JP4991452B2 - Image forming apparatus - Google Patents

Description

The present invention forms a toner image on an image carrier, transfers the toner image to a long recording medium longer than a standard size, and records the toner image transferred to the long recording medium with a fixing device. those related to the image forming equipment for fixing to the medium.

  According to the above-described image forming apparatus configured as an electronic copying machine, a printer, a facsimile, or a complex machine thereof, it is possible to form an image on a long recording medium having a length of, for example, 10 m to 15 m. is there. A fixing device used in such an image forming apparatus includes a fixing member, a pressure member pressed against the fixing member, a temperature detecting unit that detects the temperature of the fixing member, and a heating unit that generates heat from the fixing member. A long recording medium carrying a toner image is passed through the nip portion between the fixing member and the pressure member, and heat and pressure are applied to the toner of the toner image on the long recording medium during the passage. The toner image is fixed on a long recording medium.

  When a long recording medium is passed between the fixing member and the pressure member of such a fixing device, the heat of the fixing member continues to be taken away by the long recording medium for a long time. While the long recording medium passes through the fixing member, the temperature of the fixing member becomes lower than the temperature suitable for fixing the toner image, which may cause a fixing failure of the toner image.

  A general configuration of a fixing device used in an image forming apparatus is described in, for example, Patent Documents 1 to 4.

JP 2002-184554 A JP 2005-39873 A JP 2005-32558 A JP 2005-18049 A

The object of the present invention is to prevent the problem that the temperature of the fixing member falls below the temperature suitable for fixing the toner image during the fixing operation of the toner image on the long recording medium, and to produce the image with stable fixing quality. It is to provide an image forming equipment without any loss of sexual.

In order to achieve this object, the invention described in claim 1 forms a toner image on an image carrier and transfers the toner image to a long recording medium (long recording paper 11) longer than a standard size. An image forming apparatus for fixing a toner image transferred to the long recording medium to a long recording medium by a fixing device (fixing unit 202), the fixing device including a fixing member (fixing roller 1) and the fixing device. A pressure member (pressure roller 2) pressed against the member; a temperature detection means (6) for detecting the temperature of the fixing member; and a heating means for generating heat from the fixing member. An image forming apparatus (wide-width digital copy) that passes a long recording medium carrying a toner image through a nip portion of the toner image and applies heat and pressure to the toner of the toner image when passing through the nip portion to fix the toner image to the long recording medium. Machine HDC)
Main power supply means (main power supply device 21) for supplying AC power;
A plurality of auxiliary power supplies (capacitors C1 and C2) that can switch outputs by connecting them in series, in parallel, or alone;
AC power is supplied from the main power supply means to generate heat and a main heating member (main heating part 3) constituting a part of the heating means for heating the fixing member;
An auxiliary heating member (auxiliary heating unit 4) that forms part of the heating unit that generates heat by supplying power from the plurality of auxiliary power sources and heats the fixing member;
Power control means (CPU 23) for performing power-related control of the image forming apparatus,
The power supply control means uses the temperature detection means to determine the surface temperature of the fixing member when the long recording medium passes while performing heat fixing only with the main heating member that generates heat by the AC power supplied from the main power supply means. A first control to be detected;
When the detected surface temperature of the fixing member falls below a fixing temperature threshold value at which it is determined that the required toner fixing temperature cannot be maintained, and the next document reading operation is performed, the plurality of auxiliary power supplies A second control for connecting the power supply in series and supplying electric power to the auxiliary heating member to generate heat and maintain the fixing temperature;
When the detected surface temperature of the fixing member falls below the fixing temperature threshold and the next document reading operation is not performed, the plurality of auxiliary power supplies are connected individually or in parallel to supply power. And a third control for supplying heat to the auxiliary heating member to generate heat and maintaining the fixing temperature.

The above configuration and its operation are illustrated in, for example, FIGS.
In FIG. 4, in the first control, the temperature of the fixing roller 1 is detected (step S1), and it is determined whether or not the detected temperature is equal to or higher than the necessary fixing temperature (step S2). If the temperature is equal to or higher than the necessary fixing temperature (step S2: YES), this operation is continued until the end of paper passing (printing) without using the auxiliary power source (step S3). Therefore, the fixing roller 2 is always secured at a temperature higher than the necessary fixing temperature.

