EP0006553A1 - Verfahren und Vorrichtung zum Betrieb einer Heizquelle in einem Kopiergerät - Google Patents

Verfahren und Vorrichtung zum Betrieb einer Heizquelle in einem Kopiergerät Download PDF

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Publication number
EP0006553A1
EP0006553A1 EP79101972A EP79101972A EP0006553A1 EP 0006553 A1 EP0006553 A1 EP 0006553A1 EP 79101972 A EP79101972 A EP 79101972A EP 79101972 A EP79101972 A EP 79101972A EP 0006553 A1 EP0006553 A1 EP 0006553A1
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EP
European Patent Office
Prior art keywords
temperature
fuser
power
mode
machine
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EP79101972A
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English (en)
French (fr)
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Larry Mason Ernst
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International Business Machines Corp
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International Business Machines Corp
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/20—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

Definitions

  • the invention relates to a method and an apparatus including a microprocessor for controlling and regulating the electrical energy supplied to a heat source in a reproduction apparatus, e.g. a fuser in a xerographic or similar copying or printing machine.
  • a microprocessor for controlling and regulating the electrical energy supplied to a heat source in a reproduction apparatus, e.g. a fuser in a xerographic or similar copying or printing machine.
  • a problem encountered in the design and utilization of copying machines employing heat fusing apparatus is the relatively large amount of thermal energy or the extended length of time required to fuse the toner to or dry the copy sheet.
  • a heat fusing operation is relatively inefficient from a heat transfer standpoint and the heating unit must have sufficient capacity to raise the temperature of the toner above its melting point as the copy sheet is moved through the fusing apparatus.
  • Other significant and sometimes conflicting factors which enter into the design of heat fusing apparatus are the normal variations in ambient temperature and humidity and the character or density of the copy being fused.
  • any heat fusing apparatus has a thermal storage capacity and acts as a heat sink so that less power is required to fuse an image after it has been turned on for a period of time.
  • the problems created by these conflicting design criteria become more critical as attemps are made to provide faster xerographic copying machines which rapidly produce a large number of quality copies and also provide the first copy in any copying run in the shortest - possible time.
  • the regulating circuit incorporates means for compensating for the difference between the average voltage and root mean square voltage whereby the power supplied to the heating element is maintained at a constant level under varying conditions.
  • the circuit also automatically increases the power to the fusing apparatus during the period when the first copies are being produced right after the copying machine has been turned on.
  • U.S. Patent No. 3,878,358 entitled “Digital Power Control", granted April 15, 1975 to E. D. Barton et al. It discloses a digital power control circuit for controlling the temperature of fuser apparatus in a xerographic copier in three different modes of operation.
  • the circuitry utilizes digital logic principles and implements zero voltage switching of silicon controlled rectifiers.
  • a thermistor is used as a temperature sensor.
  • a voltage step generator provides eight voltage steps which are compared with the output of the thermistor. This comparison enables increments of power to be applied to the heat source, ranging from one-eighth to full power. Each increment of power is a full sine wave cycle and the silicon controlled rectifiers are switched so as to allow the determined number of power cycles to be applied to the heat source, depending upon the mode of operation and the temperature of the heat source.
  • U.S. Patent No. 3,961,236, entitled “Constant Power Regulator for Xerographic Fusing System”, granted June 1, 1976 to V. Rodek et al discloses a constant power regulator for a xerographic fuser in which power control is achieved by taking the sum of the load voltage and current.
  • the regulator includes an operational amplifier connected as a voltage adding circuit.
  • the operational amplifier circuit of the power regulator adds the voltage drop across the fuser and a reference resistor connected in series with the fuser and the voltage drop across the fixed reference resistance which represents 'the current flow through the fuser.
  • This summing circuit is detected by a photodetector that electrically isolates the power regulator from a voltage regulator which has an output for controlling the power supply to the fuser through, for example, a Triac, controlled as a function of the power supply signal and the detected voltage generated by the power regulating circuit.
  • Fuser apparatus employing a hot roll is also disclosed in US Patent No. 3,813516, entitled "Apparatus for Temperature Control for A Heated Rotating Cylinder” granted May 28, 1974, to B. S. Kudsi et al., and of common assignee with this application.
  • the Kudsi patent discloses a method and apparatus for controlling the surface temperature of a heated roll in the hot roll fusing station.
  • a web carrying the developed image - is fed through the hot roll fusing station which comprises a heated feed roll mounted adjacent to a backing roll so that the developed image is fused to the web material.
  • the peripheral surface of the heated feedroll is maintained at an elevated temperature.
