JPH0876609A - Image forming device provided with cleaning function - Google Patents

Abstract

PURPOSE: To reduce the power consumption of a device and to improve profitability by dispensing with a heating means used exclusively for cleaning and to always keep the quality of an image high by effectively and stably removing residual toner. CONSTITUTION: A web cleaner 41 is arranged on the downstream side of a transferring/fixing position A in a transferring/fixing part 21 and a web 41b pulled out from the supplying roller 41a of the web cleaner 41 is brought into press-contact with the periphery of a heating roller 21a, in a state where a dielectric endless belt 31 is held, so that toner remaining thereon can be wiped off to remove by the web 41b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention transfers and fixes a toner image on a medium by sandwiching and transporting a dielectric endless belt on which a toner image is formed between a heat roller and a pressure roller of a transfer fixing unit. And an image forming apparatus having a function of cleaning toner remaining on the dielectric endless belt after transfer and fixing.

[0002]

2. Description of the Related Art In recent years, as one of image forming apparatuses adopting an electrophotographic system, an apparatus has been developed which uses a transfer fixing belt to simultaneously transfer and fix a toner image.

FIG. 9 shows an example of the structure of this type of apparatus, which is disclosed in Japanese Patent Application Laid-Open No. 5-88566. That is, this apparatus includes a development transfer unit 2 that forms a toner image on the outer surface of the photoconductor 2a, a transfer fixing mechanism 3 that transfers and fixes the toner image of the photoconductor 2a onto a medium 1 as printing paper, and an endless type. The transfer / fixing belt 4 is provided, and the transfer / fixing belt 4 is circulated between the developing / transferring unit 2 and the transfer / fixing mechanism 3 by the conveying roller 5a. When forming an image, the toner image on the photoconductor 2a is adsorbed and transferred onto the outer surface 4a of the transfer / fixing belt 4 and conveyed to the transfer / fixing mechanism 3, where the medium 1 as a printing sheet is transferred. It is transferred to and heat-fixed at the same time.

By the way, in this type of apparatus, if the transfer and fixing of the toner image from the transfer and fixing belt 4 to the medium 1 is not complete, the residual toner remains on the transfer and fixing belt 4, and this residual toner is next transferred to the developing and transferring means 2. There is a problem that the toner image overlaps with the formed toner image, resulting in deterioration of image quality.

Therefore, in this type of apparatus, as shown in FIG. 9, for example, a cleaner 6 is provided on the downstream side of the transfer fixing means 3 in the related art.
Is provided. The cleaner 6 includes a cleaning felt 6a, a spring 6b for pressing the cleaning felt 6a against the outer surface 4a of the transfix belt 4, and a heat roller 6c arranged on the back side of the transfix belt 4.
The heat roller 6c heats the transfer fixing belt 4 to melt the residual toner on the outer surface thereof,
The melted residual toner is mixed with the cleaning felt 6 described above.
It is configured to be wiped off by a.

As another configuration of the cleaner, for example, as shown in FIG. 10, a cleaning belt 7d is stretched between a driving roller 7a and a driven roller 7b, and the cleaning belt 7d is attached to the outer surface 4a of the transfer fixing belt 4. The transfer / fixing belt 4 is circulated in the direction opposite to the conveying direction while being pressed by. A heat roller 7c is provided on the back side of the transfer / fixing belt 4 as in the case of FIG. 9, and the heat roller 7c heats the transfer / fixing belt 4 to melt the residual toner on the outer surface thereof. There is also a structure in which the molten residual toner is wiped off by the cleaning belt 7d.

In the case of an apparatus having a cleaner for residual toner as described above, the toner remaining on the transfer and fixing belt 4 is removed, whereby deterioration of the quality of the image on the subsequent page can be prevented.

[0008]

However, such a conventional device has the following problems to be improved. That is, in the conventional devices, the cleaning heat rollers 6c and 7 are exclusively used for melting the residual toner.
c is provided. Therefore, the power consumption of the device is increased and the running cost is increased.

Further, since both the cleaning felt 6a and the cleaning belt 7d are used continuously or repeatedly, there is a problem that dirt is accumulated and the cleaning effect is deteriorated as the usage time becomes longer.

Therefore, a first object of the present invention is to eliminate the need for heating means exclusively for cleaning, thereby reducing the power consumption of the apparatus to improve the economical efficiency and effectively and stably remove the residual toner. An object of the present invention is to provide an image forming apparatus having a cleaning function that can be removed to always maintain high image quality.

A second object of the present invention is to provide an image forming apparatus having a cleaning function capable of efficiently heating and melting the residual toner on the dielectric endless belt to reduce the power consumption of the apparatus. Is.

A third object of the present invention is to effectively remove not only the residual toner on the dielectric endless belt but also the unnecessary toner before transfer and fixing when the image forming operation is urgently stopped. Accordingly, it is an object of the present invention to provide an image forming apparatus having a cleaning function capable of further reliably preventing the occurrence of cleaning failure.

[0013]

In order to achieve the above object, a first invention is to provide a dielectric endless belt having a toner image formed on its outer peripheral surface between a heat roller and a pressure roller of a transfer fixing section. In an image forming apparatus having a cleaning function of transferring and fixing the toner image on a medium by nipping and conveying the toner and removing the toner remaining on the dielectric endless belt after the transfer fixing, the toner is wound around a supply roller. The web is pulled out to be used for cleaning the residual toner, and a web cleaning means for winding the used web with a take-up roller is provided, and a web pressing means is provided. The web pulled out from the supply roller of the cleaning means is attached to the outer peripheral surface of the heat roller of the transfer and fixing unit, and the dielectric endless belt after the transfer and fixing is performed. The is obtained by configured to press-contact while clamped.

In order to achieve the above-mentioned second object, a second aspect of the present invention sandwiches a dielectric endless belt having a toner image formed on its outer peripheral surface between a heat roller and a pressure roller of a transfer fixing section. In an image forming apparatus having a cleaning function of transferring and fixing the toner image onto a medium by conveying the toner image and removing the toner remaining on the dielectric endless belt after the transfer fixing, a web wound around a supply roller Is provided to clean the residual toner, and after that, a web cleaning means for winding the used web with a take-up roller and a pressing means for the web are provided, and the web is taken out from the supply roller of the web cleaning means. The web is configured to be pressed against the outer peripheral surface of the dielectric endless belt after transfer and fixing by the web pressing means, and the web pressing means is heated. Provided stage, the toner remaining on the dielectric endless belt after the transfer-fixing by the heating means by heat-melting through the web, in which so as to facilitate wiping above web.

