An optical deflection device, emission module, lidar system, and electronic device
By employing a light deflection device that adjusts the beam deflection angle in a partitioned manner in the lidar system, the problem of slow switching of the deflection angle of the liquid crystal polarization grating is solved, thereby improving the scanning frame rate and system efficiency of the lidar.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHENZHEN FUSHI TECH CO LTD
- Filing Date
- 2024-06-24
- Publication Date
- 2026-05-01
AI Technical Summary
The long switching time of the deflection angle of the liquid crystal polarization grating affects the scanning and detection frame rate of the lidar, making it difficult to meet the high frame rate lidar scanning requirements.
An optical deflection device is used, which includes a control device, a first optical deflection device, and a second optical deflection device. The second optical deflection device adjusts the deflection angle of the incident beam in sections, and the control device adjusts the deflection angle of the unscanned sections within the deflection period to reduce the switching time.
This improved the detection frame rate of lidar scanning, reduced the waiting time for beam deflection angle switching, and enhanced the scanning efficiency of the system.
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Figure CN120848085B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of depth sensing technology, and in particular to an optical deflection device, a transmitting module, a lidar system, and an electronic device. Background Technology
[0002] In recent years, depth sensing systems, such as LiDAR, have begun to be commercialized on a large scale in fields such as optoelectronic sensing, smart manufacturing, 3D navigation, and imaging. Among them, the most commercially valuable and promising application is as a light detection device for intelligent driving, providing real-time road information. This requires LiDAR to be able to detect various road signs and obstacles smaller than one meter in size within a wide field of view, ranging from approximately 300 meters away, and to have a signal update rate of ten to tens of frames per second to meet the application scenarios of high-speed vehicles. While meeting ranging performance requirements, the product also needs to have a relatively small size. To meet these performance requirements, the mainstream commercial vehicle LiDAR currently uses mechanical or semi-solid-state optical scanning methods, illuminating targets within the scanned field of view in a time-division manner. However, due to the presence of moving parts, the system reliability and maintainability are not high.
[0003] Compared to traditional mechanical and semi-solid-state lidar, all-solid-state lidar offers significant advantages in system cost and reliability. Currently, the mainstream direct-time-of-flight (DTOF) flash-type all-solid-state blind-spot lidar, such as the lidar disclosed in Chinese patent application CN202321460026.5, employs a wide-area emission method to cover the entire field of view. At the receiving end, a SPAD array is used to receive the reflected echo signals in a time-division and zone-division manner, ultimately achieving 3D imaging of targets within tens of meters. To meet vehicle navigation requirements without changing the frame rate, detection angle, and angular resolution, the detection power needs to be increased to achieve a detection range of hundreds of meters. This is currently limited by system heat dissipation capabilities and cost control requirements, making it difficult to achieve in engineering.
[0004] To improve the detection range of all-solid-state lidar, cascaded optical deflection structures are considered to expand the optical deflection angle range during all-solid-state optical scanning. For example, using AOD combined with a liquid crystal polarization grating for secondary deflection can achieve continuous and fine adjustment of the one-dimensional beam deflection angle within a large angle range. Summary of the Invention
[0005] The inventors of this application have discovered that when using a liquid crystal polarizing grating to achieve light deflection, the switching of the deflection angle of the liquid crystal polarizing grating requires a long waiting time. After completing the scanning of the area corresponding to one deflection angle, it is necessary to switch to the scanning of the area corresponding to the next deflection angle, which requires a long waiting time. The slow angle adjustment greatly affects the detection frame rate of the lidar scanning.
[0006] In view of the above problems, the present invention is proposed to provide an optical scanning method, an optical deflection device, a transmitting module, a lidar system, and an electronic device that overcomes or at least partially solves the above problems.
[0007] This invention provides an optical deflection device, including a control device, a first optical deflection device, and a second optical deflection device; the second optical deflection device includes multiple deflection zones, and the deflection angle of each deflection zone can be adjusted individually for the incident light beam.
[0008] The first optical deflecting device is configured to deflect the incident beam at multiple different first deflection angles within one deflection period, corresponding to the deflection zones of the second optical deflecting device.
[0009] The deflection zone of the current scan is used to deflect the incident beam by the second deflection angle required;
[0010] The controller is configured to control at least one currently unscanned deflection zone to adjust its deflection angle to the incident beam, such that the deflection angle of at least one deflection zone to the incident beam is adjusted to the second deflection angle required for the next deflection cycle after the current deflection cycle has been scanned by the incident beam and before the next deflection cycle begins to be scanned by the incident beam.
[0011] In some alternative embodiments, within a deflection period, the incident beams with multiple different first deflection angles are incident into multiple deflection zones in a time-division manner, and the multiple deflection zones receive the incident beams and deflect the incident beams in a time-division manner.
[0012] The deflection period is the time required for the plurality of deflection partitions to be scanned once by incident beams at the plurality of different first deflection angles, or the deflection period is the time required for a specified portion of the plurality of deflection partitions to be scanned once by incident beams at the specified portion of the plurality of different first deflection angles.
[0013] In some optional embodiments, the first optical deflection device is configured to sequentially incident multiple incident beams with different first deflection angles onto corresponding deflection partitions in the second optical deflection device in a preset order within a deflection period; a deflection partition is configured to deflect the incident beams to a corresponding second deflection angle within a deflection period.
[0014] In some alternative embodiments, within a deflection period, the deflection angles of the plurality of beams with different first deflection angles vary from large to small, or from small to large, or vary according to a preset random rule.
[0015] In some alternative embodiments, the plurality of deflection partitions are configured such that the plurality of second deflection angles deflecting the incident beam within a deflection cycle are all the same, all different, or partially the same and partially different.
[0016] In some alternative embodiments, a deflection partition may be configured to sequentially receive one, two or more incident beams incident at different first deflection angles within a deflection period.
[0017] In some optional embodiments, the arrangement direction of the plurality of deflection partitions is consistent with the scanning direction of the plurality of incident beams with different first deflection angles.
[0018] In some optional embodiments, when the incident beam is a strip beam with an aspect ratio greater than a set threshold, the first optical deflection device is configured to deflect the incident beam at multiple different first deflection angles along a first direction within one deflection period to perform a one-dimensional scan of the second optical deflection device, and the multiple deflection partitions included in the second optical deflection device are arranged along the first direction of beam deflection.
[0019] When the incident beam is a non-strip beam with an aspect ratio within a set threshold range, the first optical deflection device is configured to deflect multiple different first deflection angles in a two-dimensional array scanning manner along a first direction and a second direction that are perpendicular to each other within one deflection cycle, so as to perform two-dimensional scanning on the second optical deflection device, and the multiple deflection partitions included in the second optical deflection device are arranged in a two-dimensional array along the first direction and the second direction.
[0020] The first direction is the width direction of the light beam, and the first direction is perpendicular to the second direction.
[0021] In some alternative embodiments, the plurality of deflection partitions are configured such that the number of incident beams received by each deflection partition is the same, different, or partially the same and partially different; correspondingly, the widths of the plurality of deflection partitions are the same, different, or partially the same and partially different.
[0022] In some optional embodiments, the beam incident surface of the deflection partition is a rectangle with an aspect ratio greater than a set threshold, the width direction of the deflection partition is consistent with the scanning direction of multiple incident beams with different first deflection angles, and the width of each deflection partition is determined according to the number of incident beams received and the width of the incident beams.
[0023] In some optional embodiments, when the incident beam is a strip beam with an aspect ratio greater than a set threshold, the width direction is a first direction, the first light deflection device deflects the incident beam in the first direction by a plurality of different first deflection angles, and the second light deflection device deflects the incident beam in the first direction and the second direction by a plurality of different second deflection angles respectively.
[0024] In some alternative embodiments, the first optical deflector has a higher deflection accuracy for the light beam than the second optical deflector.
[0025] In some alternative embodiments, the first optical deflection device is configured as follows:
[0026] Among multiple different first deflection angles that deflect the incident beam, the angular interval between two adjacent first deflection angles is less than or equal to the divergence angle of the beam along the deflection direction after being deflected by the first optical deflection device.
[0027] In some optional embodiments, the controller is specifically used for:
[0028] Once a deflection zone has completed the deflection of the incident beam in the current deflection cycle and is in a non-scanning state, the deflection zone is controlled to adjust its deflection angle to the beam. Before entering the scanning state in the next deflection cycle, its deflection angle to the beam is adjusted to the second deflection angle required for the next deflection cycle.
[0029] In some optional embodiments, if a deflection partition is an incident deflection partition for scanning the incident beam, then the deflection partition is determined to be in a scanning state; otherwise, the deflection partition is determined to be in a non-scanning state; or
[0030] If a deflection zone is the deflection zone that the incident beam is currently scanning or the next deflection zone to be scanned, then the deflection zone is determined to be in a scanning state; otherwise, the deflection zone is determined to be in a non-scanning state.
[0031] In some optional embodiments, the deflection partition currently being scanned by the incident beam and the next deflection partition to be scanned are determined as deflection partitions in the scanning state, and the remaining deflection partitions are determined as deflection partitions in the non-scanning state; the deflection partition currently being scanned by the incident beam and the next deflection partition to be scanned are deflection partitions that are adjacent in position.
[0032] In some alternative embodiments, the controller is used to control the voltage applied to the electrodes of each deflection zone to adjust the refractive index of the medium in the deflection zone to the incident beam, thereby adjusting the deflection angle of the deflection zone to the incident beam.
[0033] In some optional embodiments, the second optical deflection device is a liquid crystal polarization grating, and the control device is used to control the voltage applied to the electrodes of each deflection partition to adjust the arrangement direction of liquid crystal molecules in the liquid crystal polarization grating, so as to change the second deflection angle of the deflection partition to the incident light beam.
[0034] In some optional embodiments, the second optical deflection device includes at least one optical deflection unit, the optical deflection unit including a plurality of deflector partitions; the deflection partitions include deflector partitions in the at least one optical deflection unit corresponding to a position; the deflector partitions in at least one optical deflection unit included in a deflection partition can form a deflection optical path.
[0035] In some optional embodiments, when the second optical deflection device includes one optical deflection unit, the deflection partition is a deflector partition on the one optical deflection unit; when the second optical deflection device includes two optical deflection units, the deflection partition includes two deflector partitions on the two optical deflection units corresponding to each other; when the second optical deflection device includes multiple optical deflection units, the deflection partition includes multiple deflector partitions on the multiple optical deflection units corresponding to each other.
[0036] In some optional embodiments, the controller is specifically used to: control the voltage on the two end electrodes of each deflector section respectively, and change the deflection angle of at least one deflector section to the incident beam by changing the voltage on the two end electrodes of at least one deflector section, so as to change the second deflection angle of the corresponding deflection section to the incident beam.
[0037] In some optional embodiments, the second optical deflection device includes at least one optical deflection unit that deflects the incident beam in the same direction; or
[0038] The second optical deflection device includes at least two optical deflection unit groups, each optical deflection unit group including at least one optical deflection unit, wherein at least one optical deflection unit group is configured to deflect the light beam in a first direction, and at least one optical deflection unit group is configured to deflect the light beam in a second direction.
[0039] In some optional embodiments, the optical deflection unit includes a liquid crystal half-wave plate and a liquid crystal polarizing grating, wherein the liquid crystal half-wave plate includes electrodes disposed opposite to each other on both sides and a half-wave plate liquid crystal layer disposed between the two electrodes.
[0040] One side electrode of the liquid crystal half-wave plate includes multiple first electrode blocks, and the other side electrode is a first whole electrode. Each deflector partition corresponds to at least one first electrode block. Each deflector partition includes a portion on the liquid crystal half-wave plate corresponding to the position of the at least one first electrode block and a portion on the liquid crystal polarizing grating corresponding to the position of the at least one first electrode block; or
[0041] The electrodes on both sides of the liquid crystal half-wave plate include multiple first electrode blocks, and two opposing first electrode blocks form a first electrode pair. Each sub-deflection zone corresponds to at least one first electrode pair. Each deflection zone includes a portion on the liquid crystal half-wave plate corresponding to the position of the at least one first electrode pair and a portion on the liquid crystal polarizing grating corresponding to the position of the at least one first electrode pair.
[0042] Specifically, the deflection angle of the beam by the corresponding deflector section is adjusted by changing the voltage applied to the electrode corresponding to the deflector section in the liquid crystal half-wave plate.
[0043] In some optional embodiments, the optical deflection unit includes a liquid crystal half-wave plate and a liquid crystal polarizing grating; the liquid crystal half-wave plate includes electrodes disposed opposite to each other on both sides and a half-wave plate liquid crystal layer disposed between the electrodes on both sides; the liquid crystal polarizing grating includes electrodes disposed opposite to each other on both sides and a grating liquid crystal layer disposed between the electrodes on both sides.
[0044] One side electrode of the liquid crystal half-wave plate includes multiple first electrode blocks, and the other side electrode is a first monolithic electrode; one side electrode of the liquid crystal polarizing grating includes multiple second electrode blocks, and the other side electrode is a second monolithic electrode; at least one second electrode block on the liquid crystal polarizing grating and at least one corresponding first electrode block on the liquid crystal half-wave plate form a block group; or
[0045] The electrodes on both sides of the liquid crystal half-wave plate each include multiple first electrode blocks, and two opposing first electrode blocks form a first electrode pair; the electrodes on both sides of the liquid crystal polarizing grating each include multiple second electrode blocks, and two opposing second electrode blocks form a second electrode pair; at least one second electrode pair on the liquid crystal polarizing grating and at least one corresponding first electrode pair on the liquid crystal half-wave plate form a block group; or
[0046] One side electrode of the liquid crystal polarizing grating includes multiple second electrode blocks, and the other side electrode is a second monolithic electrode; both sides of the liquid crystal half-wave plate include multiple first electrode blocks, and two opposing first electrode blocks form a first electrode pair; at least one second electrode block on the liquid crystal polarizing grating and at least one corresponding first electrode pair on the liquid crystal half-wave plate form a block group; or
[0047] Both sides of the liquid crystal polarizing grating include multiple second electrode blocks, and two opposing second electrode blocks form a second electrode pair. One side of the liquid crystal half-wave plate includes multiple first electrode blocks, and the other side electrode is a first whole electrode. At least one second electrode pair on the liquid crystal polarizing grating and at least one first electrode block corresponding to the position on the liquid crystal half-wave plate form a block group.
[0048] Each deflector partition corresponds to at least one block group; each deflector partition includes a portion on the liquid crystal half-wave plate corresponding to the position of the block group, and a portion on the liquid crystal polarizing grating plate corresponding to the position of the block group;
[0049] Specifically, the deflection angle of the beam by the corresponding deflector partition is adjusted by changing the voltage applied to the electrode corresponding to the deflector partition in the liquid crystal half-wave plate and the voltage applied to the electrode corresponding to the deflector partition in the liquid crystal polarizing grating.
[0050] In some optional embodiments, the liquid crystal polarization gratings of all the optical deflection units in the second optical deflection device are passive liquid crystal polarization gratings, or the liquid crystal polarization gratings of all the optical deflection units in the second optical deflection device are active liquid crystal polarization gratings, or the liquid crystal polarization gratings of some of the optical deflection units in the second optical deflection device are passive liquid crystal polarization gratings and the liquid crystal polarization gratings of some of the optical deflection units are active liquid crystal polarization gratings; the liquid crystal material of the liquid crystal layer is a nematic liquid crystal.
[0051] In some optional embodiments, the liquid crystal half-wave plate includes a first substrate and a second substrate disposed opposite to each other, and electrodes on both sides are respectively disposed on the inner surfaces of the first substrate and the second substrate facing each other, wherein the inner surfaces are planar.
[0052] The liquid crystal polarizing grating also includes a third substrate and a fourth substrate arranged opposite to each other, with electrodes on both sides respectively disposed on the inner surfaces of the third substrate and the fourth substrate facing each other, and the inner surfaces being planar.
[0053] In some alternative embodiments, the second optical deflection device further includes a quarter-wave plate disposed in front of the first liquid crystal half-wave plate for changing the polarization state of the incident beam.
[0054] In some optional embodiments, the adjustment time of the second deflection angle of the incident beam by the deflection partition adjustment is not greater than the time interval between two adjacent deflection cycles of the deflection partition being scanned by the incident beam.
[0055] In some optional embodiments, the number of deflection partitions is determined based on the number of second deflection angles deflected by the second optical deflection device, the time required for the second optical deflection device to deflect multiple beams with multiple different first deflection angles to multiple different second deflection angles, and the adjustment time required for the second optical deflection device to complete one deflection angle adjustment.
[0056] In some optional embodiments, the number D of the deflection partitions is an integer greater than or equal to 2 / (1-FMT), where M is the number of deflection angles of the second optical deflection device, F is the frame rate at which the second optical deflector completes one round of M deflection angles, and T is the time required for the second optical deflector to complete one deflection angle adjustment.
[0057] In some alternative embodiments, the second optical deflection device is configured as follows:
[0058] In the case where the incident beam is a strip beam:
[0059] By deflecting multiple incident beams with different first deflection angles to the same second deflection angle, scanning of one corresponding scanning zone of the field of view can be completed; by deflecting each beam with a different first deflection angle to multiple different second deflection angles, scanning of multiple scanning zones corresponding to different second deflection angles can be completed.