  • a temperature sensing means such as a thermistor, is mounted on suitable support means which positions the thermistor in the boundary layer surrounding the heated roll so that the changes in temperature in the boundary layer can be sensed.
  • the output of the temperature sensing means comprises an electrical signal which is coupled to a temperature controller means to produce signals to control the amount of heat applied by the heating means to the heated feedroll to control its surface temperature.
  • a more detailed object of the invention is to provide a microprocessor control method and circuit for the precision regulation of the electrical energy to the heat fusing apparatus of a reproduction machine.
  • a further object of the invention is to provide a microprocessor control circuit for efficiently providing precise increments of electrical energy to a fuser apparatus of a xerographic machine to bring and maintain said fuser apparatus to a desired temperature, where the desired temperature and increments of energy provided are in accordance with the mode of operation of the copier.
  • claim 1 is directed to a method for operating an electrical heat source in a specific way
  • claim 6 concerns an apparatus according to the invention.
  • a xerographic or similar reproduction machine may be considered to operate in three separate modes. These modes may be termed “warm-up”, “stand-by” and “print” or “copy” mode.
  • a copier is in its "warm-up” mode when it is initially turned on and the fuser temperature is brought up to a certain predetermined temperature level.
  • the "stand- by” mode maintains the fuser temperature at the predetermined temperature level subsequent to the "warm-up” mode and prior to the copier being activated to produce a copy or print.
  • the "print” mode is initiated.
  • the "print” mode may raise the fuser temperature to a predetermined somewhat higher temperature level to effect fusing of toner particles onto a support sheet. by providing additional energy to the fusing apparatus.
  • the support sheet is the xerographically produced print.
  • the electrophotographic member of the copying machine comprises a drum 10 which is mounted for rotation in the direction indicated by the arrow 11. Disposed on the outer periphery of the drum is photoconductor 12 coated on a flexible conductive backing material and stored on reels within the interior of the drum to permit replacement or changing of the operative photoconductor surface without removing the drum from the machine.
  • An initial charging station is provided by a corona unit 13 which deposits a uniform charge on the surface of the photoconductor 12 while the same is maintained in the dark.
  • the next station is exposure station 14 where a line image of the original document,,is projected onto the uniformly charged surface of the photoconductor 12 as the drum 10 rotates.
  • the next station in the direction of the rotation of the drum 10 is cascade developer 20 where a two component developer composition is caused to cascade or move across the surface of the drum.
  • the developer composition comprises heat fixable marking particles (toner) which are attracted to and deposited on the surface of the photoconductor 12 in accordance with the latent electrostatic image corresponding to the original.
  • the result of the cascade development operation is the formation of a toner image on the photoconductor. It is necessary to transfer the toner image to a copy sheet and this is accomplished at the toner transfer station 22.
  • the plain copy paper is stored within the copying - machine in roll form as indicated by roll 24 and is fed along a path of travel 25 in the direction indicated by the arrows leading past knives 26, toner image transfer station 22, fusing apparatus generally indicated by reference number 27 and then to an output copy hopper 28.
  • the copy paper is cut to the length selected by the operator and the cut copy sheet moves into contact with the drum.
  • a transfer corona unit 29 assists in the transfer of the toner image to the copy sheet.
  • the copy sheet is then separated from the drum, the toner image fused by heat and the final copy transported to the output hopper 28.
  • the fusing apparatus 27 is located along the upwardly inclined path of travel 25 of the copy sheets between the toner image transfer station 22 and the output copy hopper 28. It comprises a heating unit 34 and an elongated and stationary vacuum plenum 35 located below the path of travel 25 which provides a means for supporting and transporting copy sheets through the fusing apparatus.
  • the heating unit 34 is positioned above the path of travel 25 of the copy sheets in opposed overlying relation with respect to the vacuum plenum 35 and comprises a quartz heating element or lamp 38 and a reflector 39.
  • the lamp 38 and the reflector 39 are elongated and extend transversely across the path of travel 25 of the copy sheets.
  • the inner surface of the reflector 39 is generally elliptical and highly specular.
  • the heating lamp 38 and the reflector 39 cooperate to produce a transversely extending and relatively narrow band of infrared radiation on the surface of a copy sheet.
  • the heating unit 34 is mounted from a carriage, not shown, for traversing movement back and forth along the path of travel of the copy sheets.
  • the heating unit 34 moves from the initial position to a final position indicated by broken lines as a copy sheet moves through the fusing apparatus along the path of travel 25.
