Laser projection light machine
Patent Information
- Application Number
- CN202611007512.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-08
- Publication Date
- 2026-10-09
AI Technical Summary
[0003]然而，激光的高度相干性导致其在粗糙表面散射时产生随机干涉图样，即激光散斑，激光散斑会严重影响投影图像质量和观看体验
[0004]本发明公开了一种激光投影光机，其目的在于至少解决现有技术中存在的技术问题之一。
Smart Images
Figure CN122883402A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of projection display technology, and more specifically to a laser projection optical engine. Background Technology
[0002] With the development of projection technology, laser projection optical engines have been widely used. Laser projection technology is a projection display technology that uses red, green, and blue primary color lasers as light sources. It can most realistically reproduce the rich and vibrant colors of the objective world, providing a more stunning expressiveness and achieving the most perfect color reproduction in human history, allowing people to see the most realistic and magnificent world through display terminals.
[0003] However, the high coherence of laser light causes random interference patterns, or laser speckle, when scattered across rough surfaces. Laser speckle severely impacts projected image quality and the viewing experience. Existing methods for suppressing laser speckle primarily rely on mechanically vibrating the laser projector engine or its internal optical components. However, the moving parts used in mechanical vibration, such as motors and bearings, experience wear and tear after frequent use, resulting in a short lifespan for the laser projector engine. Furthermore, mechanical vibration generates noise, significantly affecting the user experience. Summary of the Invention
[0004] This invention discloses a laser projection optical engine, the purpose of which is to at least solve one of the technical problems existing in the prior art.
[0005] The present invention provides a laser projection optical engine, comprising a laser source component, a speckle suppressor, an optical path modulation component, an optical engine chip, and a projection lens arranged sequentially along the light transmission path. The speckle suppressor is used to receive laser light emitted from the laser source component and suppress laser speckle. The optical path modulation component is disposed between the speckle suppressor and the optical engine chip. The projection lens is fixed to the light-emitting side of the optical path modulation component. The speckle suppressor includes a mounting bracket, a speckle suppressor assembly, and a pressing bracket. The speckle suppressor assembly is disposed on the end face of the mounting bracket along the light transmission path, and the pressing bracket is used to press and fix the speckle suppressor assembly onto the mounting bracket. The speckle suppression assembly includes a piezoelectric ceramic optical film, an insulating buffer pad, and a uniform force pad stacked in sequence, with the uniform force pad abutting against the pressure plate support. The piezoelectric ceramic optical film includes a piezoelectric ceramic element, a light-transmitting element, and a wire. The piezoelectric ceramic element has a mounting hole in the middle. The light-transmitting element is fixedly fitted into the mounting hole. The wire is electrically connected to the piezoelectric ceramic element. The mounting bracket, the insulating buffer pad, the uniform pressure pad, and the pressure plate bracket are all provided with coaxial through holes, and the through holes are aligned with the light-transmitting element so that the laser beam can pass through the through holes and the light-transmitting element without obstruction.
[0006] Optionally, the number of speckle suppression components is two sets, which are symmetrically arranged on two opposite end faces of the mounting bracket; the tablet holder is a U-shaped structure, and the tablet holder spans across the two opposite end faces of the mounting bracket, and the tablet holder presses the uniform pressure pad on the corresponding side.
[0007] Optionally, each of the two opposite end faces of the mounting bracket is provided with a placement groove, and the two sets of speckle suppression components are respectively disposed in the two placement grooves.
[0008] Optionally, the insulating cushioning pad is made of at least one of rubber, silicone, polyimide, or epoxy resin.
[0009] Optionally, the uniform force pad is made of at least one of stainless steel, aluminum alloy or copper.
[0010] Optionally, the light-transmitting element is an optical element with an optical microstructure on its surface, wherein the microstructure is selected from any one of a rough surface, a microlens array, a diffusion microstructure, or a phase microstructure.
[0011] Optionally, the mounting bracket is made of stainless steel, and the pressure plate bracket is made of elastic metal material.