  Further, in the second control, in FIG. 4, the control of step S1 → step S2 (NO) → step S6 (YES) → step S8 → step S9 is performed. If the temperature is not higher than the fixing required temperature in step S2, it is determined whether or not the next reading operation is being performed. If the reading operation is being performed (step S6: YES), auxiliary power supplies (capacitors C1 and C2) are connected in series. Then, the auxiliary heat generating portion 4 is caused to generate heat to secure the necessary fixing temperature. In this case, since the capacitors C1 and C2 are connected in series, a high voltage can be applied as shown by a solid line in FIG. 6, and the fixing roller 1 can be heated within a short time. Therefore, even if the fixing roller 1 is below the required fixing temperature, it can be immediately maintained above the required fixing temperature.

Further, in the third control, in FIG. 4, the control of step S1, step S2 (NO), step S6 (NO), step S7, and step S9 is performed. If the temperature is not higher than the necessary fixing temperature in step S2, it is determined whether or not the next reading operation is being performed. If the reading operation is not being performed (NO in step S6), auxiliary power supplies (capacitors C1 and C2) are connected in parallel. Then, the auxiliary heat generating portion 4 is caused to generate heat to secure the necessary fixing temperature. Since the capacitors C1 and C2 are connected in parallel, a voltage can be applied for a long time as indicated by a two-dot chain line in FIG. 6, and the fixing roller 1 can be heated for a long time. Accordingly, the fixing roller 1 can be maintained at a temperature equal to or higher than the temperature required for fixing even when the temperature is lower than the temperature required for fixing.
Therefore, by performing the first to third controls, it is possible to supply auxiliary electric power corresponding to the amount of heat that is insufficient for fixing, and to pass the paper while maintaining the fixing quality without reducing productivity.

The invention according to claim 2 includes a charging means (charger 22) for charging the plurality of auxiliary power supplies, and the plurality of auxiliary power supplies are configured by chargeable / dischargeable electric double layer capacitors (capacitors C1, C2). When the AC power is not supplied from the main power supply means to the main heating member, the plurality of auxiliary power supplies are charged from the charging means.
The above configuration is illustrated in FIG. 9, for example.
In this way, it is possible to efficiently charge the auxiliary power source and secure a large amount of power during use.

The invention according to claim 3 is configured such that the charging means does not charge the plurality of auxiliary power supplies when the plurality of auxiliary power supplies are discharged.
The above configuration is illustrated in FIG. 10, for example.
In this way, higher temperature and heat can be transmitted to the toner layer and the long recording medium.

According to a fourth aspect of the present invention, the plurality of auxiliary power supplies are constituted by fuel cells that can be used repeatedly by changing fuel.
In this way, permanent auxiliary power can be secured.

According to a fifth aspect of the present invention, the plurality of fuel cells include means for detecting the remaining amount of fuel, means for passing the remaining amount of fuel to the user, and the amount of fuel when the remaining fuel amount falls below a certain value. The fuel can be replaced by the user by means of prompting replacement.
In this way, the user can change the fuel in a timely manner.

According to a sixth aspect of the present invention, when the plurality of auxiliary power supplies determine that the temperature of the fixing member detected continuously cannot maintain the fixing required temperature, the next document reading is performed during continuous paper feeding. when the power operation including is used in the main heating element is performed is decreased, certain holding fixing temperature by supplying power to the auxiliary heating element as a row cormorants configuration.
In this way, it is possible to supply the auxiliary heating member with electric power capable of assisting the amount of heat that is insufficient for fixing, and to pass the paper while maintaining the fixing quality without reducing the productivity.

According to a seventh aspect of the present invention, the plurality of auxiliary power supplies whose output can be switched to either serial, parallel or single are detected continuously during continuous paper passage or long paper passage. When it is determined that the temperature required for fixing cannot hold the temperature required for fixing, when the operation including the next document reading is performed and the power used for the main heating member is reduced, the plurality of auxiliary power supplies are connected in series. And output
When power used in the main heating element is not reduced and outputs by connecting the plurality of auxiliary power alone or in parallel, there retention of fixing temperature as row cormorants configuration.
In this way, it is possible to supply auxiliary power commensurate with the amount of heat that is insufficient for fixing, and to pass the paper without degrading productivity while maintaining the fixing quality.

