CA1072172A - Fusing apparatus having an articulated release material dispenser - Google Patents
Fusing apparatus having an articulated release material dispenserInfo
- Publication number
- CA1072172A CA1072172A CA239,727A CA239727A CA1072172A CA 1072172 A CA1072172 A CA 1072172A CA 239727 A CA239727 A CA 239727A CA 1072172 A CA1072172 A CA 1072172A
- Authority
- CA
- Canada
- Prior art keywords
- release material
- fuser
- recited
- frame
- web
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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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
- G03G15/20—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat
- G03G15/2003—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat
- G03G15/2014—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat using contact heat
- G03G15/2017—Structural details of the fixing unit in general, e.g. cooling means, heat shielding means
- G03G15/2025—Structural details of the fixing unit in general, e.g. cooling means, heat shielding means with special means for lubricating and/or cleaning the fixing unit, e.g. applying offset preventing fluid
Abstract
A FUSING APPARATUS HAVING AN
ARTICULATED RELEASE MATERIAL DISPENSER
ABSTRACT OF THE DISCLOSURE
An apparatus in which a quantity of release material is dispensed to a heated fuser member. The heated fuser member is operatively associated with a back up member. A sheet of support material having particles thereon passes between the back up member and fuser member. The particles on the sheet of support material contact the fuser member as it passes between the fuser member and back up member. Release material is periodically moved into and out of contact with the fuser member.
The foregoing abstract is neither intended to define the invention disclosed in the specification, nor is it intended to be limiting as to the scope of the invention in any way.
ARTICULATED RELEASE MATERIAL DISPENSER
ABSTRACT OF THE DISCLOSURE
An apparatus in which a quantity of release material is dispensed to a heated fuser member. The heated fuser member is operatively associated with a back up member. A sheet of support material having particles thereon passes between the back up member and fuser member. The particles on the sheet of support material contact the fuser member as it passes between the fuser member and back up member. Release material is periodically moved into and out of contact with the fuser member.
The foregoing abstract is neither intended to define the invention disclosed in the specification, nor is it intended to be limiting as to the scope of the invention in any way.
Description
107~17Z
BACKGROUND OF THE I~VENTION
This invention relates generally to an electrostato- i graphic printing machine, and more particularly concerns an apparatus for periodically dispensing release material to a ` 5 heated fuser member.
~` In a typical electrostatographic printing machine, a ~; latent image is recorded on a surface and developed with chargedparticles. A sheet of support material is positioned closely adjacent to the surface having the charged particles thereon.
The charged particles are transferred to the sheet of support material in image configuration. After the particles are transferred to the sheet of support material, they are per-manently affixed thereto forming thereon a copy of the original document. Electrophotographic printing and electrographic printing are versions of electrostatographic printing. In the process of electrophotographic printing, a photoconductive member is charged to a substantially uniform level. A light image of an original document irradiates the charged photo-conductive member dissipating the charge in accordance with the intensity thereof. This records an electrostatic latent image on the photoconductive member corresponding to the original document being reproduced. Electrographic printins differs from electrophotographic printing in that neither a photocon-ductive member nor a light image are required to create a latent image of the original document. Generally, heat settable par-ticles are employed in both of the foregoing processes to develop the latent image. Heat is applied to these particles permanently affixing them to the sheet of support material.
Different approaches have been employed for applying heat to the particles adhering to the sheet of support material.
In one technique, the sheet of support material with the par-ticles thereon pass between a pair of opposed rollers. At least
BACKGROUND OF THE I~VENTION
This invention relates generally to an electrostato- i graphic printing machine, and more particularly concerns an apparatus for periodically dispensing release material to a ` 5 heated fuser member.
~` In a typical electrostatographic printing machine, a ~; latent image is recorded on a surface and developed with chargedparticles. A sheet of support material is positioned closely adjacent to the surface having the charged particles thereon.
The charged particles are transferred to the sheet of support material in image configuration. After the particles are transferred to the sheet of support material, they are per-manently affixed thereto forming thereon a copy of the original document. Electrophotographic printing and electrographic printing are versions of electrostatographic printing. In the process of electrophotographic printing, a photoconductive member is charged to a substantially uniform level. A light image of an original document irradiates the charged photo-conductive member dissipating the charge in accordance with the intensity thereof. This records an electrostatic latent image on the photoconductive member corresponding to the original document being reproduced. Electrographic printins differs from electrophotographic printing in that neither a photocon-ductive member nor a light image are required to create a latent image of the original document. Generally, heat settable par-ticles are employed in both of the foregoing processes to develop the latent image. Heat is applied to these particles permanently affixing them to the sheet of support material.
Different approaches have been employed for applying heat to the particles adhering to the sheet of support material.
In one technique, the sheet of support material with the par-ticles thereon pass between a pair of opposed rollers. At least
- 2 - ~
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``
one of these rollers is heated. The heated fuser roller has the outer surface thereof covered with polytetrafluoroethylene, commonly known as Teflon, to which a release agent such as silicone oil is supplied. Preferably, the Teflon layer has a thickness of about several mils with the thickness of oil being less than one micron. Silicone based oil, which possess a relatively low surface energy, has been found to be useful for heated fuser rolls having an outer surface of Teflon. Generally, a thin layer of silicone oil is applied to the surface of the heated roller to form an interface between the roll surface and powdered image carried on the sheet of support material.
