CN117666263A - Projection light source and projection device - Google Patents

Abstract

The application discloses projection light source and projection equipment belongs to photoelectricity technical field. The projection light source comprises a laser and a dimming component; the laser is used for emitting laser light with multiple colors, different laser light in the multiple colors is emitted to different dimming areas in the dimming component, each dimming area comprises a plurality of diffraction microstructures, and the diffraction microstructures in the different dimming areas are different; each dimming area is used for emitting received laser after diffraction treatment by utilizing a diffraction microstructure in the dimming areas, and light spots formed by the laser with multiple colors after being emitted from the dimming areas are overlapped. The poor problem of the display effect of projection picture has been solved to this application. The method and the device are used for projection display.

Description

Projection light source and projection device

Technical Field

The application relates to the field of photoelectric technology, in particular to a projection light source and projection equipment.

Background

With the development of photoelectric technology, projection devices are widely used. The projection light source in the projection device can emit laser light of various colors, and a projection screen can be formed based on the laser light. The higher the symmetry of the laser light of each color emitted by the projection light source, the better the mixing effect, the better the display effect of the projection picture.

Fig. 1 is a schematic view of a projection light source according to the related art. As shown in fig. 1, the projection light source 00 includes a laser 01 and a light combining lens group 02. The laser 00 may include two columns of light emitting chips, one for emitting red laser light, and some of the light emitting chips in the other for emitting green laser light, and the rest for emitting blue laser light. The light combining lens set 02 may include two light combining lenses, each of which is located on the light emitting side of a row of light emitting chips, and is configured to emit laser light emitted by the row of light emitting chips along the z direction along the x direction, so as to mix the laser light of various colors emitted by the laser 01.

Fig. 2 is a schematic view of a spot formed by laser light emitted from a light converging lens set according to the related art. As can be seen from fig. 2, the mixing effect of the laser light of each color emitted from the projection light source is poor, and the display effect of the projection screen formed by the laser light is poor.

Disclosure of Invention

The application provides a projection light source and projection equipment, can solve the relatively poor problem of display effect of projection picture. The technical scheme is as follows:

in one aspect, there is provided a projection light source comprising:

a laser and a dimming component;

the laser is used for emitting laser light with multiple colors, the laser light with different colors in the laser light with multiple colors is emitted to different dimming areas in the dimming component, each dimming area comprises a plurality of diffraction microstructures, and the diffraction microstructures in different dimming areas are different;

each dimming area is used for carrying out diffraction treatment on received laser by utilizing a diffraction microstructure in the dimming areas and then emitting the laser, and light spots formed by the laser with multiple colors after being emitted from the dimming areas coincide.

In another aspect, there is provided a projection apparatus including: the projection light source, the light valve and the lens;

the laser emitted by the projection light source is emitted to the light valve, the light valve is used for modulating the received laser and emitting the modulated laser to the lens, and the lens is used for projecting the received laser to form a projection picture.

The beneficial effects that this application provided technical scheme brought include at least:

in the projection light source provided by the application, each dimming area in the dimming component can utilize the diffraction microstructure therein to carry out diffraction treatment on received laser, and the diffraction microstructures in different dimming areas can be different, so that light spots formed after laser light of various colors emitted by the laser passes through each dimming area can be overlapped. In this way, the mixing effect of the laser light of each color emitted by the projection light source is better, the color uniformity of the projection picture formed by the laser light emitted by the projection light source is higher, and the display effect of the projection picture is better.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a projection light source provided in the related art;

FIG. 2 is a schematic view of a spot formed by laser light emitted from a light converging lens set according to the related art;

fig. 3 is a schematic structural diagram of a projection light source according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a laser according to an embodiment of the present application;

fig. 5 is a schematic diagram of a spot formed on a dimming component by laser light emitted by a laser according to an embodiment of the present application;

FIG. 6 is a schematic diagram of another laser according to an embodiment of the present disclosure;

fig. 7 is a schematic view of a spot formed on a dimming component by laser light emitted by another laser according to an embodiment of the present application;

FIG. 8 is a schematic view of another projection light source according to an embodiment of the present disclosure;

fig. 9 is a schematic structural diagram of a dimming component according to an embodiment of the present disclosure;

FIG. 10 is an energy distribution diagram of a laser provided in an embodiment of the present application;

FIG. 11 is an energy distribution diagram of another laser provided in an embodiment of the present application;

FIG. 12 is an energy distribution diagram of yet another laser provided by an embodiment of the present application;

FIG. 13 is a schematic view of a structure of a projection light source according to an embodiment of the present disclosure;

fig. 14 is a schematic view of a part of the structure of a dimming component according to an embodiment of the present application;

FIG. 15 is a schematic view of a projection light source according to an embodiment of the present disclosure;

fig. 16 is a schematic structural diagram of a projection apparatus according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

With development of photoelectric technology, projection devices are widely used, and requirements on picture display effects of the projection devices are also increasing. Currently, lasers are used in projection light sources of projection devices to provide light required for forming projection pictures due to their better brightness, better monochromaticity, and the like. The laser can emit laser light of various colors, such as red laser light, green laser light and blue laser light, at one time. However, the spot positions of the lasers with different colors emitted by the lasers are different, the lasers with different colors are required to be mixed and then used for forming a projection picture, so that the color uniformity of the projection picture is ensured, and the better the mixing effect of the lasers with different colors is, the better the display effect of the formed projection picture is. However, the effect of mixing the laser light of various colors emitted by the laser is poor, and the display effect of the projection screen is still not good enough.

