Production of high fidelity copies by consideration of a receiver's characteristics

#This invention relates generally to electronic copying or printing of documents. More particularly, it relates to a method of producing high fidelity copies by considering the characteristics of the receiver.

#Copiers, printers, and other devices that produce copies of documents operate with the assumption that the receiver of the document image (such as paper, card stock, etc.) is of a given standard, such as material with a white color and certain texture and finish or a transparent material. This, however, is not always true. For example, paper for printing or copying comes in a variety of colors, textures, and finishes. Card stock, which is much thicker than most paper and often of different colors, is also commonly used for copying and printing. The variations in a receiver's actual characteristics from typical characteristics affect the colors perceived in the copy. For example, the color blue may be produced on a white sheet of paper by depositing on the paper a proper mix of subtractive toners (cyan, magenta, and yellow). But depositing the same mix of toners on a red sheet of paper will produce a color other than blue. Yet conventional copiers and printers do not take into account the receiver's colors or other characteristics when determining the mix of toners for printing the copy of a document. The fidelity of a copy may thus be less than what it would have been if the receiver's characteristics were more fully considered.

#An objective of the invention, therefore, is to provide a method and system for considering the characteristics of a receiver in producing a copy of a document, whether with a copier, printer, or other imaging device. By taking into account the receiver's characteristics, the toners deposited on a receiver may be adjusted so that the printed colors better match the intended colors.

#FIG. 1 is a block diagram of a document copying system in accordance with the invention.

#FIG. 2 is a block diagram of an image processor within the copying system of FIG. 1.

#FIG. 3 is a flowchart of a method in accordance with invention for considering a receiver's characteristics in producing a copy of a document.

#FIG. 1 is a block diagram of a document copying system 10 embodying the invention. The term “document” is to be interpreted broadly to include not only physical objects such as papers, but also computer-generated files that contain text and/or graphics. Similarly, the term “copying” is to be interpreted broadly to include the printing of a computer-generated file. Thus while the system 10 in its entirety is capable of copying physical objects, its core may be used separately to print computer-generated files or files generated by any other method such as photography.

#Beginning at the left of the figure, a document scanner 12 of conventional design scans documents and generates therefrom digital document data representing the scanned document. Each document pixel is represented by a number of bits such as twenty-four that encode the color of the pixel. This data is saved in a buffer 14 where it is processed by a software routine executed by image processor 16, as will be described. Receiver data comes, in turn, from a receiver such as paper that is initially stored in a feeder 17 such as a paper hopper. When a sheet of paper is required for copying a document, the system 10 pulls the sheet from the feeder 17 and through a receiver scanner 18 of conventional design. The scanner 18, as the scanner 12, scans its contents and generates therefrom digital data representative of the contents. In the case of scanner 18 (or other sensor appropriate to the information being collected), the scanning reveals the characteristics of the receiver such as its color, finish, texture, etc., that might affect the colors of a document printed thereon. Each receiver pixel is represented by a number of bits such as twenty-four that encode the characteristics of the pixel, such as color. The receiver data is saved in a buffer 20 where it is processed by a software routine executed by the image processor 16, as will be described.

#FIG. 2 is a block diagram of the image processor 16 showing the data inputs and output. The image processor includes a processor 22, memory 24, and firmware contained in the memory. The firmware includes software routines that work in accordance with the invention upon the document data and receiver data read from buffers 14 and 20, respectively. These software routines generate copy pigment data in the form of toner data that is sent to a printer engine 26 (FIG. 1), where it is used to select and apply toners to the scanner receiver to produce a copy of the document. The finished copy is then conveyed to the finished copy bin 28 for pick-up.