JP4422995B2 - Fixing apparatus, image forming apparatus, and fixing control method - Google Patents

Description

  The present invention relates to a fixing device for fixing an image formed on a recording medium, in particular, a fixing device having a function of preventing overheating of the fixing device in a high-speed rising type image forming apparatus, and an image including the fixing device. The present invention relates to a forming apparatus and a fixing control method.

  The fixing device of the high-speed start-up type image forming apparatus has a problem that the heat capacity is small and the temperature rises excessively when an abnormality such as a drive system trouble or a jam occurs. Patent Documents 1 and 2 below disclose that the energization to (which is heated by energization) is stopped. Specifically, in Patent Document 1, among the pressure members in contact with the back surface of the transfer material, at least one member is a driven rotation member, and a rotation detection unit that detects the rotation of the driven rotation member, and rotation detection An image forming apparatus including an energization stop device that stops energization to a heating body in accordance with a detection output of the means is disclosed.

  Patent Document 2 discloses a rotation detection unit that detects a rotation operation of a metal film that is a rotary heating member, and a control unit that suppresses the output of the heating unit when the rotation detection unit detects a stop of the rotary heating member. An image forming apparatus is disclosed.

In any of the above-described known techniques, the stop or speed reduction of the rotating body is detected by a rotary encode or an optical sensor, and the energization is stopped or suppressed.
Japanese Patent Laid-Open No. 2-131269 JP 2001-203072 A

  In the fixing device described above, when an abnormality occurs in the image forming apparatus and the rotating body stops, the rotation detection unit is not energized. However, if the rotation detection unit fails at the same time, the energization is performed as in the normal state. .

  As a result of pursuing energy saving and ease of use, in recent years, a fixing device having a high-speed rising time in which the fixing member has a rising time of 10 seconds to 30 seconds or less has been proposed and marketed. In such a fixing device, it is difficult to raise the temperature in a short time unless rotation and heating of the fixing member are started almost simultaneously. In particular, when intended for high-speed startup, heat is transferred to both the fixing member and the pressure member during rotation (the heating area is approximately doubled in the combination of the fixing roller and the pressure roller), but only the fixing member or the fixing member when stopped. Since heating concentrates only in the vicinity of the heating part, an abnormally high temperature of the fixing member is extremely likely to occur in combination with a configuration in which the temperature is raised in a short time. That is, in the case of a fixing device that starts at a high speed, since the heat capacity of the fixing member is small, when energization is performed even in the event of an abnormality, the temperature reaches several hundred degrees Celsius or higher than the fixing temperature in a few seconds, and the fixing mechanism including the fixing member There is a risk of damage. Therefore, it is required to take safety measures in double and triple, and to improve the safety by preventing the fixing member from becoming hot when an abnormality occurs.

  Also, a fixing device using induction heating has been proposed in order to realize these high-speed rises. Conventional halogen heaters and the like need to cut off high voltage and large current, and there is a problem that the safety measures are increased in size. In the case of induction heating, heating is not performed unless high-frequency oscillation is performed. Since high-frequency oscillation is performed in a low-voltage circuit, a small safety measure can be applied to this circuit.

  Furthermore, in order to realize a high-speed start-up, attempts have been made to prevent heat radiation by limiting the heating region of the fixing member. In this case, since heating is performed locally, safety measures are further important.

  In any case, in the inventions disclosed in the above-mentioned Patent Documents 1 and 2, the rotation detection unit detects rotation stop by a rotation detection unit such as a rotary encoder or an optical sensor and controls energization. In this case, energization is performed, and the occurrence of abnormal temperature rise cannot be completely prevented.

  The present invention has been made in view of such a background, and the purpose thereof is that even when the fixing member is in a stopped state or a state close to the stopped state by a mechanical mechanism that is interlocked with the driving of the fixing member, This is to prevent the fixing device from becoming an abnormally high temperature.

  Another object is to reliably prevent overheating of the fixing member by heating the fixing member only for a short time when the driving of the fixing device is stopped or nearly stopped.

In order to achieve the above object, the first means has two rotating members and a heating means for heating at least one of the rotating members, and fixes the nip portion between the rotating members through the fixing target member. The fixing device includes a control unit that obtains a rotational driving force of at least one of the rotational members and energizes the heating unit, and the control unit obtains the rotational driving force and generates electric power. And a switching means that enables energization of the heating means by an electromotive force generated by the power generation of the power generation means .

Second means includes two rotating members having a heating means for heating at least one of said rotary member, a fixing device for fixing through a fixing subject member to the nip portion between the front Symbol rotary member, the rotary A high-frequency electromagnetic wave having a control unit that obtains a rotational driving force of at least one rotating member of the member and energizes the heating unit, and the heating unit includes a high-frequency oscillation driving unit to which power is supplied from a voltage unit An induction heat source, wherein the control means obtains the rotational driving force and generates power, and switching that enables energization from the voltage unit to the high-frequency oscillation driving unit by an electromotive force generated by the power generation of the power generation means And means.

The third means is characterized in that, in the first or second means, the switching means is an on / off relay, and is turned on by an electromotive force when the power generation means is operated .

Fourth means includes two rotating members having a heating means for heating at least one of said rotary member, a fixing device for fixing through a fixing subject member to the nip portion between the front Symbol rotary member, the rotary Control means for obtaining a rotational driving force of at least one rotating member of the member and energizing the heating means, wherein the control means obtains the rotational driving force and rotates the fan; And a thermostat for turning on and off the energization of the heating means based on the surface temperature of the at least one rotating member heated by the heating means, and an operating temperature of the thermostat Is set to a temperature lower than the surface temperature at the time of fixing of the at least one rotating member heated by the heating means. .

Fifth means includes two rotating members having a heating means for heating at least one of said rotary member, a fixing device for fixing through a fixing subject member to the nip portion between the front Symbol rotary member, the rotary A control unit that obtains a rotational driving force of at least one rotating member of the member and energizes the heating unit, and the control unit includes a fan that rotates by obtaining the rotational driving force, and the heating unit. A thermostat provided so as to be movable in the direction of approaching or separating from the at least one rotating member to be heated, and for turning on and off the energization of the heating means based on the surface temperature of the rotating member. Is set to a temperature lower than the surface temperature at the time of fixing of the rotating member heated by the heating means, and the thermostat But the back pressure of the thermostat back by blowing of the fan, characterized in that it moves in a direction away from the at least one rotary member is heated by the heating means.

Sixth means includes two rotating members having a heating means for heating at least one of said rotary member, a fixing device for fixing through a fixing subject member to the nip portion between the front Symbol rotary member, the rotary A control unit that obtains a rotational driving force of at least one rotating member of the member and energizes the heating unit, and the control unit obtains the rotational driving force and generates electric power; and the heating unit A thermostat that turns on and off the energization of the heating means based on the surface temperature of the at least one rotating member that is heated by, and the thermostat with respect to the at least one rotating member according to an electromotive force generated by the power generation means Drive means for moving in the direction of approaching or separating, and the operating temperature of the thermostat is heated by the heating means. The driving member is set to a temperature lower than the surface temperature at the time of fixing the rotating member, and the driving means heats the thermostat by the heating means when an electromotive force is obtained by the power generating means. It is characterized by moving in a direction away from the rotating member.

Seventh means includes two rotating members having a heating means for heating at least one of said rotary member, a fixing device for fixing through a fixing subject member to the nip portion between the front Symbol rotary member, the rotary Control means for obtaining a rotational driving force of at least one rotating member of the member and energizing the heating means, wherein the control means obtains the rotational driving force and generates electric power; and the heating means A thermostat that is arranged with a predetermined gap from the at least one rotating member that is heated by the heater, and that turns on / off the energization of the heating unit based on the surface temperature of the rotating member, and according to an electromotive force generated by the power generation unit Drive means for advancing or retreating the heat insulating member into the gap, and the at least one rotation of the thermostat is heated by the heating means While being set to a temperature lower than the surface temperature at the time of fixation of wood, the drive means may be advanced and the heat insulating member when the electromotive force by the power generating means is obtained to the gap.

The eighth means is characterized in that, in the sixth or seventh means, the driving means is a solenoid .