In order to achieve the above-mentioned third object, a third aspect of the present invention sandwiches a dielectric endless belt having a toner image formed on its outer peripheral surface between a heat roller and a pressure roller of a transfer fixing section. In an image forming apparatus having a cleaning function of transferring and fixing the toner image onto a medium by conveying the toner image and removing the toner remaining on the dielectric endless belt after the transfer fixing, the dielectric endless belt after the transfer fixing A first cleaning means is disposed opposite to the conveying path of the above, and the toner remaining on the dielectric endless belt after the transfer fixing is removed by cleaning by the first cleaning means, and the dielectric before the transfer fixing is performed. The second cleaning unit is disposed opposite to the conveyance path of the endless belt, and the contact / separation control unit is provided.
Holding the cleaning means in a non-contact state with the outer peripheral surface of the dielectric endless belt, and when the conveyance jam of the medium is detected, the second cleaning means is brought into contact with the outer peripheral surface of the dielectric endless belt, Unnecessary toner before transfer and fixing formed on the body endless belt is removed.

[0016]

As a result, according to the first aspect of the present invention, since the web cleaner is used, the residual toner is always wiped off by a new web which is free from dirt. Therefore, it becomes possible to effectively and stably remove the residual toner as compared with the case where one cleaning felt or cleaning belt is used continuously or repeatedly.

Further, the residual toner on the dielectric endless belt is wiped off by the web in a state where the dielectric endless belt is in contact with the peripheral surface of the heat roller of the transfer fixing section. That is, the residual toner on the dielectric endless belt is wiped off by the web while the molten state is kept by the heat from the heat roller of the transfer fixing section. In other words, the heat roller of the transfer / fixing section also serves as the heating means for cleaning. For this reason, a heating unit dedicated to cleaning is not required, which makes it possible to reduce the power consumption of the apparatus.

According to the second aspect of the present invention, since the heating means for cleaning is provided in the pressing means of the web, the residual toner on the dielectric endless belt does not go through the dielectric endless belt but only through the web. It will be heated directly. Therefore, it is possible to efficiently heat the residual toner, and this makes it possible to reduce the amount of heat generated by the heating unit and reduce power consumption.

Generally, the transfix belt has a thickness of 100.
Since a resin or metal having a thickness of about μm is used, the residual toner is difficult to be heated due to the influence of its thermal conductivity or thermal diffusion efficiency. Also, the transfer / fixing belt is 250 mm / sec.
Since the toner is conveyed at a moderate speed, it is necessary to heat the residual toner in a short time. Therefore, if the residual toner is heated and melted through the transfer fixing belt 4 as in the conventional apparatus, the surface temperature of the heat roller needs to be sufficiently higher than the melting temperature of the toner, resulting in power consumption. Will be very large.

On the other hand, when the residual toner on the dielectric endless belt is directly heated from the surface side of the dielectric endless belt as in the present invention, the residual toner can be efficiently heated and melted. Therefore, there is an advantage that it consumes less power.

According to the third aspect of the present invention, in an emergency such as when the continuous printing operation is urgently stopped due to a jam of the medium being conveyed, the second cleaning means operates to transfer and fix the remaining toner on the dielectric endless belt. The unnecessary toner image remaining without being removed is removed.

Generally, when an emergency stop occurs during continuous printing operation, unmelted powder-like toner before transfer and fixing and residual toner once melted after transfer and fixing are formed on the dielectric endless belt depending on its position. Are mixed. If the dielectric endless belt in such a state is to be cleaned only by the cleaning means for removing the residual toner after transfer and fixing, it is difficult to sufficiently remove the toner and a cleaning failure is likely to occur. This is because the heat roller for transfer and fixing stops the heating operation when it is urgently stopped, so that the unnecessary toner image before the transfer and fixing is not sufficiently melted and is sent to the cleaning unit, and the unnecessary toner before the transfer and fixing is also performed. This is because the image has an extremely large amount of toner.

Therefore, as in the present invention, in an emergency, the second cleaning means is operated to remove the unnecessary toner image before transfer and fixing, and only the residual toner is removed by the first cleaning means. It is possible to effectively remove all of the different toners, thereby preventing the occurrence of defective cleaning.

According to the present invention, the second
Since the cleaning means is held in a state of being separated from the dielectric endless belt, there is no fear that the toner image formed on the dielectric endless belt is adversely affected.

[0025]

【Example】

(First Embodiment) FIG. 1 is a schematic view of the essential parts of an image forming apparatus with a cleaning function according to the first embodiment of the present invention.

In the figure, the transfer fixing section 21 has a diameter of about 8
The heat roller 21a having a length of 0 mm is provided, and the endless dielectric belt 31 is wound around the circumferential surface of the heat roller 21a for about half the circumference thereof. This dielectric endless belt 3
1 is composed of a heat-resistant resin belt having a two-layer structure made of, for example, a conductive resin having a thickness of about 50 μm on the back side and a dielectric resin such as polyimide, polyamide-imide, or fluorine having a thickness of about 25 μm on the front side. It Further, the medium 11 is superposed on the dielectric endless belt 31, and the dielectric endless belt 31 and the medium 11 are sandwiched between the heat roller 21a and the pressure roller 21c so as to move in the direction of the arrow in the figure. It is conveyed at a speed of 250 mm / sec. As the medium 11, paper, resin film, or the like is used. The pressure roller 21c has a surface hardness of about 3
The roller has a diameter of about 30 mm at 0 degree and is urged toward the peripheral surface of the heat roller 21a by a spring (not shown). A halogen lamp 21b as a heating source is housed inside the heat roller 21a, and the heat roller 21a is heated by the halogen lamp 21b. The heating temperature is controlled by a temperature sensor and a temperature control circuit (not shown) so that the surface temperature of the dielectric endless belt 31 is maintained at 110 ° C. or higher, which is the melting temperature of the toner, at the transfer fixing position shown by A in the figure. To be done.

