CA1053317A - Selective fuser for electrophotographic copier - Google Patents
Selective fuser for electrophotographic copierInfo
- Publication number
- CA1053317A CA1053317A CA196,149A CA196149A CA1053317A CA 1053317 A CA1053317 A CA 1053317A CA 196149 A CA196149 A CA 196149A CA 1053317 A CA1053317 A CA 1053317A
- Authority
- CA
- Canada
- Prior art keywords
- fuser
- documents
- signal
- signals
- accordance
- 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
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
Abstract
ABSTRACT OF THE DISCLOSURE
Selective fuser apparatus and control therefor for use in xerographic reproducing apparatus. In the xerographic repro-ducing apparatus contemplated, documents are scanned and select-ively reproduced in accordance with coded information carried thereby. The coded information is utilized for generating print o select signals when a particular document is to be reproduced and when a document is not to be reproduced a non print or non-select -signal is generated. A temperature sensor is provided for sensing..
the ambient temperature in the fuser assembly, Accordingly, the fuser energization is controlled in accordance with the number of non-select signals occuring between successive print signals and the ambient temperature of the fuser. Where a relatively large number of non-select signals and/or the ambient temperature in the fuser is low a greater quantity of thermal energy input to the fuser assembly is required.
Selective fuser apparatus and control therefor for use in xerographic reproducing apparatus. In the xerographic repro-ducing apparatus contemplated, documents are scanned and select-ively reproduced in accordance with coded information carried thereby. The coded information is utilized for generating print o select signals when a particular document is to be reproduced and when a document is not to be reproduced a non print or non-select -signal is generated. A temperature sensor is provided for sensing..
the ambient temperature in the fuser assembly, Accordingly, the fuser energization is controlled in accordance with the number of non-select signals occuring between successive print signals and the ambient temperature of the fuser. Where a relatively large number of non-select signals and/or the ambient temperature in the fuser is low a greater quantity of thermal energy input to the fuser assembly is required.
Description
\
3;~
~ACKGROU~D OF THE INVENTION
This invention relates to electroscopic fusing techniques and, more particularly, to a method of se]ectively regulating a fuser assembly and the apparatus therefor.
Electrophotographic reproducing techniques of the type described in detail in U.S. Patent No. 2,297,691 issued to Chester F. Carlson, form electrostatic latent images of original documents by selectively dissipating a uniform layer of electrostatic charges deposited on the surface of a photoxeceptor la in accordance with modulated radiation image thereon. The . .
electrostatic latent image thus formed is developed and trans-ferred to a support surface to form a final copy of an original document. The development process is effected by applying electroscopic particles, conventionally known as toners, to the electrostatic latent image whereat such particles are electro-statically attracted to the latent image in proportion to the amount of charge comprising such image. Hence the areas of small charge concentration are developed to form areas of low particle density, while areas of greater charge concentration are developed to form areas where in the particle density is greater. Once transferred ~o the support surface, the developed irnage may be permanently fixed thereto ~y heat fusing techniques wherein the indi-~idual particles soften and coalesce when heated so as to readily adhere to the support surface.
Various modifications in fusing techniques have hereto-fore been developed which achieve diverse results, such techniques including selective fusing. In selective fusing, toner areas admitting of a higher density are preferentially fused leaving low density or background areas unfused. Unfused toner particles comprising background can then be removed to yield a cleaner, more readabl~ copy. Selective fusing also contemplates the irregular, non-continuous, non-periodic operation of a fuser -. .. . ~
~S33~7 assembly in response to particular predetermined conditionsO In this regard, selective fusing techniques are readily adapted to cooperate with selective xerographic printing techniques. Thus, if copies of only selected ones of successively scanned original documents are to be printed, a fuser assembly must be energized for each time the developed image o a selected original is transferred to the support surface. It is appreciated that if the support surface comprises a web of suitable material, such as paper, the web will be transported to the fuser assembly in an irregular manner corresponding to the scanning of the unique originals to be reproduced~ Consequently, scorching or burning of the web that is stationarily disposed within the fuser assembly must be avoided, while, at the same time, sufficient heat must be accumulated in the assembly to assure an adequate fusing of the toner areas to the web.
In the implementation of either of the a~orementioned fusing techniques, i.e. the fusing of toner areas af a high ~:
aensity to the exclusion of relatively low density areas on a continuously moving support surface or the fusing of successive toner areas disposed in image configuration upon an irregularly moving support surface, it has been found, ~hat in addition to the problem of scorching the support surface, it is necessary to provide for a delay in raising the temperature of the ~user assembly to a proper value in response to the enexgization thereof, the accumulation of heat within the assembly during the duration of energization thereof and the temperature to which the assembly has cooled in the time that has expired since the immediately preceeding energization thereof.
Prior attemp~s at regula~ing a fuser assembly of the type herein contemplated in order t~ acc~unt for the foregoing has resulted in regulation without due consideration to the actual temperature in the fuser a~sembly.
': ' '
3;~
~ACKGROU~D OF THE INVENTION
This invention relates to electroscopic fusing techniques and, more particularly, to a method of se]ectively regulating a fuser assembly and the apparatus therefor.
Electrophotographic reproducing techniques of the type described in detail in U.S. Patent No. 2,297,691 issued to Chester F. Carlson, form electrostatic latent images of original documents by selectively dissipating a uniform layer of electrostatic charges deposited on the surface of a photoxeceptor la in accordance with modulated radiation image thereon. The . .
electrostatic latent image thus formed is developed and trans-ferred to a support surface to form a final copy of an original document. The development process is effected by applying electroscopic particles, conventionally known as toners, to the electrostatic latent image whereat such particles are electro-statically attracted to the latent image in proportion to the amount of charge comprising such image. Hence the areas of small charge concentration are developed to form areas of low particle density, while areas of greater charge concentration are developed to form areas where in the particle density is greater. Once transferred ~o the support surface, the developed irnage may be permanently fixed thereto ~y heat fusing techniques wherein the indi-~idual particles soften and coalesce when heated so as to readily adhere to the support surface.
Various modifications in fusing techniques have hereto-fore been developed which achieve diverse results, such techniques including selective fusing. In selective fusing, toner areas admitting of a higher density are preferentially fused leaving low density or background areas unfused. Unfused toner particles comprising background can then be removed to yield a cleaner, more readabl~ copy. Selective fusing also contemplates the irregular, non-continuous, non-periodic operation of a fuser -. .. . ~
~S33~7 assembly in response to particular predetermined conditionsO In this regard, selective fusing techniques are readily adapted to cooperate with selective xerographic printing techniques. Thus, if copies of only selected ones of successively scanned original documents are to be printed, a fuser assembly must be energized for each time the developed image o a selected original is transferred to the support surface. It is appreciated that if the support surface comprises a web of suitable material, such as paper, the web will be transported to the fuser assembly in an irregular manner corresponding to the scanning of the unique originals to be reproduced~ Consequently, scorching or burning of the web that is stationarily disposed within the fuser assembly must be avoided, while, at the same time, sufficient heat must be accumulated in the assembly to assure an adequate fusing of the toner areas to the web.
In the implementation of either of the a~orementioned fusing techniques, i.e. the fusing of toner areas af a high ~:
aensity to the exclusion of relatively low density areas on a continuously moving support surface or the fusing of successive toner areas disposed in image configuration upon an irregularly moving support surface, it has been found, ~hat in addition to the problem of scorching the support surface, it is necessary to provide for a delay in raising the temperature of the ~user assembly to a proper value in response to the enexgization thereof, the accumulation of heat within the assembly during the duration of energization thereof and the temperature to which the assembly has cooled in the time that has expired since the immediately preceeding energization thereof.
Prior attemp~s at regula~ing a fuser assembly of the type herein contemplated in order t~ acc~unt for the foregoing has resulted in regulation without due consideration to the actual temperature in the fuser a~sembly.
': ' '
- 2 ~
Thus, in ~ccordance with the present teachings, an apparatus is provided for regulating the fusing of electro-scopic particles to successive portions of a support base moved through the fuser assembly wherein the fuser assembly includes means for softening the electroscopic particle and control means therefor, the electroscopic particles correspond to documents selectively reproduced from a series o~ documents scanned for such purpose. The apparatus comprises means for sensing at least one ambient condition of the fuser assembly 1~ with means provided for generating print signals for the documen~ to be selectively reproduced and means provided for varying the operation of the control means in accordance with the number of documents not selected for reproduction occurring intermediate successive selected documents and in accordance with at least one ambient condition.
In accordance with a more specific embodiment within the present teachings, a fuser apparatus i5 pxovided for use in a xerographic reproducing apparatus for fusing electroscopic particles to successive portions of the support base intermittently moved through the fuser apparatus, the electroscopic particles correspond to reproduced documents selected from a series of documents scanned for such purposes.
The apparatus comprises means in the ~user apparatus for emitting radiant energy, means provided for generating signals for the documents selected for reproduction with power supply means provided operatively coupled through the means ~or emitting radiant energy and means provided for regulating the power supply in accordance with the number of documents not selected for reproduction intermediate successive selected documents and in accordance with the temperature sensed by a temperature ' sensing means.
' '
Thus, in ~ccordance with the present teachings, an apparatus is provided for regulating the fusing of electro-scopic particles to successive portions of a support base moved through the fuser assembly wherein the fuser assembly includes means for softening the electroscopic particle and control means therefor, the electroscopic particles correspond to documents selectively reproduced from a series o~ documents scanned for such purpose. The apparatus comprises means for sensing at least one ambient condition of the fuser assembly 1~ with means provided for generating print signals for the documen~ to be selectively reproduced and means provided for varying the operation of the control means in accordance with the number of documents not selected for reproduction occurring intermediate successive selected documents and in accordance with at least one ambient condition.
In accordance with a more specific embodiment within the present teachings, a fuser apparatus i5 pxovided for use in a xerographic reproducing apparatus for fusing electroscopic particles to successive portions of the support base intermittently moved through the fuser apparatus, the electroscopic particles correspond to reproduced documents selected from a series of documents scanned for such purposes.
