Producing glossy images on a matte laser printer

Information

  • Patent Grant
  • 6570599
  • Patent Number
    6,570,599
  • Date Filed
    Wednesday, May 2, 2001
    23 years ago
  • Date Issued
    Tuesday, May 27, 2003
    21 years ago
Abstract
A matte laser printer produces a photographic like image on media by repeatedly fusing the toners deposited thereon. In a preferred embodiment, repeated fusing is accomplished by utilizing a duplexing path in the printer. In an alternate embodiment, a processing flow direction of the media is selectively reversed after fusing to enable multiple fusing operations. In either case, toner forming the image on the media is more fully fused, thereby reducing light scatter, such that a photographic like image is produced.
Description




FIELD OF THE INVENTION




This invention relates in general to image forming devices and, more particularly, to producing a photographic image on a matte laser printer by fusing the image multiple times.




BACKGROUND OF THE INVENTION




Conventional color laser printers produce a generally low gloss, matte finish on printed sheet media. The matte finish is achieved by carefully controlling fusing temperature and fusing time so as to not over fuse the toner to the media. Fusing of toner to generate a matte finish typically leaves air pockets in the toner and a rough surface. The air pockets and rough surface cause light to be scattered when reflected back to the eye, thus presenting a matte finish or appearance. A more glossy finish is generated by further heating or fusing the toner to a point where the surface toner beads are better fused, thus the glossy finish, but the interior toner beads are generally not completely fused.




The process of properly fusing is complicated by factors such as differences in media type and whether or not duplexing is employed in the printer. For example, certain plastic media such as overhead transparencies or other heavy media require a hotter fusing temperature and/or a longer fusing time, compared to normal paper, in order to obtain an image that is sufficiently fused. However, fuser temperature is limited by the range of media supported by the printer. For example, any plastic media supported define a maximum fusing temperature because of their glass point or phase change point which causes warping. On the other hand, any heavy media supported define a minimum fusing temperature that is sufficient to actually fuse the toner to the media. Additionally, when a sheet is duplex imaged, it is a challenge to apply sufficient heat to fuse the second side to a proper appearance without over heating the first side.




When toners fuse completely, there are a minimal number of internal holes that remain to cause light scatter. This results in more light being reflected off of the media back through the toners to the eye. In the case of color toners (i.e., Cyan, Magenta and Yellow), more light means more color. In the case of black toner, less scatter means less light reflected back to the eye for a darker black. Overall, more color and darker blacks mean a more photographic look to images. However, fusing to obtain a photographic like image is also problematic. For example, merely increasing the fusing time or temperature is not always feasible because of the differences in toners, media types, or excess heat that exists during fusing of the second side of a duplex page. Disadvantageously, over fusing can cause media to curl, warp or jam the printer.




Accordingly, an object of the present invention is to provide a tool and method for enabling a photographic finish on sheet media in a matte laser printer.




SUMMARY OF THE INVENTION




According to principles of the present invention, a matte laser printer produces a photographic like image on media by repeatedly fusing the toners deposited thereon. In a preferred embodiment, this repeated fusing is accomplished by utilizing a duplexing path in the printer. In an alternate embodiment, a processing flow direction of the media is selectively reversed after fusing to enable multiple fusing operations. In either case, toner forming the image on the media is more fully fused, thereby reducing light scatter, such that a more photographic like image is produced.




Other objects, advantages, and capabilities of the present invention will become more apparent as the description proceeds.











DESCRIPTION OF THE DRAWINGS





FIG. 1

is a cross sectional view in schematic diagram of a matte color laser printer employing principles of the present invention for enabling a photographic image.





FIG. 2

is a flow chart depicting a preferred method of the present invention.





FIG. 3

is a flow chart depicting an alternate embodiment method of the present invention.











