PATENT DOCUMENT

Publication Number: US-12123589-B1
Application Number: US-202318321025-A
Country: US
Kind Code: B1

Title: Flood projector with microlens array

Abstract:
An optoelectronic apparatus includes a semiconductor substrate and an array of emitters disposed on the semiconductor substrate and configured to emit beams of optical radiation having respective chief rays. An optical diffuser is mounted over the semiconductor substrate and configured to diffuse the beams. Microlenses are disposed between the semiconductor substrate and the optical diffuser in respective alignment with the emitters and configured to steer the beams at different, respective angles, which are selected so that at least some of the chief rays cross one another before passing through the diffuser.

Claims:
The invention claimed is: 
     
       1. An optoelectronic apparatus, comprising:
 a semiconductor substrate; 
 an array of emitters disposed on the semiconductor substrate and configured to emit beams of optical radiation having respective chief rays; 
 an optical diffuser mounted over the semiconductor substrate and configured to diffuse the beams, wherein the diffuser comprises an optical substrate and an optical metasurface disposed on the optical substrate; and 
 microlenses disposed between the semiconductor substrate and the optical diffuser in respective alignment with the emitters and configured to steer the beams at different, respective angles, which are selected so that at least some of the chief rays cross one another before passing through the diffuser. 
 
     
     
       2. The apparatus according to  claim 1 , wherein the optical metasurface is configured to split the beams into respective groups of diverging sub-beams, and to direct the sub-beams to illuminate a target with flood illumination. 
     
     
       3. The apparatus according to  claim 1 , wherein the microlenses are configured to randomize the angles at which the beams are steered. 
     
     
       4. The apparatus according to  claim 1 , and comprising a controller, which is configured to actuate the apparatus so as to illuminate a target with flood illumination. 
     
     
       5. An optoelectronic apparatus, comprising:
 a semiconductor substrate; 
 an array of emitters disposed on the semiconductor substrate and configured to emit beams of optical radiation having respective chief rays; 
 an optical diffuser mounted over the semiconductor substrate and configured to diffuse the beams; 
 microlenses disposed between the semiconductor substrate and the optical diffuser in respective alignment with the emitters and configured to steer the beams at different, respective angles, which are selected so that at least some of the chief rays cross one another before passing through the diffuser; and 
 a semiconductor die mounted on the semiconductor substrate, wherein the emitters are disposed on a back side of the semiconductor die and the microlenses are formed on a front side of the semiconductor die. 
 
     
     
       6. The apparatus according to  claim 5 , wherein the microlenses comprise a monolithic part of the semiconductor die. 
     
     
       7. An optoelectronic apparatus, comprising:
 a semiconductor substrate; 
 an array of emitters disposed on the semiconductor substrate and configured to emit beams of optical radiation having respective chief rays; 
 an optical diffuser mounted over the semiconductor substrate and configured to diffuse the beams; and 
 microlenses disposed between the semiconductor substrate and the optical diffuser in respective alignment with the emitters and configured to steer the beams at different, respective angles, which are selected so that at least some of the chief rays cross one another before passing through the diffuser, 
 wherein the microlenses are laterally offset relative to the emitters with an offset that varies among the microlenses so as to steer the beams at the different, respective angles. 
 
     
     
       8. An optoelectronic apparatus, comprising:
 a semiconductor substrate; 
 an array of emitters disposed on the semiconductor substrate and configured to emit beams of optical radiation having respective chief rays; 
 an optical diffuser mounted over the semiconductor substrate and configured to diffuse the beams; and 
 microlenses disposed between the semiconductor substrate and the optical diffuser in respective alignment with the emitters and configured to steer the beams at different, respective angles, which are selected so that at least some of the chief rays cross one another before passing through the diffuser, 
 wherein the microlenses have different, respective sag angles, which are selected so as to steer the beams at the different, respective angles. 
 
     
     
       9. An optoelectronic apparatus, comprising:
 a semiconductor substrate; 
 an array of emitters disposed on the semiconductor substrate and configured to emit beams of optical radiation having respective chief rays; 
 an optical diffuser mounted over the semiconductor substrate and configured to diffuse the beams; and 
 microlenses disposed between the semiconductor substrate and the optical diffuser in respective alignment with the emitters and configured to steer the beams at different, respective angles, which are selected so that at least some of the chief rays cross one another before passing through the diffuser, 
 wherein each microlens comprises a tilted toroidal surface having a tilt selected so as to steer the beams at the different, respective angles. 
 
     
     
       10. An optoelectronic apparatus, comprising:
 a semiconductor substrate; 
 an array of emitters disposed on the semiconductor substrate and configured to emit beams of optical radiation having respective chief rays; 
 an optical diffuser mounted over the semiconductor substrate and configured to diffuse the beams; and 
 microlenses disposed between the semiconductor substrate and the optical diffuser in respective alignment with the emitters and configured to steer the beams at different, respective angles, which are selected so that at least some of the chief rays cross one another before passing through the diffuser, 
 wherein the microlenses are configured to increase a divergence of the beams emitted by the emitters. 
 
     
     
       11. A method for optical projection, comprising:
 mounting on a semiconductor substrate an array of emitters configured to emit beams of optical radiation having respective chief rays; 
 mounting an optical diffuser over the semiconductor substrate so as to diffuse the beams, wherein the diffuser comprises an optical substrate and an optical metasurface disposed on the optical substrate; and 
 aligning microlenses between the semiconductor substrate and the optical diffuser with the emitters so as to steer the beams at different, respective angles, which are selected so that at least some of the chief rays cross one another before passing through the diffuser. 
 
     
     
       12. The method according to  claim 11 , wherein the optical metasurface is configured to split the beams into respective groups of diverging sub-beams, and to direct the sub-beams to illuminate a target with flood illumination. 
     
     
       13. The method according to  claim 11 , wherein mounting the array of emitters comprises mounting a semiconductor die on the semiconductor substrate, wherein the emitters are disposed on a back side of the semiconductor die and the microlenses are formed on a front side of the semiconductor die. 
     
     
       14. The method according to  claim 11 , wherein aligning the microlenses comprises laterally offsetting the microlenses relative to the emitters with an offset that varies among the microlenses so as to steer the beams at the different, respective angles. 
     
     
       15. The method according to  claim 11 , wherein aligning the microlenses comprises forming the microlenses with different, respective sag angles, which are selected so as to steer the beams at the different, respective angles. 
     
