JP2838915B2 - Paper position correction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet positioning device disposed immediately before an image recording section in an image forming apparatus such as a copying machine or a printer, and more particularly to a sheet positioning apparatus which stops a sheet stopped by a gate member. The present invention relates to an apparatus that corrects a positional deviation when a line is displaced from a line and feeds the sheet to an image transfer unit in a state where the sheet is along a reference line.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrophotographic method, such as an electronic copying machine or a laser printer, a toner image is formed on an image carrier such as a photosensitive drum, and the toner image is transferred onto paper and then fixed. Means for making a copy by performing a fixing operation through the apparatus are used. In the image forming apparatus, a gate member and a registration roller member are disposed immediately before the image transfer unit, and the sheet conveyed in the sheet path is temporarily stopped by the gate member to form the photosensitive member. The gate is opened in a state where the leading end of the sheet is positioned with respect to the toner image to be transferred, and the sheet is sent out at a constant speed by the registration roller device so that the image is transferred from the photoconductor.

In the paper transport apparatus having the above-described configuration, the paper transported in the paper path may slightly deviate from the reference line of the paper path. The problem of the sheet misalignment does not cause a serious problem when the copy mode for the sheet is one-sided copy, but in the case of color copy or multiple copy, when the image is transferred in an overlapping state, A problem arises in that a shift occurs in the image and a defective copy is created. So, for example, Shokai 6
As shown in Japanese Unexamined Patent Application Publication No. 2-203149, for example, a sheet pause member disposed immediately before an image transfer unit is
It has been proposed to provide a means for laterally moving the paper so as to eliminate the deviation of the registration position of the paper.

In the paper position correcting device shown in the above-mentioned conventional example, a registration roller device is provided so as to be able to move laterally upstream of a gate member in the paper transport direction, and means for detecting a deviation of the paper is provided in the paper path. doing. Then, with respect to the paper stopped by the gate, the registration roller device is moved in a direction to correct the deviation of the paper, and the paper is fed toward the image transfer unit with the side of the paper along the reference line. I have.

[0005]

In a commonly used image forming apparatus, an upper frame provided with an image forming member such as a photoreceptor is provided with a paper path portion with respect to a lower frame provided with a paper feeding device. At the border, it is configured to open like a crocodile mouth. However, in the image forming apparatus, when the upper frame is opened to release the paper path, and after performing an operation such as a jam process for a sheet stopped in the paper path, the upper frame is closed. There is a problem that it is difficult to accurately match the positions of the driving roller and the pinch roller of the registration roller device. In addition, if registration is performed on a sheet while both rollers of the registration roller device are displaced, when the sheet is laterally moved by the registration roller device, the moving operation is not performed accurately. There's a problem. In the conventional paper position correcting apparatus, there is a problem that, in particular, when performing registration on thick paper, the registration position alignment operation is not performed well.

In addition to the above problem, when the paper is moved in the width direction of the paper path by the registration roller device, the pre-registration roller device arranged upstream of the registration roller device is in a state where the rear portion of the paper is nipped. However, after the paper is laterally moved by the registration roller device, the registration roller device may move in the returning direction due to the stiffness of the paper, and the registration position may be misaligned. But,
In the apparatus shown in the conventional example, means for coping with such a problem is not provided, and depending on conditions such as the thickness of the sheet, the sheet may be misaligned after being once registered by the registration roller device. There is a problem that an inconvenience occurs and a defective copy in which the transferred image is shifted is created.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the conventional paper position correcting apparatus, and to accurately perform the operation of positioning the upper and lower rollers of the registration roller device. It is an object of the present invention to provide an apparatus that enables the apparatus to perform registration of sheets without being affected by conditions such as paper quality.

[0008]

According to a first aspect of the present invention, an upper frame on which an image forming member is arranged and a lower frame on which a sheet feeding member is mounted can be opened and closed with a sheet conveying path as a boundary. A paper leading end positioning means for positioning the leading end of the paper before transporting the paper to an image transfer unit in the image forming member; and a paper position disposed at a position corresponding to a reference line on a side of the paper transport path. A lateral movement in which the paper whose leading end is positioned by the paper leading end positioning means is laterally moved in response to a signal from the paper position detecting member while nipping by a driving roller and a pinch roller; Means, the lateral movement means, the upper frame and the lower frame, while separately disposing the drive roller and the pinch roller, Characterized in that it has a positioning means for positioning the said drive roller and the pinch roller mutually when closing from an opened state upper frame and the lower frame.

