PATENT DOCUMENT

Publication Number: US-11681019-B2
Application Number: US-201916574129-A
Country: US
Kind Code: B2

Title: Optical module with stray light baffle

Abstract:
An optical device includes a substrate and an optical transmitter, which is mounted on the substrate and includes an optical emitter, which is configured to emit a beam of optical radiation, and a transmission lens assembly, which is configured to direct the beam along a transmit axis toward a target. An optical receiver is mounted on the substrate alongside the optical transmitter and includes an optical sensor and an objective lens assembly, which is configured to focus the optical radiation that is reflected from the target along a receive axis onto the optical sensor. An optical baffle is disposed asymmetrically relative to the transmit axis and has an asymmetrical shape configured to block preferentially stray radiation emitted from the optical transmitter toward the receive axis.

Claims:
The invention claimed is: 
     
       1. An optical device, comprising:
 a substrate; 
 an optical transmitter, which is mounted on the substrate and comprises an optical emitter, which is configured to emit a beam of optical radiation, and a transmission lens assembly, which comprises one or more lenses mounted in a lens barrel and is configured to direct the beam along a transmit axis toward a target; 
 an optical receiver, which is mounted on the substrate alongside the optical transmitter and comprises an optical sensor and an objective lens assembly, which is configured to focus the optical radiation that is reflected from the target along a receive axis onto the optical sensor; and 
 an optical baffle protruding asymmetrically relative to the transmit axis from an end surface of the lens barrel that is adjacent to the optical emitter toward the substrate in a location between the transmit axis and the receive axis and having an asymmetrical shape configured to block preferentially stray radiation emitted from the optical transmitter toward the receive axis. 
 
     
     
       2. The device according to  claim 1 , wherein the substrate comprises an electrical circuit substrate on which the optical emitter and the optical sensor are mounted, and the device comprises ancillary electronic components, which are mounted on the electrical circuit substrate and connected to the optical emitter and the optical sensor by electrical circuit traces. 
     
     
       3. The device according to  claim 2 , and comprising a case, which contains the transmission lens assembly and the objective lens assembly and is fixed to the substrate so that the transmission lens assembly and the objective lens assembly are positioned respectively over the optical emitter and the optical sensor. 
     
     
       4. The device according to  claim 1 , wherein the optical baffle is an integral part of the lens barrel. 
     
     
       5. The device according to  claim 1 , wherein the optical baffle comprises a collar mounted on the lens barrel. 
     
     
       6. The device according to  claim 1 , wherein the optical baffle comprises an aperture configured to pass a predefined fraction of the emitted beam through the baffle toward the optical sensor. 
     
     
       7. The device according to  claim 1 , and comprising a light guide extending through the baffle and configured to pass a predefined fraction of the emitted optical radiation through the baffle toward the optical sensor. 
     
     
       8. The device according to  claim 1 , wherein the optical baffle comprises a compressible radiation-absorbing material, which is compressed upon assembly of the device, thereby preventing the stray radiation from reaching the optical sensor. 
     
     
       9. An optical device, comprising:
 a substrate; 
 an optical receiver, which is mounted on the substrate and comprises:
 an optical sensor mounted in a chip package; 
 a gasket comprising a compressible radiation-absorbing material surrounding the optical sensor on an upper side of the chip package; and 
 an objective lens assembly, which comprises:
 one or more lenses configured to focus optical radiation along a receive axis onto the optical sensor; and 
 a lens barrel, which contains the one or more lenses, and which is mounted in the device so as to compress the radiation-absorbing material, thereby preventing stray radiation from reaching the optical sensor. 
 
 
 
     
     
       10. The device according to  claim 9 , and comprising an optical transmitter, which is mounted on the substrate alongside the optical receiver, and which is configured to emit a beam of the optical radiation along a transmit axis toward a target, wherein the one or more lenses are configured to focus the optical radiation that is reflected from the target onto the optical sensor. 
     
     
       11. The device according to  claim 10 , wherein the optical transmitter comprises a transmission lens assembly, and wherein the device comprises a case, which contains the transmission lens assembly and the objective lens assembly and is fixed to the substrate so that the transmission lens assembly and the objective lens assembly are positioned respectively over the optical emitter and the optical sensor. 
     