     
       16. The method according to  claim 11 , wherein each microlens comprises a tilted toroidal surface having a tilt selected so as to steer the beams at the different, respective angles. 
     
     
       17. The method according to  claim 11 , wherein the microlenses are configured to increase a divergence of the beams emitted by the emitters. 
     
     
       18. The method according to  claim 11 , and comprising actuating the emitters so as to illuminate a target with flood illumination.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to optoelectronic devices, and particularly to sources of optical radiation. 
     BACKGROUND 
     Various sorts of portable computing devices (referred to collectively as “portable devices” in the description), such as smartphones, augmented reality (AR) devices, virtual reality (VR) devices, smart watches, and smart glasses, comprise compact sources of optical radiation. For example, one source may project patterned radiation to illuminate a target region with a pattern of spots for three-dimensional (3D) mapping of the region. Another source may, for example, emit flood radiation, illuminating a target region uniformly over a wide field of view for the purpose of capturing a color or a monochromatic image. 
     The terms “optical rays,” “optical radiation,” and “light,” as used in the present description and in the claims, refer generally to electromagnetic radiation in any or all of the visible, infrared, and ultraviolet spectral ranges. 
     Optical metasurfaces are thin layers that comprise a two-dimensional pattern of structures, having dimensions (pitch and thickness) less than the target wavelength of the radiation with which the optical metasurface is designed to interact. Optical elements comprising optical metasurfaces are referred to herein as “metasurface optical elements” (MOEs). 
     SUMMARY 
     Embodiments of the present invention that are described hereinbelow provide improved designs and methods for use and fabrication of sources of optical radiation. 
     There is therefore provided, in accordance with an embodiment of the invention, an optoelectronic apparatus, including a semiconductor substrate and an array of emitters disposed on the semiconductor substrate and configured to emit beams of optical radiation having respective chief rays. An optical diffuser is mounted over the semiconductor substrate and configured to diffuse the beams. Microlenses are disposed between the semiconductor substrate and the optical diffuser in respective alignment with the emitters and configured to steer the beams at different, respective angles, which are selected so that at least some of the chief rays cross one another before passing through the diffuser. 
     In some embodiments, the diffuser includes an optical substrate and an optical metasurface disposed on the optical substrate. In a disclosed embodiment, the optical metasurface is configured to split the beams into respective groups of diverging sub-beams, and to direct the sub-beams to illuminate a target with flood illumination. 
     Additionally or alternatively, the apparatus includes a semiconductor die mounted on the semiconductor substrate, wherein the emitters are disposed on a back side of the semiconductor die and the microlenses are formed on a front side of the semiconductor die. In a disclosed embodiment, the microlenses include a monolithic part of the semiconductor die. 
     In a disclosed embodiment, the microlenses are laterally offset relative to the emitters with an offset that varies among the microlenses so as to steer the beams at the different, respective angles. Additionally or alternatively, the microlenses have different, respective sag angles, which are selected so as to steer the beams at the different, respective angles. 
     In one embodiment, each microlens includes a tilted toroidal surface having a tilt selected so as to steer the beams at the different, respective angles. 
     In another embodiment, the microlenses are configured to randomize the angles at which the beams are steered. Additionally or alternatively, the microlenses are configured to increase a divergence of the beams emitted by the emitters. 
     In a disclosed embodiment, the apparatus includes a controller, which is configured to actuate the apparatus so as to illuminate a target with flood illumination. 
     There is also provided, in accordance with an embodiment of the invention, a method for optical projection, which includes mounting on a semiconductor substrate an array of emitters configured to emit beams of optical radiation having respective chief rays. An optical diffuser is mounted over the semiconductor substrate so as to diffuse the beams. Microlenses are aligned between the semiconductor substrate and the optical diffuser with the emitters so as to steer the beams at different, respective angles, which are selected so that at least some of the chief rays cross one another before passing through the diffuser. 
     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 A  is a schematic side view of an optoelectronic apparatus, in accordance with an embodiment of the invention; 
         FIG.  1 B  is a schematic frontal view of a far-field pattern of spots on a target projected by the apparatus of  FIG.  1 A , in accordance with an embodiment of the invention; 
         FIG.  2 A  is a schematic side view of an optoelectronic apparatus, in accordance with an alternative embodiment of the invention; 
         FIG.  2 B  is a schematic frontal view of a far-field pattern of spots on a target projected by the apparatus of  FIG.  2 A , in accordance with an embodiment of the invention; 
         FIG.  2 C  is a schematic frontal view of flood illumination on a target projected by the apparatus of  FIG.  2 A , in accordance with an embodiment of the invention; 
         FIG.  3 A  is a schematic side view of an optoelectronic apparatus, in accordance with another embodiment of the invention; 
         FIG.  3 B  is a schematic frontal view of a far-field pattern of spots on a target projected by the apparatus of  FIG.  3 A , in accordance with an embodiment of the invention; 
         FIG.  4 A  is a schematic side view of an optoelectronic apparatus, in accordance with yet another embodiment of the invention; 
         FIG.  4 B  is a schematic frontal view of a far-field pattern of spots on a target projected by the apparatus of  FIG.  4 A , in accordance with an embodiment of the invention; 
         FIG.  5 A  is a schematic side view of an optoelectronic apparatus, in accordance with an alternative embodiment of the invention; 
         FIG.  5 B  is a schematic frontal view of a far-field pattern of spots on a target projected by the apparatus of  FIG.  5 A , in accordance with an embodiment of the invention; 
         FIG.  5 C  is a schematic frontal view of flood illumination on a target projected by the apparatus of  FIG.  5 A , in accordance with an embodiment of the invention; 
