JPH0692518A - Paper matching device for image forming device - Google Patents

Abstract

PURPOSE:To prevent generation of operation timing delay by providing an annular rotation gate member in a turnable manner through a frictional member with respect to the shaft of a registration roller, and performing locking operation of paper sheet by the use of a pawl member protruding form the rotation gate member. CONSTITUTION:A registration roller is composed of a driving roller 11 and a pinching roller 13 facing each other and a rotation gate member 15 is arranged through a frictional member. On the surface of a rotation gate member 15 a plurality of pawl members are arranged to project therefrom, and one pawl member 16 is positioned to block a paper sheet P transport line and the other pawl member 16b is locked by a gate stopper member 20 driven by a solenoid 23. When a rear end of paper sheet P passes under a state the gate stopper 20 releases its pawl member the pawl member moves to a position immediately where the fore end of next paper sheet is locked and the next pawl member is locked by the gate stopper member 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet aligning means which is arranged immediately before a portion for transferring a toner image from a photosensitive drum to a sheet in an image forming apparatus such as an electrophotographic copying machine. The present invention relates to a device in which a rotatable gate member is arranged on the shaft of a roller member with respect to a registration roller device provided in a paper aligning device to lock and hold the leading end of paper at a position just before a nip portion of the roller device.

[0002]

2. Description of the Related Art Like electrophotographic copying machines and printers,
In an image forming apparatus that makes a copy using an electrophotographic method, a mechanism is used in which a toner image is formed on an image bearing member such as a photoconductor drum, the toner image is transferred to a sheet, and then fixed through a fixing device. ing. In the image forming apparatus, the toner image formed on the photosensitive drum is
In order to transfer to a correct position on the paper, a paper aligning device is arranged immediately in front of the image transfer section. In the paper aligning device, the leading end portion of the paper is locked and held by using a stop member such as a gate member to perform the aligning operation of the paper, and then the toner image formed on the photoconductor drum is adjusted. A mechanism that feeds the paper at the correct timing is configured.

As described above, in the sheet aligning apparatus, two types of methods, that is, the gate method and the roll nip method, are used to hold and hold the sheets. Examples of the gate type device include, for example, Japanese Utility Model Laid-Open No. 62-186
A device as disclosed in Japanese Patent Publication No. 843, etc. is known.
In the conventional apparatus, two roll devices, a registration roller device and a pre-registration roller device, are arranged at a predetermined interval upstream of the image transfer portion from the photosensitive drum, and the roll device is provided in front of the registration roller device. A gate member is provided.
Then, while the leading edge of the paper is locked by the gate member, a preregistration roller device performs an additional feeding operation to form a loop on the paper, and the force of the loop formed on the paper causes the paper to align. I am trying to do it.

The registration roller device and the gate member in the paper aligning device are constructed as shown in FIG. In the paper aligning device 5 shown in FIG. 7, the registration roller device 6 is composed of a driving roller 6a and a pinch roller 6b, and the gate member 7 arranged immediately before the nip portion of the two rolls is used as a paper transport path. It is provided so that it can appear and disappear. The gate member 7 is driven by a solenoid 8 and a spring 9. With the solenoid 8 turned off, the gate member 7 is projected into the sheet conveying path, and the leading end of the sheet P is locked, so that the sheet A loop is formed on the sheet so that the sheet aligns. Then, the solenoid is energized to retract the gate member 7 from the sheet conveying path in a state where the timing is aligned with the toner image formed on the photosensitive drum, and the repulsive force of the sheet loop causes the leading edge of the sheet. Part is projected into the nip part of the registration roller device. After that, the transfer of the toner image is performed while the sheet is conveyed at a constant speed by the registration roller device.

In addition to the gate type sheet aligning device, the leading edge of the sheet is stopped in a state of being projected into the nip portion of the registration roller device, and the preregistration roller device performs additional feeding to align the sheet. In some cases, a system type device is used. As the roll nip type device, for example, a device having a mechanism as disclosed in Japanese Patent Laid-Open No. 57-86849 is known. Further, in the roll nip type apparatus, since the sheets are aligned in the nip portion of the registration roller apparatus, the sheet aligning apparatus can be configured without using a member such as a gate member.