[0060] The scanning partition is rectangular, and the length of the beam after being deflected by the second deflection angle is equal to the length of one direction of the scanning partition.
[0061] In some alternative embodiments, the second optical deflection device is configured as follows:
[0062] Within one deflection cycle, multiple incident beams with different first deflection angles are deflected to the same second deflection angle, completing the scanning of a corresponding scanning zone within the field of view; the second deflection angle is different for the multiple incident beams with different first deflection angles in different deflection cycles; or
[0063] Within one deflection cycle, incident beams with multiple different first deflection angles are deflected to one of multiple different second deflection angles, and scan a portion of the corresponding scanning partition. Within one deflection cycle, the second deflection angles of the incident beams with multiple different first deflection angles may be the same or different. The second deflection angles of the incident beams with each first deflection angle are different in different deflection cycles.
[0064] In some optional embodiments, the above-described optical deflection device further includes:
[0065] A temperature regulator is configured to adjust the time for adjusting the deflection angle of the deflection zone by changing the temperature of the second optical deflection device.
[0066] In some optional embodiments, the controller is further configured to control the first optical deflector to deflect the incident beam and to control the currently scanned deflection partition in the second optical deflector to deflect the incident beam.
[0067] In some optional embodiments, the first optical deflection device is an acousto-optic deflector, and the control device is used to apply a driving signal to the acoustic wave generator of the first optical deflection device, and control the acoustic wave frequency of the acoustic wave generator acting on the acousto-optic crystal of the first optical deflection device through the driving signal, so as to change the deflection angle of the light beam by the first optical deflection device.
[0068] In some optional embodiments, the controller is specifically used to perform the following control processes in parallel: controlling the currently scanned deflection partition in the second optical deflection device to deflect the incident beam, and controlling at least one currently unscanned deflection partition to adjust its deflection angle to the beam.
[0069] In some alternative embodiments, the controller includes a first control unit and a second control unit;
[0070] The first control unit is used to control the first optical deflection device to deflect multiple different first deflection angles in a time-division manner within a deflection cycle, and to incident the incident beam at each first deflection angle onto the corresponding deflection partition of the second optical deflection device.
[0071] The second control unit is used to control the plurality of deflection sections to receive the incident beam at different times and deflect the incident beam by the second deflection angle required, and to control the deflection sections to pre-adjust their deflection angles to the beam before being scanned by the incident beam; wherein, the deflection angle of at least one deflection section to the incident beam is adjusted to the second deflection angle required for the next deflection cycle after the current deflection cycle is scanned by the incident beam and before the next deflection cycle is scanned by the incident beam.
[0072] In some optional embodiments, the above-mentioned light deflection device further includes: a collimating device disposed between the first light deflection device and the light source, so as to collimate the light beam emitted by the light source in a first direction and a second direction that are perpendicular to each other;
[0073] The first direction is the direction in which the first optical deflection device deflects the incident beam, and the collimation requirement in the first direction is higher than the collimation requirement in the second direction.
[0074] In some optional embodiments, the above-described optical deflection device further includes: a polarization amplification device;
[0075] The polarization amplification device is configured to amplify the deflection angle of the deflected light in the corresponding deflection direction by a preset factor after it has been deflected by the first optical deflection device or the second optical deflection device.
[0076] In some optional embodiments, the optical deflection device is used in the transmitting module of a lidar system; or the optical deflection device is an optical deflection device in the transmitting module of a lidar system.
[0077] This invention provides a transmitting module, including a light source and the aforementioned light deflection device;
[0078] The light source is used to emit a light beam to the light deflection device;
[0079] The light deflection device is used to deflect the incident light beam emitted by the light source to generate scanning light beams with different deflection angles and deflection angle switching sequences to achieve scanning of the field of view.
[0080] In some alternative embodiments, the length of the light beam emitted by the light source along a first direction is less than the length along a second direction, where the first direction is the deflection direction of the incident light beam by a first light deflection device, and the second direction is perpendicular to the first direction.
[0081] In some alternative embodiments, the light source includes any one or more combinations of a vertical cavity surface-emitting laser, an edge-emitting laser, a light-emitting diode, a laser diode, a semiconductor laser, and a fiber laser.
[0082] This invention provides a lidar system, including a receiving module and the aforementioned transmitting module. The receiving module is configured to sense light signals from a field of view and obtain three-dimensional information of the field of view through processing and analysis of the sensed light signals.
[0083] This invention provides an electronic device including the aforementioned lidar system.
[0084] This invention provides an optical scanning method, comprising:
[0085] The first optical deflection device is controlled to deflect the incident beam at multiple different first deflection angles within one deflection cycle, so as to correspond to the deflection zones of the second optical deflection device.
[0086] The second optical deflection device controls multiple deflection zones to receive multiple incident beams with different first deflection angles; the deflection angle of each deflection zone can be adjusted individually for the incident beam.
[0087] The second deflection angle required to deflect the incident beam by controlling the currently scanned deflection zone; and
[0088] Control at least one currently unscanned deflection zone to adjust the deflection angle of the incident beam to the second deflection angle required for the next deflection cycle after the current deflection cycle has been scanned by the incident beam and before the next deflection cycle begins to be scanned by the incident beam.
[0089] In some optional embodiments, controlling the first optical deflector to deflect the incident beam at multiple different first deflection angles within one deflection period, so as to correspondingly incident on the corresponding deflection partitions of the second optical deflector, includes: controlling the first optical deflector to deflect the incident beam at multiple different first deflection angles in a preset order within one deflection period, and correspondingly incident the incident beam at each first deflection angle onto the corresponding deflection partition of the second optical deflector; controlling multiple deflection partitions in the second optical deflector to receive multiple incident beams at multiple different first deflection angles includes: controlling the multiple deflection partitions to receive multiple incident beams at multiple different first deflection angles at different times.
[0090] The deflection period is the time required for the plurality of deflection partitions to be scanned once by incident beams at the plurality of different first deflection angles, or the deflection period is the time required for a specified portion of the plurality of deflection partitions to be scanned once by incident beams at the specified portion of the plurality of different first deflection angles.
[0091] In some alternative embodiments, within a deflection period, the deflection angles of the plurality of beams with different first deflection angles vary from large to small, or from small to large, or vary according to a preset random rule.
[0092] In some alternative embodiments, the multiple second deflection angles that deflect the incident beam within a deflection cycle are all the same, all different, or partially the same and partially different.
[0093] In some alternative embodiments, a deflection partition may sequentially receive one, two or more incident beams with different first deflection angles within a deflection period.
[0094] In some alternative embodiments, the plurality of deflection partitions are configured such that the plurality of second deflection angles deflecting the incident beam within a deflection cycle are all the same, all different, or partially the same and partially different.
[0095] In some alternative embodiments, the number of incident beams that each deflection partition can receive is the same, different, or partially the same and partially different; correspondingly, the widths of the plurality of deflection partitions are the same, different, or partially the same and partially different.
[0096] In some alternative embodiments, the first optical deflector deflects the incident beam sequentially by a plurality of different first deflection angles in a first direction, and the second optical deflector deflects the incident beam by a plurality of different second deflection angles in the first and second directions, respectively.
[0097] In some optional embodiments, controlling the deflection angle of at least one currently unscanned deflection zone to the incident beam to a second deflection angle required for the next scan, after the current scan of the incident beam has ended and before the next scan begins, includes:
[0098] Once a deflection zone has completed the deflection of the incident beam in the current deflection cycle and is in a non-scanning state, the deflection zone is controlled to adjust its deflection angle to the beam. Before entering the scanning state in the next deflection cycle, its deflection angle to the beam is adjusted to the second deflection angle required for the next deflection cycle.
[0099] In some optional embodiments, if a deflection zone is the deflection zone currently being scanned by the incident beam, then the deflection zone is determined to be in a scanning state; otherwise, the deflection zone is determined to be in a non-scanning state; or
[0100] If a deflection zone is the deflection zone that the incident beam is currently scanning or the next deflection zone to be scanned, then it is determined to be in a scanning state; otherwise, the deflection zone is determined to be in a non-scanning state.
[0101] In some optional embodiments, the deflection partition currently being scanned by the incident beam and the next deflection partition to be scanned are determined as deflection partitions in the scanning state, and the remaining deflection partitions are determined as deflection partitions in the non-scanning state; the deflection partition currently being scanned by the incident beam and the next deflection partition to be scanned are deflection partitions that are adjacent in position.
[0102] In some alternative embodiments, the voltage applied to the electrodes of each deflection zone is controlled to adjust the refractive index of the medium in the deflection zone to the incident beam, thereby adjusting the deflection angle of the deflection zone to the incident beam.
[0103] In some optional embodiments, when the second optical deflection device is a liquid crystal polarization grating, the voltage applied to the electrodes of each deflection partition is controlled to adjust the arrangement direction of liquid crystal molecules in the liquid crystal polarization grating, thereby changing the second deflection angle of the incident beam by the deflection partition.
[0104] In some optional embodiments, the second optical deflection device includes at least one optical deflection unit, which includes multiple deflector partitions. When the deflection partition includes a deflector partition corresponding to a position in the at least one optical deflection unit, the voltage on the two end electrodes of each deflector partition is controlled respectively. By changing the voltage on the two end electrodes of at least one deflector partition, the deflection angle of at least one deflector partition to the incident light beam is changed, thereby changing the second deflection angle of the corresponding deflector partition to the incident light beam.
[0105] In some alternative embodiments, where the second optical deflection device includes at least two optical deflection unit groups, each group including at least one of the optical deflection units; the second deflection angle required to control the currently scanned deflection partition to deflect the incident beam includes:
[0106] The incident beam is deflected in the first direction by a second deflection angle required by the deflector partition of the optical deflection unit currently being scanned in at least one optical deflection unit group, and / or the incident beam is deflected in the second direction by a second deflection angle required by the deflector partition of the optical deflection unit currently being scanned in at least one optical deflection unit group, wherein the first direction and the second direction are perpendicular.
[0107] In some optional embodiments, the adjustment time of the second deflection angle of the incident beam by the deflection partition adjustment is not greater than the time interval between two adjacent scans of the deflection partition by the incident beam.
[0108] In some optional embodiments, the number of deflection partitions is determined based on the number of second deflection angles deflected by the second optical deflection device, the time required for the second optical deflection device to deflect multiple beams with multiple different first deflection angles to multiple different second deflection angles, and the adjustment time required for the second optical deflection device to complete one deflection angle adjustment.
[0109] In some optional embodiments, the number D of the deflection partitions is an integer greater than or equal to 2 / (1-FMT), where M is the number of deflection angles of the second optical deflection device, F is the frame rate at which the second optical deflector completes one round of M deflection angles, and T is the time required for the second optical deflector to complete one deflection angle adjustment.
[0110] In some optional embodiments, the method further includes: changing the temperature of the second optical deflection device to adjust the time for adjusting the deflection angle of the deflection partition.
[0111] In some optional embodiments, the field of view of the light scan is divided into multiple scanning partitions, the scanning partitions being rectangular, and the incident beam being a strip beam;
[0112] Scanning the field of view includes: deflecting multiple incident beams with different first deflection angles to the same second deflection angle to complete the scanning of one corresponding scanning partition of the field of view; and deflecting each beam with a first deflection angle of multiple beams with different first deflection angles to multiple different second deflection angles to complete the scanning of multiple scanning partitions corresponding to the multiple second deflection angles.
[0113] The length of the beam after the second deflection angle is equal to the length of one direction of the scanning partition.
[0114] In some optional embodiments, within one deflection cycle, incident beams with multiple different first deflection angles are deflected to the same second deflection angle to complete the scanning of a corresponding scanning partition of the field of view; the second deflection angle deflected by the multiple different incident beams with different first deflection angles is different for different deflection cycles; or
[0115] Within one deflection cycle, incident beams with multiple different first deflection angles are deflected to one of multiple different second deflection angles, and scan a portion of the corresponding scanning partition. Within one deflection cycle, the second deflection angles of the incident beams with multiple different first deflection angles may be the same or different. The second deflection angles of the incident beams with each first deflection angle are different in different deflection cycles.
[0116] In some optional embodiments, the above method further includes:
[0117] Before the incident beam is incident on the first optical deflection device, the incident beam is collimated by a collimation device in a first direction and a second direction that are perpendicular to each other.
[0118] The first direction is the direction in which the first optical deflection device deflects the incident beam, and the collimation requirement in the first direction is higher than the collimation requirement in the second direction.
[0119] In some optional embodiments, the above method further includes:
[0120] The deflection angle of the deflected beam after being deflected by the first or second optical deflector is amplified by a preset factor in the corresponding deflection direction by the polarization amplification device.
[0121] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:
[0122] The optical deflection device and optical scanning method provided in this invention deflect a light beam using a first optical deflection device before it is incident on a second optical deflection device. The second optical deflection device is divided into multiple deflection zones, and the deflection angle of the light beam in each of the multiple deflection zones can be adjusted independently. The light beam deflected by the first optical deflection device can be incident on the corresponding deflection zone of the second optical deflection device. The currently scanned deflection zone deflects the incident light beam by the required second deflection angle. Since the deflection angle of the light beam in different zones can be adjusted individually, the deflection zone that has not been scanned can adjust its deflection angle of the light beam during the unscanned time. At least one deflection zone adjusts its angle during the unscanned state, so that the deflection angle of the light beam in at least one deflection zone is changed within the deflection cycle, and can be changed to the second deflection angle of the next deflection cycle. This allows the incident beam in the next deflection cycle to be deflected to the required second deflection angle immediately without waiting when it re-enters the deflection zone. This reduces the waiting time for deflection angle adjustment when switching to the next deflection angle scan after completing one deflection angle scan, and improves the detection frame rate of the lidar scan.
[0123] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.
[0124] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0125] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:
[0126] Figure 1 This is one of the structural schematic diagrams of the optical deflection device in Embodiment 1 of the present invention;
[0127] Figure 2 This is a second schematic diagram of the optical deflection device in Embodiment 1 of the present invention;
[0128] Figure 3 This is a schematic diagram of a specific structure of the optical deflection device in Embodiment 1 of the present invention;
[0129] Figure 4 This is an example diagram of the deflection partition two-dimensional array arrangement in Embodiment 1 of the present invention;
[0130] Figure 5aThis is a schematic diagram of the optical deflection device with one side electrode of the liquid crystal half-wave plate in Embodiment 1 of the present invention;
[0131] Figure 5b This is a schematic diagram of the optical deflection device with electrodes on both sides of the liquid crystal half-wave plate in Embodiment 1 of the present invention;
[0132] Figure 6a This is a schematic diagram of the optical deflection device with one side electrode blocks of the liquid crystal half-wave plate and liquid crystal polarizing grating in Embodiment 1 of the present invention;
[0133] Figure 6b This is a schematic diagram of the optical deflection device with electrodes on both sides of the liquid crystal half-wave plate and the liquid crystal polarizing grating in Embodiment 1 of the present invention;
[0134] Figure 7 This is a schematic diagram of the optical path in the first direction of the optical deflection device in Embodiment 1 of the present invention;
[0135] Figure 8 This is a schematic diagram of the optical path in the second direction of the optical deflection device in Embodiment 1 of the present invention;
[0136] Figure 9 This is a schematic diagram of the optical deflection device structure using a passive liquid crystal grating in Embodiment 1 of the present invention;
[0137] Figure 10a This is an example diagram showing the relationship between the applied voltage and the deflection angle of the optical deflection device in Embodiment 1 of the present invention.
[0138] Figure 10b This is an example diagram showing the relationship between the applied voltage and the deflection angle of the optical deflection device in Embodiment 1 of the present invention.
[0139] Figure 11 This is one of the example diagrams of the deflection partition scan path in Embodiment 1 of the present invention;
[0140] Figure 12 This is the second example diagram of the deflection partition scan path in Embodiment 1 of the present invention;
[0141] Figure 13 This is the third example diagram of the deflection partition scan path in Embodiment 1 of the present invention;
[0142] Figure 14 This is a flowchart of the optical scanning method in Embodiment 2 of the present invention;
[0143] Figure 15 This is a schematic diagram of the transmitting module in Embodiment 3 of the present invention;
[0144] Figure 16 This is a schematic diagram of the lidar system in Embodiment 3 of the present invention.
