Paper feeder, control method thereof, and control program thereof

Abstract

To provide a paper feeding device that can reliably feed various types of paper of different sizes, thicknesses, weights, etc. sheet by sheet.SOLUTION: A perforated endless conveying belt 3 is stretched between drive and idle rollers 1 and 2, and a suction box 8 is placed between the upper and lower belt parts 3c and 3d of the perforated endless conveying belt. Abutting bodies 11a-11d are attached to the positions corresponding to the perforated endless conveying belt of support means 10, and are pressed against the perforated endless conveying belt. A suction area 12 is formed on the upstream side of the abutting bodies of the suction box, and a suction hole 8b is formed in the suction area. Elevating plates 14a-14c extend at least within the intake holes of the suction area between the perforated endless conveying belts. The elevating plates open the intake holes upward and downward and move between a first position that protrudes from a transport surface 3b of the perforated endless conveying belt and a second position that closes the intake holes and retracts from the transport surface of the perforated endless conveying belt.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a paper feeding device of the so-called top feed type (a type in which the topmost paper is fed sequentially from a paper stack) or bottom feed type (a type in which the bottommost paper is fed sequentially from a paper stack), and a control method and control program for the same. [Background technology]

[0002] 2. Description of the Related Art A conventional top-feed type paper feeder is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-233696. The paper feeding device described in Patent Document 1 comprises a liftable paper loading table on which a paper stack is placed, an alignment 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 alignment plate as the paper loading table gradually rises.

[0003] 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 an idle roller each extending perpendicular to the transport direction, a perforated endless transport belt stretched between the drive roller and the idle roller, a suction box arranged between the upper and lower belt portions of the perforated endless transport belt and having multiple air intakes formed on its underside, and a suction unit that creates negative pressure in the internal space of the suction box.

[0004] The suction unit is composed of a suction pump, an intake pipe connecting the suction box and the suction pump, and an electromagnetic valve arranged in the intake pipe. The suction box is switched between suction and release of suction by opening and closing the electromagnetic valve.

[0005] During operation of the paper feeder, the endless perforated conveyor belt moves in a circular motion, and the solenoid valve opens and closes at a predetermined timing.

[0006] The alignment plate is also provided with an air blowing unit, which constantly blows air toward the upper layer of the paper stack on the paper placement table while the paper feeder is in operation, causing the upper layers of the paper stack to float above the paper stack in a separated state.

[0007] In this manner, while the paper feeder is in operation, the topmost sheet of paper that has been raised by receiving air is attracted to the suction box and the endless perforated transport belt that moves in an orbit, and is sent forward.

[0008] Furthermore, a conventional bottom-feed type paper feeder is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-233996. 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.

[0009] 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 backward from the bottom. The regulating guide inclined wall is provided with a slip-in prevention member that prevents the paper abutting thereon from slipping downward along the inclined surface.

[0010] The bottom feed mechanism is arranged on the entrance side of the paper storage section and has a first group of conveying rolls that can rotate around an axis extending perpendicular to the paper feed direction, a second group of conveying rolls arranged parallel to the first group of conveying rolls downstream of the first group of conveying rolls, a first support roll that shares a common rotation axis with the second group of conveying rolls, a second support roll arranged adjacent to the retard roll, and a conveying belt stretched between the first and second support rolls.

[0011] 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. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] International Publication No. 2014 / 006747 [Patent Document 2] JP 2001-97563 A Summary of the Invention [Problem to be solved by the invention]

[0013] However, when there is a wide range of differences in the size, thickness, weight, and other characteristics of paper, it becomes difficult to simultaneously address both paper multifeeds and misfeeds (paper feed problems). Moreover, it is cumbersome to set separation parameters for separating each sheet of paper in accordance with the size, thickness, weight, etc. of the paper.

[0014] Therefore, the object of the present invention is to provide a paper feeding device, a control method and a control program for the same that can reliably separate and supply paper one sheet at a time from a paper stack even when there are wide ranges of differences in paper size, thickness, weight, etc. [Means for solving the problem]

[0015] A paper feeding device according to one embodiment of the present invention comprises a conveying belt which places the top or bottom paper of a paper stack on its conveying surface and conveys it in a sending direction, the conveying belt having a plurality of air vent holes formed therein; a suction section which is arranged on the back side of the conveying belt opposite the conveying surface and has a first air intake hole formed therein which sucks in the paper through the air hole; a lifting plate which reciprocates between a first position which is located in the paper stacking direction relative to the conveying surface and a second position which is located at the same height as the conveying surface or on the back side of the conveying surface, the lifting plate opening a second air intake hole different from the first air intake hole formed in the suction section when positioned at the first position and closing the second air intake hole when positioned at the second position; and a control unit which controls the operation of the lifting plate, wherein the control unit operates the lifting plate from the second position to the first position when the top or bottom paper is being conveyed.

