CA2149738C - Printing machine architecture - Google Patents
Printing machine architecture Download PDFInfo
- Publication number
- CA2149738C CA2149738C CA 2149738 CA2149738A CA2149738C CA 2149738 C CA2149738 C CA 2149738C CA 2149738 CA2149738 CA 2149738 CA 2149738 A CA2149738 A CA 2149738A CA 2149738 C CA2149738 C CA 2149738C
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- Prior art keywords
- printing machine
- black
- belt
- station
- photoconductive belt
- Prior art date
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Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/01—Apparatus for electrographic processes using a charge pattern for producing multicoloured copies
- G03G15/0142—Structure of complete machines
- G03G15/0147—Structure of complete machines using a single reusable electrographic recording member
- G03G15/0152—Structure of complete machines using a single reusable electrographic recording member onto which the monocolour toner images are superposed before common transfer from the recording member
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/01—Apparatus for electrographic processes using a charge pattern for producing multicoloured copies
- G03G15/0105—Details of unit
- G03G15/0131—Details of unit for transferring a pattern to a second base
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/01—Apparatus for electrographic processes using a charge pattern for producing multicoloured copies
- G03G15/0142—Structure of complete machines
- G03G15/0147—Structure of complete machines using a single reusable electrographic recording member
- G03G15/0152—Structure of complete machines using a single reusable electrographic recording member onto which the monocolour toner images are superposed before common transfer from the recording member
- G03G15/0163—Structure of complete machines using a single reusable electrographic recording member onto which the monocolour toner images are superposed before common transfer from the recording member primary transfer to the final recording medium
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/01—Apparatus for electrographic processes using a charge pattern for producing multicoloured copies
- G03G15/0142—Structure of complete machines
- G03G15/0147—Structure of complete machines using a single reusable electrographic recording member
- G03G15/0152—Structure of complete machines using a single reusable electrographic recording member onto which the monocolour toner images are superposed before common transfer from the recording member
- G03G15/0168—Structure of complete machines using a single reusable electrographic recording member onto which the monocolour toner images are superposed before common transfer from the recording member single rotation of recording member to produce multicoloured copy
Abstract
A monocolor, multipass multicolor, and single pass multicolor printing machine architecture uses a vertically oriented belt. Transfer of the toner powder images occur at the uppermost portion of the photoconductive belt. All of the developer units are arranged on one side of the photoconductive belt adjacent to a surface thereof. The other side of the photoconductive belt is devoid of developer units. This architecture facilitates image registration, optimizes the sheet path and minimizes the printing machine foot print.
Description
G
PATENT APPLICATION
Attorney Docket No. D/93534 PRINTING MACHINE ARCHITECTURE
This invention relates to a printing machine architecture, and more particularly concerns a vertically oriented photoconductive belt in which transfer of the toner image to a receiving member occurs at the uppermost portion of the photoconductive belt, and a plurality of developer units are located on one side of the photoconductive belt with the other side being devoid of developer units.
A typical electrophotographic printing machine employs a photoconductive member that is charged to a substantially uniform potential so as to sensitize the surface thereof. The charged portion of the photoconductive member is exposed to a light image of an original document being reproduced. Exposure of the charged photoconductive member selectively dissipates the charge thereon in the irradiated areas to record an electrostatic latent image on the photoconductive member corresponding to the informational areas contained within the original document. After the electrostatic latent image is recorded on the photoconductive member, the latent image is developed by bringing a developer material into contact therewith. Generally, the electrostatic latent image is developed with dry developer material comprising carver granules having toner particles adhering triboelectrically thereto However, a liquid developer material may be used as well. The toner particles are attracted to the latent image forming a visible powder image on the photoconductive surface. After the electrostatic latent image ~s developed with the toner particles, the toner powder image is transferred to a sheet. Thereafter, the toner image is heated .to permanently fuse it to the sheet.
It is highly desirable to use an electrophotographic printing machine of this type to produce color prints. In order to produce a color print, it is frequently necessary to form yellow magenta and cyan colo~
separations. One skilled in the art will appreciate that the black separation can be made either first or last with respect to the other color separations.
In this way, a permanent color print is formed. It is highly desirable to be capable of utilizing a common architecture for both monocolor and multicolor printing. In order to minimize the size of the printing machine, not only must the various parts of the printer be reduced in size, but the orientation of the photoconductive belt and transfer station must be optimized. When optimizing the size of the printing machine, it is necessary to consider registration of images for multicolor printing. Thus, the placement of the development stations with respect to the photoconductive belt effects registration of each developed image relative to one another. Various types of monocolor and multicolor printing machines have heretofore been employed. The following disclosure appears to be relevant:
U.S 4,757,471 Patentee: Fukae et al.
Issued: July 12,1988 U.S. 5,313,259 Patentee: Smith Issued: May 17,1994 US-A-4,757,471 disclosed an electrographic printer having a vertically oriented photocondudive belt. A copy sheet travels along a substantially planar path with the photoconductive belt being located below the planar path. The copy sheet contacts the photocondudive belt at the transfer zone. A transfer unit is located at the top of the belt path to attract toner from the belt to the sheet passing through the transfer zone.
U.S. Patent 5,313,259 discloses a multicolor electrophotographic printing machine in which a photoconductive belt is vertically oriented. The printing machine includes four groups of stations for printing in cyan, magenta, yellow and black. Each station includes a charge corona generator, a raster output scanning _2_ A
2~~~9~a laser assembly, and a developer unit. In the architecture depicted in this application, three stations are positioned on one side of the photoconductive belt with a fourth station disposed on the other side of thereof. Successive different color toner powder images are formed in superimposed registration with one another on the photoconductive belt and transferred to a copy sheet simultaneously. Transfer occurs at the lowermost portion of the photoconductive belt.
