JP7654255B2 - Paper feeder, control method thereof, and control program thereof - Google Patents

Description

The present invention relates to a paper feeder that uses the so-called top-feed method (a method in which the topmost paper is fed from a paper stack in sequence) or bottom-feed method (a method in which the bottommost paper is fed from a paper stack in sequence), as well as a control method and control program for the same.

A conventional top-feed type paper feeder is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-233666.
The paper feeding device described in Patent Document 1 comprises a liftable paper loading table on which a paper stack is placed, an aligning plate arranged close to the front of the paper loading table and facing the front end surface of the paper stack on the paper loading table, and a transport unit arranged above and facing the topmost sheet of the paper stack on the paper loading table, which adsorbs the topmost sheet and sends it forward over the aligning plate as the paper loading table gradually rises.

The transport unit is arranged above the paper loading platform with a gap between them in the paper transport direction, and includes a horizontal drive roller and idle roller that each extend perpendicular to the transport direction, a perforated endless transport belt stretched between the drive roller and idle roller, a suction box with multiple air intakes formed on its underside that is arranged between the upper and lower belt portions of the perforated endless transport belt, and a suction unit that creates a negative pressure in the internal space of the suction box.

The suction unit is composed of a suction pump, an intake pipe that connects the suction box and the suction pump, and a solenoid valve arranged in the intake pipe. The suction box is switched between suction and release by opening and closing the solenoid valve.

When the paper feeder is operating, the perforated endless conveyor belt moves in an orbit and the solenoid valve opens and closes at a predetermined timing.

The alignment plate is also provided with an air blowing unit. When the paper feeder is in operation, air is constantly blown from the air blowing unit toward the upper layer of the paper stack on the paper loading table, causing the upper layers of the paper stack to float above the paper stack while being separated from each other.

Thus, while the paper feeder is operating, the topmost sheet of paper is raised by air and is picked up by the suction box and the rotating, perforated endless conveyor belt, and sent forward.

Furthermore, a conventional bottom-feed type paper feeder is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-233666.
The paper feeding device described in Patent Document 2 comprises a paper storage section that stores paper in a stacked state, a bottom feed mechanism that is located at the bottom of the paper storage section and sequentially feeds out the lowest paper from the paper stack stored in the paper storage section, a retard roll that separates and transports multiple sheets of paper one by one that are fed in a overlapping state from the paper storage section by the bottom feed mechanism, and a regulating guide slope wall that is provided on the exit side of the paper storage section and slopes downward from the upstream side in the paper feed direction toward the retard roll.

The regulating guide sloped wall abuts against the leading ends of the sheets stored in the sheet storage section, thereby gradually shifting the sheets forming the stack of sheets rearward from the bottom.
The sloping regulation guide wall is provided with a slip-in prevention member that prevents the paper abutting thereon from slipping downward along the sloping surface.

The bottom feed mechanism is arranged on the entrance side of the paper storage section and has a first transport roll group that can rotate around an axis extending perpendicular to the paper feed direction, a second transport roll group arranged parallel to the first transport roll group downstream of the first transport roll group, a first support roll that shares a common rotation axis with the second transport roll group, a second support roll arranged adjacent to the retard roll, and a transport belt stretched between the first and second support rolls.

The retard roll has a torque limiter and is in contact with the conveyor belt on the second support roll of the bottom feed mechanism.
During paper feeding, the retard roll is stopped by the torque limiter, allowing the entry of the bottommost sheet of multiple sheets of paper fed in a double-feed state between the retard roll and the rotating conveyor belt, while preventing the remaining sheets of the multiple sheets from entering. After that, when the bottommost sheet is sandwiched between the retard roll and the conveyor belt, the retard roll overcomes the torque limiter's stopping action and rotates freely, thereby sending only the bottommost sheet forward.

International Publication No. 2014/006747 JP 2001-97563 A

However, when the differences in size, thickness, weight, and the like of paper become more widespread, it becomes difficult to simultaneously address both the problem of multiple paper feeds and misfeeds (paper feed failures).
Furthermore, it is cumbersome to set separation parameters for separating the paper one by one in accordance with the size, thickness, weight, etc. of the paper.

The objective of the present invention is therefore to provide a paper feeder that can reliably separate and feed paper one by one from a paper stack, even when there are wide variations in paper size, thickness, weight, etc., and a control method and control program for the same.

A paper feeder according to one aspect of the present invention includes a conveyor belt that places the top or bottom paper of a paper stack on a conveying surface and conveys it in a sending direction, the conveyor belt having a plurality of ventilation holes formed therein, a suction section that is disposed on the reverse side of the conveyor belt opposite to the conveying surface and has a first intake hole formed therein that sucks the paper through the ventilation hole, a lift plate that reciprocates between a first position located in the paper stacking direction from the conveying surface and a second position located at the same height as the conveying surface or on the reverse side from the conveying surface, and that opens a second intake hole different from the first intake hole formed in the suction section when located at the first position and closes the second intake hole when located at the second position, and a control unit that controls the operation of the lift plate, and the control unit operates the lift plate from the second position to the first position when the top or bottom paper is being conveyed.

The top or bottom sheet of the stack of sheets is sucked and adsorbed on the conveying surface of the conveyor belt through the first suction hole of the suction unit. The sheet is conveyed in this state of being adsorbed on the conveying surface. Then, while the top or bottom sheet is being conveyed, the lift plate is operated from the second position to the first position. As a result, the sheet is separated from the conveying surface of the conveyor belt by the lift plate, and the second suction hole blocked by the lift plate is opened. As the sheet is separated from the conveying surface of the conveyor belt, a change in height position occurs between the lift plate and the conveying surface, and the sheet is deformed, facilitating separation of the sheet being conveyed from the next sheet stacked on the sheet. Also, as the second suction hole blocked by the lift plate is opened, the suction force from the first suction hole is reduced, and the adsorption force of the sheet on the conveying surface is reduced, and the conveying force of the next sheet following the sheet being conveyed can be reduced.
As a result, the paper can be reliably separated and fed one by one from the paper stack, regardless of differences in size, thickness, weight, and the like of the paper.

Furthermore, in a paper feeding device according to one aspect of the present invention, the conveyor belts are provided in a plurality of units, and are arranged in parallel at a predetermined interval in the width direction perpendicular to the sending direction, and the lifting plates are provided in a plurality of units, and are arranged between adjacent conveyor belts and/or to the sides of the conveyor belts.

By providing a plurality of lift plates between and/or to the sides of the conveyor belts, the paper can be stably manipulated.
In addition, since the lifting plates and the conveying belts are arranged alternately in the width direction, when the lifting plates are positioned at the first position, the paper is corrugated (waved), thereby facilitating separation of the paper.

