Laser scanning projection system and vehicle

Abstract

The utility model provides a laser scanning projection system which comprises a plurality of laser channels, each laser channel is used for independently emitting laser, at least one laser channel comprises a laser source and a collimating and shaping assembly, the laser source is used for emitting the laser, the collimating and shaping assembly is located on a light path of the laser, and the collimating and shaping assembly is located on the light path of the laser. The collimation module is used for collimating the slow axis direction and the fast axis direction of the laser and expanding the beam in the slow axis direction of the laser; the light combining module is positioned on a light path of the laser and is used for combining the laser emitted by the plurality of laser channels into light source light; the scanning module is located on a light path of the light source light and used for modulating and reflecting the angle of the light source light so as to emit image light, and the image light is used for displaying a projection image. The utility model further provides a vehicle.

Description

Technical Field

[0001] This application relates to the field of projection display technology, and in particular to a laser scanning projection system and a vehicle including the laser scanning projection system. Background Technology

[0002] Laser beam scanning (LBS) projection devices use micro-electro-mechanical systems (MEMS) to modulate laser light for imaging.

[0003] While the aforementioned LBS projection devices offer advantages such as rich colors, high optical-mechanical efficiency, and small size, they also suffer from problems such as low projection brightness, low screen refresh rate, poor resolution, and narrow field of view. How to achieve high projection brightness, high resolution, high screen refresh rate, and wide field of view while maintaining high light output efficiency and a small system size has become a design challenge for LBS projection devices. Utility Model Content

[0004] This application provides a laser scanning projection system, comprising: multiple laser channels, each laser channel independently emitting laser light, at least one laser channel including a laser source and a collimation and shaping component, the laser source emitting the laser light, the collimation and shaping component being located in the optical path of the laser light and used to collimate the slow axis and fast axis directions of the laser light and expand the laser beam in the slow axis direction; a beam combining module, located in the optical path of the laser light, used to combine the laser beams emitted from the multiple laser channels to form a light source; and a scanning module, located in the optical path of the light source, used to modulate the angle of reflection of the light source to emit image light, the image light being used to display a projected image.

[0005] In at least one embodiment of this application, the collimation and shaping component includes an aspherical lens, a cylindrical negative lens, and a cylindrical positive lens arranged sequentially at intervals. The aspherical lens is used to collimate the slow axis and fast axis of the laser, and the cylindrical negative lens and the cylindrical positive lens are used to expand the laser beam in the slow axis direction.

[0006] In at least one embodiment of this application, the plurality of laser channels includes two laser channels for emitting red laser light.

[0007] In at least one embodiment of this application, one of the two laser channels is used to emit P-polarized red laser and the other is used to emit S-polarized red laser.

[0008] In at least one embodiment of this application, each of the two laser channels includes a laser source, the laser source having a light-emitting end face, the light-emitting end faces of the laser sources in the two laser channels are located on the same plane and are positioned at angles differing by 90°, so that the fast axes of the red lasers emitted by the two laser channels are perpendicular to each other.

[0009] In at least one embodiment of this application, the light combining module includes a reflective polarizer for transmitting the P-polarized red laser and for reflecting the S-polarized red laser.

[0010] In at least one embodiment of this application, the laser scanning projection system includes a first light source optical path and a second light source optical path that are independent of each other. The first light source optical path and the second light source optical path each include the plurality of laser channels and the light combining module. The first light source optical path is used to emit first light source light, and the second light source optical path is used to emit second light source light. The scanning module is used to modulate the first light source light to emit first image light and to modulate the second light source light to emit second image light. The optical paths of the first image light and the second image light are not parallel.

[0011] In at least one embodiment of this application, the scanning module is used to project the first image light onto a first image region and to project the second image light onto a second image region, wherein the first image region and the second image region are stitched together.

[0012] In at least one embodiment of this application, the optical paths of the first light source and the second light source are not parallel.

[0013] In at least one embodiment of this application, the optical path of the first light source and the optical path of the second light source are arranged axially symmetrically.

[0014] In at least one embodiment of this application, the light combining module includes a beam splitter, and the laser scanning projection system further includes a photodiode; the beam splitter is used to guide a portion of the light source light to the scanning module and to guide a portion of the light source light to the photodiode; the photodiode is used to sense the light intensity of the light source light.

[0015] A second aspect of this application provides a vehicle, including: a vehicle body; and any of the above-mentioned laser scanning projection systems, the laser scanning projection system being connected to the vehicle body for projecting image light toward the interior or exterior of the vehicle body to display the projected image.

[0016] The aforementioned laser scanning projection system and vehicle include multiple laser channels, with at least one laser channel including a collimation and shaping component. The collimation and shaping component is used to collimate the slow and fast axes of the laser and expand the laser beam along the slow axis to give the laser a circular spot. This avoids the problems of a large lens focusing spot diameter and poor display effect caused by a small diameter and large divergence angle of the collimated laser beam, and also avoids the problems of excessive system size and low light efficiency caused by a large collimated laser beam size. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the optical path structure of a laser scanning projection system according to an embodiment of this application.

[0018] Figure 2 This is a schematic diagram of the collimation and shaping effect of the red laser in the first laser channel in at least one embodiment.

[0019] Figure 3 for Figure 1 The diagram shows the collimated right-angle distribution of the red laser beam in the laser scanning projection system.

[0020] Figure 4 for Figure 1 The diagram shows the spot structure of the red laser beam in the laser scanning projection system.

[0021] Figure 5 for Figure 1 A schematic diagram of the planar structure of the first and fourth laser sources.

[0022] Figure 6 This is a schematic diagram of another optical path structure of the laser scanning projection system according to an embodiment of this application.

[0023] Figure 7 This is a three-dimensional structural diagram of the laser scanning projection system according to an embodiment of this application.

[0024] Figure 8 This is a schematic diagram showing the distribution of the projected image projected by the laser scanning projection system according to an embodiment of this application.

[0025] Explanation of main component symbols

[0026] Laser scanning projection system: 100;

[0027] First light source optical path: 101;

[0028] Second light source optical path: 102;

[0029] First laser channel: 10;

[0030] First laser source: 11;

[0031] First light-emitting end face: 111;

[0032] First collimation and shaping component: 12;

[0033] First aspherical lens: 121;

[0034] First cylindrical negative lens: 122;

[0035] First cylindrical positive lens: 123;

[0036] Second laser channel: 20;

[0037] Second laser source: 21;

[0038] Second collimation and shaping component: 22;

[0039] Second aspherical lens: 221;

[0040] Second cylindrical negative lens: 222;

[0041] Second cylindrical positive lens: 223;

[0042] Third laser channel: 30;

[0043] Third laser source: 31;

[0044] Third collimation and shaping component: 32;

[0045] Third aspherical lens: 321;

[0046] Third cylindrical negative lens: 322;

[0047] Third cylindrical positive lens: 323;

[0048] Fourth laser channel: 40;

[0049] Fourth laser source: 41;

[0050] Fourth collimation and shaping component: 42;

[0051] Fourth aspherical lens: 421;

[0052] Fourth cylindrical negative lens: 422;

[0053] Fourth cylindrical positive lens: 423;

[0054] Photonics module: 50;

[0055] Reflector: 51;

[0056] Reflective polarizer: 52;

[0057] First beam splitter: 53;

[0058] Second beam splitter: 54;

[0059] Third beam splitter: 55;

[0060] Aperture stop: 56;

[0061] Scanning module: 60;

[0062] Optical modulator: 61;

[0063] First reflecting mirror: 62;

[0064] First positive lens: 63;

[0065] Second reflecting mirror: 64;

[0066] Second positive lens: 65;

[0067] Photodiode: 70;

[0068] Glass window: 80;

[0069] Light-receiving surface: 81;

[0070] First fast axis direction: L1;

[0071] Second fast axis direction: L2;

[0072] First axis: α;

[0073] Second axis: β;

[0074] Third axis: γ;

[0075] First image region: P1;

[0076] Second image region: P2;

[0077] First light source: L11;

[0078] First image light: L12;

[0079] Second light source: L21;

[0080] Second image light: L22.

[0081] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0082] Firstly, the laser scanning projection system of this application improves the collimation and shaping components to modulate the laser beam into a circular spot, which is beneficial to improving the resolution of the projected image. Secondly, by setting two laser channels that emit red lasers, the light intensity of the light source is improved, thereby improving the brightness of the projected image. Thirdly, by setting two scanning optical paths, the field of view is increased while ensuring the refresh rate.

[0083] Please see Figure 1 The laser scanning projection system 100 of this application embodiment includes a first laser channel 10, a second laser channel 20, a third laser channel 30, a beam combining module 50, and a scanning module 60. The four laser channels (10 / 20 / 30) are used to independently emit laser light. The beam combining module 50 is located in the optical path of the laser beam and is used to combine the light from the four laser channels (10 / 20 / 30) into a single beam for emission as the light source. The scanning module 60 is located in the optical path of the light source and is used to modulate the light source to generate image light for emission. When this image light is projected onto a display medium, it can present a projected image that can be observed by the human eye. The display medium can be, for example, a projection screen, a wall, a floor, a desktop, etc.

[0084] The first laser channel 10 emits red laser light, the second laser channel 20 emits green laser light, and the third laser channel 30 emits blue laser light. The combined light source includes red, green, and blue laser light, therefore the image light generated based on the modulation of the light source can be used to display color projection images.

[0085] The first laser channel 10 includes a first laser source 11 and a first collimation and shaping component 12. The first laser source 11 may be a laser diode, used to emit red laser light. The first collimation and shaping component 12 is used to collimate and shape the red laser light sequentially. The first collimation and shaping component 12 includes a first aspherical lens 121, a first cylindrical negative lens 122, and a first cylindrical positive lens 123 arranged sequentially at intervals along the red laser light path.

[0086] The first aspherical lens 121 is a glass aspherical lens used to collimate the fast and slow axes of the red laser emitted from the first laser source 11. According to the law of conservation of optical spread, this avoids the problems of a large focused spot diameter and poor display effect caused by a small diameter and large divergence angle of the collimated red laser beam. It also avoids the problems of an excessively large system size and low optical efficiency caused by a large collimated red laser beam size. The aspherical surface of the first aspherical lens 121 better corrects system aberrations and facilitates better collimation of the divergence angles along the fast and slow axes of the red laser.

[0087] The first cylindrical negative lens 122 and the first cylindrical positive lens 123 form a beam expander, which expands the collimated red laser beam along the slow axis by 2 to 3 times before it is emitted. According to the law of conservation of optical expansion, the area of ​​the collimated red laser beam increases and the divergence angle decreases. Therefore, the slow axis divergence angle of the collimated red laser beam is reduced to be consistent with the fast axis direction, so that the red laser is collimated and shaped into a circular spot after passing through the first collimation and shaping component 12.

[0088] Please see Figure 2 In at least one embodiment, the first laser source 11 is a single-mode laser with a fast-axis divergence angle of 14°-21° and a slow-axis divergence angle of 6°-9°, exhibiting a small optical spread, which helps to maintain a small system size. The first aspherical lens 121 is a glass aspherical lens with a focal length of 2mm-4.5mm, used to collimate the fast and slow axes of the red laser, respectively. The first cylindrical negative lens 122 and the first cylindrical positive lens 123 are used to expand the red laser beam by 2.2 times in the slow-axis direction, thereby shaping the red laser spot into a circular spot.

[0089] Please see Figure 3 , Figure 3 Figure (a) shows the red laser spot on a plane perpendicular to the optical path of the red laser, with the center of the spot as the zero point of the Cartesian coordinate system. Figure 3 Figure (b) shows the divergence angle distribution of the red laser beam along the horizontal axis, while Figure 3 Figure (c) shows the divergence angle distribution of the light spot along the horizontal axis. According to... Figure 3 It can be seen that the first collimation and shaping component 12 can achieve a beam divergence angle of less than 0.03° for the red laser emitted from the first laser channel 10.

[0090] Please see Figure 4 , Figure 4 Figure (a) shows a red laser spot on a plane perpendicular to the optical path of the red laser. The center of the spot is taken as the zero point of the Cartesian coordinate system, and the horizontal and vertical coordinates represent the distances relative to the zero point (the center of the spot). Figure 4 Figure (b) shows the intensity distribution of the light spot along the horizontal axis, while Figure 4 Figure (c) shows the light intensity distribution of the light spot along the vertical axis. According to the formula D=2*f*tanθ (D is the diameter of the light spot, f is the focal length formed by the first cylindrical negative lens 122 and the light modulator in the scanning module 60, and θ is the divergence angle of the red laser), it can be seen that the smaller the divergence angle of the beam, the smaller the diameter of the light spot. Figure 4 It can be seen that the diameter of the red laser spot in this embodiment is <0.2mm.

[0091] In some related laser scanning projection systems, laser collimation and shaping primarily employ a single aspherical lens or only two cylindrical lenses. While using only one aspherical lens for laser collimation is simple, it results in a large divergence angle of the collimated beam. Furthermore, the inability to reshape the laser beam leads to an elliptical projected spot with a large diameter, resulting in poor image quality. Conversely, using only two cylindrical lenses can reshape the laser beam into a circular projected spot. However, due to the large divergence angle along the fast axis of the laser, the cylindrical lenses alone cannot adequately correct system aberrations, leading to poor laser collimation and a large projected spot diameter with low projection clarity.

[0092] In this embodiment, the first collimation and shaping component 12 includes a first aspherical lens 121, a first cylindrical negative lens 122, and a first cylindrical positive lens 123, which can collimate and shape the red laser so that the first laser channel 10 can emit a red laser beam with a spot diameter of <0.2mm and a divergence angle of less than 0.03°.

[0093] Please refer to the following: Figure 1 The second laser channel 20 includes a second laser source 21 and a second collimation and shaping component 22. The second laser source 21 emits green laser light, and the second collimation and shaping component 22 collimates and shapes the green laser light sequentially. The second collimation and shaping component 22 includes a second aspherical lens 221, a second cylindrical negative lens 222, and a second cylindrical positive lens 223 arranged sequentially at intervals along the green laser light path. The second aspherical lens 221, the second cylindrical negative lens 222, and the second cylindrical positive lens 223 are as described above with the first aspherical lens 121, the first cylindrical negative lens 122, and the first cylindrical positive lens 123.

[0094] The third laser channel 30 includes a third laser source 31 and a third collimation and shaping component 32. The third laser source 31 emits blue laser light, and the third collimation and shaping component 32 collimates and shapes the blue laser light sequentially. The third collimation and shaping component 32 includes a third aspherical lens 321, a third cylindrical negative lens 322, and a third cylindrical positive lens 323 arranged sequentially at intervals along the blue laser light path. The third aspherical lens 321, the third cylindrical negative lens 322, and the third cylindrical positive lens 323 are the same as the first aspherical lens 121, the first cylindrical negative lens 122, and the first cylindrical positive lens 123 described above.

[0095] In other embodiments, the first laser channel 10, the second laser channel 20, and the third laser channel 30 may partially include the collimation and shaping components described above, rather than all including the collimation and shaping components described above. In other embodiments, the first laser channel 10, the second laser channel 20, and the third laser channel 30 may each include different collimation and shaping components, or at least two laser channels may include different collimation and shaping components.

[0096] The laser scanning projection system 100 also includes a fourth laser channel 40. The fourth laser channel 40 includes a fourth laser source 41 and a fourth collimation and shaping assembly 42. The fourth laser source 41 emits red laser light. The fourth collimation and shaping assembly 42 collimates and shapes the red laser light from the fourth laser source 41. The fourth collimation and shaping assembly includes a fourth aspherical lens 421, a fourth cylindrical negative lens 422, and a fourth cylindrical positive lens 423. The fourth aspherical lens 421, the fourth cylindrical negative lens 422, and the fourth cylindrical positive lens 423 are as described above with the first aspherical lens 121, the first cylindrical positive lens 122, and the first cylindrical negative lens 123.

[0097] A related laser scanning projection system includes one laser each for emitting red, green, and blue lasers, with the laser emitting red laser being the most temperature-sensitive. When the operating temperature of the laser emitting red laser increases from 25°C to 60°C, its output optical power decreases by nearly 50% compared to when it is at 25°C. Therefore, the projection output luminous flux is relatively low in this laser scanning projection system.

[0098] Therefore, the laser scanning projection system 100 of this application embodiment includes two laser channels (10 / 40) for emitting red lasers, one laser channel (20) for emitting green lasers, and one laser channel (30) for emitting blue lasers. That is, there are more laser channels for emitting red lasers than for emitting green and blue lasers, and the number of laser channels for emitting green and blue lasers is the same. On the one hand, this is beneficial to increase the luminous flux of the laser scanning projection system 100 (projection output white field luminous flux > 100lm) and improve the brightness of the projected image. On the other hand, it is beneficial to improve the uniformity of various colors of lasers in the light source.

[0099] Please continue reading. Figure 1 The first laser channel 10, the second laser channel 20, the third laser channel 30 and the fourth laser channel 40 are arranged in sequence at intervals, and the optical paths of the first laser channel 10, the second laser channel 20, the third laser channel 30 and the fourth laser channel 40 are parallel to each other and emit lasers in the same direction.

[0100] The beam combining module 50 includes a reflector 51, a reflective polarizer 52, a first beam splitter 53, a second beam splitter 54, and an aperture stop 56 arranged sequentially at intervals. The reflector 51, the reflective polarizer 52, the first beam splitter 53, and the second beam splitter 54 are parallel to each other and form a 45° angle with the optical paths of the first laser channel 10, the second laser channel 20, the third laser channel 30, and the fourth laser channel 40.

[0101] Reflector 51 is used to reflect the red laser from the fourth laser channel 40 to reflective polarizer 52. Reflective polarizer 52 is used to transmit the red laser from reflector 51 and to reflect the red laser from the first laser channel 10. Specifically, the fourth laser channel 40 is used to emit P-polarized red laser, the first laser channel 10 is used to emit S-polarized red laser, and reflective polarizer 52 is used to transmit P-polarized red laser and to reflect S-polarized red laser.

[0102] The structure and function of the fourth laser source 41 are the same as those of the first laser source 11. The fourth laser source 41 and the first laser source 11 are placed at a mutually perpendicular angle, thereby realizing that the fourth laser channel 40 emits P-polarized red laser and the first laser channel 10 emits S-polarized red laser.

[0103] Please see Figure 5 The first laser source 11 has a first emitting end face 111 for emitting red laser light, and the fourth laser source 41 has a second emitting end face 411 for emitting red laser light. The first emitting end face 111 and the second emitting end face 411 are the same size and shape, and the first emitting end face 111 and the second emitting end face 411 face the same direction (along the direction of the laser light emitted). Figure 5 The laser emits red laser light perpendicular to the plane of the paper. The first light-emitting end face 111 and the second light-emitting end face 411 are located on the same plane, and the placement angle of the fourth laser source 41 is rotated by 90° relative to the first laser source 11 on this plane, so that the angle of the second light-emitting end face 411 is rotated by 90° relative to the first light-emitting end face 111 on this plane.

[0104] Therefore, when red laser light is emitted from the first emitting end face 111 and the second emitting end face 411, the fast axis of the red laser light emitted from the first emitting end face 111 is perpendicular to the fast axis of the red laser light emitted from the second emitting end face 411. This results in the red laser light emitted from the first laser source 11 being S-polarized red laser light, while the red laser light emitted from the fourth laser source 41 is P-polarized red laser light. In other words, the first laser channel 10 emits S-polarized red laser light, while the fourth laser channel 40 emits P-polarized red laser light.

[0105] By setting a fourth laser channel 40 to emit P-polarized red laser and a first laser channel 10 to emit S-polarized red laser, and correspondingly setting a reflective polarizer 52 to transmit the P-polarized red laser and reflect the S-polarized red laser, the red laser beams from the fourth laser channel 40 and the first laser channel 10 can be combined and emitted in the same direction. In other embodiments, the red laser beam combining of the fourth laser channel 40 and the first laser channel 10 can also be achieved in other ways.

[0106] Please refer to the following: Figure 1The first beam splitter 53 is a green-to-red beam splitter, used to transmit red laser light from the reflective polarizer 52 and to reflect green laser light from the second laser channel 20. The second beam splitter 54 is a blue-to-yellow beam splitter, used to transmit the combined beam (yellow laser) of the red and green laser light from the first beam splitter 53 and to reflect blue laser light from the third laser channel 30. The combined beam of red, green, and blue laser light emitted from the second beam splitter 54 serves as the source light. The aperture stop 56 is used to block stray light from the periphery of the source light beam, allowing the central portion of the source light beam to propagate into the subsequent optical path (including the scanning module 60).

[0107] The beam combining module 50 also includes a third beam splitter 55 between the second beam splitter 54 and the aperture stop 56, and the laser scanning projection system 100 also includes a photodiode 70. The third beam splitter 55 is used to reflect 1% to 2% of the light source light to the photodiode 70 and to transmit the remaining light source light. The photodiode 70 can monitor the optical power of the red, green, and blue lasers in the light source light based on this 1% to 2% light source light. This facilitates timely feedback and adjustment of the power of the first laser source 11, the second laser source 21, the third laser source 31, and the fourth laser source 41, ensuring the color balance of the projected image.

[0108] In other embodiments, the third beam splitter 55 may also be configured to transmit 1% to 2% of the light from the light source to the photodiode 70 and reflect the remaining light from the light source. The third beam splitter 55 can guide a small portion of the light from the light source to the photodiode 70.

[0109] Please refer to the following: Figure 6 and Figure 7 The laser scanning projection system 100 includes a first light source optical path 101 and a second light source optical path 102. The first light source optical path and the second light source optical path 102 have essentially the same structure and function, and respectively include, for example... Figure 1 The first laser channel 10, the second laser channel 20, the third laser channel 30, the fourth laser channel 40, the light combining module 50, and the photodiode 70 are shown.

[0110] The first light source optical path 101 and the second light source optical path 102 are axially symmetrically distributed. The first light source optical path 101 is defined as emitting the first light source light L11, and the second light source optical path 102 is defined as emitting the second light source light L12. The scanning module 60 is located on the optical paths of the first light source light L11 and the second light source light L21, and is used to modulate the first light source light L11 to emit the first image light L12, and modulate the second light source light L21 to emit the second image light L22. The optical paths of the first light source light L11 and the second light source light have a non-zero angle, that is, the optical paths of the first light source light L11 and the second light source light L21 are not parallel. Thus, the light modulator 61 emits the first image light L12 and the second image light L22 in a non-parallel manner.

[0111] The laser scanning projection system 100 typically also includes a housing that serves as support, protection, and light shielding, for mounting supports such as... Figure 6 The optical elements shown are described. The housing typically includes a glass window 80 for light transmission, allowing image light to be projected from the glass window 80. The glass window 80 is defined as having a light-receiving surface 81 for receiving a first image light L12 and a second image light L22. The first light source path 101 and the second light source path 102 are arranged symmetrically about an axis perpendicular to the light-receiving surface 81.

[0112] The scanning module 60 includes a light modulator 61, a first reflector 62, a first positive lens 63, a second reflector 64, and a second positive lens 65. The first reflector 62 is located between the first light source optical path 101 and the glass window 80, and the first positive lens 63 is located between the light modulator 61 and the glass window 80. The second reflector 64 is located between the second light source optical path 102 and the glass window 80, and the second positive lens 65 is located between the light modulator 61 and the glass window 80. The optical path formed by the first reflector 62 and the first positive lens 63, and the optical path formed by the second reflector 64 and the second positive lens 65, are also symmetrically arranged about the axis perpendicular to the light-receiving surface 81.

[0113] The optical modulator 61 modulates the received first light source L11 and second light source L21. A first reflector 62 reflects the first light source L11 from the aperture stop 56 to a first positive lens 63, which then transmits the first light source L11 back to the optical modulator 61. A second reflector 64 reflects the second light source L21 from the aperture stop 56 to a second positive lens 65, which then transmits the second light source L21 back to the optical modulator 61. The first image light L12 and the second image light L22 emitted from the optical modulator 61 exit through the glass window 80.

[0114] The light modulator 61 is a MEMS device used to reflect the received first light source L11 as the first image light L12 to the glass window 80 at a preset angle, and to reflect the received second light source L21 as the second image light L22 to the glass window 80 at a preset angle. Within one display cycle (defined in this embodiment as the time period for displaying a complete frame of image), the light modulator 61 can present a projected image in a specific area on the surface of the display medium by modulating the reflection angles of the first light source L11 and the second light source L21.

[0115] When the first light source L11 and the second light source L21 exit from the first light source optical path 101 and the second light source optical path 102, they form a non-zero angle with the light-receiving surface 81, causing the first image light L12 and the second image light L22 to be incident on the light-receiving surface 81 non-perpendicularly. That is, within one display cycle, the first image light L12 and the second image light L22 are projected onto different areas of the display medium surface to present projected images in different areas. The projected images formed by the first image light L12 and the second image light L22 are stitched together to form a complete projected image, thus increasing the field of view.

[0116] Please refer to the following: Figure 7 and Figure 8 In at least one embodiment, a first axis α, a second axis β, and a third axis γ are defined as mutually perpendicular. The first axis α is parallel to the optical path of the red, green, and blue lasers (i.e., the direction perpendicular to the plane of the paper). The first axis α and the second axis β (i.e., the direction perpendicular to the plane of the paper) are defined as perpendicular to each other. Figure 6 The vertical direction) defines the light-receiving surface 81, and the third axis γ (that is, the ... Figure 6 (Horizontal direction) is perpendicular to the light-receiving surface 81.

[0117] The first reflector 62 reflects the first light source L11 at an angle of -15° relative to the first axis α and an angle of 11° relative to the second axis β, causing the first light source L11 to pass through the optical axis of the first positive lens 63 and enter the light modulator 61. The light modulator 61 reflects the first light source L11 at a preset angle, causing it to be emitted as the first image light L12. Within one display cycle, the light modulator 61 tilts to adjust the angle at which the first light source L11 is reflected, thereby allowing the first image light L12 to be projected onto different points within the first image region P1 in a time-division manner (this process is defined as "scanning" in this embodiment). Based on the persistence of vision effect, within one display cycle, the first image light L12 can present an image in the first image region P1.

[0118] The second reflector 64 reflects the second light source L21 at an angle of 15° relative to the first axis α and an angle of 11° relative to the second axis β. The second light source L21 passes through the optical axis of the second positive lens 65 and is incident on the light modulator 61. The light modulator 61 reflects the second light source L21 at a preset angle, causing it to be emitted as the second image light L22. Within one display cycle, the light modulator 61 deflects to adjust the angle at which the second light source L21 is reflected, thereby allowing the second image light L22 to be projected onto different points within the second image region P2 in a time-division manner, thus presenting an image in the second image region P2.

[0119] The first image region P1 and the second image region P2 are rectangular regions of the same shape and size. The first image region P1 and the second image region P2 are spliced ​​together along two sides of the same length, so that the projected images presented by the first image region P1 and the second image region P2 are spliced ​​together, thereby increasing the field of view.

[0120] The aforementioned scanning module 60 enables the first image light L12 to scan and project a first image region P1 with a horizontal angle of 0–34° and a vertical angle of -9–15°, and the second image light L22 to scan and project a second image region P2 with a horizontal angle of 0–34° and a vertical angle of -9–15°. The projected images formed by the scanning of the first light source optical path 101 and the second light source optical path 102 (i.e., the images displayed in the first image region P1 and the second image region P2) can be stitched together to achieve a large field-of-view projection with a horizontal angle of -34° to 34° and a vertical angle of -9 to 15°.

[0121] Furthermore, in this embodiment, the first light source L11 is emitted from the first light source optical path 101 and then reflected once by the first reflector 62, and the second light source L21 is emitted from the second light source optical path 102 and then reflected sequentially by the second reflector 64. That is, the scanning module 60 has folded the optical path, which makes the system structure more compact and helps to reduce the system size.

[0122] In a relevant projection scanning system, the light modulator cannot simultaneously possess a large scanning angle and a high scanning vibration frequency. A large scanning projection angle inevitably reduces the refresh rate of the projected image, causing flickering to be perceived by the human eye and degrading the viewing experience. Conversely, a high image refresh rate inevitably reduces the scanning projection angle, resulting in an excessively small scanning angle.

[0123] The embodiments of this application, by setting two laser optical paths (101 / 102), realize image stitching after scanning and imaging by the two optical paths respectively. This can achieve a large field of view projection while maintaining a high projection screen refresh rate (>60HZ), which helps to avoid the human eye from perceiving screen flicker and improves the viewing effect.

[0124] In summary, the laser scanning projection system 100 of this application embodiment can achieve:

[0125] (1) High projection brightness, projection output luminous flux > 100lm;

[0126] (2) Large projection field of view, with a horizontal projection field of view of 64° and a vertical field of view of -9° to 15°;

[0127] (3) High projection resolution > 1500*500, single pixel projection spot diameter < 0.2mm;

[0128] (4) High projection screen refresh rate, screen refresh rate > 60Hz;

[0129] (5) The system is small in size, simple in structure, and highly reliable.

[0130] This application embodiment also provides a vehicle including the laser scanning projection system 100 described above. The vehicle includes a vehicle body and the laser scanning projection system 100 connected to the vehicle body. The laser scanning projection system 100 can project projected images to the interior or exterior of the vehicle body. That is, the laser scanning projection system 100 described above can be applied to at least in-vehicle scenarios. It can serve as an image generation unit (PGU) in a vehicle head-up display (HUD), or as a projected head-up display (PHUD), vehicle dynamic ground projection light, etc.

[0131] The vehicle in this application embodiment includes a laser scanning projection system 100, which can achieve all the beneficial effects of the laser scanning projection system 100 described above.

[0132] Those skilled in the art should recognize that the above embodiments are only used to illustrate this application and are not intended to limit this application. Any appropriate changes and variations made to the above embodiments within the essential spirit and scope of this application fall within the scope of protection claimed by this application.

Claims

1. A laser scanning projection system, characterized in that, include: Multiple laser channels, each laser channel is used to emit laser independently, and at least one laser channel includes a laser source and a collimation and shaping component. The laser source is used to emit the laser, and the collimation and shaping component is located in the optical path of the laser and is used to collimate the slow axis and fast axis directions of the laser and to expand the laser beam in the slow axis direction. A beam combining module, located in the optical path of the laser, is used to combine the laser beams emitted from the multiple laser channels to form a light source. as well as The scanning module, located in the optical path of the light source, is used to modulate the angle of the reflected light source to emit image light, which is used to display the projected image.

2. The laser scanning projection system as described in claim 1, characterized in that, The collimation and shaping assembly includes an aspherical lens, a cylindrical negative lens, and a cylindrical positive lens arranged at intervals in sequence. The aspherical lens is used to collimate the slow axis and fast axis of the laser, and the cylindrical negative lens and the cylindrical positive lens are used to expand the laser beam in the slow axis direction.

3. The laser scanning projection system as described in claim 1, characterized in that, The plurality of laser channels includes two laser channels for emitting red laser light.

4. The laser scanning projection system as described in claim 3, characterized in that, One of the two laser channels is used to emit P-polarized red laser, and the other is used to emit S-polarized red laser.

5. The laser scanning projection system as described in claim 4, characterized in that, Both laser channels include a laser source, and the laser source has a light-emitting end face. The light-emitting end faces of the laser sources in the two laser channels are located on the same plane and are placed at angles that differ by 90°, so that the fast axes of the red lasers emitted by the two laser channels are perpendicular to each other.

6. The laser scanning projection system as described in claim 4, characterized in that, The light combining module includes a reflective polarizer, which is used to transmit the P-polarized red laser and to reflect the S-polarized red laser.

7. The laser scanning projection system as described in any one of claims 1-6, characterized in that, The laser scanning projection system includes a first light source optical path and a second light source optical path that are independent of each other. The first light source optical path and the second light source optical path respectively include the plurality of laser channels and the light combining module. The first light source optical path is used to emit first light source light, and the second light source optical path is used to emit second light source light. The scanning module is used to modulate the first light source light to emit a first image light, and to modulate the second light source light to emit a second image light, wherein the optical paths of the first image light and the second image light are not parallel.

8. The laser scanning projection system as described in claim 7, characterized in that, The scanning module is used to project the first image light onto the first image area and to project the second image light onto the second image area, wherein the first image area and the second image area are stitched together.

9. The laser scanning projection system as described in claim 7, characterized in that, The light paths of the first light source and the second light source are not parallel.

10. The laser scanning projection system as described in claim 7, characterized in that, The optical path of the first light source and the optical path of the second light source are arranged symmetrically.

11. The laser scanning projection system as described in any one of claims 1-6, characterized in that, The light combining module includes a beam splitter, and the laser scanning projection system also includes a photodiode; The beam splitter is used to guide a portion of the light source to the scanning module and to guide a portion of the light source to the photodiode; The photodiode is used to sense the light intensity of the light source.

12. A vehicle, characterized in that, include: Vehicle body; as well as The laser scanning projection system as described in any one of claims 1-11 is connected to the vehicle body and is used to project the image light toward the inside or outside of the vehicle body to display the projected image.

Images