JPH0764429A - Image forming device - Google Patents

Abstract

PURPOSE:To surely detect that web is empty by moving a moving member to another position when the amount of remaining web is decreased below a predetermined amount, and detecting the moving member. CONSTITUTION:A moving member 37, which, when more than a predetermined amount of web W is wound on a feed roller 25 with a fixing unit 8 mounted in a main body storage portion 4, is kept from moving by a remaining amount display member 28 so as to be located in a first position, and which, when the amount of web remaining on the feed roller 25 is decreased below a predetermined amount, is released from the remaining amount display member 28 so as to move to a second position, is provided, and a sensor 41 detects the movement of the moving member 37 from first to second position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image provided with a fixing device for contacting a web for heating and fixing the toner adhering to a transfer material such as a sheet with a web and cleaning the outer peripheral surface of the roll with the web. Forming apparatus

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus, one having a fixing device 50 shown in FIG. 10 is known. In the fixing device 50, the heating roller 51 includes a heater 52. The pressure roller 53 is arranged in parallel below the heating roller 51 and is in pressure contact with the lower outer peripheral surface of the heating roller 53. The sheet P having a toner image formed on the upper surface by an image forming process (not shown) is conveyed from the direction of arrow i toward the contact portion between the heating roller 51 and the pressure roller 53. Then, the sheet P that has entered the contact portion is nipped by the heating roller 51 and the pressure roller 53, conveyed based on the rotation of the heating roller 51 and the pressing roller 53 in the directions of the arrows j and k, and the toner applied by the heat applied from the heating roller 51 It is fixed. On the other hand, when the toner is fixed, the heating roller 51
The toner adhered to is removed by the web type cleaning device 54.

The cleaning device 54 includes a supply roll 55, a take-up roll 56, a feed roller 57, and a remaining amount indicating plate 58.
The feed roller 57 is pressed against the outer peripheral surface of the heating roller 51. A web W containing oil is wound around the supply roll 55, and one end side of the web W passes through the contact portion between the feed roller 57 and the heating roller 51 and is fixed to the winding roll 56, and is heated at the contact portion. The heating roller 5 removes the toner adhering to the roller 51.
Apply oil to the outer peripheral surface of 1. The remaining amount indicating plate 58 is rotatably supported by a support shaft 59, contacts the web W wound around the supply roll 55, and has its tip end protruding from a slit 60 formed in the casing 59. Therefore, the remaining amount of the web W wound around the supply roll 55 can be known by observing the remaining amount indicating plate 58 protruding from the slit 60.

[0004]

However, in the remaining amount detecting method for the web W, although the remaining amount indicating plate 58 moves along the slit 60 according to the remaining amount of the web, the remaining amount indicating plate 58 is observed. You can tell that the remaining amount of the web is low by just doing it, but it is possible to distinguish whether it is not enough to replace with a new web or whether it is an emergency because the remaining amount of the web is extremely small. I didn't. A method of providing a sensor such as a photo interrupter and confirming the position of the remaining amount indicating plate 58 with this may be considered, but the remaining amount indicating plate 5 is located at a position just near the detection position of the sensor.
8 is present, there is a problem that the sensor causes chattering due to vibrations caused by driving the image forming apparatus, vibrations caused by operation, or fluctuations in the remaining amount indicating plate due to expansion of the web itself.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention has been made to solve the above-mentioned problems, and a supply roll for sending out a web to an image forming apparatus and a fixing roller for fixing the web sent out from the supply roll. And a pressing member for contacting the fixing roller, a winding roll that winds the web that has passed through the contact portion with the fixing roller, and a remaining amount indicating member that moves according to the web winding amount of the supply roll, and a fixing unit. In the accommodating portion of the fixing unit, and when the fixing unit is mounted in the accommodating portion, when the supply roll is wound with more web than the predetermined amount, the remaining amount indicating member moves the web. A moving member which is regulated and is located at the first position, and which moves to the second position outside the regulation of the remaining amount indicating member when the remaining amount of the web of the supply roll becomes smaller than the predetermined amount; Moving member from the first position second
The image forming apparatus main body is provided with a detection member that detects that the image forming apparatus has moved to the position.

[0006]

In the image forming apparatus, the fixing unit is mounted on the mounting portion of the image forming apparatus body. In this unit mounted state, when the web winding amount of the supply roll that sends out the web is equal to or larger than the predetermined amount, the moving member is restricted by the remaining amount indicating member and is located at the first position. On the other hand, when the web winding amount of the supply roll decreases and becomes smaller than the predetermined amount, the moving member moves out of the regulation of the remaining amount indicating member and moves to the second position. Further, the moving member of the detecting member is moved from the first position to the second position.
It detects that it moved to the position of.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a state in which a front cover 2 of an image forming apparatus 1 such as a copying machine or a printer is opened, and a main body 3 of the image forming apparatus is provided with a fixing unit accommodating portion 4 which is open toward a front side, that is, an operating side. ing. Storage part 4
A guide 5 is provided at the bottom of the guide from the operation side to the back side. As shown in FIGS. 3 and 4, a connector 6 and a web remaining amount detecting device 7 are provided on the inner side of the accommodating portion 4.

The fixing unit 8 has a box-shaped casing 9 as shown in FIGS. Casing 9
Is composed of an upper frame 10 with an open bottom, a lower frame 11 with an open top, and side frames 12, 13 that connect the ends of the upper and lower frames 10, 11 together. A sheet inlet 14 and a sheet outlet 15 are formed between the sheets, and sheet guides 16 and 17 are provided inside them. A web remaining amount detection hole 18 is formed in the back side frame 12,
A connector 19 and a motor 20 connected to the connector 19 are provided.

The heating roller 21 has a heater 22 at its center and is rotatably provided above the line connecting the paper guides 16 and 17, and the heater 22 is connected to a connector 19. The pressure roller 23 is rotatably provided in parallel with the heating roller 21 and in pressure contact with the bottom of the heating roller 21. Then, the heating roller 21 and the pressure roller 23
Are rotated in the directions of arrows a and b based on the drive of the motor 20, respectively.

The web type cleaning device 24 includes the supply roll 2
5, a winding roll 26, and a feed roller 27, which are arranged in parallel above the heating roller 21 and are in contact with the outer peripheral surface of the heating roller 21.
The take-up roll 26 is drivingly connected to the motor 20 and rotates in the direction of arrow e based on the drive of the motor 20. Further, the web W is wound around the supply roll 25, and the leading end side of the web W is fixed to the take-up roll 26 via the feed roller 27, and the outer periphery of the heating roller 21 is at the contact portion between the feed roller 27 and the heating roller 21. It is in contact with the surface. It is not necessary for the roller to bring the web W into contact with the heating roller 21. The remaining amount indicating plate 28 is rotatably supported above the supply roll 25 via a shaft 29 parallel to the supply roll 25, and is pressed against the outer peripheral portion of the web W wound around the supply roll 25 by a spring 30. The remaining amount indicating plate 28 rotates in the direction of arrow f as the remaining amount of the web W wound around the supply roll 25 decreases. Further, a wall 31 extending in the vertical direction is provided at the rear end portion of the remaining amount indicating plate 28, and this wall 31 is located on the extension of the remaining amount detecting hole 18 when the remaining amount of the web is large, and When the remaining amount is reduced and the replacement becomes necessary, the remaining amount detecting hole 18 is retracted from the extension.

As shown in FIGS. 3, 4, 6 and 7, the detection device 7 is provided with a pair of walls 33 and 34 facing each other at a predetermined interval on the frame 32, and these walls 33 and 34 are formed on these walls 33 and 34. Two through holes 35 and 36 are formed on the same straight line. The rod 37 has a head portion 38 having a larger diameter than the through holes 35 and 36 on the tip side, and is inserted into the through holes 35 and 36 from one end side of the frame 32, and is located in a portion located between the walls 33 and 34. The stopper 39 is fixed, and a coil spring 40 is wound around a portion located between the stopper 39 and the wall 34, and is biased by the coil spring 40 in the arrow g direction. The sensor 41 is fixed to the frame 32 behind the wall 34, and detects the rod 37 that has moved in the direction of the arrow g ′ against the biasing force of the coil spring 40. The detection device 7 is fixed to the main body 3 via the frame 32 with the head 38 of the rod 37 facing the unit 8 on the back side of the unit housing portion 4.

In the image forming apparatus 1 having the above structure,
The front cover 2 is opened, and the unit 8 is attached to the accommodation portion 4 along the guide 5. At this time, the connectors 6 and 19 are connected and the rod 37 is inserted into the web remaining amount detection hole 18. Further, if the web W is sufficiently wound around the supply roll 25 of the cleaning device 24, the rod head 38 abuts the wall 31 of the remaining amount indicating plate 28 when the fixing unit 8 is loaded, and from that state, When the fixing unit 8 is pushed in, the pushing force causes the rod 37 to retract in the direction of the arrow g ′, and the sensor 41 detects the rod 37. The output of the sensor 41 is output to the control device (not shown) of the main body 3 via the connectors 6 and 19. The motor 20 of the unit 8 is connected to the power source (not shown) of the main body 3 via the connectors 6 and 19.

In the unit 8 mounted on the main body 3, as shown in FIG.
As shown in FIG.
When it is conveyed from the direction, the heating roller 21 and the pressure roller 23 are driven by the motor 20, and the heating roller 21 and the pressure roller 23 respectively move in the directions indicated by arrows a,
Rotating in the b direction, the heater 22 is heated to the temperature required for fixing the toner. Then, the sheet P is heated while being held by the contact portion between the heating roller 21 and the pressure roller 23 to fix the toner, and is ejected to a tray (not shown) by the sheet ejection roller 42 provided in the main body 3.

In the cleaning device 24, the roll 26 rotates in the direction of arrow e, and the web E is wound around the roll 26. Then, the web W sent from the supply roll 25
Contacts the outer peripheral surface of the heating roller 21 at the contact portion between the feed roller 27 and the heating roller 21, removes the toner adhering to the heating roller 21 during fixing, and removes the oil contained in the web W to the heating roller 21. Apply. The feed amount of the web W is generally about 0.1 mm per sheet.

As the web W is consumed in this manner, the remaining amount of the web on the supply roll 25 decreases, and the remaining amount indicating plate 2
8 rotates in the direction of arrow f. Then, when the remaining amount of the web is reduced to a state where the web should be replaced with a new one, the remaining amount indicating plate 28 is retracted from the extension of the remaining amount detecting hole 18. At this time, the wall 31 disengages from the rod 37 that has been in contact with the wall 31 until then, the rod 37 moves in the direction of arrow g by the urging force of the coil spring 40, and the sensor 41 is turned off. Further, the control device of the main body 3 detects the OFF signal of the sensor 41, and as shown in FIG.
Display web empty on. The same unit 8
As long as is attached to the main body 3, the remaining amount indicator plate 28 is not restricted by the rod 37 and returns backward (that is, rotates in the direction opposite to the arrow f direction), and the off state of the sensor 41 is maintained. Further, even if the unit 8 in the web-empty state is pulled out from the main body 3 and is reattached to the accommodating portion 4, since the wall 31 is retracted from the extension of the remaining amount detection hole 18 and the rod 37, the sensor 41 is turned on. It never returns to the state. However, a new web W is added to the supply roll 25.
When is attached, the remaining amount indicating plate 28 returns to the position shown in FIG. Therefore, when the unit 8 with the web W replaced is mounted on the main body 3, the rod 37 causes the wall 31 of the remaining amount indicating plate 28 to move.
Then, the sensor 41 is switched to the ON state.

[0016]

As is apparent from the above description, in the image forming apparatus according to the present invention, more webs than the predetermined amount are wound around the supply roll in the state where the fixing unit is mounted in the main body accommodating portion. When the moving member is being moved, the moving member is located at the first position with its movement restricted by the remaining amount indicating member. However, when the web remaining amount of the supply roll becomes less than the predetermined amount, the moving member moves out of the regulation of the remaining amount indicating member and moves to the second position. That is, when the remaining amount of the web becomes less than a certain amount, the web is moved to another position. Therefore, by detecting that the moving member has moved from the first position to the second position by the detection member, it can be confirmed that the web has surely reached the predetermined amount or less.

[Brief description of drawings]

FIG. 1 is a partial perspective view of an image forming apparatus with a front cover opened.

FIG. 2 is a perspective view of a fixing unit.

FIG. 3 is a perspective view showing a state in which a fixing unit is attached to a main body accommodating portion.

FIG. 4 is a perspective view showing a state in which the fixing unit is mounted in the main body accommodating portion.

FIG. 5 is a sectional view of a fixing unit.

FIG. 6 is a perspective view of a remaining amount detecting device.

FIG. 7 is a plan view of a remaining amount detecting device.

FIG. 8 is a side view of the cleaning device.

FIG. 9 is a plan view showing a display unit of the image forming apparatus.

FIG. 10 is a sectional view of a conventional fixing device.

FIG. 11 is a diagram showing a display state of a web remaining amount by a conventional fixing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 3 ... Image forming apparatus main body, 4 ... Fixing unit accommodating part, 7 ... Remaining amount detecting device, 8 ... Fixing unit,
21 ... Heating roller, 23 ... Pressure roller, 24 ... Cleaning device, 25 ... Supply roll, 26 ... Winding roll, 27 ... Feed roller, 28 ... Web remaining amount indicating plate, 31 ... Wall, 37 ... Rod, 41 ... Sensor, W ... Web.

Claims (1)

[Claims] 1. A supply roll for sending out a web, a pressing member for bringing the web sent out from the supply roll into contact with a fixing roller, a winding roll for winding up the web passing through a contact portion with the fixing roller, A fixing unit having a remaining amount indicating member that moves according to the web winding amount of the supply roll, an accommodating portion of the fixing unit, and a fixing unit mounted in the accommodating portion, the fixing roller being attached to the supply roll. When more web than the predetermined amount is wound, the movement is restricted by the remaining amount indicating member and the web is located at the first position, and when the web remaining amount of the supply roll becomes smaller than the predetermined amount, An image forming apparatus including a moving member that moves to a second position out of the regulation of the remaining amount indicating member, and a detection member that detects that the moving member has moved from the first position to the second position. An image forming apparatus comprising: a main body.