JPH03232644A - Sheet conveying device - Google Patents

Abstract

PURPOSE:To effect reliable correction of a skew by providing sheet pick-up means located in two spots at a given distance therebetween in the direction of the width of a sheet, a means to detect the skew direction and a skew amount of a sheet, and a means to vary the conveyance speed of one sheet pick-up means according to a detected result therefrom. CONSTITUTION:A controller 66 calculates a difference in times, at which the tip of a sheet is detected by means of sensors 64a and 64b, and discriminates the skew direction and a skew amount of a sheet. When the controller 66 detects a leftwardly upward skew, a clutch 48a is engaged, and a rotation drive force transmitted from a transmission gear 44 to a shaft 42 is transmitted to a prime move gear 30a engaged with a drive gear 46a. When the rotation is transmitted to the gear 46a, a drive pulley 32a is rotated by means of the power of the gear 46a through the working of a one-way clutch. Since the size of the gear 46a is larger than that of the gear 30a, a current sheet conveyance speed is higher than a conveyance speed provided by means of a rotation drive force transmitted to a shaft 24. Thus, the leftwardly upward skew is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Field of Industrial Application) The present invention relates to a paper conveying device for feeding paper sheet by sheet in an optical character reading device or the like.

(Prior Art) Generally, an optical character reading device or the like is provided with a paper conveying device that takes out each sheet from the top of a bundle of sheets stacked on a hopper and supplies them to a character reading mechanism. The paper transport device is provided with a skew correction mechanism for transporting the paper taken out from the hopper so that the paper is not tilted. The structure of such a paper conveyance device having a skew mechanism is shown in FIG. 3 (plan view) and FIG. 4 (side view). The paper bundle 2 loaded on the hopper 1 is transferred to the hopper l.
The feed roller 3 is pressed against the feed roller 3 by the action of a spring provided at the lower part (not shown) of the feed roller 3 . Feed roller 3
is rotated in the direction of arrow A, and the uppermost sheet is taken out in the direction of separator roller 4 by its frictional force. The separator roller 4 is in pressure contact with the feed roller 3, so that when two or more sheets of paper are taken out by the rotation of the feed roller 3, only the topmost sheet is taken out in the direction of the skinny mechanism. . The paper taken out from above the hopper L by the feed roller 3 is fixed in the paper transport direction by a plurality of steel balls 5 constituting a skew mechanism and a skew correction belt B that rotates in the direction of arrow B while being in pressure contact with each steel ball. transported to. The skew correction belt 6 is provided at a predetermined angle with respect to a reference plane 7 set in the correct conveyance direction of the paper. That is, while the sheet is being conveyed by the skew correction belt 6, the left end of the sheet is pressed against the reference surface 7 to correct the skew.

(Problem 8 to be Solved by the Invention) As described above, the conventional paper conveyance device is configured to correct the skew by pressing the left end of the paper against the reference surface 7 while conveying the paper. Therefore, as a condition for reliably performing skew correction, a certain degree of paper stiffness (strength) is required.

That is, for thin paper, it was not possible to reliably correct the skew.

Also, since the paper is conveyed only between the skew correction belt 6 and the steel balls 5, in order to process long paper, the length of the skew correction belt 6 must correspond to the length of the paper. becomes. That is, when a long sheet of paper is to be processed, the skew correction belt 6 becomes long, resulting in an increase in the size of the apparatus.

The present invention has been made in view of the above points, and it is possible to reliably perform skew correction even for thin paper, and it is also possible to process long paper without increasing the size of the device. The purpose of the present invention is to provide a paper conveying device that is easy to use.

[Structure of the Invention (Means for Solving the Problems) The present invention takes out sheets one by one from a stack of sheets loaded in a hopper and transports them, and the sheets are transported at two locations at a predetermined interval in the width direction of the sheets. a skew detection means for detecting the skew direction and skew amount of the paper taken out from the hopper by the paper ejection means; It is configured to include a conveying speed changing means for changing one of the conveying speeds.

(Function) According to such a configuration, the paper transport speed of one of the two paper take-out means provided in the paper width direction (left and right) for taking out the paper from the hopper is adjusted according to the skew direction and skew amount of the paper. Correct the skew by changing the That is, the paper conveyance speed on one side, whose conveyance has been delayed due to skew, is increased to correct the difference in conveyance distance on the other side.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. 1 and 2 are diagrams showing the structure of a paper conveying device according to the same embodiment, with FIG. 1 showing a plan view and FIG. 2 showing a side view. In FIGS. 1 and 2, a pulley (not shown) fixed to a drive shaft 24 is connected to a pulley 22 fixed to the shaft of a motor 20 serving as a drive source.
They are dynamically connected via a belt 26. The drive shaft 24 includes a transmission gear 28 and two driving gears 30.
a.

Driving pulleys 32a and 32b corresponding to the driving gears 30b1 and the driving gears 30a and 30b, respectively, are arranged at a predetermined interval. The drive pulleys 32a and 32b connect to the drive shaft 24 via a one-way clutch (not shown).
Fixed. A one-way clutch has the function of locking when rotating in one direction and idling when rotating in the other direction. The drive gears 30a30b have corresponding drive pulleys 32a.