By the way, a web cleaner 41 is disposed at a position downstream of the transfer / fixing position A in the conveying direction of the dielectric endless belt 31. The web cleaner 41 includes a web supply roller 41a, a web winding roller 41c, and a pressure contact roller 41d.
A long web 41b made of, for example, heat-resistant paper having a thickness of 30 μm is wound around the web supply roller 41a in advance.

The pressing roller 41d is made of a foam material, and presses the web 41b fed from the web supply roller 41a against the peripheral surface of the heat roller 21a with the dielectric endless belt 31 sandwiched therebetween. The web take-up roller 41c is driven by a motor (not shown) to approximately 20 mm / sec.
The web 41b that has passed through the pressure contact roller 41d is wound up.

Due to such a constitution, when the dielectric endless belt 31 on which the toner image is formed by the not-shown developing transfer portion is conveyed to the transfer fixing portion 21, the toner image on the dielectric endless belt 31 is formed. After being heated and melted by the heat roller 21a, the medium 11 is pressed and transferred and fixed on the medium 11 at the transfer fixing position A by the pressing roller 21c.

Further, the toner remaining on the dielectric endless belt 31 after the transfer and fixing is conveyed to the cleaning position B while being kept in a molten state by the heat of the heat roller 21a, and at the cleaning position B, the supply roller 41a.
It is wiped off by a new web 41b pulled out at a constant speed.

As described above, in the apparatus of the present embodiment, the web cleaner 41 is arranged on the downstream side of the transfer / fixing position A in the transfer / fixing section 21, and the web 41b pulled out from the supply roller 41a of the web cleaner 41 is heated. Laura 2
The residual toner on the dielectric endless belt 31 is wiped off by pressing the peripheral surface of the dielectric 1a with the dielectric endless belt 31 sandwiched therebetween.

Therefore, the residual toner on the dielectric endless belt 31 can be wiped off by the web 41b while being kept in a molten state by the heat of the heat roller 21a of the transfer / fixing section 21, whereby the dielectric endless belt 31 is wiped. The residual toner can be effectively removed. Also,
Since the heat roller 21a of the transfer / fixing unit 21 is also used as the heating means for cleaning, it is not necessary to newly provide a heater dedicated to cleaning, and thus the power consumption of the apparatus can be reduced.

Further, since the web cleaner 41 is used, the residual toner can be wiped off by the new web 41b which is always clean, so that one cleaning felt can be continuously used or the cleaning belt can be repeatedly used. The residual toner can always be removed more stably than when used.

(Second Embodiment) In this embodiment, a plurality of pressure rollers are used to press the web of the web cleaner against the surface of the dielectric endless belt, whereby the contact area of the web with respect to the dielectric endless belt, That is, the wiping area is increased.

FIG. 2 is a block diagram of the essential parts of an image forming apparatus with a cleaning function according to this embodiment. In the figure, the same parts as those in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted.

Web supply roller 4 of web cleaner 42
The web 41b pulled out from the la 1a is composed of two pressure contact rollers 42a, 42b which are arranged at regular intervals.
As a result, the dielectric endless belt 31 is pressed against the peripheral surface of the heat roller 21a. Then, in the pressing range B ', the web 41b is covered with the dielectric endless belt 31.
The residual toner on the upper side is wiped off, and then it is wound around the web winding roller 41c and collected.

As described above, according to this embodiment, the web 41
b is pressed against the dielectric endless belt 31 on the circumferential surface of the heat roller 21a by the two pressure contact rollers 42a and 42b. For this reason, the web 41b comes into surface contact with the dielectric endless belt 31 in the range B ', whereby the residual toner on the dielectric endless belt 31 is effectively removed as compared with the case of line contact.

(Third Embodiment) In the present embodiment, a heater for preheating the web is provided in the web supply roller of the web cleaner, and the heater preheats the web to wipe off residual toner. Is.

FIG. 3 is a block diagram of the essential parts of an image forming apparatus with a cleaning function according to this embodiment. In the figure, the same parts as those in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted.

A ceramic heater 43a is housed in the supply roller 41a of the web cleaner 43. The ceramic heater 43a maintains a temperature of about 100 ° C., and thereby preheats the web 41b. Then, the preheated web is supplied to the residual toner cleaning position B.

With such a structure, the following operational effects can be obtained. That is, when the web 41b is not preheated, the web 41b at the cleaning position B is
The surface temperature of is equal to the temperature inside the device, for example, 35 ° C. In this case, the temperature of the dielectric endless belt 11 and the residual toner heated by the heat roller 21a decreases when the web 41b contacts the web 41b at the cleaning position B because the heat is absorbed by the web 41b. Then, the residual toner instantly starts to coagulate, and as a result, a part of the coagulated toner is not sufficiently wiped off by the web 41b and remains attached to the dielectric endless belt 31, which causes a cleaning failure. Sometimes.

On the other hand, in this embodiment, since the web 41b is preheated and is used for cleaning, the heat is not taken when the dielectric endless belt 31 and the residual toner are contacted, and as a result, the residual toner is melted. Is retained. Therefore, the residual toner is wiped off more effectively by the web 41b, which prevents the occurrence of cleaning failure.

Further, since the ceramic heater 43a for preheating is housed in the web supply roller 41a, it is not necessary to secure a new installation space for the preheating means, thereby preventing the apparatus from becoming large. it can. Also,
By providing the ceramic heater 43a in the web supply roller 41a, the heat generated by the ceramic heater 43a can be efficiently applied to the web 41b, and thus the power consumption by the ceramic heater 43a can be reduced. As a heater for preheating, a halogen lamp or a heating wire may be used instead of the ceramic heater 43a.

(Fourth Embodiment) In this embodiment, one of the pressing members of the web cleaner is a wedge-shaped pressing contact separating member having a sharp tip, and the tip of the pressing contact separating member is used. The section is arranged close to the transfer fixing position by the heat roller and the pressure roller, and this member is provided with a function of pressing the web and a function of separating the dielectric endless belt from the medium.

FIG. 4 is a block diagram of the essential parts of an image forming apparatus with a cleaning function according to this embodiment. In the figure, the same parts as those in FIG. 2 are designated by the same reference numerals and detailed description thereof will be omitted.

