JPH026165A - Automatic paper feeder - Google Patents

Abstract

PURPOSE:To reduce a frictional force between first paper and second paper to prevent a double-paper feeding by a method wherein a paper reaching signal to be sent to a printer-side paper feed mechanism is inputted to a control circuit, and the control circuit sends an operation command to an actuator to separate a friction pad from the paper. CONSTITUTION:When a leading end of paper 21 is gripped by feed rollers 65 of a printer 64, a detection signal is outputted to a control circuit 66. In this manner, an electric conduction to a solenoid 59 is brought to a stop, and an electromagnetic plunger 42 is magnetized. Therefore, a friction pad 51 is turned rightward about a rotating shaft 57, and the friction pad 51 is separated from a paper supply roller 31. Namely, a gap (l) is obtained. On the other hand, the paper supply roller 31 is raised upward from the paper surface to establish a gap (g) by the magnetization of the electromagnetic plunger 42. In this manner, the paper 21 is payed out from a paper stacking part by the paper feed rollers 65, thus going ahead along the paper supply roller 31. At this time, the paper supply roller 31 is rotated simultaneously, but the gaps (l) and (g) almost eliminate the frictional force between the paper 21 and paper 22. Therefore, the paper 22 remains in the paper stacking part, which prevents a double-paper feeding action.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an automatic paper feeding device applied to laser printers and other page links, and in particular, the present invention relates to an automatic paper feeding device that is applied to laser printers and other page links, and in particular, the present invention relates to an automatic paper feeding device that is applied to laser printers and other page links, and in particular, the present invention relates to an automatic paper feeding device that is applied to laser printers and other page links. The present invention relates to an automatic paper feeder that separates and feeds sheets.

[Conventional technology]

Razor printers and other page printers employ automatic paper feeding devices of a friction separation paper feeding type that have a relatively simple structure.

FIGS. 10 and 11 are side views of main parts of a conventional automatic paper feeder.

In the figure, ■ is an elevating table on which a large number of sheets 2 of various sizes such as A4 and 84 are stacked, and this elevating table l is supported by a vertical guide member 3 so as to be movable up and down. Reference numeral 4 denotes a rope for raising and lowering the lifting platform 1. Its lower end is connected to the lifting platform 1, and the other end is wrapped around a fixed pulley 5 attached to the upper end of the guide member 3, and is composed of a hoisting drum (not shown) or the like. It is connected to a hoisting drive mechanism. Reference numeral 6 denotes a paper feed roller located above the guide member 3 and arranged horizontally.
, a one-way clutch 8 is attached to the drive shaft 7 that rotates in the six directions of arrows.
It is attached via. Reference numeral 9 denotes a friction pad disposed along the outer periphery of the paper feed roller 6, which is made of cork, rubber, or the like having a friction coefficient smaller than the surface friction coefficient of the paper feed roller 6.

In the conventional automatic paper feeder configured as described above,
When feeding sheets of paper 2 on the lifting platform 1 to a printer (not shown), raise the lifting platform 1 and hold the stacked paper so that the upper end of the stack is pressed against the lower surface of the paper feed roller 6. .

In this state, when the drive device (not shown) is started in response to a paper feed command and the drive shaft 7 is rotated in the six directions of arrows in FIG.
Paper feed roller 6 coupled via one-way clutch 8 also rotates in the same direction. Along with this, the uppermost paper 2I of the stacked paper 2 pressed against the paper feed roller 6 is transferred in the direction of arrow B by the frictional force with the paper feed roller 6, and is inserted between the paper feed roller 6 and the friction pad 9. It will be done. Here, if the friction coefficient between the paper feed roller 6 and the laminated paper 2 is μm, the friction coefficient between the sheets is μ2, and the friction coefficient between the laminated paper 2 and the friction pad 9 is μm, then the distance between them is μm>
μ.

