JPH054733A - Sheet feeder of picture image forming device - Google Patents

Abstract

PURPOSE:To facilitate installation and so forth of a roller member in the sheet feed part of a picture image forming device by providing plural sheet feeders in a stacked condition, disposing a sheet storage device such as a sheet feed tray to the sheet feeder, and constituting members such as a pick-up roller installed on the sheet feeder as one unit. CONSTITUTION:There is provided a unit 20 where a pick-up roller 21 and a feed roller 22 are disposed detachably in a sheet feeder 15 which is provided at the sheet feed part of a picture image forming device 1. The roller unit 20 is provided through an oscillating device 50 so as to move the pick-up roller in a vertical direction to the supporting member of the sheet feeder, and only when a sheet is fed from the sheet feed tray, the pick-up roller 21 is oscillated at the position where the roller presses the sheet. A means for supporting both the end parts of a driving shaft to the sheet feeder is provided in the roller unit 20, so that installation is conducted easily. Besides, it is possible to conduct inspection work and the like of the roller device easily by taking out the roller unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device in an image forming apparatus such as an electronic copying machine or a printer, and more particularly,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device in which a roller member that is heavily worn is configured as a unit in a paper feed device using a friction retard roller system so that replacement work can be performed easily.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electronic copying machine or a laser printer, a paper accommodating means such as a plurality of paper feeding trays or cassettes is attached to a paper feeding portion, and the paper accommodating apparatus is mounted on the paper accommodating apparatus. By accommodating sheets of different sizes, a means for selecting a sheet of an appropriate size in accordance with information such as the size of the original document and the reduction / enlargement ratio and making a copy is used. In the image forming apparatus, a paper accommodating device is generally mounted from the side of the device, but recently, as referred to as a front loading type, the paper accommodating device is moved in and out from the front side of the device. The one configured to obtain is often used.

An example of the conventional front-loading type image forming apparatus is, for example, Japanese Patent Laid-Open No. 2-231324.
An example as shown in Japanese Patent Publication is known. In the conventional electronic copying machine, a plurality of sheet feeding devices are arranged in multiple stages in the sheet feeding section of the apparatus main body, and a sheet accommodating device such as a sheet feeding tray is attachable to each sheet feeding device. Fig. 8
It is configured as shown in. The example shown in FIG. 8 shows the case of an electronic copying machine as an image forming apparatus. The copying machine 1 includes, for example, an upper device 2 provided with a mechanism for forming a xerographic toner image. , And a lower device 3 mainly equipped with a paper feeding device.

In the electronic copying machine 1, the upper device 2 includes an optical device 10 for scanning an image of a document corresponding to the platen 4 arranged on the upper part, as in the case of a general copying machine. , A photosensitive drum 11 for forming a toner image, and a developing device 1 arranged around the drum 11.
2, a transfer device 13, a cleaning device and the like are arranged. Further, a conveyor belt device for conveying the sheet on which the toner image has been transferred from the photosensitive drum 11 toward the fixing device 17 is provided, the sheet is guided to the fixing device, and the fixing operation is performed in the fixing device 17. Copy tray 1
Eject toward 8.

The upper device 2 is provided with one sheet accommodating device 5 so as to be capable of feeding paper, whereas the lower device 3 has a sheet accommodating device 6 such as a plurality of sheet feeding trays. ~
8 are arranged so that sheets of arbitrary size can be fed from the respective sheet storage devices. The intermediate tray 9 arranged at the lower part of the sheet accommodating device 7 is used when a back side copy is made with respect to a one sided copy that has been passed through the fixing device 17. A single-sided copy is introduced via path 19. Further, the lowermost sheet storage device 8 is configured as a large capacity tray. In order to feed the sheets from the sheet accommodating device, the sheet feeding devices 15 ... Are arranged corresponding to the sheet accommodating device. The sheet feeding devices 15 ... Use sheet feeding units having the same configuration except the sheet feeding section from the intermediate tray. The sheet feeding roller devices provided in the sheet feeding devices 15. Is used to carry out the paper from the paper storage device, and the paper is carried toward the image recording section by the carrying device 14 via the paper path 16.

