JP2001187649A - Sheet feeding device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeding device separating and carrying sheets stuck together by static electricity or adhesion of liquid one by one. SOLUTION: This sheet feeding device 1 separating and carrying the uppermost sheet 2 from the stacked sheets is provided with (a) a suction part 12 sucking an adjacency to the tip of the uppermost sheet, (b) a drive means moving the suction part 12 so as not causing deviation between the uppermost sheet and the second sheet and separating, at least, the tip of the uppermost sheet from the second sheet, and (c) carrier rollers 44a, 44b carrying the uppermost sheet, at least, with its tip separated from the second sheet in a prescribed direction. The sheet feeding device 1 is also provided with an air blast means 42 separating an interval between the uppermost sheet, at least, with its tip separated therefrom and the second sheet to the rear end of the uppermost sheet. This means separates the uppermost sheet from the second sheet till its rear end simultaneously with or before carrying the uppermost sheet by the carrier rollers 44a, 44b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a sheet feeding apparatus and a sheet feeding method for separating and conveying stacked sheets one by one.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of resource reuse, copying machines,
2. Description of the Related Art Various apparatuses have been proposed for reproducing a sheet by removing a printing material (toner, ink, etc.) from a used sheet (copies, printed matter) on which an image is formed by an image forming apparatus such as a printer.

Such a sheet reproducing apparatus has a sheet feeding tray or cassette similar to that provided in a copying machine or the like, and sheets stacked on this tray are separated one by one by a sheet feeding mechanism. Supplied to

[0004]

The sheet that has passed through the image forming apparatus is charged due to the characteristics of the image forming apparatus. Further, in the color image forming apparatus, since the printing material is prevented from offsetting to the fixing roller by applying the oil to the fixing roller, the oil adheres to the sheet on which the image is formed. Further, in the case of an OHP sheet having high electric resistance and not absorbing oil, the adhesive force between the sheets in a state where the sheets are stacked is considerably large.

On the other hand, to separate the sheets stacked on the tray one by one, in a roller separation used in a normal copying machine or the like, the roller is brought into contact with the uppermost sheet and the roller is rotated. Then, friction occurs between the roller and the uppermost sheet, and the frictional force acts as a conveying force to convey the uppermost sheet. However, since this conveying force acts in a direction in which the sheets (the uppermost sheet and the second sheet) shift, it is difficult to separate and convey only one sheet having a large adhesive force between the sheets. It is. Also, in a system in which the uppermost sheet is sucked by using a negative pressure as generally used in printing, thereby separating and conveying only the uppermost sheet, the sheets are separated and conveyed by shifting the sheets. Therefore, it is difficult to separate and convey only one sheet when the adhesive force between the sheets is large.

It is conceivable to regenerate plain paper as a sheet. Plain paper has low electric resistance (it is difficult to be charged), and even if oil adheres, it is absorbed between the fibers, so that the amount of oil existing on the surface is very small, and the adhesive force between sheets is small. Furthermore, the air permeability differs between plain paper and OHP sheet (plain paper has higher air permeability).

[0007] Considering the convenience of the user, the user can store a plurality of types of sheets (including unused sheets) having different adhesive forces and air permeability between the sheets in the sheet feeding tray of the sheet reproducing apparatus. Advantageously, they can be stacked without separation.
Therefore, it is necessary to separate and convey these plural types of sheets under the same conditions.

Therefore, a first object of the present invention is to provide a static electricity
An object of the present invention is to provide a sheet feeding apparatus and a sheet feeding method that separates and conveys sheets adhered to each other by liquid adhesion one by one.

A second object of the present invention is to provide a sheet feeding apparatus and a method for separating and conveying a plurality of types of sheets having different adhesive forces and air permeability under the same conditions.

Although the sheet feeding apparatus according to the present invention is optimally used for a sheet reproducing apparatus, it has a feeding mechanism for separating and conveying one sheet at a time from a plurality of sheets stacked on a tray or the like. The present invention may be applied to any device such as a copying machine as long as it is a device.

[0011]

In order to achieve the above object, the present invention provides (a) suction means for sucking the vicinity of the leading end of the uppermost sheet, and (b) moving the suction means, whereby at least the uppermost sheet is moved. A driving unit for separating the leading end of the sheet from the second sheet; and (c) a conveying unit for conveying at least the uppermost sheet having the separated leading end in a predetermined direction, wherein the driving unit is configured to adsorb to the uppermost sheet. Provided is a sheet feeding device that moves the suction means so that the suction portion to be drawn draws a substantially cycloid curve.

Further, the sheet feeding apparatus according to the present invention further has a separating means for separating at least the uppermost sheet having the leading end separated from the second sheet to the trailing end of the uppermost sheet. The separating unit separates the uppermost sheet from the second sheet up to the trailing end at the same time as or before the uppermost sheet is conveyed by the conveying unit. This is to prevent the second and subsequent sheets from being conveyed and causing a jam due to the adhesive force of the non-separable portion between the uppermost sheet and the second sheet.

[0013] The suction means has a suction cup disposed so as to face the vicinity of the leading end of the uppermost sheet, and a negative pressure supply section for supplying a negative pressure to the suction cup. The suction cups are a plurality of suction cups arranged substantially parallel to the top end of the uppermost sheet. In addition, the shortest distance between the suction part by the suction cup and the tip of the uppermost sheet is 3
mm. This is to prevent a so-called double field in which two sheets are separated and conveyed at the same time when the suction position is apart from the leading end of the sheet.

[0014]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

I. 1. First Embodiment (1) Configuration of Sheet Feeding Apparatus FIGS. 1 and 2 show a side view and a top view, respectively, of a first embodiment of a sheet feeding apparatus according to the present invention. A tray or cassette 4, which is a rectangular container having a plurality of rectangular sheets 2 and open at the top, is removably mounted on the sheet supply device 1. The tray 4 is disposed on the left bottom of the tray 4 in FIG. Is connected to one end of a spring 6 (in the following description, the direction parallel to the long side of the rectangular tray 4 is the vertical direction, the direction parallel to the short side is the horizontal direction, and the direction perpendicular to both directions is the vertical direction). Direction.) The other end of the spring 6 is connected to a plate 8 arranged in the tray 4 and stacking the sheets 2, so that the sheets 2 are pushed upward together with the plates 8, and the opening of the tray 4 is shown in FIG. In FIG. 2, the distal ends are brought into contact with a pair of separation claws 10 (FIG. 2) provided at the upper left and lower left corners.

Referring to FIGS. 1A and 2, the tray 4
Above the opening, a plurality of suction portions 12 for sucking the sheet 2 are provided at predetermined intervals in the horizontal direction in the vicinity of the leading end of the sheet 2 (three in the present embodiment; Is not limited to this.) Each suction unit 12
Has a suction cup 14 made of, for example, rubber and having an opening (for example, a circular shape) facing the sheet 2, a suction pipe 16 connected to the suction cup 14, and a hose (not shown) connected to the suction pipe 16. This hose is connected to a vacuum pump to be described later. As a result, by operating the vacuum pump, the suction section 12 suctions the leading end of the sheet 2 by negative pressure.

As best shown in FIG. 3, which is an enlarged view of the suction section 12, the suction pipe 14 of the suction section 12 is fixed to a support member 18 extending in the lateral direction. One end of a moving member 20 extending in a direction substantially perpendicular to the sheet 2 while adsorbing the sheet 2 is fixed to each end of the support member 18. Each moving member 20 includes first and second circular cross-section projections 22a and 22b protruding outward in the lateral direction.
At one end and the other end, respectively. As shown in FIG. 4, the first and second projections 22a and 22b are respectively formed in guide grooves 26a and 26b provided on a first side plate 24 disposed outside and close to the moving member 20. It is designed to engage.

The guide grooves 26a and 26b have a width slightly larger than the diameters of the first and second projections 22a and 22b. At a position 20A (at this time, the first and second protrusions 22a and 22b are located at one ends of the guide grooves 26a and 26b) and at a predetermined angle in the clockwise direction in FIG. However, the present invention is not limited to this.) The second position 20B that has been rotated and translated by a predetermined distance (in this case, the first and second protrusions 22).
a and 22b are located at the other ends of the guide grooves 26a and 26b. ) Is set so that you can move between them. More specifically, the shape of the guide grooves 26a and 26b is
When 0 moves from the first position 20A to the second position 20B, the center of the suction area of the suction unit 12 by the suction cup 14 (hereinafter, referred to as a suction center; see FIG. 4) is indicated by a dotted line in FIG. It is set to draw a simple cycloid curve. Note that points other than the suction center (for example, the rear end side of the sheet in the suction area) may be set to draw a cycloid curve.

Referring again to FIGS. 1 and 2, a driving mechanism 30 for moving the moving member 20 is provided outside the upper first side plate 24 in FIG. Drive mechanism 30
A rack 32 extending in the vertical direction and capable of moving in the vertical direction; a support member (not shown) such as an Accuride rail for supporting the rack 32 for reciprocating the rack 32 in the vertical direction; A pinion (gear) 34 for engaging teeth formed on the upper surface of FIG.
4 connected to the motor 3 so that the motor 3
The rack 32 slides left and right in the vertical direction by the forward and reverse rotation of 6. On the left side of the rack 32 in the drawing, a guide member 38 is provided to extend vertically downward from the lower surface of the rack 32. The guide member 38 has a guide groove 40 (FIG. 1B) formed in a vertical direction. The guide groove 40 has a width slightly larger than the diameter of the second protrusion 22 b of the moving member 20. As a result, the protrusion 22b moves vertically along the guide groove 40 (relative to the guide member 38). As shown in FIG. 2, the length of the protrusion 22a of the moving member 20 is set to avoid interference with the guide member 38 extending downward from the rack 32.
It is shorter than the projection 22b.

As shown in FIG. 1, an air blowing means 42 is provided at the upper left of the separation claw 10, and the uppermost sheet 2 whose tip is turned up by the suction section 12 and the second sheet Air is blown between them.