The low surface energy of this layer prevents the particles from transferring to the roller rather than remaining adhered to the sheet of support material. In this manner, the particles are permanently affixed to the sheet of support material, .~ i An alternate approach employs a bare metal heated roller having low molecular weight polyethylene applied thereto as a release agent. This release agent is generally a solid at room temperature. Hereinbefore, the release agent has been maintained in a sump adjacent the heated fuser roller. As the-fuser roller reaches its operating temperature, the release agent melts. The life expectancy of polyethylene release material is greater in the solid state than in the liquid state, --It is, therefore, evident that it is undesirable to maintain the rèlease material in the liquid state an unnecessary duration of time, 1(~7Z172 In accordance with one aspect of this invention there is provided in an electrostatographic printing machine, an apparatus for dispensing a quantity of release material to a heated fuser member operatively associated with a backup member : wherein a sheet of support material having particles thereon passes therebetween with the particles contacting the fuser member, including: means for applying the release material : to the surface of the fuser member; and means for automatically, periodically moving the applying means into and out of engage-ment with the surface of the continuously operating fuser member to apply the release material thereto.
In accordance with another aspect of this invention there is provided a fusing apparatus employed in an electro-statographic printing machine for permanently affixing toner particles to a sheet of support material, including: a heated fuser roll; a backup roll operatively associated with said fuser roll to enable the sheet of support material to pass there-between with the toner particles contacting said fuser roll;
means for applying a release material to the surface of said fuser roll; and means for automatically, periodically moving said applying means into and out of engagement with the surface of said continuously operating fuser roll to apply the release material thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention will become more apparent upon read-ing the following detailed description and upon reference to the drawings, in which:
Figure 1 is a schematic elevational view of an electrophotographic printing machine incorporating the features of the present invention therein;
Figure 2 is a schematic elevational view of one _ 4 _ ~t.~,~i JX
lO~'~lq~
embodiment of a release material dispenser employed in the .; Figure 1 printing machine fuser; and .. Figure 3 is a schematical elevational view of another embodiment of a release material dispenser employed in the Figure 1 printing machine fuser.
" While the present invention will hereinafter be described in connection with various embodiments thereof, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may l.e ;` ' - ' - 4a -" lOqZ17Z
included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
~; For a general understanding of an electrophotographicprinting machine in which the present invention may be incor-porated, reference is had to Figure 1 which depicts schematically the various components thereof. Hereinafter, like reference numerals will be employed throughout to designate like elements.
Although the apparatus for dispensing the release material to a fusing member employed in the electrophotographic printing machine of Figure 1 is particularly well adapted for use therein, it should become evident from the following discussion that it is equally well suited for use in a wide variety of devices and is not necessarily limited in its application to the particular embodiment shown herein.
Since the practice of electrophotographic printing is well known in the art, the various processing stations for pro-ducing a copy of an original document are represented in Figure 1 schematically by the reference letters A through F, inclusive.
As in all electrophotographic printing machines of the type illustrated; a drum 10 having a photoconductive surface 12 entrained about and secured to the exterior circumferential surface thereof is rotated, in the direction of arrow 14, through - 25 the various processing stations. One type of suitable photo-conductive material is described in U.S. Patent No. 2,970,906 issued to Bixby in 1961. In general, photoconductive surface 12 is made from a selenium alloy.
Initially, drum 10 rotates photoconductive surface 12 through charging station A. At charging station A, a corona generating device, indicated generally at 16, sensitizes photo-conductive surface 12. Corona generating device 16 is ` iO'~217Z
positioned closely adjacent to photoconductive ~urface 12. When corona generating device 16 i9 energized, photoconductive surface 12 is charged to a relatively high substantially uniform potential.
One type of suitable corona generating device is described in U.S.
Patent No. 2,836,725 issued to Vyverberg in 1958.
After a portion of photoconductive surface 12 is charged to a substantially uniform potential, the charged portion thereof is rotated to exposure station B. Exposure station B includes an exposure mechanism, indicated generally by the reference numeral 18, having a stationary housing for supporting an original document thereon. The housing comprises a transparent platen such as a glass plate or the like having the original document disposed thereon.
Lamps illuminate the original document. Scanning of the original document may be achieved by oscillating a mirror in a timed re-lationship with the movement of drum 10. The light image of the original document is reflected through a lens onto another mirror which, in turn, transmits the light image through a slit onto the charged portion of photoconductive surface 12. Irradiation of the charged photoconductive surface 12 dissipates the charge thereon recording an electrostatic latent image thereon corresponding to the original document.
~hereafter, drum 10 rotates the electrostatic latent image recorded on photoconductive surface 12 to development station C. Development station C includes a developer unit 20 having a housing with a supply of developer mix therein. The developer mix comprises carrier granules with toner particles adhering thereto.
Preferably, the carrier granules are formed from magnetic material with the toner particles being a heat settable plastic. Developer unit 20 is, preferably, a magnetic brush development system. In such a system, the developer mix is brought through a directional '`
`- flux field to form a brush thereof. The brush of developer mix contacts the electrostatic latent image recorded on photoconductive surface 12. The latent image attracts electrostatically the toner particles from the carrier granules forming a toner powder image on `` 5 photoconductive surface 12.
Prior to continuing with the remaining processing sta-tions, the sheet feeding path will be briefly described. With continued reference to Figure 1, a sheet of support material is advanced by sheet feeding apparatus 22 to transfer station D.
Sheet feeding apparatus 22 includes a feed roll 24 contacting the uppermost sheet of the stack of sheets of support material 26.
Feed roll 24 rotates in the direction of arrow 28 to advance the uppermost sheet from stack 26. Registration rolls 30, rotating in the direction of arrow 32, align and forward the advancing sheet of support material into chute 34. Chute 34 directs the advancing sheet of support material into contact with photoconductive surface 12 in registration with the toner powder image developed thereon.
In this manner, the sheet of support material is positioned to receive the toner powder image from photoconductive surface 12 at transfer station D.
Transfer station D includes a corona generating device 36 adapted to apply a spray of ions onto the side of the sheet of support material opposed from photoconductive surface 12. The toner powder image adhering to photoconductive surface 12 is then attracted therefrom to the sheet of support material in contact therewith. After transferring the toner powder image to the sheet of support material, the sheet of support material is advanced to fusing station E.