[0145] 1. Transmitting module; 2. Receiving module;
[0146] 10. Optical deflection device;
[0147] 100. First optical deflection device; 200. Second optical deflection device; 300. Light source; 400. Collimation device; 500. Polarization expansion device; 600. Control device;
[0148] 110. First control unit;
[0149] 210. Optical deflection unit; 220. Optical deflection unit group; 230. Second control unit; 240. Temperature regulator;
[0150] 211. First electrode block; 2110. First electrode pair; 212. Deflection zone; 2121. Deflector zone; 213. First monolithic electrode; 214. Liquid crystal half-wave plate; 215. Half-wave plate liquid crystal layer; 216. Liquid crystal polarizing grating; 217. First substrate; 218. Second substrate; 2160. Second electrode pair; 2161. Third substrate; 2162. Fourth substrate; 2163. Second electrode block; 2164. Grating liquid crystal layer; 2165. Second monolithic electrode. Detailed Implementation
[0151] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
[0152] To address the issues of long waiting times and slow adjustment times when using liquid crystal polarization gratings for beam deflection in existing lidar technologies, which affect the lidar scanning and detection frame rate, this invention provides an all-solid-state two-dimensional optical deflection and scanning scheme. The optical deflection device is divided into different deflection zones, and laser light is emitted to illuminate different deflection zones in a time-division manner. Unileveraged deflection zones can adjust their deflection angles. Therefore, the scanning system does not need to wait for the optical deflection device to adjust its state to change the deflection angle, enabling continuous scanning. This design achieves a high frame rate, a large field of view, and long-range ranging capabilities, meeting the requirements of applications such as automotive lidar. Furthermore, by combining fine and coarse polarization devices, the fine polarization device's fast response speed and high number of resolvable points enable detailed scanning within a small angle range. The coarse polarization device's high diffraction efficiency and large deflection angle extend the scanning range to cover a wide field of view.
[0153] Example 1
[0154] Embodiment 1 of the present invention provides an optical deflection device 10, the structure of which is as follows: Figure 1 and Figure 2 As shown, it includes: a control device 600, a first optical deflection device 100 and a second optical deflection device 200; the second optical deflection device 200 includes multiple deflection zones 212, and the deflection angle of each deflection zone 212 can be adjusted individually for the incident beam.
[0155] The first optical deflecting device 100 is configured to deflect the incident beam at multiple different first deflection angles within a deflection period, corresponding to the incident beam onto the corresponding deflection partition 212 of the second optical deflecting device 200.
[0156] The deflection zone 212 of the current scan is used to deflect the incident beam by the second deflection angle required.
[0157] The controller 600 is configured to control at least one currently unscanned deflection partition 212 to adjust its deflection angle to the incident beam, such that the deflection angle of at least one deflection partition 212 to the incident beam is adjusted to the second deflection angle required for the next deflection cycle after the current deflection cycle has been scanned by the incident beam and before the next deflection cycle has begun to be scanned by the incident beam.
[0158] Optionally, the controller 600 is also used to control the first optical deflector 100 to deflect the incident beam and to control the currently scanned deflection partition 212 in the second optical deflector 200 to deflect the incident beam.
[0159] In the aforementioned optical deflection device, the controller 600 can be used to control the first optical deflection device 100 to deflect the incident beam at multiple different first deflection angles within one deflection cycle, corresponding to the incident beam onto the corresponding deflection partitions of the second optical deflection device 200; it can also be used to control the currently scanned deflection partitions in the second optical deflection device 200 to deflect the incident beam at the required second deflection angle; and it can also be used to control at least one currently unscanned deflection partition 212 to adjust its deflection angle to the beam, so that the deflection angle of at least one deflection partition 212 to the incident beam is adjusted to the required second deflection angle for the next deflection cycle after the current deflection cycle has ended and before the next deflection cycle begins. Optionally, the controller 600 is specifically used to execute the following control processes in parallel: controlling the currently scanned deflection partitions in the second optical deflection device 200 to deflect the incident beam, and controlling at least one currently unscanned deflection partition 212 to adjust its deflection angle to the beam. In other words, while the second optical deflection device 200 deflects the incident beam in the currently scanned deflection partition 212, at least one currently unscanned deflection partition 212 can adjust its deflection angle to the beam under the control of the controller 600.
[0160] Within one deflection period, incident beams with multiple different first deflection angles are time-divisionally incident into multiple deflection partitions 212. Each deflection partition 212 receives and deflects the incident beams in a time-division manner. The deflection period is the time required for each of the multiple deflection partitions 212 to be scanned once by the incident beams with multiple different first deflection angles. Alternatively, the deflection period is the time required for the incident beams with multiple different first deflection angles to traverse and scan the multiple deflection partitions 212. In this case, within one deflection period, all the incident beams with multiple different first deflection angles will scan all the deflection partitions 212; that is, each deflection partition 212 is scanned and no partition is missed.
[0161] Alternatively, the deflection period is the time required for a specified portion of deflection partitions 212 out of multiple deflection partitions 212 to be scanned once by incident beams at a specified portion of the first deflection angles out of multiple different first deflection angles. In other words, the deflection period is the time required for incident beams at a specified portion of the first deflection angles out of multiple different first deflection angles to traverse and scan the specified portion of deflection partitions 212. Within one deflection period, a portion of the deflection partitions 212 are scanned, meaning that some deflection partitions 212 are missed. The specified portion of deflection partitions 212 can be the same or different in different deflection periods; correspondingly, the specified portion of the first deflection angle incident beams can be the same or different.
[0162] See below for a specific structure of the aforementioned optical deflection device 10. Figure 3 As shown, a light beam can be generated by the light source 300. A light source control unit (not shown) can control the light source to emit light according to a preset time sequence. The shape of the generated light beam is determined as needed; for example, its length along a first direction may be less than its length along a second direction. Thus, the first direction can be used as the width direction of the light beam, and the second direction can be used as the length direction of the light beam. The first direction is the deflection direction of the incident light beam by the first light deflection device 100. In some embodiments, the first direction can be set perpendicular to the second direction; for example, the first direction can be vertical, and the second direction can be horizontal. In some embodiments, the light source 300 may include multiple light-emitting units, which are spliced together to emit a light beam of the desired shape.
[0163] The light-emitting unit can be, for example but not limited to, a vertical-cavity surface-emitting laser (VCSEL), an edge-emitting laser (EEL), a light-emitting diode (LED), a laser diode (LD), a semiconductor laser, or a fiber laser. The edge-emitting laser can be a Fabry-Perot (FP) laser, a distributed feedback (DFB) laser, or an electro-absorption modulated (EML) laser, etc., and this application does not limit this specific type.
[0164] In some alternative embodiments, see Figure 3 As shown, the aforementioned light deflection device 10 may further include a collimating device 400 between the light source 300 and the first light deflecting device 100 to collimate the light beam emitted from the light source 300 in a first direction and a second direction that are perpendicular to each other. The collimation requirement in the first direction is higher than the collimation requirement in the second direction; that is, the divergence angle of the collimated light beam in the first direction is smaller than the divergence angle in the second direction. The collimated light beam then enters the first light deflecting device 100. The collimating device 400 includes at least one collimating lens, such as two cylindrical lenses, a spherical lens, or a cylindrical lens and a spherical lens, to collimate the strip-shaped light beam emitted from the light source in the first direction and the second direction that are perpendicular to each other.
[0165] In some alternative embodiments, see Figure 3 As shown, the above-mentioned optical deflection device 10 may further include a polarization amplification device 500, which is configured to amplify the deflection angle of the deflected light after being deflected by the first optical deflection device 100 or the second optical deflection device 200 in the corresponding deflection direction by a preset factor. Figure 3Taking the polarizing device 500 disposed between the first optical deflecting device 100 and the second optical deflecting device 200 as an example, the polarizing device 500 can also be disposed after the second optical deflecting device 200. The aforementioned polarizing device 500 includes at least one polarizing lens, which can be a single lens or a combination of two or more lenses; the polarizing lens includes at least one or any combination of cylindrical lenses, spherical lenses, superlenses, and Fresnel lenses; when the polarizing lens includes a combination of two or more lenses, the combination of the two or more lenses can be considered as one lens. The polarizing lens is configured to amplify the deflection angle of the beam deflected by the first optical deflecting device 100 or the second optical deflecting device 200 by a preset factor in at least one of a first direction and a second direction that are mutually perpendicular. The polarizing device 500 can also amplify the divergence angle of the beam deflected by the first optical deflecting device 100 or the second optical deflecting device 200 in the corresponding deflection direction by a preset factor, and the amplification factor of the divergence angle is the same as the amplification factor of the deflected beam in that deflection direction. The focal length of the polarizing lens is set according to the magnification factor of the deflection angle.
[0166] The aforementioned first optical deflecting device 100 can deflect the light beam at multiple first deflection angles within a preset angle range. Within one deflection cycle, the controller 600 can control the first optical deflecting device 100 to deflect the incident light beam at multiple different first deflection angles in a time-division manner. The incident light beams at multiple different first deflection angles are then incident into multiple deflection zones in a time-division manner. The multiple deflection zones of the second optical deflecting device 200 receive the incident light beams at different times and deflect them. Furthermore, the first optical deflecting device 100 is configured to sequentially incident the incident light beams at multiple different first deflection angles into the corresponding deflection zones of the second optical deflecting device 200 in a preset order within one deflection cycle; a deflection zone 212 is configured to deflect the incident light beam at a corresponding second deflection angle within one deflection cycle.
[0167] Within each deflection cycle, the controller 600 can control the first optical deflector 100 to generate multiple incident beams with different first deflection angles within a preset angle range and according to a preset deflection time interval, and project them onto the corresponding deflection zones of the second optical deflector 200. For example, within the range of -1.5 to +1.5 degrees, the beam is deflected by multiple first deflection angles with certain intervals. The first deflection angle is an angle sequence: -1.5, -1.0, -0.5, 0, 0.5, 1, 1.5, etc., and the angle interval can be set as needed. Therefore, the deflection cycle is also the time required for the first optical deflector 100 to complete one round of deflection of multiple preset first deflection angles within the preset angle range. After completing one deflection cycle, the first optical deflector 100 can enter the next deflection cycle and continue to deflect the beam for a new round.
[0168] The first optical deflector 100 is configured such that, among a plurality of different first deflection angles for deflecting the incident beam, the angular interval between two adjacent first deflection angles is less than or equal to the divergence angle of the beam deflected by the first optical deflector 100 along the deflection direction. This allows for a small overlap at the edges of adjacent beams deflected by the first optical deflector 100, ensuring full coverage of the scanning area and preventing any missed scans.
[0169] The first optical deflecting device 100 is, for example but not limited to, an acousto-optic deflecting device (AOD). The AOD can deflect the light beam according to a preset acoustic frequency. The AOD may include an entrance aperture, an acousto-optic crystal, an acoustic generator, and an exit aperture. Depending on the specific configuration, the acousto-optic crystal can achieve one-dimensional or two-dimensional quasi-continuous deflection of the light beam. The deflection response time is proportional to the width of the light beam within the crystal. The control device 600 is used to apply a driving signal to the acoustic generator of the first optical deflecting device 100. The driving signal controls the acoustic frequency of the acoustic generator acting on the acousto-optic crystal of the first optical deflecting device 100, thereby changing the deflection angle of the light beam by the first optical deflecting device 100.
[0170] Using a first optical deflector 100 as a fine deflector and a second optical deflector 200 as a coarse deflector, the light beam is deflected. Specifically, the first optical deflector 100 deflects the beam sequentially by a relatively small angle, while the second optical deflector 200 deflects the beam, deflected by the first optical deflector 100, by a relatively large angle over time, ultimately achieving a comprehensive scan of the field of view. The first optical deflector 100 can sequentially deflect the incident beam at least in one of the first and second directions by multiple different first deflection angles. The second optical deflector 200 can sequentially deflect the incident beam at least in one of the first and second directions by multiple different second deflection angles. For example, when the incident beam is a strip beam with an aspect ratio greater than a set threshold, with the width direction being the first direction, the first optical deflector 100 sequentially deflects the incident beam at multiple different first deflection angles in the first direction, and the second optical deflector 200 deflects the incident beam at multiple different second deflection angles in both the first and second directions. That is, the first optical deflection device 100 deflects the light beam in one dimension, and the second optical deflection device 200 deflects the light beam in one or two dimensions, thereby reducing the number of deflection angles of the second optical deflection device 200 and making the second optical deflection device 200 thinner.
[0171] The deflection accuracy of the first optical deflector 100 pairs of beams is higher than that of the second optical deflector 200 pairs of beams.
[0172] The aforementioned second optical deflection device 200 can control at least one deflection partition 212 to complete a second deflection angle adjustment within the scanning interval of two adjacent deflection cycles through the control device 600. This allows at least one deflection partition to be adjusted to the required second deflection angle before the incident beam of the previously scanned deflection partition 212 ends. In other words, the control device 600 can control the beam emitted by the first optical deflection device 100 to be time-divisionally applied to each deflection partition 212. At least one deflection partition 212 will respond in advance to prepare for receiving the incident beam in the next deflection cycle. Before the beam of the next deflection cycle is incident on the deflection partition 212, the deflection angle of the incident beam of the deflection partition 212 has been pre-adjusted to the second deflection angle required for the next deflection cycle. This can reduce the waiting time for angle adjustment to a certain extent, so that at least one incident beam can be irradiated without waiting in the next deflection cycle, thereby improving the scanning frame rate of optical scanning. To further improve the scanning frame rate, optionally, the controller 600 can control each deflection partition 212 to complete a second deflection angle adjustment within the incident interval of two adjacent deflection cycles, so that each deflection partition 212 can be adjusted to the required second deflection angle before the incident of the previous deflection partition 212 ends, so that the incident beam of each first deflection angle can be directly irradiated without waiting, thereby improving the scanning frame rate of optical scanning.
[0173] Within one deflection period, multiple incident beams with different first deflection angles can be sequentially incident onto the corresponding deflection partition 212 in a preset order. The incident order of the multiple incident beams with different first deflection angles can be preset and controlled by the controller 600. Within one deflection period, the deflection angles of the multiple beams with different first deflection angles can vary from large to small, from small to large, or according to a preset random rule. Optionally, the deflection angles of the multiple beams with different first deflection angles can vary from large to small, for example, from -1.5, -1.0, -0.5, 0, 0.5, 1, 1.5 sequentially. Optionally, the deflection angles of the multiple beams with different first deflection angles can vary from small to large, for example, from 1.5, 1.0, 0.5, 0, -0.5, -1, -1.5 sequentially. Optionally, the deflection angles of one or more beams with different first deflection angles can also vary according to a preset random rule, such as: randomly varying from -1.5, 1, -0.5, 0, -1.0, 0.5, 1.5. Within different deflection periods, the incident order of the incident beams can be the same or different.
[0174] The aforementioned second optical deflecting device 200 has multiple deflection sections 212 configured such that, within one deflection cycle, the multiple second deflection angles deflecting the incident beam are all the same, all different, or partially the same and partially different. Optionally, within one deflection cycle, the second deflection angle that further deflects the incident beams with multiple first deflection angles can be one, two, or more. For example: within one deflection cycle, multiple deflection sections 212 deflect multiple incident beams with multiple different first deflection angles by 1 degree; in the next cycle, multiple deflection sections 212 deflect multiple incident beams with multiple different first deflection angles by 2 degrees; ... and so on; another example: within one deflection cycle, the first deflection section 212 deflects at least one incident beam with a first deflection angle by 1 degree; the second deflection section 212 deflects at least one incident beam with a first deflection angle by 2 degrees; ... and so on. For example, within one deflection cycle, the first deflection zone 212 deflects the incident beam at least one first deflection angle by 1 degree; the second deflection zone 212 deflects the incident beam at least one first deflection angle by 1 degree; the third deflection zone 212 deflects the incident beam at least one first deflection angle by 3 degrees; the fourth deflection zone 212 deflects the incident beam at least one first deflection angle by 5 degrees; and so on.
[0175] The aforementioned second optical deflection device 200 may have a deflection partition 212 configured to receive an incident beam with at least one first deflection angle. Optionally, a deflection partition 212 may be configured to sequentially receive one, two, or more incident beams with different first deflection angles within one deflection cycle.
[0176] In the aforementioned second optical deflection device 200, the arrangement direction of the multiple deflection partitions 212 is consistent with the scanning direction of the incident beams at multiple different first deflection angles. The multiple deflection partitions 212 can be arranged one-dimensionally along a single direction or in a two-dimensional array. Their arrangement direction can be consistent with the scanning direction of the incident beam at the first deflection angle. For example, if the incident beam scans along a first direction, then the multiple deflection partitions 212 are also arranged along the first direction; if the incident beam performs a two-dimensional array scan, then the multiple deflection partitions are arranged in a two-dimensional array. The scanning method of the incident beam can be related to the shape of the incident beam.
[0177] When the incident beam is a strip beam with an aspect ratio greater than a set threshold, the first optical deflector 100 is configured to deflect the incident beam at multiple different first deflection angles along a first direction within one deflection period, so as to perform a one-dimensional scan of the second optical deflector 200, and the multiple deflection partitions 212 included in the second optical deflector 200 are arranged along the first direction of beam deflection; for example Figure 1 and Figure 2As shown, multiple deflection partitions 212 are arranged vertically. Each deflection partition 212 can be a rectangle with an aspect ratio greater than a set threshold. The width direction of the deflection partition is consistent with the scanning direction of the incident beams at multiple different first deflection angles; that is, the width direction of the deflection partition is along the first direction, and the length direction of the deflection partition is along the second direction.
[0178] When the incident beam is a non-strip beam with an aspect ratio within a set threshold range, the first optical deflector 100 is configured to deflect multiple different first deflection angles in a two-dimensional array scanning manner along a first direction and a second direction that are perpendicular to each other within one deflection cycle, so as to perform a two-dimensional scan of the second optical deflector 200, and the multiple deflection partitions 212 included in the second optical deflector 200 are arranged in a two-dimensional array along the first direction and the second direction. The first direction is the width direction of the beam, and the first direction is perpendicular to the second direction.
[0179] In the aforementioned second optical deflection device 200, multiple deflection partitions 212 are configured such that the number of incident beams received by each deflection partition 212 is the same, all different, or partially the same and partially different; correspondingly, the widths of the multiple deflection partitions 212 are the same, all different, or partially the same and partially different. The width of each deflection partition 212 is determined based on the number of incident beams received and the width of the incident beams.
[0180] The number of incident beams received by each deflection partition 212 can be configured to be the same. For example, each deflection partition 212 can receive one incident beam, meaning there is a one-to-one correspondence between the incident beams in each deflection partition 212. Alternatively, each deflection partition 212 can receive two or more incident beams, with a one-to-two or one-to-many relationship between the deflection partition 212 and the incident beams. In this case, the width of each deflection partition 212 can be the same, equal to the sum of the widths of the beams it receives. For instance, in a one-to-two configuration, the width of one deflection partition 212 is equal to the sum of the widths of the two beams.
[0181] The number of incident beams received by each deflection partition 212 can be configured to be different. For example, the first deflection partition 212 receives one incident beam, the second deflection partition 212 receives two incident beams, the third deflection partition 212 receives three incident beams, and so on. In this case, the width of each deflection partition 212 is different, and the width of each deflection partition 212 is equal to the sum of the widths of the beams it receives.
[0182] The number of incident beams received by each deflection partition 212 can be configured such that some parts are the same and some parts are different. For example, the first deflection partition 212 receives one incident beam, the second deflection partition 212 receives two incident beams, the third deflection partition 212 receives one incident beam, the fourth deflection partition 212 receives two incident beams, and so on. In this case, the width of each deflection partition 212 is the same in some parts and different in others, and the width of each deflection partition 212 is equal to the sum of the widths of the beams it receives.
[0183] In some optional embodiments, the controller 600 can determine whether the deflection angle of each deflection partition 212 can be adjusted based on its scanning state. Each deflection partition 212 can adjust its deflection angle when it is in a non-scanning state. The controller 600 can also be used to determine whether each deflection partition 212 is in a scanning state. After determining that a deflection partition 212 has completed the incident beam deflection of the current deflection cycle and is in a non-scanning state, the controller controls the deflection partition 212 to adjust its deflection angle. Before entering the scanning state in the next deflection cycle, the deflection angle of the deflection partition 212 is adjusted to the second deflection angle required for the next deflection cycle. Each deflection partition 212 can start adjusting its deflection angle after it has completed the deflection of the beam in the current deflection cycle and is in a non-scanning state, thereby better ensuring that the angle can be adjusted in a timely manner. The non-scanning state refers to a state where there is no incident beam and no beam deflection is required.
[0184] In practical applications, the deflection zone 212 currently being scanned by the beam can be defined as the deflection zone in the scanning state, and the remaining deflection zones 212 can be defined as the deflection zones in the non-scanning state. That is, if a deflection zone is the deflection zone currently being scanned by the incident beam, then the deflection zone is determined to be in the scanning state; otherwise, the deflection zone is determined to be in the non-scanning state.
[0185] Optionally, the deflection partition 212 currently being scanned by the incident beam and the next deflection partition 212 to be scanned can be determined as deflection partitions in a scanning state, while the remaining deflection partitions 212 are determined as deflection partitions in a non-scanning state. The remaining deflection partitions 212 include all deflection partitions in the second optical deflecting device 200 other than the deflection partition 212 currently being scanned by the incident beam and the next deflection partition to be scanned. The deflection partition currently being scanned by the incident beam and the next deflection partition to be scanned can be either adjacent in position or not adjacent in position. That is, if a deflection partition 212 is either currently being scanned or will be scanned by the incident beam, then the deflection partition 212 is determined to be in a scanning state; otherwise, the deflection partition 212 is determined to be in a non-scanning state. The deflection partition currently being scanned by the incident beam and the next deflection partition to be scanned can be either adjacent in position or not adjacent in position. The incident beam is usually scanned into each deflection zone 212 in a set order. The controller 600 can determine the next deflection zone to be scanned based on the currently scanned deflection zone and the scanning order.
[0186] Since the incident beam deflected by the first optical deflector 100 can illuminate different positions of the second optical deflector 200, and different positions of the second optical deflector 200 correspond to different deflection zones, it is possible to determine which deflection zones are in a scanning state and which are in a non-scanning state based on the incident position. Specifically, the control device 600 is used to determine the deflection zone 212 currently in a scanning state and the deflection zone 212 currently in a non-scanning state based on the incident position of the incident beam on the second optical deflector 200. For the deflection zone 212 in a non-scanning state, if the incident sequence of this deflection zone 212 is before that of the deflection zone 212 in a scanning state, the deflection angle of this deflection zone 212 relative to the beam is adjusted to the second deflection angle required for the next deflection cycle.
[0187] The deflection angle of each deflection zone in the aforementioned second optical deflecting device 200 can be adjusted by changing the voltage on the electrodes. Different deflecting devices operate on different principles. For optical deflecting devices that change the deflection angle by altering the refractive index, the aforementioned control device 600 controls the voltage applied to the electrodes of each deflection zone 212 to adjust the refractive index of the medium in the deflection zone 212 relative to the incident beam, thereby adjusting the deflection angle of the deflection zone 212 relative to the incident beam. For example, if the second optical deflecting device 200 uses a liquid crystal polarization grating, the control device 600 controls the voltage applied to the electrodes of each deflection zone 212 to adjust the arrangement direction of the liquid crystal molecules in the liquid crystal polarization grating, thereby changing the second deflection angle of the deflection zone relative to the incident beam.
[0188] In some alternative embodiments, see Figure 5a , 5b and Figure 6a , 6b As shown, the second optical deflection device 200 includes at least one optical deflection unit 210, and each optical deflection unit 210 includes a plurality of deflector partitions 2121; each deflection partition 212 includes a deflector partition 2121 corresponding to a position in the at least one optical deflection unit 210. When the second optical deflection device 200 includes one optical deflection unit 210, the deflection partition is one deflector partition 2121 on this one optical deflection unit 210; when the second optical deflection device 200 includes two optical deflection units 210, the deflection partition includes two deflector partitions 2121 corresponding to positions on these two optical deflection units 210. When the second optical deflection device 200 includes multiple optical deflection units 210, the deflection partition 212 includes multiple deflector partitions 2121 corresponding to positions on these multiple optical deflection units 210. The aforementioned second optical deflection device 200 may include one or more optical deflection units 210, and the number of optical deflection units 210 is related to the number of second deflection angles. Figure 5a , 5b and Figure 6a , 6b The diagram uses four optical deflection units 210 as an example. In practical applications, the number of optical deflection units 210 can be set as needed. Multiple deflection angles can be combined using the deflection angles of each optical deflection unit 210. For example, if one optical deflection unit 210 can achieve two angles of deflection, and four angles of deflection are required during optical scanning, then two optical deflection units 210 are used; if eight angles of deflection are required, then three optical deflection units 210 are used; if sixteen angles of deflection are required, then four optical deflection units 210 are used; and so on. That is, the relationship between the number of optical deflection units 210 N and the required number of deflection angles M satisfies M = 2. N .
[0189] The optical deflection unit 210 includes deflector sections 2121 whose deflection angles can be independently adjusted. Since the optical deflection unit 210 has multiple deflector sections 2121 whose deflection angles can be independently controlled, beams with different deflection angles can be incident on one of the deflector sections 2121 and deflected. Therefore, the deflection angle of the deflector section 2121 on the beam can be adjusted during the time when it is not scanned. When the second optical deflection device 200 includes at least one optical deflection unit 210, the controller 600 is specifically used to control the voltage on the two electrodes of each deflector section 2121. By changing the voltage on the two electrodes of at least one deflector section 2121, the deflection angle of at least one deflector section on the incident beam is changed, thereby changing the second deflection angle of the corresponding deflection section 212 on the incident beam. In other words, by adjusting the deflection angle of some or all of the multiple deflector sections 2121 on the beam, the second deflection angle of the entire deflection section 212 on the incident beam is changed.
[0190] The aforementioned second optical deflecting device 200 can deflect the incident beam in one direction or in two different directions. When only one direction needs to be deflected, the second optical deflecting device 200 includes at least one optical deflecting unit 210 that deflects the incident beam in the same direction. In this case, the number of optical deflecting units 210 is set according to the number of second deflection angles required, and can be one, two, or more.
[0191] To achieve angular deflection of the light beam in two different directions, the second optical deflection device 200 may include at least two optical deflection units 210, or the second optical deflection device 200 may include at least two optical deflection unit groups 220, each optical deflection unit group 220 including at least one optical deflection unit 210, wherein at least one optical deflection unit group 220 is configured to deflect the light beam in a first direction and at least one optical deflection unit group 220 is configured to deflect the light beam in a second direction, and the first direction and the second direction may be perpendicular to each other.
[0192] Optionally, the optical deflection unit group 220, which has a smaller number of deflection angles for the beam, is positioned relatively closer to the incident light side. This results in a better deflection effect. For example... Figure 5a , 5b and Figure 6a , 6b As shown, the optical deflection unit group 220 for deflecting in the first direction includes one optical deflection unit 210, placed on the far left, to achieve deflection at two angles in the first direction. See also Figure 7The diagram shows the optical path of the light deflection device 10 deflecting the light beam along the first direction. The light beam emitted by the light source 300 is collimated by the collimating device 400 and then incident on the first light deflection device 100. After being deflected, the light beam is amplified by the polarizing device 500 and then incident on different deflection zones corresponding to the second light deflection device 200. The second light deflection device 200 can deflect the light beam at two different angles in the first direction. The light deflection unit group 220 for deflecting the light beam in the second direction includes three light deflection units 210, which are placed on the far right to achieve deflection at eight angles in the second direction. See [reference needed]. Figure 8 The diagram shows the optical path of the light deflection device 10 deflecting the light beam along the second direction. The light beam emitted by the light source 300 is collimated by the collimating device 400 and then incident on the first light deflection device 100. After being deflected, the light beam is amplified by the polarizing device 500 and then incident on the second light deflection device 200. The second light deflection device 200 can deflect the light beam at eight different angles in the second direction. Figure 8 Only three angles are shown in the diagram. Placing the optical deflection units 210, which deflect the beam along the deflection direction with the fewest deflection angles, earlier in the optical path can improve the diffraction efficiency of the beam. The beam deflection function can also be achieved without following the above-mentioned order.
[0193] In some optional embodiments, the light deflection unit 210 may be, for example but not limited to, a liquid crystal polarization grating. The liquid crystal polarization grating can deflect the outgoing light to a predetermined angle without amplifying the incident light divergence angle; the angle range can reach ± tens of degrees, making it very suitable for expanding the scanning field of view. However, it can only deflect discrete angles and has a slow response speed; therefore, this application employs a partitioned approach for angle switching adjustment. Each light deflection unit 210 can deflect left-handed and right-handed circularly polarized light at two different angles, corresponding to the +1 and -1 diffraction order angles of the liquid crystal grating. By cascading N light deflection units 210, the diffraction of 2... N Light deflection at discrete angles.
[0194] The optical deflection unit 210 includes a liquid crystal half-wave plate 214 and a liquid crystal polarizing grating (LCPG) plate 216; the liquid crystal half-wave plate 214 includes electrodes disposed opposite to each other on both sides and a half-wave plate liquid crystal layer 215 disposed between the electrodes on both sides.
[0195] One side electrode of the liquid crystal half-wave plate 214 includes multiple first electrode blocks 211, and the other side electrode is a first monolithic electrode 213. Each deflector partition corresponds to at least one first electrode block 211. Each deflector partition 2121 includes a portion on the liquid crystal half-wave plate 214 corresponding to the position of at least one first electrode block 211, and a portion on the liquid crystal polarizing grating 216 corresponding to the position of at least one first electrode block 211; or
[0196] Both sides of the liquid crystal half-wave plate 214 include multiple first electrode blocks 211, and two opposing first electrode blocks 211 form a first electrode pair 2110. Each deflector partition 2121 corresponds to at least one first electrode pair 2110. Each deflector partition 2121 includes a portion on the liquid crystal half-wave plate 214 corresponding to the position of at least one first electrode pair 2110 and a portion on the liquid crystal polarizing grating 216 corresponding to the position of at least one first electrode pair 2110.
[0197] Specifically, the deflection angle of the beam by the corresponding deflector section 2121 is adjusted by changing the voltage applied to the electrode corresponding to the deflector section 2121 in the liquid crystal half-wave plate 214.
[0198] In other words, the liquid crystal half-wave plate 214 in the optical deflection unit 210 is equipped with electrodes, which can be divided into blocks on one side or both sides. The liquid crystal polarizing grating 216 can be equipped with electrodes or not. The two cases are described below.
[0199] In some optional embodiments, the liquid crystal polarizing grating 216 is a passive liquid crystal deflection grating without electrodes. The light deflection unit 210 changes the deflection direction of the light beam through the passive liquid crystal deflection grating by adjusting the voltage applied to the electrodes on both sides of the liquid crystal half-wave plate 214. The deflection rotor partition 2121 of the light deflection unit 210 can be realized by dividing one or both sides of the liquid crystal half-wave plate 214 into a block structure. The required voltage can be applied to each electrode block, thereby realizing the independent adjustment of the deflection angle of each deflection rotor partition 2121.
[0200] For cases where one electrode is made into a modular structure, see [link / reference]. Figure 5a As shown. One side electrode of the liquid crystal half-wave plate 214 includes multiple first electrode blocks 211, and the other side electrode is a first monolithic electrode 213. Each deflector partition 2121 corresponds to at least one first electrode block 211. Each deflector partition 2121 includes a portion on the liquid crystal half-wave plate 214 corresponding to the position of at least one first electrode block, and a portion on the liquid crystal polarizing grating 216 corresponding to the position of at least one first electrode block 211. The portion corresponding to the position refers to the portion that is directly opposite in position. See [reference needed]. Figure 5aAs shown in the dashed box, the portion corresponding to the position of at least one first electrode block 211 refers to the portion on the liquid crystal polarizing grating 216 located within the same dashed box as at least one first electrode block 211. In this case, each first electrode block 211 corresponds to one deflector partition 2121. Alternatively, multiple first electrode blocks 211 may correspond to one deflector partition 2121. Multiple first electrode blocks 211 may include two or more first electrode blocks 211. Multiple first electrode blocks 211 may be arranged in a regular array, such as, but not limited to, a one-dimensional or two-dimensional array arrangement, or they may be arranged in an irregular array arrangement.
[0201] For cases where the electrodes on both sides are made into a block structure, see example... Figure 5b As shown, both sides of the liquid crystal half-wave plate 214 include multiple first electrode blocks 211, and two opposing first electrode blocks form an electrode pair. Each deflector partition 2121 corresponds to at least one electrode pair. Each deflector partition includes a portion on the liquid crystal half-wave plate 214 corresponding to the position of at least one electrode pair, and a portion on the liquid crystal polarizing grating 216 corresponding to the position of at least one electrode pair. The portion corresponding to the position refers to the portion that is directly opposite each other in position. See [reference needed]. Figure 5b As shown in the dashed box, the portion corresponding to the position of at least one electrode pair refers to the portion on the liquid crystal polarizing grating 216 located in the same dashed box as at least one electrode pair. Figure 5b In the liquid crystal half-wave plate 214, the corresponding electrode blocks on both sides are directly opposite each other. However, these corresponding electrode blocks may not be strictly aligned, and a slight misalignment between them is also acceptable. In this case, each electrode pair corresponds to one deflector partition 2121, and alternatively, multiple electrode pairs may correspond to one deflector partition 2121. Multiple electrode pairs may include two or more electrode pairs. The multiple first electrode blocks 211 in each side may be arranged in a regular array, such as, but not limited to, a one-dimensional or two-dimensional array arrangement, or an irregular array arrangement.
[0202] Specifically, the deflection angle of the beam by the corresponding deflector section 2121 is adjusted by changing the voltage applied to the electrode corresponding to the deflector section 2121 in the liquid crystal half-wave plate 214.
[0203] In some optional embodiments, the optical deflection unit 210 includes a liquid crystal half-wave plate 214 and a liquid crystal polarizing grating 216. The liquid crystal half-wave plate 214 includes electrodes disposed opposite to each other on both sides and a liquid crystal layer disposed between the electrodes on both sides. The liquid crystal polarizing grating 216 is an active liquid crystal polarizing grating, which includes electrodes disposed opposite to each other on both sides and a grating liquid crystal layer 2164 disposed between the electrodes on both sides. The controller 600 needs to adjust the voltage applied to the electrodes of the liquid crystal half-wave plate 214 and the electrodes of the active liquid crystal polarizing grating 216 to change the deflection angle of the light beam. The deflection rotor partition 2121 of the optical deflection unit 210 can be realized by making one or both sides of the electrodes of the liquid crystal half-wave plate 214 into a block structure and making one or both sides of the electrodes of the liquid crystal polarizing grating into a block structure. The required voltage can be applied to each electrode block, thereby realizing the independent adjustment of the deflection angle of each deflection rotor partition 2121. In the optical deflection unit 210, the liquid crystal half-wave plate 214 further includes a first substrate 217 and a second substrate 218 disposed opposite to each other; the liquid crystal polarizing grating 216 further includes a third substrate 2161 and a fourth substrate 2162 disposed opposite to each other.
