CA1063666A - Cylindrical high efficiency flash fusing apparatus - Google Patents
Cylindrical high efficiency flash fusing apparatusInfo
- Publication number
- CA1063666A CA1063666A CA237,638A CA237638A CA1063666A CA 1063666 A CA1063666 A CA 1063666A CA 237638 A CA237638 A CA 237638A CA 1063666 A CA1063666 A CA 1063666A
- Authority
- CA
- Canada
- Prior art keywords
- flash
- lamp
- fusing
- sheet
- cylindrical
- 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
Links
- 239000000463 material Substances 0.000 claims abstract description 16
- 230000005855 radiation Effects 0.000 claims abstract description 6
- 239000002245 particle Substances 0.000 claims description 6
- 239000012780 transparent material Substances 0.000 abstract description 2
- 238000000034 method Methods 0.000 description 13
- 239000003570 air Substances 0.000 description 4
- 238000003384 imaging method Methods 0.000 description 2
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 1
- 239000012080 ambient air Substances 0.000 description 1
- -1 as for example Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 231100000206 health hazard Toxicity 0.000 description 1
- 235000012054 meals Nutrition 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 239000011669 selenium Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
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
- G03G15/2007—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat using radiant heat, e.g. infrared lamps, microwave heaters
- G03G15/201—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat using radiant heat, e.g. infrared lamps, microwave heaters of high intensity and short duration, i.e. flash fusing
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Fixing For Electrophotography (AREA)
Abstract
CYLINDRICAL HIGH EFFICIENCY FLASH FUSING APPARATUS
ABSTRACT OF THE DISCLOSURE
A flash fusing apparatus for fusing toner images onto flexible support material in which the support material is transported in a cylindrical path encircling the flash fusing lamp which is positioned along longitudinal axis of the path. The cylindrical path is defined an outer cylin-drical member and an inner cylindrical member encircling the flash fusing lamp. The inner cylindrical member is made of a transparent material. Air pressure is used to advance the support material along its path with the toner images facing inwardly toward the lamp to receive uniform radiation upon pulsing of the lamp.
ABSTRACT OF THE DISCLOSURE
A flash fusing apparatus for fusing toner images onto flexible support material in which the support material is transported in a cylindrical path encircling the flash fusing lamp which is positioned along longitudinal axis of the path. The cylindrical path is defined an outer cylin-drical member and an inner cylindrical member encircling the flash fusing lamp. The inner cylindrical member is made of a transparent material. Air pressure is used to advance the support material along its path with the toner images facing inwardly toward the lamp to receive uniform radiation upon pulsing of the lamp.
Description
i36~;~
The invention relate~ generally to flash fusing and in particular to methods and apparatus for fusing toner images onto flexible support materials. More specifically this invention relates to a xerographic flash fusing apparatus and methods for rapidly and efficiently producing uniform image fixing on a flat support material.
In the xerographic process, a plate, generally ~; comprising a conductive backing upon which is placed a photo-conductive insulating surface, is uniformly charged and the photoconductive surface then exposed to a light image of an ; original to be reproduced. The photoconductive surface iscaused to become conductive under the influence of the light `~ image so as to selectively dissipate the electrostatic charge - found thereon to produce what is developed by means of a; 15 variety of pigmented resin materials specifically made for this purpose which are known in the xerographic art as "toners".
- The toner material is electrostatically~attracted to thelate image areas on the plate in proportion to the charge concentration found thereon. Areas of high charge concen-tration become areas of high toner density while correspondingly low charge image areas become proportionally less dense. The `~ developed image is transferred to a final support material, typically paper, and fixed thereto to for a permanent record or copy of the original.
Many forms of image fixing techni~ue are known in the prior art, the most prevalent of which are vapor fixing, heat fixing, pressure fixing or combinations ' thereof a~ described in U. S. Patent ~lo. 3,539,161. Each ; of these techniques, by itself or in combination ~uffer from deficiencies which make their use impractical or difficult for ~pecific xerographic applications. In :. ~ ,.. -.
.. . .
. , .. , ~ ' , ' , ' .', . ,' ' ' ' ~ ', . ' ', ' ., ' ' : ' "
1~63666 general, it has been difficult to construct an entirely satisfactory heat fuser having a short warm up time, high efficiency, and ease of control. ~ further problem associ-ated with heat fusers has been their tendency to burn or scorch the support material. Pressure fixing methods, whether hot or cold have created problems with image offsetting, resolution degradation and producing consistently a good class of fix. On the other hand, vapor fixing, which typically employs a toxic solvent has proven commer-cially infeasible because of the health hazard involved.