The ninth means is any one of the fourth to eighth means, wherein the operating temperature of the thermostat is 30 ° C. or more lower than the surface temperature at the time of fixing of the at least one rotating member heated by the heating means. characterized in that there.

The tenth means is any one of the first , second, third, sixth, seventh, and eighth means, and the power generation means rotates the rotary member body at the final stage of the rotation transmission system of the rotary member. The power generation is performed by obtaining a driving force from the rotating member .
According to an eleventh means, in any one of the first to tenth means, the one rotating member whose rotational driving force is utilized by the control means is a rotational member on the main driving side that obtains the driving force directly from the driving source. characterized in that there.

According to a twelfth means, in any one of the first to tenth means, the one rotating member whose rotational driving force is utilized by the control means obtains the driving force directly from the driving source and rotates. The rotating member is a driven side rotating member that rotates by obtaining a rotational driving force from the rotating member .

A thirteenth means is characterized in that, in the twelfth means, the driven-side rotating member obtains a driving force through a nip between the driven-side rotating member and the driven-side rotating member, and is driven to rotate .

The fourteenth means is characterized in that, in any one of the first to thirteenth means, one of the two rotating members is a fixing member and the other is a pressure member .

A fifteenth means is characterized in that, in the fourteenth means, the heating means is provided inside or outside the fixing member .

A sixteenth means is the fifteenth means characterized in that the heating means heats a heat source by energization to heat the fixing member .

The seventeenth means is characterized in that, in the sixteenth means, the heating range of the heat source is a part of the outer peripheral portion of the fixing member in the axial direction .

The eighteenth means includes: two rotating members; and a heating unit that heats at least one of the rotating members. The fixing device that fixes the nip portion between the rotating members through a fixing target member. At least one of the rotating members includes an endless belt member and a roller on which the belt member is stretched, and has a control unit that obtains a rotational driving force of the roller and energizes the heating unit. The control means includes power generation means for generating power by obtaining the rotational driving force, and switching means for enabling energization of the heating means by electromotive force generated by power generation of the power generation means. .

A nineteenth means includes: two rotating members; and a heating unit that heats at least one of the rotating members. In the fixing device that fixes a nip portion between the rotating members through a fixing target member, the rotating member At least one of the rotating members includes an endless belt member and a roller on which the belt member is stretched, and has a control unit that obtains a rotational driving force of the roller and energizes the heating unit. The heating means includes a high-frequency electromagnetic induction heat source including a high-frequency oscillation drive unit to which power is supplied from a voltage unit, and the control unit obtains the rotational driving force to generate power, and the power generation unit Switching means for enabling energization from the voltage unit to the high-frequency oscillation driving unit by electromotive force generated by the power generation .

A twentieth means is characterized in that, in the eighteenth or nineteenth means, the switching means is an on / off relay, and is turned on by an electromotive force when the power generating means is operated .

The twenty-first means is characterized in that the image forming apparatus includes a fixing device according to any one of the first to twentieth means.

A twenty-second means is the image forming means for forming a toner image on the image carrier in any one of the first to thirteenth means, and the toner image formed by the image forming means by the heating means. a transfer unit for transferring the heated surface of said at least one rotating member, transferring the toner image transferred onto the heated at least one rotary member by said heating means, again on the recording medium at the nip portion to together, by performing heating and pressurization, wherein the image forming apparatus having a fixing device according to any one of the recording medium to 請 Motomeko 1 to you fixing on 13.

The twenty-third means has two rotating members and a heating means for heating at least one of the rotating members, and in the fixing control method for fixing through the fixing target member to the nip portion between the rotating members, the rotation A control for obtaining the rotational driving force of at least one of the members and energizing the heating means is executed. In the control, the rotational driving force is obtained to generate power, and the switching means is operated by the electromotive force generated by the power generation. The heating means can be energized .

  According to the present invention, when the fixing member is in a stopped state or a state close to the stopped state, heating by the heating unit is not performed, so that the fixing device can be prevented from becoming abnormally high temperature. In addition, when the driving of the fixing device is stopped or nears to a stop, heating by the heating means is not performed, so the fixing member is heated only for a short time, and overheating of the fixing device is reliably prevented. can do.

  In other words, when an abnormality occurs, the rotation of a rotating member such as a fixing member or a pressure member that obtains a rotational driving force stops, so that the rotational driving force cannot be obtained by stopping the rotation of the rotating member. As a result, the control unit cannot energize the heating unit, and the heating unit is not heated. As a result, the temperature of the fixing device is not increased, and an abnormally high temperature can be prevented, so that the function as a safety device can be reliably exhibited.

At that time, since the control means includes a power generation means that obtains power by obtaining a rotational driving force and a switching means that enables energization of the heat source of the heating means by the electromotive force generated by the power generation means, the rotation member is provided when an abnormality occurs. the rotation is stopped, power generation means for generating obtains rotational driving force of the rotating member is no longer actuated, that such does not occur electromotive force. As a result, energization of the switching means becomes impossible. As a result, the heating unit cannot be energized, and the heating unit is brought into a non-heated state and can reliably prevent overheating of the fixing device.

  When the control means comprises a power generation means that generates power by obtaining a rotational driving force, and a switching means that enables energization from the low voltage portion of the high frequency oscillation drive section of the high frequency electromagnetic induction heat source by the electromotive force generated by the power generation of the power generation means When an abnormality occurs, the rotation of the rotating member stops, the power generating means that generates power by obtaining the rotational driving force of the rotating member stops operating, and no electromotive force is generated, so that the switching means cannot be energized. As a result, the heating unit cannot be energized, and the heating unit is brought into a non-heated state and can reliably prevent overheating of the fixing device. The high frequency generation circuit has a low voltage, and the switching means can be made compact, so that the reaction can be enhanced. In addition, the low voltage can be shut off stably over a longer period than the high voltage.

  The control means is composed of a fan that rotates by obtaining a repetitive driving force and blows air, and a thermostat that is provided at a position facing the fixing member at a position close to the fixing member and that turns on and off the power supply to the heat source of the heating means. Then, the thermostat is cooled by blowing air from the fan, and the thermostat having a driving temperature set to a temperature lower than the fixing temperature of the fixing roller is turned on to continuously energize the heat source. When an abnormality occurs such as when the rotation transmission unit to the cooling fan fails, the rotation of the rotating member stops, and the rotating fan stops by obtaining the rotational driving force of the rotating member. Thereby, since the thermostat is not cooled, the thermostat is heated in a short time, and the energization is cut off before the fixing device reaches an abnormally high temperature, so that the fixing device can be reliably prevented from overheating. Further, since the contact does not operate every time it rises like a relay, the fixing device can be used for a long time.

  A fan that rotates by obtaining a rotational driving force and blows air, and a position that faces the fixing member at a position close to the fixing member so as to be able to move close to and away from the fixing member. The fixing member includes a thermostat that turns on and off energization, and when rotational driving force is obtained, blows air from the fan to the back surface of the thermostat and generates back pressure on the back surface of the thermostat. When the thermostat is separated from the surface and the thermostat set to a temperature lower than the fixing temperature of the fixing roller is turned on to continuously energize the heat source, the rotation to the cooling fan is performed. When an abnormality occurs, such as when the transmission unit fails, the rotation of the rotating member stops, and the rotating fan that receives the rotational driving force of the rotating member stops. . This eliminates the back pressure generated on the back of the thermostat and moves to a position close to the fixing member, so that the thermostat is heated in a short time, and the energization is cut off before the fixing device becomes abnormally hot, It is possible to reliably prevent overheating of the fixing device. Further, since the contact does not operate every time it rises like a relay, the fixing device can be used for a long time.

  A power generation unit that generates power by obtaining a rotational driving force and a position that is close to the fixing member and that is opposed to the fixing member so as to be movable toward and away from the fixing member. The control means is composed of a thermostat that is turned on and off, and a drive means that supports the thermostat and moves the thermostat close to and away from the fixing member in accordance with an electromotive force generated by the power generation means, and a rotational driving force is obtained. In this case, the driving means moves the thermostat to the side away from the fixing member, and turns on the thermostat in which the driving temperature is set lower than the fixing temperature of the fixing roller. When a continuous energization is performed, the rotation of the rotating member stops when an abnormality occurs, and the generator generates electricity by obtaining the rotational driving force of the rotating member. There will not operate, since the electromotive force is not generated, can not be allowed to move the thermostat on the side spaced apart with respect to the fixing member. As a result, the thermostat moves to a position close to the fixing member, so that the thermostat is heated in a short time, and the energization is cut off before the fixing device reaches an abnormally high temperature, so that it is possible to reliably prevent overheating of the fixing device. .

  A power generation means for generating electric power by obtaining a rotational driving force; a thermostat disposed at a position facing the fixing member at a position close to the fixing member and configured to turn on / off the power supply to the heat source of the heating means; and the thermostat A heat insulating member provided so as to be able to advance and retract between the fixing member and the heat insulating member, and supports the heat insulating member and advances the heat insulating member between the thermostat and the fixing member according to an electromotive force generated by the power generation means. When the rotational driving force is obtained, the driving means advances the heat insulating member between the thermostat and the fixing member, and the driving temperature is set to the fixing roller. If the thermostat set to a temperature lower than the fixing temperature is turned on to continuously energize the heat source, the rotating member rotates when an abnormality occurs. Stops, the power generating means for generating power by obtaining the rotational driving force of the rotating member does not operate, and no electromotive force is generated, so that the heat insulating member is retracted from between the thermostat and the fixing member, and the fixing member is The radiant heat from the fixing member is directly received. As a result, the thermostat is heated in a short time, and the energization is cut off before the fixing device reaches an abnormally high temperature, so that it is possible to reliably prevent overheating of the fixing device.

  The best mode for carrying out the present invention will be described below with reference to the drawings. In the following description, equivalent parts are denoted by the same reference numerals, and description of overlapping parts is omitted as appropriate.

1. Overall Configuration FIG. 1 is a diagram showing a schematic configuration of an entire image forming apparatus according to a first embodiment of the present invention.

  In FIG. 1, an image forming unit 110 is disposed substantially at the center of the tandem type color image forming apparatus MFP according to the present embodiment, and a sheet feeding unit 120 is disposed immediately below the image forming unit 110. 120 is provided with a paper feed tray 121 at each stage. A scanner unit 130 for reading a document is disposed above the image forming unit 110. On the downstream side (left side in the figure) of the image forming unit 110 in the paper conveyance direction, a paper discharge storage unit, a so-called paper discharge tray 140, is provided, and the discharged image-formed recording paper is stacked.

  In the image forming unit 110, a plurality of image forming units 160 for yellow (Y), cyan (C), magenta (M), and black (K) are juxtaposed above an intermediate transfer belt 150 formed of an endless belt. ing. In each image forming unit 160, along the outer periphery of a drum-shaped photoreceptor (photoreceptor drum) 161 provided for each color, a charging charger 162, an exposure unit 165, a developing unit 163, a cleaning unit 164, an eraser (QL). 167 and the like are arranged. The charging charger 162 performs a charging process on the surface of the photoconductor 161, and the exposure unit 165 irradiates the laser light from the writing unit 170 that irradiates the image information onto the surface of the photoconductor 161 with the laser light. The developing unit 163 develops and visualizes the electrostatic latent image formed by exposing the surface of the photoreceptor 161 with toner, and the cleaning unit 164 removes and collects the toner remaining on the surface of the photoreceptor 161 after the transfer.

  As an image forming process, an image for each color is formed on the intermediate transfer belt 150, and four colors are superimposed on the intermediate transfer belt 150 to form one color image. At that time, first, yellow (Y) toner is developed in the yellow (Y) image forming unit, and transferred to the intermediate transfer belt 150 by the primary transfer device (roller) 166. Next, cyan toner is developed and transferred onto the intermediate transfer belt 150 in the cyan (C) image forming unit. Next, the magenta (M) image forming unit develops the magenta toner and transfers it to the intermediate transfer belt 150. Finally, the black (K) toner is developed and transferred onto the intermediate transfer belt 150. A full-color toner image in which four colors are superimposed is formed. Then, the four color toner images transferred onto the intermediate transfer belt 150 are transferred to the recording paper 122 fed from the paper feeding unit 120 by the secondary transfer device (roller) 151 and fixed by the fixing unit 180. Thereafter, the paper is discharged onto a paper discharge tray 140 by a paper discharge roller, or is conveyed to a duplex unit 190. During double-sided printing, the conveyance path is branched by the branching unit 191, and the recording paper 120 is reversed via the double-sided unit 190. Then, the sheet skew is corrected by the registration roller 123, and the image forming operation on the back surface is performed in the same manner as the image forming operation on the front surface. On the other hand, after the full-color toner image is transferred, the toner remaining on the surface of the intermediate transfer belt 150 is removed and collected by the cleaning unit 152. Reference numeral 192 denotes a paper feed reverse path from the duplex unit 190. In FIG. 2, Y, C, M, and K representing colors are added after the symbols of the respective parts to distinguish the image forming parts of the respective colors.

  In the paper feeding unit 120, unused recording paper 122 is stored in the paper feeding tray 121, and the uppermost recording paper 122 is picked up by the pickup roller 125, and the vertical feeding path 127 is rotated by the rotation of the paper feeding roller 126. Then, it is conveyed to the registration roller 123 side. The registration roller 123 temporarily stops the conveyance of the recording paper 120 and sends out the recording paper 120 at a timing so that the positional relationship between the toner image on the intermediate transfer belt 150 and the leading edge of the recording paper 120 becomes a predetermined position.

  In the scanner unit 130, the first and second traveling bodies on which the document illumination light source and the mirror are mounted reciprocate in order to scan the document placed on the contact glass. The image information scanned by the traveling body is condensed on the imaging surface of the CCD installed behind by the lens, and is read as an image signal by the CCD. The read image signal is digitized and subjected to image processing. Then, based on the image-processed signal, optical writing is performed on the surface of the photoreceptor 161 by the light emission of the laser diode LD in the writing unit 7 to form an electrostatic latent image. The optical signal from the LD reaches the photosensitive member 161 via a known polygon mirror or lens. An automatic document feeder (ADF) 136 that automatically feeds a document onto the contact glass is attached to the upper portion of the scanner unit 130.

  The color image forming apparatus according to the present embodiment has a control device (not shown) in addition to a function as a so-called digital color copying machine that optically scans and reads a document, digitizes it, and copies it on paper as described above. This is a multi-function image forming apparatus having a facsimile function for exchanging image information of a document with a remote place and a so-called printer function for printing image information handled by a computer on paper. An image formed by any function forms an image on the recording paper 120 by a similar image forming process, and is discharged to one discharge tray 140 and stored.

  In FIG. 1, a full color machine of a four-tandem type intermediate transfer system is shown as an example of the image forming apparatus according to the present invention, but this is only drawn as a representative example of the image forming apparatus. A full-color machine such as a continuous tandem direct transfer system or a one-drum intermediate transfer system may be used, or a direct transfer type monochrome machine or another type of image forming apparatus is provided with a heating and pressing type fixing device. As long as the present invention is applicable.

2. FIG. 2 is a diagram showing a schematic configuration of a fixing device (fixing unit) according to a first embodiment of the present invention, FIG. 3 is a diagram showing a configuration of a fixing device including a power generation device, and FIG. 4 is an electric diagram of FIG. FIG. As shown in FIG. 2, the fixing device according to this embodiment includes a fixing roller 1a and a pressure roller 2 as two rotating members, a halogen heater 3a as a heating unit, and a rotational drive of the fixing roller 1a shown in FIG. The motor is basically composed of a DC motor 7 that generates electric power based on the force, and an ON / OFF relay 8 as a switching means that is turned ON / OFF by the electromotive force of the electromotive force generation circuit 7a of the DC motor 7. A DC motor 7, an electromotive force generation circuit 7 a, and an on / off relay 8 are included.

  The fixing roller 1a is formed in a thin cylindrical shape, and the pressure roller 2 is pressed toward the fixing roller 1a. The halogen heater 3a is provided to face a predetermined position on the outer peripheral portion of the fixing roller 1a. The predetermined position is selected such that the temperature distribution on the surface of the fixing roller 1a becomes maximum at a nip portion N to be described later when the fixing roller 1a is heated.