The apparatus comprises means in the ~user apparatus for emitting radiant energy, means provided for generating signals for the documents selected for reproduction with power supply means provided operatively coupled through the means ~or emitting radiant energy and means provided for regulating the power supply in accordance with the number of documents not selected for reproduction intermediate successive selected documents and in accordance with the temperature sensed by a temperature ' sensing means.
' '
-3-~os;33:~7 Thi~ inventlon will ~e mo~e cleaxly undexstood by reference to the followin~ detailed description of an ex~mplary em~odiment thereo~ in conjunction with the accompanying drawings in which:
Figure 1 is a schematic diagram of a selective printing apparatus with which the instrument invention may be utilized;
Figure 2A is a schematic diagram of a con~en-tional heating element that may be utilized in the fuser assembly of Figure 1 and variable supply of energy therefor;
Figure 2B depicts an AC form that is helpful in explaining the operation of the electrical circuit illustrated in Figure 2A;
Figure 3 is a schematic illustration of logic circuitry that may be utilized to selectively regulate the variable supply o~ energy depicted in Figure 2A.
DETAIIIED DESCRIPTIOM OF THE INVENTION
For a general understanding of the selective pri~ting apparatus in which the instant invention may be incorpoxated, reference is made to Figure 1, in which some of the various system components for the apparatus are schematically illustrated. ~he printing apparatus illustrated herein employs electrophotographic concepts originally disclosed in U.S. Patent No. 2,297,691, which issued in the name of Chester F. Carlson~ Accordingly, '.',,' ' `
''``', ' ,, ' .
~
Figure 1 is a schematic diagram of a selective printing apparatus with which the instrument invention may be utilized;
Figure 2A is a schematic diagram of a con~en-tional heating element that may be utilized in the fuser assembly of Figure 1 and variable supply of energy therefor;
Figure 2B depicts an AC form that is helpful in explaining the operation of the electrical circuit illustrated in Figure 2A;
Figure 3 is a schematic illustration of logic circuitry that may be utilized to selectively regulate the variable supply o~ energy depicted in Figure 2A.
DETAIIIED DESCRIPTIOM OF THE INVENTION
For a general understanding of the selective pri~ting apparatus in which the instant invention may be incorpoxated, reference is made to Figure 1, in which some of the various system components for the apparatus are schematically illustrated. ~he printing apparatus illustrated herein employs electrophotographic concepts originally disclosed in U.S. Patent No. 2,297,691, which issued in the name of Chester F. Carlson~ Accordingly, '.',,' ' `
''``', ' ,, ' .
~
-4- ~ :
:
; '`
~ ~33~7 the selective prin~ing apparatus comprises an electrostatic system wherein a light image of an original to be reproduced is projected onto the sensitized surface of a photosensitive plate to form an electrostatic latent image thereon. Thereafter, the latent image is developed with an oppositely charged ;
developing material comprising electroscopic particles, known as toner particles, to form a powder image corresponding to the latent image on the photosensitive surface. The powder image is ;
then electrostatically transferred to a support base to which `
it may be fixed by a fuser assembly whereby the powder is caused to adhere ~ermanently to the support surface.
In the illustrated apparatus, visible document information is provided on each of the data cards 1 that are successively ~^
transported from a feeder tray 2 to a restack tray 49. The data cards are transported in timed sequence with respect to the operation of the remaining apparatus illustrated herein, and are caused to traverse detecting station A, scanning station B and slit exposure device 34 in successive order. Each data card is additionally provided with pre-coded information thereon, which pre-coded information is determinative of the selective printing of the visible document information carried by the card. More particularly, if the pre-coded information scanned from the card by scanning station B admits of a particular pre-condition, ;
additional logic circuitry, not shown, responds to such scanned inormation to derive a print signal. The thus derived print signal is operated upon in timed sequence to provide a direct correspondence between the sequential manipula-tion of such print signal and the particular operation performed by the apparatus illustrated in Figure 1.
3~ The sequential passage of data cards from the scanning station 3 through the projection system 33 to the restack tray ~9 `~
will cause optical images of the visible document information on 33~L7 each of the data cards passing through the slit exposure device 34 to be sequentially projected upon the surface of photosensitive drum 20. If desired, the projected images may admit of magnifica-tion. The photosensitive drum 2~ is continuously driven at a constant angular velocity such that the sur-face thereof is moving at a velocity equal to that of data cards moving past the exposure device 34. In moving in the direction indicated by the arrow prior to reaching the exposure station C, that portion of the photosensitive drum being exposed is uniformly charged by a corona discharge station G. The exposure of the photosensitive drum surface to t!e light image selectively dissipates the electro-static charge on the surface thereof in the area struck by light, thereby forming an electrostatic latent image in image configuration corresponding to the light image projected from the visible document information on the data card transported through the slit exposure device 34 As the photosensi-tive drum surface continues its movement, electrostatic image passes through a developing station D in which there is positioned a developing apparatus generally indicated by the reference numeral 13.
In the electrostatic latent image passing through develo-opment station D is derived from a data card having a print signal associated therewith, such print signal is utilized to activate the developer motor 24 such that the developing apparatus may be operated to develop such electrostatic latent image. In contra-distinction thereto, should the electrostatic latent image passing through the developing station D be derived from a data card not `
having a print signal associated therewith, the developer motor ~ -24 is not activated and such electrostatic latent image is not developed. It is therefore, appreciated that the developing 3a apparatus 13 is operated in an intermittent manner wherein only those electrostatic images derived from data cards having print ~S33~7 signals associated therewith are developed at station ~. As the photosensitive drum 20 continues to rotate in the directlon indi-cated by the arrow, successive areas thereo~F will be provided with image information distributed thereon in the form of a distri-buted electrostatic charge pattern. However, only selec-ted ones o~ successive areas ~ e developed. As illustrated herein, the developing appartus 13 may typically be provided with electro-scopic particles that are cascaded across the surface of photosen-sitive drum 20, ~hich particles are attracted electrostatically to the distributed charge pattern to form powder images.
The developed electrostatic image is transported by the photosensitive drum 20 to a transfer station E located at a point of tangency on the photosensitive drum whereat a support base 9 is intermittently moved at a speed in synchronism with the moving drum in order to accomplish transfer of the developed image.
The support base 9 is here depicted as a web comprised of suitable material such as paper, plastic or the like, that it is driven from a supply 13 to selective transfer mechanism 25 through ~user assembly 40, about strip driving means 16 and into a strip receiving tray 14. It will be appreciated that the support base 9 in addition to comprising paper and plastic in the form of a web, the support base 9 may also comprise a continuous strip of paper having gummed labels supported thereon which can be readily removed ;~
from the web subsequent to the reproducing operation. At the -time a developed image having a print signal associated therewith arrives at the transfer station E, the associated print signal is operated upon to cause the web driving means 16 to be activated, thereby transporting the support base 9 at a velocity equal to the surface velocity of the photosensitive drum 20. Moreover, the print signal is used to operate the selective transfer mechanism 25 whereby the support base 3 engages the photosensitive drum 20 in an arc contact. In addition, charging means 30 may ~ [)S~3~7 be energized to provide a charge on the support base 9 prior to its engagement with the photosensitive drum so that the developed image may be electrostatically transferred from the surface of drum 20 to the adjacent side of the support base as such support base is brought into contact therewith. Thus, it is seen, that each developed electrostatic image is transferred to the support base 9; and the support base is, therefore, advanced in an inter-mittant manner in accordance with each print signal that is derived from the scanning info~mation carried by the transported data cards.
After transfer, the support base 9 is transported to the fuser assembly, generally indicated by the reference number 40, wherein the developed and transferred powder image on the support base is permanently fixed thereto. The fuser assembly 40 may com~
prise conventional apparatus capable of carrying out various fusing techniques such as oven fusing, hot air fusing, radiant fusing, hot and cold pressure fixing and fusing and flash fusing as well as other known techniques. Merely for the purpose of explanation, it will be assumed that the fuser assem~ly 40 is comprised of one or more ribbon heating elements adpated to emit a sui-table amount of heat when energized. The dimensions of the assembly may be such as to admit of a plurality of transferred images to be disposed therein simultaneously. Additionally, the fuser assembly is maintained at a quiescen-t operatiny temperature ~ ;~
when not energized, the quiescent operating temperature beiny slightly less than the temperature normally required to fi~ the powder image to prevent scorching of the support base 9. It is, therefore, readily apparent ~hat the print siynal derived from a data card is operated upon in a pre-selected sequential manner in correspondence with the transporting of a transferred image to the fuser assembly 40. Since, however, immediately succeediny areas of the support base 9 are provided with transferred images, but ~533~L7 succeeding on&s of the data cards are not necessarily provided with the unique pre-coded scanning information, lt is recognized that the support base is moved intermittently through the fuser assembly in an irregular manner. Consequently, the fuser assembly must not be continuously energized in order to avoid the scorching of the support base that is ~aintained in a temporary stationery relation-ship with respect thereto. Nevertheless, as an immediately suc-ceeding portion of the support base is advanced to the fuser assembly, the latter must be rapidly energized to an operating level capable of ~ixing the electroscopic powder image upon the support base. The manner in which the fuser assembly 40 is regulated to provide the just-mentioned selective fusing is described in detail hereinbelow.
The excess electroscopic particles remaining as residue on the developed images, as well as those particles not otherwise transferred therefrom, are carried by the photosensitive drum 20 to a cleaning station F on the periphery of the drum adjacent the charging station G. The cleaning station may comprise a rotating brush and a corona discharge device for neutrali2ing charges remaining on the non-transferred electroscopic particles.
Various other configurations and components may comprise a clean-ing station F as is well-~no~hn to those skilled in the art.
.~ ' i33~L7 It should, however, be clearly understood that the selective fusing techniques to be described in detail herein-below are readily adapted for broad application and should not unnecessarily be limited to the specific system described aboveO
It will, ~herefore, become readily apparent that the instant invention may be readily utilized whenever selected ones of original documents are to be reproduced. Stated otherwise, the selectiv~ fusing techni~ues described hereinbelow are readily adapted to fix powder i~ages to a support base therefor on an , 10 irregular basis in accordance with thè occurrence of pre-selected conditions as well as the environmental conditions of ~ -the fuser assembly itself~ Thus, in addition to *he selected use described with respect to Figure 1, the selective fusing techniques of the pres~nt invention may be employed for the preferentia~ fusing of dense images while leaving low density or background areas unfused.
Turning now to the basic matter of the pxesent inven-tion, and in particular, to Figures 2A and 2B, there is schemat-ically illustrated a conventional heating el~ment in the form of a ribbon fuser 105 that may be typically included in the fuser assembly 40 of Figure 1. The heating element 105 is coupled to a variable supply of voltage generally designated by the reference numeral 100, the latter being adapted by the heating element 105 with energy. The variable supply 100 may be a conventional voltage regulator such as Model 9T68Y7001 manufactured by General Electric and therefore, need not be described in detail herein. It should, however, be ` '~ !
', , . , . : . : .
` :~
~0~33~
noted that variable supply 100 includes a bi-directional current conducting means 101 which may be silicon bi-directional triode device, such as a triac capable of conducting relatively high AC
current in both directions and whose time of initial conduction during a half cycle is dependent upon the magnitude of the control ~oltage applied to the trigger input lOla thereof. Hence, the bi-directional current ~onducting mea~s 101 may function as a trig-gerable switch that is rendered conductive during a half cycle of an AC voltage applied thereto when the voltage exceeds a thresh-hold or firing level. Those of ordinary skill in the art will recognize that the bi-directional current conducting means be a con'~entional t~yrister. Once rendered conducti'~e, the bi-directional current conducting means 101 is adapted to remain conductive until the voltage supply thereto commences a successive half-cycle.
It may be observed that the control voltage applied to the trigger input lOla bi-directional current conducting means 101 is derived from a voltage dividing means that comprises series connected resistance means 102, 103, and 104. Trigger input lOla is coupled to the junction form by the series connection of resistance means 102 and 1030 The value of the resistance of resistance means 102 is, to some degree, determined by the intensity of radiant energy admitted by lamp 108 and, therefore, is pr~cisely regulated. In accordance with '~he prPsent invention the threshold leveI at which the bi-directional current conducting means 101 is rendered conducti've, is decreased by selecti'~ely reducing the voltage derived by the illustrated voltage division means. Adjustable resistance means 106 is capable of being selectively connected in parallel relationship to resistance means 102 by energizable switch 107. It should be appreciated that the effective resistance of the first stage of the illustrated voltaye dividing means is decreased when the adjust-. ' ~' ~5~3:gL7 able resistance means 106 is connected in parallel with resistancemeans 102. Consequently, the threshold or firing level voltage applied to the trigger input lOla of bi-directional current conducting means 101 thus correspondingly is increased. Thus, the time of initial conduction during half-c~cle is advanced and the duration of the bi-directional current conducting means 101 is increased With adjustable resistance means 106 connected in parallel with resistance means 102, the root mean square (RMS) voltage applied to heating element 105 is decreased, resulting in ~ -a decrease in the amount of heat radiated therefrom. Adjustable ~ ;
resistance means 106 may comprise a conventional potentiometer, rheostat or the like whereby an adjustment of resistance value thereof enables a corresponding adjustment in the threshold or firing level of bl-directional current means. EIence, a suitably wide range ln the RMS voltage applied -to heat element 105 may be `~
obtained.
The manner in which the variable supply 100 is utilized to regulate t~e heat radiated b~ heating element 105 may be readily understood by referring to Fig. 2s. Normally, the heating ~0 element 105 is maintained-at a quiescent low of energization to radiate the amount of heat that is not quite sufficient to ~use electroscopic material to a support base. Nevertheless, this quiescent energization enables the radiant eneryy emltted by the heating element to be rapidly increased to the proper fusing level ~
when the voltage applied to the heating element is increased.
When adjustable resistance means 106 is connected in parallel with resistance means 102, a quiescent threshold level is applied to trigger input lOla bi~directional current conducting means 101.
As illustrated in Fig. 23, this quiescent threshold level renders the bi-directional current conducting means conducted at a point on the positive half c~vcle of the AC voltage supplied to the - ' : , , ..... , , ,. ,.
~0533~7 bi-directio~al current conducting means defined by the inter-section of broken line 121a and AC wave form 120 The bi~
directional current conducting means 101 is rendered non-conductive at the conclusion of a positive half cycle. However, at a point on the negative half cycle defined by the intersection of broken line 121b and AC wave form 120, the bi-directional current conducting means is again rendered conductive. It is appreciated that when the quiescent threshold level is applied to triggering point lOla of bi-directional current conducting means 101, the bi-directional current conducting means is rendered conductive for only a relatively small portion of an AC cycle. This duration of conductivity, however~ is sufficient to apply an RMS voltage to heating element 105 whereby the heating element is maintained at a quiescent level of energization. Should the RMS
voltage applied to heating element 105 be increased, the heat radiated thereby will be sufficent to fuse electroscopic material.
When energizable switch means is energized so as to assume an "open" state, adjustable resistance means 106 is thereby disconnected from resissance means 102. It may be recognized za that switch means 107 may comprise a movable contact of a conventional relay, an electronic switch or the like. The dis- ;
connecting of adjustable resistance means 106 from resistance means 102 alters the ratio of division of the voltaye dividing means to thereby alter the threshold level applied to triggering point lOla. Accordingly, the point at which the bi-directional current `~
conducting means 101 is rendered conductive during the positive half cycle of the AC voltage applied thereto is defined by the intersection of line 12~a and AC wave form 120 illustrated in Fig. 2B. ~he conductivity of the bi-directional current conducting means is maintained until the conclusion of the positive half cycle. During the negative half cycle the AC voltage, bi-direct-... ...
i3;~
ional current conducting means 1~1 is rendered conductive at the point of intersection of line 122b and AC wave fcrm 120. The relatively large duration o~ conductivity during each cycle is effective to apply an increased ~ S voltage ko heating element 105 whereby the heat radiated by the heating element is sufficient to fuse the electroscopic matarial. It should be readily under-stood that if energizable switch 107 is energized for a plurality o~ AC cycles, the amount of heat radiated by heating element 105 is proportionally increased. Therefore, the total amount of heat radiated by the heating element and consequently, ~he increase in temperature obtained thereby, is a function of the duration of energization of enercJizable switch means 107.
An exemplary embodiment of apparatus that may be utilized to energize energizable switch means 107 is schematically illus-trated by the logic circuit of Fig. 3 and comprises storage means 200, temperature sensor 203, decoding means 20~ and relay 205 with driver means 206 therefor.
The decoding ~eans 204 comprises a first gating means i~
comprising a coincidence member 207 which is adapted to produce an output signal in response to the application of predetermined signal at each of two input terminals thereof. Accordingly, coincidence means 207 may comprise a conventional .~D gate whereby a binary "1" is produced at the output terminal thereof when a binary i'l" is supplied to each input terminal thereof.
For the purpose of the present discussion, it ~ill be assumed that a binary "1" is represented by a positive DC potential and a binary "0" is represented by ground potential. It is, of course, understood that the foregoincJ binary signals may be represented by any suitable voltage potentials. Similarly, coincidence means 207 may comprise a conventional N~ND gate whereby a binary "0"
is produced at an output terminal thereof when a binary "1" is supplied to each input terminal thereof.
, ~, ~533~7 A first input terminal 208 of the gating means 207 is provided with a machine, start-up signal while a second input terminal 209 thereof coupled to the output of a second gating device 210 is provided with a signal representative o the ambient temperature of the fusing assembly. In this particular case the signal is representative of a low temperature range or an ambient temperature of less than 109F. From the foregoing, it can be seen that when operation or start-up of the machine is initiated and the ar~ient temperature of the fuser asser~ly is in the low range, there are present high levels or positive DC potentials at the input to the gating device 207 which effects a high level output therefrom to thereby trigger a one-shot multivibrator 211 having a duty cycle of 1.3 seconds. The output from the one-shot provides a high level input to a gating means 212 the output of whic.h provides an input to the driver means 205 for driving the relay 206 which opens the switch means 107 thereby providing .
a high intensity input to the heater 105 for a perlod of 1.3 seconds.
The gating means 212 may comprise a conventional OR gate whereby a ~inary "1" is produced at the output terminal thereof when a binary "1" is supplied to any one of the input terminals thereof. As in the case the gating means 207 and 213 and for the purpose of the present discussion, it will. be assumed that a ~inary "1" is represented by a positive DC potential and a binary "0" is represented by ground potential.
Gating means similar in function to gating means 207 com-prises coincidence means 213 which is adapted to produce an out-put signal in response to the application of a predetermined sig-nal at each of its two input terminals, one of which is the ~ :
terminal 208 from which is derived a start-up signal and the other of which -- 15 -- ~
10533:17 is a terminal 214 from which is derived a signal from a thermistor amplifier 215 indicative of a middle temperature range in the fuser assembly as sensed by the thermistor 203.
The output of the gating means 213 triggers a one-shot multi-vibrator 216 from which is derived a 1.1 second pulse for energizing the fuser 105 in the high intensity range for that period of time through the opening of the switch means 107.
Storage means 200 is adapted to store a history of the preceeding energiæations of the heating element included in the fuser assambly 40 illustrated in FigO ~ and therefore, may comprise a plural shift register means including an input terminal for receiving an irregularly ocurring selective energizing-signal and a shift terminal for receiving a perio~ic shift signal. It is recalled that the selective printing apparatus with which the present invention may be utilized is adapted to develop and transfex an image of a given data card when the card is provided with scanning information from which a print signal i5 derived. A derived print signal is shifted through shift register means 200 in timed relation with the rotation of image information obtained from a corresponding data card. The image information is distributed on the surface o a rotating photosensitive drum in the form of a distributed electrostatic charge pattern. Accordingly~ the relative position of the image information at any given time may be determined by the particular position occupied by the print signal as the print signal is shifted through the register means. Moreover, once the image information is developed and transferred to a portion of the support base, the movement of that portion may be represented by a ~orresponding shifting of the print signal through the shift register means. It should, theref~re, be readily apparent ~3,'!, ~
' ' ' .' . .` ' 3~7 that a prlnt signal will be shifted to a predetermined position within the shift register means when a portion of the support base is advanced to the fuser assembly. ~Ience, electroscopic particles that are disposed in image configuration on the support base are to be fused to the support base when a print signal occupies the predetermined position. As will ~e soon become apparent, the print signal occupying the predetermined position need not be associated with that particular portion of the support - ~-base that is advanced to the fuser assembly. However, except for initial portions of the support base, each succeeding portion that ; .
is transported to the fuser has a powder image disposed thereon.
Storage means 200, may, therefore, comprise a portion of the afore-mentioned shift register means having a first stage corresponding to the predetermined position and includlng a plurality of suc-ceeding stages. ~lternatively, the storage means 200 may comprise an individual plural stage shift register means having a first stage corresponding to the aforementioned predetermined position and including a plurality of succeeding stages. In either case, the storage means is illustrated in ~ig. 3 as comprising a plural stage shift re~ister means wherein only seven stages have been designated as only these stages are of i.nterest here. As is understood by those of ordinary skill in the art, a conventional shift register is adapted to shift an input signal applied there-to consecutively through the stages ~hereof in accordance with a transition in the shift signal applied. The shift register may, therefore, comprise a counter capable of representing timing information reLa~ing to the times of occurrences of successive input signals in accordance wlth the particular stages occupied thereby~
The input terminal of storage means 200 is coupled to ter-minal 201 to which is applied a preselected information signal such as the aforementioned print signal. The shift terminal storage . .
~1)53~3~7 ,:
means 200 is coupled to terminal 202 to which is applied a periodic shift signal. The periodic shit signal may be derived ~:
from the system clock. Accordingly, the periodic shift signal may take the form of a clock pulse having a period corresponding to the rate at which the data cards are scanned and lmagedO The clock pulse period is thus equal to the interval of tie required to transfer successive developed images from the photo-sensitive drum to the support base 9. Consequently, the clock pulse period is also equal to the interval of time re~uired to translate successive por~tions of the support base 9 to the fuser assembly.
The outputs of the stages of storage means 200 are coupled to the illustrated decoding means 204, which decoding means is adapted to analyze the sequence of print signals that have been supplied to storage means 200 as well as the ambient temperature of the fuser 40. The decoding means 204 in addition . .
to the already de~cribed gating means further includes gating means 220 and 221. The gating means ~220 includes a plurality of input terminals coupled to each of the seven s~ages of the storage means 200 and an output terminal 222 coupled to the gating means 212. The gating means 220 has an additional input terminal 223 which is coupled to the output of the gating means 210 through an inverter member 224.
The gating means 220 may comprise a conventional NOR
gate whereby a binary "1" is produced at the output terminal .
thereof when a binary"0" is supplied to each input terminal thereof.
The gating means 220 is adapted to sense the expira-tion of a first interval of time intermediate successive occurr-e~ces of a print si-gnal. The gating means 220 is also adapted to sense a low temperature range in ~he fuser assembly 40 In accordance r ~3~
:` . ., ' ~5~33~
with the ~oregoing, the gating means 220 at the output thereof produces a signal admitting of a pre-established duration, for example 332 milliseconds. More particularly, gating means 220 is adapted to detect when more than six clock pulses have occurred since the occurrence of the immediately preceeding print signal.
Stated differently, the gating means 220 is adapted to produce a signal of 332 milliseconds duration, tws cycles before the image is transferred from the drum to the web 9 if six non-selects occur with lsw temperature range in thP fuser chamber. Such expiration lV corresponds to an elapsed time since the previous energization of the heating elements 105 included in the fuser assembly 40 and that the fuser assembly has cooled to a temperature requiring an energization thereof for a duration longer than the minimum durat~on to attain a suitable accumulation of radiant energy in the assembly.
The first input terminal of the gating means 2~0 is coupled to the first stage of the storage means by means of an inverting means 225 while successive terminals to the input of the gating ~ -means 220 are coupled to successive output stages, directly, of ~he storage means 200. An output signal is produced by the ga~ing means 220 when the first stage of storage means 220 is occupied by a print signal and the other six stages o~ the stor-age mea~s are not occupied by a print signal~ combined with the fact that the fuser assembly is in the low temperature range.
The inverting means 224 and 225 may comprise conventional logic negation circuits adapted to produce a binary "0" in response to a binary "1" supplied thereto, and conversely~ to produce a binary "1" in response to a binary "0" supplied thereto. ~;
The gating means 221 is provided with input terminals coupled to the second through fifth stages of the storage means 200 along with the terminal 223 which as noted is c~upled to the output of the gating means 210. The input terminal 221 coupled .
t ~ ~i33~7 ~ :
to the second stage of the storage means 2~0 is via an inverter means 226 inverter means 224 and 225. It can be seen from a consideration of the input terminals to the gating means 221 that an output pulse is provided at output terminal 237 if three non-selects occur with the fuser chal~ber in the low tempera-ture range.
It can be Eurther seen that the occurrence of such a signal takes place one cycle before transfer of the image from the photoreceptor drum to the web 9 takes place. The duration of the signal derived on output terminal 227 is 332 rnilliseconds.
Stated differently, it can ~e seen that when a print c~cle occupies the second stage of the storage means and no such signal occupies the third, fourth and fifth stages of the storage means along with a low temperature range sensed in the fuser chamber an output signal corresponding to such conditions is produced along output terminal 227.
The successive stages of the storage means 200 are labeled 2, 1, 0, 1, 2, 3 and 4 and therefore correspond to, in the case of t~e first stage, a point in time two cycles prior to transfe~ of an image from the photoreceptor drum to the web 9. ~;
Likewise the second stage of the storage means corresponds to a point in time one cycle prior to such transfer while the third stage corresponds to and coincides with transfer. The stages four throuyh 7 correspond to points in time su~sequent to trans-fer of an image and correspond to one, two, -three or four cycles after such transfer.
Gating means 228 in the form of an A~D gate similar in function to gates 207 and 213 is provided with a pair of input terminals 229 and 230 the former of which is coupled to the third stage of the storage means 200 and the latter of which is coupled to the gating means 231 in the form of an OR gate.
It can be seen that an output signal on output terminal 232 is derived when the third stage of the storage means 200 is ~5~3~L~
occupied b~ a print signal and the temperature in the fuser is in the low or mid range.
The pulse repetition rate for shifting the prlnt signals through the storage means 200 is 332 milliseconds with the duration of such shift signals being 220 milliseconds duration.
In view of the foregoing, the duration of the signals from the gating means 220, 221 and 228 is equal to the pulse repetition rate of the shift signals.
Gating means 233 is provided with a plurality of inputs one of which is coupled to the shlft terminal 202 and the other two of which are coupled, respectively to the third stage of the storage means 200 and the high range take-off of the thermistor amplifier 215. It can be seen that since one of the inputs to the yating means 233 is derived from the shift terminal the output signal from terminal 234 of the gating device 233 has a duration equal to the shift signal pulse duration of 220 milli-seconds and therefore when the third stage of the storage means 200 is occupied by a print signal and the fuser assembly is in the high temperature range an output signal of 220 milliseconds duration will be provided on output terminal 234.
The operation of the apparatus illustrated in Fig. 3 ~ill now be described. It will be recalled that the successive portions of the support base 9 upon which the electroscopic particles are disposed in imacJe configuration are intermittently moved through the fuser assembly 40 even though the data cards and photosensitive drum are continuously advanced and rotated respectively. Additionally, it can be seen from a consideration o Fig. 1 and the storage means 200 of Fig. 3 that there is a time delay bet~een the incidence of transfer of the image from the photoreceptor to the support 9 and movement of a particular trans~erred image to the fuser assembly ~0. This delay is ~ y i3~L7 inherent even though all the cards being scanned would contain print signal data or coding. Accordinyly, the apparatus dis-closed in Fig. 3 including the storage means 200 and decoding means 204 is arranged to take into consideration that there is a delay of a plurality of cycles between the time an image is transferred and that image sees the i~side of the fuser assembly 40. For purposes of this description it will be assumed that the apparatus disclosed in Fig. 1 has not ~een operated for some time and therefore the ambient temperature of the fuser is in a low temperature range corresponding to a temperature of less than 109F.
When the start button of the machine is depressed by an operator, a start-up signal is generated at the input of gating device .- .
207 via input terminal 208 and simultaneously therewith a second signal is pxovided via input terminal 209 to the gating device 207 which represents a low temperature condition in the ~user assembly. The coincidence of the pulses at input terminals 208 and 209 establishes an output signal from the gating device 207 which triggers a one-shot multivibrator 211 having a pulse duration of 1.3 seconds which provides an input to the gating device 212 the output of which is responded to by the driver ;
means 20~ to thereby supply the energi7ing coil 206 with ground potential. Accordingly, the drivi.ng means 206 may comprise a conventional transistor means having a base electrod~ coupled ~ :
to the gating means 212, and collector electrode coupled to the energizing coil 205 and an emitter electrode coupled to yround ~.
potential. The supplying of the energizing coil 205 with ground potential serves to open the switch 107 to establish high intcnsity operation of the heating element 105. If at the time the apparatus were operated in the fuser assembl~ ~lO contain-ed residual thermal energy, it can be seen that the gating device 213 with coincident signals via terminal inputs 208 and 214 would produce . .~ . , ~ .. ...
~533~
an output signal for triggering a 1.1 second one-shot multivibrator to provide an input to the gating device 212 for supplying energy to the coil 205 from the output of the gating means 212 via the driver means 206 actuated thereby. It should be borne in mind that the foregoing has taken place prior to any card code infor-mation being sensed.
Once the code information is being sensed, the pattern of select and non-select images is transmitted to the decoding means 204 via the storage means 200. The output of the decoding means provides signals to regulate the fuser to provide high intensity levels ~or fusing or the holding level to keep the fuser chamber warm and to minimize the ribbon element heat up response time.
The thermistor sensor signal is divided into three temperature ranges: below 109~; between 109 and 150F; and over 150F.
The shift register select pattern is divided into three groups: selects which are preceeded by other selects within the last three machine cycles (1 label per cycle), selects preceeded by at least three non-selects, and selects, preceeded by at least six non-selects. The shit register signals are combined to form four basic output signals as follows: AND gating device 220 pro-vides an output for 332 milliseconds if a select is preceeded by ' Si.Y non-selects and the fuser temperature is in the low range.
This output occurs two cycles before the paper starts moving;
Gating means 221 provides an output for 332 milliseconds if a select is preceeded by three non-selects and the fuser temperature is in the low range. ~his output occurs one cycle before the paper starts moving;
3a Gating means 228 provides an output for 332 milliseconds if a select occurs in the cycle that the paper is moving and the .
:, ' ':
~IQ533~
temperature is in the low or mid temperature range; and Gating means 223 provides an output for 220 milliseconds if a select occurs in the cycle that the paper is moving (i~e.
print signal in third stage of means 200) and the temperature is in the high range.
From the above, it can be seen that if the fuser chamber is in the low temperature range and a select occurs which is preceeded by six non-selects, the fuser will swltch to high intensity two cycles before the paper advances from the output of gating means 220 and will continue at high intenslty in the following cycle from the output of gating means 221 and also in the paper advance cycle by the output of gating device or means 228. This will provide 996 milliseconds of high intensity fuser operation in three consecutive cycles.
For the case where the chal~er is in the ].ow ranye and the select is preceeded by at least three but not more than six non-selects, the fuser will remain at high intensity for 664 milliseconds from the output of gating means 221 and then gating ~;
means 228.
2~ While the invention has been particularly ~hown and described with reference to an exemplary embodiment thereof, it will be obvious to those skilled in the art that various changes and modifications in form and details may be made without departing from the spirit ancl scope of the invention~ Thus, it is intended that the appended claims be interpreted as including obvious changes and modifications.
3a `
~ 24 -
:
; '`
~ ~33~7 the selective prin~ing apparatus comprises an electrostatic system wherein a light image of an original to be reproduced is projected onto the sensitized surface of a photosensitive plate to form an electrostatic latent image thereon. Thereafter, the latent image is developed with an oppositely charged ;
developing material comprising electroscopic particles, known as toner particles, to form a powder image corresponding to the latent image on the photosensitive surface. The powder image is ;
then electrostatically transferred to a support base to which `
it may be fixed by a fuser assembly whereby the powder is caused to adhere ~ermanently to the support surface.
In the illustrated apparatus, visible document information is provided on each of the data cards 1 that are successively ~^
transported from a feeder tray 2 to a restack tray 49. The data cards are transported in timed sequence with respect to the operation of the remaining apparatus illustrated herein, and are caused to traverse detecting station A, scanning station B and slit exposure device 34 in successive order. Each data card is additionally provided with pre-coded information thereon, which pre-coded information is determinative of the selective printing of the visible document information carried by the card. More particularly, if the pre-coded information scanned from the card by scanning station B admits of a particular pre-condition, ;
additional logic circuitry, not shown, responds to such scanned inormation to derive a print signal. The thus derived print signal is operated upon in timed sequence to provide a direct correspondence between the sequential manipula-tion of such print signal and the particular operation performed by the apparatus illustrated in Figure 1.
3~ The sequential passage of data cards from the scanning station 3 through the projection system 33 to the restack tray ~9 `~
will cause optical images of the visible document information on 33~L7 each of the data cards passing through the slit exposure device 34 to be sequentially projected upon the surface of photosensitive drum 20. If desired, the projected images may admit of magnifica-tion. The photosensitive drum 2~ is continuously driven at a constant angular velocity such that the sur-face thereof is moving at a velocity equal to that of data cards moving past the exposure device 34. In moving in the direction indicated by the arrow prior to reaching the exposure station C, that portion of the photosensitive drum being exposed is uniformly charged by a corona discharge station G. The exposure of the photosensitive drum surface to t!e light image selectively dissipates the electro-static charge on the surface thereof in the area struck by light, thereby forming an electrostatic latent image in image configuration corresponding to the light image projected from the visible document information on the data card transported through the slit exposure device 34 As the photosensi-tive drum surface continues its movement, electrostatic image passes through a developing station D in which there is positioned a developing apparatus generally indicated by the reference numeral 13.
In the electrostatic latent image passing through develo-opment station D is derived from a data card having a print signal associated therewith, such print signal is utilized to activate the developer motor 24 such that the developing apparatus may be operated to develop such electrostatic latent image. In contra-distinction thereto, should the electrostatic latent image passing through the developing station D be derived from a data card not `
having a print signal associated therewith, the developer motor ~ -24 is not activated and such electrostatic latent image is not developed. It is therefore, appreciated that the developing 3a apparatus 13 is operated in an intermittent manner wherein only those electrostatic images derived from data cards having print ~S33~7 signals associated therewith are developed at station ~. As the photosensitive drum 20 continues to rotate in the directlon indi-cated by the arrow, successive areas thereo~F will be provided with image information distributed thereon in the form of a distri-buted electrostatic charge pattern. However, only selec-ted ones o~ successive areas ~ e developed. As illustrated herein, the developing appartus 13 may typically be provided with electro-scopic particles that are cascaded across the surface of photosen-sitive drum 20, ~hich particles are attracted electrostatically to the distributed charge pattern to form powder images.
The developed electrostatic image is transported by the photosensitive drum 20 to a transfer station E located at a point of tangency on the photosensitive drum whereat a support base 9 is intermittently moved at a speed in synchronism with the moving drum in order to accomplish transfer of the developed image.
The support base 9 is here depicted as a web comprised of suitable material such as paper, plastic or the like, that it is driven from a supply 13 to selective transfer mechanism 25 through ~user assembly 40, about strip driving means 16 and into a strip receiving tray 14. It will be appreciated that the support base 9 in addition to comprising paper and plastic in the form of a web, the support base 9 may also comprise a continuous strip of paper having gummed labels supported thereon which can be readily removed ;~
from the web subsequent to the reproducing operation. At the -time a developed image having a print signal associated therewith arrives at the transfer station E, the associated print signal is operated upon to cause the web driving means 16 to be activated, thereby transporting the support base 9 at a velocity equal to the surface velocity of the photosensitive drum 20. Moreover, the print signal is used to operate the selective transfer mechanism 25 whereby the support base 3 engages the photosensitive drum 20 in an arc contact. In addition, charging means 30 may ~ [)S~3~7 be energized to provide a charge on the support base 9 prior to its engagement with the photosensitive drum so that the developed image may be electrostatically transferred from the surface of drum 20 to the adjacent side of the support base as such support base is brought into contact therewith. Thus, it is seen, that each developed electrostatic image is transferred to the support base 9; and the support base is, therefore, advanced in an inter-mittant manner in accordance with each print signal that is derived from the scanning info~mation carried by the transported data cards.
After transfer, the support base 9 is transported to the fuser assembly, generally indicated by the reference number 40, wherein the developed and transferred powder image on the support base is permanently fixed thereto. The fuser assembly 40 may com~
prise conventional apparatus capable of carrying out various fusing techniques such as oven fusing, hot air fusing, radiant fusing, hot and cold pressure fixing and fusing and flash fusing as well as other known techniques. Merely for the purpose of explanation, it will be assumed that the fuser assem~ly 40 is comprised of one or more ribbon heating elements adpated to emit a sui-table amount of heat when energized. The dimensions of the assembly may be such as to admit of a plurality of transferred images to be disposed therein simultaneously. Additionally, the fuser assembly is maintained at a quiescen-t operatiny temperature ~ ;~
when not energized, the quiescent operating temperature beiny slightly less than the temperature normally required to fi~ the powder image to prevent scorching of the support base 9. It is, therefore, readily apparent ~hat the print siynal derived from a data card is operated upon in a pre-selected sequential manner in correspondence with the transporting of a transferred image to the fuser assembly 40. Since, however, immediately succeediny areas of the support base 9 are provided with transferred images, but ~533~L7 succeeding on&s of the data cards are not necessarily provided with the unique pre-coded scanning information, lt is recognized that the support base is moved intermittently through the fuser assembly in an irregular manner. Consequently, the fuser assembly must not be continuously energized in order to avoid the scorching of the support base that is ~aintained in a temporary stationery relation-ship with respect thereto. Nevertheless, as an immediately suc-ceeding portion of the support base is advanced to the fuser assembly, the latter must be rapidly energized to an operating level capable of ~ixing the electroscopic powder image upon the support base. The manner in which the fuser assembly 40 is regulated to provide the just-mentioned selective fusing is described in detail hereinbelow.
The excess electroscopic particles remaining as residue on the developed images, as well as those particles not otherwise transferred therefrom, are carried by the photosensitive drum 20 to a cleaning station F on the periphery of the drum adjacent the charging station G. The cleaning station may comprise a rotating brush and a corona discharge device for neutrali2ing charges remaining on the non-transferred electroscopic particles.
Various other configurations and components may comprise a clean-ing station F as is well-~no~hn to those skilled in the art.
.~ ' i33~L7 It should, however, be clearly understood that the selective fusing techniques to be described in detail herein-below are readily adapted for broad application and should not unnecessarily be limited to the specific system described aboveO
It will, ~herefore, become readily apparent that the instant invention may be readily utilized whenever selected ones of original documents are to be reproduced. Stated otherwise, the selectiv~ fusing techni~ues described hereinbelow are readily adapted to fix powder i~ages to a support base therefor on an , 10 irregular basis in accordance with thè occurrence of pre-selected conditions as well as the environmental conditions of ~ -the fuser assembly itself~ Thus, in addition to *he selected use described with respect to Figure 1, the selective fusing techniques of the pres~nt invention may be employed for the preferentia~ fusing of dense images while leaving low density or background areas unfused.
Turning now to the basic matter of the pxesent inven-tion, and in particular, to Figures 2A and 2B, there is schemat-ically illustrated a conventional heating el~ment in the form of a ribbon fuser 105 that may be typically included in the fuser assembly 40 of Figure 1. The heating element 105 is coupled to a variable supply of voltage generally designated by the reference numeral 100, the latter being adapted by the heating element 105 with energy. The variable supply 100 may be a conventional voltage regulator such as Model 9T68Y7001 manufactured by General Electric and therefore, need not be described in detail herein. It should, however, be ` '~ !
', , . , . : . : .
` :~
~0~33~
noted that variable supply 100 includes a bi-directional current conducting means 101 which may be silicon bi-directional triode device, such as a triac capable of conducting relatively high AC
current in both directions and whose time of initial conduction during a half cycle is dependent upon the magnitude of the control ~oltage applied to the trigger input lOla thereof. Hence, the bi-directional current ~onducting mea~s 101 may function as a trig-gerable switch that is rendered conductive during a half cycle of an AC voltage applied thereto when the voltage exceeds a thresh-hold or firing level. Those of ordinary skill in the art will recognize that the bi-directional current conducting means be a con'~entional t~yrister. Once rendered conducti'~e, the bi-directional current conducting means 101 is adapted to remain conductive until the voltage supply thereto commences a successive half-cycle.
It may be observed that the control voltage applied to the trigger input lOla bi-directional current conducting means 101 is derived from a voltage dividing means that comprises series connected resistance means 102, 103, and 104. Trigger input lOla is coupled to the junction form by the series connection of resistance means 102 and 1030 The value of the resistance of resistance means 102 is, to some degree, determined by the intensity of radiant energy admitted by lamp 108 and, therefore, is pr~cisely regulated. In accordance with '~he prPsent invention the threshold leveI at which the bi-directional current conducting means 101 is rendered conducti've, is decreased by selecti'~ely reducing the voltage derived by the illustrated voltage division means. Adjustable resistance means 106 is capable of being selectively connected in parallel relationship to resistance means 102 by energizable switch 107. It should be appreciated that the effective resistance of the first stage of the illustrated voltaye dividing means is decreased when the adjust-. ' ~' ~5~3:gL7 able resistance means 106 is connected in parallel with resistancemeans 102. Consequently, the threshold or firing level voltage applied to the trigger input lOla of bi-directional current conducting means 101 thus correspondingly is increased. Thus, the time of initial conduction during half-c~cle is advanced and the duration of the bi-directional current conducting means 101 is increased With adjustable resistance means 106 connected in parallel with resistance means 102, the root mean square (RMS) voltage applied to heating element 105 is decreased, resulting in ~ -a decrease in the amount of heat radiated therefrom. Adjustable ~ ;
resistance means 106 may comprise a conventional potentiometer, rheostat or the like whereby an adjustment of resistance value thereof enables a corresponding adjustment in the threshold or firing level of bl-directional current means. EIence, a suitably wide range ln the RMS voltage applied -to heat element 105 may be `~
obtained.
The manner in which the variable supply 100 is utilized to regulate t~e heat radiated b~ heating element 105 may be readily understood by referring to Fig. 2s. Normally, the heating ~0 element 105 is maintained-at a quiescent low of energization to radiate the amount of heat that is not quite sufficient to ~use electroscopic material to a support base. Nevertheless, this quiescent energization enables the radiant eneryy emltted by the heating element to be rapidly increased to the proper fusing level ~
when the voltage applied to the heating element is increased.
When adjustable resistance means 106 is connected in parallel with resistance means 102, a quiescent threshold level is applied to trigger input lOla bi~directional current conducting means 101.
As illustrated in Fig. 23, this quiescent threshold level renders the bi-directional current conducting means conducted at a point on the positive half c~vcle of the AC voltage supplied to the - ' : , , ..... , , ,. ,.
~0533~7 bi-directio~al current conducting means defined by the inter-section of broken line 121a and AC wave form 120 The bi~
directional current conducting means 101 is rendered non-conductive at the conclusion of a positive half cycle. However, at a point on the negative half cycle defined by the intersection of broken line 121b and AC wave form 120, the bi-directional current conducting means is again rendered conductive. It is appreciated that when the quiescent threshold level is applied to triggering point lOla of bi-directional current conducting means 101, the bi-directional current conducting means is rendered conductive for only a relatively small portion of an AC cycle. This duration of conductivity, however~ is sufficient to apply an RMS voltage to heating element 105 whereby the heating element is maintained at a quiescent level of energization. Should the RMS
voltage applied to heating element 105 be increased, the heat radiated thereby will be sufficent to fuse electroscopic material.
When energizable switch means is energized so as to assume an "open" state, adjustable resistance means 106 is thereby disconnected from resissance means 102. It may be recognized za that switch means 107 may comprise a movable contact of a conventional relay, an electronic switch or the like. The dis- ;
connecting of adjustable resistance means 106 from resistance means 102 alters the ratio of division of the voltaye dividing means to thereby alter the threshold level applied to triggering point lOla. Accordingly, the point at which the bi-directional current `~
conducting means 101 is rendered conductive during the positive half cycle of the AC voltage applied thereto is defined by the intersection of line 12~a and AC wave form 120 illustrated in Fig. 2B. ~he conductivity of the bi-directional current conducting means is maintained until the conclusion of the positive half cycle. During the negative half cycle the AC voltage, bi-direct-... ...
i3;~
ional current conducting means 1~1 is rendered conductive at the point of intersection of line 122b and AC wave fcrm 120. The relatively large duration o~ conductivity during each cycle is effective to apply an increased ~ S voltage ko heating element 105 whereby the heat radiated by the heating element is sufficient to fuse the electroscopic matarial. It should be readily under-stood that if energizable switch 107 is energized for a plurality o~ AC cycles, the amount of heat radiated by heating element 105 is proportionally increased. Therefore, the total amount of heat radiated by the heating element and consequently, ~he increase in temperature obtained thereby, is a function of the duration of energization of enercJizable switch means 107.
An exemplary embodiment of apparatus that may be utilized to energize energizable switch means 107 is schematically illus-trated by the logic circuit of Fig. 3 and comprises storage means 200, temperature sensor 203, decoding means 20~ and relay 205 with driver means 206 therefor.
The decoding ~eans 204 comprises a first gating means i~
comprising a coincidence member 207 which is adapted to produce an output signal in response to the application of predetermined signal at each of two input terminals thereof. Accordingly, coincidence means 207 may comprise a conventional .~D gate whereby a binary "1" is produced at the output terminal thereof when a binary i'l" is supplied to each input terminal thereof.
For the purpose of the present discussion, it ~ill be assumed that a binary "1" is represented by a positive DC potential and a binary "0" is represented by ground potential. It is, of course, understood that the foregoincJ binary signals may be represented by any suitable voltage potentials. Similarly, coincidence means 207 may comprise a conventional N~ND gate whereby a binary "0"
is produced at an output terminal thereof when a binary "1" is supplied to each input terminal thereof.
, ~, ~533~7 A first input terminal 208 of the gating means 207 is provided with a machine, start-up signal while a second input terminal 209 thereof coupled to the output of a second gating device 210 is provided with a signal representative o the ambient temperature of the fusing assembly. In this particular case the signal is representative of a low temperature range or an ambient temperature of less than 109F. From the foregoing, it can be seen that when operation or start-up of the machine is initiated and the ar~ient temperature of the fuser asser~ly is in the low range, there are present high levels or positive DC potentials at the input to the gating device 207 which effects a high level output therefrom to thereby trigger a one-shot multivibrator 211 having a duty cycle of 1.3 seconds. The output from the one-shot provides a high level input to a gating means 212 the output of whic.h provides an input to the driver means 205 for driving the relay 206 which opens the switch means 107 thereby providing .
a high intensity input to the heater 105 for a perlod of 1.3 seconds.
The gating means 212 may comprise a conventional OR gate whereby a ~inary "1" is produced at the output terminal thereof when a binary "1" is supplied to any one of the input terminals thereof. As in the case the gating means 207 and 213 and for the purpose of the present discussion, it will. be assumed that a ~inary "1" is represented by a positive DC potential and a binary "0" is represented by ground potential.
Gating means similar in function to gating means 207 com-prises coincidence means 213 which is adapted to produce an out-put signal in response to the application of a predetermined sig-nal at each of its two input terminals, one of which is the ~ :
terminal 208 from which is derived a start-up signal and the other of which -- 15 -- ~
10533:17 is a terminal 214 from which is derived a signal from a thermistor amplifier 215 indicative of a middle temperature range in the fuser assembly as sensed by the thermistor 203.
The output of the gating means 213 triggers a one-shot multi-vibrator 216 from which is derived a 1.1 second pulse for energizing the fuser 105 in the high intensity range for that period of time through the opening of the switch means 107.
Storage means 200 is adapted to store a history of the preceeding energiæations of the heating element included in the fuser assambly 40 illustrated in FigO ~ and therefore, may comprise a plural shift register means including an input terminal for receiving an irregularly ocurring selective energizing-signal and a shift terminal for receiving a perio~ic shift signal. It is recalled that the selective printing apparatus with which the present invention may be utilized is adapted to develop and transfex an image of a given data card when the card is provided with scanning information from which a print signal i5 derived. A derived print signal is shifted through shift register means 200 in timed relation with the rotation of image information obtained from a corresponding data card. The image information is distributed on the surface o a rotating photosensitive drum in the form of a distributed electrostatic charge pattern. Accordingly~ the relative position of the image information at any given time may be determined by the particular position occupied by the print signal as the print signal is shifted through the register means. Moreover, once the image information is developed and transferred to a portion of the support base, the movement of that portion may be represented by a ~orresponding shifting of the print signal through the shift register means. It should, theref~re, be readily apparent ~3,'!, ~
' ' ' .' . .` ' 3~7 that a prlnt signal will be shifted to a predetermined position within the shift register means when a portion of the support base is advanced to the fuser assembly. ~Ience, electroscopic particles that are disposed in image configuration on the support base are to be fused to the support base when a print signal occupies the predetermined position. As will ~e soon become apparent, the print signal occupying the predetermined position need not be associated with that particular portion of the support - ~-base that is advanced to the fuser assembly. However, except for initial portions of the support base, each succeeding portion that ; .
is transported to the fuser has a powder image disposed thereon.
Storage means 200, may, therefore, comprise a portion of the afore-mentioned shift register means having a first stage corresponding to the predetermined position and includlng a plurality of suc-ceeding stages. ~lternatively, the storage means 200 may comprise an individual plural stage shift register means having a first stage corresponding to the aforementioned predetermined position and including a plurality of succeeding stages. In either case, the storage means is illustrated in ~ig. 3 as comprising a plural stage shift re~ister means wherein only seven stages have been designated as only these stages are of i.nterest here. As is understood by those of ordinary skill in the art, a conventional shift register is adapted to shift an input signal applied there-to consecutively through the stages ~hereof in accordance with a transition in the shift signal applied. The shift register may, therefore, comprise a counter capable of representing timing information reLa~ing to the times of occurrences of successive input signals in accordance wlth the particular stages occupied thereby~
The input terminal of storage means 200 is coupled to ter-minal 201 to which is applied a preselected information signal such as the aforementioned print signal. The shift terminal storage . .
~1)53~3~7 ,:
means 200 is coupled to terminal 202 to which is applied a periodic shift signal. The periodic shit signal may be derived ~:
from the system clock. Accordingly, the periodic shift signal may take the form of a clock pulse having a period corresponding to the rate at which the data cards are scanned and lmagedO The clock pulse period is thus equal to the interval of tie required to transfer successive developed images from the photo-sensitive drum to the support base 9. Consequently, the clock pulse period is also equal to the interval of time re~uired to translate successive por~tions of the support base 9 to the fuser assembly.
The outputs of the stages of storage means 200 are coupled to the illustrated decoding means 204, which decoding means is adapted to analyze the sequence of print signals that have been supplied to storage means 200 as well as the ambient temperature of the fuser 40. The decoding means 204 in addition . .
to the already de~cribed gating means further includes gating means 220 and 221. The gating means ~220 includes a plurality of input terminals coupled to each of the seven s~ages of the storage means 200 and an output terminal 222 coupled to the gating means 212. The gating means 220 has an additional input terminal 223 which is coupled to the output of the gating means 210 through an inverter member 224.
The gating means 220 may comprise a conventional NOR
gate whereby a binary "1" is produced at the output terminal .
thereof when a binary"0" is supplied to each input terminal thereof.
The gating means 220 is adapted to sense the expira-tion of a first interval of time intermediate successive occurr-e~ces of a print si-gnal. The gating means 220 is also adapted to sense a low temperature range in ~he fuser assembly 40 In accordance r ~3~
:` . ., ' ~5~33~
with the ~oregoing, the gating means 220 at the output thereof produces a signal admitting of a pre-established duration, for example 332 milliseconds. More particularly, gating means 220 is adapted to detect when more than six clock pulses have occurred since the occurrence of the immediately preceeding print signal.
Stated differently, the gating means 220 is adapted to produce a signal of 332 milliseconds duration, tws cycles before the image is transferred from the drum to the web 9 if six non-selects occur with lsw temperature range in thP fuser chamber. Such expiration lV corresponds to an elapsed time since the previous energization of the heating elements 105 included in the fuser assembly 40 and that the fuser assembly has cooled to a temperature requiring an energization thereof for a duration longer than the minimum durat~on to attain a suitable accumulation of radiant energy in the assembly.
The first input terminal of the gating means 2~0 is coupled to the first stage of the storage means by means of an inverting means 225 while successive terminals to the input of the gating ~ -means 220 are coupled to successive output stages, directly, of ~he storage means 200. An output signal is produced by the ga~ing means 220 when the first stage of storage means 220 is occupied by a print signal and the other six stages o~ the stor-age mea~s are not occupied by a print signal~ combined with the fact that the fuser assembly is in the low temperature range.
The inverting means 224 and 225 may comprise conventional logic negation circuits adapted to produce a binary "0" in response to a binary "1" supplied thereto, and conversely~ to produce a binary "1" in response to a binary "0" supplied thereto. ~;
The gating means 221 is provided with input terminals coupled to the second through fifth stages of the storage means 200 along with the terminal 223 which as noted is c~upled to the output of the gating means 210. The input terminal 221 coupled .
t ~ ~i33~7 ~ :
to the second stage of the storage means 2~0 is via an inverter means 226 inverter means 224 and 225. It can be seen from a consideration of the input terminals to the gating means 221 that an output pulse is provided at output terminal 237 if three non-selects occur with the fuser chal~ber in the low tempera-ture range.
It can be Eurther seen that the occurrence of such a signal takes place one cycle before transfer of the image from the photoreceptor drum to the web 9 takes place. The duration of the signal derived on output terminal 227 is 332 rnilliseconds.
Stated differently, it can ~e seen that when a print c~cle occupies the second stage of the storage means and no such signal occupies the third, fourth and fifth stages of the storage means along with a low temperature range sensed in the fuser chamber an output signal corresponding to such conditions is produced along output terminal 227.
The successive stages of the storage means 200 are labeled 2, 1, 0, 1, 2, 3 and 4 and therefore correspond to, in the case of t~e first stage, a point in time two cycles prior to transfe~ of an image from the photoreceptor drum to the web 9. ~;
Likewise the second stage of the storage means corresponds to a point in time one cycle prior to such transfer while the third stage corresponds to and coincides with transfer. The stages four throuyh 7 correspond to points in time su~sequent to trans-fer of an image and correspond to one, two, -three or four cycles after such transfer.
Gating means 228 in the form of an A~D gate similar in function to gates 207 and 213 is provided with a pair of input terminals 229 and 230 the former of which is coupled to the third stage of the storage means 200 and the latter of which is coupled to the gating means 231 in the form of an OR gate.
It can be seen that an output signal on output terminal 232 is derived when the third stage of the storage means 200 is ~5~3~L~
occupied b~ a print signal and the temperature in the fuser is in the low or mid range.
The pulse repetition rate for shifting the prlnt signals through the storage means 200 is 332 milliseconds with the duration of such shift signals being 220 milliseconds duration.
In view of the foregoing, the duration of the signals from the gating means 220, 221 and 228 is equal to the pulse repetition rate of the shift signals.
Gating means 233 is provided with a plurality of inputs one of which is coupled to the shlft terminal 202 and the other two of which are coupled, respectively to the third stage of the storage means 200 and the high range take-off of the thermistor amplifier 215. It can be seen that since one of the inputs to the yating means 233 is derived from the shift terminal the output signal from terminal 234 of the gating device 233 has a duration equal to the shift signal pulse duration of 220 milli-seconds and therefore when the third stage of the storage means 200 is occupied by a print signal and the fuser assembly is in the high temperature range an output signal of 220 milliseconds duration will be provided on output terminal 234.
The operation of the apparatus illustrated in Fig. 3 ~ill now be described. It will be recalled that the successive portions of the support base 9 upon which the electroscopic particles are disposed in imacJe configuration are intermittently moved through the fuser assembly 40 even though the data cards and photosensitive drum are continuously advanced and rotated respectively. Additionally, it can be seen from a consideration o Fig. 1 and the storage means 200 of Fig. 3 that there is a time delay bet~een the incidence of transfer of the image from the photoreceptor to the support 9 and movement of a particular trans~erred image to the fuser assembly ~0. This delay is ~ y i3~L7 inherent even though all the cards being scanned would contain print signal data or coding. Accordinyly, the apparatus dis-closed in Fig. 3 including the storage means 200 and decoding means 204 is arranged to take into consideration that there is a delay of a plurality of cycles between the time an image is transferred and that image sees the i~side of the fuser assembly 40. For purposes of this description it will be assumed that the apparatus disclosed in Fig. 1 has not ~een operated for some time and therefore the ambient temperature of the fuser is in a low temperature range corresponding to a temperature of less than 109F.
When the start button of the machine is depressed by an operator, a start-up signal is generated at the input of gating device .- .
207 via input terminal 208 and simultaneously therewith a second signal is pxovided via input terminal 209 to the gating device 207 which represents a low temperature condition in the ~user assembly. The coincidence of the pulses at input terminals 208 and 209 establishes an output signal from the gating device 207 which triggers a one-shot multivibrator 211 having a pulse duration of 1.3 seconds which provides an input to the gating device 212 the output of which is responded to by the driver ;
means 20~ to thereby supply the energi7ing coil 206 with ground potential. Accordingly, the drivi.ng means 206 may comprise a conventional transistor means having a base electrod~ coupled ~ :
to the gating means 212, and collector electrode coupled to the energizing coil 205 and an emitter electrode coupled to yround ~.
potential. The supplying of the energizing coil 205 with ground potential serves to open the switch 107 to establish high intcnsity operation of the heating element 105. If at the time the apparatus were operated in the fuser assembl~ ~lO contain-ed residual thermal energy, it can be seen that the gating device 213 with coincident signals via terminal inputs 208 and 214 would produce . .~ . , ~ .. ...
~533~
an output signal for triggering a 1.1 second one-shot multivibrator to provide an input to the gating device 212 for supplying energy to the coil 205 from the output of the gating means 212 via the driver means 206 actuated thereby. It should be borne in mind that the foregoing has taken place prior to any card code infor-mation being sensed.
Once the code information is being sensed, the pattern of select and non-select images is transmitted to the decoding means 204 via the storage means 200. The output of the decoding means provides signals to regulate the fuser to provide high intensity levels ~or fusing or the holding level to keep the fuser chamber warm and to minimize the ribbon element heat up response time.
The thermistor sensor signal is divided into three temperature ranges: below 109~; between 109 and 150F; and over 150F.
The shift register select pattern is divided into three groups: selects which are preceeded by other selects within the last three machine cycles (1 label per cycle), selects preceeded by at least three non-selects, and selects, preceeded by at least six non-selects. The shit register signals are combined to form four basic output signals as follows: AND gating device 220 pro-vides an output for 332 milliseconds if a select is preceeded by ' Si.Y non-selects and the fuser temperature is in the low range.