Equipment to sufficiently isolate the fuser from the ~; surrounding ambient air must by its very nature be complex and costly.
With the advent of new materials and new xero-graphic processing techniques, it is now feasible to con-struct automatic xerographic reproducing apparatus capable of producing copies at an extremely rapid rate. Radiant flash fusing is one practical method of image fixing that ,~
will lend itself rea~ily to use in a high speed automatic process as described in U. SO Patent ~o. 3,529,129. The .- main advantage of the flash fuser over the other known methods i9 that the energy, which is propagated in the form of electromagnetic waves, is instantaneously available - and requires no intervening medium for its propagation.
As can be seen, such apparatus does not require long warm up periods nor does the energy have to be transferred through a relatively slow conductive or convective heat transfer mechanism.
Although an extremely rapid transer of energy between the souxce and the receiving body is afforded by .
:, .
,: , ~' ~ , ''`, :
' . , 3L~63~66 the flash fusing process, a major problem with flash fusing as applied to the xerographic fixing art, has been designing apparatus which can fully and efficiently utilize a prepon-derance of the radiant energy emitted by the source during the relatively short flash period. The toner images typically constitutes a relatively small percentage oi the total area of the copy receiving the radiant energy. secause of the properties of most copy materials, as for example, paper most of the energy incident thereon is wasted by being transmitted through the copy or by being reflected away from the fusing area. Another disadvantage associated with the prior art flash fusing apparatus has heretofore been the non-uniformity of image fixing produced. This phenomena .: .
is primarily due to the fact that it is difficult to produce highly uniform irradiance on a large receiving .
surface as for example, a sheet of paper, from a relatively ~ -small source such as a Elash lamp.
While considerable effort has been expended in , . .
providing schemes for enhancing the efficiency and unformity s 20 f fix of electrographic flash fusing systems, most efforts ` have been directed toward the provision of specially con-toured reflecting surfaces which are designed to at least partially surround the flashlamp and thereby conserve .,: , energy via multiple reflections as set forth in U. S~ Patent ~o. 3,529,129, In addition to being costly to fabricate, ~ -~ such reflecting surfaces tend to become contaminated by -~l loose toner particles and thereby necessitate frequent v cleaning operations.
. :
. :
. .
;, , .. ., , . , . , . ... ,. , . . ~ , ~6366~
In accordance with this invention there is provided an improved flash fusing apparatus for fusing toner images onto copy sheet comprising an elongated flash lamp, an outer cylindrically shaped member encircling said : flash lamp along the longitudinal axis thereof, an inner cylindrically shaped member encircling said flash lamp along the longitudinal axis thereof, said inner cylindrical member being made of material :~ transparent to flash radiation, and air pressure means for directing air flow between sàid members for transporting the copy sheet bearing toner - images along the cylindrical path defined by said inner and outer cylindrical members whereupGn energizing said lamp -:
uniform radiation is imparted to the sheet to fuse a toner particle thereto at reduced power input. ~.
` For a better understanding of the invention, re- :
ference is had to the following description of the invention ~` to be read in conjunction with the drawings wherein:
., Figure 1 is a schematic diagram illustrating xero-graphic apparatus embod~ving the fusing apparatus of the invention; and :
Figure 2 is a detailed side view of the preferred ~ embodiment of the flash fusing apparatus of the invention.
;l Referring now to Figure 1, there is illustrated a schematic representation of an automatic xerographic re-producing machine employing the flash fusing apparatus of the present invention. It should be noted that while the apparatus ` - of the present invention will be explained in conjunction with the reusable xerographic process; however, it should be clear ~ 30 to one skilled in the art that the :~'. ' .. , ~ .
;
, :. , . . . ~ . , :
;3666 apparatus of the present invention is not so limited and that the invention has wider application in any environment where it is desirous or necessary to permanently fix resinous toner particles onto a flexible support material.
Because the xerographic copying process is well known and used in the art, the processing steps herein employed will only be briefly described in reference to Figure 1. Basically, the heart oE the machine involves a .` ' .
.~ 1 '' -., ' .
.,~ ' .