[0012] Optionally, the laser source component has a source optical axis, the optical path modulation component has a modulation optical axis, the projection lens has a projection optical axis, the source optical axis is parallel to the projection optical axis, and the modulation optical axis is perpendicular to both the source optical axis and the projection optical axis; the laser projection optical engine further includes a vertically fixed first housing and a second housing, the laser source component and the speckle suppressor are fixed in the first housing, the optical path modulation component is fixed in the second housing, the reflective surface of the optical engine chip faces the modulation optical axis and is perpendicular to the modulation optical axis, and the optical engine chip is fixed on the side of the second housing away from the first housing, and the projection lens is fixed on the second housing and close to the optical engine chip.
[0013] Optionally, the laser source assembly includes a green laser source, a blue laser source, a red laser source, a green reflector, a blue dichroic mirror, and a red dichroic mirror. The green reflector, the blue dichroic mirror, and the red dichroic mirror are all arranged parallel to each other along the optical axis of the source, and all three form a 45° angle with the optical axis of the source. The red dichroic mirror is located close to the speckle suppressor. The green laser source is located below the green reflector along a direction perpendicular to the optical axis of the source, the blue laser source is located below the blue dichroic mirror along a direction perpendicular to the optical axis of the source, and the red laser source is located below the red dichroic mirror along a direction perpendicular to the optical axis of the source.
[0014] Optionally, the optical path modulation assembly includes a first reflecting mirror, a first relay lens, a compound eye lens, a second relay lens, and a polarizing beam splitter arranged sequentially along the modulation optical axis. The first reflecting mirror and the polarizing beam splitter are arranged in parallel and both form a 45° angle with the modulation optical axis. The first reflecting mirror is close to the speckle suppressor, and the polarizing beam splitter is close to the optomechanical chip.
[0015] Optionally, the compound eye lens has a microlens unit disposed on the surface along the modulation optical axis, and the refractive index Nd of the compound eye lens is 1.48 to 1.58, and its dispersion coefficient Vd is greater than 63.
[0016] Optionally, the first relay lens is an aspherical plastic lens with a refractive index Nd of 1.48–1.58, a dispersion coefficient Vd greater than 63, and a focal length of 30 mm–38 mm; the second relay lens is a spherical plastic lens with a refractive index Nd of 1.48–1.58, a dispersion coefficient Vd greater than 63, and a focal length of 30 mm–38 mm; the polarizing beam splitter is a glass plane mirror with a refractive index Nd of 1.48–1.58 and a dispersion coefficient Vd greater than 64.
[0017] Optionally, the projection lens has a total length of 78mm to 88mm, an effective focal length of 25mm to 30mm, an aperture value of F of 1.8 to 2.4, and an entrance pupil diameter of 10mm to 16mm. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the assembly of a laser projection optical engine provided in an embodiment of the present invention; Figure 2 for Figure 1 An exploded view of the laser projection optical engine shown. Figure 3 This is a schematic diagram of the assembly of the speckle suppressor provided in an embodiment of the present invention; Figure 4 for Figure 3 The exploded view of the speckle suppressor shown; Figure 5 for Figure 4 A partial schematic diagram of the speckle suppressor shown; Figure 6 This is a schematic diagram of a piezoelectric ceramic optical film provided in an embodiment of the present invention. Detailed Implementation
[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0020] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0022] The laser projection optical engine provided in the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0023] like Figure 1 and Figure 2As shown, this invention provides a laser projection optical engine, comprising a laser source component 1, a speckle suppressor 2, an optical path modulation component 3, an optical engine chip 4, and a projection lens 5 arranged sequentially along the light transmission path. The speckle suppressor 2 receives laser light emitted from the laser source component 1 and suppresses laser speckle. The optical path modulation component 3 is disposed between the speckle suppressor 2 and the optical engine chip 4. The projection lens 5 is fixed on the light-emitting side of the optical path modulation component 3. The optical path modulation component 3 receives light from the speckle suppressor 2 and guides the light to the optical engine chip 4. The optical engine chip 4 converts the received light into image light and reflects it back to the optical path modulation component 3. The optical path modulation component 3 reflects the image light to the projection lens 5, and finally projects the image out by the projection lens 5. The optical engine chip 4 can be any one of a DMD chip, a silicon-based liquid crystal chip, or a MEMS galvanometer scanning chip. Preferably, the optical engine chip 4 is a DMD chip, i.e., a digital micromirror device. A DMD chip is a semiconductor chip containing millions of micromirrors, capable of generating detailed and rich projected images.
[0024] Specifically, such as Figure 3 , Figure 4 and Figure 5 As shown, the speckle suppressor 2 includes a mounting bracket 21, a speckle suppressor component 22, and a clamping bracket 23. The speckle suppressor component 22 is disposed on the end face of the mounting bracket 21 along the light transmission path, and the clamping bracket 23 is used to press and fix the speckle suppressor component 22 onto the mounting bracket 21. It should be noted that the end face of the mounting bracket 21 along the light transmission path refers to the end face of the mounting bracket 21 on the light transmission path, ensuring that light can pass through the speckle suppressor component 22 disposed on the end face of the mounting bracket 21. The speckle suppressor component 22 is an optical element used to receive laser light emitted from the laser source assembly 1 and suppress laser speckle. The speckle suppressor component 22 is fixed to the mounting bracket 21 by clamping with the clamping bracket 23, eliminating the need for adhesive bonding and facilitating the disassembly, assembly, and replacement of the speckle suppressor component 22.
[0025] Furthermore, the speckle suppression assembly 22 includes a piezoelectric ceramic optical film 221, an insulating buffer pad 222, and a uniform force pad 223 stacked sequentially, with the uniform force pad 223 abutting against the pressure plate support 23. That is, the piezoelectric ceramic optical film 221, insulating buffer pad 222, and uniform force pad 223 are stacked sequentially from the mounting bracket 21 side towards the pressure plate support 23 side. This design, consisting of a three-layer stacked speckle suppression assembly 22 composed of the piezoelectric ceramic optical film 221, insulating buffer pad 222, and uniform force pad 223, achieves dynamic speckle suppression through high-frequency vibration of the piezoelectric ceramic optical film 221 after it is energized. Simultaneously, the insulating buffer pad 222 provides electrical insulation and vibration damping, while the uniform force pad 223 ensures stable and consistent vibration of the entire piezoelectric ceramic optical film 221, preventing stress concentration and damage to other components. This ensures both the uniformity of vibration and avoids interference from the vibration of the piezoelectric ceramic optical film 221 transmitted to other optical elements. In this design, the piezoelectric ceramic optical film 221 is driven to vibrate by the principle of piezoelectric ceramic vibration, which avoids large wear and vibration noise of the speckle suppression component 22 and improves the service life of the speckle suppression component 22; at the same time, the piezoelectric ceramic optical film 221 has a fast response speed and a significant speckle suppression effect.
[0026] Please refer to the following: Figure 3 and Figure 6 The piezoelectric ceramic optical film 221 includes a piezoelectric ceramic element 2211, a light-transmitting element 2212, and a wire 2213. A mounting hole 2214 is formed in the center of the piezoelectric ceramic element 2211, and the light-transmitting element 2212 is fixedly fitted into the mounting hole 2214. The wire 2213 is electrically connected to the piezoelectric ceramic element 2211. Specifically, the wire 2213 extends from the side of the mounting bracket 21 and is used to connect an external drive circuit to supply power to the piezoelectric ceramic element 2211. When the piezoelectric ceramic element 2211 is energized, it vibrates, which in turn drives the light-transmitting element 2212 mounted on the piezoelectric ceramic element 2211 to vibrate at high frequency, achieving dynamic speckle suppression.
[0027] Preferably, the piezoelectric ceramic element 2211 has a ring-shaped structure, with a mounting hole 2214 in its center for fixing and fitting the light-transmitting element 2212. Furthermore, the piezoelectric ceramic element 2211 is composed of a diaphragm support and a piezoelectric ceramic layer disposed on the diaphragm support. When the piezoelectric ceramic layer is energized, it vibrates, causing the light-transmitting element 2212 to vibrate. This vibration suppresses speckle on the laser light passing through the light-transmitting element 2212. Of course, when the frequency of the electrical signal applied to the piezoelectric ceramic layer matches the thickness of the light-transmitting element 2212 to satisfy the Raman-Nice diffraction conditions, the incident laser light passing through the light-transmitting element 2212 will produce Raman-Nice diffraction, thereby achieving speckle suppression. In other words, the vibration amplitude and frequency generated by the light-transmitting element 2212 under the drive of the piezoelectric ceramic layer are sufficient to achieve speckle suppression of the laser light.
[0028] like Figure 5 As shown, Figure 5 A partial structural assembly alignment diagram of the speckle suppressor 2 is provided. For ease of understanding, the mounting bracket 21, insulating buffer pad 222, and uniform force pad 223 are separated along the same axis. However, considering that the pressure plate bracket 23 is used to clamp and fix the uniform force pad 223 to the mounting bracket 21, the pressure plate bracket 23 is split along a direction perpendicular to the aforementioned same axis. Specifically, please refer to... Figure 3 , Figure 4 and Figure 5 The mounting bracket 21, insulating buffer pad 222, force equalizing pad 223, and tablet holder 23 are all provided with coaxial through-holes 24, and the through-holes 24 are aligned with the light-transmitting element 2212, so that the laser beam can pass through the through-holes 24 and the light-transmitting element 2212 without obstruction. In other words, the mounting bracket 21, insulating buffer pad 222, force equalizing pad 223, and tablet holder 23 are all annular structures, ensuring that the laser beam can pass through the through-holes 24 and be directed towards the light-transmitting element 2212, and finally pass through the light-transmitting element 2212 and exit from the through-holes 24.
[0029] In some embodiments, such as Figure 4 As shown, there are two sets of speckle suppression components 22, symmetrically arranged on two opposite end faces of the mounting bracket 21. It can be understood that the two opposite end faces refer to the two end faces of the mounting bracket 21 along the light transmission path, i.e., the two end faces through which the light passes sequentially. By employing two sets of symmetrically arranged speckle suppression components 22, dual-level dynamic speckle suppression is achieved, reducing speckle contrast to less than half of a single level, significantly improving the uniformity and comfort of the projected image. Simultaneously, the two sets of speckle suppression components 22 can operate intermittently and independently, greatly extending the continuous working time of the speckle suppressor 2 and significantly increasing the overall lifespan of the speckle suppressor 2.
[0030] Furthermore, the tablet holder 23 has a U-shaped structure and spans across the two opposite end faces of the mounting bracket 21, pressing the corresponding force-equalizing pads 223. In other words, the mounting bracket 21 and the speckle suppression components 22 are sandwiched between the tablet holder 23. The U-shaped tablet holder 23 spans and presses against the speckle suppression components 22 located on both sides of the mounting bracket 21, meaning that two sets of speckle suppression components 22 can be fixed simultaneously in a single assembly, significantly improving assembly efficiency. The symmetrical force distribution prevents deformation of the mounting bracket 21 and ensures the coaxiality of the light-transmitting holes 24 on both sides.
[0031] In some embodiments, each of the two opposite end faces of the mounting bracket 21 is provided with a placement groove 211, and the two sets of speckle suppression components 22 are respectively disposed in the two placement grooves 211. Of course, the placement grooves 211 communicate with the light-transmitting holes 24 on the mounting bracket 21, ensuring that the laser beam can pass through the placement grooves 211 and the light-transmitting holes 24 sequentially. The placement grooves 211 on the mounting bracket 21 achieve precise positioning of the speckle suppression components 22, eliminating the need for additional coaxial alignment during assembly and reducing assembly difficulty and errors. Simultaneously, the placement grooves 211 can limit the radial and axial displacement of the speckle suppression components 22, enhancing the vibration resistance of the speckle suppressor 2 and preventing optical path offset caused by displacement of the speckle suppression components 22 during transportation or use.
[0032] In some embodiments, the insulating buffer pad 222 is made of at least one of rubber, silicone, polyimide, or epoxy resin. Using elastic insulating materials such as rubber, silicone, polyimide, or epoxy resin to make the insulating buffer pad 222 effectively absorbs the high-frequency vibrations generated during the operation of the piezoelectric ceramic optical film 221, preventing vibrations from being transmitted to the mounting bracket 21 and other optical components, thus avoiding resonance and image jitter. Simultaneously, these materials possess excellent electrical insulation and high-temperature resistance, preventing short circuits between the piezoelectric ceramic optical film 221 and metal structures such as the pressure plate bracket 23, while also adapting to the high-temperature operating environment inside the laser projection optical engine, and are less prone to aging and failure with long-term use.
[0033] In some embodiments, the uniform force pad 223 is made of at least one of stainless steel, aluminum alloy, or copper. Using rigid metals such as stainless steel, aluminum alloy, or copper to make the uniform force pad 223 can uniformly convert the force generated by the vibration of the piezoelectric ceramic optical film 221 and the force generated during the installation of the pressure plate bracket 23 into surface pressure, which then acts uniformly on the surfaces of the insulating buffer pad 222 and the piezoelectric ceramic optical film 221, preventing localized stress concentration that could lead to breakage of the piezoelectric ceramic optical film 221, deformation of the light-transmitting element 2212, or changes in polarization characteristics.
[0034] In some embodiments, the light-transmitting element 2212 is an optical element with an optical microstructure on its surface. The microstructure is selected from any one of a rough surface, a microlens array, a diffusion microstructure, or a phase microstructure. The microstructure on the light-transmitting element 2212 can simultaneously homogenize the laser spot, improve the illumination uniformity of the surface of the optomechanical chip 4, avoid the phenomenon of bright center and dark edge, and improve the overall brightness uniformity of the projected image.
[0035] In some embodiments, the mounting bracket 21 is made of stainless steel, which has extremely high rigidity and dimensional stability, and is not easily deformed during long-term use or temperature changes, thus ensuring the coaxiality of each light-transmitting hole 24 and the installation accuracy of the speckle suppression component 22 at all times. The tablet holder 23 is made of an elastic metal material, which has good elasticity and low stress relaxation rate, providing a durable and stable clamping force. The clamping force will not decrease due to long-term use or temperature cycling, ensuring that the speckle suppression component 22 is always in a reliably fixed state. Preferably, the tablet holder 23 is made of elastic steel.
[0036] In some embodiments, such as Figure 1 As shown, the laser light source assembly 1 has a light source optical axis L, the optical path modulation assembly 3 has a modulation optical axis M, and the projection lens 5 has a projection optical axis P. The light source optical axis L is parallel to the projection optical axis P, and the modulation optical axis M is perpendicular to both the light source optical axis L and the projection optical axis P. This layout gives the laser projection optical engine a U-shaped structure, significantly shortening its overall length and making it more compact, facilitating integration into miniaturized devices.
[0037] Please refer to Figure 2 The laser projection optical engine also includes a vertically fixed first housing 6 and a second housing 7. The laser light source assembly 1 and speckle suppressor 2 are fixed inside the first housing 6, and the optical path modulation assembly 3 is fixed inside the second housing 7. The reflective surface of the optical engine chip 4 faces the modulation optical axis M and is perpendicular to the modulation optical axis M. The optical engine chip 4 is fixed on the side of the second housing 7 away from the first housing 6. The projection lens 5 is fixed on the second housing 7 and close to the optical engine chip 4. That is, both the optical engine chip 4 and the projection lens 5 are located on the side of the second housing 7 away from the first housing 6, and the mounting surfaces of the optical engine chip 4 and the projection lens 5 on the second housing 7 are perpendicular to each other. By adopting a separate and vertically fixed first housing 6 and second housing 7, the laser light source assembly 1 and the optical path modulation assembly 3 are separated, which can effectively isolate the heat generated by the laser light source assembly 1, reduce the impact of heat on the optical path modulation assembly 3 and the optical engine chip 4, and improve the working stability and service life of the optical engine. At the same time, the modular housing design facilitates the independent assembly, debugging and maintenance of each component, reducing production and after-sales costs.
[0038] In some embodiments, the laser source assembly 1 includes a green laser source 11, a blue laser source 12, a red laser source 13, a green reflector 14, a blue dichroic mirror 15, and a red dichroic mirror 16. The green reflector 14, blue dichroic mirror 15, and red dichroic mirror 16 are all arranged parallel to each other along the optical axis L of the source, and all three form a 45° angle with the optical axis L. The red dichroic mirror 16 is positioned close to the speckle suppressor 2. The green laser source 11 is located below the green reflector 14 along the direction perpendicular to the optical axis L of the source; the blue laser source 12 is located below the blue dichroic mirror 15 along the direction perpendicular to the optical axis L of the source; and the red laser source 13 is located below the red dichroic mirror 16 along the direction perpendicular to the optical axis L of the source. The green laser source 11, blue laser source 12, and red laser source 13 are arranged along the optical axis L of the light source, with a green reflector 14, a blue dichroic mirror 15, and a red dichroic mirror 16 correspondingly positioned on the optical axis L. This scheme, employing three independent laser sources combined with dichroic mirrors, achieves higher brightness and a wider color gamut than LED light sources, resulting in more realistic and vibrant color reproduction. Furthermore, the green reflector 14, blue dichroic mirror 15, and red dichroic mirror 16 are arranged parallel to the optical axis L at a 45° angle, resulting in high light combining efficiency, a compact structure, and ease of optical path adjustment and color temperature calibration. Preferably, the green laser source 11, blue laser source 12, and red laser source 13 are fixed in place by a light source bracket 17, meaning the three light sources are centrally mounted on the bracket 17, ensuring both installation accuracy and convenience.
[0039] It should be noted that the green light reflector 14 is used to reflect green light shining on its front side; the blue light dichroic mirror 15 is used to reflect blue light shining on its front side and allows green light shining on its back side to pass through; the red light dichroic mirror 16 is used to reflect red light shining on its front side and allows green and blue light shining on its back side to pass through. Here, the "front side" of the green light reflector 14, blue light dichroic mirror 15, and red light dichroic mirror 16 refers to the surface facing the light source, and the "back side" refers to the surface opposite to the front side.
[0040] To facilitate understanding of the optical path principle of the laser light source assembly 1 of the present invention, the following detailed description is provided in conjunction with each component of the laser light source assembly 1. The green laser light source 11 emits green light. The green light reflector 14 reflects the green light and transmits it along the optical axis L of the light source, then directs it towards the blue light dichroic mirror 15. After reaching the blue light dichroic mirror 15, the green light continues to transmit through it. The blue laser light source 12 emits blue light. The blue light dichroic mirror 15 reflects the blue light and transmits it along the optical axis L of the light source, then directs it towards the red light dichroic mirror 16. The green and blue light continue to transmit through the red light dichroic mirror 16. The red laser light source 13 emits red light. The red light dichroic mirror 16 reflects the red light and transmits it along the optical axis L of the light source. The red light combines with the transmitted green and blue light to form a beam, thus completing the convergence and integration of the three light sources.
[0041] In some embodiments, combined with Figure 1 and Figure 2 The optical path modulation component 3 includes a first reflecting mirror 31, a first relay lens 32, a compound eye lens 33, a second relay lens 34, and a polarizing beam splitter 35 arranged sequentially along the modulation optical axis M. Light entering the optical path modulation component 3 passes sequentially through the first reflecting mirror 31, the first relay lens 32, the compound eye lens 33, the second relay lens 34, and the polarizing beam splitter 35, and is finally directed by the polarizing beam splitter 35 onto the optomechanical chip 4. Using this optical path modulation architecture, the functions of optical path redirection, light collimation, light spot homogenization, and polarization beam splitting can be sequentially completed, converting the divergent and non-uniform light emitted from the laser source component 1 into uniform parallel polarized light, which is then precisely projected onto the surface of the optomechanical chip 4.
[0042] Furthermore, the first reflecting mirror 31 and the polarizing beam splitter 35 are arranged in parallel and both form a 45° angle with the modulation optical axis M. The first reflecting mirror 31 is close to the speckle suppressor 2, and the polarizing beam splitter 35 is close to the optomechanical chip 4. The polarizing beam splitter 35 is used to transmit the first polarized light and reflect the second polarized light. That is, the polarizing beam splitter 35 can transmit the first polarized light from the speckle suppressor 2 side and reflect the second polarized light from the optomechanical chip 4 side, realizing the separation of incident light and imaging light, avoiding stray light interference, and significantly improving the contrast of the projected image.
[0043] It is understandable that a quarter-wave plate is disposed in the optical path between the polarizing beam splitter 35 and the optomechanical chip 4, which is used to convert the first polarized light from the polarizing beam splitter 35 into second polarized light and then send it back to the polarizing beam splitter 35. In the art, it is common knowledge to use a quarter-wave plate in the optical path between the polarizing beam splitter 35 and the optomechanical chip 4 to convert the first polarized light into the second polarized light, and this will not be elaborated here.
[0044] Specifically, when the first polarized light from the laser source assembly 1 is P-polarized light, it passes through the polarizing beam splitter 35 and is directed towards a quarter-wave plate. The quarter-wave plate receives the first polarized light and performs a first conversion. Subsequently, the optomechanical chip 4 receives the polarized light after the first conversion, adjusts its angle, and directs it back towards the quarter-wave plate. The quarter-wave plate receives the polarized light again and performs a second conversion, resulting in second polarized light, which is then directed back to the polarizing beam splitter 35. The polarizing beam splitter 35 reflects the second polarized light to the projection lens 5, where the second polarized light is S-polarized light. Of course, if the coating characteristics of the polarizing beam splitter 35 are reversed, the first polarized light can also be S-polarized light, and the corresponding second polarized light can be P-polarized light.
[0045] In some embodiments, the compound eye lens 33 has microlens units disposed on its surface along the modulation optical axis M. The refractive index Nd of the compound eye lens 33 is 1.48 to 1.58, and its dispersion coefficient Vd is greater than 63. This effectively reduces chromatic aberration, avoids color edges in the projected image, and improves the uniformity of the light spot, ensuring consistent illumination across all areas of the optomechanical chip 4. Preferably, the dispersion coefficient Vd of the compound eye lens 33 is greater than 63 and less than 75.
[0046] In some embodiments, the first relay lens 32 is an aspherical plastic lens with a refractive index Nd of 1.48–1.58, a dispersion coefficient Vd greater than 63, and a focal length of 30 mm–38 mm. The second relay lens 34 is a spherical plastic lens with a refractive index Nd of 1.48–1.58, a dispersion coefficient Vd greater than 63, and a focal length of 30 mm–38 mm. The polarizing beam splitter 35 is a glass plane mirror with a refractive index Nd of 1.48–1.58 and a dispersion coefficient Vd greater than 64. The uniform refractive index range of the first relay lens 32, the second relay lens 34, and the polarizing beam splitter 35 ensures excellent optical matching of the entire optical path modulation assembly 3, reduces Fresnel reflection loss between different component interfaces, and improves overall light transmission efficiency. Simultaneously, all three utilize low-dispersion materials, fundamentally eliminating the chromatic aberration superposition problem in the optical path system, avoiding focusing deviations of different wavelengths of light, and significantly improving the color reproduction and edge sharpness of the projected image. The first relay aspherical lens effectively corrects spherical aberration and coma. Combined with a second relay spherical lens of similar focal length, it achieves optimal light collimation and focusing, accurately projecting the uniform light spot emitted from the compound eye lens 33 onto the effective imaging area of the optomechanical chip 4. Preferably, the dispersion coefficient Vd of the first relay lens 32 is greater than 63 and less than 75, the dispersion coefficient Vd of the second relay lens 34 is greater than 63 and less than 75, and the dispersion coefficient Vd of the polarizing beam splitter 35 is greater than 64 and less than 80.
[0047] In some embodiments, the total length of the projection lens 5 is 78mm to 88mm, and its effective focal length is 25mm to 30mm, meeting the requirements of miniaturization design while ensuring the quality of the projected image. The aperture value of the projection lens 5 is 1.8 to 2.4, and its entrance pupil diameter is 10mm to 16mm, which is suitable for the limited space of the laser projection optical engine and can project a bright and clear image, ensuring that the image projected by the projection lens 5 is clearly visible.
[0048] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concept, should be covered within the scope of protection of the present invention.
Claims
1. A laser projection optical engine, characterized in that, include: The laser source component, speckle suppressor, optical path modulation component, optomechanical chip and projection lens are arranged sequentially along the light transmission path. The speckle suppressor is used to receive laser light emitted from the laser source component and suppress laser speckle. The optical path modulation component is disposed between the speckle suppressor and the optomechanical chip. The projection lens is fixed to the light-emitting side of the optical path modulation component. The speckle suppressor includes a mounting bracket, a speckle suppressor assembly, and a pressing bracket. The speckle suppressor assembly is disposed on the end face of the mounting bracket along the light transmission path, and the pressing bracket is used to press and fix the speckle suppressor assembly onto the mounting bracket. The speckle suppression assembly includes a piezoelectric ceramic optical film, an insulating buffer pad, and a uniform force pad stacked in sequence, with the uniform force pad abutting against the pressure plate support. The piezoelectric ceramic optical film includes a piezoelectric ceramic element, a light-transmitting element, and a wire. The piezoelectric ceramic element has a mounting hole in the middle. The light-transmitting element is fixedly fitted into the mounting hole. The wire is electrically connected to the piezoelectric ceramic element. The mounting bracket, the insulating buffer pad, the uniform pressure pad, and the pressure plate bracket are all provided with coaxial through holes, and the through holes are aligned with the light-transmitting element so that the laser beam can pass through the through holes and the light-transmitting element without obstruction.
