Facsimile and static presentation processing – Static presentation processing – Attribute control
Reexamination Certificate
1999-11-24
2003-03-25
Wallerson, Mark (Department: 2622)
Facsimile and static presentation processing
Static presentation processing
Attribute control
C358S504000
Reexamination Certificate
active
06538770
ABSTRACT:
This disclosure relates to an improved on-line color measurement and control system for color printers, especially, for providing frequently updated color correction information for a color printer from a spectrophotometer in the output path of a color printer which is measuring the colors on color test patches printed on test sheets, wherein reduced wastage of paper for said printed test sheets, and reduced interruptions of normal printing, is provided by printing both banner sheet information and said color test patches on dual mode banner sheets.
As is well known in the art, it is a common practice, especially in shared user or system printers, to automatically generate and output an identifying banner sheet ahead of each individual print job being printed and outputted. Examples of banner sheets and their generation are disclosed, for example in Xerox Corp. U.S. Pat. Nos. 5,547,178 and 5,316,279, and in various commercial printer products. Accordingly, the generation, content and use of banner sheets per se need not be described in detail herein. A banner sheet may typically have automatically printed thereon by system and/or printer controller software a limited amount of printed information about that particular document or print job, such as one or more of the following text items: the print job or document name, printer user's (document transmitter's) name or acronym, printer code name, the host intranet system name, file name, date, the numbers of pages in that document or print job, etc.
In the present system, some or all of the banner sheets generated by the printer are also compatibly printed with color test patterns or patches and used as color test sheets for automatically generating and updating printer color control, as will be described in the example herein. Thus, there are automatically provided dual-mode color test sheets/banner sheets, in which multiple color patches of different colors are printed on otherwise blank areas of each, or selected, banner sheets.
This automatic dual mode banner sheet/color test sheet system can be implemented by relatively minor software changes well within the skill of that art at low cost and without having to otherwise modify the color printer, or interfere with or interrupt normal printing, or require any hardware changes. It can provide color test sheet printing intervals at regular timed intervals, and/or at each machine “cycle-up”, or as otherwise directed by the system software. It does not limit, however, the alternative or intermixed printing of conventional banner sheets without colors, or fully dedicated color test sheets which are not banner sheets.
The term “banner sheets” as used herein broadly encompasses various on-line printed cover sheets or other inter-document or inter-print-job separator sheets. Providing the subject dual use of such sheets saves both print paper and printer utilization time, and provides frequent color re-calibration opportunities, with no extra fed sheet requirements, where the printing system is one in which banner sheets are being printed at frequent intervals anyway. As noted, is quite common for shared user printers (even those with mailbox system job separators) to automatically generate and print a banner sheet immediately preceding the first page of each actual document being printed. Thus, banner sheets are being fed, printed, and fed out through the output path of a printer at frequent intervals.
Furthermore, it is common for printers, as described in the above-cited patents, to already provide automatic lateral offsetting of its banner sheets as they stack in the output tray, as compared to the other or actual document sheets, to provide print job separators, and to make the banner sheets readily separable from the actual documents. With the present dual mode sheets system, this makes separation and removal of color test sheets equally easy, in fact, accomplished at the same time by the same steps.
As indicated, with the disclosed dual mode banner sheet and color test sheets system the same banner sheets already being generated and printed in many printers may now also be used to variously print thereon the multiple color test patches for the spectrophotometer analysis by the disclosed or other output color control systems. This dual mode sheet usage system saves substantial amounts of otherwise wasted paper which would otherwise be used for non-image color test sheets which would be separated out and discarded after being outputted by the printer in addition to the banner sheets. Furthermore, this system enables frequent color re-correction inputs with no reduction in printer productivity. That is, normal document printing in a color printer does not have to be relatively frequently interrupted to print extra (non-document imaged) color test sheets to keep each color printer re-calibrated.
As discussed elsewhere herein, relatively frequent color re-calibration of a color printer is desirable, since the colors actually printed on the output can change or drift out of calibration with the intended colors for various known reasons. For example, changes in the selected or loaded print media (differences paper or plastic sheet types, materials, weights, calendering, coating, humidity, etc.), changes in the printer's ambient conditions, changes in image developer materials, aging or wear of printer components, varying interactions of the different colors being printed, etc.
The disclosed embodiment is thus a valuable feature for a practical on-line “real time” color printing color calibration or correction system which regularly measures with a spectrophotometer the actual colors currently being printed on printed sheets being outputted by the printer, as compared to the intended (or selected, or “true”) colors of the electronic document images being inputted to the printer for printing.
As used in the patent claims and elsewhere herein unless otherwise specifically indicated, the term “spectrophotometer” may encompass a spectrophotometer, colorimeter, and densitometer, as broadly defined herein. That is, the word “spectrophotometer” is to be given the broadest possible definition and coverage in the claims herein, consistent with the rest of the claims themselves. The definitions or uses of terms vary or differ among various scientists and engineers. However, the following is an attempt to provide some simplified clarifications relating and distinguishing the respective terms “spectrophotometer”, “calorimeter”, and “densitometer”, as they may be used in the specific context of specification examples of providing components for an on-line color printer color correction system, but not as limitations.
A typical “spectrophotometer” measures the reflectance of an illuminated object of interest over many light wavelengths. Typical prior spectrophotometers in this context use 16 or 32 channels measuring from 400 nm to 700 nm or so, to cover the humanly visible color spectra or wavelength range. A typical spectrophotometer gives color information in terms of measured reflectances or transmittances of light, at the different wavelengths of light, from the test surface. (This is to measure more closely to what the human eye would see as a combined image of a broad white light spectra image reflectance, but the spectrophotometer desirably provides distinct electrical signals corresponding to the different levels of reflected light from the respective different illumination wavelength ranges or channels.)
A “colorimeter” normally has three illumination channels, red, green and blue. That is, generally, a “calorimeter” provides its three (red, green and blue or “RGB”) values as read by a light sensor or detector receiving reflected light from a color test surface sequentially illuminated with red, green and blue illuminators, such as three different color LED's or three lamps with three different color filters. It may thus be considered different from, or a limited special case of, a “spectrophotometer”, in that it provides output color information in the trichometric qua
Wallerson Mark
Xerox Corporation
LandOfFree
Color printer color control system using dual mode banner... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Color printer color control system using dual mode banner..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Color printer color control system using dual mode banner... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3036191