JPH09297489A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leakage of a releasing agent by disposing a shutter for hermetically closing a releasing agent storage member, linked with the removal of a fixing device from a device main body, at the time of executing the removal. SOLUTION: A fixing unit 1 is constituted so that it is moved in the direction of an arrow S, to be attached to/detached from the image forming device main body and further, a coating unit 11 is supported by the device main body, differently from the fixing unit 1. Then, a freely slidable shutter 6 is disposed in a tray 4 in the fixing unit 1 and when it is in a fixed position in the device main body, the shutter 6 is in a full line position and the releasing agent scraped from a pressure roller by a blade 7 is received in the tray 4. Further, when the fixing unit 1 is removed from the device main body, the shutter 6 is moved to a dotted line position, to close the opening of the tray 4. Therefore, at the time of removing the fixing unit 1, the releasing agent is prevented from leaking out from the tray 4, even if the unit 1 is inclined after the removal.

Description

Detailed Description of the Invention

[0001]

[Object of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus utilizing an electrostatic transfer process, such as an electrostatic wire copying machine and a printer.
Fuchuko is related to the fixing device.

In the known image forming apparatus as described above, it is necessary to fix and fix the unfixed toner image formed on the transfer material such as paper at the image forming portion.
Various fixing means have been proposed for this purpose, but recently, an unfixed toner image is formed at a pressure contact nip portion between a fixing roller whose surface is controlled to a predetermined temperature and a pressure roller which is in pressure contact with the fixing roller. It is well known that the one in which the fixing is carried out by passing the transfer material carrying the is widely used.

In this type of fixing device, since the unfixed toner directly contacts the fixing roller, a part of the toner is transferred to the fixing roller, and this toner is further moved to the pressure roller for subsequent transfer. Since an offset phenomenon that contaminates the material occurs, the surface material of the fixing roller is formed of a material to which toner is hard to adhere, and a release agent such as silicon oil is applied to the roller to prevent the occurrence of the offset phenomenon. There is a need.

FIG. 5 shows a typical example of such a fixing device, which will be briefly described below. A heat fixing roller 2 and a pressure roller 3 that presses against the heat fixing roller 2 are disposed in the fixing device casing 101, and a transfer material 17 that electrostatically carries a toner image at an image forming portion (not shown).
Is conveyed and passed from the left side of the drawing to the nip portion of the roller pair.

A tank 5 containing a mold release agent such as silicone oil is arranged near the fixing roller 2, and the mold release agent pumped up by the pump 102 is used by the nozzle 15.
Is applied to the coating roller 12 through the blade 13 and the blade 13
After being evenly distributed on the surface of the coating roller by means of, it is transferred to the fixing roller 2 and a thin layer of release agent is formed thereon.

By forming the release agent layer on the fixing roller 2 as described above, the offset phenomenon can be prevented. At this time, the release agent which has not been absorbed by the transfer material and has moved to the pressure roller 3 is removed by the blade 7 and scraped off to the tray 4. The release agent stored in the tray 4 may be collected in the tank 103 and reused. Further, reference numeral 8 in the drawing denotes a cleaning web for the fixing roller 2.

By the way, in the fixing device having such a structure,
As can be seen immediately, since there is a release agent accommodating member in an open state like the tank 103 and the receiving tray 4 in the fixing device, tilting them inevitably causes the release agent to spill and contaminate the surroundings. It was

Conventionally, in order to avoid such a problem, the handling of the fixing device usually needs to be limited to a service person. At the same time, as the size and cost of image forming apparatuses have been reduced in recent years, such a state has hindered cost reduction and has become a major obstacle to the spread of image forming apparatuses. Further, with the progress of downsizing of the image forming apparatus, the image forming apparatus can be easily transported, and in the process, the image forming apparatus often tilts to move the fixing device. The presence of the released release agent storage in the apparatus has become a big problem.

The present invention has been made to cope with such a situation, and the user can easily attach / detach the fixing device to / from the main body of the fixing device, and the release agent spills even when the fixing device is removed from the main body. It is an object of the present invention to provide a fixing device that does not have any problems.

[0009]

Configuration of the Invention

In order to achieve the above object, the present invention provides an image forming apparatus which is detachably attached to the main body of the image forming apparatus and has means for applying a releasing agent to a fixing roller. In the fixing device, the release agent storage member arranged in the fixing device and storing the release agent is interlocked with the release agent storage member when the fixing device is pulled out from the main body of the apparatus. A fixing device, in which a storage member is hermetically sealed, and a shutter for releasing the release agent storage member in conjunction with the fixing device when the fixing device is mounted at a predetermined position in the main body of the device. Alternatively, in an image forming apparatus including a fixing device that is detachably attached to the image forming apparatus main body and has a means for applying a release agent to the fixing roller, the fixing device is attached to the image forming apparatus main body when attaching and detaching the fixing device to the image forming apparatus main body. The image forming apparatus is provided with a shutter for blocking at least a part of the release agent moving path that remains in the apparatus main body in cooperation with each other and for preventing the release agent from leaking when the fixing device is taken out.

With such a configuration, it is possible to effectively prevent the release agent, which mainly uses silicon oil or the like, from leaking into or out of the apparatus main body, which is extremely effective in improving the handleability of this type of image forming apparatus. .

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS "FIG. 1" is a schematic side sectional view of a fixing device showing an embodiment of the present invention, in which a fixing roller 2, a pressure roller 3, a receiving tray 4 disposed in a fixing unit 1, The blade 7, the cleaning web 8 and the like are the same as those shown in FIG. 5, and the transfer material 17 carrying the unfixed toner image is supplied from the left side of the drawing to the nip portion of the roller pair and the discharge roller pair 9 Is discharged to the outside of the aircraft.

A coating unit 11 is separately provided in the vicinity of the fixing unit 1, and a coating roller 12, a blade 13, a release agent storing blade 14, a nozzle 15 and the like are arranged on the coating unit 11.

A coating roller 12 and a blade 14 abutting on the coating roller 12 are provided by a nozzle 15 from a release agent tank (not shown).
The mold release agent is stored in the recess formed by, the mold release agent is pumped up and adheres to the surface as the coating roller rotates, and the blade 13 forms a uniform mold release agent layer over the entire surface. Further, this adheres to the fixing roller 2 to prevent the offset phenomenon.

The part of the release agent applied to the fixing roller 2 that is not absorbed by the transfer material or removed by the cleaning web is transferred to the pressure roller 3 and is scraped off by the blade 7 and received in the tray 4 Will be stored in.

The fixing roller usually has a heat source inside, and as a material thereof, a multi-layer or single-layer silicone rubber layer is formed on a core metal, and an LTV silicone rubber layer is provided on the surface to improve releasability. Used. Further, as the pressure roller, the same one as the fixing roller, one whose surface is covered with a tube such as PFA, or one whose surface is coated with a fluororesin can be used.

As the release agent, silicone oil such as dimethyl type and methyl phenyl type is favorably used.
It is preferable that the viscosity is about 50 to 10,000 CS (centistokes).

The fixing unit 1 is constructed so that it can be attached to and detached from the main body of the image forming apparatus by moving it in the direction of the white arrow A in the figure, and the coating unit 11 is separate from the fixing unit 1. Be supported by.

A slidable shutter 6 is provided on a tray 4 in the fixing unit 1. When the unit 1 is at a predetermined position in the main body of the apparatus, the shutter 6 is in a solid line position as shown in the figure. Then, the release agent scraped off from the pressure roller by the blade 7 is received by the tray 4.

When the fixing unit is removed from the main body of the apparatus, the shutter 6 moves to the position shown by the dotted line in the figure to close the opening of the tray 4. Therefore, when removing the fixing unit, even if it is tilted at a later time, the tray 4
It is possible to prevent the release agent from leaking out. As means for displacing the shutter 6 with the movement of the fixing unit,

As a means for moving the shutter 6 as described above, for example, when the unit 1 is mounted on the main body of the apparatus when the opening is normally closed by the force of a spring or the like provided on the shutter 6, Appropriate means such as engaging the member with the protrusion and moving the shutter 6 to release the opening can be used.

In the coating unit 11, as shown in FIG. 2, the fixing unit 1 is removed and the fixing roller 2 is attached.
Is moved from the dotted line position 2'in the figure to the solid line position 2 direction, the release portion where the coating roller 12 faces the fixing roller is
The release portion is closed by the movement of the shutter 34, which moves in the direction of the arrow B in the drawing, from the dotted line position 34 'to the solid line position.

When the fixing unit 1 is mounted at a predetermined position in the apparatus main body, the shutter 34 of the coating unit 11 moves from the solid line position in the figure to the dotted line position, and the coating roller 12 contacts the fixing roller 2. It will be easily understood that the desired action can be obtained by the same means as the shutter 6 of the tray 4 as to the means for moving the shirt 34.

With such a construction, when the fixing unit 1 is taken out of the main body of the apparatus, since the tray 4 is closed, the releasing agent does not overflow even if it is tilted. Also, when transporting the image forming apparatus main body, even if it is tilted,
Application unit 1 if the fixing unit is removed beforehand
It is also possible to prevent the release agent from leaking out of 1.

Incidentally, instead of the coating unit 11, the tray 4 and other releasing agent moving paths are fixed to the apparatus main body,
The opening / closing operation may be performed in association with the insertion / removal of the fixing unit 1.

FIG. 3 is a side sectional view of a fixing device showing a second embodiment of the present invention. The basic structure of the fixing device is the same as that of the above-mentioned fixing devices, and the parts common to them are shown. The description is omitted.

A mold release agent container 2 is provided above the fixing roller 2.
1 is disposed, and an application member 20 made of porous PTFE, felt or the like is disposed in an opening formed at the bottom of the container 21, and an outer end of the application member 20 is a fixing roller. It is in contact with 2. Further, a cleaning roller 19 is disposed in contact with the fixing roller on the downstream side of the coating member 20 as viewed in the running direction of the fixing roller 2.

Since the container 2 is constructed as described above, the container 2
The release agent in 1 is sequentially supplied to the surface of the fixing roller 2 by the capillarity of the coating member 20, and is further smoothed by the cleaning roller 19 to form a uniform release agent layer on the surface of the fixing roller to serve as a fixing portion. It reaches the pressure contact nip portion, and this provides an offset prevention function.

Further, the release agent attached to the pressure roller 3 is removed by the blade 7, and the removed release agent is absorbed by the absorbing member 23 installed in the recovery tray 24.

With this structure, even if the fixing device is tilted, the liquid release agent is absorbed by the absorbing member. Therefore, if the opening of the container 21 is closed, the release agent is released. It is possible to suitably prevent the situation where the leak occurs.

On the other hand, when the releasing agent is absorbed by the absorbing member as described above, the absorbing member can reliably hold the releasing agent in a relatively small amount, and the absorbed releasing agent is inclined. If so, it is unavoidable that the gravity moves to move inside the absorbing member and causes local leakage for a long time.

In order to deal with such a problem, in the apparatus shown in the drawing, when the fixing unit 18 is moved in the direction of the outlined arrow A to be attached to and detached from the apparatus main body, the inlet side and the outlet side of the transfer material are interlocked with this. The shutters 25 and 26 provided on the
The door is opened and closed by moving the fixing unit in the direction, so that the entrance is closed when the fixing unit is taken out from the apparatus main body, and the entrance is opened when the fixing unit is mounted at a predetermined position in the apparatus main body.

It can be easily understood that the means for displacing the shutters 25 and 26 can be the same as that described in FIG. 1 above.

FIG. 4 is a side sectional view of a fixing device showing a third embodiment of the present invention. In the case of this apparatus as well, the basic constitutional operation of the child fixing operation is the same as that of each of the above-mentioned embodiments, and corresponding parts are designated by the same reference numerals.

In this apparatus, the release agent 5 is the container 30.
And a felt 29 attached to the bottom opening of the container is placed in contact with the surface of the fixing roller 2 so that the release agent applied to the fixing roller 2 is transferred to the blade 31.
The coating unit 28 is integrally formed with each of the above parts, and is detachably attached to the fixing unit 27.

The blade 31 is designed to even out the release agent on the fixing roller to make it uniform and to keep the amount of release agent adhering to the roller as small as possible. There is no need for a release agent collecting member below the pressure roller.

With such a structure, the release agent can be prevented from overflowing as much as possible, but it is difficult to prevent it completely. Therefore, in the illustrated apparatus, the shutters 32 and 33 are opened and closed in the direction of arrow B at the inlet side opening through which the transfer material enters the fixing portion for fixing and the outlet side opening through which the transfer material is discharged outside the machine. There is.

When the fixing unit 27 is moved in the direction of arrow A and attached to the apparatus main body, the shutters 32 and 33 are released.
The fixing operation can be performed by taking the position indicated by the solid line in the figure. Further, when the child fixing unit is pulled out from the main body of the apparatus, each shutter takes the position of the dotted line in the drawing to close the fixing unit, so that the release agent can be surely prevented from leaking.

With this structure, the shutter can be used as a member for guiding the transfer material to the fixing portion, so that the number of parts can be reduced and the apparatus can be made compact.
The cost can be reduced.

[0039]

In the fixing device of the image forming apparatus, which is detachable from the main body of the image forming apparatus and has the releasing agent applying means for preventing the offset phenomenon occurring at the time of fixing, When attaching or detaching the fixing device, or when transporting the image forming apparatus, a shutter member that closes the releasing agent should be provided at a portion that holds a large amount of the release agent, or the fixing device should be kept in a hermetically sealed state as a whole. Therefore, even if the fixing device portion is inclined, it is possible to suitably prevent the release agent inside from overflowing into the inside and outside of the device and contaminating it, thereby significantly improving the handling property of the fixing device or the image forming apparatus. Can be made.

[Brief description of drawings]

FIG. 1 is a side sectional view of a fixing device showing a first embodiment of the present invention.

FIG. 2 is an enlarged side sectional view of the coating unit of the above.

FIG. 3 is a side sectional view of a fixing device showing a second embodiment of the present invention.

FIG. 4 is a side sectional view of a fixing device showing a third embodiment of the present invention.

FIG. 5 is a side sectional view of a known fixing device.

[Explanation of symbols]

 1 Fixing Unit 2 Fixing Roller 3 Pressurizing Roller 4 Saucet 6 Shutter 7 Blade 8 Cleaning Web 11 Coating Unit 12 Coating Roller 13 Blade 15 Nozzle 17 Transfer Material 19 Cleaning Roller 20 Coating Member 21 Release Agent Storage Container 23 Absorbing Member 25, 26 Shutter 28 Coating unit 29 Felt 30 Release agent container 31 Blades 32, 33 Shutter

Claims (2)

[Claims] 1. A fixing device of an image forming apparatus, which is detachably attached to a main body of the image forming apparatus and has means for applying a releasing agent to a fixing roller, wherein the releasing agent is stored in the fixing device. When the fixing device is removed from the main body of the apparatus, the release agent storage member is interlocked with the release agent storage member to seal the release agent storage member, and the fixing device is mounted at a predetermined position in the main body of the apparatus. In this case, a fixing device is provided with a shutter for releasing the release agent storage member in conjunction with this. 2. An image forming apparatus comprising a fixing device which is detachably attached to the image forming apparatus main body and has a means for applying a releasing agent to a fixing roller, wherein the fixing device is attached to or detached from the image forming apparatus main body. An image forming apparatus comprising a shutter for blocking at least a part of a release agent moving path remaining in the apparatus main body in cooperation with a fixing device and for preventing leakage of the release agent when the fixing device is taken out.