By using the various sheet aligning devices as described above, the sheets fed from the sheet feeding device such as the sheet feeding tray and sent through the long sheet conveying path are
Even when the sheet is obliquely fed, the sheet can be corrected to a normal posture and fed to the image transfer section. Then, by transferring the toner image formed on the photosensitive drum or the like onto the paper in a state in which there is no deviation, it is possible to create a good-quality copy.

[0007]

In the sheet aligning apparatus as described above, in the apparatus using the gate member, the leading end of the sheet can be locked and the aligning action can be achieved by the loop formed on the sheet. It can be exhibited well. However, in the gate member type apparatus, since the gate member is directly driven by the drive mechanism such as the solenoid, it is necessary to set the timing for operating the gate member accurately. However, in an electrophotographic copying machine, under the present circumstances where the paper conveyance speed is high and the distance between the papers conveyed in the paper conveyance path is narrow, there is a slight time lag in the detection action of the leading edge of the paper by the sensor. There is a problem that occurs. Further, even when a signal is output from the control device to the solenoid, a slight timing difference occurs between the signal and the time when the gate member closes the sheet conveyance path.

Further, even if the operation time difference between the sensor and the solenoid is, for example, 0.05 sec, when the sheet conveying speed is 400 mm / sec, it is converted into a sheet length of 20 mm. Becomes However, in order to increase the number of copies per unit time in an electrophotographic copying machine,
The space between the sheets in the sheet conveyance path may be set to be very narrow. In that case, the state in which the next sheet of paper passes through the part of the gate member occurs after the sensor outputs the detection signal of the leading edge of the paper until the gate member is closed, and the sheet is stopped. There is a problem that it cannot be done.

On the other hand, in the roll nip type device, the registration roller device is stopped and stopped with the leading edge of the paper protruding into the nip portion of the roll, so that the timing is the same as when a gate member is used. Misalignment is less likely to occur. However, the leading edge of the paper may be stopped in a state of protruding beyond the stop position of the nip portion, and it is difficult to accurately set the stop position of the paper in a high-speed device.

[0010]

SUMMARY OF THE INVENTION The present invention solves the problems of the conventional sheet aligning apparatus as described above, in which the rotary gate member is arranged coaxially with the roll member constituting the registration roller device,
An object of the present invention is to provide a device that can stop the pawl member of the rotary gate member at the nip position of the sheet and can stop the sheet at high speed.

[0011]

SUMMARY OF THE INVENTION The present invention relates to an apparatus for aligning sheets by disposing a sheet aligning device upstream of an image transfer section and locking the leading end of the sheet to form a loop. In the sheet aligning device of the image forming apparatus of the present invention, a rotating gate member is arranged with respect to one axis of a roll member that constitutes the registration roller device, and around the annular main body of the rotating gate member, A claw member is provided so as to project at a predetermined interval, a gate stopper member is arranged corresponding to the rotating gate member, a mechanism for fixing and holding the rotating gate member by the gate stopper member is provided, and a claw of the rotating gate member is provided. A mechanism for stopping the member at the nip position between the two roll members of the registration roller device and locking the paper is provided.

As described above, by disposing the rotating gate member rotatably with respect to the axis of the roll member,
It is possible to easily set the timing for locking and holding the sheet by the rotation gate member and operate the sheet at high speed. Further, unlike the conventional gate member, the rotating gate member of the present invention does not need to swing the stopping member largely, and the solenoid operates the rotating gate member so that the gate stopper member stands by at the operating position. Can be controlled at high speed. Then, at the same time as driving the solenoid, the locking of the leading edge of the sheet by the claw member provided on the rotating gate member is released to set the sheet conveying action, and the driving of the solenoid is released, and at the same time, the claw member is moved to the roll. Positioning can be performed toward the nip portion between them, and the stopping action of the paper can be exhibited well.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet aligning device of an image forming apparatus of the present invention will be described with reference to the illustrated example. The example shown in FIG. 1 shows a configuration of an image transfer section of an electrophotographic copying machine and a sheet conveyance path arranged upstream of the image transfer section. An image formed by a transfer corotron 2 in correspondence with a photosensitive drum 1 is shown. The transfer part is arranged. A registration roller device 10 and a pre-registration roller device 4 are arranged in a paper conveyance path 3 arranged upstream of the image transfer portion from the photoconductor drum 1 to form a paper alignment mechanism. Then, the claw member 1 of the rotary gate member 15 provided at the tip of the paper P coaxially with the pinch roller 13 which is a roll member of the registration roller device 10.
6 and the pre-registration roller device 4 provides an additional feeding action to form a loop on the sheet to perform the aligning action.