Furthermore, in a paper feeder according to one aspect of the present invention, the multiple conveyor belts and the multiple lift plates are arranged symmetrically with respect to the center of the width direction perpendicular to the paper feed direction.

The conveyor belt and lift plate are positioned symmetrically about the center of the width, perpendicular to the paper feed direction, so the paper can be transported accurately.

Furthermore, in a paper feeder according to one aspect of the present invention, a discharge roller is provided that grips the leading edge of the paper transported from the conveyor belt and discharges the paper, and the control unit operates the lift plate from the second position to the first position when the discharge roller grips the leading edge of the paper transported from the conveyor belt.

When the leading edge of the paper is gripped by the discharge roller, the paper is supported by the discharge roller, so operating the lift plate has little effect on the separation of the paper. Therefore, more reliable control can be achieved by operating the lift plate when the leading edge of the paper is gripped by the discharge roller. For example, it is preferable to provide a paper detection sensor downstream of the discharge roller in the feed direction.

Furthermore, in a paper feeder according to one aspect of the present invention, a contact body that contacts the leading edge of the paper is provided upstream of the discharge roller in the feed direction.

By locating the contact body upstream of the discharge roller in the feeding direction, a paper stack can be formed in which the paper is temporarily stacked upstream of the discharge roller.

Furthermore, in a paper feeder according to one aspect of the present invention, the conveyor belts are provided in a plurality of pieces and are arranged in parallel at a predetermined interval in the width direction perpendicular to the sending direction, and the abutting bodies are provided between adjacent conveyor belts and/or on the sides of the conveyor belts, and are elastic plate-like bodies whose free ends abut against the paper.

Since the contact body is provided between the conveyor belts and/or on the side of the conveyor belt, the contact body does not come into contact with and slide against the conveyor belt, thereby reducing wear of the contact body.
The contact body is an elastic plate-like body, and since the free end contacts the paper, it can bend with its elastic force when the end contacts the paper, thereby applying an appropriate contact force to the paper.
As the elastic contact body, for example, rubber is suitably used.

Furthermore, in a paper feeder according to one aspect of the present invention, a contact surface with which the tip of the abutting body comes into contact is provided at a position opposite the tip of the abutting body, and the contact surface is at the same height as the conveying surface.

A contact surface is provided with which the tip of the abutting body comes into contact, and this contact surface is at the same height as the conveying surface, so that the paper traveling on the conveying surface can be conveyed smoothly without being deformed.

Furthermore, the paper feeder according to one aspect of the present invention is provided with a guide plate having an inclined portion that guides the paper toward the tip of the contact body.

By guiding the paper along the inclined portion of the guide plate, the leading edge of the paper can be reliably directed toward the leading edge of the abutting body. Specifically, the inclined portion is provided so that the distance between the leading edge of the abutting body and the contact surface that comes into contact with the abutting body becomes gradually smaller toward the abutting body.
The inclined portion can prevent the leading edge of the paper from curling up when it hits the contact body, and even if the paper is curled up, the inclined portion can hold it down.

Furthermore, in a paper feeder according to one aspect of the present invention, the guide plate has a gap between it and the contact body and is provided with an abutment portion against which the contact body abuts when it is elastically deformed toward the guide plate.

An abutment portion is provided on the guide plate so that when the abutment body elastically deforms towards the guide plate, it abuts against the abutment portion. This makes it possible to prevent excessive deformation of the abutment body. For example, when a paper jam occurs and the paper is pulled out in the opposite direction to the transport direction (towards the guide plate), the abutment body deforms towards the guide plate along with the paper. The abutment portion can suppress excessive deformation of the abutment body at this time.

Furthermore, in a paper feeder according to one aspect of the present invention, the contact body is a retard roller that is arranged to be pressed against the conveyor belt.

By using a retard roller as the contact body, the paper can be reliably separated and transported.

Furthermore, in a paper feeder according to one aspect of the present invention, at least one of the lifting plates has an extension portion that is provided at a position corresponding to the contact portion or that extends downstream of the contact portion in the feed direction.

At least one of the lifting plates is provided to extend to the position corresponding to the retard roller or downstream of the retard roller in the sending direction, so that when the lifting plate is in the first position, the paper sandwiched between the retard roller and the conveyor belt can be significantly deformed by the lifting plate. This makes it difficult for the paper being conveyed and the next paper to enter the retard roller by making the shape of the paper different.
The position corresponding to the retard roller means the position immediately adjacent (directly below) the retard roller and in the vicinity thereof.

Furthermore, in a paper feeder according to one aspect of the present invention, the extension portion is removable from the existing lift plate.

The extension is removable from the existing lift plate, so the length of the lift plate can be changed as needed.

A control method for a paper feeder according to one aspect of the present invention is a control method for a paper feeder that includes a conveyor belt that places the top or bottom paper of a paper stack on a conveying surface and conveys it in a sending direction, the conveyor belt having a plurality of air holes formed therein, a suction section that is disposed on the back side of the conveyor belt opposite to the conveying surface and has a first air intake hole formed therein that sucks the paper through the air holes, and a lift plate that reciprocates between a first position located in the paper stacking direction from the conveying surface and a second position located at the same height as the conveying surface or on the back side of the conveying surface, and that opens a second air intake hole different from the first air intake hole formed in the suction section when located at the first position and closes the second air intake hole when located at the second position, and that operates the lift plate from the second position to the first position when the top or bottom paper is being conveyed.

A control program for a paper feeder according to one aspect of the present invention causes a computer to control any of the paper feeders described above.

Even when there is a wide range of differences in paper size, thickness, weight, etc., the paper can be reliably separated and fed one sheet at a time from the paper stack.

1A and 1B are schematic diagrams of a paper feeder according to a first embodiment of the present invention, in which FIG. FIG. 2 is an enlarged front view showing a suction box and abutment body of the paper feeder of FIG. 1, in which the suction box is illustrated as being cut away vertically. 3A is a vertical cross-sectional view taken along a direction intersecting the sending direction as viewed from the upstream side in the sending direction of FIG. 2, and FIG. 3B is a side view taken from the downstream side in the sending direction of FIG. 2. FIG. 2. (A) is a cross-sectional view taken along line XX in FIG. 2, and (B) is a cross-sectional view taken along line YY in FIG. 2A is an enlarged front view showing the suction box and abutment body of the paper feeding device of FIG. 1, and FIG. 2B is a longitudinal cross-sectional view taken along a direction transverse to the paper feed direction as viewed from the upstream side of the paper feed direction of FIG. 2 for explaining the paper feeding operation of the paper feeding device of FIG. 1. FIG. 3A is a view similar to FIG. 3A for explaining the paper feeding operation of the paper feeding device of FIG. 1; 2A is a front view showing the movement of the carriage of the paper feeder of FIG. 1, where (A) shows the carriage in a position where the length of the paper accumulation area is the smallest, and (B) shows the carriage in a position where the length of the paper accumulation area is the largest. 11 is a schematic front view of a paper feeder according to another embodiment of the present invention; FIG. FIG. 11 is a side view showing a paper feeder according to a second embodiment of the present invention. FIG. 11 is a partially enlarged side view showing the vicinity of the abutment plate in FIG. 10 . FIG. 11 is a plan view showing a paper feeder according to a second embodiment of the present invention. 13A and 13B show an extension of the lift plate, in which FIG. 13 is a plan view of the paper feeder with the lift plate extension attached; FIG.

