Structured light projection and imaging

Abstract

An optical system, including: (a) an emitter array including a plurality of individual emitters, wherein each emitter in the emitter array is operable to emit a light beam which is characterized by a native beam width; (b) an optical subunit, operable to transform a plurality of light beams emitted by the emitter array, wherein each of the transformed light beams is characterized by an expanded beam width that is wider than the native beam width of the corresponding light beam and is wider than a facilitating beam width; and (c) a diffractive optical element that is capable of diffracting the transformed light beams to provide light patterns whose angular resolution meets a light pattern target angular resolution criteria.

1 - 139 . (canceled) 
     
     
         140 . An optical system, comprising:
 an emitter array comprising a plurality of individual emitters, wherein each emitter in the emitter array is operable to emit a light beam which is characterized by a first beam divergence;   an optical subunit, operable to: (a) transform a plurality of light beams emitted by the emitter array, wherein each of the transformed light beams is characterized by a second beam divergence that is smaller than the first beam divergence of the corresponding light beam; (b) to direct the plurality of transformed light beams onto the diffractive optical element at different angles of incidence, resulting in providing of a plurality of light patterns by the diffractive optical element; and   a diffractive optical element that is capable of diffracting the transformed light beams to provide a plurality of light patterns.   
     
     
         141 . The optical system according to  claim 140 , wherein the second beam divergence is lesser than or equal to a facilitating beam divergence of the diffractive optical element. 
     
     
         142 . The optical system according to  claim 140 , wherein the optical subunit comprises a plurality of optical elements having a common optical axis. 
     
     
         143 . The optical system according to  claim 140 , wherein the optical subunit comprises transforming optical components which are common to the plurality of light beams. 
     
     
         144 . The optical system according to  claim 140 , wherein the emitter array and the optical subunit are positioned relative to one another such that the optical subunit further transforms the plurality of light beams by deflecting the plurality of light beams so that the plurality of transformed light beams are projected onto the diffractive optical element at different angles of incidence, resulting in providing of a plurality of light patterns by the diffractive optical element. 
     
     
         145 . The optical system according to  claim 140 , wherein a combination of the optical subunit and the diffractive optical element is characterized by a distortion function, wherein the plurality of individual emitters is arranged in a non-uniform configuration whose relation to a predefined uniform grid is an inverse function of the distortion function. 
     
     
         146 . The optical system according to  claim 140 , wherein the plurality of individual emitters is positioned on a focal plane of the optical subunit. 
     
     
         147 . The optical system according to  claim 140 , wherein the plurality of light patterns provided by the diffractive optical element are copies of a light pattern. 
     
     
         148 . The optical system according to  claim 147 , wherein each provided copy of the light pattern partly overlaps at least one other provided copy of the light pattern, wherein the light pattern comprises multiple copies of a repeated subpattern, wherein in each provided copy of the light pattern at least one subpattern overlaps a subpattern of at least one other provided copy of the light pattern generated by light originating from another light emitter. 
     
     
         149 . The optical system according to  claim 147 , further comprising an emitter array control system which is configured and operable to control activation of different subgroups of emitters of the emitter array, thereby resulting in providing of offset overall output patterns of the optical system at different times. 
     
     
         150 . The optical system according to  claim 140 , wherein a width of each one of the plurality of transformed light beams is greater than a beam width of a facilitating beam of the diffractive optical element. 
     
     
         151 . The optical system according to  claim 140 , wherein a width of each one of the plurality of transformed light beams is greater than the native beam width of the light beam. 
     
     
         152 . The optical system according to  claim 151 , wherein a width of each one of the plurality of transformed light beams is greater than the native beam width by at least a factor 3. 
     
     
         153 . The optical system according to  claim 140 , wherein for each individual emitter of the emitter array there is at least one other individual emitter of the emitter array positioned at a distance which is smaller than any beam width of any transformed light beam out of the plurality of transformed light beams. 
     
     
         154 . The optical system according to  claim 140 , wherein each of the plurality of individual emitters of the emitter array is a vertical-cavity surface-emitting laser emitter. 
     
     
         155 . The optical system according to  claim 140 , further comprising at least one processing unit, and wherein the optical system is operable to project onto an object at least a part of a structured light pattern which comprises the plurality of light patterns, and wherein the at least one processing unit is configured to decode an image of a reflected portion of the projected structured light pattern to determine range parameters. 
     
     
         156 . A method for projection, the method comprising:
 emitting a plurality of light beams, wherein each of the plurality of light beams is characterized by a first beam divergence;   transforming the plurality of light beams, so that each of the transformed light beams is characterized by a second beam divergence that is smaller than the first beam divergence of the corresponding light beam;   directing the plurality of the transformed light beams onto a diffractive optical element at different angles of incidence; and   diffracting the transformed light beams by a diffractive optical element to provide a plurality of light patterns.   
     
     
         157 . The method according to  claim 156 , wherein a combination of the optical subunit and the diffractive optical element is characterized by a distortion function, wherein the plurality of individual emitters is arranged in a non-uniform configuration whose relation to a predefined uniform grid is an inverse function of the distortion function. 
     
     
         158 . The method according to  claim 156 , wherein the second beam divergence is lesser than or equal to a facilitating beam divergence of the diffractive optical element. 
     
     
         159 . The method according to  claim 156 , wherein said transforming and said directing comprises using an optical subunit which is an optical assembly comprising a plurality of optical elements having a common optical axis. 
     
     
         160 . The method according to  claim 159 , wherein said transforming comprises using transforming optical components common to the plurality of light beams. 
     
     
         161 . The method according to  claim 156 , wherein the plurality of light beams are emitted by an emitter array, and the method further comprises positioning the emitter array and the optical subunit relative to one another such that the optical subunit further transforms the plurality of light beams by deflecting the plurality of light beams, and the method further comprises projecting the plurality of transformed light beams onto the diffractive optical element at different angles of incidence, thereby producing a plurality of light patterns 
     
     
         162 . The method according to  claim 161 , wherein the plurality of light patterns are copies of a light pattern. 
     
     
         163 . The method according to  claim 162 , wherein the plurality of copies of the light pattern are generated using the diffractive optical element as a single diffractive optical element, thereby facilitating projection of a high contrast and high clarity overall output pattern of the optical system. 
     
     
         164 . The method according to  claim 162 , wherein each provided copy of the light pattern partly overlaps at least one other provided copy of the light pattern, wherein the light pattern comprises multiple copies of a repeated subpattern, wherein in each provided copy of the light pattern at least one subpattern overlaps a subpattern of at least one other provided copy of the light pattern generated by light originating from another light emitter. 
     
     
         165 . The method according to  claim 156 , further comprising controlling activation of different subgroups of emitters of the emitter array, thereby resulting in providing of offset overall output patterns of the optical system at different times. 
     
     
         166 . The method according to  claim 161 , wherein the transforming is accomplished by an optical subunit, wherein the emitting is accomplished by a plurality of individual emitters which are positioned at a focal plane of the optical subunit. 
     
     
         167 . The method according to  claim 156 , further comprising:
 projecting onto an object at least a part of a structured light pattern which comprises the plurality of light patterns; and   processing an image of a reflected portion of the projected structured light pattern to determine range parameters.   
     
     
         168 . The method according to  claim 156 , wherein a width of each one of the plurality of transformed light beams is greater than a beam width of a facilitating beam of the diffractive optical element. 
     
     
         169 . The method according to  claim 156 , wherein a beam width of each one of the plurality of transformed light beams is greater than the native beam width of the light beam. 
     
     
         170 . The method according to  claim 169 , wherein a width of each of the plurality of transformed light beams is greater than the native beam width by at least a factor 3.