.'. . , ,'' '~' , , ' ' ''~''''' . ... ..
.. . .
., , ',, : - 5a - :
"
: . - ,.,: , :, .' : , ,. ,, .. ' ' .; ' " . : . : . . ' .' ': " - ' , ' 36~6 photosensitive plate 10 which is formed in a drum configu-ration. The drum is mounted upon a horizontally aligned support shaft 12 and caused to rotate in the direction indicated so that the photosensitive plate passes sequentially through a series of processing stations. The drum shaped plate basically consists of an outer layer 13 of photo-conductive material, such as selenium or the like that is placed over a grounded substrate 14.
In operation, the plate is initially charged to a uniform potential at a charging station A by means of a corona generator 15. The uniformly charged plate surface is then moved into an imaging station s wherein a flowing light image of the original document, which is supported upon a viewing platen 17 is projected onto the photoconductive plate surface by means of a moving scanning lens element 18 and a pair of mirrors 19 and 20. As a result of the imaging process a latent electrostatic image containing the original ~` subject matter is recorded on the photoconductive plate surface.
,~ 20 The latent image is next transported on the drum through a developing station C wherein the latent image is `l rendered visible by the application of specially prepared charge toner particles which are cascaded over ~he image plate surface. The now visible toner image is then trans-f 25 ported into the next subsequent processing station, an image -~ transfer station D, wherein a sheet of final support material is fed from either one of two supply tray areas, an upper supply tray 24 and a lower supply tray 25, via a sheet ':1 registering and forwarding mechanism 30 in synchronous , 30 moving contact with the visible image carried on the plate ., .
~ -6-~ ~ .
~C~63666 surface. The support sheet and the charged toner image on the drum surface are moved together under a transfer corona generator 27 which serves to electrostatically transfer the toner images in image configuration from the drum surface onto the contacting side of the support sheet. The imaged , sheet is then stripped from the drum surface by means of a ; ~ pickoff finger 28 and directed along a stationary vacuum c ~
transport 29 towards fusing station F ~e the flash fusing apparatus of the invention ~e~r~ e~g~abed-5~-for hi~h efficiency rapid fusing of the toner image onto the support sheet as will as be explained more fully hereinafter.
-~ As noted above, the automatic copying device has-the capability of producing either single sided copy, that is copy bearing a toner image on one side thereof or double sided copy. In a single sided mode of operation, the final support sheets are fed from either one of the two supply trays directly into the image transfer station via the sheet forwarding and registering mechanism 30. Upon the accom-plishment of the transfer step, the image sheet is passed ; 20 through and forwarded directly into a copy tray 29 where the copies are stored and held until such time as the machine operator removes them. On the other hand, when a two sided copying mode of operation is selected, movable transport 26 within the circular paper path, is lowered to the dotted line position as shown in Figure 1 and the upper supply tray, which has previously been emptied of all support material is automatically prepared to accept a copy sheet directed therein. The copy sheets are then fed from the lower support tray to the image transfer station and the image fusing station directly into the upper support -' - . . . .. ... . . . . . . .. . .
~63~66 tray area where the sheets are stored until the machine is further programmed for a second run. Upon the inltialization o~ the second copy run, the movable transport 26 is once again raised to solid line position as shown in Figure 1 and the once image copy sheets are fed again directly from the upper supply tray through the transfer and fusing stations wherein a second image is created on the opposite or previously non-image side of the sheet. After fusing, the two sided copy sheets are fed directly into a copy tray in the manner herein described above.
It is believed that the foregoing description is sufficient for purposes of the present application to show , the general operation of a xerographic or electrostatographic reproducing machine. For a more detailed explanation of the components reference is made to UO S. Patent ~o. 3,645,615 entitled Copying Apparatus.
Referring now to Figure 2 in accordance with the present invention loose toner particles I carried on flexible support sheet S are fused thereto by cylindrically curling the support sheet about the axis of an elongated source of radiant energy in the form of a flash lamp 102.
The support sheet S which is made out of a sheet of copy paper is transported along a circular path by means of low pressure air from one or more air nozzles 110. The ~; 25 cylindrical path is defined by an outer cylindrically i shaped member 114. Cylindrical member 114 is made of transparent material such as quartz so that the radiation from flash lamp 102 is received on the images I carried on the sheet. Desirably the length of the path ground flash lamp 102 is approximately equal to the length of ..