DETAILED DESCRIPTION OF THE INVENTION





FIG. 1

is a cross sectional view in schematic diagram of a printer


10


employing principles of the present invention. Although printer


10


is shown and discussed herein as a color laser printer having duplexing capabilities, it will be understood by those of ordinary skill in the art that the present invention is equally applicable to other electrophotographic (EP) image forming devices such as photocopiers, facsimile machines and the like, and to in-line EP devices, EP devices using an intermediate transfer drum or using no intermediate transfer mechanism, single or dual heated fusing roller configurations, and also to duplexing mechanisms, paths and configurations beyond that shown and described herein. Additionally, it is understood that fusing of an image on media occurs as the image is passed through the fuser roller or rollers regardless of: on which side of the media the image is disposed; whether one or both rollers are heated; and on which side of the media the heated roller is disposed (if there is only one heated roller) when fusing. Note, also, that the discussion of sheet media includes opaque and transparent paper sheets, plastic sheets such as overhead transparencies, vellum sheets, envelopes, cardstock and the like as is conventionally processed in a laser imaging device. Moreover, many conventional components are omitted from the drawing to maintain clarity with respect to the media processing paths for single sided and duplex printing as they relate to the present invention.




As conventional in the art, printer


10


is a matte business printer and includes developer carousel


15


, photoconductive drum


20


, laser optics


25


, laser beam


30


for discharging drum


20


, and intermediate transfer belt (ITB)


35


. A cyan (C) developer


40


, magenta (M) developer


42


, yellow (Y) developer


44


and black (K) developer


46


are each mounted on developer carousel


15


in a respective developer station. Formatter


50


receives print data from a host system (not shown) and forms a raster print data stream. The raster print data stream is sent to engine controller


52


for conversion to a format suitable for controlling the pulsing of laser beam


30


. Control panel


54


is disposed on an external surface of printer


10


and enables a user to directly interact with and control printer


10


. Control panel


54


includes buttons, switches, or the like, and a display area such as a liquid crystal display (LCD). Firmware


56


stores data and routines to enable the operation of printer


10


. Importantly, firmware


56


includes data and executable instructions for enabling a photographic like image on printer


10


under principles of the present invention.




Printer


10


further includes removable input tray


60


and biased bed


65


for holding sheet media to be processed through the printer. Output tray


70


receives the image processed media. Sensor


75


detects whether media is available on bed


65


. Duplexing path


150


not only enables conventional duplexing but, importantly, further enables the present invention in a preferred embodiment as will be discussed herein.




Printer


10


forms a printed image onto sheet media


80


by first printing one of the four color planes CMYK onto photoconductive drum


20


and then immediately transferring that plane image to ITB


35


. Once transferred, a next color plane is printed onto drum


20


and then also immediately transferred to ITB


35


over the previous color plane image. This process is repeated for each color plane required to form the image. Once all color planes are printed onto ITB


35


, they are transferred to sheet media


80


to form a full color image thereon.




Now, under principles of the present invention, generally, printer


10


produces a photographic like image on sheet


80


by repeatedly fusing the toners deposited thereon to reduce light scatter, or until light scatter is minimized. In a preferred embodiment, sheet


80


is a white glossy media for enabling a most desirable overall photographic look. However, other media are feasible under the invention. Also in a preferred embodiment, this repeated fusing is accomplished by utilizing duplexing path


150


of printer


10


. In an alternate embodiment, a processing flow direction of sheet media


80


is selectively reversed after fusing to enable multiple fusing operations.




To this regard, upon initiation of a single sided (non-duplex) print job, sheet


80


is picked from bed


65


by pick roller


85


and passed through transport rollers


90


and skew rollers


95


to transfer roller


100


and ITB


35


as supported by roller


105


for imaging of the sheet on a first side. Once the image is transferred to the first side, sheet


80


continues on through fuser rollers


110


where the toner is fused to the sheet. Subsequently, sheet


80


is passed along path


112


to transport rollers


115


, sensor


120


, and transport rollers


125


. Once the trailing end of sheet


80


triggers sensor


120


near transport rollers


125


, firmware


56


signals transport rollers


125


to retain the sheet and enable reversing mechanism


145


. Consequently, reversing mechanism


145


reverses the direction of transport rollers


125


to draw the sheet down duplexing path


150


. When the sheet is drawn down, it is guided to follow the duplexing path through transport rollers


