JPH0774052B2 - Automatic paper feeder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic paper feeder used in a facsimile, a copying machine, a data input scanner, or the like.

2. Description of the Related Art Conventionally, as shown in FIG. 4, a conventional device of this type has a paper feed roller 1 driven in the direction of an arrow and a paper feed roller 1 that is pressed against the paper feed roller 1 and is opposite to the paper conveyance direction by the paper feed roller 1. Has a separation roller 2 with a torque limiter that is driven in the direction, and a paper tray 3 obliquely above it, and holds a large number of sheets of paper 4 in the paper tray 3
When placed on top, the lower end of the paper is inserted between the paper feed roller 1 and the separation roller 2 by its own weight, and while the separation roller 2 prevents the feeding of a plurality of papers, the paper is fed by the paper feed roller 1. The sheets are pulled out one by one and fed to the reading position below them. In the figure, 5 is a sheet conveying roller, and 6 is a reading means such as an image sensor. However, this structure has a drawback in that the entire height becomes large because its own weight is used to introduce the paper into the position of the paper feed roller. Therefore, as shown in FIG. 5, from the viewpoint of making the height of the device low and ensuring the introduction of paper more reliably in recent years,
Upstream of the feed roller 1 and the separation roller 2 (on the right side in the drawing)
, The paper table 3 is arranged horizontally, and an introducing roller 8 and a pinch roller 10 pressed by the solenoid 9 to the introducing roller 8 are provided between the paper table 3 and the sheet feeding roller 1.
It has been proposed that the introduction roller 8 is rotated in association with the paper feed roller 1 so that a large number of sheets 4 on the paper tray 3 are introduced between the paper feed roller 1 and the separation roller 2. . FIG. 6 shows a drive system for these paper feed roller 1, separation roller 2, conveying roller 5, introduction roller 8 and the like. The introduction roller 8 includes a pulley 12, a belt 13 and a pulley.
The paper feed roller 1 is drivingly connected via 14
Is connected to a pulse motor 16 via an electromagnetic clutch 15. The pulse motor 16 also acts as a drive source for the transport roller 5. Reference numeral 17 in the figure is a position sensor.
In the above device, when the pulse motor 16 rotates, the paper feed roller 1, the introduction roller 8 and the conveyance roller 5 all rotate,
At the same time, the solenoid 9 operates to press the pinch roller 10 against the introducing roller 8, and the sheet 4 is supplied to the paper feeding roller 1 by the introducing roller 8 and the pinch roller 10. The paper feed roller 1 and the separation roller 2 separate one sheet from a large number of sheets 4 and send it to the pulling and conveying roller 5. When the leading edge of the sheet fed by the sheet feeding roller 1 passes through the first conveying roller 5 and is detected by the position sensor 17 immediately thereafter, the electromagnetic clutch 15 is deenergized, and the sheet feeding roller 1 and the introducing roller 8 are deenergized. The rotation is stopped. The sheet is conveyed by the conveying roller 5 through the reading position and is read. When the reading of one sheet is completed, the electromagnetic clutch 15 is energized again, and the paper feed roller 1 and the separation roller 2 pull out and feed the next paper. The same operation is repeated thereafter, and when the reading and discharging of the final sheet are completed, the pulse motor 16 stops, and at the same time, the energization of the solenoid 9 for raising the pinch roller 10 is cut off, and the pinch roller 10 rises. Stops the device.

However, with such a configuration, the introduction roller 8 and the pinch roller are not solved.
When a large number of sheets are inserted between the sheet 10 and the sheet and the sheet is inserted too strongly, the leading edge of the sheet is positioned between the sheet feed roller 1 and the separation roller 2 as shown in FIG. There is a problem in that the sheets are inserted and a plurality of sheets are fed or the sheet cannot be fed. Further, in such a configuration, the solenoid 9 is required to raise and lower the pinch roller facing the introduction roller, and an electric circuit for controlling the mechanism is also required, which causes a problem that the apparatus becomes complicated and the cost increases. there were.

In order to prevent a large number of sheets from being inserted between the paper feed roller 1 and the separation roller 2 when setting the paper, as shown in FIG. It is conceivable to provide a paper stopper 19 that moves up and down by a solenoid 18 to determine the position when setting paper. But,
This method is not preferable because it further requires the solenoid 18 and its control circuit and further increases the cost of the apparatus.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an automatic paper feeder capable of easily setting a sheet at a fixed position without complicating the apparatus. .