Endless belt conveyor 38 advances the sheet of support material with the toner powder image adhering thereon to fusing lOqZlqZ
? station E. Fusing station E includes a fuser assembly, indicated generally by the reference numeral 40. Fuser assembly 40 heats the transferred toner powder image permanently affixing it to the sheet of support material. Fuser assembly 40 includes a heated fuser member or roll, shown generally at 42 and a backup member or roll indicated generally by the reference numeral 44. The sheet of support material with the toner powder image thereon is inter-posed betwaen fuser roll 42 and backup roll 44 with the toner pow-der image contacting fuser roll 42. Dispenser 45 periodically applies release material to fuser roll 42. Blade 46 adjusts the thickness of the release material layer coating fuser roll 42. The detailed structural configuration of fuser assembly 40 will be de-scribed hereinafter with reference to Figures 2 and 3. After the toner powder image is permanently affixed to the sheet of support material, the sheet of support material is advanced by a series of rollers 48 to catch tray 50 for subsequent removal therefrom by the machine operator.
Invariably, after the sheet of support material is separated from photoconductive surface 12, some residual toner particles adhere thereto. These residual toner particles are re-moved from photoconductive surface 12 at cleaning station F.
Cleaning station F includes a cleaning mechanism, designated generally by the reference numeral 51. Cleaning mechanism 51 in-cludes a corona generating device and a brush. Initially, toner particles are brought under the influence of the corona generating device to neutralize the remaining electrostatic charge on photo-conductive surface 12 and the residual toner particles. The neu-tralized toner particles are cleaned from photoconductive surface 12 by the rotatably mounted fibrous brush in contact therewith.
Subsequent to cleaning, a discharge lamp floods photoconductive iOq'~172 surface 12 with light to dissipate any residual charge thereon.
In this manner, the charge on photoconductive surface 12 is returned to the initial level prior to recharging photoconductive surface ; 12 for the next successive imaging cycle.
It is believed that the foregoing description is suf-ficient for purposes of the present application to illustrate the general operation of an electrophotographic printing machine em-bodying the features of the present invention therein. Referring now to the specific subject matter of the present invention, Figure 2 depicts one embodiment of dispensing apparatus 45 asso-ciated with fuser assembly 40.
Fuser assembly 40 comprises a heated fuser roll, indi-cated generally by the reference numeral 42, and a backup roll, indicated generally by the reference numeral 44. Fuser roll 42 cooperates with backup roll 44 to form a nip 52 therebetween ` through which the sheet of support material having a toner powder image thereon passes therethrough. The sheet of support material is arranged to have the toner powder thereon contacting fuser roll 42. A channel shaped base is provided for supporting fuser assembly 40 in the electrophotographic printing machine shown in Figure 1.
Backup roll 44 is mounted rotatably on a pair of brackets secured to the channel shaped base by means of a right angle bracket. As shown, backup roll 44 is adapted to rotate in the direction of arrow 54. Preferably, backup roll 44 includes a rigid steel core or shaft 56 having a Viton elastomeric surface or layer 58 dis-posed thereover and affixed thereto. Shaft 56 is secured rotat-ably on the brackets by a pair of bearings held in place by re-- taining rings. By way of example, backup roll 44 has an overall - dimension of approximately 1.55 inches with a 0.1 inch cover or layer of Viton or other suitable high temperature elastomeric _ g _ material, for example, fluorosilicone or silicone rubber. Backup roll 44 is preferably 15 1/2 inches long to accommodate various ` widths of support material.
A pair of brackets having a generally E-shaped configura-tion are provided for mounting fuser roll 42 rotatably in fuser -; assembly 40. To this end, a pair of ball bearings, one in each of the support brackets, are provided. The bearings are retained in the brackets by means of retaining rings. A pair of end caps are secured to a hollow cylinder or core 60 forming a part of fuser roll 42. The end caps have reduced end portions so as to be mounted in the bearings permitting fuser roll 42 to rotate in the direction of arrow 62. A heating element 64 is supported internally of cylinder 60 for providing thermal energy to cylinder 60 to the operating temperature thereof. Heating element 64 employs a suit-able type of heater for elevating the surface temperature of ` cylinder 60 to operational temperature, i.e. 285F to 295F. By way of example, heating element 64 may include a quartz enevelope having a tungsten resistance heating element disposed therein.
Preferably, cylinder 60 is fabricated from any suitable material capable of efficiently conducting the heat to the external surface thereof. For example, suitable materials are aluminum and alloys thereof, steel, stainless steel, nickel and nickel alloys thereof, nickel plated copper, chromium plated copper, copper and alloys thereof. The resultant fuser roll 42 has an outside diameter pre-ferably of about 1.5 inches with the length thereof about equal to that of backup roll 44. In operation, fuser roll 42 requires about 420 watts peak power with the average power being about 320 watts, and about 100 watts being provided for standby operation. Heating element 64 is supported internally of cylinder 60 by a pair of spring supports which are mounted in an insulator block secured to lO"~'~qZ
support brackets. The free ends of the spring supporting the heating elements are provided with a locating ball while the opposite end of the spring is disposed in contract with an electrical terminal to which electrical wires may be attached 5 for applying electrical energy to heating element 64. The insulator blocks can be secured to the support brackets in any suitable manner, for example by screws. The spring supports and terminals are, preferably riveted to the insula-ting block.
The aforementioned materials from which cylinder 60 are fabricated have a relatively high surface energy. Thus, hot toner material contacting such surfaces would readily wet the surface of cylinder 60. Toner wetting the surface of cylinder 60 is difficult to remove therefrom. Accordingly, 15 there is provided a dispenser 44 containing a material capable of interacting with cylinder 60 in a manner described in U. S.
Patent 3,937,637, issued February 10, 1976, Robin Moser et al.
