JPH1020702A - Paper separating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure an operator's safety when a separating claw is moved back from the surface of a fixing roll in a copying machine in which a unit including a fixing device is provided in such a way that it can be pulled out of a copying machine main body. SOLUTION: This paper separating device includes a separating claw 30 for a heat roll and a separating claw 38 for a pressure roll, both of which are used in a fixing device provided in such a way that it can be pulled out of an image forming device main body. In this case, the paper separating device includes a first support member 23, which is provided in such a way as to be turnable relative to a frame 22 accommodating the heat roll 14 and the pressure roll 15, and which is capable of taking a position where it brings the heat roll separating claw 30 into contact with the heat roll 14 and a position where it shifts the separating claw 30 back from the heat roll 14, and a second support member 25 which is freely turnably provided at the loose end of the first support member 23 to support the heat roll separating claw 30. When the first support member 23 is rotated to the retreat position of the heat roll separating claw 30, the first support member 25 is turned in the opposite direction to the turning direction of the first support member 23 so as to point the end of the heat roll separating claw 30 toward the first support member 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine, and at least one of fixing a toner image transferred onto a copy sheet by heat or pressure, peels the sheet from a fixing device of a roll. The present invention relates to a paper peeling device.

[0002]

2. Description of the Related Art In a roll-type fixing device, a sheet passing through a nip portion between a pair of fixing rolls composed of a roll and a pressure roll is fixed on the fixing roll due to adhesiveness generated when toner is melted. Tend to wrap around. Conventionally, in order to prevent the paper from being wound, a peeling claw that comes into contact with the surface of the fixing roll is provided, and the sheet is peeled from the surface of the fixing roll with the tip of the peeling claw. Further, in the fixing device, when a jam (paper jam) occurs, a mechanism is adopted in which the peeling claw can be retracted from the surface of the fixing roll so that the jam can be easily removed.

[0003]

However, since there is generally no space around the fixing device accommodating portion of the copying machine to sufficiently separate the peeling claw from the fixing roll, the jam is removed. At this time, there is a possibility that the operator's hand touches the tip of the peeling claw to injure the hand.

[0004] In order to prevent the operator from being injured when removing the jammed paper, when the peeling claw is retracted from the surface of the fixing roll, the tip of the peeling claw is directed upward to prevent the operator from being injured. Japanese Patent Publication No. 4-43268 discloses a paper peeling device that prevents a hand from directly contacting the tip of a peeling claw.

On the other hand, in order to facilitate the removal of jammed paper and the repair and maintenance of the copying machine, a fixing device or an image forming apparatus including the fixing device is unitized, and the unit including the fixing device is provided in the copying machine main body. On the other hand, a copier provided so as to be able to be pulled out in the front-rear direction is known.

In a copying machine in which a unit including the fixing device is provided so as to be able to be pulled out from the body of the copying machine,
When this unit is pulled out of the copier body, the upper surface of the fixing device is exposed to the outside. For this reason, when the paper peeling device described in the above publication is applied to this type of fixing device, the tip of the peeling claw faces upward when the peeling claw is retracted from the surface of the fixing roll. This is very dangerous when the operator including the fixing device is pulled out of the main body to perform maintenance and inspection.

To prevent such a danger, it is conceivable to provide a cover member for covering the tip of the peeling claw. However, there is a problem that the cost increases and the unit including the fixing device becomes large. Occurs.

Further, in the paper peeling device described in the above-mentioned publication, only the peeling claw for the heating roll can be retracted. Therefore, when the paper is wound around the pressure roll,
There is a problem that it is difficult to remove the jammed paper.

Accordingly, the present invention secures safety for an operator when a peeling claw is retracted from the surface of a fixing roll in a copying machine in which a unit including a fixing device is provided so as to be able to be pulled out from the copying machine body. The task is to Another object of the present invention is to make it possible to easily cope with a jam on the pressure roll side.

[0010]

According to the present invention, at least one is a roll, and the other is a press-contact member which presses against the roll, and at least one of which has a heat source and can be pulled out from the image forming apparatus main body. A paper peeling device used in the provided fixing device, wherein the paper peeling device comprising a roll peeling claw contacting the surface of the roll and a pressure contact member peeling claw contacting the surface of the pressure contact member, A first support member rotatably provided with respect to a frame accommodating the roll and the pressure contact member, and a first support member capable of taking a position where the roll peeling claw contacts the roll and a position where the claw is retracted from the roll; A second support member rotatably provided on the free end side of the first support member and supporting the roll peeling claw, wherein the first support member is peeled off by the roll. When pivoted to the retracted position of said second
Is rotated in the direction opposite to the direction of rotation of the first support member, so that the tip of the peeling claw for the roll faces the first support member.

Further, according to the present invention, a part of the second support member constitutes an upper sheet guide plate of a pair of sheet guide plates for guiding a sheet passing between the roll and the pressing member. It is characterized by being.

Further, the present invention is characterized in that the peeling claw for the pressure contact member and the lower sheet guide plate of the pair of sheet guide plates move integrally with the second support member.

Further, according to the present invention, a third support member is provided rotatably with respect to the frame, and the third support member retracts the peeling claw for the press-contact member from the press-contact member, and is rotatable by the third support member. And a fourth support member for supporting the peeling claw for the pressure contact member, wherein when the third support member is rotated to the retracted position of the peeling claw for the pressure contact member, the fourth support member The tip of the peeling claw is directed to the third support member side by the rotation.

Further, according to the present invention, the fourth support member includes:
When the third support member is rotated to the normal position, a stopper is formed which collides with a part of the frame to change the direction of the fourth support member.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a sheet peeling apparatus according to the present invention.

FIG. 1 is a schematic sectional view showing the principle configuration of a copying machine to which the sheet peeling device of the present invention is applied. Image reading for reading an image of a document (not shown) placed on a platen glass (not shown) and covered with a platen cover 1 on the top of the copier, and converting the image into an electric image signal The device 2 is arranged. An image signal from the image reading device 2 is supplied to an exposure device 3, and a laser beam modulated by the image signal is transmitted from the exposure device 3 to the photosensitive drum 4.
Is irradiated. Since the surface of the photosensitive drum 4 is uniformly charged by the charging corotron 5, an electrostatic latent image is formed on the surface of the photosensitive drum 4 by exposure. This electrostatic latent image is developed by the developing device 6. In the present embodiment, a rotary developing device is used as the developing device 6, and four electrostatic latent images sequentially formed on the photosensitive drum 4 are converted into four color toners of yellow, magenta, cyan, and black. In order to form yellow, magenta, cyan, and black color toner images on the photosensitive drum 4. The transfer drum 7 is provided in pressure contact with the photosensitive drum 4.

On the other hand, the sheet fed from one of the paper feed trays 8a, 8b, 8c or the manual feed tray 8d is
The charged corotron 9 electrostatically attracts the surface of the transfer drum 7. When the sheet passes through the nip between the photosensitive drum 4 and the transfer drum 7 according to the rotation of the transfer drum 7, the color toner image on the photosensitive drum 4 is transferred to the sheet on the transfer drum 7 by the transfer corotron 10. The sheet on which the toner image of the first color (for example, yellow) has been transferred passes through the charge removing corotron 11 as the transfer drum 7 rotates.
After the charge on the transfer drum surface is erased, the toner is sent again to the nip portion between the photosensitive drum 4 and the transfer drum 7, and the color toner image of the second color (for example, magenta) is transferred to the paper on the transfer drum 7. . Similarly, a third color (for example, cyan) and a fourth color (for example, cyan) for each rotation of the transfer drum 7.
The black (color) toner image is transferred to the paper on the transfer drum 7, and the four color toner images are multiplex-transferred onto the paper to form a full-color toner image.

The paper on which the full-color toner image is formed is peeled off from the surface of the transfer drum 7 by the peeling corotron 12 and is fixed by passing through the nip between the heating roll 14 and the pressure roll 15 of the fixing device 13. After receiving the processing, it is discharged to the copy receiver 16.

In the copying machine shown in FIG.
And its peripheral components are integrally configured as a transfer unit 17, and the heating roll 14 and the pressure roll 15 of the fixing device 13 and the peripheral components are integrally configured as a fixing unit 18. Then, the transfer unit 1
The fixing unit 7 and the fixing unit 18 can be pulled out in the front-rear direction with respect to the copying machine main body.

FIG. 2 shows the transfer unit 17 from the copying machine main body.
FIG. 3 is a perspective view illustrating a state in which the fixing unit 18 is pulled out. The fixing unit 18 is configured integrally with the transfer unit 17 in a state where the fixing unit 18 is attached to the transfer unit 17.
A telescopic rail 19 is provided between the lower portion of the transfer unit 17 and the copying machine main body so that the transfer unit 17 and the fixing unit 18 can be pulled out in the front-rear direction with respect to the copying machine main body.
Is provided.

The transfer unit 17 and the fixing unit 18
Opening the front cover 20 which can be freely opened and closed on the front surface of the copying machine main body, turning the lever 21 in a predetermined direction to release the locked state between the transfer unit 17 and the fixing unit 18 and the copying machine main body, By pulling 21 forward, it can be pulled out from the copier body.

Hereinafter, several embodiments of the paper peeling device used in the above-described fixing unit 18 will be described.

[Embodiment 1] FIG. 3 is a schematic sectional view showing Embodiment 1 of a paper peeling apparatus of the present invention. Fixing unit 1
The heating roll 14 and the pressure roll 15 are provided in a state of being pressed against each other inside the frame 22 constituting the housing 8. A plate-like first support member 23 is provided on the side surface of the fixing unit 18 in the sheet discharging direction so as to be openable and closable with respect to the fixing unit 18. The base end of the first support member 23 is rotatably supported by the upper end of the frame 22 on the sheet discharge side via a rotation support shaft 24. A second support member 25 is rotatably supported by a support plate 39 formed at the free end of the first support member 23 via a rotation support shaft 26. One end 27a of the second support member 25 is bent in an L-shape, and the other end 2
An L-shaped peeling claw support arm 28 is attached to 7b via a rotation support shaft 29. Peeling claw support arm 2
8 is provided with a heating roll peeling claw 30 which comes into contact with the surface of the heating roll 14, and is provided between the other end and the hook 31 formed on the rotary support shaft 26 and the second support member 25. , A tension spring 32 is stretched. Further, a leaf spring 33 is provided on the second support member 25 so as to cover the other end of the peeling claw support arm 28.
Further, a stopper 35 projecting from a part of the support plate 34 supported by the rotation support shaft 26 of the second support member 25 in a direction perpendicular to the paper surface is formed. Further, a tie bar 36 is provided near the rotation support shaft 26 and connected between a pair of frames 22 arranged at a certain interval in a direction perpendicular to the paper surface. The pressure roll 15 is also provided with a pressure roll peeling claw 38 about the rotation support shaft 37 as the center of rotation.

An upper paper guide plate 40 is integrally formed at the end of the second support member 25 on the side of the peeling claw 30 for the heating roll, and the lower paper guide plate 4 is formed on the pressure roll 15 side.
1 is provided in a state fixed to the frame 22.

Next, the operation of the sheet peeling apparatus according to the first embodiment of the present invention shown in FIG. 3 will be described. At the time of normal operation, the first support member 23 and the second support member 25 are at the normal position indicated by the symbol A, and the tip of the peeling claw 30 for the heating roll is in a state of being in contact with the surface of the heating roll 14. . Further, the tip of the peeling claw 38 for the pressure roll is always a pressure roll 1.
5 is in contact with the surface. Therefore, even if the paper that has passed through the nip between the heating roll 14 and the pressure roll 15 adheres to the surface of the heating roll 14 or the pressure roll 15, unless the adhesion is very strong, the heating The peeling can be performed by the roll peeling claw 30 or the pressure roll peeling claw 38. The paper that has passed through the nip between the heating roll 14 and the pressure roll 15 is guided by the upper paper guide plate 40 and the lower paper guide plate 41 and is discharged to the paper receiver 16.

Next, when a paper jam occurs for some reason, the first support member 23 is rotated clockwise in FIG. Rotate. In the drawings, dashes are attached to the reference numerals of the respective members at the retracted position. At this time, the second support member 25 rotates counterclockwise by its own weight about the rotation support shaft 26, and the stopper 35 formed on the second support member 25 causes the first support member 23 to play. By colliding with the support plate 39 formed at the end, the attitude of the second support member 25 is determined. Thereby, the peeling claw 3 for the heating roll
The leading end of 0 faces the first support member 23 side, that is, the lower side. Therefore, even when the operator brings his hand close to the fixing device in order to remove the jammed paper, his / her hand does not touch the tip of the peeling claw 30 for the heating roll and does not get hurt.

Next, after removing the jammed paper, the first
The support member 23 is rotated counterclockwise around the rotation support shaft 24 and returned to the original position. At this time, the leaf spring 33 provided on the second support member 25 comes into contact with the tie bar 36 and Then, the peeling claw 30 for the heating roll is pushed down.
Thereby, the tip of the heating roll peeling claw 30 does not collide with the surface of the heating roll 14 at an angle close to a right angle, and it is possible to prevent the surface of the heating roll 14 from being damaged.

[Embodiment 2] FIG. 4 is a schematic sectional view showing Embodiment 2 of the paper peeling apparatus of the present invention. Example 1
The members corresponding to are denoted by the same reference numerals.

In the first embodiment, the second support member 25 is rotated by its own weight when the first support member 23 is rotated to the retracted position around the rotation support shaft 24. In the second embodiment, the rotation support shaft 26
A coil spring 42 is provided to bias the second support member 25 in a counterclockwise direction, that is, a direction in which the tip end of the heating roll peeling claw 30 faces the first support member 23 side. Thus, the second support member 25 receives not only its own weight but also the force of the coil spring 42 when it is at the retracted position, so that the tip of the peeling claw 30 for the heating roll surely faces the first support member 23 side. Can turn. However, the strength of the coil spring 42 is set such that the first support member 23 is pushed back by its own weight to the second support member 25 when returning to the normal position.

[Embodiment 3] FIG. 5 is a schematic sectional view showing Embodiment 3 of the paper peeling apparatus of the present invention. Example 1
The members corresponding to are denoted by the same reference numerals.

In the third embodiment, the second support member 25
An extension 43 is formed by extending the end on the side of the peeling claw 30 for the heating roll, and a peeling claw 38 for the pressure roll is provided at the tip of this extension 43 with the rotation support shaft 37 as the center of rotation. I have.

In the normal state, the first supporting member, the second supporting member, the peeling claw for the heating roll 14, and the peeling claw for the pressure roll 15 are located at positions indicated by reference numerals 23, 25, 30, and 38, respectively. However, when a paper jam occurs, the first support member 23 is rotated about the rotation support shaft 24 to the retracted position. At this time, the second support member 25 is
, The stopper 35 formed on the second support member 25 collides with a support plate 39 formed on the free end of the first support member 23, and the second support member 25 is rotated. 25
Stops.

In the third embodiment, since the peeling claw 38 for the pressure roll for the pressure roll 15 also retreats together with the peeling claw 30 for the heating roll for the heating roll 14, the pressure roll 15
If a paper jam occurs on the side, it can be easily removed.

[Embodiment 4] FIG. 6 is a schematic sectional view showing Embodiment 4 of the paper peeling apparatus of the present invention. Example 1
The members corresponding to are denoted by the same reference numerals.

The retracting mechanism of the heating roll peeling claw 30 for the heating roll 14 in the fourth embodiment is the same as that shown in the first embodiment.

In the fourth embodiment, the base end of the third support member 44 is rotatably supported at the lower end of the frame 22 on the sheet discharge side via a rotation support shaft 45. Third
A base end of a fourth support member 47 is rotatably supported via a rotation support shaft 48 at a distal end of a lever 46 integrated with the support member 44. Further, a lever portion 49 and a lower paper guide plate 50 are formed integrally with the fourth support member 47. A stopper 51 projecting in a direction perpendicular to the paper surface is formed at an end of the lower paper guide plate 50 on the downstream side in the paper transport direction. In addition, the fourth support member 4
7, a rotation support shaft 37 is provided on a support plate 52 formed integrally therewith.
The peeling claw 38 for the pressure roll is rotatably supported via the.

In the normal state, the peeling claw 30 for the heating roll and the peeling claw 38 for the pressure roll are in contact with the heating roll 14 and the pressure roll 15, and Is peeled off.

When a paper jam occurs, the operator holds the lever 46 integrated with the support member 44 by hand, and as shown in FIG. Rotate. At this time, the fourth support member 47
Rotates in the clockwise direction in the figure by its own weight around the rotation support shaft 48, so that the posture shown by the reference numeral C in FIG. 7 is obtained, and the tip of the peeling claw 54 for the pressure roll 15 is positioned inside the fixing unit 18. Turn around. Therefore, even if a paper jam occurs in the pressure roll 15, the jammed paper can be easily removed. Further, the tip of the peeling claw 54 is not touched by the operator's hand, so that it is safe.

Next, after removing the jammed sheet, the operator holds the lever portion 49 formed integrally with the fourth support member 47 by hand and moves the lever portion 49 to a normal position around the rotation support shaft 45. Returning, the stopper 51 provided on the fourth support member 47 collides with the frame 22 as shown by reference numeral D in FIG. It rotates counterclockwise about the contact position with the center of rotation. Therefore, the direction of the tip of the peeling claw 54 changes from the lower right direction to the upper right direction, and contacts the surface of the pressure roll 15 along the surface of the pressure roll 15 as shown in FIG. Accordingly, the tip of the peeling claw 54 does not collide with the surface of the pressure roll 15 at an angle close to a right angle, and the surface of the pressure roll 15 can be prevented from being damaged.

In the above-described embodiment, the fixing unit 18 is integrally formed with the transfer unit 17 while being attached to the transfer unit 17, so that the fixing unit 18 and the transfer unit 17 are simultaneously pulled out. However, the fixing unit and the transfer unit 17 can be pulled out independently, or the fixing unit 18
The present invention can also be applied to a device that allows only the pull-out.

[0041]

According to the paper peeling apparatus of the present invention, when the peeling claw is moved to the retracted position, the tip of the peeling claw does not face upward, so that the unit including the fixing device can be moved from the image forming apparatus main body. Even in a device that can be pulled out, the operator's hand does not touch the tip of the peeling claw when the jammed paper is removed, and the safety of the operator can be ensured.
Also, paper jams in the pressure roll can be easily removed.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a basic configuration of a copying machine to which a sheet peeling device of the present invention is applied.

FIG. 2 is a perspective view showing a state in which a transfer unit and a fixing unit are pulled out from a copying machine main body.

FIG. 3 is a schematic sectional view showing Embodiment 1 of the paper peeling device of the present invention.

FIG. 4 is a schematic sectional view showing a second embodiment of the paper peeling device of the present invention.

FIG. 5 is a schematic sectional view showing Embodiment 4 of the paper peeling device of the present invention.

FIG. 6 is a schematic cross-sectional view illustrating a normal state of a sheet peeling apparatus according to a fifth embodiment of the present invention.

FIG. 7 is a schematic sectional view showing a retracted state of a sheet peeling apparatus according to a fifth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Platen cover, 2 ... Image reading device, 3 ... Exposure device, 4 ... Photoconductor drum, 5 ... Charging corotron, 6 ... Developing device, 7 ... Transfer drum, 8a, 8b, 8c ... Feeding tray, 9 ... Charging Corotron, 10 transcription corotron ..., 11
... Electrostatic removing corotron, 12 ... Peeling corotron, 13 ... Fixing device, 14 ... Heating roll, 15 ... Pressurizing roll, 16 ... Copy receiving, 17 ... Transfer unit, 18 ... Fixing unit,
19 ... telescopic rail, 20 ... front cover, 21 ... lever, 22 ... frame, 23 ... first support member, 24 ... rotation support shaft, 25 ... second support member, 26 ... rotation support shaft,
27a, 27b ... end, 28 ... peeling claw support arm, 29
... Rotating support shaft, 30 ... Peeling claw, 31 ... Hook, 32 ... Tension spring, 33 ... Leaf spring, 34 ... Support plate, 35 ... Stopper, 36 ... Tie bar, 37 ... Rotating support shaft, 38 ... Peeling claw, 39 ... Support plate, 40: Upper paper guide plate, 41: Lower paper guide plate, 42: Coil spring, 43: Extension, 44:
3rd support member, 45 ... rotation support shaft, 46 ... lever part,
47: fourth support member, 48: rotation support shaft, 49: lever part, 50: lower paper guide plate, 51: stopper, 52 ...
Support plate

Claims (5)

[Claims] At least one is a roll, the other is a press-contact member that presses against the roll, and is used in a fixing device provided with a heat source on at least one of the rolls and provided so as to be able to be drawn out from an image forming apparatus main body. A paper peeling device, comprising a roll peeling claw that contacts the surface of the roll and a pressing member peeling claw that contacts the surface of the pressing member, wherein the roll and the pressing member are housed. A first support member rotatably provided with respect to the frame to be moved, the first support member being capable of setting a position where the roll peeling claw comes into contact with the roll and a position where it is retracted from the roll, and a free end of the first support member. A second support member rotatably provided on the side and supporting the roll peeling claw, when the first support member is rotated to a retracted position of the roll peeling claw. The second support member is rotated in a direction opposite to a rotation direction of the first support member, so that a tip of the peeling claw for the roll faces the first support member. Paper peeling device. 2. A method according to claim 1, wherein a part of said second support member constitutes an upper sheet guide plate of a pair of sheet guide plates for guiding a sheet passing between said roll and said pressing member. The sheet peeling device according to claim 1, wherein: 3. The apparatus according to claim 1, wherein the lower sheet guide plate of the pair of sheet guide plates and the peeling claw for the pressure contact member move integrally with the second support member. The paper peeling device as described in the above. 4. A third support member rotatably provided with respect to the frame, for retracting the peeling claw for the pressure contact member from the pressure contact member, and a third support member rotatably provided on the third support member. A fourth support member for supporting the peeling claw for the pressure contact member, wherein when the third support member is rotated to the retracted position of the peeling claw for the pressure contact member, the fourth support member rotates. 2. The sheet peeling device according to claim 1, wherein a tip of the peeling claw faces the third support member. 5. A stopper for changing the direction of the fourth support member by colliding with a part of the frame when rotating the third support member to the normal position side. The sheet peeling device according to claim 4, wherein a sheet is formed.