In accordance with one aspect of the features of the present invention, there is provided an electrophotographic printing machine having a common architecture for black printing machine architecture and for multi-color printing architecture, including:
a moveable photoconductive belt having minor axis and a major axis with the major axis being oriented substantially vertically, and the minor axis being oriented substantially horizontally;
a developer station comprising a black developer unit with the black printing machine architecture being devoid of a non-black developer unit, and a black developer unit and a non-black developer unit for the multi-color printing machine architecture, said developer station being positioned on one side of said photoconductive belt adjacent a surface thereof substantially perpendicular to the minor axis for developing latent images recorded on the surface of said photoconductive belt with the surface of said photoconductive belt opposed from the one side and spaced therefrom and substantially perpendicular to the minor axis being devoid of developer units for the black and multi-color printing machine architecture, said black developer unit being positioned before said non-black developer unit in a direction of movement of said photoconductive belt;
a transfer station positioned adjacent the uppermost surface of said photoconductive belt substantially perpendicular to the major axis, for transferring a developed image from the surface to a final sheet of support material; and means for fusing the developed image transferred from the surface to the final sheet of support material.
PATENT APPLICATION
Attorney Docket No. D/93534 PRINTING MACHINE ARCHITECTURE
This invention relates to a printing machine architecture, and more particularly concerns a vertically oriented photoconductive belt in which transfer of the toner image to a receiving member occurs at the uppermost portion of the photoconductive belt, and a plurality of developer units are located on one side of the photoconductive belt with the other side being devoid of developer units.
A typical electrophotographic printing machine employs a photoconductive member that is charged to a substantially uniform potential so as to sensitize the surface thereof. The charged portion of the photoconductive member is exposed to a light image of an original document being reproduced. Exposure of the charged photoconductive member selectively dissipates the charge thereon in the irradiated areas to record an electrostatic latent image on the photoconductive member corresponding to the informational areas contained within the original document. After the electrostatic latent image is recorded on the photoconductive member, the latent image is developed by bringing a developer material into contact therewith. Generally, the electrostatic latent image is developed with dry developer material comprising carver granules having toner particles adhering triboelectrically thereto However, a liquid developer material may be used as well. The toner particles are attracted to the latent image forming a visible powder image on the photoconductive surface. After the electrostatic latent image ~s developed with the toner particles, the toner powder image is transferred to a sheet. Thereafter, the toner image is heated .to permanently fuse it to the sheet.
It is highly desirable to use an electrophotographic printing machine of this type to produce color prints. In order to produce a color print, it is frequently necessary to form yellow magenta and cyan colo~
separations. One skilled in the art will appreciate that the black separation can be made either first or last with respect to the other color separations.
In this way, a permanent color print is formed. It is highly desirable to be capable of utilizing a common architecture for both monocolor and multicolor printing. In order to minimize the size of the printing machine, not only must the various parts of the printer be reduced in size, but the orientation of the photoconductive belt and transfer station must be optimized. When optimizing the size of the printing machine, it is necessary to consider registration of images for multicolor printing. Thus, the placement of the development stations with respect to the photoconductive belt effects registration of each developed image relative to one another. Various types of monocolor and multicolor printing machines have heretofore been employed. The following disclosure appears to be relevant:
U.S 4,757,471 Patentee: Fukae et al.
Issued: July 12,1988 U.S. 5,313,259 Patentee: Smith Issued: May 17,1994 US-A-4,757,471 disclosed an electrographic printer having a vertically oriented photocondudive belt. A copy sheet travels along a substantially planar path with the photoconductive belt being located below the planar path. The copy sheet contacts the photocondudive belt at the transfer zone. A transfer unit is located at the top of the belt path to attract toner from the belt to the sheet passing through the transfer zone.
U.S. Patent 5,313,259 discloses a multicolor electrophotographic printing machine in which a photoconductive belt is vertically oriented. The printing machine includes four groups of stations for printing in cyan, magenta, yellow and black. Each station includes a charge corona generator, a raster output scanning _2_ A
2~~~9~a laser assembly, and a developer unit. In the architecture depicted in this application, three stations are positioned on one side of the photoconductive belt with a fourth station disposed on the other side of thereof. Successive different color toner powder images are formed in superimposed registration with one another on the photoconductive belt and transferred to a copy sheet simultaneously. Transfer occurs at the lowermost portion of the photoconductive belt.
In accordance with one aspect of the features of the present invention, there is provided an electrophotographic printing machine having a common architecture for black printing machine architecture and for multi-color printing architecture, including:
a moveable photoconductive belt having minor axis and a major axis with the major axis being oriented substantially vertically, and the minor axis being oriented substantially horizontally;
a developer station comprising a black developer unit with the black printing machine architecture being devoid of a non-black developer unit, and a black developer unit and a non-black developer unit for the multi-color printing machine architecture, said developer station being positioned on one side of said photoconductive belt adjacent a surface thereof substantially perpendicular to the minor axis for developing latent images recorded on the surface of said photoconductive belt with the surface of said photoconductive belt opposed from the one side and spaced therefrom and substantially perpendicular to the minor axis being devoid of developer units for the black and multi-color printing machine architecture, said black developer unit being positioned before said non-black developer unit in a direction of movement of said photoconductive belt;
a transfer station positioned adjacent the uppermost surface of said photoconductive belt substantially perpendicular to the major axis, for transferring a developed image from the surface to a final sheet of support material; and means for fusing the developed image transferred from the surface to the final sheet of support material.
Other aspects of the present invention will become apparent as the following dexription proceeds and upon reference to the drawings, in which Figure 1 is a schematic, elevational view showing a monocolor printing machine architecture;
Figure 2 is a schematic elevational view showing a multipass, multicolor printing machine architecture; and Figure 3 is a xhematic elevational view showing a single pass, multicolor printing machine architecture.