[0016] The top or bottom paper of the paper stack is sucked and adsorbed on the conveying surface of the conveyor belt through the first intake hole of the suction unit and the ventilation hole. The paper is conveyed in this state of being adsorbed on the conveying surface. Then, while the top or bottom paper is being conveyed, the lift plate is operated from the second position to the first position. As a result, the paper is separated from the conveying surface of the conveyor belt by the lift plate, and the second intake hole that was blocked by the lift plate is opened. As the paper 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 paper is deformed, facilitating separation of the paper being conveyed from the next paper stacked on the paper. Also, as the second intake hole that was blocked by the lift plate is opened, the suction force from the first intake hole decreases, and the adsorption force of the paper on the conveying surface decreases, so that the conveying force of the next paper following the paper 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 paper size, thickness, weight, and the like.

[0017] Furthermore, in a paper feeding device according to one embodiment of the present invention, the conveying belts are multiple and arranged parallel to each other at a predetermined interval in the width direction perpendicular to the sending direction, and the lifting plates are multiple and arranged between adjacent conveying belts and / or to the sides of the conveying belts.

[0018] By providing a plurality of lift plates between and / or to the sides of the conveyor belts, the paper can be stably manipulated. Furthermore, since the lift plates and the conveyor belts are provided alternately in the width direction, the paper is corrugated (waved) when the lift plates are positioned at the first position, thereby facilitating separation of the paper.

[0019] Furthermore, in the paper feeder according to one aspect of the present invention, the plurality of conveyor belts and the plurality of lift plates are provided symmetrically with respect to the center in the width direction perpendicular to the paper feed direction.

[0020] Since the transport belts and the lift plates are provided symmetrically with respect to the center in the width direction perpendicular to the paper feed direction, the paper can be transported accurately.

[0021] Furthermore, in a paper feeding device according to one embodiment of the present invention, a discharge roller is provided which grasps the leading edge of the paper transported from the conveyor belt and discharges it, and the control unit operates the lifting plate from the second position to the first position when the discharge roller grasps the leading edge of the paper transported from the conveyor belt.

[0022] 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 sending direction.

[0023] Furthermore, in the 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.

[0024] By providing the contact body on the upstream side of the discharge roller in the feeding direction, a paper stack in which the papers are temporarily stacked can be formed on the upstream side of the discharge roller.

[0025] Furthermore, in a paper feeding device according to one embodiment of the present invention, the conveying belts are multiple and arranged parallel to each other at a predetermined interval in the width direction perpendicular to the sending direction, and the abutment body is arranged between adjacent conveying belts and / or to the side of the conveying belt, and is an elastic plate-like body whose free end abuts against the paper.

[0026] 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 the conveyor belt and slides thereon, 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.

[0027] Furthermore, in the paper feeding device 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 transport surface.

[0028] 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 transport surface, so that the paper traveling on the transport surface can be transported smoothly without being deformed.

[0029] Furthermore, the paper feeder according to one aspect of the present invention includes a guide plate having an inclined portion that guides the paper toward the tip of the contact body.

[0030] 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, it can be held down by the inclined portion.

[0031] Furthermore, in the 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.

[0032] An abutment portion is provided on the guide plate so that the abutment body abuts against the abutment portion when it elastically deforms toward the guide plate. This makes it possible to restrict 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 (toward the guide plate), the abutment body also deforms toward the guide plate along with the paper. The abutment portion can suppress excessive deformation of the abutment body at this time.

[0033] Furthermore, in the paper feeding device according to one aspect of the present invention, the contact body is a retard roller provided so as to be pressed against the conveyor belt.

[0034] By using the retard roller as the contact body, the paper can be reliably separated and transported.

[0035] Furthermore, in a paper feeding device according to one embodiment of the present invention, at least one of the lifting plates has an extension portion that is provided at a position corresponding to the abutment portion or that extends downstream of the abutment portion in the feed direction.

[0036] At least one of the lifting plates is provided to extend to the position corresponding to the retard roller or further downstream in the feed direction than the retard roller, 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 shapes of the paper different. The position corresponding to the retard roller means the position immediately adjacent to (directly below) the retard roller and in the vicinity thereof.

[0037] Furthermore, in the paper feeding device according to one aspect of the present invention, the extension portion is detachable from the existing lift plate.

[0038] Since the extension is removable from the existing lift plate, the length of the lift plate can be changed as required.