.
~ ., , . , , .: , , ' ' ,' ,: ' : : , ,, ~ .
~ , . . . . . . .. ..
~L~636~6 sheet S. It will be appreciated that the sheet is moved along a circular path such that the toner images I are untouched and continuously face the center of curvature of the path where flash fusing lamp 102 is situated. It will further be appreciated that the flash ~using apparatus has a configuration such that uniform irradiance is insured to all points on the cylindrical surface from the flash lamp 102 provided along the central axis thereof. In this manner it is not necessary to fuse the images onto the sheet in piece meal fashion by energizing the lamp a number of times as different portions of the toner images on the sheet are transported pastthe flash lamp. Flash lamp 102 is energized by a sensing member 120 which is positioned to sense the portion of the web just before completing the circular path defined by cylindrical elements 112 and 114.
` Alternatively the lamp can be energized by a timing circuit as is known by those skilled in the art.
It has been found that a Xenon flash lamp operating at power levels between 600 and 1200 Joules produces very good toner fusion. Pulse durations between ~ 0.25 and l.5 milliseconds were found to provide acceptable : fusing with pulses between 0.5 and lo 2 milliseconds giving ~'~ better fusing result. It has also been found that longer ' ~ pulses of energy are required as the power level increases.
Power input to the flash lamp ~ is provided by any suitable ` power supply such as a DC source with an adjustable voltage.
-` It will be appreciated that the energy described would be the power input to the flash fusing lamp itself and not the energy that actually strikes the paper. The _ 9 _ ., .
,:
:. - . i ~, , .. :j , , : , . . ~ . ~ , : , .
~63666 energy to fuse toner in this case would be about 3~5 Joules/in2 incident on the paper. Thus for a 9'~x12" area this would be 378 Joules. In other words the lamp is typically about 60 to 70 percent efficient bringing the power to 600 Joules.
Therefore, 600 Joules normally has to be supplied to the lamp.
While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention~
.~
, ~
;~
' .
.~
.
' ~' :, --10--, . . .
:, , ., , . . ~ , , . ., :.: . .
The invention relate~ generally to flash fusing and in particular to methods and apparatus for fusing toner images onto flexible support materials. More specifically this invention relates to a xerographic flash fusing apparatus and methods for rapidly and efficiently producing uniform image fixing on a flat support material.
In the xerographic process, a plate, generally ~; comprising a conductive backing upon which is placed a photo-conductive insulating surface, is uniformly charged and the photoconductive surface then exposed to a light image of an ; original to be reproduced. The photoconductive surface iscaused to become conductive under the influence of the light `~ image so as to selectively dissipate the electrostatic charge - found thereon to produce what is developed by means of a; 15 variety of pigmented resin materials specifically made for this purpose which are known in the xerographic art as "toners".
- The toner material is electrostatically~attracted to thelate image areas on the plate in proportion to the charge concentration found thereon. Areas of high charge concen-tration become areas of high toner density while correspondingly low charge image areas become proportionally less dense. The `~ developed image is transferred to a final support material, typically paper, and fixed thereto to for a permanent record or copy of the original.
Many forms of image fixing techni~ue are known in the prior art, the most prevalent of which are vapor fixing, heat fixing, pressure fixing or combinations ' thereof a~ described in U. S. Patent ~lo. 3,539,161. Each ; of these techniques, by itself or in combination ~uffer from deficiencies which make their use impractical or difficult for ~pecific xerographic applications. In :. ~ ,.. -.
.. . .
. , .. , ~ ' , ' , ' .', . ,' ' ' ' ~ ', . ' ', ' ., ' ' : ' "
1~63666 general, it has been difficult to construct an entirely satisfactory heat fuser having a short warm up time, high efficiency, and ease of control. ~ further problem associ-ated with heat fusers has been their tendency to burn or scorch the support material. Pressure fixing methods, whether hot or cold have created problems with image offsetting, resolution degradation and producing consistently a good class of fix. On the other hand, vapor fixing, which typically employs a toxic solvent has proven commer-cially infeasible because of the health hazard involved.
Equipment to sufficiently isolate the fuser from the ~; surrounding ambient air must by its very nature be complex and costly.