In the second embodiment shown in FIG. 2, two pressing rollers 42 are used to press the web 41b pulled out from the web supply roller 41a against the dielectric endless belt 31.
a and 42b were used. In the present embodiment, of these pressure contact rollers 42a and 42b, the pressure contact roller 42b located on the upstream side of the dielectric endless belt 31 is replaced with the pressure contact separation member 44a. The pressing / separating member 44a has a wedge shape in which a tip portion is formed in a taper shape with an acute angle.
4b is arranged at a position close to the transfer fixing position A. Further, the tip end portion 44b of the pressing contact separation member 44a is
As shown in an enlarged manner in FIG. 5, it is curved, and the curved portion prevents the web 41b from being damaged or cut.

With such a structure, the web 41b
Is simultaneously in contact with the dielectric endless belt 31 in a wide area B'by the pressure contact roller 42a and the pressure separating member 44a, so that the residual toner can be wiped off in a wide area. Therefore, the residual toner is effectively removed.
Along with that, the tip end portion 44b of the pressing contact separation member 44a
Is formed in an acute angle and is arranged at a position close to the transfer fixing position A by the heat roller 21a and the pressure roller 21c, the medium 11 is temporarily pressed against the dielectric endless belt 31. Even if it is carried out from the transfer fixing position A, it is separated and separated by the tip end portion 44b of the pressing and separating member 44a. Therefore, it is possible to prevent the occurrence of obstacles such as jams and improve the stability.

(Fifth Embodiment) In this embodiment, the position of the pressure contact roller of the web cleaner is set at a position downstream from the transfer fixing position along the peripheral surface of the heat roller by ¼ or more. Thus, the dielectric endless belt is wound around a part of the peripheral surface of the pressure roller.

FIG. 6 is a schematic view of the essential parts of an image forming apparatus with a cleaning function according to this embodiment. In the figure, the same parts as those in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted.

Pressure contact roller 45a of web cleaner 45
Is arranged at a position on the downstream side, which is separated from the transfer fixing position A along the peripheral surface of the heat roller 21a by at least 1/4 round, and is pressed against the peripheral surface of the heat roller 21a at this position. There is. Further, the dielectric endless belt 31 has its conveying direction changed to the right direction in the drawing by a guide roller (not shown) located further downstream of the dielectric endless belt 31. As a result, the dielectric endless belt 31 is moved to the pressing roller. It is wound around a part of the peripheral surface of 45a.

Therefore, the contact area of the web 41b with the dielectric endless belt 31 is increased, whereby the residual toner on the dielectric endless belt 31 is effectively wiped off by the web 41b.

(Sixth Embodiment) In this embodiment, a heater as a heating means is accommodated in the pressure roller of the web cleaner, and the residual toner on the dielectric endless belt is heated and melted through the web by this heater. , So that the web can effectively wipe off the residual toner,
In addition, a temperature sensor and a temperature control circuit are provided, and the heat generation temperature of the heater is feedback-controlled to maintain a constant temperature.

FIG. 7 is a block diagram of the essential parts of an image forming apparatus with a cleaning function according to this embodiment. In the figure, the same parts as those in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted.

A ceramic heater 46e as a heating source is housed in the pressure roller 46d of the web cleaner 46. Further, a temperature sensor 46g including, for example, a thermistor is arranged near the peripheral surface of the pressure contact roller 46d, and the detection output of the temperature sensor 46g is input to the temperature control circuit 46h. The temperature control circuit 46h monitors the detection output of the temperature sensor 46g,
The surface temperature of the pressing roller 46d is the toner melting temperature 1
The energization to the ceramic heater 46e is controlled so as to be 10 ° C.

The guide roller 46 is provided at a position downstream of the pressure contact roller 46d from the dielectric endless belt 31.
f is provided. The guide roller 46f bends the dielectric endless belt 31 in the conveying direction on the downstream side of the pressure contact roller 46d to wind the dielectric endless belt 31 around about 1/4 of the pressure contact roller 46d. Is.

With such a configuration, the residual toner on the dielectric endless belt 31 is heated and melted by the heat of the ceramic heater 46e while being in surface contact with the peripheral surface of the pressure contact roller 46d of the web cleaner 46, and At the same time, the web 46b pulled out from the web supply roller 46a is wiped and removed. Therefore, even if the residual toner on the dielectric endless belt 31 is solidified after the transfer fixing by the heat roller 21a and the pressure roller 21c, the residual toner is ceramic while contacting the peripheral surface of the pressure contact roller 46d. It is again heated and melted by the heater 46e, and in this state, it is wiped off by the web 46b. Therefore, the residual toner is effectively and stably removed. Reference numeral 46c is a web winding roller.

Further, in this embodiment, the residual toner on the dielectric endless belt 31 is directly fed by simply passing the extremely thin web 46b from the surface side of the dielectric endless belt 31 by the ceramic heater 46e provided in the pressure contact roller 46d. Since the heating is efficiently performed, the residual toner on the dielectric endless belt 31 can be efficiently heated compared to the case where the residual toner on the back surface of the dielectric endless belt 31 is heated through the dielectric endless belt 31. it can. Therefore, the same cleaning effect can be obtained with less power consumption than the conventional one.

Further, since the surface temperature of the pressure roller 46d is feedback-controlled by the temperature sensor 46g and the temperature control circuit 46h, the heating temperature can always be maintained at a necessary and sufficient temperature higher than the melting temperature of the toner. Therefore, the residual toner can be efficiently melted with necessary and sufficient power consumption. That is, it is possible to provide an apparatus that has both excellent cleaning performance and economical efficiency. As the heating means, a halogen lamp, a heating wire or the like may be used instead of the ceramic heater 46e.

(Seventh Embodiment) In this embodiment, a web cleaner for removing the residual toner after transfer and fixing is arranged in the conveying path of the dielectric endless belt after transfer and fixing, and this web cleaner is used. Thus, the toner remaining on the dielectric endless belt after transfer and fixing is removed by cleaning, and a fur brush cleaner is arranged in the transport path of the dielectric endless belt before being subjected to transfer and fixing, and a contact / separation mechanism is provided. By the separation mechanism, the fur brush cleaner is normally held in a non-contact state with the outer peripheral surface of the dielectric endless belt,
In an emergency, the fur brush cleaner is brought into contact with the outer peripheral surface of the dielectric endless belt to remove unnecessary toner formed on the dielectric endless belt before transfer fixing.