[0039] A control method for a paper feeding device according to one embodiment of the present invention is a control method for a paper feeding device comprising: a conveying belt which places the top or bottom paper of a paper stack on a conveying surface and conveys it in a sending direction, the conveying belt having a plurality of air vent holes formed therein; a suction section which is arranged on the back side of the conveying belt opposite the conveying surface and has a first air intake hole formed therein which sucks in the paper through the air hole; and a lifting plate which reciprocates between a first position which is located in the paper stacking direction relative to the conveying surface and a second position which is located at the same height as the conveying surface or on the back side of the conveying surface, the lifting plate opening a second air intake hole different from the first air intake hole formed in the suction section when positioned at the first position and closing the second air intake hole when positioned at the second position, wherein when the top or bottom paper is being conveyed, the lifting plate is operated from the second position to the first position.

[0040] A control program for a paper feeder according to one aspect of the present invention causes a computer to execute control of any one of the paper feeders described above. Effect of the Invention

[0041] Even when the size, thickness, weight, etc. of the paper varies widely, the paper can be reliably separated and fed one by one from the paper stack. [Brief description of the drawings]

[0042] [Figure 1] 1A and 1B are schematic diagrams of a paper feeder according to a first embodiment of the present invention, in which (A) is a plan view and (B) is a front view. [Diagram 2] FIG. 2 is an enlarged front view showing a suction box and a contact body of the paper feeder of FIG. 1, in which the suction box is illustrated as being cut away vertically. [Diagram 3] 3A 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 FIG. 2, and FIG. 3B is a side view taken from the downstream side in the sending direction of FIG. [Figure 4] 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. [Diagram 5] 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 feeding direction as viewed from the upstream side of the feeding direction of FIG. [Figure 6] 2 for explaining the paper feeding operation of the paper feeder of FIG. 1. [Figure 7] 3A is a view similar to FIG. 3A for explaining the paper feeding operation of the paper feeding device of FIG. 1. [Figure 8] FIG. 2 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 at its shortest, and (B) shows the carriage in a position where the length of the paper accumulation area is at its longest. [Figure 9] 11 is a schematic front view of a paper feeder according to another embodiment of the present invention; FIG. [Figure 10] FIG. 11 is a side view showing a paper feeding device according to a second embodiment of the present invention. [Figure 11] 11 is a partially enlarged side view showing the vicinity of the abutment plate in FIG. 10 in an enlarged manner. [Figure 12]FIG. 11 is a plan view showing a paper feeding device according to a second embodiment of the present invention. [Figure 13] 1 shows the extension of the lift plate, (A) is a plan view, and (B) is a side view. [Figure 14] 13 is a plan view of the paper feeder with the extension of the lift plate attached. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] [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 the suction box and abutment body of the paper feeder of Fig. 1, in which the suction box is depicted as being cut vertically.

[0044] Fig. 3(A) 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. 3(B) is a side view taken from the downstream side in the sending direction of Fig. 2. Fig. 4(A) is a horizontal cross-sectional view taken along line XX in Fig. 2, and Fig. 4(B) is a horizontal cross-sectional view taken along line YY in Fig. 2.

[0045] Also, Figure 5(A) is an enlarged front view showing the suction box and abutment body of the paper feeding device of Figure 1, and Figure 5(B) is a vertical cross-sectional view taken along a direction transverse to the feeding direction as viewed from the upstream side of the feeding direction of Figure 5(A).

[0046] In this embodiment, the paper feeder is a paper feeder (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.

[0047] With reference to Figures 1 to 5, this embodiment includes a drive roller 1 and an idle roller 2 spaced apart from each other in the paper feed direction, each extending horizontally and perpendicular to the paper feed direction, at least one (four in this embodiment) perforated endless conveying belt (conveying belt) 3 stretched between the drive roller 1 and the idle roller 2, and a roller drive mechanism 4 that rotates the drive roller 1.

[0048] The drive roller 1 has a horizontal rotation shaft 1a and four first roller elements 1b attached to the rotation shaft 1a at intervals in the axial direction so as to be rotatable integrally with the rotation shaft 1a.

[0049] 1(A) and 4(A), in this embodiment, the four first roller elements 1b are arranged symmetrically with respect to a predetermined center line CL extending perpendicular to the drive roller 1 and the idle roller 2. The center line CL coincides with the center of the paper P1 being transported in the width direction perpendicular to the sending direction.

[0050] The idle roller 2 is rotatable about 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, respectively.

[0051] Each of the perforated endless conveying belts 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 perforated endless conveying belts 3 are arranged symmetrically with respect to the center line CL. Each of the perforated endless conveying belts 3 has a plurality of ventilation holes 3a uniformly distributed over its entire length.