         FIG.  6    is a schematic side view of an optoelectronic apparatus, in accordance with an embodiment of the invention; 
         FIGS.  7 A and  7 B  are schematic side views of optoelectronic apparatuses, in accordance with additional embodiments of the invention; and 
         FIG.  8    is a schematic side view of an optoelectronic apparatus, in accordance with a further embodiment of the invention; and 
         FIG.  9    is a schematic side view of an optoelectronic apparatus, in accordance with yet another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Overview 
     Compact structured light projectors that are used to project patterns of spots in portable devices may use a single-element MOE, which splits each of the beams emitted by an array of light sources into multiple sub-beams and projects the beams to form a pattern of spots on a target. To detect the radiation returned from the spots in the pattern with a sufficient signal-to-noise ratio from even a distant target, the emitters in the array emit beams with high optical power. However, high-power beams that are concentrated on a small area of the MOE or any subsequent layers above it, i.e., impinging on the MOE with a high irradiance, may damage the MOE or any of these layers, as well as any other adjacent elements transmitting these beams. There is thus a need to reduce the irradiance on the MOE in a structured light projector while still maintaining high overall signal-to-noise ratio. 
     Embodiments of the present invention that are described herein address this need by using an MOE, which comprises multiple optical apertures, and multiple emitter arrays. Each emitter array emits optical beams to a respective optical aperture of the MOE, thus spreading out the optical power over a large surface area. 
     The disclosed embodiments provide optoelectronic apparatus comprising a semiconductor substrate, multiple arrays of emitters disposed on the semiconductor substrate and emitting beams of optical radiation, an optical substrate mounted over the semiconductor substrate, and an MOE comprising multiple optical apertures disposed on the optical substrate. Each optical aperture receives, collimates and splits the beams emitted by a respective array of emitters into a respective group of collimated sub-beams. The MOE directs the collimated sub-beams toward a target at different, respective angles to form a pattern of spots on the target. The power of the emitted optical beams is spread over multiple optical apertures on the MOE, thus reducing the irradiance on the MOE and preventing damage to it and any subsequent layers above the MOE. 
     In some embodiments, that apparatus also comprises multiple microlenses. Each microlens array is aligned with a respective array of emitters and projects the beams emitted by the array toward the respective optical apertures of the MOE. The employment of microlenses relieves constraints on the design of the apparatus by decoupling the design of the emitter arrays on the semiconductor surface from the design of the MOE, allowing for the design of emitter arrays with smaller size and reduced cost. 
     In additional embodiments, similar arrangements are used to project flood illumination onto a target. 
     For the sake of concreteness and clarity, the embodiments described hereinbelow present optical projectors having certain specific configurations, including particular numbers of emitters, dies, and MOEs in certain geometries and with certain dimensions. These configurations are shown and described solely by way of examples. Alternative configurations, based on the principles described herein, will be apparent to those skilled in the art after reading the present description and are considered to be within the scope of the present invention. 
     Spot Projectors 
       FIG.  1 A  is a schematic side view of an optoelectronic apparatus  100 , and  FIG.  1 B  is a schematic frontal view of a far-field pattern of spots  102  on a target  104  projected by the apparatus, in accordance with an embodiment of the invention. 
     Apparatus  100  comprises a spot projector  106  and a controller  108 . Projector  106  comprises a semiconductor substrate  110 , on which hexagonal III-V semiconductor dies  116   a ,  116   b ,  116   c ,  116   d ,  116   e ,  116   f , and  116   g  are mounted. Dies  116   a - 116   c  comprise respective arrays  112   a ,  112   b , and  112   c  of emitters of optical radiation, for example VCSELs (Vertical-Cavity Surface-Emitting Lasers)  114 . In the present embodiment, semiconductor substrate  110  comprises a silicon (Si) substrate, and III-V semiconductor dies  116   a - 116   g  comprise GaAs (gallium arsenide). GaAs dies  116   a - 116   g  are mounted on Si substrate  110  in a VCSEL-on-silicon (VoS) configuration, wherein the Si substrate comprises the drive and control circuits for the VCSELs. A similar VoS configuration can be utilized in the additional apparatuses described hereinbelow. VCSELs  114  are formed on the back sides of GaAs dies  116   a - 116   g  and emit beams of optical radiation through the respective dies. In alternative embodiments, other semiconductor materials, as well as other kinds of emitters and emitter configurations, may be used. Microlenses may be formed on the top surfaces of GaAs dies  116   a - 116   g , as shown in the figures that follow, so as to refract and direct the beams emitted by VCSELs  114 , for example as illustrated in  FIG.  1 A . 
     GaAs dies  116   a - 116   g  are shown in a schematic frontal view in an inset  118 , with a line A-A corresponding to the plane of  FIG.  1 A . VCSELs  114  are arranged in non-repeating patterns in arrays  112   a - 112   c  in order to enable differentiating far distances from near distances when apparatus  100  is used for 3D mapping of target  104 . (The VCSELs on dies  116   d - 116   g  are omitted from the figure for the sake of simplicity.) In the current embodiment, the width of each GaAs die  116   a - 116   g  is 260 μm, the thickness is 110 μm, and the separations between adjacent dies are 1 mm. Alternative embodiments may have other dimensions for the dies and their separations. 
     Projector  106  further comprises an MOE  120 , comprising an optical metasurface  122  disposed on an optical substrate  124 . Optical metasurface  122  comprises optical apertures  126   a - 126   g , which are aligned with respective GaAs dies  116   a - 116   g  and contain respective parts of the MOE pattern for diffracting the beams emitted by the VCSELs on the respective dies. (The term “optical aperture” of an MOE will hereinbelow be used to refer to the portion of the MOE defined by the optical aperture. Thus, the optical aperture will have the optical properties of the MOE within the aperture, such as focusing, splitting, and tilting optical beams.) The diameters of optical apertures  126   a - 126   g  are 1 mm, thus providing sufficient surface area for the impinging beams of optical radiation from VCSELs  114  to avoid high and potentially damaging irradiance on MOE  120 . MOE  120  and optical apertures  126   a - 126   g  are shown in a schematic frontal view in an inset  128 , with a line B-B corresponding to the plane of  FIG.  1 A . The spacing between Si substrate  110  and MOE  120  is typically 3 mm, although other spacings may alternatively be used. 