The material is, preferably, a low molecular weight substance which is a solid at room temperature and has a relatively low 20 viscosity at the operating temperature cylinder 60. An exam-ple of such a material is polyethylene manufactured by Allied Chemical Company and having a designation AC-8 homopolymer. -~
The foregoing polyethylene is employed in dispenser 45. As shown in Figure 2, dispenser 45 includes a supply spool 66 25 mounted rotatably on a frame secured to the electrophotographic machine. Take-up spool 68 is also mounted rotatably on the frame and is spaced from supply spool 66. A web of flexible material 70 is entrained about supply spool 66 and has the leading edge thereof secured to take-up spool 68. A layer of 30 polyethylene material is coated on the surface of flexible material 78 opposed from fuser roll 42. In the operative lOq'~lqZ
- position, the layer of polyethylene material coating web 78 contacts fuser roll 42. Web 78 is articulated so as to move . periodically --'''' . ' ' .
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.
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into and out of engagement with fuser roll 42. An indexing motor operatively associated with take-up spool 68 intermit-tently advances flexible material 78 so as to position new portions of the polyethylene coating opposed from the surface thereof having the polyethylene coating. Rod 80 is recipro-cated to move the polyethylene coating on web 78 into and out of contact with fuser roll 42. Articulation of rod 80 is achieved by a bell crank mechanism 82 associated with drive motor 84. By way of example, rod 80 may articulate at about two revolutions per minute, thereby moving the polyethylene coating on flexible material 78 into and out of contact with fuser roll 42 two times per minute.
Blade 46 adjusts the thickness of the release material layer coating fuser roll 42 so as to maintain a pre-scribed thickness thereof. The detailed structural configu-ration of blade 46 is described in U. S. Patent No. 3,935,836, issued February 3, 1976.
Referring now to Figure 3, there is shown another embodiment for release material dispenser 45. As shown there-in, fuser roll 42 is operatively associated with backup roll44 and includes blade 46 adapted to adjust the thickness of the release material layer applied thereto. Housing 70 defining an open ended compartment having a bar of polyethylene material 72 disposed therein, is mounted slidably in frame 74 secured to the electrophotographic printing machine. Drive motor 84 associated with bell crank mechanism 82 reciprocates housing 70 in the direction of arrow 76. In this manner, polyethylene bar 78 melts on contact with heat fuser roll 42 and forms a layer of release material on the outer surface thereof. The thickness of the layer is adjusted by blade 46.
By way of example, a layer of less than one micron thick is preferably applied thereto.
" iO~Y'~qZ
In recapitulation, it is apparent that pursuant to the features of the present invention, as heretofore described, the dispensing apparatus includes a release material dispenser adapted to reciprocate into and out of engagement with a heated fuser roll.
In this manner, the fuser roll is periodically coated with a layer of release material. The thickness of the release material layer -- is regulated by a blade in contact therewith. This type of system insures that the prescribed amount of release material is applied to the fuser roll and that the life of the polyethylene material is optimized in that it remains in the solid state except for that portion thereof contacting the heated fuser roll.
It is, therefore, evident that there has been provided, in accordance with the present invention, an apparatus for dispen-i - sing release material to a fuser roll employed in an electrophoto-graphic printing machine. The apparatus of the present invention fully satisfies the objects, aims and advantages hereinbefore set forth. While this invention has been described in conjunction with specific embodiments thereof, it is evident that many alter-: natives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the appended claims.
~` 1(;~7217Z
``
one of these rollers is heated. The heated fuser roller has the outer surface thereof covered with polytetrafluoroethylene, commonly known as Teflon, to which a release agent such as silicone oil is supplied. Preferably, the Teflon layer has a thickness of about several mils with the thickness of oil being less than one micron. Silicone based oil, which possess a relatively low surface energy, has been found to be useful for heated fuser rolls having an outer surface of Teflon. Generally, a thin layer of silicone oil is applied to the surface of the heated roller to form an interface between the roll surface and powdered image carried on the sheet of support material.
The low surface energy of this layer prevents the particles from transferring to the roller rather than remaining adhered to the sheet of support material. In this manner, the particles are permanently affixed to the sheet of support material, .~ i An alternate approach employs a bare metal heated roller having low molecular weight polyethylene applied thereto as a release agent. This release agent is generally a solid at room temperature. Hereinbefore, the release agent has been maintained in a sump adjacent the heated fuser roller. As the-fuser roller reaches its operating temperature, the release agent melts. The life expectancy of polyethylene release material is greater in the solid state than in the liquid state, --It is, therefore, evident that it is undesirable to maintain the rèlease material in the liquid state an unnecessary duration of time, 1(~7Z172 In accordance with one aspect of this invention there is provided in an electrostatographic printing machine, an apparatus for dispensing a quantity of release material to a heated fuser member operatively associated with a backup member : wherein a sheet of support material having particles thereon passes therebetween with the particles contacting the fuser member, including: means for applying the release material : to the surface of the fuser member; and means for automatically, periodically moving the applying means into and out of engage-ment with the surface of the continuously operating fuser member to apply the release material thereto.
In accordance with another aspect of this invention there is provided a fusing apparatus employed in an electro-statographic printing machine for permanently affixing toner particles to a sheet of support material, including: a heated fuser roll; a backup roll operatively associated with said fuser roll to enable the sheet of support material to pass there-between with the toner particles contacting said fuser roll;
means for applying a release material to the surface of said fuser roll; and means for automatically, periodically moving said applying means into and out of engagement with the surface of said continuously operating fuser roll to apply the release material thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention will become more apparent upon read-ing the following detailed description and upon reference to the drawings, in which:
Figure 1 is a schematic elevational view of an electrophotographic printing machine incorporating the features of the present invention therein;
Figure 2 is a schematic elevational view of one _ 4 _ ~t.~,~i JX
lO~'~lq~
embodiment of a release material dispenser employed in the .; Figure 1 printing machine fuser; and .. Figure 3 is a schematical elevational view of another embodiment of a release material dispenser employed in the Figure 1 printing machine fuser.