[0052] 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.

[0053] During operation of the paper feeding device, the four perforated endless conveying belts 3 rotate simultaneously at a constant speed as the motor 4b drives and rotates the drive roller 1, and the paper P1 placed on the conveying surfaces 3b of the four perforated endless conveying belts 3 is transported from the idle roller 2 side toward the drive roller 1 side.

[0054] In addition, there is provided a carriage 5 arranged above the perforated endless conveying belt 3 so as to be able to move back and forth in the longitudinal direction of the perforated endless conveying belt 3, at least one slide guide 6 (two in this embodiment) extending in the longitudinal direction of the perforated endless conveying belt 3 and to which the carriage 5 is attached so as to be able to slide, and a carriage drive mechanism 7 which causes the carriage 5 to perform a sliding motion.

[0055] The carriage drive mechanism 7 has a motor 7a and a pulley 7b arranged at an interval in the longitudinal direction 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.

[0056] 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. A carriage 5 is fixed to the endless belt 7d.

[0057] The endless belt 7 d is rotated forward and backward by the motor 7 a , so that the carriage 5 can perform a reciprocating sliding motion along the slide guide 6 .

[0058] A suction box (suction section) 8 is arranged between the upper belt portion 3c and the lower belt portion 3d of the four perforated endless conveying belts 3 so as to be capable of reciprocating movement in the longitudinal direction of the perforated endless conveying 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.

[0059] The upstream side in the sending direction of the surface 8a of the suction box 8 facing the upper belt portion 3c is made to be a suction area 12. In the suction area 12, a plurality of intake holes (first intake holes) 8b are formed, and the upper surface of the paper stack S is disposed opposite to the intake hole 8a.

[0060] 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 perforated endless conveying belt 3 in the width direction. 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.

[0061] The contact bodies 11a to 11d are formed of retard rollers.

[0062] 1, 2, 3 and 5, a fixed plate 5a having an L-shaped cross section is attached to the lower surface of the carriage 5. The fixed plate 5a extends perpendicular to the surface 8a of the suction box 8 and in a direction transverse to the perforated endless conveyor belt 3 (width direction).

[0063] 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 crossing the perforated endless conveyor belt 3 and are each attached to the fixed plate 5a so as to be slidable up and down.

[0064] The first support plate 10a is in an inverted U-shape, and horizontal support shafts 10e are provided on the outer sides of each leg of the first support plate 10a, extending in the width direction of the perforated endless conveyor belt 3. A pair of contact bodies 11a, 11d, which are located on both outer sides of the four contact bodies 11a to 11d, are attached to these support shafts 10e.

[0065] A spring receiving portion 10c is provided at the center of the upper end of the first support plate 10a, and a compression spring 10d is arranged between the spring receiving portion 10c and the fixed plate 5a to constantly urge the first support plate 10a downward against the fixed plate 5a (thus pressing the pair of abutment bodies 11a, 11d against the corresponding perforated endless conveying belt 3).

[0066] 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 contact bodies 11b, 11c located in the center of the four contact bodies 11a to 11d are attached to both ends of the support shaft 10h.

[0067] A spring receiving 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 receiving portion 10f. A compression spring 10g is fitted into the through hole with its lower end pressed against the spring receiving 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).

[0068] 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 located symmetrically with respect to the center line CL are separately connected and supported, and pressed against the corresponding perforated endless conveying belt 3, so that the pressing force of the abutment bodies 11a to 11d against the perforated endless conveying belt 3 can be made uniform with respect to the center line CL, thereby reliably preventing not only double feeding of paper P1, but also skewing of paper P1.

[0069] 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).

[0070] The three lifting plates 14a to 14c are disposed 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 delivery direction to a position corresponding to the contact bodies 11a to 11d, as shown in FIG. 4(A) for example (hereinafter, the lifting plate 14b may be referred to as the "extended lifting plate 14b").

[0071] The expanded lift plate 14b is arranged so that its center in the width direction coincides with the center line CL (so as to be symmetrical with respect to the center line CL) as shown in FIG. 4(A).

[0072] The carriage 5 is provided with a lift plate drive mechanism 15 for moving 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 FIGS. 2 and 3) where the lift plates 14a to 14c move away from the surface 8a to open the intake holes 8b and protrude from the conveying surface 3b of the perforated endless conveying belt 3, and a second position (see FIG. 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 retract below the conveying surface 3b.