While the present invention will hereinafter be described in connection with a preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary , -3 a-A
~:t~~~~~
it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
For a general understanding of the features of the present invention, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate identical elements.
Referring initially to Figure 1, there is shown a monocolor electrophotographic printing machine architecture. The printing machine employs a belt 10 having a photoconductive surface deposited on a conductive substrate. The photoconductive surface comprises an anti-curl layer, a supporting substrate layer and an electrophotographic imaging single layer or multiple layers. The imaging layers may contain homogeneous, hetrogeneous, inorganic or organic compositions.
Preferably, finely divided particles of a photoconductive inorganic compound are dispersed in an electrically insulating organic resin binder.
The substrate layer may be made from any suitable conductive material such as Mylar. Another well known conductive material that can be used in the substrate layer is aluminum. Belt 10 advances successive portions of the photoconductive surface sequentially through the various processing stations disposed about the path of movement thereof. A plurality of rollers or bars 12 provide support for belt 10. These rollers are spaced apart.
Belt 10 advances in the direction of arrow 14. One of these rollers is rotatably driven by a suitable motor and drive (not shown) so as to rotate and advance belt 10 in the direction of arrow 14.
Initially, belt 10 passes through a charging station. At the charging, a corona generating device 16 charges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential.
After the photoconductive surface of~belt 10 is charged, the charged portion thereof is advanced to an exposure station. At the exposure station, an imaging beam 18, generated by a raster output scanner (ROS) 20 illuminates the charged portion of the photoconductivc surface. ROS 20 employs a laser with rotating polygon mirror blocks to .~_ ._. .... . . _ .._ ... _ . . _ . _.. ... ~....~ _~__.__.~.. _.._.. ~.
M.....__. .-_.._. ... ....
X14°'~~~
create the electrostatic latent image on the photoconductive surface of belt 10. This electrostatic latent image is developed by developer unit 22.
Developer unit is a magnetic brush developer unit which deposits black toner particles on the electrostatic latent image. In this way, black toner develops the latent image. After the toner image has been developed on the photoconductive surface of belt 10 with black toner particles, belt 10 continues to advance in the direction of arrow 14 to transfer station 24.
At transfer station 24, a sheet of support material is advanced from a stack 26 by sheet feeders 28 thereto. Alternatively, the support material may be advanced from stack 30 or stack 32. In either case, the sheet of support material is advanced to transfer station 24 in registration with the toner image on belt 10. A corona generating device sprays ions onto the backside of the sheet of support material. This attracts the developed image from the photoconductive surface of belt 10 to the sheet of support material. A vacuum transport 34 moves the sheet of support material in the direction of arrow 36 to fusing station 38. While transferring the developed image to a receiving medium has been described wherein the receiving medium is a sheet of support material, e.g.
paper, one skilled in the art will appreciate that the developed image may be transferred to an intermediate member, such as a belt or drum, and then, subsequently transferred from the intermediate member to the sheet of paper and fused thereto.
Fusing station 38 includes a heated fuser roller 40 and backup or pressure roller 42. The backup roller is resiliently urged into engagement with the fuser roll to form a nip through which the sheet passes. In the fusing operation, the toner particles coalesce and bond to the sheet in image configuration forming a monocolor image thereon. After fusing, the finished sheet is discharged to finishing station 44. At finishing station 44, sheets are compiled and stapled and/or adhesive bound to one another.
After the finishing operation is completed, the finished set of sheets is advanced to a catch tray 46 for removal therefrom by the operator.
.5_ ~~~97~~
Invariably, after the sheet is separated from the photoconductive surface of belt 10 at the transfer station, some residual particles remain adhering thereto. These residual particles are removed from the photoconductive surface at cleaning station 48. Cleaning station 48 includes a pair of rotatably mounted fibrous brushes or a rotating brush and a blade which are electrically biased to attract particles from the photoconductive surface. The brushes are in contact with the photoconductive surface. Subsequent to cleaning, a discharge lamp (not shown) floods the photoconductive surface with light to dissipate any residual or electrostatic charge remaining thereon prior to the charging thereof for the successive imaging cycle.
Referring now to Figure 2, there is shown a multipass multicolor printing machine architecture. As shown thereat, photoconductive belt 10 is entrained about a plurality of rollers 12. One of the rollers is coupled to a suitable motor (not shown) so as to be rotatably driven thereby. In this way, photoconductive belt 10 advances in the direction of arrow 14.
Initially, belt 10 passes through a charging station. At the charging station, a corona generating device 16 charges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential.
After the photoconductive surface of belt 10 is charged, the charged portion thereof is advanced to an exposure station. At the exposure station, an imaging beam 18 generated by the raster output scanner 20 exposes the charged portion of the photoconductive surface to record a color separated electrostatic latent image thereon. This color separated electrostatic latent image is developed by developer unit 22 Developer unit 22 develops the electrostatic latent image recorded on photoconductive belt 10 with black toner particles.
After the black toner image has been developed on the photoconductive surface of belt 10, belt 10 continues to advance in the direction of arrow 14. The developed image on belt 10 passes beneath transfer station 24 and cleaning station 48. Both of these stations are nonoperative, i.e. the cleaning brushes are spaced from the photoconductive belt. Thereafter, the developed image returns to the charging station 16 where the photoconductive belt having the first developed image thereon is recharged to a relatively high, substantially uniform potential. Thereafter, a different imaging beam 18 from ROS 20 selectively dissipates the charge to record another partial electrostatic latent image on the photoconductive surface of belt 10 corresponding to regions to be developed with yellow toner particles. This partial electrostatic latent image is now advanced to the next successive developer unit SO which deposits yellow toner particles thereon.