" While the present invention will hereinafter be described in connection with various embodiments thereof, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may l.e ;` ' - ' - 4a -" lOqZ17Z
included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
~; For a general understanding of an electrophotographicprinting machine in which the present invention may be incor-porated, reference is had to Figure 1 which depicts schematically the various components thereof. Hereinafter, like reference numerals will be employed throughout to designate like elements.
Although the apparatus for dispensing the release material to a fusing member employed in the electrophotographic printing machine of Figure 1 is particularly well adapted for use therein, it should become evident from the following discussion that it is equally well suited for use in a wide variety of devices and is not necessarily limited in its application to the particular embodiment shown herein.
Since the practice of electrophotographic printing is well known in the art, the various processing stations for pro-ducing a copy of an original document are represented in Figure 1 schematically by the reference letters A through F, inclusive.
As in all electrophotographic printing machines of the type illustrated; a drum 10 having a photoconductive surface 12 entrained about and secured to the exterior circumferential surface thereof is rotated, in the direction of arrow 14, through - 25 the various processing stations. One type of suitable photo-conductive material is described in U.S. Patent No. 2,970,906 issued to Bixby in 1961. In general, photoconductive surface 12 is made from a selenium alloy.
Initially, drum 10 rotates photoconductive surface 12 through charging station A. At charging station A, a corona generating device, indicated generally at 16, sensitizes photo-conductive surface 12. Corona generating device 16 is ` iO'~217Z
positioned closely adjacent to photoconductive ~urface 12. When corona generating device 16 i9 energized, photoconductive surface 12 is charged to a relatively high substantially uniform potential.
One type of suitable corona generating device is described in U.S.
Patent No. 2,836,725 issued to Vyverberg in 1958.
After a portion of photoconductive surface 12 is charged to a substantially uniform potential, the charged portion thereof is rotated to exposure station B. Exposure station B includes an exposure mechanism, indicated generally by the reference numeral 18, having a stationary housing for supporting an original document thereon. The housing comprises a transparent platen such as a glass plate or the like having the original document disposed thereon.
Lamps illuminate the original document. Scanning of the original document may be achieved by oscillating a mirror in a timed re-lationship with the movement of drum 10. The light image of the original document is reflected through a lens onto another mirror which, in turn, transmits the light image through a slit onto the charged portion of photoconductive surface 12. Irradiation of the charged photoconductive surface 12 dissipates the charge thereon recording an electrostatic latent image thereon corresponding to the original document.
~hereafter, drum 10 rotates the electrostatic latent image recorded on photoconductive surface 12 to development station C. Development station C includes a developer unit 20 having a housing with a supply of developer mix therein. The developer mix comprises carrier granules with toner particles adhering thereto.
Preferably, the carrier granules are formed from magnetic material with the toner particles being a heat settable plastic. Developer unit 20 is, preferably, a magnetic brush development system. In such a system, the developer mix is brought through a directional '`
`- flux field to form a brush thereof. The brush of developer mix contacts the electrostatic latent image recorded on photoconductive surface 12. The latent image attracts electrostatically the toner particles from the carrier granules forming a toner powder image on `` 5 photoconductive surface 12.
Prior to continuing with the remaining processing sta-tions, the sheet feeding path will be briefly described. With continued reference to Figure 1, a sheet of support material is advanced by sheet feeding apparatus 22 to transfer station D.
Sheet feeding apparatus 22 includes a feed roll 24 contacting the uppermost sheet of the stack of sheets of support material 26.
Feed roll 24 rotates in the direction of arrow 28 to advance the uppermost sheet from stack 26. Registration rolls 30, rotating in the direction of arrow 32, align and forward the advancing sheet of support material into chute 34. Chute 34 directs the advancing sheet of support material into contact with photoconductive surface 12 in registration with the toner powder image developed thereon.
In this manner, the sheet of support material is positioned to receive the toner powder image from photoconductive surface 12 at transfer station D.
Transfer station D includes a corona generating device 36 adapted to apply a spray of ions onto the side of the sheet of support material opposed from photoconductive surface 12. The toner powder image adhering to photoconductive surface 12 is then attracted therefrom to the sheet of support material in contact therewith. After transferring the toner powder image to the sheet of support material, the sheet of support material is advanced to fusing station E.
Endless belt conveyor 38 advances the sheet of support material with the toner powder image adhering thereon to fusing lOqZlqZ
? station E. Fusing station E includes a fuser assembly, indicated generally by the reference numeral 40. Fuser assembly 40 heats the transferred toner powder image permanently affixing it to the sheet of support material. Fuser assembly 40 includes a heated fuser member or roll, shown generally at 42 and a backup member or roll indicated generally by the reference numeral 44. The sheet of support material with the toner powder image thereon is inter-posed betwaen fuser roll 42 and backup roll 44 with the toner pow-der image contacting fuser roll 42. Dispenser 45 periodically applies release material to fuser roll 42. Blade 46 adjusts the thickness of the release material layer coating fuser roll 42. The detailed structural configuration of fuser assembly 40 will be de-scribed hereinafter with reference to Figures 2 and 3. After the toner powder image is permanently affixed to the sheet of support material, the sheet of support material is advanced by a series of rollers 48 to catch tray 50 for subsequent removal therefrom by the machine operator.
Invariably, after the sheet of support material is separated from photoconductive surface 12, some residual toner particles adhere thereto. These residual toner particles are re-moved from photoconductive surface 12 at cleaning station F.