According to the first aspect of the present invention, there is an effect that the auxiliary electric power corresponding to the amount of heat that is insufficient for fixing is supplied, and the sheet can be passed without degrading productivity while fixing the fixing quality.
According to the second aspect of the present invention, there is an effect that the auxiliary power source can be efficiently charged and a large amount of power can be secured during use.
According to the third aspect of the invention, there is an effect that higher temperature and heat quantity can be transmitted to the toner layer and the long recording medium.

According to invention of Claim 4, there exists an effect that permanent auxiliary electric power can be ensured.
According to the invention described in claim 5, there is an effect that the user can change the fuel in a timely manner.
According to the sixth aspect of the present invention, there is an effect that power can be supplied to the auxiliary heating member to assist the insufficient fixing heat amount, and the sheet can be passed without degrading productivity while maintaining the fixing quality.
According to the seventh aspect of the present invention, there is an effect that the auxiliary electric power corresponding to the amount of heat that is insufficient for fixing is supplied, and the paper can be passed without degrading productivity while fixing the fixing quality.

Hereinafter, the present invention will be described based on the illustrated embodiments.
1 is a side sectional view of a wide digital copying machine HDC according to an embodiment of the image forming apparatus of the present invention, FIG. 2 is a perspective view of a fixing unit of the wide digital copying machine HDC, and FIG. 3 is an enlarged view of a main part of the fixing unit. It is sectional drawing.
As shown in FIG. 1, an image forming unit 200 is disposed on a paper feeding unit 100, and a reading unit (scanner unit) 300 is disposed on the image forming unit 200, so that a wide digital copying machine HDC is configured as a whole. Has been.

The document placed on the document table 301 is fed to the reading unit 300 one by one, and after the image is read by the contact image sensor (CIS) 302, the document is discharged onto a discharge tray.
The document on the document table 301 is aligned in the width direction by a side fence (not shown), fed by the feed roller 303, and conveyed below the contact image sensor 302. On the document table 301, a document width detection sensor and a document length detection sensor (not shown) are provided. The size of the document sent from the document table 301 is detected by both sensors. The document under the contact image sensor 302 is exposed by a light source such as an LED array or a fluorescent lamp, and the reflected light is passed through a rod lens array to form an image on the image sensor, and photoelectric conversion is performed. After the document reading is completed, the paper is discharged onto the paper discharge tray by the transport roller 304 and the paper discharge roller 305.

  The image forming unit 200 includes an image forming unit 201, a fixing unit 202, and a paper discharge unit 203. The image signal read by the contact image sensor 302 is subjected to image processing, and the LED writing unit 204 uses a charger. An electrostatic latent image is formed on the uniformly charged photoconductor 205. The original image is copied on the recording paper fed from the paper feed unit 100, and the paper passes through the paper discharge unit 203 and is discharged from the paper output tray 206 on the upper surface of the image forming unit 200 or behind the image forming unit 200. It is discharged to a paper tray (not shown).

The paper feed unit 100 has two upper and lower roll paper trays 101 and 102. The roll paper trays 101 and 102 can be pulled out from the apparatus housing in the left direction in the figure, and are configured to perform roll paper setting and jam processing with the tray being pulled out.
Two roll papers can be set on each of the roll paper trays 101 and 102. The roll papers 103 to 106 wound around the paper tube are set in the paper feeding unit 100 via a pair of paper holders 107 to 110.

Paper feed rollers 111 to 114 for each roll paper are arranged in the vicinity of the roll paper. The roll paper sent out by the paper feed rollers 111 to 114 is cut into a predetermined length by roll cutter units 115 and 116 provided on the front side of the tray (left side in the figure) and sent to the image forming unit 200. . The cut and fed roll paper is synchronized with the image forming timing by the registration roller 208, guided to the photoconductor 205, and the image formed on the photoconductor 205 is transferred by the transfer unit 209 and separated. The image is separated from the photosensitive member 205 by the unit 210 and guided to the fixing unit 202 by the conveyance belt 211 to thermally fix the image.
The roll paper on which the image is fixed is discharged by discharge rollers 212 and 213 forming a discharge unit 203. The paper discharge direction is switched by the branching claw 214 to be a paper discharge tray 206 on the upper surface of the image forming unit 200 or a paper discharge tray (not shown) behind the image forming unit 200.

