Patent Application
20090010498
In printers, print quality can degrade for a variety of reasons. For example, in ink jet printers, nozzles that fire ink can dry out either through not being used over extended periods of time, or just in the course of normal operation. Some printers include automatic nozzle firing detection. For example, during a test cycle before printing, the printer can monitor ejection of ink into a spittoon in order to verify proper operation of each print nozzle. The information generated by automatic nozzle firing detection can be used to trigger a printhead recovery sequence or trigger a warning message to a user.
Many printers also allow a user to print out a print pattern than can aid users in visually diagnosing print quality. This is an especially useful feature for users who want to see the effect on print quality when one or more nozzles of a printhead are not operating properly. For a desktop printer with six hundred nozzles, a 20 centimeter by 2 centimeter space can be sufficient to produce a readable test pattern. For a twelve-color printer with more than fourteen thousand nozzles, a 20 centimeter by 20 centimeter space may be required to produce a readable test pattern. For a twelve-color printer with thirty to sixty thousand nozzles printer, a much larger area may be required to produce a readable test pattern.
Information on pixel quality for pixels is stored as print health information 14. For example, for an inkjet printer, print health information 14 includes information indicating which nozzles are not firing ink, which nozzles are firing a reduced amount of ink and which nozzles are firing ink in a wrong direction. In other types of printers, other printer parts may be monitored to determine print health. For example, in a laser printer using multiple lasers, laser operation can be monitored instead of nozzle operation.
A print emulator 16 receives a test pattern 15 and produces an emulated print 17 of test pattern 15. This emulated print 17 is forwarded to a display 18 for view by a user of the printer. For example, display 18 is a display on a printer, or is a computer monitor of a computing system that is in communication with the printer. Alternatively, display 18 is a display of a computer system that has received a copy of emulated print 17.
When producing emulated print 17 of test pattern 15, print emulator 16 modifies test pattern 15 in accordance with print health information 14. For example, when producing emulated print 17 for an inkjet printer, print emulator omits or alters pixels that would be printed by nozzles that are not firing ink. Likewise, when producing emulated print 17, print emulator 16 omits or alters pixels that would be printed by nozzles that are firing a reduced amount of ink or are firing ink in the wrong direction. This alteration of test pattern 15 is for the purpose of allowing a user who views emulated print 17 to visually see how defects in pixel quality will affect print quality. This is done without the necessity of actually printing test pattern 15 on media.
Providing emulated print 17 to a user on a display, rather than printing test pattern 15, can save time and prevent waste of media. It can save time because it is not necessary for a printer to warm up and turn on accessories such as fans and heaters. It can save print media because no printing is performed and therefore no media is utilized.
Providing emulated print 17 to a user on a display 18 can provide information to a user in a more useful format than printing test pattern 15 on media. For example, when providing emulated print 17 to a user on a display 18, various close-up views can be provided. When test pattern 15 is printed on media, a magnified glass or other optical device would be necessary to obtain a more detailed view of print quality.
In addition to, or instead of, providing emulated print 17 to a user on display 18, emulated 17 can also be forwarded to others, such as service personnel, to evaluate the functionality of the printer.
For example, print engine 10, pixel detector 13, print emulator 16 and display 18 can all reside within a printer. Alternatively, some of the functionality can reside outside the printer itself. For example, display 18 or both display 18 and print emulator 16 can reside in a computing system with access to the printer while print engine 10 and pixel detector 13 reside within the printer.
The list of misfiring nozzles 52 is made available to a printmask application engine 59. Printmask application engine 59 is a print engine that receives a raster test pattern 57 and default print mode information 58. For example, raster test pattern 57 is an ideal pattern that shows what printing should look like when all nozzles are functioning correctly. Raster test pattern 57 is, for example, a stair step pattern or some other pattern that can indicate nozzle health to a user.
Default print mode information 58 indicates how nozzles would be used to print raster test pattern 57. For example, default print mode information 58 indicates a single pass print mask is generated where each nozzle for each color is used to print a single row of pixels for that color.
Printmask application engine 59 uses raster test pattern 57, default print mode information 59 and list of misfiring nozzles 52 to generate a modified test pattern 60. For example, when producing modified test pattern 60, printmask application engine 59 omits or alters pixels that would be printed by nozzles that are not firing ink. Likewise, when producing modified test pattern 60. printmask application engine 59 omits or alters pixels that would be printed by nozzles that are firing a reduced amount of ink or are firing ink in the wrong direction. This will allow a user to visually see how non-firing or misfiring nozzles will affect print quality without the necessity of actually printing on media.
A display zoom adapter 64 receives modified test pattern 60 and at the direction of an integrated information and user interface 55, modifies the modified test pattern 60 to allow zoom-in on a selected portion of modified test pattern 60.
A printmask application engine 53 receives best print mode information 61, normal print mode information 62, draft print mode information 63 and list of prominent misfiring nozzles 52 and generates a list of prominent misfiring nozzles 54. Prominent misfiring nozzles 54 are those misfiring nozzles for each print mode that are likely to create a user-visible print artifact. List of prominent misfiring nozzles 54 is helpful for printers using multi-pass print modes because defective nozzles can affect print quality differently dependent upon the number of print passes and how the defective nozzles are used or not used in each pass. While
Integrated information and user interface 55 receives information from display zoom adapter 64 and places the information on a display 56. When applicable, integrated information and user interface 55 modifies the information from display zoom adapter 64 based on list of prominent misfiring nozzles 54, dependent upon a print mode selected by the user.
As will be understood by persons of ordinary skill in the art, the emulated test pattern could be any test pattern useful to display print quality. A simple example of a test pattern is shown in
A message 25 informs a user that by placing a cursor over a location in one of color bands 21 through 24 and using a point device, such as a mouse, to make a selection (click), a user can get an enlarged view of the region clicked by the user.
Since print mode can affect things like firing frequency, firing order and so on of how print nozzles place ink on media, a different close up nozzle print pattern can be provided dependent upon whether the printer is printing in a print mode, a normal mode or a best node, as illustrated by buttons 33.
The foregoing discussion discloses and describes merely exemplary methods and embodiments of the present invention. As will be understood by those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.
