JP2002220133A - Press adjusting mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for taking the balance of a nip pressure of a press roller for a drive roller on the right and left sides of the roller to prevent a disadvantage such as oblique feed from occurring in a paper fed by a conveyance roller device in the conveyance roller device. SOLUTION: This conveyance roller device 1 is constituted such that the press roller 3 is arranged by opposing it to the drive roller 2 to press it by a plate spring 5. The plate spring 5 is constituted into a substantially U-shape to press a support shaft 3a of the press roller 3 on both sides of the roller and is fixed to a frame 4 by a fixing screw 8 to adjust a pressing force by changing a degree of tightening of an adjusting screw 9. Moreover, since pressing members on the right and left sides of the plate spring 5 are separately tightened by adjusting screws, it is possible to easily adjust a pressing force on the right and left sides of the roller 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper transport apparatus in which a feed roller and a press roller are combined. The present invention relates to a device for preventing the occurrence of the above.

[0002]

2. Description of the Related Art In an image forming apparatus such as a facsimile machine or a copying machine, an image reading apparatus is arranged in combination with an image forming section.
A flatbed scanner (FBS) for setting and reading a large-size original or a book original is provided, and a large-sized platen corresponding to the FBS is arranged. In addition to the FBS, an automatic document feeder (A
DF) is often provided, and in the ADF, an image is read while the documents set on the document tray are conveyed one by one. The AD
In F, in order to make the apparatus compact and reduce the occupied space, the document tray and the discharge tray are arranged vertically and the document conveying path is curved. In the curved transport path, the document transport operation is performed by a plurality of transport roller devices. In the ADF, a plurality of transport roller devices are arranged in the document transport path for transporting the document along a curved path, and in the transport roller device, a press roller is provided so as to face a feed roller, The press roller is configured to be pressed by using urging means such as two leaf springs arranged on both sides.

[0003]

However, in the transport roller device disposed on the curved document transport path, the accuracy of component parts, the type of sheet material (paper),
An inconvenient state, such as oblique feeding, is likely to occur on the conveyed paper depending on the use environment of the apparatus. If the sheet is skewed or the like, it may cause a jam in the document conveyance path or cause a conveyance failure, which may cause a problem in the image quality of the read image information. is there. When the above-mentioned problem occurs, the service staff visits the user and adjusts the pressing force of the leaf spring pressing the press roller to change the nip state of the paper between the two opposing rollers. I am adjusting. However, the adjustment work for the press roller cannot be easily performed, and there is a problem that the adjustment work for the oblique feeding of the paper requires a very troublesome work.

SUMMARY OF THE INVENTION The present invention makes it possible to easily adjust the above-mentioned problems such as the oblique feeding of a sheet in a curved document conveying path, and to adjust the pressing force of a leaf spring supporting a press roller. It is an object of the present invention to provide a mechanism that can easily perform the above.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a feed roller for feeding a sheet document and a pressure adjusting mechanism used in a transport device having a press roller arranged opposite to the feed roller. The invention according to claim 1 of the present invention is characterized in that the press roller is pressed against the feed roller by using an elastic body capable of adjusting a right and left pressing force of a shaft of the roller. Therefore, since the pressure balance between the left and right of the press roller with respect to the drive roller can be adjusted, it is possible to easily cope with the adjustment of the oblique feeding (skew) of the sheet.

According to a second aspect of the present invention, the elastic body is a U-shaped leaf spring, and a fixing means is attached to a base end of the leaf spring, and the roller presses the roller from the base end. An adjusting tool for adjusting the pressing force is provided on each of the right and left sides on the unit side. By providing a fixing tool on the base end side of the leaf spring and providing an adjusting tool near the action section, the right and left balance of the pressing force of the press roller can be easily adjusted.

[0007] According to a third aspect of the present invention, the pressing adjustment mechanism comprises:
The automatic document feeder is provided on a press roller of a curved transfer section of the automatic document feeder. Therefore, in the automatic document feeder, adjustment when the document is skewed can be easily performed, and maintenance of the device is simple.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the apparatus of the present invention will be described with reference to the illustrated example. In the example shown in FIGS. 1 and 2, the transport roller device 1 is provided with a drive roller 2 and a press roller 3 facing each other, and sets a predetermined nip pressure between the two rollers to drive the drive roller 2. Thus, the sheet can be conveyed at a predetermined speed. In the transport roller device 1, a pressing action by a leaf spring member 5 is applied to the support shaft 3 a of the press roller 3 on both sides of the press roller 3. As shown in FIG. 2, the leaf spring member 5 is formed in a substantially U-shape in plan view, and pressing arms 7, 7 a are provided on both sides of a base 6 so as to project therefrom. Gives an effect of pressing the support shaft 3a toward the drive roller 2.

The leaf spring member 5 is fixed to the frame 4 of the apparatus by using fixing screws 8 and 8a. Even if the leaf spring member 5 is only supported by the frame 4 by the fixing screws 8 and 8a, the pressing is performed. The pressing force against the roller 3 can be exerted. However, in the positioning of the leaf spring member 5 with only the fixing screws 8 and 8a, it is often impossible to set a sufficient nip pressure between the rollers. Therefore, in this embodiment, the fixing screws 8, 8a
The adjusting screws 9 and 9a are provided on the distal end side of the arm, and the adjusting screws 9 and 9a are screwed into the frame 4 so that the two pressing arms 7 and 7a
The adjustment of the pressing force with respect to. Further, in the above substantially U-shaped leaf spring member 5, by separately providing the adjusting screws 9, 9a for the two pressing arms 7, 7a, it is easy to adjust the pressing force of each pressing arm. To be able to do.

For example, as shown in FIG.
When the adjusting screw 9 is loosely tightened, the pressing action of the press roller 3 against the driving roller 2 is given by the light pressing force set by the fixing screw 8, and the nip pressure in the transport roller device 1 is small. Become. As shown in FIG. 3, when the adjusting screw 9 is strongly tightened, the degree of freedom of the pressing arm 7 is reduced, and the support shaft 3a of the press roller 3 is pressed with a large pressure. The nip pressure at 1 is set as a large value.

The transport roller device 1 constructed as described above
In the nip portion formed by the driving roller 2 and the press roller 3, the nip pressure is not balanced between the left and right portions of the roller with respect to the sheet, so that the sheet or the original may be obliquely fed. When such inconvenience occurs, since the leaf spring member 5 pressing the press roller 3 does not have an average pressing force on the left and right sides of the roller, the pressing arm 7 of the leaf spring member 5 , 7a may be adjusted. Therefore, as shown in FIG. 3, the adjusting screw 9 is strongly tightened and the pressing force of the pressing arm 7 is strongly adjusted to balance with the pressing force of the other pressing arm 7a. Is balanced on the left and right sides of the roller.

In the leaf spring member 5 shown in FIG. 2, the left and right pressing arms 7, 7a are used when the leaf spring is manufactured.
In many cases, the thickness and elastic modulus are not balanced. Even when the pressing force of the left and right pressing arms is not balanced, when the leaf spring member 5 is mounted on the frame 4, the force for tightening one of the adjusting screws 9, 9a is increased. In addition, the pressing action of the leaf spring member 5 can be averaged on the left and right. If the pressing action of the leaf spring member 5 on the press roller 3 is not balanced, a problem such as oblique feeding of the sheet occurs when the conveying roller apparatus is incorporated in the sheet conveying apparatus. Immediately know the state of imbalance. Also, during the operation of the paper transport apparatus, the mounting state of the members may change, and the nip pressure may fluctuate. In such a case, even when oblique feeding occurs during use of the apparatus, By adjusting the balance between the left and right nip pressures, the oblique feed can be easily eliminated.

As an apparatus using the transport roller configured as described above, it can be applied to all paper transport apparatuses of an image forming apparatus. In particular, an automatic document transport apparatus (ADF) as shown in FIGS. If the present invention is applied to an image reading apparatus provided with the above, the oblique feeding of the document can be easily eliminated. The image reading apparatus 10 is configured by combining an FBS function for reading a book original and an ADF function, and includes a platen glass 15 corresponding to an FBS (flatbed scanner) function,
An ADF platen glass 16 corresponding to a DF (automatic document feeder) function is disposed above the main body frame of the image reading device 10, and the image reading device function can be moved inside the frame 11. Scanner device 1
2 are provided. When the scanner device 12 is used in correspondence with the FBS, an image of a document set on the ADF platen glass 15 is read while moving at a constant speed by a driving unit (not shown). When the ADF function is used, the scanner device 12 is fixed at a position indicated by a virtual line in the figure, and an image of a conveyed document is read using the ADF function.

The scanner device 12 includes a lamp 13 for irradiating the image surface of the document, a plurality of mirrors, and a CCD 1.
A lens 14 for forming a light image is arranged on 4a. The CCD 14a converts a light signal into a digital signal, and transmits the digital signal to an image signal processing means of the image reading apparatus. The image signal transmitted to the image reading device is used as an image writing signal for a photoreceptor in a recording unit of a copying machine, and in the case of an image forming device having a facsimile function, the image signal is transmitted through a telephone line. It is also possible to transmit to a facsimile machine.

At the upper part of the frame 11, a platen cover 17 and an ADF device 20 are integrally combined and provided so as to be openable and closable via a hinge (not shown) arranged at a rear end of the main body frame. . And the FB
When using the S function, an original is set on the platen glass 15 and pressed by the elastic body 18 of the platen cover 17 so that the image surface is brought into close contact with the platen glass 15 to read an image. A discharge tray 24 is disposed on the upper surface of the platen cover 17, and the discharge tray 24
A document tray 23 on which a document is set is provided on the upper part of the ADF device 20. The discharge tray 24 and the document tray 23 are provided corresponding to the ADF device 20. The ADF device 20
Is provided with a substantially U-shaped document transport path 27 in a horizontal direction from a document insertion port connected to the document tray 23, and a document transport path 27 leading to the ADF platen glass 16, and from the reading unit to the discharge tray 24. A discharge device 33 is provided, and a roller device for transporting the document in the document transport path is provided.

The transport roller device disposed in the document transport path includes a pickup roller 2 disposed relative to a document insertion port.
5, a sheet separating device 26 in which a feed roller 26a and a retard roller 26b are combined, and a transport roller device 28 in which a drive roller 28a and a press roller 28b are combined, and a document is transported to a reading unit. In the reading unit, the press rollers 31, 32 are arranged on both sides of the large-diameter reading roller 30 so as to sandwich the platen glass 16, and after reading of the document is completed,
The sheet is discharged toward the discharge tray 24 by the discharge roller device 34 through the discharge path 33. Then, in the ADF 20, the originals taken in from the original tray by the pickup roller 25 are separated one by one by a sheet separating device 26, and sent to the original conveying path 27. In the document transport path 27,
The scanner device 12 fixed to the position of the ADF platen glass 16 while conveying the original at a constant speed at the portion of the ADF platen glass 16 while feeding the original toward the reading unit by the reading roller 30 by the conveying roller device 28. To read an image.

In the ADF device 20, the press roller 31 for pressing the original against the reading roller 30 and the press roller 28b of the transport roller device 28 are supported by the support means for the press roller 3 shown in FIGS. Can be provided. Incidentally, the press roller 3 of FIG.
In FIG. 5, the press roller 31 is described. However, the leaf spring member 5 as a pressing means provided on the press roller 31 is configured in the same manner as in FIGS. Screws 8 and 9 so that the pressing force can be adjusted. When configured as a curved transport path like the document transport path of the ADF,
The pressing force of the press roller 31 against the reading roller 30 is
If the right and left sides of the rollers are not balanced, the problem that the document is likely to be conveyed in an obliquely fed state occurs remarkably.
Therefore, when the document to be read is obliquely fed in the ADF 20, the cover 21 is removed to expose the mounting frame 22 of the press roller 31, and the fixing screw 8 for fixing the leaf spring member in FIG. , Adjustment screw 9
By adjusting the tightening state, it is possible to easily eliminate the occurrence of the oblique feeding of the paper.

In the document feeder provided in the ADF, it is also possible to apply a pressing adjustment mechanism using the leaf spring member 5 to another press roller in addition to the press roller 31. Further, the transport roller device 1 shown in the above embodiment is not applied only to the document transport device,
Naturally, the present invention can be applied to any transport roller device that transports a sheet. For example, when a pressing force adjusting mechanism as shown in the embodiment is applied to a transport roller device in a paper transport device, it is possible to prevent occurrence of skew of the paper, and to transport the paper in a stable state. This makes it possible to handle the conveyed paper and the like normally, and to reduce the cause of jam occurrence in the conveyance path.

[0019]

Since the apparatus of the present invention is constructed as described above, the press roller is pressed against the feed roller by using an elastic body capable of adjusting the right and left pressing force of the shaft of the roller. Therefore, it is possible to adjust the pressure balance between the left and right of the press roller with respect to the driving roller, and it is possible to easily cope with the adjustment of the oblique feeding (skew) of the sheet. The elastic body is a U-shaped leaf spring, and a fixing means is attached to a base end of the leaf spring, and a pressing force is adjusted to a working portion side for pressing a roller from the base end. Since the adjusting tool is provided on each of the left and right sides, the right and left balance of the pressing force of the press roller can be easily adjusted by providing the adjusting tool near the action portion of the leaf spring. further,
In the case where the pressing adjustment mechanism is provided for the press roller of the curved conveyance section of the automatic document feeder, adjustment when oblique feeding of the document occurs can be easily performed, and maintenance of the apparatus is simple.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of a transport roller device.

FIG. 2 is a plan view of the transport roller device of FIG.

FIG. 3 is an explanatory diagram of a state in which a nip pressure is set to be strong.

FIG. 4 is an explanatory diagram showing a configuration of an ADF.

FIG. 5 is an explanatory diagram of a configuration of an image reading device.

[Explanation of symbols]

1 transport roller device, 2 drive roller, 3
Press roller, 4 frame, 5 leaf spring member,
6 base, 7 pressing arm, 8 fixing screw, 9 adjusting screw, 10 image reading device, 1
1 frame, 12 scanning devices, 13 lamps, 14 lenses, 14a CCD, 15.1
6 platen, 17 platen cover, 20
ADF, 21 cover, 23 document tray, 2
4 discharge tray, 26 paper sorting device, 27
Document conveyance path, 28 conveyance roller device, 30
Reading roller, 31/32 Press roller, 34
Discharge roller device.

Claims (3)

[Claims] 1. A press adjusting mechanism used in a transport device having a feed roller for feeding a sheet document and a press roller opposed to the feed roller, wherein the press roller has left and right shafts of the roller. A pressure adjusting mechanism, which is pressed against the feed roller by using an elastic body capable of adjusting a pressing force. 2. The elastic body is a U-shaped leaf spring. A fixing means is attached to a base end of the leaf spring, and a pressing part is provided on an action part side for pressing a roller from the base end. The pressure adjusting mechanism according to claim 1, wherein an adjusting tool for adjusting the pressure is provided on each of the left and right sides. 3. The pressure adjusting mechanism according to claim 1, wherein the mechanism is provided on a press roller of a curved transport unit of the automatic document feeder.