JP3075282B2 - Image forming device - Google Patents

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 a copying machine or a printer, and more particularly, to a paper conveying path formed along one side of the image forming apparatus in a vertical direction and opening the sheet conveying path. And a device configured to facilitate the operation.

[0002]

2. Description of the Related Art An apparatus configured to take a paper tray or the like in and out of the front of a main body frame is generally called a front loading type apparatus, and is an apparatus for mounting a paper cassette or the like from a side of the main body. This is a paper feeding unit that has recently been widely used because it has an advantage that the installation space for the main body can be reduced as compared with the above. As an image forming apparatus capable of taking the above-mentioned paper tray in and out from the front, for example, Japanese Utility Model Application Laid-Open No. 62-1946.
As shown in Japanese Patent Publication No. 34-34, etc., a large number of paper trays are arranged in multiple stages, and arbitrary paper is sent out from each paper tray via a paper feed path and directed toward an image transfer unit such as a photosensitive drum. The paper can be fed.

In the image forming apparatus, an upper frame in which a recording unit and a paper feeding unit using one paper tray are integrally formed, and a lower frame in which a number of paper trays and an intermediate tray are assembled are combined. A paper feed path and a return path for guiding the paper up and down are arranged so as to vertically penetrate both sides of the two frames. Then, the normal recording paper is created by feeding from the paper tray, the image is transferred to the back side of the single-sided copied paper to make a double-sided copy, or the image side of the single-sided copied paper is created. An arbitrary recording paper creation mode, such as creating a multiple copy by transferring another image to the printer, can be selected.

[0004]

However, in a paper feeder in which a number of paper trays are arranged in a vertical direction, a paper transport path is provided so as to penetrate up and down at a side portion thereof. There is a problem that, when a paper jam or the like occurs in the path, the work of opening the paper transport path is troublesome, and the configuration of the paper transport path is simplified so that the paper transport path can be easily opened and closed, and inspection and jam processing can be performed. There is a need for a device that can be easily performed.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned drawbacks of the conventional image forming apparatus by opening and closing a door as a cover provided on the side of the image forming apparatus main body.
It is an object of the present invention to provide an apparatus configured to easily open and close a paper transport path and to easily remove jammed paper.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an image forming apparatus for recording an image on paper. The invention according to claim 1 of the present invention provides a recording unit for recording on a sheet, a sheet tray for accommodating sheets, which is arranged below the recording unit in a vertically stacked manner, and the sheet tray. A sheet feeding unit that abuts and feeds the sheets stacked on the sheet, a sheet conveying path that allows sheets to pass from bottom to top along the side surface of the image forming apparatus main body, and a sheet feeding path for each of the plurality of sheet trays. A guide provided correspondingly and provided with a first guide unit for guiding the sheet fed by the sheet feeding unit, and a second guide unit for guiding the sheet from bottom to top along the side surface of the main body. Means, a transport device provided for the respective paper trays of the plurality of paper trays, in the paper transport direction downstream of the guide means, for transporting the paper in the paper transport path, and openable and closable to the image forming apparatus main body. Equipment An image forming apparatus comprising: a door member that covers at least a part of a side surface; and a third guide unit provided inside the door member and guiding a sheet upward from below. At least a part of the path is formed by the second guide portion and the third guide portion.

According to a second aspect of the present invention, the door member covers a portion of the transfer device.

According to a third aspect of the present invention, the door member covers a portion of the paper transport path that extends over a plurality of paper trays. The invention according to a fourth aspect is characterized in that the door member covers all portions of the paper transport path that extend over a plurality of paper trays.

Since the apparatus of the present invention is constructed as described above, the sheet transport path can be opened and closed by opening and closing the door member, so that the sheet can be easily removed when a jam or the like occurs. Can be.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of an embodiment of the apparatus of the present invention will be described with reference to the illustrated example. 1 and 2 show a case where the mechanism as the image forming apparatus 1 is applied to a copying machine. The image forming apparatus 1 is, for example, an upper apparatus provided with a xerographic mechanism. 10
And a lower device 30 mainly equipped with a paper feeding device. In the image forming apparatus 1, the upper device 10
As in the case of a general copying machine, the platen 12
The platen cover 13 is provided so as to be openable and closable with respect to the upper surface of the platen. A control panel 11 is provided to select a copy mode, set the number of copies, and perform other scanning. I have.

As shown in FIG. 1, in an image forming apparatus, a plurality of paper trays 5, 5a to 5c are housed in a vertically stacked state, and paper can be arbitrarily sent out from each paper tray. It is configured to be able to. In the image forming apparatus, the upper device 10 is provided with an image reading device and a photosensitive drum 15, xerography-type mechanisms arranged around the photosensitive drum, and one paper tray 5, A paper feed unit 6 is provided corresponding to the paper tray.

A plurality of paper trays are arranged in the lower device 30 so as to be overlapped in the vertical direction.
To 6c. The paper tray provided in the image forming apparatus is configured as a so-called front-loading type device that can be inserted into and removed from the front portion of the main body frame. The paper feeder unit can send out the paper from the printer unit. In addition, the paper feed path for sending out paper from the paper tray toward the recording section while penetrating those devices up and down, and an intermediate portion provided with a copy in the lower device are provided on both sides of the upper and lower devices. There is provided a return path 40 for carrying the sheet toward the tray.

In the lower device 30, an intermediate tray 5d is disposed at a predetermined position between the paper trays.
By sending the single-sided copied paper through the intermediate tray and again to the image transfer unit via the paper feeder unit 6d, an arbitrary copying mode such as multiplex copying or double-sided copying can be selected. In the illustrated embodiment of the image forming apparatus, the lowermost sheet tray 5c is
It is configured as a large capacity tray. When the tray 5c is pulled out, the lower part of the large capacity tray is
A caster for supporting the tip portion is provided. Then, when the tray 5c is pulled out, as described later, the weight of the tray is not added to the main body frame.