After the electrostatic latent image has been developed with yellow toner, belt 10 continues to advance in the direction of arrow 14 through transfer station 24 and cleaning station 48, both of which are nonoperative, to charging station 16. At charging station 16, a corona generating device charges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential. Thereafter, another imaging beam 18 from ROS 20 selectively discharges the charge on the photoconductive surface to record a partial electrostatic latent image for development with magenta toner particles. After the latent image is recorded on the photoconductive surface, belt 36 advances the latent image to the magenta developer unit 52. The magenta developer unit deposits magenta toner particles in registration with the yellow and black toner powder images previously formed thereon to form a magenta toner powder image in superimposed registration therewith.
After the magenta toner image has been formed on the photoconductive surface of belt 10, belt 10 advances in the direction of arrow 14 through transfer station 24 and cleaning station 48 to charging nation 16. At this time, both the transfer station 24 and cleaning station 48 are nonoperative.
At charging station 16, a corona generator recharges the photoconductive surface to a relatively high, substantially uniform potential. Thereafter, another imaging beam 18 from ROS 20 selectively discharges those portions of the charged photoconductive surface which _7_ z~.~~~~s are to be developed with cyan toner. The latent image to be developed with cyan toner is advanced to the cyan developer unit 54.
At the cyan developer unit, cyan toner particles are deposited on the latent image to produce a cyan toner powder image. The cyan toner powder image is superimposed, at least partially, on those toner powder images previously developed on photoconductive surface of belt 10.
After the cyan toner powder image is developed on the photoconductive surface of belt 10, belt 10 advances to transfer station 24.
At the transfer station, a sheet of support material, i.e. paper, is advanced from a stack 26 by sheet feeder 28. The sheet advances and is guided to the transfer station. A corona generating device located at the transfer station sprays ions onto the backside of the paper. This attracts the developed image from the photoconductive surface of belt 10 to the sheet of paper. A vacuum transport moves the sheet of paper in the direction of arrow 36 to fusing station 38.
While transferring the multicolor developed image to a sheet of paper has been described, one skilled in the art will appreciate that the multicolor developed image may be transferred to an intermediate member, such as a belt or drum and then, subsequently, transferred to the sheet and fused thereto.
The fusing station 38 includes a heated fuser roll 40 and a backup roll 42. The backup roll is resiliently urged into engagement with the fuser roll to form a nip through which the sheet of paper passes. In the fusing operation, the toner particles coalesce with one another and bond to the sheet in image configuration forming a multicolor image thereon.
After fusing, the finished sheet is discharged to a finishing station 44. At the finishing station, a plurality of sheets are bound together either by stapling and/or by applying an adhesive thereto to form a set of sheets.
This set of sheets is then advanced to a catch tray 46 for subsequent removal therefrom by the machine operator.
A multiplicity of finishing devices, such as sorter, stapler, etc., may be attached to the printing machine.
_g_ .
The cleaning brushes are brought into contact with the photoconductive belt. In this way, residual particles adhering to the photoconductive surface of belt 10 are cleaned therefrom, after the transfer of the multicolor toner image therefrom by cleaning station 48.
Referring now to Figure 3, there is shown a single pass multicolor printing machine. This printing machine employs a photoconductive belt 10 supported by a plurality of hollers or bars 12.
Photoconductive belt 10 is arranged in a vertical orientation. Belt 10 advances in the direction of arrow 14 to move successive portions of the photoconductive surface sequentially beneath the various processing stations disposed about the path of movement thereof.
Initially, belt 10 passes through charging station 16. At the charging station, a corona generating device charges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential.
After the photoconductive surface of belt 10 is charged, the charged portion thereof is advanced to an exposure station. At the exposure station, an imaging beam 18 generated by ROS 20 creates a color separated electrostatic latent image on the photoconductive surface of belt 10. This color separated electrostatic latent image is developed by developer unit 22.
The developer unit 22 deposits black toner particles on the electrostatic latent image. In this way, a black toner powder image is formed on the photoconductive surface of belt 10.
After the black toner image has been developed on the photoconductive surface of belt 10, belt 10 continues to advance in the direction of arrow 12 to a recharge station where corona generating device 56 recharges the photoconductive surface to a relatively high, substantially uniform potential. Thereafter, a different imaging beam 18 from ROS 20 selectively dissipates the charge to record another partial electrostatic latent image on the photoconductive surface of belt 10 corresponding to the regions to be developed with yellow toner particles. This partial electrostatic latent image is now advanced to the next successive developer unit 50.
_g_ ~z~4~~~$
Developer unit SO deposits yellow toner particles on the photoconductive surface of belt 10 to form a yellow toner powder image thereon.
After the electrostatic latent image has been developed with the yellow toner, belt 10 advances in the direction of arrow 12 to the next recharged station. At this recharge station, a corona generating device 58 charges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential. Thereafter, another imaging beam 18 from ROS 20 selectively discharges the charge on the photoconductive surface to record a partial electrostatic latent image for development with magenta toner particles. After the latent image is recorded on the photoconductive surface, belt 10 advances the latent image to the magenta developer unit 52.
Magenta developer unit 52 deposits magenta toner particles on the latent image. These toner particles may be partially in superimposed registration with the previously formed yellow powder image. After the magenta toner powder image is formed on the photoconductive surface of belt 10, belt 10 advances to the next recharge station.
At the next recharged station, corona generator 60 recharges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential. Thereafter, another imaging beam 18 from ROS 20 selectively discharges those portions of the charged photoconductive surface which are to be developed with cyan toner particles. The latent image to be developed with cyan toner particles is advanced to cyan developer unit 54.
At cyan developer unit 54, cyan toner particles are deposited on the photoconductive surface of belt 10. These cyan toner particles form a cyan toner powder image which may be partially or totally in superimposed registration with the previously formed yellow and magenta toner powder images. In this way, a multicolor toner powder image is formed on the photoconductive surface of belt 10.