Above the tray 4, one or more pairs of conveying rollers 44a and 44b are provided at predetermined intervals in the horizontal direction in order to convey the sheet 2 after the sheet tip is separated by the suction unit 12. (In the present embodiment, the number is two, but the present invention is not limited to this.) More specifically, the transport roller pairs 44a and 44b are arranged by pressing one outer peripheral surface against the other outer peripheral surface, and
2, the leading end of the sheet, which has been warped by about 90 degrees, is positioned near the contact portion (nip portion) of the pair of conveying rollers 44a and 44b.

As shown in FIG. 2, the conveying rollers 44a, 44
4b is fixed to the first and second shafts 46a and 46b, respectively. These first and second shafts 46a, 46b
Is a second side plate 4 arranged at a predetermined distance from each first side plate 24 in a region sandwiched between the two first side plates 24.
7 rotatably supported. Near the outer surface of the second side plate 47 above the first and second shafts, first and second gears 48a and 48b are provided.
8a and 48b are engaged with each other. One of the first and second gears 48a and 48b is connected to a motor (not shown), and the rotation of the motor causes the pair of transport rollers 44a and 44b to rotate simultaneously, thereby forming a contact portion between the rollers. The sheet 2 is conveyed to the downstream side via the sheet.

FIG. 5A shows a mechanism for supplying / releasing a negative pressure to the suction section 12. The three suction pipes 16 of the suction section 12 share a hose 54, and the hose 54
Is connected to a vacuum pump 56. A solenoid valve 58 and a chamber 60 are provided in the middle of the hose 54. The solenoid valve 58 is a three-way solenoid valve also connected to the exhaust pipe 62 connected to the atmosphere. The valve on the vacuum pump 56 side and the valve on the exhaust pipe 62 side of the solenoid valve 58 are appropriately opened and closed, so A negative pressure and an atmospheric pressure are supplied to 12. Although the electromagnetic valve 58 and the vacuum pump 56 may be directly connected without providing the chamber 60, it is preferable to provide the chamber 60 in consideration of the speed of forming the negative pressure.

(2) Feeding Operation of Sheet Feeding Apparatus Next, referring to FIGS.
Will be described.

Before starting the sheet feeding operation, FIG.
The vacuum pump 56 shown in (a) is operated, and the valve of the electromagnetic valve 58 is closed, thereby keeping the inside of the chamber 60 at a predetermined negative pressure.

Next, as shown in FIG.
5A in a state where the second suction cup 14 is close to the uppermost sheet 2 stacked in the tray 4 (the moving member 20 is located at the first position 20A).
(At this time, the valve on the exhaust pipe 62 side is closed). At this time, a negative pressure is instantaneously generated in the suction cup 14, and the suction cup 14 sucks the vicinity of the leading end of the uppermost sheet 2.

Subsequently, the gear 34 shown in FIG. 1A is rotated counterclockwise, thereby moving the rack 32 rightward in the vertical direction. At the same time, as shown in FIG. 4, the moving member 20 has the protrusion 22 a of the member 20
While engaging with the guide groove 26a provided in the
b moves to the second position 20B while engaging with another guide groove 26b provided on the first side plate 24 and the guide groove 40 of the guide member 38 fixed to the rack 32 [FIG.
(B)].

On the other hand, the leading end of the uppermost sheet 2 is
Is separated from the second sheet 2 while substantially drawing a cycloid curve by the suction roller, and the pair of transport rollers 44a, 44
4b. Here, assuming that the suction center coincides with the leading end of the uppermost sheet 2 in the cycloid curve (actually, the attracting center is located near the leading end of the sheet), the uppermost sheet 2 is the second sheet 2. Are separated from each other without any deviation from the
The curve drawn by the leading end of the uppermost sheet 2 when a force other than the suction force (for example, a bending force) does not act during the supply to the a and 44b. The separation claw 10 prevents the leading end of the second and subsequent sheets from moving together with the uppermost sheet 2.

Next, in the state shown in FIG.
Gears 48a, 48b (FIG. 2) are rotated (by rotating a motor connected to one of these gears). Immediately before the start of rotation, the three-way valve 5 shown in FIG.
8, the valve on the side of the vacuum pump 56 is closed and the exhaust pipe 62 is closed.
By opening the valve on the side, the atmospheric pressure is supplied to the suction unit 12 to release the suction force between the suction cup 14 and the sheet 2. As a result, the uppermost sheet 2 is on the opposite side (downstream in the sheet conveying direction) of the suction unit 12 with the conveying roller pairs 44a and 44b interposed therebetween by the rotation of the conveying roller pairs 44a and 44b connected to the gears 48a and 48b. Transported to At the same time as the conveyance of the sheet 2, air is blown between the uppermost sheet 2 and the second sheet 2 using the air blowing means 42 so that the space between the uppermost sheet 2 and the second sheet 2 is removed. It can be separated to the rear end.
This may be performed before the conveyance of the sheet 2. ).

