JPH08137352A - Image forming material removing device - Google Patents

Abstract

PURPOSE: To prevent the occurrence of a failure in the removal of an image forming material caused by the dropping of the surface temp. of a peeling member, in an image forming material removing device removing the image forming material from a sheet by pressing the peeling member against the image forming material stuck to the surface of the sheet. CONSTITUTION: The speed for carrying a transfer paper 10 of an offset belt 44 is made slower than a normal speed for a specified time after the carrying of the sheet is started, to reduce the quantity of heat absorbed to liquid 31. Thus, the dropping of the surface temp. of the offset belt 44 due to the decrease of the heat transmitted from a heating roller 45 and a heating block 43 to the offset belt 44 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, a printer, a printing machine or the like, and a recording sheet on which an image forming material such as a toner is stably attached to the image forming material. More specifically, the present invention relates to a device for removing an image-forming substance, and in detail, in a state in which a liquid that makes the adhesion of the sheet and the image-forming substance unstable is applied, the sheet and the image peeling member are heated and brought into contact with each other. The present invention relates to an image forming substance removing apparatus that prevents defective image forming substance removal due to a decrease in heating temperature when removing an image forming substance.

[0002]

2. Description of the Related Art Conventionally, an image forming substance such as toner is attached
Various types of image forming substance removing devices for removing an image forming substance from a transfer sheet as a fixed sheet and reusing the transfer sheet are known. For example, Japanese Patent Laid-Open No. 2-5
Japanese Patent No. 5195 discloses an image forming substance (heat-melting ink 203) attached to a sheet (printed body 103) coated with a release agent by an electrophotographic method or a thermal transfer method, and a peeling member (ink peeling member 201). And the contacting portion is heated by a heating unit (heat roll 202) and cooled, and then the sheet and the peeling member are separated, so that the image-forming substance is attached to the peeling member, and the image is printed from the sheet. An image forming substance removing device for peeling a forming substance is disclosed. Further, in JP-A-4-64472, an image forming substance (toner image 102) attached to a sheet (erasable paper 101) and a peeling member (thermofusible resin 10).
7, the endless sheet 108) is contacted, and the contact portion is heated by the heating means (heat roller 106),
There is disclosed an image forming substance removing device that separates the sheet and the peeling member to attach the image forming substance to the peeling member and peel the image forming substance from the sheet. In the above description of the prior art, the member names used in each document are shown in parentheses.

However, when each of the above devices is used to remove an image-forming substance from a recorded sheet having an image recorded on a normal paper having paper fibers exposed on the surface, the image-forming substance is removed from the surface of the sheet material. If firmly attached to the fiber,
When the image-forming substance is removed, the paper fibers on the surface may be peeled off together with the image-forming substance to damage the paper quality of the sheet.

Therefore, the present applicant previously selected from the group consisting of water, an aqueous solution containing a surfactant, an aqueous solution containing a water-soluble polymer, and an aqueous solution containing a surfactant and a water-soluble polymer in the recorded sheet. By holding at least one of the liquids, the adhesion between the sheet and the image forming substance is made unstable, and then the image forming substance and the peeling member are brought into contact with each other, and the contact portion is heated by the heating means. An image forming substance removing apparatus has been proposed in which the image forming substance is attached to the peeling member by heating and then separating the sheet and the peeling member to peel the image forming substance from the sheet. According to this,
Since the image forming substance is peeled off after the liquid makes the adhesion between the sheet and the image forming substance unstable, only the image forming substance can be removed without relatively damaging the paper quality of the sheet material.

[0005]

However, in this apparatus, the image forming substance is rather peeled off due to the use of a liquid (hereinafter referred to as a liquid) which makes the adhesion between the sheet and the image forming substance unstable. In some cases, the image-forming substance may remain on the surface of the sheet. The reason for this will be described below. In this apparatus, as described above, the peeling member is brought into contact with the image forming substance attached to the sheet, and the image forming substance is removed from the sheet by transferring the image forming substance from the sheet to the peeling member. Therefore, the peeling member needs to have a stronger adhesive force with respect to the image forming substance than the adhesive force between the image forming substance and the sheet. Therefore, in this apparatus, by heating the contact portion where the sheet and the peeling member come into contact with each other by the heating means, the adhesive force of the peeling member with respect to the image forming substance is strengthened, and the peeling member which is sufficient to remove the image forming substance is attached. It secures cohesion. However, when a liquid is used, even if the contact portion is heated, the heat is absorbed by the liquid, the temperature of the peeling member does not rise, and sufficient adhesion of the peeling member to the image forming substance cannot be ensured. is there. As a result, the use of the liquid may lead to defective removal of the image forming substance.