[0073] As shown in FIG. 2, for example, the lift plate drive mechanism 15 has two bushes 16a, 16b that are arranged facing each of the lift plates 14a-14c on the wall of the suction box 8 and spaced apart from each other in the longitudinal direction of the lift plates 14a-14c, and extend through the wall, and guide rods 17a, 17b that pass through each bush 16a, 16b, have upper ends connected to the back sides of the corresponding lift plates 14a-14c, and have lower ends that extend into the suction box 8.

[0074] The lower ends of each guide rod 17a, 17b are connected by a single horizontal connecting plate 18, and compression springs 19a, 19b surround the outside of the parts of each guide rod 17a, 17b that protrude into the suction box 8 and extend between the connecting plate 18 and the suction box 8, constantly biasing the lifting plates 14a to 14c toward the second position.

[0075] The lift plate driving mechanism 15 further has two rotating shafts 21a, 21b that extend horizontally in the width direction of the lift plates 14a to 14c, spaced apart from each other in the longitudinal direction of the lift plates 14a to 14c, below the connecting plate 18 in the suction box 8.

[0076] The two rotating shafts 21a, 21b are each rotatably supported about their axes by a pair of frame portions 20 (see, for example, Figures 4(A) and 4(B)) extending in the longitudinal direction of the lifting plates 14a to 14c in a rectangular support frame attached to the inner bottom surface of the suction box 8.

[0077] As shown in FIGS. 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 to the outside of the suction box 8.

[0078] The lifting plate driving mechanism 15 further has pairs 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 which are rotatable integrally with the rotating shafts 21a, 21b, and a cam driving mechanism 23 which rotates the two rotating shafts 21a, 21b in a synchronous manner.

[0079] In this case, as shown in FIG. 5(A), when the plate cams 22a, 22b reach their bottom dead center, the plate cams 22a, 22b are separated from the connecting plate 18 and the lifting plates 14a to 14c are positioned in a second position, whereas as shown in FIG. 2, when the plate cams 22a, 22b reach their top dead center, the connecting plate 18 is pushed up by the plate cams 22a, 22b and the lifting plates 14a to 14c are positioned in a first position.

[0080] The cam drive mechanism 23 has a pulley 24a fixed to one end of the rotary shaft 21a, a pulley 24b fixed to the rotary shaft 21b at a position corresponding to the pulley 24a, and an endless belt 25 stretched between the pulley 24a and the pulley 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 rotary shaft 21b, a pulley 27a fixed to the drive shaft of the motor 26, a pulley 27b fixed to the rotary shaft 21b at a position corresponding to the pulley 27a, and an endless belt 28 stretched between the pulley 27a and the pulley 27b.

[0081] In this way, 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 the bottom dead center, the lifting plates 14a to 14c reach the second position, and when the plate cams 22a, 22b reach the top dead center, the lifting plates 14a to 14c reach the first position.

[0082] As shown in FIG. 1(B), a region from the contact members 11a to 11d on the conveying surface 3b of the perforated endless conveying belt 3 to an upstream end u of the conveying surface 3b forms a paper accumulation area 29.

[0083] 1(A) and 1(B), there is provided an air blowing unit 30 attached to a carriage 5. The air blowing unit 30 is disposed downstream of the contact bodies 11a to 11d in the delivery 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.

[0084] The control unit is a computer system, and includes, for example, a CPU, a ROM (Read Only Memory) for storing programs executed by the CPU, etc., 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 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. Computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0085] The length of the paper accumulation area 29 can be freely changed within a range of a minimum length (see Figure 8(A)) and a maximum length (see Figure 8(B)) by changing the position of the carriage 5, i.e., the positions of the suction box 8, the abutment bodies 11a-11d, the pair of discharge rollers 13a, 13b and the air blowing unit 30.

[0086] As a result, even if the length of the paper to be fed is changed, the length of paper accumulation area 29 can be adjusted to easily and quickly accommodate the change in paper size.

[0087] 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. 3(A) for explaining the paper feeding operation of the paper feeding device of FIG.

[0088] First, referring to Figure 1, prior to operation of the paper feeding device, an upstream paper processing device is connected to the upstream end u (see Figure 1(B)) of the conveying path of the perforated endless conveying belt 3, while a downstream paper processing device is connected to the downstream end w (see Figure 1(B)) of the conveying surface 3b of the perforated endless conveying belt 3.

[0089] 1(B), as a representative of the upstream paper processing device, a pair of conveying rollers 31 is depicted which is provided at the paper exit of the paper processing device and extends in a direction crossing the paper accumulation area 29 of the paper feeder. Also, as a representative of the downstream paper processing device, a pair of conveying rollers 32 is depicted which is provided at the paper entrance of the paper processing device and extends in a direction crossing the conveying surface 3b of the perforated endless conveying belt 3 of the paper feeder.