Between the fixing unit 202 and the paper discharge roller 212, paper discharge sensors 215 and 216 are provided between the paper discharge roller 212 and the paper discharge roller 213. The paper discharge sensors 215 and 216 discharge the roll paper. It is possible to determine whether or not the unit 203 exists.
Although not shown, the image forming unit 200 includes a drive control unit that drives the paper discharge rollers 212 and 213, and the reading unit 300 includes an operation start instruction and repeat information that is information about the roll paper to be conveyed. An operation unit is provided for inputting copy and long sheet passing information.

  As shown in FIG. 2, the fixing unit 202 includes a fixing roller 1 in which a release layer is disposed on a metal tube, a pressure roller 2 in which a rubber layer and a release layer are disposed on a metal tube, and an AC that supplies AC power. Main heat generating unit 3 that generates heat when AC power is supplied from the power supply means, an auxiliary power source (preferably an electric double layer capacitor that can be charged / discharged or a fuel cell that can be replaced with fuel), and power supplied from the auxiliary power is supplied The auxiliary heat generating unit 4 that generates heat, the electromagnetic motor 5 for applying a rotational driving force to the fixing roller, the voltage sensor that detects the charging voltage of the auxiliary power source, and the surface temperature of the fixing roller / pressure roller First temperature detecting means 6 and 7, a relay gear 8 for transmitting the rotational drive of the electromagnetic motor 5 to the fixing roller, and the rotational force obtained from the electromagnetic motor 5 via the relay gear 8 to the fixing roller. Established to convey The moving gear 9 is assumed to be configured.

  The fixing roller 1 preferably has a structure in which a Teflon (registered trademark) layer is provided on the surface layer of a cylindrical aluminum tube or carbon steel tube, and the pressure roller 2 has a silicone rubber layer on a solid cylindrical aluminum tube or carbon steel tube. A configuration in which a Teflon (registered trademark) tube is disposed on the surface layer is preferable. The main heating unit 3 preferably has a halogen heater, nichrome wire heater, or IH heater, and the auxiliary heating unit 4 preferably has a halogen heater, nichrome wire heater, or IH heater. The electromagnetic motor 5 is preferably a servo motor, and the first temperature detection means 6 and 7 are preferably a thermistor or a temperature sensor.

  As shown in FIG. 3, the long recording paper 11 onto which the toner 12 has been transferred in the previous process passes between the nip formed by the fixing roller 1 and the pressure roller 2, and the main heating unit 3. And the heating roller 2 heated by the auxiliary heat generating unit 4, the paper is fixed on the long recording paper 11.

Next, the operation of this embodiment will be described with reference to FIGS. FIG. 4 is an operation flowchart of the present embodiment, FIG. 5 is a diagram showing the relationship between the fixing heater power and the elapsed time according to the presence or absence of the reading operation, FIG. 6 is a diagram showing the relationship between the capacitor voltage and the elapsed time, and FIG. FIG. 8 is a diagram showing a relationship between temperature and time, and FIG. 8 is a diagram showing a relationship between fixing temperature and time.
The electric circuit configuration of the present embodiment will be described after this operation description with reference to FIGS. 9 to 12.

  With reference to FIG. 4, the series / parallel switching control of the auxiliary power supply during copying or printing will be described. The numbers and symbols (for example, electric double layer capacitors C1 and C2) given after the member names are the same as those shown in FIGS.

(1) Description of the flow until paper passing is completed without using an electric double layer capacitor (step S1, step S2, step S3, step S4).
As shown in FIG. 4, the main power supply 21 of the wide-width digital copying machine HDC (hereinafter referred to as copying machine HDC) is turned on, and a continuous copy or a long copy is input as a job and paper feeding is started. In step S1, the fixing roller temperature TH is first detected by the first temperature detecting means 6.

  Next, in step S2, it is determined whether or not the fixing roller temperature TH is higher than the fixing required temperature determined by the toner to be used. In this case, assuming that the fixing roller temperature TH is higher than the fixing required temperature, the process proceeds to step S3, and the sheet passing is continued without using the electric double layer capacitor. In step S4, the input sheet passing job is completed.