  • This arrangement effectively increases the time during which the copy sheet and the heating unit are in operative fusing relation with respect to each other. After the fusing operation, the heating unit 34 is returned to its initial position. Additional details concerning the fusing apparatus are set forth in U.S. Patent No. 3,481,589, entitled "Xerographic Fusing Apparatus", granted December 2, 1969 to J. V. Cely et al.
  • Block 116 is a general I/O representation of control areas (not expressly shown) such as the coronas, illumination lamp, developer bias, original pick, copy paper pick, etc. except for the areas related to the fuser control which is described in detail in this specification and the drawings.
  • Power input to the xerographic machine's process control module 102 is from the AC power source 101 via lines 107 and 108. Power is directed unaer the control of process control module 102 to areas in the machine represented by I/Os in block 116 and fuser heater 103.
  • Thermistor 104 is a thermal energy to electrical resistance conversion device used to sense the temperature of the fuser or the fuser hot roll.
  • the temperature information from thermistor 104 is conveyed via lines 111 and 112 to the process control module 102.
  • Module 102 will interpret and apply the proper power level to the fuser heater 103 via lines 109 and 110.
  • Overtemperature fuse 115 is a further thermal energy to electrical value conversion element used to sense the fuser's temperature.
  • the operating temperature of the overtemperature fuse 115 is set at a higher level than the nominal controlling temperature of the fuser.
  • the process control module 102 will monitor lines 113 and 114 for continuous current flow; if this current flow should be reduced significantly (like 1/2 of nominal) the process control module 102 will assume the thermistor 104 and its related circuitry has malfunctioned (for example, the fuser's temperature has reached an excessive level).
  • the process control module 102 will force itself into a failsafe condition preventing machine operation and removing all power to all I/O devices (block 116 and fuser heater 103).
  • FIG. 3 shows a block schematic of the process control module 102.
  • the basic timing element is the AC line zero crossing circuit 124.
  • a pulse is generated on lines 118 and 142 everytime the output voltage of AC power source 101 crosses through zero potential. This pulse is inputted into the TRIAC Driver 126 and the microprocessor 127.
  • Line 130 applies an input signal to the overtemperature fuse detection circuit 129 to force the process control module 102 into a failsafe mode when the AC power source 101 changes to an abnormal low level.
  • Safety relay and related circuitry 125 is used to remove all power to all I/O devices when the process control module 102 senses a failsafe mode.
  • the actual instruction controlling the safety relay is via line 119 from microprocessor 127.
  • TRIAC driver 126 is the power controlling element used to apply power to the fuser heater 103 at the proper time as determined by input lines 142 and 143.
  • line 143 is high from the microprocessor 127, power is applied to the fuser heater 103 for a half cycle of the AC power starting when a pulse is applied to line 142.
  • line 143 is low, no power is applied to the fuser heater 103 independent of line 142.
  • the Wheatstone bridge 128 is used to interpret the thermistor's temperature information on lines 111 and 112.
  • the microprocessor 127 varies lines 120 and 121 when it is necessary to check, per the instructions in the microprocessor's ROM, for one of the variations in temperature level on the fuser, as described later herein.
  • Line 122 feeds the interpreted information into the microprocessor 127 after lines 120 and 121 have settled due to an internal delay from microprocessor 127.
  • the overtemperature fuse detection circuit 129 is used to interpret the temperature information on lines 113 and 114 ( Figure 8). This information is inputted to the micropressor 127 via line 123. Anytime line 123 is high, the microprocessor 127 will force the process control module 102 into a failsafe mode. Due to the unique design of this overtemperature fuse detection circuit 129, two additional functions are also present as described below. When the machine is first turned on, an inherent delay is present which causes line 123 (Fig. 8) to go high for about 300 milliseconds due to the integration of resistors 69 and 70, capacitor 72, and Schmitt-Trigger 173 anytime the voltage on capacitor 72 is below the threshold voltage of the Schmitt-Trigger 173.
  • the microprocessor 127 is forced to a certain predetermined location (initialization) in its ROM so the program starts from a known location (this - location in the ROM is one of the process control module's 102 failsafe modes).
  • the second function, by monitoring line 130, is to force the process control module 102 into a failsafe mode anytime the AC power source 101 drops to an unsafe voltage level.
  • Block 175 entitled "I/O Control” represents the other control circuitry used to control the I/Os in block 6 which represents other I/Os required for machine operation.
  • the microprocessor 127 may be any of the standard types available like the NEC u COM 45, Motorola 6800, TI TMS 1000, Rockwell MM 72, etc. (The foregoing names and type denominations are, at least partly, registered trademarks in one or more countries.)
