Variable field of view scanning system and method thereof

Abstract

The present disclosure provides a variable field of view scanning system and a method thereof. The variable field of view scanning system comprises a multi-curved surface rotating prism having at least a first reflecting curved surface and a second reflecting curved surface, wherein the first reflecting curved surface is designed for a first field of view, the second reflecting curved surface is designed for a second field of view, at least one of a field of view orientation and a field of view angle range of the first field of view is different from the second field of view; and a light detector adapted to receive a first light reflected from the first reflecting curved surface to generate a first image corresponding to the first field of view, and to receive a second light reflected from the second reflecting curved surface to generate a second image corresponding to the second field of view. With the variable field of view scanning system of the present disclosure, imaging or detection functions of different fields of view can be achieved. The variable field of view scanning system can be widely used in navigation fields such as vehicle autonomous driving, unmanned aerial vehicles, robots, etc.

Description

Technical Field

[0001] This application relates to the field of optical detection, and more particularly to a variable field-of-view scanning system and method thereof. More specifically, this variable field-of-view scanning system and method can be applied to radar systems such as autonomous driving and automatic field-of-view detection. Background Technology

[0002] LiDAR, as a device that uses lasers to measure information such as the distance, position, and attitude of a target, mainly includes triangulation and time-of-flight methods. The time-of-flight method involves emitting a laser signal onto the target and receiving the echo signal reflected by the target. Then, the distance between the laser radar and the target is calculated by the time difference between the emission and reception of the light.

[0003] Different application scenarios require LiDAR with different performance parameters. Some scenarios require a long detection range, while others require a wide field of view. This is especially true for autonomous driving, where switching between different fields of view may be necessary. Summary of the Invention

[0004] The purpose of this disclosure is to provide a variable field-of-view scanning system that can quickly image and detect objects within different desired fields of view.

[0005] According to a first aspect of this disclosure, a variable field-of-view scanning system is provided. The variable field-of-view scanning system includes: a multi-faceted rotating prism having at least a first reflective surface and a second reflective surface, wherein the first reflective surface is designed for a first field of view, and the second reflective surface is designed for a second field of view, wherein at least one of the field-of-view orientation and field-of-view angle range of the first field of view differs from that of the second field of view; and a photodetector adapted to receive first light reflected from the first reflective surface to generate a first image corresponding to the first field of view, and to receive second light reflected from the second reflective surface to generate a second image corresponding to the second field of view.

[0006] The variable field-of-view scanning system disclosed herein enables rapid imaging and detection of different fields of view with a simple structure. This imaging or detection capability with different fields of view can be widely used in navigation fields such as autonomous driving, robotics, and drones.

[0007] In some embodiments, the difference between the minimum lateral imaging resolution of the first image and the second image is within ±10% of the minimum lateral imaging resolution of the first image. In this way, the first and second images generated by the variable field-of-view scanning system can have substantially the same imaging resolution overall, thus facilitating viewing by the user.

[0008] In some embodiments, the furthest imaging distance within the first field of view corresponding to the first image is different from the furthest imaging distance within the second field of view corresponding to the second image. In this way, different furthest imaging distances can be matched for different fields of view, thereby enabling broader imaging of objects at different distances throughout the entire field of view.

[0009] In some embodiments, the multi-surface rotating prism has more than two reflecting surfaces, including a first reflecting surface and a second reflecting surface, which are designed for multiple different fields of view. In these embodiments, the coverage of the different fields of view can be wider.

[0010] In some embodiments, the overall field of view formed by the plurality of fields of view has an axis of symmetry, with the first and second fields of view located on the same side of the axis of symmetry. The second field of view is closer to the axis of symmetry than the first field of view but has a smaller field of view angle range and / or a greater maximum imaging distance. In yet other embodiments, the multi-faceted rotating prism further includes a third reflecting surface designed for a third field of view, and the photodetector is further configured to receive third light reflected from the third reflecting surface to generate a third image corresponding to the third field of view. The first, second, and third fields of view are located on the same side of the axis of symmetry, with the field of view angle range decreasing sequentially for the first, second, and third fields of view, but the corresponding maximum imaging distance increasing sequentially. In this way, field of view detection, such as in autonomous driving, may be advantageous because autonomous driving typically requires a large field of view for close-range detection and a small field of view for long-range detection. Furthermore, long-range detection usually requires higher emitted laser power, and reducing the field of view angle range also helps to reduce the power budget of the laser.

[0011] In some embodiments, the multi-surface rotating prism further includes a fourth reflecting surface designed for a fourth field of view, which is symmetrical to the first field of view about the axis of symmetry. In this way, a field of view that is at least partially symmetrical about the axis of symmetry can be provided, which may be advantageous for field-of-view detection, such as in autonomous vehicle driving.

[0012] In some embodiments, the furthest imaging distance corresponding to the first image is in the range of 20m-30m, the furthest imaging distance corresponding to the second image is in the range of 60m-75m, and the furthest imaging distance corresponding to the third image is in the range of 180m-220m. Utilizing these designed numerical ranges, the field-of-view detection requirements for applications such as autonomous driving can be met.

[0013] In some embodiments, the photodetector is configured to receive the first light and generate the first image during a first time period, and to receive the second light and generate the second image during a second time period, the first time period being different from the second time period. In these embodiments, this means that it is possible to detect an image using a single photodetector.

[0014] In some embodiments, during the transition period from the first time period to the second time period, the multi-faceted rotating prism can be operatively rotated to adjust its orientation, while during the first and second time periods, the multi-faceted rotating prism remains stationary. This means that the field-of-view detection of this disclosure is performed by emitting a detection beam with a two-dimensional cross-section toward a predetermined target area.

[0015] In some embodiments, the system may further include: a laser for emitting a probe beam to the multi-faceted rotating prism; and a beam splitter disposed between the laser and the multi-faceted rotating prism for transmitting the probe beam emitted from the laser and reflecting light from the multi-faceted rotating prism to the photodetector. In this manner, the arrangement of the beam splitter allows the optical path incident on the multi-faceted rotating prism and the optical path reflected back to the photodetector from the multi-faceted rotating prism to partially overlap, which allows for a more compact overall size of the variable field-of-view scanning system of this disclosure.

[0016] In some embodiments, the system may further include: a laser for emitting probe light; and a microelectromechanical scanning mirror (MEMS) for receiving the probe light emitted from the laser and projecting the probe light in a scanning manner onto a predetermined target area, wherein the multi-faceted rotating prism is configured to adjust the orientation of a corresponding reflective surface according to the scanned predetermined target area to receive light from the predetermined target area and reflect the light from the predetermined target area to the photodetector. In these embodiments, alternative arrangements of the light source for the variable field-of-view scanning system are provided.

[0017] According to a second aspect of this disclosure, a radar system is provided that includes the variable field-of-view scanning system described in the first aspect.

[0018] According to a third aspect of this disclosure, a terminal device is provided, the terminal device including the radar system described in the second aspect.

[0019] In some embodiments, the terminal device includes at least one of a vehicle, a drone, and a robot.

[0020] According to a fourth aspect of this disclosure, a variable field-of-view scanning method based on a multi-faceted rotating prism is provided. The method includes: reflecting first light from a first field of view through a first reflecting surface of the multi-faceted rotating prism, wherein the first reflecting surface is designed for the first field of view; receiving the first light using a photodetector to generate a first image corresponding to the first field of view; reflecting second light from a second field of view through a second reflecting surface of the multi-faceted rotating prism, wherein the second reflecting surface is designed for the second field of view, wherein at least one of the field-of-view orientation and field-of-view angle range of the first field of view is different from the second field of view; and receiving the second light using the photodetector to generate a second image corresponding to the second field of view.

[0021] In some embodiments, reflecting first light from a first field of view through the first reflecting surface of the multi-faceted rotating prism includes: keeping the multi-faceted rotating prism stationary for a first time period to reflect the first light from the first field of view; and reflecting second light from a second field of view through the second reflecting surface of the multi-faceted rotating prism includes: keeping the multi-faceted rotating prism stationary for a second time period to reflect the second light from the second field of view; wherein the second time period is different from the second time period.

[0022] In some embodiments, the difference between the minimum lateral imaging resolution of the first image and the second image is within ±10% of the minimum lateral imaging resolution of the first image.

[0023] In some embodiments, the farthest imaging distance within the first field of view corresponding to the first image is different from the farthest imaging distance within the second field of view corresponding to the second image.

[0024] In some embodiments, the multi-surface rotating prism has more than two reflective surfaces, including a first reflective surface and a second reflective surface. The multiple reflective surfaces are designed for different multiple fields of view. The entire field of view formed by the multiple fields of view has an axis of symmetry. The method further includes controlling the rotation of the multi-surface rotating prism so that the multiple reflective surfaces reflect light from the multiple fields of view sequentially and cyclically.

[0025] In some embodiments, the first field of view and the second field of view are located on the same side of the axis of symmetry, and the second field of view is closer to the axis of symmetry than the first field of view, but has a smaller field of view angle range and a greater corresponding maximum imaging distance.

[0026] In some embodiments, the multi-faceted rotating prism further includes a third reflecting surface designed for a third field of view, and the photodetector is further configured to receive third light reflected from the third reflecting surface to generate a third image corresponding to the third field of view, wherein the first field of view, the second field of view, and the third field of view are located on the same side of the axis of symmetry, and the angular ranges of the first, second, and third fields of view decrease sequentially, but the corresponding farthest imaging distances increase sequentially.

[0027] In some embodiments, the farthest imaging distance corresponding to the first image is in the range of 20m-30m; the farthest imaging distance corresponding to the second image is in the range of 60m-75m; and the farthest imaging distance corresponding to the third image is in the range of 180m-220m.

[0028] In some embodiments, the method further includes: emitting a probe beam using a laser; reflecting the probe beam to a target region using the reflective surface of the multi-faceted rotating prism; and transmitting the probe beam emitted from the laser using a beam splitter and reflecting light from the multi-faceted rotating prism to the photodetector.

[0029] In some embodiments, the method further includes: emitting a probe beam using a laser; receiving the probe beam emitted from the laser using a microelectromechanical scanning mirror (MEMS); and projecting the probe beam onto a target area in a scanning manner.

[0030] It should also be understood that the description in the Summary of the Invention is not intended to limit the key or essential features of the embodiments of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of the embodiments of this disclosure will become readily apparent from the following description. Attached Figure Description

[0031] Figure 1 A schematic diagram of the structure of a variable scanning system according to a first exemplary embodiment of the present disclosure is shown;

[0032] Figure 2 A schematic diagram of the structure of a variable scanning system according to a second exemplary embodiment of the present disclosure is shown;

[0033] Figure 3 A schematic diagram of the structure of a variable scanning system according to a second exemplary embodiment of the present disclosure is shown; and

[0034] Figure 4 A flowchart of a variable field-of-view scanning method according to an example embodiment of this disclosure is shown. Detailed Implementation

[0035] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0036] The purpose of this disclosure is to provide an improved variable field-of-view scanning system that can provide variable field-of-view scanning with a simple and efficient structure. To this end, the concept of this disclosure is to construct an operable rotatable multi-faceted rotating prism, wherein the multi-faceted rotating prism has at least a first reflective surface and a second reflective surface, the first reflective surface being designed for a first field of view, the second reflective surface being designed for a second field of view, and at least one of the field-of-view orientation and field-of-view angle range of the first field of view differs from that of the second field of view. Furthermore, the system is equipped with a photodetector to detect images corresponding to the aforementioned first and second fields of view. With the above configuration, as the multi-faceted rotating prism rotates, light can be projected onto and / or received from different fields of view using the different reflective surfaces on the multi-faceted rotating prism, thereby achieving imaging and / or distance detection in different fields of view.

[0037] To better understand the concept of this disclosure, Figure 1 A schematic diagram of the structure of a variable scanning system according to a first exemplary embodiment of the present disclosure is shown.

[0038] like Figure 1 As shown, the variable scanning system 100 includes at least a laser 20, a beam splitter 30, a lens 40, a multi-faceted rotating prism 10, a photodetector 50, and a controller (not shown).

[0039] Laser 20 is configured to emit a pulsed probe beam of a predetermined wavelength and project the probe beam onto the reflective surface of the multi-faceted rotating prism 10. In some embodiments, the emission power of laser 21 is also adjustable. In some embodiments, the laser can be a single light source. In still other embodiments, the laser can be a light source array consisting of multiple light sources. As a non-limiting example, the laser can be a side-emitting laser (EEL) or a vertical-cavity surface-emitting laser (VCSEL) or similar light source. The predetermined wavelength can be any suitable wavelength, including but not limited to wavelengths of visible light, infrared light, or ultraviolet light.

[0040] Lens 40 may be positioned between laser 20 and multi-faceted rotating prism 10 to shape (e.g., collimate or diverge) the beam emitted from laser 20. As an example, lens 40 may be a diverging lens to shape the collimated beam emitted from laser 20 into a diverging beam with a predetermined cross-sectional size. This predetermined cross-sectional size may be matched to the size of the reflecting surface of the multi-faceted rotating prism 10 to be incident upon. That is, lens 40 may allow the probe beam to be projected onto the reflecting surface of the multi-faceted rotating prism 10 in a two-dimensional cross-section. In some embodiments, lens 40 may be presented as a single lens or a lens assembly. In yet other embodiments, lens 40 is movable, thereby allowing adjustment of the cross-sectional shape and / or size of the emitted probe beam as needed.

[0041] The multi-faceted rotating prism 10 can be a rotating prism with multiple reflective surfaces, which is configured to be operably rotated to project a probe beam incident on its corresponding reflective surface onto a predetermined target area, and to reflect the reflected light from the target area back to the photodetector 50.

[0042] For example only, Figure 1 The multi-faceted rotating prism 10 shows six reflecting surfaces: a first reflecting surface 1, a second reflecting surface 2, a second reflecting surface 3, a fourth reflecting surface 4, a fifth reflecting surface 5, and a sixth reflecting surface 6. However, it will be understood that in other embodiments, the multi-faceted rotating prism 10 may have more or fewer even or odd numbers of reflecting surfaces, for example, 2, 3, 4, 5, 7, 8, 9, and 10 reflecting surfaces.

[0043] In some embodiments, the aforementioned plurality of reflective surfaces may be designed for different fields of view.

[0044] Here, as used herein, the term "different fields of view" means that at least one of the field of view orientation and field of view angle range differs between two or more fields of view corresponding to two or more reflective surfaces. The term "field of view angle range" is defined as the angle formed by the boundary rays of the beam reflected from the reflective surface in a predetermined plane. Generally, the field of view angle range corresponds one-to-one with the curvature of the reflective surface. Therefore, "different field of view angle ranges" can mean that the curvature designs corresponding to two or more reflective surfaces are different from each other. The term "field of view orientation" is defined as the direction pointed to by the bisector of the angle between the boundary rays of the beam reflected from the reflective surface in a predetermined plane. As a non-limiting example, the predetermined plane may, for example, be the plane containing the optical axis of the probe beam reflected from the reflective surface and the scanning direction of the region.

[0045] As an example, such as Figure 1As shown, the first reflecting surface 1 of the multi-surface rotating prism 10 is designed for the first field of view, the second reflecting surface 2 is designed for the second field of view, the third reflecting surface 3 is designed for the third field of view, the fourth reflecting surface 4 can be designed for the fourth field of view, the fifth reflecting surface 5 is designed for the fifth field of view, and the sixth reflecting surface 6 can be designed for the sixth field of view, wherein at least one of the field of view orientation and field of view angle range of the first, second, third, fourth, fifth, and sixth fields of view is different from each other.

[0046] The first to sixth fields of view corresponding to the aforementioned first to sixth reflecting surfaces 1-6 can have different field of view orientations and different or the same field of view angle ranges. For example, Figure 1 As shown, the field of view ranges corresponding to the first to sixth viewing surfaces are different or the same, for example, 40 degrees, 15 degrees, 5 degrees, 5 degrees, 15 degrees and 40 degrees respectively. In particular, the field of view of the first reflecting surface 1 and the sixth reflecting surface 6 can have different field of view orientations but the same field of view angle range, for example, 40 degrees; the second reflecting surface 2 and the fifth reflecting surface can have different field of view orientations but the same field of view angle range, for example, 15 degrees; and the third reflecting surface 3 and the fourth reflecting surface can have different field of view orientations but the same field of view angle range, for example, 5 degrees.

[0047] Furthermore, the collective field of view corresponding to the multiple reflecting surfaces of the aforementioned multi-curved rotating prism 10 can constitute the full field of view corresponding to the multi-curved rotating prism 10. In some embodiments, the full field of view may have an axis of symmetry. In particular, with respect to the axis of symmetry, the closer the field of view is to the axis of symmetry, the smaller its field of view angle range.

[0048] For example, such as Figure 1 As shown, the first, second, third, fourth, fifth, and sixth fields of view collectively constitute the full field of view of the multi-surface rotating prism 10. This full field of view can have a symmetry axis X. Specifically, the first, second, and third fields of view are located on one side of this symmetry axis X; the fourth, fifth, and sixth fields of view are located on the other side of the symmetry axis X; wherein the first, second, and third fields of view are symmetrical to the fourth, fifth, and sixth fields of view about the symmetry axis X, respectively. Furthermore, regardless of which side of the field of view is on the symmetry axis X, it can be viewed from... Figure 1 As can be seen, the closer the field of view is to the axis of symmetry, the smaller the corresponding field of view angle range.

[0049] Although the above description focuses on multiple reflective surfaces having corresponding different fields of view, it is understandable that some of the aforementioned reflective surfaces may be designed for the exact same fields of view, depending entirely on the design and / or application requirements.

[0050] Furthermore, although the above description focuses on a full field of view with an axis of symmetry, it is understood that a full field of view without an axis of symmetry is also possible. For example, in other embodiments, it is conceivable to have a full field of view lacking the field of view corresponding to any one or more of the first, second, third, fourth, fifth, and sixth reflecting surfaces, thereby easily obtaining an asymmetric full field of view. Here, it is also easy to understand that a full field of view with an axis of symmetry X may be advantageous for certain applications (e.g., radar detection for autonomous vehicles), for example, a full field of view with an axis of symmetry X can allow for the detection of symmetrical fields of view in front of and to the sides of the vehicle. In some embodiments, the field of view angle range of the aforementioned full field of view can be in the range of 120 degrees to 180 degrees.

[0051] Light from the different fields of view (i.e., echo signals from objects within the fields of view) can be incident on the photodetector 50 via the reflective surface corresponding to the multi-curved rotating prism 10, and then the photodetector 50 generates the corresponding image.

[0052] For example, photodetector 50 is adapted to receive first light reflected from a first reflective surface 1 to generate a first image corresponding to a first field of view; receive second light reflected from a second reflective surface 2 to generate a second image corresponding to a second field of view; ...; and so on, receiving third light reflected from an nth reflective surface n to generate an nth image corresponding to an nth field of view, where n is an integer greater than 2. As a non-limiting example, photodetector 50 may be at least one of a time-of-flight (TOF) sensor, a single-photon avalanche diode (SPAD) array, or a thermal imaging detector array.

[0053] It is easy to understand that the first image corresponding to the first field of view, the second image corresponding to the second field of view, and the nth image corresponding to the nth field of view can each have the farthest imaging distance and the minimum lateral imaging resolution within their respective fields of view.

[0054] Here, the term "imaging distance" is defined as the distance from the variable scanning system to the object imaged by the photodetector within the corresponding field of view. Specifically, the term "farthest imaging distance" is defined as the farthest distance from the variable scanning system to the object imaged by the photodetector within the corresponding field of view. This farthest imaging distance can depend on parameters such as the curvature of the corresponding reflective surface, the emission power of the laser, and / or the exposure time of the photodetector. Generally, the smaller the curvature of the reflective surface, the greater the emission power of the laser, or the longer the exposure time of the photodetector, the farther the farthest imaging distance within the corresponding field of view can be; conversely, the greater the curvature of the reflective surface, the lower the emission power of the laser, or the shorter the exposure time of the photodetector, the shorter the farthest imaging distance within the corresponding field of view. Therefore, the curvature of the reflective surface, the emission power of the laser, and / or the exposure time of the photodetector can be designed according to different requirements for the farthest imaging distance within the corresponding field of view.

[0055] The term "lateral imaging resolution" is defined as the lateral length of the real object corresponding to a single pixel in the image of the object captured by the photodetector. Here, "lateral" can refer to the direction in which the probe beam projected by the multi-faceted rotating prism scans within the target area. Specifically, the term "minimum lateral imaging resolution" is defined as the lateral length of the real object corresponding to a single pixel in the image of the object at its furthest imaging distance captured by the photodetector. It should be understood that this minimum lateral imaging resolution corresponds to the furthest imaging distance and reflects the sharpness of the object at that distance. Generally, as the object imaged within the field of view gets closer to the variable field-of-view scanning system, its corresponding imaging distance decreases, and its minimum lateral imaging resolution increases accordingly.

[0056] In some embodiments, the different fields of view corresponding to different reflective surfaces on the multi-curved rotating prism 10 can be designed with different or the same maximum imaging distance within the variable scanning field of view system. In yet other embodiments, the different fields of view can have different or the same minimum lateral imaging resolution, regardless of whether the maximum imaging distances corresponding to the different fields of view are the same. As used herein and hereinafter, the term "same or substantially the same minimum lateral imaging resolution" or similar terms mean that the difference between their minimum lateral resolutions is in the range of ±10%, ±5%, 3%, or 1%.

[0057] For example only, such as Figure 1As shown, the first, second, and third fields of view, or the third, fourth, and fifth fields of view, can have different maximum imaging distances; while the first and sixth fields of view, the second and fifth fields of view, and the third and fourth fields of view can have the same maximum imaging distance. Furthermore, regardless of whether the maximum imaging distances are the same or different, the minimum lateral imaging resolution of the images corresponding to the first to sixth fields of view can remain substantially the same.

[0058] For example, in Figure 1 In the embodiments, the furthest imaging distance corresponding to the first and sixth fields of view is in the range of 20m-30m; the furthest imaging distance corresponding to the second and fifth fields of view is in the range of 60m-75m; and the furthest imaging distance corresponding to the third and fourth fields of view is in the range of 180m-220m, but their minimum lateral imaging resolution is basically the same. It should be understood that, according to application requirements, the furthest imaging distance corresponding to different fields of view can be designed, and this furthest imaging distance is not limited to the above. Figure 1 The distance or range shown is used. In this way, a variable field of view can be provided with a very wide range of distances, while the minimum lateral imaging resolution remains essentially consistent.

[0059] Furthermore, in some embodiments, different maximum imaging distances can be combined with different field-of-view angle ranges. In particular, the smaller the field-of-view angle range, the greater the corresponding maximum imaging distance. Even further, in examples where the entire field of view has an axis of symmetry, the closer the field of view is to the axis of symmetry, the smaller the corresponding field-of-view angle range and / or the greater the corresponding maximum imaging distance.

[0060] For example, in Figure 1 In the example, the first field of view, the second field of view, and the third field of view can be located on the same side of the axis of symmetry, wherein the angular range of the first, second, and third fields of view decreases sequentially, but their corresponding farthest imaging distances increase sequentially.

[0061] The aforementioned matching design of maximum imaging distance, field of view angle range, and minimum lateral imaging resolution—especially the design that reduces the field of view angle range as the maximum imaging distance increases while still maintaining the same minimum lateral imaging resolution—may be advantageous for field of view scanning / distance detection, such as in autonomous vehicle systems. This is because autonomous vehicle systems typically require a large field of view for close-range detection and a small field of view for long-range detection. Furthermore, long-range detection usually requires higher emitted laser power, and reducing the field of view angle range also helps to reduce the power budget of the laser.

[0062] In order to guide the light beam (or echo signal) reflected by the corresponding reflective surface of the multi-faceted rotating prism 10 from the corresponding field of view to the photodetector 50, in some embodiments, the variable field of view scanning system 100 may further include a beam splitter 30, which may be positioned between the laser 20 and the multi-faceted rotating prism 10 (more specifically, between the laser 20 and the lens 40) to allow the probe light emitted from the laser to pass through and reflect the light from the multi-faceted rotating prism to the photodetector.

[0063] In a further embodiment, the beam splitter 30 may be a reflector with a central aperture. This beam splitter allows light emitted from the laser 20 to pass through the central aperture of the reflector, while simultaneously reflecting light from the multi-faceted rotating prism to a reflective area on the beam splitter other than the central aperture. By means of reflection from this reflective area, the reflected light from the multi-faceted rotating prism can be reflected to the photodetector 50. It is readily understood that the arrangement of the beam splitter allows the light path incident on the multi-faceted rotating prism and the light path reflected back to the photodetector from the multi-faceted rotating prism to partially overlap. In this way, the overall size of the variable field-of-view scanning system of this disclosure can be made more compact. Obviously, the embodiments of the beam splitter described above are not limiting. In other embodiments, the beam splitter 30 may be omitted, and instead arranged so that the light path incident from the laser 20 to the multi-faceted rotating prism 10 does not overlap at all, so that the light reflected from the multi-faceted rotating prism can be guided back to the photodetector.

[0064] A controller (not shown) can be coupled to at least the laser 20, the multi-faceted rotating prism 10, and the photodetector 50 to control these components. Specifically, the controller can control the emission power of the laser 20 to emit an illumination beam toward an object at a predetermined maximum imaging distance within a predetermined field of view. Furthermore, the controller can control the rotation of the multi-faceted rotating prism 10, such that a predetermined reflecting surface on the multi-faceted rotating prism 10 (e.g., ...) Figure 1 The first, second, third, fourth, fifth, or sixth reflective surfaces are oriented to allow a probe beam from the laser 20 (or, a diverging beam via the lens 40) to be incident on the predetermined reflective surface, and to allow light from a predetermined field of view to be reflected by the predetermined reflective surface to the photodetector 50, so that the photodetector 50 generates an image corresponding to the predetermined field of view. It should be specifically noted here that the predetermined reflective surfaces (e.g., Figure 1The first, second, third, fourth, fifth, or sixth reflective surfaces in the multi-faceted rotating prism 10 and thus the respective reflective surfaces thereon remain stationary throughout the entire process of allowing the probe beam from the laser 20 (or, the diverging beam via the lens 40) to be incident on the predetermined reflective surface and allowing light from the predetermined field of view to be reflected to the photodetector 50, so that the predetermined reflective surfaces (e.g., Figure 1 The first, second, third, fourth, fifth, or sixth reflective surfaces in the multi-faceted rotating prism 10 can emit a probe beam as a surface light source toward the predetermined field of view. Only after the photodetector 50 has finished detecting and / or imaging the predetermined field of view corresponding to the predetermined reflective surface will the multi-faceted rotating prism 10 be further rotated to orient the next predetermined reflective surface, so as to realize the detection of the next predetermined field of view corresponding to the next predetermined reflective surface (i.e., to further rotate the multi-faceted rotating prism 10 so that the next predetermined reflective surface is oriented to allow the probe beam to be incident on the next predetermined reflective surface, and to allow light from the next predetermined field of view to be reflected back to the photodetector 50 via the next predetermined reflective surface). In embodiments of this disclosure, the multi-faceted rotating prism 10 is operably rotated clockwise or counterclockwise to sequentially detect the fields of view corresponding to the plurality of reflective surfaces on the multi-faceted rotating prism 10 and generate corresponding images. In some embodiments, these images can be presented to the user individually. In other embodiments, these images can be stitched together and presented to the user.

[0065] For example, in Figure 1In one embodiment, the multi-faceted rotating prism 10 can be operatively rotated (e.g., by control of a controller) (clockwise or counterclockwise) such that the first reflective surface 1 is positioned facing the first field of view and remains stationary for a first time period. The first reflective surface 1 can then project light originating from the laser 10 and incident on the first reflective surface 1 via, for example, a beam splitter 30 and a lens 40 into the first field of view during the first time period. Simultaneously, during the first time period, the first reflective surface 1 can receive light from the first field of view and reflect the light to the photodetector 50 (e.g., via the lens 40 and the beam splitter 30), and the photodetector 50 can then generate a first image. Once the detection of the first field of view is complete, the multi-faceted rotating prism 10 can continue to rotate, for example, until the second reflective surface 2 is positioned facing the second field of view and remains stationary for a second time period. During this second time period, the second reflective surface 2 can project light emitted from the laser 10, incident on it via, for example, a beam splitter 30 and a lens 40, into the second field of view. Simultaneously, during this second time period, the second reflective surface 2 can receive light from the second field of view and reflect it to the photodetector 50 (e.g., via the lens 40 and the beam splitter 30). The photodetector 50 can then generate a second image, where the second time period differs from the first time period. Similarly, the third field of view corresponding to the third reflective surface 3 can be subsequently detected in a third time period, the fourth field of view corresponding to the fourth reflective surface 4 in a fourth time period, the fifth field of view corresponding to the fifth reflective surface 5 in a fifth time period, and the sixth field of view corresponding to the sixth reflective surface 6 in a sixth time period, generating corresponding images for each. Similarly, the field of view corresponding to more or fewer reflective surfaces can be detected (which may include distance detection of imaging objects within the field of view), and corresponding images can be generated.

[0066] It is easy to understand that the first, second, third, fourth, fifth, and sixth time periods mentioned above are different from each other or do not overlap. In some embodiments, a subsequent time period immediately follows a previous time period; for example, the second time period immediately follows the first time period, the third time period immediately follows the second time period, and so on to other time periods. In this way, each field of view can be scanned at the fastest speed. In yet other embodiments, it is also possible for a predetermined time interval to exist between the subsequent time period and the previous time period, depending on design requirements.

[0067] As the multi-faceted rotating prism 10 continues to rotate, after detecting and imaging the last field of view, it can return to detecting and imaging the first field of view. For example, in Figure 1In one embodiment, after detecting (which may include distance detection of the imaging object within the field of view) and imaging the sixth field of view, the system can return to detecting and imaging the first field of view as the multi-faceted rotating prism 10 rotates. In other words, by utilizing the rotation of the multi-faceted rotating prism 10, the variable field of view scanning system can sequentially and cyclically perform scanning detection and imaging between the first field of view, the second field of view, ..., and the last field of view (e.g., the sixth field of view).

[0068] Figure 2 A schematic diagram of the structure of a variable scanning system according to a second exemplary embodiment of the present disclosure is shown. Figure 2 Implementation examples and Figure 1 The embodiments are similar, but differ in that: Figure 2 In this embodiment, the probe beam emitted by the laser source is not projected onto the preset target area via the reflecting surface on the multi-faceted rotating prism 10; instead, the probe beam is projected onto the preset target area via a microelectromechanical scanning mirror (MEMS). Therefore, in the following description, to avoid redundancy, only key points will be highlighted. Figure 2 Implementation examples and Figure 1 The differences between the embodiments. Regarding Figure 2 Detailed descriptions of other components can be found in the relevant references. Figure 1 Description of the embodiments.

[0069] Specifically, such as Figure 2 As shown, the variable scanning system 200 includes at least a laser 21, a multi-faceted rotating prism 10, a photodetector 50, a microelectromechanical scanning mirror (MEMS) 70, and a controller (not shown).

[0070] Similar to Figure 1 Laser 20 in the middle, Figure 2 The laser 21 can be configured to emit a pulsed probe beam of a predetermined wavelength. In some embodiments, the emission power of the laser 21 is also adjustable. However, unlike... Figure 1 In the embodiments, Figure 2 The pulsed beam emitted by the laser 21 is guided to the microelectromechanical scanning mirror (MEMS) 70. In particular, in some embodiments, the probe beam emitted by the laser 21 can be shaped (e.g., collimated) before being guided to the MEMS 70.

[0071] The function of MEMS 70 is to reflect the probe beam incident on it to the preset target area 60, and to make the beam reflected by MEMS 70 scan different sub-regions within the target area 60 with a predetermined MEMS scanning field of view. The term "predetermined MEMS scanning field of view" can be defined by both a predetermined scanning angle range and a predetermined scanning orientation, and the term "predetermined scanning orientation" can be defined as the direction pointed to by the angle bisector of the predetermined scanning angle range in which the probe beam is actually scanned.

[0072] It is easy to understand that MEMS 70 can scan different sub-regions within the target area 60 with different predetermined MEMS scanning fields of view. Here, the term "different predetermined MEMS scanning fields of view" means that at least one of the predetermined scanning angle range and the predetermined scanning orientation is different, and "different predetermined MEMS scanning fields of view" also means that the scanned sub-regions are different from each other. In some embodiments, different predetermined MEMS scanning fields of view can be designed so that the scanned sub-regions do not overlap. In some embodiments, the depth of the scanned sub-region (or, in this case, the distance from MEMS 70 or the variable scanning system) can depend on the emission power of the probe beam emitted by laser 21. The greater the emission power of the probe beam, the deeper the scanned sub-region can be (i.e., the greater the distance from MEMS 70 or the variable scanning system).

[0073] In some embodiments, the MEMS 70 may have multiple different predetermined MEMS scanning fields of view (or, sub-regions scanned by the MEMS), which may correspond to the fields of view designed for the respective reflecting surfaces on the multi-faceted rotating prism 10 (see...). Figure 1 The descriptions of the fields of view designed for each reflective surface on the multi-faceted rotating prism 10 correspond one-to-one. Thus, in response to the MEMS 70 scanning the target region 60 with a predetermined MEMS scanning field of view, the echo signal of an object within the predetermined MEMS scanning field of view (or, the field of view designed for the corresponding reflective surface) of the target region 60 can be reflected to the photodetector 50 via the corresponding reflective surface on the multi-faceted rotating prism 10. Therefore, the photodetector 50 can generate an image corresponding to the predetermined MEMS scanning field of view (or, the field of view designed for the corresponding reflective surface) of the target region 60.

[0074] As an example, such as Figure 2As shown, the MEMS 70 can sequentially scan the target region 60 with different or the same predetermined scanning angle ranges, such as 40 degrees, 15 degrees, 5 degrees, 5 degrees, 15 degrees, and 40 degrees, but with different predetermined scanning orientations, defining a predetermined MEMS scanning field of view. In response, the echo signal from the predetermined MEMS scanning field of view can be received sequentially by the corresponding reflective surface on the multi-curved rotating prism 10 corresponding to the field of view angle ranges of, for example, 40 degrees, 15 degrees, 5 degrees, 5 degrees, 15 degrees, and 40 degrees, and the echo signal can be sequentially reflected to the photodetector 50 via the corresponding reflective surface.

[0075] In some embodiments, the echo signal may be incident on the photodetector 50 via lens 40. It is readily understood that providing lens 40 facilitates focusing and imaging of objects at a predetermined distance (i.e., the furthest imaging distance) on the photodetector 50. In still other embodiments, the echo signal may be incident on the photodetector 50 via both lens 40 and reflector 31. It is readily understood that providing reflector 31 can help make the variable field-of-view scanning system more compact.

[0076] Similar to Figure 1 In the embodiments, Figure 2 In the embodiments, the corresponding field of view (or the corresponding predetermined MEMS scanning field of view) of the corresponding reflecting surface on the multi-curved rotating prism 10 can have the same as... Figure 1 In the embodiments, similar or identical fields of view may have features such as having an axis of symmetry and a smaller field of view angle range as the field of view is closer to the axis of symmetry.

[0077] also, Figure 2 In the embodiments, the corresponding image of the corresponding field of view (or the corresponding predetermined MEMS scanning field of view) of the corresponding reflective surface on the multi-curved rotating prism 10 can also have a corresponding maximum imaging distance and minimum lateral imaging resolution. Similarly, the maximum imaging distance here can depend on the curvature of the corresponding reflective surface, the emission power of the laser, and / or the exposure time of the photodetector.

[0078] In some embodiments, different fields of view corresponding to different reflecting surfaces on the multi-faceted rotating prism 10 may have different or the same maximum imaging distance. In still other embodiments, different fields of view may have different or the same minimum lateral imaging resolution, regardless of whether the maximum imaging distances corresponding to these different fields of view are the same. Furthermore, similarly, in some embodiments, different maximum imaging distances may be combined with different field of view angle ranges. In particular, the smaller the field of view angle range, the farther the corresponding maximum imaging distance. Furthermore, in examples where the entire field of view has a symmetry axis, the closer the field of view is to the symmetry axis, the smaller the corresponding field of view angle range and / or the farther the corresponding maximum imaging distance.

[0079] The controller (not shown) can be coupled to at least the laser 21, MEMS 70, multi-faceted rotating prism 10 and photodetector 50 to control these components.

[0080] Specifically, the emission power of the laser 21, as well as the predetermined scanning angle and predetermined scanning orientation of the MEMS 70, can be controlled, for example, by a controller, to achieve sequential scanning of multiple predetermined MEMS scanning fields. Simultaneously, the rotation of the multi-faceted rotating prism 10 can be controlled by the controller, such that predetermined reflective surfaces on the multi-faceted rotating prism 10 (e.g., Figure 2 The first, second, third, fourth, fifth, or sixth reflective surfaces in the image are oriented to allow scanning from the corresponding predetermined MEMS scanning field of view (also corresponding to, for example,...). Figure 2 The echo signal of an object within the field of view corresponding to the first, second, third, fourth, fifth, or sixth reflective surface is incident on the predetermined reflective surface and reflected to the photodetector 50, so that the photodetector 50 generates an image corresponding to the MEMS scanning field of view. It should be noted that during the scanning process of each predetermined MEMS scanning field of view, the multi-surface rotating prism 10 and all reflective surfaces thereon remain stationary, so that the photodetector 50 can perform detection (which may include distance detection of objects within the field of view) and imaging of the field of view (i.e., the predetermined MEMS scanning field of view) corresponding to the predetermined reflective surface. Only after the photodetector 50 finishes detecting and / or imaging the predetermined field of view corresponding to the predetermined reflective surface, will the multi-surface rotating prism 10 be further rotated to detect the next predetermined field of view corresponding to the next predetermined reflective surface (i.e., the multi-surface rotating prism 10 is further rotated so that the next predetermined reflective surface is oriented to allow light from the field of view (or the next predetermined MEMS scanning field of view) corresponding to the next predetermined reflective surface to be reflected to the photodetector 50 via the next predetermined reflective surface).

[0081] exist Figure 2 In some embodiments, the multi-faceted rotating prism 10 is also operable to rotate clockwise or counterclockwise, thereby sequentially detecting the fields of view corresponding to multiple reflecting surfaces on the multi-faceted rotating prism 10 and generating corresponding images. In some embodiments, these images can be presented to the user individually. In still other embodiments, these images can be stitched together and presented to the user.

[0082] For example, in Figure 2In this embodiment, the multi-faceted rotating prism 10 can be operatively rotated (e.g., under the control of a controller) (counterclockwise or clockwise) such that the first reflective surface 1 is positioned facing the first field of view and remains stationary for a first time period. During this first time period, the MEMS 70 operatively scans the target area with a first predetermined MEMS scanning field of view having a first predetermined scanning angle range of, for example, 40 degrees, from the probe beam from the laser 21. The first reflective surface 1 can then reflect light corresponding to the first field of view (which corresponds to the predetermined MEMS scanning field of view, also having a field of view angle range of, for example, 40 degrees) to the photodetector 50 (e.g., via the lens 40 and the reflector 31) during the first time period, thereby generating a first image. Once the detection and / or imaging of the first field of view is complete, the multi-faceted rotating prism 10 can continue to rotate, for example, until the second reflective surface 2 is positioned facing the second field of view and remains stationary for a second time period. During the second time period, MEMS 70 can operatively scan the target area with a second predetermined MEMS scanning field of view having a second predetermined scanning angle range of, for example, 15 degrees. Then, the second reflective surface 2 can reflect the light of the corresponding second field of view (which corresponds to the predetermined MEMS scanning field of view and also has a field of view angle range of 15 degrees) to the photodetector 50 (e.g., via lens 40 and reflector 31) during the second time period. The photodetector 50 can then generate a second image, wherein the second time period is different from the first time period.

[0083] Similar to Figure 1 In this embodiment, the third field of view corresponding to the third reflecting surface 3 can be detected in a third time period, the fourth field of view corresponding to the fourth reflecting surface 4 in a fourth time period, the fifth field of view corresponding to the fifth reflecting surface 5 in a fifth time period, and the sixth field of view corresponding to the sixth reflecting surface 6 in a sixth time period, and each corresponding image can be generated. Similarly, the fields of view corresponding to more or fewer reflecting surfaces can be detected, and corresponding images can be generated.

[0084] Similar to Figure 1 In some embodiments, the first, second, third, fourth, fifth, and sixth time periods are different from each other or do not overlap. In some embodiments, a subsequent time period immediately follows a previous time period; for example, the second time period immediately follows the first time period, the third time period immediately follows the second time period, and so on. In this way, each field of view can be scanned at the fastest speed. In still other embodiments, it is also possible for a predetermined time interval to exist between the subsequent time period and the previous time period, depending on design requirements.

[0085] As the multi-faceted rotating prism 10 continues to rotate, after detecting and imaging the last field of view, it can return to detecting and imaging the first field of view. In other words, by utilizing the rotation of the multi-faceted rotating prism 10 and the synchronous scanning of the MEMS 70 with corresponding predetermined MEMS scanning fields of view, this variable field of view scanning system can sequentially and cyclically scan and detect and image between the first field of view, the second field of view, ..., and the last field of view (e.g., the sixth field of view).

[0086] Figure 3 A schematic diagram of the structure of a variable field-of-view scanning system according to a third exemplary embodiment of the present disclosure is shown. Figure 3 Implementation examples and Figure 2 The embodiments are similar, but differ only in that: Figure 3 In this embodiment, since the target area 60 itself can emit strong infrared radiation or the variable field-of-view scanning system itself has strong infrared detection capability, it does not require an additional laser source and corresponding MEMS to illuminate the object in the target area.

[0087] because Figure 3 The working principle of the embodiments and Figure 2 The principle of receiving echo signals from objects within the target region 60 and performing corresponding imaging in the embodiments is basically the same, so only a brief introduction is given below without going into details. For a detailed explanation of the working principle, please refer to [link to relevant documentation]. Figure 2 Description of the embodiments.

[0088] like Figure 3 As shown, the variable scanning system 300 may include a multi-faceted rotating prism 10, a photodetector 51, a lens 40, and a controller (not shown). As an example, the photodetector 51 may be an infrared focal plane detector. In some embodiments, infrared radiation signals originating from the target region 60, reflected by the multi-faceted rotating prism 10, can be reflected to the photodetector 50 via a reflector 31. In yet other embodiments, the reflector 31 may be omitted, thereby allowing infrared radiation signals originating from the target region, reflected by the multi-faceted rotating prism 10, to be directly reflected to the photodetector 50.

[0089] exist Figure 3 In some embodiments, the multiple reflecting surfaces on the multi-faceted rotating prism 10 can be designed for different fields of view. In some embodiments, these fields of view can be... Figure 1 and Figure 2 In the embodiments, the multiple reflecting surfaces on the multi-curved rotating prism 10 are designed for similar or identical fields of view, that is, they have characteristics such as symmetry axis characteristics, and the closer the field of view is to the symmetry axis, the smaller the corresponding field of view angle range.

[0090] Furthermore, in some embodiments, different fields of view corresponding to different reflecting surfaces on the multi-curved rotating prism 10 may have different or the same maximum imaging distance. In still other embodiments, different fields of view may have different or the same minimum lateral imaging resolution, regardless of whether the maximum imaging distances corresponding to these different fields of view are the same. Further still, similarly, in some embodiments, different maximum imaging distances may be combined with different field of view angle ranges. In particular, the smaller the field of view angle range, the farther the corresponding maximum imaging distance. Further still, in examples where the entire field of view has a symmetry axis, the closer the field of view is to the symmetry axis, the smaller the corresponding field of view angle range and / or the farther the corresponding maximum imaging distance.

[0091] The controller (not shown) can be coupled to at least the aforementioned multi-faceted rotating prism 10 and photodetector 51 to control these components.

[0092] Specifically, the rotation of the multi-faceted rotating prism 10 can be controlled by a controller, so that a predetermined reflecting surface on the multi-faceted rotating prism 10 (e.g., Figure 3 The first, second, third, fourth, fifth, or sixth reflective surfaces are oriented to allow infrared radiation signals from the corresponding field of view to be reflected to the photodetector 51 via the predetermined reflective surface, so that the photodetector 51 can generate an image of the corresponding field of view. It is important to note that during the infrared thermal imaging process of the photodetector 51 for different fields of view, the multi-faceted rotating prism 10 and all its reflective surfaces remain stationary, allowing the photodetector 51 to detect the field of view corresponding to the predetermined reflective surface. Only after the photodetector 51 finishes thermal imaging detection of the predetermined field of view corresponding to the predetermined reflective surface will the multi-faceted rotating prism 10 be further rotated to achieve thermal imaging detection of the next predetermined field of view corresponding to the next predetermined reflective surface (i.e., the multi-faceted rotating prism 10 is further rotated so that the next predetermined reflective surface is oriented to allow thermal imaging signals from the field of view corresponding to the next predetermined reflective surface to be reflected to the photodetector 51 via the next predetermined reflective surface).

[0093] For example, when performing infrared thermal imaging of a first field of view using the first reflective surface 1, the reflection from the first reflective surface 1 can be focused by the lens 40, then reflected by the reflector 31 and reaches the photodetector 51, which then generates an infrared thermal imaging result corresponding to the first field of view. During infrared thermal imaging of the first field of view using the first reflective surface 1, the multi-faceted rotating prism 10 and its reflective surfaces can remain stationary for a first time period, allowing the photodetector 51 to generate a first image. Once the detection of the first field of view is complete, the multi-faceted rotating prism 10 can continue to rotate, for example, until the second reflective surface 2 is positioned facing the second field of view and remains stationary for a second time period, allowing the photodetector 51 to generate a second image, where the second time period differs from the first time period. Similarly, the multi-faceted rotating prism can continue to rotate, thereby achieving the detection and imaging of fields of view corresponding to more reflective surfaces.

[0094] In an embodiment where the multi-faceted rotating prism 10 has six reflecting surfaces, the third field of view corresponding to the third reflecting surface 3 can be detected subsequently in a third time period, the fourth field of view corresponding to the fourth reflecting surface 4 in a fourth time period, the fifth field of view corresponding to the fifth reflecting surface 5 in a fifth time period, and the sixth field of view corresponding to the sixth reflecting surface 6 in a sixth time period, and corresponding images can be generated for each. Similar to... Figure 1 In some embodiments, the first, second, third, fourth, fifth, and sixth time periods are different from each other or do not overlap. In some embodiments, a subsequent time period immediately follows a previous time period; for example, the second time period immediately follows the first time period, the third time period immediately follows the second time period, and so on. In this way, scanning, detection, and imaging of each field of view can be performed at the fastest speed. In still other embodiments, it is also possible for a predetermined time interval to exist between a subsequent time period and a previous time period, depending on design requirements.

[0095] As the multi-faceted rotating prism 10 continues to rotate, after detecting and imaging the last field of view, it can return to detecting and imaging the first field of view. In other words, by utilizing the rotation of the multi-faceted rotating prism 10, this variable field of view scanning system can sequentially and cyclically scan and detect and image between the first field of view, the second field of view, ..., and the last field of view (e.g., the sixth field of view).

[0096] exist Figure 3 In some embodiments, the multi-faceted rotating prism 10 is also operable to rotate clockwise or counterclockwise, thereby sequentially detecting the fields of view corresponding to multiple reflecting surfaces on the multi-faceted rotating prism 10 and generating corresponding images. In some embodiments, these images can be presented to the user individually. In still other embodiments, these images can be stitched together and presented to the user.

[0097] The structure and operating principle of the variable field-of-view scanning system according to this disclosure have been described in detail above with reference to several exemplary embodiments. It will be understood that multiple different fields of view can be detected and imaged using the multi-faceted rotating prism designed in this disclosure. Specifically, the field-of-view angle ranges of these fields of view can vary depending on the field-of-view orientation. Specifically, although these fields of view differ from each other and / or have different maximum imaging distances, they can all maintain substantially the same minimum lateral imaging resolution. Specifically, the field-of-view angle ranges of these fields of view can be correlated with the maximum imaging distance of the corresponding field of view. For example, the greater the maximum imaging distance of the field of view, the smaller the field-of-view angle range. It is readily understood that, in long-distance detection, a design that reduces the field-of-view angle range can effectively improve the minimum lateral imaging resolution and reduce the light source power.

[0098] The following will refer to Figure 4 A flowchart is provided to provide a summary description of a variable field-of-view scanning method according to an example embodiment of the present disclosure.

[0099] like Figure 4 As shown, in box 410, first light from a first field of view is reflected by a first reflecting surface of a multi-faceted rotating prism, wherein the first reflecting surface is designed for the first field of view.

[0100] In frame 420, the first light is received using a photodetector to generate a first image corresponding to the first field of view;

[0101] In frame 430, second light from a second field of view is reflected by a second reflecting surface of the multi-faceted rotating prism, wherein the second reflecting surface is designed for the second field of view, and at least one of the field-of-view orientation and field-of-view angle range of the first field of view differs from the second field of view; and

[0102] In frame 440, the second light is received using the photodetector to generate a second image corresponding to the second field of view.

[0103] As previously described, in some embodiments, the multi-faceted rotating prism may further include more than two reflective surfaces, including at least a first reflective surface and a second reflective surface, wherein each reflective surface is designed for a different field of view. Specifically, the multiple fields of view corresponding to the multiple reflective surfaces can collectively constitute a full field of view, which may have an axis of symmetry. Specifically, the first field of view and the second field of view may be located on the same side of the axis of symmetry, with the second field of view being closer to the axis of symmetry than the first field of view, but having a smaller field of view angle range and a greater corresponding maximum imaging distance. More specifically, the multiple reflective surfaces may include a third reflective surface, which corresponds to a third field of view, and the photodetector can generate a third image for the third field of view, wherein the first, second, and third fields of view are located on the same side of the axis of symmetry, and the field of view angle ranges of the first, second, and third fields of view decrease sequentially, but the corresponding maximum imaging distances increase sequentially. As a non-limiting example, the farthest imaging distance corresponding to the first image is in the range of 20m-30m; the farthest imaging distance corresponding to the second image is in the range of 60m-75m; and the farthest imaging distance corresponding to the third image is in the range of 180m-220m. Although the farthest imaging distances differ for different fields of view, in some embodiments, the minimum lateral imaging resolution of these fields of view can be approximately the same; for example, the difference between the minimum lateral imaging resolution of the first image and the second image can be within ±10% of the minimum lateral imaging resolution of the first image.

[0104] In some embodiments, block 410 above may further include: keeping the multi-faceted rotating prism stationary during a first time period to reflect first light from the first field of view. Block 430 above may further include: keeping the multi-faceted rotating prism stationary during a second time period to reflect second light from the second field of view; wherein the second time period is different from the second time period.

[0105] In some embodiments, the rotation of the multi-faceted rotating prism can be controlled by a controller so that the reflection of light from the multiple reflective surfaces on the multi-faceted rotating prism in the multiple fields of view is performed sequentially and cyclically.

[0106] According to the design of this disclosure, the variable field-of-view scanning method is applicable to different application scenarios with or without a laser source. In embodiments where a laser source is required to illuminate a target area, the method may further include: emitting a probe light of a predetermined wavelength using a laser; reflecting the probe light onto the target area using the reflective surface of the multi-faceted rotating prism; and transmitting the probe light emitted from the laser using a beam splitter and reflecting light from the multi-faceted rotating prism onto the photodetector. Alternatively, the method may further include: emitting a probe light of a predetermined wavelength using a laser; receiving the probe light emitted from the laser using a microelectromechanical scanning mirror (MEMS); and projecting the probe light onto the target area in a scanning manner.

[0107] In an application scenario where a laser source is not required to illuminate the target area, the reflective surface of the multi-curved rotating prism can reflect infrared radiation signals from the corresponding field of view of the target area to the photodetector, without requiring a laser beam from an additional laser source to illuminate the target area.

[0108] The variable field-of-view scanning system and method of this disclosure have been described in detail above. It will be understood that the variable field-of-view scanning system and method of this disclosure can be applied to radar systems to achieve functions such as autonomous driving and autonomous navigation. Furthermore, the radar system can be included in a terminal device to provide radar detection or navigation functions to that terminal device. As a non-limiting example of a terminal device, it may include, for example, vehicles, drones, robots, etc. These terminal devices can be used in application scenarios such as autonomous vehicle driving, autonomous aircraft flight, intelligent machine manufacturing, or logistics warehouses.

[0109] It will also be understood that the methods and apparatus described above are merely examples. Although the steps of the method are described in a specific order in the specification, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. On the contrary, the order in which the steps are described can be changed. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0110] While the invention has been detailed and described in the accompanying drawings and foregoing description, these descriptions and descriptions should be considered illustrative or exemplary rather than restrictive; the invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments will be understood and practiced by those skilled in the art in practicing the claimed invention through study of the drawings, disclosure, and appended claims.

[0111] In the claims, the word "comprising" does not exclude other elements, and the indefinite articles "a" or "an" do not exclude a plurality. A single element or other unit may fulfill the function of multiple items set forth in the claims. The mere fact that certain features are recited only in dissimilar embodiments or dependent claims does not imply that combinations of these features cannot be used advantageously. Without departing from the spirit and scope of this application, the scope of protection of this application covers any possible combination of the various features recited in the various embodiments or dependent claims.

[0112] Furthermore, any reference numerals in the claims should not be construed as limiting the scope of the invention.

Claims

1. A variable field-of-view scanning system, characterized in that, include: A multi-faceted rotating prism has at least a first reflective surface and a second reflective surface, wherein the first reflective surface is designed for a first field of view and the second reflective surface is designed for a second field of view, at least one of the field of view orientation and field of view angle range of the first field of view is different from that of the second field of view, and the farthest imaging distance of the first field of view is different from that of the second field of view. A photodetector adapted to receive first light reflected from the first reflective surface to generate a first image corresponding to the first field of view, and to receive second light reflected from the second reflective surface to generate a second image corresponding to the second field of view, wherein the difference between the minimum lateral imaging resolution of the first image and the minimum lateral imaging resolution of the second image is less than or equal to ±10% of the minimum lateral imaging resolution of the first image.

2. The variable field-of-view scanning system according to claim 1, wherein the multi-surface rotating prism has more than two reflective surfaces, including a first reflective surface and a second reflective surface, the multiple reflective surfaces being designed for multiple fields of view that are different from each other.

3. The variable field of view scanning system according to claim 2, wherein the total field of view formed by the plurality of fields of view has an axis of symmetry, the first field of view and the second field of view are located on the same side of the axis of symmetry, and the second field of view is closer to the axis of symmetry than the first field of view, but has a smaller field of view angle range and / or a greater maximum imaging distance.

4. The variable field-of-view scanning system of claim 3, wherein the multi-surface rotating prism further comprises a third reflecting surface designed for a third field of view, the third reflecting surface being further configured to receive third light reflected from the third reflecting surface to generate a third image corresponding to the third field of view. The first field of view, the second field of view, and the third field of view are located on the same side of the axis of symmetry. The field of view angle ranges of the first field of view, the second field of view, and the third field of view decrease sequentially, but the corresponding farthest imaging distances increase sequentially.

5. The variable field-of-view scanning system according to claim 4, wherein the multi-surface rotating prism further includes a fourth reflective surface, the fourth reflective surface being designed for a fourth field of view, the fourth field of view being symmetrical to the first field of view about the axis of symmetry.

6. The variable field-of-view scanning system according to claim 4 or 5, wherein the farthest imaging distance corresponding to the first image is in the range of 20m-30m, the farthest imaging distance corresponding to the second image is in the range of 60m-75m, and the farthest imaging distance corresponding to the third image is in the range of 180m-220m.

7. The variable field-of-view scanning system according to any one of claims 1, 3-5, wherein the photodetector is configured to receive the first light and generate the first image during a first time period, and to receive the second light and generate the second image during a second time period, wherein the first time period is different from the second time period.

8. The variable field-of-view scanning system of claim 7, wherein during the transition period from the first time period to the second time period, the multi-faceted rotating prism can be operatively rotated to adjust the orientation of the multi-faceted rotating prism, while during the first time period and the second time period, the multi-faceted rotating prism remains stationary.

9. The variable field-of-view scanning system according to claim 1, further comprising: A laser is used to emit a probe beam to the multi-faceted rotating prism; as well as A beam splitter is arranged between the laser and the multi-faceted rotating prism for transmitting a probe beam emitted from the laser and reflecting light from the multi-faceted rotating prism to the photodetector.

10. The variable field-of-view scanning system according to claim 1, further comprising: Laser, used to emit a probe beam; A microelectromechanical scanning mirror is used to receive a probe beam emitted from the laser and project the probe beam onto a predetermined target area in a scanning manner. The multi-faceted rotating prism is configured to adjust the orientation of the corresponding reflective surface according to the scanned predetermined target area, so as to receive light from the predetermined target area and reflect the light from the predetermined target area to the photodetector.

11. A radar system comprising a variable field-of-view scanning system according to any one of claims 1-10.

12. A terminal device comprising the radar system according to claim 11.

13. The terminal device according to claim 12, wherein the terminal device includes at least one of a vehicle, a drone, and a robot.

14. A variable field-of-view scanning method based on a multi-surface rotating prism, characterized in that, include: The first light from the first field of view is reflected by the first reflecting surface of the multi-curved rotating prism, wherein the first reflecting surface is designed for the first field of view; The first light is received using a photodetector to generate a first image corresponding to the first field of view; The second light from the second field of view is reflected by the second reflecting surface of the multi-curved rotating prism, wherein the second reflecting surface is designed for the second field of view, wherein at least one of the field of view orientation and field of view angle range of the first field of view is different from the second field of view, and the farthest imaging distance of the first field of view is different from the farthest imaging distance of the second field of view. as well as The second light is received using the photodetector to generate a second image corresponding to the second field of view, wherein the difference between the minimum lateral imaging resolution of the first image and the minimum lateral imaging resolution of the second image is less than or equal to ±10% of the minimum lateral imaging resolution of the first image.

15. The variable field-of-view scanning method according to claim 14, wherein the reflection of the first light from the first field of view by the first reflecting surface of the multi-curved rotating prism comprises: The multi-faceted rotating prism is kept stationary during the first time period to reflect the first light from the first field of view; as well as The reflection of second light from the second field of view by the second reflecting surface of the multi-curved rotating prism includes: keeping the multi-curved rotating prism stationary during a second time period to reflect the second light from the second field of view; The second time period is different from the first time period.

16. The variable field-of-view scanning method according to claim 15, wherein the multi-surface rotating prism has more than two reflecting surfaces, including a first reflecting surface and a second reflecting surface, the multiple reflecting surfaces are designed for different multiple fields of view, the entire field of view formed by the multiple fields of view has an axis of symmetry, and the method further includes: The rotation of the multi-faceted rotating prism is controlled so that the reflection of light from the multiple reflective surfaces in the multiple fields of view is performed sequentially and cyclically.

17. The variable field of view scanning method according to claim 16, wherein the first field of view and the second field of view are located on the same side of the axis of symmetry, and the second field of view is closer to the axis of symmetry than the first field of view, but has a smaller field of view angle range and a farther corresponding farthest imaging distance.

18. The variable field-of-view scanning method of claim 16, wherein the multi-surface rotating prism further comprises a third reflecting surface designed for a third field of view, the third reflecting surface being further configured to receive third light reflected from the third reflecting surface to generate a third image corresponding to the third field of view. The first field of view, the second field of view, and the third field of view are located on the same side of the axis of symmetry. The field of view angle ranges of the first field of view, the second field of view, and the third field of view decrease sequentially, but the corresponding farthest imaging distances increase sequentially.

19. The variable field-of-view scanning method according to claim 18, wherein the farthest imaging distance corresponding to the first image is in the range of 20m-30m; the farthest imaging distance corresponding to the second image is in the range of 60m-75m; and the farthest imaging distance corresponding to the third image is in the range of 180m-220m.

20. The variable field-of-view scanning method according to claim 15, further comprising: Using a laser to emit a detection beam; The multi-faceted rotating prism reflects the detection beam to the target area via its reflective surface. as well as The detector beam emitted from the laser is transmitted through a beam splitter and reflected from the multi-faceted rotating prism to the photodetector.

21. The variable field-of-view scanning method according to claim 15, further comprising: Using a laser to emit a detection beam; The probe beam emitted from the laser is received using a microelectromechanical scanning mirror, and the probe beam is projected onto the target area in a scanning manner.

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