[0090] Next, the position of the carriage 5, i.e., the positions of the suction box 8, the abutment bodies 11a-11d, the lift plate drive mechanism 15, the pair of discharge rollers 13a, 13b and the air blowing unit 30 are adjusted according to the length of the paper to be processed (length in the feed direction), and the length of the paper accumulation area 29 is set.

[0091] When the paper feeder and each paper processing device start operating, the first (lowest) paper sheet 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 sheet P1 reaches the contact portion 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 Fig. 6(A) and Fig. 7(A).

[0092] When the lifting plates 14a-14c take the first position, the intake holes (second intake holes) 8b facing the lifting plates 14a-14c in the suction area 12 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 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.

[0093] In this way, the first (lowest) sheet P1 remains in the sheet accumulation area 29 while being blocked by the contact members 11a to 11d.

[0094] 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 feeding device, and the sheet feeding operation of the sheet feeding device is started.

[0095] At the start of the feeding operation of this first (lowest) sheet of paper P1, the perforated endless conveying 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 to 14c are lowered from the first position to the second position, as shown in Figures 6(B) and 7(B).

[0096] When the lifting plates 14a to 14c take the second position, the intake holes 8b facing the lifting plates 14a to 14c in the suction area 12 are closed, and outside air flows into the suction box 8 only through the ventilation holes 3a of the perforated endless conveying belt 3, strengthening the suction force of the perforated endless conveying belt 3. At the same time, the lowermost 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.

[0097] In this manner, the bottommost sheet P1 is conveyed while being attracted to the endless conveyor belt 3 with holes, and is sent out through between the contact members 11a to 11d and the endless conveyor belt 3 with holes.

[0098] Then, when the leading edge of the lowest sheet P1 passes through the pair of discharge rollers 13a, 13b, the paper detection sensor 13c detects the leading edge of the sheet P1, and, at the instruction of the control unit, the lifting plates 14a-14c rise from the second position to the first position, as shown in Figures 6(C) and 7(C).

[0099] When the lifting plates 14a to 14c take the first position, the intake holes 8b facing the lifting plates 14a to 14c in the suction area 12 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.

[0100] Furthermore, when the elevator plates 14a to 14c take the first position, the lowermost sheet P1 and the next sheet P2 are wavy in a direction perpendicular to the sending direction.

[0101] 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 lowermost sheet P1 is lifted by the extended lift plate 14b also directly below and downstream of the abutment bodies 11a-11d, and is pressed against the abutment bodies 11a-11d and wavy in a direction transverse to the sending direction.

[0102] This creates a gap between the lowermost sheet P1 and the next sheet P2, promoting the flow of separation air between the sheets P1 and P2, and further increasing the blocking force of the contact bodies 11a to 11d against the sheet P2.

[0103] In this way, the lowermost sheet P1 continues to be sent out, while the next sheet P2 is securely blocked by the contact members 11a to 11d.

[0104] Thereafter, when the sending out of the bottom sheet P1 is completed, 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 descend from the first position to the second position, and the feeding operation of the next sheet P2 is initiated.

[0105] Meanwhile, the bottom sheet P1 that has passed through a pair of discharge rollers 13a, 13b is transported by a perforated endless conveyor belt 3 to between a pair of conveyor rollers 32 of the downstream paper processing device, and then is taken into the downstream paper processing device by the pair of conveyor rollers 32.

[0106] Thus, according to this embodiment, the lifting plates 14a-14c are arranged in at least the suction area 12 of the suction box 8, and the lifting plates 14a-14c are raised and lowered at a predetermined timing, thereby simultaneously switching the strength of the suction force of the perforated endless conveying 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 conveying belt 3. In addition, when the bottommost paper P1 is sent out, the paper P1 and the next paper P2 are made to have a wavy shape in the direction perpendicular to the sending direction, so that even when there are wide differences in paper size, thickness, etc., the papers can be reliably separated and supplied one by one from the paper stack.

[0107] That is, the bottommost sheet P1 of the stack of sheets is sucked and adsorbed on the conveying surface 3b of the perforated endless conveying belt 3 through the first suction 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 separated from the conveying surface 3b of the perforated endless conveying belt 3 by the lifting plates 14a to 14c, and the second suction hole 8b that was blocked by the lifting plates 14a to 14c is opened. As the sheet 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 sheet P1 to deform, facilitating separation of the sheet P1 being conveyed from the next sheet P2 stacked on the sheet P1. Also, as the second intake holes 8b that were blocked by the lifting plates 14a-14c are opened, the suction force from the first intake holes 8b decreases, reducing the suction force of the sheet P1 on the conveying surface 3b, and the conveying force of the next sheet P2 following the sheet P1 being conveyed can be reduced.

[0108] Since the lift plate 14b is provided at a position corresponding to the contact bodies 11b, 11c or extended downstream of the contact bodies 11b, 11c in the sending direction, when the lift plate 14b is in the first position, the sheet P1 sandwiched between the contact bodies 11b, 11c and the perforated endless conveyor belt 3 can be significantly deformed by the lift plate 14b. This makes it difficult for the sheet P2 to enter the contact bodies 11b, 11c by making the shapes of the sheet P1 being conveyed and the following sheet P2 different.

[0109] Although a 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 can devise various modifications within the scope of the matters described in the claims of this application.

[0110] For example, in the above embodiment, a pair of discharge rollers 13a, 13b are arranged downstream of the suction box 8 in the feed direction, and the lifting plates 14a-14c are raised from the second position to the first position at the timing when the leading edge of the lowest sheet P1 in 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 necessary.

[0111] In addition, if a pair of discharge rollers 13a, 13b is not provided, after the start of the paper feeding operation, when the lowermost paper P1 is sent out a predetermined length from the contact bodies 11a to 11d, the lifting plates 14a to 14c can be raised from the second position to the first position.

[0112] 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 may be used as the contact bodies 11a to 11d.

[0113] In addition, in the above embodiment, the paper feed device is disposed between two paper processing devices, and temporarily accumulates paper discharged from the upstream paper processing device, and sequentially feeds the bottommost sheet of the accumulated paper to the downstream paper processing device. The length of the paper accumulation area 29 is changeable to accommodate various paper sizes, but the paper feed device can also be configured as a normal paper feed device.

[0114] When the paper feeder of the present invention is a normal paper feeder, the paper stacking area 29 is configured as a paper stacking area with a fixed length. Therefore, in this case, the carriage 5, the slide guide 6 and the carriage drive mechanism 7 are omitted, and 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 fixed to or supported by the frame of the paper feeder.

[0115] In addition, in the above embodiment, the paper feeding device is a bottom-feed type paper feeding device, but as shown in Figure 9, by turning the paper feeding device 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 feeding device can be made into a top-feed type paper feeding device.

[0116] 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.

[0117] In this manner, when the paper feeding operation of the paper feeding device is started, the topmost paper sheet 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 abutment bodies 11a-11d and the perforated endless conveying belt. When the topmost sheet P1' is sent out, if the next sheet P2' follows and is transported beyond the aligning plate 34, it is reliably blocked by the contact members 11a to 11d. The modified example in FIG. 9 also provides the same effects as those of the embodiment in FIGS.

[0118] [Second embodiment] Next, a second embodiment of the present invention will be described. This embodiment differs from the first embodiment described above in that abutment plates made of plate-like bodies are used as the abutment bodies 11a to 11d instead of the retard rollers. Since the rest are 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.

[0119] 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 body such as rubber and has a plate shape. As shown in FIG. 10, the abutment plate 40 is provided upright in the vertical direction with its wide surface facing the conveying direction. As shown in FIG. 11, the abutment plate 40 is supported at 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 is elastically deformed. The abutment plate 40 is detachable from the support means 10. This allows the abutment plate 40 to be easily replaced when worn out.

[0120] The lower end shape of the contact plate 40 is, for example, rectangular or trapezoidal tapering downward when viewed from the conveying direction. A lower edge 40b of a tip 40a of the contact plate 40 is provided so as to come into contact with an upper surface (contact surface) 42a of the opposing receiving plate 42.

[0121] The receiving plate 42 has a flat plate shape and is fixed to the upper surface 8a of the suction box 8. The height of the upper surface 42a of the receiving plate 42 is set to be the same height 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 passes by while sliding on the upper surface 42a of the receiving plate 42.

[0122] 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 a height adjustment means provided on the support means 10 and a compression spring 10d (see FIG. 10) that urges the contact plate 40 downward.

[0123] 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 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 an extension line of the inclined portion 44a approximately coincides with the lower edge 40b of the contact plate 40.

[0124] An abutment portion 44b, which is bent into an R shape and stands upward, is connected to the contact plate 40 side of the inclined portion 44a. The abutment portion 44b is provided with a predetermined 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.

[0125] As shown in FIG. 12, two abutment plates 40 are provided on the left and right sides in plan view. Specifically, the abutment plates 40 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 at other positions, that is, between the two central perforated endless conveying belts 3 out of the four, or may be provided outside 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 shown in FIG. 11, the abutment plate 40 is provided on a stationary receiving plate 42.

[0126] 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 on the contact plate 40 side are located upstream of the contact plate 40 in the conveying direction (to the right in FIG. 12).

[0127] When the length of the central lift-up plate 14b is extended toward the contact plate 40 as in the first embodiment, an extension 14d as shown in Fig. 13(A) and Fig. 13(B) may be attached to the central lift-up plate 14b. Fig. 14 shows a state in which the extension 14d is attached to the central lift-up plate 14b. As shown in Fig. 14, by attaching the extension 14d, the lift-up plate 14b can be extended downstream in the conveying direction beyond the contact plate 40.

[0128] As shown in Figures 13(A) and 13(B), 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 in the longitudinal direction of the extension 14d. 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.

[0129] 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 perforated endless conveying belts 3 and / or on the side of the perforated endless conveying belts 3, the contact plate 40 does not come into contact with and slide against the perforated endless conveying belts 3. This makes it possible to 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.

[0130] The receiving plate 42 has an upper surface 42a with which the lower edge 40b of the abutment plate 40 comes into contact, 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.

[0131] 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 ensures that the leading edge of the paper is directed 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.

[0132] The guide plate 44 is provided with an abutment portion 44b, so that when the contact 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 contact 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 contact plate 40 also deforms toward the guide plate 44 together with the paper. Excessive deformation of the contact plate 40 at this time can be suppressed by the abutment portion 44b.

[0133] Since the extension portion 14d is detachable from the existing lift plate 14b, the length of the lift plate 14b can be changed as required.

[0134] In each of the above-described embodiments, when the amount of loaded paper is greater than a predetermined value, the lifting plates 14a, 14b, and 14c may be raised and lowered multiple times while blowing loosening air from the air blowing unit 30 (see FIG. 1). [Explanation of symbols]

[0135] 1 Drive roller 1a Rotation axis 1b First roller element 2 Idol Roller 2a axis 2b Second roller element 3 Perforated endless conveyor belt (conveyor belt) 3a Ventilation hole 3b Transport surface 3c Upper belt part 3d Lower belt part 4 Roller drive mechanism 4a Pulley 4b Motor 4c Pulley 4d endless belt 5 Carriage 5a Fixed plate 5b Retaining plate 6 Slide Guide 7 Carriage drive mechanism 7a Motor 7b Pulley 7c Pulley 7d Endless belt 8 Suction box (suction part) 8a side 8b Intake hole (first intake hole, second intake hole) 9. Suction fan (air intake) 10 Support means 10a First support plate 10b Second support plate 10c Spring support 10d compression spring 10e support shaft 10f Spring support 10g compression spring 10h support shaft 10i back plate 11a~11d Contact body 12. Suction area 13a, 13b Discharge rollers 13c Paper detection sensor 14a~14c Lifting plate 14d extension 14d1 Clip part 15 Lift plate drive mechanism 16a, 16b Bush 17a, 17b Guide rod 18 Connecting plate 19a, 19b Compression spring 20 Frame part 21a, 21b Rotation shaft 22a, 22b Plate cam 23 Cam drive mechanism 24a, 24b pulleys 25 Endless Belt 26 Motor 27a, 27b pulleys 28 Endless Belt 29 Paper Collection Area 30 Air blowing unit 31, 32 Conveyor roller pair 33 Paper Stand 34 Alignment board 35 Lifting mechanism 40 Contact plate (contact body) 40a tip 40b lower edge 42 Support plate 42a Top surface (contact surface) 44 Guide plate 44a Slope 44b Abutment part CL center line F Frame S Paper stack P1 First (lowest) sheet P1' Top sheet P2 Next paper P2' Next paper u (Upstream end of conveying surface) w Downstream end (of conveying surface)

Claims

1. 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.

2. 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.

3. 3. The paper feeder according to claim 2, wherein the plurality of conveyor belts and the plurality of lift plates are provided symmetrically with respect to a center in a width direction perpendicular to the paper feed direction.

4. 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.

5. 5. The paper feed device according to claim 4, further comprising a contact member for contacting a leading edge of the paper, the contact member being disposed upstream of the discharge roller in the paper feed direction.

6. 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.

7. 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.

8. 8. A paper feeder according to claim 6, further comprising a guide plate having an inclined portion for guiding the paper toward the tip of the contact member.

9. 9. 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 the contact body is elastically deformed toward the guide plate.

10. 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.

11. 6. The paper feeder according to claim 5, wherein at least one of the lift 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.

12. 12. The paper feeder according to claim 11, wherein the extension portion is detachable from the existing lift plate.

13. 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.

14. 13. A control program for a paper feeder for causing a computer to execute the control of the paper feeder according to claim 1.

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