JP2021004140A - Image formation device - Google Patents

Abstract

To provide a sheet transportation device capable of opening and closing an opening/closing member without deteriorating operability, and an image formation device.SOLUTION: In closing an opening/closing member, a compression link 205 is brought to abut on an abutting part 108, and the compression link 205 is moved to a first position for compressing a compression spring 208 and bringing a driven roller 204 into pressure contact with a transportation roller 203 via a bearing 204a along with a movement of a closing direction of the opening/closing member. In opening the opening/closing member, the compression link 205 is moved from the first position to a second position for spacing the driven roller 204 away from the transportation roller 203 by opening the compression spring 208 while abutting on the abutting part 108 along with a movement to an opening direction of the opening/closing member.SELECTED DRAWING: Figure 2

Description

The present invention relates to a sheet transfer device and an image forming device, and more particularly to a configuration for reducing an operating force when opening and closing an opening / closing member.

Conventionally, an image forming apparatus such as a printer, a copying machine, or a printing machine includes a sheet conveying device that conveys a sheet by a pair of conveying rollers provided in a sheet conveying path. The sheet transfer device includes, for example, a door that is an opening / closing member that is opened to process the jammed sheet when the sheet is jammed in the sheet transfer path.

In such a sheet transfer device, in order to facilitate the removal of the jam sheet, for example, when a driven roller that is one of the transfer roller pairs is provided on the door and the door is opened, the driven roller is the other of the transfer roller pairs. There is something that is separated from. When the jam processing is completed and the door is closed, the driven roller comes into contact with the driving roller.

In a conventional sheet transfer device, a sheet transfer path is formed by a fixed guide plate and a movable guide plate, and an elastic member for pressing a driven roller and a driven roller to a drive roller is attached to the movable guide plate. .. Then, in order to bring the driven roller into contact with the drive roller in conjunction with the closing operation of the door, a link member is provided swingably between the upper side cover which is a door and the movable guide plate (see Patent Document 1). ..

In this sheet transfer device, when the upper side cover is closed, the movable guide plate is pressed by the pressure arm which is a link member via the elastic member to form a sheet transfer path and the driven roller is used as a drive roller. It is held in the pressing position. When the upper side cover is opened, the pressure by the pressurizing arm is released, the movable guide plate elastically moves in the direction of being separated from the fixed guide plate together with the upper side cover, and the driven roller is separated from the driving roller. When closing the opened upper side cover, the closing operation of the upper side cover is transmitted to the movable guide plate via the pressure arm, the movable guide plate moves to the fixed guide plate side, and the driven roller is driven. Pressed against the roller.

Japanese Unexamined Patent Publication No. 5-213476

By the way, in the conventional sheet transport device, for example, when the driven roller is provided at a position away from the opening / closing center of the opening / closing member, when the opening / closing member is opened, the opening / closing member is vigorously opened by the reaction force of the elastic member. .. In order to prevent this, it is necessary to open the opening / closing member while resisting the elastic force of the elastic member. Further, when closing the opening / closing member, it is necessary to close the opening / closing member against the elastic force of the elastic member. As described above, when the elastic member is provided, the operating force required for opening and closing the opening / closing member is increased, and the operability is lowered.

Therefore, the present invention has been made in view of such a current situation, and an object of the present invention is to provide a sheet transfer device and an image forming device capable of opening and closing an opening / closing member without deteriorating operability. Is.

According to the present invention, in a sheet transfer device, a transfer roller pair having an opening / closing member provided in the device body, a first transfer roller provided in the device body, and a second transfer roller that is in pressure contact with the first transfer roller. A holding member that rotatably holds the second transfer roller and is slidable in the pressure contact direction that presses the second transfer roller against the first transfer roller, and an urging means that urges the holding member in the pressure contact direction. The opening / closing member is provided with a reducing means for reducing the force acting on the opening / closing member by the urging means, and the reducing means is oscillatingly supported by the opening / closing member. A swing member that can be moved to a first position where the second transfer roller is pressed against the first transfer roller and a second position where the second transfer roller is separated from the first transfer roller, and a swing member provided on the apparatus main body. It has a contact portion with which the swing member comes into contact, and the urging means is arranged between the swing member and the holding member, and swings the swing member toward the contact portion. When the opening / closing member is closed by urging the swing member to move, the swing member and the contact portion come into contact with each other, and the swing member is urged as the opening / closing member moves in the closing direction. When the means is moved to the first position while being compressed and the opening / closing member is opened, the swing member is brought into contact with the abutting portion as the opening / closing member moves in the opening direction, and the second position is reached. It is characterized by being moved to.