Because of the relationship 〉μ2, even if paper 2. Even if two sheets of paper 21 and 22 are fed in overlapped, the space between paper 21 and 2□ will slip,
The lower paper 2□ is prevented from advancing by the friction pad 9, and only the upper paper 2I is separated and sent out to the delivery side of the paper feed roller 6. In this way,
The separated paper 2I is sent to the printer from the delivery opening 10 as the paper feed roller 6 rotates, and the paper 21 sent to the printer is passed through the paper feed roller 1 on the printer side.
1, it is sent to the printing section and printed sequentially.

Note that when the paper 21 is fed to the paper feed roller on the printer side, the rotation of the paper feed roller 6 is stopped.

[Problem that the invention attempts to solve]

In the conventional automatic paper feeding device as described above, the paper feeding roller 6 is always connected to the stacked paper 2 on the lifting table l and the friction pad 9.
Because the paper is placed in contact with a predetermined pressure, if the outside air humidity increases and the friction coefficient of the paper changes or the paper's M (rigidity) becomes weak, the In the case of a printer that prints at high speed, paper 2. is fed into the print section at a relatively high speed by the paper feed roller on the printer side. The next sheet 2 □, which is being fed into the friction pad 9 in a state where it partially overlaps with the paper 2 , passes between the paper feed roller 6 and the friction pad 9 without being blocked by the friction pad 9. For this reason,
As shown in FIG. There was a problem in that the trailing edge and the front edge of the paper 2□ overlapped in a continuous state, resulting in double feeding of the paper.

In order to avoid this phenomenon, if the pressure force between the friction pad 9 and the paper feed roller 6 is increased, the driving force of the paper feed roller 11 on the printer side must be increased.

The present invention has been made in order to solve the above-mentioned problems, and its purpose is to ensure separate feeding of paper, prevent double feeding of paper, and provide driving force for the paper feed roller on the printer side. The present invention provides an automatic paper feeding device that can keep the paper size small.

[Means to solve the problem]

In order to achieve the above object, the automatic paper feeder of the present invention has the following features:
a lifting table that is supported in a vertically movable manner within the main body of the paper feeder and stacks sheets of paper; a paper feeding roller that is disposed on the paper take-out side of the lifting table so as to be in contact with and separate from the paper and is rotationally driven by a motor;
a friction pad that is arranged along a part of the outer circumference of the paper feed roller and separates sheets of paper from the elevator platform by rotation of the paper feed roller; and an actuator that moves the friction pad toward and away from the feed roller; and a control circuit that controls the actuator to separate the friction pad from the paper based on a command signal that detects that a predetermined amount of paper has been fed by the paper feed roller.

The paper feed roller can be fixed to the main body of the paper feeder.

In addition, a roller actuator is connected to the paper feed roller to move it toward and away from the paper being fed, and a command signal is also connected to the paper feed roller to detect that a predetermined amount of paper has been fed by the paper feed roller. Based on this, it is possible to include a control circuit that controls the roller actuator to move the friction pad away from the paper and to move it away from the paper.

Furthermore, a lifting table is supported in a vertically movable manner within the paper feeder main body and stacks sheets of paper, and a paper feeding roller is provided on the paper take-out side of the lifting table so as to be in contact with and separate from the paper and is rotationally driven by a motor. The automatic automatic machine is equipped with a friction pad that is arranged along a part of the outer circumference of this paper feed roller and separates sheets of paper from the elevator platform by rotation of the paper feed roller, and a friction pad that is stretched between two pad support parts. A paper feeding device can also be configured.

[For production]

In the present invention, when the paper arrival signal to the paper feed mechanism on the printer side is input to the control circuit, the control circuit gives an operation command to the actuator to separate the friction pad from the paper. The frictional force between the sheets of paper is significantly reduced, thereby preventing double feeding of sheets into the printer.

〔Example] Embodiments of the present invention will be described below with reference to the drawings.

1 to 8 show the contents of an automatic paper feeder according to an embodiment of the present invention.

In FIGS. 1 and 2, reference numeral 20 denotes a box-shaped paper feeder main body, and at both left and right ends of the main body 20 there are guide plates that also serve as partitions and are passed between the bottom plate 20a and the top plate 20b of the main body 20. 21 and 22 are erected. Both ends of the lifting platform 23 are supported by the guide plates 21 and 22 so that they can move up and down horizontally, and on the lifting platform 23 are B4. A large number of sheets of paper 2, such as A4 size sheets, are stacked one on top of the other with one end in contact with a guide plate 22.