As shown, the cover member on the side of the main body frame of the image forming apparatus is provided with side doors 33 and 34 as outer covers of the sheet conveying path. The side door is swingably provided through a hinge on the back side, and is easily opened by jamming in the paper transport path or maintenance of a sheet feeding device to be described later. It is configured so that maintenance can be performed. That is, in the image forming apparatus, when the side door is opened, a wide opening can be formed on the front side up and down, so that it is possible to easily insert a hand when processing jam paper or the like. .

The side door 33 has been described as a door member, and illustrates an example in which the side door 33 is disposed with respect to a lower device. Can be covered at the same time. In the example of FIG. 1, a side cover can be provided on the side of the sheet feeding unit of the upper device 10 so as to be openable and closable via a lower hinge. Further, a side door 34 provided on the other side of the apparatus is provided as a cover member for a return path for returning the single-sided copied paper from the upper apparatus 10, and the door 34 is connected to the intermediate tray 50 from the return path. Is provided with a branch claw 44 for branching.

[0016]

[Operation of Image Forming Apparatus] In the above-described image forming apparatus, an optical system unit 14 for scanning an image of a document placed on a platen 12, a photosensitive drum 15, A device 16 and a cleaning device 17 are arranged, and an electrostatic latent image is formed on the photosensitive drum 15 by light transmitted from the optical system device, and toner is attached to the electrostatic latent image to form a toner image. As a visible image. Further, a paper transport path is provided toward an image transfer portion of the above-described xerographic system. For example, paper taken out of the paper tray 5 is provided at a position corresponding to the paper tray. The paper is fed by the unit 6.

When passing between the photosensitive drum 15 and the transfer corotron 22 through the gate 21 and the tip positioning device, the image on the photosensitive drum 15 is transferred, and is moved by the transport device 23 to be fixed. Heating and pressurizing are performed in the device 18, and the toner is melted and adhered to the paper, a copy is formed, and the copy is discharged to the discharge tray 25 via a discharge path.

The upper device 10 is provided with a branching claw 24 in the middle of the copy discharge path. When the copying mode is multiplex or double-sided copying, the return path 26 is provided via the branching claw. , And the corresponding paper is moved. As described above, a plurality of paper trays 5a to 5c are provided in the lower device 30 arranged corresponding to the upper device, and the paper feed units 6a to 6c are provided in correspondence with the respective paper trays. Is arranged.

A sheet feeder unit is disposed on one side of the plurality of sheet trays. The sheet feeder units include a pickup roller, a sheet separating mechanism, and a sheet separating mechanism, as described later. A paper feed unit 6, 6a to 6c in which a transport roller device and the like are integrally combined is disposed as a vertical transport mechanism, and a guide plate that forms a paper transport path connecting the paper feed unit vertically is provided. Are integrally formed with the unit.

From the discharge path of the upper device 10,
The lower part of the return path branched via 4 is connected to a return path 40 arranged on the opposite side of the paper transport path of the lower device 30. A transport roller device 41 driven in one direction is disposed at a predetermined interval in a return path 40 provided in the lower device, and a lower side of a switching claw 44 provided in the middle thereof as a reversing path 42. Make up. The reversing path 42 is provided with reversing rollers 43 that are driven in forward and reverse directions at predetermined intervals.

In the return path 40 configured as described above, the single-sided copied paper discharged through the fixing device 18 is directly directed to the discharge tray 25 as described above in the normal copy mode. Is discharged. When the copy mode is a multiple or double-sided copy, the switching claw 24 is swung to guide the return claw 26 toward the return path 26, and is guided to the return path 40 of the lower device 30 via the curl correcting device 27. . When the copy mode is set to the multiple copy mode, the single-sided copied sheet is guided to the intermediate tray 5d via the switching claw 44, and the sheet is fed to the sheet feeding path 6d using the sheet feeding section 6d. To the image transfer section.

On the other hand, when the copying mode is duplex copying, the single-sided copied paper is moved from the return path 40 to the reversing path 42, and the rear end of the paper is
4 is detected, the reversing roller 43 is detected.
And the switching claw 44 is swung,
The sheet is introduced into the intermediate tray 5d. Then, in the intermediate tray 5d, the side portion of the sheet is positioned by the oblique feed roller 52, the leading end portion is positioned by the gate 53, and then the sheet is fed in accordance with the timing of the image formed on the photosensitive drum. The sheet is fed using the copy unit 6d so that another image can be transferred to the back side of the single-sided copied sheet.

In the lower device 30 of the image forming apparatus configured as described above, an intermediate tray 5d is disposed at a predetermined position with respect to a sheet feeding unit in which a sheet tray and a sheet feeding unit are combined. . As shown in the above-mentioned Japanese Utility Model Application Laid-Open No. Sho 62-194634, the intermediate tray 5d stores a plurality of single-sided copied sheets, and performs the single-sided copied sheets from the intermediate tray during multiplex or double-sided copying. Instead of a tray having a mechanism for sequentially sending out paper, the tray is configured to be able to immediately send out one-sided copied paper toward the back side or multiple copy after receiving one sheet of single-sided copied paper.

Therefore, in the image forming apparatus, for example, when a plurality of double-sided copies are continuously made, the originals are circulated using an automatic original feeder or the like provided in the apparatus main body. Thus, the operation of creating one-side copied paper and the operation of continuously performing operations such as transferring an image to the back surface can be repeated. When the intermediate tray is configured to have the same mechanism as that of the conventional intermediate tray device, as shown in the conventional example, the single-sided copied paper is deposited on the intermediate tray, Alternatively, it may be configured so that the sheets are sequentially discharged for multiple copying.