Thereafter, belt 10 advances the multicolor toner powder image to the transfer station 24. At transfer station 24, a sheet of support ..._ material, i.e. paper, is advanced from stack 32 by sheet feeders 28 and guided to transfer station 24. At transfer station 24, a corona generating device sprays ions onto the backside of the paper. This attracts the developed multicolor image from the photoconductive surface of belt 10 to the sheet of paper. A vacuum transport 34 moves the sheet of paper in the direction of arrow 36 to fusing station 38.
Fusing station 38 includes a heated fuser roll 40 and backup roll 42. The backup roll is resiliently urged into engagement with the fuser roll to form a nip through which the sheet of paper passes. In the fusing operation, the toner particles coalesce with one another and bond to the sheet in image configuration forming a multicolor image thereon. After fusing, the finished sheet is discharged to a finishing station 44 where the sheets are compiled and formed into sets which may be bound to one another. These sets are then advanced to a catch tray 46 for subsequent removal therefrom by the printing machine operator.
One skilled in the art will appreciate that while the multicolor developed image has been disclosed as being transferred to a sheet of support material, e.g. paper, it may be transferred to an intermediate member, such as a belt or drum, and then, subsequently transferred and fused to the sheet of support material. Furthermore, while toner powder images and toner particles have been disclosed herein, one skilled in the art will appreciate that a liquid developer material employing toner particles ~n a liquid carrier may also be used.
Invariably, after the multicolor toner powder image has been transferred to the sheet of paper, residual toner particles remain adhering to the photocondudive surface of belt 10. These residual toner particles are removed therefrom by cleaning station 48.
In each of the printing machine architectures described hereinbefore, photoconductive belt 10 is arranged in a vertical orientation The photoconductive belt has a major axis 120 and a minor axis 118. The major and minor axes are perpendicular to one another. The major axis 110 is substantially parallel to the gravitational vector and arranged in a substantially vertical orientation. The minor axis 118 is substantially perpendicular to the gravitational vector and arranged in a substantially horizontal direction. In each case, the transfer station is located at the uppermost portion of the photoconductive surface opposed from the surface of the belt substantially perpendicular the major axis 120. All of the developer units are located on one side of the belt adjacent the surface thereof perpendicular to the minor axis 118 thereof. The other surface of the photoconductive belt opposed from the side thereof having the developer units disposed thereat is devoid of developer units. This arrangement facilitates registration of successive toner images.
Architectures of this type minimize the foot print (area of floor used by machine) of the printing machine while maximizing productivity thereof.
Furthermore, the sheet path is simplified with transfer occurring at the uppermost portion of the photoconductive belt.
In recapitulation, it is clear that the present invention is directed to a vertically oriented photoconductive belt wherein transfer occurs at the uppermost portion of the photoconductive belt and all of the developer units are arranged on one side of the photoconductive belt adjacent a surface thereof.
It is, therefore, apparent that there has been provided in accordance with the present invention, a printing machine architecture which fully satisfies the aims and advantages hereinbefore set forth. While this invention has been described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modification and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.
_12_
Figure 2 is a schematic elevational view showing a multipass, multicolor printing machine architecture; and Figure 3 is a xhematic elevational view showing a single pass, multicolor printing machine architecture.
While the present invention will hereinafter be described in connection with a preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary , -3 a-A
~:t~~~~~
it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
For a general understanding of the features of the present invention, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate identical elements.
Referring initially to Figure 1, there is shown a monocolor electrophotographic printing machine architecture. The printing machine employs a belt 10 having a photoconductive surface deposited on a conductive substrate. The photoconductive surface comprises an anti-curl layer, a supporting substrate layer and an electrophotographic imaging single layer or multiple layers. The imaging layers may contain homogeneous, hetrogeneous, inorganic or organic compositions.
Preferably, finely divided particles of a photoconductive inorganic compound are dispersed in an electrically insulating organic resin binder.
The substrate layer may be made from any suitable conductive material such as Mylar. Another well known conductive material that can be used in the substrate layer is aluminum. Belt 10 advances successive portions of the photoconductive surface sequentially through the various processing stations disposed about the path of movement thereof. A plurality of rollers or bars 12 provide support for belt 10. These rollers are spaced apart.
Belt 10 advances in the direction of arrow 14. One of these rollers is rotatably driven by a suitable motor and drive (not shown) so as to rotate and advance belt 10 in the direction of arrow 14.
Initially, belt 10 passes through a charging station. At the charging, a corona generating device 16 charges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential.
After the photoconductive surface of~belt 10 is charged, the charged portion thereof is advanced to an exposure station. At the exposure station, an imaging beam 18, generated by a raster output scanner (ROS) 20 illuminates the charged portion of the photoconductivc surface. ROS 20 employs a laser with rotating polygon mirror blocks to .~_ ._. .... . . _ .._ ... _ . . _ . _.. ... ~....~ _~__.__.~.. _.._.. ~.
M.....__. .-_.._. ... ....
X14°'~~~
create the electrostatic latent image on the photoconductive surface of belt 10. This electrostatic latent image is developed by developer unit 22.
Developer unit is a magnetic brush developer unit which deposits black toner particles on the electrostatic latent image. In this way, black toner develops the latent image. After the toner image has been developed on the photoconductive surface of belt 10 with black toner particles, belt 10 continues to advance in the direction of arrow 14 to transfer station 24.
At transfer station 24, a sheet of support material is advanced from a stack 26 by sheet feeders 28 thereto. Alternatively, the support material may be advanced from stack 30 or stack 32. In either case, the sheet of support material is advanced to transfer station 24 in registration with the toner image on belt 10. A corona generating device sprays ions onto the backside of the sheet of support material. This attracts the developed image from the photoconductive surface of belt 10 to the sheet of support material. A vacuum transport 34 moves the sheet of support material in the direction of arrow 36 to fusing station 38. While transferring the developed image to a receiving medium has been described wherein the receiving medium is a sheet of support material, e.g.
paper, one skilled in the art will appreciate that the developed image may be transferred to an intermediate member, such as a belt or drum, and then, subsequently transferred from the intermediate member to the sheet of paper and fused thereto.