With the advent of new materials and new xero-graphic processing techniques, it is now feasible to con-struct automatic xerographic reproducing apparatus capable of producing copies at an extremely rapid rate. Radiant flash fusing is one practical method of image fixing that ,~
will lend itself rea~ily to use in a high speed automatic process as described in U. SO Patent ~o. 3,529,129. The .- main advantage of the flash fuser over the other known methods i9 that the energy, which is propagated in the form of electromagnetic waves, is instantaneously available - and requires no intervening medium for its propagation.
As can be seen, such apparatus does not require long warm up periods nor does the energy have to be transferred through a relatively slow conductive or convective heat transfer mechanism.
Although an extremely rapid transer of energy between the souxce and the receiving body is afforded by .
:, .
,: , ~' ~ , ''`, :
' . , 3L~63~66 the flash fusing process, a major problem with flash fusing as applied to the xerographic fixing art, has been designing apparatus which can fully and efficiently utilize a prepon-derance of the radiant energy emitted by the source during the relatively short flash period. The toner images typically constitutes a relatively small percentage oi the total area of the copy receiving the radiant energy. secause of the properties of most copy materials, as for example, paper most of the energy incident thereon is wasted by being transmitted through the copy or by being reflected away from the fusing area. Another disadvantage associated with the prior art flash fusing apparatus has heretofore been the non-uniformity of image fixing produced. This phenomena .: .
is primarily due to the fact that it is difficult to produce highly uniform irradiance on a large receiving .
surface as for example, a sheet of paper, from a relatively ~ -small source such as a Elash lamp.
While considerable effort has been expended in , . .
providing schemes for enhancing the efficiency and unformity s 20 f fix of electrographic flash fusing systems, most efforts ` have been directed toward the provision of specially con-toured reflecting surfaces which are designed to at least partially surround the flashlamp and thereby conserve .,: , energy via multiple reflections as set forth in U. S~ Patent ~o. 3,529,129, In addition to being costly to fabricate, ~ -~ such reflecting surfaces tend to become contaminated by -~l loose toner particles and thereby necessitate frequent v cleaning operations.
. :
. :
. .
;, , .. ., , . , . , . ... ,. , . . ~ , ~6366~
In accordance with this invention there is provided an improved flash fusing apparatus for fusing toner images onto copy sheet comprising an elongated flash lamp, an outer cylindrically shaped member encircling said : flash lamp along the longitudinal axis thereof, an inner cylindrically shaped member encircling said flash lamp along the longitudinal axis thereof, said inner cylindrical member being made of material :~ transparent to flash radiation, and air pressure means for directing air flow between sàid members for transporting the copy sheet bearing toner - images along the cylindrical path defined by said inner and outer cylindrical members whereupGn energizing said lamp -:
uniform radiation is imparted to the sheet to fuse a toner particle thereto at reduced power input. ~.
` For a better understanding of the invention, re- :
ference is had to the following description of the invention ~` to be read in conjunction with the drawings wherein:
., Figure 1 is a schematic diagram illustrating xero-graphic apparatus embod~ving the fusing apparatus of the invention; and :
Figure 2 is a detailed side view of the preferred ~ embodiment of the flash fusing apparatus of the invention.
;l Referring now to Figure 1, there is illustrated a schematic representation of an automatic xerographic re-producing machine employing the flash fusing apparatus of the present invention. It should be noted that while the apparatus ` - of the present invention will be explained in conjunction with the reusable xerographic process; however, it should be clear ~ 30 to one skilled in the art that the :~'. ' .. , ~ .
;
, :. , . . . ~ . , :
;3666 apparatus of the present invention is not so limited and that the invention has wider application in any environment where it is desirous or necessary to permanently fix resinous toner particles onto a flexible support material.
Because the xerographic copying process is well known and used in the art, the processing steps herein employed will only be briefly described in reference to Figure 1. Basically, the heart oE the machine involves a .` ' .
.~ 1 '' -., ' .
.,~ ' .
.'. . , ,'' '~' , , ' ' ''~''''' . ... ..
.. . .
., , ',, : - 5a - :
"
: . - ,.,: , :, .' : , ,. ,, .. ' ' .; ' " . : . : . . ' .' ': " - ' , ' 36~6 photosensitive plate 10 which is formed in a drum configu-ration. The drum is mounted upon a horizontally aligned support shaft 12 and caused to rotate in the direction indicated so that the photosensitive plate passes sequentially through a series of processing stations. The drum shaped plate basically consists of an outer layer 13 of photo-conductive material, such as selenium or the like that is placed over a grounded substrate 14.