FIG. 8 is a schematic configuration diagram of an image forming apparatus with a cleaning function according to this embodiment. In the figure, the same parts as those in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted.

In the conveying path of the dielectric endless belt 31 after transfer and fixing, a web cleaner 41 is arranged so as to face the peripheral surface of the heat roller 21a. The web cleaner 41 is used to remove residual toner on the dielectric endless belt 31 after transfer and fixing.

On the other hand, the platen roller 71a and the developing device 71b constituting the developing section 71, and the transfer and fixing section 21.
A fur brush cleaner 61 is disposed in the transport path of the dielectric endless belt 31 between the heat roller 21a and the pressure roller 21c. The fur brush cleaner 61 is arranged at a position where the surface temperature of the dielectric endless belt 31 is lower than the glass transition point of the toner on the conveying path.

The fur brush cleaner 61 is for removing a toner image that is no longer needed before transfer and fixing, and has a fur brush 61b and a housing 61a to which the fur brush 61b is attached. A support shaft 61c for swingably supporting the housing 61a, and the housing 61a.
The eccentric cam 61e has a tension spring 61d for constantly urging the rear side. Of these, the support shaft 61c, the tension spring 61d, and the eccentric cam 61e constitute a support mechanism for the fur brush 61b. That is, the eccentric cam 61e is rotated by a servo motor or a step motor (not shown) to normally hold the fur brush 61b in non-contact with the dielectric endless belt 31, and only when necessary after an emergency stop. Is contacted with the dielectric endless belt 31.

The peripheral lengths of 51a and 51b are about 810 mm.
Platen roller for applying tension to the dielectric endless belt 31, 51c is an eraser for eliminating electric charges remaining on the dielectric endless belt 31, and 81 is for writing an electrostatic latent image on the dielectric endless belt 31. Charging unit (ion cartridge (ICG)) 81.

With such a structure, the fur brush 61b is first set in a non-contact state with the dielectric endless belt 31 in a normal state. In this state, the dielectric endless belt 31 is neutralized by the eraser 51c, and then an electrostatic latent image is formed by the charger 81. The electrostatic latent image is developed by the toner in the developing section 71. Then, the toner image passes through the fur brush cleaner 61 and is conveyed to the transfer / fixing section 21.
In No. 1, the dielectric endless belt 31 is transferred onto the medium 11 and simultaneously heat-fixed. Further, the toner remaining on the dielectric endless belt 31 after the transfer and fixing is wiped and removed by the web 41b in the web cleaner 41. After that, by repeating the above steps, the medium 1
Images are formed one after another. Photo sensors (not shown) are provided in front of and behind the transfer / fixing unit 21, and these sensors detect jamming of the medium 11 during transportation.

Now, it is assumed that during the normal operation as described above, for example, the transfer / fixing section 21 has a jam of the medium 11 which is detected by the photo sensor. Then, the heat roller 21a stops driving and the halogen lamp 21b also stops heating operation. In addition, the pressure roller 2
In order to facilitate paper jam processing, 1c is retracted to a state where it does not contact the heat roller 21a by a retracting mechanism (not shown). Further, the eccentric cam 61e rotates by a half turn in accordance with an instruction from a control circuit (not shown), whereby the fur brush 61b comes into contact with the dielectric endless belt 31.

Therefore, when the dielectric endless belt 31 is conveyed in order to initialize the apparatus in this state, the unnecessary toner image on the next page formed on the dielectric endless belt 31 becomes the above-mentioned fabrum cleaner. At 61, it is rubbed off by the fur brush 61b. On the other hand, the transfer fixing unit 2
The toner remaining on the dielectric endless belt 31 after the transfer fixing by 1 is wiped and removed by the web cleaner 41 with the web 41b. At this time, for cleaning by the web cleaner 41, the halogen lamp 21b in the heat roller 21a may be turned on only during the cleaning period to melt the residual toner.

As described above, according to this embodiment, during the cleaning period after the emergency stop, the fur brush cleaner 61 operates and the cleaner 61 removes the toner image on the next page before transfer and fixing. At this time, the fur brush cleaner 61 is installed at a position where the surface temperature of the dielectric endless belt 31 is lower than the glass transition point of the toner as described above, so that the toner is kept in a powder shape. Therefore, the toner image can be reliably scraped off by the fur brush 61b. Therefore, even if the high-density toner image is formed on the dielectric endless belt 31, the toner image conveyed to the web cleaner 41 becomes very small, and as a result, the defect that the cleaning failure occurs in the web cleaner 41 is prevented. To be done.

The present invention is not limited to the above embodiments. For example, in each of the above embodiments, the case where the dielectric endless belt 31 for developing and transferring and fixing the latent image on the medium 11 is cleaned is described as an example, but the apparatus shown in FIGS. 9 and 10 is used. The present invention may be applied to the case of cleaning the intermediate transfer medium for transferring and fixing the image formed on the photoconductor to the medium as described above.

Further, in each of the above-mentioned embodiments, the pressure contact roller 4 is used as a pressing means for the dielectric endless belt in the web cleaner.
Although the case where 1d, 42a, 42b, 44a and 46d are used has been described, a pressure contact plate may be used instead of the roller. In this case, the shape of the pressure contact surface of the pressure contact plate may be a curved surface that can be engaged with the peripheral surface of the heat roller. By doing so, it becomes possible to uniformly press the web against the dielectric endless belt over a large area, thereby further enhancing the cleaning efficiency and stability.

Further, in the embodiment shown in FIG. 7, a heater as a preheating means may be provided in the web supply roller 46a. In this way, the web can be preheated and then provided to the cleaning position by the pressure contact roller 46d, which enhances the cleaning effect and also the ceramic heater 46e as the heating means.
It is possible to reduce the burden of.

Further, different devices may be constructed by appropriately combining the above-mentioned respective embodiments, and this may be used as another embodiment. In addition, the structure and length of the dielectric endless belt, the installation position and diameter of each roller, the configuration and installation positions of the web cleaner and the fur brush cleaner, the configuration of the residual toner heating means and the web preheating means, and the temperature control means thereof. The configuration, temperature value, and the like can be modified in various ways without departing from the scope of the present invention.