Cleaning station F includes a cleaning mechanism, designated generally by the reference numeral 51. Cleaning mechanism 51 in-cludes a corona generating device and a brush. Initially, toner particles are brought under the influence of the corona generating device to neutralize the remaining electrostatic charge on photo-conductive surface 12 and the residual toner particles. The neu-tralized toner particles are cleaned from photoconductive surface 12 by the rotatably mounted fibrous brush in contact therewith.
Subsequent to cleaning, a discharge lamp floods photoconductive iOq'~172 surface 12 with light to dissipate any residual charge thereon.
In this manner, the charge on photoconductive surface 12 is returned to the initial level prior to recharging photoconductive surface ; 12 for the next successive imaging cycle.
It is believed that the foregoing description is suf-ficient for purposes of the present application to illustrate the general operation of an electrophotographic printing machine em-bodying the features of the present invention therein. Referring now to the specific subject matter of the present invention, Figure 2 depicts one embodiment of dispensing apparatus 45 asso-ciated with fuser assembly 40.
Fuser assembly 40 comprises a heated fuser roll, indi-cated generally by the reference numeral 42, and a backup roll, indicated generally by the reference numeral 44. Fuser roll 42 cooperates with backup roll 44 to form a nip 52 therebetween ` through which the sheet of support material having a toner powder image thereon passes therethrough. The sheet of support material is arranged to have the toner powder thereon contacting fuser roll 42. A channel shaped base is provided for supporting fuser assembly 40 in the electrophotographic printing machine shown in Figure 1.
Backup roll 44 is mounted rotatably on a pair of brackets secured to the channel shaped base by means of a right angle bracket. As shown, backup roll 44 is adapted to rotate in the direction of arrow 54. Preferably, backup roll 44 includes a rigid steel core or shaft 56 having a Viton elastomeric surface or layer 58 dis-posed thereover and affixed thereto. Shaft 56 is secured rotat-ably on the brackets by a pair of bearings held in place by re-- taining rings. By way of example, backup roll 44 has an overall - dimension of approximately 1.55 inches with a 0.1 inch cover or layer of Viton or other suitable high temperature elastomeric _ g _ material, for example, fluorosilicone or silicone rubber. Backup roll 44 is preferably 15 1/2 inches long to accommodate various ` widths of support material.
A pair of brackets having a generally E-shaped configura-tion are provided for mounting fuser roll 42 rotatably in fuser -; assembly 40. To this end, a pair of ball bearings, one in each of the support brackets, are provided. The bearings are retained in the brackets by means of retaining rings. A pair of end caps are secured to a hollow cylinder or core 60 forming a part of fuser roll 42. The end caps have reduced end portions so as to be mounted in the bearings permitting fuser roll 42 to rotate in the direction of arrow 62. A heating element 64 is supported internally of cylinder 60 for providing thermal energy to cylinder 60 to the operating temperature thereof. Heating element 64 employs a suit-able type of heater for elevating the surface temperature of ` cylinder 60 to operational temperature, i.e. 285F to 295F. By way of example, heating element 64 may include a quartz enevelope having a tungsten resistance heating element disposed therein.
Preferably, cylinder 60 is fabricated from any suitable material capable of efficiently conducting the heat to the external surface thereof. For example, suitable materials are aluminum and alloys thereof, steel, stainless steel, nickel and nickel alloys thereof, nickel plated copper, chromium plated copper, copper and alloys thereof. The resultant fuser roll 42 has an outside diameter pre-ferably of about 1.5 inches with the length thereof about equal to that of backup roll 44. In operation, fuser roll 42 requires about 420 watts peak power with the average power being about 320 watts, and about 100 watts being provided for standby operation. Heating element 64 is supported internally of cylinder 60 by a pair of spring supports which are mounted in an insulator block secured to lO"~'~qZ
support brackets. The free ends of the spring supporting the heating elements are provided with a locating ball while the opposite end of the spring is disposed in contract with an electrical terminal to which electrical wires may be attached 5 for applying electrical energy to heating element 64. The insulator blocks can be secured to the support brackets in any suitable manner, for example by screws. The spring supports and terminals are, preferably riveted to the insula-ting block.
The aforementioned materials from which cylinder 60 are fabricated have a relatively high surface energy. Thus, hot toner material contacting such surfaces would readily wet the surface of cylinder 60. Toner wetting the surface of cylinder 60 is difficult to remove therefrom. Accordingly, 15 there is provided a dispenser 44 containing a material capable of interacting with cylinder 60 in a manner described in U. S.
Patent 3,937,637, issued February 10, 1976, Robin Moser et al.
The material is, preferably, a low molecular weight substance which is a solid at room temperature and has a relatively low 20 viscosity at the operating temperature cylinder 60. An exam-ple of such a material is polyethylene manufactured by Allied Chemical Company and having a designation AC-8 homopolymer. -~
The foregoing polyethylene is employed in dispenser 45. As shown in Figure 2, dispenser 45 includes a supply spool 66 25 mounted rotatably on a frame secured to the electrophotographic machine. Take-up spool 68 is also mounted rotatably on the frame and is spaced from supply spool 66. A web of flexible material 70 is entrained about supply spool 66 and has the leading edge thereof secured to take-up spool 68. A layer of 30 polyethylene material is coated on the surface of flexible material 78 opposed from fuser roll 42. In the operative lOq'~lqZ
- position, the layer of polyethylene material coating web 78 contacts fuser roll 42. Web 78 is articulated so as to move . periodically --'''' . ' ' .
,~ . .
.
;:
;' .
-lla-lOq'~7Z
into and out of engagement with fuser roll 42. An indexing motor operatively associated with take-up spool 68 intermit-tently advances flexible material 78 so as to position new portions of the polyethylene coating opposed from the surface thereof having the polyethylene coating. Rod 80 is recipro-cated to move the polyethylene coating on web 78 into and out of contact with fuser roll 42. Articulation of rod 80 is achieved by a bell crank mechanism 82 associated with drive motor 84. By way of example, rod 80 may articulate at about two revolutions per minute, thereby moving the polyethylene coating on flexible material 78 into and out of contact with fuser roll 42 two times per minute.