155


,


160


, sensor


165


, and then back up again through skew rollers


95


and transfer roller


100


. Since no further imaging is to occur, sheet


80


simply passes through transfer roller


100


to arrive again at fuser


110


. Importantly, sheet


80


passes again through fuser


110


for another fusing operation to further heat and fuse the toner on sheet


80


to reduce light scatter therefrom. This additional fusing and reduced scatter causes the image on sheet


80


to appear more photographic like.




Advantageously, the trip through duplexing path


150


has allowed sheet


80


to cool, thereby reducing the chance of sheet


80


becoming overheated and thereby avoiding potential curling, warping or jamming in printer


10


by the sheet. In contrast, if fuser


110


were merely heated extra hot, or if sheet


80


were slowed in its processing path as it passed through fuser


110


, the potential for sheet


80


to curl, warp or jam printer


10


is increased.




This passing of sheet


80


through duplexing path


150


to enable additional fusing is repeated N number of times where N is indicative of as many times as is necessary to achieve a most desirable photographic appearance of an image on the sheet. Firmware


56


controls the number of iterations per design criteria of printer


10


including, for example, whether one or both fuser rollers


110


are heated, temperature setting of fuser rollers


110


, rate of movement of the media, type of media used, chemical composition and formulation of each of the toners CMYK, and the like. Additionally, any incremental improvement in the resultant image on sheet


80


due to each iteration of fusing is balanced with the time cost of those iterations. In other words, at some point a reduced time to output tray


70


is preferable over any further visual improvement after N iterations of fusing. In any case, a preferred number of fusing iterations under the present invention clearly varies according to any one or more of these factors. However, at least two fusing operations are a minimum for a sheet


80


imaged on a single side. Additionally, an odd number of iterations is preferred if sheet


80


is to be ejected into output tray


70


with its image side down as occurs with conventional non-duplex imaging for printer


10


.




After N fusing iterations, sheet


80


is again passed through transport rollers


115


and


125


but, now, reversing mechanism


145


is not engaged with transport rollers


125


. Rather, sheet


80


continues to pass through transport rollers


130


and is finally ejected through output rollers


135


into output tray


70


as designated by path indicator


140


.




On the other hand, upon initiation of a duplex print job, the same processing path


112


,


150


just described for non-duplex printing is followed. However, the first time sheet


80


is passed through duplexing path


150


, it is merely to satisfy the conventional duplexing operation for imaging the second side of sheet


80


. To this regard, after a first side of sheet


80


is imaged and after the sheet is drawn down through duplexing path


150


to sensor


165


, if data is ready for imaging on the second side of sheet


80


, then the sheet is transported up and through skew rollers


95


and back to transfer roller


100


for imaging of the second side. The second side is now presented for imaging because of the inverting effect that occurred to the sheet due to it having been drawn down through duplexing path


150


. Subsequently, the second side is fused


110


.




At this point, sheet


80


is repeatedly passed through duplexing path


150


(as described with respect to the non-duplexing operation) for enabling N iterations of fusing and producing a photographic like image on both sides of sheet


80


before being passed up path


140


and ejected through output rollers


135


into tray


70


. Notably, in this duplex imaging context, at least three fusing operations are a minimum for sheet


80


. Additionally, an even number of iterations is preferred if sheet


80


is to be ejected into output bin


70


as occurs with conventional duplex imaging.




