KR100484195B1 - Apparatus for preventing paper double feeding of printer - Google Patents

Abstract

The present invention relates to a paper jam prevention apparatus of a printing press. The paper jam prevention apparatus of the disclosed printer receives a paper picked up by a pickup roller, and feeds the paper into the main body of the printer. The anti-feed roller to prevent the conveyance of the paper conveyed in contact with the anti-feed roller, and the paper prevented from being fed by the anti-feed roller, are present in the lower portion of the feed prevention roller in the paper feed path. Sensor unit for sensing; And a control unit configured to delay the operation time of the pick-up roller by a predetermined time according to the signal transmitted by the sensor unit, to prevent jams due to heavy feeding. According to this, even when the paper is reloaded in the paper conveying path, there is an advantage of preventing jams due to feeding by delaying the time for reloaded paper to reenter the paper conveying path.

Description

App jammer for preventing paper double feeding of printer

The present invention relates to a printing press, and more particularly, to a paper jam prevention apparatus of a printing press which is employed in the feeding device of the printing press to prevent jams from occurring while two or more sheets of paper are stacked.

In general, a printer such as a printer or a copying machine is provided with a paper feeder for storing a plurality of sheets of paper and sequentially feeding the stored sheets into the printer main body.

1 is a cross-sectional view schematically showing a paper feeder of a conventional printing press.

Referring to FIG. 1, a paper cassette 10 is provided which accommodates a plurality of sheets of paper P and is detachably installed in a printer main body. The paper cassette 10 is loaded with paper P thereon. A knock-up plate 12 for lifting the loaded paper P is provided. The knock-up plate 12 is elastically biased upward by the spring 11. In the main body of the printer, a pick-up roller 18 is rotatably installed to contact the leading end of the uppermost sheet of paper P lifted by the knock-up plate 12. Therefore, when the pickup roller 18 rotates, the uppermost sheet enters the main body of the printer by the frictional force with the pickup roller 18. On the other hand, reference numeral 16 is a paper guide for guiding the paper entering the body of the printer.

The paper picked up by the pickup roller 18 enters between the feed roller 20 and the anti-feed roller 22. The paper passing through the feed roller 20 and the anti-feed roller 22 is conveyed to a developing apparatus (not shown) after the front ends thereof are aligned by the alignment roller 30. On the other hand, an idle roller 32 is disposed above the alignment roller 30, and a shutter 34 surrounding a part of the idle roller 32 and a photo for detecting rotation of the shutter 34. The sensor 36 is arranged. The idle roller 32 is elastically biased in the direction of the alignment roller 30 to apply a predetermined elastic force to the alignment roller 30. The paper fed from the feed roller 20 does not overcome the elastic force when the tip portion is not aligned, and thus the tip portion that does not touch the alignment roller 30 is prevented from passing through the alignment roller 30. Alignment is made while touching. At this time, the paper pushes the idle roller 32 and passes through the alignment roller 30, and the idle roller 32 is rotated so that the photo sensor 36 detects the rotation of the shutter 34. The photosensor 36 transmits a signal through which printing paper is drawn to the developing device in front through a controller (not shown). In the developing apparatus, the paper on which the image is printed on its front surface is discharged out of the printing press by a delivery roller (not shown).

The anti-feeding roller 22 rotates in contact with the feed roller 20, so that only the uppermost sheet of paper P is continuously conveyed when the sheet is fed by the pickup roller 18, and the paper below the sheet does not proceed. In more detail, basically, the anti-feed roller 22 is installed to rotate in a direction opposite to the feed roller 20 with a smaller torque than the feed roller 20. However, since the anti-feed roller 22 is in contact with the feed roller 20, there is no paper P or only one sheet of paper P between the feed-feed prevention roller 22 and the feed roller 20. The anti-feed feed roller 22 is rotated in the paper advance direction by the feed roller 20 having a larger torque. However, when two or more sheets of paper enter between the anti-feed roller 22 and the feed roller 20, the anti-feed roller 22 is not affected by the rotational force of the feed roller 20 due to the low friction force between the sheets. Without the paper advance direction. As a result, the paper below the sheet except the uppermost sheet that is in contact with the feed roller 20 is blocked by the feed prevention roller 22 in the paper advance direction. Therefore, the conveyed paper stays at the bottom of the feed roller 20.

