020-07-06 2022-01-07 青岛海信激光显示股份有限公司 光源组件和投影设备
CN216696895U (zh) * 2021-12-31 2022-06-07 成都极米科技股份有限公司 一种散斑消除组件及光源系统
CN218213763U (zh) * 2022-09-30 2023-01-03 青岛海信激光显示股份有限公司 一种投影设备

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060221429A1 (en) * 2005-03-31 2006-10-05 Evans & Sutherland Computer Corporation Reduction of speckle and interference patterns for laser projectors
JP2012073477A (ja) * 2010-09-29 2012-04-12 Nikon Corp スペックル低減装置およびプロジェクタ
CN110082928A (zh) * 2019-04-30 2019-08-02 中北大学 一种基于偏振多样性与角度多样性结合的激光消散斑装置
CN113900342A (zh) * 2020-07-06 2022-01-07 青岛海信激光显示股份有限公司 光源组件和投影设备
CN216696895U (zh) * 2021-12-31 2022-06-07 成都极米科技股份有限公司 一种散斑消除组件及光源系统
CN218213763U (zh) * 2022-09-30 2023-01-03 青岛海信激光显示股份有限公司 一种投影设备

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