Method of and means for inspecting workpieces traveling along a production line

• US 4,758,888 A
• Filed: 02/17/1987
• Issued: 07/19/1988
• Est. Priority Date: 02/17/1987
• Status: Expired due to Term

• Current Assignee: Orbotech Limited (KLA Corporation)
• Original Assignee: Orbot Systems Ltd. (KLA Corporation)
• Inventors: Lapidot, Zvi
• Primary Examiner(s): Britton, Howard W.
• Application Number:
  US07/015,070
• Time in Patent Office: 518 Days
• Field of Search: 358/106, 358/101, 358/108, 358/93
• US Class Current: 348/91
• CPC Class Codes: G01N 2021/8887 based on image processing techniques
• CPC Class Codes: G01N 2021/889 providing a bare video image, i.e. without visual measurement aids
• CPC Class Codes: G01N 2021/95615 with stored comparision signal
• CPC Class Codes: G01N 21/88 Investigating the presence of flaws or contamination
• CPC Class Codes: G01N 2201/102 Video camera

Abstract

Inspection of workpieces traveling along a production line includes on-line inspection of the workpieces at an upstream inspection station to detect possible flaws without interrupting the progression of workpieces along the production line. Possible flaws in the inspected workpieces are imaged, and images of possible flaws are stored in a memory in a way that associates a stored image with the workpiece containing the possible flaw. Off-line, a stored image is retrieved from the memory before the workpiece with which the image is associated reaches a downstream sorting station. The retrieved image is displayed on a monitor for verifying, by visual inspection, whether the possible flaw in the workpiece with which the retrieved image is associated, is valid. Workpieces are diverted at the downstream sorting station in response to vertification of flaws.

Claims

1. A method for inspecting individual workpieces progressing along a production line comprising the steps of:

(a) on-line inspecting the workpieces at an upstream inspection station to detect possible flaws without interrupting a progression of the workpieces along said production line;

(b) imaging possible flaws in inspected workpieces;

(c) storing images of possible flaws in a memory in a way that associates a stored image with the workpiece containing the possible flaw;

(d) retrieving a stored image from the memory before the workpiece with which the image is associated reaches a downstream sorting station;

(e) displaying the retrieved image on a monitor for verifying, by visual inspection, whether the possible flaw in the workpiece with which the retrieved image is associated, is valid; and

(f) diverting workpieces at said downstream sorting station in response to verification of flaws.

2. A method according to claim 1 wherein possible flaws are imaged with a video camera to produce a video image, and the video image is stored with indicia indicative of the workpiece containing the possible flaw.

3. Apparatus for inspecting individual workpieces progressing along a production line, said apparatus comprising:

(a) an upstream inspection station for on-line inspection of workpieces as they travel along said production line and detection of possible flaws in the workpieces;

(b) imaging means associated with the inspection station responsive to detection of a possible flaw for imaging the latter;

(c) storage means for storing images of possible flaws in such a way that associates a stored image of a possible flaw with the workpiece containing the same;

(d) a retrieval system including means for retrieving from said storage means, images of possible flaws, and a monitor on which images retrieved from said storage means are displayed for verifying, by visual inspection, the validity of a displayed possible flaw in the workpiece with which the displayed image is associated; and

(e) a downstream sorting station for diverting workpieces in response to verification of flaws.

4. Apparatus according to claim 3 wherein said monitor is remotely located with respect to said inspection station.

5. Apparatus according to claim 3 wherein said monitor is located at said inspection station.

6. Apparatus according to either of claims 4 or 5 wherein a plurality of images of possible flaws are displayed simultaneously.

7. Apparatus according to claim 6 wherein said monitor is constructed and arranged to respond to physically touching an image on the monitor for signaling verification of an actual flaw.

8. Apparatus according to claim 6 wherein a keyboard is associated with the monitor, and verification of an actual flaw is indicated by keyboard input.

9. Apparatus according to claim 6 including means for signaling verification of an actual flaw.

10. Apparatus according to claim 6 including means for signaling verification of an actual flaw, and means for effecting operator input to an image on the monitor.

11. Apparatus for inspecting individual workpieces progressing along a production line, said apparatus comprising:

(a) an upstream inspection station for on-line inspection of workpieces as they travel along said production line and detection of possible flaws in the workpieces;

(b) imaging means associated with the inspection station responsive to the detection of a possible flaw for imaging the latter;

(c) storage means for storing images of possible flaws in a way that associates a stored image of a possible flaw with the workpiece containing the same;

(d) a retrieval system including means for retrieving from said storage means, images of possible flaws, and a monitor on which images retrieved from said storage means are displayed for verifying, by visual inspection, the validity of a displayed possible flaw in the workpiece with which the displayed image is associated;

(e) a downstream sorting station for diverting workpieces in response to verification of flaws;

(f) said monitor being remotely located with respect to said inspection station, said monitor being constructed and arranged such that a plurality of images of possible flaws are displayed simultaneously.

12. Apparatus according to claim 11 wherein said monitor is constructed and arranged to respond to physically touching an image on the monitor for signaling verification of an actual flaw.

13. Apparatus according to claim 11 wherein a keyboard is associated with the monitor, and verification of an actual flaw is indicated by keyboard input.

14. Apparatus according to claim 11 including means for signaling verification of an actual flaw.

15. Apparatus according to claim 11 including means for signaling verification of an actual flaw, and means for effecting operator input to an image on the monitor.