Portable structured light measurement module/apparatus with pattern shifting device incorporating a fixed-pattern optic for illuminating a subject-under-test

• US 9,444,981 B2
• Filed: 07/26/2012
• Issued: 09/13/2016
• Est. Priority Date: 07/26/2011
• Status: Active Grant

• Current Assignee: Seikowave Health Solutions, Inc. (Seikowave, Inc.)
• Original Assignee: Seikowave, Inc.
• Inventors: Hara, Hideo, Bellis, Matthew W., Lau, Daniel L.
• Primary Examiner(s): Natnael, Paulos M
• Application Number:
  US13/559,593
• Publication Number:
  US 20130188012A1
• Time in Patent Office: 1,510 Days
• Field of Search: 348/42, 348/50, 348/135, 356/601, 356/603, 356/479
• US Class Current: 1/1
• CPC Class Codes: H04N 23/50 Constructional details
• CPC Class Codes: H04N 23/51 Housings
• CPC Class Codes: H04N 23/555 for picking-up images in sites, inaccessible due to their dimensions or hazardous conditions, e.g. endoscopes or borescopes

Abstract

A surface measurement module for 3-D image acquisition of a subject-under-inspection. The module having: (a) a casing to house a pattern shifting device having a fixed-pattern optic through which light from a light source is passed, an output of the pattern shifting device being directed at a polarizing beam splitter and the polarized output of the splitter directed through a lens assembly comprising at least one lens element; (b) a reflector to direct the polarized output exiting the lens assembly, to illuminate a surface of the subject-under-inspection; (c) a scattered light illumination off the surface is directed back through the lens assembly for capture by an image sensor; and (d) the casing also housing the polarizing beam splitter, the lens assembly, and the image sensor. The output of the fixed-pattern optic comprises a multi-frequency pattern. The pattern shifting device may be a linear or rotating type.

Claims

1. A surface measurement module for 3-D image acquisition of a subject-under-inspection, the module comprising:

(a) a casing to house a pattern shifting device from which an output comprising a multi-frequency pattern comprising a plurality of pixels representing at least a first and second superimposed sinusoid of light from a light source, is directed at a polarizing beam splitter,

(b) each said pixel of said plurality of pixels comprised of said first sinusoid having a first frequency distinct from a second frequency of said second sinusoid;

(c) the polarized output of said splitter directed through a lens assembly comprising at least one lens element;

(d) a reflector to direct said polarized output exiting said lens assembly, to illuminate a surface of the subject-under-inspection;

(e) a scattered light illumination off said surface is directed back to said reflector and then through said lens assembly for capture by an image sensor; and

(f) said casing also housing said polarizing beam splitter, said lens assembly, and said image sensor.

2. The surface measurement module of claim 1 further comprising:

(a) a quarter-wave plate interposed between said surface of the subject-under-inspection and a pathway directed to said lens assembly; and

(b) a plurality of images captured of said scattered light illumination, after passing back through said lens assembly, off said surface being used for the 3-D image acquisition.

3. The surface measurement module of claim 1 positioned for inspection of said surface having been selected from the group consisting of:

a surface of mammalian tissue;

a surface of an interior of a pipeline;

a surface within a cavity of a hydraulic system;

a surface of a semiconductor wafer undergoing fabrication;

a surface of a printed circuit board (PCB) undergoing testing; and

a surface of a product undergoing manufacture.

4. The surface measurement module of claim 3 wherein said surface of mammalian tissue comprises a surface located within a mammalian oral cavity;

and said product undergoing manufacture is selected from the group consisting of parts, assemblies, foodstuff, and packaging.

5. The surface measurement module of claim 1, wherein said pattern shifting device comprises a fixed-pattern optic having said multi-frequency pattern fixed into a substrate support.

6. The surface measurement module of claim 5, wherein said multi-frequency pattern is fixed into said substrate support such that an output of said fixed-pattern optic has half-tone characteristics during said projection onto said surface of the subject-under-inspection.

7. The surface measurement module of claim 5, wherein said multi-frequency pattern is fixed by etching said substrate support, said substrate support selected from the group consisting of silicon and metal substrate.

8. The surface measurement module of claim 5, wherein said multi-frequency pattern is fixed by incorporating a reflective material into said substrate support, said substrate support selected from the group consisting of silicon-based glass and silicon.

9. The surface measurement module of claim 5, wherein said multi-frequency pattern is fixed by depositing a material onto said substrate support, said substrate support selected from the group consisting of silicon-based glass and silicon.

10. The surface measurement module of claim 5, wherein said pattern shifting device further comprises a shifting element comprising an element for linear shifting of said multi-frequency pattern.

11. The surface measurement module of claim 10, wherein said element is conductive and to which, in operation, a voltage is applied.

12. The surface measurement module of claim 1, wherein:

(a) said pattern shifting device comprises a fixed-pattern wheel; and

(b) said wheel set in motion causes a spatial shift such that said output of said pattern shifting device comprises said multi-frequency pattern.

13. The surface measurement module of claim 1, wherein said pattern shifting device comprises a fixed-pattern optic having said multi-frequency pattern fixed into a substrate support by incorporating therein a reflective material comprising at least one mirror.

14. The surface measurement module of claim 1, wherein said pattern shifting device comprises:

(a) a fixed-pattern optic having said multi-frequency pattern fixed into a substrate support; and

(b) a shifting element.

15. The surface measurement module of claim 14, wherein said shifting element and said fixed-pattern optic are integrated such that a reflective material component comprising at least one mirror is incorporated into said substrate support.

16. A surface measurement module for 3-D image acquisition of a subject-under-inspection, the module comprising:

(a) a casing to house a pattern shifting device from which an output of light from a light source is directed at a polarizing beam splitter;

(b) the polarized output of said splitter directed through a lens assembly comprising at least one lens element;

(c) a reflector to direct said polarized output exiting said lens assembly, to illuminate a surface of the subject-under-inspection;

(d) a scattered light illumination off said surface is directed back through said lens assembly for capture by an image sensor;

(e) said casing also housing said polarizing beam splitter, said lens assembly, and said image sensor; and

wherein;

(i) said output of said pattern shifting device comprises a multi-frequency pattern comprising a plurality of pixels representing at least a first and second superimposed sinusoid projected simultaneously; and

(ii) each of the sinusoids represented by the pixels have a unique temporal frequency and each of the pixels projected to satisfy

17. A surface measurement module for 3-D image acquisition of a subject-under-inspection, the module comprising, the module comprising:

(a) a casing to house a pattern shifting device from which an output comprising a multi-frequency pattern comprising a plurality of pixels representing at least a first and second superimposed sinusoid of light from an incoherent light source is directed at a polarizing beam splitter;

(b) the polarized output of said splitter directed through a lens assembly comprising at least one lens element;

(c) a reflector to direct said polarized output exiting said lens assembly, to illuminate a surface of the subject-under-inspection;

(d) a scattered light illumination off said surface is directed back through said lens assembly for capture by an image sensor; and

(e) wherein said first and second superimposed sinusoid are projected simultaneously, and each of the sinusoids represented by the pixels have a unique temporal frequency and each of the pixels projected to satisfy

18. The surface measurement module of claim 17, wherein:

(a) said pattern shifting device comprises a fixed-pattern optic having said multi-frequency pattern fixed into a substrate support; and

(b) said casing also housing said polarizing beam splitter, said lens assembly, and said image sensor.

19. The surface measurement module of claim 18, wherein said pattern shifting device further comprises a shifting element comprising a conductive element for linear shifting of said multi-frequency pattern to which, in operation, a voltage is applied.

20. The surface measurement module of claim 18, wherein said multi-frequency pattern is fixed by incorporating a reflective material comprising at least one mirror into said substrate support.