A roller member as shown in FIG. 9 is provided in the sheet feeding device arranged corresponding to each sheet accommodating device. In the sheet feeding device shown in FIG. 9, the main body frame 24 is provided with a clutch member 41 for driving the drive device 40 and the drive shaft 30. Further, in a state of traversing the frame 24, a shaft member for each roller device is arranged, a feed roller 22 is arranged for a drive shaft 30, and side frames 25, 26 supported by the drive shaft are provided, A pickup roller 21 is swingably provided.

Further, the pickup roller and the feed roller are configured to be interlocked with each other via a drive gear device 23, and by connecting a clutch 41, a paper feeding device via a drive device 40. The roller member is driven so that the paper feeding operation can be performed. The pickup roller 21 is swingably supported via a projecting member 28 provided on the side frame 26, and only when the sheet is carried out from the sheet storage device, the pickup roller 2 is provided.
1 is pressed against the paper and driven, and the paper is fed from the paper storage device.

[0008]

In the conventional image forming apparatus configured as described above, when performing maintenance on the roller, the drive shaft 30 is removed from the main body frame 25, and the roller is removed from the shaft. Therefore, there is a problem that it is necessary to inspect and replace, and the work is troublesome. Further, in the roller device configured as described above, it is necessary to mount many members on the body frame even when assembling the image forming apparatus, which complicates the manufacturing process and increases the manufacturing cost. Will also be.

In addition to the above problem, in the conventional image forming apparatus, if the detection information is output during the operation of the paper feeding device for feeding the paper, each driving member or operating member Of vibration may affect the detection means. For example, if the detection as to whether or not the delivered sheet has arrived reaches the timing at which the pickup roller presses the sheet, there is a problem that the detection information cannot be accurately obtained due to the vibration of the operation of the pickup roller.

Further, with respect to the sheet feeding means provided in the sheet accommodating device, the sheet feeding speed from the sheet feeding section is set to be switchable between a high speed and a low speed, and the timing of switching the transport speed is set. , The position of the leading edge of the sheet and the like are used. For example, in the case where the timing of switching the transport speed is set, the driving speed of the sheet feeding unit is set to be low at the time of sheet feeding, and the sheet is nipped by the transport roller device provided in the sheet path. , Set the conveyance speed in the paper path to a high speed. Then, by increasing the paper transport speed in the paper path, the means for shortening the paper transport time in the paper path and shortening the copy discharge time is used.

On the other hand, in the sheet accommodating device, a push-up mechanism is provided for the bottom plate that supports the sheet, and the action of pushing up the bottom plate is performed by the information from the sheet height detecting device. However, as described above, when the drive mechanism for the bottom plate is actuated while the sheet is being conveyed, if the sheet is raised at such a timing that the feed speed for the sheet can be switched, There is a problem that the moving speed of the bottom plate that supports the paper is not constant. In other words, if the other devices are driven while the startup speed of the driving device in the paper feeding unit is not constant, for example, the lifting speed of the paper is increased even if the lifting device is driven for a certain time. Is not constant and the control of the paper height becomes unstable. That is, as described above, with respect to the apparatus for conveying the paper, the bottom plate is moved with respect to the bottom plate while being driven at a low speed, when being driven at a high speed, or in a state in which the speed is changed. When the driving is performed, there arises a problem that the rising speed of the paper and the height of the paper are different according to the respective conditions of the paper conveyance.

[0012]

SUMMARY OF THE INVENTION The present invention solves the problems of the conventional image forming apparatus as described above. By constructing the roller unit of the sheet feeding device as one unit, it is possible to replace a roller member which is heavily worn. It is an object of the present invention to provide a device that enables an operation to be easily performed and a detection device that can perform a detection operation in a good state.