32b, and are configured to interlock with each other. The drive pulleys 32a, 32b are connected to the idler pulley 313 via feed belts 34a, 34b, respectively.
a, transmits rotational power to 38b. Idler pulley 3
6a and 36b are idler shafts 38a, respectively.

38b. Also, drive shaft 2
4 and idler shafts 38a, 38b are supported by holders 40a, 40b. A transmission gear 44 that engages with the transmission gear 28 and transmits the rotational power of the motor 20 to the shaft 42 is fixed to the shaft 42 . The shaft 42 also includes drive gears 46a and 46b that engage with the driving gears 30a and 30b, respectively, and a drive gear 4.
6a and 48b, respectively.

48b is arranged. The clutches 48a and 48b are controlled to be turned on and off under the control of a controller 66, which will be described later. By turning on the clutch 48a,
The rotational driving force transmitted to the shaft 42 via the transmission gear 44 is transmitted to the drive gear 46a. Similarly, by turning on clutch 48b, the rotational driving force transmitted to shaft 42 is transmitted to drive gear 4[1ib. Note that the size (pitch circle) of the driving gears 48a and 4[ib is larger (the number is larger) than that of the driving gears 30a and 30b. Feed belts 34a, 34b
, a stack of sheets 52 stacked on the hopper 50 is pushed up and pressed by a spring 54 attached to the lower part of the hopper 50.

A drive pulley 32a32 is provided below the conveyance surface of the paper conveyance path 56.
A separator roller 58a58b is provided corresponding to each of the paper sheets 58a and 58b for separating a plurality of overlapping sheets one by one. In order to transport the paper in the paper transport path 56, drive rollers 60a and BOb are provided below the transport surface, and an idler roller 62a is provided on the transport surface so as to be in pressure contact with each of the drive rollers 60a and 60b.

62b is provided. Drive pulleys 32a, 32b
and the pressure contact light between the separator rollers 58a and 58b,
Sensors 64a and 64b for detecting the leading edge of paper are provided corresponding to the drive pulleys 32a and 32b, respectively.

The results of the leading edge detection of the form by the sensors 64a and 64b are output to the controller 66, and are used to calculate the inclination and direction of the paper.

Next, the operation of the paper conveyance device configured as described above will be explained.

The uppermost sheet of paper loaded in the hopper 50 is in pressure contact with the feed bolt 34 by a spring 54 attached below the hopper 50. The rotational power generated by rotationally driving the motor 20 is generated by the pulley 22 and the heald 2.
6, the signal is transmitted to the drive shaft 24. The rotational power transmitted to the drive shaft 24 is transmitted to the drive pulley 32 via a one-way clutch (not shown).

That is, when the drive shaft 24 is rotated in the direction of transporting the form, the one-way clutch is locked and transmits rotational driving force to the drive pulley 32. Furthermore, the drive pulley 32 rotates in the direction of the arrow in the figure, causing the idler pulley 36 to rotate via the feed belt 34. As a result, the uppermost sheet of paper that is in pressure contact with the feed belt 34 is taken out from the hopper 50 and is removed from the sheet conveyance path 50.
It is sent out in 6 directions. At this time, a plurality of sheets 52 may be sent out in an overlapping manner due to the frictional force between the sheets. Such overlapping sheets are separated one by one by the frictional force between the separator roller 58 and the feed belt 34, and only the topmost sheet to be taken out is transferred to the paper conveyance path 5.
6 is sent out on top.

By the way, sensors 84a and 64b provided below the paper conveyance path 56 ahead of the separator roller 58 detect the leading edge of the paper 52 sent out from the hopper 50.

The sensor 64b is provided at a position where the left edge of the paper passes, and the sensor 64a is provided at a predetermined distance from the sensor 64b (near the drive pulley 32a in the figure). Normally, when the paper is taken out from the hopper without skew and the sensors 64a and 84b detect the leading edge of the paper at the same time, the rotational power transmitted by the drive shaft 24 as described above causes the drive pulley 32a, 32b is rotated to convey the paper as it is. The paper conveyance speed due to the rotational driving force transmitted to the drive shaft 24 is defined as Vl.

On the other hand, if the leading edges are not detected simultaneously by the sensors 64a and 84b, the paper is conveyed as follows. First, if the sensor 64b detects the leading edge of the paper first,
The paper taken out from the hopper 50 is skewed upward to the left. Each sensor 64a, 64b outputs paper leading edge detection to the controller 66. The controller 66 calculates the time difference between when the leading edge of the paper is detected by the sensor 64a184b, and determines the skew direction and skew amount of the paper.

When the controller 66 detects an upward left skew,
An instruction to turn on clutch 46a is output.