     Controller  108  is coupled to the drive and control circuits in Si substrate  110 . Controller  108  typically comprises a programmable processor, which is programmed in software and/or firmware to drive VCSELs  114 . Alternatively or additionally, controller  108  comprises hard-wired and/or programmable hardware logic circuits, which drive VCSELs  114 . Although controller  108  is shown in the figures, for the sake of simplicity, as a single, monolithic functional block, in practice the controller may comprise a single chip or a set of two or more chips, with suitable interfaces for outputting the drive signals that are illustrated in the figures and are described in the text. The controllers shown and described in the context of the embodiments that follow are of similar construction. 
     For projecting a pattern of spots  102  on target  104  (as shown in  FIG.  1 B ), controller  108  drives VCSELs  114  in arrays  112   a - 112   c  to emit beams of optical radiation, represented schematically by respective chief rays  130   a ,  130   b , and  130   c . The beams are refracted by microlenses as described hereinabove and impinge on respective optical apertures  126   a - 126   c , which split, tilt, and collimate the beams into sub-beams  132   a ,  132   b , and  132   c  and direct them toward target  104 , so that projected images of GaAs dies  116   a - 116   g  are tiled on the target as replicas in an interleaved fashion, as shown schematically in  FIG.  1 B . A compact and efficient tiling is enabled by the hexagonal shapes of dies  116   a - 116   g . In alternative embodiments, other shapes may be used for the dies and VCSEL arrays, leading to tiling with varying degrees of compactness and efficiency. 
     Combined Spot and Flood Projector 
       FIG.  2 A  is a schematic side view of an optoelectronic apparatus  200 ,  FIG.  2 B  is a schematic frontal view of a far-field pattern of spots  202  on a target  204  projected by the apparatus, and  FIG.  2 C  is a schematic frontal view of flood illumination  206  on the target projected by the apparatus, in accordance with an embodiment of the invention. 
     Apparatus  200  comprises a combined spot and flood projector  208  and a controller  210 . Projector  208  comprises a Si substrate  212 , on which two sets of hexagonal GaAs dies are mounted. A first set comprises seven dies  214   a ,  214   b ,  214   c ,  214   d ,  214   e ,  214   f , and  214   g . A second set comprises similarly seven dies  216   a ,  216   b ,  216   c ,  216   d ,  216   e ,  216   f , and  216   g , each adjacent to a respective die  214   a - 214   g . The two sets of dies  214   a - 214   g  and  216   a - 216   g  differ from each other both in terms of the die thicknesses and the arrangement of the VCSEL arrays formed in the respective dies, as will be detailed hereinbelow. 
     Dies  214   a - 214   c  comprise respective VCSEL arrays  218   a ,  218   b , and  218   c , similar to arrays  112   a - 112   c , comprising VCSELs  220 . (Similarly to  FIG.  1 A , VCSELs  220  are not shown in dies  214   d - 214   g  for the sake of simplicity.) Dies  216 ,  216   b , and  216   c  comprise respective dense VCSEL arrays  222   a ,  222   b , and  222   c , comprising VCSELs  224 , while the arrays in dies  216   d - 216   g  are not shown for the sake of simplicity. Arrays  222  are “dense” in the sense that dies  216  are tightly filled with active VCSELs  224 , in contrast to arrays  218  on dies  214 , in which many of the cells do not contain active VCSELs  220 , so that arrays  218  generate patterns of light spots corresponding to the layout of the active VCSELs in arrays  218 . 
     Si substrate  212 , GaAs dies  214   a - 214   g , and GaAs dies  216   a - 216   g  are shown in a schematic frontal view in an inset  226 , with a line C-C in the inset corresponding to the plane of  FIG.  2 A . 
     Projector  208  further comprises an MOE  228 , similar to MOE  120  ( FIG.  1 A ), comprising an optical metasurface  230  disposed on an optical substrate  232 , and having a focal plane  233 . Optical metasurface  230  comprises optical apertures  234   a ,  234   b ,  234   c ,  234   d ,  234   e ,  234   f , and  234   g , which are aligned with respective GaAs dies  214   a - 214   g , and are laid out in a similar configuration to optical apertures  126   a - 126   g  shown in inset  128 . The diameters of optical apertures  234   a - 234   g  in this example are 1 mm, thus providing sufficient surface area for avoiding high and potentially damaging irradiance on MOE  228  or subsequent layers above the MOE by beams of optical radiation emitted by VCSELs  220  and  224 . 
     GaAs dies  214   a - 214   g  in the present embodiment are thinned, with a thickness of 90 μm, for example, and the top surfaces of these dies are located at focal plane  233  of MOE  228 . (Microlenses may be formed on the upper side of the dies, as described hereinabove, so that the beams emitted by VCSELs  220  are directed toward respective apertures  234   a - 234   g  of MOE  228  and also that the apparent source of the beams is located at or close to the top surface of each die. Microlenses are shown explicitly in some of the figures that follow.) Thus the beams of optical radiation emitted by VCSELs  220 , as represented by chief rays  236   a  emitted by the VCSELs in VCSEL array  218   a  from a top surface  238   a , are tilted, split, and collimated by aperture  234   a  of MOE  228  into sub-beams  240   a  and form discrete spots  202  on target  204 . 
     GaAs dies  216   a - 216   g , however, have a greater thickness, for example 250 μm, displacing their respective top surfaces from focal plane  233 . Thus, for example, the beams emitted by VCSELs  224  of array  222   a  from a top surface  242   a , represented by chief rays  244   a , are split, tilted and defocused by aperture  234   a  of MOE  228  into diverging sub-beams  246   a , and spots  248  formed on target  204  are blurred. This blur, combined with the dense VCSELs  224  in VCSEL array  222   a , leads to the target being illuminated by uniform flood illumination  206 . In alternative embodiments, other thicknesses for the GaAs dies may be used, as long as their height differences are sufficient to blur the spots illuminated by VCSELs  224 . 
     Alternative Spot Projectors 
       FIG.  3 A  is a schematic side view of an optoelectronic apparatus  300 , and  FIG.  3 B  is a schematic frontal view of a far-field pattern of spots  302  on a target  304  projected by the apparatus, in accordance with an embodiment of the invention. 
     Apparatus  300  comprises a spot projector  306  and a controller  308 , similar to controller  108  ( FIG.  1 A ). Projector  306  comprises a Si substrate  310  comprising drive and control circuits. Four GaAs dies  312   a ,  312   b ,  312   c , and  312   d  are mounted on the Si substrate in a VoS configuration, with the GaAs dies comprising VCSELs  313  in respective VCSEL arrays  314   a ,  314   b ,  314   c , and  314   d . Si substrate  310  and GaAs dies  312   a - 312   d  are shown in a schematic frontal view in an inset  316 . A line D-D in the frontal view corresponds to the plane of  FIG.  3 A . (For the sake of simplicity, VCSEL arrays  314   a - 314   d  are not shown in the frontal view.) The widths of GaAs dies  312   a - 312   d  are 380 μm in the present example, and their center-to-center spacings in the two orthogonal directions are 1.96 mm. In alternative embodiments, other dimensions and spacings for the GaAs dies may be used. 
     Projector  306  further comprises an MOE  316 , comprising an optical metasurface  318  disposed on an optical substrate  320 . Optical metasurface  318  comprises optical apertures  322   a ,  322   b ,  322   c , and  322   d , which are aligned with respective GaAs dies  312   a - 312   d . MOE  316  is shown in a schematic frontal view in an inset  324 , with a line E-E corresponding to the plane of  FIG.  3 A . The diameters of optical apertures  322   a - 322   d  are 1.66 mm, thus providing sufficient surface area for the impinging beams of optical radiation from VCSELs  313  to avoid high and potentially damaging irradiance on MOE  316  or subsequent layers above the MOE. 
     When driven by controller  308 , VCSELs  313  of VCSEL arrays  314   a - 314   d  emit beams of optical radiation. The beams emitted by arrays  314   a  and  314   c  are shown schematically by their respective chief rays  326   a  and  326   c . The beams represented by chief rays  326   a  and  326   c  impinge on respective optical apertures  322   a  and  322   c , which collimate, tilt, and split the beams into respective sub-beams  332   a  and  332   c  and direct them toward target  304 , illuminating the target by respective spot patterns  328   a  and  328   c . The collimation of the optical beams is shown by marginal rays  330   a  and  330   c  emitted by respective VCSELs  313   a  and  313   c . Beams emitted by VCSEL arrays  314   b  and  314   d  form respective spot patterns  328   b  and  328   d  on target  304 . 
       FIG.  3 B  schematically shows spot patterns  328   a - 328   d  arranged on target  304 , with their respective edges touching but with minimal overlap. (Because of the small scale of the figure, only the areas of the spot patterns are shown and not the individual spots.) Depending on the distance of target  304  from projector  306 , spot patterns  328   a - 328   d  may either be completely separated or overlapping at their edges. Spot patterns  328   a - 328   d  formed by the beams from respective, different emitter arrays thus illuminate substantially separate areas of target  304 . This illumination scheme, termed “zonal illumination,” differs from the scheme shown in  FIG.  1 B , wherein the spot patterns from different emitter arrays are tiled in an interleaved fashion. 
       FIG.  4 A  is a schematic side view of an optoelectronic apparatus  400 , and  FIG.  4 B  is a schematic frontal view of a far-field pattern of spots  402  on a target  404  projected by the apparatus, in accordance with an embodiment of the invention. 
     Apparatus  400  comprises a spot projector  406  and a controller  408 , similar to controller  108  ( FIG.  1 A ). Projector  406  comprises a Si substrate  410 , comprising drive and control circuits, and a single GaAs die  411  mounted on the Si substrate in a VoS configuration. GaAs die  411  comprises seven hexagonal sections  412   a ,  412   b ,  412   c ,  412   d ,  412   e ,  412   f , and  412   g , shown in a schematic frontal view in an inset  413 , with a line F-F in the inset corresponding to the plane of  FIG.  4 A . Sections  412   a ,  412   b , and  412   c  comprise respective emitter arrays  414   a ,  414   b , and  414   c , comprising VCSELs  416  (marked by open circles). VCSELs  416  are disposed on a back side  417  of GaAs die  411 , facing Si substrate  410 . Sections  412   a  and  412   f  additionally comprise VCSELs  418 , termed “probing emitters” and marked with filled circles. VCSELs  418  are either lit or not lit and can be used for security purposes. VCSELs  416 , used for 3D mapping of target  404 , are arranged in non-repeating patterns in order to enable differentiating far distances from near distances, similarly to emitters  114  of apparatus  100  ( FIG.  1 A ). VCSELs  416  in sections  412   d - 412   g  are not shown for the sake of simplicity. 
     As described hereinabove, VCSEL arrays  414   a - 414   c  are all disposed on a single, small GaAs die  411 , rather than in multiple dies, such as VCSEL arrays  112  of apparatus  100 . Other embodiments may similarly be produced using either a single GaAs die or multiple dies. Using a single GaAs die typically requires a more pronounced steering of beams than using multiple dies, as is seen by comparing the beam paths in  FIG.  4    to those in  FIG.  1 A , for example. 
     A microlens array  422  is etched on a top side  420  of GaAs die  411  after the die has been thinned. Microlens array  422  comprises microlenses  424 , wherein each microlens comprises a tilted toroidal surface and is aligned with a respective VCSEL array. Microlenses  424  are designed to refract the beams of optical radiation emitted by VCSELs  416  so as to satisfy the beam-steering requirements of a single-die implementation, as will be detailed hereinbelow. Typical sags of the microlenses (heights of the microlens profiles) are of the order of 1 μm with a maximal sag of 5 μm, and the diameter of each microlens is typically 15 μm in the present example. 
     Projector  406  further comprises an MOE  426 , comprising an optical metasurface  428  disposed on an optical substrate  430 . Optical metasurface  428  comprises optical apertures  432   a ,  432   b ,  432   c ,  432   d ,  432   e ,  432   f , and  432   g . MOE  426  is shown in a schematic frontal view in an inset  434 , with a line G-G corresponding to the plane of  FIG.  4 A . The diameters of optical apertures  432   a - 432   g  are 1 mm in this example, thus providing sufficient surface area for the impinging beams of optical radiation from VCSELs  416  to avoid high irradiance on MOE  426 . 
     When driven by controller  408 , VCSELs  416  of VCSEL arrays  414   a - 414   c  emit respective beams of optical radiation through GaAs die  411 , shown schematically by their respective chief rays  436   a ,  436   b , and  436   c . The beams, represented by chief rays  436   a - 436   c , are refracted by microlens array  422  and projected from the small area of GaAs die  411  as diverging beams toward respective optical apertures  432   a - 432   c . The diverging beams impinge on respective optical apertures  432   a - 432   c , which collimate, tilt, and split the beams into sub-beams  440   a ,  440   b , and  440   c  and direct them toward target  404 , illuminating the target with spots  402 . The collimation of the optical beams is shown by marginal rays  438  emitted by a VCSEL  416   b  at the center of array  414   b.    
