JP3515815B2 - Paper feeder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a printing machine, a stencil printing machine,
The present invention relates to a sheet feeding device which is connected to an image forming apparatus such as an electrophotographic copying apparatus, a printer or a facsimile and supplies sheets to these apparatuses.

[0002]

2. Description of the Related Art As a general paper feeding device,
As shown in Japanese Patent No. 87733,
A device having a separation pad that can be brought into contact with and separated from a paper feeding roller is well known. This paper feeding device is configured such that a separation pad is brought into contact with the paper feeding roller when the paper feeding roller is rotated, and the separation pad is located at a position separated from the paper feeding roller when the paper feeding roller is not rotated.

In addition to the structure of the above-described paper feeding device, a structure in which the paper feeding table is movable in a direction orthogonal to the paper feeding direction is well known.

[0004]

However, in the above-mentioned apparatus, since the separation pad is brought into contact with the paper feed roller only once, the separation pad is not properly brought into contact with the paper feed roller. There is a problem that the paper is fed in the state and skew or double feeding occurs.

In addition to the above-mentioned problems, in the paper feeding device in which the paper feeding table can be moved, when the paper feeding table is moved, the paper feeding roller is moved with the separation pad being in contact with the paper feeding roller. There is a problem that the paper sandwiched between the paper roller and the separation pad suffers skew or wrinkle.

The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a sheet feeding device in which sheet skew or wrinkle does not occur during sheet feeding.

[0007]

The invention according to claim 1 is
A paper feed tray having a paper feed tray for loading paper, a paper feed roller for feeding the paper loaded on the paper feed tray, a first position in contact with the paper feed roller, and a distance from the paper feed roller A separation pad movably provided between the second position and
In a paper feeding device comprising a separation pad moving means for moving the separation pad, when the paper feeding roller is not rotated,
The separation pad is moved to the second position, and the separation pad is moved a plurality of times between the first position and the second position prior to the rotation of the paper feed roller, and then the first pad is moved. It is characterized by comprising a control means for controlling the operation of the separation pad moving means so as to move it to the position.

The invention according to claim 2 is the supply according to claim 1.
In the paper system, comprising a top Symbol sheet supply table moves <br/> hand stage of moving the sheet supply table against the paper feed tray in the direction perpendicular to the sheet feeding direction of the sheet, said control means, the paper during movement of the feed table by the paper table moving means to stop the rotation of the paper feed roller, and wherein the moving the feeding table after moving the separation pad to the second position.

[0009]

[0010]

According to the first aspect of the invention, the control means controls the operation of the moving means so that the plurality of separation pads are provided between the first position and the second position when the sheet feeding roller is rotated. After moving it once, move it to the first position correctly.

According to the second aspect of the present invention, the control means controls the operation of the moving means to stop the rotation of the paper feed roller and move the separation pad to the second position when the paper feed tray is moved. After that, move the paper feed tray to move the separation pad to the first position .
After moving multiple times to and from the second position, move to the first position
Move it correctly .

[0012]

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 represents a printing device. The printing apparatus 1 includes a printing unit 3 and a paper discharging unit 4, and a paper feeding device 6 having a structure different from that of the housing 5 of the printing device 1 is connected below the housing 5.

The printing section 3 is mainly composed of a printing drum 16 and a press roller 17. The printing drum 16 is
It is rotatably supported by a side plate (not shown), and is rotationally driven by a driving means (not shown).

At the lower left of the printing unit 3, a paper discharge unit 4 is arranged. The paper discharge unit 4 is mainly composed of a suction conveyance unit 34 and a paper discharge tray 35. Adsorption transport unit 3
4 is attached to the housing 5 and has a printed paper P.
Is separated from the outer peripheral surface of the printing drum 16, and the paper P is stiffened to improve the paper discharge alignment and then discharged to the outside of the machine. The paper discharge tray 35 is detachably attached to the housing 5 and sequentially stacks printed papers P discharged outside the machine by the suction conveyance unit 34.

At the lower right part of the print drum 16, there is arranged a pair of registration rollers 10 for carrying the paper P carried from the paper feeding device 6 to the print drum 16 at a predetermined timing. A paper transport path 12 that guides the paper P to the printing unit 3 is provided between the print drum 16 and the registration roller pair 10.