In an alternate embodiment, it is not necessary to employ duplexing path


150


to enable N fusing iterations. To this regard, a duplexing path


150


or capability is not even required for printer


10


. Specifically, reversing mechanism


145


is coupled with transport rollers


125


and


115


, and also with fuser rollers


110


. In this context, after sheet


80


is imaged by transfer roller


100


and passed through fuser rollers


110


along path


112


, firmware


56


signals reversing mechanism


145


to reverse the processing direction such that sheet


80


is drawn back in a “reverse” direction through fuser rollers


110


along the same path


112


. Once sheet


80


is fused again, firmware


56


signals reversing mechanism


145


to again reverse the processing direction such that sheet


80


continues again in a “forward” direction through fuser rollers


110


. Thus, this back and forth fusing of sheet


80


along path


112


is repeated N times or until a photographic like image is produced as previously discussed. Finally, when completed, sheet


80


is passed up path


140


and ejected through output rollers


135


into output tray


70


.




Referring now to

FIG. 2

, a flow chart depicts a preferred method of the present invention. In discussing

FIG. 2

, pertinent elements of

FIG. 1

will also be referenced where appropriate. Preliminarily, if this is a duplex job to be processed


205


, then a second side of a sheet


80


is imaged


210


, minimally fused


215


, and then routed


220


through duplexing path


150


. Subsequently, a first side of the sheet is imaged


225


and fused


230


. On the other hand, if this is not a duplex job


205


, only the first side of sheet


80


is imaged


225


and then fused


230


.




Next, if a signal has been received


235


to process this job as a photographic image under principles of the present invention, then sheet


80


is routed


240


through duplexing path


150


to be fused again


245


. It should be noted here that the signal for controlling the photographic processing of the present invention is enabled in firmware


56


by, alternatively, an operation such as an input from control panel


54


, a command received from a host computer (not shown), or a sensor (not shown) disposed in printer


10


that detects what type of media sheet


80


is (i.e., a sensor that detects whether sheet


80


is an overhead transparency, a heavy weight paper, or the like). In any case, whatever the source for enabling the signal to occur in firmware


56


, the signal also dictates or includes the number (N) of fusing iterations for sheet


80


under the present invention.




Thus, after fusing


245


, if N fusing iterations have not occurred


250


, then sheet


80


is repeatedly routed


240


through duplexing path


150


and fused


245


until N fusing iterations are completed


250


such that a photographic like image is produced. Only then


255


is sheet


80


routed


140


to be ejected out of printer


10


into tray


70


.





FIG. 3

depicts a flow chart of an alternate embodiment for repeatedly fusing an image according to principles of the present invention. Similar to

FIG. 2

, if this is a duplex job to be processed


305


, then a second side of a sheet


80


is imaged


310


, minimally fused


315


, and then routed


320


through duplexing path


150


. Subsequently, a first side of the sheet is imaged


325


and fused


330


. On the other hand, if this is not a duplex job


305


, only the first side of sheet


80


is imaged


325


and then fused


330


.




Next, if a signal has been received


335


to process this job as a photographic image under principles of the present invention, then reversing mechanism


145


is activated to reverse the processing flow direction


340


such that sheet


80


is drawn back through fuser


110


in a “reverse” direction to be fused again


345


. Subsequently, reversing mechanism


145


is again activated to again reverse the processing flow direction


350


such that sheet


80


is drawn back through fuser


110


now in a “forward” direction to be fused again


355


.




Next, if N fusing iterations have not occurred


360


, then sheet


80


is repeatedly reverse directionally processed


340


,


345


,


350


,


355


, back and forth through fuser


110


until N fusing iterations are completed


360


such that a photographic image is produced. Only then


365


is sheet


80


finally routed


140


to output tray


70


.




It should be noted here that in this embodiment there is not, by default, as much delay time between fusing operations as occurs in the duplexing path


150


embodiment. Thus, a reduced time-to-print is achieved. However, on the other hand, sheet


80


and the imaged toner doesn't cool as much before the next fusing operation. As such, in yet a further embodiment, a delay time is inserted in firmware


56


for delaying the reversing of the processing direction


340


,


350


before each next iterative fusing operation


345


,


355


to allow for enhanced cooling of sheet


80


. Alternatively, printer


10


is configured to include a cooling device, such as a fan


167


that blows air onto the fused media (relative to either processing direction), to further cool the media.




Finally, it will be obvious to one of ordinary skill in the art that the present invention is easily implemented utilizing any of a variety of components existing in the art. Moreover, while the present invention has been described by reference to specific embodiments, it will be apparent that other alternative embodiments and methods of implementation or modification may be employed without departing from the true spirit and scope of the invention.



Claims
  • 1. A method of fusing in an imaging device, the method comprising:(a) fusing at a single fusing element an image disposed on a sheet media for a non-duplex job a first time, the image being complete relative to all color planes to be developed for the image; and, (b) fusing the image at the single fusing element at least a second time to generate a more visually preferred fused condition of the image.
  • 2. The method of claim 1 wherein the imaging device includes an electrophotographic imaging device.
  • 3. The method of claim 1 further including passing the sheet media through a duplexing path in the imaging device after fusing the first time for fusing the at least a second time.
  • 4. The method of claim 1 further including reversing a processing flow direction of the sheet media in the imaging device after fusing the first time for fusing the at least a second time.
  • 5. The method of claim 1 further including enabling a cooling of the sheet media before fusing the at least a second time.
  • 6. The method of claim 1 further including repeatedly reversing a processing flow direction of the sheet media in the imaging device after fusing the first time for fusing the at least a second time.
  • 7. The method of claim 1 wherein the image includes toner disposed on the sheet media, and wherein fusing the at least a second time includes fusing multiple times until light scatter is minimized.
  • 8. The method of claim 1 wherein the sheet media includes a glossy media.
  • 9. A computer-readable medium having computer-executable instructions configured for performing steps including:(a) fusing at a given fusing point an image disposed on a sheet media for a non-duplex job a first time, the image being complete relative to all color planes to be developed for the image; and, (b) fusing the image at the given fusing point at least a second time to generate a more visually preferred fused condition of the image.
  • 10. A method of fusing in an imaging device, the method comprising:(a) contact fusing at a fusing nip an image on a sheet media a first time; (b) contact fusing the image at the fusing nip a second time; and, (c) contact fusing the image at the fusing nip at least a third time to generate a more visually preferred fused condition of the image.
  • 11. The method of claim 10 wherein the imaging device includes an electrophotographic imaging device.
  • 12. The method of claim 10 further including passing the sheet media through a duplexing path in the imaging device after fusing the first time for fusing the second time and after fusing the second time for fusing the at least a third time.
  • 13. The method of claim 10 further including reversing a processing flow direction of the sheet media to a reverse direction in the imaging device after fusing the first time for fusing the second time, and reversing the processing flow direction to a forward direction after fusing the second time for fusing the at least a third time.
  • 14. The method of claim 10 wherein the image includes toner disposed on the sheet media, and wherein fusing the at least a third time includes fusing multiple times until light scatter is minimized.
  • 15. The method of claim 10 further including enabling a cooling of the sheet media before fusing the at least a second time.
  • 16. The method of claim 10 wherein the sheet media includes a glossy media.
  • 17. A computer-readable medium having computer-executable instructions configured for performing steps to enable:(a) contact fusing of an image on a sheet media a first time at a single fusing point; (b) contact fusing of the image a second time at the single fusing point; and, (c) contact fusing of the image at least a third time at the single fusing point to generate a more visually preferred fused condition of the image.
  • 18. An electrophotographic imaging device, comprising:(a) an imaging engine; (b) a fuser; and, (c) a controller configured to present a sheet media to the fuser at least twice for a non-duplex job to be imaged to generate a more visually preferred fused condition of the image.
  • 19. The imaging device of claim 18 wherein the means for presenting the sheet media to the fuser at least twice includes a duplexing path.
