WO2020253166A1

WO2020253166A1 - Laser light source and laser projection apparatus

Info

Publication number: WO2020253166A1
Application number: PCT/CN2019/125371
Authority: WO
Inventors: 颜珂; 田有良
Original assignee: 青岛海信激光显示股份有限公司
Priority date: 2019-06-20
Filing date: 2019-12-13
Publication date: 2020-12-24
Also published as: CN112114482A; CN116125739A; CN112114482B

Abstract

Disclosed is a laser light source (100), comprising: a first laser assembly configured to emit first laser light; a second laser assembly configured to emit second laser light; a third laser assembly configured to emit third laser light; a first light combining mirror (106) arranged at an intersection between the third laser light and the second laser light and configured to transmit the third laser light and reflect the second laser light; second light combining mirrors (107) arranged at the intersections between the first laser light and the second laser light as well as the third laser light that passes through the first light combining mirror (106), and configured to reflect the first laser light and transmit the second laser light and the third laser light; and third light combining mirrors (108) arranged in optical paths of the first laser light, the second laser light and the third laser light and reflecting the first laser light, the second laser light and the third laser light to a light exiting port of the laser light source.

Description

Laser light source and laser projection equipment

This disclosure claims the priority of the Chinese patent application filed with the Chinese Patent Office with the application number 201910538765.3 on June 20, 2019, the entire content of which is incorporated in this application by reference.

Technical field

The present disclosure relates to the technical field of laser projection, and in particular to a laser light source and laser projection equipment.

Background technique

The laser light source has the advantages of good monochromaticity, high brightness and long life. It is an ideal light source and is widely used in laser projection equipment such as laser TVs and laser projectors.

Summary of the invention

In one aspect, a laser light source is provided. The laser light source includes: a first laser assembly arranged on a first plane and configured to emit a first laser; a second laser assembly arranged in parallel with the first laser assembly on the first plane and configured to emit a second laser The laser; the third laser assembly is arranged on a second plane perpendicular to the first plane; the second laser assembly is closer to the third laser assembly than the first laser assembly; the third laser assembly is configured to emit a third laser; the first combination The light mirror is arranged at the intersection of the third laser light and the second laser light, and is configured to transmit the third laser light and reflect the second laser light; the second light combining mirror is arranged on the first laser light and the second light after passing through the first light combining mirror The intersection of the second laser and the third laser is configured to reflect the first laser and transmit the second laser and the third laser; the third combining mirror is arranged on the optical path of the first laser, the second laser and the third laser, And reflect the first laser, the second laser and the third laser to the light exit of the laser light source.

In another aspect, a laser projection device is provided. The laser projection device includes: a complete machine housing; a laser light source installed in the complete machine housing, the laser light source being the laser light source as described in the first aspect; and a laser light source installed in the complete machine housing An optical engine and a lens, the optical engine is connected to the lens, and the laser light source is configured to provide illumination to the optical engine.

Description of the drawings

In order to explain the technical solutions in the embodiments of the present disclosure more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and those of ordinary skill in the art can also obtain other drawings based on these drawings.

FIG. 1 is a schematic diagram of the whole structure of a laser projection device in some embodiments of the disclosure;

2A is a schematic diagram of the optical principle of a light source in some embodiments of the disclosure;

2B is a schematic diagram of another light source optical principle in some embodiments of the disclosure;

3 is a schematic diagram of a light source structure in some embodiments of the disclosure;

4A is a structural diagram of an ultra-short throw projection screen in some embodiments of the disclosure;

4B is a graph showing the change in reflectivity of the projection screen to the projection beam in FIG. 4A;

5A is a schematic diagram of an assembly of a laser assembly in some embodiments of the disclosure;

5B is a schematic front view of a laser assembly assembly in some embodiments of the disclosure;

5C is a schematic diagram of an exploded structure of a laser assembly in some embodiments of the disclosure;

5D is a schematic diagram of an exploded structure of another laser assembly in some embodiments of the disclosure;

5E is a schematic diagram of an exploded structure of still another laser assembly in some embodiments of the disclosure;

5F-1 is a schematic diagram of a structure of an MCL laser in some embodiments of the disclosure;

Fig. 5F-2 is a schematic diagram of the laser circuit package structure in Fig. 5F-1;

6A is a schematic diagram of a heat dissipation system of a red laser assembly in some embodiments of the disclosure;

6B is a schematic diagram of an assembly of a blue or green laser assembly heat dissipation system in some embodiments of the disclosure;

6C is an exploded schematic diagram of the heat dissipation system of the blue or green laser component in some embodiments of the disclosure;

FIG. 7 is a schematic diagram of a light-emitting chip structure of a red laser assembly in some embodiments of the disclosure;

8A is a schematic diagram of the optical path principle of a laser projection system in some embodiments of the disclosure;

FIG. 8B is a schematic diagram of the optical path principle of another laser projection system in some embodiments of the disclosure;

8C is a schematic diagram of the optical path principle of another laser projection system in some embodiments of the present disclosure;

FIG. 9A is a schematic diagram of the structure of a diffuser in some embodiments of the disclosure;

9B is a schematic diagram of the energy distribution of some embodiments of the disclosure after the laser beam passes through the diffuser shown in FIG. 9A;

10 is a schematic diagram of a light spot in the light path in some embodiments of the disclosure;

11A is a schematic diagram of the optical axis of the half-wave plate in some embodiments of the disclosure;

FIG. 11B is a schematic diagram of the principle of a 90-degree change of linearly polarized light in some embodiments of the disclosure;

11C is a schematic diagram of the polarization directions of P light and S light in some embodiments of the disclosure;

FIG. 11D is a schematic diagram of the rotation setting of the half-wave plate in some embodiments of the present disclosure;

12A is a schematic diagram of the principle of a laser projection optical path in some embodiments of the disclosure;

12B is a schematic diagram of another laser projection optical path principle in some embodiments of the disclosure;

FIG. 12C is a schematic diagram of another laser projection optical path principle in some embodiments of the disclosure.

Detailed ways

Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by a person of ordinary skill in the art fall within the protection scope of the present disclosure.

In the description of the present disclosure, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be interpreted broadly. For example, they can be fixed or detachable. Connected, or integrally connected; it may be directly connected, or indirectly connected through an intermediate medium, or it may be the internal communication between two components. For those of ordinary skill in the art, the specific meaning of the above-mentioned terms in the present disclosure can be understood according to specific circumstances.

In the specification and claims, terms may have subtle meanings implied in the context in addition to the clearly stated meanings. Likewise, the phrases "in one embodiment" or "in some embodiments" do not necessarily refer to the same embodiment, and the phrases "in another embodiment" or "in other embodiments" do not necessarily refer to different的实施例。 Example. Similarly, the phrases "in one example" or "in some examples" do not necessarily refer to the same example, and the phrases "in another example" or "in other examples" do not necessarily refer to different examples. For example, the claimed subject matter is intended to include, in whole or in part, exemplary embodiments or combinations of examples.

First, according to the laser projection device shown in FIG. 1, the structure and working process of the laser projection device in some embodiments of the present disclosure will be described.

Fig. 1 shows a schematic diagram of the structure of a laser projection device. As shown in FIG. 1, the laser projection device 10 includes a complete housing 101 and a plurality of optical parts including a light source 100, an optical engine 200 and a lens 300. Each optical part (for example, the light source 100, the optical machine 200 or the lens 300) has a corresponding casing to be wrapped, and meets certain sealing or airtight requirements; for example, the light source 100 can achieve airtight sealing through its corresponding casing, which can be better To improve the light attenuation problem of the light source 100.

The light source 100, the optical engine 200, and the lens 300 are all installed in the complete housing 101. Wherein, the optical engine 200 and the lens 300 are connected and arranged along the first direction X of the complete machine housing 101, and a light source 100 is arranged in a space enclosed by the optical engine 200, the lens 300 and a part of the complete machine housing 101. Wherein, as shown in FIG. 1, the first direction X is the width direction of the housing of the whole machine, and according to the usage mode, the first direction X is opposite to the direction viewed by the user.

The light source 100 is a three-color laser light source that can emit red laser, blue laser, and green laser. Therefore, the light source 100 is configured to provide an illumination beam to the optical machine 200. Exemplarily, the light source 100 provides the light engine 200 with illumination light beams through the three primary color illumination light beams output in a sequential manner.

It should be noted that the light source 100 may also be output in a non-sequential manner, but there are periods of superimposed output of illumination light beams of different primary colors. For example, there is a period of overlapping output of the red illumination beam and the green illumination beam, thereby increasing the proportion of the yellow illumination beam in the beam cycle, which is beneficial to improve the image brightness; or, the red illumination beam, the green illumination beam and the blue illumination beam are part of It is lit during the period, and the three-color illumination beams are superimposed to form a white illumination beam, which can increase the brightness of the white field.

Therefore, in the case where the light engine 200 includes a three-chip LCD (Liquid Crystal Display) liquid crystal light valve, in order to cooperate with the three-chip LCD liquid crystal light valve, the three-color primary color light in the light source 100 can be lit and output mixed at the same time White light.

In this example, although the light source 100 outputs the three-color primary color light sequentially, according to the principle of three-color light mixing, the human eye cannot distinguish the color of the light at a certain moment, and it still perceives mixed white light. Therefore, the output of the light source 100 is usually referred to as mixed white light.

Exemplarily, the light source 100 includes a light source housing (ie, its corresponding housing), and a blue laser assembly, a green laser assembly, and a red laser assembly installed on different side walls of the light source housing. The blue laser component can emit blue laser, the green laser component can emit green laser, and the red laser component can emit red laser. Wherein, the green laser component and the red laser component are installed side by side on the same side wall, and both are perpendicular to the blue laser component in space. That is, the side wall (first side wall) of the light source housing where the green laser component and the red laser component are located is perpendicular to the side wall (second side wall) of the light source housing where the blue laser component is located, and the two Both side walls are perpendicular to the bottom wall of the light source housing or the bottom wall of the complete machine housing. At this time, the green laser assembly and the red laser assembly are located on the first plane, and the green laser assembly is arranged side by side with the red laser assembly on the first plane; the blue laser assembly is located on the second plane perpendicular to the first plane, so that The blue laser component is perpendicular to the red laser component and the green laser component.

FIG. 2A is a schematic diagram of an optical path principle of the light source 100. As shown in Figure 2A, the green laser assembly is closer to the red laser assembly than the blue laser assembly. At this time, the first laser assembly is a red laser assembly, the first laser is a red laser; the second laser assembly is a green laser assembly, and the second laser assembly is a red laser assembly. The laser is a green laser; the third laser component is a blue laser component, and the third laser is a blue laser; the light beam emitted by the red laser component 130 is emitted from the light outlet of the light source 100 after being reflected twice; the light beam emitted by the green laser component 120 After two reflections, the light beam emitted from the blue laser component 110 is transmitted twice, and then emitted from the light outlet of the light source 100 after one transmission. It can be seen that in the above schematic diagram of the principle of the optical path, the light beam emitted by the red laser assembly 130 (that is, the red laser) has the shortest optical path, and has the least number of transmission and reflection.

In some embodiments, the laser components of the three colors respectively output rectangular light spots. After each laser component is installed on the side wall of the light source housing, the long side of the corresponding output rectangular light spot is perpendicular to the bottom wall of the light source housing. In this way, the laser spots output by the three-color laser components will not form a "cross"-shaped spot after the light is combined, which is beneficial to the reduction of the combined light spot size and the improvement of the uniformity. In the case of three-color laser components outputting red laser, green laser and blue laser sequentially, the "combined light" and "combined light spot" here refer to the effect of mixing white light perceived by the human eye.

As shown in FIG. 3, the light source housing 102 includes a bottom wall and a top cover, and a plurality of side walls located between the bottom wall and the top cover. The light source 100 includes a plurality of optical lenses, all of which are arranged on the bottom wall of the light source housing 102. A plurality of windows 1021 are opened on the side wall of the light source housing 102 to install the above-mentioned multiple laser components, so that the light beams emitted by the laser components of any color can be incident into the inside of the light source housing 102 from the corresponding installation windows, and pass Multiple optical lenses form a light transmission path. For example, the first side wall of the light source housing 102 includes a window 1021 corresponding to the red laser assembly 130 and the green laser assembly 120, and the second side wall of the light source housing 102 includes a window 1021 corresponding to the blue laser assembly 110.

In some embodiments, the light source 100 further includes an air pressure balancing device, which is arranged on the bottom wall or the top cover of the light source housing. The air pressure balance device can relieve the pressure. In the case that the internal temperature of the light source housing is too high, the air pressure balance device is used to relieve the pressure to the outside of the light source housing, or the air pressure balance device forms a gas containing space to increase the internal seal of the light source The volume of the space can balance the air pressure in the light source housing and improve the reliability of the operation of the optical devices in the light source housing.

In some examples, the air pressure balance device is a filter valve. The filter valve is configured to communicate the inside and outside of the light source housing 102 to realize the exchange of airflow. That is, when the internal temperature of the light source housing 102 rises, the internal airflow flows out to the outside, and when the temperature drops to cool the inside of the light source housing 102, the external airflow can also enter the inside of the light source housing 102. Exemplarily, the filter valve is set as an airtight and waterproof filter membrane, which can filter dust, dust and other particles within a certain diameter range from the outside, and block them out to maintain the cleanliness of the inside of the light source housing 102.

In other examples, the air pressure balancing device is a retractable airbag, and the retractable airbag may be made of elastic rubber. The retractable airbag is configured to increase in volume during an increase in the internal air pressure of the light source housing 102 to relieve the internal air pressure of the light source housing 102.

Since the assembly structure of the laser components of the three colors and the light source housing are basically the same, in order to simply illustrate the connection relationship between the laser components and the light source housing, the following will take the assembly structure of the laser components of any one of the colors as an example. .

The laser components of the above three colors are all MCL (Multi-Chip Laser diode) type laser components. The MCL type laser component includes an MCL laser and a laser drive circuit board arranged on the outer periphery of the MCL laser. The MCL laser encapsulates multiple light-emitting chips on a substrate to form a surface light source output. An MCL laser 110A as shown in FIG. 5F-1 includes a metal substrate 1102 on which multiple light-emitting chips (not shown in the figure) are encapsulated. The multiple light-emitting chips can be connected in series or in rows or The columns are driven in parallel. Multiple light-emitting chips can be arranged in a 4×6 array, or other array arrangements, such as 3×5 arrays, or 2×7 arrays, or 2×6 arrays, or 4×5 arrays, and lasers with different array numbers The overall luminous power is different. Pins 1103 extend from both sides of the metal substrate 1102, and by connecting these pins with electrical signals, the light-emitting chip can be driven to emit light. The MCL laser 110A further includes a collimating lens group 1101 covering the light-emitting surfaces of the multiple light-emitting chips, and the collimating lens group 1101 is usually fixed by glue. The collimating lens group 1101 includes a plurality of collimating lenses, which usually correspond to the light-emitting positions of the light-emitting chips one-to-one to collimate the laser beam.

As shown in FIG. 5F-2, the MCL laser assembly further includes a laser driving circuit board 1104 disposed on the outer peripheral side of the MCL laser 110A. The laser driving circuit board 1104 has a flat structure, and the laser driving circuit board and the light emitting surface of the MCL laser are approximately parallel or located in the same plane. At least one pin 1103 is provided on both sides of the MCL laser, and each pin 1103 is welded or plugged into the laser driving circuit board 1104, so that the MCL laser is electrically connected to the laser driving circuit board. The laser driving circuit board 1104 is configured to provide driving signals to the MCL laser. In some examples, the laser driving circuit board is integrally formed to surround the outer side of the metal substrate 1102 of the MCL laser. In other examples, the laser drive circuit board is two independent circuit boards, that is, the laser drive circuit board includes a first part 1104a and a second part 1104b, which enclose the MCL laser, so that the packaged MCL laser assembly is formed It is basically a flat panel structure, which is easy to install, saves space, and is also conducive to miniaturization of the light source equipment.

5A and 5B are respectively a schematic diagram of an assembly structure of a laser assembly and a fixing bracket of any color, and a schematic diagram of an exploded structure. Fig. 5A shows a schematic view when viewed from the front (right image) and a schematic view when viewed from the back (left image).

Referring to FIGS. 3, 5A and 5B, the laser light source 100 further includes a fixing bracket 104, and any color laser component is installed at the window 1021 of the corresponding light source housing through the fixing bracket 104. The fixing bracket 104 and the light source housing 102 are locked by screws, so that the laser assembly is fixed at the position of the window 1021.

It should be noted that when the laser assembly of any color is the above-mentioned MCL laser assembly, the metal substrate of the MCL laser 110A in the MCL laser assembly is provided with an assembly hole, which can be locked with the fixing bracket.

As shown in FIG. 5C, the fixing bracket 104 is a sheet metal part with a light-transmitting window frame 1041. The front of the light-transmitting window frame 1401 is installed close to the window 1021 of the light source housing 102, and the laser assembly of any color is installed at the installation position on the back of the light-transmitting window frame 1041. In addition, in order to improve the sealing performance of the installation structure, a third sealing member 1042 is provided at the back installation position of the light-transmitting window frame 1041. The third sealing member 1042 is a frame-shaped rubber member with a folded edge and can be sleeved on the MCL. On the front side of the laser assembly, fix the MCL laser assembly at the installation position. The third sealing member 1042 can also serve as a buffer to prevent the collimating lens group of the MCL laser assembly from being damaged due to hard contact with the sheet metal.

The MCL laser assembly is composed of the MCL laser 110A and the corresponding laser driving circuit board 1104. The MCL laser assembly is fixed to the fixing bracket 104 and becomes an assembly unit, and is installed together at the position of the window 1021 corresponding to the light source housing 102. For example, there are studs around the window 1021, and the studs passing through the fixing bracket are driven into the studs around the window.

Since the light source 100 is provided with multiple optical lenses, the multiple optical lenses are precision components, and the energy density during the transmission of the light beam inside the light source 100 is very high; therefore, if the internal environment of the light source 100 is not clean, dust, dust, etc. Particles will accumulate on the surface of multiple precision optical lenses, which will result in a decrease in the efficiency of light processing and further adverse effects such as light attenuation of the optical path, and the brightness of the entire laser projection equipment will also decrease. Dustproofing the inside of the light source can alleviate the aforementioned light attenuation problem. Illustratively, as shown in FIG. 5D, a sealing glass 105 is also provided at the window 1021. The sealing glass 105 isolates the inside of the light source housing from the laser assembly installed at the window 1021, so that external dust and the like will not enter the inside of the light source housing from the window 1021. The sealing glass 105 can be arranged on the inner surface of the light source housing, such as by bonding; it can also be arranged on the side of the light source housing close to the laser assembly, for example, by setting a mounting position on the outer surface of the light source housing, and the laser assembly , The sealing glass is installed outside the window 1021 of the light source housing.

For the exploded structure shown in FIG. 5D, in order to facilitate the installation of the sealing glass, in this example, the sealing glass 105 is installed on the side of the window 1021 close to the laser assembly. There is also a first receiving groove on the front side of the fixing bracket 104 for receiving the first sealing member 1051; and a second receiving groove for receiving the second sealing member 1052 at the window 1021 of the light source housing. The sealing glass 105 is located between the first sealing member 1051 and the second sealing member 1052. Exemplarily, the second sealing member 1052 is placed in the second receiving groove at the window 1021; the second sealing member 1052 is provided with a fixing groove that matches the sealing glass 105, and the sealing glass 105 is placed in the fixing groove And install the first sealing member 1051 into the first receiving groove of the light-transmitting window frame 1041 of the fixed bracket 104 by interference fit; then install the laser assembly composed of the fixed bracket and the MCL laser to the window of the light source housing At 1021; the first sealing member 1051 and the sealing glass 105 are in squeeze contact. With the completion of the fixing of the laser assembly, the sealing glass 105 is also sandwiched between the first sealing member 1051 and the second sealing member 1052 for fixing.

In some of the above examples, the MCL laser assembly of any color is fixed to the fixed bracket by the shoulder screw, and there is also a shock absorber between the shoulder screw and the fixed bracket, which can reduce the laser's driving process at a higher frequency. The resulting noise is transmitted.

The assembly structure of the laser assembly and the light source housing has been described above. The above-mentioned laser assembly is installed on the housing of the light source, emits a laser beam under the control of the drive signal, forms a light path output inside, and cooperates with an optical machine and a lens to perform projection imaging.

