Deformable light pattern for machine vision system

• US 8,646,689 B2
• Filed: 10/27/2011
• Issued: 02/11/2014
• Est. Priority Date: 12/28/2007
• Status: Active Grant

• Current Assignee: Cognex Corporation
• Original Assignee: Cognex Corporation
• Inventors: Equitz, William, Moed, Michael C, Tremblay, Robert T, Gerst, Carl W III
• Primary Examiner(s): VO, TUYEN KIM
• Application Number:
  US13/282,840
• Publication Number:
  US 20120154607A1
• Time in Patent Office: 838 Days
• Field of Search: 235/462.01, 235/462.06, 235/462.11, 235/462.14, 235/462.2, 235/462.21, 235/455, 235/454, 235/462.24, 235/462.42, 235/462.45, 235/472.01
• US Class Current: 235/462.06
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042
• CPC Class Codes: G06K 2207/1011 Aiming
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10792 Special measures in relation to the object to be scanned

Abstract

A method and apparatus for use with a camera that includes a field of view (FOV), the apparatus for indicating at least a first portion of a field of view for analysis and comprising a light source for generating a first light pattern that is directed onto an object surface within the FOV while the light source remains stationary with respect to the object, an adjuster for, while the first light pattern subtends a surface of the object and without moving the light source with respect to the object, modifying the first light pattern to generate a first deformed light pattern that is directed onto the object surface in the FOV and a manual input device for controlling the adjuster to indicate how the first light pattern is to be modified.

Claims

1. An apparatus for use with a camera that includes a field of view (FOV), the apparatus for indicating at least a first portion of a field of view for analysis and comprising:

a light source for generating a first light pattern that is directed onto an object surface that is spaced apart from the camera and that is within the FOV while the light source remains stationary with respect to the object;

an adjuster for, while the first light pattern subtends a surface of the object and without moving the light source with respect to the object, modifying the first light pattern to generate a first deformed light pattern that is directed onto the object surface in the FOV; and

a manual input device for controlling the adjuster to indicate how the first light pattern is to be modified.

2. The apparatus of claim 1 wherein the light source includes a projector.

3. The apparatus of claim 2 wherein the projector is one of a DLP projector or an LCD projector.

4. The apparatus of claim 1 wherein the light source is supported in a single position with respect to the camera when the adjuster modifies the first light pattern.

5. The apparatus of claim 4 wherein the light source is detachable from the camera and can be used with at least a second camera.

6. The apparatus of claim 1 wherein the light source is controllable to generate several predefined light patterns, the apparatus further including a selector for selecting at least one of the predefined light patterns to be generated by the light source.

7. The apparatus of claim 6 wherein the adjuster is also for modifying the location of a light pattern within the FOV and wherein the manual input device includes a position selector for positioning the light pattern while the light pattern subtends a surface of the object.

8. The apparatus of claim 1 wherein the light source generates a second light pattern in addition to the first light pattern in the FOV and wherein the adjuster is useable to independently modify each of the first and second light patterns while the light patterns subtend a surface of the object in the FOV.

9. The apparatus of claim 1 wherein the first light pattern is generated and modified during a commissioning procedure and wherein the light source also projects output information in addition to the light patterns onto the object surface during the commissioning procedure.

10. The apparatus of claim 9 wherein the output information and the light patterns are simultaneously generated.

11. The apparatus of claim 9 wherein the light source is controllable to generate several predefined light patterns, the output information including a selection tool for selecting at least one of the predefined light patterns, the apparatus further including a selector for selecting at least one of the predefined light patterns from the output information.

12. The apparatus of claim 1 wherein the first light pattern is generated and modified during a commissioning procedure and wherein the light source is further used during a run time process to illuminate object surfaces while images needed for a machine vision process are obtained.

13. The apparatus of claim 1 further including a processor that obtains at least one image from the camera that includes the first deformed light pattern and is programmed to identify the deformed light pattern in the image.