The following embodiments of the present application provide a projection light source and a projection device, where the mixing effect of the laser light of various colors emitted by the projection light source is better, and further the display effect of the projection screen formed based on the laser light may be better.

Fig. 3 is a schematic structural diagram of a projection light source according to an embodiment of the present application. As shown in fig. 3, the projection light source 10 may include a laser 101 and a dimming component 102.

The laser 101 may be used to emit multiple colors of laser light, where different colors of laser light may be directed to different dimming regions in the dimming component. For example, the lasers with multiple colors may be in one-to-one correspondence with multiple dimming regions in the dimming structure 102, where the lasers with each color are directed to the corresponding dimming region, and each dimming region is used for performing corresponding adjustment on the lasers with the corresponding colors. Each dimming region may include a plurality of diffractive microstructures, the diffractive microstructures in different dimming regions being different. For example, there are differences in the shape of the diffractive microstructures in the different light modulating regions; as another example, there is a difference in the arrangement relationship between the individual diffractive microstructures in the different light modulating regions. Each dimming area is used for emitting received laser after diffraction treatment by utilizing a diffraction microstructure in the dimming areas, and light spots formed after the laser with multiple colors is emitted by the dimming areas can be overlapped.

Illustratively, different light emitting regions of the laser 101 are used to emit different colors of laser light, e.g., the laser 101 may emit red, green, and blue laser light. The three color lasers are respectively directed to three dimming areas in the dimming component 102, and each dimming area is used for performing diffraction processing on the incident laser light of the corresponding color. The red laser, the green laser and the blue laser emitted after passing through the dimming component 102 can be emitted to the same region, and three light spots respectively formed by the three color lasers can be overlapped, so that the mixing of the three color lasers is realized. The light spot overlapping in the embodiment of the application includes the case that the light spots are approximately overlapped, and the case that some smaller areas are staggered in the two light spots also belongs to the light spot overlapping range in the embodiment of the application. In the embodiment of the present application, only the laser 101 emits laser light with three colors of red, green and blue, and the laser 101 may also be used to emit other laser light with colors different from the three colors, which is not limited in the embodiment of the present application.

By designing the structure of the diffraction member to be constant, the diffraction member can diffract light to achieve a desired effect, and the direction, intensity, position, and the like of the light can be adjusted accordingly. In this embodiment of the present application, the light modulation component is a diffraction component, so that laser beams with different colors can be emitted to the same area through the diffraction component, and light spots formed by the laser beams with different colors are approximately the same, so as to realize superposition of the light spots with different colors. The specific configuration of the diffraction element may be tailored based on the desired area to be irradiated by the laser light of each color and the desired spot size to be formed.

In summary, in the projection light source provided by the embodiment of the present application, each light modulation region in the light modulation component may utilize the diffraction microstructure thereof to diffract the received laser, and the diffraction microstructures in different light modulation regions may be different, so that light spots formed by the laser with multiple colors emitted by the laser after passing through each light modulation region may coincide with each other. In this way, the mixing effect of the laser light of each color emitted by the projection light source is better, the color uniformity of the projection picture formed by the laser light emitted by the projection light source is higher, and the display effect of the projection picture is better.

In addition, in the embodiment of the application, the light mixing of the lasers with various colors can be realized only by arranging one light adjusting component on the light emitting side of the laser, and the structure of the projection light source can be simplified without arranging a plurality of light converging lenses.

In an alternative example, fig. 4 is a schematic structural diagram of a laser provided in an embodiment of the present application. As shown in fig. 4, the laser 101 may include a base 1011 and two light emitting modules (not shown). Each light emitting module may include a ring-shaped tube wall 1012 and a plurality of light emitting chips (e.g., light emitting chips 1013a, 1013b, and 1013 c) surrounded by the tube wall 1012. Each light emitting module may further include a plurality of heat sinks 1015 and a plurality of reflecting prisms 1016. The heat sinks 1015 and the reflecting prisms 1016 are respectively in one-to-one correspondence with the light emitting chips in the light emitting module. Each light emitting chip is located on a corresponding heat sink 1015, and the heat sink 1015 is used to assist the corresponding light emitting chip in heat dissipation. Each reflecting prism 1016 is located at the light-emitting side of the corresponding light-emitting chip. Each light emitting module may further comprise a light transmissive encapsulant layer and a collimator lens group (not shown in the figures). The light-transmitting sealing layer is located on the side of the tube wall 1012 away from the bottom plate 1011 for sealing the opening on the side of the tube wall 1012 away from the bottom plate 1011. The collimating lens group is positioned on one side of the light-transmitting sealing layer far away from the bottom plate 1011 and is used for collimating laser emitted by the light-emitting chip. Each light emitting chip may emit laser light to a corresponding reflecting prism 1016, which in the embodiment of the present application is referred to as a sub-beam. Each reflecting prism 1016 can reflect the received sub-beams to the collimating lens group along a direction far away from the bottom plate 1011, and the laser light is collimated by the collimating lens and then emitted.