A sheet conveying path 14 is formed from the registration roller pair 10 to the lower portion of the housing 5. Paper transport path 1
Reference numeral 4 denotes an opening provided in the lower part of the housing 5, and a rotatable conveyance roller pair 15 is arranged in the middle thereof.

The paper feeding device 6 includes a device body 36, a plurality of paper feeding trays 37, 37, a paper feeding table 38, a paper feeding roller 8, a separating pad 9, a separating pad moving means 20 (see FIG. 5), and a pair of conveying rollers. It is mainly composed of 15 mag. Paper feed tray 37
As shown in FIG. 1, FIG. 2 and FIG. There is.

The paper feed tray 37 is constructed so as to be drawn out from the main body 36, and has a paper feed tray 38 provided therein.
Paper P is stacked on the upper part of. Paper P loaded
Is pressed against the paper feed roller 8 by a vertical movement mechanism 42 described later. Further, the paper feed tray 38 is a paper feed tray moving means 4 described later.
It is movably supported by 1.

The paper feed roller 8 is rotatably driven by a driving means (not shown), and picks up and feeds the paper P which contacts the outer peripheral surface thereof. The drive means for driving the paper feed roller 8 is controlled in its operation by the control means 76 described later.

A guide shaft 43 is installed between the side plates 37a and 37b of the paper feed tray 37. The guide shaft 43 is inserted through the side plates 38a and 38b of the paper feed table 38, and the paper feed table 38 is supported by the guide shaft 43 so as to be slidable in the arrow X direction.

A paper feed bottom plate 39 on which paper P is stacked is arranged in the middle of the paper feed tray 38. The paper feed bottom plate 39 has projections 39a, 39b provided on both sides thereof.
Then, the side plates 38a, 38b are loosely fitted in the long holes formed in the side plates 38a, 38b, and are supported by a vertically moving mechanism 42, which will be described later, so as to be vertically movable.

On the upper surface of the paper feed bottom plate 39, side guide plates 40, 40 for positioning the paper P in the width direction are arranged. The side guide plates 40, 40 have a well-known configuration that is provided symmetrically with respect to the center of the paper P and is movable in the arrow X direction.

A paper feed table moving means 41 is arranged in the lower stage of the paper feed table 38. The paper feeding table moving means 41 is mainly composed of a motor 44, a ball screw 45, a slit disk 46, a slit sensor 47 and the like.

The motor 44 is supported by a motor bracket 48, and the motor bracket 48 is attached to the bottom plate 38c of the paper feed table 38. The output shaft 44a of the motor 44 is joined to a shaft 50 having a ball screw 45 engraved through a joint portion 49, and the shaft 50 has a support member mounted on the bottom plate 38c at both ends of the ball screw 45. It is rotatably supported by 51, and a slit disk 46 is fixedly provided at its free end. A substantially L-shaped bracket 52 having one surface fixed on the bottom plate of the paper feed tray 37 is screwed into the ball screw 45. With this configuration, the ball screw 45 is rotated with respect to the immovable bracket 52 by the rotational force of the motor 44, and the paper feed tray 38 can move on the guide shaft 43 in the arrow X direction. The operation of the motor 44 is controlled by the control means 76 described later.

As shown in FIG. 4, the slit disk 46 is formed with a plurality of slits 53 radially at equal intervals. A slit sensor 47 that counts the slits 53 is disposed at a position facing the slits 53, and the slit sensor 47 is fixed on the bottom plate 38c. The slit disc 46 and the slit sensor 47 constitute a movement amount detecting means 54.

An initial position indicating plate 80 is fixed to the lower surface of the bottom plate 38c, and an initial position sensor 81 is mounted on the bottom plate of the paper feed tray 37 at a position corresponding to the initial position indicating plate 80, so that the center of the original image in the direction of the arrow X. By arranging the initial position indicating plate 80 at a position where the center of the sheet P and the center of the sheet P in the direction of the arrow X coincide with each other, the deviation of the original image with respect to the sheet P is corrected by moving the sheet feed tray 38 by the motor 44. You can

As shown in FIG. 3, the vertical movement mechanism 42 is a well-known mechanism and includes a gear motor 55, a worm 56, a worm wheel shaft 57, a hub 58, fixed pulleys 59, 59 ,.
59, 60, 60, wire 61, pulse generator 6
2. Mainly composed of the remaining amount sensor 63 and the like.

Gear motor 55 having gear head 55a
Is fixedly installed on the bottom plate 38c, and its operation is controlled by the control means 76. The worm 56 has one end joined to the gear head 55a and the other end connected to the pulse generator 6
It is fixed to 2. A remaining amount sensor 63 is arranged at a position facing the pulse generator 62, and the remaining amount sensor 63 is mounted on the bottom plate 38c.
The pulse generator 62 and the remaining amount sensor 63 form a sheet detecting unit 65. Worm wheel shaft 5 engraved with worm wheel 57a that meshes with worm 56
7 are brackets 64, 64 fixed on the bottom plate 38c.
It is rotatably supported by the side plates 38a and 38b (see FIG. 2).
(See) and are arranged so as to penetrate therethrough. A hub 58 is mounted near the side plate 38a of the worm wheel shaft 57, and a hub (not shown) is mounted on the other side of the side plate 38b, like the hub 58.

On the side plate 38a, the two vertically formed
Three long holes 38d, 38d are formed. Each long hole 38
At the upper part of d and 38d and the lower part between each long hole, a fixed pulley 5
9, 59, 59, 60, 60 are rotatably attached. The above-mentioned projections 39a, 39a of the sheet feeding bottom plate 39
Are fixed to the wire 61. A wire 61 is wound around each fixed pulley, and both ends of the wire 61 are
It is fixed to the hub 58. The hub, constant pulley, and wire are also symmetrically arranged on the side plate 38b side. With this configuration, when the worm wheel shaft 57 rotates counterclockwise in FIG. 3 by the rotation of the gear motor 55, the wire 61 is wound around the hub 58 and the projection 39
As a and 39b rise, the paper feed bottom plate 39 rises.

The paper P fed from the paper feed trays 37, 37 is carried by the carrying roller pair 15 through the paper carrying path 75 formed inside the paper feeder 6, and is opened at the bottom of the housing 5. 1 pair of registration rollers via the paper transport path 14
Carried to zero.

As shown in FIG. 5, the separation pad 9 is fixed to the upper surface of the holder 29 with an adhesive tape or the like. The holder 29 is provided with an elongated hole 29a, and the holder 2
9 is fixed to a front plate 30 of the paper feed tray 37 (see FIG. 1) in the conveyance direction of the paper P, and slides through a long hole 29a with a stepped screw 22 on a bracket 21 having a substantially L-shaped cross section. It is possible to install.

A protrusion 29b is provided at the center of the lower portion of the holder 29. Between the protrusion 29b and the stepped portion 21a of the bracket 21, the pad 9 is urged in the direction of abutting against the paper feed roller 8. A compression spring 23 is provided. A contact piece 29c is provided so as to project from one end of the lower portion of the holder 29, and one end of an arm 24 rotatably supported by a shaft 28 planted in the bracket 21 is provided on the contact piece 29c. Abutting.

The arm 24 has a shaft 28 and an E-shaped ring 28a.
It is installed in. A plunger of a solenoid 26 fixed to the bracket 21 is connected to the other end of the arm 24 by a pin 25. A tension spring 27 is provided between one end of the arm 24 and the step portion 21a of the bracket 21 so that the arm 24 is brought into contact with the contact piece 29c to urge the separation pad 9 away from the paper feed roller 8. It is hung. The biasing force of the tension spring 27 is the compression spring 2
Stronger than that of 3.

The solenoid 26 controls the operation of the solenoid 26.
6 and is excited, the arm 24 is rotated clockwise about the shaft 28 against the urging force of the tension spring 27, and the holder 29 is urged by the urging force of the compression spring 23 in FIG. , And the separation pad 9 is moved to the first position in contact with the paper feed roller 8.
On the other hand, when the solenoid 26 is demagnetized, the arm 24 causes the tension spring 27 to rotate counterclockwise about the shaft 28.
The holder 29 is rotated by the urging force of the compression spring 23 and moves downward in the figure against the urging force of the compression spring 23, and moves the separation pad 9 to a second position separated from the paper feed roller 8.
Here, the solenoid 26, the arm 24, the compression spring 23,
The tension spring 27 mainly constitutes the separation pad moving means 20.

As shown in FIG. 1, an operation panel 66 is arranged on the upper surface of the housing 5. The operation panel 66 includes a tray selection key for selecting a tray to be used from the plurality of paper feed trays 37, a paper feed tray moving key for moving the paper feed tray 38 in a direction orthogonal to the paper feed direction, and print information. A message display for displaying, a ten-key for setting printing conditions, a start key for starting printing, a plate-making start key for starting a plate-making operation, and the like are arranged.

Below the operation panel 66 and inside the housing 5, a control means 76 is provided. Control means 76
As shown in FIG. 6, the CPU 77, the RAM 78, the RO
Mainly composed of M79.

Based on the above configuration, the operation will be described below. Prior to printing, the operator sets a document on an image reading device (not shown), sets various printing conditions on the operation panel 66, and presses the start key, and the signal is input to the RAM 78 of the control means 76.

The signal input to the control means 76 is the CPU
The print data is read from the ROM 79 as judged by 77, and the paper feed tray 37 is selected according to the input content. The gear motor 55 of the vertical movement mechanism 42 provided in the selected paper feed tray 37 rotates, the wire 61 is wound around the hub 58, the protrusions 39a and 39b rise, the paper feed bottom plate 39 rises, and the paper When the upper surface of P abuts the paper feed roller 8 and the pressure on the paper feed roller 8 reaches a predetermined pressure stored in the ROM 79, the rotation of the gear motor 55 is stopped and the elevation of the paper feed bottom plate 39 is stopped. To do.

At this time, when the worm 56 rotates, the pulse generator 62 rotates and a pulse is generated.
The remaining amount sensor 63 counts the number of pulses. The amount of movement of the sheet feeding bottom plate 39 changes depending on the number of stacked sheets of paper P, and the number of pulses generated accordingly changes. Therefore, the number of sheets of paper P is detected, and this signal is sent to the RAM 78. When the CPU 77 determines from this signal that the remaining number of sheets of paper P has become smaller or has become 0, a paper supply lamp (not shown) provided on the operation panel 66 is turned on.

When the paper feed bottom plate 39 stops rising and the paper P is pressed against the paper feed roller 8 at an appropriate pressure, a command is issued from the control means 76 and the paper feed roller 8 starts to rotate. Prior to the rotation of the paper feed roller 8 (from the pressing of the print start key to the start of the rotation of the paper feed roller 8), the control means 76 energizes and demagnetizes the solenoid 26 of the separation pad moving means 20 a plurality of times. Then, the separation pad 9 is moved a plurality of times between the first position and the second position as described above to improve the contact state of the separation pad 9 with respect to the paper feed roller 8, and then the solenoid 26 is turned on again. It is excited to move the separation pad 9 to the first position.

When the paper feed roller 8 rotates, the paper P is fed. At this time, the sheets P are separated one by one by the separation pad 9 and fed to the sheet conveyance path 14 through the sheet conveyance path 75 . The paper P sent to the paper carrying path 14 is carried by the carrying roller pair 15, and when the leading end reaches a position where it abuts on the registration roller pair 10, a signal is issued from the control means 76 and the carrying roller pair 15 is stopped. To be done.

In parallel with the paper feeding operation of the paper feeding device 6, the printing unit 3 is performing the printing operation. Along with the rotation of the print drum 16, the stopped registration roller pair 10 rotates, and the paper P is transferred from the paper transport path 12 to the print drum 16.
Between the press roller 17 and the press roller 17.

Printing drum 1 by press roller 17
Paper P that has been transferred to the print image by being pressed against the outer peripheral surface of 6
Is peeled from the outer peripheral surface of the print drum 16 by a peeling claw (not shown) arranged in the vicinity of the outer peripheral surface of the print drum 16, and then is conveyed while being supported by the suction conveyance unit 34, and is then discharged from the discharge tray outside the machine. 35 is discharged.

According to the above-mentioned printing process, the control means is operated when the moving direction and the moving amount are inputted by the paper feed table moving key of the operation panel in order to move the image position of the printed matter while the printing is being performed. Reference numeral 76 stops the rotation of the paper feed roller 8, demagnetizes the solenoid 26, and moves the separation pad 9 to the second position.