Fusing station 38 includes a heated fuser roller 40 and backup or pressure roller 42. The backup roller is resiliently urged into engagement with the fuser roll to form a nip through which the sheet passes. In the fusing operation, the toner particles coalesce and bond to the sheet in image configuration forming a monocolor image thereon. After fusing, the finished sheet is discharged to finishing station 44. At finishing station 44, sheets are compiled and stapled and/or adhesive bound to one another.
After the finishing operation is completed, the finished set of sheets is advanced to a catch tray 46 for removal therefrom by the operator.
.5_ ~~~97~~
Invariably, after the sheet is separated from the photoconductive surface of belt 10 at the transfer station, some residual particles remain adhering thereto. These residual particles are removed from the photoconductive surface at cleaning station 48. Cleaning station 48 includes a pair of rotatably mounted fibrous brushes or a rotating brush and a blade which are electrically biased to attract particles from the photoconductive surface. The brushes are in contact with the photoconductive surface. Subsequent to cleaning, a discharge lamp (not shown) floods the photoconductive surface with light to dissipate any residual or electrostatic charge remaining thereon prior to the charging thereof for the successive imaging cycle.
Referring now to Figure 2, there is shown a multipass multicolor printing machine architecture. As shown thereat, photoconductive belt 10 is entrained about a plurality of rollers 12. One of the rollers is coupled to a suitable motor (not shown) so as to be rotatably driven thereby. In this way, photoconductive belt 10 advances in the direction of arrow 14.
Initially, belt 10 passes through a charging station. At the charging station, a corona generating device 16 charges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential.
After the photoconductive surface of belt 10 is charged, the charged portion thereof is advanced to an exposure station. At the exposure station, an imaging beam 18 generated by the raster output scanner 20 exposes the charged portion of the photoconductive surface to record a color separated electrostatic latent image thereon. This color separated electrostatic latent image is developed by developer unit 22 Developer unit 22 develops the electrostatic latent image recorded on photoconductive belt 10 with black toner particles.
After the black toner image has been developed on the photoconductive surface of belt 10, belt 10 continues to advance in the direction of arrow 14. The developed image on belt 10 passes beneath transfer station 24 and cleaning station 48. Both of these stations are nonoperative, i.e. the cleaning brushes are spaced from the photoconductive belt. Thereafter, the developed image returns to the charging station 16 where the photoconductive belt having the first developed image thereon is recharged to a relatively high, substantially uniform potential. Thereafter, a different imaging beam 18 from ROS 20 selectively dissipates the charge to record another partial electrostatic latent image on the photoconductive surface of belt 10 corresponding to regions to be developed with yellow toner particles. This partial electrostatic latent image is now advanced to the next successive developer unit SO which deposits yellow toner particles thereon.
After the electrostatic latent image has been developed with yellow toner, belt 10 continues to advance in the direction of arrow 14 through transfer station 24 and cleaning station 48, both of which are nonoperative, to charging station 16. At charging station 16, a corona generating device charges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential. Thereafter, another imaging beam 18 from ROS 20 selectively discharges the charge on the photoconductive surface to record a partial electrostatic latent image for development with magenta toner particles. After the latent image is recorded on the photoconductive surface, belt 36 advances the latent image to the magenta developer unit 52. The magenta developer unit deposits magenta toner particles in registration with the yellow and black toner powder images previously formed thereon to form a magenta toner powder image in superimposed registration therewith.
After the magenta toner image has been formed on the photoconductive surface of belt 10, belt 10 advances in the direction of arrow 14 through transfer station 24 and cleaning station 48 to charging nation 16. At this time, both the transfer station 24 and cleaning station 48 are nonoperative.
At charging station 16, a corona generator recharges the photoconductive surface to a relatively high, substantially uniform potential. Thereafter, another imaging beam 18 from ROS 20 selectively discharges those portions of the charged photoconductive surface which _7_ z~.~~~~s are to be developed with cyan toner. The latent image to be developed with cyan toner is advanced to the cyan developer unit 54.
At the cyan developer unit, cyan toner particles are deposited on the latent image to produce a cyan toner powder image. The cyan toner powder image is superimposed, at least partially, on those toner powder images previously developed on photoconductive surface of belt 10.
After the cyan toner powder image is developed on the photoconductive surface of belt 10, belt 10 advances to transfer station 24.
At the transfer station, a sheet of support material, i.e. paper, is advanced from a stack 26 by sheet feeder 28. The sheet advances and is guided to the transfer station. A corona generating device located at the transfer station sprays ions onto the backside of the paper. This attracts the developed image from the photoconductive surface of belt 10 to the sheet of paper. A vacuum transport moves the sheet of paper in the direction of arrow 36 to fusing station 38.
While transferring the multicolor developed image to a sheet of paper has been described, one skilled in the art will appreciate that the multicolor developed image may be transferred to an intermediate member, such as a belt or drum and then, subsequently, transferred to the sheet and fused thereto.
The fusing station 38 includes a heated fuser roll 40 and a backup roll 42. The backup roll is resiliently urged into engagement with the fuser roll to form a nip through which the sheet of paper passes. In the fusing operation, the toner particles coalesce with one another and bond to the sheet in image configuration forming a multicolor image thereon.
After fusing, the finished sheet is discharged to a finishing station 44. At the finishing station, a plurality of sheets are bound together either by stapling and/or by applying an adhesive thereto to form a set of sheets.
This set of sheets is then advanced to a catch tray 46 for subsequent removal therefrom by the machine operator.
