JPH05338865A - Paper adjusting device of image forming device - Google Patents

Abstract

PURPOSE:To enable a paper adjusting device disposed immediately in front of an image transfer portion leading from a photoreceptor drum to operate well in adjusting and feeding paper sheets by constituting a register roller device of roller members provided with a gate member. CONSTITUTION:A paper adjusting device disposed immediately in front of an image transfer portion has a register roller device 10 disposed downstream of a pre-register roller device. The register roller device 10 has a gate member 15 provided on the shaft 14 of a register roller 11 via a torque limiter 17. As a drive roller rotates the gate member 15 can be rolled between a position in which it stops paper and a position in which it urges passage of the paper, so as to be capable of dealing with an operation to form a loop in the paper P by locking the end portion of the paper P to the gate member and that to feed the paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet aligning device for an electrophotographic copying machine or the like, which is arranged immediately before a portion where a toner image formed on a photosensitive drum is transferred onto a sheet, The present invention relates to an apparatus configured so that a registration mechanism provided by a registration roller device provided in a sheet alignment apparatus is provided and a gate member operated by a solenoid or the like can be omitted.

[0002]

2. Description of the Related Art Like electrophotographic copying machines and printers,
In an image forming apparatus that forms a toner image on an image bearing member such as a photosensitive drum, a mechanism for forming a copy by transferring the toner image formed on the photosensitive drum onto a sheet and then fixing the toner image through a fixing device is provided. I am using. In the image forming apparatus, in order to transfer the toner image formed on the photosensitive drum to an accurate position on the paper, a paper aligning device is arranged immediately in front of the image transfer section. Then, the paper is temporarily stopped by the paper aligning device to provide an aligning action, and then the paper is sent out in time with the toner image formed on the photoconductor drum, so that the toner image transferred to the paper is changed. , So that there is no deviation.

As described above, in the apparatus using the means for aligning the sheets by the sheet aligning apparatus, two types of methods, the gate method and the roll nip method, are used as the means for stopping the sheets. Means for stopping the sheet by using the gate member is, for example, the actual opening 64-65.
It is configured as shown in Japanese Patent Publication No. 5 or the like. In the conventional aligning device, a gate member is swingably arranged at an upstream part of the registration roller device among the two roller devices constituting the paper aligning device, and the pre-registration roller device is provided at the upstream part of the gate member. Are arranged.

Then, with the leading end portion of the paper being stopped by being locked by the gate member, a slight additional feeding action is applied to form a loop on the paper so that the paper aligning action is performed. .. After that, according to the information of the toner image formed on the photosensitive drum, when the gate member is released, the leading end of the sheet rushes into the nip position of the registration roller device by the reaction force of the loop, and the registration roller device By being driven, the sheet can be sent to the image transfer section.

In addition to the gate type sheet aligning device,
In the paper aligning device using the roll nip method, for example,
As shown in JP-A-63-154553, etc.,
A mechanism is provided to stop the leading end of the sheet while the sheet is thrust into the nip position of the registration roller device. The pre-registration roller device performs additional feeding while the front end of the paper is supported by the registration roller device to form a loop in the paper, thereby constituting a mechanism for aligning the paper. Further, in the roll nip type sheet aligning device, when the leading edge of the sheet has advanced too far from the nip position in the registration roller device, the registration roller device is driven in reverse to position the leading edge of the sheet. In some cases, a mechanism that can perform the above is configured.

By using the above-mentioned various aligning mechanisms, the sheet aligning device is used in a state where the sheet sent from the device such as the sheet feeding tray through the long sheet conveying path is separated from the reference line. Even when the sheet reaches, it is possible to easily improve the transport state of the sheet by applying the aligning action in the sheet aligning device. Then, the position of the paper in the image transfer portion can be accurately regulated with respect to the photosensitive drum, and the transfer position of the toner image can be accurately set.

[0007]

In the above conventional example, for example, when a gate type sheet aligning device is configured, the aligning action of the sheets is performed relatively accurately, and a loop is formed on the sheet. By doing so, the effect of skew correction can be performed in a good state. However, in the gate type sheet aligning device, since it is necessary to provide the gate member together with a driving mechanism such as a solenoid,
When the gate member is arranged very close to the registration roller device, there is a problem of space limitation. Further, in order to set the timing of operating the gate member, it is necessary to accurately set the drive timing of the solenoid in the control device. Further, there is a problem that a difference is likely to occur between the sheet aligning action and the feeding timing depending on the condition of pressing the leading end of the sheet against the gate member.

Further, the sheet aligning apparatus using the roll nip system has an advantage that the mechanism of the sheet aligning apparatus is simplified because it is constituted by only the roller device without using a member such as a gate member. However, in the roll nip type sheet aligning device, there is a problem in that the position where the leading end of the sheet stops differs depending on the pressure at the nip portion of the registration roller device and the conditions such as the thickness and strength of the sheet. Further, even if a loop is formed on the sheet in the state where the leading end of the sheet is nipped by the roller, the alignment performance for the sheet is often lower than that in the gate method.

