Method and apparatus for providing a color-balanced multiple print engine

• US 7,046,391 B1
• Filed: 01/08/1999
• Issued: 05/16/2006
• Est. Priority Date: 08/07/1995
• Status: Expired due to Fees

• Current Assignee: Electronics For Imaging Incorporated
• Original Assignee: Electronics For Imaging Incorporated
• Inventors: Rowe, Francis A., Zuber, Peter A., Barry, Michael W., Bartholmae, Jack N., Tompkins, E. Neal
• Primary Examiner(s): Wallerson, Mark
• Application Number:
  US09/227,251
• Time in Patent Office: 2,685 Days
• Field of Search: 358/1.9, 358/1.12, 358/1.13, 358/1.14, 358/1.15, 358/518, 358/538, 358/537, 359/515
• US Class Current: 358/1.9
• CPC Class Codes: B41F 1/00 Platen presses, i.e. presses in which printing is effected by at least one essentially-flat pressure-applying member co-operating with a flat type-bed
• CPC Class Codes: G03G 15/5087 for receiving image data
• CPC Class Codes: G03G 2215/00021 Plural substantially independent image forming units in cooperation, e.g. for duplex, colour or high-speed simplex
• CPC Class Codes: G06F 3/1208 resulting in improved quality of the output result, e.g. print layout, colours, workflows, print preview
• CPC Class Codes: G06F 3/1226 Discovery of devices having required properties
• CPC Class Codes: G06F 3/1244 Job translation or job parsing, e.g. page banding
• CPC Class Codes: G06F 3/1285 Remote printer device, e.g. being remote from client or server
• CPC Class Codes: G06K 15/02 using printers
• CPC Class Codes: G06K 15/14 by electrographic printing, e.g. xerography; by magnetographic printing G06K15/12 takes precedence
• CPC Class Codes: G06K 15/1859 involving data processing distributed amongst different data processing apparatus
• 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 1/00015 Reproducing apparatus
• CPC Class Codes: H04N 1/00023 Colour systems
• CPC Class Codes: H04N 1/00045 using a reference pattern designed for the purpose, e.g. a test chart
• CPC Class Codes: H04N 1/00053 out of service, i.e. outside of normal operation
• CPC Class Codes: H04N 1/00058 using a separate apparatus
• 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 1/29 involving production of an electrostatic intermediate picture
• CPC Class Codes: H04N 1/32502 : in systems having a plurality of input or output devices
• CPC Class Codes: H04N 1/32529 : of different type, e.g. internal and external devices
• CPC Class Codes: H04N 1/32555 : Large jobs, i.e. performing identical parts of the same job on different devices
• CPC Class Codes: H04N 1/46 : Colour picture communication systems
• CPC Class Codes: H04N 1/50 : Picture reproducers for halftone screening H04N1/52
• CPC Class Codes: H04N 1/52 : Circuits or arrangements for halftone screening
• CPC Class Codes: H04N 1/60 : Colour correction or control H04N1/54 takes precedence
• CPC Class Codes: H04N 1/6013 : by simulating several colour corrected versions of the same image simultaneously on the same picture reproducer
• CPC Class Codes: H04N 1/6052 : Matching two or more picture signal generators or two or more picture reproducers

Abstract

A method and apparatus is disclosed for color balancing page data, from a variety of input sources having non-consistent device color profiles, among a plurality of individually accessible print engines arranged in a system for color printing multiple copies of multiple page documents. Input page data is converted to a common color space, rasterized and routed to a selected print engine. Page data routed to each marking engine is color balanced to the selected marking engine where at least a portion of the color balancing occurs following the rasterizing of the page data.

Claims

1. In a color electrophotographic printing system having a plurality of individually accessible print engines each having a unique profile, a method for color balancing color information in input page data from a variety of input sources having non-consistent device profiles, comprising:

converting color information in input page data to a common color space;

rasterizing the converted page data in the common color space;

routing the rasterized page data to a selected print engine; and

color balancing the rasterized routed page data in the rasterized space to match the device profile of the selected print engine where at least a portion of the balancing step occurs after the rasterizing step.

2. The method of claim 1, wherein the step of converting comprises:

referencing all print engines to the common color space;

inputting page data for a document to be printed; and

formatting input page data to the common color space.

3. The method of claim 2, wherein the step of referencing comprises:

selecting from available color space definitions a system color space common to all print engines used in the system to print the document; and

entering the selected color space definition into a formatter.

4. The method of claim 2, wherein the step of inputting comprises:

coupling the input page data to a translator; and

translating the input page data from an input device profile to a device-independent master color space.

5. The method of claim 2, wherein the step of formatting comprises:

translating the input page data from the device-independent master color space to the common color space.

6. The method of claim 1, wherein the step of rasterizing comprises:

decoding the page data into print strings;

rasterizing the page data to form bit-mapped page images;

compressing the bit-mapped image data; and

storing the rasterized page image data in a memory.

7. The method of claim 1, wherein the step of rasterizing comprises:

decoding the page data into print strings; and

rasterizing the page data to form bit-mapped page images.

8. The method of claim 1, wherein the step of routing comprises:

extracting printing parameters and page characteristics from the bit-mapped image data;

organizing the page data for the document into virtual printing stacks of print job data corresponding to the virtual printers and according to the extracted printing parameters and page characteristics; and

controlling distribution of the print job data from the virtual printing stacks to the print engines of the virtual printers.

9. The method of claim 1, wherein the step of color balancing comprises:

correcting the page data, expressed in common color space format, according to predetermined color calibration values corresponding to a print engine selected for the particular page data.

10. The method of claim 9, wherein the step of correcting comprises:

mapping the page data to create mapping bit values corresponding to the device profile of the selected print engine; and

downloading the mapping bit values to the print adapter for the selected print engine.

11. The method of claim 10, wherein the step of mapping comprises:

linearizing the response of the selected print engine; and

creating a set of mapping bit values to calibrate the page data file for the selected print engine.

12. The method of claim 11, wherein the step of creating comprises:

setting a look-up-table to a one-to-one ratio;

running a test pattern through the selected print engine;

evaluating the test pattern image with a color measuring device;

determining mapping relationships between the color specification of the test pattern image and the common color space; and

storing the mapping relationships as a set of mapping bit values.

13. The method of claim 12, wherein the step of evaluating comprises evaluating the test pattern image with a colorimeter.