Fig. 4 exemplifies that the laser 101 includes four red light emitting chips 1013a, two blue light emitting chips 1013b, and three green light emitting chips 1013 c. The area where the four red light emitting chips 1013a are located may be a first light emitting area Q1 of the laser 101, the area where the two blue light emitting chips 1013b are located may be a second light emitting area Q2 of the laser 101, and the area where the three green light emitting chips 1013c are located may be a third light emitting area Q3 of the laser 101. Each color of laser light emitted by the laser 101 may be directed to one of the dimming region regions in the dimming component 102, and each color of laser light may include at least one sub-beam emitted by at least one light emitting chip in the laser 101, respectively. In this embodiment, the number of light emitting chips of each color in the laser 101 is plural, and the laser of each color emitted by the laser 101 includes plural sub-beams.

Fig. 5 is a schematic diagram of a spot formed on a dimming component by laser light emitted by a laser according to an embodiment of the present application. As shown in fig. 5, the laser light emitted from the three light emitting regions of the laser 101 may be directed to the three dimming regions of the dimming component 102, which are the first dimming region G1, the second dimming region G2, and the third dimming region G3, respectively. The distribution of the dimming areas in the dimming component 102 can be the same as the distribution of the respective light-exiting areas in the laser 101. The first light emitting region Q1 of the laser 101 emits four red sub-beams to the first dimming region G1 of the dimming component 102, and the four sub-beams may form four small red spots in the first dimming region G1. The second light emitting region Q2 of the laser 101 emits two blue sub-beams to the second dimming region G2 of the dimming component, which may form two small blue spots in the second dimming region G2. The third light emitting region Q3 of the laser 101 emits three green sub-beams to the third dimming region G3 of the dimming component, and the three sub-beams may form three small green spots in the third dimming region G3.

In another alternative example, fig. 6 is a schematic structural diagram of another laser provided in an embodiment of the present application. As shown in fig. 6, the laser 101 may also include only one pipe wall 1012, and the plurality of light emitting chips 1013 in the laser 101 may be arranged in a plurality of rows and columns in the one pipe wall 1012. As shown in fig. 6, the light emitting region where the blue light emitting chip 1013b is located and the light emitting region where the green light emitting chip 1013c is located may not be one independent complete region. Fig. 6 exemplifies that the laser includes seven red light emitting chips 1013a, three blue light emitting chips 1013b, and four green light emitting chips 1013 c. Fig. 7 is a schematic diagram of a spot formed on a dimming component by laser light emitted by another laser according to an embodiment of the present application. The spot profile shown in fig. 7 is formed by the laser light emitted from the laser shown in fig. 6. The light emitting area, the dimming area and the sub-beams can be analogized based on the descriptions in fig. 4 and fig. 5, and the embodiments of the present application will not be repeated.

In this embodiment of the present application, for any dimming area in the dimming component 102, the adjustment condition of each position in the dimming area for the received laser light may be the same, and the diffraction microstructures of different positions in the dimming area may be the same. Each dimming area can take the received laser light with the corresponding color as a whole to carry out the same adjustment, and only different dimming areas are required to ensure that the adjustment conditions of the received laser light are different. As in the dimming component 102 shown in fig. 6, the first dimming area G1 has the same adjustment conditions for the four received red sub-beams, the second dimming area G2 has the same adjustment conditions for the two received blue sub-beams, and the third dimming area G3 has the same adjustment conditions for the three received green sub-beams. However, the adjustment of the red sub-beam by the first dimming area G1 is different from the adjustment of the blue sub-beam by the second dimming area G2, and is also different from the adjustment of the green sub-beam by the third dimming area G3. The three dimming areas can respectively adjust the shapes, the sizes and the positions of the emergent light spots of the red laser, the green laser and the blue laser to be consistent.

Alternatively, the area to which each sub-beam is directed in the dimming area may be the sub-dimming area to which the sub-beam corresponds, and the diffraction microstructures in the different sub-dimming areas may be different. Each sub-dimming area may diffract the received sub-beams using a diffractive microstructure therein to expand the sub-beams. Each sub-beam emitted to the dimming structure 102 can be expanded after being subjected to diffraction treatment in a corresponding sub-dimming area, so that the size of a light spot formed by each sub-beam can be increased, the shape, the size and the emitting position of each light spot can be identical, and the light spots formed by each sub-beam are overlapped.