In operation, the plate is initially charged to a uniform potential at a charging station A by means of a corona generator 15. The uniformly charged plate surface is then moved into an imaging station s wherein a flowing light image of the original document, which is supported upon a viewing platen 17 is projected onto the photoconductive plate surface by means of a moving scanning lens element 18 and a pair of mirrors 19 and 20. As a result of the imaging process a latent electrostatic image containing the original ~` subject matter is recorded on the photoconductive plate surface.
,~ 20 The latent image is next transported on the drum through a developing station C wherein the latent image is `l rendered visible by the application of specially prepared charge toner particles which are cascaded over ~he image plate surface. The now visible toner image is then trans-f 25 ported into the next subsequent processing station, an image -~ transfer station D, wherein a sheet of final support material is fed from either one of two supply tray areas, an upper supply tray 24 and a lower supply tray 25, via a sheet ':1 registering and forwarding mechanism 30 in synchronous , 30 moving contact with the visible image carried on the plate ., .
~ -6-~ ~ .
~C~63666 surface. The support sheet and the charged toner image on the drum surface are moved together under a transfer corona generator 27 which serves to electrostatically transfer the toner images in image configuration from the drum surface onto the contacting side of the support sheet. The imaged , sheet is then stripped from the drum surface by means of a ; ~ pickoff finger 28 and directed along a stationary vacuum c ~
transport 29 towards fusing station F ~e the flash fusing apparatus of the invention ~e~r~ e~g~abed-5~-for hi~h efficiency rapid fusing of the toner image onto the support sheet as will as be explained more fully hereinafter.
-~ As noted above, the automatic copying device has-the capability of producing either single sided copy, that is copy bearing a toner image on one side thereof or double sided copy. In a single sided mode of operation, the final support sheets are fed from either one of the two supply trays directly into the image transfer station via the sheet forwarding and registering mechanism 30. Upon the accom-plishment of the transfer step, the image sheet is passed ; 20 through and forwarded directly into a copy tray 29 where the copies are stored and held until such time as the machine operator removes them. On the other hand, when a two sided copying mode of operation is selected, movable transport 26 within the circular paper path, is lowered to the dotted line position as shown in Figure 1 and the upper supply tray, which has previously been emptied of all support material is automatically prepared to accept a copy sheet directed therein. The copy sheets are then fed from the lower support tray to the image transfer station and the image fusing station directly into the upper support -' - . . . .. ... . . . . . . .. . .
~63~66 tray area where the sheets are stored until the machine is further programmed for a second run. Upon the inltialization o~ the second copy run, the movable transport 26 is once again raised to solid line position as shown in Figure 1 and the once image copy sheets are fed again directly from the upper supply tray through the transfer and fusing stations wherein a second image is created on the opposite or previously non-image side of the sheet. After fusing, the two sided copy sheets are fed directly into a copy tray in the manner herein described above.
It is believed that the foregoing description is sufficient for purposes of the present application to show , the general operation of a xerographic or electrostatographic reproducing machine. For a more detailed explanation of the components reference is made to UO S. Patent ~o. 3,645,615 entitled Copying Apparatus.
Referring now to Figure 2 in accordance with the present invention loose toner particles I carried on flexible support sheet S are fused thereto by cylindrically curling the support sheet about the axis of an elongated source of radiant energy in the form of a flash lamp 102.
The support sheet S which is made out of a sheet of copy paper is transported along a circular path by means of low pressure air from one or more air nozzles 110. The ~; 25 cylindrical path is defined by an outer cylindrically i shaped member 114. Cylindrical member 114 is made of transparent material such as quartz so that the radiation from flash lamp 102 is received on the images I carried on the sheet. Desirably the length of the path ground flash lamp 102 is approximately equal to the length of ..
.
~ ., , . , , .: , , ' ' ,' ,: ' : : , ,, ~ .
~ , . . . . . . .. ..
~L~636~6 sheet S. It will be appreciated that the sheet is moved along a circular path such that the toner images I are untouched and continuously face the center of curvature of the path where flash fusing lamp 102 is situated. It will further be appreciated that the flash ~using apparatus has a configuration such that uniform irradiance is insured to all points on the cylindrical surface from the flash lamp 102 provided along the central axis thereof. In this manner it is not necessary to fuse the images onto the sheet in piece meal fashion by energizing the lamp a number of times as different portions of the toner images on the sheet are transported pastthe flash lamp. Flash lamp 102 is energized by a sensing member 120 which is positioned to sense the portion of the web just before completing the circular path defined by cylindrical elements 112 and 114.