  • the purpose of the microprocessor 127 is to provide the process control module 102 with some minimal intelligence to ensure the I/O devices perform their necessary function.
  • Figures 4, 5, 6, 7 and 8 show the circuit schematics of the circuitry represented by blocks 124, 125, 126, 128 and 129, respectively, of Figure 3.
  • the circuits per se are relatively simple and straightforward in operation and will be readily understood in view of the description hereinafter.
  • Figure 4 shows the AC line zero crossing circuit and 24 volt power supply.
  • the power line voltage is stepped down by transformer 32 to the proper voltage for the 24 volt supply.
  • the bridge 33 provides full wave rectification which may be used by transistor 73 to detect zero crossing when the current in resistor 35 approaches zero (voltage at the output of bridge 33 approaches zero).
  • Diode 36 provides the necessary isolation between the 24 volt power supply and the zero crossing circuit.
  • Capacitor 37 provides the necessary power supply filtering.
  • Figure 5 shows the safety relay and related circuitry.
  • Driver 40 causes 24 Volt to be placed across the relay 41 coil when the signal on line 119 is high.
  • the contacts of relay 41 close and power is applied to the TRIAC driver 126 and clock 175.
  • line 119 is low, the reverse of the above occurs.
  • Figure 6 shows the TRIAC driver.
  • driver 45 When line 143 is high and a pulse is applied to 142, driver 45 is turned on causing current to flow through the LED in module 46. This causes base drive to transistor 51, causing the TRIAC to be turned on.
  • Components 47, 48, 53, 52 form a relatively simple power supply for the necessary current to gate the TRIAC on.
  • Figure 7 shows the Wheatstone bridge. Its basic function is to determine when thermistor 104 is above or below a certain resistance value. For example, when the thermistor 104 resistance is greater than 7.87k ⁇ (assuming resistors 58 and 61 are open), the plus input of operational amplifier 67 will be at a lower potential than the minus input causing the operational amplifier 67 to be low. This condition will cause line 122 to be high by inverter 68. If the condition described above is reversed, (i.e., thermistor 104 restistance less than 7.87kn) all signal levels are reversed.
  • Resistors 58 and 61 are used by the microprocessor by connecting lines 121 or 120 to a +10 volt power supply using internal drive transistor at the necessary time so different thermistor 104 resistance values may be checked.
  • FIG 8 shows the overtemperature fuse detection circuit. This circuit checks for current flow in overtemperature fuse 115. The current is supplied by resistors 69, 70 and 71 and capacitor 72. Schmitt trigger 173 is used to measure the voltage across resistor 71. Anytime this voltage is above 6 volts, line 123 will be low. Capacitor 72 is used for integration so noise does not cause line 123 to change levels very quickly and provide the necessary delay as described earlier.
  • FIGS 9A and 9B show a partial flow chart of the program stored in the microprocessor's (127) ROM.
  • the terms employed in the flow chart are defined in the following table.
  • Pl represents maximum power being provided to the heater 103 of the fuser apparatus. (Every full half cycle of power of the AC source).
  • P2 represents stand-by power being provided to the heater 103 of the fuser apparatus. (A predetermined number of half cycles of power of the AC source per unit of time wherein a greater number of half cycles of power are available within said unit of time).
  • ni represents the number of half cycles of power provided to the heater 103 of the fuser apparatus out of every sixteen, for example, half cycles (eight full cycles) of the AC power source.
  • n1 represents the number of half cycles of power provided to the heater 103 of the fuser apparatus out of every sixteen, for example, half cycles (eight full cycles) of the AC power source to maintain the fuser apparatus in the stand-by mode, i.e. fuser temperature T2.
  • n2 represents the incremental, or additional, number of half cycles of power added to n1 and provided to the heater 103 of the fuser apparatus out of every sixteen, for example, half cycles (eight full cycles) of the AC power source when the fuser apparatus is in a copy mode (print mode) and the temperature,of the fuser is less than the temperature T2.
  • n3 represents the incremental, or additional, number of half cycles of power added to n1 and provided to the heater 103 of the fuser apparatus, out of every sixteen, for example, half cycles (eight full cycles) of the AC power source when the fuser apparatus is in a copy mode (print mode) and the temperature of the fuser is equal to or greater than temperature T2.
  • Tl is the up-to temperature of the fuser roll or the fusing apparatus when it is in the warm-up mode
  • T2 is the operating temperature of the fuser roll or the fusing apparatus when it is to be utilized during the copy mode (print mode) or stand-by mode.
  • X2 represents the time period during a copy cycle when additional energy must be provided to the heater 103 of the fuser apparatus to compensate for the heat loss attributable to the actual fusing operation of the toner to the copy. This is particularly important when a hot roll fuser is used.
  • line 123 changes to a DOWN level with the microprocessor 127 cycling through its program after the first initial zero crossing pulse on line 118.
  • the microprocessor 127 turns the fuser heater 103 on at full power.
  • the basic action while the fuser temperature is less than Tl is to prevent the machine from making copies.
  • This control is exercised by microprocessor 127 through control circuitry (block 175, Figure 3; block 116, Figure 2) not expressly shown herein.
  • the microprocessor 127 checks for other necessary machine functions, it returns to the beginning of the program and halts. After the next zero crossing, the microprocessor 127 will repeat the above cycle.
  • the microprocessor 127 When the microprocessor 127 senses that the fuser temperature has exceeded temperature T1, it will automatically reduce the input power level to fuser heater 103 from P1 to P2. This allows the fuser temperature to reach the correct operating point without excessive overshoot due to the thermal lag associated with the fusing pararatus, particularly when using a hot roll. While the machine is in "stand-by", the process control module 102 constantly monitors the fuser temperature to maintain the proper temperature T2. This is accomplished by varying nl at the proper rate to ensure the proper amount of energy is supplied. For example, if the fuser temperature is low as determined by the Wheatstone bridge 128, the microprocessor will increase n1 by one.
  • n1 (after a predetermined time delay) until the fuser temperature T2 is exceeded.
  • the reverse process described is performed. Namely, nl will be reduced to thereby provide less energy to the fuser. Also during this time, processing power of the microprocessor 127 is multiplexed to monitor other I/O devices (blocks 116 and 175) ensuring their proper function.
  • the microprocessor 127 Periodically, for example every 30 seconds, the microprocessor 127 will bring line 121 high for about 20 milliseconds, so resistor 58 ( Figure 7) will be in parallel with resistor 59 (resistor 61 is open circuit). This will cause the output line 122 to determine if the fuser temperature is at an excessive level (additional safety feature to the overtemperature fuse). If so, the microprocessor 127 enters a state called hard stop (similar to the failsafe mode) preventing machine operation and dropping all power to all I/O devices via the safety relay 141 ( Figure 5).
  • hard stop similar to the failsafe mode
  • the process control module 102 When the process control module 102 senses the machine is asked to produce a copy, the process control module 102 causes the I/O devices (block 116) to operate in the proper sequence. In addition, the process control module 102 changes the power level in fuser heater 103 at the proper time in the copy process sequence. From experimental studies, one finds that approximately 500 joules are required to fuse toner to an 8-1/2 by 11 inches sheet of paper using a hot roll fuser. To minimize the temperature excursions between the time the fuser is in stand-by and the time the fuser is fusing toner to paper, the rate energy is removed and the rate energy must be replaced should be the same.
  • the standby losses of the fuser remain relatively constant over any given environment, therefore, all that is necessary is a system which responds to find the optimum rate at which energy may be replaced in the fuser.
  • the paper acts very much like a heat sink removing energy at a very rapid rate; therefore, it is necessary to increase the rate energy is provided to the fuser to match the removal rate.
  • a very simple method is to increase the power to fuser heater 103 by a fixed amount for a certain duration about the time paper is entering the fuser hot roll - nip. The optimum time would be about one thermal time constant of the fuser hot roll immediately before the paper enters the fuser.
  • n2 or n3 a fixed number (n2 or n3) to nl depending upon the fuser hot roll's temperature for the duration the hot roll fuser needs additional energy. For example, if the fuser hot roll's temperature is less than T2, the fixed number n2 added to nl will cause the power in fuser heater 113 to be slightly greater than the standby losses and energy required for fusing. Similarly, the number n3 added to nl when the fuser hot roll's temperature is greater than T2, will be slightly less than the standby losses and energy required for fusing.
  • nl is set equal to one of two values depending upon the fuser hot roll's temperature (one when the fuser is below T2, and one when fuser is above T2) instead of letting the microprocessor find the optimum value of nl, as described supra for the standby losses.
  • block 201 represents the turning on of the xerographic machine, namely the initial application of power to the machine (see power source 101, Figure 2).
  • full power is provided to the fuser heater of the fusing apparatus subject to the following conditions.
  • the logical condition required by circle 202 is that the power to the xerographic machine has just been turned “on” and/or the fuser temperature is less than a predetermined temperature Tl.
  • Block 203 entitled "Hold Till Zero Crossing” represents the condition that only full half cycles of power will be provided to the fuser heater. (Reference is made to AC line zero crossing circuit 124, microprocessor 127, and Triac driver circuit 126, Figure 3).
  • Block 204 entitled "Machine Function Check Except Fuser" represents the condition that in addition to the fuser temperature all other xerographic machine functions are monitored by the microprocessor 127. The monitoring of these functions such as paper supply, corona unit, etc., as to their ready state, or status, by the microprocessor is not explicitly disclosed herein. Block 204 represents that none of these functions provides a manifestation to the microprocessor directing it to preclude by control the application of power to the heater of the fusing apparatus.
  • Block 205 entitled "Turn Fuser Heater On to Full Power Pl” represents the following status: (1) the fuser roller of the fusing apparatus is below temperature Tl (the xerographic machine has just been turned on, or the temperature of the fuser has not yet reached Tl); (2) the conditions as represented by blocks 203 and 204 have been and are being met; (3) and full power is being applied to the heater of the fusing apparatus.
  • Full power Pl being defined as in the table supra to be each and every half cycle of power available from the AC power source.
  • diamond shaped decision block 206 entitled "Check Fuser for Temperature T1". This block represents the fact that the fuser is continually monitored for the temperature Tl.
  • the block 206 may be considered a decision block in the flow chart. As long as the temperature is below Tl, maximum power will be provided to the fuser heater. This condition is depicted by the legend "No" associated with feedback line 206B. Still referring to block 206, when the temperature is equal to or greater than T1 the condition is depicted by the legend "Yes" associated with line 206A which manifests this condition to block 207 in the flow chart.
  • Power P2, as defined earlier herein, is stand-by power, wherein a predetermined number of half cycles of power of the AC source per unit of time (wherein a greater number of half cycles of power is available from said source within said unit of time) are provided to the fuser heater of the fusing apparatus.
  • Block 208 entitled "Set Machine Status From Warm-Up to Stand-By" indicates that the xerographic machine is in condition to be called upon to function to produce copies or prints. Namely, the machine is ready, including the temperature of the fuser apparatus, for a copy cycle to be initiated.
  • the logical condition required is (1) an output from block 209 that the machine status has changed from the warm-up mode to the stand-by mode, or (2) output from block 223 representing machine has completed fusing operation in a copy cycle, or is maintaining stand-by mode.
  • the block 210 entitled “Hold Till Zero Crossing” contained within the flow chart closed loop of blocks 210 through 223 corresponds in the condition represented to the like entitled block 203 contained with the flow chart closed loop of blocks 203 through 206.
  • the decision block 211 entitled “Check Fuser Over-Temperature Every 24 Minutes”, represents the fact that the overtemperature detection means of the fuser apparatus is being continually monitored. (Reference is made to block 129, Figure 3, and to the circuit of Figure 8).
  • Decision block 213 entitled “Check for Copy” represents the provision of a "No” condition on line 213B when the machine is not called upon to produce a copy (enter a copy cycle) and provides a "Yes" condition on line 213A when the machine is called upon to produce a copy (enter a copy cycle).
  • Block 220 is entitled “Decrease nl by 1 if Proper Delay Since Last Change".
  • the function represented by block 220 is a reduction of 1 in nl, where nl, as defined earlier herein, represents the number of half cycles of power provided to the heater 103 of the fuser apparatus out of every sixteen, for example, half cycles (eight full cycles) of the AC power source to maintain the fuser apparatus (temperature T2) in the stand-by mode. If the specified time interval since the last change in nl has not elapsed, then nl will not be decreased.
  • Block 221 is entitled “Increase nl by 1 If Proper Delay Since Last Change”.
  • the function represented by block 221 is an increase in nl where nl, as defined supra, is a number of half cycles of energy supplied to the fuser apparatus. Again, if the specified time interval since the last change in nl has not elapsed, then nl will not be increased.
  • operation proceeds to the function represented by decision block 215 entitled “Check Fuser for Temperature T2", Assume the temperature of the fuser is T2 or slightly greater. This condition is indicated by a “Yes” on line 215A from block 215 and operation proceeds to the function depicted by block 216.
  • Block 216 is entitled “Add n3 To nl For X2 Seconds Then Return To nl”.
  • the function represented by block 216 is an increase in the number of half cycles of energy per unit time provided to the fuser apparatus for a given number of units of time where the total elapsed time of the given number of units of time is in the order of X2 seconds.