[0009]

It is an object of the present invention to solve the above-mentioned problems in the conventional sheet aligning apparatus, in which a member acting as a gate member is provided coaxially with the roller member constituting the registration roller device, and the leading edge of the sheet is provided. It is an object of the present invention to provide a sheet aligning device that can stop the portion at the nip position of the roller, perform the positioning and aligning action of the sheet in a good state, and simplify the mechanism.

[0010]

SUMMARY OF THE INVENTION The present invention is directed to an aligning device for aligning the leading ends of sheets fed from a paper feed section through a guide path and feeding them toward an image transfer section such as a photosensitive drum. Regarding In the paper aligning device of the present invention, the registration roller device is arranged at a position close to the image transfer portion from the photosensitive drum, the registration roller device is composed of a driving roller and a pinch roller, and is coaxial with the registration roller. A gate member that locks the leading end of the paper is provided via a torque limiting means, and the gate member retracts from the paper locking position and the paper transport path by the operation of driving the registration rollers in the forward and reverse directions. It is configured to be swingable between the position and the position. Further, in the registration roller device of the present invention, a projecting member may be provided on the peripheral surface of the registration roller, and the projecting portion may be configured to be capable of projecting and retracting in the axial direction of the roller.

As described above, the gate member is arranged coaxially with the roller member of the registration roller device, and the rotation of the roller member causes the gate member to swing, thereby positioning and aligning the leading edge of the sheet. And can be performed in good condition. Further, since it is not necessary to provide a drive mechanism such as a solenoid, the configuration of the sheet aligning device can be simplified, and the arrangement relationship of the roller devices in the sheet aligning device can be easily set. further,
When the protrusion member that acts as a gate member is provided for the roller member, the leading end portion of the sheet can be accurately positioned with respect to the nip position of the roller device. Even when the registration roller device is driven to feed the paper, the feeding timing of the leading edge of the paper can be set appropriately, and the paper feeding action can be performed without being affected by conditions such as the thickness of the paper. It can be carried out.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet aligning device of an image forming apparatus according to the present invention will be described with reference to the illustrated example. In the example shown in FIG. 1, the photoconductor drum 1 is configured as a device that forms a toner image by using an electrophotographic system. It constitutes the part that transfers the image to the paper. A sheet aligning device is arranged in front of the toner image transfer portion with respect to the guide path 6, and the sheet aligning device 4 separates the registration roller device 10 and the pre-registration roller device 5 from each other by a predetermined distance. It is arranged and configured. In the sheet aligning device 4, the pre-registration roller device 5 is located with the driving roller and the pinch roller facing each other. However, in the roller device, when the sheet is locked by the gate member or the like and stopped, It is configured as a device that does not give an extra feeding action by slipping.

In the registration roller device 10 arranged immediately in front of the image transfer portion from the photosensitive drum, a registration roller 11 as a driving roller and a pinch roller 12 are arranged to face each other. The two roller members, the driving roller and the pinch roller 12, are composed of rubber rollers or the like, as in the case of a general conveying roller device, and a mechanism (not shown) that presses the pinch roller 12 against the registration roller 11. The nip pressure having a constant value can be set between the rollers via the. The registration roller 11 has a gate member 1 with respect to its axis.
5 is provided so that the gate member can be retracted from the paper transport path when the front end of the paper is locked with the gate member in the operating position and the paper is sent toward the image transfer portion. It is provided in.

In the sheet aligning device 4 shown in FIG.
With the gate member 15 protruding in the sheet conveying path, the leading end of the sheet passing through the guide path 6 is locked. And
The pre-registration roller device 5 imparts an additional feeding action to form a loop on the sheet to impart an aligning action. After that, when the driving roller 11 of the registration roller device is driven in synchronism with the toner image formed on the photosensitive drum 1, the gate member is swung to the retracted position, and the paper is transferred to the image transfer position by the registration roller device. Can be sent to.

The registration roller 11 used in the registration roller device constructed as described above can be constructed as shown in FIG. In the example shown in FIG. 2, the gate member 15 is arranged on the shaft 14 of the registration roller 11 via a torque limiter 17 as a torque limiting means. The projecting length of the gate member 15 is set so as to project slightly from the periphery of the roller, and is set so that the nip position between the two rollers can be closed. Further, by supporting the shaft 14 via the torque limiter 17, the gate member 15 also rotates following the rotation of the shaft of the roller, but the gate member comes into contact with the guide plate or the like. In some cases, it will be stopped at that position. As the torque limiter, a torque limiter having an arbitrary mechanism can be used as is generally used as a means for transmitting a rotational force to a roller member.

Further, when a plurality of gate members are arranged at a predetermined interval with respect to the shaft 14, it is possible to use a mechanism for individually supporting each gate member via a torque limiter. Alternatively, as shown in FIG. 3, a plurality of gate members may be integrally connected by a connecting arm 16. In the example shown in FIG. 3, the gate members 15, 15a ... Are provided so as to interlock with each other via one connecting arm 16, and one or more of these gate members and a shaft are provided. Between,
The torque limiter 17 is arranged to form a mechanism for transmitting the rotation of the shaft to the gate member. And the shaft 1 of the drive roller
The gate members 15 ... Can be rotated in a predetermined direction following the rotation of 4 to perform positioning at the stop position.

In the apparatus in which the registration roller device 10 is configured by combining the registration roller 11 having the above-described structure with the pinch roller 12, as shown in FIG. 4, the roller 11 is moved in the sheet conveying direction. By driving in the reverse direction, the registration roller 11 is rotated in the counterclockwise direction in the figure, and is made to follow the rotation of its shaft 14 so that the gate member 1
Rotate 5. Then, the gate member 15 is brought into contact with the end portion 7a of the upper guide plate 7 forming the guide path 6 and stopped to set a state in which the sheet is locked.

In the state shown in FIG. 4, the leading end portion of the paper P is locked to the gate member 15 and aligned by additional feeding by the pre-registration roller device, and then the toner image formed on the photosensitive drum is formed. The registration roller device 10 is driven in the normal direction according to the signal. When the driving of the registration roller device 10 is started, the registration roller 1
1 is rotated counterclockwise in the figure and follows the gate member 1
5 also rotates counterclockwise, and its gate member is stopped in a state of being locked to the end portion 8a of the lower guide plate 8, and thereafter, even if the roller shaft 14 rotates, it is held at the stop position.
Therefore, after the paper is sent out, the gate member 15 is held at the position allowing the passage of the paper until the roller shaft 14 is driven in the reverse direction, and the passage of the paper is not hindered.

(Example of Using Roller Member with Gate Incorporating Gate Member) As described above, in addition to providing the gate member to the shaft of the registration roller via the torque limiter, in the present invention, the roller member is used. Alternatively, it is possible to use a roller member with a gate in which a gate member is integrally incorporated. A sheet aligning apparatus using the gated roller member may be configured as shown in FIG. Also in the sheet aligning device 4 shown in FIG. 6, similarly to the case of FIG. 1, the registration roller device 10 is arranged immediately in front of the image transfer portion from the photosensitive drum 1, and the registration roller device 10 is driven by the drive roller. 13 and the roller member 20 with a gate are combined.
In addition, a pre-registration roller device 5 is arranged at an upstream portion of the registration roller device 10 at a predetermined interval, and a roller member constituting the pre-registration roller device 5 is provided with an extra feeding action for a sheet. It can be configured as a slip roller device so that it is not applied.

Registration roller device 1 shown in FIG.
0, as the gated roller member 20, for example, as shown in FIG. 7, a member in which a gate member 25 is integrated into a roller member can be used. In the example shown in FIG. 7, the gated roller member 20 is used.
Is made of a material such as plastic, and a cutout portion 23 is provided in a part of the roller member with gate 20, and the gate member 25 is integrally formed with the cutout portion 23.

Stopper surface 2 provided on the gate member 25
6 is provided so as to project on the surface of the roller due to the elasticity of the gate member main body, and in the state where the pressing action is not applied to the gate member 25, as shown in the figure, the peripheral surface of the roller is , The gate member is set to project outward by a predetermined length. On the other hand, when a pressing action is applied by the opposing rollers or the paper, the stopper surface 26 enters the notch 23 of the roller and does not hinder the movement of the paper.

In addition to providing the gate member to the roller body, the roller member with a gate of the present invention includes a gate member 28 on the side surface of the roller body via an auxiliary member 27 as shown in FIG. It can also be attached and configured. In the example of the roller member 20a with a gate shown in FIG. 8, auxiliary members 27 are integrally provided on both sides of the roller 22 attached to the shaft 21 so that the gate can be removed from the auxiliary member 27. The members 28 and 28a are attached. Like the roller body 22, the gate member 28 can be integrally formed using a material such as plastic, and the gate member 28 can also be integrally formed.

Using the roller member 20 with a gate as shown in FIG. 7 or 8, the registration roller device 1 is used.
In the sheet aligning device configured as 0, as shown in FIG. 9, the sheet is conveyed when the gate member projects toward the sheet conveying path. And
With the front end of the paper P locked to the gate member, a loop is formed on the paper to cause the paper to align.
After that, when the paper is sent out according to the signal of the toner image formed on the photosensitive drum, the registration roller device 1
When the drive roller 13 of 0 is driven, the roller member 20 with gate also rotates, so that the gate member 25 is retracted from the position where the sheet conveying path is closed, as shown in FIG.
Allow paper to pass.

Then, every time the gated roller member 20 rotates during the operation of feeding the paper by the registration roller device, the gate member comes into contact with the paper, but the gate member opposes the driving roller. Since the sheet is pressed by, it does not hinder the movement of the sheet. Further, as shown in FIG. 8, even in the case of the gated roller member in which the gate member is arranged on the side portion of the roller body, since the gated roller member is rotated while the gate member is pressed by the paper, There is no problem in moving the paper.

In addition to constructing the roller member with a gate as shown in FIGS. 7 and 8, in the present invention, a roller member with a gate 30 using a leaf spring is used as shown in FIG. It can also be configured. In the example of the roller member with a gate 30, a cutout portion 31 is formed in a part of the periphery of the roller body, and the gate member 32 is attached to the cutout portion 31 using a set screw 33. The gate member 32 can be formed in a hook shape by using an arbitrary material, and the tip end portion of the gate member 32 is projected as a stopper from the surface of the roller. Then, as shown in FIG. 12, when the pressing force by the facing rollers or the paper is applied in the direction of the arrow, the gate member 32 is retracted into the notch 31.

As shown in FIG. 11, when the roller body and the gate member are made of different materials, the roller is made of a rubber material and the gate member is made of plastic or metal. It can be formed using the plate member. Then, the force acting on the paper can be set as appropriate by setting the property of the material forming the gate member such that the locking and the swinging action with respect to the paper can be exhibited in a good state. Further, in the roller device incorporating the gate member of the present invention, a member for driving the roller member in the forward and reverse directions or for detecting a stop position with respect to the pinch roller is provided in order to set a state in which the paper is locked. be able to. By providing the gate member positioning means as described above, the sheet aligning operation in the sheet aligning device can be easily performed.

[0027]

Since the sheet aligning device of the image forming apparatus of the present invention has the above-mentioned structure, for example, the gate member is arranged coaxially with the roller member of the registration roller device and the roller member By rotating the gate member by rotation, positioning of the leading edge of the paper,
The matching action can be performed in good condition. Further, since it is not necessary to provide a drive mechanism such as a solenoid, the configuration of the sheet aligning device can be simplified, and the arrangement relationship of the roller devices in the sheet aligning device can be easily set. Furthermore, when the roller member is provided with the protrusion member that acts as a gate member, the leading end of the sheet can be accurately positioned with respect to the nip position of the roller device. Even when the registration roller device is driven to feed the paper, the feeding timing of the leading edge of the paper can be set appropriately, and the paper feeding action can be performed without being affected by conditions such as the thickness of the paper. It can be carried out.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of a sheet aligning device of the invention.

FIG. 2 is a side view of the pinch roller of the present invention.

FIG. 3 is a perspective view of a roller device integrally provided with a gate member.

FIG. 4 is an explanatory diagram of a standby state in the registration roller device of the present invention.

FIG. 5 is an explanatory diagram of a state of a gate member when a sheet is passing through the registration roller device.

FIG. 6 is a side view of another embodiment of the sheet aligning device of the invention.

FIG. 7 is a side view of the roller member with a gate according to the present invention.

FIG. 8 is a perspective view of another example of the roller member with a gate according to the present invention.

FIG. 9 is an explanatory diagram of a state in which a sheet is stopped using a roller member with a gate.

FIG. 10 is an explanatory diagram of a state during sheet feeding in a registration roller device using a roller member with a gate.

FIG. 11 is a side view of another embodiment of the roller member with a gate according to the present invention.

FIG. 12 is a side view of the roller member with a gate shown in FIG. 11 in a state where the gate member is accommodated.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 photoconductor drum, 4 paper alignment device, 5 pre-registration roller device, 10 registration roller device, 11 registration roller, 12 pinch roller, 13 drive roller, 15/25/28/32
Gate member, 17 torque limiter, 20 ・ 30
Roller member with gate, 23 notches.

Claims (2)

[Claims] 1. An aligning device for aligning the leading end portions of sheets fed from a paper feed section through a guide path and feeding them toward an image transfer section such as a photoconductor drum. A registration roller device is arranged at a position close to the transfer portion, and a gate member for locking the leading end of the paper is provided coaxially with the registration roller via a torque limiting means. A sheet aligning device of an image forming apparatus, wherein the sheet aligning device is configured to be swingable between a position where a sheet is locked and a position where the sheet is retracted from a sheet transport path by an operation of being driven to. 2. The sheet aligning device for an image forming apparatus according to claim 1, wherein a projecting member is provided on a peripheral surface of the registration roller, and the projecting portion is configured to be retractable in the axial direction of the roller.