The amount of heat generated by one heating means so that sufficient heat can be supplied to the peeling member even if heat is absorbed by the liquid in order to enable good removal of the image-forming substance. Controlling is certainly effective. For example, one heating unit that generates heat when power is supplied is used, and this heating unit is connected to a PID (Proportional Integral) unit.
It can be controlled or on / off controlled. Therefore, the control according to the embodiment of the present invention described later is also performed. However, since the heating means usually has a constant heat capacity, a delay occurs even if the above-mentioned respective controls are performed, and the temperature of the contact portion does not immediately rise. Therefore, even if such control is used, the temperature of the release material may not be sufficiently increased. In particular, until the temperature of the contact portion stabilizes after a lapse of a certain time from the start of the conveyance of the sheet to the contact portion, the liquid is apt to absorb the heat and the defective formation of the image-forming substance is likely to occur.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a sheet with a liquid which makes the adhesion of the sheet and the image forming substance unstable. An image forming substance removing device for removing the image forming substance from the sheet by bringing the image peeling member into heat contact,
An object of the present invention is to provide an image forming substance removing apparatus that prevents the heating temperature from lowering due to the absorption of heat by the liquid, resulting in defective removal of the image forming substance.

[0008]

In order to achieve the above-mentioned object, an image forming substance removing device according to a first aspect of the present invention comprises a sheet having an image forming substance adhered to the surface thereof and the surface and the image forming substance. A liquid supply device for supplying a liquid that makes the adhesion unstable, and strong against the image forming substance adhered on the surface of the sheet, against the image forming substance rather than the adhesive force between the surface and the forming substance. A contact separating means for separating the sheet and the peeling member after contacting the peeling member having adhesive force, and a heating means for heating the peeling member in the vicinity of a contact portion where the sheet and the peeling member contact each other. An image forming substance removing device comprising: a conveying unit that conveys the sheet so that the sheet moves relative to the contact portion, and a period of time from when the sheet starts to be conveyed until a predetermined time elapses. The sheet transfer speed Those characterized by having a conveying speed control means for slower over preparative conveying speed.

The image forming device removing device according to the second aspect is
A liquid supply device for supplying a liquid which makes the adhesion of the image forming substance to the sheet having the image forming substance attached to the surface thereof, and an image forming substance attached to the surface of the sheet. A contact separation means for separating the sheet and the peeling member after contacting a peeling member having a stronger adhesion force to the image forming substance than the adhesion force to the surface and the forming substance; And a heating means for heating the peeling member in the vicinity of the contacting portion where the peeling member comes into contact, and an image forming substance removing device comprising:
An auxiliary heating unit for heating the peeling member is provided, and the heating amount from the heating unit and the auxiliary heating unit to the peeling member from the start of sheet conveyance to a certain time is made larger than the subsequent heating amount. It is characterized by having a heating amount control means.

Further, the image forming apparatus removing apparatus according to claim 3 is
A liquid supply device for supplying a liquid which makes the adhesion of the image forming substance to the sheet having the image forming substance attached to the surface thereof, and an image forming substance attached to the surface of the sheet. A contact separation means for separating the sheet and the peeling member after contacting a peeling member having a stronger adhesion force to the image forming substance than the adhesion force to the surface and the forming substance; In the vicinity of the contact portion where the peeling member comes into contact with the heating means for heating the peeling member, and the temperature of the peeling member heated by the heating means,
An image forming substance removing device comprising: a control unit for controlling the temperature to be a predetermined set temperature, wherein the predetermined set temperature is from the start of sheet conveyance until a certain time elapses. The feature is that the temperature is set higher than the subsequent set temperature.