24a, 24b, 24c, and 24d are ropes for horizontally raising and lowering the lifting platform 23, and each of these ropes 24a to 24d
One end of the guide plate 24d is connected to a square portion of the elevator platform 23 projecting outward from the guide plate 21.22, and the other end is connected to a fixed pulley 25a fixed to the upper end of the guide plate 21.22.
25b, 25c.

After being wrapped around 25d, the robe 24 of the guide plate 21
a and 24b are fixed pulleys 26a attached to the bottom plate 20a
, 26b and 27a, 27b into the machine room 28 on the guide plate 22 side, and is wound around a drum 29 provided coaxially within the machine room 28. Further, the lobes 24c and 24d on the guide plate 22 side are wound around the drum 29 via fixed pulleys 30a and 30b attached to the bottom plate 20a. These drums 29 are connected to a drive motor M via gears (not shown).

As shown in FIGS. 1 to 5, a paper feed roller 31 is located at the upper end of the guide plate 22 and is arranged parallel to the paper 2 on the lift table 23. It is fixed concentrically to a movable shaft 32 arranged parallel to the paper 2 above, and both ends of the movable shaft 32 are connected to support arms 33a,
The support arm 33 is rotatably supported on the tip of the support arm 33b.
a and 33b are rotatably supported by a bracket 34 disposed at the upper end of the machine room 28.

As shown in FIG. 3, one support arm 33a of the movable shaft 32 is formed into an L-shape, and its bent corner is rotatably attached to the bracket 34. Between the gear 35 coaxially attached to the pivot portion of the support arm 33a and the gear 37 fixed to the movable shaft 32 of the paper feed roller 31, there is an intermediate gear 38 attached to the horizontal portion of the support arm 33a.
A pulse motor 39 for driving a paper feed roller is attached to the bracket 34. A drive gear 40 fixed to the rotating shaft of the pulse motor 39 is meshed with an intermediate gear 41 attached to a bracket 34, and the intermediate gear 41 is meshed with the gear 35. Therefore, gears 41.35 and 38.37 are
A gear train is configured to transmit the rotation of the pulse motor 39 to the paper feed roller 31.

Further, at the tip of the vertical portion 33a1 of the support arm 33a,
A movable rod 42a of an electromagnetic plunger (roller actuator) 42 fixed to the bracket 34 is connected.

The friction pad mounting means and drive mechanism will be explained with reference to FIGS. 4 to 6.

In the figure, 51 is the paper feed roller 3 on the opposite side of the lifting platform 23.
A friction pad arranged along the outer periphery of the paper feed roller 31 is made of a corrugated rubber material or the like with a friction coefficient smaller than the surface friction coefficient of the paper feed roller 31, and is used to lift sheets of paper from the elevator table 23 by the rotation of the paper feed roller 31. Separate the leaves.

Reference numeral 52 denotes a pad frame having a U-shaped cross section, and this pad frame 52 has a pad support portion consisting of an upper shaft 53, a pad support portion consisting of a lower shaft 54, and a plate-shaped support bracket 55. has been done. One end of the friction pad 51 is fixed to a support bracket 55, and the upper shaft 53. Lower shaft 54
The other end of the coil spring 56 is hooked onto one end of the coil spring 56, and the other end of the coil spring 56 is supported by the other end of the support bracket 55. Therefore, the friction pad 51, the support bracket 55, and the coil spring 56 form a triangular shape.

The lower end of the pad frame 52 is attached to a solenoid (actuator) 59 via a rotating arm 58 that rotates about a rotating shaft 57 fixed to a support member 60.

Then, when the solenoid 59 is energized, the rotating arm 5
8 is pulled to the right side, the pad frame 52 rotates to the left around the rotation axis 57, and the friction pad 5
1 is pressed by the paper feed roller 31. At this time, the coil spring 56 at one end of the friction pad 51 is expanded by the pressing force, and the friction pad 51 extends over a relatively long range a along the outer periphery of the paper feed roller 31.
A contact length of is obtained.

