JPH10207282A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device capable of dispensing with complicated expensive detect-controlling means, for detecting residual web and taking up the web, when the web is entirely taken up by a take-up member, preventing a driving member of the take-up member from being damaged, utilizing up to the last end part of the web, and restraining the web from being uselessly consumed. SOLUTION: The fixing device is provided with a fixing roller, the unwinding member 4 winding the web there around, the take-up member 6 taking up the web rotated by the driving member 5, and a pressing member 7 pressing the web to the fixing roller being arranged in a midway between these two members. Then, the relation of the coherence A of the web 3 and the unwinding member 4, to the partition force B for parting the web 3 from the unwinding member 4, within the allowable torque corresponding to the damage to the driving member 5, becomes so as to satisfy the next inequality, the coherence A < the partition force B, and the pressing member 7 parts from the fixing roller, right after the trailing end part of the web 3 is allowed to pass the position held between the fixing roller and the pressing member 7 at the time of unwinding the web 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a fixing roller,
The present invention relates to a fixing device including a web for cleaning or applying an oil to a fixing roller, and a pressing member for pressing the web against the fixing roller.

[0002]

2. Description of the Related Art A conventional fixing device of this type is as shown in FIG. 3, and in this example, an unwinding member 4 for cleaning a fixing roller comprising a heating roller 1 or winding a web 3 for oil application. And a take-up member 6 that rotates the driving member to take up the web 3, and a pressing member 7 that is disposed between the two members 4 and 6 and presses the web 3 against the fixing roller 1. Although not shown, the fixing roller 1 is composed of a pressure roller 2 in another example. 4 and 5 as a winding mechanism of the web 3. In FIG. 4, reference numeral 5 denotes a driving member for driving a winding member 6, and a pressing member 7 includes 5 is the same as that shown in FIG. 4 except that the pressing member 7 is constituted by a rotating roller. .

In such a device, a nip portion between a fixing roller 1 and a pressure roller 2 rotating at the time of fixing is provided.
The unfixed image 11 is fixed to the transfer paper 12 by passing through the transfer paper 12 carrying the unfixed image 11 and applying heat and pressure. On the other hand, while the winding member 6 is driven by the driving member 5 and the web 3 is moved in the direction of the arrow, the pressing member 7 presses the web 3 against the fixing roller 1, and the web 3 causes the surface of the fixing roller 1 to become dirty. Or an anti-offset liquid such as silicone oil impregnated in the web 3 is applied. During this time, the new web surface of the web 3 comes into contact with the surface of the fixing roller 1, so that the cleaning or coating function of the web 3 does not deteriorate over time. Has been determined.

In such a structure, when the entire web 3 is wound around the winding member 6, the end of the web 3 is connected to the unwinding member 4 and cannot be unwound. There is a problem that the web 3 cannot be rotated to take up the web 3 and the driving member 5 is damaged. In order to solve such a problem, Japanese Patent Laid-Open No. 58-1
No. 32770, JP-A-63-276079, JP-A-63-2760
The thing disclosed in 76080 gazette is proposed. Then, the end of the web 3 is detected by the detecting member, and the driving member of the winding member 6 is stopped. In this case, the number of rotations of the pressing roller constituting the pressing member 7 is detected, and the remaining amount of the web 3 is calculated and displayed. The ones
The expected length of the web 3 corresponding to the set number of transfer papers is
When the remaining length of the web 3 is exceeded, a warning is issued.

However, such a fixing device must be provided with complicated and expensive detection and control means for detecting the remaining amount of the web 3 and winding up the web 3, and also requires an end portion of the web 3. In addition, there is a problem that the web 3 cannot be used, and the web 3 is wasted. In addition to the above, when the display of the remaining amount and the warning are overlooked, the driving member as described above is used. There is a problem that it is not possible to prevent the occurrence of damage.

[0006]

In order to solve such a problem, a coupling force A between the web 3 and the unwinding member 4 is set.
And the separating force B for separating the web 3 from the unwinding member 4 within the allowable torque for the damage of the driving member 5 such that the coupling force A <the separating force B, and the web 3 is entirely a winding member. 6, the end of the web 3 is pulled out by the unwinding member 4.
It was proposed to be separated from the. However, in this case, even after the end portion of the web 3 is separated from the unwinding member 4, the pressing member 7 is continuously pressed against the fixing roller 1, so that the dirt on the surface of the fixing roller 1 is removed. And the life of the pressing member 7 is shortened.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the conventional fixing device, and to detect the remaining amount of the web and wind the web when the web is entirely wound on the winding member. However, without requiring complicated and expensive detection and control means, it is possible to prevent the drive member of the winding member from being damaged, and it is possible to use the end portion of the web, thereby wasting the web. It is an object of the present invention to provide a fixing device which does not consume any toner.

[0008]

According to the present invention, in order to achieve the above object, an invention according to claim 1 comprises a step of winding a fixing roller and a web for cleaning the fixing roller or applying oil. An unwinding member, a winding member rotated by a driving member to wind the web, and a pressing member disposed between these two members and pressing the web against the fixing roller, and the web, the unwinding member, And the separation force B for separating the web from the unwinding member within the allowable torque for the damage of the drive member, the relation being such that the connection force A is smaller than the separation force B. When the web is unwound, the pressing member is separated from the fixing roller immediately after the end of the web passes through a position where the web is sandwiched between the fixing roller and the pressing member.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a supporting member for supporting the pressing member so as to be able to be separated from the fixing roller. It is characterized in that the rotation direction is a rotation axis whose axis is parallel to the rotation axis of the roller.

[0010] The invention described in claim 3 is the invention according to claim 1 or 2.
In the invention described in (1), the pressing member comprises a rotating roller, and is rotatable in a web winding direction.

According to a fourth aspect of the present invention, there is provided the fixing roller according to any one of the first to third aspects, until the end of the web passes a position where the web is clamped between the pressing member and the fixing roller. Of the pressing member about the supporting axis of the supporting member by a moment E of a force smaller than the sum (C + D) of the friction torque C between the pressing member and the pressing member around the supporting axis of the supporting member. Are restrained from rotating.

According to a fifth aspect of the present invention, in the first aspect of the present invention, a holding member for holding the pressing member is provided after the pressing member is separated from the fixing roller. Is what you do.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First and second embodiments of the present invention shown in FIGS.
In the second embodiment, the same parts as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted. Different parts will be mainly described. In the first embodiment of the present invention shown in FIG. 1, the pressing member 7 is attached via a spring 18 to a supporting member 17 whose base end is pivotally supported by a supporting shaft 16 attached to the body 8. When the pressing member 7 is at a pressing position indicated by a dashed line pressed against the fixing roller 1, when the pressing member 7 is at a separating position indicated by a solid line separated from the fixing roller 1, Holding member abutting on support member 17
20 are attached to the body 8. The restraining member 19 and the holding member 20 are configured by a magnet or a locking claw that is unlocked by a certain force or more.

In this embodiment, during the fixing operation, the winding member 6 is driven by the driving member 5 to move the web 3 in the direction of the arrow, and the support member 17 is supported by the pressing member 7 by its own weight. The pressing member 7 is restrained at the pressing position on the web 3 and pressed by the fixing roller 1 by the force moment E of the restraining member 19 which is larger than the moment D of the force around the support shaft 16 of the member 17, and is fixed on the web 3. The dirt on the surface of the roller 1 is cleaned, or an anti-offset liquid such as silicone oil impregnated in the web 3 is applied.

When all of the web 3 is wound by the winding member 6 in this manner, the web 3 is within the allowable force A for coupling the web 3 and the unwinding member 4 and the driving member 5 to be damaged. Is separated from the unwinding member 4, the relationship between the unwinding member 4 and the separating force B satisfies the coupling force A <the separating force B. Immediately thereafter, when the end portion of the web 3 passes through the clamping portion between the fixing roller 1 and the pressing member 7, the friction between the fixing roller 1 and the pressing member 7 generates a friction torque C around the support shaft.

The friction torque C is added to the moment D of the force around the support shaft 16 of the support member 17 of the pressing member 7, and the sum (C + D) is larger than the moment E of the force of the restraining member 19. . Due to the moment (C + D) of this force, the pressing member 7 is released from the restraint by the restraining member 19, rotates in the rotation direction of the fixing roller 1, and is held at the position without abutting against the holding member 20 and vibrating. You. As a result, the web 3 does not separate from the fixing roller 1 and its surface is not stained by dirt on the surface of the fixing roller 1.

In the second embodiment of the present invention shown in FIG. 2, the pressing member 7 is constituted by a one-way clutch, a ratchet and a pawl, or the like.
Since there is no other difference except that the web 3 is constituted by a rotating roller which rotates in the rotation direction of the web 3 but does not rotate in the opposite direction, the description is omitted.

[0018]

The present invention is as described above, and includes a fixing roller, an unwinding member for winding a web for cleaning the fixing roller or applying oil, and a winding device for winding the web by rotating the driving member. And a pressing member disposed between the two members to press the web against the fixing roller, and the web is controlled within a coupling force A between the web and the unwinding member and an allowable torque against damage to the driving member. 2. The fixing device according to claim 1, wherein the relationship with the separating force B separating the unwinding member is such that the coupling force A <the separating force B. Immediately after the portion has passed the position where the fixing roller and the pressing member sandwich the same, the pressing member separates from the fixing roller. Therefore, when the entire web is wound on the winding member, the remaining amount of the web is detected and the web is detected. For winding It is possible to prevent the driving member of the winding member from being damaged without using complicated and expensive detection and control means, and it is possible to use the end portion of the web, thereby wasting the web. It has the effect of not being consumed.

According to a second aspect of the present invention, in the first aspect of the invention, there is provided a supporting member for supporting the pressing member so as to be able to be separated from the fixing roller, and the direction of separation of the pressing member by the supporting member is fixed. Since the rotation direction is the rotation axis whose axis is parallel to the rotation axis of the roller, the pressing member can be separated from the fixing roller by a simple mechanism.

The invention described in claim 3 is the first or second invention.
In the invention described in (1), the pressing member is composed of a rotating roller and is rotatable in the web winding direction, so that the pressing member rotates around the fixing roller, friction torque is eliminated, and the pressing member is moved from the fixing roller. There is an effect that it is possible to prevent the inability to separate.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the fixing roller is fixed until the end of the web passes a position where the web is clamped between the pressing member and the fixing roller. Pressing around the support shaft of the support member by the moment E of the force smaller than the sum (C + D) of the friction torque C between the pressure member and the press member and the moment D of the force around the support shaft of the support member of the press member Since the member is restrained from rotating, the web can be reliably pressed against the fixing roller even during the rotation of the fixing roller or during the web feeding operation. Etc. can be applied.

According to a fifth aspect of the present invention, in the invention of any one of the first to fourth aspects, a holding member for holding the pressing member is provided after the pressing member is separated from the fixing roller. Due to the rotational vibration of the support member around the support shaft, parts may come into contact and generate noise,
There is an effect that wear damage can be prevented.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of a first embodiment of the present invention.

FIG. 2 is a front view of a main part of a second embodiment of the present invention.

FIG. 3 is a front view of a conventional fixing device of the same type as the present invention.

FIG. 4 is a front view of a main part of the first example of the embodiment.

FIG. 5 is a front view of a main part of the second example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 heating roller 2 pressure roller 3 web 4 unwinding member 5 drive member 6 winding member 7 pressing member 8 body 9 spring 11 unfixed image 12 transfer paper 16 support shaft 17 support member 18 spring 19 restraining member 20 holding member

Claims (5)

[Claims] A fixing roller, an unwinding member for winding a web for cleaning or oil application of the fixing roller, a winding member for winding the web by being rotated by a driving member, and an intermediate member between these two members. A pressing member arranged to press the web against the fixing roller, a coupling force A between the web and the unwinding member, and a separating force B for separating the web from the unwinding member within an allowable torque for damage to the driving member. In the fixing device in which the relationship A is such that the coupling force A is smaller than the separation force B, immediately after the end of the web passes through the position where it is clamped between the fixing roller and the pressing member when the web is unwound. A fixing member, wherein the pressing member is separated from the fixing roller. And a supporting member for supporting the pressing member so as to be able to be separated from the fixing roller, wherein the separating direction of the pressing member by the supporting member is from a rotation direction having an axis parallel to the rotation axis of the fixing roller as a rotation axis. The fixing device according to claim 1, wherein: 3. The fixing device according to claim 1, wherein the pressing member includes a rotating roller, and is rotatable in a web winding direction. 4. The friction torque C between the fixing roller and the pressing member and the supporting shaft of the supporting member of the pressing member until the end of the web passes through the position where the web is clamped between the pressing member and the fixing roller. 4. A restraint so that the pressing member does not rotate around the support shaft of the support member by a moment E of a force smaller than the sum (C + D) of the moment D of the surrounding force. 3. The fixing device according to claim 1. 5. After the pressing member is separated from the fixing roller,
The fixing device according to claim 1, further comprising a holding member that holds the pressing member.