Optical pattern projector

• US 10,247,547 B2
• Filed: 12/11/2017
• Issued: 04/02/2019
• Est. Priority Date: 06/23/2015
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Thuries, Serge, Gillet, Alain, Puybras, Bernard
• Primary Examiner(s): Amara, Mohamed K
• Application Number:
  US15/837,579
• Publication Number:
  US 20180100733A1
• Time in Patent Office: 477 Days
• CPC Class Codes: G01B 11/02 for measuring length, width or thickness G01B11/08 takes precedence
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G02B 13/0005 having F-Theta characteristic scanning systems employing movable or deformable optical elements G02B26/10
• CPC Class Codes: G02B 27/0944 Diffractive optical elements, e.g. gratings, holograms gratings per se G02B5/18; holograms used as optical elements per se G02B5/32
• CPC Class Codes: G02B 27/0961 Lens arrays lens arrays per se G02B3/0006
• CPC Class Codes: G02B 27/106 for splitting or combining a plurality of identical beams or images, e.g. image replication
• CPC Class Codes: G02B 27/1093 for use with monochromatic radiation only, e.g. devices for splitting a single laser source
• CPC Class Codes: G02B 27/20 for imaging minute objects, e.g. light-pointer
• CPC Class Codes: G02B 27/4233 having a diffractive element [DOE] contributing to a non-imaging application diffusers having a diffractive element G02B5/0252; filters having a diffractive element G02B5/203; systems for controlling the direction of light having diffractive elements G02B26/0808; scanning systems having diffractive elements G02B26/106; beam shaping systems using diffractive optical elements G02B27/0944; beam splitting or combining systems operating by diffraction G02B27/1086
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: H01S 5/423 having a vertical cavity

Abstract

An optical pattern projector used for projecting a structured-light pattern onto an object for dimensioning is presented. The optical pattern projector utilizes a laser array, a lenslet array, a lens, and a diffractive optical element to create a repeated pattern of projected dots. The pattern repetition is based on the grid pattern of laser array. Each laser'"'"'s collimated beam, when projected through the lens, impinges on the diffractive optical element from a slightly different direction. The diffractive optical element creates a sub-patterns that continue propagating along these different directions and combine on a target to produce a repeating optical pattern.

Claims

1. An optical pattern projector, comprising:

a laser array comprising a plurality of lasers spaced in a grid, each of the plurality of lasers configured to radiate light;

a plurality of lenslets configured and arranged with respect to the laser array to collimate the radiated light from the plurality of lasers, providing a plurality of collimated laser beams;

an f-theta lens configured and arranged with respect to the plurality of lenslets to receive the collimated laser beams and to focus each of the plurality of collimated laser beams along a particular incident angle, each respective particular incident angle determined by the position in the grid of the laser corresponding to the respective laser beam; and

a diffractive optical element (DOE) configured and arranged with respect to the f-theta lens to, for each collimated laser beam, diffract the collimated laser beam to form a sub-pattern comprising a plurality of beam portions derived from the collimated laser beam, wherein each respective sub-pattern propagates along a resultant incident angle determined by the particular incident angle of the corresponding collimated laser beam; and

wherein when projected onto a target, the sub-patterns each respectively corresponding to one of the collimated laser beams align with one another to form a repeating optical pattern comprising non-overlapping sub-patterns, and wherein the position of each sub-pattern in the repeating optical pattern depends on the resultant incident angle.

2. The optical pattern projector of claim 1, wherein when projected onto a target, each sub-pattern respectively encompasses a region defined by a perimeter of the sub-pattern, the respective regions being non-overlapping with one another.

3. The optical pattern projector of claim 1, wherein the number of beam portions in a sub-pattern depends on the diffraction effected by the DOE.

4. The optical pattern projector of claim 1, wherein each non-overlapping sub-pattern respectively originates from only one of the plurality of lasers, the repeating optical pattern consisting of N non-overlapping sub-patterns wherein N equals the number of lasers in laser array.

5. The optical pattern projector of claim 1, wherein each sub-pattern comprises an identical arrangmene of beam portions.

6. The optical pattern projector of claim 5, wherein the focusing lens comprises an f-theta lens.

7. The optical pattern projector of claim 5, wherein each of the N sub-patterns propagates along a resultant incident angle determined by the respective particular incident angle corresponding to the respective collimated laser beam, the position of each of the N sub-patterns in the repeating optical pattern depending on the respective resultant incident angle.