[0204] The configuration of one side electrode of the liquid crystal polarizing grating 216 as a block structure is similar to that of the liquid crystal half-wave plate 214 described above. Similarly, the configuration of both side electrodes of the liquid crystal polarizing grating 216 as a block structure is also similar to that of the liquid crystal half-wave plate 214 described above, and will not be repeated here. It should be noted that:
[0205] In an optical deflection unit 210, both the liquid crystal polarizing grating 216 and the liquid crystal half-wave plate 214 can be configured as a block structure with one-sided electrodes; see [link / reference] Figure 6a As shown, one side electrode of the liquid crystal half-wave plate 214 includes multiple first electrode blocks 211, and the other side electrode is a first monolithic electrode 213; one side electrode of the liquid crystal polarizing grating 216 includes multiple second electrode blocks 2163, and the other side electrode is a second monolithic electrode 2165; at least one second electrode block 2163 on the liquid crystal polarizing grating 216 and at least one corresponding first electrode block 211 on the liquid crystal half-wave plate 214 form a block group; each deflector partition 2121 corresponds to at least one block group, that is, each deflector partition 2121 corresponds to at least one first electrode block 211 of the liquid crystal half-wave plate 214, and also corresponds to at least one second electrode block 2163 of the liquid crystal polarizing grating 216. Each deflector partition 2121 includes a portion on the liquid crystal half-wave plate 214 corresponding to the position of the block group, and a portion on the liquid crystal polarizing grating 216 corresponding to the position of the block group.
[0206] In a single optical deflection unit 210, both the liquid crystal polarizing grating 216 and the liquid crystal half-wave plate 214 can be configured with block structures using electrodes on both sides, see [link / reference] Figure 6b As shown, the electrodes on both sides of the liquid crystal half-wave plate 214 each include a plurality of first electrode blocks 211, and two opposing first electrode blocks 211 on the liquid crystal half-wave plate 214 form a first electrode pair 2110; the electrodes on both sides of the liquid crystal polarizing grating 216 each include a plurality of second electrode blocks 2163, and two opposing second electrode blocks 2163 on the liquid crystal polarizing grating 216 form a second electrode pair 2160; at least one second electrode pair 2160 on the liquid crystal polarizing grating 216 and at least one first electrode pair 2110 on the liquid crystal half-wave plate 214 form a block group; each deflector partition 2121 corresponds to at least one block group, that is, each deflector partition 2121 corresponds to at least one first electrode pair 2110 of the liquid crystal half-wave plate 214, and also corresponds to at least one second electrode pair 2160 of the liquid crystal polarizing grating 216. Each deflector partition 2121 includes a portion on the liquid crystal half-wave plate 214 corresponding to the block group position, and a portion on the liquid crystal polarizing grating plate 216 corresponding to the block group position.
[0207] In one optical deflection unit 210, one side electrode of the liquid crystal polarizing grating 216 can be selected as a block structure, and both sides electrodes of the liquid crystal half-wave plate 214 can be selected as a block structure. Two opposing first electrodes on the liquid crystal half-wave plate form a first electrode pair. At least one second electrode block on the liquid crystal polarizing grating 216 and at least one first electrode pair on the liquid crystal half-wave plate 214 corresponding to a block group are formed. Each deflector partition 2121 corresponds to at least one block group, that is, each deflector partition 2121 corresponds to at least one first electrode pair of the liquid crystal half-wave plate 214, and also corresponds to at least one second electrode block of the liquid crystal polarizing grating 216. Each deflector partition 2121 includes the portion on the liquid crystal half-wave plate 214 corresponding to the position of the block group, and the portion on the liquid crystal polarizing grating 216 corresponding to the position of the block group.
[0208] In one optical deflection unit 210, the two side electrodes of the liquid crystal polarizing grating 216 can be selected as a block structure, and the one side electrode of the liquid crystal half-wave plate 214 can be selected as a block structure. Two opposing second electrodes on the liquid crystal polarizing grating 216 are divided into blocks to form a second electrode pair. At least one second electrode pair on the liquid crystal polarizing grating 216 and at least one first electrode block on the liquid crystal half-wave plate 214 corresponding to a position form a block group. Each deflector partition 2121 corresponds to at least one block group, that is, each deflector partition 2121 corresponds to at least one first electrode block of the liquid crystal half-wave plate 214, and also corresponds to at least one second electrode pair of the liquid crystal polarizing grating 216. Each deflector partition 2121 includes the portion on the liquid crystal half-wave plate 214 corresponding to the position of the block group, and the portion on the liquid crystal polarizing grating 216 corresponding to the position of the block group.
[0209] Specifically, the deflection angle of the beam by the corresponding deflector partition 2121 is adjusted by changing the voltage applied to the electrode corresponding to the deflector partition 2121 in the liquid crystal half-wave plate 214 and the voltage applied to the electrode corresponding to the deflector partition 2121 in the liquid crystal polarizing grating 216.
[0210] It should be noted that, in the case where the second optical deflection device 200 includes at least two optical deflection units 210, the deflection rotor partitions 2121 on the at least two different optical deflection units 210 are respectively arranged correspondingly to each other. In this case, the multiple deflection rotor partitions 2121 that are located at the positions of different optical deflection units 210 and can form a deflection optical path can be adjusted simultaneously when the deflection angle is adjusted. At this time, it is necessary to adjust the voltage applied to these multiple deflection rotor partitions 2121 respectively.
[0211] From another perspective, the multiple deflector partitions 2121, belonging to different optical deflection units 210 and corresponding to each other, which can form a deflection optical path, can also be understood as a structurally separable deflection partition 212. Each deflection partition 212 has a uniform deflection angle to the light beam and can be independently adjusted as a whole. The multiple deflection partitions 212 are arranged sequentially according to the deflection direction of the light beam at the first deflection angle. That is to say, the deflector partitions 2121 of at least one optical deflection unit 210 included in a deflection partition 212 can form a deflection optical path. When a deflection partition 212 includes one optical deflection unit 210, the deflector partitions 2121 in that optical deflection unit 210 can form a deflection optical path. When a deflection partition 212 includes two optical deflection units, the deflector partitions 2121 in these two optical deflection units 210 can form a deflection optical path. When a deflection partition 212 includes multiple optical deflection units 210, the deflection rotor partitions 2121 in these multiple optical deflection units can form a deflection optical path.
[0212] Optionally, a quarter-wave plate can be set in front of the first liquid crystal half-wave plate to change the polarization state of the incident beam, so as to change the linearly polarized light emitted by the first light deflection device 100 into circularly polarized light.
[0213] The electrodes, for example but not limited to ITO electrodes, are used. The shape and arrangement of the electrode blocks depend on the shape of the beam to be deflected and its scanning position on the light deflection unit 210. The incident beam is an elongated beam with its length direction along the second direction, and it scans on the light deflection unit 210 along the first direction. Correspondingly, the electrode blocks are also elongated with their length direction along the second direction, and multiple electrode blocks are also arranged in parallel along the first direction. Different electrode blocks are set separately, so voltage can be applied independently to control the arrangement state of the corresponding liquid crystal molecules within the partition.
[0214] Theoretically, within the same optical deflection device, the liquid crystal half-wave plates 214 belonging to different optical deflection units 210 can also have different ITO electrode structures. For example, the electrode structure of some of the liquid crystal half-wave plates 214 belonging to different optical deflection units 210 can be partitioned on both sides, while the electrode structure of others can be partitioned on one side and not partitioned on the other. Similarly, the liquid crystal polarization gratings 216 belonging to different optical deflection units can also have different ITO electrode structures. For example, the electrode structure of some of the liquid crystal polarization gratings 216 belonging to different optical deflection units 210 can be partitioned on both sides, while the electrode structure of others can be partitioned on one side and not partitioned on the other.
[0215] See Figure 5a , 5b and Figure 6a , 6b As shown, the liquid crystal half-wave plate 214 may further include a first substrate 217 and a second substrate 218 disposed opposite to each other, with electrodes on both sides respectively disposed on the inner surfaces of the first substrate 217 and the second substrate 218 facing each other, and the inner surfaces being, for example, planar. The liquid crystal polarizing grating 216 further includes a third substrate 2161 and a fourth substrate 2162 disposed opposite to each other, with electrodes on both sides respectively disposed on the inner surfaces of the third substrate 2161 and the fourth substrate 2162 facing each other, and the inner surfaces being, for example, planar.
[0216] In some optional embodiments, all the liquid crystal polarization gratings 216 of the optical deflection units 210 in the second optical deflection device 200 are passive liquid crystal polarization gratings, or all the liquid crystal polarization gratings 216 of the optical deflection units 210 in the second optical deflection device 200 are active liquid crystal polarization gratings, or some of the liquid crystal polarization gratings 216 of the optical deflection units 210 in the second optical deflection device 200 are passive liquid crystal polarization gratings and some of the liquid crystal polarization gratings 216 of the optical deflection units 210 are active liquid crystal polarization gratings; the liquid crystal material of the liquid crystal layer is a nematic liquid crystal. The liquid crystal material of the liquid crystal layer may be, for example, but not limited to, a nematic liquid crystal.
[0217] Taking a passive liquid crystal polarizing grating as an example, the passive liquid crystal polarizing grating does not require an applied voltage to change the liquid crystal arrangement during operation. The polarization state of the passing light beam can be changed by selecting whether or not a voltage is applied to the liquid crystal half-wave plate 214, thereby controlling the deflection direction of the light beam through the passive liquid crystal polarizing grating. The deflection angle of the light beam by the passive liquid crystal polarizing grating is preset. The left-handed and right-handed polarization components of the incident light beam are deflected towards the positive and negative first-order diffraction directions of the liquid crystal polarizing grating. The angles between these two diffraction directions and the incident direction are equal, but the deflection directions are opposite. Therefore, by combining light deflection units with different deflection angles and applying corresponding voltages to the liquid crystal half-wave plate, multiple preset angles of deflection of the passing light beam can be achieved.
[0218] For each incident beam emitted by the first optical deflector 100 at a first deflection angle varying along the first direction, as the beam begins scanning, the voltage applied to the scanned deflection partitions in the second optical deflector 200 is simultaneously and sequentially changed, switching the liquid crystal molecule arrangement of the scanned deflection partitions to the state required by the next beam deflection angle. Thus, each deflection partition 212 can switch its liquid crystal arrangement state by using the gap between other deflection partitions scanned by the first optical deflector 100 along the first direction. When the beam deflected by the first optical deflector 100 has finished scanning the last deflection partition of the second optical deflector 200 within the deflection cycle, the liquid crystal molecule arrangement in the first deflection partition to be scanned in the next deflection cycle has already switched to the state required by the next beam deflection angle. Therefore, the first optical deflector 100 can be immediately controlled to deflect the beam along the first direction to the first deflection partition to be scanned to begin scanning the next deflection cycle without waiting. It can also be understood that the liquid crystal half-wave plate can update the liquid crystal arrangement in real time along the scanning direction of the beam at a preset frequency to achieve seamless switching of the beam deflection angle.
[0219] See Figure 9The diagram illustrates a structural example of a passive liquid crystal polarizing grating used in the second optical deflector 200. In the second optical deflector 200, the optical deflection units 210 are cascaded in a binary configuration. Multiple optical deflection units are arranged sequentially along the beam propagation direction, and the deflection angles of the passing beam increase progressively in a power of two according to their arrangement. That is, the first optical deflector unit closest to the incident light side has the smallest deflection angle, while the unit farthest from the incident light side has the largest deflection angle. Assuming the deflection angle of the first optical deflector unit is r, the deflection angles of the N optical deflection units 210 arranged sequentially along the beam's exit direction are ±r, ±2r, ±4r, ..., ±2... N-1 r. Correspondingly, the entire second optical deflection device 200, including N optical deflection units, can deflect the passing light beam by preset deflection angles of ±r, ±3r, ±5r…, ±(2 N -1)·r, it can be seen that the beam deflection angle provided by the second optical deflection device 200 is an odd multiple of the minimum deflection angle r of a single optical deflection unit on the beam, and the maximum value of the odd multiple is two to the power of N minus one, where N is the number of optical deflection units included in the second optical deflection device 200. The angular interval between the preset deflection angles of adjacent levels is 2r, that is, the multiple preset deflection angles of the second optical deflection device 200 on the beam are distributed in an arithmetic sequence according to the preset angular interval, and the deflection accuracy of the beam is 2r. The angular interval can be regarded as the angular tolerance of the arithmetic sequence. Therefore, the relationship between the range Ψ of the second deflection angle of the beam on the beam based on the binary cascaded optical deflection unit 210 and the total number M of different deflection angles that can be provided is expressed as:
[0220] Ψ=(2 N -1)·r
[0221] M=2 N
[0222] Where r is the minimum deflection angle of the passing beam among the N optical deflection units, and N is the total number of optical deflection units 210 in the second optical deflection device 200.
[0223] During use, the polarization state of the light beam incident on the passive liquid crystal polarization grating 216 in the light deflection unit 210 can be selected by applying a voltage to the liquid crystal half-wave plate 214 in the light deflection unit 210, thereby controlling the deflection direction of the light beam when it passes through the passive liquid crystal polarization grating 216. For example, if the light beam is deflected in the positive first-order diffraction direction when it passes through the liquid crystal half-wave plate 214 with a saturated voltage applied and then through the passive liquid crystal polarization grating 216, then the light beam will be deflected in the negative first-order diffraction direction when it passes through the liquid crystal half-wave plate 214 without a voltage applied and then through the passive liquid crystal polarization grating 216. Since the polarization state of the light beam is changed when it is diffracted by the passive liquid crystal polarization grating 216, if the light beam is to continue to be deflected to the same diffraction level in the next light deflection unit 210, the voltage applied to the liquid crystal half-wave plate 214 in the next light deflection unit 210 needs to be turned off so that the liquid crystal half-wave plate 214 can change the polarization state of the light beam back to the polarization state before the last deflection. If the light beam is to be deflected to the opposite diffraction level in the next light deflection unit 210, a saturation voltage needs to be applied to the liquid crystal half-wave plate 214 in the next light deflection unit 210 so that the polarization state of the light beam is not changed.
[0224] Figure 10a This diagram illustrates the relationship between the voltage control of the binary cascaded optical deflection unit 210 and the deflection angle of the one-dimensional deflection of the light beam. The shaded area indicates that a saturation voltage is applied to the corresponding liquid crystal half-wave plate 214; in this case, the liquid crystal half-wave plate 214 does not change the polarization state of the light beam. The white area indicates that the saturation voltage applied to the liquid crystal half-wave plate 214 is turned off, and the corresponding liquid crystal half-wave plate 214 will change the polarization state of the light beam. Since all liquid crystal polarization gratings are passive, no voltage can be applied to any of the passive liquid crystal polarization gratings 216; they will deflect the light beam by a preset angle in the direction corresponding to the positive or negative diffraction order, depending on the polarization state of the light beam. Figure 10aThe example illustrates a second optical deflection device comprising four cascaded optical deflection units in a binary configuration. Each optical deflection unit includes a liquid crystal half-wave plate and a passive liquid crystal polarization grating. The units are arranged sequentially along the beam emission direction: the first unit includes a liquid crystal half-wave plate I and a passive liquid crystal polarization grating I; the second unit includes a liquid crystal half-wave plate II and a passive liquid crystal polarization grating II; the third unit includes a liquid crystal half-wave plate III and a passive liquid crystal polarization grating III; and the fourth unit includes a liquid crystal half-wave plate IV and a passive liquid crystal polarization grating IV. Furthermore, the passive liquid crystal polarization gratings I-IV have the same grating vector direction. The deflection angle of the beam by the passive liquid crystal polarization gratings I-IV increases sequentially in power of 2, with the value being the optical deflection unit number minus one, corresponding to r, 2r, 4r, and 8r. In practical applications, the deflection angle of each liquid crystal polarization grating can be selected as needed.