When the clutch 48a is turned on in response to an instruction from the controller 66, the rotational driving force transmitted to the shaft 42 by the transmission gear 44 is transmitted to the driving gear 30a that engages with the drive gear 46a. When the rotation is transmitted to the drive gear 46a, the drive pulley 32a is rotated by the power of the drive gear 46a due to the action of the one-way clutch. That is, the one-way clutch idles relative to the rotation of the drive shaft 24 and transfers the rotation of the drive gear 46a to the driving gear 30.
a to the drive pulley 32a. Drive gear 46
Since the size of a is larger than the drive gear 4flia, the paper conveyance speed at this time is the same as that of the drive shaft 2.
The paper conveyance speed v1 due to the rotational driving force transmitted to the paper transport speed v1 is faster than the paper transport speed v1. In this way, the controller 66 corrects the upward left skew by controlling the clutch 48a to be in the on state for a period corresponding to the skew amount.

When the skew is corrected by turning on the clutch 48a for a predetermined period of time corresponding to the amount of skew, the clutch 48a is turned off and the paper is transported with the paper transport speed on the drive pulley 32a side set to Vl.

Next, if the sensor 64a detects the leading edge of the paper first, it means that the paper taken out from the hopper 50 is skewed upward to the right. As in the case of the upward left skew, the controller 66 calculates the time difference between when the leading edge of the paper is detected by the sensors 64a and 64b, and determines the skew direction and amount of the paper. The controller 66 is
When an upward skew to the right is detected, an instruction to turn on clutch 4Eib is output. When clutch 46b is turned on in response to an instruction from controller 66, transmission gear 44
The rotational driving force transmitted to the shaft 42 is transmitted to the driving gear 30b that engages with the driving gear 46b. When the rotation is transmitted to the drive gear 46b, the drive pulley 32b is rotated by the power of the drive gear 46b due to the action of the one-way clutch. That is, the one-way clutch rotates idly with respect to the rotation of the drive shaft 24, and the one-way clutch rotates idly with respect to the rotation of the drive shaft 24,
6b is transmitted to the drive pulley 32b via the driving gear 30b.
to communicate. The size of the driving gear 46b is the driving gear 30b.
Therefore, the paper conveyance speed at this time is 2 which is faster than the paper conveyance speed 1 caused by the rotational driving force transmitted to the drive shaft 24. In this way, the controller 66 controls the clutch 4 for a period of time corresponding to the skew amount.
8b is turned on to correct the upward skew to the right. For a predetermined time depending on the amount of skew, clutch 4
When the skew is corrected by turning on the clutch 48b, the clutch 48b is turned off and the sheet conveying speed on the driving pulley 32b side is set to Vl to convey the sheet.

In this way, the skew-corrected paper is transferred to the drive roller 6.
0a, 1liOb and idler rollers 82a, 62b
The paper is transported on the paper transport path 56 by the optical character reading device, and is subjected to character reading processing, etc. in an optical character reading device.

In this way, the skew correction of the paper can be performed in the feeder mechanism portion that takes out the paper from the hopper 5o and sends it to the paper transport path 56.

That is, since skew correction is not performed while conveying the paper as in the conventional method, the apparatus does not become larger even when long sheets are to be processed. In addition, unlike conventional methods, the skew is not corrected by pressing the paper against the reference surface, so the stiffness (strength of the paper) is not required.
Skew correction can be performed reliably even on thin paper.

[Effects of the Invention] As described above, according to the present invention, when it is detected that the paper taken out from the hopper is skewed, the paper conveyance speed of either the left or right side is changed depending on the inclination of the paper. Since the skew is corrected by doing this, there is no need for the paper to be particularly stiff (firmness). In addition, since the skew is corrected in the feed mechanism that takes paper from the hopper, there is no need for a conveyance path to correct skinny, which may lead to an increase in the size of the device even when processing long forms. There is no.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the structure of a paper transport device according to an embodiment of the present invention, FIG. 2 is a side view of the paper transport device shown in FIG. 1, and FIG. 3 is a diagram showing the structure of a conventional paper transport device. FIG. 4 is a side view of the paper conveying device shown in FIG. 3. 20... Motor, 22... Pulley, 24... Drive shaft, 2 B-... Belt, 28.44-...
Transmission gear, 30a +'sob... Driving gear, 32
a, 32b... drive pulley, 34a. 34b... Feed belt, 36a, 36b... Idler pulley, 38a, 38b =- Idler shaft, 40a. 40b...Holder, 42...Shaft, 4Ba, 4
8b... Drive gear, 48a, 48b... Clutch, 50... Hopper, 52... Paper bundle, 54... Spring, 56... Paper transport path, 58a. 58b... Separator roller, 60a, 60b...
- Drive rollers, 62a, 62b--Idler rollers, 64a, 64b-=Sensor, 66...Controller

Claims (1)

[Scope of Claims] A device for taking out and conveying sheets one by one from a stack of sheets loaded in a hopper, comprising a sheet take-out means provided at two locations at a predetermined interval in the paper width direction; and the paper take-out means. skew detection means for detecting the skew direction and skew amount of the paper taken out from the hopper by the means; and conveyance speed changing means for changing the conveyance speed of one of the paper take-out means according to the detection result by the skew detection means. A paper conveying device characterized by comprising the following.