DIGITAL OPTICAL COMPARATOR

• US 20100225666A1
• Filed: 03/04/2009
• Published: 09/09/2010
• Est. Priority Date: 03/04/2009
• Status: Active Grant

• Current Assignee: Visionx Inc.
• Original Assignee: Visionx Inc.
• Inventors: Beauchemin, Patrick
• Granted Patent: US 8,917,320 B2
• Time in Patent Office: Days
• US Class Current: 345/629
• CPC Class Codes: G01B 9/08 Optical projection comparators
• CPC Class Codes: G06F 17/00 Digital computing or data processing equipment or methods, specially adapted for specific functions information retrieval, database structures or file system structures therefor G06F16/00
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 7/001 using an image reference approach
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes
• CPC Class Codes: G06V 2201/06 Recognition of objects for industrial automation
• CPC Class Codes: G06V 30/422 Technical drawings; Geographical maps
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

A digital optical comparator has a holder for a part under study. A light source illuminates the part and casts an image of the part onto a camera, which is provided with a lens. The image captured by the camera is displayed on a screen, and a drawing of the part is overlaid on the image of the part. Thus, defects in manufacturing can be easily and readily identified. In addition, a determination of whether the part is manufactured within tolerances can also be visually determined.

Claims

1. A digital optical comparator comprising:

a holder for holding a part;

a light source for illuminating the part;

a camera for capturing an image of the illuminated part and a lens placed in front of said camera; and

a data processing system for receiving the image, for obtaining a CAD drawing of said part, for displaying said image and said drawing on a computer screen, where said drawing is digitally overlaid on said image, said data processing system further including means for aligning said drawing with said image.

2. A digital optical comparator according to claim 1, wherein said comparator further includes an image enhancement module.

3. A digital optical comparator according to claim 1, wherein said means for aligning said drawing with said image include a joystick operatively associated with said data processing system.

4. A digital optical comparator according to claim 1, wherein said means for aligning said drawing with said image include a mouse and a keyboard or a trackball.

5. A digital optical comparator according to claim 1, wherein said means for aligning said drawing with said image include a pattern matching subsystem, said subsystem being adapted to determine a position and orientation of said part, and to align said drawing with said part based on said position and orientation.

6. A digital optical comparator according to claim 1, wherein said computer screen includes a plurality of screens, so that said image is displayed in 1:

1 resolution.

7. A digital optical comparator according to claim 1, wherein said part is mounted on a moveable carriage.

8. A digital optical comparator according to claim 1, wherein said data processing system is a general purpose computer.

9. A digital optical comparator according to claim 1, wherein said comparator further includes a defective pixel corrector.

10. A digital optical comparator according to claim 1, wherein said drawing displays said part, and also graphically displays tolerances for said part, so that a determination whether the part is manufactured within tolerances can be visually made without measuring said part.

11. A digital optical comparator according to claim 1, wherein said data processing system further includes a measurement package for enabling on-screen measurements.

12. A digital optical comparator according to claim 1, wherein said camera provides a streaming video signal to said data processing apparatus.

13. A method for permitting comparison between a part under study and a reference drawing, said part having been manufactured to specifications contained in said drawing, said method comprising the steps of:

(a) placing said part on a support;

(b) illuminating said part;

(c) capturing an image of said part with a camera, said camera being provided with a lens; and

(d) overlaying said drawing and said image of said part on a display.

14. A method according to claim 13, wherein said method further includes the step of correcting said image with an image correction module prior to displaying said image on said display.

15. A method according to claim 13, wherein said method further includes the step of enhancing said image with an image enhancement module prior to displaying said image on said display.

16. A method according to claim 13, wherein said method further includes the step of manually or automatically aligning said part with said drawing.

17. A method according to claim 13, wherein said method further includes the step of correcting a distortion introduced by said lens with a distortion correction module.

18. A method according to claim 13, further comprising the step of providing a measurement module in order to enable on-screen measurements of said part.