Further, in FIGS. 1 and 2, 61 is a microswitch that detects the presence or absence of paper on the lifting table 23, and 62 is a microswitch that detects the presence or absence of paper on the lifting table 23.
This is a microswitch that detects the rising end position of the paper 2 on the top of the paper 2.
As the paper 2 on the elevating table 23 is fed by the paper feed roller 31, the elevating table 23 is raised, and the laminated paper 2 is held at a level with the paper feed roller 31 by a predetermined pressure. It has become.

Reference numeral 63 denotes a paper feed port formed on the top plate 20b of the paper feeder main body 20, facing between the paper feed roller 31 and the friction pad 51. A printer 64 is placed on the top plate 20b, and the paper feed port 63 The paper 2 is fed to a paper feed roller 65 of a printer 64.

In FIG. 8, the control circuit 66 controls the electromagnetic plunger 42 for moving the paper feed roller 31 toward and away from the laminated paper 2.
This control circuit 6 controls the pulse motor 39 for driving the paper feed roller, and the solenoid 59 for moving the friction pad 51 toward and away from the laminated paper 2.
A paper feed command signal from the printer 64 and a detection signal for detecting that the paper 2 has reached the paper feed roller 65 of the printer 64 are input to the input side of the printer 6. is the drive circuit 6 of the pulse motor 39
7, a drive circuit 6 for the electromagnetic plunger 42, and a drive circuit 69 for the solenoid 59 are connected, respectively.

Next, the operation of this embodiment configured as described above will be explained.

First, with a predetermined amount of paper 2 set on the lifting table 23, when a forward rotation start command is given to the drive motor M, the drive motor M starts, rotates the drum 29, and rotates each lobe 24.
The lifting platform 23 is raised by winding up the parts a to 24d. Then, when the uppermost surface of the stacked paper 2 comes into pressure contact with the paper feed roller 31 and the stacked paper 2 turns off the microswitch 62, the drive motor M stops and the elevator table 23 also stops.

In this state, when a paper feed command signal is input to the control circuit 66 as the printer 64 starts printing, the control circuit 66
outputs a paper feeding command to the drive circuit 67 to start the pulse motor 39 in normal rotation. When the pulse motor 39 is started to rotate normally, its rotation is caused by the drive gear 40 . Intermediate gear 41. @Car 35. The signal is transmitted to the gear 37 through the intermediate gear 38, and further rotates the paper feed roller 31 via the movable shaft 32. Along with this, the uppermost paper 2I of the stacked paper 2 pressed against the paper feed roller 31 is sent out in the direction of the friction pad 51 by the frictional force with the paper feed roller 31, and the paper 2I is moved between the paper feed roller 31 and the friction pad 51. inserted into. At this time, as shown in FIG. 6, the next sheet 2 □ located directly below the topmost sheet 2I is also sent out in the direction of the friction pad 51 due to the frictional force with the sheet 21, but this sheet 2 □ is as well as friction para)
51 and paper 2. Only the paper is sent out toward the paper feeding roller 65 of the printer 64 as shown by arrow C through the paper feeding port 63 of the top plate 20b.

At this time, the solenoid 59 is energized, and its rod 59a contracts, pulling the rotating arm 58 to the right. Therefore, the rotating arm 58 rotates counterclockwise about the rotating shaft 57 and presses the friction pad 51 toward the paper feed roller 31. Here, the friction pad 51 is stretched between the upper shaft 53 and the lower shaft 54 and is in an elastic tension state, so the friction pad 51 pressed against the paper feed roller 31 It contacts the outer periphery over a long distance and increases the frictional force that feeds the paper 2I.
Paper 2 is completely separated into one sheet and sent out.

Then, as shown in FIG. 7, when the leading end of the paper 2I is caught in the feed roller 65 of the printer 64, a detection signal indicating this state is output to the control circuit 66. As a result, the control circuit 66 stops the pulse motor 39, simultaneously stops the energization of the solenoid 59, and excites the electromagnetic plunger 42. When the solenoid 59 is de-energized, the elastic pressure of the friction pad 51 against the roller 31 and the pad frame 52 automatically tilt to the right around the rotation shaft 57, causing the friction pad 51 to move away from the paper feed roller 31. Leave. That is, for a stroke L of the solenoid 59, a gap l between the paper feed roller 31 and the friction pad 51 is obtained. On the other hand, when the electromagnetic plunger 42 is excited, the paper feed roller 31 is lifted above the plane of the paper, creating a gap g. As a result, paper 2.
is pulled out from the stacked paper section by the paper feed roller 65 and advances along the paper feed roller 31. At this time, the paper feed roller 31 is rotated, but due to the gaps f and g mentioned above, the paper 2. There is almost no frictional force between the paper 2 and paper 2□.

Therefore, the paper 22 remains in the stack of paper sheets, thereby preventing double feeding of the paper sheets.

That is, paper 2. Compared to the friction between the paper feed roller 31, the paper 2□, and the friction pad 51, the friction pad 5
1 and the paper feed roller 31, the friction between the paper 21 and the paper 22 is overwhelmingly small, so double feeding of paper can be reliably avoided.

In this way, the paper 2I is completely fed into the printer 64 side, and accordingly, when the next paper feeding command is sent from the printer 64 to the control circuit 66, the %i E1f plunger 42 is demagnetized and the solenoid 59 is activated. Power is applied. Therefore, the paper feeding roller 31 is pressed against the stacked paper 2 as shown by the two-dot chain line in FIG. 7, and returns to the paper feeding position. on the other hand,
When the solenoid 59 is energized, the friction pad 5
The work returns to its original position as shown in Figure 6. Then, by starting the pulse motor 39 again, the next sheet 2□ is separated and fed to the printer 64 side.

Thereafter, sheet feeding becomes possible by repeating the above-described operations.

In the automatic paper feeder of this embodiment, when the paper on the elevator platform 23 fed by the paper feed roller 31 reaches the paper feed roller 65 on the printer side, the electromagnetic plunger 42 and the solenoid 59 to feed the paper feed roller 31.
Also, the friction pad 59 is separated from the paper so that there is almost no frictional force between the paper sheets, which ensures the separation of sheets of paper, prevents double feeding of paper, and makes it possible to transfer sheets to high-speed printers such as laser printers. It has a favorable effect on leaf feeding. As a result, when the paper is pulled out by the printer-side feed roller 65, the resistance caused by the paper being pinched between the paper feed roller 31 and the friction pad 51 is eliminated, and the paper feed roller 31, which is attached to the movable shaft 32 via a one-way bearing, is always supported. The driving force of the printer-side paper feed roller 65 is sufficient to feed one sheet of paper, and the driving force of the printer-side paper feed roller 65 can be kept small and the structure can be made smaller. can.

In this embodiment, the paper feed roller 31 is separated from the paper, but the structure can be simplified by fixing the paper feed roller 31 to the paper feeder main body 1.

Additionally, the amount of paper fed to the paper feeding roller 65 of the printer 64 is set according to the predetermined number of revolutions or time of the paper feeding roller 31, and this controls the functions of stopping the pulse motor and excitation of the solenoid and electromagnetic plunger. If the circuit 66 is provided, the paper detection mechanism on the printer side can be omitted.

FIG. 9 shows the main parts of an automatic paper feeder according to another embodiment of the present invention, which is different from the first embodiment in the contact and separation structure of the friction pads.

In the figure, reference numeral 71 denotes a rotating arm consisting of a pair of left and right arms, which is rotatably supported by a rotating shaft 72 fixed to a support member 79. A solenoid 73 is linked to the lower end of the arm, and a solenoid 73 is linked to the upper end of the rotating arm. A rod shaft 74 is attached to a pair of left and right arms.

Reference numeral 75 denotes a friction pad, one end of which is attached to the rod shaft 74, and the other end of which is wound around a rod shaft 77 horizontally suspended on the upper end of the frame 76 and is elastically hooked to the frame 76 via a coil spring 78. However, solenoid 7
With the suction force of 3, the friction pad 75 moves the paper feed roller 78
When the suction force is released, the paper is pushed back to the right by the torsion spring 80 and separated from the paper feed roller 78 .