  As shown in FIG. 2, the transfer paper 14 is inserted into the nip N at the contact point between the fixing roller 1a and the pressure roller 2, and the unfixed toner 15 is inserted toward the fixing roller 1a for fixing. . The fixing roller 1a has a heat insulating layer of 4 mm thickness made of foamed silicone on an iron core, and a heat storage layer of a thin sleeve of stainless steel or nickel thereon, and further a 20 μm mold release made of PFA. Forming a layer. In order to make the gloss of the fixed image uniform, an elastic layer of 100 to 300 μm made of silicone rubber may be formed between the heat storage layer and the release layer. In this embodiment, the outer diameter is φ30, the thin sleeve is made of stainless steel, and the thickness is 60 μm.

  The outer diameter of the pressure roller 2 is also φ30, and a release layer made of foamed silicone and a 5 mm thick elastic layer and a PFA tube is formed on an iron core as in the fixing roller 1a. As described above, the halogen heater 3a is provided as a heat source at a position close to the fixing roller 1a, and the reflection plate 12 for concentrating the radiation from the halogen heater 3a on the fixing roller 1a is provided. The halogen heater 3a is 100V and 800W in this embodiment. In this case, when the fixing roller 1a is stopped, the heat storage layer reaches an extremely high temperature of 300 ° C. in one second, but the fixing roller 1a rotates and is transmitted to the pressure roller 2 and the transfer paper 14 in the nip portion N. The fixing roller 1a can maintain a surface temperature of 150 to 180 ° C. or less by heat.

  As shown in FIG. 3, the fixing roller 1a passes through a plurality of gears 19 and 18 constituting a gear reduction mechanism from a motor 20 as a driving source, and a gear 16 provided coaxially at one end of the rotating shaft 1s of the fixing roller 1a. It is rotationally driven by. The pressure roller 2 is pressed against the fixing roller 1a by a pressure mechanism (not shown) with a predetermined pressure, and a driving force is obtained from the fixing roller 1a by a frictional force and is driven to rotate. Further, a gear 17 is coaxially installed at the other end of the rotation shaft 1s of the fixing roller 1a, and the DC motor 7 as a generator is rotated by the gear 21 to generate electric power using the rotational driving force of the fixing roller 1a. Is done.

  The heat insulating layer may be any material having low thermal conductivity containing air (rubber, resin, ceramic, etc.), and can also be realized by containing particles containing foam or bubbles. Further, the heat storage layer of the stainless steel or nickel thin-walled sleeve is not necessarily required, and is set according to the productivity of image formation.

  As shown in FIG. 4, the position opposite to the electromotive force generation circuit 7a of the DC motor 7 that is gear-connected to the rotation shaft on the other end side of the fixing roller 1a is caused by the electromotive force generated by the electromotive force generation circuit 7a. An on / off relay 8 that is turned on / off is provided. An electrical circuit having an on / off relay 8 includes a power supply unit 9, a halogen heater 3a that generates heat by energization from the power supply unit, heats the fixing roller 1a, a temperature sensor 5 that detects a surface temperature of the halogen heater 3a, and this temperature. A temperature regulator 6 to which the detection output of the sensor 5 is input, and a thermostat 10 provided in series between the temperature regulator 6 and the on / off relay 8 are provided. The on / off relay 8 energizes the halogen heater 3a. Open and close the circuit. That is, when the DC motor 7 rotates and the on / off relay 8 is turned on by the electromotive force generated in the electromotive force generating circuit 7a, a current flows through the halogen heater 3a, which functions as a heating source for the fixing roller 1a. On the other hand, when the DC motor 7 does not rotate, no electromotive force is generated in the electromotive force generation circuit 7a, so that the on / off relay 8 does not operate as shown in FIG. For this reason, the electric power from the power supply 9 is not supplied to the halogen heater 3a, and the halogen heater 3a is not heated.

  In this fixing device, there is some abnormality in the drive transmission system to the DC motor 7 and the fixing roller 1a, and the ON / OFF relay 8 does not operate if the fixing roller 1a is stopped. Never energized. On the other hand, in the inventions disclosed in Patent Documents 1 and 2 described above, the rotation detection unit detects a rotation stop by a rotation detection unit such as a rotary encoder or an optical sensor and controls energization. However, in this embodiment, power is generated by the rotation of the rotating body, and the on / off relay 8 is activated by the voltage. Then energization is never performed. As long as relays and thermostats that have acquired safety standards such as UL and CSA are used as on / off relays, it can be said that the safety as a device is basically guaranteed. On the other hand, safety devices using semiconductors Since shorts and opens in fine semiconductor elements occur stochastically, they are not recognized as final safety devices in the safety standards.

FIG. 5 is a diagram showing a schematic configuration of a fixing device according to the second embodiment of the present invention.
In the second embodiment, the driving source of the DC motor 7 is the rotating shaft 1s of the fixing roller 1a as the power generation means in the first embodiment, whereas the heating roller 2 is used as the driving source of the DC motor 7. The rotation axis 2s is taken. That is, a gear 17 provided on the other end side of the rotating shaft 1 s of the fixing roller 1 a is provided at an end of the rotating shaft 2 s of the pressure roller 2 on the side opposite to the motor 20, and the gear 17 of the DC motor 7 is attached to the gear 17. The DC motor is arranged so as to mesh with each other. The other parts are configured in the same way as in the first embodiment shown in FIGS. 2 to 4, and therefore, the same parts are denoted by the same reference numerals and redundant description is omitted.

  When the DC motor 7 is arranged in this way, the DC motor 7 generates electric power by the rotational driving force of the pressure roller 2 driven by frictional contact with the fixing roller 1 a, and the electromotive force generation circuit 7 a is generated by the rotational driving force of the pressure roller 2. The on / off relay 8 is activated. Therefore, even when the pressure roller 2 is not driven and rotated with respect to the fixing roller 1a due to some abnormality, the on / off relay 8 is turned off and the energization to the fixing roller 1a is cut off. Thus, in the first embodiment, the configuration in which the rotation of the pressure roller 2 is not taken into consideration is a system with higher safety in consideration of the rotation of the pressure roller 2. I understand.

  In this embodiment, the DC motor 7 is provided on a side different from the side where the motor 20 is provided. However, the DC motor 7 may be provided on the same side. It is a design matter.

  Other parts not specifically described are configured in the same manner as the first embodiment and function in the same manner.

FIG. 6 is a diagram showing the configuration of the main part of the fixing device according to the third embodiment of the present invention.
In the fixing device according to this embodiment, the fixing roller 1a in the first embodiment is a fixing belt 1b. The fixing belt 1b is a fixing member, and the heating member is disposed inside the fixing belt 1b. The sheet resistance heating element 3b includes an elastic auxiliary roller 13 for forming the nip portion N, a pressure roller 2 pressed against the auxiliary roller 13 via the fixing belt 1b, and the like. The fixing belt 1b is stretched between the sheet resistance heating element 3b and the auxiliary roller 13 so as to adjust the tension. The sheet resistance heating element 3b functions as a heating element when heated, and heats the fixing belt 1b, thereby fixing the unfixed toner 15 on the transfer body 14. A rotating shaft 22 is provided at a position opposite to the sheet resistance heating element 3b to sandwich the fixing belt 1b between the sheet resistance heating element 3b.

  The rotating shaft 22 is driven to rotate in accordance with the rotation of the fixing belt 1b. A DC motor 7 (shown by a dotted line) as a power generation means is connected to the rotating shaft 22 via a gear, for example, as in the first embodiment, and the DC motor 7 is rotated by the rotation of the fixing belt 1b. Then, power generation is performed. In the DC motor 7, as shown in FIG. 4, an electromotive force generating circuit 7a is provided at a position where the on / off relay 8 can be operated, and the DC motor 7 rotates by obtaining a driving force from the rotary shaft 22. When power is generated, the on / off relay 8 is turned on, the sheet resistance heating element 3b is energized, and the fixing belt 1b is heated. However, if the rotating shaft 22 does not rotate, the DC motor 7 does not generate power, so the on / off relay 8 is in an off state, and the sheet resistance heating element 3b is not energized.

  With the above structure, the sheet resistance heating element 3b is energized only when the fixing belt 1b rotates. When the fixing belt 1b does not rotate, the sheet resistance heating element 3b is not energized. Is prevented.

  The fixing belt 1b has a polyimide t = 100 μm substrate on which an elastic layer 100 μm made of silicone rubber and a release layer PFA 20 μm are formed. Also in this embodiment, when the sheet resistance heating element 3b is energized with the fixing belt stopped, the fixing belt 1b reaches a high temperature of about 300 ° C. in one second, but 150 to 180 during rotation. It is possible to maintain the temperature below ℃.

  In this embodiment, the rotational driving force of the fixing belt 1b is picked up by the rotating shaft 22. However, as in the second embodiment, the rotating shaft 2s of the pressure roller 2 or the auxiliary roller 13 is used. It is also possible to take out the continuous driving force from the rotating shaft 13s.

  Other parts not specifically described are configured in the same manner as the first and second embodiments and function in the same manner.

FIG. 7 is a diagram showing the configuration of the main part of the fixing device according to the fourth embodiment of the present invention.
In the fixing device according to this embodiment, a halogen heater 3c as a heating source is installed inside a fixing belt 1c as a fixing member, and a pad 11 for forming a nip portion N is added inside the fixing belt 1c. It is pressed by the pressure roller 2. In this fixing device, the fixing belt 1c is heated by radiant heat from the halogen heater 3c. The rotational driving force is taken out from the rotating shaft 22c by sandwiching the fixing belt 1c between the rotating shaft 22c connected to the DC motor 7 (shown by a dotted line) and a shaft 23 for backup. The other parts are the same as in the third embodiment.

  With this configuration, the rotation of the fixing belt 1c is transmitted to the DC motor 7 via the rotary shaft 22, and the DC motor 7 generates power by the rotation of the fixing belt 1c, and the electromotive force generation circuit 7a turns on the on / off relay 8. Thus, the halogen heater 3c can be energized. When the rotation of the fixing belt 1c stops, the DC motor 7 does not generate electricity, so the on / off relay 8 is turned off and the halogen heater 3c is not energized, so that the fixing belt 1c is prevented from being heated too much.

  Other parts not specifically described are configured in the same manner as the first to third embodiments and function in the same manner.

FIG. 8 is a diagram showing the configuration of the main part of the fixing device according to the fifth embodiment of the present invention.
In the fixing device according to this embodiment, the pressure roller 2 is pressed against the fixing roller 1d as a fixing member, and the heating roller 4 as a heating member further contacts the fixing roller 1d. A halogen heater 3d as a heating source is arranged. A DC motor 7 (indicated by a dotted line) is connected to the rotating shaft of the heating roller 4 via, for example, a gear train, and the rotation of the heating roller 4 is taken out to generate electric power, and the on / off relay 8 is operated by the electromotive force generation circuit 7a. Energization of the halogen heater 3d is performed.

  In this embodiment, since the rotational driving force is taken out from the heating roller 4 that is closest to the halogen heater 3d as the heating source and reaches the highest temperature to drive the DC motor 7, even if only the heating roller 4 is stopped due to some abnormality. The halogen heater 3d in the heating roller 4 is not energized and is safe.

  Other parts not specifically described are configured in the same manner as the first embodiment and function in the same manner.

FIG. 9 is a diagram showing the configuration of the main part of the fixing device according to the sixth embodiment of the present invention.
The fixing device according to this embodiment is a combination of the third embodiment and the fifth embodiment, and the heating roller 4 as a heating member and the nip portion N are formed inside the fixing belt 1e as the fixing member. An auxiliary roller 13 and an auxiliary pad 24 are disposed. A halogen heater 3e is provided inside the heating roller 4, and heat from the halogen heater 3e is transmitted to the fixing belt 1e via the heating roller 4, and the fixing is performed by the heated fixing belt 1e. . In this embodiment, since the auxiliary roller 13 and the auxiliary pad 24 are in contact with the pressure roller 2 so as to wind the fixing belt 1e around the pressure roller 2, a wide nip width can be obtained, and a low temperature or Fixability can be secured even under low pressure conditions. Also in this embodiment, a DC motor 7 (indicated by a dotted line) is connected to the rotating shaft of the heating roller 4 via, for example, a gear train, and the heating roller 4 is rotated to generate electric power, which is turned on / off by the electromotive force generation circuit 7a. The relay 8 is activated to energize the halogen heater 3e. Also in this embodiment, as in the fifth embodiment, the heating source is not energized unless the highest temperature portion rotates, so the safety is high.

  Other parts that are not particularly described are configured in the same manner as the first, third, and fifth embodiments and function in the same manner.

FIG. 10 is a diagram showing the configuration of the main part of the fixing device according to the seventh embodiment of the present invention.
In the fixing device according to this embodiment, the halogen heater 3e in the sixth embodiment is provided not inside the heating roller 4 but inside the fixing belt 1f that is a fixing member, thereby forming the halogen heater 3f. In this embodiment, a fixing belt 1 f is stretched between the auxiliary roller 13, the auxiliary pad 24 and the tension roller 25 in order to form the nip portion N. A driving force from the motor 20 (not shown) is transmitted from the shaft 2s of the pressure roller 2 to the pressure roller 2, and first, the pressure roller is rotationally driven. Since the pressure roller 2 is pressed against the auxiliary roller 13 and the auxiliary pad 24 with a predetermined pressure, the auxiliary roller 13 and the tension roller 25 are driven and rotated via the fixing belt 1f stretched between them. The A rotary shaft of the DC motor 7 is connected to a rotary shaft (not shown) of the tension roller 25 via a gear train, and the DC motor 7 is rotated by the rotation of the tension roller 25 to generate electric power. When the DC motor 7 rotates, the on / off relay 8 is turned on by the electromotive force of the electromotive force generation circuit 7a, and energization to the halogen heater 3f is started. In the present embodiment, the DC motor 7 is provided in the final step of drive transmission, and the energization is performed for the first time by the rotation of the tension roller 25 which is the last component rotated by the follower. When it is stopped, power is never supplied and safety is high.

  Other parts not specifically described are configured in the same manner as the first and sixth embodiments and function in the same manner.

FIG. 11 is a diagram showing the configuration of the main part of the fixing device according to the eighth embodiment of the present invention.
The fixing device according to this embodiment is a cooling fan 31 instead of the DC motor 7 in the second embodiment, a low temperature thermostat 32 instead of the on / off relay 8, and the cooling fan 31 on the back of the low temperature thermostat 32. The flow path 33 which guides the cooling air from is formed. The on / off of the halogen heater 3a is controlled by on / off of the low temperature thermostat 32. Therefore, in this embodiment, the control means includes the cooling fan 31, the low temperature thermostat 32 and the flow path 33.

  In order to prevent an abnormally high temperature of the fixing device, a thermal fuse or a thermostat is generally used. This thermostat has a higher operating temperature when it is placed in contact so as not to operate at the continuous use temperature of the fixing device, or 30 ° C. lower than the lower limit temperature of the fixing temperature when placed without contact. An operating temperature of a low temperature is generally used. This is because even if the temperature is as low as about 30 ° C., the air becomes a heat insulating layer in the non-contact state and does not operate at the time of continuous use and operates at the lowest possible temperature at an abnormally high temperature.