     
       12. The device according to  claim 9 , wherein the substrate comprises an electrical circuit substrate on which the optical emitter and the optical sensor are mounted, and the device comprises ancillary electronic components, which are mounted on the electrical circuit substrate and connected to the optical emitter and the optical sensor by electrical circuit traces. 
     
     
       13. A method for optical sensing, comprising:
 mounting an optical transmitter on a substrate, the optical transmitter comprising an optical emitter, which is configured to emit a beam of optical radiation, and a transmission lens assembly, which comprises one or more lenses mounted in a lens barrel and is configured to direct the beam along a transmit axis toward a target; 
 mounting an optical receiver on the substrate alongside the optical transmitter, the optical receiver comprising an optical sensor and an objective lens assembly, which is configured to focus the optical radiation that is reflected from the target along a receive axis onto the optical sensor; and 
 positioning an optical baffle to protrude asymmetrically relative to the transmit axis from an end surface of the lens barrel that is adjacent to the optical sensor toward the substrate in a location between the transmit axis and the receive axis, the optical baffle having an asymmetrical shape configured to block preferentially stray radiation emitted from the optical transmitter toward the receive axis. 
 
     
     
       14. The method according to  claim 13 , wherein the substrate comprises an electrical circuit substrate on which the optical emitter and the optical sensor are mounted, and the method comprises mounting ancillary electronic components on the electrical circuit substrate for connection to the optical emitter and the optical sensor by electrical circuit traces. 
     
     
       15. The method according to  claim 13 , wherein the optical baffle is an integral part of the lens barrel. 
     
     
       16. The method according to  claim 13 , wherein positioning the optical baffle comprises mounting a collar comprising the optical baffle on the lens barrel. 
     
     
       17. The method according to  claim 13 , wherein the optical baffle comprises an aperture configured to pass a predefined fraction of the emitted beam through the baffle toward the optical sensor. 
     
