Method, system and test sheet image bitmap for carrying out a scanner-and-processor based image-to-paper registration setup

1. A scanner-and-processor based method for carrying out image-to-paper registration setup in a printer, comprising:

using a printer undergoing image-to-sheet registration setup, printing a test pattern on a sheet having a plurality of reference targets within a printable region of the sheet;

using a grayscale scanner, scanning the test pattern-bearing sheet to generate an image bitmap of the test pattern-bearing sheet such that the bitmap image exceeds or includes the edges of the sheet so that the image bitmap contains the edges of the sheet within it;

using the grayscale scanner, measuring a plurality of distances in units of pixels between the reference targets and/or edges of the sheet using a plurality of swaths of the image bitmap itself as the measurement tool to produce a set of measured distances in units of pixels, the measuring taking the form of producing a waveform of current corresponding to an amount of light reflected by features in each of the swaths;

using a processor, calculating positional errors of the image bitmap on the sheet based on the set of measured distances after conversion from pixels to a device independent unit of length;

using the processor and based on the calculated positional errors, determining a plurality of actuator adjustment values to use to correct the image-to-paper registration setup of the printer; and

using the processor, transferring the actuator adjustment values to the printer to adjust actuators of the printer and thereby correct the image-to-paper registration setup of the printer.

2. The method of claim 1 wherein said scanning using the grayscale scanner takes the form of scanning using flatbed grayscale scanner.

3. The method of claim 1 , wherein one coordinate of the waveform is a distance measurement in counts of pixels between reference targets and/or edges of the sheet and the other coordinate of the waveform is a particular shade of gray per pixel ranging between zero, representing pure black, to 255, representing pure white.

4. The method of claim 3 wherein said calculating takes the form of reading digital signals representing counts of pixels using said processor and converting said counts of pixels to measurements in units of a device independent unit of length for calculating the positional errors of the image bitmap on the sheet.

5. The method of claim 1 wherein said measuring includes identifying a first vertical swath to use to determine a top margin error at a left side of said sheet.

6. The method of claim 1 wherein said measuring includes identifying a first vertical swath at a left side of said sheet to determine a measured process direction line-length from a top reference target to a bottom reference target.

7. The method of claim 1 wherein said measuring includes identifying a second vertical swath to use to determine a top margin error at a right side of said sheet.

8. The method of claim 1 wherein said measuring includes identifying a second vertical swath at a right side of said sheet to determine a measured process direction line-length from a top reference target to a bottom reference target.

9. The method of claim 1 wherein said measuring includes identifying a third horizontal swath to use to determine margin errors at left and right sides of said sheet along a top of said swath.

10. The method of claim 1 wherein said measuring includes identifying a fourth horizontal swath to use to determine margin errors at left and right sides of said sheet along a bottom of said sheet.

11. The method of claim 1 wherein said calculating includes calculating at least one of top margin, bottom margin, left margin, right margin and skew errors.

12. A scanner-and-processor based system for carrying out image-to-paper registration setup in a printer, comprising:

a printer, that is undergoing image-to-sheet registration setup, configured to print a test pattern on a sheet having a plurality of reference targets in the test pattern within a printable region of the sheet;

a grayscale scanner configured to scan the test pattern-bearing sheet, generate an image bitmap of the test pattern-bearing sheet such that the bitmap image is larger than the sheet itself so that the image bitmap contains the edges of the sheet within it, and measure a plurality of distances in units of pixels between the reference targets and/or edges of the sheet in the image bitmap using a plurality of swaths of the image bitmap itself as the measurement tool to produce a set of measured distances in units of pixels; and

a processor configured to convert the set of measured distances from units of pixels to units of a device independent unit of length, calculate positional errors of the image bitmap on the sheet based on the set of measured distances, determine from the calculated positional errors a plurality of associated actuator adjustment values to use to correct registration setup of the image-to-paper printer registration setup, and transfer the actuator adjustment values to the printer to adjust the actuators and thereby correct the image-to-paper registration setup thereof.

13. The system of claim 12 wherein said grayscale scanner is a flatbed type of scanner.

14. The system of claim 12 wherein a first swath of said image bitmap is a vertical swath thereof on a left side of said sheet used to determine a top margin error at the left side of said sheet.

15. The system of claim 12 wherein a second swath of said image bitmap is a vertical swath thereof on a right side of said sheet used to determine a top margin error at the right side of said sheet.

16. The system of claim 12 wherein a third swath of said image bitmap is a horizontal swath thereof along a top of said sheet used to determine margin errors at left and right sides of said sheet along the top of said sheet.

17. The system of claim 12 wherein a fourth swath of said image bitmap is a horizontal swath thereof along a bottom of said sheet used to determine margin errors at left and right sides of said sheet along the bottom of said sheet.

18. A test page image bitmap in a scanner, comprising:

an image of a sheet having a test pattern thereon with reference targets of a darker color than said sheet, said sheet bounded by a plurality of interconnected edges extending about a perimeter of said sheet; and

a border strip around at least a portion of said edges of said sheet being of a darker color than said sheet so as to provide a contrast with said edges allowing said edges to be identifiable in said image of said sheet;

wherein the image of the sheet has a marking thereon identifying a printer that is readable by the scanner.

19. A scanner-and-processor based method for carrying out image-to-paper registration setup in a printer, comprising:

using a printer undergoing image-to-sheet registration setup, printing a test pattern on a sheet having a plurality of reference targets within a printable region of the sheet;

using a grayscale scanner, scanning the test pattern-bearing sheet to generate an image bitmap of the test pattern-bearing sheet such that the bitmap image exceeds or includes the edges of the sheet so that the image bitmap contains the edges of the sheet within it;

using the grayscale scanner, measuring a plurality of distances in units of pixels between the reference targets and/or edges of the sheet using a plurality of swaths of the image bitmap itself as the measurement tool to produce a set of measured distances in units of pixels;

using a processor, calculating positional errors of the image bitmap on the sheet based on the set of measured distances after conversion from pixels to a device independent unit of length;

using the processor and based on the calculated positional errors, determining a plurality of actuator adjustment values to use to correct the image-to-paper registration setup of the printer; and

using the processor, transferring the actuator adjustment values to the printer to adjust actuators of the printer and thereby correct the image-to-paper registration setup of the printer,

wherein said calculating includes using at least one of predetermined nominal values of margin width, sheet length, sheet width and grayscale resolution which is compared to the corresponding at least one of said measured distances to determine the corresponding error.

20. The method of claim 1 , further comprising using analog-to-digital conversion, storing each current reading of the waveform as a digital number between zero and 225 for each of the coordinates.