[First embodiment]
Hereinafter, the configuration of the present invention will be described based on a preferred embodiment with reference to the accompanying drawings.
Fig. 1 is a schematic diagram of a paper feeder according to an embodiment of the present invention, Fig. 1(A) is a plan view, and Fig. 1(B) is a front view. Fig. 2 is an enlarged front view showing a suction box and abutment body of the paper feeder of Fig. 1, in which the suction box is illustrated as being cut in the vertical direction.

Figure 3(A) is a vertical cross-sectional view taken along a direction transverse to the sending direction as viewed from the upstream side in the sending direction of Figure 2, and Figure 3(B) is a side view taken from the downstream side in the sending direction of Figure 2. Also, Figure 4(A) is a horizontal cross-sectional view taken along line X-X of Figure 2, and Figure 4(B) is a horizontal cross-sectional view taken along line Y-Y of Figure 2.

Also, FIG. 5(A) is an enlarged front view showing the suction box and abutment body of the paper feeder of FIG. 1, and FIG. 5(B) is a vertical cross-sectional view taken along a direction transverse to the feed direction as viewed from the upstream side of the feed direction of FIG. 5(A).

In this embodiment, the paper feeder is a bottom-feed type paper feeder that is disposed between two paper processing devices, temporarily stacks paper discharged from the upstream paper processing device, and sequentially feeds the bottommost sheet of the stack to the downstream paper processing device.

Referring to Figures 1 to 5, this embodiment includes a drive roller 1 and an idle roller 2 that are spaced apart from each other in the paper feed direction and that extend horizontally and perpendicular to the paper feed direction, at least one (four in this embodiment) endless perforated conveyor belt (conveyor belt) 3 that is stretched between the drive roller 1 and the idle roller 2, and a roller drive mechanism 4 that rotates the drive roller 1.

The drive roller 1 has a horizontal rotating shaft 1a and four first roller elements 1b attached to the rotating shaft 1a at intervals in the axial direction so as to be rotatable integrally with the rotating shaft 1a.

As shown in FIG. 1(A) and FIG. 4(A), in this embodiment, the four first roller elements 1b are arranged symmetrically with respect to a predetermined center line CL that extends perpendicular to the drive roller 1 and the idle roller 2. The center line CL coincides with the center of the width direction of the paper P1 being transported, which is perpendicular to the feed direction.

The idle roller 2 is rotatable around an axis 2a parallel to the rotation axis 1a of the drive roller 1, and has four second roller elements 2b arranged opposite the four first roller elements 1b.

Each endless perforated conveying belt 3 is stretched between a pair of the first roller element 1b of the drive roller 1 and the second roller element 2b of the idle roller 2, and the four endless perforated conveying belts 3 are arranged symmetrically with respect to the center line CL. Each endless perforated conveying belt 3 has multiple ventilation holes 3a uniformly distributed over its entire length.

The roller drive mechanism 4 has a pulley 4a fixed to one end of the rotating shaft 1a of the drive roller 1, a motor 4b whose drive shaft extends parallel to the drive roller 1, a pulley 4c fixed to the drive shaft of the motor 4b, and an endless belt 4d stretched between the pulley 4a and the pulley 4c.

When the paper feeder is in operation, the four perforated endless conveyor belts 3 rotate simultaneously at a constant speed as the motor 4b drives the drive roller 1, and the paper P1 placed on the conveying surface 3b of the four perforated endless conveyor belts 3 is transported from the idle roller 2 side toward the drive roller 1 side.

The system also includes a carriage 5 arranged above the perforated endless conveying belt 3 so as to be capable of reciprocating motion in the length direction of the perforated endless conveying belt 3, at least one slide guide 6 (two in this embodiment) extending in the length direction of the perforated endless conveying belt 3 and to which the carriage 5 is attached so as to be capable of sliding motion, and a carriage drive mechanism 7 which causes the carriage 5 to perform a sliding motion.

The carriage drive mechanism 7 has a motor 7a and a pulley 7b that are spaced apart along the length of the slide guide 6. The drive shaft of the motor 7a and the rotation shaft of the pulley 7b extend parallel to the drive roller 1 and the idle roller 2.

A pulley 7c is fixed to the drive shaft of the motor 7a, and an endless belt 7d is stretched between the pulleys 7c and 7b and extends parallel to the slide guide 6. The carriage 5 is fixed to the endless belt 7d.

The endless belt 7d is rotated forward and backward by the motor 7a, so that the carriage 5 can perform a reciprocating sliding motion along the slide guide 6.

A suction box (suction unit) 8 is arranged between the upper belt portion 3c and the lower belt portion 3d of the four perforated endless conveyor belts 3 so as to be capable of reciprocating movement in the longitudinal direction of the perforated endless conveyor belts 3, and is attached to the carriage 5, and a suction fan (suction source) 9 is directly connected to the suction box 8 and generates negative pressure within the suction box 8.

The upstream side in the sending direction of the surface 8a of the suction box 8 that faces the upper belt portion 3c is the suction area 12. The suction area 12 has a plurality of intake holes (first intake holes) 8b formed therein, and is arranged opposite the upper surface of the paper stack S.

Support means 10 is provided downstream of the suction area 12 in the delivery direction of the suction box 8. The support means 10 is disposed above the surface 8a and extends across the width of the perforated endless conveying belt 3. Four contact bodies 11a to 11d are supported on the support means 10 at positions corresponding to the perforated endless conveying belts 3. Each of the contact bodies 11a to 11d is in pressure contact with the corresponding perforated endless conveying belt 3.
The four contact bodies 11a to 11d are disposed symmetrically with respect to the center line CL.

The contact bodies 11a to 11d consist of retard rollers.