On the other hand, in the high speed printing machine, since the margin between the paper to be fed is very narrow, the paper prevented by the feeding prevention roller 22 has a margin narrower than the margin set by the driving of the pickup roller 18. Supplied to the path.

FIG. 2 is a view for explaining a change in margin between papers in the pick-up process when a paper prevented from being fed between the pick-up roller and the feed roller in the paper feeder of the conventional printer.

Referring to FIG. 2, the paper P1 advances on the printing path in the printing machine in a state in which the paper P2 which is prevented from being fed by the anti-feed roller 22 is present in the lower portion of the non-feed roller 22. High speed presses are designed for faster print speeds as the margins between papers become narrower, and the minimum length design of these margins allows the sensors to detect the entry of new paper, for example the photo sensor 36, to detect the entry of new paper. The control unit sends a signal to the control unit, and the control unit needs a time to prepare a print corresponding to a new sheet to perform printing, that is, a margin interval of the sheet.

For example, when the margin between sheets is 70 mm, the distance on the printing path between the pickup roller 18 and the feed roller 20 is 50 mm, and the minimum margin required for new paper recognition by the sensors is 30 mm, Fig. 2 As the two sheets of paper are picked up, one sheet P1 proceeds along the paper path, and the sheet P2 that is prevented from being fed is positioned at the bottom of the sheet feed prevention roller 22, and then the lower end of the sheet of paper P1 is conveyed. When entering the 20 mm printing path from the roller 20, the pickup roller 18 is driven to enter the paper P2 into the printing path. At this time, the distance between the sheets (P1, P2) is 20 mm, so the sensors do not detect the entry of new sheets, or even if the control unit detects the print command corresponding to the new printing sheet (P2) to the developing device. Before the new printing is performed, a new paper P2 enters the printing path and overlaps with the previous paper P1, causing a jam.

The present invention was created to improve the above problems of the prior art, by detecting the conveyed paper and delay the operation of the pickup roller to secure the margin between the paper to prevent the jam caused by the paper transport of the paper It is to provide a paper jam prevention device.

In order to achieve the above object, the paper jam prevention apparatus of the printing press of the present invention includes a feed roller which receives the paper picked up by the pickup roller and transfers the paper into the main body of the printer, and is installed to face the feed roller so that the paper is picked up by the pickup roller. In the paper jam prevention device, the paper jam prevention device of the printing machine having a non-feeding roller to prevent the conveying of the conveyed paper in contact with the anti-feeding roller while rotating in the opposite direction to the paper feed direction,

A sensor unit configured to detect that the paper, which is prevented by the feed prevention roller, exists in the lower portion of the feed prevention roller in a paper feed path; And

And a control unit for preventing a jam due to the feeding by delaying the operation time of the pick-up roller by a predetermined time according to the signal transmitted by the sensor unit.

The sensor unit includes a light emitting unit for emitting a laser beam on one side of the conveyed paper, and a light receiving unit for receiving the light reflected from the paper conveyed by the laser beam, and the light receiving unit has a path of the laser beam reflected and returned. It is a reflecting sensor that senses that the conveyed paper exists between the pickup roller and the conveying roller by measuring the distance of.

On the other hand, the sensor unit is disposed so that the light emitting unit and the light receiving unit is opposed to each other with the paper conveyed between the light receiving unit to detect the presence of the paper transported between the pickup roller and the transfer roller when the light receiving unit does not detect It may be configured as a photosensor.

The sensor unit may be disposed such that the sum of the distance between the lower end of the paper out of the conveying roller and the conveying roller and the distance between the conveying roller and the sensor part among the conveyed sheets corresponds to the minimum margin between the sheets of the printing press.

The control unit receives a signal from which the paper is detected between the transfer roller and the sensor from the sensor unit, and delays the driving of the pickup roller by at least a time corresponding to the distance between the transfer roller and the sensor unit. It is preferable to drive.

Hereinafter, with reference to the accompanying drawings will be described in detail a paper jam prevention device of the printing press according to an embodiment of the present invention. In this process, the thicknesses of layers or regions illustrated in the drawings are exaggerated for clarity.

3 is a partial perspective view of a printer to which a paper jam prevention apparatus of a printing machine according to a preferred embodiment of the present invention is applied, and the same reference numerals are used for objects having the same structure as the conventional invention, and detailed description thereof will be omitted.

Referring to FIG. 3, the knock-up plate 112, the pickup roller 118, the transfer roller 120, and the alignment roller 130 are sequentially disposed in the paper feed path.

The knock-up plate 112 is installed in the paper cassette 110 detachably installed in the main body of the printing press, and is elastically biased upward while supporting a plurality of sheets thereon by a spring 111 installed below. . Therefore, knock-up plate 112 lifts the supported paper upwards.

The pickup roller 118 is rotatably installed in the main body of the printer so as to contact the leading end of the uppermost sheet loaded on the knock-up plate 112. Therefore, when the pickup roller 118 is rotated, one sheet of the uppermost paper P is picked up by the friction force between the paper and the pickup roller 118, and the feed roller 120 is moved along the paper feed path formed by the paper guide. And enters between the anti-feed roller 122.

The anti-feeding roller 122 rotates in contact with the feed roller 120, so that only the uppermost paper P continues to be conveyed when the paper is fed by the pickup roller 118, and the paper below the paper does not proceed. In more detail, basically, the anti-feed roller 122 is installed to rotate in a direction opposite to the feed roller 120 with a smaller torque than the feed roller 120. However, since the anti-feed roller 122 is in contact with the feed roller 120, there is no paper P or only one sheet of paper P between the anti-feed roller 122 and the feed roller 120. The anti-feeding roller 122 is rotated in the paper advancing direction by the feed roller 120 having a larger torque. However, when two or more sheets of paper enter between the anti-feed roller 122 and the feed roller 120, the anti-feed roller 122 is not affected by the rotational force of the feed roller 120 due to the low friction force between the sheets. Without the paper advance direction. Accordingly, the paper below the sheet except the uppermost sheet that is in contact with the feed roller 120 is prevented from being conveyed in the paper advance direction by the anti-feed roller 122.

The paper P passing through the feed roller 120 and the anti-feed roller 122 is transferred to the alignment roller 130. An idle roller 132 is disposed above the alignment roller 130, and a shutter 134 surrounding a part of the idle roller 132 and a photosensor for detecting rotation of the shutter 134. 136 is disposed. The idle roller 132 is elastically biased in the direction of the alignment roller 130 to apply a predetermined elastic force to the alignment roller 130. The paper fed from the feed roller 120 does not overcome the elastic force when the front end is not aligned, and thus the front end does not touch the alignment roller 130 while the front end does not touch the alignment roller 130. Alignment is made while touching. At this time, the paper pushes the idle roller 132 and passes through the alignment roller 130, the idle roller 132 is rotated so that the photo sensor 136 detects the rotation of the shutter 134. The photosensor 136 transmits a signal through which printing paper is drawn to the developing device in front through a control unit (not shown). In the developing apparatus, the paper on which the image is printed on its front surface is discharged out of the printing press by a delivery roller (not shown).

On the other hand, the lower portion of the conveying roller 120 and the anti-feed roller 122 is disposed in the sensor unit 140 for detecting the paper sheet is prevented by the feed-feeding roller 122, as described above.

The sensor unit 140 uses a reflect sensor or a photo sensor.

The reflecting sensor includes a light emitting part for emitting a laser beam on one side of the conveyed paper and a light receiving part for receiving the light reflected by the laser beam from the conveyed paper. By measuring the distance, the conveyed paper is detected to exist between the pickup roller 118 and the transfer roller 120.

On the other hand, the photosensor is disposed opposite the light emitting unit and the light-receiving unit sandwiched between the paper, the paper conveyed between the pickup roller 118 and the transfer roller 120 when the light receiving unit does not detect the light from the light emitting unit Detect what exists.

It is a figure explaining the drive of the paper jam prevention apparatus of the printing machine of this invention.

Referring to FIG. 4, the sensor unit 140, which is a feature of the present invention, has a predetermined position in the paper feed path between the pickup roller 118 and the feed roller 120, and the paper feed at the lower portion of the look-ahead feed roller 120. It is installed to detect the point D 10 mm apart from the path.

The sensor unit 140 detects the presence of the paper when the paper is detected at the point D, that is, when the paper P2 is between the point D and the feed roller 120. The sensor unit 140 transmits the detected information to the controller 150.

The controller 150 receives the information from the sensor unit 140 and delays a time for driving the pickup roller 118 by a predetermined time. For example, if the design margin between the sheets is 70 mm, the distance on the printing path between the pick-up rollers 18 and the feed rollers 20 is 50 mm, and the minimum margin required for new paper recognition by the sensors is 30 mm, FIG. When 2 sheets of paper are picked up as in 4, and one sheet P1 proceeds along the paper path, and the sheet P2 prevented from feeding is located between the lower portion of the feed prevention roller 22 and the point D, The control unit 150 of the pick-up roller 118 when the lower end of the paper P1 is 20 mm away from the feed roller 20, that is, 70 mm away from the paper loaded on the knock-up plate 112, which is a design margin. Instead of driving, the driving of the pickup roller 118 is delayed so that the margin of the paper corresponding to the predetermined time, for example, the minimum time required for the new paper recognition, is 30 mm.

The paper P2 picked up by the pick-up roller 118 driven with a delay corresponding to the feeding distance of 10 mm is pulled into the alignment roller 130 by being separated by a 30 mm to 40 mm margin from the preceding paper P1. At this time, the photosensor 136 detects that the new paper is inserted and transmits the signal to the controller 150. The controller 150 performs a printing operation so that jam does not occur by controlling a subsequent printing process.

As described above, the paper jam prevention apparatus of the printing press according to the present invention has an advantage of preventing jams due to heavy feeding by delaying the time for reloaded paper to reenter the paper feed path even when the paper is fed back into the paper feed path. .

Although the present invention has been described with reference to the embodiments with reference to the drawings, this is merely exemplary, it will be understood by those skilled in the art that various modifications and equivalent embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined only by the appended claims.

1 is a cross-sectional view schematically showing a paper feeder of a conventional printing press.

FIG. 2 is a view for explaining a change in margin between papers in the pickup process when the sheet prevented from being fed between the pick-up roller and the feed roller in the paper feeding device of FIG.

3 is a schematic cross-sectional view of a printing press to which a paper jam prevention apparatus of the printing press according to the preferred embodiment of the present invention is applied.

It is a figure explaining the drive of the paper jam prevention apparatus of the printing machine of FIG.

* Description of Signs of Major Parts of Drawings *

110: paper cassette 111: spring

112: knock-up plate 118: pickup roller

120: feed roller 122: heavy feed prevention roller

130: alignment roller 132: idle roller

134: shutter 136: photo sensor

140: sensor unit 150: control unit

Claims (5)

A feed roller which receives the paper picked up by the pickup roller and transports the paper into the main body of the printer, and is installed to face the feed roller so that the paper is fed by the pickup roller, the paper feed prevention roller is rotated in the opposite direction to the paper feed direction. In the paper jam prevention apparatus of the printing press provided with the anti-feed roller which prevents the conveyance of the paper conveyed in contact with the At least one sensor unit for detecting that the paper, which is prevented by the feed prevention roller, exists in the lower portion of the feed prevention roller in a paper feed path; And And a control unit for preventing a jam due to the feeding by delaying an operation time of the pickup roller according to a signal transmitted by the sensor unit for a predetermined time. The sensor unit may be arranged such that the sum of the distance between the lower end of the paper out of the conveying roller and the conveying roller and the distance between the conveying roller and the sensor unit among the conveyed sheets corresponds to the minimum margin between the sheets of the printing press. A paper jam prevention device of a printing press. The method of claim 1, The sensor unit, A light emitting part for emitting a laser beam on one side of the conveyed paper, and a light receiving part for receiving the light reflected from the paper conveyed by the laser beam, the light receiving part measuring a distance of a path of the laser beam reflected and returned The paper jam prevention apparatus of the printing machine characterized by that it is a reflecting sensor which detects that the conveyed paper exists between a pick-up roller and a feed roller. The method of claim 1, The sensor unit, The light-emitting unit and the light-receiving unit are disposed opposite to each other with the paper conveyed therebetween, so that the light-receiving unit cannot detect the light from the light-emitting unit. Paper jam prevention device of printing press. delete The method of claim 1, The control unit receives a signal from which the paper is detected between the transfer roller and the sensor from the sensor unit, and delays the driving of the pickup roller by at least a time corresponding to the distance between the transfer roller and the sensor unit. Paper jam prevention device of the printing press, characterized in that for driving.