(2) Description of the flow from when the electric double layer capacitor is used in a parallel connection state until paper passing is completed (step S1, step S2, step S6, step S7, step S9).
When the main power supply 21 of the copying machine HDC is turned on and continuous copying or long copying is input as a job and paper feeding is started, first, the fixing roller temperature TH is set to the first temperature detecting means 6 in step S1. Detect at. Next, in step S2, it is determined whether or not the fixing roller temperature TH is higher than the necessary fixing temperature determined by the toner used. In this case, assuming that the fixing roller temperature TH is lower than the necessary fixing temperature, step S6 is performed. Proceed to

  In step S6, it is determined whether the next document reading operation is performed in parallel. In this case, it is assumed that the next document reading operation is not performed. The fixing power supplied to the main heating unit 3 does not reach the power drop ΔW shown in FIG. 5 used in the reading operation. However, since power assistance is necessary, the process proceeds to step S7, and the electric double layer capacitor is installed. The paper is continuously passed while the auxiliary heat generating unit 4 generates heat by connecting in parallel. FIG. 6 shows a discharge curve when a plurality of electric double layer capacitors are individually connected in parallel or connected in series.

  In the case of step S7, since the electric double layer capacitor is connected in parallel (two-dot chain line in FIG. 6), the output possible time of the electric double layer capacitor is twice the single output possible time T (dotted line in FIG. 6). 2T output time can be earned. In step S9, the input job is completed.

(3) Description of the flow from when the electric double layer capacitors are connected in parallel and used until paper passing is completed (step S1, step S2, step S6, step S8, step S9).
Since the operation from step S1 to step S2 to step S6 is the same as the operation already described in the above (2), the redundant description is omitted.
In step S6, it is determined whether or not the next document reading operation is being performed in parallel. In this case, assuming that the next document reading operation is being performed, the fixing power supplied to the main heating unit 3 does not have the power decrease ΔW shown in FIG. Since the supply from the multilayer capacitor is necessary, the process proceeds to step S8, and the electric double layer capacitor is connected in series, and the paper is continuously passed while the auxiliary heat generating unit 4 generates heat.

In the case of step S8, since the electric double layer capacitor is connected in series (solid line in FIG. 6), the output time of the electric double layer capacitor is equal to the single output time T, but the electric double layer capacitor alone is discharged. It is possible to earn a discharge amount that is twice as large as the amount. In step S9, the input job is completed.
In each of the cases (1), (2), and (3) described above, if the paper passing job input in steps S4 and S9 is not completed, the process proceeds to step S1 and the same operation as described above is repeated. .

  FIG. 7 shows the transition of the fixing temperature when power assistance is not performed, and there is a possibility that the fixing required temperature (the fine dotted line in FIG. 7) may be interrupted. However, by assisting the electric double layer capacitor in the operations (2) and (3), the transition of the fixing temperature can be passed without interrupting the necessary fixing temperature as shown in FIG. .

  When the length of the paper to be passed is short and the paper is continuously passed, if the fixing roller temperature is lower than the fixing temperature, the fixing roller temperature is increased by widening the interval between the paper to be passed. It is possible to continue passing the paper while encouraging the return. However, when the paper to be passed is a long and long paper, it is difficult to promote the return of the fixing roller temperature because there is no paper space. Therefore, the above (2) and (3) for supplying auxiliary power can be said to be effective means.

Next, a circuit operation for generating heat from the heat generating member of the wide-width digital copying machine HDC will be described with reference to circuit diagrams at various operations shown in FIGS.
[1] Circuit state during charging: See FIG. 9 FIG. 9 is a diagram showing a circuit state during charging.
Indicates the state of the circuit being charged with no copy operation or print job.

In the standby mode of the copying machine HDC, the main switch 17 is switched while the surface temperature of the fixing roller 1 is monitored by the first temperature detecting means 6 for detecting the temperature of the fixing roller (fixing member) 1 to maintain the set temperature. To do.
When the main switch 17 is open and the power from the main power supply device 21 is not used, the charger 22 charges the plurality of capacitors C1 and C2 arranged in the capacitor device 400.
For this charging, the voltage detection means (not shown) detects the charging voltage of the capacitors C1 and C2, and the minimum AC power necessary for maintaining the operation of the copying machine HDC is removed until the detected charging voltage is satisfied. AC power is sent from the charger 22 to charge the capacitors C1 and C2.
Each capacitor C1, C2 is provided with a charge equalization circuit (not shown).