As shown in Figures 1, 2, 3 and 5, a fixed plate 5a with an L-shaped cross section is attached to the underside of the carriage 5. The fixed plate 5a extends perpendicular to the surface 8a of the suction box 8 and in a direction (width direction) across the perforated endless conveyor belt 3.

The support means 10 has first and second support plates 10a, 10b arranged on the upstream and downstream sides of the fixed plate 5a in the sending direction. The first and second support plates 10a, 10b extend in a direction transverse to the perforated endless conveyor belt 3 and are each attached to the fixed plate 5a so as to be able to slide up and down.

The first support plate 10a is inverted U-shaped, and horizontal support shafts 10e extending in the width direction of the perforated endless conveyor belt 3 are protruding from the outer sides of each leg of the first support plate 10a. A pair of abutting bodies 11a, 11d located on both outer sides of the four abutting bodies 11a to 11d are attached to these support shafts 10e.

A spring bearing portion 10c is provided at the center of the upper end of the first support plate 10a, and a compression spring 10d is disposed between the spring bearing portion 10c and the fixed plate 5a, which constantly urges the first support plate 10a downward against the fixed plate 5a (thus pressing the pair of contact bodies 11a, 11d against the corresponding perforated endless conveyor belt 3).

The second support plate 10b is T-shaped, and a horizontal support shaft 10h is provided at the lower end of the second support plate 10b, extending in the width direction of the perforated endless conveyor belt 3. A pair of abutting bodies 11b, 11c, which are located in the center of the four abutting bodies 11a to 11d, are attached to both ends of the support shaft 10h.

A spring bearing portion 10f is provided at the center of the upper end of the second support plate 10b, and a through hole extending vertically is formed in the carriage 5 at a position corresponding to the spring bearing portion 10f. A compression spring 10g is fitted into the through hole with its lower end pressed against the spring bearing portion 10f, and the upper opening of the through hole is closed by the pressing plate 5b.
The second support plate 10b is constantly biased downward against the fixed plate 5a by the compression spring 10g (therefore, the pair of contact bodies 11b, 11c are pressed against the corresponding perforated endless conveyor belt 3).

In this way, of the four abutment bodies 11a to 11d arranged symmetrically with respect to the center line CL, pairs of abutment bodies 11a, 11d; 11b, 11c that are symmetrically positioned with respect to the center line CL are separately connected and supported, and pressed against the corresponding endless perforated conveyor belt 3, so that the pressing force of the abutment bodies 11a to 11d against the endless perforated conveyor belt 3 can be made uniform with respect to the center line CL, thereby reliably preventing not only double feeding of the paper P1, but also skewing of the paper P1.

A pair of discharge rollers 13a, 13b are attached to the carriage 5. The pair of discharge rollers 13a, 13b face each other vertically across the conveying path between adjacent perforated endless conveying belts 3 on the downstream side of the suction box 8 in the sending direction, and are each capable of rotating around a horizontal axis perpendicular to the sending direction. Three lifting plates 14a to 14c extending in the length direction of the perforated endless conveying belt 3 are provided between adjacent perforated endless conveying belts 3 on the surface 8a of the suction box 8.
A paper detection sensor 13c is provided downstream of the pair of discharge rollers 13a and 13b in the sending direction. The paper detection sensor 13c detects the leading edge of the paper P1 discharged from the discharge rollers 13a and 13b. The output of the paper detection sensor 13c is sent to a control unit (not shown).

The three lifting plates 14a to 14c are arranged symmetrically with respect to the center line CL. The two outer lifting plates 14a, 14c of the three lifting plates 14a to 14c extend within the range of the intake hole (second intake hole) 8b of the suction area 12. The central lifting plate 14b of the three lifting plates 14a to 14c extends from the upstream end of the suction area 12 (the upstream end of the suction box 8) in the sending direction to a position corresponding to the abutment bodies 11a to 11d, for example, as shown in FIG. 4(A) (hereinafter, lifting plate 14b may be referred to as "extended lifting plate 14b").

As shown in FIG. 4(A), the extended lift plate 14b is positioned so that its center in the width direction coincides with the center line CL (so that it is symmetrical with respect to the center line CL).

The carriage 5 is provided with a lift plate drive mechanism 15 that moves the lift plates 14a to 14c up and down. The lift plate drive mechanism 15 is controlled by a control unit (not shown). The lift plate drive mechanism 15 reciprocates the lift plates 14a to 14c between a first position (see Figures 2 and 3) where the lift plates 14a to 14c move away from the surface 8a to open the intake holes 8b and protrude above the conveying surface 3b of the perforated endless conveying belt 3, and a second position (see Figure 5) where the lift plates 14a to 14c press against the surface 8a to close the intake holes 8b and become flush with the conveying surface 3b of the perforated endless conveying belt 3 or recede below the conveying surface 3b.

As shown in FIG. 2, the lift plate drive mechanism 15 is arranged at a distance from each other in the longitudinal direction of the lift plates 14a to 14c at positions facing each of the lift plates 14a to 14c on the wall of the suction box 8, and has two bushes 16a, 16b that extend through the wall, and guide rods 17a, 17b that pass through the bushes 16a, 16b, have upper ends connected to the backsides of the corresponding lift plates 14a to 14c, and have lower ends that extend into the suction box 8.

The lower ends of the guide rods 17a, 17b are connected by a single horizontal connecting plate 18, and compression springs 19a, 19b surround the outside of the portions of the guide rods 17a, 17b that protrude into the suction box 8, extending between the connecting plate 18 and the suction box 8, and constantly bias the lifting plates 14a to 14c toward the second position.

The lift plate drive mechanism 15 further has two rotating shafts 21a and 21b that extend horizontally in the width direction of the lift plates 14a to 14c, spaced apart from each other in the length direction of the lift plates 14a to 14c, below the connecting plate 18 inside the suction box 8.

The two rotating shafts 21a, 21b are supported rotatably around their axes by a pair of frame sections 20 (see, for example, Figures 4(A) and 4(B)) that extend in the length direction of the lifting plates 14a to 14c in a rectangular support frame attached to the inner bottom surface of the suction box 8.

As shown in Figures 4(A) and 4(B), one end of one of the two rotating shafts 21a and 21b, the rotating shaft 21b, penetrates the frame portion 20 and protrudes outside the suction box 8.

The lifting plate drive mechanism 15 further includes a pair of plate cams 22a, 22a; 22b, 22b attached to the rotating shafts 21a, 21b at positions corresponding to both sides of the connecting plate 18, and cam drive mechanism 23 that rotates the two rotating shafts 21a, 21b in a synchronized manner.

In this case, as shown in FIG. 5(A), when the plate cams 22a, 22b are at bottom dead center, the plate cams 22a, 22b are separated from the connecting plate 18 and the lifting plates 14a to 14c are in the second position, while as shown in FIG. 2, when the plate cams 22a, 22b are at top dead center, the connecting plate 18 is pushed up by the plate cams 22a, 22b and the lifting plates 14a to 14c are in the first position.

The cam drive mechanism 23 has a pulley 24a fixed to one end of the rotating shaft 21a, a pulley 24b fixed to the rotating shaft 21b at a position corresponding to the pulley 24a, and an endless belt 25 stretched between the pulleys 24a and 24b. As shown in FIG. 1(A), the cam drive mechanism 23 further has a motor 26 fixed to the carriage 5 outside the suction box 8 and having a drive shaft extending parallel to the rotating shaft 21b, a pulley 27a fixed to the drive shaft of the motor 26, a pulley 27b fixed to the rotating shaft 21b at a position corresponding to the pulley 27a, and an endless belt 28 stretched between the pulleys 27a and 27b.

In this manner, the two rotary shafts 21a, 21b are rotated synchronously by the motor, and the plate cams 22a, 22b rotate accordingly.
When the plate cams 22a, 22b reach their bottom dead points, the lifting plates 14a to 14c reach their second positions, and when the plate cams 22a, 22b reach their top dead points, the lifting plates 14a to 14c reach their first positions.

As shown in FIG. 1B, the area from the contact members 11a-11d on the conveying surface 3b of the perforated endless conveying belt 3 to the upstream end u of the conveying surface 3b forms the paper accumulation area 29.

1A and 1B, there is provided an air blowing unit 30 attached to the carriage 5. The air blowing unit 30 is disposed downstream of the contact bodies 11a to 11d in the sending direction and above the conveying surface 3b of the perforated endless conveying belt 3, and blows sweeping air toward the upstream side in the conveying direction along the conveying surface 3b.
The air blowing unit 30 is provided as necessary, and may be omitted.

The control unit is a computer system, and includes, for example, a CPU, a ROM (Read Only Memory) for storing programs and the like executed by the CPU, a RAM (Random Access Memory) that functions as a work area when each program is executed, a hard disk drive (HDD) as a large-capacity storage device, and a communication unit for connecting to a network, etc. These units are connected via a bus.
A series of processing steps for realizing the various functions described below are recorded in the form of a program on a hard disk drive or the like, and the CPU reads this program into a RAM or the like and executes information processing and arithmetic processing to realize the various functions described below. The program may be pre-installed in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

The length of the paper stacking area 29 can be freely changed within a range of a minimum length (see FIG. 8(A)) and a maximum length (see FIG. 8(B)) by changing the position of the carriage 5, i.e., the positions of the suction box 8, the abutting bodies 11a-11d, the pair of discharge rollers 13a, 13b, and the air blowing unit 30.

As a result, even if the length of the paper to be fed is changed, the length of the paper stacking area 29 can be adjusted to easily and quickly accommodate the change in paper size.

Next, the operation of the paper feeder of this embodiment will be described.
6 is a diagram similar to FIG. 2 for explaining the paper feeding operation of the paper feeding device of FIG. 1, and FIG. 7 is a diagram similar to FIG. 3A for explaining the paper feeding operation of the paper feeding device of FIG.

First, referring to FIG. 1, prior to the operation of the paper feeder, an upstream paper processing device is connected to the upstream end u (see FIG. 1(B)) of the transport path of the perforated endless transport belt 3, while a downstream paper processing device is connected to the downstream end w (see FIG. 1(B)) of the transport surface 3b of the perforated endless transport belt 3.

In FIG. 1B, a pair of conveying rollers 31 is depicted as a representative of the upstream paper processing device, located at the paper exit of the paper processing device and extending in a direction crossing the paper stacking area 29 of the paper feeder. Also, a pair of conveying rollers 32 is depicted as a representative of the downstream paper processing device, located at the paper entrance of the paper processing device and extending in a direction crossing the conveying surface 3b of the perforated endless conveying belt 3 of the paper feeder.

Then, the position of the carriage 5, i.e., the positions of the suction box 8, the abutting bodies 11a to 11d, the lift plate drive mechanism 15, the pair of discharge rollers 13a, 13b, and the air blowing unit 30, are adjusted to match the length of the paper to be processed (length in the feed direction), and the length of the paper accumulation area 29 is set.

When the paper feeder and each paper processing device start operating, the first (lowest) paper P1 is transported by the transport roller pair 31 of the upstream paper processing device and enters the paper stacking area 29 of the paper feeder. Then, before the leading edge of the first (lowest) paper P1 reaches the contact point between the contact bodies 11a-11d and the perforated endless transport belt 3, the lifting plates 14a-14c rise from the second position to the first position, as shown in Figures 6(A) and 7(A).

When the lifting plates 14a to 14c take the first position, the intake hole (second intake hole) 8b facing the lifting plates 14a to 14c in the suction area 12 is opened, and outside air flows into the suction box 8 from the opened intake hole 8b, weakening the suction force of the perforated endless conveying belt 3. At the same time, the first (lowest) sheet P1 on the suction area 12 is separated from the perforated endless conveying belt 3.
As a result, the conveying force of the perforated endless conveying belt 3 in the suction area 12 decreases.

In this way, the first (lowest) sheet of paper P1 remains in the paper stacking area 29, blocked by the abutting bodies 11a to 11d.

Then, when the next sheet P2 is transported by the transport roller pair 31 and stacked on top of the first (lowest) sheet P1, a sheet feed signal is sent from the downstream sheet processing device to the sheet feed device, and the sheet feed device starts its sheet feed operation.

At the start of the feeding operation for this first (lowest) sheet of paper P1, the perforated endless conveyor belt 3, the suction fan 9, the air blowing unit 30 and the pair of discharge rollers 13a, 13b start to operate continuously, and the lifting plates 14a-14c move down from the first position to the second position, as shown in Figures 6(B) and 7(B).

When the lifting plates 14a to 14c take the second position, the intake holes 8b in the suction area 12 facing the lifting plates 14a to 14c are closed, and outside air flows into the suction box 8 only through the ventilation holes 3a in the perforated endless conveying belt 3, strengthening the suction force of the perforated endless conveying belt 3. At the same time, the bottommost sheet P1 and the perforated endless conveying belt 3 come into contact with each other.
As a result, the conveying force of the perforated endless conveying belt 3 in the suction area 12 increases.

In this way, the bottommost sheet P1 is adsorbed and transported by the perforated endless transport belt 3, and is sent out between the contact bodies 11a to 11d and the perforated endless transport belt 3.

Then, when the leading edge of the bottom sheet P1 passes between the pair of discharge rollers 13a, 13b, the paper detection sensor 13c detects the leading edge of the sheet P1, and, in response to a command from the control unit, the lifting plates 14a to 14c rise from the second position to the first position, as shown in Figures 6(C) and 7(C).

When the lifting plates 14a to 14c take the first position, the intake holes 8b in the suction area 12 facing the lifting plates 14a to 14c are opened, and outside air flows into the suction box 8 from the opened intake holes 8b, weakening the suction force of the perforated endless conveying belt 3. At the same time, the lowermost sheet P1 on the suction area 12 is separated from the perforated endless conveying belt 3.
As a result, the conveying force of the perforated endless conveying belt 3 in the suction area 12 decreases.

In addition, when the lifting plates 14a to 14c are in the first position, the bottommost sheet P1 and the next sheet P2 are wavy in a direction transverse to the feed direction.

Furthermore, with regard to the extended lift plate 14b, when the extended lift plate 14b is in the first position, in addition to obtaining the above-mentioned effect, the lowest sheet P1 is also lifted by the extended lift plate 14b directly below and downstream of the contact bodies 11a to 11d, and is pressed against the contact bodies 11a to 11d and wavy in a direction transverse to the sending direction.

This creates a gap between the bottom sheet P1 and the next sheet P2, promoting the flow of separation air between sheets P1 and P2 and further increasing the blocking force of sheet P2 by the contact bodies 11a to 11d.

In this way, the lowest sheet P1 continues to be fed, while the next sheet P2 is securely blocked by the contact bodies 11a to 11d.

After that, when the lowest sheet P1 has been fed, a sheet feed signal is sent from the downstream sheet processing device to the sheet feed device, and in response to this sheet feed signal, the lifting plates 14a to 14c are lowered from the first position to the second position, and the feeding operation of the next sheet P2 is started.

Meanwhile, the bottommost sheet P1 that has passed through the pair of discharge rollers 13a, 13b is transported by the endless perforated transport belt 3 to the space between the transport roller pair 32 of the downstream paper processing device, and then is taken into the downstream paper processing device by the transport roller pair 32.

Thus, according to this embodiment, the lifting plates 14a to 14c are arranged in at least the suction area 12 of the suction box 8, and the lifting plates 14a to 14c are raised and lowered at a predetermined timing, thereby simultaneously switching the strength of the suction force of the perforated endless conveyor belt 3 on the paper and switching between contact and non-contact between the bottommost paper P1 of the paper stack S and the perforated endless conveyor belt 3. Furthermore, when the bottommost paper P1 is sent out, the paper P1 and the next paper P2 are made wavy in the direction transverse to the sending direction, so that even when there is a wide range of differences in paper size and thickness, the paper can be reliably separated and supplied one by one from the paper stack.

That is, the bottommost sheet P1 of the paper stack is sucked and adsorbed on the conveying surface 3b of the perforated endless conveying belt 3 through the first intake hole 8b of the suction box 8 and the ventilation hole 3a. The sheet P1 is conveyed while being adsorbed on the conveying surface 3b in this manner. Then, when the leading edge of the sheet P1 is gripped by the discharge rollers 13a and 13b, the lifting plates 14a to 14c are moved from the second position to the first position. As a result, the sheet P1 is moved away from the conveying surface 3b of the perforated endless conveying belt 3 by the lifting plates 14a to 14c, and the second intake hole 8b that was blocked by the lifting plates 14a to 14c is opened. As the paper P1 is separated from the conveying surface 3b of the perforated endless conveying belt 3, a change in height occurs between the lifting plates 14a-14c and the conveying surface 3b, causing the paper P1 to deform, facilitating the separation of the paper P1 being conveyed from the next paper P2 stacked on top of the paper P1. Also, as the second intake hole 8b that was blocked by the lifting plates 14a-14c is opened, the suction force from the first intake hole 8b decreases, reducing the suction force of the paper P1 on the conveying surface 3b, and the conveying force of the next paper P2 following the paper P1 being conveyed can be reduced.

The lift plate 14b is provided at the position corresponding to the contact bodies 11b and 11c or is extended downstream of the contact bodies 11b and 11c in the sending direction, so that when the lift plate 14b is in the first position, the paper P1 sandwiched between the contact bodies 11b and 11c and the perforated endless conveyor belt 3 can be significantly deformed by the lift plate 14b. This makes it difficult for the next paper P2 to enter the contact bodies 11b and 11c by making the shapes of the paper P1 being conveyed and the following paper P2 different.

Although the preferred embodiment of the present invention has been described above, the configuration of the present invention is not limited to the above embodiment, and it goes without saying that a person skilled in the art may devise various modifications within the scope of the matters described in the claims of this application.

For example, in the above embodiment, a pair of discharge rollers 13a, 13b is disposed downstream of the suction box 8 in the sending direction, and the lifting plates 14a-14c are raised from the second position to the first position when the leading edge of the bottommost sheet P1 of the paper stack S passes the pair of discharge rollers 13a, 13b. However, the pair of discharge rollers 13a, 13b is not a required component of the present invention and may be provided as needed.

If the pair of discharge rollers 13a, 13b is not provided, the lifting plates 14a-14c can be raised from the second position to the first position when the bottom sheet P1 is sent out a predetermined length from the contact members 11a-11d after the start of the paper feed operation.

In addition, in the above embodiment, the contact bodies 11a to 11d are configured as retard rollers, but instead of retard rollers, for example, plate-shaped or block-shaped elastic bodies can be used as the contact bodies 11a to 11d.

In the above embodiment, the paper feeder is disposed between the two paper processing devices, and temporarily stacks the paper discharged from the upstream paper processing device, and sequentially feeds the bottommost sheet of the stack to the downstream paper processing device. The length of the paper stacking area 29 is changeable to accommodate various paper sizes, but the paper feeder can also be configured as a normal paper feeder.

When the paper feeder of the present invention is a normal paper feeder, the paper accumulation area 29 is configured as a paper stacking area with a fixed length. Therefore, in this case, the carriage 5, slide guide 6 and carriage drive mechanism 7 are omitted, and the suction box 8, abutment bodies 11a to 11d, lift plate drive mechanism 15, pair of discharge rollers 13a, 13b and air blowing unit 30 are fixed to or supported by the frame of the paper feeder.

In addition, in the above embodiment, the paper feeder is a bottom-feed type paper feeder, but as shown in FIG. 9, by turning the paper feeder of the above embodiment upside down and configuring it so that the top surface of the paper stack S faces the suction area of the suction box 8, the paper feeder can be made into a top-feed type paper feeder.

In FIG. 9, reference numeral 33 denotes a paper loading platform that is movably mounted on the frame F of the paper feeder and on which the paper stack S is placed, reference numeral 34 denotes a vertical alignment plate that is disposed adjacent to the front of the paper loading platform 33 and opposite the front end surface of the paper stack S on the paper loading platform, and reference numeral 35 denotes a lifting mechanism that raises and lowers the paper loading platform 33.

In this manner, when the paper feeding operation of the paper feeding device is started, the topmost paper P1' of the paper stack S is adsorbed by the perforated endless conveying belt 3, transported over the alignment plate 34, and sent out between the abutting bodies 11a to 11d and the perforated endless conveying belt.
When the topmost sheet P1' is being sent out, if the next sheet P2' follows and is transported beyond the aligning plate 34, it will be securely blocked by the contact members 11a to 11d.
The modified example of FIG. 9 also provides the same effects as those of the embodiment of FIGS.

[Second embodiment]
Next, a second embodiment of the present invention will be described. This embodiment differs from the first embodiment described above in that plate-shaped abutment plates are used as the abutment bodies 11a to 11d instead of retard rollers. Since the rest of the embodiment is basically the same, the following description will focus on the differences from the first embodiment, and the same reference numerals will be used to designate the same components, and the description thereof will be omitted.

As shown in FIG. 10, an abutment plate (abutment body) 40 is attached to the support means 10 provided below the carriage 5. The abutment plate 40 is made of an elastic material such as rubber and has a plate shape. As shown in FIG. 10, the abutment plate 40 is erected vertically, with its wide surface facing the conveying direction. As shown in FIG. 11, the abutment plate 40 is supported on its back side (the downstream side in the conveying direction: the left side in FIG. 11) by the back plate 10i of the support means 10. The tip 40a of the abutment plate 40 protrudes downward from the back plate 10i. Within the range of this protruding area, the tip 40a side of the abutment plate 40 elastically deforms. The abutment plate 40 is removable from the support means 10. This allows the abutment plate 40 to be easily replaced when worn out.

When viewed from the conveying direction, the lower end shape of the abutment plate 40 is, for example, rectangular or trapezoidal, tapering downward. The lower edge 40b of the tip 40a of the abutment plate 40 is arranged to contact the upper surface (contact surface) 42a of the opposing receiving plate 42.

The receiving plate 42 is flat and fixed to the upper surface 8a of the suction box 8. The height of the upper surface 42a of the receiving plate 42 is the same as the conveying surface 3b of the perforated endless conveying belt 3. Therefore, the paper conveyed on the conveying surface 3b of the perforated endless conveying belt 3 slides over the upper surface 42a of the receiving plate 42.

The contact state between the lower edge 40b of the contact plate 40 and the upper surface 42a of the receiving plate 42 is set so that one sheet of paper can pass through. This contact state is set by the height adjustment means provided on the support means 10 and the compression spring 10d (see Figure 10) that urges the contact plate 40 downward.

A guide plate 44 is provided on the upstream side of the contact plate 40 in the conveying direction (the right side in FIG. 11). The guide plate 44 is fixed to the support means 10 side. The guide plate 44 has an inclined portion 44a that is provided so that the distance from the receiving plate 42 gradually decreases in the conveying direction. It is preferable to provide the inclined portion 44a so that the extension line of the inclined portion 44a approximately coincides with the lower edge 40b of the contact plate 40.

The inclined portion 44a is connected to the contact plate 40 side with abutment portion 44b that is bent into an R shape and stands upright. The abutment portion 44b is provided with a specified gap between it and the contact plate 40. When the tip 40a of the contact plate 40 elastically deforms toward the guide plate 44, the abutment portion 44b restricts the deformation of the contact plate 40.

As shown in FIG. 12, two abutment plates 40 are provided on the left and right sides when viewed from above. Specifically, they are provided between two of the four perforated endless conveying belts 3 from one end and between two of the four perforated endless conveying belts 3 from the other end. The abutment plates 40 may be provided in other positions, i.e., between the two central perforated endless conveying belts 3 out of the four, or on the outside of the four perforated endless conveying belts. Unlike the retard roller described in the first embodiment, the abutment plate 40 is not provided above the perforated endless conveying belts 3. That is, as also shown in FIG. 11, the abutment plate 40 is provided on a stationary receiving plate 42.

In this embodiment, the three lift plates 14a, 14b, and 14c have the same longitudinal dimension. Therefore, the ends of the three lift plates 14a, 14b, and 14c facing the abutment plate 40 are located upstream of the abutment plate 40 in the conveying direction (to the right in FIG. 12).

When the length of the central lift plate 14b is extended toward the contact plate 40 as in the first embodiment, an extension 14d as shown in Figures 13(A) and 13(B) may be attached to the central lift plate 14b. Figure 14 shows the state in which the extension 14d is attached to the central lift plate 14b. As shown in Figure 14, by attaching the extension 14d, the lift plate 14b can be extended downstream in the conveying direction from the contact plate 40.

As shown in Figures 13A and 13B, the extension 14d is a plate material having the same width as the lift plates 14a, 14b, and 14c. The extension 14d is, for example, about 0.5 mm thick and made of stainless steel. Clip portions 14d1 formed by cutting and bending are provided at two locations on the extension 14d in the longitudinal direction.
As shown in FIG. 14, the extension 14d is fixed to the lift plate 14b by inserting the clip portion 14d1 into a hole formed in the central lift plate 14b and then sliding it in the longitudinal direction.
The configuration in which the lift plate 14b is extended by the extension portion 14d can also be applied to the first embodiment.

According to the present embodiment, in addition to the advantageous effects of the first embodiment, the following advantageous effects are achieved.
Since the contact plate 40 is provided between the endless conveying belts 3 and/or on the sides of the endless conveying belts 3, the contact plate 40 does not come into contact with and slide against the endless conveying belts 3. This can reduce wear of the contact plate 40.
The contact plate 40 is an elastic plate-like body, and the lower edge 40b of the free end 40a contacts the paper, so that the lower edge 40b can bend with elasticity when it contacts the paper. This allows an appropriate contact force to be applied to the paper.

The receiving plate 42 has an upper surface 42a that contacts the lower edge 40b of the abutment plate 40, and this upper surface 42a is at the same height as the conveying surface of the perforated endless conveying belt 3, so that the paper running on the conveying surface can be conveyed smoothly without being deformed.

The guide plate 44 is provided upstream of the contact plate 40, and the leading edge of the paper is guided along the inclined portion 44a of the guide plate 44. This makes it possible to reliably direct the leading edge of the paper toward the leading edge 40a of the contact plate 40.
The inclined portion 44a can prevent the leading edge of the paper from being turned up when it hits the contact plate 40. Even if a turned-up paper enters, it can be held down by the inclined portion 44a.

The guide plate 44 is provided with an abutment portion 44b, so that when the abutment plate 40 elastically deforms toward the guide plate 44, it abuts against the abutment portion 44b. This makes it possible to restrict excessive deformation of the abutment plate 40. For example, when a paper jam occurs and the paper is pulled out in the opposite direction to the transport direction (toward the guide plate 44), the tip 40a of the abutment plate 40 also deforms toward the guide plate 44 along with the paper. Excessive deformation of the abutment plate 40 at this time can be suppressed by the abutment portion 44b.

The extension 14d is removable from the existing lift plate 14b, so the length of the lift plate 14b can be changed as needed.

In addition, in each of the above-described embodiments, if the amount of paper loaded is greater than a predetermined value, the lifting plates 14a, 14b, and 14c may be raised and lowered multiple times while blowing separating air from the air blowing unit 30 (see FIG. 1).

1 Drive roller 1a Rotation shaft 1b First roller element 2 Idle roller 2a Shaft 2b Second roller element 3 Perforated endless conveying belt (conveying belt)
3a Ventilation hole 3b Conveying surface 3c Upper belt portion 3d Lower belt portion 4 Roller drive mechanism 4a Pulley 4b Motor 4c Pulley 4d Endless belt 5 Carriage 5a Fixed plate 5b Pressing plate 6 Slide guide 7 Carriage drive mechanism 7a Motor 7b Pulley 7c Pulley 7d Endless belt 8 Suction box (suction unit)
8a Surface 8b Intake holes (first intake hole, second intake hole)
9. Suction fan (air intake)
10 Support means 10a First support plate 10b Second support plate 10c Spring receiving portion 10d Compression spring 10e Support shaft 10f Spring receiving portion 10g Compression spring 10h Support shaft 10i Back plate 11a to 11d Contact body 12 Suction area 13a, 13b Discharge roller 13c Paper detection sensor 14a to 14c Lift plate 14d Extension portion 14d1 Clip portion 15 Lift plate drive mechanism 16a, 16b Bushing 17a, 17b Guide rod 18 Connecting plate 19a, 19b Compression spring 20 Frame portion 21a, 21b Rotating shaft 22a, 22b Plate cam 23 Cam drive mechanism 24a, 24b Pulley 25 Endless belt 26 Motor 27a, 27b Pulley 28 Endless belt 29 Paper accumulation area 30 Air blowing units 31, 32 Pair of conveying rollers 33 Paper placement table 34 Alignment plate 35 Lifting mechanism 40 Contact plate (contact body)
40a: Tip 40b: Lower edge 42: Support plate 42a: Upper surface (contact surface)
44 Guide plate 44a Inclined portion 44b Abutment portion CL Center line F Frame S Sheet stack P1 First (lowest) sheet P1' Uppermost sheet P2 Next sheet P2' Next sheet u Upstream edge (of conveying surface) w Downstream edge (of conveying surface)

Claims (14)

a conveyor belt that places the top or bottom sheet of a stack of sheets on a conveying surface and conveys the sheet in a sending direction, the conveyor belt having a plurality of ventilation holes;
a suction section that is disposed on a back surface side of the conveyor belt opposite to the conveying surface and has a first intake hole formed therein to suck the paper through the ventilation hole;
a lift plate that reciprocates between a first position located in a stacking direction of the sheets from the conveying surface and a second position located at the same height as the conveying surface or on the back side of the conveying surface, and opens a second intake hole, different from the first intake hole formed in the suction section, when located at the first position, and closes the second intake hole when located at the second position;
A control unit for controlling the operation of the lift plate;
Equipped with
The control unit operates the lift plate from the second position to the first position when the topmost or bottommost sheet is being transported. The conveyor belts are provided in a plurality of types and are arranged in parallel at predetermined intervals in a width direction perpendicular to the sending direction,
2. The sheet feeding device according to claim 1, wherein the lifting plate is provided in a plurality of positions, and is provided between adjacent ones of the conveyor belts and/or to the sides of the conveyor belts. The paper feeder according to claim 2, wherein the plurality of conveyor belts and the plurality of lift plates are arranged symmetrically with respect to the center of the width direction perpendicular to the paper feed direction. a discharge roller for gripping and discharging the leading edge of the paper conveyed from the conveyor belt;
The paper feeding device according to claim 1 , wherein the control unit operates the lift plate from the second position to the first position when the discharge roller grasps the leading edge of the paper conveyed from the conveyor belt. The paper feeder according to claim 4, further comprising a contact body that contacts the leading edge of the paper and is provided upstream of the discharge roller in the feed direction. The conveyor belts are provided in a plurality of types and are arranged in parallel at predetermined intervals in a width direction perpendicular to the sending direction,
The paper feeding device according to claim 5, wherein the abutment body is provided between adjacent conveyor belts and/or to the side of the conveyor belt, and the free end is an elastic plate-like body that abuts against the paper. a contact surface with which the tip of the abutting body comes into contact is provided at a position opposite the tip of the abutting body,
7. The paper feeder according to claim 6, wherein the contact surface is flush with the transport surface. The paper feeder according to claim 6 or 7, which is provided with a guide plate having an inclined portion that guides the paper toward the tip of the contact body. The paper feeder according to claim 8, wherein the guide plate has a gap between it and the contact body and is provided with an abutment portion against which the contact body abuts when it is elastically deformed toward the guide plate. 6. The paper feeder according to claim 5 , wherein the contact member is a retard roller provided so as to be pressed against the conveyor belt. 6. The paper feeder according to claim 5 , wherein at least one of the lifting plates includes an extension portion provided at a position corresponding to the contact member or extending downstream of the contact member in the paper feed direction. The paper feeder according to claim 11, wherein the extension is removable from the existing lift plate. a conveyor belt that places the top or bottom sheet of a stack of sheets on a conveying surface and conveys the sheet in a sending direction, the conveyor belt having a plurality of ventilation holes;
a suction section that is disposed on a back surface side of the conveyor belt opposite to the conveying surface and has a first intake hole formed therein to suck the paper through the ventilation hole;
a lift plate that reciprocates between a first position located in a stacking direction of the sheets from the conveying surface and a second position located at the same height as the conveying surface or on the back side of the conveying surface, and opens a second intake hole, different from the first intake hole formed in the suction section, when located at the first position, and closes the second intake hole when located at the second position;
A method for controlling a paper feeder comprising:
A method for controlling a paper feeder, the method comprising: moving the elevator plate from the second position to the first position while the topmost or bottommost paper is being transported. A control program for a paper feeder for causing a computer to execute control of the paper feeder according to any one of claims 1 to 12.