When opening and closing the opening / closing member as in the present invention, the swinging member is brought into contact with the abutting portion to press-contact the second transport roller with the first transport roller, or the second transport roller is separated from the first transport roller. By doing so, the opening / closing member can be opened / closed without deteriorating the operability.

The figure which shows the schematic structure of the full-color laser beam printer which is an example of the image forming apparatus provided with the sheet transfer apparatus which concerns on embodiment of this invention. Enlarged view of the main part of the above full-color laser beam printer. The schematic diagram explaining the operation of the door operating force reducing means provided in the said full-color laser beam printer. The figure explaining the state of the said door operating force reducing means when the door is opened. The figure explaining another configuration of the said door operation force reducing means.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In all the drawings, the directions of the up / down, right / left arrows in the drawings point to the same direction, and the vertical direction on the paper surface of FIG. 1 is the front-back direction of the device.

FIG. 1 is a diagram showing a schematic configuration of a full-color laser beam printer which is an example of an image forming apparatus according to an embodiment of the present invention. The vertical and right / left arrow directions in FIG. 1 are the directions when the full-color laser beam printer (hereinafter referred to as the printer) is viewed from the front, and the vertical direction on the paper surface is the front-back direction of the printer. Further, the directions of the arrows on the top, bottom, right and left are the same in other figures.

As shown in FIG. 1, the printer main body 100A, which is the main body of the image forming apparatus of the printer 100, includes an image forming unit 100B for forming an image on a sheet. Further, the printer main body 100A includes a sheet feeding unit 100C for feeding the sheet S from the paper feed cassette 101 for storing the sheet S, a manual feeding unit 100D for feeding the sheet placed on the manual feed tray 101a, and a sheet. The sheet transport device 100F for transporting is provided.

The image forming unit 100B is of a 4-drum full-color system, and forms a laser scanner 122 and four toner images of four colors of yellow (Y), magenta (M), cyan (C), and black (K). The process cartridge 120 is provided. Here, each process cartridge 120 includes a photoconductor drum 121, a charger 123 as a charging means, a developing device 124 as a developing means, and a cleaner 125. Further, the image forming unit 100B includes an intermediate transfer unit 100E arranged above the process cartridge 120 and a toner cartridge 126.

The intermediate transfer unit 100E includes an intermediate transfer belt 130 wound around a drive roller 131, a tension roller 132, and a secondary transfer inner roller 104. Further, the intermediate transfer unit 100E is provided inside the intermediate transfer belt 130, and includes a primary transfer roller 133 that abuts on the intermediate transfer belt 130 at a position facing the photoconductor drum 121. Here, the intermediate transfer belt 130 is rotated in the direction of arrow B by a drive roller 131 driven by a drive unit (not shown). Then, each color toner image having a negative electrode property on the photoconductor drum is sequentially multiple-transferred to the intermediate transfer belt 130 by the primary transfer roller 133.

At a position of the intermediate transfer unit 100E facing the secondary transfer inner roller 104, a secondary transfer roller 105 for transferring a color image formed on the intermediate transfer belt to the sheet S is provided. Then, the secondary transfer unit 103 is configured by the secondary transfer inner roller 104 and the secondary transfer roller 105.

Further, a fixing portion 150 is arranged on the upper portion of the secondary transfer roller 105, and a first discharge roller pair 170, a second discharge roller pair 171 and a double-sided reversing portion 162 are arranged on the upper left portion of the fixing portion 150. .. The double-sided reversing portion 162 is provided with a reversing roller pair 163 capable of forward / reversing and a re-conveying passage R or the like for re-transporting a sheet having an image formed on one surface to the image forming unit 100B. Further, in the sheet transfer device 100F, the transfer rollers 203, 204 and the transfer rollers for transferring the sheet S on which the image is fixed to the first discharge roller pair 170, the second discharge roller pair 171 or the reversing roller pair 163. A pair 151 is provided.

Next, the image forming operation of the printer 100 will be described. When the image forming operation is started, an image signal is input to the laser scanner 122 from a personal computer or the like (not shown), and the laser beam corresponding to the image signal is rotated from the laser scanner 122 in each process cartridge 120 in the direction of arrow A. The photoconductor drum 121 is irradiated. At this time, the surface of the photoconductor drum 121 is uniformly charged to a predetermined polarity and potential in advance by the charger 123, and an electrostatic latent image is formed on the surface by irradiating the laser beam from the laser scanner 122. To.

After that, the electrostatic latent image is developed by the developing device 124 to form a toner image of four colors of yellow, magenta, cyan, and black on the photoconductor drum of each process cartridge 120. Then, a full-color toner image is formed on the intermediate transfer belt by sequentially transferring the four-color toner images onto the intermediate transfer belt by the primary transfer bias applied to the primary transfer roller 133. After the toner image is transferred, the toner remaining on the surface of the photoconductor drum is removed by the cleaner 125.

The sheet S housed in the paper feed cassette 101 in parallel with this toner image forming operation is fed by the sheet feeding unit 100C and then transported to the registration roller pair 102 to correct the skew. In the case of manual paper feeding, the sheet placed on the manual paper feed tray 101a is fed by the manual paper feeding unit 100D and then conveyed to the registration roller pair 102. The sheet S to which the skew correction has been performed is conveyed to the secondary transfer unit 103 at the same timing by the registration roller pair 102. Then, in the secondary transfer unit 103, by applying a positive electrode bias to the secondary transfer roller 105, the full-color toner image on the intermediate transfer belt is secondarily transferred to the conveyed sheet S.

After the toner image is transferred, the sheet S is conveyed to the fixing portion 150 and heated and pressurized in the fixing portion 150 to fix the toner image on the surface. After that, the sheet S on which the image is fixed is placed on the first paper discharge tray 160 by the first discharge roller pair 170 provided downstream of the fixing portion 150 or on the second paper discharge tray 161 by the second discharge roller pair 171. It is discharged. When forming an image on both sides of the sheet S, after the image is fixed, the sheet S is conveyed to the re-conveyance passage R by the reversing roller pair 163, and is conveyed to the image forming unit 100B again.

By the way, as shown in FIG. 1, the transport roller pair 203, 204 includes a transport roller 203 and a driven roller 204. Further, on one side (right side) of the printer body 100A which also serves as the device body of the sheet transfer device 100F, an opening / closing shaft 206 whose rotation center is a door 201 which is an opening / closing member that is opened when a sheet jam or the like occurs. It is provided so that it can be opened and closed with the fulcrum.

Here, as shown in FIG. 2, the transport roller 203, which is the first transport roller, is rotatably attached to the fixed guide member 106 provided in the printer main body 100A. The driven roller 204, which is the second transport roller, is rotatably supported by the movement guide member 107 attached to the door 201 shown in FIG. 1 described above. The fixed guide member 106 and the moving guide member 107 that moves together with the door 201 form a seat transport path R1 through which the seat passes.

The driven roller 204 is rotatably supported by a bearing 204a slidably provided in the pressure contact direction, which is the direction in which the driven roller 204 is in pressure contact with the transport roller 203. By urging the bearing 204a, which is a holding member that rotatably holds the driven roller 204, in the direction of the transport roller 203 by the pressure spring 208, which is an urging means, the driven roller 204 is a fixed guide member of the moving guide member 107. It protrudes from the side surface 107a.

Then, when the door 201 is closed, the driven roller 204 urged by the pressure spring 208 presses against the transfer roller 203 while compressing the pressure spring 208. At this time, the side surface 107a on the fixed guide member side of the moving guide member 107 and the side surface 106a on the moving guide member side of the fixed guide member 106 form a sheet transport path R1 through which the sheet on which the image is fixed passes.

A pressure link 205, which is a swing member that is swingably supported around a swing shaft 207, is attached to the movement guide member 107. Further, the printer main body 100A is provided with a contact portion 108 with which the pressurizing link 205 comes into contact with each other so as to be in contact with each other.

The pressurizing link 205 has a first arm 205a and a second arm 205b, and a swing shaft 207 is arranged between the first arm 205a and the second arm 205b. A pressure spring 208 is arranged between the first arm 205a and the bearing 204a. That is, the first arm 205a engages with the pressure spring 208 for urging the driven roller 204 to the transport roller 203. The second arm 205b comes into contact with the contact portion 108 when the pressure link 205 swings clockwise.

FIG. 2 shows a state when the door 201 is closed, and the driven roller 204 urged by the compressed pressure spring 208 via the bearing 204a is in pressure contact with the transport roller 203. The position of the pressure link 205 that compresses the pressure spring 208 in this way and presses the driven roller 204 against the transport roller 203 via the bearing 204a is referred to as the first position. Further, a reaction force F1 of the pressure spring 208 is applied to the first arm 205a of the pressure link 205, and the reaction force F1 causes the pressure link 205 to swing clockwise around the swing shaft 207. The second arm 205b of the pressure link 205 is in pressure contact with the contact portion 108 by the force of F3.