Although the embodiments have been described above, the following inventions are included in the present specification. (1) A dielectric endless belt having a toner image formed on its outer peripheral surface is nipped and conveyed between a heat roller and a pressure roller of a transfer fixing unit to transfer and fix the toner image to a medium, and In the image forming apparatus having the cleaning function of removing the toner remaining on the dielectric endless belt after the transfer and fixing, the web wound around the supply roller is pulled out to be used for cleaning the residual toner, and after this use The web cleaning means for winding the web of the above with a winding roller, and the web pulled out from the supply roller of the web cleaning means is applied to the outer peripheral surface of the heat roller of the transfer fixing portion with the dielectric endless belt after the transfer fixing. An image forming apparatus having a cleaning function, comprising: a web pressing means for pressing in a held state.

The embodiments relating to the present invention correspond to the first, second, third, fourth and fifth embodiments of the above-mentioned embodiments.

According to the present invention, since the web cleaner is used, the residual toner is always wiped off by a new, clean web. Therefore, it becomes possible to effectively and stably remove the residual toner as compared with the case where one cleaning felt or cleaning belt is used continuously or repeatedly.

The residual toner on the dielectric endless belt is wiped off by the web in a state where the dielectric endless belt is in contact with the peripheral surface of the heat roller of the transfer and fixing section. That is, the residual toner on the dielectric endless belt is wiped off by the web while the molten state is kept by the heat from the heat roller of the transfer fixing section. In other words, the heat roller of the transfer / fixing section also serves as the heating means for cleaning. For this reason, a heating unit dedicated to cleaning is not required, which makes it possible to reduce the power consumption of the apparatus.

(2) A dielectric endless belt having a toner image formed on its outer peripheral surface is sandwiched between a heat roller and a pressure roller of a transfer fixing unit and conveyed, whereby the toner image is transferred and fixed onto a medium. In the image forming apparatus having a cleaning function of removing the toner remaining on the dielectric endless belt after the transfer and fixing, after the web wound around the supply roller is pulled out and used for cleaning the residual toner, A web cleaning means for winding the used web by a take-up roller, and a web for pressing the web pulled out from the supply roller of the web cleaning means against the outer peripheral surface of the dielectric endless belt after the transfer fixing. The pressing means and the toner, which is provided on the web pressing means and remains on the dielectric endless belt after transfer and fixing, is heated and melted through the web. An image forming apparatus having a cleaning function, comprising: a heating unit for heating the image forming apparatus.

The sixth embodiment of the above-described embodiments corresponds to the embodiment of the present invention.

According to the present invention, since the heating means for cleaning is provided in the pressing means of the web, the residual toner on the dielectric endless belt is directly passed through the web without passing through the dielectric endless belt. Will be heated to. Therefore, it is possible to efficiently heat the residual toner, and this makes it possible to reduce the amount of heat generated by the heating unit and reduce power consumption.

Generally, the transfix belt has a thickness of 100.
Since a resin or metal having a thickness of about μm is used, the residual toner is difficult to be heated due to the influence of its thermal conductivity or thermal diffusion efficiency. Also, the transfer / fixing belt is 250 mm / sec.
Since the toner is conveyed at a moderate speed, it is necessary to heat the residual toner in a short time. Therefore, if the residual toner is heated and melted through the transfer fixing belt 4 as in the conventional apparatus, the surface temperature of the heat roller needs to be sufficiently higher than the melting temperature of the toner, resulting in power consumption. Will be very large.

On the other hand, when the residual toner on the dielectric endless belt is heated directly from the surface side of the dielectric endless belt as in the present invention, the residual toner can be efficiently heated and melted. Therefore, there is an advantage that it consumes less power.

(3) A dielectric endless belt having a toner image formed on its outer peripheral surface is sandwiched between a heat roller and a pressure roller of a transfer fixing section and conveyed, whereby the toner image is transferred and fixed on a medium. In the image forming apparatus having a cleaning function of removing the toner remaining on the dielectric endless belt after the transfer and fixing, the image forming apparatus is disposed so as to face the transport path of the dielectric endless belt after the transfer and fixing. And a first cleaning means for removing residual toner on the dielectric endless belt, and the dielectric endless belt before being subjected to the transfer fixing, the dielectric endless belt being disposed so as to face the conveyance path of the dielectric endless belt before being subjected to the transfer fixing. A second cleaning means for removing unnecessary toner formed on the recording medium, a medium jam detecting means for detecting jamming of the medium during conveyance, The leaning means is held in a non-contact state with the outer peripheral surface of the dielectric endless belt, and the second cleaning means is used as the outer peripheral surface of the dielectric endless belt when the medium jam detecting means detects the conveyance jam of the medium. An image forming apparatus having a cleaning function, which is provided with a contact / separation control unit for bringing the apparatus into contact with.

The seventh embodiment of the above-described embodiments corresponds to the embodiment relating to the present invention.

According to the present invention, in an emergency such as when the continuous printing operation is urgently stopped, the second cleaning means operates to leave the unnecessary toner remaining on the dielectric endless belt without being transferred and fixed. The image will be removed.

In general, when an emergency stop occurs during continuous printing operation, unmelted powder-like toner before transfer and fixing and residual toner once melted after transfer and fixing are formed on the dielectric endless belt depending on its position. Are mixed. If the dielectric endless belt in such a state is to be cleaned only by the cleaning means for removing the residual toner after transfer and fixing, it is difficult to sufficiently remove the toner and a cleaning failure is likely to occur. This is because the heat roller for transfer and fixing stops the heating operation when it is urgently stopped, so that the unnecessary toner image before the transfer and fixing is not sufficiently melted and is sent to the cleaning unit, and the unnecessary toner before the transfer and fixing is also performed. This is because the image has an extremely large amount of toner.

Therefore, as in the present invention, in an emergency, the second cleaning means is operated to remove the unnecessary toner image before transfer and fixing, and only the residual toner is removed by the first cleaning means. It is possible to effectively remove all of the different toners, thereby preventing the occurrence of defective cleaning.

According to the present invention, the second
Since the cleaning means is held in a state of being separated from the dielectric endless belt, there is no fear that the toner image formed on the dielectric endless belt is adversely affected.

(4) The web pressing means holds the web pulled out from the supply roller of the web cleaning means between the heat roller peripheral surface of the transfer fixing section and the dielectric endless belt after transfer fixing. An image forming apparatus having a cleaning function as described in the above item (1), characterized in that the image forming apparatus has a plurality of pressure contact rollers that are pressed against a plurality of positions on the outer peripheral surface of the dielectric endless belt.

The second embodiment of the above-described embodiments corresponds to the embodiment relating to the present invention.

With such a structure, the contact area of the web with the outer peripheral surface of the dielectric endless belt can be increased, whereby more effective and stable cleaning can be performed.

(5) The image forming apparatus having the cleaning function described in the above item (1), wherein the web cleaning means is provided with a preheating means for preheating the web before it is used for cleaning the residual toner.

The third embodiment of the above-described embodiments corresponds to the embodiment relating to the present invention.

With such a structure, the web is pressed against the dielectric endless belt while being preheated by the preheating means. Therefore, while the web is being pressed against the dielectric endless belt, there is no fear that the web takes away the heat of the dielectric endless belt and the residual toner to solidify the residual toner, thereby maintaining the residual toner in its molten state. It can be wiped off effectively and stably.

(6) The web cleaning means has a cleaning function as described in the above item (1), characterized in that preheating means for preheating the web before the cleaning of residual toner is provided in the supply roller. Image forming apparatus.

The third embodiment of the above-described embodiments corresponds to the embodiment relating to the present invention.

According to this structure, the web can effectively and stably remove the toner without taking away the heat of the dielectric endless belt and the residual toner, and the installation space for the preheating means is newly added. There is no need to secure
This makes it possible to prevent the device from becoming large. Further, by providing the preheating means in the supply roller, it is possible to efficiently generate heat to the web, thereby reducing the power consumption by the preheating means.

(7) The web pressing means is arranged such that the web is placed on the outer peripheral surface of the dielectric endless belt at a downstream side position close to the sandwiching position of the dielectric endless belt and the medium by the heat roller and the pressure roller of the transfer fixing section. An image forming apparatus having a cleaning function as described in the above item (1), characterized in that it is provided with a pressing contact separating member for slidingly pressing against.

The fourth embodiment of the above-described embodiments corresponds to the embodiment of the present invention.

According to this structure, the pressing / separating member can press the web against the outer peripheral surface of the dielectric endless belt and separate the medium from the dielectric endless belt. That is, the pressing member of the web can be used also as the separating member of the medium. Therefore, it is not necessary to separately provide a separating member for the medium, whereby the device can be simplified and downsized.

(8) The web pressing means is a dielectric endless belt formed by the heat roller and the pressure roller of the transfer and fixing section, and the outer circumference of the heat roller rotated at least one quarter turn or more from the holding position of the medium. The image forming apparatus having the cleaning function described in the above item (1), wherein the web is pressed against the surface position while holding the dielectric endless belt.

The embodiment relating to the present invention corresponds to the fifth embodiment among the above-mentioned embodiments.

According to this structure, the dielectric endless belt can be kept in contact with the peripheral surface of the heat roller for a sufficiently long time, and the residual toner on the dielectric endless belt can be wiped off with the web while being sufficiently heated and melted. Thereby, more effective and stable cleaning can be performed.

(9) The heating means includes a temperature sensor for measuring the heating temperature, and temperature control for maintaining the heating temperature at a predetermined temperature higher than at least the melting temperature of the toner according to the measurement result of the temperature sensor. An image forming apparatus having a cleaning function as described in the above item (2), which is provided with a means.

The sixth embodiment of the above-described embodiments corresponds to the embodiment of the present invention.

According to this structure, the heating temperature is always kept at an optimum temperature higher than the melting temperature of the toner, so that the residual toner on the dielectric endless belt is always reliably melted. It becomes possible to perform stable removal. Further, since it becomes possible to perform necessary and sufficient heating, it is possible to prevent wasteful power consumption.

(10) The web pressing means includes a first roller for pressing the web pulled out from the supply roller of the web cleaning means against the outer peripheral surface of the dielectric endless belt after transfer and fixing, and this first roller. A second roller for guiding the carrying-out direction of the dielectric endless belt so that the dielectric endless belt is in surface contact with the circumferential surface of the first roller while sandwiching the web. An image forming apparatus having the cleaning function according to the above item (2).

The sixth embodiment of the above-described embodiments corresponds to the embodiment of the present invention.

With such a structure, the contact area between the dielectric endless belt and the web can be increased, and thereby the residual toner on the dielectric endless belt can be removed more effectively and stably. it can. Further, when the heating means is provided in the first roller, the large contact area of the dielectric endless belt with the peripheral surface of the first roller is utilized,
The heat of the heating means can be more effectively applied to the residual toner on the dielectric endless belt, whereby the stable residual toner can be melted.

(11) In the second cleaning means, the surface temperature of the dielectric endless belt before transfer and fixing is higher than the glass transition point of the toner in the conveying path of the dielectric endless belt before transfer and fixing. The image forming apparatus having the cleaning function described in the above item (3), which is arranged to face the lower position.

The seventh embodiment of the above-described embodiments corresponds to the embodiment of the present invention.

With this configuration, the second cleaning means only needs to remove the powder-like toner before melting, which allows a relatively simple cleaning such as a fur brush or a blade. It is possible to use components, which makes the device construction as simple as possible.

[0112]

As described above in detail, in the first aspect of the invention, the web wound around the supply roller is pulled out to be used for cleaning the residual toner, and then the used web is wound up by the winding roller. In addition to providing the cleaning means, the web pressing means is provided, and the web pulled out from the supply roller of the web cleaning means is transferred to the outer peripheral surface of the heat roller of the transfer fixing portion by the web pressing means after the transfer fixing. The dielectric endless belt is configured to be pressed and held while being held.

Therefore, according to the present invention, the heating means dedicated to cleaning is not required, thereby reducing the power consumption of the apparatus to improve the economical efficiency and remove the residual toner effectively and stably to form an image. It is possible to provide an image forming apparatus having a cleaning function capable of constantly maintaining high quality.

According to the second aspect of the invention, the web wound around the supply roller is pulled out to be used for cleaning the residual toner, and then the used web is wound up by the winding roller, and a web cleaning means for this web. A pressing means is provided so that the web pulled out from the supply roller of the web cleaning means is pressed against the outer peripheral surface of the dielectric endless belt after the transfer and fixing by the web pressing means, and The pressing means is provided with a heating means, and by this heating means, the toner remaining on the dielectric endless belt after the transfer and fixing is heated and melted through the web,
The web is designed to be easily wiped.

Therefore, according to the present invention, it is possible to provide an image forming apparatus having a cleaning function capable of efficiently heating and melting the residual toner on the dielectric endless belt to reduce the power consumption of the apparatus. .

Further, in the third invention, the first cleaning means is disposed opposite to the conveying path of the dielectric endless belt after transfer and fixing, and the dielectric endless belt after transfer and fixing is provided by the first cleaning means. The residual toner is removed by cleaning, and the second cleaning means is disposed opposite to the conveyance path of the dielectric endless belt before being subjected to transfer and fixing, and the contact / separation control means is provided. Normally, the second cleaning means is held in a non-contact state with the outer peripheral surface of the dielectric endless belt, and when the conveyance jam of the medium is detected, the second cleaning means is attached to the outer peripheral surface of the dielectric endless belt. The unnecessary toner before transfer and fixing formed on the dielectric endless belt is removed by contact.

Therefore, according to the present invention, when the image forming operation is urgently stopped, not only the residual toner on the dielectric endless belt but also the unnecessary toner before transfer fixing can be effectively removed. As a result, it is possible to provide an image forming apparatus having a cleaning function capable of further reliably preventing the occurrence of defective cleaning.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of an image forming apparatus having a cleaning function according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a main part of an image forming apparatus having a cleaning function according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a main part of an image forming apparatus having a cleaning function according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a main part of an image forming apparatus having a cleaning function according to a fourth embodiment of the present invention.

5 is a partially enlarged view of the device shown in FIG.

FIG. 6 is a configuration diagram of main parts of an image forming apparatus having a cleaning function according to a fifth embodiment of the present invention.

FIG. 7 is a configuration diagram of a main part of an image forming apparatus having a cleaning function according to a sixth embodiment of the present invention.

FIG. 8 is a schematic configuration diagram of an image forming apparatus having a cleaning function according to a seventh embodiment of the present invention.

FIG. 9 is a sectional view showing an example of an image forming apparatus having a conventional cleaning function.

FIG. 10 is a sectional view showing another example of an image forming apparatus having a conventional cleaning function.

[Explanation of symbols]

 11 ... Medium 21 ... Transfer / fixing section 21a ... Heat roller 21b ... Halogen lamp 21c ... Pressure roller 31 ... Dielectric endless belt 41, 42, 43, 44, 45, 46 ... Web cleaner 41a, 46a ... Web supply roller 41b, 46b ... Web 41c, 46c ... Web take-up roller 41d, 42a, 42b, 45a, 46d ... Pressure contact roller 43a, 46e ... Ceramic heater 44a ... Pressure contact separating member 46f ... Guide roller 46g ... Temperature sensor 46h ... Temperature control circuit 51a, 51b ... platen roller 51c ... eraser 61 ... fur brush cleaner 61a ... housing 61b ... fur brush 61c ... spindle 61d ... tension spring 61e ... eccentric cam 71 ... developing part 71a ... platen roller 71b ... developing device 81 ... charger (ion cartridge) (ICG))

Claims (3)

[Claims] 1. A toner endless belt having a toner image formed on its outer peripheral surface is nipped and conveyed between a heat roller and a pressure roller of a transfer fixing section to transfer and fix the toner image onto a medium. In the image forming apparatus having the cleaning function of removing the toner remaining on the dielectric endless belt after the transfer and fixing, the web wound around the supply roller is pulled out and used for cleaning the residual toner. A web cleaning unit that winds up the used web with a take-up roller, and a web drawn from the supply roller of the web cleaning unit is attached to the outer peripheral surface of the heat roller of the transfer fixing unit, and the dielectric endless member after the transfer fixing is performed. An image forming apparatus having a cleaning function, comprising: a web pressing unit for pressing the belt while holding it. Location. 2. A toner endless belt having a toner image formed on the outer peripheral surface thereof is nipped and conveyed between a heat roller and a pressure roller of a transfer fixing unit to transfer and fix the toner image onto a medium. In the image forming apparatus having the cleaning function of removing the toner remaining on the dielectric endless belt after the transfer and fixing, the web wound around the supply roller is pulled out and used for cleaning the residual toner. A web cleaning means for winding the used web by a take-up roller, and a web pressing means for pressing the web pulled out from the supply roller of the web cleaning means against the outer peripheral surface of the dielectric endless belt after the transfer fixing. The contact means and the web pressing means are provided, and the toner remaining on the dielectric endless belt after the transfer and fixing is heated and melted through the web. An image forming apparatus having a cleaning function, comprising: a heating unit for heating the image forming apparatus. 3. A toner endless belt having a toner image formed on its outer peripheral surface is nipped and conveyed between a heat roller and a pressure roller of a transfer fixing unit to transfer and fix the toner image onto a medium. In the image forming apparatus having a cleaning function of removing the toner remaining on the dielectric endless belt after the transfer and fixing, the image forming apparatus is disposed so as to face the conveyance path of the dielectric endless belt after the transfer and fixing, and A first cleaning unit for removing residual toner on the dielectric endless belt, and a dielectric endless belt before being subjected to the transfer fixing, which are arranged to face the conveyance path of the dielectric endless belt before being subjected to the transfer fixing. Second for removing unnecessary toner formed
Cleaning means, a medium jam detecting means for detecting conveyance jam of the medium, and normally, the second cleaning means is held in a non-contact state with the outer peripheral surface of the dielectric endless belt to prevent the medium jam. An image forming apparatus having a cleaning function, comprising: a contact / separation control unit for bringing the second cleaning unit into contact with the outer peripheral surface of the dielectric endless belt when the detection unit detects that the medium is jammed. apparatus.