CN113625523B - A laser and laser projection system - Google Patents

Abstract

The invention discloses a laser and a laser projection system. The diffractive optical element shapes the laser beam emitted by the laser chip component, so that the laser beam emitted by the laser can be shaped and homogenized according to actual needs, components such as a light guide pipe and a diffusion sheet do not need to be arranged in the projection system, energy loss caused by the light guide pipe is avoided, the structural design of the projection system is effectively simplified, and the miniaturization design is favorably realized.

Description

A kind of laser and laser projection system

technical field

The invention relates to the technical field of projection display, in particular to a laser and a laser projection system.

Background technique

Laser projection display technology, also known as laser projection technology or laser display technology, uses laser light as a light source for projection display. Laser projection can most truly reproduce the rich and gorgeous colors of the objective world, providing more shocking expressiveness. Its color gamut coverage can reach more than 90% of the color space that can be recognized by the human eye, which is more than twice the color gamut coverage of traditional displays.

At present, the laser projection system usually sets an illumination system on the light output side of the laser light source for shaping and homogenization. Illumination systems are usually implemented with light pipes, but when the light emitted by a laser light source is irradiated into a narrow light pipe, a lot of energy loss will occur. In order to achieve a certain uniformity, the light pipe needs to be relatively long, usually more than 30mm, so the length of the entire optical engine is very long, and a smaller volume cannot be achieved.

Contents of the invention

In some embodiments of the present invention, the laser includes multiple laser chip components, and a diffractive optical element located on the light-emitting side of the laser chip component. Diffractive optical elements shape the laser beam emitted by the laser chip assembly, so that the laser beam emitted by the laser can be shaped and homogenized according to actual needs, so that it is no longer necessary to set up light pipes, diffusers and other components in the projection system to avoid light due to The energy loss caused by the conduit effectively simplifies the structural design of the projection system and is conducive to the realization of miniaturized design.

In some embodiments of the present invention, the diffractive optical element includes a plurality of diffractive units, and each diffractive unit is distributed in a two-dimensional matrix. Wherein, the diffraction unit is a stepped structure composed of multi-layer microstructures, and the size of one layer of microstructures is 10nm-100μm. The diffractive optical element is a two-dimensionally distributed diffraction unit formed by micro-nano etching process. Each diffraction unit can have a specific shape, size, refractive index, etc., and can fine-tune the phase distribution of the laser wavefront. The laser beam is diffracted after passing through each diffraction unit, and interferes at a certain distance to form a specific light intensity distribution.

In some embodiments of the present invention, the laser spot emitted by the laser chip assembly is shaped into a rectangular spot with uniform intensity distribution and a set size after passing through a diffractive optical element, so as to meet the lighting requirements in the projection system.

In some embodiments of the present invention, the laser further includes a tube shell, the laser chip assembly and the reflector on the light output side of the laser chip assembly are arranged in the tube shell, and the diffractive optical element is located on the light output side of the reflector. In the form of reflecting the light emitted by the laser chip assembly through the reflector, the position of the light emitted can be adjusted by adjusting the reflector, so as to achieve higher precision.

In some embodiments of the present invention, the laser chip assembly includes a red laser chip assembly, a green laser chip assembly and a blue laser chip assembly. Correspondingly, the diffractive optical element includes a first diffractive optical element, a second diffractive optical element and a third diffractive optical element. The first diffractive optical element is located on the light emitting side of the red laser chip assembly and is used to shape the red laser beam; the second diffractive optical element is located on the light emitting side of the green laser chip assembly and is used to shape the green laser beam; the third diffractive optical element The element is located on the light emitting side of the blue laser chip assembly and is used to shape the blue laser beam. In this way, the laser beams of different colors are all shaped into rectangular spots with uniform energy distribution.

In some embodiments of the present invention, the laser further includes sealing glass, forming a sealing structure with the tube shell. The diffractive optical element is located on the side of the sealing glass away from the laser chip assembly. In this way, there is no need to change the packaging structure of the laser, and the diffractive optical element can be installed after the laser packaging is completed.

In some embodiments of the present invention, the diffractive optical element is arranged on the side of the sealing glass facing the laser chip assembly. Encapsulating the diffractive optical element inside the laser can protect the diffractive optical element, thereby prolonging the service life of the diffractive optical element and making the intensity distribution of the laser beam emitted by the laser uniform.

In some embodiments of the present invention, the diffractive optical element is located on a side of the annular sidewall of the tube shell away from the bottom plate, and the diffractive optical element and the tube shell form a closed space. The diffractive optical element is used instead of the sealing glass, so that the diffractive element and the shell form a sealed structure, and the laser chip assembly is packaged, thereby simplifying the structural design.

In some embodiments of the present invention, a Fresnel structure is provided on the surface of the diffractive optical element facing the laser chip assembly, and a plurality of diffraction units are formed on the surface of the diffractive optical element facing away from the laser chip assembly. Among them, the Fresnel structure is used to collimate the outgoing light of the laser chip assembly; the diffraction unit is used to shape the incident laser beam. Therefore, the collimating lens is omitted, so that the structure of the laser is more compact.

In some embodiments of the present invention, the projection system includes any of the above-mentioned lasers, a light-combining assembly located on the light-emitting side of the laser, a reflective assembly located on the light-emitting side of the light-combining assembly, a light valve modulation component located on the reflected light path of the reflecting assembly, and a light valve Modulate the projection lens on the light exit side of the component.

In some embodiments of the present invention, the output beam of the laser is a rectangular spot with uniform intensity distribution. When the intensity distribution and divergence angle of the laser beam emitted by the laser meet the requirements for the use of the light valve modulation component, the light combining component is directly used to output the laser beam. The laser beams of different colors are simply combined and incident on the reflective assembly, and the reflective assembly reflects the light to the light valve modulation part at a suitable angle. After the light is modulated by the light valve modulation part, it is emitted to the projection lens. The lens performs imaging to project the image on the projection screen or a set position, and the viewer can watch the display screen by watching the projection screen.

In some embodiments of the present invention, the projection system includes at least two of the above-mentioned lasers, and the light combining component is located at the intersection of the outgoing light of the lasers, and is used to combine the outgoing beams of each laser. A light valve modulating component is arranged on the reflection path of the reflecting component, and a projection lens is arranged on the light output side of the light valve modulating component. Any of the above-mentioned lasers is equipped with a diffractive optical element, and the diffractive optical element shapes the laser beam emitted by the laser chip assembly, so that the laser beam emitted by the laser can be shaped and homogenized according to actual needs, so that it is no longer necessary in the projection system. The light pipe, diffuser and other components are arranged to avoid energy loss caused by the light pipe, effectively simplify the structural design of the projection system, and facilitate the realization of miniaturized design.

In some embodiments of the present invention, the projection system further includes an illumination lens group located between the light combination assembly and the reflection assembly. The illumination lens group is used to shape and homogenize the light beam incident on the light valve modulation component, so as to meet the use requirements of the light valve modulation component.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings required in the embodiments of the present invention. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without making creative efforts.

1 is a schematic diagram of a spot intensity curve provided by an embodiment of the present invention;

FIG. 2 is one of the structural schematic diagrams of the laser provided by the embodiment of the present invention;

FIG. 3 is a schematic structural view of a tube shell provided by an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a diffractive optical element provided by an embodiment of the present invention;

Fig. 5 is one of the schematic diagrams of the spot before and after the laser beam passes through the diffraction element provided by the embodiment of the present invention;

Fig. 6 is the second schematic diagram of the spot before and after the laser beam passes through the diffraction element provided by the embodiment of the present invention;

Fig. 7 is the second structural schematic diagram of the laser provided by the embodiment of the present invention;

Fig. 8 is the third structural schematic diagram of the laser provided by the embodiment of the present invention;

FIG. 9 is one of the structural schematic diagrams of the projection system provided by the embodiment of the present invention;

FIG. 10 is the second structural schematic diagram of the projection system provided by the embodiment of the present invention;

FIG. 11 is the third structural schematic diagram of the projection system provided by the embodiment of the present invention.

Detailed ways

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. Example embodiments may, however, be embodied in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals denote the same or similar structures in the drawings, and thus their repeated descriptions will be omitted. The words expressing position and direction described in the present invention are all described by taking the accompanying drawings as an example, but changes can also be made according to needs, and all changes are included in the protection scope of the present invention. The drawings of the present invention are only used to illustrate the relative positional relationship and do not represent the true scale.

Projection display is a method or device in which the light source is controlled by planar image information, and the image is enlarged and displayed on the projection screen by using the optical system and projection space. With the development of projection display technology, projection display is gradually used in business activities, conferences and exhibitions, scientific education, military command, traffic management, centralized monitoring, advertising and entertainment, etc. Its advantages such as large display screen size and clear display are also suitable for Large screen display requirements.

At present, the commonly used projection system is a digital light processing (Digital Light Processing, referred to as DLP) architecture, with a digital micromirror device (Digital Micromirror Device, referred to as DMD) as the core device, the light emitted by the projection light source is incident on the DMD to generate an image, and then the The outgoing light of the image generated by the DMD enters the projection lens, is imaged by the projection lens, and finally received by the projection screen.

Among them, MCL laser can be used as the projection light source, and MCL laser has a high degree of integration, which is conducive to the miniaturization of the laser light source. MCL lasers usually include multiple laser chips, and can include laser chips of three primary color lights at the same time, so the emission of three primary color lights can be realized by using one MCL laser.

FIG. 1 is a schematic diagram of a spot intensity curve provided by an embodiment of the present invention.

The current full-color laser display, because the light energy distribution of a single laser chip is a Gaussian distribution, as shown in (a) in Figure 1, the Gaussian distribution shows that the light intensity at the center is relatively high, while the light intensity at the edge decreases sharply The trend cannot meet the requirements of uniform lighting.

In order to achieve uniform illumination, it is necessary to convert the outgoing laser light into a rectangular spot, as shown in (b) in Figure 1. The light intensity of the rectangular spot is uniform at each position, which meets the lighting requirements in the projection system.

In order to homogenize the light intensity of the laser beam, a diffuser can be installed on the light output side of the laser to homogenize the beam, but in fact, the diffuser is used to homogenize the beam, and the spot intensity becomes as shown in (c) in Figure 1 , the center brightness is high, and the edge brightness is low. If you want to make the light intensity more uniform, you need to increase the diffusion angle, which will lose a lot of edge energy.

In addition, in the projection system, it is also necessary to set up uniform components such as light pipes to homogenize the light. However, when the light emitted by the laser light source is irradiated into the narrow light pipe, a lot of energy loss will occur. In order to achieve a certain uniformity, the light pipe needs to be relatively long, usually more than 30mm, so the length of the entire optical engine is very long, and a smaller volume cannot be achieved.

In view of this, an embodiment of the present invention provides a laser and a projection system, which can effectively homogenize the intensity distribution of a laser beam, and omit the function of a light pipe, thereby realizing a small-volume design of a projection system.

Fig. 2 is one of the structural schematic diagrams of the laser provided by the embodiment of the present invention.

As shown in FIG. 2 , the laser includes: a tube shell 100 , a plurality of laser chip components 200 , a mirror 300 , a sealing glass 400 , a collimating lens 500 and a diffractive optical element 600 .

FIG. 3 is a schematic structural diagram of a tube shell provided by an embodiment of the present invention.

As shown in FIG. 3 , the tube case 100 is used to accommodate the laser chip assembly 200 and package the laser chip assembly 200 . The tube case 100 includes a bottom plate 101 and an annular side wall 102 located on the bottom plate. The bottom plate 101 and the annular side wall 102 form an accommodating space. Wherein, the bottom plate 101 and the annular side wall 102 can be made of the same material, such as oxygen-free copper or Kovar metal. The bottom plate 101 and the annular side wall 102 can be fabricated separately, and then welded together to form an accommodating space.

A plurality of laser chip assemblies 200 are fixed on the bottom plate 101 of the package. The laser chip assembly 200 includes a laser chip 201 and a heat sink 202 . The laser chip 201 and the heat sink 202 are welded by a high-precision eutectic welding machine to form a laser chip assembly, which is also called a Cos (Chip on submount, Cos for short) assembly. The heat sink 202 is used to dissipate heat from the laser chip 201 , and can usually be made of metal material, which is not limited here.

As shown in FIGS. 2 and 3 , a plurality of mirrors 300 are located inside the package 100 . One reflector 300 corresponds to at least one laser chip assembly 200, and the reflector 300 is located on the light emitting side of the corresponding laser chip assembly 200, and is used to receive the emitted light of the corresponding laser chip assembly 200 and reflect it to a set direction.

The reflective mirror 300 is used to deflect the outgoing light of the laser chip assembly 200 . Generally, the included angle between the reflective surface of the reflective mirror 300 and the light emitting direction of the laser chip assembly 200 may be 45°. The embodiment of the present invention adopts such an optical path design, and the reflection mirror 300 reflects the output light of the laser chip assembly 200 , and the position of the light output can be adjusted by adjusting the reflection mirror 300 , thereby achieving higher precision.

The laser also includes a cover plate not shown in the figure, and a metal frame is arranged around the cover plate for welding with the tube shell. Specifically, the cover plate can be welded to the tube shell by parallel sealing welding technology. Wherein, the sealing glass 400 is fixed on the cover plate by a kind of green glue.

The collimating lens 500 is located on the side of the sealing glass 400 facing away from the package 100. In specific implementation, the collimating lens 500 can be an aspheric lens, and the aspheric collimating lens 500 can be collimated and debugged through the control of the alignment process. And fixed on the cover with UV glue.

Since the laser beam emitted by the laser chip assembly 200 has a Gaussian distribution, it does not meet the requirement of uniform intensity distribution required by the projection system. In view of this, in the embodiment of the present invention, a diffractive optical element 600 is further disposed on the light emitting side of the laser chip assembly 200 , specifically, the diffractive optical element 600 may be disposed on the light emitting side of the reflector 300 . The diffractive optical element can shape the laser beam emitted by the laser chip assembly 200, so that the energy distribution of the shaped laser beam is uniform, and the Gaussian-distributed light spot can be shaped into a rectangular light spot with uniform energy distribution, so as to meet the lighting requirements of the projection system .

Fig. 4 is a schematic structural diagram of a diffractive optical element provided by an embodiment of the present invention.

As shown in FIG. 4 , specifically, a diffractive optical element (Diffractive Optical Element, DOE for short) 600 includes a plurality of diffractive units 60 , and each diffractive unit 60 is distributed in a two-dimensional matrix. Wherein, the diffraction unit 60 is a stepped structure composed of multi-layer microstructures, and the size of one layer of microstructures is 10 nm˜100 μm.

DOE (600) is a two-dimensionally distributed diffraction unit 60 formed by micro-nano etching process. Each diffraction unit 60 can have a specific shape, size, refractive index, etc., and can fine-tune the phase distribution of the laser wavefront. The laser beam is diffracted after passing through each diffraction unit 60, and interferes at a certain distance to form a specific light intensity distribution.

FIG. 5 is one of the schematic diagrams of the light spot before and after the laser beam passes through the diffraction element provided by the embodiment of the present invention.

As shown in Fig. 5, through the special design of each diffraction unit in the DOE (600), the spot of the laser beam after passing through the DOE (600) can be made into a rectangular spot. The energy distribution of the rectangular spot is more uniform, which can meet the lighting requirements in the projection system.

By setting diffractive optical elements in the laser to shape the laser beam emitted by the laser chip assembly, the laser beam emitted by the laser can be shaped and homogenized according to actual needs, so that it is no longer necessary to set up light pipes, diffusers, etc. in the projection system components, avoid energy loss caused by the light guide, effectively simplify the structural design of the projection system, and facilitate the realization of miniaturized design.

As shown in FIG. 2 , the above-mentioned laser provided by the embodiment of the present invention may use an MCL laser. Each laser chip assembly 200 in the laser is arranged in an array. Wherein, the laser chip assembly may include a red laser chip assembly 201, a green laser chip assembly 202 and a blue laser chip assembly 203; each red laser chip assembly 201 is arranged in an array to form an array of red laser chip assemblies, each green laser The chip components 202 are arranged in an array to form a green laser chip component array, and the blue laser chip components 203 are arranged in an array to form a blue laser chip component array. For example, the red laser chip assembly 201 can form a 2×4 red laser chip assembly array, the green laser chip assembly 202 can form a 1×4 green laser chip assembly array, and the blue laser chip assembly 203 can form a 1×4 array. The array of blue laser chip components, thus forming two rows of red laser chip components 201, one row of green laser chip components 202 and one row of blue laser chip components 203 are arranged in sequence to form a 4×4 laser chip component array.

Correspondingly, the diffractive optical element 600 may include a first diffractive optical element 6001, a second diffractive optical element 602, and a third diffractive optical element 603; wherein, the first diffractive optical element 601 is located on the light-emitting side of the red laser chip assembly array, and the second The second diffractive optical element 602 is located on the light emitting side of the green laser chip assembly array, and the third diffractive optical element 603 is located on the light emitting side of the blue laser chip assembly array.

The first diffractive optical element 601 is used for shaping the laser beam emitted by the red laser chip assembly, the second diffractive optical element 602 is used for shaping the laser beam emitted by the green laser chip assembly, and the third diffractive optical element 603 is used for Shaping the laser beam emitted by the blue laser chip assembly.

FIG. 6 is the second schematic diagram of the light spot before and after the laser beam passes through the diffraction element provided by the embodiment of the present invention.

As shown in FIG. 6, the outgoing laser beam of the red laser chip assembly 201 is a Gaussian-distributed light spot 201x shown on the left, and the outgoing laser beam of the green laser chip assembly 202 is a Gaussian-distributed light spot shown on the left. 202x, the laser beam emitted by the blue laser chip assembly 203 is a Gaussian-distributed light spot 203x shown on the left. When the laser beam emitted by the red laser chip assembly 201 is shaped by the first diffractive optical element 601, the rectangular spot 201y with uniform intensity distribution shown on the right can be formed; when the laser beam emitted by the green laser chip assembly 202 passes through the second After shaping by the diffractive optical element 602, the rectangular spot 202y with uniform intensity distribution shown on the right can be formed; A rectangular light spot 203y with uniform intensity distribution. Therefore, by sequentially arranging corresponding diffractive optical elements on the light emitting side of the laser chip assembly array of each color, the outgoing laser beam of the laser chip assembly can be shaped into a rectangular spot with uniform intensity distribution and a set size. Thus, the emitted light of the laser can meet the illumination requirement of the projection system.

Among them, the size and divergence angle of the red light spot, green light spot and blue light spot can be different, and can be designed separately according to the specific combination light path, illumination light path and optical etendue required by the projection system, and the first diffractive optical unit can be adjusted accordingly , the parameters of the second diffractive optical unit and the third diffractive optical unit, so as to meet the requirements of practical applications, and are not limited here.

In actual implementation, the laser chip components in the laser may also be arranged according to other rules. At this time, it is only necessary to adjust the parameters of the diffraction unit according to the needs of the emitted rectangular spot, so that the specific diffraction optical element corresponds to it. The embodiment of the present invention does not limit the specific arrangement structure of the laser chip assembly and the specific parameters of the diffractive optical element.

In some embodiments, as shown in FIG. 2 , the diffractive optical element 600 may be disposed on the side of the sealing glass 400 away from the laser chip assembly 200 . In this way, there is no need to change the packaging structure of the laser, and the diffractive optical element can be installed after the laser packaging is completed.

Fig. 7 is the second structural schematic diagram of the laser provided by the embodiment of the present invention.

As shown in FIG. 7 , in some embodiments, the diffractive optical element 600 may also be disposed on the side of the sealing glass 400 facing the laser chip assembly 200 . Encapsulating the diffractive optical element 600 inside the laser can protect the diffractive optical element 600, thereby prolonging the service life of the diffractive optical element 600 and making the intensity distribution of the laser beam emitted by the laser uniform.

FIG. 8 is a third structural schematic diagram of a laser provided by an embodiment of the present invention.

As shown in FIG. 8 , in some embodiments, the diffractive optical element 600 is located on the side of the annular sidewall 102 of the housing away from the bottom plate 101 , and the diffractive optical element 600 and the housing 100 form a closed space. The diffractive optical element 600 is used instead of the sealing glass, so that the diffractive element 600 and the shell form a sealed structure, and the laser chip assembly 200 is packaged, thereby simplifying the structural design.

In some embodiments, as shown in FIG. 8 , a Fresnel structure f may also be provided on the surface of the diffractive optical element 600 facing the side of the laser chip assembly 200 , and formed on the surface of the diffractive optical element 600 away from the side of the laser chip assembly 200 . Multiple Diffraction Units. Wherein, the Fresnel structure f is used to collimate the outgoing light of the laser chip assembly 200; the diffraction unit is used to shape the incident laser beam.

With the structure of the diffractive optical element 600 shown in Figure 8, no additional collimating lens is required, and the Fresnel structure f on the side of the diffractive optical element 600 facing the laser chip assembly 200 can function as a collimating lens, and the light Perform collimation. By arranging the Fresnel structure f and the diffraction unit on the two surfaces of the diffractive optical element, the light can be collimated and the laser beam can be shaped, making the structure of the laser more compact.

On the other hand, an embodiment of the present invention provides a projection system. FIG. 9 is one of the structural schematic diagrams of the projection system provided by the embodiment of the present invention.

As shown in Figure 9, the projection system includes any of the above-mentioned lasers 1, a light combination assembly 2 located on the light output side of the laser 1, a reflective assembly 3 located on the light output side of the light combination assembly 2, and a light valve modulation component located on the reflected light path of the reflection assembly 3 4, and the projection lens 5 located on the light emitting side of the light valve modulating part 4.

The output light class of the laser provided by the embodiment of the present invention is a rectangular spot with uniform intensity distribution. When the intensity distribution and divergence angle of the laser beam emitted by the laser meet the requirements for the use of the light valve modulation component 4, the light combination component 2 can be used directly. The laser beams of different colors emitted by the laser are simply combined and incident on the reflective component 3, and the reflective component 3 reflects the light to the light valve modulation component 4 at a suitable angle, after the light valve modulation component 4 modulates the light Emitted to the projection lens 5, the projection lens 5 performs imaging to project the image on the projection screen or a set position, and the viewer can watch the display screen by watching the projection screen.

Since the laser provided in the embodiment of the present invention is provided with a diffractive optical element, the diffractive optical element can shape the laser beam emitted by the laser chip assembly, so that the laser beam emitted by the laser can be shaped and homogenized according to actual needs, so that it is no longer necessary to The projection system is equipped with components such as light pipes and diffusers to avoid energy loss caused by light pipes, effectively simplify the structural design of the projection system, and facilitate the realization of miniaturized design.

Specifically, as shown in FIG. 9, when the laser 1 includes a red laser chip assembly, a green laser chip assembly, and a blue laser chip assembly, the light combination assembly 2 may include a reflector 21, a first light combination mirror 22 and a second light combination mirror. Combining mirror 23.

Wherein, wherein, the reflecting mirror 21 is located at the light-emitting side of the blue laser chip assembly; the first light combining mirror 22 is located at the intersection of the outgoing light of the reflecting mirror 21 and the outgoing light of the green laser chip assembly; the second light combining mirror 23 is located at the first The intersection of the outgoing light of the light combining mirror 22 and the outgoing light of the red laser chip assembly.

The reflector 21 is used to reflect the blue laser beam emitted by the blue laser chip assembly to the first light combining mirror 22; the first light combining mirror 22 is used to transmit the blue laser beam emitted by the blue laser chip assembly and reflect the green laser chip assembly The green laser beam emitted; the second light combining mirror 23 is used to transmit the blue laser beam and the green laser beam emitted by the blue laser chip assembly and the green laser chip assembly, and reflect the red laser beam emitted by the green laser chip assembly. Therefore, the red, green and blue laser beams are combined, and the combined beams are emitted from the side of the second light combining mirror 23 .

The reflective assembly 3 can be arranged on the light output side of the second light combining mirror 23 . The reflection component 3 can be, for example, a total reflection prism. Normally, the reflective assembly 3 will include two opposite total reflection prisms, when the laser beam is incident on one of the total reflection prisms at a set angle, the incident angle meets the total reflection conditions of the total reflection prism, and the total reflection prism can All the light is reflected to the light valve modulating part 4. After being modulated by the light valve modulation part 4, the light is emitted to the total reflection prism again. At this time, the light no longer satisfies the total reflection condition and can exit smoothly; then the light is refracted by another total reflection prism to make the modulated light vertical incident on the projection lens 5.

In addition, the reflective assembly 4 can also be a reflective mirror. After the laser beam is incident on the reflective mirror at a set angle, the reflective mirror reflects the light to the light valve modulator 4 in a direction that satisfies the incident angle of the light valve modulator 4 . The light valve modulation component 4 modulates the light and then emits it to the projection lens.

The light valve modulation part 4 can adopt DMD, and DMD is a reflective light valve device. The surface of DMD includes thousands of tiny mirrors, and each small mirror can be driven to deflect independently. By controlling the deflection angle of DMD, the reflected light Incident to the projection lens 5, the light is modulated.

The outgoing light modulated by the light valve modulation component 4 needs to be imaged through the projection lens 5 to project the image on the projection screen or a set position, and the viewer can watch the display screen by watching the projection screen.

FIG. 10 is the second structural schematic diagram of the projection system provided by the embodiment of the present invention.

As shown in FIG. 10 , in some embodiments, the projection system further includes an illumination lens group 6 located between the light combination assembly 2 and the reflection assembly 3 . The illumination lens group 6 is used to shape and homogenize the light beam incident on the light valve modulation component 4 , so as to meet the use requirements of the light valve modulation component 4 .

FIG. 11 is the third structural schematic diagram of the projection system provided by the embodiment of the present invention.

As shown in FIG. 11 , in some embodiments, the projection system may include at least two of the above-mentioned lasers. In addition, it also includes a light-combining assembly 2 located at the intersection of the outgoing light of the lasers. The light-combining assembly 2 is used for each laser. The outgoing beams are combined.

For example, as shown in FIG. 11 , the projection system includes a first laser 1a and a second laser 1b; wherein the first laser 1a and the second laser 1b may be two lasers with the same structure. Both the first laser 1a and the second laser 1b may include a red laser chip assembly, a green laser chip assembly and a blue laser chip assembly. In the two lasers, the arrangement rules of the three laser chip components can be the same.

The laser projection system further includes: a light combining assembly 2, which is located at the intersection of the outgoing beams of the first laser 1a and the second laser 1b, and is used for combining the outgoing beams of the first laser 1a and the second laser 1b.

The light combination assembly 2 may include a first light combination mirror 22 and a second light combination mirror 23 . Wherein, the first light-combining mirror 22 is used for transmitting the red laser beam and reflecting the green and blue laser beams; the second light-combining mirror 23 is used for transmitting the green and blue laser beams and reflecting the red laser beam, so that the output of the two lasers Laser beams of different colors are combined.

In addition, the light beam after combining the above-mentioned lights can be directly incident on the reflection assembly 3 so that the light valve modulator 4 can modulate the incident light, and an illumination lens group 6 can also be arranged between the light combination assembly 2 and the reflection assembly 3, so that The laser beam is further shaped and homogenized.

Any of the above-mentioned lasers is equipped with a diffractive optical element, and the diffractive optical element shapes the laser beam emitted by the laser chip assembly, so that the laser beam emitted by the laser can be shaped and homogenized according to actual needs, so that it is no longer necessary in the projection system. The light pipe, diffuser and other components are arranged to avoid energy loss caused by the light pipe, effectively simplify the structural design of the projection system, and facilitate the realization of miniaturized design.

According to the first inventive concept, the laser includes a plurality of laser chip components, and a diffractive optical element located on the light emitting side of the laser chip components. Diffractive optical elements shape the laser beam emitted by the laser chip assembly, so that the laser beam emitted by the laser can be shaped and homogenized according to actual needs, so that it is no longer necessary to set up light pipes, diffusers and other components in the projection system to avoid light due to The energy loss caused by the conduit effectively simplifies the structural design of the projection system and is conducive to the realization of miniaturized design.

According to the second inventive concept, the diffractive optical element includes a plurality of diffractive units, and each diffractive unit is distributed in a two-dimensional matrix. Wherein, the diffraction unit is a stepped structure composed of multi-layer microstructures, and the size of one layer of microstructures is 10nm-100μm. The diffractive optical element is a two-dimensionally distributed diffraction unit formed by micro-nano etching process. Each diffraction unit can have a specific shape, size, refractive index, etc., and can fine-tune the phase distribution of the laser wavefront. The laser beam is diffracted after passing through each diffraction unit, and interferes at a certain distance to form a specific light intensity distribution.

According to the third inventive concept, the laser spot emitted by the laser chip assembly is shaped into a rectangular spot with uniform intensity distribution and a set size after passing through the diffractive optical element, so as to meet the lighting requirements in the projection system.

According to the fourth inventive concept, the laser further includes a casing, the laser chip assembly and the reflection mirror on the light-emitting side of the laser chip assembly are arranged in the casing, and the diffractive optical element is located on the light-emitting side of the reflection mirror. In the form of reflecting the light emitted by the laser chip assembly through the reflector, the position of the light emitted can be adjusted by adjusting the reflector, so as to achieve higher precision.

According to the fifth inventive concept, the laser chip assembly includes a red laser chip assembly, a green laser chip assembly and a blue laser chip assembly. Correspondingly, the diffractive optical element includes a first diffractive optical element, a second diffractive optical element and a third diffractive optical element. The first diffractive optical element is located on the light emitting side of the red laser chip assembly and is used to shape the red laser beam; the second diffractive optical element is located on the light emitting side of the green laser chip assembly and is used to shape the green laser beam; the third diffractive optical element The element is located on the light emitting side of the blue laser chip assembly and is used to shape the blue laser beam. In this way, the laser beams of different colors are all shaped into rectangular spots with uniform energy distribution.

According to the sixth inventive concept, the laser further includes a sealing glass forming a sealing structure with the tube shell. The diffractive optical element is located on the side of the sealing glass away from the laser chip assembly. In this way, there is no need to change the packaging structure of the laser, and the diffractive optical element can be installed after the laser packaging is completed.

According to the seventh inventive concept, the diffractive optical element is arranged on a side of the sealing glass facing the laser chip assembly. Encapsulating the diffractive optical element inside the laser can protect the diffractive optical element, thereby prolonging the service life of the diffractive optical element and making the intensity distribution of the laser beam emitted by the laser uniform.

According to the eighth inventive concept, the diffractive optical element is located on the side of the annular sidewall of the tube shell away from the bottom plate, and the diffractive optical element and the tube shell form a closed space. The diffractive optical element is used instead of the sealing glass, so that the diffractive element and the shell form a sealed structure, and the laser chip assembly is packaged, thereby simplifying the structural design.

According to the ninth inventive concept, a Fresnel structure is provided on the surface of the diffractive optical element facing the laser chip assembly, and a plurality of diffraction units are formed on the surface of the diffractive optical element facing away from the laser chip assembly. Among them, the Fresnel structure is used to collimate the outgoing light of the laser chip assembly; the diffraction unit is used to shape the incident laser beam. Therefore, the collimating lens is omitted, so that the structure of the laser is more compact.

According to the tenth inventive concept, the projection system includes any of the above-mentioned lasers, a light combination assembly located on the light output side of the laser, a reflective assembly located on the light output side of the light combination assembly, a light valve modulation component located on the reflected light path of the reflection assembly, and a light valve modulation component located on the light output side of the light combination assembly. Projection lens on the light exit side of the component.

According to the eleventh inventive concept, the output beam of the laser is a rectangular spot with uniform intensity distribution. When the intensity distribution and divergence angle of the laser beam output by the laser meet the requirements for the use of the light valve modulation component, the light combining component is directly used to output the laser beam. The laser beams of different colors are simply combined and incident on the reflective assembly, and the reflective assembly reflects the light to the light valve modulation part at a suitable angle. After the light is modulated by the light valve modulation part, it is emitted to the projection lens. The lens performs imaging to project the image on the projection screen or a set position, and the viewer can watch the display screen by watching the projection screen.

According to the twelfth inventive concept, the projection system includes at least two of the above-mentioned lasers, and the light combining component is located at the intersection of the outgoing light of the lasers, and is used to combine the outgoing beams of each laser. The light emitting side of the light combining component is also provided with a reflection A light valve modulating component is arranged on the reflection path of the reflecting component, and a projection lens is arranged on the light output side of the light valve modulating component. Any of the above-mentioned lasers is equipped with a diffractive optical element, and the diffractive optical element shapes the laser beam emitted by the laser chip assembly, so that the laser beam emitted by the laser can be shaped and homogenized according to actual needs, so that it is no longer necessary in the projection system. The light pipe, diffuser and other components are arranged to avoid energy loss caused by the light pipe, effectively simplify the structural design of the projection system, and facilitate the realization of miniaturized design.

According to the thirteenth inventive concept, the projection system further includes an illumination lens group located between the light combination assembly and the reflection assembly. The illumination lens group is used to shape and homogenize the light beam incident on the light valve modulation component, so as to meet the use requirements of the light valve modulation component.

While preferred embodiments of the invention have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, it is intended that the appended claims be construed to cover the preferred embodiment as well as all changes and modifications which fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (7)

1. A laser, characterized in that, comprising: Tube shell; the tube shell includes a bottom plate and an annular side wall above the bottom plate, the bottom plate and the annular side wall form an accommodating space; a plurality of laser chip assemblies fixed on the bottom plate of the package; and A diffractive optical element, located on the light emitting side of the laser chip assembly; the diffractive optical element is used to shape the laser beam emitted by the laser chip assembly; Wherein, the diffractive optical element is located on the side of the annular side wall of the tube shell away from the bottom plate, forming a closed space with the tube shell, and the surface of the diffractive optical element facing the laser chip assembly has Fresnel structure, the surface of the diffractive optical element away from the laser chip assembly has a plurality of diffraction units; the Fresnel structure is used to collimate the outgoing light of the laser chip assembly; the diffraction unit is used for Shaping of the incident laser beam. 2. The laser according to claim 1, wherein each of the diffraction units is distributed in a two-dimensional matrix; The diffraction unit is a stepped structure composed of multi-layer microstructures. 3. The laser according to claim 2, wherein the size of the microstructure in one layer is 10 nm˜100 μm. 4. The laser of claim 1, further comprising: A plurality of reflectors are located inside the casing; one reflector corresponds to at least one laser chip assembly, and the reflector is located on the light-emitting side of the corresponding laser chip assembly for receiving the corresponding The outgoing light of the laser chip component is reflected in the set direction; The diffractive optical element is located on the light exit side of the reflector. 5. The laser according to any one of claims 1-4, wherein the laser chip assembly comprises a red laser chip assembly, a green laser chip assembly and a blue laser chip assembly; each of the red laser chips The components are arranged in an array to form an array of red laser chip components, each of the green laser chip components is arranged in an array to form an array of green laser chip components, and each of the blue laser chip components is arranged in an array to form an array of blue laser chip components ; The diffractive optical element includes a first diffractive optical element, a second diffractive optical element, and a third diffractive optical element; the first diffractive optical element is located on the light-emitting side of the red laser chip assembly array, and the second diffractive optical element The element is located on the light emitting side of the green laser chip assembly array, and the third diffractive optical element is located on the light emitting side of the blue laser chip assembly array. 6. A laser projection system, characterized in that it comprises at least one laser as claimed in any one of claims 1-5, a light-combining assembly located on the light-emitting side of the laser, and a light-combining assembly located on the light-emitting side of the light-combining assembly A reflection assembly, a light valve modulation component located on the reflection light path of the reflection assembly, and a projection lens located on the light output side of the light valve modulation component. 7. The laser projection system according to claim 6, further comprising: an illumination lens group located between the light combination assembly and the reflection assembly.

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