[0025]

[Structure of Paper Feeding Unit] The mechanism of each component in the image forming apparatus and its operation will be described below. As described above, in the image forming apparatus 1, a large number of paper trays are arranged in a vertically stacked state, and a paper feeding operation can be performed from those paper trays using the paper feeding unit. Is configured. As shown in FIG. 3, the paper feed unit includes a paper feed unit 6 corresponding to the paper tray of the upper device 10, a paper tray mounted on the lower device, and a paper feed corresponding to the intermediate tray. The paper feeder units are constituted by device units 6a to 6c. These paper feeder units are individually supported on the main body frame 31 in an independent state.

Each of the sheet feeder units is connected to the main body frame 3
The unit support brackets 35 and 35a are provided so as to protrude inward from the vertical members of the main body frame, respectively, in order to mount the unit support bracket 1 on the unit frame. Then, the brackets 35, 35, which are configured as described above and are disposed to face each other,
a, each paper feeder unit is fixed,
The paper is fed from the paper tray via these paper feed units, and a paper transport path from the paper feed unit to the image transfer unit is formed. As the paper feeder unit, for example, an apparatus as shown in FIGS. 4 to 11 is formed. The sheet feeder unit described below is denoted by the reference numeral 100, but a sheet feeder unit described later has the same configuration as the above-described sheet feeder units 6 to 6c.

The paper feeder unit is not constructed by assembling the respective constituent members in the main body frame, but is constructed as shown in FIG.
As shown in FIG. 9 and FIG.
To the unit frame 101 and the frames 101 on both sides.
a, 101b, etc., and each component is integrally incorporated therein. Then, the side frames 101a, 101 of the sheet feeding unit 100
b, a drive gear mechanism and the like are provided in an exposed state, and when the paper feeder unit is mounted on the main body frame of the image forming apparatus, the drive gear mechanism and the like are provided with respect to the drive mechanism of the main body. Are connected to drive the respective components such as the paper feed roller and the pickup roller.

The paper feeder unit is configured as shown in detail in FIG. 5 and the like, and includes a transport roller device 110, a pickup roller 145 supported via a support frame 120, Paper feed roller 140 disposed at the base of support frame 120;
And a retard roller 130 disposed opposite to the reference numeral 40.

Of the above-described roller devices, the transport roller device 110 can be used as a transport roller device in the paper transport path of the main body. In this embodiment, the transport roller device of the main body is connected to the upper device. To transport the paper from the paper tray toward the printer and to transport the paper from the lower paper tray. The pickup roller 145 comes into contact with the sheet stored in the sheet tray 60 in the same manner as in the case of a normal sheet feeding apparatus, and the pickup roller 145 is rotated to take out the sheet and supply the sheet. Paper roller 1
The sheet separating mechanism constituted by the sheet 40 and the retard roller 130 performs the sheet separating operation.

In the sheet separating mechanism shown in the above-described embodiment, the sheet feeding roller 140 is driven in the direction in which the sheet is fed, while the retard roller 130 is driven in the direction opposite to the direction in which the sheet feeding roller is transported. When the sheet is nipped between the rollers in the double feeding state, only the upper sheet can be sent out. In the retard roller 130, the roller is supported via a torque limiter 132 between the retard roller 130 and the drive shaft 131, and when one sheet of paper is nipped at a nip portion between the retard roller 130 and the paper feed roller 140. In this case, the torque limiter 132 slides and rotates the roller 130 in the transport direction.

Further, the retard roller 130 is provided on a bracket 1 provided so as to be swingable with respect to a support shaft 136.
The retard roller 130 is supported by a spring (not shown) disposed on the bracket 135 with a constant pressing force against the sheet feeding roller 140. Then, when the sheet enters the nip portion of the sheet separating mechanism in the double feeding state, similarly to the case of the conventionally used sheet separating mechanism,
The rollers 130 are rotated in the opposite direction so as to perform the sheet separating operation.

In the above-described example of the paper feeding mechanism, the paper feeding roller 140 and the pickup roller 145 are connected to the gears 146 to 146.
Synchronous driving is performed by a gear device constituted by 148, and the two rollers are provided via a support frame 120. Further, the support frame is supported by a drive shaft 141 of the paper feed roller 140, and is supported on one side 120.
a and a projection 156 projecting from the other side 120 so as to be able to swing. A swinging device 150 is provided to drive the projection 156. Have been.

The above-described swinging device 150 includes the solenoid 1
51 and a link mechanism, and the link device includes a link 152 protruding from the shaft 153,
Connect to the plunger of solenoid 151 and
2a is connected to the spring 154. The swinging plate 155 protruding from the shaft 153 toward the frame engages with the projection 156 of the support frame 120 to perform the swinging operation of the support frame via the projection. The roller 145 performs an operation of separating from and contacting the sheet. In the paper feed mechanism, the pickup roller is pressed against the paper only when performing the paper feeding operation. In other states, the pickup roller is separated from the paper, and the pickup roller is pressed extra against the paper. And prevent them from doing so. (The mechanism and operation for this will be described in detail later.) When the paper feeding unit 100 is mounted on a paper feeding unit, as shown in FIG.
The positioning and fixing are performed with respect to the unit support bracket 35 by using a projecting member 97 provided on the side frame 101a of the 00 and a screw hole 98. In this embodiment, a bracket 95 is provided at a predetermined position of the unit support bracket 100 so as to be cut and raised, and the bracket 95 is provided with a positioning hole 96. When mounting the paper feeder unit on the main body frame, a projecting member 97 provided on a side frame of the unit is provided.
Into the hole 96 of the bracket 95 to position one side of the sheet feeding unit. After that, a bolt or the like is inserted into the screw hole 98 to fix the other end of the unit to a fixing member (not shown) of the support bracket.