A multiplicity of finishing devices, such as sorter, stapler, etc., may be attached to the printing machine.
_g_ .
The cleaning brushes are brought into contact with the photoconductive belt. In this way, residual particles adhering to the photoconductive surface of belt 10 are cleaned therefrom, after the transfer of the multicolor toner image therefrom by cleaning station 48.
Referring now to Figure 3, there is shown a single pass multicolor printing machine. This printing machine employs a photoconductive belt 10 supported by a plurality of hollers or bars 12.
Photoconductive belt 10 is arranged in a vertical orientation. Belt 10 advances in the direction of arrow 14 to move successive portions of the photoconductive surface sequentially beneath the various processing stations disposed about the path of movement thereof.
Initially, belt 10 passes through charging station 16. At the charging station, a corona generating device charges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential.
After the photoconductive surface of belt 10 is charged, the charged portion thereof is advanced to an exposure station. At the exposure station, an imaging beam 18 generated by ROS 20 creates a color separated electrostatic latent image on the photoconductive surface of belt 10. This color separated electrostatic latent image is developed by developer unit 22.
The developer unit 22 deposits black toner particles on the electrostatic latent image. In this way, a black toner powder image is formed on the photoconductive surface of belt 10.
After the black toner image has been developed on the photoconductive surface of belt 10, belt 10 continues to advance in the direction of arrow 12 to a recharge station where corona generating device 56 recharges the photoconductive surface to a relatively high, substantially uniform potential. Thereafter, a different imaging beam 18 from ROS 20 selectively dissipates the charge to record another partial electrostatic latent image on the photoconductive surface of belt 10 corresponding to the regions to be developed with yellow toner particles. This partial electrostatic latent image is now advanced to the next successive developer unit 50.
_g_ ~z~4~~~$
Developer unit SO deposits yellow toner particles on the photoconductive surface of belt 10 to form a yellow toner powder image thereon.
After the electrostatic latent image has been developed with the yellow toner, belt 10 advances in the direction of arrow 12 to the next recharged station. At this recharge station, a corona generating device 58 charges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential. Thereafter, another imaging beam 18 from ROS 20 selectively discharges the charge on the photoconductive surface to record a partial electrostatic latent image for development with magenta toner particles. After the latent image is recorded on the photoconductive surface, belt 10 advances the latent image to the magenta developer unit 52.
Magenta developer unit 52 deposits magenta toner particles on the latent image. These toner particles may be partially in superimposed registration with the previously formed yellow powder image. After the magenta toner powder image is formed on the photoconductive surface of belt 10, belt 10 advances to the next recharge station.
At the next recharged station, corona generator 60 recharges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential. Thereafter, another imaging beam 18 from ROS 20 selectively discharges those portions of the charged photoconductive surface which are to be developed with cyan toner particles. The latent image to be developed with cyan toner particles is advanced to cyan developer unit 54.
At cyan developer unit 54, cyan toner particles are deposited on the photoconductive surface of belt 10. These cyan toner particles form a cyan toner powder image which may be partially or totally in superimposed registration with the previously formed yellow and magenta toner powder images. In this way, a multicolor toner powder image is formed on the photoconductive surface of belt 10.
Thereafter, belt 10 advances the multicolor toner powder image to the transfer station 24. At transfer station 24, a sheet of support ..._ material, i.e. paper, is advanced from stack 32 by sheet feeders 28 and guided to transfer station 24. At transfer station 24, a corona generating device sprays ions onto the backside of the paper. This attracts the developed multicolor image from the photoconductive surface of belt 10 to the sheet of paper. A vacuum transport 34 moves the sheet of paper in the direction of arrow 36 to fusing station 38.
Fusing station 38 includes a heated fuser roll 40 and backup roll 42. The backup roll is resiliently urged into engagement with the fuser roll to form a nip through which the sheet of paper passes. In the fusing operation, the toner particles coalesce with one another and bond to the sheet in image configuration forming a multicolor image thereon. After fusing, the finished sheet is discharged to a finishing station 44 where the sheets are compiled and formed into sets which may be bound to one another. These sets are then advanced to a catch tray 46 for subsequent removal therefrom by the printing machine operator.
One skilled in the art will appreciate that while the multicolor developed image has been disclosed as being transferred to a sheet of support material, e.g. paper, it may be transferred to an intermediate member, such as a belt or drum, and then, subsequently transferred and fused to the sheet of support material. Furthermore, while toner powder images and toner particles have been disclosed herein, one skilled in the art will appreciate that a liquid developer material employing toner particles ~n a liquid carrier may also be used.
Invariably, after the multicolor toner powder image has been transferred to the sheet of paper, residual toner particles remain adhering to the photocondudive surface of belt 10. These residual toner particles are removed therefrom by cleaning station 48.
In each of the printing machine architectures described hereinbefore, photoconductive belt 10 is arranged in a vertical orientation The photoconductive belt has a major axis 120 and a minor axis 118. The major and minor axes are perpendicular to one another. The major axis 110 is substantially parallel to the gravitational vector and arranged in a substantially vertical orientation. The minor axis 118 is substantially perpendicular to the gravitational vector and arranged in a substantially horizontal direction. In each case, the transfer station is located at the uppermost portion of the photoconductive surface opposed from the surface of the belt substantially perpendicular the major axis 120. All of the developer units are located on one side of the belt adjacent the surface thereof perpendicular to the minor axis 118 thereof. The other surface of the photoconductive belt opposed from the side thereof having the developer units disposed thereat is devoid of developer units. This arrangement facilitates registration of successive toner images.
Architectures of this type minimize the foot print (area of floor used by machine) of the printing machine while maximizing productivity thereof.
Furthermore, the sheet path is simplified with transfer occurring at the uppermost portion of the photoconductive belt.