In the invention of claim 2 of the present invention, the positioning means in the lateral moving means is positioned by an engaging member which slides the axis of the pinch roller in the axial direction, and is positioned by the positioning means. It is characterized by further comprising a pressing force applying means for applying a pressing force of the pinch roller to the driving roller later.

[0010]

With the above construction, the registration roller device of the present invention is provided with a mechanism for aligning the upper and lower rollers, so that when the open upper frame is closed, the operation of positioning the upper and lower rollers can be accurately performed. It can be moved laterally with the upper and lower rollers of the registration roller device linked.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The paper position correcting apparatus of the present invention will be described with reference to the illustrated example. A sheet aligning apparatus 1 of the present invention shown in FIG. 1 is disposed immediately before a portion where a toner image is transferred from a photoreceptor in an image forming apparatus such as an electronic copying machine, and includes a registration roller device 10 and a gate member. 6 and a pre-registration roller device 20 disposed upstream thereof. The registration roller device 10 and the pre-registration roller device 20 are arranged such that drive rollers 11 and 21 are disposed at a lower portion and pinch rollers 15 and 25 are disposed at an upper portion with a sheet path interposed therebetween, and the rollers are transported in a state where the sheet is nipped by the roller devices. It is configured to perform.

Further, the gate member 6 disposed at a position close to the registration roller device 10 is conveyed in the paper path with the gate claw member 7 disposed at the tip of the member protruding into the paper path. Stop incoming paper.
In the sheet aligning apparatus of the present invention, the sheet is temporarily stopped by the gate member 6, and the take-away roller 20a continues the feeding operation in that state, so that the leading end is locked by the gate claw. An operation of forming a loop is performed on the sheet. When the take-away roller 20a performs the feeding operation, the nip of the pre-registration roller 20 is released. Then, after lowering the gate member 6 at a predetermined timing, the leading end of the sheet enters the nip portion of the registration roller device 10, and the registration roller device 10 is moved in the width direction of the sheet, and Performs position matching.
In the sheet aligning apparatus 1 of the present invention, each of the pinch rollers 15 and 25 is supported by a member that can be separated from and brought into contact with the driving roller, and the upper and lower rollers 11 and 15 of the registration roller apparatus 10 are It is provided so that it can move in the axial direction (width direction of the paper path).

In the sheet aligning apparatus 1 shown in FIG. 1, the lower members including the drive rollers 11 and 21 are configured as shown in FIG. In the example shown in FIG. 2, the lower frame 2 includes a driving roller 11 of a registration roller device and a driving roller 21 of a pre-registration roller device.
Are arranged, and each roller is formed by providing a roller member in a skewered shape at predetermined intervals on the drive shafts 12 and 22. Also, input gears 13 and 23 are arranged for each shaft, and each input gear meshes with the transmission gear 14 and the like to transmit the driving force. A sheet detection sensor 8 is disposed at a position corresponding to a reference line H for carrying the sheet with respect to the sheet path constituted by the roller device, and the sensor 8 conveys the sheet in the sheet path. The position of the incoming sheet is detected, and based on the information, each device of the registration device 30 is operated to perform the sheet aligning operation.

The driving roller 11 of the registration roller device 10
Is provided at one end of the shaft 12 with an engaging member 31 for a pinch roller. As described later, when the pinch roller is combined with the driving roller 11, the engaging member 31 is provided on the shaft of the driving roller. 31 for the grooved roller 33
A roller with a protruding strip in the shape of a solo bang provided on the shaft of the pinch roller meshes with each other, and the upper and lower rollers are positioned so as to correspond to each other.

At the other end of the shaft 12 of the drive roller, in addition to the input gear 13 described above, a registration device 30 for moving the shaft 12 and performing a positioning operation is arranged. ing. The registration device 30 includes a motor 40, a pinion 41, and a rack member 42.
In addition to the member for moving the shaft 12 constituted by the above in the axial direction, a positioning means for the registration roller device 10 including the actuator 45 and the sensor 46 is provided. In addition,
The detection mechanism by the actuator 45 and the sensor 46 is used for positioning the driving roller 11. After the shaft 12 is moved to perform the aligning operation on the sheet, the driving roller 11 is moved by the sensor 46. The home position is returned to the set home position so that the next matching operation can be dealt with.

In the registration roller device 10, an input gear 23 is provided at one end of a shaft 22 for a driving roller 21 of a pre-registration roller device 20 arranged at an upstream portion in the sheet conveying direction, and the shaft is driven. The shaft 22
The arm operating member 72 is arranged at the other end of the arm. Then, as will be described in detail later, by operating the arm operating member 72, when the nip of the sheet is released in the pre-registration roller device, the pinch roller is separated from the driving roller. .

(Configuration of Upper Member of Sheet Alignment Apparatus) In the present invention, the lower member shown in FIG.
Using a pinch roller assay 50 as shown in FIG. 3, a pinch roller is disposed for each drive roller so that a paper nip action can be performed between each roller. In the example shown in FIG. 3, the upper frame 51 is disposed with respect to the main body frame 2 shown in FIG. 2, and the pinch roller 15 is supported by a support arm 52 protruding from the upper frame 51. The shaft of the pinch roller 25 is vertically movably supported by a shaft support hole 54 provided in the frame. Further, a torsion spring member 60 is attached to the upper frame 51 via a support shaft 55.
And the bracket 65 are disposed, and the arm member protruding forward and backward of the torsion spring member 60 is attached to the bracket 65.
To be supported.

The torsion spring member 60 includes
As shown in FIG.
1 and 62 are arranged, and pressing members 63 and 64 are provided at the distal ends of the arm members 61 and 62. The pressing member 6
Reference numerals 3 and 64 denote a function of pressing the shafts of the pinch rollers 15 and 25 from above, so that the shaft 16 of the pinch roller 15 can slide in the axial direction even when pressed by the pressing member. Like that. In addition, the bracket 6 arranged with respect to the torsion spring member 60 is provided.
Numeral 5 is swingably supported with respect to the support shaft 55, and functions to regulate the torsion spring member 60 so as not to swing greatly.

In the pinch roller assay 50 constructed as described above, when the upper frame 51 is mounted on the main body frame, as shown in FIG. Members 63, 6
Reference numeral 4 is arranged at a position with some margin, and is in a state where the shaft is not pressed by the pressing member. On the other hand, the upper frame 51 is fixed by a fixing unit (not shown).
When the positioning is performed with respect to the main body frame, as shown in FIG. 4, the shaft 26 of the pinch roller 25 is engaged with the swing arm member 70 held at the fixed position, and is pushed up by the swing arm member 70. It will be in a state that can be done. Then, the pressing member 64 is pressed against the upper portion of the shaft 26, and the driving roller 21 positioned below the pinch roller 25 comes into contact with the pinch roller 25 with a predetermined pressing force. The swing arm member 70 will be described later with reference to FIG. 8, but is used to release the paper nip in the pre-registration roller device.

As described above, the pre-registration roller device 20
Is set, the one arm member 52 of the torsion spring member 60 is counteracted by being pushed up by the shaft 26, and the other arm member 61 swings counterclockwise through the support shaft 55. Be moved.
Therefore, the pressing member 63 disposed at the tip of the arm 61 presses the shaft 16 of the pinch roller 15, and the nip state between the upper and lower rollers is set in the registration roller device 10. Then, as shown in FIG. 4, in a state where the respective roller devices of the sheet aligning device 1 are positioned, the operation of conveying and positioning the sheet is performed.

(Alignment Mechanism of Upper and Lower Rollers in Registration Roller Apparatus) When the paper alignment apparatus 1 as shown in FIG. 1 is set by combining the apparatuses shown in FIGS. Uses an engagement member 31 as shown in FIG. The engaging member 3 shown in FIG.
1, a roller with a protruding strip 32 in the shape of a solo bang is arranged on the shaft 16 of the pinch roller 15,
A grooved roller 33 provided with a groove is arranged with respect to the shaft 12. When the upper frame of the main body opened like an alligator is closed with respect to the lower frame, the pinch roller 15 supported by the upper frame is accurately positioned with respect to the driving roller 11 supported by the main frame. To perform the action of

When positioning the upper and lower roller members, if the central projection of the ridged roller 32 is within the range of the width d of the groove of the grooved roller 33, the ridged roller 32 becomes concave. While sliding along the slope of the groove of the grooved roller 33,
It is mounted while moving the shaft 16, and the function of positioning the upper and lower rollers is performed. As described above, when the pinch roller 15 is engaged with the drive roller 11,
Since the pressing action of the pressing member shown in FIGS. 3 to 5 is not applied to the shaft of the pinch roller 15, the shaft 16 of the pinch roller is Is easily moved in the axial direction.

Then, with the upper and lower rollers positioned, the registration device 30 shown in FIG.
When performing the sheet aligning operation, the registration roller device is moved in the axial direction via the engagement member 31 for positioning the upper and lower rollers, and has an effect of moving the sheet nipped in the registration roller device in the width direction. Do. That is, the engaging member 31 of the present invention is used not only as a means for positioning the upper and lower rollers but also as an interlocking means for moving the sheet in the horizontal direction.

As described above, in addition to the provision of the roller positioning means in the engagement member 31, in the present invention,
As a means for interlocking the upper and lower rollers, a mechanism as shown in FIG. 7 can be used. The engaging member shown in FIG. 7 is used when the upper and lower roller devices are moved laterally in a linked state by separately providing means for positioning the pinch roller with respect to the driving roller. In the engagement member shown in FIG. 7, a grooved pulley 35 is disposed on the shaft of the drive roller 11, and a disk member 36 is provided on the shaft 16 of the pinch roller 15. As in the case of FIG. 6, the upper and lower roller members are moved in the axial direction in a state where the disc member 36 is engaged with the groove of the grooved pulley 35, and the action of alignment with the sheet is performed. Let them do it.

(Nip Release Mechanism in Pre-Registration Roller Apparatus) As shown in FIGS. 2 and 3, the pre-registration roller apparatus 20 includes a swing arm member 70 which engages with the lower portion of the shaft 26 of the pinch roller 25. Have been placed. As shown in FIG. 2, the swing arm member 70 is supported on both sides of the main body frame 2 via a support shaft 71, and is swung about the shaft 71 by rotating the cam member 75. It is provided as follows. In addition, the cam member 75
Are supported by a drive shaft 73, and an arm operating member 72 is provided between the shaft 73 and the shaft 22 of the drive roller 21.

When the registration roller device 10 aligns the paper, the nip of the paper at the pre-registration roller device 20 is released to set a state in which the lateral movement of the paper is allowed. At this time, the arm operating member 72 shown in FIG. 2 is operated, the cam member 75 is rotated to swing the swing arm member 70, and the pinch roller 25 engaged with the swing arm member 70 is rotated. The shaft 26 is raised. Therefore, by separating the roller 25 from the driving roller 21, the nip by the pre-registration roller device is released with respect to the sheet whose front end portion is nipped by the registration roller device, and the paper is moved with respect to the sheet on which the alignment operation is performed. Failures are prevented from occurring. In this case, the trailing end of the sheet is nipped by the take away roller 20a. The take-away roller 20a is preferably located at a position as far as possible from the registration roller 10 in order to facilitate the movement of the sheet by the registration roller device 10. Is set at a position where the rear end of the minimum size sheet is nipped.

As described above, the cam member 75 for oscillating the arm member is provided with the cam member 75 for oscillating the pinch roller 25, as shown in FIG. A surface 76 is formed. The cam surface 76 has two surfaces in the illustrated example,
When the cam member 75 is driven, even when the stop position of the cam varies, the swing arm member 70 can be held at a raised position. That is, even if the operation of the sensor for controlling the arm operating member 75 with respect to the swing arm member 70 or the operation of the clutch mechanism is not performed accurately, and the operations of those members vary, the cam member 75 does not move. When one of the plurality of cam surfaces provided on the pre-registration roller device accurately acts on the swing arm member 70, the nip of the sheet in the pre-registration roller device can be released.

Then, the state as shown in FIG.
Alternatively, as shown in FIG. 9, even when another cam surface pushes up the swing arm member 70, the swing arm member 70
Performs the action of pushing up the shaft 26 of the pinch roller to separate the pinch roller 25 from the drive roller 21 and release the nip of the sheet in the pre-registration roller device. Therefore, as described above, by using the cam member 75 having a plurality of cam surfaces, for example, when the clutch of the arm operating member 72 is operated and the drive shaft 73 is stopped, a slight Even if the deviation occurs, the nip state in the pre-registration roller device can be accurately released.

(Sheet Alignment Action) In the sheet alignment apparatus of the present invention having the above-described configuration, when the sheet alignment action is performed using the registration roller device, first, the pawl 7 of the gate member 6 is moved to the sheet path. And the leading edge of the conveyed sheet is locked by the claw member 7. In this state, the nip by the pre-registration roller device 20 is released, and a feeding force is applied to the sheet by the takeaway roller 20a at the upstream portion, thereby forming a loop on the sheet. Next, when the gate is opened while the paper is nipped by the take-away roller 20a, the leading end of the paper projects into the registration roller device 10 and is nipped between the drive roller 11 and the pinch roller 15. In this state, the paper sensor 8 provided in the paper path detects the position of the side of the paper, and outputs a drive signal to the registration device 30.

When the paper is to be aligned based on the signal from the paper sensor 8, the nip of the pre-registration roller device 20 is released while the leading end of the paper is nipped by the registration roller device 10, as shown in FIG. In this way, a means for performing alignment while moving the sheet P in the position direction with respect to the sensor 8 is used. In other words, as shown in FIG. A, in a state where the side of the paper P blocks the sensor 8, as shown in B, the paper P is moved to the right using the registration roller device, and At the position where the side is detected by the sensor 8, the alignment operation is terminated.

As shown in FIG. 10C,
If the paper is located inside the sensor, the paper is excessively moved so that the paper first passes the position detected by the sensor, and the paper is moved to the position shown in FIG. To stop. Next, the sheet is moved to the position shown in FIG. E, and when the side of the sheet is detected by the sensor 8, the aligning operation is terminated.
As described above, after performing the operation of aligning the paper, the operation of pushing up the pinch roller of the pre-registration roller device is released, the nip state of the paper in the pre-registration roller device is set, and the registration roller device, the pre-registration roller device, To feed the paper toward the image transfer unit.

In the present invention, when the sheet is aligned as described above, the position of the roller in the registration roller device is shifted from the original position of the roller. Then, the actuator 45 provided on the pinch roller of the registration roller device is returned to the position detected by the sensor 46, and the driving roller 1
It is necessary to perform an operation for setting the home position of No. 1. However, when the image forming apparatus is used continuously, it is not necessary to return the rollers of the registration roller apparatus to the home position, so that means for performing an initializing operation when the image forming apparatus is started up is provided. To be used. In addition, when performing the above-described initialization operation, while performing the operation of driving the shaft of the roller in the axial direction while rotating the drive shaft 12,
Even when the shaft is pressed by the pressing member 63, the pinch roller 15 can be easily moved in the axial direction.

If the position of the roller of the registration roller device is kept moving during the operation such as the above-described jam processing, the operation of positioning the pinch roller with respect to the driving roller is hindered. At the time of opening, it is necessary to configure so as to be able to perform the above-mentioned initialization, and the operation program is set in the control device of the image forming apparatus. Therefore, as described above, by causing the drive roller 11 to perform the initialization operation, the action of positioning the upper and lower rollers can be easily performed when the crocodile mouth is closed.

[0035]

Since the sheet aligning apparatus of the present invention is constructed as described above, it is possible to accurately perform the aligning operation on the sheet immediately before the image transfer section. It is possible to prevent the occurrence of misalignment, and to obtain a copy in a good state. Further, by providing the upper and lower roller alignment mechanisms in the registration roller device of the present invention, for example, when the opened upper frame is closed, the operation of positioning the upper and lower rollers can be performed accurately. The upper and lower rollers can be moved laterally in conjunction with each other.

[Brief description of the drawings]

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

FIG. 2 is a plan view illustrating a configuration of a lower member of the sheet aligning device.

FIG. 3 is a side view showing a configuration of an upper member.

FIG. 4 is an explanatory diagram illustrating a state in which a pinch roller supported by an upper member is positioned on a driving roller.

FIG. 5 is a plan view of a pressing member supporting mechanism of the present invention.

FIG. 6 is a front view illustrating a configuration of an engagement member of upper and lower rollers in the registration roller device.

FIG. 7 is a front view of another embodiment of the engagement member.

FIG. 8 is an explanatory diagram of an operation of a nip release member in the pre-registration roller device.

FIG. 9 is an explanatory view of the operation of the swing arm member corresponding to FIG. 8 when the cam member rotates extra.

FIG. 10 is an explanatory diagram showing a sheet alignment operation in the sheet alignment device of the present invention.

[Reference numerals in the drawings] 1 paper aligning device 6 gate device 8 paper sensor 10 registration roller device 20 pre-registration roller device 30 registration device 32 ridged roller 33 grooved roller 46 sensor 50 pinch roller assay 60 torsion spring member 63, 64 pressing Member 70 Swing arm member

Claims (2)

(57) [Claims] An upper frame on which an image forming member is disposed and a lower frame on which a sheet feeding member is mounted are provided so as to be openable and closable with a paper conveying path as a boundary; Paper leading end positioning means for positioning the leading end of the paper before; a paper position detecting member disposed at a position corresponding to a reference line on the side of the paper transport path; and a leading end by the paper leading end positioning means. Laterally moving means for moving the positioned sheet laterally in response to a signal from the sheet position detecting member while nipping the sheet by a driving roller and a pinch roller, the lateral direction moving means comprising: The drive roller and the pinch roller are separately disposed on the upper frame and the lower frame, respectively, and the upper frame and the lower frame are arranged separately. Paper position correcting device, characterized in that when closing from an open state with a positioning means for positioning the said driving roller and said pinch roller to each other. 2. The positioning means in the lateral movement means positions the pinch roller by an engaging member that slides in the axial direction, and after being positioned by the positioning means, the pinch roller with respect to the drive roller. 2. The sheet position correcting apparatus according to claim 1, further comprising a pressing force applying means for applying the pressing force.