Patent ID: 12196855

DETAILED DESCRIPTION OF THE EMBODIMENTS

Technical solutions of the present disclosure will be described in detail with reference to the drawings. It will be appreciated that the described embodiments represent some, rather than all, of the embodiments of the present disclosure. Other embodiments conceived or derived by those having ordinary skills in the art based on the described embodiments without inventive efforts should fall within the scope of the present disclosure.

Here the illustrative embodiments will be described in detail, examples of which are shown in the accompanying drawings. In the following descriptions, when the accompanying drawings are involved, unless there are other express indication, the same numbers in different accompanying drawings indicate the same or similar elements. The implementation methods described in the following illustrative embodiments do not represent all implementation methods consistent with the present disclosure. Conversely, they are only examples of the device and method that are consistent with some aspects of the present disclosure that are described in the accompanying claims.

The technical terms used in the present disclosure are only for describing certain embodiments, and are not intended to limit the scope of the present disclosure. In addition, the singular forms “a,” “said,” and “the” are intended to include the plural forms as well, unless the context indicates otherwise. The term “and/or” used herein includes any suitable combination of one or more related items listed. Unless otherwise indicated, the terms “front,” “rear,” “lower portion,” and/or “upper portion” and similar terms are only used for the convenience of description, and do not limit a position or location, or a space orientation. The terms “connect” or “connection” and other similar terms do not limit the connection to be physical or mechanical connections. The connection may also include electrical connection. The connection may be direct connection or indirect connection. The term “plurality” means at least two.

The distance detection device of the embodiments of the present disclosure may include a light source, a scanning module, and a detector. The light source can be used to emit light beams. The scanning module may include a first optical module, a second optical module, and a driver. The first optical module and the second optical module may be sequentially positioned on the optical path of the light beam emitted by the light source. The driver can drive the movement of the first optical module and the second optical module to sequentially project the light beam emitted by the light source to different directions, and form a strip-shaped scanning range after being emitted from the scanning module. The detector can be used to covert at least a part of the returned light reflected by a detection object into an electrical signal. The electrical signal can be used to measure the distance between the detection object and the distance detection device. By using the first optical module and the second optical module, a strip-shaped scanning range can be scanned to perform horizontal and vertical scanning, and the scanning range is wide.

The distance detection device100of the present disclosure will be described in detailed below with reference to the drawings. In the case of no conflict, the features of the following embodiments and examples can be combined with each other.

FIG.1is a schematic diagram of a distance detection device100according to an embodiment of the present disclosure. The distance detection device100can be used to measure the distance and orientation of a detection object101to the distance detection device100. In one embodiment, the distance detection device100may include a radar, such as a lidar. The distance detection device100can measure the light propagation time between the distance detection device100and the detection object101, that is, the Time-of-Flight (TOF) of light, to detect the distance between the detection object101ad the distance detection device100.

The distance detection device100may include a light source103, a scanning module102, and a detector105. The light source103can be used to emit light beams. In one embodiment, the light source103can emit a laser beam. The light beams emitted by the light source103may be a narrow-bandwidth beam with a wavelength outside the visible light range, for example, a laser with a wavelength of 905 nm. In some other embodiments, the light source103may emit light beams in other wavelength bands, such as millimeter waves, microwaves, ultrasonic waves, and infrared.

The scanning module102can be used to change the propagation direction of the light beam emitted by the light source103and project it to the space around the distance detection device100. In some embodiments, the distance detection device100may also include a collimating lens104. The collimating lens104may be disposed between the light source103and the light source103and used to collimate the light beam emitted by the light source103into a parallel light119(or close to a parallel light). The scanning module102can change the transmission direction of the parallel light119and project the parallel light119to the space around the distance detection device100.

The scanning module102may include a first optical module130, a second optical module140, and drivers150and151. The first optical module130and the second optical module140may be sequentially positioned on the optical path of the light beam emitted by the light source103. The drivers150and151may be respectively used to drive the first optical module130and the second optical module140to move in order to project the light emitted by the light source103in different directions (for example, directions111and113), and scan a strip-shaped scanning range, thereby scanning the space around the distance detection device100. By using the first optical module and the second optical module, a strip-shaped scanning range can be scanned to perform horizontal and vertical scanning, and the scanning range is wide.

When the first optical module130moves, it may continuously change the direction of the light projected on it from the side close to the light source103. When the incident direction of the light beam projected from the side close to the light source103to the first optical module130does not change, the first optical module130changing the exit direction of the light beam may include causing the emitted light beam scan back and forth along a straight line (or substantially along an arc), or causing a constant rotation scan, in which the angle between the light beam and a central axis of the first optical module may change or remain unchanged or change during the rotation.

When the second optical module140moves, it may continuously change the exit direction of the light beam projected on it from the side close to the light source103. When the incident direction of the light beam projected from the side close to the light source103to the first optical module130does not change, the second optical module140changing the exit direction of the light beam may include causing the emitted light beam scan back and forth along a straight line (or substantially along an arc); or, causing the emitted light beam perform a constant rotation scan, in which the angle between the light beam and a central axis of the first optical module may change or remain unchanged or change during the rotation.

In some embodiments, the first optical module130may be close to the light source103relative to the second optical module140. The incident direction of the light beam emitted by the light source103onto the first optical module130may be substantially unchanged. The following description takes the first optical module130being close to the light source103relative to the second optical module140as an example.

In some embodiments, when the first optical module130and the second optical module140change the light path of the light beam in such a way that the light beam scans back and forth or scans repeatedly along a straight line (or substantially a straight line, or along an arc), in the scanning module102, the placement positions of the first optical module130and the second optical module140may be that the straight lines (or substantially straight lines or arcs) corresponding to the two optical modules form a certain included angle. In some embodiments, the included angle may be greater than 20°, or greater than 40°, or greater than 60° or, greater than 80°. In this way, the scanning module102may change the light beam emitted by the light source103, such that the light beam can scan a scanning range similar to a quadrilateral whose adjacent sides are not perpendicular.

In some embodiments, the included angle may be 90°, or close to 90°. In this way, when the incident direction of the light beam incident on the scanning module102from the side close to the light source103does not change, the scanning module102may change the light beam emitted by the light source103, such that the light beam can scan a scanning range similar to a quadrilateral whose adjacent sides are perpendicular to each other.

In some embodiments, the straight line scanned by one of the first optical module130and the second optical module140may be longer than the straight line scanned by the other optical module, such that when the first optical module130and the second optical module140are combined to change the direction of the light beam of the light source103, a scanning range similar to a strip may be scanned.

In some embodiments, one of the first optical module130and the second optical module140may scan along a straight line in the horizontal direction and the other optical module may scan along a straight line in the vertical direction, and the straight line in the horizontal direction may be longer than the straight line in the vertical direction. In this way, when the first optical module130and the second optical module140are combined to change the direction of the light beam of the light source103, a strip-shaped scanning range extending in the horizontal direction may be scanned.

In other embodiments, when the incident direction of the light beam projected from the side close to the light source103to the first optical module130does not change, the light beam emitted by the first optical module130may scan a straight line. When the incident direction of the light beam projected from the side close to the light source103to the second optical module140does not change, the light beam emitted by the second optical module140may scan a circle. When the first optical module130and the second optical module140are combined, a circular strip-shaped scanning range may be scanned. The width of the strip scanning range may be the length of the straight line scanning by the first optical module130.

In other embodiments, when the incident direction of the light beam projected from the side close to the light source103to the first optical module130does not change, the light beam emitted by the first optical module130may scan a straight line. When the incident direction of the light beam projected from the side close to the light source103to the second optical module140does not change, the light beam emitted by the second optical module140may scan an arc. When the first optical module130and the second optical module140are combined, an arc-shaped strip scanning range may be scanned. The width of the strip scanning range may be the length of the straight line scanning by the first optical module130.

In other embodiments, when the incident direction of the light beam projected from the side close to the light source103to the first optical module130does not change, the light beam emitted by the first optical module130may scan a circle. When the incident direction of the light beam projected from the side close to the light source103to the second optical module140does not change, the light beam emitted by the second optical module140may scan a straight line. When the first optical module130and the second optical module140are combined, a long strip-shaped scanning range extending in multiple spirals may be scanned.

In other embodiments, when the incident direction of the light beam projected from the side close to the light source103to the first optical module130does not change, the light beam emitted by the first optical module130may scan a circle. When the incident direction of the light beam projected from the side close to the light source103to the second optical module140does not change, the light beam emitted by the second optical module140may scan a circle. When the first optical module130and the second optical module140are combined, a circular strip-shaped scanning range extending in multiple spirals may be scanned.

In other embodiments, when the incident direction of the light beam projected from the side close to the light source103to the first optical module130does not change, the light beam emitted by the first optical module130may scan a circle. When the incident direction of the light beam projected from the side close to the light source103to the second optical module140does not change, the light beam emitted by the second optical module140may scan an arc. When the first optical module130and the second optical module140are combined, an arced strip-shaped scanning range extending in multiple spirals may be scanned.

In other embodiments, when the incident direction of the light beam projected from the side close to the light source103to the first optical module130does not change, the light beam emitted by the first optical module130may scan an arc. When the incident direction of the light beam projected from the side close to the light source103to the second optical module140does not change, the light beam emitted by the second optical module140may scan a straight line. When the first optical module130and the second optical module140are combined, a long strip with arc-shaped scanning range may be scanned.

In other embodiments, when the incident direction of the light beam projected from the side close to the light source103to the first optical module130does not change, the light beam emitted by the first optical module130may scan an arc. When the incident direction of the light beam projected from the side close to the light source103to the second optical module140does not change, the light beam emitted by the second optical module140may scan a circle. When the first optical module130and the second optical module140are combined, a circular-shaped strip scanning range arranged in arc lines may be scanned.

In other embodiments, when the incident direction of the light beam projected from the side close to the light source103to the first optical module130does not change, the light beam emitted by the first optical module130may scan an arc. When the incident direction of the light beam projected from the side close to the light source103to the second optical module140does not change, the light beam emitted by the second optical module140may scan an arc. When the first optical module130and the second optical module140are combined, an arc-shaped strip scanning range arranged in arc lines may be scanned.

In other embodiments, when the incident directions of the light beams respectively incident on the first optical module and the second optical module do not change, the first optical module and the second optical module may also scan other shapes, respectively. When the first optical module130and the second optical module140are combined, a strip-shaped scanning ranges of other shapes may be scanned.

In other embodiments, the second optical module140may be close to the light source103relative to the first optical module130. The incident direction of the light beam emitted by the light source103onto the second optical module140may be substantially unchanged. The combination of the second optical module140and the first optical module130may also scan various strip-shaped scanning ranges described above.

In some embodiments, the optical elements of the first optical module130and the second optical module140may be respectively driven by the respective drivers150and151.FIG.1only illustrates two drivers150and151, but it is not limited to this. The number of the drivers150and151may be the same as the number of moving optical elements of the first optical module130and the second optical module140. Each driver may correspond to each moving optical element, and each driver may be used to drive the corresponding optical element to move. In some embodiments, there may be moving optical elements in each optical module, and the number of drivers may be the same as the number of drivers or optical modules and correspond to each other. Each driver may be used to drive at least a part of the optical elements in the corresponding optical module to move. In some embodiments, optical elements with the same movement may be driven by the same driver, and optical elements with different movements may be driven by different drivers. For example, in one embodiment, the movements of the first optical module130and the second optical module140may be different, and the drivers150and151may be respectively connected to the first optical module130and the second optical module140. A controller154may control the drivers150and151, thereby controlling the optical elements in the first optical module130and the optical elements in the second optical module140to move in different ways.

The drivers150and151may include at least one of a motor, a gear transmission assembly, and a belt transmission assembly. In some embodiments, the drivers150and151may include motors to drive the optical elements to rotate or vibrate. The controller154may control the rotation speed and/or rotation of the motors. The motor may include a hollow motor, and the optical elements may be disposed in the hollow motor and directly driven by the motor. In other embodiments, the drivers150and151may be driven by a gear transmission assembly and/or a toothed belt transmission assembly. The gear transmission assembly and/or the toothed belt transmission assembly may be connected with the motor to transmit the power of the motor to the optical element.

In some embodiments, the first optical module130may include at least one of a light-transmitting prism and a reflective element, and the second optical module140may include at least one of a light-transmitting prism and a reflective element. By using the moving light-transmitting prisms and/or the reflective elements to project light to different directions, a strip-shaped scanning range may be scanned, such that the cost is low and the scanning accuracy is high. The light-transmitting prism can refract the light beam and change the direction of the light beam. The reflective element can reflect the light beam. In some embodiments, the reflective element may include at least one of a reflective mirror, a reflective prism, a polygon mirror, and a galvanometer. The reflective prism, such as a 45° reflective prism, may have a reflective surface to reflect the light beam. The polygon mirror may include at least two reflective surfaces extending at an angle, such as a polygon mirror in which five reflective surfaces form a pentagon. In some embodiments, the polygon mirror may be a prism, and a reflective surface may be arranged on side of the prism. The galvanometer may include a MEMS (micro-electro-mechanical system) galvanometer.

In some embodiments, the scanning length of the strip-shaped scanning range in the horizontal direction may be greater than the scanning height of in the vertical direction, such that a larger range can be scanned in the horizontal direction. In some embodiments, the distance detection device100may be mounted on a vehicle and used for scanning the detection objects around the vehicle. The distance detection device100may be used in vehicles such as unmanned vehicles and mobile cars, and scan obstacles around the vehicle. The scanning length in the horizontal direction is long, which can scan a wider range of the vehicle in the horizontal direction. In some other embodiments, the distance detection device100may be mounted on an unmanned aerial vehicle or other equipment.

In some embodiments, the second optical module140may be positioned on the side of the first optical module130away from the light source103. The light emitted by the light source103may pass through the first optical module130, project to the second optical module140, and project to the surrounding space of the distance detection device100through the second optical module140. In other embodiments, the second optical module140may be positioned on the side of the first optical module130close to the light source103. The light emitted by the light source103may pass through the second optical module140, project to the first optical module130, and project to the to the surrounding space of the distance detection device100through the first optical module130.

In some embodiments, at least a part of the returned light reflected by the detection object101may sequentially pass through the optical modules130and140in the scanning module102and return to the distance detection device100. The optical modules130and140may include the first optical module130and the second optical module140. At least a part of the returned light passing through the scanning module102may be indecent on the detector105directly or through other optical elements. When the light111projected by the scanning module102hits the detection object101, a part of the light may be reflected by the detection object101to the distance detection device100in a direction opposite to the projected light111. The scanning module102may receive a part of the returned light112reflected by the detection object101. A part of the returned light120reflected by the detection object101may not propagate to the scanning module102and may not be received by the scanning module102.

The detector105may be used to convert at least a part of the returned light reflected by the detection object101into an electrical signal. The electrical signal may be used to measure the distance between the detection object101and the distance detection device100. In the embodiment shown inFIG.1, at least a part of the returned light passing through the scanning module102is converted into an electrical signal by the detector105. In some embodiments, the detector105may include an avalanche photodiode. The avalanche photodiode is a highly sensitive semiconductor device that can convert an optical signal into an electrical signal by using the photocurrent effect.

In some embodiments, the detector105and the light source103may be positioned on the same side of the scanning module102. In some embodiments, the distance detection device100may include a condensing lens106, which may be positioned upstream of the detector105for converting the returned light to the detector105. In one embodiment, the distance detection device100may include a reflective element118. The reflective element108may be positioned between the collimating lens104and the scanning module102, and between the scanning module102and the condensing lens106. In one embodiment, the reflective element108may be used to reflect the returned light passing through the scanning module102to the condensing lens106and allow the light beam119collimated by the collimating lens104to pass through. In one embodiment, an opening or light-transmitting area corresponding to the positions of the light source103and the collimating lens104may be formed in the middle of the reflective element108, and the collimated light beam119may pass through the opening or the light-transmitting area. In another embodiment, the positions of the light source103and the detector105shown inFIG.1may be reversed. In some embodiments, the reflective element108may include a reflective mirror or a reflective prism.

In one embodiment, the condensing lens106and the collimating lens104may be independent lens. In another embodiment, the condensing lens106and the collimating lens104may be the same lens, which may be positioned on the side of the reflective element108facing the scanning module102. The lens may be used to collimate the light beam emitted by the light source103, and converge the returned light passing through the scanning module102to the detector105. In one embodiment, the condensing lens106and/or the collimating lens104may be coated with an anti-reflective coating to increase the intensity of the transmitted light beam.

In other embodiments, the detector105and the light source103may be positioned on opposite sides of the scanning module102. The returned light reflected by the detection object101may be condensed to the detector105through the optical element outside the scanning module102and the condensing lens106. The optical element, the condensing lens106, and the detector105may be positioned on the same side of the scanning module102.

In some embodiments, the distance detection device100may include a measuring circuit, such as a TOF unit107, which can be used to measure the TOF to measure the distance of the detection object101. For example, the TOF unit107may be used to calculate the distance through the formula of t=2Dcorresponding, where D represents the distance between the distance detection device and the detection object, c represents the speed of light, a t represents the total time it takes for light to project from the distance detection device100to the detection object101and returned from the detection object101to the distance detection device100. The distance detection device100can determine the time t based on the time difference between the light emitted by the light source103and the return light received by the detector105, and then determine the distance D. The distance detection device100can also detect the orientation of the detection object101relative to the distance detection device100. The distance and orientation detected by the distance detection device100can be used for remote sensing, obstacle avoidance, surveying and mapping, modeling, navigation, and the like.

In some embodiments, the light source103may include a laser diode, and a nanosecond-level laser pulse sequence may be emitted through the laser diode. For example, the laser pulse emitted by the light source103may last 10 ns. Further, the laser pulse receiving time may be determined. For example, by detecting the rising edge time and/or falling edge time of the electrical signal pulse to determine the laser pulse receiving time. In some embodiments, a multi-stage amplification of the electrical signal may be performed. In this way, the distance detection device100may calculate the TOF by using the pulse receiving time information and the pulse sending time information, thereby determining the distance from the detection object101to the distance detection device100.

In some embodiments, the distance detection device100may include a window (not shown) positioned outside the scanning module102. The light projected by the scanning module102may be projected to the outside space through the window, and the returned light may pass through the window to the scanning module102. The light source103, the scanning module102, the detector105, the collimating lens104, the condensing lens106, and the reflective element108may be packaged in a packaging device, and the window may be formed in the packaging device. In one embodiment, the window may include a glass window. In one embodiment, a long-wave pass film may be plated on the window. In one embodiment, the long-wave pass film may have a low transmittance of visible light from about 400 nm to 700 nm, and a high transmittance to the light of the emitted light beam band.

In one embodiment, at least one of the inner surface of the window, the surface of the scanning module102, the mirror of the detector105, the surface of the collimating lens104, the surface of the condensing lens106, and the surface of the reflective element108may be coated with a positive water membrane. The positive water membrane may be a hydrophilic membrane. The oil volatilized when the distance detection device100heats up can be spread flat on the surface of the positive water membrane to prevent oil from forming oil droplets on the surface of the optical elements, thereby avoiding the influence of oil droplets on the light propagation. In some embodiments, the positive water membrane may be coated on the surface of other optical elements of the distance detection device100.

In some embodiments, the first optical module130may be a light-transmitting prism, and the second optical module140may be a reflective element.FIG.2is a schematic diagram of an embodiment of the first optical module130and the second optical module140of the scanning module102shown inFIG.1. In the embodiment shown inFIG.2, the second optical module140is positioned on the side of the first optical module130away from the light source103, and the reflective element140is positioned on the side of the light-transmitting prism130away from the light source103.

The light-transmitting prism130may rotate around a rotation axis131. In the embodiment shown inFIG.2, thickness of the light-transmitting prism130may vary along the radial direction, such as a wedge-angle prism. In one embodiment, an incident surface132of the light-transmitting prism130receiving the light beam from the light source103may be perpendicular to the rotation axis131, and the exit surface133relative to the incident surface132may be inclined relative to the incident surface132, and inclined relative to the rotation axis131. In other embodiments, the incident surface132may be inclined with respect to the rotation axis131. The light beam emitted by the light source103may scan the FOV range through the 360° rotation of the light-transmitting prism130. In another embodiment, the incident surface132of the light-transmitting prism130may be inclined to the rotation axis131, and the exit surface133may be perpendicular to the rotation axis131. In some other embodiments, the light-transmitting prism130may be a prism with other shapes, for example, a prism whose indecent surface and/or exit surface are curved.

In the embodiment shown inFIG.2, the reflective element140may be a reflective mirror and a reflective prism. In one embodiment, the reflective element140may rotate around a rotation axis141. The rotation axis141may be coaxial with the rotation axis131or a different axis. The rotation axis141and the rotation axis131may be parallel or formed at a certain angle, for example, at an angle of 90°. The reflective element140and the light-transmitting prism130may be driven by the same driver, or driven by different drivers. In one embodiment, the rotation speed of the reflective element140may be different from the rotation speed of the light-transmitting prism130, and may be driven by different drivers. In one embodiment, the rotation speed of the reflective element140may be opposite to the rotation speed of the light-transmitting prism130, such that the scanned point cloud is more uniform.

The reflective element140may include a reflective surface that reflects the light beam. The reflective surface may be inclined with respect to the rotation axis141of the reflective element140and face the first optical module130. The reflective surface may be a plane such as shown inFIG.2, or a curved surface, or it may be a reflective surface of a polygon mirror.

In one embodiment, the reflective element140may rotate 360° around the rotation axis141. In an embodiment where the reflective element140is a plane, when the incident direction of the light beam incident on the reflective element140does not change, the reflective element140may scan a circle. When the reflective element140and the light-transmitting prism130are combined, the light beam emitted from the light-transmitting prism130may be sequentially projected in different directions within a 360° circular area, and scanning the circular-shaped strip scanning range extending in multiple spirals.FIG.3is a scanning pattern scanned by this embodiment, which can scan a circle in the horizontal direction with a large scanning range. In order to see the scan pattern clearly, the scan pattern shown inFIG.3is relatively sparse. However, in actual scanning, a very dense scanning pattern may be realized by the rotation speed of the reflective element140and/or the light-transmitting prism130to ensure the accuracy of the distance detection.FIG.3is merely an example scanning pattern, and different patterns may be scanned by changing the rotation speed of the reflective element140and/or the light-transmitting prism130. Similar toFIG.3, the scanning pattern in the subsequent drawings are also relatively sparse, and are merely example scanning patterns.

In another embodiment, the reflective element140may continue to rotate around the rotation axis141within an angle less than 360°, or the reflective element140may rotate 360° around the rotation axis141, and the reflective surface of the reflective element140may be set, such as a polygon mirror, to scan an arc-shaped strip scanning range less than 360°. For example, it may scan the horizontal arc-shaped scanning range within a certain angle range in the forward direction of the vehicle to detect obstacles in the forward direction of the vehicle.

In another embodiment, the reflective element140may vibrate. The angle of the reflective element140relative to the rotation axis131of the light-transmitting prism130may be sequentially changed, such that the scanning pattern shown inFIG.4may be scanned, and a substantially rectangular scanning range may be scanned.

FIG.5is a schematic diagram illustrating a first optical module230and a second optical module240according to another embodiment of the present disclosure. The first optical module230may be a light-transmitting prism and the second optical module240may be a reflective element. The light-transmitting prism230shown inFIG.5is similar to the light-transmitting prism130shown inFIG.2, and will not be repeated here.

In the embodiment shown inFIG.5, the reflective element240is a polygon mirror, and the rotation axis of the polygon mirror240is perpendicular to a rotation axis231of the first optical module230. In the illustrated embodiment, the rotation axis231of the light-transmitting prism230extends vertically in the paper plane, and the rotation axis of the polygon mirror240is perpendicular to the paper plane. A plurality of reflective surfaces of the polygon mirror240may be arranged around the rotation axis. The polygon mirror240may rotate in the direction of the arrow shown inFIG.5, or in the opposite direction of the arrow. In another embodiment, the rotation axis of the polygon mirror240may be perpendicular to the rotation axis231of the light-transmitting prism230in the paper plane, or perpendicular to the rotation axis231of the paper plane in other planes. In another embodiment, the rotation axis of the polygon mirror240may be parallel to the rotation axis231of the light-transmitting prism230, or may be coaxial with the rotation axis231.

In the embodiment shown inFIG.5, the polygon mirror240is positioned on the side of the light-transmitting prism230away from the light source103. The polygon mirror240may be a prism, the rotation axis may be the central axis of the prism, and it may be perpendicular to the rotation axis231of the light-transmitting prism230in a plane perpendicular to the paper plane or other planes. The reflective surface of the polygon mirror240can alternately reflect the light beam emitted by the light-transmitting prism230. When the incident direction of the light beam incident on the polygon mirror does not change, the polygon mirror240may scan an arc. The polygon mirror240may reflect the light beam emitted by the light-transmitting prism230, and may scan an arc-shaped strip scanning range extending in multiple spirals. For example, inFIG.5, the cross-section is a regular pentagonal polygon mirror240, which scans a strip-shaped scanning range of a 72° angle range. The polygon mirror240is not limited to a polygon mirror with a regular pentagon in cross section, and may also be a polygon mirror with other shapes, such as a polygon mirror with a triangular cross section, a polygon mirror with a with a square cross section, and a polygon mirror with a with a hexagon cross section.

In another embodiment, the polygon mirror may be a prism pedestal, the smaller top surface of the prism pedestal may face the first optical module230, and the side surface of the prism pedestal may be a reflective surface inclined toward the first optical module230. The rotation axis of the polygon mirror may be parallel to the rotation axis231of the light-transmitting prism230or coaxial with the rotation axis231. The rotation axis of the polygon mirror may be perpendicular to its top surface, or intersect with the top surface by less than 90°. When the incident direction of the light beam incident on the polygon mirror does not change, the polygon mirror may scan an arc. The polygon mirror may reflect the light beam emitted by the first optical module230, and may scan an arc-shaped strip scanning range extending in multiple spirals.

FIG.6is a schematic diagram illustrating a first optical module330and a second optical module340according to another embodiment of the present disclosure. The first optical module330may be a light-transmitting prism and the second optical module340may be a reflective element. In the embodiment shown inFIG.6, the second optical module340is positioned on the side of the first optical module330close to the light source103, and the reflective element340is positioned on the side of the light-transmitting prism330close to the light source103.

In the embodiment shown inFIG.6, the reflective element340is a galvanometer, such as a MEMS galvanometer, and the reflective surface of the galvanometer340faces the first optical module330. In one embodiment, the galvanometer340may vibrate left and right within the paper plane, and vibrate in the direction of the arrow inFIG.6. In another embodiment, the galvanometer340may vibrate in a plane perpendicular to the paper plane. The galvanometer340may reflect the light beam emitted by the light source103and scan a straight line. The light beam reflected by the galvanometer340may be projected to the light-transmitting prism330, and the light-transmitting prism330may rotate around a rotation axis331to scan a long strip-shaped scanning range extending in multiple spirals, such as the strip-shaped scanning range shown inFIG.7. The shape and arrangement of the light-transmitting prism330shown inFIG.6are similar to the light-transmitting prism130. In other embodiments, the light-transmitting prism330may have other shapes and/or arrangement method.

In another embodiment, the second optical module340may be positioned on the side of the first optical module330away from the light source103. The galvanometer340may be positioned on the side of the light-transmitting prism330away from the light source103, and may scan a strip-shaped scanning area. The scanning area may be different from the scanning area shown inFIG.7.

In other embodiments, the first optical module may include at least two light-transmitting prisms, and the at least two light-transmitting prisms may include a first light-transmitting prism and a second light-transmitting prism.FIG.8is a schematic diagram of a first optical module430and a second optical module440. In the embodiment shown inFIG.8, the first optical module430includes a first light-transmitting prism434and a second light-transmitting prism435. The first light-transmitting prism434and the second light-transmitting prism435may rotate around the same rotation axis431, or respectively rotate around two parallel rotation axes. The first light-transmitting prism434and the second light-transmitting prism435may rotate in opposite directions, the rotation speed difference may be less than a rotation speed threshold, and a substantially straight line. In one embodiment, the rotations speeds of the first light-transmitting prism434and the second light-transmitting prism435may be the same.

In some embodiments, at least one time during the rotation of the first light-transmitting prism434and the second light-transmitting prism435, a mirror surface4341of the first light-transmitting prism434away from the second light-transmitting prism435and a mirror surface4351of the second light-transmitting prism435away from the first light-transmitting prism434may be symmetrical with respect to a plane perpendicular to the rotation axis431of the first light-transmitting prism434and the second light-transmitting prism435. A mirror surface4342of the first light-transmitting prism434close to the second light-transmitting prism435and a mirror surface4352of the second light-transmitting prism435close to the first light-transmitting prism434may be symmetrical with respect to a plane perpendicular to the rotation axis431.

The thickness of the first light-transmitting prism434may change in the radial direction, and the thickness of the second light-transmitting prism435may change in the radial direction. In the embodiment shown inFIG.8, the mirror surfaces4341and4342of the first light-transmitting prism434and mirror surfaces4351and4352of the second light-transmitting prism435are both flat surfaces. The mirror surfaces4341and4342of the first light-transmitting prism434and mirror surfaces4351and4352of the second light-transmitting prism435may intersect the rotation axis431. In one embodiment, the mirror surface4341of the first light-transmitting prism434and the mirror surface4351of the second light-transmitting prism435may be inclined to the rotation axis431, and the mirror surface4342of the first light-transmitting prism434and the mirror surface4352of the second light-transmitting prism435may be perpendicular to the rotation axis431. In other embodiments, the mirror surface4341of the first light-transmitting prism434and the mirror surface4351of the second light-transmitting prism435may be curved surfaces, and/or the mirror surface4342of the first light-transmitting prism434and the mirror surface4352of the second light-transmitting prism435may be curved surfaces.

The second optical module440may include at least one light-transmitting prism. In the embodiment shown inFIG.8, the second optical module440is a light-transmitting prism rotating around a rotation axis441. The rotation axis441of the light-transmitting prism of the second optical module440, the rotation axis of the first light-transmitting prism434, and the rotation axis of the second light-transmitting prism435may all be coaxial or parallel, or two of them may be coaxial and parallel to the other. The rotation speed of the light-transmitting prism440may be different from the rotation speed of the first light-transmitting prism434and the second light-transmitting prism435. In the embodiment shown inFIG.8, the second optical module440is positioned on the side of the first optical module430away from the light source103. The first optical module430and the second optical module440may scan a long strip-shaped scanning range extending in multiple spirals. By adjusting the rotation speed of the first optical module430and/or the second optical module440, patterns such as shown inFIG.9andFIG.10can be scanned.

When the prism rotation speed is limited, the first light-transmitting prism434and the second light-transmitting prism435may rotate in opposite directions at the same speed, and the scanned scan line may be along the horizontal direction. Moreover, the speed of the first light-transmitting prism434and the second light-transmitting prism435may be greater than the speed of the light-transmitting prism of the second optical module440, and the point cloud scanned in this way may be mainly arranged in the horizontal direction, as shown inFIG.9, which can be used in areas such as autonomous driving. Of course, when the rotation speed of the prims434,435, and440can reach very high speed, the point cloud can be very dense. The rotation speed of the prims434,435, and440may not be restricted by the rotation speed restriction condition when the prism rotation speed is limited.

In one embodiment, the wedge angles of the three light-transmitting prisms434,435, and440may be respectively α1˜α3, the refractive indexes may be respectively n1˜n3, and the rotation angles may be respectively θ1˜θ3. The rotation angle of the light-transmitting prism may be defined as the angle between the direction of the prism wedge angle and the x-axis. The parameters of the three light-transmitting prisms434,435, and440may be the same or different.

In one embodiment, the geometric dimensions and material refractive index of the first light-transmitting prism434and the second light-transmitting prism435may be the same, such as α1=α2 and n1=n2. When the first light-transmitting prism434and the second light-transmitting prism435rotate and satisfy the condition of θ1+θ2=2n π (n is an integer), after the light passes through the first light-transmitting prism434and the second light-transmitting prism435, the exit direction may scan in the horizontal direction. The scanning range may be related to the wedge angle and refractive index of the first light-transmitting prism434and the second light-transmitting prism435, which may be similar to F1=2(n1−1)α1.

After the light passes through the third light-transmitting prism440, it may rotate around the incident direction. The deflection angle of the rotation may be related to the wedge angle and refractive index of the prism, and the deflection angle may be similar to F3=(n3−1)α3. After the light passes through the three prisms434,435, and440, the exit direction may be equivalent to the superposition of the horizontal scanning and the circular scanning, such that a flat FOV may be formed. By controlling the refractive index and wedge angle parameters of the prisms, the FOC in two directions may be flexibly adjusted. The horizontal and vertical FOV ranges may be respectively similar to:
FOVH=F1+F3=2(n1−1)α1+(n3−1)α3
FOVV=F3=(n3−1)α3

The shape and arrangement of the light-transmitting prism of the second optical module shown inFIG.8are similar to the light-transmitting prism of the first optical module130shown inFIG.2. In other embodiments, the light-transmitting prism of the second optical module440may have other shapes and/or arrangement methods. In one embodiment, the second optical module440may be positioned on the side of the first optical module430close to the light source103. The first light-transmitting prism434and the second light-transmitting prism435may be positioned on the side of the light-transmitting prism440away from the light source103.

In other embodiments, the first light-transmitting prism434and the second light-transmitting prism435may rotate at different speeds to scan the strip-shaped scanning range, which may be different from the scanning range of the first optical module430and the second optical module440shown inFIG.8.

FIG.11is a schematic diagram of a first optical module530and a second optical module540according to another embodiment of the present disclosure. The first optical module530may include a first light-transmitting prism534and a second light-transmitting prism535. The first optical module530may be similar to the first optical module430shown inFIG.8, which will not be repeated here. Compared with the embodiment shown inFIG.8, the second optical module540of the embodiment shown inFIG.11includes at least two light-transmitting prisms, and the at least two light-transmitting prisms includes a third light-transmitting prism544and a fourth light-transmitting prism545.

In the embodiment shown inFIG.11, the third light-transmitting prism544and the fourth light-transmitting prism545can rotate around the same rotation axis541, or rotate around two parallel rotation axes. The rotation axes of the third light-transmitting prism544, the fourth light-transmitting prism545, the first light-transmitting prism534, and the second light-transmitting prism535may all be coaxial or parallel, or at least two of them may be coaxial and parallel to the other rotation axis. The third light-transmitting prism544and the fourth light-transmitting prism545may rotate in opposite directions, and the rotation speed difference may be less than the rotation speed threshold. In one embodiment, the rotation speeds of the third light-transmitting prism544and the fourth light-transmitting prism545may be the same. The third light-transmitting prism544may be close to the first optical module530and configured to receive the light emitted from the second light-transmitting prism535of the first optical module530. The fourth light-transmitting prism545may be configured to receive the emitted light of the third light-transmitting prism544. The first optical module530shown inFIG.11may scan substantially a straight line. When the direction of the incident light incident on the second optical module540does not change, the second optical module540may scan substantially a straight line and intersect the straight line scanned by the first optical module530. When the first optical module530and the second optical module540are combined, the scanning range of a rectangular or other parallelogram may be scanned, such that scanning patterns shown inFIG.11andFIG.12may be scanned.

Similar to the first light-transmitting prism534and the second light-transmitting prism535, the thickness of the third light-transmitting prism544may change along the radial direction, and the thickness of the fourth light-transmitting prism545may change along the radial direction. In some embodiments, at least one time during the rotation of the third light-transmitting prism544and the fourth light-transmitting prism545, a mirror surface5441of the third light-transmitting prism544away from the fourth light-transmitting prism545and a mirror surface5451of the fourth light-transmitting prism545away from the third light-transmitting prism544may be symmetrical with respect to a plane perpendicular to the rotation axis541of the third light-transmitting prism544and the fourth light-transmitting prism545. A mirror surface5442of the third light-transmitting prism544close to the fourth light-transmitting prism545and a mirror surface5452of the fourth light-transmitting prism545close to the third light-transmitting prism544may be symmetrical with respect to a plane perpendicular to the rotation axis541of the third light-transmitting prism544and the fourth light-transmitting prism545.

The mirror surface5441of the third light-transmitting prism544and the mirror surface5451of the fourth light-transmitting prism545may be flat or curved, and the mirror surface5442of the third light-transmitting prism544and the mirror surface5452of the fourth light-transmitting prism545may be flat or curved. In the embodiment shown inFIG.11, the mirror surface5441of the third light-transmitting prism544and the mirror surface5451of the fourth light-transmitting prism545are both curved, and the mirror surface5442of the third light-transmitting prism544and the mirror surface5452of the fourth light-transmitting prism545are both flat. In another embodiment, the third light-transmitting prism544and the fourth light-transmitting prism545may be similar to the first light-transmitting prism534and the second light-transmitting prism535. In other embodiment, the rotation speeds of the third light-transmitting prism544and the fourth light-transmitting prism545may be different from the rotation speeds of the first light-transmitting prism534and the second light-transmitting prism535.

The wedge angles of the four prisms534,535,544, and545may be respectively α1˜α4, the refractive indexes may be respectively n1˜n4, and the rotation angles may be respectively θ1˜θ4. The rotation angle of the prism may be defined as the angle between the direction of the prism wedge angle and the x-axis. The parameters of the four prisms534,535,544, and545may be the same or different.

In one embodiment, the geometric dimensions and material refractive indexes of the first light-transmitting prism534and the second light-transmitting prism535may be the same, and the geometric dimensions and material refractive indexes of the third light-transmitting prism544and the fourth light-transmitting prism545may be the same. As such, α1=α2, α3=α4, n1=n2, and n3=n4.

When the first light-transmitting prism534and the second light-transmitting prism535rotate and satisfy the condition of θ1+θ2=2n π (n is an integer), after the light passes through the first light-transmitting prism534and the second light-transmitting prism535, the exit direction may scan in the horizontal direction. The scanning range (i.e., the horizontal direction FOV) may be related to the wedge angle and refractive index of the first light-transmitting prism534and the second light-transmitting prism535, which may be similar to FOVH=2 (n1−1) α1.

When the third light-transmitting prism544and the fourth light-transmitting prism545rotate and satisfy the condition of θ3+θ4=2 (n+1) π (n is an integer), the light may scan the vertical direction after passing through the third light-transmitting prism544and the fourth light-transmitting prism545. The scanning range may be similar to FOVv=2 (n2−1)α1.

Therefore, by designing the wedge angle and refractive index of the prism, the horizontal and vertical FOV may be designed flexibly.

In other embodiments, the third light-transmitting prism544and the fourth light-transmitting prism545may rotate at different speeds and scan the scanning range different from the scanning range of the first optical module530and the second optical module540shown inFIG.11. In other embodiments, the second optical module540may include three or more light-transmitting prisms. In other embodiments, the rotation speeds of the first light-transmitting prism534and the second light-transmitting prism535may be different.

FIG.14is a schematic diagram of a first optical module630and a second optical module640according to another embodiment of the present disclosure. The first optical module630may include a first light-transmitting prism634and a second light-transmitting prism635. The shape and arrangement method of the first optical module630may be similar to the shape and arrangement method of the first optical modules430and530shown inFIG.8andFIG.11, and will not be repeated here.

In the embodiment shown inFIG.14, the second optical module640includes a reflective element. In this embodiment, the reflective element640is a reflective mirror. The reflective mirror640shown inFIG.14may be similar to the reflective mirror140shown inFIG.2, in which the reflective mirror640may face the first optical module630and rotate around the rotation axis641. For detailed description, reference may be made to the corresponding description inFIG.2, which will not be repeated here. In another embodiment, the reflective mirror640may be a reflective prism. In the embodiment shown inFIG.14, the reflective element640is positioned on the side of the first optical module630away from the light source103and reflects the light emitted by the second light-transmitting prism635of the first optical module630. In another embodiment, the reflective element640may be positioned on the side of the first optical module630close to the light source103.

In the embodiment shown inFIG.14, the rotation speed of one of the first light-transmitting prism634and the second light-transmitting prism635may be equal to the rotation speed of the reflective element640plus a set rotation speed, and the rotation speed of the other may be equal to the rotation speed of the reflective element640minus the set rotation speed. In one example, the rotation speed of the reflective element640may be a, the set rotation speed may be w, the rotation speed of the second light-transmitting prism635may be a-w, and the rotation speed of the second light-transmitting prism635may be a+w. In another example, the rotation speed of the second light-transmitting prism635may be a+w, and the rotation speed of the second light-transmitting prism635may be a-w. In one embodiment, the reflective element640may rotate 360° and scan the scanning range of a circular strip. In another embodiment, the reflective element640may rotate repeatedly within an angle range less than 360° or perform a 360° rotation through a polygon mirror to scan an arc-shaped strip scanning range of a certain angle range. In yet another embodiment, the reflective element640may vibrate and scan a rectangular strip scanning range.

FIG.15is a schematic diagram illustrating a first optical module730and a second optical740module according to another embodiment of the present disclosure. The first optical module730may include a first light-transmitting prism734and a second light-transmitting prism735. The first optical module730may be similar to the first optical modules430and530shown inFIG.8andFIG.11. The rotation speed difference between the first light-transmitting prism734and the second light-transmitting prism735may be smaller than the rotation speed threshold and the rotation direction may be opposite. In one embodiment, the rotation speeds of the first light-transmitting prism734and the second light-transmitting prism735may be the same. The second optical module740may include a reflective element. In the embodiment shown inFIG.15, the reflective element740is a polygon mirror, similar to the polygon mirror shown inFIG.5, and combined with the first optical module730, it can scan an arc-shape strip scanning range. The polygon mirror may be a prism, for detailed description, reference may be made to the above embodiment.

In the embodiment shown inFIG.15, the polygon mirror740is positioned on the side of the first optical module730away from the light source103.

FIG.16is a schematic diagram illustrating a first optical module830and a second optical module840according to another embodiment of the present disclosure. The first optical module830may include a first light-transmitting prism834and a second light-transmitting prism835. The first light-transmitting prism834and the second light-transmitting prism835shown inFIG.16may be similar to the third light-transmitting prism544and the fourth light-transmitting prism545shown inFIG.11. In other embodiments, the first light-transmitting prism834and the second light-transmitting prism835may be similar to the first light-transmitting prisms434,534,634, and734, and the second light-transmitting prisms435,535,635, and735shown inFIGS.8,11,14, and15, respectively.

The first optical module830may be positioned on the side of the second optical module840away from the light source103. The second optical module840may include a reflective element. In the embodiment shown inFIG.16, the reflective element840is a galvanometer, similar to the galvanometer340shown inFIG.6. The galvanometer840can reflect the light beam emitted by the light source103, and the light beam reflected by the galvanometer840may sequentially pass through the first light-transmitting prism834and the second light-transmitting prism835, and scan a rectangular scanning range.

In another embodiment, the galvanometer840may be positioned on the side of the first optical module830away from the light source103. The light beam emitted by the light source103may sequentially pass through the first light-transmitting prism834and the second light-transmitting prism835, project to the galvanometer840, and reflected by the galvanometer840.

In some embodiments, the first optical module may include a reflective element, and the second optical module may include a reflective element. In some embodiments, the first optical module may include a galvanometer, and the second optical module may include at least one of a reflective mirror, a reflective prism, and a polygon mirror.

FIG.17is a schematic diagram illustrating a first optical module930and a second optical module940according to another embodiment of the present disclosure. In the embodiment shown inFIG.17, the first optical module930is a galvanometer, and the second optical module940is a reflective mirror. The galvanometer930may be positioned on the side of the reflective mirror940close to the light source103. When the reflective mirror940rotates 360° around the rotation axis941, in combination with the galvanometer930, a circular strip-shaped scanning range may be scanned. When the reflective mirror rotates repeatedly within an angle range less than 360°, it may scan a certain angle range of an arc-shaped strip scanning range. When the reflective mirror vibrates, a rectangular strip-shaped scanning range may be scanned. In another embodiment, the galvanometer930may be positioned on the side of the reflective mirror940away from the light source103. In another embodiment, the/640may be a reflective prism.

FIG.18is a schematic diagram illustrating a first optical module1030and a second optical module1040according to another embodiment of the present disclosure. The embodiment shown inFIG.18is similar to the embodiment shown inFIG.17, and the first optical module1030is a galvanometer. Compared with the embodiment shown inFIG.17, in the embodiment shown inFIG.18, the second optical module1040is a polygon mirror. The polygon mirror1040may be positioned on the side of the galvanometer1030away from the light source103. The polygon mirror1040may reflect the light beam reflected by the galvanometer1030, and scan an arc-shaped strip scanning range. In another embodiment, the polygon mirror1040may be positioned on the side of the galvanometer1030close to the light source103.

In some other embodiments, the first optical module1030and the second optical module1040may be one or a combination of two or more of a galvanometer, reflective mirror, reflective prism, and polygon mirror.

FIG.19is a schematic diagram of a reflective element190according to an embodiment of the present disclosure. The reflective element190may include a reflective mirror or a reflective prism. The reflective surface of the reflective element190may extend obliquely with respect to a rotation axis191of the reflective element190. The reflective element190may be fixed on a rotating body192, and the rotating body192may be used to balance the dynamic balance of the reflective element190, such that the reflective element190may maintain balance when rotating at a high speed.

In one embodiment, the rotating body192may supplement the mass at places where the quality is defective. For example, counterweights193and194whose densities are higher than the density of the rotating body192may be added, such that the rotating body192and the reflective element190can be balanced. In the embodiment shown inFIG.19, the reflective element190is a reflective mirror. The reflective element190extends obliquely from the upper right to the lower left of the rotating body192, the lower right of the rotating body192includes a counterweight194, and the upper left includes a counterweight193to achieve dynamic balance. The reflective element190may be used in the embodiments described inFIG.2,FIG.14, andFIG.17.

It should be noted that the relationship terms used in the text of this application, such as first and second, are only for distinguishing an object or operation from another object or operation, but not for defining or implying any practical relation or order between the object or operation. The terms “include”, “contain” or other alternatives shall be non-exclusiveness, the inclusion of a series of element such as process, method, object or equipment shall include not only the already mentioned elements but also those elements not mentioned, and shall include the elements which are inherent in the process, method, object or equipment. However, under the condition of no more limitations, the definition of an essential element limited by the sentence “including a . . . ” shall not obviate that in addition to containing the said essential element in the process, method, object or equipment, other essential element of the same nature may also exist in the above-mentioned process, method, object or equipment.

The method and apparatus provided in embodiments of the present disclosure have been described in detail above. In the present disclosure, particular examples are used to explain the principle and embodiments of the present disclosure, and the above description of embodiments is merely intended to facilitate understanding the methods in the embodiments of the disclosure and concept thereof, meanwhile, it is apparent to persons skilled in the art that changes can be made to the particular implementation and application scope of the present disclosure based on the concept of the embodiments of the disclosure, in view of the above, the contents of the specification shall not be considered as a limitation to the present disclosure.