This output occurs two cycles before the paper starts moving;
Gating means 221 provides an output for 332 milliseconds if a select is preceeded by three non-selects and the fuser temperature is in the low range. ~his output occurs one cycle before the paper starts moving;
3a Gating means 228 provides an output for 332 milliseconds if a select occurs in the cycle that the paper is moving and the .
:, ' ':
~IQ533~
temperature is in the low or mid temperature range; and Gating means 223 provides an output for 220 milliseconds if a select occurs in the cycle that the paper is moving (i~e.
print signal in third stage of means 200) and the temperature is in the high range.
From the above, it can be seen that if the fuser chamber is in the low temperature range and a select occurs which is preceeded by six non-selects, the fuser will swltch to high intensity two cycles before the paper advances from the output of gating means 220 and will continue at high intenslty in the following cycle from the output of gating means 221 and also in the paper advance cycle by the output of gating device or means 228. This will provide 996 milliseconds of high intensity fuser operation in three consecutive cycles.
For the case where the chal~er is in the ].ow ranye and the select is preceeded by at least three but not more than six non-selects, the fuser will remain at high intensity for 664 milliseconds from the output of gating means 221 and then gating ~;
means 228.
2~ While the invention has been particularly ~hown and described with reference to an exemplary embodiment thereof, it will be obvious to those skilled in the art that various changes and modifications in form and details may be made without departing from the spirit ancl scope of the invention~ Thus, it is intended that the appended claims be interpreted as including obvious changes and modifications.
3a `
~ 24 -
Claims (9)
1. Apparatus for regulating the fusing of electro-scopic particles to successive portions of a support base moved through a fuser assembly wherein said fuser assembly includes means for softening said electroscopic particles and control means therefor, said electroscopic particles corresponding to documents selectively reproduced from a series of documents scanned for such purposes, said apparatus comprising:
means for sensing at least one ambient condition of such fuser assembly;
means for generating print signals for the document to be selectively reproduced; and means for varying the operation of said control means in accordance with the number of documents not selected for re-production occurring intermediate successive selected documents and in accordance with at least one ambient condition.
means for sensing at least one ambient condition of such fuser assembly;
means for generating print signals for the document to be selectively reproduced; and means for varying the operation of said control means in accordance with the number of documents not selected for re-production occurring intermediate successive selected documents and in accordance with at least one ambient condition.
2. Fuser apparatus for use in the xerographic reproducing apparatus for fusing electroscopic particles to successive portions of the support base intermittently moved through said fuser apparatus, said electroscopic particles cor-responding to reproduced documents selected from a series of documents scanned for such purposes, said apparatus comprising:
means in said fuser apparatus for emitting radiant energy;
means for generating signals for the documents selected for reproduction;
power supply means operatively coupled through said means for emitting radiant energy; and means for regulating said power supply in accordance with the number of documents not selected for reproduction intermediate successive selected documents and in accordance with temperature sensed by a temperature sensing means.
means in said fuser apparatus for emitting radiant energy;
means for generating signals for the documents selected for reproduction;
power supply means operatively coupled through said means for emitting radiant energy; and means for regulating said power supply in accordance with the number of documents not selected for reproduction intermediate successive selected documents and in accordance with temperature sensed by a temperature sensing means.
3. Apparatus according to claim 2 wherein said power supply means comprises a variable voltage supply including switch means; and said means for regulating said power supply means comprises means for actuating said switch means whereby to establish different voltage levels from said power supply means to said radiant energy emitting means.
4. Apparatus according to claim 3 including storage means for storing said signals in accordance with the manner in which they are generated.
5. Apparatus according to claim 4 wherein said storage means comprises shift register means including an input terminal to which is applied said signals representing documents to be reproduced and means for continually shifting on a periodic basis each signal applied to said input terminal through said shift register means whereby the relative positions occupied by signals within the shift register means are a function of the history of those documents both selected and non-selected for reproduction.
6. Apparatus according to claim 5 including decoding means coupling said shift register means and said temperature sensing means to means for acutating said switch means.
7. Apparatus according to claim 6 including start-up signal means for generating a signal when the xerographic apparatus commences operation; and wherein said decoding means comprises gating means responsive to start-up signal means and the temperature sensed by said temperature sensing means for actuating said switch means for a first pre-determined period of time when said fuser appar-atus is at a first temperature level.
8. Apparatus according to claim 7 wherein said decoding means comprises second gating means responsive to said start-up signal means and the temperature sensed by said temper-ature sensing means for actuating said switch means for a longer predetermined period of time when said fuser apparatus is at a second temperature level.
.
.
9. Apparatus according to claim 8 wherein said second temperature level is lower than said first temperature level.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US00363440A US3851144A (en) | 1973-05-24 | 1973-05-24 | Feedback fuser for 730s |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1053317A true CA1053317A (en) | 1979-04-24 |
Family
ID=23430216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA196,149A Expired CA1053317A (en) | 1973-05-24 | 1974-03-27 | Selective fuser for electrophotographic copier |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US3851144A (en) |
| JP (1) | JPS5021735A (en) |
| CA (1) | CA1053317A (en) |
| CH (1) | CH579294A5 (en) |
| DE (1) | DE2417877C3 (en) |
| GB (1) | GB1450841A (en) |
| IT (1) | IT1012745B (en) |
| NL (1) | NL7401529A (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1103744A (en) * | 1975-10-14 | 1981-06-23 | Eastman Kodak Company | Electrophotographic apparatus having compensation for rest-run performance variations |
| JPS60671B2 (en) * | 1976-07-30 | 1985-01-09 | キヤノン株式会社 | Fusing device |
| US4162847A (en) * | 1977-10-06 | 1979-07-31 | International Business Machines Corporation | Hot roll fuser early closure inhibitor |
| JPS5566826U (en) * | 1978-11-01 | 1980-05-08 | ||
| JPS55146466A (en) * | 1979-05-01 | 1980-11-14 | Dainippon Screen Mfg Co Ltd | Fixing heater controller of electrophotographic copier |
| NL8002065A (en) * | 1980-04-09 | 1981-11-02 | Oce Nederland Bv | ELECTROGRAPHIC DEVICE. |
| US4603245A (en) * | 1982-08-23 | 1986-07-29 | Canon Kabushiki Kaisha | Temperature control apparatus |
| JPS6063261U (en) * | 1983-10-07 | 1985-05-02 | トヨタ自動車株式会社 | Seat back structure |
| JPS61129347A (en) * | 1984-11-26 | 1986-06-17 | Toyoda Autom Loom Works Ltd | Seat for automobile |
| US4822977A (en) * | 1987-04-20 | 1989-04-18 | Xerox Corporation | Paper temperature measurement fuser control |
| JPH01303470A (en) * | 1988-05-31 | 1989-12-07 | Sharp Corp | Copying machine |
| JP2941827B2 (en) * | 1988-12-15 | 1999-08-30 | キヤノン株式会社 | Recording device |
| JPH05281878A (en) * | 1992-03-31 | 1993-10-29 | Canon Inc | Image forming device |
| KR960013670B1 (en) * | 1992-08-18 | 1996-10-10 | 삼성전자 주식회사 | Temperature controlling circuit for laser printer |
| US7189949B1 (en) * | 2005-09-27 | 2007-03-13 | Lexmark International, Inc. | Power control system and method for regulating power provided to a heating device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3772497A (en) * | 1971-03-03 | 1973-11-13 | D Gray | Fuser for electrostatic image |
-
1973
- 1973-05-24 US US00363440A patent/US3851144A/en not_active Expired - Lifetime
-
1974
- 1974-02-04 NL NL7401529A patent/NL7401529A/xx not_active Application Discontinuation
- 1974-03-27 CA CA196,149A patent/CA1053317A/en not_active Expired
- 1974-04-11 DE DE2417877A patent/DE2417877C3/en not_active Expired
- 1974-04-17 CH CH532474A patent/CH579294A5/xx not_active IP Right Cessation
- 1974-05-22 JP JP49057761A patent/JPS5021735A/ja active Pending
- 1974-05-22 IT IT23089/74A patent/IT1012745B/en active
- 1974-05-24 GB GB2325074A patent/GB1450841A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2417877A1 (en) | 1974-12-12 |
| IT1012745B (en) | 1977-03-10 |
| CH579294A5 (en) | 1976-08-31 |
| JPS5021735A (en) | 1975-03-07 |
| NL7401529A (en) | 1974-04-25 |
| GB1450841A (en) | 1976-09-29 |
| DE2417877C3 (en) | 1979-10-31 |
| US3851144A (en) | 1974-11-26 |
| DE2417877B2 (en) | 1979-03-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1053317A (en) | Selective fuser for electrophotographic copier | |
| US3449548A (en) | Fusing device | |
| US3837741A (en) | Control arrangement for transfer roll power supply | |
| US3291466A (en) | Xerographic fixing device | |
| US4006985A (en) | Xerographic apparatus having time controlled fusing | |
| US3331592A (en) | Xerographic fusing apparatus | |
| US4434353A (en) | Fusing system | |
| CA1066354A (en) | Corona generator for multicolor electrocopier | |
| US3685896A (en) | Duplicating method and apparatus | |
| US3881085A (en) | Fuser control circuit for copying apparatus | |
| US4897691A (en) | Apparatus for drying and fusing a liquid image to a copy sheet | |
| US5233397A (en) | Thermal transfer apparatus | |
| US3324791A (en) | Xerographic roller fuser drive apparatus | |
| US3961193A (en) | Self adjusting corona device | |
| US4003650A (en) | Controller for reproduction apparatus | |
| US3627523A (en) | Multiple powder transfer in photoelectrostatic duplicator | |
| US3076083A (en) | Xerographic fixing apparatus | |
| US3227549A (en) | Multiple image forming xerographic reproduction process | |
| GB2042746A (en) | Multiple Variable Light Source Photographic Printer | |
| US4027960A (en) | Transfer system for electrostatic reproduction machine | |
| US3745304A (en) | Selective fusing | |
| US3916146A (en) | Selective fusing | |
| US3743779A (en) | Selective fusing | |
| US3954332A (en) | Reproduction machine with improved transfer roll | |
| US3788203A (en) | Justification apparatus |