     Microlens array  422  and MOE  426  are designed so that the beams of optical radiation emitted by VCSELs  416  tile target  404  with a repeating and interleaving pattern of images of sections  412   a - 412   g.    
     Alternative Spot and Flood Projector 
       FIG.  5 A  is a schematic side view of an optoelectronic apparatus  500 ,  FIG.  5 B  is a schematic frontal view of a far-field pattern of spots  502  on a target  504  projected by the apparatus, and  FIG.  5 C  is a schematic frontal view of flood illumination  506  on the target projected by the apparatus, in accordance with an embodiment of the invention. 
     Apparatus  500  comprises a spot projector  508  and a flood projector  510 , sharing a common Si substrate  512 , and a controller  514 . 
     Spot projector  508  comprises a GaAs die  516  mounted on Si substrate  512 . Die  516  is similar to die  411  ( FIG.  4 A ), comprising seven hexagonal sections, with arrays of VCSELs  517  shown on three of the sections. GaAs die  516  is shown in a schematic frontal view in an inset  518 . For the sake of clarity of the figure, the labels of the sections and the VCSEL arrays on die  516  are omitted. A line H-H in inset  518  corresponds to the plane of  FIG.  5 A . GaAs die  516  also comprises a microlens array  520 , similar to microlens array  422  ( FIG.  4 A ). Spot projector  508  furthermore comprises an MOE  522 , comprising an optical metasurface  524  disposed on an optical substrate  526 . MOE  522 , shown (together with an MOE  544 , detailed hereinbelow) in a schematic frontal view in an inset  528 , comprises optical apertures  530   a - 530   g  within optical metasurface  524 , similar to optical apertures  432   a - 432   g  ( FIG.  4 A ). A line J-J in inset  528  corresponds to the plane of  FIG.  5 A . Optical apertures  530   a - 530   g  are designed to collimate the beams of optical radiation emitted from VCSELs  517  in GaAs die  516  and directed by microlens array  520 . When controller  514  drives VCSELs  517  in GaAs die  516 , the emitted beams are split, tilted, and collimated into respective sub-beams  531   a ,  531   b , and  531   c , which are directed to target  504  similarly to beams  436   a - 436   c  in  FIG.  4 A , and illuminate the target with spots  502 . 
     Flood projector  510  comprises a GaAs die  532  mounted on Si substrate  512 . Die  532  comprises seven hexagonal sections  534   a ,  534   b ,  534   c ,  534   d ,  534   e ,  534   f , and  534   g . Sections  534   a ,  534   b , and  534   c  comprise dense arrays  536   a ,  536   b , and  536   c  of VCSELs  538 . (Dense VCSEL arrays in sections  534   d - 534   g  are not shown for the sake of simplicity.) Die  532  is shown in a schematic frontal view in an inset  540 , with a line K-K in the frontal view corresponding to the plane of  FIG.  5 A . Die  532  also comprises an etched microlens array  542 , similar to microlens array  520 . 
     Flood projector  510  further comprises MOE  544 , comprising an optical metasurface  546  on an optical substrate  548 . MOE  544 , shown in a schematic frontal view in inset  528 , comprises optical apertures  550   a - 550   g  within optical metasurface  546 . Optical apertures  550   a - 550   g  are designed not to collimate the optical beams emitted by VCSELs  538  in GaAs die  532 , but rather cause them to diverge. Controller  514  drives VCSELs  538  in arrays  536   a - 536   c , which emit beams of radiation. The beams are refracted by microlens array  542  into diverging beams, represented by chief rays  552   a - 552   c , and directed toward respective optical apertures  550   a - 550   c . Optical apertures  550   a - 550   c  split and tilt these beams, and direct them toward target  504  as respective diverging sub-beams  556   a ,  556   b , and  556   c , illuminating the target with dense blurred and overlapping spots  554 , forming flood illumination  506 . 
     The diameters of optical apertures  550   a - 550   g , as well as those of optical apertures  550   a - 550   c , are typically 1 mm in the present example, thus providing sufficiently large areas for the impinging beams for avoiding damage on the MOEs. Although MOE  522  and MOE  544  are shown as having separate respective optical substrates  526  and  548 , they may alternatively be disposed on a common optical substrate. 
       FIG.  6    is a schematic side view of an optoelectronic apparatus  600 , in accordance with an embodiment of the invention. Apparatus  600  comprises a spot projector  602  and a flood projector  604  comprising a common Si substrate  606  and a common MOE  608 , and a controller  610 . 
     MOE  608  comprises an optical metasurface  612  disposed on an optical substrate  614 , with twelve optical apertures  616   a - 6161 , shown in a schematic frontal view in an inset  618 . A line L-L in inset  618  corresponds to the plane of  FIG.  6   . All twelve optical apertures  616   a - 6161  of MOE  608  have the same focal length and thus a common focal plane  619 . As detailed hereinbelow, both spot and flood illumination are achieved using MOE  608  with its twelve identical optical apertures, rather than using a combination of two different MOEs  522  and  544  ( FIG.  5 A ) with a total of fourteen optical apertures and with different focal lengths for the two MOEs. 
     Spot projector  602  comprises a GaAs die  620  mounted on Si substrate  606 . Die  620  is similar to die  516  ( FIG.  5 A ), comprising seven hexagonal sections comprising arrays of VCSELs  622 . GaAs die  620  is shown in a schematic frontal view in an inset  624 , with a line M-M corresponding to the plane of  FIG.  6   . GaAs die  620  also comprises a microlens array  626 , similar to microlens array  520  ( FIG.  5 A ). 
     When controller  610  drives VCSELs  622 , the emitted beams are refracted by microlens array  626  into beams represented by chief rays  627   a ,  627   b , and  627   c . Microlens array  626  directs these beams toward respective optical apertures  616   a ,  616   b , and  616   c . Optical apertures  616   a - 616   c  collimate, tilt and split the impinging beams into respective sub-beams  621   a ,  621   b ,  621   c , similarly to beams  436   a - 436   c  in  FIG.  4 A , direct them toward a target, and illuminate the target with a spot pattern (not shown in this figure). 