[0011]

In the image forming apparatus removing device of the first aspect, the sheet conveying speed from the start of sheet conveying to the elapse of a predetermined time is slower than the subsequent sheet conveying speed. For this reason, the area of the sheet passing through the contact portion where the sheet and the peeling member come into contact with each other per unit time is narrowed until a certain time elapses from the start of the sheet conveyance. Therefore, the amount of the liquid adhering to the surface of the sheet, which functions to absorb the heat from the heating means, passing through the contact portion is also reduced. Therefore, the heat due to being absorbed by the liquid is reduced,
It is possible to prevent the temperature of the peeling member from rapidly decreasing at the start of sheet conveyance.

In the image forming apparatus removing device according to the second aspect, the auxiliary heating means as well as the heating means heats the peeling member from the start of sheet conveyance until a predetermined time elapses. Therefore, even if heat is absorbed by the liquid adhering to the sheet, both heating members perform sufficient heating, so that the temperature of the peeling member is prevented from dropping sharply at the start of sheet conveyance.

In the image-forming-apparatus removing apparatus according to the third aspect of the present invention, a preset temperature for heating the peeling member, which is set in advance, from the start of sheet conveyance until a predetermined time elapses, Also make it higher. Therefore, even if heat is absorbed by the liquid adhering to the sheet, the temperature originally set is high, so that the temperature of the peeling member is prevented from dropping sharply at the start of sheet conveyance.

[0014]

EXAMPLES In the following, the present invention is applied to a heat-fusible toner (hereinafter referred to as toner) as an image forming substance from a transfer paper as a sheet on which an image is formed by a transfer type electrophotographic copying machine.
An embodiment applied to an image forming substance removing device (hereinafter, referred to as a toner removing device) for removing a sheet from which a sheet is removed will be described.

First, an outline of the toner removing device according to the embodiment will be described. In FIG. 1, the toner removing device includes a liquid supply unit 30 as a liquid supply device that supplies liquid to the transfer paper 10 sent from a paper supply unit (not shown), and a toner from the transfer paper 10 to which the liquid is supplied. A toner peeling unit 40 as a peeling unit for peeling the toner, and a drying unit 6 for drying the transfer paper 10 from which the toner is removed.
0, and a paper receiving unit (not shown) that receives the transfer paper 10 discharged from the drying unit 60.

The paper feeding unit feeds the transfer papers 10 to the liquid supply unit 30 one by one with the surface on which the toner image is formed (hereinafter referred to as the toner image surface) facing down, for example, electrophotographic copying. It is similar to the paper feed unit in the machine.

The liquid supply unit 30 is made of water or an aqueous solution containing a surfactant in order to improve the permeability of the transfer paper 10, and makes the adhesion between the surface of the transfer paper 10 and the toner unstable. A liquid 31 serving as a liquid is supplied to the transfer paper 10, and a liquid container 32 for containing the liquid and a liquid container 32 provided so as to be partially submerged in the liquid in the liquid container 32 are pumped by the rotation to transfer the liquid. An application roller 33 that supplies the toner image surface of the paper 10 and a regulation roller 34 as a paper regulation member that is provided so as to face the application roller 33 with the paper conveyance path interposed therebetween are provided.

The toner peeling unit 40 includes a toner offset belt (hereinafter referred to as an offset) as a peeling member wound around a heating block 43 having a built-in heater 43a facing the driving roller 41, the tracking roller 42, and the transfer sheet conveying path. 44) and a heating roller 45 with a built-in heating lamp 45a provided so as to be pressed against the heating block 43 with the offset belt 44 interposed therebetween.
And a belt cleaning device 47 that removes toner from the surface of the offset belt 44. Further, a wiping roller 80 as a wiping means for removing the residue from the surface of the offset belt 44 after being cleaned by the belt cleaning device 47 is provided. Here, the driving roller 41 and the tracking roller 4
2, the heating block 43, the offset belt 44, and the heating roller 45 function as a conveyance unit that conveys the transfer paper 10. Further, the heating block 43 and the heating roller 45 function as a contact separation unit that separates the offset belt 44 and the transfer paper 10 after they are brought into contact with each other. Further, the heating block 43 and the heating roller 4 are
5 functions as a heating unit that heats the offset belt 44 at a portion where the transfer paper 10 and the offset belt 44 are in contact with each other.