The transport roller 4 extends to the rear end of the first sheet 2
After being conveyed by 4a and 44b, the suction portion 12 in the state of FIG. 1B is returned to the position of FIG. Prepare for conveyance of sheet 2.

(3) Effects and Modifications In the present embodiment, the entire sheet is separated by blowing air between the uppermost sheet 2 and the second sheet 2 by the air blowing means 42. The reason is that only the leading end of the uppermost sheet 2 is separated, and if the uppermost sheet 2 is transported by the transport rollers 44a and 44b without separating the entire sheet, the non-separable portion between the uppermost sheet and the second sheet is added. This is because the second and subsequent sheets are also conveyed due to the applied force and a jam occurs. In addition, instead of blowing air,
The sheets may be separated mechanically through a separating member.

Further, since the moving member 20 is provided outside the second side plate 47, the moving member 20 is moved to the first position 20.
Even if it moves between A and the second position 20B, it does not interfere with the shafts 46a and 46b of the transport roller pairs 44a and 44b. Therefore, the degree of freedom in design is increased, and the radius of curvature of the sheet 2 is reduced (for example, about 20 mm).
(Here, the radius of curvature of the sheet 2 refers to the time when the tip of the sheet 2 draws a substantially cycloid curve and the sheet 2 is in the state of FIG. 2B. Of the sheet curve.)

FIG. 5 for supplying a negative pressure / atmospheric pressure to the suction section 12
In the mechanism (a), since the valve on the vacuum pump 56 side of the electromagnetic valve 58 is kept open to attract the sheet 2, the negative pressure in the chamber 60 decreases with the opening of the electromagnetic valve 58. Therefore, in order to adsorb the next sheet 2, it is necessary to operate the vacuum pump 56 every time to set the negative pressure in the chamber 60 to a predetermined value. Therefore, as shown in FIG. 5B, another (two-way) solenoid valve 64 is provided between the solenoid valve 58 and the chamber 60, and the solenoid valve 58 is opened in a state where the solenoid valve 64 is opened. It is preferable to close the solenoid valve 64 (preferably immediately after) to prevent the negative pressure of the chamber 60 from decreasing. In such a configuration,
It is not necessary to operate the vacuum pump 56 for each suction, and therefore, the speed of suction and conveyance of the sheet 2 can be increased. Further, the operating time and the number of times of the vacuum pump 56 are reduced, which is advantageous in terms of the life of the pump.

Further, it is preferable that the suction position by the suction section 12 near the sheet front end is as close as possible to the sheet front end. The reason is that if the suction position is far from the leading edge of the sheet, there is a possibility that a so-called double field, in which two sheets are separated and conveyed at the same time, may occur. If the leading edge of the sheet and the suction position are sufficiently close, the separating force acts on the leading edge of the sheet, and the sheet is easily separated, and as a result, double field does not occur.

(Experiment) The negative pressure supplied to the adsorption section 12 was set to about 5
3 kPa, three suction parts 12, diameter L _{1 of} suction cup 14 8 m
m, the separation curvature radius of the sheet 2 is 20 mm, the vertical length L ₂ and the horizontal length L ₃ of the separation claw 10 are 6 mm and 3 m, respectively.
m, the distance from the sheet end surface of the suction sections 12 on both sides is 26 m
m, and the sheet 2 is an A4 OHP sheet to which silicone oil (fixing oil) is attached, plain paper, and the shortest distance L ₄ from the sheet front end to the adsorbed sheet portion.
And the uppermost sheet 2 was separated (see FIGS. 2 and 3 for L _{1 to} L ₄ ).

The experimental results are shown in the following table.

As shown in the above table, the sheet tip and the suction cup 1
When the distance L _{4 from the} front end side of No. ₄ was 3 mm or less, the separability was good, but when it was 5 mm, a double field occurred. From this, it was found that the distance between the leading end of the sheet and the leading end side of the suction cup 14 was preferably within 3 mm.

Note that, as shown in FIG.
4a and 44b and the suction section 12 are arranged to be shifted from each other in the lateral direction, so that the rollers 44a and 44b and the suction section 1 are displaced.
Therefore, in the configuration of the present invention in which the suction unit 12 suctions the sheet 2 near the sheet front end, it is easy to convey the sheet front end to the nip portion of the conveying roller pair 44a, 44b.

When the leading end of the uppermost sheet 2 is moved to the nip portion of the pair of conveying rollers 44a and 44b by the suction section 12, the sheet 2 comes into contact with one of the conveying rollers 44a and 44b first. Therefore, in some cases, the leading end of the sheet may bend by hitting the transport roller, and the sheet 2 may not be transferred to the transport roller pair 44a, 44b. Therefore, the transport rollers 44a,
It is better to rotate the transfer roller 44b.
The sheet leading end contacting the sheet can be more smoothly conveyed to the nip portion. Instead, by increasing the suction force (negative pressure) for sucking the vicinity of the sheet front end relatively, the sheet 2
It is also possible to ensure stability when the sheet comes into contact with the conveying rollers 44a or 44b (however, if the negative pressure is increased, a sheet having a high air permeability such as plain paper will not reach the second sheet). Negative pressure is apt to cause double field, so there is a limit to the size of negative pressure for suction.)

Further, instead of the transport roller pair 44a,
As shown in FIG. 6, when the sheet 2 is separated by the suction unit 12 by using the half-moon-shaped conveyance roller 66,
The sheet 2 can be brought into contact with the transport roller 44b without contacting the roller 66. However, since the sheet conveyance amount per one rotation of the half-moon roller 66 is small, another conveyance roller pair 68a, 68b is provided immediately downstream of the half-moon roller 66 and the conveyance roller 44b.

In such a configuration, the half moon roller 66
As shown in FIG. 6, the printer 1 waits in a state where the pressure contact with the transport roller 44b is released, and rotates after the leading end of the uppermost sheet 2 separated by the suction unit 12 comes into contact with the transport roller 44b. The half-moon roller 66 stops after one rotation. At this point, the sheet has its leading end convey roller pair 68a,
68b, and the transport roller pair 68
It is further conveyed further downstream by the rotation of a and 68b.

Further, as shown in FIG.
The lower side of the supporting member 18 supporting the second suction tube 16 (when the moving member 20 moves from the first position 20A [FIG. 1 (a)] to the second position 20B [FIG. 1 (b)], 2 (a side facing 2), a curvature regulating member 70 (FIG. 7) extending in the lateral direction may be attached. The curvature of the outer surface of the curvature regulating member 70 that comes into contact with the sheet 2 is set uniformly in the lateral direction so that the leading end of the sheet draws a substantially cycloidal curve and separates. Stable sheet separation is possible without bending. Further, during conveyance by the conveyance roller pairs 44a and 44b, the sheet 2 is supplied to the nip portion along the curvature regulating member 70, so that the curvature of the sheet 2 changes and the suction cup 14 is worn by the sheet 2. In addition, it is possible to prevent the sheet 2 from being damaged.

II. 2. Second Embodiment (1) Configuration of Sheet Feeding Apparatus FIGS. 8 and 9 show a side view and a top view of a sheet feeding apparatus according to a second embodiment of the present invention, respectively. The sheet feeding device 80 of the present embodiment retracts the conveying roller pairs 44a and 44b when the sheet leading end is separated by the suction unit 12, and after the sheet leading end separation by the suction unit 12, ends the conveying roller pairs 44a and 44b. Is moved so that the nip portion comes to the front end of the sheet. Other members and configurations are the same as in the first embodiment, and will not be described here.

As shown in FIG. 9, the two first side plates 24
The first and second gears 48a and 48b fixed to the first and second shafts 46a and 46b and the tray 4
A first position 82A shown in FIG. 8A (the conveying roller pair 44a, 44b is at a position retracted above the suction unit 12) between the side wall (extending in the vertical direction) and FIG.
The second position 82B shown in FIG.
44b, the nip portion is located at the front end of the sheet. ) Is provided. The side plate 82
The first and second shafts 46a and 46b are rotatably supported. The side plate 82 also rotatably supports a third shaft 84 extending in the lateral direction at a predetermined distance from the second shaft 46b. The third shaft 84 is rotatably supported by the first side plate 24, and serves as a rotation center of the side plate 82 as described later. Third shaft 84 is also connected to motor 85.

A first pulley 86 is fixed to the second shaft 46b outside the second gear 48b. Third axis 8
4, a second pulley 88 is fixed at a position facing the first pulley 86, and a belt 90 is suspended by these pulleys 86, 88. More specifically, FIG.
As shown in (a), when the side plate 82 is located at the first position 82A, the belt 90 is arranged substantially in parallel in the vertical direction,
When the side plate 82 is located at the second position 82B as shown in FIG.
It is arranged so as to form a downward gradient in the direction toward 6.

The right side surface 92 in the vertical direction of the side plate 82 has a circular shape, and a gear corresponding to a rack is cut. Further, a pinion which is opposed to the side surface 92 and engages with the gear.
(Gear) 94 is provided. A shaft 96 for driving the gear 94 is rotatably supported by the first side plate 24,
It is connected to a motor 98.

(2) Movement of transport roller and supply operation by transport roller Next, an operation for moving the side plate 82 and the transport roller pair 44a, 44b and an operation for rotating the transport roller pair 44a, 44b are described. explain. In addition, the top sheet 2
The operation of separating the leading end portion is the same as the operation described in the first embodiment, and will not be described here.

First, the gear 98 is rotated clockwise by driving the motor 98 from the retracted state shown in FIG. 8A. At this time, the side plate 82 rotates counterclockwise about the third shaft 84 while the gear provided on the side surface 92 and the gear 94 are engaged. Transport roller pair 44
a and 44b move from the retracted position to a position where the nip portion is arranged at the leading end of the sheet in conjunction with the movement of the side plate 92.
[FIG. 8 (b)].