[0225] See Figure 9 and Figure 10a As shown, a reference frame is established with a horizontally incident beam as 0 degrees, a leftward deflection as a positive angle, and a rightward deflection as a negative angle. If the polarization state of the beam when it enters the second optical deflector 200 causes the passive liquid crystal polarizing grating to deflect the beam in the direction of positive first-order diffraction, and the beam wants to obtain a +r deflection angle after passing through the entire second optical deflector, the voltage to the liquid crystal half-wave plate I must be turned off. This causes the beam passing through the liquid crystal half-wave plate I to change its polarization state first. In this way, the passive liquid crystal polarizing grating I will deflect the passing beam by -r and simultaneously change the polarization state of the beam back to its incident polarization state. Since the passive liquid crystal polarizing gratings II and III are then required to continue deflecting the beam in the directions of -2r and -4r respectively, the voltages of the liquid crystal half-wave plates II and III must be turned off accordingly so that the beam changes its polarization state before entering the corresponding passive liquid crystal polarizing gratings II and III. Finally, a saturation voltage is applied to the liquid crystal half-wave plate IV to maintain the polarization state of the light beam after passing through the passive liquid crystal polarizing grating III, returning it to its incident polarization state. This allows the light beam to be deflected back to +8r in the opposite direction when passing through the passive plate IV, ultimately obtaining the deflection direction r. Similarly, the second optical deflection device 200 can also be deflected in the same way... Figure 10aThe voltage application method shown deflects the passing light beam to other preset deflection angles, such as 3r, 5r, 7r, 9r, 11r, 13r, 15r, -r, -3r, -5r, -7r, -9r, -11r, -13r, and -15r in the figure. By changing the voltage application of the liquid crystal half-wave plates I-IV, the polarization state of the light beam before entering the corresponding passive liquid crystal polarization grating I-IV is adjusted. Through the cooperation of the four optical deflection units 210, 16 different deflection angles can be achieved. It can be understood that different numbers of deflection angles can be achieved by setting different numbers of optical deflection units 210.
[0226] Figure 10b This is a schematic diagram showing the relationship between the voltage control of the binary cascaded optical deflection unit 210 and the deflection angle for two-dimensional deflection of the light beam. Figure 10a The difference is that, Figure 10a The four deflection units in the middle deflect the beam in the same direction, such as horizontal or vertical. Figure 10b In the middle section, one of the four deflection units deflects the beam in the first direction, and the other three deflection units deflect the beam in the second direction. Here, p represents the minimum deflection angle of the beam in the vertical direction, and h represents the minimum deflection angle of the beam in the horizontal direction. The four deflection units working together can achieve two deflection angles in the vertical direction and eight deflection angles in the horizontal direction. For example... Figure 10b The angles shown are (-p, h), (p, h), (-p, 3h), (p, 3h), (-p, 5h), (p, 5h), (-p, 7h), (p, 7h), (-p, -7h), (p, -7h), (-p, -5h), (p, -5h), (-p, -3h), (p, -3h), (-p, -h), (p, -h).
[0227] The difference between using an active liquid crystal polarizing grating and a passive liquid crystal polarizing grating is that a passive grating does not require an applied voltage during operation. Beam deflection is achieved simply by applying a corresponding voltage to the liquid crystal half-wave plate, resulting in fast response and a simple driving program. An active grating, on the other hand, requires applying a corresponding voltage for different deflection angles. This necessitates adjusting the applied voltages to both the liquid crystal half-wave plate and the active grating separately for each deflection angle. When using an active grating, the applied voltages to both the liquid crystal half-wave plate and the active grating in the optical deflection unit 210 of the second optical deflection device can be changed. By altering the applied voltage, different deflection angles can be achieved; further details are omitted here.
[0228] In some optional embodiments, in the second optical deflection device 200 described above, the adjustment time for the second deflection angle of the incident beam by the deflection partition adjustment is no greater than the time interval between two adjacent deflection cycles of the deflection partition being scanned by the incident beam. To ensure that each deflection partition has sufficient time for deflection angle adjustment, the number of deflection partitions can be reasonably set within the duration of the deflection cycle. This is because if the number of deflection partitions is too small, it cannot be guaranteed that the time interval between two adjacent deflection cycles of each deflection partition being scanned by the incident beam is sufficient to complete the deflection angle adjustment. Therefore, the number of deflection partitions is determined based on the number of second deflection angles deflected by the second optical deflection device 200, the time required for the second optical deflection device 200 to deflect multiple beams with multiple different first deflection angles to multiple different second deflection angles, and the adjustment time required for the second optical deflection device 200 to complete one deflection angle adjustment. Alternatively, the number of deflection partitions can be set based on the number of deflection angles of the second optical deflection device, the required frame rate, and the time required for the second optical deflection device to complete one deflection angle adjustment. This ensures that, while meeting the required frame rate, the deflection partitions can complete the deflection angle adjustment within the interval between two scans. Specifically, the number D of deflection partitions 212 is an integer greater than or equal to 2 / (1-FMT), where M is the number of deflection angles of the second optical deflection device 200, F is the frame rate at which the second optical deflection device 200 completes one round of deflection of M angles, and T is the time required for the second optical deflection device 200 to complete one deflection angle adjustment. Setting the number of deflection partitions according to this formula is a preferred method, ensuring that each deflection partition does not need to wait and can complete the angle adjustment during the scan interval. Even setting a smaller number can still reduce waiting time to some extent.
[0229] The response speed of the liquid crystal half-wave plate 214 is on the order of milliseconds. The system is inactive during the adjustment of the liquid crystal switching state. To meet the requirement of a 10Hz frame rate for optical scanning, a single pass through all scanning angles must be completed within 100ms. Therefore, to ensure system scanning efficiency, the ITO electrode layer of the liquid crystal half-wave plate is segmented. During beam scanning, the beam is incident on one electrode segment, while the remaining electrode segments not incident on the beam can be adjusted to change the phase delay.
[0230] Taking the first optical deflection device 100 deflecting the emitted light beam in the vertical direction as an example. Assuming the liquid crystal response time is S ms, and N optical deflection units combined need to achieve a total deflection of multiple discrete angles, then each optical deflection unit needs to be divided into D deflection zones along the vertical direction. See [link / reference] Figure 11 , Figure 12 , Figure 13As shown, at the beginning of a frame (100ms in duration), the light beam enters the first deflection zone, and the beam width in the vertical direction is designed to be the width of one deflection zone. The first light deflecting device 100 deflects the beam quasi-continuously downwards at a downward angle, and the beam begins to enter the second deflection zone. At this time, the first and second deflection zones are in a "scanning" state, and the state of the liquid crystal molecules within them cannot be adjusted, while the remaining K-2 layers are in a "non-scanning" state. When the beam leaves the first deflection zone and begins to enter the third deflection zone, the first deflection zone enters a "non-scanning" state, while the second and third deflection zones are in a "scanning" state. According to the above rules, when the beam enters the Dth deflection zone, one deflection cycle is completed. At this time, the first light deflecting device 100 deflects the beam back into the first deflection zone, and the second deflection cycle begins. Multiple deflection cycles are required within one frame, and in each deflection cycle, the second light deflecting device 200 deflects the light to one of multiple discrete angles.
[0231] See Figure 11 , Figure 12 , Figure 13 As shown, in some embodiments, the light deflection unit 210 is divided into 1-D parallel deflection partitions. Corresponding to each second deflection angle, incident light beams at different first deflection angles scan vertically from the first partition to the Dth deflection partition. After the light beam deflected by the first light deflection device 100 leaves the first deflection partition and scans the second deflection partition, the first deflection partition, which has already been scanned, can begin to change the voltage applied to it through corresponding independently configured ITO electrode blocks, thereby switching the liquid crystal molecule arrangement state corresponding to the first deflection partition to the liquid crystal molecule arrangement state required for the next second deflection angle. In other words, during the process of the incident light beam scanning from the second deflection partition to the Dth deflection partition, the liquid crystal molecule arrangement state corresponding to the first deflection partition can be synchronously changed through the corresponding ITO electrode blocks, and the entire process is sufficient to complete the change of the liquid crystal molecule arrangement state of the first deflection partition. Therefore, for a second deflection angle, when the incident beam at the first deflection angle has scanned from the first deflection partition to the Dth deflection partition, and some liquid crystal molecules corresponding to the first deflection partition have completed the state change required for the next second deflection angle, the incident beam can immediately and seamlessly start scanning the next second deflection angle again from the first deflection partition.
[0232] For example, to meet a scan frame rate of 10Hz, for Figure 1 and Figure 2All 16 second deflection angles need to be scanned within 100ms. The scanning time for each second deflection angle is 100 / 16 = 6.25ms. The optical deflection unit is divided into 10 deflection zones, so the scanning time for each deflection zone is 6.25 / 10 = 0.625ms. As mentioned above, the liquid crystal state of the deflection zone cannot be changed during the scanning of the current deflection zone and the next deflection zone. Therefore, for a deflection zone, the time to adjust the deflection angle is 6.25 - 2 * 0.625 = 5ms. This time is equal to the adjustment time of the liquid crystal state during the switching of the next deflection angle. Therefore, 5ms is sufficient to meet the requirement of seamless switching of deflection angles.
[0233] The above description assumes that the beam scans each deflection zone sequentially from top to bottom within one deflection cycle, and then continues to scan each deflection zone sequentially from top to bottom in the next deflection cycle. In practical applications, the scanning order does not need to be followed; the scanning order can be randomly adjusted. For example, the beam may not be incident in a top-to-bottom order. Furthermore, within one deflection cycle, the second deflection angle of each beam can be the same or different, as long as it ultimately covers the entire field of view.
[0234] In the aforementioned second optical deflection device 200, the optical deflection unit is divided into D deflection rotor partitions along the first direction. The size of the optical deflection unit 210 in the first direction is greater than D*d_v, where d_v is the size of the light beam in the first direction at this time. Correspondingly, the size of the optical deflection unit in the second direction must satisfy the requirement of including the size of the light beam in the second direction.
[0235] The second optical deflection device 200 described above can be any suitable device besides an LCPG capable of coarse beam deflection, as long as it is divided into multiple deflection zones 212 and the deflection angle of each zone can be adjusted individually. This invention is consistent with the concept of this application. The second optical deflection device 200 is typically thin; therefore, when the incident beam enters the device, the beam path is not affected by the thickness of the device, allowing for approximately straight-line illumination.
[0236] In some optional embodiments, the second optical deflecting device 200 further includes a temperature regulator 240 configured to adjust the time for the optical deflection sections to adjust their deflection angles by changing the temperature of the second optical deflecting device 200. To ensure the proper functioning of the liquid crystal molecules within the liquid crystal polarizing grating of the second optical deflecting device, the temperature of the second optical deflecting device 200 needs to be controlled within a certain temperature range. The temperature regulator can control the temperature of the second optical deflecting device 200 within a preset temperature range. Furthermore, the speed at which liquid crystal molecules adjust their state differs at different temperatures, resulting in different adjustment times for the deflection angles of each deflection section. Therefore, the adjustment time for the deflection angles of the deflection sections can be changed by altering the temperature of the second optical deflecting device 200.
[0237] The aforementioned second optical deflection device 200 with a partitioned structure can, during the change in incident position caused by the change in the first deflection angle of the incident beam, synchronously refresh the liquid crystal molecule arrangement of the scanned deflection partitions to the state required for the next second deflection angle by applying a voltage change. This allows for seamless switching of the beam deflection angle without waiting. For existing LCPG modules, since a uniform voltage is applied to the entire ITO electrode on the liquid crystal half-wave plate, when the LCPG module needs to switch the deflection angle of the beam, it needs to correspondingly change the voltage applied to the ITO electrode of the liquid crystal half-wave plate. This process requires waiting for the change in the liquid crystal molecule arrangement state, which takes a long time. Therefore, in existing LCPG modules, the entire system can only wait and cannot scan and detect during the aforementioned deflection angle switching process.
[0238] In some optional embodiments, the incident beam can be a strip beam. The second light deflector 200 is configured such that, when the incident beam is a strip beam: multiple incident beams with different first deflection angles are deflected to the same second deflection angle to complete scanning of a corresponding scanning partition of the field of view; and each beam with a different first deflection angle is deflected to multiple different second deflection angles to complete scanning of multiple scanning partitions corresponding to different second deflection angles. The scanning partition is rectangular, and the length of the beam after deflection by the second deflection angle is equal to the length of one direction of the scanning partition.
[0239] It is understood that, in some embodiments, when scanning the entire field of view, the angle and order of the beams with the first and second deflection angles can be configured to complete the scanning of one scanning area first, then proceed to the next scanning area, and so on, until all scanning areas are scanned. That is, within one deflection cycle, multiple incident beams with different first deflection angles can be deflected to the same second deflection angle to complete the scanning of a corresponding scanning partition of the field of view; different deflection cycles deflect the incident beams with different first deflection angles at different second deflection angles, thus completing the scanning of a corresponding scanning partition within one deflection cycle; after completing one scanning partition, the next deflection cycle scans the next scanning partition; thus, multiple different scanning partitions can be scanned correspondingly through multiple deflection cycles.
[0240] See Figure 1 As shown, the entire field of view can be divided into multiple scanning zones. Figure 1 Taking 16 scanning zones as an example, corresponding to 16 grids in the diagram. The second optical deflector 200, with different deflection zones, deflects the received strip-shaped incident light at different second deflection angles, illuminating different scanning zones. One second deflection angle corresponds to one scanning zone. Multiple incident beams with first deflection angles, after being deflected by the second deflection angle, can completely cover a scanning zone. Therefore, 16 second deflection angles can correspond to 16 scanning zones. See also... Figure 1 As shown, by deflecting two second deflection angles in the first direction and eight second deflection angles in the second direction, it is possible to achieve... Figure 1 The scanning of the 16 scanning partitions shown corresponds to a second deflection angle. That is, multiple different first deflection angles deflected by the first optical deflector 100 are deflected by the second optical deflector 200 to the same second deflection angle, thus covering one scanning partition. The scanning partition is rectangular, and the length of the strip beam after deflection by the second deflection angle is equal to the length of one direction of the scanning partition. In actual scanning, within the first deflection cycle, beams with multiple first deflection angles are all deflected by the first second deflection angle to complete the scanning of the first square in the first row; within the second deflection cycle, beams with multiple first deflection angles are all deflected by the second second deflection angle to complete the scanning of the second square in the first row; ...; within the fourth deflection cycle, beams with multiple first deflection angles are all deflected by the fourth second deflection angle, such as... Figure 1 The scan of the fourth square in the first row is completed; and so on, after 16 deflection cycles, the scan of all the scan partitions corresponding to the 16 squares is completed.
[0241] In some other embodiments, the second optical deflecting device 200 deflects incident beams with multiple different first deflection angles to one of multiple different second deflection angles within one deflection cycle, respectively scanning a portion of the corresponding scanning partition. Within one deflection cycle, the second deflection angles of the incident beams with multiple different first deflection angles may be the same or different; the second deflection angles of the incident beams with each first deflection angle are different in different deflection cycles. Within one deflection cycle, each incident beam with multiple different first deflection angles is randomly deflected to one of multiple different second deflection angles, such that the second deflection angles of all incident beams with first deflection angles within one deflection cycle are the same, partially the same, partially different, or completely different from each other. Optionally, within one deflection cycle, at least two incident beams with multiple different first deflection angles are deflected to different second deflection angles, such that the second deflection angles of all incident beams with first deflection angles within one deflection cycle are partially the same, partially different, or completely different from each other.
[0242] For example, within one deflection cycle, deflected beams incident at different first deflection angles can be deflected at two or more different second deflection angles. In this case, within one deflection cycle, instead of focusing on scanning a single corresponding scan partition, the beams are scanned at different positions along the first deflection angle within two or more different scan partitions in a skipping manner. After multiple deflection cycles, scanning of all scan partitions can be completed. For example, in this embodiment, within one deflection cycle, the scanned positions of the beams formed after deflection at the second deflection angle and the scan partitions corresponding to different second deflection angles are far apart, which can reduce crosstalk between adjacent scans.
[0243] See Figure 2As shown, the entire field of view can be divided into multiple scanning zones, with 16 scanning zones corresponding to the 16 grids in the diagram. Within one deflection cycle, the second optical deflector 200 can deflect beams with multiple first deflection angles to different second deflection angles, so as to alternately scan different scanning zones. For example, within the first deflection cycle, the second optical deflector 200 deflects a beam with a first first deflection angle to a first second deflection angle, scanning a small strip area in the first square of the first row; deflects a beam with a second first deflection angle to a second second deflection angle, scanning a small strip area in the second square of the first row; and so on. Within the second deflection cycle, the second optical deflector 200 deflects a beam with a first first deflection angle to a first second deflection angle, scanning a small strip area in the second square of the first row; deflects a beam with a second first deflection angle to a second second deflection angle, scanning a small strip area in the third square of the first row; and so on. By repeating this process, the scanning area corresponding to each square is scanned crosswise. After multiple deflection cycles, the scanning of all scanning partitions corresponding to all squares is completed. This configuration allows the two scanning areas corresponding to each other within the field of view to be relatively far apart in two adjacent deflection cycles. Consequently, the photosensitive pixels used by the receiving module to sense these two corresponding scanning areas are also relatively far apart during these two adjacent scanning periods, reducing crosstalk between these photosensitive pixels that operate sequentially.
[0244] Compared to scanning with a circular or near-circular light spot, using a long beam to scan the field of view and deflecting the beam in the width direction with a first light deflector (e.g., AOD) allows for a significant reduction in the number of angles the second light deflector (e.g., LCPG) deflects in the first and second directions. Figure 1 and Figure 2 As shown, the second optical deflection device 200 deflects 16 angles, 8 angles in the horizontal direction and 2 angles in the vertical direction. The number of angles deflected by the second optical deflection device 200 is related to the number of layers it contains (i.e. the number of optical deflection units in the optical deflection device). Therefore, the number of layers of the second optical deflection device 200 can also be reduced. For example, when deflecting 16 angles, the second optical deflection device 200 only needs four layers. The second optical deflection device 200 can be made thinner and smaller in size.