At least the surface of the offset belt 44 is formed of a material having an adhesive force to the softened toner that is larger than the adhesive force between the surface of the transfer paper 10 and the toner. For example, the belt itself is made of a metal material such as an aluminum-based material, a copper-based material, a nickel-based material, or a polymer-based material such as polyethylene terephthalate (PET) in which titanium oxide is dispersed.

Further, the corner portion 43b of the heating block 43 on the downstream side in the transfer paper conveying direction is formed at an angle of about 90 degrees, and the offset belt portion passing through the corner portion 43b suddenly changes the moving direction to move from the offset belt 44. The separation of the curvature of the transfer paper 10 is performed.

Further, the heating block 43 and the heating roller 45 adhere the toner image surface of the transfer paper 10 sent from the liquid supply unit 30 to the offset belt 44 and the toner fixed to the transfer paper 10. Is softened by heating.

Further, the belt cleaning device 47 is
The offset belt 44 is provided with a rotating brush roller 50 that applies intermittent scratching force to the peripheral surface of the offset belt 44 to remove the adhered toner, and a blade 51 for toner removal made of metal or resin, and the toner removed from the peripheral surface of the belt by these. Are housed in the unit casing 52.

In the illustrated toner peeling unit 40, the transfer paper 10 sent from the liquid supply unit 30 side is sent.
A guide plate 70 is provided to guide the heating roller 45 to the contact portion between the offset belt 44 and the heating roller 45 which are backed up by the heating block 43. Further, a lower guide plate 71 for guiding the transfer paper 10 that passes through the contact portion and is curvature-separated from the offset belt 44 around the downstream corner portion 43b of the heating block 43 to the drying unit 60 side is also provided. ing.

The drying unit 60 is, for example, the transfer paper 1.
The heating lamp 61a is for drying the transfer paper 10 so that the liquid holding amount of 0 is 10% or less of the paper weight.
It is composed of a built-in heating drum 61 made of, for example, aluminum, and a paper pressing belt 63 which is stretched around a plurality of support rollers 62 and is endlessly moved while being wound around the peripheral surface of the heating drum 61 at a constant angle. . In the illustrated example, one support roller 62 also serves as a tension roller. As the material of the paper pressing belt 63, a material having heat resistance and air permeability, for example, cloth such as canvas cloth, cotton cloth, and Tetoron cloth can be used.

In the paper receiving unit, the upper and lower guide members for guiding the transfer paper 10 that has passed through the holding region between the heating drum and the paper pressing belt in the drying unit 60, and the transfer paper guided by the guide member. It can be configured by a pair of paper discharge rollers that convey the sheet 10, a tray that receives the transfer paper discharged by the pair of paper discharge rollers, and the like.

In the above-mentioned structure, the transfer paper 10 sent from the paper feeding unit is supplied with the liquid uniformly on the toner image surface by the liquid supply unit 30 and sent to the toner peeling unit 40. With this toner peeling unit 40, the transfer paper 10
The toner adhered to is softened by heating from the heating block 43 and the heating roller 45 and adheres to the surface of the offset belt 44. Then, the transfer paper 10 and the offset belt 4 are provided around the downstream corner portion 43b of the heating block 43.
When separated from No. 4, the toner adhering to the surface of the offset belt 44 is peeled off from the transfer paper 10, whereby the toner is removed from the transfer paper 10. The transfer paper 10 from which the toner has been removed is dried by the drying unit 61 and discharged to the paper receiving unit.

According to the above construction, the liquid is supplied to the transfer paper 10 to which the toner adheres, and the toner is peeled off in a state where the liquid permeates into the interface of the transfer paper 10 with the toner, so that the paper fiber is damaged. The toner can be removed without

Further, the rotating brush roller 50 and the cleaning blade 51 of the belt cleaning device 47 remove the toner adhering to the offset belt 44 and prevent the toner from non-uniformly adhering and depositing on the offset belt 44. It is possible to prevent defective toner removal due to partial poor adhesion between the toner 44 and the transfer paper 10 due to residual toner. (Hereinafter, margin)

Next, a description will be given of the toner peeling unit 40 of the toner removing device outlined above.
The heating roller 45 described above has a structure in which a pipe-shaped core metal is covered with a rubber portion 45b having a thickness of 4 mm, and the offset belt 44 is sandwiched between the heating roller 43 and the heating roller 43 to press the heating roller 43.
A nip portion of about 0 mm is formed. Also, the heating roller 4
In the vicinity of 5, a temperature sensor 53 for detecting the surface temperature of the roller is provided. Then, based on the detection result from the temperature sensor 53, a control means (not shown) including a microcomputer, for example, changes the electric power supplied to the heating lamp 45a to adjust the heating value of the lamp and heat the lamp. The surface temperature of the roller 45 is controlled.

More specifically, the above-mentioned control means uses the PI to stabilize the surface temperature of the heating roller 45 at about 140 degrees.
D control is performed. FIG. 2 is a graph showing the temperature of the heating roller 45 when such control is performed. The transfer paper 10 starts to be conveyed at the time of 200 seconds shown on the horizontal axis, and
It shows the case where the conveyance is completed at the time of 000 seconds. In this example, about 2
At 00 seconds, that is, from about 200 seconds to about 400 seconds, the temperature fell below the target temperature of 140 degrees from this control, and fell below the maximum allowable temperature of 130 degrees by up to 16 degrees. This is because, as described above, since the rubber portion 45b constituting the heating means has a large heat capacity, even if the heat generation amount of the heating lamp 45a is increased, the heat is not immediately transmitted to the surface of the heating roller 45. To cause. Therefore, until the heating roller 45 is sufficiently heated and is in a stable state, the decrease in the surface temperature of the heating roller 45 due to the heat being absorbed by the liquid 31 cannot be eliminated.

In this embodiment, an example in which PID control is performed has been shown, but on / off control may be performed instead. Further, the temperature of the heating block 43 is controlled similarly to the heating roller 45. However, control is performed to stabilize the surface at 100 degrees. Further, in performing the temperature control described above, the preset temperature for heating the offset belt 44, which is set in advance, is set higher than the subsequent preset temperature from the start of sheet conveyance to the elapse of a certain time. You may.
Further, as described above, it is the offset belt 4 that directly affects the removal of toner from the surface of the offset belt 44.
In this embodiment, the temperature of the offset belt 44 is indirectly controlled by controlling the temperatures of the heating roller 45 and the heating block 43 that supply heat to the belt.

In the transfer paper in which the toner is removed from the time of 200 seconds to 450 seconds while performing the above control, the ratio of the toner adhering portion to the total surface area is 6%, and about 20% of the adhering toner is obtained. It remained on the transfer paper surface without being removed. The conditions in this case are that the transfer speed of the transfer paper 10 is 20 mm / sec, and the supply amount of the liquid 31 is 4 grams per A4 transfer paper.

As described above, even if the temperatures of the heating roller 45 and the heating block 43 are controlled, the toner removal failure due to the decrease in the temperature of the offset belt 44 cannot be eliminated. Therefore, in this apparatus, the defective toner removal is eliminated by controlling the transport speed of the transfer paper 10. That is, until a certain time elapses from the start of the conveyance of the transfer paper 10, the conveyance speed control means including a timer (not shown) compares the offset belt 4 with that in the normal time.
Decrease the rotation speed of 4. As a result, the heating roller 45
The speed at which the offset belt 44 passes through a portion where the heating belt 43 and the heating block 43 are in contact with each other, that is, a portion where the offset belt 44 is heated is slowed. Specifically, the temperature of the heating roller 45 is below the target value, as shown in FIG.
The transport speed from the time of 0 second to the time of 450 seconds is set to 10 mm / sec, which is a half of the subsequent transport speed. As described above, if the transfer speed of the transfer paper 10 is reduced,
The amount of the liquid 31 adhering to the transfer paper 10 passing through the portion where the heating roller 45 and the heating block 43 contact each other is small. Therefore, the amount of heat absorbed by the liquid is also reduced, and the temperature drop of the heating roller 45 and the heating block 43 can be suppressed. When the transfer speed of the transfer paper 10 was controlled in this manner, the above-mentioned decrease in temperature of the heating roller 45 of 16 degrees, which was caused when the transfer speed control was not performed, could be suppressed to 7 degrees. Further, the transfer paper from which the toner was removed from the time of 200 seconds to the time of 450 seconds with the toner adhering portion of 6% was completely regenerated without the toner remaining.