With continued reference to fig. 5 and 7, the size of a spot formed on the dimming component 102 by the laser 101 in the first direction (e.g., x-direction) is larger than the size of a spot formed on the dimming component in the second direction (e.g., y-direction), which is a spot obtained by regarding a small spot formed by each sub-beam as a whole. The first direction may be perpendicular to the second direction. The size of a spot in either direction refers to the distance between the two points of the spot that are furthest apart in that direction. The aspect ratio of the light spot formed by the laser light of the plurality of colors emitted by the laser 101 is large, and the matching degree with the light spot required by the subsequent light receiving component is low.

In this embodiment, the dimming component 102 may also adjust the laser, so that the spot shape of the outgoing laser meets a certain requirement. For example, the light control unit 102 may adjust a spot formed by the emitted laser light to a spot matching a spot shape required by the light receiving unit by performing diffraction processing on the received laser light. For example, the aspect ratio of the light spot required by the light receiving means is small, e.g. the length of the light spot may refer to its dimension in the first direction and the width may refer to its dimension in the second direction. Alternatively, the aspect ratio of the light spot required by the light receiving component may be 16:9, or may be 1:1, or may be other ratios, which is not limited in the embodiment of the present application.

The diffraction processing of the laser by each dimming area in the dimming component 102 can shrink the laser in the first direction, so that the size of a light spot formed by the laser emitted by the dimming component 102 in the first direction is reduced, the aspect ratio of the light spot is reduced, the shape of the light spot is close to the required shape of the light spot, and the matching degree of the light spot and the required shape of the light spot is improved. Alternatively, the diffraction processing of the laser may be further performed by each dimming area to expand the laser in the second direction, so that the size of a spot formed by the laser emitted by the dimming component 102 in the second direction is increased, and the aspect ratio of the spot may be reduced. Alternatively, the individual dimming regions may also be simultaneously contracted in the first direction and expanded in the second direction for the laser light. Alternatively, each dimming region may also contract the laser light in both the first direction and the second direction at the same time, but the degree of contraction in the first direction is greater than the degree of contraction in the second direction. Alternatively, each dimming region may be expanded in both the first direction and the second direction simultaneously, but the degree of expansion in the first direction is smaller than the degree of expansion in the second direction.

Alternatively, the desired spot shape of the light receiving member is rectangular. In the embodiment of the present application, each dimming area in the dimming component may be subjected to diffraction processing by using the received laser, so that the shape of a light spot formed by the laser emitted through each dimming area is rectangular. The laser beams with various colors emitted after passing through the dimming areas respectively can be emitted to the same area to realize mixing, so that light spots formed by the laser beams with various colors after passing through the dimming parts are rectangular. Alternatively, the dimming component 102 may also utilize each sub-dimming area to adjust the received sub-beams so that the light spot formed after each sub-beam exits the dimming component is rectangular.

In this embodiment of the present application, the dimming component 102 may further adjust the laser, so that the energy distribution of the outgoing laser is relatively uniform. Each sub-beam directed to the dimming component 102 is gaussian, the energy in the sub-beam is gaussian, and the brightness of the center of the spot formed by each sub-beam is high and the brightness of the edge is low. Each dimming area in the dimming component 102 may be adjusted according to the energy distribution of the received laser light, and the energy difference of each position in the light spot formed by the laser light with multiple colors emitted by the laser 101 after being diffracted by the multiple dimming areas in the dimming component 102 may be smaller than the energy threshold, so as to ensure that the energy distribution of the laser light emitted from the dimming component 102 is uniform. For example, the laser light emitted from the light adjustment member 102 may form a square spot having uniform brightness at each position.

In the related art, in order to adjust the spot shape of the laser beam emitted from the laser to be matched with the desired spot shape, a corresponding adjusting lens needs to be provided in the projection light source. In order to homogenize the laser beam emitted from the laser, it is necessary to provide a diffusion sheet or the like in the projection light source. In the embodiment of the present application, the light combining, shaping and homogenizing of the laser light of each color emitted by the laser 101 can be realized only by one component, namely the light adjusting component 102. Therefore, the components such as the adjusting lens and the diffusion sheet are not required to be arranged, the number of the components in the projection light source can be reduced, the structure and the preparation process of the projection light source are simplified, and the miniaturization of the projection light source is facilitated.

In addition, in order to ensure miniaturization of each component for transmitting laser light in the related art, a beam shrinking component is further arranged on the light emitting side of the laser to ensure smaller size of the laser beam transmitted subsequently. In this embodiment, if each dimming area in the dimming component 102 simultaneously contracts the laser in both the first direction and the second direction, the beam shrinking component may not be disposed in the projection light source, so that the structure of the projection light source is further simplified.

Several optional dimming components 102 in embodiments of the present application are described below in conjunction with the accompanying figures.

