Information
-
Patent Grant
-
6271870
-
Patent Number
6,271,870
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Date Filed
Thursday, April 22, 199925 years ago
-
Date Issued
Tuesday, August 7, 200123 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 347 156
- 347 115
- 347 119
- 399 194
- 399 67
- 399 68
- 399 320
- 399 328
- 399 309
- 399 364
- 399 340
- 399 307
- 399 298
- 399 322
- 399 341
- 399 401
- 430 124
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International Classifications
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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 the steps of:(a) fusing 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 least a second time to generate a more visually preferred fused condition of the image, wherein the sheet media is passed through a duplexing path in the imaging device after fusing the first time for fusing the at least a second time.
- 2. A method of fusing in an imaging device, the method comprising the step of:(a) fusing 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 least a second time to generate a more visually preferred fused condition of the image, the fusing occurring by 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.
- 3. A method of fusing in an imaging device, the method comprising the steps of:(a) fusing 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; (b) enabling a cooling of the sheet media before fusing at least a second time; and then (c) fusing the image at least a second time to generate a more visually preferred fused condition of the image.
- 4. A method of fusing in an imaging device, the method comprising the steps of:(a) fusing 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 least a second time to generate a more visually preferred fused condition of the image, the fusing occurring by 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.
- 5. A computer-readable medium having computer-executable instructions configured for performing image fusing comprising the steps of steps:(a) fusing 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 least a second time to generate a more visually preferred fused condition of the image, wherein the sheet media is passed through a duplexing path in the imaging device after fusing the first time for fusing the at least a second time.
- 6. A method of fusing in an imaging device, the method comprising the steps of:(a) contact fusing an image on a sheet media a first time; (b) contact fusing the image a second time; and, (c) contact fusing the image at least a third time to generate a more visually preferred fused condition of the image, wherein the sheet media is passed 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.
- 7. A method of fusing in an imaging device, the method comprising the steps of:(a) contact fusing an image on a sheet media a first time; (b) contact fusing the image a second time; and, (c) contact fusing the image at least a third time to generate a more visually preferred fused condition of the image, the fusing occurring by 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.
- 8. A method of fusing in an imaging device, the method comprising the steps of:(a) contact fusing an image on a sheet media a first time; (b) enabling a cooling of the sheet media before fusing at least a second time; (c) contact fusing the image a second time; and, (d) contact fusing the image at least a third time to generate a more visually preferred fused condition of the image.
- 9. A computer-readable medium having computer-executable instructions configured for performing image fusing comprising the steps of steps:(a) contact fusing of an image on a sheet media a first time; (b) contact fusing of the image a second time; and, (c) contact fusing of the image at least a third time to generate a more visually preferred fused condition of the image, wherein the sheet media is passed through a duplexing path in an 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.
- 10. A method of fusing toner on a sheet media in an image forming device, the image forming device having a fuser and a duplexer, the method comprising:(a) receiving a user initiated signal indicative for fusing the toner to a reduced light scatter for generating a photograrphic-like glossy image; (b) passing the sheet media through the fuser a first time; (c) in the event of a non-duplex job and in response to the signal, passing the sheet media through the fuser at least a second time; and, (d) in the event of a duplex job, passing the sheet media through the fuser a second time, and in response to the signal, passing the sheet media through the fuser at least a third time.
- 11. 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 an image, wherein the sheet media is presented to the fuser at least twice by way of including a duplexing path.
- 12. 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 an image, wherein the sheet media is presented to the fuser at least twice by reversing a processing flow direction of the sheet media in the imaging device.
- 13. 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 an image, and wherein the controller is further configured to enable a cooling of the sheet media before fusing the at least a second time.
- 14. 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 thrice for a job to be imaged to generate a more visually preferred fused condition of an image, wherein the sheet media is presented to the fuser at least thrice via a route including a duplexing path.
- 15. 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 thrice for a job to be imaged to generate a more visually preferred fused condition of an image, wherein the sheet media is presented to the fuser at least thrice by selectively reversing a processing flow direction of the sheet media in the imaging device.
- 16. 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 thrice for a job to be imaged to generate a more visually preferred fused condition of an image, wherein the sheet media is enabled to cool before fusing a second time.
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