Means for Solving the Problems The present invention relates to an introducing roller for introducing a sheet into a separating section, and a stopper section for holding the shaft of the introducing roller at one end and preventing the sheet from being introduced into the separating section at the other end. Stopper means rotatable about a fulcrum between the shaft of the introducing roller and the stopper portion, introducing roller holding means having a vertically elongated hole for holding the shaft of the introducing roller, and the separating portion. The rotation of the paper feed roller that constitutes the above is transmitted to the introduction roller, and the forward rotation of the paper feed roller raises the shaft of the introduction roller while contacting one side surface of the elongated hole, and the reverse rotation of the paper feed roller. Means for lowering the shaft of the introducing roller to the lower end of the slot, the stopper portion is lowered by the rotation of the paper feeding roller, and the introduction of the paper by the introducing roller is started.

Effect of the Invention According to the present invention, when the rotation is transmitted from the sheet feeding roller, the introducing roller rotates in the forward direction and the shaft of the introducing roller comes into contact with one side surface of the elongated hole of the introducing roller holding means. Ascending, the introducing roller introduces the paper toward the paper feeding roller. At this time, the stopper portion descends following the movement of the introducing roller to release the inhibition of the introduction of the sheet, so that the stopper portion does not hinder the introduction of the sheet. Next, after finishing the sheet introduction by the introduction roller, when the introduction roller is rotated in the opposite direction and stopped, the reverse rotation causes the introduction roller to automatically descend due to the contact between the introduction roller shaft and one side surface of the slot. At the same time, the stopper part rises. For this reason, since the stopper portion is located at a position that prevents the sheet from being introduced into the sheet feeding roller, the sheet can be regulated by the stopper portion and set at a predetermined position.

Examples Hereinafter, preferred examples of the present invention will be described in detail. FIG. 1 is a schematic perspective view showing a roller arrangement and its drive system of a reading device equipped with an automatic paper feeding device according to an embodiment of the present invention.
The figure is a perspective view of the above-described automatic sheet feeder. In the figure, 21 is a paper feed roller that pulls out the lowermost one of a large number of papers by applying a feeding force, and 22 is a paper feed roller 21 for a plurality of papers.
It is a separation roller which constitutes a separation means for preventing the sheet from being pulled out by. The paper feed roller 21 is held by the drive shaft 23 so as to rotate integrally therewith, and the separation roller 22 is held by the drive shaft 24 via a torque limiter 25. The drive shaft 23 and the drive shaft 24 are connected via a gear mechanism so as to rotate in the same direction.Therefore, when the paper feed roller 21 rotates in the arrow direction to convey the paper, the separation roller 22 is Through the torque limiter 25, the paper feed roller 21 rotates in a direction opposite to the paper feeding direction. This rotation prevents a large number of sheets from being fed at the same time. As the separating means, a plate-like separating / sorting piece made of rubber or the like may be used instead of the separating roller 22. The drive shaft 23 is connected to the pulse motor 30 via an electromagnetic clutch 27, a pulley 28, a belt 29 and the like.

31 is a sheet of paper, 32 is a sheet stand that supports a large number of sheets of paper 31, 33 is a guide roller for introducing a large number of stacked sheets of paper 31 on the stand 32 of paper to a feed roller position, and 34 is a roller for introducing the sheet. A pinch roller movable so as to be pressed, a spring 35, and an introducing roller holding member 36 for holding the introducing roller 33. The introduction roller 33 has a shaft 38 that rotates integrally, while the introduction roller holding member 36 has a long hole that movably guides the shaft 38.
Equipped with 39. The slot 39, as shown in FIG.
Is located at the upper end, the introducing roller 33 is in the operating position where it contacts the pinch roller 34, and as shown in FIG. 3B, when the shaft 38 is located at the lower end, the introducing roller 33 is in the standby position away from the pinch roller 34. Is formed in such a position as to have a circular arc shape centered on the drive shaft 23 of the paper feed roller 21.
The pinch roller 34 is supported by an appropriate stopper so that the pinch roller 34 cannot move downward from a certain position even if the introducing roller 33 descends. The drive shaft 23 of the paper feed roller 21 has a drive roller 41, and an introduction belt 42 is stretched around the drive roller 41 and the introduction roller 33. The introduction belt 42 rotationally drives the introduction roller 33 by the rotation of the drive roller 41 while pressing the shaft 38 of the introduction roller 33 against the side surface 39A of the elongated hole 39 on the drive shaft 23 side. Therefore, the drive roller 41, the introduction belt 42, and the like constitute an introduction roller driving means that drives the shaft of the introduction roller while contacting one side surface of the elongated hole.

A paper stopper 44 is provided between the paper feed roller 21 and the introduction roller 33. The paper stopper 44 is rotatably provided around a support shaft 45, and has a stopper portion 44A at one end for preventing the introduction of paper and a shaft 38 of the introduction roller 33 at the other end.
It has a long hole 44B for inserting. Therefore, the paper stopper 44 swings around the support shaft 45 in conjunction with the vertical movement of the introduction roller 33. The swing range of the paper stopper 44 is
As shown in FIG. 3A, when the introducing roller 33 is in the raised operating position, the stopper portion 44A descends to a non-operating position that does not hinder the introduction of the paper, and as shown in FIG. When in the lowered standby position, the stopper portion 44A is set so as to rise to the operating position for stopping the introduction of the paper.

In FIG. 1, 47 is a feed roller, 48 is a discharge roller, 49 is a feed roller shaft, and 50 and 51 are gears held by the feed roller shaft 49 via a one-way clutch that allows rotation in opposite directions. One gear 50 directly meshes with a gear 53 provided on a drive shaft 52 driven by the pulse motor 30, and the other gear 51 meshes with a gear 54 on the drive shaft 52 via an idle gear 55. This configuration enables the feed roller 47 and the discharge roller 48 to always rotate in one direction indicated by an arrow, regardless of whether the pulse motor 30 rotates in any of forward and reverse directions. Reference numerals 56 and 57 are paper sensors, and 58 is a reading means such as an image sensor.

Next, the operation of the device having the above structure will be described. When the device is stopped, it is in the state shown in FIG. 3B. The reason for this state when the apparatus is stopped will be described later. Paper with many sheets stacked
31 is passed between the introducing roller 33 and the pinch roller 34 and set on the paper table 32. In the state shown in FIG.
Since 33 is located away from the pinch roller 34, insertion is easy, and the stopper portion 44 of the paper stopper 44 is
Since A is raised, the paper hits the stopper portion 44A and is set at a predetermined position without entering between the paper feed roller 21 and the separation roller 22.

When the start switch is turned on, the pulse motor 30 starts to rotate in the forward direction, and this rotation is transmitted to the drive shaft 23 of the paper feed roller 21 via the electromagnetic clutch 27, and the paper feed roller 21 and the separation roller are separated.
22 is rotated in the direction shown by the arrow in FIG. 2, and the introduction roller 33 is rotated via the introduction belt 42. The rotation of the introduction roller 33 also rotates the shaft 38, but since the shaft 38 is in contact with the side surface 39A of the elongated hole 39 due to the belt tension, the side surface 3
The friction with 9A causes it to rise along the long hole 39, and the introduction roller 33
Moves to the operating position shown in FIG. 3A, and at the same time, the stopper portion 44A of the paper stopper 44 descends to a position that does not hinder the introduction of paper. Since the introducing roller 33 continues to rotate in this state, the sheet 31 is sandwiched by the pinch roller 34 and the introducing belt 42 and sent to the nip position between the sheet feeding roller 21 and the separating roller 22. In addition, the paper 31 is inserted between the introduction roller 33 and the paper feeding roller 21.
In order to prevent the paper from flexing excessively, the paper feeding force by the introduction belt and the pinch roller is set to a small value, and after the leading edge of the paper comes in contact with the paper feeding roller and the separation roller and the movement is stopped, It slips with the introduction belt.

The feed roller 21 cooperates with the separation roller 22 to produce a large number of sheets of paper 31.
Pull out the bottom sheet of paper from the feed roller 47
To feed. When the leading edge of the pulled-out sheet is detected by the sensor 56 provided immediately after the feed roller 47, the electromagnetic clutch 27 is disengaged, which causes the sheet feed roller 2
1. Transmission of the rotational force to the separation roller 22 and the introduction roller 33 is cut off. The first sheet is conveyed by the feed roller 47 and read by the reading means 58 at the reading position.
When the rear end of the first sheet of paper is detected by the sensor 56, the electromagnetic clutch 27 is energized again, and the second sheet of paper is fed by the paper feed roller 21 and the separation roller 22.
By repeating the above-described movement, a large number of sheets are read one by one.

When the sensor 57 of the sheet tray 32 detects that the last sheet has been fed, and then when the sensor 56 detects the trailing edge of the last sheet, the pulse motor 30 reverses the rotation with a reading end signal from the reading unit 58. First, the electromagnetic clutch 27 is engaged. This causes the introduction roller 33 to start reverse rotation and
Due to the friction between the 38 and the side surface 39A of the elongated hole 39, the introducing roller 33 descends and the stopper portion 44A of the sheet stopper 44 rises to the state shown in FIG. 3B. On the other hand, even if the pulse motor 30 rotates in the reverse direction, the feed roller 47 and the discharge roller 48 rotate in the direction of feeding the paper, so that the paper is discharged and the pulse motor 30 stops at the same time as the confirmation of the discharge of the final paper. Thus, the introduction roller 33 and the paper stopper 44 are stopped in the state shown in FIG. 3B to prepare for the next operation.

In the above embodiment, in order to drive the introduction roller 33, the introduction belt 42 is directly hung on the outer periphery of the introduction roller 33, and the sheet 31 is conveyed by the introduction belt 42.
Alternatively, pulleys may be provided on the shafts on both sides of the introduction roller 33, and a pulley may be provided on the drive shaft 23 of the paper feed roller 21 so that both pulleys are connected by a belt to drive them.
However, in the case of the illustrated embodiment, the introducing belt 42 can also act as a guide for the sheet, and the shafts 38 on both sides of the introducing roller can evenly contact the side surfaces of the elongated holes 39 on both sides with a single belt. The effect that can be obtained is obtained.
Further, the above-described embodiment is a case where the present invention is applied to automatic document feeding of a reading device, but the present invention is not limited to this case and may be used for automatic feeding of recording paper in a recording device. Needless to say.

EFFECTS OF THE INVENTION As is apparent from the above description, according to the present invention, the stopper portion is lowered by the start of rotation of the sheet feeding roller to release the sheet introduction inhibition to the sheet feeding roller by the stopper portion. Until the paper roller starts to rotate, the stopper portion can reliably prevent the introduction of the paper into the paper feed roller, and thus it is possible to reliably prevent the feeding of a plurality of paper sheets or the failure to feed paper. be able to.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing a roller arrangement and a drive system of a reading device equipped with an automatic paper feeding device according to an embodiment of the present invention, and FIG. 2 is an automatic paper feeding device in the device of FIG. 3A and 3B are side views for explaining the operation of the automatic paper feeder, FIG. 4 is a schematic side view of a reading device equipped with a conventional automatic paper feeder, and FIG. FIG. 6 is a side view showing another example of the automatic paper feeder of FIG. 6, FIG. 6 is a schematic perspective view showing a drive system of the apparatus of FIG. 5, and FIG. 7 is a side view for explaining problems in the apparatus of FIG. FIG. 8 is a side view of a device considered to solve the problem. 21 …… Paper feed roller, 22 …… Separation roller, 23 …… Drive shaft,
31 …… Paper, 32 …… Paper stand, 33 …… Introduction roller, 34 ……
Pinch roller, 36 …… Introduction roller holding member, 38 …… Axis,
39 …… Oval hole, 39A …… Side, 42 …… Introduction belt, 44 ……
Paper stopper, 44A ... Stopper part, 45 ... Spindle.

Claims (1)

[Claims] 1. An introduction roller for introducing a sheet into a separating section,
It has a stopper portion for holding the shaft of the introduction roller at one end and for preventing the introduction of the paper to the separation portion at the other end, and rotates about a fulcrum to turn on either the introduction roller or the stopper portion. Stopper means for moving the sheet to the conveying path, introducing roller holding means having an elongated hole for regulating the vertical movement of the axis of the introducing roller, and rotation of the paper feeding roller forming the separating section of the introducing roller. A transmission means for transmitting the shaft to rotate the introduction roller and a drive means for rotating the paper feed roller in forward / reverse directions are provided, and the transmission means rotates the paper feed roller in a direction for feeding the paper. With this, the shaft of the introduction roller is raised while being pressed against one side surface of the elongated hole, and the stopper portion is lowered to start the introduction of the sheet.