JPH0683227A - Fixing device - Google Patents

Abstract

PURPOSE:To make a coating unit compact and to prevent offset preventing liquid from being leaked from a tank in the case of transportation by providing a seal cover hermetically sealing the tank in contacting liquid tight with each other and integrally attaching the coating unit with the seal cover. CONSTITUTION:A fixing roller 4 incorporating a heater, a pressure roller 5 pressuring and abutting on the roller 4, and the coating unit 6 applying the offset preventing liquid to the roller 4 are installed in a main body. By allowing transfer paper on whose lower surface a toner image is formed to pass between the rollers 4 and 5, the toner image is fixed on the transfer paper. The coating unit 6 is provided with the tank 21 filled with the offset preventing liquid, one or more supply members installed in the tank and supplying the offset preventing liquid to the fixing roller 4, and the seal cover 35 hermetically sealing the tank 21 in contacting liquid tight with each other and the unit 6 is integrally attached to the main body with the cover 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device, and more particularly to a fixing device provided in an image forming apparatus and having a coating unit for coating an offset preventing liquid on a fixing roller.

[0002]

2. Description of the Related Art As a conventional fixing device of this type, for example, there is a fixing device described in JP-A-52-9441. This fixing device is provided in the main body of the image forming apparatus, has a heater with a built-in heater, a pressure roller that is pressed against the fixing roller, and a fixing roller that is provided below the fixing roller and prevents the fixing roller from being offset. A coating unit for coating the liquid, the coating unit including a tank filled with the offset prevention liquid, and a supply roller provided in the tank for supplying the offset prevention liquid to the fixing roller. I have it.

In this fixing device, a transfer paper having a toner image formed on the lower surface thereof is passed between a fixing roller and a pressure roller to fix the toner image on the lower surface of the transfer paper. There is. At this time, by supplying the offset prevention liquid from the supply roller to the fixing roller,
The toner transferred to the transfer paper is prevented from adhering to the fixing roller to form a double image (this is called offset).

[0004]

However, in such a conventional fixing device, since the cover filled with the offset prevention liquid is opened to the outside, the offset prevention liquid is stored in the tank when the coating unit is transported. I sometimes leaked from it. Therefore, there is a problem that when the coating unit is set in the image forming leaving main body, oil is scattered in the main body and stains the surrounding members.

Further, since there is no means for detecting the remaining amount of the offset preventing liquid, the remaining amount of the offset preventing liquid cannot be grasped and the preventing liquid cannot be effectively used. Therefore, in the invention according to claim 1, a seal cover for liquid-tightly sealing the tank is provided, and the coating unit is integrally attached to the main body together with the seal cover, whereby the coating unit can be made compact. At the same time, it is possible to reliably prevent the offset prevention liquid from leaking from the tank during transportation of the coating unit, and to prevent the surrounding members from being soiled even when the coating unit is attached to the main body. The purpose is to provide a device.

According to a second aspect of the present invention, when the coating unit is mounted on the main body, the removing member is brought into contact with the seal cover to remove at least a part of the seal cover from the tank, so that the coating unit is attached to the main body. It is possible to reliably remove the seal cover at the time of mounting to the main body and perform the supply work of the offset prevention liquid, and also to prevent the coating set prevention liquid from leaking before mounting the coating unit to the main body. It is intended to provide a fixing device.

According to the third aspect of the present invention, the regulating member is rotatably provided on the main body, and the regulating member and the removing member are integrally provided. When the coating unit is attached to the main body, the regulating member is provided on the tank. By preventing the coating unit from coming out of the main unit by making contact with it, it is possible to prevent the coating unit from coming out of the main unit and at the same time securely remove the seal cover, improving the workability of mounting work. It is an object of the present invention to provide a fixing device that can be used.

According to a fourth aspect of the present invention, the remaining amount of the offset prevention liquid is detected by detecting the remaining amount of the offset prevention liquid and raising the tank based on the detection information. An object of the present invention is to provide a fixing device that can effectively use the prevention liquid without waste.

[0009]

The invention according to claim 1 is
In order to solve the above problems, a fixing roller that is housed in the main body and has a built-in heater, a pressure roller that is in pressure contact with the fixing roller, and a fixing roller that is provided below the fixing roller and that prevents the fixing roller from being offset A coating unit for coating the liquid is provided, and the transfer sheet having the toner image formed on the lower surface thereof is passed between the fixing roller and the pressure roller to fix the toner image on the transfer sheet. In the fixing device, the coating unit is a tank filled with an offset preventing liquid, at least one or more supply member that is provided in the tank and supplies the offset preventing liquid to the fixing roller, and the tank is liquid-tight. And a seal cover which is hermetically sealed, and the coating unit is integrally attached to the main body together with the seal cover.

In order to solve the above-mentioned problems, the invention according to claim 2 is provided with a removing member which can be brought into contact with and separated from the seal cover, and the removing member is provided when the coating unit is mounted on the main body. It is characterized in that it abuts on the seal cover and removes at least a part of the seal cover from the tank. In order to solve the above-mentioned problems, the invention according to claim 3 is such that the removing member is integrally provided with a regulating member rotatably provided on the main body, and the regulating member is mounted on the main body by a coating unit. When applied, the coating unit is prevented from coming out of the main body by coming into contact with the tank.

According to a fourth aspect of the present invention, in order to solve the above-mentioned problems, a fixing roller having a heater built therein, a pressure roller pressed against and abutting the fixing roller, and provided below the fixing roller. A coating unit that coats the fixing roller with the offset prevention liquid is provided, and the transfer sheet having the toner image formed on the lower surface thereof is passed between the fixing roller and the pressure roller to form the toner image on the transfer sheet. In a fixing device for fixing, the coating unit is provided in a tank filled with an offset preventing liquid, and is slidably provided in the tank, and at least one or more of the offset preventing liquid is supplied to a fixing roller. Provided in the supply member and the tank,
An urging member that urges the supply member to the fixing roller, a remaining amount detection unit that detects the remaining amount of the offset prevention liquid, and a raising unit that raises the tank based on the detection information of the remaining amount detection unit are provided. It is characterized by that.

[0012]

According to the first aspect of the present invention, the seal cover for liquid-tightly sealing the tank is provided, and the coating unit is integrally mounted on the main body together with the seal cover. Therefore,
The coating unit is made compact, the offset preventing liquid does not leak from the tank during transportation, and the surrounding members are not contaminated when the coating unit is mounted on the main body.

According to the second aspect of the invention, when the coating unit is mounted on the main body, the removing member is brought into contact with the seal cover to remove at least a part of the seal cover from the tank. Therefore, when the coating unit is mounted on the main body, the seal cover is reliably removed to perform the offset prevention liquid supply work, and the coating set prevention liquid leaks before the coating unit is mounted on the main body. Never.

According to the third aspect of the invention, the regulating member is rotatably provided on the main body, and the regulating member and the removing member are integrally provided. When the coating unit is mounted on the main body, the regulating member is provided. Is prevented from coming into contact with the tank and the coating unit from coming out of the main body. Therefore, the coating unit is prevented from slipping out of the main body, and at the same time, the seal cover is surely removed, and the workability of mounting the coating unit is improved.

In the invention according to claim 4, the remaining amount of the offset prevention liquid is detected, and the tank is raised based on the detection information. Therefore, the remaining amount of the offset prevention liquid is easily grasped, and the tank is raised according to the remaining amount. At this time, since the supply member is urged by the urging member and does not move as the tank rises, the lower portion of the supply member is immersed in the offset prevention liquid. As a result, the supply member is soaked in the anti-offset liquid even when the remaining amount of the anti-offset liquid becomes small, and the anti-offset liquid is effectively used without waste.

[0016]

EXAMPLES The present invention will be described below based on examples.
1 to 5 are views showing an embodiment of a fixing device according to any one of claims 1 to 4. First, the configuration will be described. In FIG. 1, reference numeral 1 denotes a transfer belt provided inside the main body of the image forming apparatus, and a toner image is formed on the transfer belt 1 by a developing device (not shown). A transfer roller 2 is in contact with the end portion of the transfer belt 1, and the transfer roller 2 transfers the toner image T formed on the transfer belt 1 onto the lower surface of the transfer paper P.