In a first alternative configuration, the dimming component 102 in the projection light source 10 may be a grating waveguide. The grating waveguide comprises an in-coupling grating, an optical waveguide and an out-coupling grating, the diffractive microstructure in the dimming component 102 referring to the microstructure in the in-coupling grating and the microstructure in the out-coupling grating. The coupling grating is used for diffracting received laser in a first direction and then emitting the received laser to the optical waveguide, the optical waveguide is used for transmitting the laser received from the coupling grating to the coupling grating, the coupling grating is used for diffracting the received laser in a second direction and then emitting the laser, and the first direction is perpendicular to the second direction. Each dimming region in the dimming component 102 can include a first region coupled into the grating and a second region coupled out of the grating. The distinction between the first direction and the second direction is here only used to indicate that the coupling-in grating and the coupling-out grating process the laser light in both directions, respectively. The first direction and the second direction may be the same as the first direction and the second direction in fig. 5 and 7, or the first direction may be the second direction in fig. 5 and 7, and the second direction is the first direction in fig. 5 and 7, which is not limited in the embodiment of the present application.

In an alternative example, fig. 8 is a schematic structural diagram of another projection light source provided in an embodiment of the present application. As shown in fig. 8, the grating waveguide includes an in-grating 1021, an optical waveguide 1022, and an out-grating 1023, and the diffractive microstructure in the dimming component 102 is the microstructure in the in-grating 1021 and the out-grating 1022. Alternatively, the in-coupling grating 1021, the optical waveguide 1022 and the out-coupling grating 1023 may be integrally formed, or may be separate components, and may be formed by bonding and fixing. The optical waveguide 1022 has a plate shape having two relatively large plate surfaces. As shown in fig. 8, the in-coupling grating 1021 and the out-coupling grating 1023 may be located on the two boards, respectively. The in-coupling grating 1021 is located on the face of the optical waveguide 1022 that is remote from the laser 101, and the out-coupling grating 1023 is located on the face of the optical waveguide 1022 that is close to the laser 101. The orthographic projection of the in-coupling grating 1021 on the optical waveguide 1022 may be located outside the orthographic projection of the out-coupling grating 1023. The in-coupling grating 1021 and the out-coupling grating 1023 may be reflective gratings. The laser light emitted from the laser 101 may be emitted to the coupling grating 1021 through the optical waveguide 1022, diffracted by the coupling grating 1021, and then emitted back to the optical waveguide 1022, and then emitted to the coupling grating 1023 through total reflection in the optical waveguide 1022, and then emitted through the optical waveguide 1022 after being diffracted by the coupling grating 1023, so that the adjustment of the received laser light by the dimming component 102 is completed.

In this embodiment of the present application, the irradiation area of each color of laser light in the coupling grating 1021 is referred to as a first area corresponding to the laser light, the irradiation area of each color of laser light in the coupling grating 1022 is referred to as a second area corresponding to the laser light, and the corresponding dimming area of each color of laser light in the dimming component 102 includes the first area and the second area. Similarly, the illuminated area of each sub-beam in the coupling-in grating 1021 may be referred to as a first sub-area corresponding to the sub-beam, the illuminated area of each sub-beam in the coupling-out grating 1022 may be referred to as a second sub-area corresponding to the sub-beam, and the corresponding sub-dimming area of each sub-beam in the dimming component 102 comprises the first sub-area and the second sub-area.

With continued reference to fig. 8, the diffractive microstructures in the dimming component 102 can be saw-tooth shaped, and the in-coupling grating 1021 and the out-coupling grating 1023 can each include a plurality of saw-tooth shaped diffractive microstructures. Alternatively, each diffractive microstructure may be in the form of a stripe. The length direction of the diffraction microstructures in the coupling-in grating 1021 may be perpendicular to the length direction of the diffraction microstructures in the coupling-out grating 1023, e.g. the length direction of the diffraction microstructures in the coupling-in grating 1021 is a first direction and the length of the diffraction microstructures in the coupling-out grating 1023 is a second direction.

The wedge angles of the saw-tooth diffraction microstructures may be different in different dimming regions of the dimming component 102 to achieve different treatments of the received laser light in the different dimming regions. The wedge angle refers to the top angle of the serration, as angle a in fig. 8. The wedge angle is different and the corresponding grating thickness is also different. Alternatively, the widths of the diffractive microstructures may be different in different dimming regions to achieve different treatments of the received laser light in the different dimming regions. The width may be the width d in fig. 8. The width, i.e. the pitch of the grating, may also be referred to as the grating constant. Illustratively, at least one of the wedge angle and the width of the diffractive microstructure in a different first region of the in-coupling grating 1021 is different, and at least one of the wedge angle and the width of the diffractive microstructure in a different second region of the out-coupling grating 1022 is different. Also for example, at least one parameter of the wedge angle and the width of the diffraction microstructure in the different first sub-region of the in-grating 1021 is different and at least one parameter of the wedge angle and the width of the diffraction microstructure in the different second sub-region of the out-grating 1022 is different.

Fig. 9 is a schematic structural diagram of a dimming component provided in an embodiment of the present application, and the dimming component may be the dimming component 102 shown in fig. 8. The laser beam emitted after being diffracted by the diffraction microstructure has a plurality of diffraction energy levels, and the state in which the diffraction energy level is 0 corresponds to reflection of the laser beam. In fig. 9, the transmission direction of the laser beam in a state where the diffraction energy level is 0 is illustrated by taking an angle θ as an incident angle of the laser beam on one diffraction microstructure and a width of the diffraction microstructure as d as an example, and the exit angle of the laser beam in this state is θ. The laser and diffraction microstructure can satisfy the following relationship: dsin2 θ=mλ, where m represents a diffraction energy level (may also be referred to as a grating order), λ represents a wavelength of the laser light, d represents a width of a desired diffraction microstructure (i.e., a grating constant), θ represents an exit angle (i.e., a diffraction angle) of the desired laser light, and m is different from θ corresponding to different ones. By way of example, assuming that the wavelength of the incident light is 525 nanometers, the reflection angle needs to satisfy 2θ=45 degrees, d= 1.3468um.

In the embodiment of the application, the grating can be designed based on the relation, so that the energy of the injected laser is uniformly distributed on each diffraction energy level after diffraction, and further the expansion of the laser is realized. The energy distribution of the incident laser beam may be such that the energy of the incident laser beam is distributed only at a certain diffraction energy level after diffraction, so as to achieve the contraction of the laser beam. Illustratively, fig. 10 is an energy distribution diagram of one laser provided by an embodiment of the present application, fig. 11 is an energy distribution diagram of another laser provided by an embodiment of the present application, and fig. 12 is an energy distribution diagram of yet another laser provided by an embodiment of the present application. Wherein the abscissa represents the diffraction energy level and the ordinate represents the energy of the laser. Fig. 10 shows the energy distribution of the laser light when it is directed to the grating, and the energy distribution is gaussian. Fig. 11 shows the energy distribution when the laser beam is emitted from one type of grating, and as shown in fig. 11, the energy of the laser beam can be uniformly distributed at each diffraction level, and thus the expansion of the laser beam can be realized. The grating in this manner may be a multi-level grating. Fig. 12 shows the energy distribution when the laser beam is emitted from another grating, and as shown in fig. 12, the energy of the laser beam can be concentrated at one diffraction level, so that the laser beam can be contracted. The grating in this way may be a grating of a certain order, and the laser may be focused on different diffraction energy levels by adjusting the grating order.

Alternatively, the diffraction microstructure in the embodiment of the present application may also be rectangular protrusions, that is, columns with rectangular cross sections. The cross section may be other shapes, or the structures of the coupling-in grating and the coupling-out grating may be similar to a blazed grating, and the cross section of the diffraction microstructure may be triangular, which is not limited in this embodiment.

In another alternative example, fig. 13 is a schematic structural diagram of still another projection light source according to an embodiment of the present application. As shown in fig. 13, the in-coupling grating 1021 and the out-coupling grating 1023 in the dimming component 102 may be respectively located on two opposite board surfaces of the optical waveguide 1022. The in-coupling grating 1021 is located on the face of the optical waveguide 1022 close to the laser 101, and the out-coupling grating 1023 is located on the face of the optical waveguide 1022 remote from the laser 101. On the optical waveguide 1022, the front projection of the in-coupling grating 1021 and the front projection of the out-coupling grating 1023 may overlap. The in-coupling grating 1021 and out-coupling grating 1023 may be transmissive gratings. The description of the dimming areas of the dimming component 102 in fig. 13 and the effect on the laser light can be referred to the related description about fig. 8, and the embodiments of the present application will not be repeated. Alternatively, the front projection of the in-coupling grating 1021 and the front projection of the out-coupling grating 1023 may not overlap on the optical waveguide 1022.

Alternatively, the diffractive microstructures in the in-coupling grating 1021 and the out-coupling grating 1023 in fig. 13 may comprise grooves, e.g. the grooves may be scores. The grooves may be opaque portions, and portions between adjacent grooves correspond to a slit, and may transmit light. Fig. 14 is a schematic view of a part of a structure of a dimming component according to an embodiment of the present application. Fig. 14 shows a part of the dimming component 102 of fig. 13, which is coupled into the grating 1021, or the part of the coupling-out grating 1023. As shown in fig. 14, the laser light entering the structure undergoes a diffraction process in such a manner that the emission direction is changed to some extent. The laser and the diffraction light structure meet the following relation: dpi×sin θ=mλ, where m represents a diffraction energy level (may also be referred to as a grating order), λ represents a wavelength of the laser light, θ represents a diffraction angle of the laser light, d represents a distance (i.e., a grating constant) between adjacent grooves C, and θ corresponding to m is different. The distance of the adjacent grooves C is equal to the sum of the width of one groove C and the interval between the adjacent grooves C. The grating can be designed based on the relation, so that the energy of the incident laser is uniformly distributed on each diffraction energy level after diffraction, and further the expansion of the laser is realized. The energy distribution of the incident laser beam may be such that the energy of the incident laser beam is distributed only at a certain diffraction energy level after diffraction, so as to achieve the contraction of the laser beam. Reference may be made here to the above description related to fig. 10 to 12, and the embodiments of the present application will not be repeated.