  • nl represents the number of half cycles of power (energy) provided to the heater 103 of the fuser apparatus out of every sixteen, for example, half cycles (eight full cycles) of the AC power source to maintain the fuser apparatus in the stand-by mode (temperature T2);
  • n3 represents the incremental, or additional, number of half cycles of power (energy) added to nl and provided to the heater 103 of the fuser apparatus, out of every sixteen,, for example, half cycles (eight full cycles) of the AC power source, when the fuser apparatus (temperature T2) is in a copy cycle (print mode) and the actual temperature of the fuser is equal to or greater than temperature T2;
  • X2 represents the time period during a copy cycle when additional energy must be provided to the heater 103 of the fuser apparatus to compensate for the heat loss attributable to the actual fusing operation.
  • the function represented by block 217 is an increase in the number of half cycles of power per unit time provided to the fuser apparatus for a given number of units of time where the total elapsed time of the given number of units of time is in the order of X2 seconds, where n2 is the incremental or additional number of half cycles of power added to n1 out of, e.g., every sixteen half cycles of the AC power source, when the machine is in a copy cycle and the fuser temperature is lower than T2.
  • nl, n3 and X2 are as defined earlier herein. It is to be appreciated that n2 > n3; and hence nl+n3 ⁇ nl+n2.
  • Warm-up Mode The closed loop operations and functions represented by legends and symbols bearing reference characters 202, 203, 204, 205 and via line 206B to 202.
  • Stand-by Mode The closed loop operations and functions represented by legends and symbols bearing reference characters (I)(Fuser Temperature is equal to T2 or slightly greater): 209, 210, 211, 213, 218, 219, 220, 222, 223 and via line 223A to 209; (II) (Fuser Temperature is less than T2): 209, 210, 211, 213, 218, 219, 221, 222, 223 and via line 223A to 209.
  • microprocessor controlled power supply for xerographic fusing apparatus provides during the stand-by mode and the copy mode the monitoring of the temperature of the fuser apparatus and the control of the energy increments per unit time provided to the fuser apparatus in a manner which approaches actual real time continuous fuser temperature control.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Fixing For Electrophotography (AREA)
  • Control Of Temperature (AREA)
  • Control Or Security For Electrophotography (AREA)
EP79101972A 1978-07-03 1979-06-15 Verfahren und Vorrichtung zum Betrieb einer Heizquelle in einem Kopiergerät Withdrawn EP0006553A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US92165978A 1978-07-03 1978-07-03
US921659 1978-07-03

Publications (1)

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EP0006553A1 true EP0006553A1 (de) 1980-01-09

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US (1) UST100804I4 (de)
EP (1) EP0006553A1 (de)
JP (1) JPS559593A (de)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0030372A2 (de) * 1979-12-11 1981-06-17 International Business Machines Corporation Elktrophotographisches Kopiergerät
EP0053438A2 (de) * 1980-11-28 1982-06-09 Xerox Corporation Variable Leistungssteuerung für Schmelzfixiervorrichtung
EP0085950A1 (de) * 1982-02-08 1983-08-17 Hitachi, Ltd. Temperatursteuervorrichtung für eine Fixierheizquelle in einem Kopiergerät
EP0159570A1 (de) * 1984-03-30 1985-10-30 Mita Industrial Co. Ltd. Steuerungsverfahren für ein Kopiergerät
EP0193914A2 (de) * 1981-12-21 1986-09-10 Mita Industrial Co. Ltd. Elektrostatisches Kopiergerät
EP0264968A2 (de) * 1983-04-12 1988-04-27 Mita Industrial Co. Ltd. Elektrostatisches Kopiergerät
AU597528B2 (en) * 1988-05-17 1990-05-31 Fujitsu Limited Method of controlling fuser unit of image forming apparatus
EP0658246A1 (de) * 1992-09-04 1995-06-21 Elonex Technologies, Inc. Energiespargerät für laserdrucker
EP0878749A2 (de) * 1997-05-14 1998-11-18 Canon Kabushiki Kaisha Bilderwärmungsgerät