8. The optical pattern projector of claim 1, wherein the laser array comprises an array of vertical cavity surface emitting lasers.

9. The optical pattern projector of claim 1, wherein each sub-pattern comprises an identical arrangmene of beam portions.

10. An optical pattern projector, comprising:

an array of vertical cavity surface emitting lasers (VCSELs), the VCSELs configured to emit a plurality of collimated laser beams, the plurality being a whole number equal to N;

a focusing lens configured and arranged with respect to the VCSELs to receive the N collimated laser beams and to focus each of the N collimated laser beams along a particular incident angle, each respective particular incident angle determined by the position of the corresponding collimated laser beam when emitted from the VCSEL; and

a diffractive optical element (DOE) configured and arranged with respect to the focusing lens to diffract each of the N collimated laser beams, forming N sub-patterns, each of the N sub patterns comprising a plurality of beam portions derived from the respective one of the N collimated laser beams, the plurality of beam portions being a whole number equal to Y, wherein Y depends on the diffraction effected by the DOE;

wherein when projected onto a target, the N sub-patterns align with one another without overlapping to form a repeating optical pattern.

11. A method of creating an optional pattern, the method comprising:

projecting light from each of a plurality of lasers in a laser array;

collimating the light from each of the plurality of lasers using a plurality of lenslets, the plurality of lenslets configured and arranged with respect to the laser array to provide a pluralty of collimated laser beams;

focusing each of the plurality of collimated laser beams along a particular incident angle using an f-theta lens configured and arranged with respect to the plurality of lenslets to receive the collimated laser beams and to provide the particular incident angle, the particular incident angle corresponding to a respective laser beam determined by the position in the grid of the laser corresponding to the respective laser beam;

diffracting each collimated laser beam using a diffractive optical element (DOE) to form a sub-pattern comprising a plurality of beam portions derived from the collimated laser beam, the DOE configured and arranged to propagate each respective sub-pattern along a resultant incident angle determined by the particular incident angle of the corresponding collimated laser beam; and

projecting the sub-patterns onto a target, wherein the sub-patterns each respectively corresponding to one of the collimated laser beams align with one another for form a repeating optical pattern comprising non-overlapping sub-patterns, and wherein the position of each sub-pattern in the repeating optical pattern depends on the resultant incident angle.

12. The method of claim 11, wherein when projected onto a target, each sub-pattern respectively encompasses a region defined by a perimeter of the sub-pattern, the respective regions being non-overlapping with one another.

13. The method of claim 11, wherein the number of beam portions in a sub-pattern depends on the diffraction effected by the DOE.

14. The method of claim 11, wherein each non-overlapping sub-pattern respectively originates from only one of the plurality of lasers, the repeating optical pattern consisting of N non-overlapping sub-patterns wherein N equals the number of lasers in laser array.

15. The optical pattern projector of claim 11, wherein each sub-pattern comprises an identical arrangmene of beam portions.

16. The optical pattern projector of claim 11, wherein the laser array comprises an array of vertical cavity surface emitting lasers.

17. A method of creating an optional pattern, the method comprising:

emitting a plurality of collimated laser beams from an array of vertical cavity surface emitting lasers (VCSELs), the plurality being a whole number equal to N;

focusing each of the N collimated laser beams along a particular incident angle using a focusing lens configured and arranged with respect to the VCSELs to receive the N collimated laser beams, each respective particular incident angle determined by the position of the corresponding collimated laser beam when emitted from the VCSEL; and

diffracting each of the N collimated laser beams using a diffractive optical element (DOE) configured and arranged with respect to the focusing to form N sub-patterns, each of the N sub patterns comprising a plurality of beam portions derived from the respective one of the N collimated laser beams, the plurality of beam portions being a whole number equal to Y, wherein Y depends on the diffraction effected by the DOE; and

projecting the N sub-patterns onto a target, the N sub-patterns aligning with one another without overlapping to form a repeating optical pattern.

18. The method of claim 17, wherein the focusing lens comprises an f-theta lens.

19. The method of claim 17, wherein each of the N sub-patterns propagates along a resultant incident angle determined by the respective particular incident angle corresponding to the respective collimated laser beam, the position of each of the N sub-patterns in the repeating optical pattern depending on the respective resultant incident angle.

20. The optical pattern projector of claim 17, wherein each sub-pattern comprises an identical arrangmene of beam portions.