     
       18. The method according to  claim 13 , wherein the optical baffle comprises a compressible radiation-absorbing material.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to devices and methods for optical sensing, and particularly to optical transmitter/receiver modules. 
     BACKGROUND 
     Some types of optical sensing systems include an optical transmitter, which transmits a beam of optical radiation toward a target, and an optical receiver, which collects and senses the optical radiation that is reflected from the target. (The term “optical radiation,” in the context of the present description and in the claims, refers to electromagnetic radiation in any of the visible, infrared, and ultraviolet spectral ranges, and may be used interchangeably with the term “light.”) For example, in some depth sensing systems, the transmitter emits pulses of radiation toward a target, and the optical receiver senses the times of flight (ToF) of the pulses, and thus measures the distance to the target. 
     For many sensing applications, including ToF-based depth sensing, it can be advantageous to package the transmitter and receiver together on the same substrate in a compact package. An integrated optoelectronic module of this sort is described, for example, in U.S. Pat. No. 9,157,790. 
     ToF-based depth sensing devices are almost inevitably subject to stray reflections, which reflect or otherwise scatter from optical surfaces within the device back toward the receiver. In general, such stray reflections are regarded as noise, and designers of the devices do their best to eliminate them. On the other hand, U.S. Pat. No. 9,335,220, whose disclosure is incorporated herein by reference, describes a ToF-based scanner in which the stray reflections are used intentionally in calibrating the ToF measurements. In the disclosed scanner, a transmitter emits a beam comprising optical pulses toward a scene, and a receiver receives reflections of the optical pulses and outputs electrical pulses in response thereto. Processing circuitry is coupled to the receiver so as to receive, in response to each of at least some of the optical pulses emitted by the transmitter, a first electrical pulse output by the receiver at a first time due to stray reflection within the apparatus and a second electrical pulse output by the receiver at a second time due to the beam reflected from the scene. The processing circuitry generates a measure of the time of flight of the optical pulses to and from points in the scene by taking a difference between the respective first and second times of output of the first and second electrical pulses. 
     SUMMARY 
     Embodiments of the present invention that are described hereinbelow provide improved devices for optical transmission and reception. 
     There is therefore provided, in accordance with an embodiment of the invention, an optical device, including a substrate and an optical transmitter, which is mounted on the substrate and includes an optical emitter, which is configured to emit a beam of optical radiation, and a transmission lens assembly, which is configured to direct the beam along a transmit axis toward a target. An optical receiver is mounted on the substrate alongside the optical transmitter and includes an optical sensor and an objective lens assembly, which is configured to focus the optical radiation that is reflected from the target along a receive axis onto the optical sensor. An optical baffle is disposed asymmetrically relative to the transmit axis and has an asymmetrical shape configured to block preferentially stray radiation emitted from the optical transmitter toward the receive axis. 
     In some embodiments, the substrate includes an electrical circuit substrate on which the optical emitter and the optical sensor are mounted, and the device includes ancillary electronic components, which are mounted on the electrical circuit substrate and connected to the optical emitter and the optical sensor by electrical circuit traces. In a disclosed embodiment, the device includes a case, which contains the transmission lens assembly and the objective lens assembly and is fixed to the substrate so that the transmission lens assembly and the objective lens assembly are positioned respectively over the optical emitter and the optical sensor. 
     In some embodiments, the transmission lens assembly includes one or more lenses mounted in a lens barrel, and the optical baffle protrudes asymmetrically from the lens barrel toward the substrate in a location between the transmit axis and the receive axis. In one embodiment, the optical baffle is an integral part of the lens barrel. Alternatively, the optical baffle includes a collar mounted on the lens barrel. Additionally or alternatively, the optical baffle includes an aperture configured to pass a predefined fraction of the emitted beam through the baffle toward the optical sensor. 
     In a disclosed embodiment, the device includes a light guide extending through the baffle and configured to pass a predefined fraction of the emitted optical radiation through the baffle toward the optical sensor. 
     In another embodiment, the optical baffle includes a compressible radiation-absorbing material, which is compressed upon assembly of the device, thereby preventing the stray radiation from reaching the optical sensor. 
     There is also provided, in accordance with an embodiment of the invention, an optical device, including a substrate. An optical receiver, which is mounted on the substrate, includes an optical sensor and a compressible radiation-absorbing material surrounding the optical sensor. An objective lens assembly includes one or more lenses configured to focus optical radiation along a receive axis onto the optical sensor, and a lens barrel, which contains the one or more lenses, and which is mounted in the device so as to compress the radiation-absorbing material, thereby preventing stray radiation from reaching the optical sensor. 
     In a disclosed embodiment, the device includes an optical transmitter, which is mounted on the substrate alongside the optical receiver, and which is configured to emit a beam of the optical radiation along a transmit axis toward a target, wherein the one or more lenses are configured to focus the optical radiation that is reflected from the target onto the optical sensor. 
     Additionally or alternatively, the substrate includes an electrical circuit substrate on which the optical emitter and the optical sensor are mounted, and the device includes ancillary electronic components, which are mounted on the electrical circuit substrate and connected to the optical emitter and the optical sensor by electrical circuit traces. 
     There is additionally provided, in accordance with an embodiment of the invention, a method for optical sensing, which includes mounting an optical transmitter on a substrate. The optical transmitter includes an optical emitter, which is configured to emit a beam of optical radiation, and a transmission lens assembly, which is configured to direct the beam along a transmit axis toward a target. An optical receiver is mounted on the substrate alongside the optical transmitter. The optical receiver includes an optical sensor and an objective lens assembly, which is configured to focus the optical radiation that is reflected from the target along a receive axis onto the optical sensor. An optical baffle is positioned asymmetrically relative to the transmit axis. The optical baffle has an asymmetrical shape configured to block preferentially stray radiation emitted from the optical transmitter toward the receive axis. 
     The present invention will be more fully understood from the following detailed description of the embodiments thereof, taken together with the drawings in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic sectional view of an optical module, in accordance with an embodiment of the invention; 
         FIG.  2    is a schematic pictorial view of a transmission lens assembly, in accordance with an embodiment of the invention; 
         FIG.  3 A  is a schematic pictorial view of a stray light baffle, in accordance with an embodiment of the invention; 
         FIG.  3 B  is a schematic pictorial view of a transmission lens assembly incorporating the stray light baffle of  FIG.  3 A  in an optical module, in accordance with an embodiment of the invention; 
         FIG.  4    is a schematic sectional view of an optical module, in accordance with another embodiment of the invention; 
         FIG.  5    is a schematic pictorial view of a light guide used in the optical module of  FIG.  4   , in accordance with an embodiment of the invention; 
         FIG.  6    is a schematic sectional view of an optical module, in accordance with yet another embodiment of the invention; and 
         FIG.  7    is a schematic pictorial view of a sensing assembly with a compressible baffle, in accordance with an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     In designing an optical module that includes a transmitter and a receiver, it is important to minimize the amount of stray radiation that reaches the receiver, and particularly stray radiation emitted from the transmitter toward the receiver. This radiation is “stray” in the sense that it does not exit the module along the intended transmit path toward the target and then return from there to the receiver through the objective lens assembly, but rather reflects internally with the module, typically from one or more of the optical or mechanical surfaces in the module. Even a small amount of this sort of stray radiation can severely degrade the performance of the optical module, by adding substantial noise to the signals output by the receiver. 
     Baffles are mechanical elements that are introduced into optical designs in order to block stray radiation and prevent it from reaching the target of the objective lens assembly (such as the sensor in a ToF sensing device). Baffles are usually designed to be a part of or attached to the barrel (i.e. the housing) of the objective lens assembly, with circular symmetry around the optical axis of the lens assembly. 
     Careful optical design and baffling can eliminate most stray reflections; but when the transmitter and receiver are mounted together on the same substrate in a compact package, it is generally not possible to close off all possible paths that stray radiation could follow. For example, when ancillary electronic components are mounted on the substrate together with the optical emitter and the optical sensor, it may not be possible to surround the emitter or the sensor completely with a baffle that extends all the way down to the substrate. Furthermore, in ToF sensing modules, it may actually be desirable to allow a small amount of stray radiation to reach the optical sensor from the emitter in order to serve as a zero-reference for the ToF measurements, for example as described in the above-mentioned U.S. Pat. No. 9,335,220. 
     Some embodiments of the present invention address these problems using an asymmetrical stray light baffle. In these embodiments, an optical device comprises an optical transmitter and an optical receiver, both mounted on a substrate, one alongside the other. The optical transmitter comprises an optical emitter, which emits a beam of optical radiation (a pulsed beam in the case of ToF measurement), and a transmission lens assembly, which directs the beam along a transmit axis toward a target. The optical receiver comprises an optical sensor and an objective lens assembly, which focuses the optical radiation that is reflected from the target along a receive axis onto the optical sensor. An optical baffle is disposed asymmetrically relative to the transmit axis and has an asymmetrical shape that is designed to preferentially block stray radiation emitted from the optical transmitter from propagating toward the receive axis. 
     In some of the present embodiments, the optical baffle protrudes asymmetrically from the lens barrel toward the substrate in a location between the transmit axis and the receive axis. This optical baffle may be an integral part of the lens barrel, or it may be a separate piece, for example in the form of a collar mounted on the lens barrel. In either case, the asymmetrical design makes it possible to mount ancillary electronic components on the substrate in close proximity to the emitter, typically on the side of the emitter opposite to the protruding baffle (i.e., on the opposite side from the receiver). The baffle can also be designed to permit a small, controlled amount of stray light to reach the optical sensor in order to serve as the zero reference. In one embodiment, the optical baffle comprises an aperture configured to pass a certain fraction of the emitted beam through the baffle toward the optical sensor. 
     Reference is now made to  FIGS.  1  and  2   , which schematically illustrate an optical device in the form of an optical module  20 , in accordance with an embodiment of the invention.  FIG.  1    is a sectional view of the optical module, while  FIG.  2    shows a pictorial view of a transmission lens assembly  30  in module  20 . 
     Module  20  comprises an optical transmitter  21  and an optical receiver  23 , which are mounted one alongside the other on a substrate  26 . Substrate  26  typically comprises an electrical circuit substrate, such as a printed circuit board. Transmitter  21  comprises an optical emitter  22 , for example a suitable light-emitting diode (LED) or laser, such as a vertical-cavity surface-emitting laser (VCSEL), or an array of such LEDs or lasers, which may emit pulsed, continuous, or modulated radiation. Receiver  23  comprises an optical sensor  24 , for example an avalanche photodiode (APD) or a single-photon avalanche diode (SPAD) or an array of such photon detectors, or alternatively a detector or detector array that is capable of continuous or gated sensing. Emitter  22  and sensor  24  are mounted on substrate  26  together with ancillary electronic components  28 , such as drivers, amplifiers and control circuits, which are typically connected to the emitter and the sensor by electrical circuit traces. 
     Emitter  22  emits a beam of optical radiation, and a transmission lens assembly  30  collects and directs the beam along a transmit axis  31  toward a target (not shown in the figures). Transmission lens assembly  30  comprises one or more lenses  32  (multiple lenses in the pictured example), which are mounted in a lens barrel  34 . Lenses  32  direct the beam through an exit window  36 , which opens through a case  38 . 
     Receiver  23  comprises an objective lens assembly  42 , comprising one or more lenses  44 , which are mounted in a barrel  46 . Lenses  44  focus the optical radiation that is reflected from the target along a receive axis  45  through an entrance window  40  in case  38  onto optical sensor  24 . Case  38  is fixed to substrate  26  so that transmission lens assembly  30  and objective lens assembly  42  are positioned respectively over optical emitter  22  and optical sensor  24 . 
     An optical baffle  48  protrudes asymmetrically from lens barrel  34  toward substrate  26  in a location between transmit axis  31  and receive axis  45 . The asymmetrical shape and disposition of baffle  48  relative to transmit axis  31  will preferentially block stray radiation emitted from emitter  22  toward receive axis  45  (including both rays emitted directly from the emitter itself and rays reflected from other elements of transmitter  21 , such as from the surfaces of lenses  32 ). In this embodiment, optical baffle  48  is an integral part of lens barrel  34 ; but alternatively, the baffle may be produced separately and fastened to the lens barrel or otherwise mounted within case  38 . All such alternative implementations of an asymmetrical baffle of this sort are considered to be within the scope of the present invention. 
     The asymmetrical design of optical baffle  48  has a number of advantages in the context of module  20 . This design can relieve other packaging constraints, for example by making it possible to mount relatively large ancillary components, such as component  28  to the right of emitter in  FIG.  1   , in close proximity to the emitter. Furthermore, the baffle can be designed to permit a small amount of stray light to reach sensor  24 , in order to enable ToF calibration without causing excessive noise in receiver  23 . 
     Reference is now made to  FIGS.  3 A and  3 B , which schematically illustrate the design and operation of a stray light baffle  50 , in accordance with another embodiment of the invention.  FIG.  3 A  is a pictorial view of baffle  50 , while  FIG.  3 B  is a pictorial view of transmission lens assembly  30  incorporating baffle  50  inside case  38  of an optical module. 
     Baffle  50  in this embodiment comprises a collar  52 , which mounts on lens barrel  34 . An asymmetrical protrusion  54  extends above collar  52  in the area between transmit axis  31  and receive axis  45 , and thus preferentially blocks stray radiation emitted from the optical transmitter toward the receive axis. The use of this sort of separate collar component allows for greater flexibility of design and possibly easier assembly of the module. For example, the shape of baffle  50  can readily be molded as a separate component, but might be difficult to mold as an integral component of the lens barrel or might interfere with subsequent assembly of lenses  32  into the barrel. The use of a separate baffle of this sort also makes it possible to update and improve the baffle design without having to modify the entire lens barrel. 