[0013]

According to the present invention, there is provided a pickup roller and a feed roller which are arranged in a sheet feeding section of an image forming apparatus and rotate in a sheet conveying direction. Is arranged so as to face a retard roller to which a driving torque is applied in the opposite direction, and is configured to perform a sheet separating action between both rollers, and a sheet fed from the sheet accommodating device by the sheet feeding device,
The present invention relates to a sheet feeding device configured to be conveyed toward an image forming unit by a conveying device arranged in a sheet path of an image forming apparatus.

In the present invention, the pickup roller and the feed roller arranged in the sheet feeding device are formed as one unit, and are formed separately from the driving means of the sheet feeding section main body for driving the unit. The roller unit is supported by a swinging mechanism, and the pickup roller is configured to press the paper stored in the paper storage device only at the time of paper feeding, and the roller unit arranged in the paper feeding device is separated from the driving means. It is provided so that it can be replaced while it is open.

Further, in the present invention, a detecting means for the fed-out sheet is arranged with respect to the roller unit,
The control means can be configured to interrupt the detection operation of the detection means when the roller unit swings toward the paper. Further, in the present invention, the sheet accommodating device is configured as an elevator type tray, and the sheet supporting unit is configured to be raised according to information from the detecting unit provided in association with the roller unit to form an image. For a sheet conveyed in the sheet path of the apparatus, the speed of the part fed out from the sheet feeding device and the conveying speed in the sheet path are set to be switchable to two or more types, and at the same time in the sheet path. The control means can be configured so that the timing for raising the paper support means is set only when the paper is fed at a certain speed.

As described above, by constructing the pickup roller and the feed roller as one roller unit, the paper feeding device can be easily assembled and the maintenance work is simplified. Further, by providing a means for limiting the operation of the detection means provided in the paper feeding device and the operation for raising the paper, it is possible to obtain accurate detection information.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet feeding device of an image forming apparatus according to the present invention will be described with reference to the illustrated example. The sheet feeding device shown in FIG. 1 is provided for the image forming apparatus as shown in FIG. 7, and is provided for a large number of sheet accommodating devices mounted in multiple stages on the frame of the image forming apparatus. It is arranged so that the paper is fed from the paper storage device. In the sheet feeding device 15 shown in FIG. 1, a roller unit 20 is arranged with respect to a main body frame 24, and the roller unit 20 is driven by a pickup roller 21, a feed roller 22, and a driving means as an interlocking means for both rollers. A gear device 23 is provided.

Further, the paper feeding device 15 has a driving device 40 arranged on one side of the frame, and the driving device 40 is used to drive the conveying roller device 48 and the rollers provided in the roller unit. I am trying. In order to drive the roller unit 20, an output gear 42 and an intermediate gear 43 are arranged via a clutch 41. Then, the input gear 31 arranged at the end of the drive shaft 30 of the roller unit 20 meshes with the intermediate gear 43 to drive the pickup roller and the feed roller.

As described in detail in FIG. 2, the roller unit 20 has side frames 25 and 26 arranged on both sides of a support frame 27, and the axes of the pickup roller 21 and the feed roller 22 are arranged in the frames. Support. Further, a drive gear device 23 is arranged between the two roller members, and an end portion of the drive shaft 30 supporting the feed roller 22 protruding from the side frame 25 is
The input gear 31 is arranged as described above. Further, an arm member 28 is arranged on the side portion of the other side frame 26, and the arm member 28 is engaged with the operating member of the rocking device 50.
The roller unit is swung via the drive shaft 30. In addition to the above configuration, an actuator 29 corresponding to a paper height detection sensor is provided at a predetermined position of the frame 27.
Is arranged, and the height of the actuator is detected to detect the position of the paper stored in the paper storage device.

When the roller unit 20 of the present invention constructed as described above is mounted on the sheet feeding device 15, one bearing member 33 is fitted in the recess 36 provided in the main body frame 24.
Is inserted for positioning, and the bearing member 34 is locked on the other side of the shaft 30 by using a positioning means (not shown). The input gear 31 provided at the end of the drive shaft 30 is meshed with the intermediate gear 43 so that the driving force is transmitted to the rollers of the roller unit.