US5972659A (en) * 1984-08-22 1999-10-26 Connaught Laboratories Limited Multispecific antigenic proteins

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5140132A (en) * 1988-12-29 1992-08-18 Seikosha Co., Ltd. Method of and apparatus for controlling fixing device in electrophotographic recording system
JP3036028B2 (ja) * 1990-09-10 2000-04-24 ブラザー工業株式会社 熱定着装置
US6192283B1 (en) 1998-07-31 2001-02-20 Siemens Energy & Automation, Inc. Method and apparatus for adaptive control of a system or device
US6188854B1 (en) * 1999-11-09 2001-02-13 Tommy C. Coleman Non-contact thermal temperature controller

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3532855A (en) * 1968-12-30 1970-10-06 Ibm Power regulating circuit for xerographic fusing apparatus
DE1497119B1 (de) * 1964-08-12 1971-08-12 Addressograph Multigraph Automatisches elektrophotographisches kopiergeraet
US3878358A (en) * 1972-11-16 1975-04-15 Xerox Corp Digital power control
DE2717265A1 (de) * 1976-04-19 1977-11-10 Canon Kk Fixiervorrichtung eines elektrofotografischen kopiergeraets
DE2720537A1 (de) * 1976-05-06 1977-11-10 Sharp Kk Elektrofotografisches kopiergeraet
US4144835A (en) * 1976-11-05 1979-03-20 Rank Xerox Limited Contact heat fixing apparatus

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1497119B1 (de) * 1964-08-12 1971-08-12 Addressograph Multigraph Automatisches elektrophotographisches kopiergeraet
US3532855A (en) * 1968-12-30 1970-10-06 Ibm Power regulating circuit for xerographic fusing apparatus
US3878358A (en) * 1972-11-16 1975-04-15 Xerox Corp Digital power control
DE2717265A1 (de) * 1976-04-19 1977-11-10 Canon Kk Fixiervorrichtung eines elektrofotografischen kopiergeraets
DE2720537A1 (de) * 1976-05-06 1977-11-10 Sharp Kk Elektrofotografisches kopiergeraet
US4144835A (en) * 1976-11-05 1979-03-20 Rank Xerox Limited Contact heat fixing apparatus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
IBM TECHNICAL DISCLOSURE BULLETIN, Vol. 21, Nr. 2, July 1978 G.J. HOWARD et al. "Copier Fuser Controls" pages 481 to 482. *

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0030372B1 (de) * 1979-12-11 1985-10-16 International Business Machines Corporation Elktrophotographisches Kopiergerät
EP0030372A2 (de) * 1979-12-11 1981-06-17 International Business Machines Corporation Elktrophotographisches Kopiergerät
EP0053438A2 (de) * 1980-11-28 1982-06-09 Xerox Corporation Variable Leistungssteuerung für Schmelzfixiervorrichtung
EP0053438A3 (en) * 1980-11-28 1983-03-16 Xerox Corporation Variable power fuser control
EP0193914A3 (en) * 1981-12-21 1987-01-07 Mita Industrial Co. Ltd. Electrostatic copying apparatus
EP0193914A2 (de) * 1981-12-21 1986-09-10 Mita Industrial Co. Ltd. Elektrostatisches Kopiergerät
EP0085950A1 (de) * 1982-02-08 1983-08-17 Hitachi, Ltd. Temperatursteuervorrichtung für eine Fixierheizquelle in einem Kopiergerät
EP0264968A2 (de) * 1983-04-12 1988-04-27 Mita Industrial Co. Ltd. Elektrostatisches Kopiergerät
EP0264968A3 (en) * 1983-04-12 1989-05-31 Mita Industrial Co. Ltd. Electrostatic copying apparatus
EP0511685A1 (de) * 1983-04-12 1992-11-04 Mita Industrial Co., Ltd. Elektrostatisches Kopiergerät
EP0159570A1 (de) * 1984-03-30 1985-10-30 Mita Industrial Co. Ltd. Steuerungsverfahren für ein Kopiergerät
US5972659A (en) * 1984-08-22 1999-10-26 Connaught Laboratories Limited Multispecific antigenic proteins
AU597528B2 (en) * 1988-05-17 1990-05-31 Fujitsu Limited Method of controlling fuser unit of image forming apparatus
EP0658246A1 (de) * 1992-09-04 1995-06-21 Elonex Technologies, Inc. Energiespargerät für laserdrucker
EP0658246A4 (de) * 1992-09-04 1995-08-09 Oakleigh Systems Inc Energiespargerät für laserdrucker.
EP0878749A2 (de) * 1997-05-14 1998-11-18 Canon Kabushiki Kaisha Bilderwärmungsgerät
EP0878749A3 (de) * 1997-05-14 1999-10-20 Canon Kabushiki Kaisha Bilderwärmungsgerät
US6040558A (en) * 1997-05-14 2000-03-21 Canon Kabushiki Kaisha Image heating apparatus

Also Published As

Publication number Publication date
UST100804I4 (en) 1981-07-07
JPS559593A (en) 1980-01-23

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