As described above, in the present embodiment, when the door 201 is closed, the pressure link 205 swings due to the reaction force F1 of the compressed pressure spring 208 and presses against the contact portion 108. That is, in the present embodiment, as shown in FIG. 3, the pressure link 205 is brought into contact with the contact portion 108 by converting the reaction force F1 of the pressure spring 208 into the reaction force F3 which is the swing force of the swing shaft 207. I try to press it against. As a result, when the door 201 is closed, the reaction force F1 of the pressure spring 208 is applied to the contact portion 108 (printer body 100A), and the reaction force F1 of the pressure spring 208 applied to the door 201 accordingly. The magnitude of the force F1 decreases.

In this way, when the door 201 is closed, the magnitude of the reaction force F1 of the pressure spring 208 applied to the door 201 is reduced by the pressure link 205 and the contact portion 108. As described above, in the present embodiment, the pressure link 205 and the contact portion 108 constitute the door operating force reducing means 20 for reducing the operating force of the door 201.

Next, the operating force when the door 201 is opened from the state where the door 201 is closed will be described. When the door 201 is closed, the reaction force F1 of the pressure spring 208 is mainly applied to the contact portion 108 as shown in FIG. 2 described above. When the door 201 is opened by 1 ° as shown in FIG. 4 by unlocking the lock portion (not shown) provided on the printer main body 100A, the movement guide member 107 moves with the movement of the door 201 in the opening direction. It moves integrally with the door 201 in the opening direction indicated by the arrow C.

With the movement of the movement guide member 107, the pressure contact position between the second arm 205b of the pressure link 205 and the contact portion 108 moves downstream in the opening direction. Here, since the contact portion 108 is inclined so as to be lower on the downstream side in the opening direction, when the pressure contact position moves, the pressure link 205 is directed by the arrow D due to the reaction force F1 due to the opening of the compressed pressure spring 208. Swing in the direction shown in.

As a result, the movement guide member 107 moves to the second position where the driven roller 204 is separated from the transport roller 203 while the second arm 205b of the pressure link 205 is in pressure contact with the contact portion 108. At this time, the reaction force F3 generates a frictional force F4 between the second arm 205b of the pressure link 205 and the contact portion 108. Therefore, when the door 201 is opened, the pressure spring 208 applied to the door 201 The magnitude of the reaction force F1 is reduced. As a result, when the door 201 is opened, it is possible to prevent a large force from being applied to the door 201 due to the reaction force F1 of the pressure spring 208, and it is possible to reduce the operating force when the door 201 is opened.

After that, when the door 201 is further opened, the contact with the contact portion 108 is released, and the pressure link 205 comes into contact with a stopper (not shown) provided on the movement guide member 107 to reach a predetermined swing position. Be retained.

Next, the operating force when the door 201 is closed from the state where the door 201 is opened will be described. When the door 201 is closed, the second arm 205b of the pressure link 205, which has moved to a predetermined swing position, comes into contact with the contact portion 108. After that, when the door 201 is further closed, a reaction force F5 in the direction opposite to F3 shown in FIG. 4 is applied to the pressurizing link 205 from the contact portion 108 as the door 201 moves in the closing direction.

Here, when such a reaction force F5 is applied, the pressure link 205 swings in the direction of arrow E while contracting the pressure spring 208. That is, when the door 201 is closed, the pressure link 205 swings in the direction of arrow E while contracting the pressure spring 208 due to the reaction force F5 from the contact portion 108. As a result, the pressurizing link 205 moves to the first position. While the pressurizing link 205 is swinging in the direction of arrow E while contracting the pressurizing spring 208, the transport roller 203 and the driven roller 204 come into contact with each other. Even after the transport roller 203 and the driven roller 204 are in contact with each other, the pressure link 205 swings in the direction of arrow E while contracting the pressure spring 208.

In this way, when the pressure link 205 comes into contact with the contact portion 108, the pressure link 205 swings due to the reaction force F5 from the contact portion 108, so that the pressure link 205 is operated when the door 201 is closed. The force for rocking is received from the printer main body 100A. Along with this, the magnitude of the reaction force F1 of the pressure spring 208 applied to the door 201 decreases. That is, when the door 201 is closed, the magnitude of the reaction force F1 of the pressure spring 208 applied to the door 201 is reduced by the pressure link 205 and the contact portion 108. As a result, the operating force when closing the door 201 can be reduced.

As described above, in the present embodiment, when the door 201 is closed, the pressure link 205 is brought into contact with the contact portion 108, and the pressure link 205 is moved as the door 201 moves in the closing direction. I am trying to move it to the first position. Further, when the door 201 is opened, the pressure link 205 is brought into contact with the contact portion 108 and moved to the second position as the door 201 moves in the opening direction.

As a result, when the door 201 is opened and closed, the printer main body 100A receives the force acted by the pressure spring 208, so that the force received by the door 201 is reduced, and the operating force when opening and closing the door 201 is reduced accordingly. To do. As a result, the door 201 can be opened and closed without deteriorating operability.

In the above description, the printer in which the door 201 is provided on one side (right side) of the printer main body 100A has been described, but the present invention is not limited to this. For example, as shown in FIG. 5, it can be applied to a printer in which the door 201 is openably and closably provided on the upper surface of the printer main body 100A.

Further, the case where the movement guide member 107 is integrally provided with the door 201 has been described so far, but the present invention is not limited to this, and the movement guide member 107 is provided swingably on the printer body to provide the door 201. When opening and closing, it may be movable together with the door 201.

20 ... Door operating force reducing means, 100 ... Full-color laser beam printer (image forming device), 100A ... Printer body (device body), 100B ... Image forming unit, 100F ... Sheet transfer device, 106 ... Fixed guide member, 107 ... Moving Guide member, 108 ... contact portion, 151 ... transfer roller pair, 201 ... door (opening / closing member), 203 ... transfer roller (first transfer roller), 204 ... driven roller (second transfer roller), 204a ... bearing (holding) Member), 205 ... Pressurized link (swing member), 205a ... 1st arm, 205b ... 2nd arm, 206 ... Open / close shaft (rotation center), 208 ... Pressurized spring (biasing means), R1 ... Seat Transport path, S ... sheet

The present invention relates to images formed equipment.

There was room for improvement in the means for pressing and releasing the pressure welding of the driven roller to the driving roller when the door was opened and closed in the conventional image forming apparatus.

One aspect of the present invention is an image forming apparatus for forming an image on a sheet, which includes an opening / closing member rotatably supported at a lower end portion about a horizontal axis, a first transport roller, and the first transport. A second transport roller that sandwiches and conveys the sheet on which the image is formed together with the rollers, a holding member that is provided on the opening / closing member and holds the axis of the second transport roller, and a rock that extends parallel to the axis. A swing member oscillatingly provided on the opening / closing member with a center of motion as the center, and an opening / closing member having one end engaged with the holding member and the other end engaging with the swing member. When the opening / closing member has a compression spring and the opening / closing member is in a closed position, the compression spring is compressed, and the force that the compression spring tries to restore causes the second transfer roller via the holding member. The image forming apparatus is provided with a contact portion that acts to bring the first transfer roller into pressure contact with a part of the swing member when the opening / closing member is in a closed position. The contact portion swings the reaction force when the compression spring presses the second transport roller against the first transport roller via the holding member when the opening / closing member is in the closed position. When the opening / closing member is in the open position, the swing member and the contact portion are separated from each other, and the opening / closing member is opened from the closed position to the open position. In the process of operation, the swinging member rotates about the swinging center in the first rotation direction with respect to the opening / closing member, the compressed compression spring extends, and the abutting portion with respect to the horizontal. In the process of closing the opening / closing member from the open position to the closed position, a part of the swing member slides the inclined portion of the contact portion. An image characterized in that the swing member, which is opposite to the first rotation direction, rotates in the second rotation direction for compressing the compression spring with respect to the opening / closing member while moving around the swing center. It is a forming device.

In the present invention, it is possible to improve the mechanism for pressing and releasing the pressure contact of the driven roller with respect to the drive roller when the door is opened and closed .

Claims (1)

Opening and closing members provided on the main body of the device
A transport roller pair having a first transport roller provided on the main body of the apparatus and a second transport roller that is in pressure contact with the first transport roller.
A holding member that rotatably holds the second transfer roller and is slidable in the pressure contact direction that presses the second transfer roller against the first transfer roller.
An urging means for urging the holding member in the pressure contact direction,
When opening and closing the opening / closing member, a reducing means for reducing the force acting on the opening / closing member by the urging means is provided.
The reduction means
It is oscillatingly supported by the opening / closing member and can be moved to a first position where the second transport roller is pressed against the first transport roller and a second position where the second transport roller is separated from the first transport roller. Swinging member and
It has a contact portion provided on the main body of the device and with which the swinging member comes into contact.
The urging means is arranged between the oscillating member and the holding member, and urges the oscillating member so as to oscillate toward the abutting portion.
When the opening / closing member is closed, the rocking member and the contact portion come into contact with each other, and as the opening / closing member moves in the closing direction, the rocking member is moved to the first position while compressing the urging means. When the opening / closing member is opened, the swinging member is moved to the second position while being in contact with the abutting portion as the opening / closing member moves in the opening direction. Sheet transfer device.

Images