` Alternatively the lamp can be energized by a timing circuit as is known by those skilled in the art.
It has been found that a Xenon flash lamp operating at power levels between 600 and 1200 Joules produces very good toner fusion. Pulse durations between ~ 0.25 and l.5 milliseconds were found to provide acceptable : fusing with pulses between 0.5 and lo 2 milliseconds giving ~'~ better fusing result. It has also been found that longer ' ~ pulses of energy are required as the power level increases.
Power input to the flash lamp ~ is provided by any suitable ` power supply such as a DC source with an adjustable voltage.
-` It will be appreciated that the energy described would be the power input to the flash fusing lamp itself and not the energy that actually strikes the paper. The _ 9 _ ., .
,:
:. - . i ~, , .. :j , , : , . . ~ . ~ , : , .
~63666 energy to fuse toner in this case would be about 3~5 Joules/in2 incident on the paper. Thus for a 9'~x12" area this would be 378 Joules. In other words the lamp is typically about 60 to 70 percent efficient bringing the power to 600 Joules.
Therefore, 600 Joules normally has to be supplied to the lamp.
While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention~
.~
, ~
;~
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.~
.
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Claims (4)
1. An improved flash fusing apparatus for fusing toner images onto copy sheet comprising an elongated flash lamp, an outer cylindrically shaped member encircling said flash lamp along the longitudinal axis thereof, an inner cylindrically shaped member encircling said flash lamp along the longitudinal axis thereof, said inner cylindrical member being made of material transparent to flash radiation, and air pressure means for directing air flow between said members for transporting the copy sheet bearing toner images along the cylindrical path defined by said inner and outer cylindrical members whereupon energizing said lamp uniform radiation is imparted to the sheet to fuse a toner particle thereto at reduced power input.
2. Apparatus according to claim 1 including sensing means for detecting a predetermined portion of sheet to provide a signal to energize the flash lamp.
3. Apparatus according to claim 1 wherein said air pressure means includes at least one air nozzle positioned in the cylindrical path.
4. Apparatus according to claim 1 wherein the length of the cylindrical path is substantially the length of the copy sheet.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US516041A US3903394A (en) | 1974-10-18 | 1974-10-18 | High efficiency flash fusing apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1063666A true CA1063666A (en) | 1979-10-02 |
Family
ID=24053879
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA237,638A Expired CA1063666A (en) | 1974-10-18 | 1975-10-15 | Cylindrical high efficiency flash fusing apparatus |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US3903394A (en) |
| CA (1) | CA1063666A (en) |
| GB (1) | GB1523908A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4004127A (en) * | 1976-03-02 | 1977-01-18 | Xerox Corporation | On line fusing system |
| JPS53101439A (en) * | 1976-12-23 | 1978-09-04 | Riso Kagaku Corp | Exposure device for photooanddthermosensive copying |
| US4126565A (en) * | 1976-12-27 | 1978-11-21 | Xerox Corporation | Toners for color flash fusers containing a permanent colorant and a heat sensitive dye |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3311040A (en) * | 1964-04-08 | 1967-03-28 | Minolta Camera Kk | Heat-developing apparatus for positive picture copiers |
| US3371915A (en) * | 1965-08-13 | 1968-03-05 | Fuji Photo Film Co Ltd | Treatment machine for heat treatment of sensitive material |
| US3436523A (en) * | 1966-07-27 | 1969-04-01 | Ricoh Kk | Developing mechanism for heat developable light sensitive copy paper |
| US3464680A (en) * | 1966-12-30 | 1969-09-02 | Konishiroku Photo Ind | Heating apparatus for sheet-like material |
-
1974
- 1974-10-18 US US516041A patent/US3903394A/en not_active Expired - Lifetime
-
1975
- 1975-10-02 GB GB40330/75A patent/GB1523908A/en not_active Expired
- 1975-10-15 CA CA237,638A patent/CA1063666A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US3903394A (en) | 1975-09-02 |
| GB1523908A (en) | 1978-09-06 |
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