Further, as shown in FIG. 3, in the vicinity of the surface of the heating roller 45, an auxiliary heating means 5 for heating the surface from the outside is provided.
4, the auxiliary heating means 46 may be used to control the surface temperature of the transfer belt 44 instead of or in addition to the transfer speed control of the transfer belt 10 described above. Good. Specifically, from 200 seconds to 450 seconds, the heating roller 45 is appropriately heated by the auxiliary heating means 46 according to the temperature detection result of the heating roller 45 by the temperature sensor 53. Unlike the heating lamp 45a provided inside the heating roller 45, the auxiliary heating means 4
Since 6 directly heats the surface of the heating roller 45, the surface temperature of the heating temperature 45, and thus the surface temperature of the offset belt 44, can be efficiently controlled.

In the control described above, the heating roller 4 is used.
The surface temperature of No. 5 was controlled to 140 ° C. and the temperature of the heating block 43 was controlled to 100 ° C. However, if the temperatures of both members are within a certain range, these values do not have to be these values. The temperature setting of the heating roller 45 and the heating block 43 will be described below.

The temperature of the heating roller 45 and the heating block 43 must be a temperature at which the toner is completely removed without the toner remaining on the surface of the transfer paper 10. That is, the ratio of the peeled area of the toner (the ratio of the area of the portion where the toner is peeled to the area of the transfer paper to which the toner is attached) must be 100%. Therefore, the temperature of the heating block 43 and the heating roller 45 was changed, the state of toner removal at that temperature was confirmed, and the combination of both temperatures at which the toner separation area ratio was 100% was specified. In the area A shown in FIG. 4, the toner peeling area ratio is 1
This is an area that is 00%.

To determine the temperatures of the heating roller 45 and the heating block 43, not only the temperature is determined so that the toner is completely removed from the transfer paper 10, but also the cleaning of the offset belt 44 is performed. Must also be considered. When the toner remains on the surface of the offset belt 44, the transfer paper from which toner is subsequently removed may adhere to the transfer belt 44 due to the remaining toner and may not be separated. If the transfer sheet is not separated, the transfer sheet may be in the main body of the apparatus, that is, the apparatus cannot be used. As described above, the cleaning device 47 removes the toner separated from the transfer paper 10 and attached to the offset belt 44. However, depending on the set temperatures of the heating roller 45 and the heating block 43, the toner adheres to the offset belt 44 with a large adhesive force, which makes it difficult to remove the toner, and the toner remains on the surface of the offset belt 44. It ends up.

Therefore, when white PET is used as the material of the offset belt 44, the conveyance speed of the offset belt 44 is 20 mm / sec, the cleaning brush roller 50 constituting the cleaning device 47 is set to the offset belt 4.
A temperature condition under which the toner did not remain on the offset belt 44 was confirmed under the conditions of the pressing load of No. 4 being 147 N and the rotating speed of the brush being 250 times per minute. The temperature conditions concerning the area | region B of FIG. 5 are shown. If the temperatures of the heating roller 45 and the heating unit block 43 are set within the range shown by the area B, the transfer belt 10 adheres to the belt because the offset belt 44 can be cleaned satisfactorily without remaining toner. This prevents the transfer paper from being jammed in the device.

From the above, it is not always necessary to set the surface temperature of the heating roller 45 to 140 ° C. and the temperature of the heating block 43 to 100 ° C. The temperature of both members is such that the toner is satisfactorily separated from the transfer paper 10 and The temperature at which the surface of the offset belt 44 is satisfactorily cleaned, that is,
It is understood that the temperature may be in the area C where the area A and the area B shown in FIG. 5 are overlapped.

As described above, by controlling the temperatures of the heating roller 45 and the heating block 43, the cleaning of the offset belt 44 by the cleaning device 47 can be performed well, but the cleaning brush roller 50 is used. The toner can be satisfactorily removed from the offset belt 44 by adjusting the pressing load of the offset belt 44 (hereinafter, referred to as pressing load) and controlling the rotation speed of the brush roller. You can Specifically, the action of removing toner from the offset belt can be strengthened by increasing the pressing load or increasing the number of rotations of the brush roller per unit time.

However, the cleaning brush roller 50
The durability of the offset belt 44 must be taken into consideration when the pressing load of the offset belt 44 is adjusted or the rotation speed of the roller is adjusted. That is, when the toner on the surface of the offset belt 44 is removed by the cleaning brush roller 50, the belt itself is scraped off as well as the toner is removed. Therefore, in order to reduce the amount of abrasion of the belt itself and improve the durability of the belt, the pressing load is weakened and the rotation speed of the brush roller 50 is kept low within a range where the toner attached to the offset belt 44 can be removed. Will be needed.

For example, using white PET as the material of the offset belt 44, the conveyance speed of the offset belt 44 is 20 mm / sec, the pressing load is 245 N, and the rotation speed of the brush is the rotation speed per minute (hereinafter, rpm). Say)
Of 640 times, the life of the offset belt 44 was such that toner was removed from about 200 to 300 sheets of transfer paper, while the pressing load was 147 N and the rotation speed of the brush was Was set to 250 rpm, the life could be extended to 10,000 sheets.

However, in order to perform good cleaning, the pressing load of the cleaning brush roller 50 against the offset belt 44 has a lower limit, and 8 × 1.
The present inventor has confirmed that it should be 0 ⁴ N / m ² or more. FIG. 6 is a graph showing the cleaning rate of the surface of the offset belt 44 when the pressing load, the rotation speed of the cleaning brush roller 45, and the pressing load are specified. Characteristic line a is 510r when the rotation speed of the cleaning brush roller 50 is 640 rpm.
pm, the characteristic line b shows the case of 400 rpm, and the characteristic line c shows the case of 250 rpm. From this graph, it is not possible to increase the cleaning rate to 95% or more only by increasing the rotation speed of the cleaning brush roller, and the pressing load is 8 × 10 ⁴ N / m ²
It turns out that it is necessary to do the above.

Further, in order to extend the life of the offset belt 44, it is effective to adjust the rotation speed of the cleaning brush roller 50 and the above-mentioned pressing load depending on the toner adhesion state of the transfer paper 10 on which the toner removal processing is performed. Is. For example, when a sensor for detecting whether or not there is a black solid portion of 1 cm square or more is provided in the conveyance path of the transfer paper 10 and the presence of such a black solid is detected by the sensor, the cleaning brush roller is more than usual. The number of rotations of 50 is increased, or the pressing load of the roller on the offset belt 44 is increased. As a result, the transfer paper 1
It is possible to sufficiently remove the toner, which has been transferred from 0 to the offset belt 44 and has formed a black solid image, on the belt. On the other hand, except for solid black, the offset belt 4 sets the rotation speed and the pressing load.
The offset belt 44 is less likely to be damaged if it is set as low as possible within the range in which the toner can be removed satisfactorily. For example, the pressing load of 147 N when black solid is not detected is 196 to 2 when black solid is present.
The rotation speed of the cleaning brush roller 50 is usually set to about 45 N or about 200 rpm, and is set to about 400 to 600 rpm when there is a black solid.

A flow chart of the control according to FIG. 7 is shown.
When the paper is fed, the sensor detects whether or not there is solid black. When a black solid is detected, a timer measures the time until the portion of the offset belt 44 on which the toner forming the black solid adheres reaches the position in contact with the cleaning brush roller 50, and the time is measured in synchronization therewith. And change the cleaning conditions according to the black solid. on the other hand. If black solid is not detected and the normal setting (setting not for black solid) is made at that time, the normal setting is not changed and the cleaning is performed with the setting. Further, when the cleaning condition is set for the black solid even though the black solid is not detected, the portion of the surface of the offset belt 44 in which the black solid is not detected forms the toner-attached portion, The time required to reach the position in contact with the cleaning brush roller 50 is measured by a timer, and the cleaning condition is set to a normal state in synchronization with the time.

[0046]

According to the first aspect of the present invention, the amount of liquid passing through the contact portion where the sheet and the peeling member come into contact with each other decreases per unit time until a certain time elapses from the start of sheet conveyance. The amount of heat absorbed by the liquid is reduced, and the temperature of the peeling member is prevented from dropping sharply. Therefore, it is possible to prevent the adhesion of the peeling member to the image forming member from decreasing due to the decrease in the temperature and to prevent the defective image forming material from the sheet.

According to the second aspect of the present invention, the peeling member is heated by the auxiliary heating means together with the heating means from the start of sheet conveyance until a predetermined time elapses. The temperature is prevented from dropping sharply. Therefore, it is possible to prevent the adhesion of the peeling member to the image forming member from decreasing due to the decrease in the temperature and to prevent the defective image forming material from the sheet.

According to the third aspect of the present invention, the set temperature is set to be higher than the set temperature thereafter when the predetermined peeling member is heated from the start of sheet conveyance until a predetermined time elapses. Even if heat is absorbed by the liquid adhering to the sheet, the temperature of the peeling member is prevented from dropping sharply at the start of sheet conveyance. Therefore, the lowering of the temperature lowers the adhesive force of the peeling member to the image forming member,
The occurrence of defective image forming material from the sheet is prevented.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a toner removing device according to an embodiment.

FIG. 2 is a graph showing a result of temperature control of a heating roller.

FIG. 3 is a schematic configuration diagram of a toner removing device according to a modification.

FIG. 4 is a graph showing set temperatures of a heating roller and a heating block, in which toner is satisfactorily removed.

FIG. 5 is a graph showing set temperatures of a heating roller and a heating block for favorably cleaning the offset belt.

FIG. 6 is a pressing load of a cleaning brush roller,
The graph which shows the relationship between the rotation speed of this roller, and the cleaning rate of an offset belt.

[Fig. 7] Pressing load of the cleaning brush roller,
The flowchart which shows control with the rotation speed of this roller.

[Explanation of symbols]

 10 Transfer Paper (Sheet) 20 Paper Feed Unit 24 Paper Feed Conveying Roller Pair 30 Liquid Supply Unit (Liquid Supply Device) 40 Toner Removal Unit 43 Heating Block 44 Offset Belt (Peeling Member) 45 Heating Roller 44 Peeling Belt 47 Cleaning Device 53 Temperature sensor 54 Auxiliary heating means 60 Drying unit 61 Heating drum

Claims (3)

[Claims] 1. A liquid supply device for supplying a liquid having a surface on which an image-forming substance is adhered, which makes the adhesion between the surface and the image-forming substance unstable, and an image adhered on the surface of the sheet. Contact separation for separating the sheet and the peeling member after contacting a peeling member having a stronger adhesive force for the image forming substance than the adhesive force between the surface and the forming substance for the forming substance Means, heating means for heating the peeling member in the vicinity of the contact portion where the sheet contacts the peeling member, and conveyance for conveying the sheet so that the sheet moves relative to the contact portion An image forming substance removing device including a means, and a conveyance speed control means for setting a conveyance speed of the sheet from the start of the sheet conveyance until a predetermined time elapses to be lower than a subsequent sheet conveyance speed. Removal of image-forming substances Apparatus. 2. A liquid supply device for supplying a liquid, which makes the adhesion of the image forming substance to the surface unstable, to a sheet having an image forming substance attached to the surface thereof, and an image attached on the surface of the sheet. Contact separation for separating the sheet and the peeling member after contacting a peeling member having a stronger adhesive force for the image forming substance than the adhesive force between the surface and the forming substance for the forming substance An image forming substance removing device comprising: a heating means for heating the peeling member in the vicinity of a contact portion where the sheet and the peeling member come into contact with each other, wherein the peeling member is heated in the vicinity of the contact portion. A heating amount control unit for increasing the heating amount from the heating unit and the auxiliary heating unit to the peeling member from the start of sheet conveyance until a certain time elapses after the sheet conveyance starts. Characterized by having Image forming substance removing apparatus. 3. A liquid supply device for supplying a liquid having a surface on which an image-forming substance is adhered, which makes the adhesion of the surface and the image-forming substance unstable, and an image adhered on the surface of the sheet. Contact separation for separating the sheet and the peeling member after contacting a peeling member having a stronger adhesive force for the image forming substance than the adhesive force between the surface and the forming substance for the forming substance Means, heating means for heating the peeling member in the vicinity of the contact portion where the sheet and the peeling member come into contact with each other, and the temperature of the peeling member heated by the heating means is set to a predetermined set temperature. An image forming substance removing apparatus comprising: a control unit that controls the control unit to set the predetermined setting temperature to a predetermined time from the start of sheet conveyance until a predetermined temperature To set higher Image forming substance removing apparatus according to symptoms.