The registration roller device 10 is constructed as shown in FIG. 2 and FIG.
The registration roller device 10 is configured by arranging the drive roller 11 provided on the drive roller 2 and the pinch roller 13 supported by the driven shaft 14 so as to face each other. Further, as in the case of a general conveying roller device, a mechanism for pressing the pinch roller against the drive roller may be arranged, and a mechanism for setting a predetermined nip pressure between both rollers may be provided. As shown in FIG. 3, a rotating gate member 15 is arranged on the shaft 14 of the pinch roller 13. As shown in FIG. 4, the rotary gate member 15 is provided with a friction member 17 on the inner surface of an annular member, and a mechanism for transmitting the rotation of the shaft 14 to the rotary gate member 15 via the friction member 17. is doing. Further, a plurality of claw members 16, 16a ... Are provided so as to project around the rotary gate member 15.

The height L of the claw members 16 ... Projecting on the surface of the rotary gate member 15 is set higher than the diameter R of the pinch roller 13 as shown in FIG.
Then, by stopping one of the claw members 16 of the rotary gate member 15 at a position where the paper conveying path between the two rolls is closed, the leading end of the paper is locked and the leading end of the paper is stopped. Do not enter the nip part of both rollers. Further, as shown in FIG. 2, a gate stopper member 20 operated by a solenoid 23 is arranged with respect to the rotary gate member 15, and the claw member of the rotary gate member 15 is locked by the gate stopper member 20. As a result, the distance between the claw members is set so that the other claw member is stopped at the nip position of the roll.

In the gate stopper member 20, a shaft 22 is driven by a spring 24 provided so as to face the solenoid 23. The shaft 22 corresponds to the number of rotating gate members as shown in FIG. Gate stopper member 2
0, 20a ... are arranged. The gate stopper member 20 is provided with a locking claw 21 at its tip, and the rotary gate member is positioned in a state where the locking claw of the rotating gate member 15 is locked by the locking claw. Further, in the embodiment of the present invention, the claw member provided on the rotary gate member 15 is such that the three claw members 16, 16a, 16b are arranged at an equal angle θ as shown in FIG. With one of the members positioned in the nip portion of the roll, another claw member is locked by the locking claw 21.
The gate stopper member 20 is arranged.

The rotary gate member 15 supported by the shaft 14 of the pinch roller 13 is rotated in the paper conveying direction by the pinch roller shaft 14 following the rotation of the driving roller. It is rotated by the friction of.
The coefficient of friction between the friction member 17 and the shaft 14 is
By setting a relatively small value, when the claw member is engaged with the paper, the rotary gate member is stopped in a state of sliding with respect to the shaft, and the claw member is not strongly pressed against the paper. To be done.

In the registration roller device of the present invention constructed as described above, when the leading end of the sheet is locked to form a loop, as shown in FIG. 16c is locked and held at a position corresponding to 16b, and the claw member 16 is stopped immediately before the nip portion of the two roll members. Then, the front end portion of the paper P conveyed through the paper conveyance path is locked by the claw member 16 to form a loop with respect to the paper, and the aligning action of the paper is exhibited. After that, when the transfer information of the toner image formed on the photosensitive drum is output from the control device, the solenoid 23 is driven in synchronization with the toner image, and as shown in FIG. The locking claw 21 of the member 20 releases the locking with respect to the claw member 16b.

Then, by the roll member rotated by the paper feed command and the force of the rotating gate member supported by one of the roll members via the friction member to rotate, The rotating gate member is rotated clockwise in the figure. Also, at the same time as the rotation of the rotating gate member,
When the claw member of the rotating gate member is pressed by the reaction force of the paper loop, the leading end of the paper enters the nip portion of both rolls, and the paper is fed out by the registration roller device at a predetermined speed. At the same time that the sheet is conveyed, the rotating gate member 15 is also rotated clockwise along the shaft 14. Then, as shown in FIG. 6, with respect to the paper P being conveyed by the registration roller device, the next claw member 16b is stopped and held at a position in contact with the upper surface of the paper.

As described above, when the energization of the solenoid 23 is stopped during the conveyance of the paper P by the registration roller device, the gate stopper member 20 is moved to the position where the pawl member is locked by the pulling force of the spring 24. Will be returned.
However, while the sheet is being conveyed, the rotation gate member is stopped in the state in which one claw member is locked to the upper surface of the sheet, so that the rotation gate member is stopped and held at the position shown in FIG. It is in. Then, when the trailing end of the conveyed sheet has finished passing through the claw member 16b and the support of the claw member by the sheet is released, the rotary gate member 15 is rotated clockwise due to friction with the shaft 14. It spins and immediately after that,
The claw member 16a is locked by the gate stopper member 20, and the claw member 16b is stopped and held at a position where the claw member 16b closes the sheet conveyance path, as shown in FIG.

Therefore, in the registration roller device according to the present invention, the claw member provided on the rotating gate member has a claw member for the gap between the paper before and after the paper even when the paper is conveyed at a narrow space. Can be positioned,
The effect of stopping the paper can be exhibited in good condition. Further, the solenoid used in the present invention is not a member that directly operates on a sheet, but is used as a member that indirectly acts on the sheet.
When the front end of the sheet is locked and held by the claw member, the claw member is made to stand by in advance at a position where the gate stopper member is locked with respect to the claw member. Since the mechanism that locks another claw member after dropping the claw member in the gap between the paper and the other claw member corresponding to the paper is used, the operation timing of the solenoid, etc. Does not affect.

In the above-described sheet aligning device of the present invention, the rotary gate member can be supported on the drive shaft, and the friction coefficient between the shaft and the friction member can be set arbitrarily. it can. Further, as for the arrangement interval of the rotary gate members, as in the case of the conventional gate device, an arbitrary number of gates can be arranged at an arbitrary interval, and the claw members that project with respect to these rotary gate members. Also, not only three but more can be provided. Further, as for the shape of the gate stopper member driven by the solenoid, other than using the locking claws having the shape shown in the embodiment, a locking member having any shape can be configured.

[0023]

The sheet aligning device of the image forming apparatus of the present invention uses the rotating gate member constructed as described above, and is rotatable about the shaft of the roll member via the friction member. By arranging the gate member, it is possible to easily set the timing for locking and holding the sheet by the rotating gate member and operate the sheet at high speed. Further, unlike the conventional gate member, the rotating gate member of the present invention does not require a large swinging of the stop member, and the gate stopper member provided on the solenoid is set to the standby position in advance, so that the rotating gate member It is possible to control the operation of locking the sheet by the member at high speed. Then, at the same time as driving the solenoid, the locking of the leading edge of the sheet by the claw member provided on the rotating gate member is released to set the sheet conveying action, and the driving of the solenoid is released, and at the same time, the claw member is moved to the roll. Positioning can be performed toward the nip portion between them, and the stopping action of the paper can be exhibited well.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a sheet conveyance path equipped with a registration roller device of the present invention.

FIG. 2 is a side view showing a relationship between a registration roller device and a rotary gate member.

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

FIG. 4 is an explanatory diagram showing a positional relationship of each member in the registration roller device of the present invention.

FIG. 5 is an explanatory diagram of a sheet feeding state by a registration roller device.

FIG. 6 is an explanatory diagram of a state in which a sheet is being fed.

FIG. 7 is an explanatory diagram of a sheet aligning device using a conventional gate device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 photoconductor drum, 3 paper transport path, 5 paper alignment device, 6 · 10 registration roller device, 11
Drive roller, 13 pinch roller, 14 driven shaft, 15 rotating gate member, 16 claw member,
17 friction member, 20 gate stopper member, 2
1 locking claw, 23 solenoid.

Claims (1)

[Claims] 1. A device for aligning a sheet, wherein a sheet aligning device is arranged upstream of an image transfer portion, a leading end portion of the sheet is locked to form a loop, and a roll member that constitutes the sheet aligning device is provided. A rotary gate member is arranged with respect to one of the shafts, and claw members are provided so as to project around the annular main body of the rotary gate member at predetermined intervals, and the gate stopper member is associated with the rotary gate member. And a mechanism for fixing and holding the rotary gate member by the gate stopper member is provided, and the claw member of the rotary gate member is stopped at the nip position of the two roll members of the paper aligning device to lock the paper. A sheet aligning device for an image forming apparatus, which is characterized in that: