Method and apparatus for color separation scanning

• US 5,075,768 A
• Filed: 02/15/1991
• Issued: 12/24/1991
• Est. Priority Date: 09/02/1988
• Status: Expired due to Fees

• Current Assignee: Itek Colour Graphics Ltd (Leonardo S.p.A.)
• Original Assignee: Itek Graphix Corp.
• Inventors: Wirtz, John S., Neilson, Peter J.
• Primary Examiner(s): Coles, Sr., Edward L.
• Assistant Examiner(s): Grant, II, Jerome
• Application Number:
  US07/657,352
• Time in Patent Office: 312 Days
• Field of Search: 358/78, 358/80, 358/75, 358/474, 358/494, 358/496, 358/497, 358/447, 358/448, 358/452, 358/463, 355/326
• US Class Current: 358/512
• CPC Class Codes: H04N 1/32443 with asynchronous operation of the image input and output devices connected to the memory
• CPC Class Codes: H04N 1/409 Edge or detail enhancement; Noise or error suppression
• CPC Class Codes: H04N 2201/3294 of several complete lines, e.g. a band of data

Abstract

A method and apparatus for color separation scanning wherein a workpiece is movably supported and scanned by a linear detector. At least one color filter is interposed in the optical path between the workpiece and the linear detector and multiple scans are taken of a linear portion of the workpiece. The data obtained from multiple scans are averaged and stored in memory. A second memory may be provided to accept data input during a scan of a subsequent portion of the workpiece while the data in the first memory is output to a print device.

Claims

1. A data input apparatus for a color separation scanner, comprising

(a) a continuously movable support for a workpiece;

(b) a linear detector adapted to scan individual pixels across a linear portion of said workpiece;

(c) means for interposing at least one color filter between said workpiece and said linear detector;

(d) means for averaging individual pixel data received from multiple successive scans of said workpiece by said linear detector; and

(e) means for storing said averaged data.

2. The data input apparatus according to claim 1, wherein said movable support comprises a scanning table.

3. The data input apparatus according to claim 1, wherein said linear detector comprises a charge-coupled device.

4. The data input apparatus according to claim 1, wherein said means for interposing at least one color filter comprises a filter wheel.

5. The data input apparatus according to claim 1, wherein said at least one color filter comprises at least one set of red, green and blue filters.

6. The data input apparatus according to claim 5, wherein said at least one set of red, green, and blue filters comprises four sets of red, green and blue filters.

7. The data input apparatus according to claim 6 wherein said means for averaging data is adapted to average data from corresponding red, green and blue filters.

8. The data input apparatus according to claim 1 wherein said means for averaging the data received from multiple scans of the workpiece comprises an adder for summing the data.

9. The data input apparatus according to claim 1, wherein said means for storing said averaged data comprises a random access memory.

10. A data input method for a color separation scanner, comprising the steps of:

(a) continuously movable supporting a workpiece;

(b) scanning individual pixels across a linear portion of said workpiece with a linear detector;

(c) interposing at least one color filter between said workpiece and said linear detector;

(d) averaging individual pixel data received from multiple successive scanning of said workpiece with said linear detector; and

(e) storing said averaged individual pixel data.

11. The data input method according to claim 10, wherein said step of interposing at least one color filter comprises rotatably interposing at least one color filter using a filter wheel.

12. The data input method according to claim 10, wherein said step of interposing at least one color filter comprises interposing at least one red, green and blue filter.

13. The data input method according to claim 12, wherein the step of interposing at least one red, green, and blue filter comprises interposing four red, green and blue filters.

14. The data input method according to claim 13, wherein said step of averaging data includes averaging data from corresponding red, green, and blue filters.

15. The data input method according to claim 10, wherein said step of averaging data obtained from multiple scanning said workpiece comprises summing data for each color.

16. A color separation scanner, comprising:

(a) a continuously movable support for a workpiece;

(b) a linear detector for scanning a linear portion of said workpiece;

(c) means for interposing at least one color filter between said workpiece and said linear detector;

(d) first storage means for storing data from said linear detector;

(e) second storage means for storing data from said linear detector;

(f) switching means for switching between said first storage means and said second storage means;

(g) a continuously movable support for photosensitive material; and

(h) means for printing said stored data on said photosensitive material, wherein said printing means travels in conjunction with said continuously movable support for said workpiece.

17. The color separation scanner of claim 16, wherein said movable support for a workpiece comprises a scanning table.

18. The color separation scanner of claim 16, wherein said linear detector comprises a charge-coupled device.

19. The color separation scanner according to claim 16, wherein said means for interposing at least one color filter comprises a filter wheel.

20. The color separation scanner according to claim 16, wherein said at least one color filter comprises at least one set of red, green and blue filters.

21. The color separation scanner according to claim 17, wherein said at least one set of red, green, and blue filters comprises four sets of red, green and blue filters.

22. The color separation scanner according to claim 16, further comprising means for averaging the data received from multiple scans of the workpiece.

23. The color separation scanner according to claim 16, wherein said first and second storage means for storing said data comprises random access memory.

29. The color separation scanner according to claim 22, wherein said means for averaging the data received from multiple scans of the workpiece comprises an adder for summing data.

24. A method of color separation scanning, comprising the steps of:

(a) movably supporting a workpiece;

(b) scanning a linear portion of said workpiece with a linear detector;

(c) interposing at least one color filter between said workpiece and said linear detector;

(d) storing data obtained from said scan in a first storage means

(e) switching the storage of data to a second storage means at the completion of a scan;

(f) outputting data from the first storage means to be printed while data is being stored in said first storage means.

25. The method of color separation scanning according to claim 24, wherein said step of interposing at least one color filter comprises rotatably interposing at least one color filter using a filter wheel.

26. The method of color separation scanning according to claim 24, wherein said step of interposing at least one color filter comprises interposing at least one red, green and blue filter.

27. The method of color separation scanning according to claim 26, wherein the step of interposing at least one red, green, and blue filter comprises interposing four red, green and blue filters.

28. The method of color separation scanning according to claim 24, wherein said step of averaging data obtained from multiple scanning said workpiece comprises summing data values for each color.