[0245] The scanning partition is rectangular. The length of the strip beam after being deflected by the second deflection angle is equal to the length of one direction of the scanning partition, for example... Figure 1 and Figure 2The length of the strip beam after being deflected by the second deflection angle is equal to the length of the scanning partition in the second direction. The long side of the strip beam emitted from the first optical deflector 100 is perpendicular to the optical deflection direction of the first optical deflector 100, which means that compared to the blocky scanning light, the beam deflected by the second deflection angle can cover a larger field of view at the same total power. Therefore, the second optical deflector 200 can cover a larger overall field of view by deflecting fewer different angles. This results in fewer layers of the second optical deflector 200 (i.e., fewer optical deflection units 210), lower cost, and faster response speed.
[0246] The aforementioned optical deflection device 10 is used, for example but not limited to, in lidar systems employing all-solid-state scanning. As an optical deflection structure, it achieves full-field-of-view coverage scanning, thereby increasing detection range and emission power per unit field of view. It can also be used in high-speed photography, optical engineering, space optical communication, non-destructive testing, optical sensing technology, optical multimode guidance technology, magneto-optical recording technology, magneto-optical imaging technology, laser display technology, and precision optical instruments. The second optical deflector 200 in the optical deflection device 10 can further deflect the beam emitted from the first optical deflector 100. The first optical deflector 100 performs fine deflection, while the second optical deflector 200 performs coarse deflection. The first optical deflector 100 can also be an optical phased array (OPA), an acousto-optic deflector (AOD), or an electro-optic deflector (EOD). Since the deflection angle of these deflectors is only about 2-3 degrees, the second optical deflector 200 needs to further expand the deflection angle or deflect in different directions to achieve coverage of the field of view. The second optical deflection device 200 mentioned above can be a liquid crystal optical deflection device.
[0247] In some optional embodiments, the control device 600 of the above-described optical deflection device 10 can be an independent device, enabling control of the first optical deflection device 100 and the second optical deflection device 200 through a single independent device. The control device 600 can also be a discrete device, see [reference needed]. Figure 3 As shown, it includes a first control unit 110 and a second control unit 230;
[0248] The first control unit 110 is used to control the first optical deflection device 100 to deflect multiple different first deflection angles in a deflection cycle, and to project the incident beam of each first deflection angle onto the corresponding deflection zone of the second optical deflection device 200. The first control unit 110 can be set up separately or integrated with the first optical deflection device.
[0249] The second control unit 230 is used to control multiple deflection sections 212 to receive the incident light beam in a time-division manner and to deflect the incident light beam by the required second deflection angle, and to control the deflection sections 212 to pre-adjust their deflection angles to the light beam before being scanned by the incident light beam; wherein, the deflection angle of at least one deflection section 212 to the incident light beam is adjusted to the required second deflection angle for the next deflection cycle after the current deflection cycle has been scanned by the incident light beam and before the next deflection cycle begins to be scanned by the incident light beam. The second control unit 230 can be set independently or integrated with the second optical deflection device.
[0250] In some alternative embodiments, the device further includes a temperature regulator 240 configured to adjust the time for adjusting the deflection angle of the deflection zone by changing the temperature of the second optical deflector 200. The temperature regulator 240 may be provided separately or integrated with the second optical deflector.
[0251] The aforementioned partitioned optical deflection unit 210, during the change in incident position caused by the change in the first deflection angle of the incident beam, can synchronously refresh the liquid crystal molecule arrangement of the scanned deflection partitions to the state required for the next second deflection angle by applying a voltage change. This allows for seamless switching of the beam deflection angle without waiting. In contrast, existing LCPG modules apply a uniform voltage across the entire ITO electrode on the liquid crystal half-wave plate. When the LCPG module needs to switch the beam deflection angle, it needs to correspondingly change the voltage applied to the ITO electrode of the liquid crystal half-wave plate. This process requires waiting for the liquid crystal molecule arrangement state to change, which takes a considerable amount of time. Therefore, in existing LCPG modules, the entire system can only wait and cannot scan or detect during the aforementioned deflection angle switching process.
[0252] Example 2
[0253] Embodiment 2 of the present invention provides an optical scanning method, the process of which is as follows: Figure 14 As shown, it includes:
[0254] S101: Control the first optical deflection device 100 to deflect the incident beam at multiple different first deflection angles within one deflection cycle, so as to correspond to the incident beam onto the corresponding deflection partition 212 of the second optical deflection device 200.
[0255] S102: Control the multiple deflection sections 212 in the second optical deflection device 200 to receive multiple incident beams with different first deflection angles; the deflection angle of each deflection section 212 can be adjusted individually for the incident beam. The second optical deflection device 200 includes multiple deflection sections 212, and the deflection angle of each deflection section 212 can be adjusted individually for the incident beam.
[0256] The first optical deflector 100 deflects the incident beam sequentially by multiple different first deflection angles in the first direction, and the second optical deflector 200 deflects the incident beam by multiple different second deflection angles in the first and second directions respectively.
[0257] A deflection partition 212 can sequentially receive two or more incident beams incident at different first deflection angles.
[0258] S103: Control the current scanned deflection zone 212 to deflect the incident beam by the second deflection angle required.
[0259] S104: Control at least one currently unscanned deflection zone 212 to adjust the deflection angle of the incident beam to the second deflection angle required for the next deflection cycle after the current deflection cycle has been scanned by the incident beam and before the next deflection cycle has begun to be scanned by the incident beam.
[0260] In practical applications, steps S103 and S104 are executed in parallel, without any order.
[0261] In step S104, at least one currently unscanned deflection partition 212 is controlled to adjust its deflection angle to the incident beam to the second deflection angle required for the next deflection cycle after the current deflection cycle has been scanned by the incident beam and before the next deflection cycle begins scanning by the incident beam. After determining that a deflection partition 212 has completed the incident beam deflection for the current deflection cycle and is in a non-scanning state, the deflection partition is controlled to adjust its deflection angle to the beam, and before entering the scanning state in the next deflection cycle, its deflection angle to the beam is adjusted to the second deflection angle required for the next deflection cycle. The adjustment process may include: determining the deflection partition 212 currently in a scanning state and the deflection partition 212 in a non-scanning state based on the incident position of the incident beam on the second optical deflection device 200; for the deflection partition 212 in a non-scanning state, if the incident sequence of the deflection partition 212 is before that of the deflection partition 212 in a scanning state, then adjusting the deflection angle of the deflection partition 212 to the beam to the second deflection angle required for the next deflection cycle. Specifically, if a deflection partition is the current incident deflection partition of the incident beam, then the deflection partition is determined to be in a scanning state; otherwise, the deflection partition is determined to be in a non-scanning state; or, if a deflection partition is the deflection partition currently being scanned or the next to be scanned by the incident beam, then the deflection partition is determined to be in a scanning state; otherwise, the deflection partition is determined to be in a non-scanning state. Optionally, the deflection partition 212 currently being scanned by the incident beam and the next deflection partition 212 to be scanned can be defined as deflection partitions in the scanning state, and the remaining deflection partitions 212 can be defined as deflection partitions in the non-scanning state; the deflection partition currently being scanned by the incident beam and the next deflection partition to be scanned are deflection partitions that are adjacent in position.
[0262] In the above method, controlling the first optical deflecting device 100 to deflect the incident beam at multiple different first deflection angles within one deflection period, so as to correspondingly incident on the corresponding deflection partition 212 of the second optical deflecting device 200, includes: controlling the first optical deflecting device 100 to deflect the incident beam at multiple different first deflection angles in a preset order within one deflection period, and correspondingly incident the incident beam at each first deflection angle onto the corresponding deflection partition 212 of the second optical deflecting device; controlling the multiple deflection partitions 212 in the second optical deflecting device 200 to receive multiple incident beams at multiple different first deflection angles, includes: controlling the multiple deflection partitions 212 to receive multiple incident beams at multiple different first deflection angles in a time-division manner.
[0263] The deflection period is the time required for multiple deflection partitions 212 to be scanned once by incident beams at multiple different first deflection angles, or the deflection period is the time required for a specified portion of the multiple deflection partitions 212 to be scanned once by incident beams at a specified portion of the multiple different first deflection angles.
[0264] In the above method, within one deflection period, the deflection angles of multiple beams with different first deflection angles change from large to small, or from small to large, or change according to a preset random rule.
[0265] In the above method, multiple deflection partitions 212 are configured such that multiple second deflection angles for deflecting the incident beam within one deflection period are all the same, or all different, or partially the same and partially different.
[0266] In the above method, a deflection partition 212 can sequentially receive one, two or more incident beams with different first deflection angles within one deflection period.
[0267] In the above method, multiple deflection partitions 212 are configured such that multiple second deflection angles for deflecting the incident beam within one deflection cycle are all the same, or all different, or partially the same and partially different.
[0268] In the above method, the number of incident beams that each deflection partition 212 can receive is the same, different, or partially the same and partially different; correspondingly, the widths of multiple deflection partitions 212 are the same, different, or partially the same and partially different.
[0269] The above method adjusts the refractive index of the medium in the deflection partition 212 to the incident light beam by controlling the voltage applied to the electrodes of each deflection partition 212, thereby adjusting the deflection angle of the deflection partition 212 to the incident light beam. When the second optical deflection device 200 uses a liquid crystal polarization grating, the arrangement direction of the liquid crystal molecules in the liquid crystal polarization grating is adjusted by controlling the voltage applied to the electrodes of each deflection partition 212, thereby changing the second deflection angle of the deflection partition 212 to the incident light beam.
[0270] The second optical deflection device 200 includes at least one optical deflection unit 210, and the optical deflection unit 210 includes a plurality of deflector partitions 2121. When the deflection partition 212 includes the deflector partition 2121 corresponding to the position in the optical deflection unit 210, the voltage on the two end electrodes of each deflector partition 2121 is controlled respectively. By changing the voltage on the two end electrodes of at least one deflector partition 2121, the deflection angle of at least one deflector partition 2121 to the incident light beam is changed, so as to change the second deflection angle of the corresponding deflection partition 212 to the incident light beam.
[0271] Optionally, if the second optical deflection device 200 includes at least two optical deflection unit groups 220, each optical deflection unit group 220 including at least one optical deflection unit 210; controlling the second deflection angle required to deflect the incident beam by the currently scanned deflection partition 2121 includes: the second deflection angle required to deflect the incident beam in a first direction by the deflection partition 2121 of the optical deflection unit 210 currently scanned in at least one optical deflection unit group 220, and / or the second deflection angle required to deflect the incident beam in a second direction by the deflection partition 2121 of the optical deflection unit 210 currently scanned in at least one optical deflection unit group 220, wherein the first direction and the second direction are perpendicular.
[0272] In the above method, the adjustment time of the deflection partition 212 to adjust the second deflection angle of the incident beam is no greater than the time interval between two adjacent scans of the deflection partition 212 by the incident beam. The number of deflection partitions 212 is determined based on the number of second deflection angles deflected by the second optical deflection device 200, the time required for the second optical deflection device 200 to deflect multiple beams with multiple different first deflection angles to multiple different second deflection angles, and the adjustment time required for the second optical deflection device 200 to complete one deflection angle adjustment. Optionally, the number D of deflection partitions 212 is an integer greater than or equal to 2 / (1-FMT), where M is the number of deflection angles of the second optical deflection device 200, F is the frame rate at which the second optical deflection device 200 completes one round of deflection angle M, and T is the time required for the second optical deflection device 200 to complete one deflection angle adjustment.
[0273] The above method also includes: changing the temperature of the second optical deflection device 200 to adjust the time for adjusting the deflection angle of the deflection zone.
[0274] The field of view of the optical scan is divided into multiple scanning zones, each of which is rectangular, and the incident beam is a strip beam. Scanning the field of view includes: deflecting multiple incident beams with different first deflection angles to the same second deflection angle to complete the scanning of one corresponding scanning zone of the field of view; deflecting each beam with a different first deflection angle to multiple different second deflection angles to complete the scanning of all scanning zones corresponding to the different second deflection angles; the length of the strip beam after deflection by the second deflection angle is equal to the length of one direction of the scanning zone.
[0275] Within one deflection cycle, incident beams with multiple different first deflection angles are deflected to the same second deflection angle to complete the scanning of a corresponding scanning partition of the field of view; the second deflection angles deflected by the multiple different incident beams with first deflection angles are different in different deflection cycles; or within one deflection cycle, incident beams with multiple different first deflection angles are deflected to one of multiple different second deflection angles respectively to scan a portion of the corresponding scanning partition; wherein, within one deflection cycle, the second deflection angles deflected by the multiple different incident beams with first deflection angles are the same or different; the second deflection angles deflected by the incident beams with each first deflection angle are different in different deflection cycles.
[0276] The above method further includes: before the incident beam is incident on the first optical deflection device, the incident beam is collimated by the collimating device 400 in a first direction and a second direction that are perpendicular to each other;
[0277] The first direction is the direction in which the incident beam is deflected by the first optical deflector 100.
[0278] The above method also includes: amplifying the deflection angle of the deflected beam after being deflected by the first optical deflector 100 or the second optical deflector 200 in the corresponding deflection direction by a preset multiple through the polarization amplification device 500.
[0279] The methods described in the embodiments of the present invention have been described in the relevant descriptions of optical deflection devices, and will not be repeated in the method section.
[0280] Example 3
[0281] Embodiment 3 of the present invention provides a transmitting module, the structure of which is described in [reference needed]. Figure 15 As shown, it includes: a light source 300 and a light deflection device 10; the light deflection device 10 can be the light deflection device provided in Embodiment 1.
[0282] Light source 300 is used to emit a light beam to the light deflection device;
[0283] The light deflection device 10 is used to deflect the incident light beam emitted by the light source 300 to generate scanning beams with different deflection angles and deflection angle switching sequences to achieve scanning of the field of view.
[0284] The light beam emitted by the light source 300 has a shorter length along a first direction than along a second direction. The first direction is the deflection direction of the incident light beam by the first optical deflection device, and the second direction is perpendicular to the first direction. The light source 300 includes any one or more combinations of a vertical-cavity surface-emitting laser, an edge-emitting laser, a light-emitting diode, a laser diode, a semiconductor laser, and a fiber laser.
[0285] Embodiment 3 of the present invention provides a lidar system, the structure of which is described in [reference needed]. Figure 16 As shown, it includes: a receiving module 2 and the aforementioned transmitting module 1. The receiving module 2 is configured to sense light signals from the field of view and obtain three-dimensional information of the field of view by processing and analyzing the sensed light signals.
[0286] Embodiment 3 of the present invention provides an electronic device, including the above-described lidar system.
[0287] The aforementioned transmitting module, lidar system, and electronic device of this invention have been described in the relevant description of the optical deflection device, and will not be repeated in the method section.
[0288] In the above description of the embodiments of the present invention, when multiple are mentioned, it should be understood that two or more are included.
[0289] Unless otherwise specifically stated, terms such as processing, calculation, operation, determination, display, etc., may refer to the actions and / or processes of one or more processing or computing systems or similar devices that represent the manipulation and conversion of data representing physical (e.g., electronic) quantities within the registers or memory of the processing system into other data similarly representing physical quantities within the memory, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals can be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.
[0290] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.
[0291] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.
[0292] Those skilled in the art will also understand that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments herein can be implemented as electronic hardware, computer software, or a combination thereof. To clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in alternative ways for each specific application; however, such implementation decisions should not be construed as departing from the scope of this disclosure.
[0293] The steps of the methods or algorithms described in conjunction with the embodiments herein can be directly embodied in hardware, software modules executed by a processor, or a combination thereof. The software modules can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. The ASIC can reside in a user terminal. Alternatively, the processor and storage medium can exist as discrete components in the user terminal.
[0294] For software implementation, the techniques described in this application can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described in this application. This software code can be stored in memory units and executed by a processor. The memory units can be implemented within the processor or outside the processor; in the latter case, they are communicatively coupled to the processor via various means, as is well known in the art.
[0295] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."
Claims
1. An optical deflection device, characterized in that, It includes a control device, a first optical deflector, and a second optical deflector; the second optical deflector includes multiple deflection zones, each of which can individually adjust the deflection angle of the incident beam. The first optical deflection device is configured to deflect the incident beam at multiple different first deflection angles within a deflection period, corresponding to the deflection zones of the second optical deflection device. The currently scanned deflection zone is used to deflect the incident beam by the second deflection angle required. The controller is configured to control at least one currently unscanned deflection zone to adjust its deflection angle to the incident beam, such that the deflection angle of at least one deflection zone to the incident beam is adjusted to the second deflection angle required for the next deflection cycle after the current deflection cycle has been scanned by the incident beam and before the next deflection cycle begins to be scanned by the incident beam.
2. The optical deflection device as described in claim 1, characterized in that, Within one deflection period, the incident beams with multiple different first deflection angles are incident into the multiple deflection zones in a time-division manner, and the multiple deflection zones receive the incident beams and deflect the incident beams in a time-division manner. The deflection period is the time required for the plurality of deflection partitions to be scanned once by incident beams at the plurality of different first deflection angles, or the deflection period is the time required for a specified portion of the plurality of deflection partitions to be scanned once by incident beams at the specified portion of the plurality of different first deflection angles.