       FIG.  4    is a schematic sectional view of an optical module  60 , in accordance with another embodiment of the invention. In this embodiment, transmission lens assembly  30  is contained in a dual barrel, including an inner barrel  62  in which lenses  32  are mounted and an outer barrel  64 , which is fixed to substrate  26 . Outer barrel  64  includes a baffle  65 , which protrudes asymmetrically toward substrate  26 , between transmitter  21  and receiver  23 . In this case, however, baffle  65  has an aperture that is configured to pass a small fraction of the radiation output by emitter  22  through the baffle toward optical sensor  24 . 
     In the pictured embodiment, a light guide  66  extends through baffle  65  order to control and direct the stray radiation from emitter  22  toward sensor  24 . Light guide  66  is designed to pass a predefined fraction of the emitted optical radiation through the baffle and direct it toward the optical sensor. Alternatively, baffle  65  may simply contain an aperture for such stray light, without the light guide. 
       FIG.  5    is a schematic pictorial view of light guide  66 , in accordance with an embodiment of the invention. Light guide  66  comprises a suitable transparent material, such as a glass or transparent plastic. An entrance face  68  of the light guide is angled in this example to receive stray radiation that is reflected from lower lens  32  in transmission lens assembly  30 . An exit face  70  of the light guide outputs the stray light toward sensor  24 . Entrance face  68  and/or exit face  70  may be masked and/or coated in order to control the amount of radiation that is passes through the light guide. Additionally or alternatively, light guide  66  itself may comprise a volume of material that absorbs radiation for this purpose. 
     Further additionally or alternatively, light guide  66  may be shaped or patterned to control the spatial distribution of the stray radiation that is emitted through exit face  70 . For example, light guide  66  may be configured to direct the radiation specifically toward certain reference pixels in sensor, while avoiding irradiation of the pixels that receive radiation from the target. For such purposes, exit face  70  may be cylindrical or wedged, or may be patterned with a nano-structured diffractive optical element to control the direction of the light. Alternatively, the stray light transmitted through light guide  66  may be diffused by roughening exit face  70  or adding a lenslet array on the exit face. 
       FIG.  6    is a schematic sectional view of an optical module  80 , in accordance with yet another embodiment of the invention. In this embodiment, optical receiver  23  comprises a sensing assembly  82 , which includes a submount  86 , on which optical sensor  24  (not shown in this figure) is installed. An optical baffle  84  comprising a compressible radiation-absorbing material, such as a suitable closed-cell foam, surrounds the optical sensor. This compressible baffle  84  may be used instead of or in conjunction with a baffle on barrel  34  of transmission lens assembly  30 , such as the asymmetrical barrels described above. Alternatively or additionally, optical transmitter  21  may comprise a compressible baffle of this sort. 
     When module  80  is assembled, barrel  46  of objective lens assembly  42  presses against and compresses baffle  84 , thus shutting out stray light from emitter  22 . Alternatively, barrel  46  and baffle  84  may be designed to permit a small, controlled amount of stray light to reach sensor  24  for ToF calibration purposes. The use of such a compressible material in baffle  84  is also helpful in relaxing the manufacturing tolerances of module  80  and in absorbing mechanical shocks to sensing assembly  82  from objective lens assembly  42 . 
       FIG.  7    is a schematic pictorial view of a sensing assembly  90  with compressible baffle  84 , in accordance with another embodiment of the invention. In this example, baffle comprises a compressible, radiation-absorbing foam disposed as a gasket around sensor  24  on the upper side of the chip package containing the sensor. Other configurations of this sort of compressible baffle will be apparent to those skilled in the art after reading the above description and are considered to be within the scope of the present invention. 
     It will thus be appreciated that the embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.

Metadata:
Filing Date: 20190918
Publication Date: 20230620
Grant Date: 20230620
Priority Date: 20190918
Inventors: O'CONNOR, EAMON H.
COHOON, GREGORY A.
WONG, CALVIN K.
MISCHKE, COLLEEN F
Assignee: APPLE INC
CPC Classifications: [{"code": "G01S17/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/003", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B7/021", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S7/4813", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01S17/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S7/481", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01S7/4813", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01S7/4816", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/003", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S17/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S7/497", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01S7/4816", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S17/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S7/4814", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/4204", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S7/4814", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B7/021", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S7/4813", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 71170450