2. The laser projection optical engine according to claim 1, characterized in that, The number of speckle suppression components is two sets, which are symmetrically arranged on two opposite end faces of the mounting bracket; The tablet holder has a U-shaped structure and spans across two opposite end faces of the mounting bracket, pressing the uniform pressure pad on the corresponding side.
3. The laser projection optical engine according to claim 2, characterized in that, The mounting bracket has placement slots on both opposite end faces, and the two sets of speckle suppression components are respectively placed in the two placement slots.
4. The laser projection optical engine according to claim 1, characterized in that, The insulating cushioning pad is made of at least one of rubber, silicone, polyimide, or epoxy resin.
5. The laser projection optical engine according to claim 1, characterized in that, The uniform force pad is made of at least one of stainless steel, aluminum alloy or copper.
6. The laser projection optical engine according to claim 1, characterized in that, The light-transmitting element is an optical element with an optical microstructure on its surface, and the microstructure is selected from any one of rough surface, microlens array, diffusion microstructure or phase microstructure.
7. The laser projection optical engine according to claim 1, characterized in that, The mounting bracket is made of stainless steel, and the tablet holder is made of elastic metal material.
8. The laser projection optical engine according to claim 1, characterized in that, The laser source component has a source optical axis, the optical path modulation component has a modulation optical axis, the projection lens has a projection optical axis, the source optical axis is parallel to the projection optical axis, and the modulation optical axis is perpendicular to both the source optical axis and the projection optical axis. The laser projection optical engine further includes a vertically fixed first housing and a second housing. The laser source assembly and the speckle suppressor are fixed inside the first housing. The optical path modulation assembly is fixed inside the second housing. The reflective surface of the optical engine chip faces the modulation optical axis and is perpendicular to the modulation optical axis. The optical engine chip is fixed on the side of the second housing away from the first housing. The projection lens is fixed on the second housing and close to the optical engine chip.
9. The laser projection optical engine according to claim 8, characterized in that, The laser source assembly includes a green laser source, a blue laser source, a red laser source, a green reflector, a blue dichroic mirror, and a red dichroic mirror. The green reflector, the blue dichroic mirror, and the red dichroic mirror are all arranged parallel to each other along the optical axis of the source, and all three form a 45° angle with the optical axis of the source. The red dichroic mirror is located close to the speckle suppressor. The green laser source is located below the green reflector along a direction perpendicular to the optical axis of the source, the blue laser source is located below the blue dichroic mirror along a direction perpendicular to the optical axis of the source, and the red laser source is located below the red dichroic mirror along a direction perpendicular to the optical axis of the source.
10. The laser projection optical engine according to claim 8, characterized in that, The optical path modulation assembly includes a first reflector, a first relay lens, a compound eye lens, a second relay lens, and a polarizing beam splitter arranged sequentially along the modulation optical axis. The first reflector and the polarizing beam splitter are arranged in parallel and both form a 45° angle with the modulation optical axis. The first reflector is close to the speckle suppressor, and the polarizing beam splitter is close to the optomechanical chip.
11. The laser projection optical engine according to claim 10, characterized in that, The compound eye lens has microlens units disposed on its surface along the modulation optical axis. The refractive index Nd of the compound eye lens is 1.48 to 1.58, and its dispersion coefficient Vd is greater than 63.
12. The laser projection optical engine according to claim 10, characterized in that, The first relay lens is an aspherical plastic lens with a refractive index Nd of 1.48 to 1.58, a dispersion coefficient Vd greater than 63, and a focal length of 30 mm to 38 mm. The second relay lens is a spherical plastic lens with a refractive index Nd of 1.48 to 1.58, a dispersion coefficient Vd greater than 63, and a focal length of 30 mm to 38 mm. The polarizing beam splitter is a glass plane mirror with a refractive index Nd of 1.48 to 1.58 and a dispersion coefficient Vd greater than 64.
13. The laser projection optical engine according to claim 8, characterized in that, The projection lens has a total length of 78mm to 88mm, an effective focal length of 25mm to 30mm, an aperture value of F of 1.8 to 2.4, and an entrance pupil diameter of 10mm to 16mm.