Alternatively, the in-coupling grating 1021 and the out-coupling grating 1023 of the dimming component 102 may be located on the same surface of the optical waveguide 1022, where one grating is a transmissive grating and the other grating is a reflective grating. The corresponding structure can be referred to above for the transmissive grating by way of fig. 8 and for the reflective grating by way of fig. 13.

In a second alternative configuration, the dimming component 102 in the projection light source 10 may be a diffractive optical element (Diffractive Optical Elements, DOE). The DOE is a two-dimensional diffraction device that can directly adjust the received laser light in both directions. For example, the received laser beam can be directly emitted after being subjected to diffraction treatment in the first direction and the second direction, so that the emitted laser beam can form a required light spot.

For example, the diffractive optical element may include a plurality of diffractive microstructures that are two-dimensionally distributed by a micro-nano etching process, each of the diffractive microstructures may have a specific morphology, refractive index, and the like, and fine adjustment and control of the laser light may be achieved by the respective diffractive microstructures. If each diffraction microstructure can be rectangular, the size and depth (or called height) of each diffraction microstructure can be different, and the interval distance between different diffraction microstructures can also be different, so as to realize targeted adjustment of the incident laser. Alternatively, the dimming component 102 may also be a holographic optical element (Holographic Optical Elements, HOE).

Fig. 15 is a schematic structural diagram of another projection light source according to an embodiment of the present application. As shown in fig. 15, the projection light source 10 may further include a converging lens 103 and a light uniformizing member 104 on the basis of any one of the above projection light sources, and for example, the light uniformizing member 104 may be a light pipe. The laser light emitted from the light adjusting member 102 may be directed to the condensing lens 103 to be condensed to the light homogenizing member 104 by the condensing lens 103. The light homogenizing component 104 can homogenize the received laser light and emit the homogenized laser light for subsequent use.

The light homogenizing component 104 may be the light receiving component, and the light inlet of the light homogenizing component 104 may be rectangular, and the rectangular has a small aspect ratio. In this embodiment, due to the effect of the light modulation component 102, the shape of the laser emitted to the light modulation component 104 and the shape matching degree of the light inlet of the light modulation component 104 can be higher, so that the light receiving effect of the light modulation component 104 is better, the utilization rate of the laser is higher, and the homogenizing effect of the light modulation component 104 on the laser can be better.

Optionally, with continued reference to fig. 15, the projection light source 10 may further include a diffuser 105 positioned between the converging lens 103 and the light homogenizing member 104, the diffuser 105 may function to dissipate speckle. The diffuser 105 may be a stationary diffuser or may be a moving diffuser, such as being rotatable or movable back and forth in a direction parallel to the plate surface.

In summary, in the projection light source provided by the embodiment of the present application, each light modulation region in the light modulation component may utilize the diffraction microstructure thereof to diffract the received laser, and the diffraction microstructures in different light modulation regions may be different, so that light spots formed by the laser with multiple colors emitted by the laser after passing through each light modulation region may coincide with each other. In this way, the mixing effect of the laser light of each color emitted by the projection light source is better, the color uniformity of the projection picture formed by the laser light emitted by the projection light source is higher, and the display effect of the projection picture is better.

Fig. 16 is a schematic structural diagram of a projection apparatus according to an embodiment of the present application. As shown in fig. 16, the projection device may include the projection light source 10 shown in fig. 15, and may further include a light valve 20 and a lens 30. Fig. 10 does not illustrate the diffractive optical element 104. The projection device 10 may further comprise an illumination lens (not shown) located between the projection light source 10 and the light valve 20. The laser light emitted from the projection light source 101 may be directed to the light valve 20 through the illumination lens group.

Illustratively, the illumination lens set may include a lens T and a total internal reflection (total internal reflection prism, TIR) prism L. The laser light emitted from the projection light source 10 may be directed to the convex lens T, which may converge the incident laser light to the total internal reflection prism L, which reflects the incident laser light to the light valve 20. Alternatively, the light valve 20 may be a digital micromirror device (Digtial Micromirror Devices, DMD). The light valve 20 may include a plurality of reflective sheets, each of which may be used to form a pixel in the projection screen, and the light valve may reflect the laser to the lens according to the image to be displayed, where the reflective sheet corresponding to the pixel to be displayed in a bright state, so as to implement modulation of the laser. The lens 30 may include a plurality of lenses (not shown). The laser light emitted from the light valve 20 may be sequentially emitted through a plurality of lenses in the lens 30.