Therefore, the operation of fixing the sheet feeding unit to the sheet feeding section is easily performed by engaging the hole provided in the bracket with the projecting member of the unit. Can be performed by means such as adjusting the bracket 95. In the embodiment of the paper feeder unit, each roller device is driven via a roller driving device 80 shown in FIG. 9, but a gear mechanism 75 disposed on the other side is provided in FIG. As will be described, it is used as a driving device for swinging the bottom plate of the paper tray.

Further, since each of the paper feeder units does not have an independent drive mechanism, an input gear is connected to the drive mechanism of the main body so that the respective units are interlocked. An apparatus as shown in FIG. 8 can be used as a driving mechanism of the sheet feeding unit. The driving mechanism of the sheet feeding unit shown in FIG. 8 has an intermediate gear 192 provided on the main body frame, and a swing gear 193 provided on both sides of the intermediate gear 192 via swingable arms 194. Swing gear 19
3 is urged by a spring 195 so that the intermediate gear and the swing gear mesh with each other, and when the paper feeder unit is mounted, the swing gear 1
93 is made to mesh with the input gear 191 of the unit.

When a paper feeding unit is mounted on the paper feeding section of the main body frame, the input gear 191 of the unit is mounted.
Meshes with the oscillating gear 193, so that the drive from the upper drive gear (not shown) can be transmitted to the input gear of the unit. As described above, when the paper feeder units are mounted on the paper feeder unit mounting portions of the main body frame, the drive gear devices of all the paper feeder units are connected, and the respective paper feeder units are connected. Can be driven. In the above-described driving mechanism, when one sheet feeding unit in the middle is omitted, the lower sheet feeding unit is not driven.

The paper feeder unit is configured as shown in FIGS. The embodiment of the paper feeder unit shown in FIG. 10 shows the case of the paper feeder unit 6 provided in the upper device 10, and the embodiment shown in FIG. The configuration in the case of is shown. In the paper feeder unit, a paper tray 60 can be inserted on the left side of the paper feeder unit 100, and the other side (the right side in the figure) of the paper feeder unit 100 has a main body. A paper transport path 102 and a paper feed path 105 from a paper feed unit are arranged, respectively. These transport paths merge at a transport roller device 110 disposed at an upper portion of the unit, and are joined at an upper portion. It is designed to be connected to a paper transport path.

In the paper feeder unit, the paper transport path 102 of the paper feeder unit 6 is provided with a guide plate 103 as a third guide portion provided so as to be swingable together with the jam clear side door 33a. , And a guide plate 104 as a second guide unit on the unit side, and the paper feed path 105 is constituted by an upper guide plate 107 and a lower guide plate 106 as a first guide unit. Also,
The sheet transport path provided in the sheet feeding unit of the lower device is such that the guide plate 103 is formed by a rib member protruding inside the side door 33, and the other guide members are formed by the sheet feeding unit 6. The configuration is the same as in the case of The guide plate 104 and the lower guide plate 106 among the respective guide plates are incorporated in the sheet feeder unit as an integral member, as shown in the drawing.

In the paper transport path mechanism, the main body paper transport path 102 is configured such that its lower part is spread in a trumpet shape so that a paper transport path from a lower paper feed unit can be connected. To be. A pair of rollers is disposed above the paper transport path via a substantially horizontal shaft, and constitutes a transport roller device 110. In the paper feeder unit, a paper sensor 160 is provided to detect paper stored in the paper tray 60.
Are arranged, and the arm 16 of the paper sensor 160 is
1 is swingably provided at a position corresponding to the hole provided in the bottom plate 61, and detects that the end of the arm 161 is greatly dropped when there is no paper on the bottom plate 61, Information without paper can be output.

A sensor 165 for detecting the passage of a sheet is disposed near the confluence of the sheet feeding path from the sheet tray and the main body sheet conveying path. The arm 166 of the sensor 165 is swung each time a sheet passes through the paper path passing through the paper path or the transport path 102 arranged so as to vertically pass through the sheet feeding unit. .

[0041]

[Swing Mechanism of Bottom Plate] Further, a bottom plate 61 is provided on the paper tray 60 so as to be swingable. In order to swing the bottom plate 61, FIG.
2, a push-up arm 70 is provided.
When information indicating that the paper tray has been mounted on the paper feed unit is input, the push-up arm 70 is activated to swing, and the upper part of the paper is moved to a certain height via the bottom plate. And the pickup roller 145
Is pressed against the paper, and the bracket 120 is raised to a position where the bracket 120 is substantially horizontal.

The rise of the bracket 120 is detected by a sensor 125 shown in FIG. 5. The sensor 125 detects the bracket by an actuator 126 provided on the bracket. It is done by having entered between. Then, as described above, the sheet is raised to the predetermined position, and the state in which the pickup roller 145 is pressed against the sheet is set, so that the sheet can be fed from the sheet tray.

The driving mechanism of the push-up arm 70 is shown in FIG. 12, and will be described in more detail. The shaft 71 of the push-up arm 70 is provided so as to penetrate the side frame of the sheet feeding unit. A half-moon gear 72 is provided at the end of the shaft 71. Half moon gear 72 described above
Are driven by a gear drive 73, which comprises a drive input gear 73a and an output gear 73b.
, And a reduction mechanism is provided between the output gear 73b and an engagement gear 75 that meshes with the half-moon gear 72.

A gear device for locking is arranged for the output gear 73b. The gear device for locking is located at the back of the paper tray mounting portion of the main body frame.
The arm 78 is supported by a swingable holding arm 78, and is urged by a spring 78 a in a direction away from the driving device 73. Further, a one-way clutch is provided on the gear 77 of the locking gear device 76, and control is performed such that the output gear 73b is rotated only in one direction.