     Flood projector  604  comprises a GaAs die  628  mounted on a pedestal  630 , which in turn is mounted on Si substrate  606 . (Alternatively, Si substrate  606  and pedestal  630  may be formed by, for example, etching from a single piece of Si.) Die  628  is similar to die  532  ( FIG.  5 A ), comprising seven hexagonal sections, which comprise dense arrays of VCSELs  632 . GaAs die  628  is shown in a schematic frontal view in an inset  634 , with a line N-N corresponding to the plane of  FIG.  6   . GaAs die  628  also comprises a microlens array  636 , similar to microlens array  520  ( FIG.  5 A ). 
     When controller  610  drives VCSELs  632 , the emitted beams are refracted by microlens array  636  into beams represented by chief rays  638   d ,  638   h , and  638   i . Microlens array  636  directs these beams toward respective optical apertures  616   d ,  616   h , and  616   i . (Element  616   d  is behind element  616   c  in the side view of  FIG.  6   .) Optical apertures  616   d ,  616   h , and  616   i  tilt and split the impinging beams into respective sub-beams  642   d ,  642   h , and  642   i , but do not collimate them due to the elevation of GaAs die  628  by pedestal  630  to well above focal plane  619 . Thus the beams directed toward a target by optical apertures  616   d ,  616   h , and  616   i  diverge and illuminate the target with defocused (blurred) spots. As, in addition to the blur, the spots originate from dense arrays of VCSELs  632 , the target is illuminated by even and broad flood illumination, similar to flood illumination  506  ( FIG.  5 C ). 
     Spot Projectors with Additional Lenses 
       FIGS.  7 A and  7 B  are schematic side views of respective optoelectronic apparatuses  700   a  and  700   b , in accordance with additional embodiments of the invention. Similar or identical items in apparatuses  700   a  and  700   b  are indicated by the same labels. 
     Optoelectronic apparatus  700   a  comprises a spot projector  702   a  and a controller  704 . Spot projector  702   a  comprises a Si substrate  706 , on which four GaAs dies  708   a ,  708   b ,  708   c , and  708   d  are mounted, similarly to GaAs dies  312   a - 312   d  ( FIG.  3 A ). A schematic frontal view of Si substrate  706  with GaAs dies  708   a - 708   d  is shown in an inset  709 , where a line O-O corresponds to the plane of  FIG.  7 A . Each GaAs die  708   a - 708   d  comprises an array of VCSELs (not shown in  FIG.  7 A  for the sake of simplicity). Spot projector  702   a  further comprises respective optical lenses over dies  708   a - 708   d , of which only lenses  710   a  and  710   b  are shown in the figure, and an MOE  712 , comprising an optical metasurface  716  disposed on an optical substrate  718 . Optical metasurface  716  comprises optical apertures  714   a ,  714   b , . . . . Optical lenses  710   a ,  710   b , . . . , as well as optical apertures  714   a ,  714   b , . . . , are aligned with respective GaAs dies  708   a - 708   d . (Similarly to apparatus  200  in  FIG.  2 A , microlenses may be formed on the upper side of the dies so that the apparent source of the beams is located at or close to the top surface of each die.) 
     Optical lenses  710   a ,  710   b , . . . may be formed to reduce the optical aberrations of the beams emitted by the VCSELs on GaAs dies  708   a - 708   d . Alternatively, the optical aberrations may be reduced by an additional MOE, either disposed on the bottom side of MOE  712 , or fabricated on a separate substrate, which is either positioned adjacent to MOE  712  or cemented to it. 
     When controller  704  drives the VCSELs in arrays  708   a - 708   d , the VCSELs of each array emit respective sets of beams  720   a ,  720   b , . . . . (Although each array  708   a - 708   d  comprises several VCSELs, the beams from only one VCSEL are shown for the sake of clarity.) Beams  720   a ,  720   b , . . . , are refracted by respective lenses  710   a ,  710 , . . . , and directed onto respective optical apertures  714   a ,  714   b , . . . . The optical apertures collimate, tilt, and split the beams into respective sub-beams  724   a ,  724   b , . . . , and direct the sub-beams toward a target, illuminating the target with spot pattern (the target not shown in the figure). Lenses  710   a ,  710   b , . . . , are designed optically so as to reduce the sizes of the spots projected onto the target, thus increasing the signal-to-noise ratio when detecting the reflections of the spots in, for example, 3D mapping. Additionally, the use of lenses  710   a ,  710   b , . . . , may relieve the alignment requirements for spot projector  702   a.    
     Optoelectronic apparatus  700   b  in  FIG.  7 B  comprises a spot projector  702   b  and controller  704 . Spot projector  702   b  is identical to spot projector  702   a  in  FIG.  7 A , with the exception that the four discrete optical lenses  710   a ,  710   b , . . . , have been replaced by a monolithic plastic lens  722 , which replicates the functions of the discrete lenses. The monolithic design of lens  722  and the choice of plastic material can reduce the fabrication costs and further relieve the alignment requirements for projector  702   b , as compared to projector  702   a.    
       FIG.  8    is a schematic side view of an optoelectronic apparatus  800 , in accordance with a further embodiment of the invention. Optoelectronic apparatus  800  comprises a spot projector  802  and a controller  804 . Spot projector  802  is similar to spot projector  406  of apparatus  400  ( FIG.  4 A ), with an added compound lens  806  for reducing the size of the projected spots on a target. Compound lens  806  may be more costly than the lenses shown in  FIGS.  7 A and  7 B , but it may enable finer collimation of the beams emitted by apparatus  800 , as well as reducing the width of apparatus  800  and sensitivity to decentering of the components. 
     Spot projector  802  comprises a Si substrate  808 , comprising drive and control circuits, and a GaAs die  810  mounted on the Si substrate. GaAs die  810  comprises four VCSEL arrays  812   a ,  812   b ,  812   c , and  812   d , comprising VCSELs  814 . GaAs die  810 , together with VCSEL arrays  812   a - 812   d , is shown in a schematic frontal view in an inset  816 , with a line P-P corresponding to the plane of  FIG.  8   . GaAs die  810  also comprises an etched microlens array  818 , similar to microlens array  422  ( FIG.  4 A ). In addition to compound lens  806 , the optics of spot projector  802  also comprise an MOE  820 , comprising an optical metasurface  822  disposed on an optical substrate  823 . Optical metasurface  822  comprises four optical apertures  824   a ,  824   b , . . . , with respective diameters of 1.6 mm. (In the side view, only VCSEL arrays  812   a  and  812   b  and optical apertures  824   a  and  824   b  are visible.) 
     Compound lens  806  may be formed to reduce the aberrations of the beams emitted by VCSELs  814  in order to reduce spot sizes on the target, even for large VCSEL-arrays. Alternatively, the optical aberrations may be reduced by an additional MOE, either disposed on the bottom side of MOE  820  or fabricated on a separate substrate, which is either positioned adjacent to MOE  820  or cemented to it. 