According to this embodiment, the same effects as those of the above-mentioned embodiments are achieved.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

Claim 1g11! In the automatic paper feeder described above, when a predetermined amount of paper on the elevating table fed by the paper feed roller is sent out to the printer side, the actuator is activated to separate the friction pad from the paper, thereby reducing the friction caused by the friction pad. Since almost no force is generated between the sheets, sheets of paper can be separated reliably, double feeding of sheets can be prevented, and this effect is suitable for sheet feeding to high-speed printers such as laser printers.

In the automatic paper feeder according to the second aspect, since the paper feed roller is fixed to the main body of the paper feeder, the structure can be simplified.

In the automatic paper feeder according to claim 3, the paper feed roller is connected to a roller actuator that moves the roller toward and away from the fed paper, and the paper feed roller also separates from the paper at the same timing as the friction pad. Therefore, it is possible to more reliably separate sheets of paper.

In the automatic paper feeder according to the fourth aspect of the present invention, a friction pad is stretched between two pad support parts. Therefore, the friction pad is elastically pressed against the paper and comes into contact with the paper feed roller over a long distance, increasing the frictional force that feeds the paper and completely separating the paper into single sheets. I can do it. Further, the driving force of the paper feed roller on the printer side can be kept small.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of an automatic paper feeder according to an embodiment of the present invention. FIG. 2 is a partially cross-sectional explanatory diagram taken along the line XX in FIG. 1. FIG. 3 is a cross-sectional explanatory diagram showing the rotating mechanism of the paper feed roller. FIG. 4 is a perspective view showing the support means for the friction pad. FIG. 5 is a perspective view showing the drive mechanism of the friction pad. FIG. 6 is an explanatory cross-sectional view of the friction pad drive mechanism. FIG. 7 is an explanatory diagram of the operation of the drive mechanism for the paper feed roller and friction pad. FIG. 8 is a block diagram for controlling the operation of the pulse motor for driving the paper feed roller, the paper feed roller, and the friction pad in this embodiment. FIG. 9 is a longitudinal sectional front view showing the main parts of an automatic paper feeder according to another embodiment of the present invention. 10 and 11 are side views of a paper feed roller section of a conventional paper feed device. [Explanation of symbols of main parts] 2...Paper 20...Paper feeder body 23...Elevating table 31... -Paper feed roller 39...Pulse motor 42...Electromagnetic plunger (for rollers) Actuator) 51... Friction pad 59... Solenoid (actuator) 66... Control circuit. Figure Figure b'I Figure # Figure 2

Claims (4)

[Claims] (1) An elevating table that is movably supported in the paper feeder main body and stacks sheets of paper, and a paper feed roller that is arranged on the paper take-out side of the elevating table so as to be in contact with and separate from the paper and is rotationally driven by a motor. , a friction pad arranged along a part of the outer periphery of the paper feed roller, which separates sheets of paper from the elevator table by rotation of the paper feed roller, and an actuator which moves the friction pad towards and away from the feed roller. and a control circuit that controls the actuator to separate the friction pad from the paper based on a command signal that detects that a predetermined amount of paper has been fed by the paper feed roller. Device. (2) The automatic paper feeder according to claim 1, wherein the paper feed roller is fixed to the main body of the paper feeder. (3) The paper feed roller is connected to a roller actuator that moves it toward and away from the paper being fed, and also receives a command signal that detects that a predetermined amount of paper has been fed by the paper feed roller. 2. The automatic paper feeder according to claim 1, further comprising a control circuit that controls a roller actuator to separate the friction pad from the paper based on the above-mentioned equation. (4) A lift table that is supported in a vertically movable manner within the paper feeder main body and stacks sheets of paper, and a paper feed roller that is disposed on the paper take-out side of the lift table so as to be in contact with and separate from the paper and is rotationally driven by a motor. , a friction pad is arranged along a part of the outer periphery of the paper feed roller, separates sheets of paper from the elevating platform by rotation of the paper feed roller, and is stretched between two pad support parts. automatic paper feeder.