Inspection system for inspecting an imprinted substrate on a printing press

• US 7,732,796 B2
• Filed: 07/16/2008
• Issued: 06/08/2010
• Est. Priority Date: 08/09/2004
• Status: Active Grant

• Current Assignee: Baldwin Americas Corporation (Forsyth Baldwin LLC)
• Original Assignee: Quad/Tech Incorporated
• Inventors: Pearson, Eric, Hansen, Mark R., Moersfelder, Bradly S., Seymour, John C., Noffke, Patrick James
• Primary Examiner(s): Luu; Thanh X
• Assistant Examiner(s): Legasse, Jr; Francis M
• Application Number:
  US12/174,481
• Publication Number:
  US 20080289528A1
• Time in Patent Office: 692 Days
• Field of Search: 25055904-55907, 25055937-55944, 356/429, 356/430, 356/431, 358/474
• US Class Current: 250/559.39
• CPC Class Codes: B41F 33/0081 Devices for scanning register marks

Abstract

An inspection system for inspecting an imprinted substrate on a printing press has a light source, a contact image sensor, and a processor. The light source is configured to illuminate a portion of the substrate which has been imprinted with different colors at a plurality of printing units of the printing press. The contact image sensor has a plurality of sensing elements. Each sensing element senses light reflected by a corresponding region on the substrate to produce data representative of the corresponding region printed on the substrate. The processor is configured to receive the data representative of the imprinted substrate and to compare the data representative of the corresponding region printed on the substrate with stored reference data.

Claims

1. An inspection system for inspecting an imprinted substrate on a printing press, comprising:

a light source for illuminating a portion of the substrate which has been imprinted with different colors at a plurality of printing units of the printing press, each printing unit comprising a plate cylinder;

a contact image sensor having a plurality of sensing elements, wherein each sensing element senses light reflected by a corresponding region on the substrate to produce data representative of the corresponding region printed on the substrate; and

a processor configured to receive the data representative of the imprinted substrate and to compare the data representative of the corresponding region printed on the substrate with stored reference data.

2. The inspection system of claim 1, wherein the sensed region of the substrate is a graphical/textual printed work.

3. The inspection system of claim 1, wherein the processor is configured to detect color registration based on the comparison.

4. The inspection system of claim 1, wherein the substrate comprises a web.

5. The inspection system of claim 1, further comprising a lens between the substrate and the contact image sensor having a continuous index of refraction.

6. The inspection system of claim 1, wherein a dimension of each sensing element is substantially equal to a dimension of the corresponding region of the substrate.

7. The inspection system of claim 1, wherein the inspection system inspects a newspaper substrate on a newspaper press.

8. The inspection system of claim 2, wherein the processor is configured to detect an ink color error based on the comparison.

9. The inspection system of claim 8, wherein the processor is configured to generate ink key control signals based on the ink color error.

10. An inspection system for inspecting an imprinted substrate on a printing press, comprising:

a light source for illuminating a portion of the substrate which has been imprinted with an image at a printing unit of the printing press, the printing unit comprising a plate cylinder;

a plurality of sensing elements, wherein each sensing element senses light reflected by a corresponding region on the substrate to produce data representative of the corresponding region printed on the substrate, wherein a dimension of each sensing element is substantially equal to a dimension of the corresponding region printed on the substrate; and

a processor configured to receive the data representative of the imprinted substrate and to compare the data representative of the corresponding region printed on the substrate with stored reference data.

11. The inspection system of claim 10, wherein the dimensions of the sensing elements and corresponding regions is a width.

12. The inspection system of claim 10, wherein the sensed region of the substrate is a graphical/textual printed work.

13. The inspection system of claim 10, wherein the processor is configured to detect color registration based on the comparison.

14. The inspection system of claim 10, wherein the sensed region of the substrate comprises color patches, wherein the processor is configured to detect an ink color error based on the comparison.

15. The inspection system of claim 10, wherein the substrate comprises a web.

16. The inspection system of claim 10, further comprising a lens between the substrate and the sensing elements having a continuous index of refraction.

17. The inspection system of claim 10, wherein the inspection system inspects a newspaper substrate on a newspaper press.

18. The inspection system of claim 10, wherein the substrate has been imprinted with different colors at a plurality of printing units of the printing press.

19. The inspection system of claim 12, wherein the processor is configured to detect an ink color error based on the comparison and to generate ink key control signals based on the ink color error.

20. The inspection system of claim 12, wherein the processor is configured to detect a defect in the graphical/textual printed work based on the comparison.

21. An inspection system for inspecting an imprinted substrate on a printing press, comprising:

a light source for illuminating a portion of the substrate which has been imprinted with different colors at a plurality of plate cylinders of the printing press, each of the plurality of plate cylinders being configured to imprint one of the different colors on the substrate;

a contact image sensor having a plurality of sensing elements, wherein each sensing element senses light reflected by a corresponding region on the substrate to produce data representative of the corresponding region printed on the substrate; and

a processor configured to receive the data representative of the imprinted substrate and to compare the data representative of the corresponding region printed on the substrate with stored reference data.