Automatic scanner calibration

• US 6,327,047 B1
• Filed: 01/22/1999
• Issued: 12/04/2001
• Est. Priority Date: 01/22/1999
• Status: Expired due to Term

• Current Assignee: Electronics For Imaging Incorporated
• Original Assignee: Electronics For Imaging Incorporated
• Inventors: Motamed, Margaret
• Primary Examiner(s): Williams, Kimberly A.
• Application Number:
  US09/235,642
• Time in Patent Office: 1,047 Days
• Field of Search: 358/1.1, 358/1.2, 358/1.3, 358/1.4, 358/1.12, 358/1.15, 358/1.16, 358/1.18, 358/504, 358/506, 358/513, 358/518, 358/527, 358/526, 358/406, 399/72
• US Class Current: 358/1.15
• CPC Class Codes: H04N 1/00002 Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for error detection, error correction or monitoring in digital computers or digital computer components G06F11/00
• CPC Class Codes: H04N 1/00013 Reading apparatus
• CPC Class Codes: H04N 1/00031 Testing, i.e. determining the result of a trial H04N1/00029 takes precedence; using test signals for transmission mode changing H04N2201/33371
• CPC Class Codes: H04N 1/00045 using a reference pattern designed for the purpose, e.g. a test chart
• CPC Class Codes: H04N 1/0005 in service, i.e. during normal operation
• CPC Class Codes: H04N 1/00055 automatically on a periodic basis
• CPC Class Codes: H04N 1/00063 using at least a part of the apparatus itself, e.g. self-testing
• CPC Class Codes: H04N 1/00068 Calculating or estimating
• CPC Class Codes: H04N 1/00087 Setting or calibrating picture signal circuits H04N1/40
• CPC Class Codes: H04N 1/0009 Storage
• CPC Class Codes: H04N 1/6033 using test pattern analysis H04N1/6055 takes precedence

Abstract

An automatic scanner calibration method and apparatus is disclosed in which a calibrated target, such as a Kodak® gray strip, is attached to a scanning surface of a scanner. The target is thin and has a width or length of platen of a scanner. During a normal scan, the calibration target area can be ignored or scanned depending on user selection. If the strip is scanned, then the resulting information is used to calibrate the scanner automatically. Such calibration is more accurate than an older in time or preset default calibration Another embodiment of the invention actuates a print of a printer calibration target on a printer on a scheduled basis. Thereafter, the user can take the printer calibration target and place it on the scanner and perform a calibration of a scanner/printer system.

Claims

1. A method for automatically calibrating a scanner, comprising the steps of:

affixing a calibration target to a scanning surface of said scanner; and

when automatic scanning of said calibration target is selected, selectably using said calibration target for automatically calibrating said scanner during a normal scan of an object.

2. A method as in claim 1, wherein said scanner comprises a platen;

and

wherein said calibration target comprises a width of approximately or equal to a length of or a width of said platen.

3. A method as in claim 1, wherein said calibration target is a Kodak®

Gray Strip, an IT8™

target, or an equivalent manufactured calibration target.

4. A method as in claim 1, wherein the calibration target comprises a photograph on photographic paper.

5. A method as in claim 1, wherein the calibration target strip comprises a dye sublimation print on photographic paper or paper equivalent to photographic.

6. A method as in claim 1, wherein the calibration target comprises:

a plastic material, said plastic material having an adhering surface and a covering over said adhering surface such that the adhering surface allows the plastic material to adhere to a part of the scanner when the covering is removed from the adhering surface.

7. A method as in claim 1, wherein the calibration target comprises:

a dye sublimation print onto a plastic material, said plastic material having an adhering surface and a covering over said adhering surface such that said adhering surface allows said dye sublimated plastic material to adhere to a part of said scanner when said covering is removed from said adhering surface.

8. A method as in claim 1, further comprising the step of:

providing a calibration target having a protective coating.

9. A method as in claim 1, wherein the calibration target comprises decal paper.

10. A method as in claim 1, wherein the scanner has a scanning range that comprises a first surface area that spans a part of or all of the glass of the scanner and a second surface area that extends beyond the first surface area of the scanning range;

and

the step of affixing said calibration target comprises;

attaching said calibration target to a cover of said scanner in such a way that said calibration target is not fully covering any part of the first surface area of the scanning range but is covering a part of the second surface area of said scanning range, wherein said calibration target is within said scanning range of said scanner.

11. A method as in claim 1, wherein the scanner further comprises a tray device located proximate to a scanning surface for holding said calibrated target fixedly therein.

12. A method as in claim 1, wherein the scanner further comprises a plastic non-reflective sleeve located proximate to a scanning surface for fixedly holding said calibration target in said sleeve.

13. An apparatus for automatically calibrating a scanner, comprising:

a calibration target;

means for attaching said calibration target proximate to a scanning surface of said scanner; and

means for automatically calibrating said scanner with said calibration target during a normal scan of said object when said calibration target is selectably scanned.

14. An apparatus as in claim 13, wherein the scanner further comprises;

a platen; and

wherein said calibration target comprises a width approximately equal to a length of or a width of said platen.

15. An apparatus as in claim 13, wherein the calibration target is a Kodak®

Gray Strip, an IT8™

target, or an equivalent manufactured calibration target.

16. An apparatus as in claim 13, wherein calibration target comprises a photograph on photographic paper.

17. An apparatus as in claim 13, wherein the calibration target comprises a dye sublimation print on photographic paper or paper equivalent to photographic paper.

18. An apparatus as in claim 13, wherein the calibration target strip comprises a plastic material, said plastic material having an adhering surface and a covering over said adhering surface such that said adhering surface allows said plastic material adhere to said scanner when said covering is removed from said adhering surface.

19. An apparatus as in claim 13, wherein the calibration target comprises a dye sublimation print onto a plastic material, said plastic material having an adhering surface and a covering over said adhering surface such that said adhering surface allows said dye sublimated plastic material to adhere to a part of said scanner when said covering is removed from said adhering surface.

20. A calibration target strip in claim 13, wherein said calibration target has a protective coating.

21. A calibration target strip in claim 13, wherein said calibration target comprises decal paper.

22. An apparatus as in claim 13, wherein the scanner has a scanning range that comprises a first surface area that spans a part of or all of said scanning surface of the scanner and a second surface area that extends beyond the first surface area of said scanning range;

and

wherein said calibration target is attached to the cover of said scanner in such a way that said calibrated target is not fully covering any part of the first surface area of the scanning range but is covering a part of the second surface area of the scanning range, wherein the calibrated target is within said scanning range of said scanner.

23. An apparatus as in claim 13, wherein said scanner has a tray fixedly located proximate to said scanning surface for holding calibrated target in said tray.

24. An apparatus as in claim 13, wherein. said scanner has a plastic non-reflective sleeve located proximate to said scanning surface for holding said calibrated target thereto.

25. A method for automatically printing a printer calibration target on a printer and automatically calibrating said printer using a scanner, comprising the steps of:

providing a calibration target strip attached to said scanner;

actuating automatically a print of the printer calibration target;

placing said printer calibration target on said scanner;

scanning said printer calibration target on said scanner; and

performing a calibration of said printer using said scanned printer calibration target; and

automatically scanning the calibration target slip and automatically calibrating said scanner.

26. The method of claim 25, wherein a client engine and a printer controller engine are employed and wherein the method further comprises the steps of:

generating a scheduled first message from the client engine to the printer controller engine, said scheduled first message automatically actuating the print of the printer calibration target on said printer;

generating a second message from the printer controller engine to the client engine after the print of the printer calibration target, said second message indicating that the printer calibration target has been printed and indicating that the printer calibration target needs to be placed on said scanner; and

waiting for the client engine to respond to the printer controller engine that the printer calibration target has been printed on said printer and has been placed on said scanner.

27. The method of claim 26, wherein the printer calibration target has interpretable data, said data identifying said printer and said printer controller engine, and the date that the printer calibration target was printed, and wherein the step of performing a calibration of said printer using said scanned printer calibration target further comprises the client engine interpreting said data to identify said printer to be calibrated and to identify said printer controller engine.

28. The method of claim 27, wherein said interpretable data is included in a printed barcode and wherein the step of scanning said printer calibration target on said scanner comprises scanning said barcode.

29. The method of claim 25, wherein the step of automatically calibrating said scanner further comprises a scanner controller engine or a multi-function scanner/printer controller engine and further comprises the steps of:

selecting to ignore said calibration target strip or selecting to scan said calibration target strip; and

calibrating automatically said scanner during scanning of said printer calibration target when said target calibration strip is selectably scanned.

30. An apparatus for automatically printing a printer calibration target on a printer and automatically calibrating said printer using a scanner comprising:

a printer calibration target;

a printer;

means for automatically actuating said printer calibration target to print on said printer;

a scanner;

means for placing said printer calibration target on said scanner;

a lookup table (LUT) for the printer, such LUT mapping a plurality of absolute density values to a corresponding plurality of calibrated density values;

means for updating said LUT for the printer after the printer calibration target is scanned and by using the printer calibration target, thereby calibrating said printer;

a client engine and a printer controller engine, and wherein means for automatically actuating said printer calibration target to print on said printer further comprises means for generating a scheduled first message from the client engine to the printer controller engine;

means for generating a second message from the printer controller engine to the client engine after the print of the printer calibration target, said second message indicating that the printer calibration target has been printed and indicating that the printer calibration target needs to be placed on said scanner; and

means for waiting for the client engine to respond o the printer controller engine that the printer calibration target has been placed on said printer and has been placed on said scanner.

31. The apparatus of claim 30, wherein the printer calibration target has interpretable data, said data representing information that identifies the printer, the printer controller engine, and the date that the printer calibration target was printed on the printer, and further comprising means for the client engine to interpret said data.

32. The apparatus of claim 31 further comprising:

a calibrated target strip fixedly attached to said scanner;

means for automatically scanning said calibrated target strip;

a lookup table (LUT) for said scanner, said LUT mapping a plurality of input scanner signals to a plurality of corresponding calibrated density values; and

means for updating the LUT for the scanner by using the scanned calibrated target strip, thereby calibrating said scanner.

33. The apparatus of claim 32, wherein means for automatically calibrating said scanner further comprises:

means for selecting to ignore said calibration target strip or selecting to scan said calibration target strip; and

means for automatically calibrating the scanner during scanning of the printer calibration target when the calibration target strip is selectably scanned.

34. The apparatus of claim 31, wherein said interpretable data is included in a printed barcode and further comprising means for scanning said barcode.