In summary, in the projection device provided in the embodiment of the present application, since the mixing effect of the laser beams of each color emitted by the projection light source is better, the uniformity of the formed light spot is higher, and the aspect ratio of the light spot meets the requirements. Therefore, the color uniformity of the projection screen formed based on the laser light emitted from the projection light source can be high, and the display effect of the projection screen is good.

The terms "at least one of a and B" and "a and/or B" in this application are merely an association relationship describing an association object, and indicate that three relationships may exist, that is, three cases where a exists alone, while a and B exist together, and B exists alone. The term "at least one of A, B and C" means that there may be seven relationships, which may be represented: there are seven cases where a alone, B alone, C alone, a and B together, a and C together, C and B together, A, B and C together. In the present embodiments, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "at least one" means one or more, the term "plurality" means two or more, unless expressly defined otherwise.

In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. By "substantially" is meant that within an acceptable error range, a person skilled in the art is able to solve the technical problem within a certain error range, substantially achieving the technical effect. Certain terms are used throughout the description and claims to refer to particular components, and it will be appreciated by those skilled in the art that manufacturers may refer to a component by different names. The description and claims do not take the form of an element differentiated by name, but rather by functionality.

The foregoing description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, since it is intended that all modifications, equivalents, improvements, etc. that fall within the spirit and scope of the invention.

Claims (10)

1. A projection light source, the projection light source comprising: a laser and a dimming component;

the laser is used for emitting laser light with multiple colors, the laser light with different colors in the laser light with multiple colors is emitted to different dimming areas in the dimming component, each dimming area comprises a plurality of diffraction microstructures, and the diffraction microstructures in different dimming areas are different;

each dimming area is used for carrying out diffraction treatment on received laser by utilizing a diffraction microstructure in the dimming areas and then emitting the laser, and light spots formed by the laser with multiple colors after being emitted from the dimming areas coincide.

2. The projection light source of claim 1, wherein the laser comprises a plurality of light emitting chips, each light emitting chip configured to emit a sub-beam, each of the plurality of colors of laser light comprising a plurality of sub-beams;

the diffraction processing of the received laser in the dimming area is used for expanding each sub-beam, and light spots formed after the sub-beams in the laser with multiple colors are emitted from the dimming areas are overlapped.

3. The projection light source of claim 1, wherein the spots of the multiple color lasers on the dimming component have a dimension in a first direction that is greater than a dimension in a second direction, the first direction being perpendicular to the second direction;

the diffraction processing of the received laser light by the dimming area is used for shrinking the laser light in the first direction and/or expanding the laser light in the second direction.

4. The projection light source of claim 1, wherein the energy difference between each position in the light spots formed by the laser light of the plurality of colors after being emitted from the plurality of dimming areas is smaller than an energy threshold;

and/or, the light spots formed after the laser beams with the multiple colors are emitted through the multiple dimming areas are rectangular.

5. The projection light source of any one of claims 1 to 4, wherein the dimming component is a grating waveguide comprising an in-coupling grating, an optical waveguide, and an out-coupling grating;

the coupling-in grating is used for diffracting received laser in a first direction and then emitting the received laser to the optical waveguide, the optical waveguide is used for transmitting the laser received from the coupling-in grating to the coupling-out grating, the coupling-out grating is used for diffracting the received laser in a second direction and then emitting the laser, and the first direction is perpendicular to the second direction;

each of the plurality of dimming regions includes a first region in the in-coupling grating and a second region in the out-coupling grating.

6. The projection light source of claim 5, wherein the in-coupling grating is located on a face of the optical waveguide remote from the laser, the out-coupling grating is located on a face of the optical waveguide proximate to the laser, and an orthographic projection of the in-coupling grating on the optical waveguide is located outside of an orthographic projection of the out-coupling grating; the diffraction microstructures are zigzag, and in different dimming areas, at least one of wedge angles and widths of the diffraction microstructures are different;

or the coupling-in grating is positioned on a plate surface close to the laser in the optical waveguide, the coupling-out grating is positioned on a plate surface far away from the laser in the optical waveguide, and the orthographic projection of the coupling-in grating overlaps with the orthographic projection of the coupling-out grating on the optical waveguide; the diffractive microstructure includes grooves, and at least one of a width of the groove and a pitch of adjacent grooves is different in different ones of the dimming regions.

7. The projection light source of any one of claims 1 to 4, wherein the dimming component is a diffractive optical element DOE.

8. The projection light source of claim 7, wherein the dimming component is a holographic optical element HOE.

9. The projection light source of any of claims 1-4, further comprising: a converging lens and a light homogenizing member;

the laser emitted by the light adjusting component is emitted to the converging lens, the converging lens is used for converging the received laser to the light homogenizing component, and the light homogenizing component is used for homogenizing the received laser and then emitting the homogenized laser.

10. A projection device, the projection device comprising: the projection light source of any one of claims 1 to 9, and a light valve and lens;

the laser emitted by the projection light source is emitted to the light valve, the light valve is used for modulating the received laser and emitting the modulated laser to the lens, and the lens is used for projecting the received laser to form a projection picture.