By rotating the motor 85 (FIG. 9) from the state shown in FIG. 8B, the second pulley 88 is rotated clockwise. This rotational force is applied to the belt 90, the first
Of the pulley 86 and the second shaft 46b in this order.
The power is transmitted to the first shaft 46a via the gears 48a and 48b. As a result, the transport rollers 44a and 44b rotate, and transport the sheet 2 to the downstream side.

Conveying roller pair 44 up to the rear end of uppermost sheet 2
The motor 85 is stopped at the time when the sheet is conveyed by a and 44b. Next, by reversely rotating the motor 98 this time,
The gear 94 rotates counterclockwise, and the side plate 92
The position 82B shown in FIG. 8A from the position 82B shown in FIG.
Retreat to A and prepare for the next suction operation.

In order to speed up the separation and conveyance of the sheet 2, it is preferable to move the pair of conveyance rollers 44a and 44b in conjunction with the operation of separating the leading end of the sheet by the suction unit 12.

III. 3. Third Embodiment (1) Configuration of Sheet Feeding Apparatus FIGS. 10 and 11 show a side view and a top view of a sheet feeding apparatus according to a third embodiment of the present invention, respectively. In the sheet feeding apparatus 100 of the present embodiment, two motors are used so that the suction center of the suction section 12 of the suction cup 14 draws a cycloid curve. It should be noted that a transport roller for transporting the uppermost sheet 2 whose leading end is separated is omitted in the figure for easy viewing.

More specifically, as shown in FIG. 11, the support member 18 supporting the suction section 12 is supported by a first shaft 102. The shaft 102 is rotatably supported by a rectangular side plate 104 extending in the vertical direction in the vicinity of both ends thereof, and serves as a rotation center of the suction unit 12 as described later. The side plate 104 is the first plate shown in FIG.
(In this state, the vicinity of the leading end of the sheet 2 is sucked by the suction unit 12) and the first position 104A.
FIG. 10 (b) that has been translated rightward in the vertical direction by a predetermined distance from
A second position 104B (at this point, the separation of the leading edge of the sheet is completed, and the sheet is subsequently delivered to a not-shown transport roller) is used to support the side plate 104. And the like can be reciprocated along a supporting member (not shown). FIG.
, A member 105 is provided between the upper and lower side plates 104 to maintain a space between the side plates 104. The upper side plate 104 rotatably supports a second shaft 106 extending in the lateral direction at a predetermined interval from the first shaft 102. The second shaft 106 is connected to a motor 108.

The first shaft 102 further has a first pulley 110 between the upper side plate 104 and the lateral end of the support member 18 in FIG. A second pulley 112 is fixed to the second shaft 106 at a position facing the first pulley 110, and these pulleys 110, 11
2, the belt 114 is suspended.

The upper side plate 104 is also provided with the lower side plate 10.
A third shaft 116 extending in the lateral direction up to 4 and a fourth shaft 118 provided in parallel with the third shaft 116 and at a predetermined interval from the third shaft 116 are rotatably supported. I do.
The third shaft 116 has a first gear 120 between the inner surface of each side plate 104 and the outer surface of the tray 4 extending in the vertical direction. A second gear 122 that is engaged with the first gear 120 on the right side and has an outer diameter smaller than that of the first gear 120 is fixed to the fourth shaft 118.
24 are connected.

Near the outer surface of the tray 4 extending in the vertical direction, a frame 124 is provided at least in a region close to the first gear 120. A vertically extending rack 126 is fixed to the frame 124 for engaging with the upper portion of the first gear 120 in FIG.

(2) Sheet Separation Operation of Sheet Leading Device Next, the separation operation of the leading end of the uppermost sheet 2 by the suction unit 12 will be described.

First, as described in the first embodiment,
The suction section 12 suctions the vicinity of the leading end of the uppermost sheet 2 [FIG. 10 (a)].

Next, by rotating the motor 108, the second pulley 112 is rotated clockwise in FIG. This rotational force is transmitted to the first shaft 102 via the belt 114 and the first pulley 106, and as a result, the suction unit 12 rotates clockwise about the first shaft 102.

At the same time, the motor 124 is rotated to rotate the second gear 122 clockwise. As a result, the first gear 120 rotates counterclockwise and engages with the rack 126 of the frame 124 while the side plate 10 is rotated.
4 moves to the right in the vertical direction. The suction unit 12 also
It moves parallel to the right side in the vertical direction in conjunction with the side plate 104 [FIG.
0 (b)].

In this embodiment, the rotation and the parallel movement of the suction unit 12 are simultaneously performed by simultaneously rotating the motors 108 and 124. Furthermore, the length of the arc drawn by the suction center (see FIG. 4) with respect to the first axis 102 is set to be equal to the distance that the suction unit 12 moves to the right in the vertical direction. The locus drawn by the adsorption center is a cycloid curve.

Subsequently, the first sheet 2 is conveyed to the rear end by a conveying roller (not shown). Finally, by reversely rotating the motors 108 and 124, the motor shown in FIG.
Is returned to the position shown in FIG. 10A and prepares for the conveyance of the second sheet 2.

IV. 4. Fourth Embodiment (1) Configuration of Sheet Feeding Apparatus FIGS. 12 and 13 are a side view and a top view, respectively, of a sheet feeding apparatus according to a fourth embodiment of the present invention. In the sheet feeding apparatus 130 of the present embodiment, the suction center draws a cycloid curve by using one motor. It should be noted that a transport roller for transporting the uppermost sheet 2 whose tip is separated is omitted in the figure for easy viewing.

As shown in FIG. 13, a support member 132 having a rectangular cross section for supporting the suction tube 16 of the suction section 12 has both ends fixed to a first gear 134. This fixing method may be any method. For example, when the first gear 134 is formed by plastic molding or the like, grooves for fitting both ends of the support member 132 are previously formed in the first gear 1.
34.

A first shaft 136 extending in the horizontal direction is fixed to each of the first gears 134. The shaft 136 is rotatably mounted on a rectangular side plate 138 extending in the vertical direction in the vicinity of its end. Supported. The side plate 138 is shown in FIG.
(In this state, the vicinity of the leading end of the sheet 2 is sucked by the suction unit 12) and the first position 138A shown in FIG. 12B that has been moved to the right in the vertical direction by a predetermined distance from the first position 138A. (For example, an Accuride rail) for supporting the side plate 138 between a second position 138B (at this point, the separation of the leading end of the sheet is completed, and the sheet is subsequently delivered to a transport roller (not shown)). It can be moved along a support member (not shown) such as.
In FIG. 13, between the upper and lower side plates 138,
A member 140 is provided for maintaining the distance between the side plates 138. Each side plate 138 rotatably supports a second shaft 142 that extends at a predetermined distance from the first shaft 136 and extends laterally upward and to the right of the first shaft 136 in FIG. The second shaft 142 has the first gear 134 shown in FIG.
The second gear 146 that engages with the upper right part is fixed. A motor 144 is connected to the upper second shaft 142 in FIG.

Near the outer surface of the tray 4 extending in the vertical direction, a frame 148 is provided at least in a region close to the second gear 146. Fixed to the frame 148 is a vertically extending rack 150 for engaging the upper portion of the second gear 146 in FIG.

(2) Separating Operation of Sheet Leading Edge of Sheet Feeding Apparatus Next, the separating operation of the leading end of the uppermost sheet 2 by the suction unit 12 will be described.

First, as described in the first embodiment,
The vicinity of the leading end of the uppermost sheet 2 is suctioned by the suction unit 12 (FIG. 12A).

Next, the motor 144 is rotated to rotate the second gear 146 counterclockwise in FIG.
As a result, the second gear 146 moves to the right in the vertical direction together with the side plate 138 while engaging with the rack 150 of the frame 148. The suction unit 12 also moves in the vertical direction to the right in conjunction with the side plate 138. On the other hand, the first gear 134
Rotates clockwise, thereby causing the suction section 12 to rotate.
Rotates clockwise about a first axis 136.

In the present embodiment, the rotation and the parallel movement of the suction unit 12 are simultaneously performed by rotating the motor 144. In addition, as shown in FIG.
Is the center line (this line passes through the adsorption center).
And is fixed to the support member 132 such that the distance between the suction center and the first shaft 136 is substantially equal to the outer diameter of the first gear 134. Further, the first gear 134 and the second gear 146 have the same number of teeth. As a result, the length of the arc drawn by the suction center with respect to the first axis 136 is equal to the distance that the suction unit 12 moves to the right in the vertical direction, and the locus drawn by the suction center is a cycloid curve. .

Subsequently, the first sheet 2 is conveyed to the rear end by a conveying roller (not shown). Finally, by reversely rotating the motor 144, the suction unit 12 in the state of FIG. 12B returns to the position of FIG. 12A and prepares for the conveyance of the second sheet 2.

Note that, without providing the second gear 146, the first gear
The motor is directly connected to the shaft 136 of the first gear 134, and the rack 150 is arranged to engage with the lower portion of the first gear 134.
By rotating the gear 134 clockwise, the suction center can be moved so as to draw a cycloid curve. However, there are restrictions on the configuration such as the direction in which the tray 4 is taken out of the sheet feeding device is limited. Specifically, with respect to the frame 148 shown in FIGS. 11 and 12, the tray 4 can be pulled out in either the vertical direction or the horizontal direction.
In the configuration arranged below 4, the tray 4 can be pulled out only in the vertical direction.

[0073]

According to the sheet feeding apparatus and method according to the present invention, first, the leading end portion of the uppermost sheet is separated from the second sheet without displacement, and then the uppermost sheet is conveyed. Therefore, it is possible to separate the sheets adhered to each other due to the adhesion of static electricity and liquid.

Further, under the same condition (a negative pressure as low as not to generate double fields) as a sheet having a high air permeability (for example, plain paper), sheets having a large adhesive force (for example, OHP) can be separated from each other.

[Brief description of the drawings]

FIG. 1A is a side view showing a state in which separation (adsorption) of a leading end of an uppermost sheet is started in a sheet feeding apparatus according to a first embodiment of the present invention. FIG. 4B is a side view illustrating a state where the leading end of the uppermost sheet has been separated in the first embodiment of the sheet feeding apparatus according to the invention.

FIG. 2 is a top view of the sheet feeding device in the state of FIG. 1B (the top sheet is omitted).

FIG. 3 is a partially enlarged side view of the suction unit in the state of FIG.

FIG. 4 illustrates a first side plate provided with a guide groove for moving a suction unit (and a moving member) used in the first embodiment of the sheet feeding apparatus between a separation start position and a separation end position. FIG.

FIG. 5A is a diagram illustrating a mechanism for supplying a negative pressure and an atmospheric pressure to an adsorption unit. (B) Modified example of FIG.

FIG. 6 is a side view showing another embodiment of the transport roller.

FIG. 7 is a side view showing another embodiment of the suction unit.

FIG. 8A is a side view illustrating a retracted position of a pair of conveying rollers in the second embodiment of the sheet feeding apparatus according to the invention. (B) A side view showing a sheet conveying position of a conveying roller pair in the second embodiment of the sheet feeding device according to the present invention.

FIG. 9 is a top view of the sheet feeding device in the state of FIG. 8B.

FIG. 10A shows a third example of the sheet feeding apparatus according to the present invention.
In the embodiment, the leading end of the uppermost sheet is separated (adsorbed).
The side view which shows a starting state. (B) A side view showing a state in which the leading end of the uppermost sheet has been separated in the third embodiment of the sheet feeding apparatus according to the present invention.

FIG. 11 is a top view of the sheet feeding apparatus in the state shown in FIG.

FIG. 12A shows a fourth example of the sheet feeding apparatus according to the present invention.
In the embodiment, the leading end of the uppermost sheet is separated (adsorbed).
The side view which shows a starting state. (B) A side view showing a state where the leading end of the uppermost sheet has been separated in the fourth embodiment of the sheet feeding apparatus according to the present invention.

FIG. 13 is a top view of the sheet feeding apparatus in the state of FIG.

[Explanation of symbols]

1: sheet feeding device, 2: sheet, 4: tray, 12:
Suction unit, 14: suction cup, 18: support member, 20: moving member, 32: rack, 34: pinion (gear), 42: air blowing means, 44: transport roller, 48: gear, 54:
Hose, 58: solenoid valve, 60: chamber.

Claims (7)

[Claims] 1. A sheet feeding apparatus for separating and conveying a top sheet from a stacked sheet, comprising:
Suction means for suctioning the vicinity of the top end of the uppermost sheet; (b)
A driving unit that moves the suction unit to separate at least the top end of the top sheet from the second sheet; and (c) a conveyance unit that conveys the top sheet with at least the top end separated in a predetermined direction. A sheet feeding device, wherein the driving means moves the suction means such that a suction portion adsorbed on the uppermost sheet draws a substantially cycloidal curve. 2. A sheet feeding apparatus for separating and conveying an uppermost sheet from a stacked sheet, comprising:
Suction means for suctioning the vicinity of the top end of the uppermost sheet; (b)
Driving means for moving the suction means, thereby separating at least the top end of the top sheet from the second sheet; (c) conveyance means for conveying at least the top sheet having the top end separated in a predetermined direction; (D) separating means for separating at least the top sheet from which the leading end has been separated and the second sheet to the rear end of the top sheet, wherein the separating means conveys the top sheet by the conveying means At the same time as or before transport
A sheet feeding device for separating a sheet from a first sheet. 3. The sheet according to claim 1, wherein said suction means includes a suction cup disposed so as to be opposed to the vicinity of the leading end of the uppermost sheet, and a negative pressure supply section for supplying a negative pressure to said suction cup. Feeding device. 4. The sheet feeding apparatus according to claim 3, wherein the suction cups are a plurality of suction cups arranged substantially in parallel with a front end of the uppermost sheet. 5. The sheet feeding apparatus according to claim 3, wherein a shortest distance between a suction portion of the suction cup and a tip of the uppermost sheet is within 3 mm. 6. A sheet feeding method for separating and conveying the uppermost sheet from the stacked sheets, wherein (a)
(B) moving the suction means so as to separate at least the top end of the uppermost sheet from the second sheet, and (c) step (b). A) transporting the uppermost sheet having at least the leading end separated in a predetermined direction, wherein in step (b), the suction portion of the uppermost sheet draws a substantially cycloidal curve. 7. A sheet feeding method for separating and conveying an uppermost sheet from a stacked sheet, wherein (a)
(B) moving the suction means so as to separate at least the top end of the uppermost sheet from the second sheet, and (c) step (b). A) transporting the uppermost sheet having at least the leading end separated in a predetermined direction;
(D) simultaneously with the step (c) or before the step (c), a step of separating at least the top sheet from which the leading end is separated and the second sheet to the rear end of the top sheet. A sheet supply method comprising: