JPH06263274A - Paper feeder and paper feed method for information processing device - Google Patents

Abstract

PURPOSE:To provide a paper feeder and a paper feed method by which throughput of a paper sheet is heightened and looseness or skew of the paper sheet is not caused between rollers. CONSTITUTION:A backward rotation transmitting mechanism 45 and a forward rotation transmitting mechanism 46 are arranged in parallel with each other as a transmission mechanism to connect an upstream roller 2 and a downstream roller 3 in a paper sheet passage in rotation to each other, and one-way clutches 16 and 52 are arranged in both transmitting mechanisms 45 and 46 so as to transmit only rotation in the paper feed direction to a downstream roller shaft 15, and a one-way clutch 50 is arranged in a driving system of the upstream roller 2 so as to transmit only torque in the paper feed direction to the upstream roller 2. A clearance in the rotational direction is arranged inside of transmission mechanisms 6-8 to rotate a paper feed upstream roller 4 and a downstream roller 5 in the same direction. Before the tip of a paper sheet reaches the downstream roller, peripheral speed of the downstream roller is increased more than peripheral speed of the upstream roller, and after the tip of the paper sheet is gripped by the downstream roller, the peripheral speeds of the downstream roller and the upstream roller are synchronized with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing device using paper as a medium, for example, a paper feeding device of a printer or a document reading device, and particularly to a paper path of a paper path formed by a plurality of roller pairs drivingly connected by a transmission mechanism. The present invention relates to a sheet feeding device having a structure in which a sheet is sandwiched and fed between an upstream side and a downstream side and a driving method thereof.

[0002]

2. Description of the Related Art FIG. 9 shows an example of a paper feeding device of this type having a conventional structure, in which a paper feed roller 1, a first feed roller 2 and a second feed roller 3 are arranged from an upstream side to a downstream side of a paper path. The paper feed roller 1 is composed of two rollers, an upstream pick roller 4 and a downstream separation roller 5. The pick roller 4 and the separation roller 5 are drivingly connected by gear trains 6, 7 and 8 so as to synchronously rotate in the same direction with respect to the paper, and the paper feed roller 1 and the first feed roller 2 are gear trains 8, The first feed roller 2 and the second feed roller 3 are synchronously rotated in the same direction with respect to the paper by the gear trains 10, 11 and 12 by being drive-coupled by 9 and 10 so as to rotate in the opposite directions with respect to the paper. And the driving force for rotating the second feed roller shaft 15 in the paper feeding direction (clockwise rotation in the figure) is transmitted between the gear 12 of the second feed roller and the shaft 15 thereof. The one-way clutch 16 that does not transmit the rotational force in the paper return direction is provided.

The paper feeding device 14 shown in FIG. 9 is a paper feeding device of an original reading device having a function of automatically feeding the stacked sheets of paper by lowering the paper. The reading unit 17 is provided between the first feed roller 2 and the second feed roller 3, and the first paper sensor 18 and the second paper sensor 19 are arranged on the upstream side and the downstream side of the first feed roller 2. Further, the separation roller 5 is provided with a separation pad 21 which comes into contact with the peripheral surface of the separation roller 5 by a spring 20, and a pick spring 22 for ensuring the feeding of the paper to the separation roller 5 side is provided above the pick roller 4. And a gate plate 23 that limits the amount of paper sent to the separation roller 5 side. Further, the transmission mechanisms 6 to 8, 8 to 10 and 10 to 12 constituted by the respective gear trains are structured so that there is no backlash in the rotation direction, so that the rollers rotate accurately in synchronization. It is considered. Each of the rollers 1, 2 and 3 is driven by a motor capable of rotating in the normal and reverse directions, and a motor shaft 24 is connected to a transmission gear 11 between the first feed roller 2 and the second feed roller 3. .

A conventional paper feeding method in the paper feeding device 14 having the above structure is as follows. When paper is supplied, the motor shaft 24 is rotated clockwise in the figure. Due to the action of the clutch 16, this rotation is not transmitted to the second feed roller 3,
The first feed roller 2 rotates in the paper return direction, and the paper feed roller 1 rotates in the paper feed direction. One sheet of paper separated by passing between the separation roller 5 and the separation pad 21 is the first
After being fed toward the feed roller 2 and the leading edge of the sheet is detected by the first sheet sensor 18, the motor shaft 24 is further rotated in the same direction by a predetermined amount to rotate the leading edge of the sheet in the reverse direction. The motor shaft 24 is stopped in a state of abutting the nip portion of the roller 2 and slightly overfeeding. In this state, the paper 25 is fed to the first feed roller 2 and the separation roller 5 by
Is slightly bent, and the restoring force thereof presses the leading edge of the sheet against the nip portion of the first feed roller 2 to correct the skew of the sheet.

Next, the motor shaft 24 is rotated counterclockwise in the figure. This rotation causes the first feed roller 2 and the second feed roller 3 to rotate synchronously in the paper feed direction, and the paper is sent toward the second feed roller 3 after being caught by the first feed roller. On the other hand, the paper feed roller 1 rotates in the paper return direction, and a slip occurs between the paper fed by the feed rollers 2 and 3 and the peripheral surface of the paper feed roller 1. After the leading edge of the paper is detected by the second paper sensor 19 while the paper is being fed by the feed rollers 2 and 3, the paper reading operation is started when the paper is fed by a predetermined amount, and the reading of the preset range is completed. Reading operation ends.

After the trailing edge of the paper is detected by the second paper sensor 19, the motor shaft 24 is stopped, the motor shaft 24 is rotated clockwise in the figure, and the paper feed roller 1 is again rotated in the paper feed direction. Paper. At this time, the previous paper is still the second
Although the sheet is nipped by the feed roller 3, the one-way clutch 16 blocks the rotation of the second feed roller 3 in the sheet returning direction, so that the preceding sheet remains in the stopped state and the next sheet is stopped. After the tip reaches the first feed roller 2, when the motor shaft 24 rotates counterclockwise in the figure, it is fed by the second feed roller 3.

The example of FIG. 9 shows an example of a structure in which the paper is fed to the feed rollers 2 and 3 from the paper feed roller 1 driven by the same motor shaft 24, but FIG. 7 shows a structure of the feed rollers having the same structure. 2 and 3 show a structure in which a sheet is fed from a sheet feeding device 26 of a sheet reversing device which is rotationally driven by different motor shafts 29. In the reversing device shown in FIG. 7, three pressing rollers 28, 28, 28 are arranged around the reversing roller 27, and further, a driving roller 31 fixed to a motor shaft 29 and a driven roller 32 abutting against the driving roller 31 from below. The receiving roller 33 is constituted by the same, and the sending roller 35 is constituted by the same driving roller 31 and the driven roller 34 abutting on the same driving roller 31. The driving roller 31 and the reversing roller 27 are rotationally driven in the same direction at the same peripheral speed by a transmission mechanism 39 composed of gear trains 36, 37, 38. In the case where the first feed roller 2 receives the sheet sent from the sending roller 35 of the sheet reversing device 40 configured as described above, conventionally, the peripheral speeds of the sending roller 35 and the first feed roller 2 are constant. In addition, the drive motor of the paper feeding device 14 of the document reading device and the drive motor of the paper feeding device 26 of the paper reversing device are synchronized to transfer the paper.

[0008]

However, in the conventional paper feeding device as described above, when the slack of the paper occurs between the upstream side roller and the downstream side roller, which reduces the paper throughput, There are problems that the slack is not eliminated, and that skew occurs when the paper is delivered from the upstream roller to the downstream roller.

That is, in the case of the automatic paper feed reading in the original reading apparatus having the paper feeding device 14 shown in FIG. 9, even if the reading area is smaller than the paper size, the trailing edge of the paper is located at the position of the second paper sensor 19. The next sheet cannot be fed until the sheet passes, and the gap between the preceding sheet and the next sheet is widened, and there is room for improving the sheet throughput.

As means for improving the paper throughput, the diameter of the paper feed roller 1 is increased or the first feed roller 2 of the transmission gears 6 and 8 connected to the pick roller 4 and the separation roller 5 is used. By changing the gear ratio with respect to the transmission gear 10 to increase the roller peripheral speed of the paper feed roller 1, or by increasing the rotation speed of the motor during paper feed (when the paper feed roller 1 rotates in the paper feed direction). Although it is possible, there is a problem that the required output torque of the motor becomes large, and the slip that occurs between the paper feed roller and the paper at the time of paper feeding becomes large, which causes unevenness in feeding and dirt on the paper. To do.

Further, for example, the paper feeding device 14 having the structure shown in FIG.
In the conventional structure in which there is no play in the rotational direction between the pick roller 4 and the separation roller 5, when a slack 41 of the sheet occurs between the rollers 4 and 5 as shown in FIG. When the peripheral speeds of the pick roller 4 and the separation roller 5 are the same, the slack 41 remains unresolved and remains, causing skew in the paper and unstable paper feeding. If the peripheral speeds of the pick roller 4 and the separation roller 5 are made different from each other to absorb the slack 41, the slack 41 is removed and the sheet is stretched between the rollers 4 and 5, Laura 4,
The sheet is fed while slippage occurs between one of the sheets 5 and the sheet, which is not preferable.

Further, as shown in FIG. 7, when the leading edge of the sheet is passed from the upstream roller 35 rotating at the same peripheral speed to the downstream roller 2, the leading edge of the sheet is curled or the leading edge of the sheet is changed as shown in FIG. When the paper is drooped as shown in (4), after the leading edge of the paper reaches the peripheral surface of the downstream roller 2, the side previously fed into the nip portion is slightly faster, and skew is generated in the paper nipped by the downstream roller 2. Sometimes. This problem is particularly problematic when it is not possible to provide a guide plate extending between the upstream side roller 35 and the downstream side roller 2 in the vicinity of both rollers 35, 2.

As described above, in the conventional paper feeding device and paper feeding method of the information processing device, the paper feeding interval at the time of automatic paper feeding is wasted and the paper throughput is reduced. It is difficult to eliminate the slack between the roller 5 and the roller 5, and when trying to eliminate the slack, the paper and the roller peripheral surface are constantly slipped. There is a problem that a sheet may be skewed when the sheet is delivered to the roller 2.

Therefore, the present invention solves these problems,
An object of the present invention is to obtain a paper feeding device and a paper feeding method that can increase the paper throughput and do not cause slack or skew between the upstream roller and the downstream roller during paper feeding.

[0015]

In a paper feeding device of an information processing apparatus according to the present invention, a paper feed roller 1, a first feed roller 2 and a second feed roller 3 are arranged in this order along a paper feeding direction. The feed roller 1 is drivingly connected so as to rotate in the paper return direction when the first feed roller 2 rotates in the paper feed direction, and the first feed roller 2 and the second feed roller 3 are rotationally connected. In a paper feeding device of an information processing apparatus provided with a transmission mechanism, a reverse rotation transmission mechanism 4 in which the transmission mechanism causes the first feed roller 2 and the second feed roller 3 to rotate in directions opposite to each other with respect to a sheet.
5 and a forward rotation transmission mechanism 46 that makes the same direction. Each of the reverse rotation transmission mechanism 45 and the forward rotation transmission mechanism 46 has only the second feed roller shaft 15 that rotates in the paper feed direction. Clutches 16 and 52 that transmit the rotation in the paper return direction are provided, and the drive system of the first feed roller 2 transmits only the rotational force in the paper feed direction to the first feed roller 2 and the paper return direction. It is characterized in that a clutch 50 that does not transmit the rotational force of is provided.

The paper feeding method according to the present invention is the paper feeding roller 1.
The paper of the paper feeding device described above, which includes a first paper sensor 18 between the first feed roller 2 and the first feed roller 2, and a second paper sensor 19 between the first feed roller 2 and the second feed roller 3. In the feeding method, the motor shaft 24 is driven so that the paper feed roller 1 rotates in the paper feeding direction, and after the first paper sensor 18 detects the presence of paper, the motor shaft 24 is further driven in the same direction by a predetermined amount. The first operation of bringing the leading edge of the sheet into contact with the first feed roller 2 and the second rotation of the motor shaft 24 and the second sheet sensor 19 detecting the presence of the sheet and continuing the rotation until the sheet is fed by a predetermined amount And a third operation of reversing the motor shaft 24 and returning to the first operation on condition that the first paper sensor 18 issues a no-paper signal before the motor shaft 24 rotates a certain amount. It is characterized by repeating It is intended.

The paper feeding device of the information processing apparatus according to the present invention is a transmission mechanism 6 for rotating two rollers 4, 5 arranged on the upstream side and the downstream side of the paper path in the same direction with respect to the paper 25. In the paper feeding device of the information processing device including the items 1 to 8, the transmission mechanisms 6 to 8 are internally provided with the play 55 in the rotational direction. Transmission mechanism 6-8
The rotary transmission element 6 and its shaft 56 are freely rotatably fitted, and the radial projection 57 provided on the shaft 56 and the groove 58 provided on the rotation transmission element 6 are engaged with each other, and the projection 57 and the groove 58. The play 55 can be provided at the contact portion with. The rotation transmitting element 6 of the transmission mechanism is mounted on a shaft 65 whose chamfer is formed by a central hole 67 having flat portions 66, 66 formed on the opposite surface, and the plane forming width D of the central hole is chamfered on the shaft 65. The play 55 can be made internal by making it larger than the width d.

A paper feeding method for an information processing apparatus according to the present invention is an information processing apparatus provided with rollers 2 and 35 which are driven in the same direction with respect to a sheet by different driving sources on an upstream side and a downstream side of a sheet path. In the paper feeding method of the paper feeding device of
Before the leading edge of the paper reaches the downstream roller 2, the downstream roller 2
Is set higher than the peripheral speed of the upstream roller 35, and the peripheral speeds of the downstream roller 2 and the upstream roller 35 are synchronized after the leading edge of the sheet is gripped by the downstream roller 2. is there.

Further, in the paper feeding apparatus of the present invention, when the paper is automatically fed, the feeding distance of the feed rollers 1 and 35 is slightly smaller than the feeding distance of the feed rollers 2 and 3 per one rotation of the motor. Keep it late. This can be dealt with by the gear ratio between the transmission gears 6 and 8 of the paper feed roller and the transmission gears 10 and 12 of the feed roller.

[0020]

The automatic paper feeding operation of the paper feeding apparatus of the present invention is as follows. Pick roller 4 and separation roller 5
And rotate in the paper feed direction. At this time, the first feed roller 2 is kept stopped by the action of the clutch 50,
The feed roller 3 receives a rotational force from the reverse rotation transmission mechanism 45 and rotates in the paper feeding direction. After the first paper sensor 18 detects the leading edge of the paper fed from the paper feed roller 1, the motor shaft 24 is rotated by a specified amount and stopped. By this operation, the leading edge of one sheet fed from the sheet feeding roller 1 comes into contact with the nip portion of the stopped first feed roller 2, and the skew of the sheet is corrected by the same operation as the conventional device.

Next, when the motor shaft 24 is reversed, the first feed roller 2 rotates in the paper feeding direction, and the forward rotation transmission mechanism 46.
The second feed roller 3 synchronously rotates in the same direction by receiving the rotational force from the. The paper supplied by this rotation is sent from the first feed roller 2 to the second feed roller 3,
Then, it is nipped by both rollers 2 and 3 and further fed.
During this period, the leading edge of the sheet is detected by the second sheet sensor 19, and a predetermined process such as document reading is performed with the detected position as a reference, and then the motor shaft 24 is stopped when the trailing edge of the sheet separates from the separation roller 5. Let

Next, the motor shaft 24 is reversed again and the paper feed roller 1 is rotated in the paper feed direction to start the next paper feed operation. At this time, the second feed roller 3 rotates in the paper feeding direction and performs an operation of discharging the previously processed paper. The trailing edge of the preceding paper is also nipped by the first feed roller 2, but at this time the first feed roller 2 is in the free rotation state by the action of the clutch 50, so that the ejection operation of the preceding paper is hindered. Absent. When the first paper sensor 18 outputs the no-paper signal, the trailing edge of the preceding paper has passed the position of the first paper sensor 18 before the leading edge of the next paper reaches the position of the first paper sensor 18. Since this is confirmed, the paper feeding operation for the next paper is continued. If the first paper sensor 18 does not output a paper-out signal even if the motor shaft 24 is rotated by a predetermined amount, the trailing edge of the preceding paper and the leading edge of the following paper overlap, or a paper jam has occurred. Either, either, an alarm is displayed and the device is stopped.

By the above operation, the gap between the trailing edge of the preceding sheet and the leading edge of the following sheet can be reduced, and the feeding of the next sheet before the trailing edge of the preceding sheet leaves the first feed roller. Since the operation can be started, the throughput of paper is improved as compared with the conventional device.

Further, like the separating roller 5 and the pick roller 4, a transmission mechanism 6 to 8 for drivingly connecting the upstream roller and the downstream roller of the paper path is provided with a play 55 in the rotational direction, and is provided downstream. When the upstream roller 4 is driven from the side roller 5, when the slack 41 of the sheet occurs between the rollers 5 and 4, when the driving of the rollers 5 and 4 starts, the downstream roller 5 starts to rotate first and the upstream roller 4 to the upstream side. After the sheet is pulled between the side roller 4 and the slack 41 is eliminated, the upstream roller 4 can be synchronized with the downstream roller 5 to feed the sheet without slippage between the two rollers 5 and 4. It will be possible. The play 55 in the rotation direction needs to be larger than the rotation angle required for the downstream roller 5 to take the slack 41. Therefore, the play 55 in the play 55 remains after the slack of the paper is taken. Upstream roller 4 or downstream roller 5 for the remaining play
However, since the amount of slippage is small, the damage to the paper can be far less than that of the conventional device.

From the upstream roller 35 to the downstream roller 2
If the peripheral speed of the downstream roller 2 is increased when delivering the leading edge of the sheet to the sheet, the time difference until the leading edge of the sheet contacting the circumferential surface of the downstream roller 2 is guided to the nip portion can be shortened. Further, the sheet edge previously sent to the nip portion side is also restrained by the upstream roller 35 having a low peripheral speed and is not immediately caught in the nip portion, and when the sheet is delivered from the upstream roller 35 to the downstream roller 2. The occurrence of skew can be eliminated. After the leading edge of the paper is nipped by the downstream roller 2, the upstream roller 35 and the downstream roller 2 have the same peripheral speed, so that the slip between the downstream roller 2 and the paper 25 is
It occurs only at a small portion of the leading edge of the sheet, and there is no risk of stains on the reading section or the printing section of the sheet.

[0026]

FIG. 1 is a diagram showing an embodiment in which the paper feeding device of the present invention is adopted as a paper feeding device of an original reading device having an automatic paper feeding device similar to that of FIG. A reverse rotation transmission mechanism 45 connecting the first feed roller 2 and the second feed roller 3 is shown in FIG. 1A, and a forward rotation transmission mechanism 46 is shown in FIG. 1B. . In the figure, the same members as those described in FIG. 9 are designated by the same reference numerals,
Here, only the parts different from the conventional device will be described in detail.

The reverse rotation transmission mechanism 45 for drivingly connecting the first feed roller 2 and the second feed roller 3 has four gear trains 10, 11, 47, 1 including two transmission gears 11, 47.
Therefore, the first feed roller 2 and the second feed roller 3 are reversely connected by the reverse rotation transmission mechanism 45. The motor shaft 24 is connected to the transmission gear 11 on the right side of the drawing. Gear 1 of the second feed roller
A unidirectional clutch 16 similar to that described in FIG. 9, that is, a unidirectional clutch that transmits only a rotational force that rotates the second feed roller shaft 15 in the paper feeding direction is provided between the second feed roller shaft 15 and the second feed roller shaft 15. Is provided. The gear 10 of the first feed roller is fixed to the first feed roller shaft 49, but between the first feed roller shaft 49 and the first feed roller 2, the first feed roller shaft 49 in the paper feeding direction is disposed. A one-way clutch 50 that transmits only the rotation to the first feed roller 2 and does not transmit the rotation in the paper returning direction is interposed.

The first feed roller 2 and the second feed roller 3 are drivingly connected not only by the reverse rotation transmission mechanism 45 but also by a forward rotation transmission mechanism 46 shown in FIG. 1 (b).
In the forward transmission mechanism 46, the gear 10a of the first feed roller
And the gear 12a of the second feed roller are connected via one transmission gear 51, and thus the first feed roller 2 and the second feed roller 3 are connected in a forward direction. A one-way clutch 52 is provided between the gear 12a of the second feed roller and the second feed roller shaft 15 to transmit only the rotational force that rotates the second feed roller shaft 15 in the paper feeding direction.

In the above embodiment, when the motor shaft 24 rotates clockwise in the drawing, the first feed roller shaft 49 rotates in the paper returning direction, but this rotation is blocked by the clutch 50 and the first feed roller shaft 49 is cut off. 2 is not transmitted. Further, the rotation transmitted from the transmission gear 11 provided with the motor shaft 24 to the gear 12 of the second feed roller via the transmission gear 47 is transmitted to the second feed roller shaft 15 through the clutch 16 to feed the second feed roller 3 to the paper. Rotate in the direction. The rotation in the paper return direction transmitted from the first feed roller shaft 49 rotating in the paper return direction to the gear 12a of the second feed roller via the forward transmission mechanism 46 is blocked by the clutch 52, and the second feed roller is blocked. Axis 1
Not transmitted to 5. The paper feed roller 1 is driven in the paper feed direction from the gear 10 of the first feed roller via the transmission gear 9, and feeds the paper toward the first feed roller 2.

On the other hand, when the motor shaft 24 rotates counterclockwise in the figure, the gear 10 of the first feed roller rotates in the paper feeding direction, and this rotation passes through the first feed roller shaft 49 and the clutch 50. 2 is transmitted.
The rotation of the first feed roller shaft 49 is transmitted to the gear 12a of the second feed roller via the forward transmission mechanism 46, and is transmitted to the second feed roller shaft 15 via the one-way clutch 52 to generate the second feed roller shaft 15. The feed roller 3 is rotated in the paper feeding direction. On the other hand, the gear 11 equipped with the motor shaft 24
Via the transmission gear 47 from the second feed roller gear 1
The rotation in the paper return direction transmitted to the two
It is not transmitted to the second feed roller shaft 15 due to the interposition of 2. The rotation of the gear 10 of the first feed roller in the paper feed direction causes the paper feed roller 1 to rotate in the paper return direction via the transmission gear 9, but the rotation of the paper feed roller in the paper return direction causes the rotation transmission system thereof. It can also be shut off by interposing a one-way clutch on.

The paper feeding operation of the paper feeding device shown in FIG. 1 described above has been described in detail in the section of the above-mentioned operation, and therefore, will be omitted here.

As shown in FIG. 2, there is a play 55 in the rotational direction in the transmission mechanisms 6 to 8 connecting the separation roller 5 of the paper feed roller and the pick roller 4. That is, the gear 6 of the pick roller is rotatably fitted to the pick roller shaft 56, and the pin 57 protruding in the radial direction of the pick roller shaft 56 is engaged in the key groove 58 provided in the shaft hole of the gear 6. The rotation of the gear 6 is transmitted to the pick roller shaft 56, and thus to the pick roller 4 fixed to the pick roller shaft 56. By making the key groove 58 wider than the diameter of the pin 57, A play 55 is formed.

In such a structure, when the paper feed roller 1 driven from the separation roller 5 side starts to rotate in the paper feeding direction, after the separation roller 5 first rotates by an angle corresponding to the play 55, The separation roller 5 and the pick roller 4 rotate synchronously. Therefore, when the sheet between the separating roller 5 and the pick roller 4 has a slack 41 as shown in FIG. 2, when only the separating roller 5 rotates in the sheet feeding direction, the leading end of the sheet is pulled and the slack 41 is generated. Resolved, then pin 5
The sheet slides between the separation roller 5 or the pick roller 4 and the sheet until the sheet 7 comes into contact with the side surface of the key groove 58, and then the separation roller 5 and the pick roller 4 rotate synchronously to feed the sheet.
Therefore, in the paper feed roller having the two rollers 5 and 4 as shown in FIG. 2, the drive system for drivingly connecting the two rollers 5 and 4 is provided with the play 55 in the rotational direction, so that the separation roller 5 on the downstream side is provided. The paper feed start time of is set earlier than the paper feed start time of the pick roller 4 on the upstream side, and the slack of the paper between the rollers 5 and 4 can be adjusted by the operation, and paper jam can be prevented. .

The structure in which there is a play in the rotational direction between the upstream roller and the downstream roller is provided between the first feed roller 2 and the second feed roller 3 shown in FIG. 1 (b). The forward transmission mechanism 46 can also be adopted. That is, conventionally, the diameter of the feed roller 3 on the downstream side is made larger than the diameter of the feed roller 2 on the upstream side in order to prevent the sheet from being bent between the first feed roller and the second feed roller. By doing so, there is a problem that the driving load of the feed rollers 2 and 3 becomes large, and the sheet running becomes unstable. In such a case, the forward feed mechanism 46 that rotatably connects the first feed roller 2 and the second feed roller 3 has a play in the rotation direction therein, so that the first feed roller 2 side is in a free state. The slack of the paper can be removed at the start of rotation, and the steady slip between the paper and the roller can be removed to reduce the feed load.

Further, the structure shown in FIG. 2 in which the shaft 56 and the gear 6 fitted to the shaft 56 have a play in the rotational direction can be used also in a place where a pair of gears are engaged and disengaged. it can. For example, in the paper feeding device shown in FIG. 1, the drive side rollers of the feed rollers 2 and 3 are axially attached to the upper casing, the driven side rollers are axially attached to the lower casing, and the upper casing is opened upward. Therefore, a structure in which the paper path is opened may be used, and in such a case, the gears 10 and 12 of the drive side rollers of the feed rollers 2 and 3,
The gears 61 and 62 on the driven roller side are disengaged as the upper housing is opened and closed (see FIG. 4). In such a case, as shown in FIG. 3, when the driven roller shaft 60 and the gears 61 and 62 of the driven roller shaft 60 are fitted with a clearance 55 in the same rotation direction as that shown in FIG. Side gear 10,
12 and the gears 61 and 62 on the driven side are meshed with each other, the problem that the cutting edges of both gears collide with each other to prevent meshing is avoided, and the gear 10 when the upper housing is closed,
The meshing of 12 with 61, 62 can be carried out more smoothly.

In the above embodiment, the play 55 in the rotational direction between the shaft and the gear fitted to the shaft is generated by the dimensional difference between the pin 57 and the key groove 58. It is of course possible to provide a key 64 instead of the pin 57 as shown in the drawing, and as shown in FIG. 6, a shaft 65 having a chamfered facing surface and a shaft having flat portions 66, 66 formed on opposite surfaces of the circular hole. It is possible to use a structure in which the holes 67 are fitted with the chamfering width d smaller than the plane forming interval D.

Further, as shown in FIG. 7, in the transfer operation of the sheet from the reversing device 40 to the first feed roller 2,
Before the leading edge of the paper sent out from the delivery roller 35 of the reversing device is caught in the nip portion of the first feed roller 2, the paper feeding operation of the reversing device 40 is stopped, and the first feed roller 2 is rotated to a constant value. High speed and reversing device roller 3
5 is rotated at a rotational speed slower than that of the roller 2 of the original reading device (for example, a rotational speed of 3/4), and the paper is sent out.
The paper is delivered from the reversing device 40 to the document reading device by the paper feeding operation of synchronizing the paper feeding speeds of the reversing device 40 and the document reading device when the paper is fed several mm further after the leading end of the paper is caught in the feed roller 2. It is possible to prevent the skew that occurs when the error occurs.

That is, by operating in this way, as shown in FIG. 8, the leading edge of the sheet sent out from the reversing device 40 comes into contact with the peripheral surface of the first feed roller 2 and is then guided to the nip portion thereof. The effect of reducing the difference in the drawing operation in the paper width direction to prevent skew and the effect of pulling the slack formed between the feed roller 35 and the feed roller 2 to prevent skew occur. It is possible to prevent the occurrence of skew of the sheet when the sheet is transferred from the upstream roller 35 to the downstream roller 2.

[0039]

According to the apparatus and the sheet feeding method of the present invention described above, when feeding a medium sheet to an information processing apparatus such as a document reading apparatus or a printer, the interval between sheets fed automatically is shortened. As a result, it is possible to improve the through-but of the paper, and it is possible to avoid the slack of the paper that occurs between the upstream roller and the downstream roller and the steady slip between the paper and the roller. There is an effect that it is possible to avoid the occurrence of skew that may occur when the leading edge of the sheet sent from the upstream roller is caught in the downstream roller.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a paper feeding device of the present invention.

FIG. 2 is a side view showing a sheet feeding roller provided with a play in a rotation direction.

FIG. 3 is a schematic side view showing a collision phenomenon of a cutting edge when meshing a transmission gear.

FIG. 4 is a schematic side view showing an example in which a transmission gear is disengaged.

FIG. 5 is a side view showing another embodiment for forming a play in the rotation direction.

FIG. 6 is a side view showing still another embodiment for forming a play in the rotation direction.

FIG. 7 is a side view showing a paper feeding device when a document is delivered from a reversing device to a document reading device.

FIG. 8 is a schematic explanatory diagram showing a phenomenon in which a leading edge of a sheet that enters a roller sags.

FIG. 9 is a side view showing an example of a conventional paper feeding device.

FIG. 10 is a side view showing bending of a sheet in a conventional sheet feeding roller.

[Explanation of symbols]

 1 Paper Feed Roller 2 First Feed Roller 3 Second Feed Roller 4 Pick Roller 5 Separation Roller 6-12 Transmission Gear 15 Second Roller Shaft 16 One-way Clutch 18 First Paper Sensor 19 Second Paper Sensor 24 Motor Shaft 25 Paper 31 Drive roller 35 Sending roller 45 Reverse rotation transmission mechanism 46 Forward rotation transmission mechanism 49 First feed roller shaft 50 One-way clutch 52 One-way clutch 55 Play gap 56 Pick roller shaft 57 Pin 58 Key groove 66 Flat surface 67 Shaft hole D Flat forming width d chamfer width

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukichi Morita No. 98, Unoki-nu, Unoki-cho, Kawakita-gun, Ishikawa Prefecture 2 PIE Co., Ltd. (72) Inventor Shuji Imamura 98 Uno-nu, Unoku-cho, Kawakita-gun, Ishikawa Prefecture Address No.2 PFU Co., Ltd. (72) Inventor Shunpei Teranishi Unokenu, Unoku-cho, Kawakita-gun, Ishikawa Prefecture No. 98 No.2 PFU Co., Ltd.

Claims (6)

[Claims] 1. A paper feed roller (1) along a paper feed direction.
The first feed roller (2) and the second feed roller (3) are arranged in this order, and the paper feed roller (1) is in the paper return direction when the first feed roller (2) is rotated in the paper feed direction. The first feed roller (2) is rotatably connected to the first feed roller (2)
In a paper feeding device of an information processing apparatus, which is provided with a transmission mechanism for rotationally connecting the second feed roller (3) and the second feed roller (3), the transmission mechanism includes a first feed roller (2) and a second feed roller (3) for the sheet. A reverse rotation transmission mechanism (45) that makes the rotation directions of the two are opposite to each other and a forward rotation transmission mechanism (46) that makes them the same direction are provided, and the reverse rotation transmission mechanism (45) and the forward rotation transmission mechanism (46) are provided. ) Each has a second feed roller shaft (15)
Is provided with clutches (16) and (52) that transmit only the rotation in the paper feed direction but not the rotation in the paper return direction, and
The drive system of the feed roller (2) includes the first feed roller
A paper feeding device of an information processing apparatus, characterized in that a clutch (50) that transmits only the rotational force in the paper feeding direction and does not transmit the rotational force in the paper returning direction is provided in (2). 2. A paper feed roller (1) and a first feed roller
A first paper sensor (18) is provided between the first feed roller (2) and the second feed roller (3), and a second paper sensor (19) is provided between the first feed roller (2) and the second feed roller (3). In the paper feeding method of the paper feeding device described, the motor shaft (24) is driven so that the paper feeding roller (1) rotates in the paper feeding direction, and the first paper sensor (18)
After detecting that there is paper, drive the motor shaft (24) in the same direction and move the motor shaft (24) in the same direction to bring the leading edge of the paper into contact with the first feed roller (2). The second operation of reversing and continuing the rotation until the second paper sensor (19) detects the presence of paper until a predetermined amount of paper is fed, and then reversing the motor shaft (24) again to 2. The paper feed according to claim 1, wherein the third operation of returning to the first operation is repeated on condition that the first paper sensor (18) issues a no-paper signal before the fixed rotation of 24). Paper feeding method in machine. 3. A transmission mechanism (6-8) for rotating two rollers (4), (5) arranged on the upstream side and the downstream side of the paper passage in the same direction with respect to the paper (25). A paper feed device for an information processing device, wherein the transmission mechanism (6 to 8) has a play (55) in the rotational direction therein. 4. A rotary transmission element (6) of a transmission mechanism (6-8) and a shaft (56) thereof are rotatably fitted to each other, and a radial projection (57) provided on the shaft (56). Grooves (58) in the rotation transmitting element (6)
And the gap between the protrusion (57) and the groove (58).
The paper feeding device according to claim 3, further comprising (55). 5. A rotation transmission element (6) of a transmission mechanism is mounted on a shaft (65) whose facing surface is chamfered by a central hole (67) having flat surfaces (66), (66) formed on the facing surface. The width of the center hole (D) is larger than the chamfer width (d) of the shaft (65).
4. The paper feeding device according to claim 3, wherein (55) is incorporated. 6. A roller that is driven in the same direction with respect to the paper by different drive sources on the upstream side and the downstream side of the paper path.
In the paper feeding method of the paper feeding device of the information processing device including (2) and (35), the peripheral speed of the downstream roller (2) is set to the upstream roller (2) before the leading edge of the paper reaches the downstream roller (2). 35), and after the leading edge of the paper is gripped by the downstream roller (2),
A paper feeding method for an information processing apparatus, characterized in that the peripheral speeds of the downstream roller (2) and the upstream roller (35) are synchronized.