JPH05105293A - Remainder detection device of take-up roll material - Google Patents

Abstract

PURPOSE:To detect any specified remainder of a take-up roll material in a simple structure. CONSTITUTION:On a pressure welding member 21 welded.with pressure on the outer periphery of a roll part 11a of a take-up roll material 11 supported at a specified position, an electrically conductive switch contact point 23a facing an edge part 23b of an electrically conductive core 12 projected from the roll part 11a of the take-up roll material 11 and making contact with the edge part 23b after the take-up roll material 11 reaches a specified amount of remainder on the electrically conductive core 12 is provided. Consequently, this electrically conductive switch contact point 23a makes contact with the edge part 23b of the electrically conductive core 12 and makes it in the electrically conductive state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remaining amount detecting device of a winding roll material such as a web used for cleaning a fixing roller of an image forming apparatus for forming an image by an electrophotographic method. ..

[0002]

2. Description of the Related Art Various types of residual quantity detecting devices for a winding roll material of this type have been conventionally proposed. For example, the remaining amount of the cleaning web, which is consumed almost in proportion to the number of formed images, is detected by counting the number of formed images (Prior example 1).

On the other hand, JP-A-58-132770 discloses that
What is detected by contacting a cleaning web, which is a take-up roll material, with an actuator of a microswitch and fitting the actuator into a notch formed at the end or the start of the cleaning web (preceding example 2), or the cleaning web. An actuator (a prior art example 3) is disclosed in which a micro switch actuator is brought into pressure contact with a roll portion, and the remaining amount is detected by the actuator responding to a decrease in the winding diameter of the cleaning web.

Further, Japanese Patent Laid-Open No. 221876/1983 discloses that
A lever is pressed against a roll portion of the cleaning web, and a micro switch responds to a change in the inclination of the lever according to a decrease in the winding diameter of the cleaning web to detect the remaining amount of the cleaning web (prior example 4). Is disclosed.

Further, Japanese Utility Model Publication No. 49-49934 discloses that
One that optically detects the surface of the core exposed when the roll photosensitive paper is fed to the end (Prior example 5), in which the actuator of the micro switch is pressed against the feeding portion of the roll photosensitive paper, and this actuator What detects the remaining amount of the roll photosensitive paper by responding to the change of the inclination of the feeding part due to the change of the roll diameter of the paper (Prior example 6), and the change of the roll diameter of the roll photosensitive paper and the end of the roll photosensitive paper. Disclosed is a device (Prior example 7) for detecting the end of the roll photosensitive paper in response to the change of the feeding angle caused by the rotation of the winding core to move the connecting portion with the winding core. ..

[0006]

However, in the first prior art,
It is difficult to detect the remaining amount because it does not correspond to the actual amount used, and when the cleaning web is replaced with a new cleaning web, the remaining amount is erroneously detected by forgetting to reset the counter for counting. There is also a disadvantage.

Further, in the preceding examples 2, 5, and 7, only the end of the winding roll material can be detected (the preceding example 1 can detect the starting end). Therefore, it cannot be applied when detecting when the take-up roll material has been consumed up to the prescribed remaining amount and issuing a warning prompting the user to replace the take-up roll material while enabling the subsequent use. It is inconvenient because the control is to stop the use suddenly.

In the case of the prior art example 5, when it is applied to a roll photosensitive paper, there is a problem that it is partially exposed by the optical detecting means.

In the prior art examples 3, 4, and 6, the support position and eccentricity of the winding roll material, the installation position of the detection means such as the micro switch, the installation position of this interlocking member if there are those that interlock, and further those It is difficult to perform accurate detection because the dimensional error and the like influence the detection conditions and the detection conditions change for each device and for each winding roll material.

Therefore, an object of the present invention is to provide a remaining amount detecting device for a winding roll which can accurately detect a predetermined remaining amount with a simpler structure.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a roll-up roll material in the vicinity of a support position for supporting the roll-up roll material at a predetermined position by its winding core. The winding roll is provided with a pressure contact member that is pressed against the outer periphery of the roll portion, and the remaining amount of the winding roll material is detected by the displacement of the pressure contact member in response to a change in the roll diameter of the winding roll material. In the remaining amount detecting device, the pressure contact member faces the end of the conductive core protruding from the roll portion of the winding roll material, and the winding roll material reaches a predetermined remaining amount on the winding core. After that, a conductive switch contact that comes into contact with the end portion is provided, and the switch contact comes into contact with the end portion of the winding core to establish an electrical conduction state.

[0012]

According to the above construction of the present invention, the pressure contact member is located in the vicinity of the winding roll material which supports the core at a predetermined position, and is pressed against the outer circumference of the roll portion of the winding roll material. The winding roll material is fed out and used in the supported state, and the winding diameter of the roll portion decreases. At this time, the pressure contact member uniquely changes the interval between the switch contact of the pressure contact member and the end of the winding core depending only on the remaining amount of the winding roll material on the winding core. After reaching the predetermined remaining amount, the switch contact is brought into contact with the end of the core so that both the switch contact and the core are electrically conductive so that they are electrically connected to each other. , The switch contact is provided on the press contact member with an appropriate dimensional accuracy corresponding to the predetermined remaining amount, the support position and eccentricity of the winding core of the winding roll material, the installation position of the press contact member, and their dimensional accuracy. Regardless of the above, the conduction state can be obtained at the same time when the take-up roll material reaches a predetermined remaining amount state.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.
Will be described in detail with reference to.

The present embodiment shows the case of a fixing device used for fixing an image when an image is formed by an electrophotographic method.

FIG. 1 shows a schematic structure of this fixing device. An upper fixing roller 2 having a heater 1 incorporated therein is in pressure contact with a lower fixing roller 4 having a heater 3 incorporated therein.

The sheet 6 bearing the toner image 5 after the transfer of the image is guided between the upper and lower fixing rollers 2 and 4 while being guided by the guide plate 7. At this time, the toner image 5 on the sheet 6 is fused and fixed on the sheet 6 by heating and pressing by the upper and lower fixing rollers 2, 4.

The sheet 6 after fixing is separated from the upper and lower fixing rollers 2 and 4 by separating claws 7 and 8, and is sent out through a pair of discharge rollers 9.

Toner on the sheet 6 adheres to the surface of the upper fixing roller 2 at the time of the fixing, and the toner is transferred to another portion of the sheet 6 or adheres to the surface of the lower fixing roller 4 and the sheet 6 further. A so-called offset phenomenon occurs in which the image is transferred to the back surface of the sheet.

In order to prevent this, a releasing agent such as silicone oil is applied to the surface of the upper fixing roller 2 so that the toner does not adhere to it.

However, the offset cannot be reliably prevented only by applying the release agent, and foreign matter such as paper dust may adhere to the fixed image to stain it.

Therefore, the surfaces of the fixing rollers 2 and 4 are also cleaned.

In this embodiment, on the surface of the upper fixing roller 2,
A cleaning web 11 in which the surface of the upper fixing roller 2 is impregnated with a release agent in order to apply and clean the release agent.
Are in contact.

The cleaning web 11 is provided on the upper fixing roller 2 and is a detachable support shaft 2 as is well known.
This support shaft 2 is rotatably supported by 8
8 is used by being wound up by a winding roller 13 provided so as to face 8.

As well known, the winding roller 13 is also supported by a detachable drive shaft 29 so as to be detachable and rotatably driven, and is driven so as to feed the cleaning web 11 in the direction of arrow B. This feeding direction is opposite to the moving direction of the surface of the upper fixing roller 2 which is rotationally driven in the direction of arrow A.

The take-up roller 13 is driven by the AC motor 14 every time image formation is performed, for example, to take up the cleaning web 11 by a predetermined amount. As a result, the cleaning web 11 is fed by about 0.47 mm, for example, to apply a release agent to the surface of the upper fixing roller 2 and wipe off the toner and foreign matter adhering to the surface of the upper fixing roller 2.

The cleaning web 11 is the upper fixing roller 2
A coating feed roller 17 is provided in a portion in contact with the back-up roller, so that the cleaning web 11 is reliably brought into contact with the upper fixing roller 2 and moved, so that the release agent can be coated and cleaned sufficiently. Is becoming

The rotation of the motor 14 is performed by the reduction gear train 15
And a one-way clutch 16 including a spring clutch and the like, are transmitted to the drive shaft 29. The one-way clutch 1 from the reduction gear 15 to the application feed roller 17
The rotation is transmitted without going through 6.

This deceleration drive enables the above-mentioned winding up little by little, and the drive of the drive shaft 29 through the one-way clutch 16 is such that the cleaning web 11 is driven when the motor 14 is stopped.
Is trying to follow the upper fixing roller 2 and the take-up roller 13
To prevent it from rotating in the reverse direction.

It is convenient for the cleaning web 11 to detect and warn when a predetermined remaining amount has been reached and to prompt a replacement with a new cleaning web 11.

In order to do this, in this embodiment, the cleaning web 11 used is wound around a conductive core 12 made of a metal such as aluminum.

On the other hand, a conductive residual amount detecting lever 21 made of copper-based metal or the like is provided near the supporting position of the winding core 12 as shown in FIG. It is adapted to be pressed against the outer circumference of the end of the portion 11a.

The remaining amount detecting lever 21 is provided with a bent piece which is laterally removed from the roll portion 11a, and this is used as a first switch contact 23a facing the end portion of the winding core 12 projecting from the roll portion 11a. Roll part 1 of web 11
After 1a reaches a predetermined remaining amount t (FIGS. 6 and 7),
The first switch contact 23a comes into contact with the end of the winding core 12, and this end is used as a second switch contact 23b to form a remaining amount detection switch 23 that is electrically connected to each other.

For this reason, the dimension S of the first switch contact 23a from the remaining amount detecting lever 21 to the most protruding position is made equal to the predetermined remaining amount t.

As the take-up roll material 11 is fed and used, the winding diameter of the roll portion 11a decreases. At this time, the remaining amount detection lever 21 moves the core 1 of the winding roll material 11
2 according to only the remaining amount on the first switch contact 23a
And the interval between the end of the winding core 12 and the second switch contact 23b is uniquely changed.

As a result, when the take-up roll material 11 has not reached the predetermined remaining amount t, the first switch contact 23a is separated from the second switch contact 23b as shown in FIGS. After the predetermined remaining amount t is reached, the first switch contact 23a comes into contact with the second switch contact 23b as shown in FIGS. 6 and 7, and both are electrically conductive so that they are electrically connected to each other. It becomes a state.

Therefore, the support position and eccentricity of the winding core 12 of the take-up roll material 11 and the remaining amount detecting lever are simply provided by providing the first switch contact 23a with appropriate dimensional accuracy corresponding to the predetermined remaining amount t. It is possible to obtain the conduction state at the same time when the take-up roll material 11 reaches a predetermined remaining amount t regardless of the installation position of 21 and the dimensional accuracy thereof.

To determine the remaining amount of the cleaning web 11 by turning on / off the remaining amount detecting switch 23,
In this embodiment, it is as follows.

A potential V _CC is supplied to the remaining amount detecting lever 21 via a shaft 24 which pivotally supports the remaining amount detecting lever 21 as a DC power source 30.
And the core 12 is grounded.

Then, the potential of the remaining amount detecting lever 21 is compared with the reference voltage V _TH by the comparator 26, and the CPU 27 sends a signal when the potential of the remaining amount detecting lever 21 falls to the ground by turning on the remaining amount detecting switch 23. Upon receipt, it is determined that the cleaning web 11 has reached a predetermined remaining amount S.

The mounting substrate 31 shown in FIG.
The bearing 32 is made of synthetic resin so as not to interfere with the electrical discrimination.

The CPU 27 uses the cleaning web 11
When it is determined that has reached a predetermined remaining amount t, the replacement signal C of the cleaning web 11 is output and a warning is issued by display or sound.

When the predetermined remaining amount t is set to 0, the content of the warning can be adjusted to this, and if necessary, the apparatus can be forcibly stopped or the subsequent image formation cannot be performed.

FIG. 8 shows a second embodiment of the present invention. A non-lever type remaining amount detecting piece 42 directly supported by a coil spring 41 on a mounting substrate 31 detects the remaining amount of the cleaning web 11. One switch contact 23a is provided, and the remaining amount detecting piece 42 is pressed against the outer peripheral end of the winding portion 11a of the cleaning web 11 by the bias of the coil spring 41, so that the cleaning web 11a has a predetermined remaining amount t.
When it reaches, the first switch contact 23a comes into contact with the second switch contact 23b, and it is possible to detect that the predetermined remaining amount t is reached. The voltage is applied to the first switch contact 23a via the coil spring 41.

As a result, the structure of the second embodiment is simpler than that of the first embodiment.

Although the core 12, the remaining amount detecting lever 21, and the remaining amount detecting piece 42 are all made of the same metal in each of the above embodiments, the first and second switch contacts 23a, 23 are formed.
Similar effects can be obtained even if only the portion b is made conductive.

[0046]

According to the present invention, the pressure contact member located in the vicinity of the take-up roll material that supports the winding core at a predetermined position is brought into pressure contact with the outer circumference of the roll portion of the take-up roll material, The gap between the switch contact of the pressure contact member and the end of the core is uniquely changed depending only on the remaining amount on the winding core, and after the winding roll material reaches the predetermined remaining amount, the switch contact The switch contact and the core so that they are electrically conductive with each other because both the switch contact and the core are electrically conductive. It is possible to set the remaining amount of winding roll material regardless of the support position and eccentricity of the winding core of the winding roll material, the installation position of the pressure contact member, and their dimensional accuracy, simply by providing the appropriate dimensional accuracy. To obtain the conduction state at the same time when Can, also what the remaining amount of the take-up roll material by a simple structure can be detected accurately.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing a remaining amount detection mechanism of a cleaning web of the fixing device of FIG.

FIG. 3 is a block connection diagram of a remaining amount detection mechanism and a control unit in FIG.

FIG. 4 is a cross-sectional view showing a state before the predetermined remaining amount of the remaining amount detection mechanism of FIG. 2 is reached.

5 is a side view showing a state before the predetermined remaining amount of the remaining amount detecting mechanism in FIG. 2 is reached.

6 is a cross-sectional view showing a case where a predetermined remaining amount state of the remaining amount detecting mechanism of FIG. 2 is reached.

7 is a side view showing a case where a predetermined remaining amount state of the remaining amount detecting mechanism of FIG. 2 is reached.

FIG. 8 is a perspective view of a remaining amount detecting mechanism showing a second embodiment of the present invention.

[Explanation of symbols]

 11 Cleaning Web 11a Winding Part 12 Core 13 Winding Roller 14 Motor 21 Remaining Amount Detection Lever 22 Spring 23 Remaining Amount Detection Switch 23a First Switch Contact 23b Second Switch Contact 41 Coil Spring 42 Remaining Amount Detection Piece t Remaining amount

Claims (1)

[Claims] 1. A roll of winding roll material is provided in the vicinity of a support position for supporting the winding roll material at a predetermined position with its winding core, the pressing member being in pressure contact with the outer circumference of the roll portion of the winding roll material. A remaining amount detection device for a winding roll configured to detect the remaining amount of the winding roll material by the displacement of the pressure contact member in response to a change in diameter, wherein the pressure contact member includes a roll portion of the winding roll material. A conductive switch contact is provided which faces the end of the conductive core projecting from the core and contacts the end after the winding roll material reaches a predetermined remaining amount on the core. A device for detecting the remaining amount of a winding roll material, wherein a contact is brought into contact with an end portion of the winding core so as to be in an electrically conductive state.