A fixing device 3 is provided on the downstream side of the transfer roller 2 in the conveying direction of the transfer paper P, and the fixing device 3 is provided.
Is composed of a fixing roller 4, a pressure roller 5, and a coating unit 6. The fixing roller 4 is rotatably supported by the lower main body (main body) 7, has a heater 8 inside, and is heated to a constant temperature by the heater 8. A thermistor 9 is provided on the outer peripheral portion of the fixing roller 4, and the temperature of the fixing roller 4 is measured by the thermistor 9 and maintained at a constant temperature.

The pressure roller 5 is rotatably supported by the upper main body (main body) 10 and is pressed against the fixing roller 4 by a spring 11 so that the transfer sheet P can pass together with the fixing roller 4. It forms a nip part. Therefore, the transfer paper P having the toner image T transferred to the lower surface by the transfer roller 2 is pressed toward the fixing roller 4 by the pressure roller 5 when passing through the nip portion, so that the toner image T is fixed. It

A pair of paper discharge rollers 12 and 13 are provided downstream of the fixing roller 4 and the pressure roller 5 in the conveying direction of the transfer paper P, and the transfer paper P on which the toner image is fixed is discharged. The rollers 12 and 13 discharge the paper onto a paper discharge tray (not shown). A branch claw 14 is coaxially provided on the paper discharge roller 13, and the branch claw 14 guides the transfer paper P between the paper discharge rollers 12 and 13.

The coating unit 6 has a tank 21, and the tank 21 is filled with oil 22 as an offset preventing liquid. In addition, a supply roller made of a heat resistant elastic material such as silicon rubber or a heat resistant felt material is provided in the tank 21.
23 (supply member) is rotatably provided in the clockwise direction. The lower side of the supply roller 23 is immersed in the oil 22, and the oil 22 is supplied to the fixing roller 4 as it rotates.

The rotating shaft 23a of the supply roller 23 is a bearing 23b.
It is slidably fitted into fitting holes 21a formed at both ends of the tank 21 via. Also, supply roller 23 bearing
23b is urged toward the fixing roller 4 by a spring 24 as an urging member, and the supply roller 23 is the spring.
It is pressed against the fixing roller 4 by 24. Also,
A blade 25 is in contact with the supply roller 23, and the blade 25 regulates the amount of the oil 22 applied to the fixing roller 4. In addition, a remaining amount detection sensor (remaining amount detection means) 26 that detects the remaining amount of the oil 22 is provided in the tank 21, and the detection sensor 26 detects the remaining amount of the oil 22 in the tank 21. This detection information is output to a controller (not shown).

A rail 27 is provided in the lower portion of the tank 21, and a pair of links 29a, 29b intersecting each other around an intersection 28 are provided in the lower portion of the rail 27 as shown in FIG.
One end of is attached. The other ends of the links 29a, 29b are attached to a base 30 provided in the image forming apparatus main body, and a pair of springs 31a are provided between one end and the other end of the links 29a, 29b facing each other. 31b is interposed. These springs 31a and 31b are links 29a,
One end of 29b is urged toward the base 30, and the tank 21 is always urged downward by the springs 31a and 31b.

One end of a wire 33 is attached to the other end of the link 29a via a pin 32.
The other end of 33 is connected to the solenoid 34. The solenoid 34 is adapted to be operated by a signal from the controller. When the controller outputs an operation signal in accordance with the remaining amount of the oil 22 based on the detection information of the remaining amount detection sensor 26, the solenoid 34 is operated in response to the operation signal. It is designed to be activated. Then, at the time of operation, the wire 33 is pulled in the direction of the arrow to resist the urging force of the springs 31a, 31b, and the link 29.
By moving a and 29b upward, the tank 21 is raised. The links 29a and 29b and the spring described above
31a, 31b, the wire 33, the solenoid 34, and the controller constitute the raising means.

On the other hand, a seal cover 35 is provided on the upper surface of the tank 21.
As shown in FIG. 3 (b), the seal cover 35 has a central portion formed in substantially the same shape as the outer peripheral surface of the upper portion of the supply roller 23 so as to liquid-tightly seal the tank 21. ing. Further, a part of the seal cover 35 is composed of a polymer film, and this part constitutes a removing portion 35a (linear portion) which is removed by a removing member described later.

Further, the tank 21 is formed with a concave storage portion 21b, and the removing member 36 is inserted into the storage portion 21b via the seal cover 35. The removing member 36 is provided so as to come into contact with and separate from the seal member 35,
As shown in FIG. 4, the removing member 36 is made of a rigid plate such as SUS, extends along the longitudinal direction of the tank 21, and has a sharp projection at its tip.

The removing member 36 is a lever as a regulating member.
The lever 37 is integrally attached to the lower body 7, and the lever 37 is rotatably provided on the lower body 7. The lever 37 comes into contact with the tank 21 when rotated in a predetermined direction, and when the lever 37 comes into contact with the tank 21, the coating unit 6
Is restricted from coming out of the lower main body 7. Next, the operation will be described.

In order to mount the coating unit 6 on the lower main body 7, the coating unit 6 is transported and mounted on the lower main body 7 in a state where the tank 21 is closed by the seal cover 35 in advance. At this time, the lever 37 is placed in the open position as shown in FIG. 5 (a) so as not to interfere with the mounting of the coating unit 6 on the lower main body 7. After mounting, the lever 37 is rotated in a predetermined direction as shown in FIG. 5B, and the lever 37 is brought into contact with the tank 21. Therefore, the movement of the coating unit 6 to the front side in FIG. 5 is restricted, and the mounting of the coating unit 6 is completed.

At this time, the release member 36 is removed by the removing portion 35a.
After being pierced through, it is inserted into the storage portion 21b together with the release portion 35a. As a result, the supply roller 23 is exposed to the outside and is urged by the springs 31a and 31b to be fixed to the fixing roller 4.
It becomes possible to supply the oil 22. Then
The supply of the oil 22 is started as the image forming work is started. That is, the supply roller 23 is rotated, the oil 22 applied to the supply roller 23 is regulated to a certain amount by the blade 25, and then applied to the fixing roller 4. When the oil 22 is gradually reduced by continuing this operation, the remaining amount of the oil 22 is detected by the remaining amount detection sensor 26, and this detection information is output to the controller.

The controller outputs a signal to the solenoid 34 based on this detection information to operate the solenoid 34.
Since the solenoid 34 pulls the wire 33 by a predetermined amount according to the remaining amount of the oil 22, the other end of the link 29a moves to the right side in FIG. Therefore, one ends of the links 29a, 29b move upward in FIG. 2 against the urging force of the springs 31a, 31b to raise the tank 21 as shown by a broken line.

At this time, since the supply roller 23 is restricted from coming into contact with the fixing roller 4 and moving upward, the supply roller 23 is biased by the fixing spring 24 to restrict the movement,
The lower part is immersed in oil 22. As described above, in this embodiment, the seal cover 35 that liquid-tightly seals the tank 21 is provided, and the coating unit 6 together with the seal cover 35 is attached to the lower main body 7.
The coating unit 6 can be made compact, and the oil 22 can be prevented from leaking from the tank 21 during transportation, so that the coating unit 6 can be attached to the lower main body 7. It is possible to prevent the surrounding members from being soiled even when mounted.

When the coating unit 6 is attached to the lower main body 7, the removing member 36 is brought into contact with the seal cover 35 to remove the removing portion 35a from the tank 21. At the time of mounting on the side main body 7, the removing portion 35a can be surely removed to perform the oil 22 supply work, and the oil 22 is prevented from leaking before the coating unit 6 is mounted on the lower main body 7. Can be prevented.

A lever 37 is rotatably provided on the lower main body 7, and the lever 37 and a removing member 36 are integrally provided. When the coating unit 6 is attached to the lower main body 7, the lever 37 is Since the coating unit 6 is prevented from coming out of the main body by being brought into contact with the tank 21, it is possible to prevent the coating unit 6 from coming out of the lower main body 7 and at the same time securely remove the removing portion 35a. Can be applied, coating unit 6
It is possible to improve the workability of the mounting work.

Further, since the remaining amount of the oil 22 is detected by the sensor 26 and the tank 21 is raised based on the detection information, the remaining amount of the oil 22 can be easily grasped, and the oil 22 It is possible to raise the tank 21 according to the remaining amount. Therefore, the supply roller 23 can be dipped in the oil 22 even when the remaining amount of the oil 22 is low.
22 can be used effectively without waste.

Further, in this embodiment, since the seal cover 35 is partly composed of the removing portion 35a made of the polymer film, the removing portion 35a can be easily removed by the removing member 36. In this embodiment, the lever 37
Is rotatably attached to the lower main body 7, but the present invention is not limited to this, and may be attached to a predetermined position of the image forming apparatus main body. Further, although the supply roller 23 is used in this embodiment, a coated felt may be used. Further, although only one supply roller 23 is provided, one or more may be provided.

[0035]

According to the invention described in claim 1, the coating unit can be made compact, and it is possible to reliably prevent the offset preventing liquid from leaking from the tank during transportation of the coating unit. It is possible to prevent the surrounding members from being soiled even when the coating unit is mounted on the main body.

According to the second aspect of the present invention, when the coating unit is mounted on the main body, the seal cover can be reliably removed to perform the work of supplying the offset prevention liquid, and the coating unit can be mounted on the main body. It is possible to prevent the smearing prevention liquid from leaking before mounting. According to the third aspect of the present invention, it is possible to prevent the coating unit from coming out of the main body, and at the same time, to reliably remove the seal cover, so that the workability of the mounting work can be improved.
According to the invention described in claim 4, the remaining amount of the offset prevention liquid can be easily grasped, and the offset prevention liquid can be effectively used without waste.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a fixing device according to any one of claims 1 to 4.

FIG. 2 is a configuration diagram of an elevating means according to an embodiment.

FIG. 3A is a configuration diagram of a tank and a supply roller of one embodiment. (b) is a block diagram of the cover.

FIG. 4 is a perspective view of a lever and a release member according to an embodiment.

FIG. 5 is a diagram showing an operation when the coating unit according to the embodiment is mounted.

[Explanation of symbols]

 3 Fixing device 4 Fixing roller 5 Pressure roller 6 Coating unit 7 Lower body (main body) 21 Tank 22 Oil (offset prevention liquid) 23 Supply roller (supply member) 24 Spring (biasing member) 26 Remaining amount detection sensor ( Remaining amount detecting means) 29a, 29b Link (raising means) 31a, 31b Spring (raising means) 33 Wire (raising means) 34 Solenoid (raising means) 35 Seal cover 36 Removal member 37 Lever (regulating member)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sotohiro Tsujihara 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Inventor Yoshikazu Yamazoe 1-3-6 Nakamagome, Ota-ku, Tokyo No. Within Ricoh Co., Ltd. (72) Inventor Yasuhiro Kodaira 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd.

Claims (4)

[Claims] 1. A fixing roller which is housed in a main body and has a built-in heater, a pressure roller which is in pressure contact with the fixing roller, and a fixing roller which is provided below the fixing roller and which is coated with an offset preventing liquid. And a coating unit for applying the toner image onto the transfer paper by passing the transfer paper having the toner image formed on the lower surface between the fixing roller and the pressure roller. The coating unit is a tank filled with an offset prevention liquid,
At least one supply member that is provided in the tank and that supplies the offset prevention liquid to the fixing roller, and a seal cover that liquid-tightly seals the tank are provided, and the coating unit is attached to the main body together with the seal cover. The fixing device is characterized in that it is integrally mounted. 2. A removing member that can be brought into contact with and separated from the seal cover is provided, and the removing member comes into contact with the seal cover when the coating unit is mounted on the main body, and at least a part of the seal cover is attached to the tank. The fixing device according to claim 1, wherein the fixing device is removed from the fixing device. 3. The removing member is integrally provided with a regulating member rotatably provided on the main body, and the regulating member is in contact with the tank when the coating unit is mounted on the main body to apply the coating member. The fixing device according to claim 2, wherein the unit is prevented from coming out of the main body. 4. A fixing roller having a built-in heater, a pressure roller that is pressed against the fixing roller, and a coating unit that is provided below the fixing roller and applies an offset prevention liquid to the fixing roller. In the fixing device, wherein the toner image is fixed on the transfer paper by passing the transfer paper having the toner image formed on the lower surface between the fixing roller and the pressure roller, A tank filled with an offset prevention liquid, at least one supply member slidably provided in the tank for supplying the offset prevention liquid to the fixing roller, and provided in the tank to fix the supply member An urging member for urging the roller, a remaining amount detecting means for detecting the remaining amount of the offset preventing liquid, and a raising means for raising the tank based on the detection information of the remaining amount detecting means are provided. The fixing device according to claim.