When the paper tray is mounted on the paper feeding section, the arm is pressed toward the driving device by the side plate of the tray, and the gears 73b and 77 are brought into mesh with each other. When the paper tray is mounted on the paper feeding unit, the paper size sensor detects the mounting of the tray, and thereafter, the operation of raising the bottom plate is started. As the paper is raised by the above-described operation, the sensor 161 performs an operation of detecting no paper, and the sensor 125 detects that the support frame 120 pressed against the upper surface of the paper is rocked, When the sensor 125 detects that the support frame has been lifted, the operation of swinging the push-up arm 70 at that position is stopped. When the operation of raising the push-up arm is stopped as described above, the drive to the input gear 73a is cut off. However, since the two gears 73b and 77 are engaged as described above, the driving device 73 The one-way clutch 77 holds the sheet at the stop position, and even when the weight of the sheet is added to the push-up arm, the sheet can be held at that position.

Then, as described above, the sheet is raised by raising the sheet to the sheet feeding position, and the sheet is fed by rotating the pickup roller. When the number of sheets is reduced during the sheet feeding, the state is detected. The driving device is operated by the information from the paper sensor, and the half-moon roller 72 is actuated.
Then, the operation of raising the bottom plate 70 is further performed. In this case, for example, 5
The lifting of the bottom plate 61 is stopped by raising the height by about mm. At that position, the paper tray 60 is set in a state where the paper feeding operation can be continued.

When the above-described operation of raising the paper is continued and the paper is fed from the paper tray and the paper in the paper tray runs out, the arm 166 of the paper sensor falls into the hole of the bottom plate. Therefore, the information of the swing of the arm is output by the paper sensor, the fact is displayed on the display unit of the control panel, and a command is issued to the operator.

When the paper tray is pulled out, the pressing of the paper tray 60 against the arm 78 is released, so that the engagement of the two gears 73b and 77 is released, and the driving device is in a free state. , Push-up arm 70
Is pushed down by the force of the return spring 72a, the weight of the half-moon gear and the weight of the bottom plate and paper,
It will be returned to its original position. As described above, in order to allow the push-up arm to slide with respect to the bottom of the paper feed tray, a hole provided in the bottom plate of the paper feed tray is provided in a general paper feed cassette or the like. The arm is formed to be longer in the horizontal direction than in the case, so that the arm is not caught even if the lowering of the arm is delayed when the paper feed tray is pulled out.

[0049]

[Transport roller device nip release mechanism when jam clearing]
In the image forming apparatus, as shown in FIG.
The transport roller device 110 constituting the paper transport path includes a drive roller 111 and a pinch roller 112. The two roller devices disposed opposite to each other have a driving force that is reduced by a driving gear 114 provided on a shaft of a driving roller 111 meshing with a gear 115 of a driving system via an intermediate gear 116. It is configured to be transmitted. In the transport roller device 110, in order to accurately transport the paper in the paper transport path, the shafts of the rollers arranged opposite to each other are configured such that a nip force can be secured by a spring 113 or the like. ing.

However, in the transport roller device configured as described above, if the paper stops while being nipped between the two rollers, the rollers are held in a stopped state. Even if you try to remove the paper by opening the side door, if you forcibly pull out the paper nipped by the transport roller device, problems such as tearing of the paper will occur, and the broken paper pieces will be completely removed. It may remain in the machine without being cut off, causing troubles in the subsequent paper transport path.

On the other hand, in a paper feed path for connecting a paper tray and a recording unit of a conventional image forming apparatus, a driving roller constituting a transport roller device is fixedly disposed on a main body frame, and a pinch roller is provided. The pinch roller is separated from the drive roller by opening the door to open the sheet transport path by opening the door. In the case of a device in which a nip pressure is set in a state in which a spring is wound around two axes of a drive roller and a pinch roller, at the time of jam clearing, the device is opposed to the force of the spring, It is necessary to provide a means for opening the gap between the rollers with a larger force.

Therefore, in the transport roller device of this embodiment, as shown in FIGS. 13 and 14, when the jam clearing door 118 is opened, the intermediate gear 116 is released from the drive gear 115. The configuration is such that both rollers of the transport roller device 110 can be freely rotated without releasing the nip therebetween. The door 118 is provided corresponding to the sheet feeding unit 6 shown in FIG. 1, and is swingably provided on the opening / closing door 33a via a link or the like as shown in FIG. This is shown as an example of the case where However, as shown in FIG. 11, in the case of arranging the sheet feeding units 6a to 6c so as to correspond to the sheet feeding unit 6a to 6c, the drive mechanism of the transport roller device is provided by providing a push rod at the hinge of the door. Can be released.

In the driving mechanism of the transport roller device,
The intermediate gear 116 is connected to the drive roller 11 via a link 117.
And the link 117 is supported by a spring 117.
By swinging the intermediate gear 116, the intermediate gear 116 can swing. In addition, the jam clearing door 118 described above may be, for example, a
When the door is opened and closed via the door 18a, a push rod 119 is provided at the top of the door, and when the door is closed, the arm 117a protrudes from the link holding the intermediate gear 116 by the push rod 119. , And the two gears 114 and 115 are connected via the gear 116.

Accordingly, in the drive system of the transport roller device, when the transport roller device 110 is set to transport the sheet, as shown in FIG. Since the rod 119 presses the arm 117a, the rotation of the gear 115
The state is transmitted to the drive roller 14 so that the transport roller device is driven.

On the other hand, when the door 118 is opened, as shown in FIG. 14, the pressing of the push rod 119 against the arm 117a is released. Since the link 117 supporting the intermediate gear is pulled by the spring 117b, the link 117 swings clockwise about the axis of the drive roller 111, so that the intermediate gear 116 is separated from the drive gear 115, and Set the device to free state. In the transport roller device, when the side door is configured to swing through a hinge on the back side as shown in FIG. 1, a push rod corresponding to an arm is provided at an end of the door. Can be arranged. Then, similarly to the case of the illustrated door 118, the gear of the transport roller device is released from the gear of the drive system, and the paper nipped between the rollers can be easily pulled out by hand. It is possible.

[0056]

[Driving Control of Paper Feeding Device] In the paper feeding device unit, as described above with reference to FIGS. And the sheet is fed out while the pickup roller is pressed against the sheet. Further, in the paper feeding device, the pickup roller 145 and the paper feeding roller 140 are driven by the driving shaft 141 of the paper feeding roller in the paper feeding direction to drive those rollers in the counterclockwise direction in the drawing. Then, the sheet P is fed, and the retard roller 130 is driven in the counterclockwise direction in the figure, and is driven in a direction to return the sheet toward the sheet tray.

However, the retard roller 130 has
Since the torque limiter 132 is provided between the drive shaft 131 and the drive shaft 131, when only one sheet is inserted into the sheet separating mechanism, the frictional resistance to the sheet conveyed by the sheet feed roller 140 is large. The torque limiter slips and rotates the retard roller in the feed direction. In contrast, a plurality of sheets are simultaneously picked up by the pickup roller 1.
When the sheet is unloaded from the sheet tray by 45, the upper sheet P1 is sent out through the sheet separating mechanism, but the lower double sheet P2 is stopped by the rotation of the retard roller 130 in the opposite direction. You. This is because the coefficient of friction between the retard roller and the sheet is larger than the coefficient of friction between the sheets that cause double feeding.

When paper is fed by the paper feeder unit, as shown in FIGS. 15 and 16, the support frame 120 supporting the pickup roller 145 is used.
Is moved down toward the bottom plate 61, and the pickup roller 145 disposed at the tip end of the support frame 120 is driven in a counterclockwise direction to feed the sheet P. And the bottom plate 6
When the paper sent from above 1 is in the double feeding state, only the upper one sheet is sent out, and the other papers remain in a state where they are nipped by the paper separating mechanism.

However, as described above, when the operation of the image forming apparatus is stopped and the paper tray is pulled out of the main body in a state where the leading end of the paper remains in the paper separating mechanism immediately before the nip portion. In order to prevent the paper left in front of the nip portion of the paper separating mechanism from remaining in a state protruding from the paper tray, the paper may be caught on the protruding portion of the main body frame while the paper tray is being pulled out. It may be damaged.

In order to solve the above-mentioned problem, in the paper feeder unit 100 according to the present embodiment, at the end of the copy cycle, the pickup roller and the paper feed roller are rotated in the opposite directions, and Means are provided so that the paper stopped in the state of being nipped by the separating mechanism can be returned to the paper tray. As a mechanism for this, in the apparatus of the present embodiment, as shown below, using the driving of the retard roller that rotates in the reverse direction,
By using a method in which the sheet feeding roller and the pickup roller are driven in the opposite directions by the retard roller, the function of returning the sheet can be performed.

In order to achieve the above-described object, as shown in FIG. 15, the pickup roller 145 is rotated while being pressed against the paper to perform the paper feeding operation. The solenoid is turned off to swing the support frame 120, and the pickup roller 1
45 away from the paper. In this state, when the sheet carried out by the conveying roller device 11 is detected by the sensor 165, the driving of the sheet feeding roller 140 is turned off. In this state, the sheet is carried out by the conveying roller device 11, so that the sheet feeding roller continues to rotate in a co-rotating state. When the rear end of the sheet has passed through the sheet separating mechanism, the sheet feeding roller is rotated in the direction opposite to the sheet feeding direction by the reverse rotation of the retard roller. At the same time, the solenoid is turned off for a short time to lower the support frame 120, and the pickup roller 145 is turned off.
Is returned to the position where the sheet is pressed against the sheet, and the operation of returning the sheet is performed.

Then, as described above, the sheet feeding roller and the pickup roller are rotated in the reverse direction, and the reverse feeding operation for the sheet is performed for a short time. The portion is returned to a state where it does not protrude significantly from the end of the paper tray. Therefore, the reverse rotation of the paper feed roller and the pickup roller is performed by using the rotation of the retard roller according to the reverse drive program of the paper feed device set in the control device of the image forming apparatus, and for a short time. When the paper tray is pulled out by performing the operation of pressing the pickup roller against the paper, the paper may be caught by a projection or the like protruding in the middle of the passage of the tray, and the paper may be damaged, or other troubles may occur. Can be prevented.

In the above-described paper feeder,
The drive mechanism of each roller is configured as shown in FIG. In the drive mechanism shown in FIG. 17, an input gear 142a and an electromagnetic clutch 142 are provided at the end of the drive shaft of the paper feed roller 140.
The control of the driving of the paper feed roller is performed by 42. Further, as described above, the pickup roller 145 is driven interlockingly via the gear mechanism provided between the pickup roller 145 and the paper feed roller.

Further, the drive shaft 1 of the retard roller 130
An input gear 133 is disposed at an end of the drive shaft 1.
A torque limiter 132 is provided between the retard roller 31 and the retard roller 130. When the paper is inserted between the paper feed roller and the retard roller in a double feed state, the frictional resistance between the overlapped papers is smaller than the frictional resistance between the paper and the roller. Is also smaller than
The retard roller is driven in a direction opposite to the sheet feeding direction to stop the lower sheet and feed only the upper sheet by the sheet feeding roller. When only one sheet is inserted into the sheet separating mechanism, the drive of the retard roller is stopped by the action of the torque limiter, and the retard roller is rotated in the feeding direction according to the sheet.

[0065]

[When a large capacity tray is installed at the bottom of the paper feeding unit] Fig. 1
As described with reference to FIG. 2 and FIG. 2, in the image forming apparatus according to the present embodiment, among the paper trays arranged in multiple stages in the vertical direction, the lowermost tray is configured as a large-capacity paper tray. I have. And the paper tray 5
For c, a system is provided in which a caster is provided so that the weight of the paper tray is not burdened by the main body frame when the paper tray is pulled out.

As the large-capacity tray described above, for example,
It can be configured as shown in FIG. The large-capacity tray 85 shown in FIG. 18 will be described by changing the reference numerals, but the same tray as the paper tray 5c in FIG. 1 will be described. As shown in FIG. 18, in the image forming apparatus according to the present embodiment, the lowermost sheet tray of the lower device 30 is configured as a large-capacity tray 85,
A caster 86 is provided at the lower end side of the large capacity tray. On both sides of the large capacity tray 85, a pair of rollers 87, 87a are arranged, respectively, and these rollers move along guide rails provided in the accommodating portion 80 and can support the weight of the tray. To be.

The lower device 30 of the image forming apparatus includes:
A storage section 80 for the tray is formed, and guide rails 81 are arranged at both sides inside the storage section 80 to guide the movement of the tray. As shown in FIG. 19, the tray 8
A guide portion 82 for guiding the roller No. 5 is provided. The guide portion 82 is formed in such a shape that a lower end portion of the rail is expanded so that the roller 87a can be easily inserted.

Further, in order to stop the tray at a predetermined position when the large capacity tray 85 is pulled out, a stopper 83 is provided on the main body side, and a locking portion 88 is projected from the side of the tray. Provided. As shown in FIG. 18, when the large-capacity tray 85 is pulled out, paper can be supplied to the tray 83 in a state where the locking portion is engaged with the stopper 83.

The large capacity tray 8 configured as described above
In 5, when the tray is mounted on the main body, the bottom plate is raised, so that the upper portion of the paper accommodated in the tray is pressed by the pickup roller, and the tray is set in a state where the paper can be fed. The mechanism for raising the bottom plate and the like can be configured in the same manner as that described in, for example, JP-A-58-183532. When a new sheet is to be supplied to the tray 85, the tray is moved to the front of the apparatus by releasing the fixed position by rotating the handle of the tray or the like and pulling out the handle. Let it. At this time, the front roller 87 is
When it moves along 2, the front portion of the tray gradually descends, and the casters 86 come into contact with the floor, so that the load on the front side of the tray can be borne.

Therefore, even if the large capacity tray 85 is pulled out a predetermined distance and replenished with paper, the weight can be borne by the casters, so that the main frame need not bear the load of the protruding portion of the tray. . When the large-capacity tray is returned to the storage section 80, the main body frame bears the load from the time when the rollers 87 are engaged with the guide rails 81 during the insertion. Since the protruding portion of the tray is reduced, the unbalance load applied to the front side of the frame is small, and there is no problem such as the device being rolled over.

In the image forming apparatus, the structure of the tray, the guide rail, and the mechanism of the traveling member are not particularly limited to those shown in the figures, and any mechanism may be used. is there. Further, as the sheet feeding device for the tray, the above-described sheet feeding unit can be used.

[0072]

[Case where Paper Feeder Units with Different Performances are Used] In the above-mentioned paper feeder unit, as shown in FIG. 4 to FIG. Although it is configured so that paper can be fed from a tray, in the image forming apparatus, it is necessary to equip all the paper trays with a high-performance paper feeding device as shown in the figure. May not be needed. In other words, even when a large number of paper trays are provided in the same apparatus, there is a case where it is not necessary to configure all of the paper trays, which are particularly important and the paper trays which are not frequently used, with a high-performance paper feeder. is there.

Further, when the image forming apparatus is configured as a device such as a laser printer and the printer has a large recording paper producing capability, the obstacle caused by the double feeding of the paper becomes very large. However, when a mechanism arranged in the image forming apparatus is applied to a low-speed image forming apparatus or the like, using a high-performance sheet feeding apparatus as described above increases the manufacturing cost of the apparatus. And raises financial problems. Therefore, in the paper feeder shown in this embodiment, the high-performance paper feeder as described above and a paper feeder which is relatively inexpensive and simple in configuration are configured as units of the same size, and the feeders thereof are provided. It can be provided in the paper feed unit according to the importance of the paper device. In order to achieve the above-described object, in the image forming apparatus of the present embodiment, in addition to the high-performance sheet feeding unit as shown in FIG. The paper feed unit having a simple mechanism can be configured according to the same standard, and can be rearranged as needed in the paper feed unit of the same image forming apparatus.

The paper feeder unit 1 shown in FIG.
00a is a side view of the sheet feeding device corresponding to FIG.
The main body paper conveyance path 102 and the paper supply path 105
The configuration is the same as that shown in FIG. On the other hand, in the case of the illustrated example, a half-moon roller 185 is provided for the paper tray, instead of the pickup roller, as in the case of the conventional paper feed cassette, and the leading end of the paper tray on the paper feed side is provided. A snubber 183 is disposed on the sheet to constitute a sheet separating mechanism. Further, a bottom plate 181 supporting the paper is supported by a biasing member such as a spring at a leading end portion of the paper stored in the paper tray 180 on the paper feed side.
5 is pressed. Further, since there is no need to dispose a sheet separating mechanism downstream of the feeding portion by the half-moon roller, the sheet can be fed toward the transport roller device 110 in the main body paper transport path by the action of paper feeding by the half-moon roller. I can do it.

In the case of using the paper feeder configured as described above, the rate of occurrence of double feed may increase when paper is fed from the paper feeder. Since the apparatus has a configuration similar to that of a conventionally used paper feeding apparatus, no particular problem occurs when the image forming apparatus is configured as an image forming apparatus. In addition, paper can be fed.

Further, in addition to the above-mentioned paper feeding device using a half-moon roller as described above, it is also possible to use a device having another configuration. The size and the like are the same as those of the sheet feeding unit, so that a plurality of types of apparatuses having different sheet feeding performances and different prices can be prepared. Then, as described above, a paper feeder having a different paper feed performance and configuration is provided for a paper feeder unit of the same size, and the paper feed units of the image forming apparatus are combined as necessary. By mounting the paper feeding device in the upright position, the paper feeding performance required for the paper feeding device can be exhibited in a good state.

Further, in the above-mentioned image forming apparatus, particularly when the apparatus is connected to a computer and continuously prints, or a high-performance apparatus such as a laser printer, In the sheet sorting apparatus as shown in FIGS. 4 and 5, it is necessary to provide a sheet feeding apparatus that performs the sheet sorting operation accurately and has a very low double feed rate. On the other hand, in the case of a device such as a small-sized copier, which does not hinder the use thereof even if the double feed occurrence rate is the same as that of a conventionally used paper feeding device, a diagram is shown. Even if a paper feeder having a simple configuration as shown in FIG. 20 is used, it is possible to sufficiently cope with a demand for the paper feeder. Therefore, in the image forming apparatus, a plurality of types of sheet feeding apparatuses having the same size and different sheet feeding performances are prepared, and are configured so that they can be mounted on the image forming apparatus according to the required performance of the apparatus. This makes it possible to configure a device having any performance.

[0078]

Since the apparatus according to the present invention is constructed as described above, the image forming apparatus main body side of the door member is used as a sheet conveying path, and the sheet conveying path is opened and closed by opening and closing the door member. Thus, the work of removing the paper when a jam or the like occurs can be easily performed. Further, when the door member is configured to cover a portion of the transport device in which a jam is likely to occur or a portion extending over a plurality of paper trays, the jam and the like can be more easily processed by opening the door member.

[Brief description of the drawings]

FIG. 1 is a perspective view of an image forming apparatus of the present invention.

FIG. 2 is an explanatory diagram showing a configuration of the device of FIG.

FIG. 3 is a side view showing an arrangement state of a sheet feeding unit.

FIG. 4 is a perspective view of the sheet feeding unit of the present invention.

FIG. 5 is a perspective view illustrating a relationship between roller devices constituting a sheet feeding unit.

FIG. 6 is an enlarged explanatory view of a part a in FIG. 5;

FIG. 7 is an explanatory view of a mounting unit of the sheet feeding unit.

FIG. 8 is an explanatory diagram of a driving mechanism for a sheet feeding unit.

FIG. 9 is a plan view of the sheet feeding device unit.

FIG. 10 is a cross-sectional view of a sheet feeding unit.

FIG. 11 is a cross-sectional view of the paper feeding unit in a state where the paper tray has run out of paper.

FIG. 12 is a perspective view of a mechanism for pushing up a bottom plate.

FIG. 13 is an explanatory diagram of a nip state of a sheet in a transport roller device.

FIG. 14 is an explanatory diagram of a jam clear mechanism in the transport roller device.

FIG. 15 is an explanatory diagram of a state where a sheet is sent out from a sheet tray.

FIG. 16 is an explanatory diagram illustrating an operation of returning a sheet.

FIG. 17 is an explanatory diagram of a drive mechanism such as a retard roller and a paper feed roller.

FIG. 18 is an explanatory view showing a configuration of a storage section of a large capacity tray of the apparatus main body.

FIG. 19 is an explanatory diagram showing a state in which the large-capacity tray is pulled out.

FIG. 20 is a side view illustrating the configuration of another sheet feeding unit applicable to the sheet feeding unit of the image forming apparatus.

[Explanation of symbols]

Reference Signs List 1 image forming device, 10 upper device, 15
Photoreceptor drum, 20 manual feed tray, 26 return path, 27 curl correcting device, 30 lower device,
31 body frame, 32 body caster, 3
3.34 side door, 42 reversing path, 45 paper transport path, 5d intermediate tray, 60 paper tray, 61 bottom plate, 70 push-up arm, 72 half moon gear, 85 large capacity tray, 1
00 paper feeder unit, 101 unit frame, 102 main body paper transport path, 105 paper feed path, 110 transport roller device, 111 drive roller, 112 pinch roller, 118 opening / closing door,
120 support frame, 130 retard roller, 132 torque limiter, 140 paper feed roller, 145 pickup roller, 150 swinging device, 151 solenoid, 160 sensor, 165 paper sensor,

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-53944 (JP, A) JP-A 61-176130 (JP, U) JP-A 60-69244 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) B65H 1/00-3/68

Claims (4)

(57) [Claims] A recording unit configured to perform recording on a sheet; a sheet tray configured to stack a plurality of sheets below the recording unit in a vertical direction; and a sheet stacked on the sheet tray. Paper feed means for feeding paper in contact with the paper feeder, a paper transport path for passing paper from bottom to top along the side surface of the image forming apparatus main body, and a paper feed path provided for each of the plurality of paper trays. A first guide unit for guiding the sheet fed by the sheet feeding unit, and a second guide unit for guiding the sheet upward from below along the side surface of the main body; Corresponding to each paper tray of the paper tray, provided at the downstream side of the guide means in the paper transport direction, a transport device for transporting the paper in the paper transport path, and provided to be openable and closable in the image forming apparatus main body; Low side of device An image forming apparatus comprising: a door member that covers at least a part thereof; and a third guide portion provided inside the door member and guiding a sheet upward from below. At least a part of the image forming apparatus is formed by the second guide portion and the third guide portion. 2. The image forming apparatus according to claim 1, wherein the door member covers a portion of the transport device. 3. The image forming apparatus according to claim 1, wherein the door member covers a portion of the paper transport path that extends over a plurality of paper trays. 4. The image forming apparatus according to claim 3, wherein the door member covers all portions of the paper transport path that extend over a plurality of paper trays.