  • 20. The imaging device of claim 18 wherein the means for presenting the sheet media to the fuser at least twice includes a reversing mechanism for reversing a processing flow direction of the sheet media in the imaging device.
  • 21. The imaging device of claim 18 further including means for enabling a cooling of the sheet media before fusing the at least a second time.
  • 22. The imaging device of claim 18 wherein the sheet media includes a glossy media.
  • 23. An electrophotographic imaging device, comprising:(a) an imaging engine; (a) a fuser; and, (b) a controller configured to present a sheet media to the fuser at least thrice for a job to be imaged to generate a more visually preferred fused condition of the image.
  • 24. The imaging device of claim 23 wherein the means for presenting a sheet media to the fuser at least thrice includes a duplexing path.
  • 25. The imaging device of claim 23 wherein the means for presenting a sheet media to the fuser at least thrice includes a reversing mechanism for selectively reversing a processing flow direction of the sheet media in the imaging device.
  • 26. The imaging device of claim 23 further including means for enabling a cooling of the sheet media before fusing a second time.
  • 27. The imaging device of claim 23 wherein the sheet media includes a glossy media.
  • 28. A method of fusing an image in an electrophotographic imaging device, the method comprising:(a) fusing the image on a sheet media a first time at a fusing nip; (b) fusing the image a second time at the fusing nip; and, (c) fusing the image at least a third time at the fusing nip to generate a more visually preferred fused condition of the image.
  • 29. A method of processing in an imaging device, the method comprising fusing an image on a substrate N number of times by passing the substrate through a fuser N number of times, wherein (i) the image is not subject to any further color plane development, (ii) N is defined relative to establishing a preferred final image appearance on the substrate, and (iii) N is at least two.
  • 30. A computer readable medium having computer-executable instructions configured to perform steps for enabling processing in an imaging device, the steps including enabling the fusing of an image on a substrate N number of times at a fusing element, wherein (i) the image is not subject to any further color plane development, (ii) N is defined relative to establishing a preferred final image appearance on the substrate, and (iii) N is at least two.
  • 31. A method of imaging in an imaging device, the method comprising:(a) detecting a user initiated signal indicative of a request to generate a glossy image for a print job for the imaging device; and, (b) responsive to the signal, fusing the image on a substrate N number of times at a single fusing source, wherein (i) the image is not subject to any further color plane development, (ii) N is defined relative to establishing a preferred final image appearance on the substrate, and (iii) N is at least two.
  • 32. An imaging device, comprising:(a) an imaging engine; and, (b) a controller in communication with the imaging engine, wherein the controller is configured to enable fusing of an image on a substrate N number of times by passing the substrate through a fuser N number of times, and wherein (i) the image is not subject to any further color plane development, (ii) N is defined relative to establishing a preferred final image appearance on the substrate, and (iii) N is at least two.
  • 33. An imaging device, comprising a controller in communication with an imaging engine, wherein the controller is configured to:(a) detect a user initiated signal indicative of a request to generate a glossy image for a print job for the imaging device, and, (b) responsive to the signal, fuse an image on a substrate N number of times at a given fusing element, wherein (i) the image is not subject to any further color plane development, (ii) N is defined relative to establishing a preferred final image appearance on the substrate, and (iii) N is at least two.
CROSS REFERENCE TO RELATED APPLICATION(S)

This is a continuation of copending application Ser. No. 09/298,983 filed on Apr. 22, 1999, now U.S. Pat. No. 6,271,870 which is hereby incorporated by reference herein.

US Referenced Citations (11)
Number Name Date Kind
4401024 Frentress Aug 1983 A
5293537 Carrish Mar 1994 A
5402436 Paoli Mar 1995 A
5408302 Manzer et al. Apr 1995 A
5424163 Tokunaga et al. Jun 1995 A
5436711 Hauser Jul 1995 A
5839016 Folins et al. Nov 1998 A
5907348 Ogasawara et al. May 1999 A
5987270 Hulan et al. Nov 1999 A
6212354 Garzolini et al. Apr 2001 B1
6271870 Jacob et al. Aug 2001 B1
Continuations (1)
Number Date Country
Parent 09/298983 Apr 1999 US
Child 09/847875 US