  In a fixing device that raises temperature at a high speed in recent years, there is a time lag in the temperature rise of the thermostat, so the setting of the operating temperature and distance is very difficult. Even with a thermostat with an operating temperature of about 150 ° C., the fixing device is It may become abnormally high up to 400 ° C. In this embodiment, the low-temperature thermostat 32 operates at a temperature lower by 30 to 60 ° C. than the fixing temperature of 150 to 180 ° C. The distance L is 0.5 mm away from the contact state, that is, 0 mm <L ≦ 0.5 mm. Using. The low temperature thermostat 32 is mechanically connected by a gear train including a gear provided on a rotating shaft 2s of the pressure roller 2 while the fixing roller 1a is driven by the motor 20 and the pressure roller 2 is driven to rotate. Since the cooling fan 31 is rotated by receiving the rotational driving force of the pressure roller 2 and directly cools the low temperature thermostat 32 from the back side, the operating temperature of the low temperature thermostat 32 is set lower than the continuous use temperature. However, the low temperature thermostat 32 does not operate, and the halogen heater 3a can be used continuously. On the other hand, when the halogen heater 3a is heated without rotating the pressure roller 2, the rotation of the cooling fan 31 stops and the low temperature thermostat 32 is not cooled, so that the surface temperature of the fixing roller 1a is increased. The low temperature thermostat 32 is operated at about 220 to 260 ° C. to cut off the energization to the halogen heater 3a. As a result, the occurrence of an abnormally high temperature of the fixing roller 1a can be prevented.

  Other parts not specifically described are configured in the same manner as the first and second embodiments and function in the same manner.

FIG. 12 is a view showing the main part of the fixing device according to the ninth embodiment of the present invention.
In the fixing device according to this embodiment, the low-temperature thermostat 32 in the eighth embodiment is fixed to the flow path 33, the front surface faces the fixing roller 1a side, and the back surface is exposed to the flow path side. It is arranged on a branch path 33 a branched from the path 33. The low-temperature thermostat 32 is disposed so as to be movable in the direction perpendicular to the surface of the fixing roller 1a in the branch path 33a, and is elastically biased toward the fixing roller 1a with a predetermined pressure by a spring 34 on the back side. This predetermined pressure is driven by the pressure roller 2 rotating at a normal fixing speed in the flow path 33, and the fan 31 is driven, and the flow path is generated by the back pressure generated on the back side of the low temperature thermostat 32 by the wind speed supplied by the fan 31. This pressure is sufficient to move to the side 33 (elastic force). When the wind speed is reduced and the absolute value of the back pressure is reduced, the pressure is such that the spring 34 moves to a position close to the surface of the fixing roller 1a due to the elastic force. Elastic force). Therefore, in this embodiment, the control unit cooling fan 31, the low temperature thermostat, the flow path 33, the branch path 33a, and the spring 34 are configured.

  With this configuration, when the rotation of the pressure roller 2 decreases or stops, the fan 31 stops, and when the low temperature thermostat 32 moves to a position set in the L range close to the surface of the fixing roller 1a, In the range of 0 mm <L ≦ 0.5 mm, the fixing roller 1a receives heat and operates at a temperature 30 to 60 ° C. lower than the fixing temperature 150 to 180 ° C. Therefore, the surface temperature of the fixing roller 1a is 220 to 260. The low temperature thermostat 32 operates at about 0 ° C. to cut off the energization of the halogen heater 3a. As a result, the occurrence of an abnormally high temperature of the fixing roller 1a can be prevented.

  Other parts that are not particularly described are configured in the same manner as the first, second, and eighth embodiments and function in the same manner.

FIG. 13 is a view showing the main part of the fixing device according to the tenth embodiment of the present invention.
In the fixing device according to this embodiment, the operation in which the low-temperature thermostat 32 in the ninth embodiment moves close to and away from the surface of the fixing roller 1a is replaced with a solenoid 35 and a DC motor 7 as a generator for driving the solenoid 35. Thus, the driving force of the DC motor 7 is taken out from the rotating shaft 2s of the pressure roller 2 as in the second embodiment. Therefore, in this embodiment, the control means includes the DC motor 7, the low temperature thermostat 32, and the solenoid 35.

  In this embodiment, when the pressure roller 2 is rotating, the DC motor 7 obtains a rotational driving force from the pressure roller 2 to generate electric power, and the actuator 35a of the solenoid 35 is sucked to fix the low temperature thermostat 32 to the fixing roller. When the rotation of the pressure roller 2 stops or becomes lower than a predetermined speed, the electromotive force of the DC motor 7 drops and the actuator of the solenoid 35 of the solenoid 35 is held at a position separated from the surface of 1a (solid line state in FIG. 13). The suction is released, and the low temperature thermostat 32 comes close to the surface of the fixing roller 1a, and the low temperature thermostat 32 operates to cut off the energization to the halogen heater 3a as in the ninth embodiment. As a result, the occurrence of an abnormally high temperature of the fixing roller 1a can be prevented.

  Other parts not specifically described are configured in the same manner as the first, second, and ninth embodiments and function in the same manner.

FIG. 14 is a view showing the main part of the fixing device according to the eleventh embodiment of the present invention.
The fixing device according to this embodiment is different from the tenth embodiment in that the low temperature thermostat 32 is fixed at a position close to the surface of the fixing roller 1a, and the surface of the fixing roller 1a and the low temperature thermostat 32 are used using the solenoid 35. The heat insulating material 36 can be advanced and retracted between. In this case, when the DC motor 7 rotates in conjunction with the pressure roller 2 and power generation is performed, the actuator 35a of the solenoid 35 protrudes, and the heat insulating material 36 is advanced between the fixing roller 1a and the thermostat 32. When the rotation of the pressure roller 2 stops or becomes lower than a predetermined speed, the electromotive force of the DC motor 7 drops, the actuator of the solenoid 35 is sucked, and the low temperature thermostat 32 is exposed on the surface of the fixing roller 1a. In the same manner as in the embodiment, the low temperature thermostat 32 operates to cut off the energization to the halogen heater 3a. As a result, the occurrence of an abnormally high temperature of the fixing roller 1a can be prevented. Therefore, in this embodiment, the control means comprises the DC motor 7, the solenoid 35, the thermostat 32 and the heat insulating material 36.

  The heat insulating material was lighter than the thermostat, and a small solenoid could be used. Further, since the connection line of the thermostat through which a large current flows does not operate, higher safety is ensured.

  Other parts that are not particularly described are configured in the same manner as the first, second, and tenth embodiments and function in the same manner.

FIG. 15 is a view showing the main part of the fixing device according to the twelfth embodiment of the present invention.
The fixing device according to this embodiment is an example in which an induction heating unit is used in place of a radiant heat source such as a halogen heater or a sheet resistance heating element in the above embodiments. In this embodiment, the metal portion of the fixing roller 1a generates heat by the induction current generated on the surface of the fixing roller 1a by flowing a high-frequency current through the induction coil, and fixing is performed using the generated heat. FIG. 15 is a block diagram showing an outline of a circuit configuration using this induction heating. In the figure, an induction coil 41 converts a commercial power source 43 into a direct current by a converter 42, inputs the converted direct current to a switching element 45, and drives the switching element 45 with a high frequency generated by a high frequency generation circuit 44. An induction magnetic field is generated in the coil 41, and an induction current is induced on the surface of a predetermined region of the fixing roller 1a by the induction magnetic field. The high frequency generation circuit 44 is supplied with a drive voltage from a DC low voltage source 46, and this supply is controlled by the low temperature thermostat 32 or the on / off relay 8. The on / off relay 8 is turned on / off by the circuit of FIG. 4 in the first embodiment, and the low temperature thermostat 32 is connected to the high frequency generating circuit 44 by the same operation as in the eighth to eleventh embodiments. Is called. Therefore, in this embodiment, the control means includes a DC motor 7 and a mechanism for operating the on / off relay 8 by the DC motor 7, a mechanism for turning on / off the low temperature thermostat 32 using the fan 21 and the air blown by the fan 21, or a DC The motor 7 and the DC motor 7 actuate a solenoid to configure the low temperature thermostat 32 to be turned on / off. These mechanisms are as described in the previous embodiment.

  Thus, in order to generate the induced current, generation of a high frequency is indispensable, and energization control is performed on the high frequency generation circuit 44 which is the origin by the relay 8 or the low temperature operation thermostat 32. In this case, the voltage for driving the high frequency generation circuit 44 is sufficient for the energization control, and a low voltage (5 to 24 V) is sufficient. Therefore, a small relay or thermostat can be used, and the reaction speed can be increased. The low voltage can be shut off stably over a longer period of time compared to the case of directly generating heat at a high voltage (100 to 240 V) such as the halogen heater described above.

  It should be noted that this embodiment can be applied to embodiments other than the fourth embodiment shown in FIG. 7 and the seventh embodiment shown in FIG. Heating is possible, and the heat radiation area can be reduced. Thereby, energy saving can be further promoted.

  Other parts that are not particularly described are configured in the same manner as the first embodiment and function in the same manner.

FIG. 16 is a view showing a main part of a fixing device according to a thirteenth embodiment of the present invention.
The fixing device according to this embodiment is an example in which a separating member and an auxiliary heat source are provided immediately after the nip portion N between the fixing roller 1a and the pressure roller 2a in the eleventh embodiment shown in FIG. .

  For example, when image formation is performed in an oil-less state in FIG. 14, wrapping around the fixing member occurs when the recording medium is a thin paper of 50 g / m 2 or less. In order to prevent this, a claw 51 made of a heat-resistant resin is brought into contact with the downstream side of the nip portion N as a separating member. When an image formation test for 1000 sheets is performed in this state, toner sticks to the tip of the nail, and when the image formation is started thereafter, the fixing member is easily damaged.

  Therefore, an auxiliary heat source 52 of 50 W to 150 W is disposed in the vicinity of the separation claw 51 together with the reflecting plate 52a, and after generating heat for about 2 seconds before the fixing roller 1a rotates, rotation of the fixing roller 1a and energization of the main heat source 1000W are started. However, the winding did not occur. This is the same as rotating in the conventional fixing device after heating in the state where the fixing roller 1a is stopped to near the softening temperature of the toner in the initial stage. However, since the auxiliary heat source 43 has an extremely small electric power, an abnormally high temperature did not occur.

FIG. 17 is a view showing the main part of the fixing device according to the fourteenth embodiment of the present invention.
In the fixing device according to this embodiment, the recording medium in which the toner image 15 is transferred is passed between the fixing roller 1a and the nip portion N of the pressure roller 2 in the first embodiment shown in FIG. In contrast to fixing the toner image 15 on the toner image 15, the toner image 15 formed on the intermediate transfer belt 5 is transferred to the fixing roller 1a side, and the toner image is heated by the fixing roller 1a. The toner image 15 is transferred onto the recording medium 14 at the nip portion N 2 and heated and pressurized on the recording medium 14 to fix the toner image 15 on the recording medium 14. The fixing device of the system as in the first embodiment is generally referred to as a heat fixing device, and the fixing device of the system as in this embodiment is generally referred to as a heat transfer fixing device.

  This embodiment is different from the first embodiment in that the toner image 15 is transferred from the intermediate transfer belt (body) 5 to the fixing roller 1a, and the halogen heater 3a is transferred from the intermediate transfer belt 5 to the fixing roller 1a. Since only the points provided on the upstream side in the vicinity of the position are different, the other parts are configured in the same way and function in the same way, and therefore redundant description is omitted.

  The constituent elements in the first to fourteenth embodiments are not limited to those described above, and it goes without saying that known techniques are used. Further, in the present invention, since the rotational driving force is obtained from at least one member of the rotating member and the heating means is energized, when the rotational driving force cannot be obtained, the heating means is energized. Is never done. Therefore, the present invention functions as a safety device for a fixing device operated by a mechanical element, but such a safety device can be used alone or in combination with a safety device using conventional electrical means. Needless to say.

  In the first, third, fifth, sixth, eighth to fourteenth embodiments, the outer periphery of the fixing roller 1a such as the halogen heater 3a, the sheet resistance heating element 3b, the heating roller 4 or the induction coil 41 is used. Is heated in the axial direction (main scanning direction) to raise the temperature. If comprised in this way, since the heating range is narrow, the area which becomes high temperature reduces, the energy loss by heat radiation can be prevented, and the prevention function from becoming abnormally high temperature also becomes large.

The DC motor 7 or the fan 31 is preferably provided at the final stage of the power transmission path or a driving force transmission part close to the final stage as much as possible, but the arrangement with the motor 20 on the driving side is as follows.
1) A motor 20 and a DC motor 7 or a fan 31 are provided on the fixing roller 1a side.
2) The motor 20 and the DC motor 7 or the fan 31 are provided on the pressure roller 2 side.
3) A motor 20 is provided on the fixing roller 1a side, and a DC motor 7 or a fan 31 is provided on the pressure roller 2 side.
4) A DC motor 7 or fan 31 is provided on the fixing roller 1a side, and a motor 20 is provided on the pressure roller 2 side.
There are four combinations, and are set as appropriate in consideration of the space of the image forming apparatus.

  As described above, in the fixing device according to the embodiment of the present invention, the fixing member having a small heat capacity on the premise of heating at the time of rotation overheats at the time of abnormality (heating at the time of stopping due to a drive system trouble or a jam). This can be prevented. Moreover, since it is fail-safe and energization to the heating source is not performed when the safety device malfunctions, it works on the safe side. Basically, no power is supplied when there is an abnormality, so there is no damage to the fixing member due to temperature rise. Moreover, when energization is controlled by the rotation of the heating member closest to the heating source and having the fastest heating rate, safety can be further improved. In addition, when the energization is controlled by the rotation of the last-stage component that is driven and rotated, the energization can be stopped even when a slip occurs in any of the power transmission processes, thereby further improving safety. it can. Further, since the circuit is energized using the on / off relay, the reliability can be improved. Further, when a thermostat is used in place of the relay, the contact does not operate every time it rises, so that the reliability can be further improved.

  The present invention relates to a fixing device. The application range, that is, the range to be used is a heating fixing device and a heating transfer fixing device. The heat fixing device heats and fixes the toner image on the recording medium together with the recording medium. The heat transfer fixing device heats the toner image formed on the transfer fixing member and then transfers the toner image onto the recording medium. And heated together with the recording medium. In some cases, the image is transferred from the photosensitive member to the transfer fixing member, or is transferred to the transfer fixing member via the photosensitive member or the intermediate transfer member. In the fourteenth embodiment, the fixing roller 1a functions as a transfer fixing member.

1 is a diagram illustrating a schematic configuration of an entire image forming apparatus according to a first embodiment of the present invention. 1 is a diagram illustrating a schematic configuration of a fixing device (fixing unit) according to a first embodiment of the present invention. FIG. 1 is a diagram illustrating a schematic configuration of a fixing device including a power generation device according to a first embodiment of the present invention. FIG. 4 is a diagram illustrating an electrical configuration of the fixing device in FIG. 3. FIG. 6 is a diagram illustrating a schematic configuration of a fixing device according to a second embodiment of the present invention. FIG. 6 is a diagram illustrating a configuration of a main part of a fixing device according to a third embodiment of the present invention. FIG. 10 is a diagram illustrating a configuration of a main part of a fixing device according to a fourth embodiment of the present invention. FIG. 10 is a diagram illustrating a configuration of a main part of a fixing device according to a fifth embodiment of the present invention. It is a figure which shows schematic structure of the fixing device which concerns on the 6th Example of this invention. FIG. 10 is a diagram illustrating a configuration of a main part of a fixing device according to a seventh embodiment of the present invention. It is a figure which shows the structure of the principal part of the fixing device which concerns on the 8th Example of this invention. It is a figure which shows the structure of the principal part of the fixing device which concerns on the 9th Example of this invention. FIG. 10 is a diagram illustrating a schematic configuration of a fixing device according to a tenth embodiment of the present invention. It is a figure which shows the structure of the principal part of the fixing device which concerns on the 11th Example of this invention. It is a figure which shows the structure of the principal part of the fixing device which concerns on the 12th Example of this invention. It is a figure which shows the structure of the principal part of the fixing device which concerns on 13th Example of this invention. It is a figure which shows the structure of the principal part of the fixing device which concerns on the 14th Example of this invention.

Explanation of symbols

1a, 1d Fixing roller 1b, 1c, 1e, 1f Fixing belt 2 Pressure roller 3a, 3c, 3d, 3e, 3f Halogen heater 3b Planar resistance heating element 4 Heating roller 7 DC motor 8 On-off relay 9 Power supply 10 Thermostat 14 Transfer Paper (transfer material)
15 Unfixed toner 16, 17, 18, 19, 21 Gear 20 Motor 31 Fan 32 Low temperature thermostat 33 Flow path 33a Branch path 34 Spring 35 Solenoid 36 Heat insulating material 41 Inductive coil 45 Switching element 44 High frequency generating circuit 46 DC low voltage source 51 Separation member (nail)
52 Auxiliary heat source 150 Intermediate transfer belt 180 Fixing device (fixing unit)
N nip

Claims (23)

Two rotating members;
Heating means for heating at least one of the rotating members;
A fixing device for fixing through a fixing target member in a nip portion between the rotating members,
Having a control means for obtaining a rotational driving force of at least one of the rotating members and energizing the heating means;
The control means is a power generation means that generates power by obtaining the rotational driving force, and a switching means that enables energization of the heating means by an electromotive force generated by the power generation of the power generation means,
A fixing device comprising: Two rotating members;
Heating means for heating at least one of the rotating members;
In the a fixing device for fixing through a fixing subject member to the nip portion between the front Symbol rotating member,
Having a control means for obtaining a rotational driving force of at least one of the rotating members and energizing the heating means;
The heating means is a high-frequency electromagnetic induction heat source including a high-frequency oscillation driving unit to which power is supplied from a voltage unit,
The control means includes a power generation means for generating power by obtaining the rotational driving force, and a switching means for enabling energization from the voltage section to the high-frequency oscillation drive section by an electromotive force generated by power generation of the power generation means,
A fixing device comprising:   The fixing device according to claim 1, wherein the switching unit is an on / off relay and is turned on by an electromotive force when the power generation unit is operated. Two rotating members;
Heating means for heating at least one of the rotating members;
In the a fixing device for fixing through a fixing subject member to the nip portion between the front Symbol rotating member,
Having a control means for obtaining a rotational driving force of at least one of the rotating members and energizing the heating means;
Based on the surface temperature of the at least one rotating member heated by the heating unit, the control unit being arranged to be cooled by the fan that rotates by obtaining the rotational driving force and the air blown by the fan. A thermostat for turning on and off the energization of the heating means,
With
The fixing device, wherein an operating temperature of the thermostat is set to a temperature lower than a surface temperature at the time of fixing of the at least one rotating member heated by the heating unit. Two rotating members;
Heating means for heating at least one of the rotating members;
In the a fixing device for fixing through a fixing subject member to the nip portion between the front Symbol rotating member,
Having a control means for obtaining a rotational driving force of at least one of the rotating members and energizing the heating means;
The control means is provided so as to be movable in a direction approaching or separating from the fan rotating with the rotational driving force and the at least one rotating member heated by the heating means, and the surface of the rotating member A thermostat for turning on and off the energization of the heating means based on temperature,
The operating temperature of the thermostat is set to a temperature lower than the surface temperature at the time of fixing of the rotating member heated by the heating means,
The fixing device according to claim 1, wherein the thermostat moves in a direction away from the at least one rotating member heated by the heating means by back pressure on the back surface of the thermostat caused by blowing air from the fan. Two rotating members;
Heating means for heating at least one of the rotating members;
In the a fixing device for fixing through a fixing subject member to the nip portion between the front Symbol rotating member,
Having a control means for obtaining a rotational driving force of at least one of the rotating members and energizing the heating means;
The control means obtains the rotational driving force to generate electric power, the thermostat for turning on and off the heating means based on the surface temperature of the at least one rotating member heated by the heating means, Driving means for moving the thermostat in a direction approaching or separating from the at least one rotating member in accordance with an electromotive force generated by the power generation means;
With
The operating temperature of the thermostat is set to a temperature lower than the surface temperature at the time of fixing of the at least one rotating member heated by the heating means,
The fixing device, wherein the driving unit moves the thermostat in a direction away from the at least one rotating member heated by the heating unit when an electromotive force is obtained by the power generation unit. Two rotating members;
Heating means for heating at least one of the rotating members;
In the a fixing device for fixing through a fixing subject member to the nip portion between the front Symbol rotating member,
Having a control means for obtaining a rotational driving force of at least one of the rotating members and energizing the heating means;
The control means is disposed with a predetermined gap from a power generation means for generating electric power by obtaining the rotational driving force and at least one rotary member heated by the heating means, and based on a surface temperature of the rotary member A thermostat that turns on and off the energization of the heating means, and a drive means that advances or retracts the heat insulating member into the gap according to the electromotive force generated by the power generation means,
The operating temperature of the thermostat is set to a temperature lower than the surface temperature at the time of fixing of the at least one rotating member heated by the heating means,
The fixing device, wherein the driving unit causes the heat insulating member to advance into the gap when an electromotive force is obtained by the power generation unit.   The fixing device according to claim 6, wherein the driving unit is a solenoid.   The operating temperature of the thermostat is 30 ° C. or more lower than the surface temperature at the time of fixing of the at least one rotating member heated by the heating unit. Fixing device.   The power generation means performs power generation by obtaining a driving force from the rotary member in conjunction with the rotation of the rotary member body at the final stage of the rotation transmission system of the rotary member. The fixing device according to any one of 6, 7, and 8.   11. The one rotating member that uses a rotational driving force by the control means is a main-rotation-side rotating member that directly obtains a driving force from a driving source. Fixing device.   The one rotating member that uses the rotational driving force by the control means is a driven side rotating member that rotates by obtaining a rotational driving force from a rotating member on the main drive side that rotates by obtaining a driving force directly from a driving source. The fixing device according to claim 1, wherein the fixing device is a fixing device.   The fixing device according to claim 12, wherein the driven-side rotating member obtains a driving force via a nip between the driven-side rotating member and the driven-side rotating member, and is driven to rotate.   The fixing device according to claim 1, wherein one of the two rotating members is a fixing member and the other is a pressure member.   The fixing device according to claim 14, wherein the heating unit is provided inside or outside the fixing member.   The fixing device according to claim 15, wherein the heating unit heats the fixing member by generating a heat source when energized.   The fixing device according to claim 16, wherein a heating range of the heat source is a part in an axial direction of an outer periphery of the fixing member. Two rotating members;
Heating means for heating at least one of the rotating members;
A fixing device for fixing through a fixing target member in a nip portion between the rotating members,
At least one rotating member of the rotating member includes an endless belt member and a roller on which the belt member is stretched,
Control means for obtaining a rotational driving force of the roller and energizing the heating means;
The control means is a power generation means that generates power by obtaining the rotational driving force, and a switching means that enables energization of the heating means by an electromotive force generated by the power generation of the power generation means,
A fixing device comprising: Two rotating members;
Heating means for heating at least one of the rotating members;
A fixing device for fixing through a fixing target member in a nip portion between the rotating members,
At least one rotating member of the rotating member includes an endless belt member and a roller on which the belt member is stretched,
Control means for obtaining a rotational driving force of the roller and energizing the heating means;
The heating means is a high-frequency electromagnetic induction heat source including a high-frequency oscillation driving unit to which power is supplied from a voltage unit,
The control means includes a power generation means for generating power by obtaining the rotational driving force, and a switching means for enabling energization from the voltage section to the high-frequency oscillation drive section by an electromotive force generated by power generation of the power generation means,
A fixing device comprising:   The fixing device according to claim 18, wherein the switching unit is an on / off relay, and is turned on by an electromotive force when the power generation unit is operated.   21. An image forming apparatus comprising the fixing device according to claim 1. An image forming means for forming a toner image on the image carrier;
Transfer means for transferring the toner image formed by the image forming means to the surface of the at least one rotating member heated by the heating means;
The toner image transferred onto the at least one rotating member heated by the heating unit is transferred again onto the recording medium at the nip portion, and is fixed on the recording medium by heating and pressing. The fixing device according to any one of Items 1 to 13,
An image forming apparatus comprising: Two rotating members;
Heating means for heating at least one of the rotating members;
In a fixing control method for fixing through a fixing target member in a nip portion between the rotating members,
Executing a control to obtain energization to the heating means by obtaining at least one rotational driving force of the rotating member;
In the control, the rotation control force is obtained to generate electric power, and the switching means is operated by the electromotive force generated by the electric power generation to enable energization to the heating means.

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