     When VCSELs  814  of VCSEL arrays  812   a ,  812   b , . . . , are driven by controller  804 , they emit beams of optical radiation through GaAs die  810 . The beams emitted by arrays  812   a  and  812   b  are refracted by microlens array  818  toward compound lens  806 , with the beams denoted schematically by respective chief rays  826   a  and  826   b . The refracted beams are further refracted by compound lens  806 , and impinge on optical apertures  824   a ,  824   b , . . . , of MOE, which collimate, tilt, and split the beams into respective sub-beams  830   a ,  830   b , . . . , and direct them toward a target, illuminating the target with a spot pattern (not shown in this figure). The collimation of the beams is shown by marginal rays  828  emitted by a central VCSEL  814   b  in array  812   b.    
     Alternative Flood Projector 
       FIG.  9    is a schematic side view of an optoelectronic apparatus  900 , in accordance with yet another embodiment of the invention. Optoelectronic apparatus  900  comprises a flood projector  902  and a controller  904 . 
     Flood projector  902  comprises a Si substrate  906 , comprising drive and control circuits, and a GaAs die  908  mounted on the Si substrate. GaAs die  908  comprises a VCSEL array  910 , comprising VCSELs  912   a - 912   i . (Although only a single row of VCSELs is shown in this side view, die  908  may comprise a two-dimensional array of VCSELs as in the preceding embodiments.) VCSELs  912   a - 912   i  are formed on the back side of GaAs die  908 , while microlenses, referred to as on-chip lenses (OCLs)  914   a - 914   i , are formed on the front side. Each OCL is aligned with a respective VCSEL (for example,  914   a  to  912   a ), but offset laterally as will be detailed hereinbelow. Alternative embodiments may comprise VCSEL arrays with a higher or lower number of VCSELs, as well as either one-dimensional or two-dimensional arrays. 
     Flood projector  902  further comprises an MOE  916 , which spreads and homogenizes the spatial and angular profile of light output by the projector. 
     When VCSELs  912   a - 912   i  are driven by controller  904 , they emit respective beams of optical radiation  920   a - 920   i  through GaAs die  908 . Beams  920   a - 920   i  impinge on respective OCLs  914   a - 914   i , which refract them to beams  922   a - 922   i . Each of OCLs  914   a - 914   i  is decentered within the hexagonal aperture of respective VCSEL  912   a - 912   i  so that it steers the respective one of beams  922   a - 922   i  in a desired direction, causing the chief rays of some of the beams to cross with those of other beams. For improved compatibility with the manufacturing process, OCLs  914   a - 914   i  are paired so that each left-steered beam has as its counterpart a symmetrically positioned right-steered beam. Additionally or alternatively, the OCLs may have different, non-symmetrical sag profiles, resulting in different beam tilt angles. Further additionally or alternatively, the OCLs in flood projector may be toroidal, as in the embodiments described above, with appropriate tilt to cause the beams to cross as appropriate for the present embodiment. 
     In the pictured example, OCL  914   c  is offset so that beam  922   c  crosses beams  922   a  and  922   b . The optical powers (focal lengths) of OCLs  914   a - 914   i  are chosen so as to reduce the numerical aperture (NA) of each of beams  922   a - 922   i  relative to the NA of beams  920   a - 920   i . The NA of beams  920   a - 920   i  is typically 0.16-0.25, for example, while that of beams  922   a - 922   i  is lower, for example around 0.1. Due to the difference between the refractive indices of GaAs and air (3.5 vs. 1), however, the angular divergence of beams  922   a - 922   i  is larger than that of beams  920   a - 920   i . Beams  922   a - 922   i  impinge on MOE  916 , which diffracts the beams into multiple spread-out diffracted orders  924  that propagate toward a target (not shown in the figure). 
     The mutual crossing of beams  922   a - 922   i , together with their divergence, spreads them uniformly across MOE  916 , thus reducing the thermal load on the MOE and on any subsequent layers above the MOE. Furthermore, crossing of the beams reduces inhomogeneities in the flood illumination that might otherwise occur due to temperature differences among VCSELs  912   a - 912   i , because the VCSELs at the center of the array tend to become substantially hotter than those in the periphery. MOE  916  is designed to diffract beams  922   a - 922   i  into a large number of overlapping diffracted orders in two dimensions, such as 100×100 orders, thus increasing the beam overlap on the target and providing highly diffuse flood illumination on the target with reduced tiling artifacts. 
     In an alternative embodiment, a random component may be added to the offsets and/or sag profiles of OCLs  914   a - 914   i  with respect to VCSELs  912   a - 912   i  in order to randomize the directions into which the OCLs steer beams  922   a - 922   i . This kind of randomization increases the resilience of the system with respect to thermal power gradients. The offsets and/or sag profiles may further be utilized to adjust the overall shape of diffracted orders  924  exiting from flood projector  902  in order to accommodate functional and aesthetic considerations. The partial collimation (non-zero divergence) of beams  922   a - 922   i  reduces the size of MOE  916  required to accommodate these beams, while taking into account the tolerances of the NAs of the emitted beams  920   a - 920   i.    
     Controller  904  typically drives VCSELs  912   a - 912   i  with pulses; for example, driving the VCSELs with  22  pulses of a duration of 33 μs per pulse, with an interval between the pulses of 205 μs, leads to a total flood illumination time (and hence to a total acquisition time of a target image) of 5.05 ms. In alternative embodiments, controller  904  may drive VCSELs  912   a - 912   i  with pulses of different durations and intervals, or alternatively with a drive current that is constant in time (DC current). 
     It will 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: 20230522
Publication Date: 20241022
Grant Date: 20241022
Priority Date: 20230522
Inventors: TSUR, YUVAL
DELLA PERGOLA, REFAEL
REMEZ, ROEI
AVRAHAM, ASSAF
Alnahhas, Yazan
Assignee: APPLE INC
CPC Classifications: [{"code": "F21V5/004", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21V5/007", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21V3/04", "inventive": true, "first": true, "tree": "[]"}, {"code": "F21V5/004", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21V3/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21V5/007", "inventive": true, "first": true, "tree": "[]"}, {"code": "F21V5/004", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21V3/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "F21V5/007", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 93123202