14. The apparatus of claim 1 wherein the manual input device includes at least one of a joystick, a knob, a touch sensitive pad, a roller wheel, a roller sphere and a mechanical button.

15. The apparatus of claim 1 wherein the camera has an optical axis and wherein the light source is arranged to project the light pattern substantially along the optical axis of the camera.

16. The apparatus of claim 1 wherein the adjuster is also for modifying at least one non-shape characteristic of the light pattern to indicate at least one of a processing function associated with the pattern, an aspect of the processing function associated with the pattern, or a processing parameter of the function associated with the pattern.

17. The apparatus of claim 16 wherein the non-shape characteristic of the light pattern is at least one of color of the light pattern and line type used to circumscribe the light pattern.

18. The apparatus of claim 16 wherein the non-shape characteristic indicates at least one of a processing threshold and an acceptance criteria.

19. The apparatus of claim 1 further including a processor linked to the camera, the camera obtaining images of the FOV, the processor programmed to perform a first predefined process on the portion of an obtained image associated with the region specified by the first deformed light pattern.

20. The apparatus of claim 19 wherein the first predefined process is at least one of a measurement process, an inspection process, an alignment process or machine readable indicia decoding.

21. The apparatus of claim 1 further including a processor that identifies a region of interest within the FOV that is associated with the modified light pattern, obtains an image of the FOV, identifies at least one aspect of the obtained image within the region of interest and adjusts at least one aspect of illumination during subsequent image capture as a function of the at least one aspect of the obtained image.

22. The apparatus of claim 21 wherein the at least one aspect of the obtained image within the region of interest is brightness.

23. The apparatus of claim 21 wherein the at least one aspect of illumination is illumination brightness.

27. The apparatus of claim 1 wherein the adjuster modifies the first light pattern by modifying the shape of the first light pattern.

28. The apparatus of claim 1 wherein the adjuster modifies the first light pattern by modifying at least one non-shape pattern characteristic.

29. The apparatus of claim 28 wherein the non-shape pattern characteristic is one of color and line type of a line that circumscribes the pattern.

24. An apparatus for use with a camera that includes a field of view (FOV), the apparatus for indicating at least a first portion of a field of view for analysis and comprising:

a light source for generating a first light pattern that is directed onto an object surface that is spaced apart from the camera and that is in the FOV;

an adjuster for, during a commissioning procedure while the light source remains stationary with respect to the object surface, modifying the first light pattern to generate a first deformed light pattern that is directed onto the object surface in the FOV; and

a projector for, during the commissioning procedure, projecting output information onto the object surface to indicate options for modifying light pattern characteristics.

25. The apparatus of claim 24 wherein the projector provides the light source.

26. The apparatus of claim 24 wherein the projector provides object surface illumination during a run time procedure which follows the commissioning procedure during which the camera obtains images of object surfaces for processing.

30. A method for use with a camera that includes a field of view (FOV), the method for indicating at least a first portion of a field of view for analysis and comprising the steps of:

controlling a light source to generate a first light pattern that is directed onto an object surface that is spaced apart from the camera and that is within the FOV while the light source remains stationary with respect to the object;

while the first light pattern subtends a surface of the object and without moving the light source with respect to the object, modifying the first light pattern to generate a first deformed light pattern that is directed onto the object surface in the FOV; and

using a manual input device to control the adjuster to indicate how the first light pattern is to be modified.

31. A method for use with a camera that includes a field of view (FOV), the method for indicating at least a first portion of a field of view for analysis and comprising the steps of:

providing a light source for generating a first light pattern that is directed onto an object surface that is spaced apart from the camera and that is within the FOV while the light source remains stationary with respect to the object;

providing a processor for controlling the light source; and

while the first light pattern subtends a surface of the object and without moving the light source with respect to the object, using the processor to modify the first light pattern to generate a first deformed light pattern that is directed onto the object surface in the FOV.

32. The method of claim 31 further including the step of projecting output information onto the object surface to indicate options for modifying light pattern characteristics.