Thereafter, the control means 76 controls the paper feed tray 37.
The gear motor 55 of the up-and-down moving mechanism 42 provided in the above is rotated in the opposite direction to the above-mentioned case, the wire 61 is pulled out from the hub 58, the protrusions 39a and 39b are lowered, and the paper feed bottom plate 39 is
Is lowered by a predetermined distance and the paper P and the paper feed roller 8 are separated from each other.

A command is issued from the control means 76, the ball screw 45 engraved on the shaft 50 is rotated by the rotational force of the motor 44, and the paper feed tray 38 is moved in the set direction with respect to the paper feed tray 37. The slit disk 46 also rotates with the rotation of the shaft 50, and the slit sensor 47 counts the slits 53 to detect the movement amount of the paper feed tray 38. The movement amount detected by the movement amount detecting means 54 is input to the RAM 78 and compared with the data set in the ROM 79 in advance, and when the movement amount and the setting data match, the CPU
A movement stop command is output from 77.

The control means 76 then raises the paper feed bottom plate 39 as described above to bring the paper P into contact with the paper feed roller 8, and energizes and degausses the solenoid 26 of the separation pad moving means 20 a plurality of times. As described above, the separation pad 9 is moved between the first position and the second position a plurality of times to improve the contact state of the separation pad 9 with the paper feed roller 8, and then the solenoid 26 is excited again. Then, the separation pad 9 is moved to the first position, the paper feed roller 8 is rotated, and the feeding of the paper P is restarted.

When the set number of sheets have been printed according to the above-described printing process, the solenoid 26 is demagnetized and the separation pad 9 is moved to the second position.

[0050]

According to the first aspect of the invention, the control means controls the operation of the separation pad moving means to move the separation pad to the first position and the second position when the sheet feeding roller rotates. After the sheet is moved a plurality of times, the sheet is correctly moved to the first position, so that it is possible to prevent the occurrence of skew or wrinkle at the time of feeding the sheet due to the partial contact of the separation pad.

According to the second aspect of the invention, the control means is
And controls the operation of the moving means, when moving the sheet supply table, stops the rotation of the paper feed roller moves the sheet supply table separation pad after moving to the second position, the separation pad, the Position 1 and
After moving multiple times to and from the second position, move to the first position
Since it is moved correctly, it is necessary to move the paper tray or separate the separation pad.
It is possible to prevent the occurrence of paper skew and wrinkle due to a hit.

[0052]

[Brief description of drawings]

FIG. 1 is a schematic front view of a main part of a printing apparatus that employs a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a side sectional view showing a paper feed tray moving means of the paper feed device shown in FIG.

3 is a perspective view showing a vertical movement mechanism of the paper feeding device shown in FIG. 1. FIG.

FIG. 4 is a diagram showing a movement amount detecting means in the paper feed tray moving means shown in FIG.

5 is a perspective view showing a separation pad moving means of the paper feeding device shown in FIG. 1. FIG.

FIG. 6 is a diagram illustrating control means of the present invention.

[Explanation of symbols]

1 printing device 6 Paper feeder 8 separation rollers 9 Separation pad 16 printing drum 17 Press roller 20 Separation pad moving means 37 paper tray 38 paper feed table 76 Control means

Claims (2)

(57) [Claims] 1. A paper feed tray having a paper feed tray for loading paper, a paper feed roller for feeding the paper loaded on the paper feed tray, a first position for abutting the paper feed roller, and the above A sheet feeding device comprising a separation pad movably provided between a separation roller and a second position separated from the sheet feeding roller, and a separation pad moving means for moving the separation pad. Sometimes, the separation pad is moved to the second position, and the separation pad is moved a plurality of times between the first position and the second position prior to the rotation of the paper feed roller, A sheet feeding device, comprising a control means for controlling the operation of the separation pad moving means so as to move it to the position 1. The sheet feeder 2. A method according to claim 1, wherein, provided with a paper feed table moves the hand stage for moving the feeding table relative to the paper feed tray in the direction perpendicular to the sheet feeding direction of the sheet, the The control means stops the rotation of the paper feeding roller when the paper feeding table is moved by the paper feeding table moving means, moves the separation pad to the second position, and then moves the paper feeding table.
A paper feeding device characterized by being made.