Blade 46 adjusts the thickness of the release material layer coating fuser roll 42 so as to maintain a pre-scribed thickness thereof. The detailed structural configu-ration of blade 46 is described in U. S. Patent No. 3,935,836, issued February 3, 1976.
Referring now to Figure 3, there is shown another embodiment for release material dispenser 45. As shown there-in, fuser roll 42 is operatively associated with backup roll44 and includes blade 46 adapted to adjust the thickness of the release material layer applied thereto. Housing 70 defining an open ended compartment having a bar of polyethylene material 72 disposed therein, is mounted slidably in frame 74 secured to the electrophotographic printing machine. Drive motor 84 associated with bell crank mechanism 82 reciprocates housing 70 in the direction of arrow 76. In this manner, polyethylene bar 78 melts on contact with heat fuser roll 42 and forms a layer of release material on the outer surface thereof. The thickness of the layer is adjusted by blade 46.
By way of example, a layer of less than one micron thick is preferably applied thereto.
" iO~Y'~qZ
In recapitulation, it is apparent that pursuant to the features of the present invention, as heretofore described, the dispensing apparatus includes a release material dispenser adapted to reciprocate into and out of engagement with a heated fuser roll.
In this manner, the fuser roll is periodically coated with a layer of release material. The thickness of the release material layer -- is regulated by a blade in contact therewith. This type of system insures that the prescribed amount of release material is applied to the fuser roll and that the life of the polyethylene material is optimized in that it remains in the solid state except for that portion thereof contacting the heated fuser roll.
It is, therefore, evident that there has been provided, in accordance with the present invention, an apparatus for dispen-i - sing release material to a fuser roll employed in an electrophoto-graphic printing machine. The apparatus of the present invention fully satisfies the objects, aims and advantages hereinbefore set forth. While this invention has been described in conjunction with specific embodiments thereof, it is evident that many alter-: natives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the appended claims.
Claims (14)
1. In an electrostatographic printing machine, an apparatus for dispensing a quantity of release material to a heated fuser member operatively associated with a backup member wherein a sheet of support material having particles thereon passes therebetween with the particles contacting the fuser member, including:
means for applying the release material to the surface of the fuser member; and means for automatically, periodically moving the applying means into and out of engagement with the surface of the continuously operating fuser member to apply the release material thereto.
means for applying the release material to the surface of the fuser member; and means for automatically, periodically moving the applying means into and out of engagement with the surface of the continuously operating fuser member to apply the release material thereto.
2. In an electrostatographic printing machine, an apparatus as recited in claim 1, further including a blade member contacting the fuser member to adjust the thickness of the release material layer applied thereto.
3. In an electrostatographic printing machine, an apparatus as recited in claim 2, wherein said applying means includes:
a frame;
a supply spool mounted rotatably on said frame;
a take-up spool spaced from said supply spool and mounted rotatably on said frame; and a web of flexible material entrained about said take-up spool and said supply spool, said web having a layer of release material adhering to one surface thereof.
a frame;
a supply spool mounted rotatably on said frame;
a take-up spool spaced from said supply spool and mounted rotatably on said frame; and a web of flexible material entrained about said take-up spool and said supply spool, said web having a layer of release material adhering to one surface thereof.
4. In an electrostatographic printing machine, an apparatus as recited in claim 3, wherein said applying means further includes means for indexing said take-up spool to periodically advance said web from said supply spool positioning fresh release material in the region opposed from said fuser member.
5. In an electrostatographic printing machine, an apparatus as recited in claim 4, wherein said moving means includes:
a rod mounted slidably on said frame and engaging the other surface of said web; and means for reciprocating said rod to move said web from an inoperative position spaced from the fuser member to an operative position in contact therewith and for returning said rod to the inoperative position.
a rod mounted slidably on said frame and engaging the other surface of said web; and means for reciprocating said rod to move said web from an inoperative position spaced from the fuser member to an operative position in contact therewith and for returning said rod to the inoperative position.
6. In an electrostatographic printing machine, an apparatus as recited in claim 2, wherein said applying means includes:
a frame;
a housing having an open ended chamber therein, said housing being mounted movably on said frame; and a bar of release material disposed in the chamber of said housing with a portion thereof extending outwardly from the open end of the chamber of said housing.
a frame;
a housing having an open ended chamber therein, said housing being mounted movably on said frame; and a bar of release material disposed in the chamber of said housing with a portion thereof extending outwardly from the open end of the chamber of said housing.
7. In an electrostatographic printing machine, an apparatus as recited in claim 6, where said moving means includes means for reciprocating said housing to move said bar of re-lease material from an inoperative position spaced from the fuser member to an operative position in contact therewith and for returning said bar of release material to the inoperative position.
8. A fusing apparatus employed in an electrostatographic printing machine for permanently affixing toner particles to a sheet of support material including:
a heated fuser roll;
a backup roll operatively associated with said fuser roll to enable the sheet of support material to pass therebetween with the toner particles contacting said fuser roll;
means for applying a release material to the surface of said fuser roll; and means for automatically, periodically moving said applying means into and out of engagement with the surface of said continuously operating fuser roll to apply the release material thereto.
a heated fuser roll;
a backup roll operatively associated with said fuser roll to enable the sheet of support material to pass therebetween with the toner particles contacting said fuser roll;
means for applying a release material to the surface of said fuser roll; and means for automatically, periodically moving said applying means into and out of engagement with the surface of said continuously operating fuser roll to apply the release material thereto.
9. An apparatus as recited in claim 8, further including a blade member contacting said fuser roll to adjust the thick-ness of the release material layer applied thereto.
