JPS62196236A - Sheet feeding device - Google Patents

Abstract

PURPOSE:To enable the substantial cost reduction of the device by providing cam means for interlocking vertical movement of a pickup roller of sheet takeout means with drive means of sheet separating means. CONSTITUTION:Hand inserting rollers 74, 74 are so constituted that they can be driven to synchronously rotate same as a pickup roller 40 at the same timing as a sheet feeding roller 52 in the sheet feeding direction A through a belt 78 strained around pullies 75, 76, 77 which are provided on a rotary shaft 51 for the sheet feeding roller 52, a lever shaft 36 and a rotary shaft 73 respectively. Second arms 71, 72 are abutted on a rotatable plate 82 pivoted on a shaft 81, and lifted usually by an urging force of a spring 83 for urging the plate 82. When the plate 82 is interlocked with a magnet 85 which operates at the time of a hand inserting switch turning ON, and pulled by the retractive motion of the magnet against the urging force of the spring 83, the hand inserting rollers 74, 74 are lowered by its deadweight to contact onto a hand inserted sheet P, so that the sheet P is carried toward a sheet separating device 45 by the rotations of the hand inserting rollers.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement in a paper feeding device applied to an image forming apparatus such as an electronic copying machine.

(Prior Art) Conventionally, in this electronic copying machine, especially in the paper feeding device for paper that is an image recording medium, paper of multiple sizes has been stacked individually.
Attach each of the paper feed cassettes stored in m in a removable manner,
In addition, sheets of a designated size can be selectively taken out one by one from each paper feed cassette and fed into the transfer section.

(Problems to be Solved by the Invention) However, in the above-described conventional paper feeding device, the up and down movement of the pickup rollers constituting the paper ejecting means that can take out sheets one by one from each paper feeding cassette Since this is carried out by means such as magnets, there is a problem in that the cost of the entire apparatus inevitably increases.

The present invention has been made under the above circumstances, and its object is to reduce the overall cost of paper feeding by devising the means for vertically moving the pickup roller. The goal is to provide equipment.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a paper take-out unit equipped with a vertically movable pickup roller that takes out sheets of paper stacked in a paper storage unit one by one; A paper feeder comprising a paper separating means for preventing multiple sheets of paper taken out from the paper taking out means from being stacked, and a paper feeding means comprising a pair of rollers into which the paper passing through the paper separating means is fed. The paper device includes a cam means for interlocking the vertical movement of the pickup roller of the paper ejecting means with the drive means of the paper separation means, and a maximum speed for determining that one rotation of the cam constituting the cam means is a paper feeding failure. In addition to approximately corresponding to the driving time, a detection means for confirming the presence or absence of paper conveyance is provided immediately before the paper feeding means, and after the detection means detects the paper, the paper separation means is rotated a certain amount of time. The structure is such that it can be driven and stopped.

(Function) That is, by having the above configuration, the present invention has the following features:
Since the pickup roller of the paper ejecting means is linked to the drive system of the paper separating means via the cam means, other parts such as magnets are not required separately, and a significant cost reduction can be achieved. , since the operation is completed by one rotation of the cam within the detection of a paper feed error or jam,
There is no problem even if slippage occurs between the rollers in the paper feed section, and reliability can be improved because the number of parts is small.

Furthermore, just before the pair of restro rollers, which is the paper feeding means,
Since the Rennost switch is installed in the cam, the Rennost switch serves to detect one revolution of the cam, thereby making it possible to eliminate the need for a detection switch for the cam means.

[Implementation row]

Hereinafter, the present invention will be explained with reference to an illustrated embodiment.

FIG. 1 schematically shows the overall configuration of an image forming unit device equipped with a paper feeding device according to the present invention, and in the figure, 1 is a main body of a copying machine as an image forming device.

The main body 1 of the copying machine has an original placing table 2 made of a transparent glass plate on which an original (not shown) is placed on the upper surface thereof, and an exposure system 3 is provided below the original placing table 2. This exposure system 3 has a ramp angle of 4°, first to third reflection mirrors 7-s, e, 7. Lens unit 8 and fourth to sixth reflecting mirrors 9, JO.

1, which scans the original placed on the original document mounting table 2 and forms a light image on an image carrier (hereinafter referred to as a photosensitive drum) 12 as an exposed part. There is.

The photosensitive drum 12 is rotatably mounted approximately in the center of the copying machine body 1, and around it are a charging device (zs, two-color developing device 14, transfer device 15, peeling device) 6, and a cleaning device. 17 and an afterimage erasing device 18 are arranged sequentially along the rotation direction, and on the upstream side thereof, paper P as an image recording medium fed from a paper feeding device to be described later is connected to the photosensitive drum 12 and a transfer device. Image transfer section 19 between 15 and 15
Pair of reso rollers 20 as paper feeding means
is provided.

That is, when copying an original, the original placed on the original placing table 2 of the copying machine main body 1 is exposed to the lamp 4 of the exposure system 3.
The reflected light is applied to the first to third reflecting mirrors 5, 6, 7 . Lens unit 8 and fourth to sixth reflecting mirrors 9. I.Q.

Charging device y through 11! An electrostatic latent image is formed by forming an image on the surface of the rotating photosensitive drum 2, which is uniformly charged in advance by L13. This static latent image is sent to the developing device 14 by the rotation of the photosensitive drum 12, and is developed with, for example, a red or black developer.
from the registration roller pair 20 to the image transfer section 1.
The developer image is transferred onto the paper P fed into the photosensitive drum 12 by a peeling device J6. Further, the photosensitive drum 12 after transferring and peeling off the developer image onto the paper P is sent to a cleaning device 17 to clean residual developer remaining on the surface, and then to an afterimage erasing device! 8, the potential on the photosensitive drum 12 is lowered to below a certain level to enable the next copying operation.

On the other hand, the paper P to which the developer image has been transferred and peeled off from the photosensitive drum I2 is introduced into the fixing device 22 via a conveying device +21 provided downstream of the photosensitive drum 12, where the image is fixed. - After that, the paper is ejected to the paper ejection tray 24 side by a pair of paper ejection rollers 23.

Thus, there is a paper feeding device 30 that feeds the sheets of paper P one by one to the pair of registration rollers 20, and a first to third paper feeding cassette 32 that serves as a paper storage section in which sheets of paper P are stacked and stored according to their sizes. , 32, and 33 are removably attached to the upstream lower part of the copying machine main body J in three stages, upper and lower, and the sheets P stacked and stored in each of these paper feed cassettes 3J, 32 and 33 are taken out one by one and placed in the It is designed to be able to feed paper to the stroller 20 side, and in particular, a manual paper feed section 34 is installed on the top surface of the paper feed cassette 33 at the top. Taking the paper feeding portion of the upper paper feeding cassette 33 as an example, its schematic structure is shown in FIGS. 2 and below.

That is, as shown in FIGS. 2 and 3, numeral 35 in the drawings denotes a paper take-out device, which includes a lever shaft 36, a first arm 37 pivotably supported by the lever shaft 36, and rotatable in the vertical direction. , a pickup roller 40 having a one-way clutch 39 attached to the free end of this arm 37 via a rotating shaft 38, and a cam lever 4 attached to one shaft end 36a of the lever shaft 36.
1 is fixed. This cam lever 4 is in sliding contact with a rotatable cam 43 via a gear 42 that meshes with a gear provided on a rotating shaft of a paper feed roller constituting a paper separating device, which will be described later. The lever shaft 36 is rotated to move the first arm 37 vertically by 1.
As a result, when the first arm 37 descends, the pick-a-raglow 240 picks up the highest sheet of paper P stored in the paper feed cassette 33, as shown by the dotted line in FIG.
It has a K shape so that it can be pressed against the top with its own weight,
These cam lever 41, gear 42, and cam 43 constitute a cam means 4 for vertically moving the pickup roller 40.

In addition, 45 in the figure is a paper separation device, and the paper ejecting device 3
It is configured to prevent the paper P taken out from the paper P from being taken out from the 21i, and is composed of a drive motor 46, a gear 49 that meshes with a float 48 provided on the drive IJJ shaft 41 of the drive motor 46, and A first rotating shaft 5 interlocked with a gear 49 via a one-way clutch 50, and a weight 52 constantly rotating in the paper feeding direction A by the one-way clutch 50 attached to the first rotating shaft 5. roller 52
and a separation roller 53 which is in rolling contact with this paper feed row 252, and this separation roller 53 is connected to the first rotating shaft 51.
It is attached via a chain 54 to a second rotating shaft 55 which rotates synchronously in the same direction as the paper feeding direction A via a spring clutch 56.

In addition, 57 in the figure indicates the first rotation 11 of the paper feed roller 52.
A gear attached to the shaft end of the cam means 4
A cam 43 is rotated by meshing with a gear 42 provided on a camshaft of No. 4.

That is, the spring clutch 56 is set to be able to slip when the contact pressure between the rolling contact portion of the paper feed roller 52 and the separation roller 53 becomes 28 or more,
Assuming that the frictional force at the rolling contact between 2 and 53 is F, when there is no paper P such as F+<'x, the separation roller 53 follows the paper feed roller 52 in the direction B of the solid line arrow, as shown in FIG.
Even if only one sheet of paper P enters the rolling contact section in this state, the conveyance force of the paper feed roller 52 is stronger than the conveyance force of the separation roller 53, so the rotation is maintained as it is.

If there are two sheets of paper P at the rolling contact between both rollers at a time, the force (adsorption force) between the two sheets is F, and
If the tSS force between the roller and the paper is F, then T, L> since the roller is generally made of a material with a high coefficient of friction such as rubber.
Under the setting conditions of F4>Ft>Fs, as shown in FIG. J
(The paper P of Ill is returned in the opposite direction in the direction of the dotted arrow.

Further, the pickup roller 40 constituting the paper take-out device 35 has a first rotating shaft si on the paper feed roller 52 side,
A belt 64.6 is attached to the pulleys 61, 62.63 provided on the lever shaft 36 and the rotating shaft 38, respectively.
5 rotates in the paper feed direction at the same timing as the paper feed row 252, and when the first arm 37 is lowered by the cam means 44 and brought into pressure contact with the paper P stored in the paper feed cassette 33, By rotation, the paper P is separated from the paper Tl! It is conveyed between 145 rollers 52 and 53.

In addition, 70 in the figure is a manual paper ejecting device that takes out paper P that is manually fed from the manual paper feed section 34 provided on the upper surface of the uppermost paper feed cassette 33, and the lever shaft 36
A pair of second arms 71.
72 and a pair of manual feed rows 274.74 attached to a rotating shaft 73 provided between the second arms 71.72, and the manual feed rows 274.74
Similarly to the pickup row 240, the pulleys 75, 76, and 77 provided on the rotating shaft 5, the lever shaft 36, and the rotating shaft 73 are connected via a belt 78 to the paper feed roller 52 at the same timing. It is configured so that it can be driven to rotate synchronously in the paper feeding direction A. As shown in FIG.
D7'L/- While normally lifted by the urging force of the spring 83 that urges the paper P, the manual feed switch 84 installed near the insertion port 3'4a of the manual paper feed section 34 When the grate 82 is pulled against the biasing force of the spring 83 due to the suction action of the magnet 85, which is activated when the grate is turned on by the insertion of the grate, the grate 82 descends under its own weight. A manual feed roller 74.degree. 74 comes into contact with the manual feed paper P, and its rotation allows the paper P to be conveyed to the paper separation device 45.

Further, reference numeral 90 in the figure is a registration switch installed near the pair of registration rollers 2° to check the paper P conveyed through the paper separation device 45. If the power does not turn on after a certain period of time has passed, determine that a paper feed error or jam has occurred, and then turn the power on.
By feeding a certain amount of paper after the paper reaches the position, it is possible to accurately feed the paper to the registration rows 2 and 20. Further, 100 in the figure is an e-empty switch installed at the bottom of the paper feed cassette 33 for determining the presence or absence of paper P.
Since it is a reflective optical sensor, if there is no paper P in the cassette, it will no longer be able to receive the reflected light, so it will indicate "no paper".
It is now possible to judge.

The paper feeding state of the paper feeding device 30 described above will now be explained. 6 to 8 show the paper feeding state of the paper P set in the paper feed cassette 33. First, when the copy switch (not shown) is pressed, the drive motor 46 is driven 17 and the paper feed roller 52 is rotated. The shaft 5) rotates, and one of the rotating shafts 51
The cam lever 4 is rotated by turning the cam 43 through the gear 42 of the cam means 44 meshed with the gear 57 at the iqtl end.
1 and the lever shaft 36, the pickup row 240 is lowered as shown in FIG. At this time, the number of teeth Z of the gear 57 of the paper feed roller rotation shaft 5.

and the number of teeth of the gear 42 on the cam means 44 side is 2. The rotation angle θ of the paper feed row 252 is 2! θZ is set to 360°, and as shown in FIG. 11, when paper feeding starts, the drive motor 46 does not rotate from the start time T0 to time T1, and rotates at time T1. On the other hand, the cam 43 of the cam means 44 is
During the rotation θ1 from T to time T8, the cam lever 41 is kept in contact with the cam lever 41 in the state shown in FIG. The pickup roller 40 begins to descend due to the action of the cam 43 as shown in b), and the paper P is conveyed by coming into contact with the paper P at a rotation angle θ. And from T3 to T4
The paper P is sent to the paper separation device i't 45 by the pickup roller 4o for the rotation 01 minutes up to the time T4, and after the time T4, the pickup roller 40 is again rotated by the cam 430 of the cam means 44 as shown in Fig. 2g8. Raise and maintain the upper position. In this state, the leading edge of the paper P that has passed between the paper feed roller 52 and separation roller 53 of the paper separation device 45 reaches the point T.
, until the paper P is rotated by a certain amount and a fixed value of 0.
It is sent to the sister roller pair 20 side for only 4 minutes, and at time T, the drive motor 46 is stopped. At this time, T.

Rotation θ of the paper feed row 52 from to T.

corresponds to the amount by which the paper P is fed.

By the way, in the case of the paper feeding timing described above, the explanation has been made assuming that there is no slip between the paper feeding roller 52 and the paper P, but in reality, it is necessary to check the margin for the occurrence of slip. That is, the time from T to T shown in FIG. This waiting time is the resist switch 9
This corresponds to the time until 0 is entered. In other words, the drive motor 4
6 rotates the paper feed roller 52 from T1 to T.

In other words, when the paper P does not reach the pair of registration rollers 20 until the cam 43 of the cam means 44 rotates once, or the paper feed roller 52
If the paper P does not reach the renost switch 90 by the time the paper P rotates from T1 to T (θ, -θ4), it is considered to be a paper feeding failure such as a paper feeding error or noyam. . After the first paper feeding is completed in this way, when the next paper feeding is performed, the time between T Since the cam 43 stops before turning 11 degrees, it rotates by that amount, and then the same paper feeding operation is repeated.

Moreover, FIGS. 9 and 10 show the case of manual paper feeding, and when manual paper P is set, the intermediate feed switch 84
is turned on, and as a result, as shown in FIG.
1.72, and at the same time the manual feed roller 74.74 is lowered by its own weight, and this manual feed roller 7
4 and 74 to convey the paper P to the paper separation device 145 side. After setting one or more sheets of paper P in the manual paper feed section 34, if you press the copy switch (not shown), the above-mentioned cassette paper feed It's something that is designed to be done in the same way.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the sheets stacked in the paper storage section are fed to the paper separation means via the paper take-out means equipped with a pickup roller that can move up and down, and the sheets are separated. In a paper feeding device that feeds sheets of paper one by one to a paper feeding means consisting of a pair of registration rollers via a means, a pickup roller of the paper ejecting means can be moved up and down by a cam means linked to a drive system of a paper separating means. In addition, one rotation of the cam constituting the cam means corresponds approximately to the maximum driving time for determining a paper feeding failure, and a detection means is provided immediately before the paper feeding means to check the presence or absence of the paper conveyance state. After the paper is detected by the detection means, the paper separation means is driven for a constant period of 44 hours and then stopped, so that a separate drive means such as a magnet is not required for the up and down movement of the pickup roller as in the conventional case. It is possible to achieve significant cost reductions,
In addition, one revolution of the cam means ends the operation within the detection range of paper feeding failures such as paper feeding errors and jams.
There is no problem even if slippage occurs between the rollers, and together with the small number of parts, reliability can be improved. Furthermore, the paper structuring means installed just before the paper feeding means makes one revolution of the cam means! Since it serves as a sensor, there is no need to newly provide a detection means for the cam means, and the mechanism is reduced to one.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing the overall configuration of a copying machine main body as an image forming apparatus in which a paper feeding device according to the present invention is adopted;
FIG. 2 is a cross-sectional view of the main parts of the manual feeder 17 showing an implementation f911 of the paper feeder according to the present invention, FIG. 3 is a schematic perspective view of the main parts, The figure is an explanatory diagram showing the operating state of the paper separation device, FIG. 6 is an explanatory diagram showing the downward movement state of the pickup roller constituting the paper take-out device, and FIGS. 7(a) and (b) are cam means. Figure 8 is an explanatory diagram showing the operating state of the pickup roller.
1 and 10 are schematic diagrams showing the state of paper feeding by the manual paper feeding means, and FIG. 11 is an explanatory diagram showing the control state of the paper take-out device and the paper separation device. 20... Paper feeding device, P... Image recording body (paper)
, 30... paper feed device, 35... paper take-out device, 40
...Pickup roller, 42...Gear, 43...
-Cam, 44...Cam means, 45...Paper separation device, 46...Drive motor, 5...First rotating shaft, 5
2...Paper feed roller, 53...Separation roller, 57...
・Gear, 9J...Resist switch. Figure 4 Figure 5 Sword Figure 6 Figure 7 (a> Figure 7 (b) 7n Figure 8 9nη Figure 10

Claims (1)

[Claims] a paper take-out means including a vertically movable pick-up roller that takes out sheets of paper stacked in a paper storage unit one by one; a paper separation means that prevents stacking of multiple sheets of paper taken out from the paper take-out means; In a paper feeding device comprising a paper feeding means consisting of a pair of registration rollers into which the paper that has passed through the paper separation means is fed, a cam means for interlocking the vertical movement of the pickup roller of the paper ejection means with the drive means of the paper separation means. and a detection means for checking the presence or absence of paper conveyance immediately before the paper feeding means, in which one rotation of the cam constituting the cam means corresponds approximately to the maximum driving time for determining a paper feeding failure. . A paper feeding device characterized in that the paper separating means can be rotated by a certain amount and then stopped after the paper is detected by the detecting means.