In the laser projection equipment provided by some embodiments of the present disclosure, as shown in the schematic diagram of the principle of the light source optical path as shown in FIG. 2A, the first light combining mirror 106 is provided at the intersection of the blue laser and the green laser. Color laser, reflecting green laser. A second light combining mirror 107 is set at the intersection of the blue laser and green laser output in time sequence (in the eyes of human eyes, the blue laser and green laser are the combined light effect) and the red laser light, the second combining mirror 107 reflects red The laser light transmits blue and green laser light to the third light combining mirror 108. The third light combining mirror 108 reflects and outputs the three-color laser light to the light exit of the light source.

The optical axis direction of the light-emitting surface beam of the blue laser component 110 and the optical axis direction of the light outlet of the light source are perpendicular to each other, the optical axis direction of the light-emitting surface beam of the green laser component 120, and the optical axis direction of the light-emitting surface beam of the red laser component 130 All are parallel to the optical axis direction of the light outlet of the light source, and the direction is the same. The green laser light emitted by the green laser component 120 is reflected by the first light combining mirror 106 and then incident on the second light combining mirror 107. The blue laser light emitted by the blue laser component 110 is transmitted through the first light combining mirror 106 and passes through the first combining mirror 106. The mirror 106 can combine the blue laser and the green laser to output.

The output direction of the blue laser and the green laser that are combined and output by the first light combining mirror 106 is perpendicular to the output direction of the red laser emitted by the red laser assembly 130 and has an intersection. A second light combining mirror 107 is provided at the intersection of the three light beams. The second light combining mirror 107 reflects the red laser light and transmits the green laser light and the blue laser light. The three-color laser beams are combined to form a beam that enters the third combining mirror 108. The third combining mirror 108 reflects the three-color laser beams to the homogenization element 109, and exits from the light source after narrowing the spot by the condenser lens group 111 Mouth shot.

As shown in the light source structure in FIG. 3, the green laser component 120 and the red laser component 130 are installed side by side on one side wall of the light source housing, and the blue laser component 110 is installed on the other side wall of the light source housing 102. The two side walls of the body are in a vertical relationship. The laser components of the three colors respectively output rectangular light spots. After each laser component is installed on the side wall of the light source housing, the long side of the corresponding output rectangular light spot is perpendicular to the bottom wall of the light source housing.

Inside the housing of the light source, a plurality of light combining mirrors and a converging lens group are also arranged. Among them, the first light combining mirror is located between the blue laser component and the green laser component, at the intersection of the blue laser and the green laser. The second light combining mirror is arranged obliquely toward the light emitting surface of the red laser assembly, reflects the red laser light, and transmits the blue laser light and the green laser light. The first light combining mirror, the second light combining mirror, and the third light combining mirror are arranged substantially in parallel. The first light combining lens, the second light combining lens, and the third light combining lens are clamped and fixed on the bottom wall of the light source housing by the base. In addition, considering the assembly tolerance, the angles of the first light combining lens, the second light combining lens, and the third light combining lens can be fine-tuned, such as within plus or minus 3 degrees.

The first light combining mirror transmits the blue laser, and after reflecting the green laser, the blue laser and the green laser are output to the second combining mirror; the second combining mirror reflects the red laser, and after transmitting the blue laser and green laser, the three The colored laser beam is output to the third light combining mirror; the third light combining mirror reflects the red laser, blue laser, and green laser to the light exit of the light source housing.

Exemplarily, the third light combining mirror is a reflecting mirror, and both the first light combining mirror and the second light combining mirror are dichroic plates.

The light reflectivity of the first light combining mirror is greater than its light transmittance; the light reflectivity of the second light combining mirror is greater than its light transmittance. For example, the light reflectivity of each light combining mirror can reach 99%, and the transmittance is usually 95%-97%.

Exemplarily, the three-color laser components in the laser projection device all include MCL lasers. As shown in Figure 5F-1, the MCL laser includes multiple light-emitting chips packaged on a metal substrate. Due to the different light-emitting principles, the light-emitting power of different color light-emitting chips is also different. For example, the light-emitting power of green light-emitting chips is about 1W per chip, while the light-emitting power of blue light-emitting chips is more than 4W per chip. When the above-mentioned three color lasers use the same number of light-emitting chips, for example, they all use a package type of 4×6 arrangement, the three color lasers also have different overall light-emitting powers. For example, the luminous power of the green laser component is less than the luminous power of the red laser component, and also less than the luminous power of the blue laser component; the luminous power of the red laser component is less than the luminous power of the blue laser component.

In addition, in some of the foregoing embodiments, the red laser component, the blue laser component, and the green laser component are all packaged with the same array of light-emitting chips, such as a 4×6 array. However, due to the different light-emitting principles of red light-emitting chips, as shown in Figure 7, there will be two light-emitting points (X1 and X2) at a red light-emitting chip, which makes the divergence angle of the red laser in the fast axis direction and the slow axis direction Compared with blue laser and green laser, it is larger. In the optical transmission process, for the same optical lens, on the one hand, because the red laser has a large divergence angle, on the other hand, because the optical lens has a certain light receiving range or has better light processing performance in a certain angle range, the red laser The longer the light path or optical path passed, the more serious the divergence, resulting in the lower the optical processing efficiency of the red laser light by the rear optical lens. Although the luminous power of the red laser component is greater than the luminous power of the green laser component, the light loss rate of the red laser is greater than the light loss rate of the green laser and the blue laser after passing through the same length of light path. Light loss ranking: red>green>blue; power ranking: green＜red＜blue.

In the optical path as shown in FIG. 2A, after the blue laser is output along the light-emitting surface of the blue laser assembly, it passes twice through transmission, one reflection, and passes through the homogenization element 109 and the condenser lens group 111 and then exits from the light outlet of the light source. For the green laser, after two reflections and one transmission, it enters the homogenization element 109 and the converging lens group 111 and exits the light exit of the light source housing. The red laser light enters the homogenization element 109 and the condensing lens group 111 after being reflected twice and exits the light exit of the light source. It can be seen that before output from the light outlet of the light source, the light path of the red laser is shorter than the light path of the blue laser and the green laser. In this way, the light loss generated by the red laser during the transmission of the light path can be reduced. Regardless of the influence of the light path on the light loss, after the red laser is reflected by the second light combining mirror and the third light combining mirror, the light energy can reach about 99%*99%=98%, it needs to be explained that Here, the calculation of the light energy efficiency of the red laser does not consider the case where the red laser has a large divergence angle and large-angle light loss, but only considers the influence of the optical lens transmittance.

The blue laser is transmitted twice and reflected once. When only considering the influence of transmittance on light loss, the blue laser passes through the first and second light combining mirrors, and then passes through the third light combining mirror. The output light energy after reflection can reach about 97%*97%*99%=93%. After the green laser is reflected twice, the light energy output from the third light combining mirror after one transmission can reach about 99%*99%*97%=95%. Therefore, the transmittance loss of the red laser through the lens is the smallest, and its optical path is the shortest so that the optical loss is small. In practical applications, the red laser has the largest divergence angle in the transmission optical path, which is easy to lose. At the same time, the luminous power of the blue laser component can be higher, and the human eye's visual function of blue is relatively low, so it can be regarded as red The loss of laser, blue laser and green laser is equivalent. Based on the above-mentioned layout of the laser components of each color, under the different optical characteristics of each color laser, the loss of each color laser beam during transmission can be better balanced, and the optical loss caused by the easy loss of the red laser in the optical path can be reduced, so that The power ratio of the three-color laser is close to the preset value, no obvious imbalance will occur, and it is also conducive to achieving the color ratio and the desired white balance that meet the theoretical design. When the three-color laser beams are combined and output from the third light combiner, the light paths experienced by the three lasers are the same, and it is easy to achieve uniform light loss, and the unbalance and inconsistency will be weakened.

The optical path formed by the arrangement of all the above-mentioned laser components is roughly L-shaped, which is relatively regular, which helps to reduce the length of the light source housing in one direction, and is also conducive to structural design. It can reserve a regular space for the whole housing, such as easy installation Radiator parts.

It should be noted that the above-mentioned laser components all use MCL type laser components. Compared with traditional BANK type laser components, the volume of MCL type laser components is significantly smaller. Therefore, in some embodiments, the structural volume of light source 100 is larger than that of traditional BANK type laser components. The type of laser assembly should be significantly reduced, so that more space can be reserved near the light source 100, which facilitates heat dissipation design. For example, the placement of the radiator and the fan will be more flexible; and, it may also be equipped with a circuit board and other structures; it is also beneficial to reduce the length of the whole structure in a certain direction, or the volume of the whole machine.

In the structure of the whole machine, the laser light source is the heat source of the laser projection equipment. Due to the above-mentioned L-shaped optical path arrangement, the laser light source can be arranged as close as possible to the side of the whole machine casing, and the laser light source is reserved on the side far from the whole casing. Out of space. The reserved space can be used as an isolation space between the laser light source and the lens, which can prevent the heat of the laser light source from being quickly transferred to the lens and other precision optical lenses, and avoid affecting the optical performance.

As a modification of FIG. 2A, different from the optical path shown in FIG. 2A, the positions of the blue laser assembly and the green laser assembly can also be exchanged, as shown in FIG. 2B. The positions of the blue laser component 110 and the green laser component 120 are swapped so that the blue laser component 110 is closer to the red laser component 130 than the green laser component 120; at this time, the first laser component is a red laser component, and the first laser is a red laser ; The second laser component is a blue laser component, the second laser is a blue laser; the third laser component is a green laser component, and the third laser is a green laser; the first light combining mirror 106 is configured to transmit green laser and reflect blue Laser; the second light combining mirror 107 is configured to reflect the red laser, and transmit green laser and blue laser; the third light combining mirror 108 is configured to reflect the green laser, blue laser and red laser to the laser light source mouth.

The red laser light emitted by the red laser assembly 130 is still sequentially reflected by the second light combining mirror 107 and the third light combining mirror 108, and the optical energy loss of the red laser assembly remains unchanged. According to the above calculation of transmittance, the light energy loss of the green laser component is 1-97%*97%*99%=7%, and the light energy loss of the blue laser is 1-99%*97%*99%= 5%, by increasing the proportion of the light-emitting period of the green laser in the circuit, the relatively high light loss of the green light caused by the above-mentioned light source layout can be reduced or alleviated.

In some of the above embodiments, by setting the optical path of the red laser to the shortest, the number of transmission or reflection of the red laser is reduced, that is, the red laser is set to only pass through the reflection optical path twice, which can reduce the optical transmission loss of the red laser. It is ensured that the light loss of the red laser before the beam combination is reduced as much as possible, which is beneficial to maintain the ratio of the power and color of the three-color light source, so that the white balance of the system is close to the theoretical setting value, and a higher projection image quality is achieved.

2A and 2B, in the light source used in the above laser projection device, the three-color laser light passes through the light combining lens group (the light combining lens group includes the first light combining mirror, the second light combining mirror, and the third light combining mirror). The homogenization element and the condensing lens group are also used to homogenize and shrink the beam to improve the light collection efficiency and homogenization efficiency of the light receiving element in the rear light machine.

In some embodiments, as shown in FIG. 2A, the light source 100 further includes a homogenizing element 109 and a condenser lens group 111. The homogenization element 109 is disposed between the third light combining lens 108 and the converging lens group 111. Exemplarily, the homogenization element is a homogenization diffusion sheet with regularly arranged microstructures, as shown in FIG. 9A. At present, the microstructure of the commonly used homogenization diffusion sheet is arranged randomly and irregularly, but the homogenization diffusion sheet used in the light source architecture uses a regularly arranged microstructure. The homogenization diffuser uses a principle similar to that of a fly-eye lens to homogenize the beam, and can change the energy distribution of the laser beam from a Gaussian shape to the shape shown in FIG. 9B. As shown in Figure 9B, the energy near the central optical axis of the laser is greatly weakened and becomes smoother, and the divergence angle of the laser beam is also increased, so that the effect of energy homogenization is much better than the commonly used microstructures with irregular arrangements. Of the diffuser.

The above-mentioned homogenization diffusion sheet may only be provided with regularly arranged microstructures on one side, or may be respectively provided with regularly arranged microstructures on both sides.

After homogenization by the above homogenization diffusion sheet, the laser beam passes through the condenser lens group to reduce the spot size. On the one hand, the high-energy laser beam is homogenized first, which can reduce the impact on the uneven energy distribution of the back-end components. On the other hand, the homogenization is performed first, and the beam contraction can also reduce the beam spot after contraction. Difficulty of homogenization again.

Exemplarily, the above-mentioned homogenization element 109 is a diffractive element, such as a linear grating or a two-dimensional grating (ie, a two-dimensional diffractive element), or a Fresnel lens. A better homogenization effect can also be achieved by configuring the homogenization element 109 as a diffraction element.

In some embodiments, the convergent lens group includes a combination of two convex lenses, and any one of the two convex lenses includes at least one of a plano-convex lens, a double-convex lens, or a meniscus lens. For example, the combination of two convex lenses includes a combination of a double convex lens and a positive meniscus (positive meniscus lens). Among them, the meniscus lens refers to a lens whose concave surface (curvature of the concave surface) is smaller than that of the convex surface (curvature of the convex surface), that is, the radius of curvature of the concave surface of the meniscus lens is smaller than the radius of curvature of the convex surface. Both of the above-mentioned two lenses are spherical lenses, and of course, both aspheric lenses may be used. However, spherical lenses are easier than aspheric lenses in terms of molding and precision control, and the cost can also be reduced. In this example, the condensing lens group is used to converge the light beam, and the focus of the condensing lens group is set at the light receiving port of the rear light receiving element, that is, the focal plane of the converging lens group is located at the light incident surface of the light receiving element. In order to improve the light collection efficiency of the light collection element.

Exemplarily, the above-mentioned converging lens group only includes a convex lens, so that the light beam can be condensed, and the number of lenses is reduced, and the structure of the converging lens group is simplified.

In some embodiments, the rear lens of the condenser lens group or the entire lens group is installed at the light outlet of the light source housing (that is, the light source outlet), and the housing around the condenser lens group and the light source outlet is filled with a seal , Such as sealing rubber ring. In this way, while the condensing lens group is fixed, the airtight seal inside the light source housing can be maintained to prevent dust particles from entering the inside of the light source housing from the light outlet of the light source. Moreover, directly fixing the condenser lens group to the position of the light outlet of the light source is also beneficial to shorten the light path and reduce the volume of the light source housing.

The convergent light beam output from the light outlet of the light source is finally collected by the light receiving part of the light path of the light engine. As shown in the schematic diagram of the principle of the optical path as shown in FIG. 8A, in this example, the light receiving component 250 is a light pipe. The light pipe has a rectangular light entrance surface and a light exit surface. The light pipe serves as both a light receiving part and a homogenizing part. The light incident surface of the light pipe is the focal plane of the condenser lens group 111. The converging lens group 111 inputs the condensed light beam into the light pipe 250, and the light beam undergoes multiple reflections inside the light pipe and exits from the light emitting surface. Since a homogenization diffuser is arranged in the front light path, the homogenization of the light pipe can achieve a better homogenization effect of the three-color mixing and improve the quality of the illumination beam.

It should be noted that the light source is a pure three-color laser light source, and speckle is a unique phenomenon of laser. In order to obtain a higher display quality of the projected picture, the three-color laser needs to be processed for de-speckle. In the example, a diffusion wheel 260, that is, a rotating diffusion sheet, is also provided between the converging lens group 111 and the light receiving part 250. The diffuser wheel 260 is located in the condensing light path of the converging lens group 111, and the distance from the wheel surface of the diffuser wheel 260 to the light incident surface of the light collecting part 250 (such as the light pipe) is about 1.5mm to 3mm, such as 1.5mm, 2.0mm, 2.5mm , 3mm. The diffuser wheel can diffuse the convergent beam, increase the divergence angle of the beam, and increase the random phase. In some embodiments, since human eyes have different speckle sensitivity to different colors of laser light, the diffusion wheel can be partitioned. For example, the diffusion wheel is divided into a first partition and a second partition. The first partition is used to transmit red laser light, and the second partition is used to transmit blue laser and green laser light. The divergence angle of the first partition is slightly larger than the second partition. Or, divide the diffusion wheel into three zones, corresponding to red laser, green laser, and blue laser. Among the above three regions, the relationship between the divergence angle of each color laser region is that the red laser region has the largest divergence angle and the blue laser region has the smallest divergence angle. When the diffuser wheel has corresponding partitions, the rotation period of the diffuser wheel can be consistent with the lighting period of the light source. Generally, when the diffuser wheel is a diffuser, its rotation period is not particularly limited.

The light pipe has a certain light-receiving angle range. For example, light beams within the range of plus or minus 23 degrees can enter the light pipe and be used by the rear-end illumination light path, while other large-angle light beams become stray light and are blocked, causing light loss. The light exit surface of the diffusion wheel is arranged close to the light entrance surface of the light pipe, which can increase the amount of light that the laser beam is collected into the light pipe after diffusion and improve the light utilization rate.

In addition, in other examples, the above-mentioned light receiving component is a fly-eye lens.

As mentioned above, since the homogenization diffuser 109 is arranged in the front optical path, the light source beam is homogenized, is condensed by the condensing lens group 111, and enters the diffuser 260. The laser beam passes through a stationary diffuser (homogenization diffuser 109), and then a moving diffuser (diffuser 260). In this way, based on the homogenization of the beam by the stationary diffuser, the laser beam Diffusion homogenization can enhance the homogenization effect of the laser beam, reduce the energy ratio of the beam near the optical axis of the laser beam, thereby reducing the coherence of the laser beam, and greatly improve the speckle phenomenon of the projection screen.

It should be noted that the light source 100 may include at least one of the above-mentioned homogenization diffusion sheet 109, the condenser lens group 111 and the diffusion wheel 260. For example, in the optical path from the third light combining mirror 108 to the light exit of the light source, the homogenizing diffuser 109, the converging lens group 111 and the diffuser 260 are arranged. When one or two of them are omitted, the arrangement order of the homogenizing diffuser 109, the converging lens group 111 and the diffuser 260 remains unchanged.

In the light source provided by some of the above embodiments, after the light source beam is incident on the light pipe for collection, the light pipe homogenizes the light again. The inventor of the present disclosure measured the light spot distribution on the light incident surface of the light pipe to show a relatively obvious color boundary phenomenon between the inner and outer circles. For example, the convergent light spot is circular, the outermost circle is red, and the inward is purple, blue and other concentric apertures, as shown in Figure 10. Through research, it is found that, as mentioned above, the divergence angle of the fast and slow axis of the red laser assembly is larger than the divergence angle of the blue laser and the green laser due to the different light emitting principles. Although in this example, the three-color laser components are arranged in an array with the same number of chips and have the same size in terms of volume appearance, but due to the characteristics of the red laser itself, the spot size of the red laser beam during transmission is larger than that of the blue laser. And the spot size of the green laser. This phenomenon already exists when the three-color combined light is performed, and as the transmission distance of the light path increases, its divergence angle increases faster than the other two colors of laser light, so that although the three-color combined light will homogenize and shrink The beam, and possibly through the re-diffusion and homogenization of the rotating diffuser, but the spot size of the red laser is always larger. The test spot on the light entrance surface of the light pipe also showed this phenomenon.

In order to improve the coincidence of the three-color laser spots, in some examples, the length of the light pipe is increased to improve the homogenization effect of light mixing, but this will increase the length of the light path and increase the structural volume.

In this example, a solution is proposed. Based on the optical path schematic diagrams provided in Figures 2A and 2B, as shown in Figure 8B, a third diffuser is provided in the combined light path of the blue laser and the green laser. 112. The blue laser and the green laser are diverged first and then combined with the red laser beam. The third diffusion sheet 112 is disposed in the light path between the first light combining mirror 106 and the second light combining mirror 107. Of course, stationary third diffusers 112 can also be provided for the blue laser and the green laser, for example, respectively, in the optical paths between the light-emitting surfaces of the two-color laser components and the corresponding light combining mirrors.

By arranging a third diffuser 112 in the light path of the blue laser and the green laser, the blue laser and the green laser can be expanded, for example, set to a diffusion angle of 1 to 3 degrees, passing through the third diffuser. After 112, the expanded blue laser and green laser are combined with the red laser. At this time, the spot size of the three-color laser is the same, and the spot overlap is improved. The three-color spot with a higher degree of coincidence is also conducive to the homogenization and speckle reduction of the subsequent optical path, and the beam quality is improved.

Another example of the present disclosure provides another solution. Based on the optical path schematic diagrams provided in FIGS. 2A and 2B, as shown in FIG. 8C, a telescope system 113 is provided in the optical path of the red laser. The telescope system 113 is configured to transmit the red laser light and reduce the beam of the red laser light. Exemplarily, as shown in FIG. 8C, the telescope system includes a convex lens 1131 and a concave lens 1132. The convex lens 1131 is closer to the red laser assembly than the concave lens 1132, so that the red light beam emitted by the red laser assembly can be reduced. Among them, as shown in Figure 8C, the convex lens 1131 is a plano-convex lens, the plano-convex lens has opposite flat and convex surfaces, and the convex surface of the plano-convex lens faces the red laser component; the concave lens 1132 is a plano-concave lens, and the plano-concave lens has opposite flat and concave surfaces. The concave surface faces the plane of the plano-convex lens.

The laser light emitted by the laser assembly is linearly polarized light. During the light-emitting process of the red laser component and the blue laser component and the green laser component, the oscillation mode of the resonator is different, resulting in the polarization direction of the red laser linearly polarized light and the polarization of the blue laser linearly polarized light and the green laser linearly polarized light The direction is 90 degrees. That is, the red laser light is P-ray polarized light, and the blue laser and green laser light are S-ray polarized light.

In some of the above embodiments, the polarization direction of the red laser component is 90 degrees different from the polarization directions of the blue laser component and the green laser component. Among them, the red laser is P light, and the blue laser and green laser are S light. The three-color light beam projected and imaged by the laser projection device has different polarization directions.

In practical applications, in order to better restore color and contrast, laser projection equipment usually needs to be matched with a projection screen with higher gain and contrast, such as an optical screen, which can better restore high brightness and high contrast projection images.

Figure 4A shows an ultra-short throw projection screen, which is a Fresnel optical screen. Along the incident direction of the projection beam, the Fresnel optical screen includes a substrate layer 401, a diffusion layer 402, a homogeneous medium layer 403, a Fresnel lens layer 404, and a reflective layer 405. The thickness of the Fresnel optical screen is usually between 1 and 2 mm, and the substrate layer 401 occupies the largest proportion of the thickness. The substrate layer 401 also serves as a support layer structure of the entire screen, and has a certain light transmittance and hardness. The projection light beam first transmits through the substrate layer 401, then enters the diffusion layer 402 for diffusion, and then enters the uniform medium layer 403. The uniform medium layer includes a uniform light-transmitting medium, such as a medium of the same material as the base layer 401. The light beam transmits through the uniform medium layer 403 and enters the Fresnel lens layer 404. The Fresnel lens layer 404 converges and collimates the beam. The collimated beam is reflected by the reflective layer and then folded back through the Fresnel lens 404, uniform medium layer 403, diffusion layer 402, and base material layer 401, and is incident on the user In the eyes.

During the research and development process, the inventors of the present disclosure discovered that the ultra-short-focus projection screen using the above-mentioned three-color laser light source will have partial color casts, resulting in "color spots", "color blocks" and other chromaticity unevenness. On the one hand, the reason for this phenomenon is that in currently used three-color lasers, the polarization directions of laser beams of different colors are different. There are usually multiple optical lenses, such as lenses and prisms, in the optical system. The optical lenses themselves have different transmittances for P-polarized light and S-polarized light. For example, the transmittance of optical lenses for P light is relatively greater than that of S The transmittance of light. On the other hand, due to the structure of the screen material, with the change of the incident angle of the ultra-short-throw projection beam, the ultra-short-throw projection screen itself will exhibit obvious changes in the transmittance and reflectance of the beams with different polarization directions. As shown in Figure 4B, for the red projection beam, when the projection angle is about 60 degrees, after experiments, the reflectivity of the projection screen to the red projection beam of the P light type is different from that of the red projection beam of the S light type. More than 10%. In other words, the reflectivity of the ultra-short throw projection screen to P light is greater than that of S light, which will cause more P light to be reflected by the screen and enter the human eye, while the S light reflected by the screen and enter the human eye is relatively cut back. This phenomenon of difference in transmission and reflection of light of the same color with different polarization directions also exists when the projected beam is of other colors. When the three primary colors are in different polarization states, after passing through the above-mentioned projection optical system and the projection screen, this difference in transmission and reflection (especially the relatively obvious difference in transmission and reflection on the projection screen) will cause different colors of light to be reflected by the screen. The luminous flux entering the human eye is unbalanced, which eventually leads to a partial color cast on the projection screen, which is especially obvious when presenting a color screen.

In order to solve the above problems, improvements are made on the basis of the light sources provided by some of the above embodiments, and another light source structure is proposed.

In some embodiments, the blue laser component and the green laser component are arranged adjacent to each other, and a phase retarder (for example, a half-wave plate) is provided in the output path of the blue laser and the green laser before being incident on the third light combining mirror to Change the polarization direction of the blue laser and the green laser to make it the same as the polarization direction of the red laser, so as to solve the phenomenon of color cast in the projected image due to the different polarization directions.

First introduce the working principle of the phase retarder. The phase retarder corresponds to the wavelength of a certain color, and the degree of phase change of the transmitted light beam is affected by the thickness of the crystal growth. In this example, the phase retarder is a half-wave plate, also called a λ1/2 wave plate, which can change the phase of the light beam corresponding to the color wavelength by π, that is, 180 degrees, and rotate the polarization direction of the corresponding color wavelength by 90 degrees, such as Change P light to S light, or change S light to P light. As shown in FIG. 11A, the half-wave plate is a crystal, and the crystal has its own optical axis W, which is located in the plane of the half-wave plate. The half-wave plate is arranged in the optical path and is perpendicular to the optical axis O of the light source, so the optical axis W of the half-wave plate and the optical axis O of the light source are perpendicular to each other.

As shown in FIG. 11B, a coordinate system is established with the optical axis W of the half-wave plate, and the coordinate system formed by the P-polarized light along the optical axis W and the direction perpendicular to the optical axis W has components Ex and Ey. Among them, Ex and Ey can be expressed by light wave formula. P light can be regarded as a spatial synthesis of two-dimensional waves of components Ex and Ey.

After the P light passes through the half-wave plate, the phase changes by π, that is, 180 degrees. The phase constants of Ex and Ey both have a change of π. For the light waves b0, c0, and a0 at a certain moment in the original polarization direction, the phase of the light waves b0, c0, a0 is changed by 180 degrees, and after the light waves of the two direction components are superimposed, the polarization position of the light waves in space changes, forming b1, c1 , A1, which becomes light in the S polarization direction. The above-mentioned changes in the spatial positions of b0, c0, a0 and b1, c1, a1 are only examples.

After passing through the half-wave plate, the light originally in the P polarization direction becomes light in the S polarization direction. As shown in Fig. 11C, the two polarization directions are perpendicular to each other.

Based on the above description, as shown in the schematic diagram of the optical path principle shown in FIG. 12A, phase retarders of corresponding wavelengths are respectively arranged in the light exit paths of the blue laser assembly and the green laser assembly, and the phase retarders are, for example, half-wave plates. In this example, the center wavelength of the blue laser is about 465 nm, and the center wavelength of the green laser is about 525 nm. In the principle diagram of the optical path shown in FIG. 12A, the first half-wave plate 121 (ie, the first phase retarder) is located in the light path of the blue laser, which is set corresponding to the center wavelength of the blue laser, and the second half-wave plate 131 (that is, the second phase retarder) is located in the light exit path of the green laser, which is set corresponding to the center wavelength of the green laser. In this way, the polarization directions of both the green laser and the blue laser can be changed by 90 degrees, and the green laser and the blue laser can be changed from S light to P light.

Based on the foregoing optical path principle, in some embodiments, the foregoing half-wave plates (for example, the first half-wave plate 121 and the second half-wave plate 131) are arranged in the light source housing, and are located inside the light source housing and corresponding to the laser assembly. Between the mirrors, a lens base is arranged on the bottom wall of the light source housing to fix the half-wave plate.

In other examples, the half-wave plates (for example, the first half-wave plate 121 and the second half-wave plate 131) are arranged on the inside of the window opened for the laser assembly on the light source housing, such as being fixed to the laser assembly by means of gluing or fixing brackets. Inside the window.

In other examples, the half-wave plate (for example, the first half-wave plate 121 and the second half-wave plate 131) is arranged between the laser assembly and the outer side of the light source housing window, for example, the half-wave plate is mounted or fixed on the window On the outside, the laser assembly (including the fixing bracket) is installed on the installation position outside the window through the fixing bracket.

In other examples, when the sealing glass is provided at the window, the half-wave plates (for example, the first half-wave plate 121 and the second half-wave plate 131) may be located between the sealing glass and the light-emitting surface of the laser assembly. As shown in the exploded view of the structure of the laser assembly as shown in FIG. 5E, there is also a supporting table (not shown in the figure) on the front of the transparent window frame 1041 of the fixing bracket of the laser assembly, and the half-wave plate 141 can be fixed on the supporting table by gluing on. There is also a containing groove around the supporting platform for containing the first sealing member 1051. FIG. 5B shows a schematic diagram of the half-wave plate installed on the front of the fixed bracket. The half-wave plate 141 is installed at the position of the light-transmitting window frame 1041 of the fixed bracket and fixed by dispensing glue on the surrounding glue groove 104A. The length and width ranges of the half-wave plate 141 are 25-30 mm and 21-28 mm respectively; the length and width ranges of the light-transmitting window frame of the fixed bracket are 20-24 mm and 18-20 mm, respectively. For example, in an embodiment, the half-wave plate is 30mm*28mm, and the size of the transparent window frame is 24mm*20mm.

After the half-wave plate 141 is fixed to the fixing bracket 104, it is installed on the installation position of the window 1021 of the light source housing 102 together with the MCL laser assembly installed on the fixing bracket. As mentioned above, the installation position of the window 1021 of the light source housing is also provided with a second accommodating groove for accommodating the second sealing member 1052. The sealing glass 105 is covered by the first sealing member 1051 and the second sealing member on the laser assembly. 1052 is caught in the middle. Based on the above structure, after the light beam of the laser assembly is emitted from the light-emitting chip, it passes through the half-wave plate 141 and the sealing glass 105 in sequence, and then enters the interior of the light source housing from the window 1021 of the light source housing.

In the above light source structure, half-wave plates of corresponding colors are installed on the fixing brackets of the blue laser assembly and the green laser assembly, so that after passing through the corresponding half-wave plates, the polarization of the light beam changes by 90 degrees. The green laser light is already P light when it enters the first light combining mirror, and the blue laser light is already P light when it enters the first light combining mirror, so the blue laser and green laser light are combined through the first light combining mirror and output The light beams are all P-polarized light, which is the same as the polarization direction of the red laser. The second light combiner combines the three-color light beams with the same polarization direction and outputs them, and then undergoes homogenization and contraction processing, so that the light beam enters the light path of the opto-mechanical illumination, reflected by the DMD and enters the lens, and the lens is projected onto the screen for imaging. Due to the same polarization direction of the three colors, the phenomenon of uneven chromaticity such as "color spots" and "color blocks" in the projection screen can be eliminated or greatly alleviated.

As a variation of some of the above embodiments, in other embodiments, the blue laser and the green laser are combined first and then combined with the red laser. In this case, the half-wave plate can also be set in the blue laser and the green laser. In the optical path after the laser beam is combined and before the red laser beam is combined. For example, as shown in FIG. 12B, another schematic diagram of the principle of the optical path of the light source is provided, and the fourth half-wave plate 141 (that is, the fourth phase retarder) is arranged between the first light combining lens 106 and the second light combining lens 107, The combined light beam of the blue laser light and the green laser light emitted from the first light combining mirror 106 is transmitted. Based on the above optical path principle, the green laser and the blue laser respectively output S-polarized light, the green S light enters the first light combining mirror 106 and is reflected, and the blue S light enters the first light combining mirror 106 and is transmitted. After the first light combining mirror 106 combines the blue laser light and the green laser light that are both S light, the light beam passes through the fourth half-wave plate 141. The fourth half-wave plate 141 changes the polarization directions of the green laser light and the blue laser light, and then the combined light beam with the changed polarization direction is incident on the second light combining mirror 107.

It should be noted that in the schematic diagram of the optical path principle shown in FIG. 12B, the fourth half-wave plate 141 can be set for the wavelength of one of the colors. For example, the fourth half-wave plate 141 is set for the wavelength of the green laser, and the green laser is transparent. After passing through the fourth half-wave plate 141, the polarization direction is rotated by 90 degrees, changing from the original S light to P light. After the blue laser passes through the fourth half-wave plate 141, since the wavelength of the fourth half-wave plate 141 is not set corresponding to the blue wavelength, the polarization direction of the blue laser is not 90 degrees, but close to the P polarization direction. Since the human eye has a low visual function for blue and a low sensitivity to blue, the visual discomfort when the blue color cast appears is not as obvious as when the red and green color casts appear. For another example, the fourth half-wave plate 141 is set for the middle value of the blue and green center wavelengths, so that the polarization direction of the green laser and the blue laser are not 90 degrees, but both are close to 90 degrees. The green laser is not deflected from S light to P light, but neither is the original S light polarization state. It can also improve the consistency of the light processing process of the red, green, and blue primary colors of the entire system, and improve the local area on the projection screen. Technical problems such as "color spots" and "color blocks" appearing to have uneven chromaticity, the principle of which will not be repeated.

In some of the above examples, the half-wave plate 141 may be fixed by a fixing base provided on the bottom wall of the light source housing.

It should be noted that the solution of setting a half-wave plate shown in FIG. 12B is also applicable to the optical path architecture provided in the optical path schematic diagram shown in FIG. 2A, FIG. 2B, FIG. 8A, FIG. 8B, or FIG. 8C. Its working principle is the same as above, so I won't repeat it.

In the optical system, for different wavelengths, the same optical lens has a slight difference in the transmittance of P light and S light at different wavelengths, and the reflectance of P light and S light also has a slight difference. The optical lens here includes various optical lenses in the entire laser projection device, such as a convergent lens group, a lens group in the illumination light path in the optical machine part, and a refractive lens group in the lens part. Therefore, when the light beam emitted by the laser light source passes through the entire projection optical system, this difference in transmission and reflection is the result of the superposition of the entire system and will be more obvious.

In the example of the present disclosure, before the half-wave plate is added, the red laser is P-ray polarized light, and the blue laser and green laser are S-ray polarized light. Whether it is the optical lens of the optical system or the projection screen, the selective transmission of P light and S light is obvious. For example, as the incident angle of the projection beam is different, the transmittance of the projection screen for P light (red light) is significantly greater than that for S light (green and blue), which causes the local color of the projection screen The degree of unevenness is the phenomenon of "color spots" and "color blocks" that appear on the screen.

In some embodiments provided above, when half-wave plates of corresponding wavelengths are respectively set for the blue laser and the green laser, the polarization directions of the blue laser and the green laser can be changed by 90 degrees. In this example, the blue laser and the green laser both change from the polarization direction of S light to the polarization direction of P light, which is consistent with the polarization direction of the red laser, so that they pass through the same set of optical imaging system and reflect into the human eye through the projection screen. At this time, the transmittance of the blue laser and the green laser that become P-polarized light in the optical lens is equivalent to the transmittance of the red laser that is originally P-light, and the consistency of the light processing process is close. The difference in the reflectivity of the laser is also reduced, and the consistency of the light processing process of the three-color primary light of the entire projection system is improved, which can fundamentally eliminate the color cast phenomenon of "color spots" and "color blocks" in local areas on the projection screen. Improve the display quality of the projection screen.

In some embodiments provided above, when a half-wave plate is provided in the combined light path of the blue laser and the green laser, the polarization direction of the green laser or the blue laser can be changed by 90 degrees. , Or the polarization direction of the two colors of laser light is not changed to 90 degrees, but both are close to 90 degrees. In this way, the polarization difference between the S light of the blue laser and the green laser and the P light of the red laser can also be reduced. Based on the above principles, it can also improve the consistency of the light processing process for the three primary colors of red, green and blue in the entire system, and can improve the technical problems of uneven chromaticity such as "color spots" and "color blocks" in local areas on the projection screen. .

Since the transmittance of the optical lens to P-polarized light in the optical system is generally greater than the transmittance of S-polarized light, and the projection screens used in some examples of the present disclosure have a greater reflectivity for P-polarized light than for S-polarized light. Reflectivity, therefore, by converting the S-polarized blue laser and green laser into P-polarized light, so that the red, green, and blue lasers are all P light, and the light transmission efficiency of the projection beam in the entire system can be improved. It can increase the brightness of the entire projection screen and improve the quality of the projection screen.

As another means to solve the technical problems of uneven chromaticity such as "color spots" and "color blocks" appearing on the projection screen, some embodiments of the present disclosure also provide a laser projection device, the application shown in FIG. 12C Light source. In this embodiment, a half-wave plate corresponding to the red wavelength is provided before the red laser beam is combined with the blue and green laser beams. For example, the third half-wave plate 151 (that is, the third phase retarder) is disposed between the red laser assembly 110 and the second light combining mirror 107.

For the arrangement scheme of the third half-wave plate 151, refer to the scheme of separately arranging half-wave plates for the blue laser and the green laser in some of the above embodiments.

For example, the third half-wave plate 151 is arranged in the light source housing in the light path between the inner side of the light source housing and the third light combining lens, and the half-wave plate is fixed by setting a lens base on the bottom surface of the light source housing.

Alternatively, the third half-wave plate 151 is arranged on the inside of the window opened for the red laser assembly on the light source housing, for example, is fixed on the inside of the window by means of glue or a fixing bracket.

Alternatively, the third half-wave plate 151 is arranged between the red laser assembly and the outside of the light source housing window, for example, the half-wave plate is mounted or fixed on the outside of the window, and the laser assembly (including the fixing bracket) is then installed on the window through the fixing bracket The mounting position on the outside.

Alternatively, in the case where a sealing glass is provided at the window, the third half-wave plate 151 may be located between the sealing glass and the light-emitting surface of the laser assembly. The specific installation method can also refer to the introduction of FIG. 5E, which will not be repeated here.

The third half-wave plate 151 corresponds to the wavelength setting of the red laser. Similarly, the polarization direction of the red laser can be rotated by 90 degrees through the half-wave plate 151, and the red laser changes from P-polarized light to S-polarized light.

It should be noted that the above scheme of arranging a half-wave plate for the red laser is also applicable to the optical path schematic diagram shown in FIG. 2A, FIG. 2B, FIG. 8A, FIG. 8B or FIG.

In some of the above examples, by setting the third half-wave plate 151 in the red laser output light path, the red laser that was originally P-polarized light is converted into S-polarized light, which is consistent with the polarization directions of the blue laser and green laser. The three colors of light have the same polarization direction. With reference to the principle description of some of the foregoing embodiments, the transmittance of the projection optical system to the red laser, blue laser, and green laser of the same S-polarized light is reduced compared to when it is polarized light in different polarization directions, ultra-short focus projection The reflectivity of the screen to the three-color light of the same S-polarized light is basically the same, so that the uniformity of the light processing of each primary color is improved, and the uneven chromaticity such as "color spots" and "color blocks" in the projection screen can be eliminated or improved phenomenon.

In some of the above embodiments, the laser emitting surface is rectangular. Correspondingly, the phase retarder is correspondingly arranged in the light output path of one color or two colors, and its shape is also rectangular. The long sides and short sides of the rectangular light-emitting area of the laser are respectively parallel to the long sides and short sides of the rectangular light-receiving area of the phase retarder.

Because the laser beam contains high energy, the performance of optical lenses, such as lenses and prisms, will be accompanied by temperature changes during operation. For example, an optical lens has internal stress formed during the manufacturing process, and this internal stress is released with temperature changes, resulting in stress birefringence. This kind of stress birefringence will cause different phase delays for beams of different wavelengths, which can be regarded as secondary phase delays. Therefore, in the actual optical path, the phase change of the beam is based on the superimposed effect of the stress birefringence of the half-wave plate and the optical lens, and the inherent retardation caused by this optical lens will vary according to the system design. When the technical solutions of some of the above embodiments are applied, the secondary phase delay caused by the actual system can be corrected to approach or reach the theoretical value that the polarization direction of the beam changes by 90 degrees.

Each half-wave plate has an optical axis in its plane. As shown in Fig. 11A, the optical axis W of the half-wave plate is in a spatial vertical relationship with the optical axis O of the system, and the optical axis of the half-wave plate is parallel to the long side of the half-wave plate. Or the short side. When applying the above solution, as shown in Figure 11D, the half-wave plate is set as follows: along the long or short side of the rectangular half-wave plate, rotate the half-wave plate at a preset angle, such as C degrees, as shown in the figure Shown by the dotted line. After the above-mentioned angle deflection, the optical axis of the half-wave plate is also deflected by plus or minus C degrees, so that the phase of the beam is changed to about 180 degrees ± 2C degrees, and then superimposed with the secondary phase delay of the system optical lens, and finally The polarization direction of the beam is changed at about 90 degrees to approach the theoretical design value. In some of the above embodiments of the present disclosure, C may take the value 10.

In one or more of the above embodiments, for the case where the laser projection light source has three primary colors with different polarization directions, a half-wave plate is provided in the light output path of one color or two colors in the light source of the laser projection device. , The polarization direction of one or two colors of light passing through the half-wave plate can be changed to make the polarization direction of other colors consistent, so that the polarization directions of the three primary colors output by the laser projection device are the same. Therefore, when the laser beam emitted by the light source of the laser projection equipment passes through the same set of optical imaging system and is reflected by the projection screen into the human eye, the optical system has a similar transmittance to the three-color laser. The difference in reflectivity is also reduced, and the consistency of the light processing process of the three-color primary color light in the entire projection system is improved, which can fundamentally eliminate the "color spots" and "color blocks" that appear in the local area on the projection screen. Phenomenon, improve the display quality of the projection screen.

In laser projection equipment, the light source is the main heat source, and the high-density energy beam of the laser irradiates the surface of the optical lens to generate heat. The DMD (Digital Micromirror Device) chip has an area of a few tenths of an inch, but it needs to bear the beam energy required for the entire projected image, so its heat generation is also very high. On the one hand, the laser has a set working temperature to form a stable light output, thus taking into account the service life and performance. In addition, the laser projection device also contains multiple precision optical lenses, especially the ultra-short focal lens contains multiple lenses. If the temperature inside the laser projection device is too high, heat will collect, which will cause the lens in the lens to "warm drift". Phenomenon, the image quality of laser projection equipment will be seriously degraded. Moreover, the electronic devices on the circuit board are driven by electrical signals, and they also generate a certain amount of heat, and each electronic device also has a set operating temperature. Therefore, good heat dissipation and temperature control are very important guarantees for the normal operation of laser projection equipment.

In some embodiments, as shown in FIG. 6B and FIG. 6C, the laser projection device further includes a heat dissipation fin 601, a heat pipe 602 and a heat conduction block 603. Wherein, the heat conducting block 603 is in contact with the green laser component and the blue laser component through a heat sink, so as to realize heat conduction. One end of the heat pipe 602 is in contact with the heat conducting block 603 and is the hot end, and the other end of the heat pipe 602 is in contact with the heat dissipation fin 601 and is the cold end. The heat transfer is achieved by contacting the outer surface of the heat pipe 602 with the heat conducting block 603 and the heat dissipation fin 601. Exemplarily, the heat pipe is a closed system with liquid inside, and the heat transfer can be realized through the gas-liquid change of the liquid. The heat dissipation fin 601 contacting the cold end of the heat pipe is usually cooled by air cooling, so that the cold end of the heat pipe is also cooled, and the gas is liquefied and returned to the hot end of the heat pipe. For example, the number of heat dissipation fins 601 is multiple, and the multiple heat dissipation fins 601 are all sleeved on the heat pipe 602. In addition, a plurality of heat dissipation fins 601 can be air-cooled and cooled by a fan 606.

In some embodiments, as shown in FIG. 6A, the laser projection device further includes a liquid-cooled circulation system, and the liquid-cooled circulation system includes a cold head 610 and a cold row 611 that are connected through a pipeline. The red laser assembly is connected to the cold head 610 and dissipates heat through liquid cooling. In the liquid-cooled circulation system, the cold head 610 takes the heat of the heat source components back to the cold row 611, and the cooling liquid at the cold row 611 is cooled by the fan 615. The cooled coolant, for example, water is commonly used, and flows again. Return to the cold head 610, and circulate in turn to conduct heat transfer to the heat source. The liquid-cooled circulation system also includes a pump. The pump is configured to drive the coolant in the liquid-cooled circulation system to keep flowing. In some examples, the pump and the cold head are integrated to reduce the volume of components. The cold head mentioned below can be Refers to the integrated structure of cold head and pump.

In the liquid-cooled circulation system of the laser projection device of this example, a liquid supplement is also included to supplement the liquid-cooled circulation system so that the liquid pressure in the entire liquid-cooled circulation system is greater than the external pressure of the system. In this way, external air will not enter the circulation system due to the volatilization of the coolant or the poor sealing of the pipe joints, causing internal noise in the circulation system, and even causing cavitation to damage the device.

Compared with the air-cooled heat dissipation system, the liquid-cooled circulation system is more flexible in that the volume of the cold head 610 and the cold exhaust 611 is smaller than that of the traditional heat dissipation fins, and the choices of their shapes and structural positions are more diverse. Since the cold head 610 and the cold row 611 are connected by pipelines, and are always a circulatory system, the cold row 611 can be set close to the cold head 610, or it can have other relative positional relationships with the cold head 610. This is determined by the complete machine of the laser projection device. The space in the housing is determined.

A plurality of circuit boards and a second fan are also arranged in the space enclosed by the optical machine, the lens and another part of the whole machine casing. The second fan is arranged close to the whole machine casing, and the number of the second fans is one or more.

In the laser projection device, the light source 100 is a laser light source, and the included laser components of different colors have different operating temperature requirements. Among them, the working temperature of the red laser component is less than 50°C, and the working temperature of the blue laser component and the green laser component is less than 65°C. The working temperature of the DMD chip in the optical machine is usually controlled at about 70°C, and the temperature of the lens part is usually controlled below 85°C. As for the circuit board, the operating temperature of different electronic devices is different, usually controlled between 80°C and 120°C. It can be seen that because the optical components and the circuit board in the laser projection device have different temperature tolerances, for example, the operating temperature tolerance of the optical part is generally lower than that of the circuit board. Therefore, in some embodiments, the airflow blows from the optical part. To the circuit part, both parts can achieve the purpose of heat dissipation and maintain their normal operation.

It should be noted that since the working temperature of the red laser component is less than 50°C, for example, when it is controlled below 45°C, liquid cooling is used, and the difference between the surface temperature of the cold row and the surface temperature of the cold head is controlled within the range of 1 to 2°C. Inside. That is, if the surface temperature of the cold head is 45°C, the surface temperature of the cold row is 43°C to 44°C. The surface temperature of the cold head refers to the temperature of the contact surface between the cold head and the heat sink of the laser assembly. Exemplarily, the first fan sucks in air with an ambient temperature, which is usually 20-25°C, and cools the cold row to dissipate heat, reducing the surface temperature of the cold row to 43°C. The working temperature of the blue laser component and the green laser component is below 65°C, the temperature of the heat dissipation fin needs to be 62°C to 63°C, and the temperature difference between the temperature of the heat dissipation fin and the heat sink of the laser assembly is in the range of 2 to 3°C Inside. It can be seen that the temperature of the cold row is lower than the temperature of the heat dissipation fins. Therefore, the cold row is arranged at the front end of the heat dissipation path, and is also located before the heat dissipation fins in the heat dissipation path. The airflow formed by the rotation of the fan dissipates the heat of the cold row and then blows to the radiating fins again, and the radiating fins can still be dissipated.

In the same way, since the working temperature of the lens is controlled at 85°C and the temperature of the heat dissipation fins is at 63°C, which is still lower than the working temperature of the lens, the second airflow flowing through the heat dissipation fins is still cold airflow compared to the lens. , The cold air flow can be further utilized for heat dissipation. The operating temperature of the circuit board is generally higher than the operating temperature of the lens. Therefore, the airflow after the lens is cooled is still cold airflow compared to most circuit boards, and it can continue to flow through multiple circuit boards for heat dissipation.

In this example, the cold exhaust, heat dissipation fins, lens, and the plurality of circuit boards have gradually increased operating temperature thresholds. The layout of the above-mentioned structure is also conducive to designing the heat dissipation path, so that the heat dissipation airflow can be lower than the operating temperature threshold. Low components flow to components with higher operating temperature thresholds, and multiple heat source components can be used to dissipate heat in a heat dissipation path, which not only meets the working heat dissipation requirements of multiple heat source components, but also has high heat dissipation efficiency of the whole machine.

In another embodiment, in order to enhance the heat transfer coefficient, structural improvements may be made on the surface of the heat dissipation fins to increase the heat dissipation area, or increase the wind flow rate, so as to increase the heat dissipation capacity.

In the laser projection equipment provided by some of the above embodiments, the luminous power range of the red laser component can be 24W～56W, the luminous power range of the blue laser component can be 48W～115W, and the luminous power range of the green laser component can be 12W～ 28W. For example, the luminous power of the red laser component is 48W, the luminous power of the blue laser component is 82W, and the luminous power of the green laser component is 24W. The above-mentioned three-color lasers all use MCL laser components. Compared with BANK type laser components, under the same output power, the volume of MCL type laser components is greatly reduced.

From the above description, it can be seen that in the laser projection equipment, the heat dissipation requirement of the light source 100 is the most stringent, which is the part of the entire equipment with relatively low operating temperature control. Moreover, the working temperature of the red laser component is lower than the working temperature of the blue laser component and the green laser component, which is determined by the light-emitting principle of the red laser. The blue laser and the green laser are generated using gallium arsenide luminescent material, and the red laser is generated using gallium nitride luminescent material. The luminous efficiency of the red laser is low and the heat generation is high. The temperature requirements of red laser luminescent materials are also more stringent. Therefore, when dissipating the light source components composed of three-color lasers, different heat dissipation structures need to be set according to the temperature requirements of different laser components, which can ensure that the lasers of each color work in a better state and improve the use of laser components. Life, its luminous efficiency is also more stable.

The air-cooled heat dissipation method can control the temperature difference between the hot end and the cold end of the heat source at about 3°C, while the temperature difference control for liquid cooling can be more precise and smaller, such as 1 to 2°C. For red laser components with a lower operating temperature threshold, liquid cooling is used, while for blue laser components and green laser components with relatively high operating temperature thresholds, air-cooling is used to dissipate heat, which can meet the operating temperature requirements of red lasers. , To dissipate heat with lower heat dissipation cost. Therefore, the air-cooled heat dissipation method only needs to meet the small temperature difference control, so that the fan speed requirement can be reduced. However, the component cost of liquid cooling is higher than that of air cooling.

Therefore, in the laser projection device in this example, a mixed heat dissipation method of liquid cooling and air cooling is adopted for the heat dissipation of the light source, which can satisfy the operating temperature control of different laser components and is economical and reasonable.

In some embodiments, referring to FIG. 6A, the metal substrate on the back of the red laser assembly 130 is connected to the cold head through a first heat conducting block 613. The area of the first heat conducting block 613 is larger than the area of the heat conducting surface of the cold head. It is also larger than the area of the heat conducting surface of the heat sink on the back of the red laser component 110. In this way, the heat of the heat sink of the laser assembly can be quickly concentrated and transferred to the cold head, and the heat transfer efficiency is improved.

In the heat dissipation system structure shown in FIG. 6A, the outlet of the cold head 610 is connected to the inlet of the cold row 611 through a pipe, and the outlet of the cold row 611 is connected to the inlet of the cold head 610 through a pipe. In the liquid cooling circulation system composed of the cold head 610, the cold row 611 and the pipeline, a liquid supplement 612 is also provided. As mentioned above, the liquid supplement 612 is used to supplement the cooling liquid for the system circulation, so the liquid supplement can be arranged in multiple positions in the entire circulation system. According to the system structure space and other factors, there can be one or more liquid replacement devices, and they can be connected with the pump, or they can be set close to the cold row.

In this example, the blue laser component and the green laser component have the same operating temperature control and share a heat dissipation fin structure. For example, as shown in FIGS. 6B and 6C, the heat sinks on the back of the blue laser assembly and the green laser assembly 120 are in contact with the heat dissipation fin 601 through the heat conducting block 603, and the heat pipe 602 extends into the heat dissipation fin 601. Corresponding to different colors of laser components set their own thermal blocks. For example, in order to facilitate the distinction, corresponding to the blue laser component, the heat conducting block 603 is the second heat conducting block, and corresponding to the green laser component, the heat conducting block 603 is the third heat conducting block. The second heat conduction block and the third heat conduction block can be two independent components that conduct heat conduction for different laser components, or can be a whole structure, which is easy to install, and when the heat dissipation requirements of the two colors of laser components are the same, Easy to control temperature.

The above-mentioned heat pipes are multiple heat pipes. Illustratively, the number of heat pipes corresponding to the blue and green laser components is the same. In this example, the heat pipe is a straight heat pipe, and there are multiple heat pipes, and multiple through holes are opened in the heat dissipation fin 601 for inserting multiple heat pipes. The heat dissipation fins 601 are arranged close to the blue and green laser components. Multiple heat pipes can be directly inserted into the heat dissipation fins 601 without bending. The straight heat pipes are beneficial to reduce the transmission resistance during the gas-liquid change in the heat pipes and improve the heat transfer efficiency.

Through the above-mentioned combined heat dissipation structure, the light source component can be radiated, thereby ensuring the normal operation of the three-color laser light source component. The light source emits three-color lasers to provide high-quality illuminating beams, which can be projected to form projection images with high brightness and good colors. Since the three-color laser components are arranged in different spatial positions, multiple optical lenses are needed in the cavity of the light source to combine and homogenize the laser beams in different directions.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, not to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: It is still possible to modify the technical solutions described in the foregoing embodiments, or equivalently replace some or all of the technical features; these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present disclosure. range.

Claims

A laser light source, including:

The first laser assembly is arranged on the first plane and configured to emit the first laser;

A second laser component, arranged in parallel with the first laser component on the first plane, and configured to emit a second laser;

The third laser component is arranged on a second plane perpendicular to the first plane; the second laser component is closer to the third laser component than the first laser component; the third laser component is configured to Emit a third laser;

The first light combining mirror is arranged at the intersection of the third laser light and the second laser light and is configured to transmit the third laser light and reflect the second laser light;

The second light combining mirror is arranged at the intersection of the first laser light and the second laser light and the third laser light after passing through the first light combining mirror, and is configured to reflect the first laser light and transmit The second laser and the third laser;

The third light combining mirror is arranged on the optical path of the first laser, the second laser and the third laser, and reflects the first laser, the second laser and the third laser to the light exit of the laser light source.
The laser light source according to claim 1, wherein:

The first laser component includes a red laser component, and the first laser includes a red laser;

The second laser assembly includes a green laser assembly, and the second laser includes a green laser;

The third laser assembly includes a blue laser assembly, and the third laser includes a blue laser.
The laser light source according to claim 1, wherein:

The first laser component includes a red laser component, and the first laser includes a red laser;

The second laser component includes a blue laser component, and the second laser includes a blue laser;

The third laser assembly includes a green laser assembly, and the third laser includes a green laser.
The laser light source according to any one of claims 1 to 3, wherein:

The light reflectivity of the first light combining mirror is greater than the light transmittance of the first light combining mirror;

The light reflectivity of the second light combining mirror is greater than the light transmittance of the second light combining mirror.
The laser light source according to any one of claims 1 to 3, wherein:

The first light combining mirror, the second light combining mirror and the third light combining mirror are parallel to each other.
The laser light source according to any one of claims 1 to 3, further comprising at least one of the following:

The homogenization element is arranged in the optical path from the third light combining mirror to the light exit;

The condensing lens group is arranged in the optical path from the homogenization element to the light exit; or,

The diffusion wheel is arranged in the light path from the converging lens group to the light exit.
The laser light source according to claim 6, wherein the homogenization element comprises at least one of the following:

A homogenization and diffusion sheet with regularly arranged microstructures; or,

Diffractive element.
The laser light source according to claim 6, wherein the condensing lens group includes a combination of two convex lenses, and any one of the two convex lenses includes at least one of a plano-convex lens, a double-convex lens, or a meniscus lens.
The laser light source according to claim 2 or 3, further comprising at least one of the following:

The first diffuser and the second diffuser; the first diffuser is arranged in the light path of the blue laser, and is configured to diffuse and transmit the blue laser; the second diffuser is arranged on the green In the optical path of the laser, it is configured to diffuse and transmit the green laser; or,

A telescope system, the telescope system is arranged in the optical path of the red laser, configured to pass the red laser and shrink the beam of the red laser.
The laser light source according to claim 9, wherein the telescope system includes a convex lens and a concave lens, and the convex lens is closer to the red laser assembly than the concave lens.
The laser light source according to claim 2 or 3, further comprising:

The third diffusion sheet is arranged in the optical path from the first light combining mirror to the second light combining mirror, and the third diffusion sheet is configured to diffuse and transmit the green laser light and the blue laser light.
The laser light source according to claim 2 or 3, wherein the polarization directions of the blue laser and the green laser are the same, and the polarization directions of the red laser and the green laser are different;

The laser light source further includes one of the following:

A first phase retarder and a second phase retarder, the first phase retarder is arranged in the optical path of the blue laser, and is configured to change the polarization direction of the blue laser; the second phase retarder is arranged In the optical path of the green laser, it is configured to change the polarization direction of the green laser; or,

The third phase retarder is arranged in the optical path of the red laser light and is configured to change the polarization direction of the red laser light.
The laser light source according to claim 12, wherein:

The first phase retarder is configured to correspond to the wavelength of the blue laser;

The second phase retarder is configured to correspond to the wavelength of the green laser;

The third phase retarder is configured to correspond to the wavelength of the red laser.
The laser light source according to claim 12, wherein:

The first phase retarder includes a first half-wave plate;

The second phase retarder includes a second half-wave plate;

The third phase retarder includes a third half-wave plate.
The laser light source according to claim 2 or 3, wherein the polarization directions of the blue laser and the green laser are the same, and the polarization directions of the red laser and the green laser are different;

The laser light source further includes:

The fourth phase retarder is arranged in the optical path from the first light combining mirror to the second light combining mirror;

The fourth phase retarder is configured as one of the following:

Corresponds to the wavelength of the green laser; or,

It corresponds to the wavelength between the wavelength of the green laser and the wavelength of the blue laser.
The laser light source according to claim 2 or 3, wherein:

The light-emitting power of the green laser component is less than the light-emitting power of the red laser component and the light-emitting power of the blue laser component;

The light-emitting power of the red laser component is less than the light-emitting power of the blue laser component.
The laser light source according to claim 2 or 3, wherein:

The luminous power of the green laser assembly is 12W-28W;

The luminous power of the red laser assembly is 24W～56W;

The light-emitting power of the blue laser assembly is 48W-115W.
The laser light source according to claim 1 or 2, further comprising:

A light source housing, the light source housing comprising a bottom wall and a top cover, and a plurality of side walls located between the bottom wall and the top cover;

The first laser component and the second laser component are arranged in parallel on the first side wall of the light source housing, and the third laser component is arranged on the first side wall of the light source housing perpendicular to the first side wall. On the two side walls;

The light source housing further has a light outlet, and the laser light reflected by the third light combining mirror is emitted out of the light source housing through the light outlet.
The laser light source according to claim 18, wherein:

The first side wall of the light source housing includes windows corresponding to the first laser assembly and the second laser assembly, and the second side wall of the light source housing includes windows corresponding to the third laser assembly window;

The laser light source further includes sealing glass, the sealing glass is provided at each of the windows, and the sealing glass connects the first laser assembly, the second laser assembly, and the third laser assembly to the light source housing The internal cavity is isolated.
A laser projection equipment, including:

Whole machine shell;

A laser light source installed in the housing of the complete machine, the laser light source being the laser light source according to any one of claims 1 to 19; and

An optical machine and a lens installed in the housing of the complete machine, the optical machine is connected to the lens, and the laser light source is configured to provide illumination to the optical machine.