Device and process for reading out identification information on reticles

• US 6,880,757 B2
• Filed: 09/03/2003
• Issued: 04/19/2005
• Est. Priority Date: 09/04/2002
• Status: Active Grant

• Current Assignee: Brooks Automation Ltd. (United Kingdom) (Azenta, Inc.)
• Original Assignee: Brooks Automation Incorporated (Azenta, Inc.)
• Inventors: Richter, Harald, Blattner, Jakob, Federici, Rodolfo
• Primary Examiner(s): Tremblay, Mark
• Application Number:
  US10/654,107
• Publication Number:
  US 20040089719A1
• Time in Patent Office: 594 Days
• Field of Search: 235/454, 235/462.12, 382/144, 382/149
• US Class Current: 235/462.12
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1473 error correction
• CPC Class Codes: G06T 2207/30148 Semiconductor; IC; Wafer

Abstract

A device for reading and identifying a plate, with a camera means (100) with an optical device (110; 112, 114)) for digital image recording and an image processing device for the analysis of the image recorded by the camera means (100). In one embodiment, identification codes can be imaged from both sides of the plate (20)* by a mirror means (120; 122, 124, 126) onto the optical device (110; 112, 114) of the camera. The device is designed in such a way that each plate (40) can be recorded with two camera images, wherein a camera image is produced through the arrangement of several mirrors (122, 124, 126) of the mirror means (120) in such a way that one image half represents the right edge and the other image half represents the left edge of the plate (40) over a predetermined length.

Claims

1. A plate identification device for identifying a plate, the plate having an indicia pattern disposed on a predetermined region of the plate, the device comprising:

an image reader;

an image processor connected to the image reader for analysis of an image read by the image reader; and

a mirror connected to the image reader for imaging at least part of the indicia pattern onto the image reader;

wherein the mirror is disposed so that the image formed by the mirror onto the image reader is a composite image of at least two partial images of different sections of the plate.

2. The device according to claim 1, wherein the different sections of the plate are separate and spaced apart from each other.

3. The device according to claim 1, wherein at least one of the at least two partial images includes at least part of the indicia pattern.

4. The device according to claim 1, wherein the different sections are proximate opposing edges of the plate.

5. The device according to claim 1, wherein the image reader comprises an optical device for digital image recording, the optical device including focusing optics and a digital scanner.

6. The device according to claim 1, wherein the indicia pattern comprises one or more identification codes.

7. The device according to claim 1, wherein the image reader has an imaging area capable of reading images of a predetermined image size, the predetermined region on which the indicia pattern is disposed having a size greater than the predetermined image size.

8. The device according to claim 1, wherein one of the at least two partial images is of a first plate edge, and another of the at least two partial images is of an opposite plate edge relative to the first plate edge.

9. The device according to claim 1, wherein one of the at least two partial images is of a predetermined partial length of one of the different sections of the plate.

10. The device according to claim 9, wherein the predetermined length is less than a length of the indicia pattern distributed on the one of the different sections.

11. The device according to claim 1, wherein the mirror comprises side mirrors and a deviation mirror located in-between the side mirrors.

12. The device according to claim 11, wherein the side mirrors redirect rays from a first direction to a second direction onto the deviation mirror, and the deviation mirror redirects rays from the second direction to a third direction onto the image reader, and wherein a first of the at least two partial images is imaged by one of the side mirrors and another of the at least two partial images is imaged by another of the side mirrors.

13. The device according to claim 12, wherein the side mirrors are substantially parallel to each other, and wherein the second direction is substantially orthogonal to the first direction and the third direction is substantially orthogonal to the second direction.

14. The device according to claim 1, wherein the image reader and the mirror are housed in a camera.

15. The device according to claim 14, further comprising a plate support adapted to allow the plate to be moved relative to the camera so that the camera can image different sections of the predetermined region of the plate.

16. The device according to claim 1, wherein the image reader and mirror are adapted to image the predetermined region in sections, different sectional images of the different sections of the predetermined region being recorded by the image processor, the image processor being programmed to process the different sectional images to identify the indicia pattern on the predetermined region from indicia pattern portions in the different sectional images.

17. The device according to claim 16, wherein the different sectional images overlap each other.

18. The device according to claim 17, wherein the image processor has programming for processing the different sectional images arranged so that the different sectional images are processed for candidates for an expected identification code until a specific code can be analyzed, wherein, depending on a position of indicia in the indicia pattern, an expected overlap between the indicia is calculated from predetermined imaging ratios and, an actual overlap is determined through a comparison of indicia profiles in the different sectional images.

19. The device according to claim 18, wherein the image processor programming is arranged so that, if a clear zone of overlap is determined, a weighted combination of the indicia profiles is carried out so that a continuous area of analysis results, but, when no clear zone of overlap can be recognized, an individual window of analysis is processed for each area.

20. The device according to claim 19, wherein the image processor programming includes a code-specific decoding algorithm that can be applied to a resulting window of analysis.

21. The device according to claim 20, wherein the image processor programming is arranged so that the code-specific decoding algorithm seeks out respective code-specific start and stop symbols in the indicia pattern and determines intervening symbols by use of a code table.

22. A method for identifying a plate having an indicia pattern disposed on a predetermined region of the plate, the method comprising:

providing a camera with an image reader and optics for imaging the plate;

connecting an image processor to the camera for analyzing images from the camera;

taking with the camera a first image of the predetermined region;

taking with the camera a second image of the predetermined region; and

analyzing with the image processor the first and second images for determining an identification code embodied by the indicia pattern.

23. The method according to claim 22, wherein the first image and the second image are taken alternately relative to each other.

24. The method according to claim 22, further comprising moving the plate relative to the camera between taking the first image and taking the second image.

25. The method according to claim 22, wherein the first image is of a first section of the predetermined region, and the second image is of a second section of the predetermined region.

26. The method according to claim 25, wherein the first section has part of the indicia pattern disposed thereon, and the second section has a different part of the indicia pattern disposed thereon.

27. The method according to claim 26, wherein the first section and the second section overlap.

28. The method according to claim 22, wherein analyzing comprises processing the first and second images for candidates for an expected identification code until a specific code can be analyzed, wherein, depending on a position of indicia in the indicia pattern, an expected overlap of indicia in the first and second images is calculated from predetermined imaging ratios, and an actual overlap is determined through comparing of indicia profiles on the first and second images.

29. The method according to claim 28, wherein analyzing comprises, if an actual overlap is determined, forming a weighted combination of the indicia profiles so that a continuous area of analysis is provided, but when no actual overlap is recognized, individually analyzing the indicia profiles in the first and second images.

30. The method according to claim 22, wherein taking the first image comprises imaging onto the image reader different sections of the predetermined region so that the first image is a composite image of different partial images.

31. The method according to claim 30, wherein taking the second image comprises imaging onto the image reader other different sections of the predetermined region so that the second image is another composite image of other different partial images.