As described above, the pickup roller 21
And a roller unit 20 including a feed roller 22,
By being provided detachably with respect to the main body frame of the paper feeding device 15, in the present invention, the inspection and replacement work of those rollers can be easily performed. Further, it is not necessary to attach roller members or the like at the time of manufacturing the image forming apparatus, and the manufacturing process of the paper feeding device can be simplified.

The paper feeding device 15 incorporating the roller unit 20 shown in FIG. 2 will be further described. The frame 24 of the paper feeding device 15 corresponds to the actuator 29 provided in the roller unit as described above. A paper height sensor 45 and a no-paper sensor 46 are arranged to detect the state of the paper in the paper storage device. Further, the rocking device 50 is arranged with respect to the arm member 28 arranged on the side of the roller unit 20, and the roller unit 20 is centered on the shaft 30 via the driving arm member 52 of the rocking device 50. I try to rock it.

As shown in FIG. 3, the swinging device 50 is arranged on the side of the side frame 26 of the roller unit 20, and is different from the arm member 28 provided on the side frame 26 in the drive arm member. 52 to be engaged.
Further, a solenoid 51 and a spring 54 are arranged to swing the arm 52, and the arm 52 is swung via a shaft 53.

For example, when the paper feeding operation is not performed,
Since the solenoid 51 is turned off, the swing device 5
The spring 52 of 0 raises the arm 52 to hold the pickup roller 21 of the roller unit 20 in a state of being separated from the sheet via the shaft 30. Also,
When feeding the paper, turn on the solenoid 51,
The arm 52 is lowered, and the weight of the roller unit and the action of the spring 55 cause the pickup roller 21 to be pressed against the sheet while driving the roller 21 to feed the sheet. The time during which the solenoid is energized is the time until the leading end of the sheet is nipped by the conveyance roller device arranged in the downstream portion of the separating device,
Alternatively, it is set only for a very short time until the leading edge of the sheet passes through the separating section and slightly advances further. Further, the actuator 29 arranged at the tip of the frame of the roller unit is in a position detected by the paper height sensor 45. Then, the roller unit 20
The position of the actuator 29 is detected by the sensor 45 in a state where the
A mechanism for controlling the height of the sheet corresponding to the sheet accommodating device is operated so that the position where the pickup roller contacts the sheet can be constantly adjusted.

(Paper Height Control Device in Paper Containing Device) In the embodiment of the present invention shown in FIG. 4, a paper feeding tray 65 as a paper accommodating device is attached to the paper feeding device 15 to feed the paper. The case where the paper is fed from the tray 65 by the pickup roller 21 is shown. In the example shown in FIG. 4, the bottom plate 66 for supporting the paper is arranged inside the paper feed tray 65, and the bottom plate 66 is pushed up by the push-up arm 61, whereby the height of the paper P relative to the pickup roller 21 is increased. It is configured to control the height.

Further, as described above, the paper feeding device 15 in which the paper feeding tray 65 is mounted is provided with the roller unit 20, and the pickup roller 21 takes out the paper from the paper feeding tray. Feed roller 2
2 and the retard roller 47 perform a separating operation on the sheets, and the sheets separated one by one are conveyed by the conveying roller device 48 in the sheet path 16.
The separating device in which the feed roller 22 and the retard roller 47 are arranged so as to face each other is generally called a friction retard roller type device, and a driving torque is applied to the retard roller 47 in a direction opposite to the sheet feeding direction. The retard roller 47 pushes back the lower sheet fed in the double feed state. Further, an insertion guide 67 is provided for guiding when the paper feed tray 65 is attached to the paper feed unit, and the paper feed tray is attached via the insertion guide 67 to provide a paper feed device. It is configured so that the paper feed tray can be attached to the correct position.

The push-up arm 61 of the drive unit 60 is arranged with respect to the bottom plate 66 placed in the paper feed tray, and the bottom plate 66 is raised by the push-up arm 61. It is configured as shown in. The drive device 60 shown in FIG.
A substantially fan-shaped input gear 63 is arranged with respect to an output gear of a drive gear device 64 connected to a drive device of the image forming apparatus main body, and a push-up arm 61 is attached to a shaft 62 provided on the gear 63. Then, by driving the drive gear device 64 little by little in correspondence with the height of the paper, the bottom plate 66 is raised via the push-up arm 61, and the height of the paper is maintained at a constant height. To do.

Further, in the drive unit 60, as described above, the drive gear unit 64 is formed by the drive connection means (not shown) based on the information from the paper height detection sensor.
Is controlled to drive the paper so that the paper supported by the bottom plate 66 has a constant height. When the driving device 60 is driven, until the roller unit moves in the descending direction and the roller 21 presses the paper, the detection operation by the paper height detection device shown in FIG. The detection timing is set so as not to detect whether or not the delivered sheet has arrived, and the sensor 45 or the like detects the pickup roller 21 of the roller unit in a stable state on the sheet. .

Therefore, by detecting the height of the sheet and detecting the presence / absence of the fed sheet at the timing as described above, the detection information from each sensor is vibrated by the oscillation of the roller unit. Is not affected, accurate detection information can be obtained. further,
In the apparatus of the present invention, when the driving device 60 is driven to raise the bottom plate, the paper fed from the paper feeding device is being conveyed at a constant speed in the paper path. Only, the control means for the drive device is configured to raise the push-up arm 61. Then, only when the drive mechanism connected to the drive device 60 drives other members at a constant speed,
By performing the driving operation for the push-up arm 61,
It becomes possible to limit the drive speed with respect to the bottom plate so that the height at which the paper is raised can be accurately controlled.

In addition to using the paper feed tray 65 as described above, in the present invention, a large capacity tray 70 as shown in FIG. 6 can be used as the paper storage device.
The large-capacity tray 70 shown in FIG. 6 is configured to have the same structure as a tray generally used as a large-capacity sheet accommodating device, and a bottom for supporting sheets inside the tray body. The plate 71 is provided so as to be vertically movable. Further, the large-capacity tray 70 can be attached to the paper feeding device 15 via the insertion guide 74, and can be positioned with respect to the paper feeding device. Furthermore, the bottom plate 71 of the present invention
Uses a means for arranging the wire 73 between it and the drive device 72 and winding the wire to raise the bottom plate 71.

Then, in the large capacity tray 70, as in the case of the paper feeding tray shown in FIG. 4, the large capacity tray 70 is driven by the information of the paper height from the detecting means arranged corresponding to the roller unit. The device 72 is driven to raise the bottom plate 71 so that the height of the sheet with respect to the pickup roller 21 is kept constant. Further, the operation for raising the paper is performed inside the large capacity tray only when the paper is conveyed at a constant speed in the paper path. As described above, the operation of raising the sheet in the sheet storage device will be described with reference to FIG. In the image forming apparatus shown in FIG. 7, the paper fed from the paper feeding device is regulated by the rotation speed of the feed roller within the section where the paper speed is controlled by the feed roller 22 in the paper feeding portion of each device. To be done. On the other hand, in the paper path 16, the carrying action is carried out at a high speed by the carrying roller device 48. That is, when trying to convey the paper at a high speed in the paper feeding unit, the feed roller 22 and the retard roller 47 in the paper separating unit are used.
Therefore, the performance of the sorting operation is deteriorated, and a problem that double feeding is likely to occur occurs. Therefore, the sheet is conveyed at a low speed in the separating section, and the sheet is conveyed at a high speed in the sheet path 16, so that the time required for the sheet to reach the image transfer section from the photosensitive drum 11 is shortened. Make it possible to reduce the time required for.

In the image forming apparatus of the present invention in which the above-mentioned transport mode is set, while the paper is being fed out of the paper feeding device at the speed v1, the operation of raising the paper inside the paper accommodating device is performed. If the sheet is not carried out and the sheet is being conveyed at a constant speed v2 in the sheet path 16,
Perform the operation to raise the paper. This allows
Since the action of raising the sheet inside the sheet accommodating device is performed at a constant speed, the amount of raising the sheet with respect to the drive time of the device is stable.

In the embodiment of the present invention, the case where each mechanism is provided for the electronic copying machine as the image forming apparatus has been described. However, each apparatus of the present invention can be applied to other apparatuses such as a laser printer. However, it can be applied. Further, each of the constituent members of the present invention is not only applied to the image forming apparatus having the above-described configuration, but can be easily applied to a recording apparatus using a cut sheet.

[0034]

Since the sheet feeding device of the image forming apparatus of the present invention is configured as described above, the sheet feeding device is assembled by configuring the pickup roller and the feed roller as one roller unit. And the maintenance work is simplified. Further, it is not necessary to attach roller members or the like to the sheet feeding device when manufacturing the image forming apparatus, and the manufacturing process of the sheet feeding device can be simplified. further,
Accurate detection information can be obtained by providing a means for limiting the operation of the detection means provided in the sheet feeding device and the operation for raising the sheet, and the information from each detection device can be obtained accurately.

[Brief description of drawings]

FIG. 1 is a plan view of a paper feeding device of the present invention.

FIG. 2 is a plan view showing a configuration of a roller unit of the present invention.

FIG. 3 is a perspective view of a rocking device of the present invention.

FIG. 4 is a side view when a paper feed tray is attached to the paper feed device.

FIG. 5 is a perspective view of a drive device for driving the bottom plate of the paper feed tray.

FIG. 6 is an explanatory diagram of a case where an elevator type large capacity tray is provided in a sheet feeding device.

FIG. 7 is an explanatory diagram of a sheet conveying mechanism in the image forming apparatus of the present invention.

FIG. 8 is a side view showing the configuration of a general image forming apparatus.

FIG. 9 is an explanatory diagram showing a configuration of a conventional paper feeding device.

[Symbols in the figure]

1 Image forming device 15 Paper feeder 20 Roller unit 21 Pickup roller 22 Feed roller 30 drive shaft 31 input gear 40 drive 42 output gear 43 Intermediate gear 45 Paper height sensor 47 retard roller 48 Conveyor roller device 50 rocking device 60 drive 61 Push-up arm 65 paper tray 66 Bottom plate 70 large capacity tray

Claims (3)

[Claims] 1. A pickup roller and a feed roller, which are arranged in a sheet feeding portion of an image forming apparatus and rotate in a sheet conveying direction, are provided with a driving torque in a direction opposite to the sheet feeding direction. Conveying is arranged so as to face the retard roller so as to separate the paper between the two rollers, and the paper delivered from the paper accommodating device by the paper feeding device is arranged in the paper path of the image forming device. In a paper feeding device configured to be conveyed by an apparatus toward an image forming unit, a pickup roller and a feed roller arranged in the paper feeding device are one unit, and a paper feeding unit driving the unit. Formed separately from the drive means of the main body, the roller unit is supported by a swinging mechanism, and the pickup roller is attached to the paper stored in the paper storage device only at the time of paper feeding. A sheet feeding device of an image forming apparatus, wherein the roller unit is configured to be pressed toward and is replaceably provided in a state of being separated from a driving unit, the roller unit being disposed in the sheet feeding device. 2. A detection unit for detecting a sheet to be fed is arranged in the sheet feeding unit, and when the roller unit performs an operation of swinging toward the sheet, the detection action by the detection unit is interrupted. The sheet feeding device of the image forming apparatus according to claim 1, further comprising a control unit corresponding to the detection unit. 3. The sheet accommodating device is configured as an elevator tray, and is configured to raise the sheet supporting means in accordance with information from a detecting means provided in association with the roller unit. For the paper conveyed in the paper path, the speed of the part fed out from the paper feeding device and the conveyance speed in the paper path are set to be switchable to two or more types, and the paper path is set in the paper path. The image forming apparatus according to claim 2, wherein the control means of the drive unit is configured so that the timing for raising the sheet supporting means is set only when the sheet is being fed at a certain speed. Paper feeder of the device.