10. An apparatus as recited in claim 9, wherein said applying means includes:
a frame;
a supply spool mounted rotatably on said frame;
a take-up spool spaced from said supply spool and mounted rotatably on said frame; and a web of flexible material entrained about said take-up spool and said supply spool, said web having a layer of release material adhering to one surface thereof.
a frame;
a supply spool mounted rotatably on said frame;
a take-up spool spaced from said supply spool and mounted rotatably on said frame; and a web of flexible material entrained about said take-up spool and said supply spool, said web having a layer of release material adhering to one surface thereof.
11. An apparatus as recited in Claim 10, wherein said applying means further includes means for indexing said take-up spool to periodically advance said web from said supply spool positioning fresh release material in the region opposed from said fuser roll.
12. An apparatus as recited in Claim 11, wherein said moving means includes:
a rod mounted slidably on said frame and engaging the other surface of said web; and means for reciprocating said rod to move said web from an inoperative position spaced from said fuser roll to an opera-tive position in contact therewith and for returning said rod to the inoperative position.
a rod mounted slidably on said frame and engaging the other surface of said web; and means for reciprocating said rod to move said web from an inoperative position spaced from said fuser roll to an opera-tive position in contact therewith and for returning said rod to the inoperative position.
13. An apparatus as recited in Claim 9, wherein said applying means includes:
a frame;
a housing having an open ended chamber therein, said housing being mounted movable on said frame; and a bar of release material disposed in the chamber of said housing with a portion thereof extending outwardly from the open end of the chamber of said housing.
a frame;
a housing having an open ended chamber therein, said housing being mounted movable on said frame; and a bar of release material disposed in the chamber of said housing with a portion thereof extending outwardly from the open end of the chamber of said housing.
14. An apparatus as recited in Claim 13, wherein said moving means includes means for reciprocating said housing to move said bar of release material from an inoperative position spaced from said fuser roll to an operative position in contact there-with and for returning said bar of release material to the in-operative position.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US540731A US3924564A (en) | 1975-01-13 | 1975-01-13 | Fusing apparatus having an articulated release material dispenser |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1072172A true CA1072172A (en) | 1980-02-19 |
Family
ID=24156693
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA239,727A Expired CA1072172A (en) | 1975-01-13 | 1975-11-12 | Fusing apparatus having an articulated release material dispenser |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US3924564A (en) |
| JP (1) | JPS594702B2 (en) |
| CA (1) | CA1072172A (en) |
| DE (1) | DE2552885A1 (en) |
| FR (1) | FR2297449A1 (en) |
| GB (1) | GB1519817A (en) |
| NL (1) | NL7515026A (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2703382C3 (en) * | 1977-01-27 | 1979-07-19 | Siemens Ag, 1000 Berlin Und 8000 Muenchen | Device for supplying separating liquid to the surface of a fixing roller |
| US4079229A (en) * | 1977-02-22 | 1978-03-14 | Rank Xerox Ltd. | Contacting and heating fixing apparatus |
| DE2717391C3 (en) * | 1977-04-20 | 1979-11-29 | Canon K.K., Tokio | Device for applying a toner-repellent liquid to the heating roller of a toner fixing device in a copier |
| JPH0128521Y2 (en) * | 1980-10-27 | 1989-08-30 | ||
| US4393804A (en) * | 1981-11-12 | 1983-07-19 | Minnesota Mining And Manufacturing Company | Apparatus for removing toner from and applying offset preventive liquid to a fixing roller |
| JPH0679189B2 (en) * | 1982-04-20 | 1994-10-05 | キヤノン株式会社 | Web cleaning equipment |
| JPS5973760U (en) * | 1982-11-05 | 1984-05-18 | キヤノン株式会社 | Fusing device |
| EP1752836B1 (en) * | 2005-08-12 | 2008-03-19 | Eastman Kodak Company | Toner fusing device with a supply of fusing oil |
| US8563116B2 (en) * | 2010-09-02 | 2013-10-22 | Xerox Corporation | Fuser manufacture and apparatus |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2313891A (en) * | 1943-03-16 | Izing material to curved surfaces | ||
| US3103459A (en) * | 1963-09-10 | Paperboard corrugating medium treatment | ||
| US2284590A (en) * | 1941-01-15 | 1942-05-26 | Polaroid Corp | Apparatus and method for forming plastic film |
| US3130933A (en) * | 1960-12-15 | 1964-04-28 | Ampex | Magnetic tape apparatus |
| US3637976A (en) * | 1969-06-14 | 1972-01-25 | Ricoh Kk | Fixing device of toner images |
| US3861863A (en) * | 1973-12-19 | 1975-01-21 | Ibm | Fusing apparatus |
-
1975
- 1975-01-13 US US540731A patent/US3924564A/en not_active Expired - Lifetime
- 1975-10-21 GB GB43159/75A patent/GB1519817A/en not_active Expired
- 1975-11-12 CA CA239,727A patent/CA1072172A/en not_active Expired
- 1975-11-25 DE DE19752552885 patent/DE2552885A1/en not_active Withdrawn
- 1975-12-23 FR FR7539448A patent/FR2297449A1/en active Granted
- 1975-12-23 NL NL7515026A patent/NL7515026A/en not_active Application Discontinuation
-
1976
- 1976-01-06 JP JP51001078A patent/JPS594702B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2297449A1 (en) | 1976-08-06 |
| JPS5194237A (en) | 1976-08-18 |
| DE2552885A1 (en) | 1976-07-15 |
| NL7515026A (en) | 1976-03-31 |
| JPS594702B2 (en) | 1984-01-31 |
| GB1519817A (en) | 1978-08-02 |
| FR2297449B1 (en) | 1980-04-30 |
| US3924564A (en) | 1975-12-09 |
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Legal Events
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| MKEX | Expiry |