3. The optical deflection device as described in claim 1, characterized in that, The first optical deflection device is configured to sequentially incident multiple incident beams with different first deflection angles onto the corresponding deflection partitions in the second optical deflection device in a preset order within one deflection period. A deflection zone is configured to deflect the incident beam by a corresponding second deflection angle within one deflection period.
4. The optical deflection device as described in claim 1, characterized in that, Within one deflection period, the deflection angles of the multiple beams with different first deflection angles change from large to small, or from small to large, or change according to a preset random rule. The plurality of deflection zones are configured such that the plurality of second deflection angles deflecting the incident beam within one deflection cycle are all the same, all different, or partially the same and partially different. A deflection partition can be configured to sequentially receive one, two or more incident beams with different first deflection angles within a deflection period.
5. The optical deflection device as described in claim 1, characterized in that, The arrangement direction of the plurality of deflection partitions is consistent with the scanning direction of the plurality of incident beams with different first deflection angles.
6. The optical deflection device as described in claim 5, characterized in that, When the incident beam is a strip beam with an aspect ratio greater than a set threshold, the first optical deflection device is configured to deflect the incident beam at multiple different first deflection angles along the first direction within one deflection period, so as to perform a one-dimensional scan of the second optical deflection device, and the multiple deflection partitions included in the second optical deflection device are arranged along the first direction of beam deflection. When the incident beam is a non-strip beam with an aspect ratio within a set threshold range, the first optical deflection device is configured to deflect multiple different first deflection angles in a two-dimensional array scanning manner along a first direction and a second direction that are perpendicular to each other within one deflection cycle, so as to perform two-dimensional scanning on the second optical deflection device, and the multiple deflection partitions included in the second optical deflection device are arranged in a two-dimensional array along the first direction and the second direction. The first direction is the width direction of the light beam, and the first direction is perpendicular to the second direction.
7. The optical deflection device as described in claim 1, characterized in that, The plurality of deflection partitions are configured such that the number of incident beams received by each deflection partition is the same, different, or partially the same and partially different; correspondingly, the widths of the plurality of deflection partitions are the same, different, or partially the same and partially different.
8. The optical deflection device as described in claim 7, characterized in that, The incident surface of the deflection partition is a rectangle with an aspect ratio greater than a set threshold. The width direction of the deflection partition is consistent with the scanning direction of multiple incident beams with different first deflection angles. The width of each deflection partition is determined according to the number of incident beams received and the width of the incident beams.
9. The optical deflection device as described in claim 1, characterized in that, When the incident beam is a strip beam with an aspect ratio greater than a set threshold, the first optical deflection device deflects the incident beam sequentially by multiple different first deflection angles in the first direction, and the second optical deflection device deflects the incident beam by multiple different second deflection angles in the first and second directions respectively. The first direction is the width direction of the light beam, and the first direction is perpendicular to the second direction.
10. The optical deflection device as described in claim 1, characterized in that, The first optical deflection device has a higher deflection accuracy for the light beam than the second optical deflection device. The first optical deflection device is configured such that, among a plurality of different first deflection angles for deflecting the incident beam, the angular interval between two adjacent first deflection angles is less than or equal to the divergence angle of the beam after deflection by the first optical deflection device along the deflection direction.
11. The optical deflection device as described in claim 1, characterized in that, The control device is specifically used for: Once a deflection zone has completed the deflection of the incident beam in the current deflection cycle and is in a non-scanning state, the deflection zone is controlled to adjust its deflection angle to the beam. Before entering the scanning state in the next deflection cycle, its deflection angle to the beam is adjusted to the second deflection angle required for the next deflection cycle.
12. The optical deflection device as described in claim 11, characterized in that, If a deflection zone is the deflection zone currently being scanned by the incident beam, then the deflection zone is determined to be in a scanning state; otherwise, the deflection zone is determined to be in a non-scanning state. If a deflection zone is the deflection zone that the incident beam is currently scanning or the next deflection zone to be scanned, then the deflection zone is determined to be in a scanning state; otherwise, the deflection zone is determined to be in a non-scanning state.
13. The optical deflection device as described in claim 11, characterized in that, The deflection partition currently being scanned by the incident beam and the next deflection partition to be scanned are defined as deflection partitions in the scanning state, and the remaining deflection partitions are defined as deflection partitions in the non-scanning state; the deflection partition currently being scanned by the incident beam and the next deflection partition to be scanned are deflection partitions that are adjacent in position.
14. The optical deflection device as described in claim 1, characterized in that, The control device is used to control the voltage applied to the electrodes of each deflection zone to adjust the refractive index of the medium in the deflection zone to the incident beam, so as to adjust the deflection angle of the deflection zone to the incident beam. The adjustment time for the second deflection angle of the incident beam by the deflection partition adjustment is no greater than the time interval between two adjacent deflection cycles of the deflection partition being scanned by the incident beam.
15. The optical deflection device as described in claim 1, characterized in that, The second optical deflection device employs a liquid crystal polarization grating. The control device is used to control the voltage applied to the electrodes of each deflection zone to adjust the arrangement direction of liquid crystal molecules in the liquid crystal polarization grating, thereby changing the second deflection angle of the deflection zone to the incident light beam.
16. The optical deflection device as described in claim 1, characterized in that, The second optical deflection device includes at least one optical deflection unit, and the optical deflection unit includes multiple deflector partitions; the deflection partitions include deflector partitions in the at least one optical deflection unit that correspond to the position; the deflector partitions in at least one optical deflection unit included in a deflection partition can form a deflection optical path.
17. The optical deflection device as described in claim 16, characterized in that, When the second optical deflection device includes one optical deflection unit, the deflection partition is one deflector partition on this optical deflection unit; when the second optical deflection device includes two optical deflection units, the deflection partition includes two deflector partitions on the two optical deflection units corresponding to their positions; when the second optical deflection device includes multiple optical deflection units, the deflection partition includes multiple deflector partitions on the multiple optical deflection units corresponding to their positions.
18. The optical deflection device as described in claim 17, characterized in that, The controller is specifically used to: control the voltage on the two electrodes of each deflector section respectively, and change the deflection angle of at least one deflector section to the incident beam by changing the voltage on the two electrodes of at least one deflector section, so as to change the second deflection angle of the incident beam of the corresponding deflection section.
19. The optical deflection device as described in claim 17, characterized in that, The second optical deflection device includes at least one optical deflection unit that deflects the incident beam in the same direction; or The second optical deflection device includes at least two optical deflection unit groups, each optical deflection unit group including at least one optical deflection unit, wherein at least one optical deflection unit group is configured to deflect the light beam in a first direction, and at least one optical deflection unit group is configured to deflect the light beam in a second direction.
20. The optical deflection device as described in claim 16, characterized in that, The optical deflection unit includes a liquid crystal half-wave plate and a liquid crystal polarizing grating. The liquid crystal half-wave plate includes electrodes disposed opposite to each other on both sides and a half-wave plate liquid crystal layer disposed between the electrodes on both sides. One side electrode of the liquid crystal half-wave plate includes multiple first electrode blocks, and the other side electrode is a first whole electrode. Each deflector partition corresponds to at least one first electrode block. Each deflector partition includes a portion on the liquid crystal half-wave plate corresponding to the position of the at least one first electrode block and a portion on the liquid crystal polarizing grating corresponding to the position of the at least one first electrode block; or The electrodes on both sides of the liquid crystal half-wave plate include multiple first electrode blocks, and two opposing first electrode blocks form a first electrode pair. Each sub-deflection zone corresponds to at least one first electrode pair. Each deflection zone includes a portion on the liquid crystal half-wave plate corresponding to the position of the at least one first electrode pair and a portion on the liquid crystal polarizing grating corresponding to the position of the at least one first electrode pair. Specifically, the deflection angle of the beam by the corresponding deflector section is adjusted by changing the voltage applied to the electrode corresponding to the deflector section in the liquid crystal half-wave plate.
21. The optical deflection device as described in claim 16, characterized in that, The optical deflection unit includes a liquid crystal half-wave plate and a liquid crystal polarizing grating; the liquid crystal half-wave plate includes electrodes disposed opposite to each other on both sides and a half-wave plate liquid crystal layer disposed between the electrodes on both sides; the liquid crystal polarizing grating includes electrodes disposed opposite to each other on both sides and a grating liquid crystal layer disposed between the electrodes on both sides. One side electrode of the liquid crystal half-wave plate includes multiple first electrode blocks, and the other side electrode is a first monolithic electrode; one side electrode of the liquid crystal polarizing grating includes multiple second electrode blocks, and the other side electrode is a second monolithic electrode; at least one second electrode block on the liquid crystal polarizing grating and at least one corresponding first electrode block on the liquid crystal half-wave plate form a block group; or The electrodes on both sides of the liquid crystal half-wave plate each include multiple first electrode blocks, and two opposing first electrode blocks form a first electrode pair; the electrodes on both sides of the liquid crystal polarizing grating each include multiple second electrode blocks, and two opposing second electrode blocks form a second electrode pair; at least one second electrode pair on the liquid crystal polarizing grating and at least one corresponding first electrode pair on the liquid crystal half-wave plate form a block group; or One side electrode of the liquid crystal polarizing grating includes multiple second electrode blocks, and the other side electrode is a second monolithic electrode; both sides of the liquid crystal half-wave plate include multiple first electrode blocks, and two opposing first electrode blocks form a first electrode pair; at least one second electrode block on the liquid crystal polarizing grating and at least one corresponding first electrode pair on the liquid crystal half-wave plate form a block group; or Both sides of the liquid crystal polarizing grating include multiple second electrode blocks, and two opposing second electrode blocks form a second electrode pair. One side of the liquid crystal half-wave plate includes multiple first electrode blocks, and the other side electrode is a first whole electrode. At least one second electrode pair on the liquid crystal polarizing grating and at least one first electrode block corresponding to the position on the liquid crystal half-wave plate form a block group. Each deflector partition corresponds to at least one block group; each deflector partition includes a portion on the liquid crystal half-wave plate corresponding to the position of the block group, and a portion on the liquid crystal polarizing grating plate corresponding to the position of the block group; Specifically, the deflection angle of the beam by the corresponding deflector partition is adjusted by changing the voltage applied to the electrode corresponding to the deflector partition in the liquid crystal half-wave plate and the voltage applied to the electrode corresponding to the deflector partition in the liquid crystal polarizing grating.
22. The optical deflection device as described in claim 20, characterized in that, In the second optical deflection device, all the liquid crystal polarization gratings of the optical deflection units are passive liquid crystal polarization gratings, or all the liquid crystal polarization gratings of the optical deflection units in the second optical deflection device are active liquid crystal polarization gratings, or some of the liquid crystal polarization gratings of the optical deflection units in the second optical deflection device are passive liquid crystal polarization gratings and some of the liquid crystal polarization gratings of the optical deflection units are active liquid crystal polarization gratings; the liquid crystal material of the liquid crystal layer is a nematic liquid crystal.
23. The optical deflection device as described in claim 21, characterized in that, The liquid crystal half-wave plate also includes a first substrate and a second substrate disposed opposite to each other, and electrodes on both sides are respectively disposed on the inner surfaces of the first substrate and the second substrate facing each other, wherein the inner surfaces are planar. The liquid crystal polarizing grating also includes a third substrate and a fourth substrate arranged opposite to each other, with electrodes on both sides respectively disposed on the inner surfaces of the third substrate and the fourth substrate facing each other, and the inner surfaces being planar.
24. The optical deflection device as described in claim 20, characterized in that, The second optical deflection device also includes a quarter-wave plate disposed in front of the first liquid crystal half-wave plate, used to change the polarization state of the incident beam.
25. The optical deflection device as described in claim 1, characterized in that, The number of deflection zones is determined based on the number of second deflection angles deflected by the second optical deflection device, the time required for the second optical deflection device to deflect multiple beams with multiple different first deflection angles to multiple different second deflection angles, and the adjustment time required for the second optical deflection device to complete one deflection angle adjustment.
26. The optical deflection device as described in claim 25, characterized in that, The number of deflection partitions D is an integer greater than or equal to 2 / (1-FMT), where M is the number of deflection angles of the second optical deflection device, F is the frame rate at which the second optical deflector completes one round of deflection of M deflection angles, and T is the time required for the second optical deflection device to complete one deflection angle adjustment.
27. The optical deflection device as described in claim 1, characterized in that, The second optical deflection device is configured as follows: In the case where the incident beam is a strip beam: By deflecting multiple incident beams with different first deflection angles to the same second deflection angle, scanning of one corresponding scanning zone of the field of view can be completed; by deflecting each beam with a different first deflection angle to multiple different second deflection angles, scanning of multiple scanning zones corresponding to different second deflection angles can be completed. The scanning partition is rectangular, and the length of the beam after being deflected by the second deflection angle is equal to the length of one direction of the scanning partition.
28. The optical deflection device as described in claim 27, characterized in that, The second optical deflection device is configured as follows: Within one deflection cycle, multiple incident beams with different first deflection angles are deflected to the same second deflection angle to complete the scanning of a corresponding scanning zone of the field of view; the second deflection angle deflected by the multiple incident beams with different first deflection angles is different in different deflection cycles. or Within one deflection cycle, incident beams with multiple different first deflection angles are deflected to one of multiple different second deflection angles, and scan a portion of the corresponding scanning partition. Within one deflection cycle, the second deflection angles of the incident beams with multiple different first deflection angles may be the same or different. The second deflection angles of the incident beams with each first deflection angle are different in different deflection cycles.
29. The optical deflection device as claimed in claim 1, characterized in that, Also includes: A temperature regulator is configured to adjust the time for adjusting the deflection angle of the deflection zone by changing the temperature of the second optical deflection device.
30. The optical deflection device according to any one of claims 1-29, characterized in that, The control device is also used to control the first optical deflector to deflect the incident beam and to control the currently scanned deflection partition in the second optical deflector to deflect the incident beam.
31. The optical deflection device as described in claim 30, characterized in that, The first optical deflection device is an acousto-optic deflector. The control device is used to apply a driving signal to the acoustic wave generator of the first optical deflection device, and control the acoustic wave frequency of the acoustic wave generator acting on the acousto-optic crystal of the first optical deflection device through the driving signal, so as to change the deflection angle of the light beam by the first optical deflection device.
32. The optical deflection device as described in claim 30, characterized in that, The controller is specifically used to execute the following control processes in parallel: controlling the currently scanned deflection partition in the second optical deflection device to deflect the incident beam, and controlling at least one currently unscanned deflection partition to adjust its deflection angle to the beam.
33. The optical deflection device as described in claim 30, characterized in that, The controller includes a first control unit and a second control unit; The first control unit is used to control the first optical deflection device to deflect multiple different first deflection angles in a time-division manner within a deflection cycle, and to incident the incident beam at each first deflection angle onto the corresponding deflection partition of the second optical deflection device. The second control unit is used to control the plurality of deflection sections to receive the incident beam at different times and deflect the incident beam by the second deflection angle required, and to control the deflection sections to pre-adjust their deflection angles to the beam before being scanned by the incident beam; wherein, the deflection angle of at least one deflection section to the incident beam is adjusted to the second deflection angle required for the next deflection cycle after the current deflection cycle is scanned by the incident beam and before the next deflection cycle is scanned by the incident beam.
34. The optical deflection device according to any one of claims 1-29, characterized in that, Also includes: A collimating device is disposed between the first optical deflecting device and the light source to collimate the light beam emitted by the light source in a first direction and a second direction that are perpendicular to each other. The first direction is the direction in which the first optical deflector deflects the incident beam; and / or The polarization amplification device is configured to amplify the deflection angle of the deflected beam after it has been deflected by the first optical deflection device or the second optical deflection device by a preset factor in the corresponding deflection direction.
35. The optical deflection device according to any one of claims 1-29, characterized in that, The optical deflection device is used in the transmitting module of the lidar system; or the optical deflection device is an optical deflection device in the transmitting module of the lidar system.
36. A transmitting module, characterized in that, Includes a light source and a light deflection device as described in any one of claims 1-35; The light source is used to emit a light beam to the light deflection device; The light deflection device is used to deflect the incident light beam emitted by the light source to generate scanning light beams with different deflection angles and deflection angle switching sequences to achieve scanning of the field of view.
37. The transmitting module as described in claim 36, characterized in that, The light beam emitted by the light source has a length along the first direction that is shorter than its length along the second direction. The first direction is the deflection direction of the incident light beam by the first light deflection device, and the second direction is perpendicular to the first direction.
38. The transmitting module as described in claim 36 or 37, characterized in that, The light source includes any one or more combinations of vertical cavity surface-emitting lasers, edge-emitting lasers, light-emitting diodes, laser diodes, semiconductor lasers, and fiber lasers.
39. A lidar system, characterized in that, It includes a receiving module and a transmitting module as described in any one of claims 36-38, wherein the receiving module is configured to sense light signals from the field of view and obtain three-dimensional information of the field of view by processing and analyzing the sensed light signals.
40. An electronic device, characterized in that, Including the lidar system as described in claim 39.
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