[2] Circuit state when discharging from capacitors connected in series ... see FIG. 10 First, the switch 13 is opened, the main switch 17 is closed, and the long copy that performs heat fixing with the amount of heat generated only by the main heating unit 3 Or it is in the print state.
The surface temperature of the fixing roller 1 is detected by the first temperature detection means 6, and the surface temperature of the pressure roller 2 is detected by the second temperature detection means 7 that detects the surface temperature of the pressure roller 2.

The CPU 23 always calculates the inclination of the change in the fixing temperature, the amount of fixing supply heat to the toner layer and the inclination of the change, the total amount of heat supplied to the transfer paper (long recording medium) and the inclination of the change.
When the fixing temperature is below a certain fixing limit temperature and the slope of the change in the fixing temperature is larger than the set threshold value, a larger amount of heat is required, so that switches 13, 14, 15, and 16 are set as shown in FIG. By switching, the capacitors C1 and C2 are connected in series to provide a large auxiliary power to the auxiliary heat generating unit 4.

[3] Circuit state during discharge from capacitors connected in parallel. See FIG. 11. First, the switch 13 is opened and the main switch 17 is closed. Or it is in the print state.
The surface temperature of the fixing roller 1 is detected by the first temperature detecting means 6.
If a reading operation or the like is not performed when the fixing temperature falls below a certain fixing temperature, there is no reduction in the power supplied to the main heat generating unit 3 and a small amount of heat assistance is required, as shown in FIG. The switches 13, 14, 15 and 16 are switched to connect the capacitors C1 and C2 in parallel to supply auxiliary power to the auxiliary heat generating unit 4.

[4] Series / Parallel Switch Type Auxiliary Power Circuit Using Fuel Cell See FIG. 12 In the examples shown in [1] to [3] above, the capacitors C1 and C2 are used as the auxiliary power supply means. On the other hand, this example is a case where fuel cells C3 and C4 are used as auxiliary power supply means.
Initially, the main switch 17 is opened, the main switch 17 is closed, and a long copy or print state in which heat fixing is performed with the amount of heat generated only by the main heat generating portion 3 is performed.
The surface temperature of the fixing roller 1 is detected by the first temperature detecting means 6.

  If the reading operation is performed in parallel when the fixing temperature falls below a certain fixing temperature, a plurality of fuel cells are output in series connection. If the reading operations are not performed in parallel, a plurality of fuel cells are output individually or in parallel. As shown in FIG. 12, the switches 18, 19, 20 are switched, and the fuel cells C 3, C 4 are switched in series or in parallel to be connected to supply auxiliary power to the auxiliary heat generating unit 4.

As peripheral circuits of the fuel cells C3 and C4, means for detecting the remaining amount of fuel (not shown), means for passing the remaining amount of fuel to the user, and replacement of fuel when the remaining fuel amount falls below a certain value. And means for urging.
Further, the fuel cell does not include a charging circuit (see FIG. 12).

  In FIG. 1, the case where only the roll paper is arranged in the paper supply unit 100 has been described. However, as shown in FIG. 13, the paper supply unit 100A includes a roll paper and paper supply cassettes 120A and 120B. Of course, the present invention can also be applied to a wide-width digital copying machine.

1 is a side sectional view of a wide digital copier according to an embodiment of an image forming apparatus of the present invention. It is a perspective view of the fixing part of the wide digital copying machine. FIG. 3 is an enlarged cross-sectional view of a main part of the fixing unit. It is an operation | movement flowchart of the same wide digital copying machine. FIG. 6 is a diagram illustrating a relationship between fixing heater power and elapsed time according to the presence or absence of a reading operation. It is a figure which shows the relationship between a capacitor voltage and time passage. It is a figure which shows the relationship between fixing temperature and time passage. It is a figure which shows the relationship between the fixing temperature and time passage in this embodiment. It is a figure which shows the circuit state at the time of charge. It is a figure which shows the circuit state at the time of discharge of the capacitor of a serial connection. It is a figure which shows the circuit state at the time of discharge of the capacitor of a parallel connection. This is an auxiliary power circuit for switching between series and parallel when a fuel cell is used. It is a sectional side view of the other example of a wide digital copying machine.

Explanation of symbols

HDC: Wide digital copier C1, C2: Capacitor C3, C4 ... Fuel cell 1 ... Fixing roller (fixing member)
2 ... Pressure roller (Pressure member)
DESCRIPTION OF SYMBOLS 3 ... Main heat generating part 4 ... Auxiliary heat generating part 6 ... 1st temperature detection means 7 ... 2nd temperature detection means 21 ... Main power supply device 22 ... Charger 23 ... CPU

Claims (7)

A toner image is formed on the image carrier, the toner image is transferred to a long recording medium longer than a standard size, and the toner image transferred to the long recording medium is fixed to the long recording medium by a fixing device. In the image forming apparatus, the fixing device includes a fixing member, a pressure member in pressure contact with the fixing member, a temperature detection unit that detects the temperature of the fixing member, and a heating unit that generates heat from the fixing member. Then, a long recording medium carrying a toner image is passed through the nip portion between the fixing member and the pressure member, and heat and pressure are applied to the toner of the toner image during the passage so that the toner image is applied to the long recording medium. In the image forming apparatus to be fixed,
Main power supply means for supplying AC power;
A plurality of auxiliary power supplies whose outputs can be switched by connecting them in series, parallel or single, and
AC power is supplied from the main power supply means to generate heat, and a main heating member constituting a part of the heating means for heating the fixing member;
An auxiliary heating member that forms part of the heating unit that generates heat by supplying power from the plurality of auxiliary power sources and heats the fixing member;
Power control means for performing power-related control of the image forming apparatus,
The power supply control means uses the temperature detection means to determine the surface temperature of the fixing member when the long recording medium passes while performing heat fixing only with the main heating member that generates heat by the AC power supplied from the main power supply means. A first control to be detected;
When the detected surface temperature of the fixing member falls below a fixing temperature threshold value at which it is determined that the required toner fixing temperature cannot be maintained, and the next document reading operation is performed, the plurality of auxiliary power supplies A second control for connecting the power supply in series and supplying electric power to the auxiliary heating member to generate heat and maintain the fixing temperature;
When the detected surface temperature of the fixing member falls below the fixing temperature threshold and the next document reading operation is not performed, the plurality of auxiliary power supplies are connected individually or in parallel to supply power. And a third control for supplying the auxiliary heating member to generate heat and maintaining the fixing temperature.   The image forming apparatus includes a charging unit that charges the plurality of auxiliary power sources. The plurality of auxiliary power sources are configured by chargeable / dischargeable electric double layer capacitors, and AC power is supplied to the main heating member from the main power source unit. The image forming apparatus according to claim 1, wherein the plurality of auxiliary power supplies are charged from the charging unit when the charging is not performed.   The image forming apparatus according to claim 2, wherein the charging unit does not charge the plurality of auxiliary power sources when the plurality of auxiliary power sources are discharged.   The image forming apparatus according to claim 1, wherein the plurality of auxiliary power sources are constituted by fuel cells that can be used repeatedly by changing fuel.   The plurality of fuel cells includes a means for detecting the remaining amount of fuel, a means for informing the user of the remaining amount of fuel, and a means for prompting the user to change the fuel when the remaining amount of fuel falls below a certain value. The image forming apparatus according to claim 4, wherein the image forming apparatus is replaceable. When the plurality of auxiliary power supplies determine that the temperature of the fixing member detected continuously cannot maintain the fixing required temperature, the main heating is performed by performing an operation including the next document reading during continuous paper feeding. 6. The image formation according to claim 1, wherein when the power used for the member is reduced, the fixing temperature is maintained by supplying power to the auxiliary heating member. equipment. Auxiliary power before Kifuku number, when the temperature of the fixing member detected continuously during continuous printing or during long sheet passing is determined not to hold the fixing temperature required, including the following document reading When the operation is performed and the power used for the main heating member is reduced, the plurality of auxiliary power supplies are connected in series and output, and
When power used in the main heating element is not reduced and outputs by connecting the plurality of auxiliary power alone or in parallel, of claims 1 to 5, characterized in that for holding the fixing temperature the image forming equipment according to any one.