In recapitulation, it is clear that the present invention is directed to a vertically oriented photoconductive belt wherein transfer occurs at the uppermost portion of the photoconductive belt and all of the developer units are arranged on one side of the photoconductive belt adjacent a surface thereof.
It is, therefore, apparent that there has been provided in accordance with the present invention, a printing machine architecture which fully satisfies the aims and advantages hereinbefore set forth. While this invention has been described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modification and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.
_12_
Claims (10)
1. An electrophotographic printing machine having a common architecture for black printing machine architecture and for multi-color printing architecture, including:
a moveable photoconductive belt having minor axis and a major axis with the major axis being oriented substantially vertically, arid the minor axis being oriented substantially horizontally;
a developer station comprising a black developer unit with the black printing machine architecture being devoid of a non-black developer unit, and a black developer unit and a non-black developer unit for the multi-color printing machine architecture, said developer station being positioned on one side of said photoconductive belt adjacent a surface thereof substantially perpendicular to the minor axis for developing latent images recorded on the surface of said photoconductive belt with the surface of said photoconductive belt opposed from the one side and spaced therefrom and substantially perpendicular to the minor axis being devoid of developer units for the black and multi-color printing machine architecture, said black developer unit being positioned before said non-black developer unit in a direction of movement of said photoconductive belt;
a transfer station positioned adjacent the uppermost surface of said photoconductive belt substantially perpendicular to the major axis, for transferring a developed image from the surface to a final sheet of support material; and means for fusing the developed image transferred from the surface to the final sheet of support material.
a moveable photoconductive belt having minor axis and a major axis with the major axis being oriented substantially vertically, arid the minor axis being oriented substantially horizontally;
a developer station comprising a black developer unit with the black printing machine architecture being devoid of a non-black developer unit, and a black developer unit and a non-black developer unit for the multi-color printing machine architecture, said developer station being positioned on one side of said photoconductive belt adjacent a surface thereof substantially perpendicular to the minor axis for developing latent images recorded on the surface of said photoconductive belt with the surface of said photoconductive belt opposed from the one side and spaced therefrom and substantially perpendicular to the minor axis being devoid of developer units for the black and multi-color printing machine architecture, said black developer unit being positioned before said non-black developer unit in a direction of movement of said photoconductive belt;
a transfer station positioned adjacent the uppermost surface of said photoconductive belt substantially perpendicular to the major axis, for transferring a developed image from the surface to a final sheet of support material; and means for fusing the developed image transferred from the surface to the final sheet of support material.
2. A printing machine according to Claim 1, further including a cleaning station positioned adjacent the surface of said photoconductive belt devoid of developer units.
3. A printing machine according to Claim 2, wherein said photoconductive belt moves in a recirculating path.
4. A printing machine according to Claim 3, further including a charging station, positioned adjacent said photoconductive belt, for forming a charged surface.
5. A printing machine according to Claim 4, further including an exposure station adapted to expose the charged surface to record a latent image thereon
6. A printing machine according to Claim 5, wherein said charging station includes a first charging unit positioned before a black developer unit of said plurality of developer units in the direction of movement of said photoconductive belt.
7. A printing machine according to Claim 6, wherein said charging station includes a second charging unit positioned between said black developer unit and a non-black developer unit of said plurality of developer units.
8. A printing machine according to Claim 7, wherein said exposure station exposes the charged surface after said second charging unit charges the surface to record a second latent image thereon.
9. A printing machine according to Claim 8, wherein said black developer unit develops the first mentioned latent image with toner of a black color to form a first developed image, and said non-black developer unit develops the second latent image with toner of a non-black color to form a second developed image.
10. A printing machine according to Claim 9, wherein the non-black developed image includes at least a portion thereof superimposed over the black developed image.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US27094694A | 1994-07-05 | 1994-07-05 | |
| US270,946 | 1994-07-05 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2149738A1 CA2149738A1 (en) | 1996-01-06 |
| CA2149738C true CA2149738C (en) | 2001-04-10 |
Family
ID=23033521
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2149738 Expired - Fee Related CA2149738C (en) | 1994-07-05 | 1995-05-18 | Printing machine architecture |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0691591A1 (en) |
| JP (1) | JPH0844133A (en) |
| CA (1) | CA2149738C (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0823673A3 (en) * | 1996-07-08 | 1998-06-10 | Aetas Peripheral Corporation | Developing unit and developing method |
| US6762856B2 (en) * | 2001-10-04 | 2004-07-13 | Xerox Corporation | Method for accelerating paper tray programming |
| JP4697573B2 (en) * | 2004-01-23 | 2011-06-08 | 富士ゼロックス株式会社 | Image forming apparatus |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4757471A (en) | 1987-04-01 | 1988-07-12 | Kentek Information Systems, Inc. | Electrographic printer/copier with photoconductive belt |
| US5270769A (en) * | 1991-02-21 | 1993-12-14 | Matsushita Electric Industrial Co., Ltd. | Electrophotographic apparatus for formation of color image on intermediate transfer device |
| US5160946A (en) * | 1991-07-19 | 1992-11-03 | Xerox Corporation | Image registration system |
| US5258820A (en) * | 1992-07-29 | 1993-11-02 | Xerox Corporation | Pre-recharge device for voltage uniformity in read color systems |
| JP3323251B2 (en) * | 1992-10-23 | 2002-09-09 | 株式会社リコー | Color image forming equipment |
-
1995
- 1995-05-18 CA CA 2149738 patent/CA2149738C/en not_active Expired - Fee Related
- 1995-06-21 EP EP95304328A patent/EP0691591A1/en not_active Withdrawn
- 1995-06-27 JP JP7160761A patent/JPH0844133A/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| CA2149738A1 (en) | 1996-01-06 |
| EP0691591A1 (en) | 1996-01-10 |
| JPH0844133A (en) | 1996-02-16 |
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| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |