JPH10101237A - Paper feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To draw a paper loading part without burdening a cover, and prevent the occurrence of jamming when carelessly drawing the paper loading part. SOLUTION: In a paper feeding device having a bottom plate 5 rotatedly elevated to a paper feeding position where the upper surface of a paper sheet to be loaded abuts on a paper feeding roller, and equipped with a paper feeding part 3 drawable this side, and a driving part for rotatedly elevating the bottom plate 5 of the loading part 3 to the paper sheet position; a cover part 14 is equipped which is covering this side surface of the loading part 3, and being drawn to this side together with the loading part 3; a handle 41, for drawing the loading part 3 and the cover part 14, is provided on the loading part 3, and the loading part 3 is made drawable to this side of a device main body without burdening the cover part 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder applied to an image forming apparatus such as a copying machine, a facsimile, a printer, a printing machine, etc. The present invention relates to an improvement of a sheet feeding device which has a sheet stacking section (sheet tray) which can be taken in and out of the operation surface side and pulls out the sheet stacking section toward the front to supply sheets, that is, a so-called front loading type sheet feeding apparatus.

[0002]

2. Description of the Related Art As a paper feeding device of an image forming apparatus, a so-called side-loading type paper feeding device in which a paper stacking section is inserted into and removed from an apparatus main body in a paper feeding direction or a reverse paper feeding direction to supply paper. As is also known, a so-called front loading type paper feeder which replenishes paper by taking a paper stacking section in and out of the direction perpendicular to the paper feeding direction, in recent years, requires a small occupied floor area. It has become mainstream from the viewpoint of operability in small places.
In this front-loading type image forming apparatus,
Generally, a paper tray is slidably supported by a guide rail or the like, pulled out from the apparatus main body to supply paper, stored in the apparatus main body, and performs a paper feeding operation.

However, in the case of an image forming apparatus of a front loading type and the paper transport reference is the depth reference or the center reference, when replenishing the paper, the paper must be set at the rear end or center of the paper tray. In order to do so, even when replenishing small-sized paper, the paper tray has to be pulled out to the front or in the vicinity. Therefore, there has been a problem that the operation is troublesome and an empty space for drawing out the paper tray is required in front of the apparatus. This problem is remarkable especially in the case of a large-sized machine because the depth of the apparatus is deep.

[0004] For this reason, the present applicant has already disclosed in Japanese Patent Application Laid-Open No. Hei 6-263268 that the paper loading position at the time of paper supply is set to the near side in the paper tray, so that the paper tray can be pulled out. A technology has been proposed in which the empty space in front of the apparatus is reduced by reducing the amount of paper tray pulled out by making the paper tray smaller in size.

[0005]

In an image forming apparatus having a front-loading type sheet feeding device, a cover is provided mainly from the design point of view on the front portion of the main body of the apparatus where the sheet stacking section enters and exits. Often have. During loading, the sheet stacking section and the cover are both pulled out toward the apparatus body.

Here, conventionally, a lock mechanism for preventing the paper stacking unit from being arbitrarily pulled out is not provided due to a problem of cost, and the user is generally instructed to pay attention to the mechanism. For this reason, when the user accidentally pulls out the paper stacking section during paper feeding, the paper is jammed and a jam occurs.

Accordingly, the present invention provides a paper feeder which can pull out the paper stacking portion without putting a load on the cover, and can prevent the occurrence of a jam when the paper stacking portion is carelessly pulled out. The purpose is to provide.

[0008]

According to a first aspect of the present invention, there is provided a sheet feeding apparatus having a bottom plate which rotates upward to a sheet feeding position where an upper surface of a sheet to be stacked comes into contact with a sheet feeding roller, and is pulled out to the near side. In a sheet feeding device including a possible sheet stacking unit and a driving unit that rotates the bottom plate of the sheet stacking unit to a sheet feeding position, the front side of the sheet stacking unit is covered, and the sheet stacking unit is pulled out together with the sheet stacking unit. It has a cover part, and a paper loading part and a handle for pulling out the cover part are provided on the paper loading part.

According to a second aspect of the present invention, there is provided a sheet stacking section which has a bottom plate whose upper surface is pivotally moved up to a sheet feeding position where the sheet stacking sheet comes into contact with a sheet feeding roller, and which can be pulled out to the near side, and a bottom plate of the sheet stacking section. And a drive unit for rotating the paper stack to the paper feeding position. The cover unit covers the front surface of the paper stacking unit, and is pulled out toward the front together with the paper stacking unit. A drive unit for automatic insertion and ejection on the front side, and a drive control unit that detects the set state of the cover unit, controls the start of operation of the drive unit, and sends a paper feed enable signal to the device control unit after the operation is completed. Wherein the amount of pull-out of the cover portion is larger than the amount of automatic insertion and discharge of the sheet stacking portion.

[0010] In a third aspect of the present invention, in the second aspect,
A paper feed control unit that determines whether the paper stacking unit is performing a paper feed operation,
A warning unit is provided which warns of an abnormality in trying to pull out the sheet stacking unit during the sheet feeding operation.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic front view of a sheet feeding device according to an embodiment of the present invention. Here, the front means the front of the hand on which the operator stands for operation. A paper feeding device 2 is installed at the bottom of the image forming apparatus main body 1. The sheet feeding device 2 includes a sheet stacking unit 3 and a sheet feeding roller 4 installed above and forward of the sheet stacking unit 3 (downstream in the sheet conveying direction).

The sheet stacking section 3 is of a front loading type capable of being pulled out toward the near side (vertical direction in the drawing) and capable of replenishing sheets. Is provided with a bottom plate 5 which rotates in a counterclockwise direction. Further, on the back surface of the bottom plate 5, a bottom plate raising lever portion 6 for acting on the bottom plate 5 to swing the bottom plate 5 in a counterclockwise direction is provided.

The bottom plate raising lever 6 also acts on the bottom plate 5 to rotate the bottom plate 5 while rotating counterclockwise in FIG. The bottom plate raising lever 6 is driven by a driving source described later.

Sheets are stacked on the sheet stacking section 3, and when the tip of the bottom plate 5 rotates counterclockwise by driving the bottom plate raising lever 6, the tip of the paper on the bottom plate 5 also rises, and The contact is made at an appropriate sheet feeding pressure. This position is the sheet feeding position. When the paper feed roller 4 is driven to rotate in this state, the paper is fed one by one from the uppermost paper and sent out to an image forming unit (not shown).

FIG. 2 is a plan view mainly showing a sheet stacking portion of the sheet feeding device according to the embodiment of the present invention. In the figure,
The lower part is the front of the hand (front). The bottom plate 5 having an H-shaped planar shape is not installed on the entire surface of the sheet stacking unit 3 but is installed on the right half in the drawing. The bottom plate raising lever portion 6 is composed of a shaft 10 and a lever 11 mounted at a right angle to the tip of the shaft 10. here,
The distance a from the left end of the paper stacking unit 3 to the shaft 10 and the distance b from the right end of the paper stacking base 3 to the shaft 10 are substantially the same.

FIG. 3 is an external perspective view of a shaft and a lever portion constituting a bottom plate raising lever portion. As described above, the bottom plate raising lever portion 6 includes the shaft 10 and the lever 11 mounted at a right angle to the tip of the shaft 10, and the wide lever 11 is fixed to the shaft 10 by two screws 12. ing. The shaft 10 is substantially perpendicular to the paper transport direction, that is, substantially horizontal to the front loading direction. A locking member 13 is provided in parallel with the shaft 10, and a locking claw 13 a is formed upright on the locking member 13. When the paper stacking unit 3 is pulled out to the front side, as shown in FIG.
The lock claw 13a is engaged with the lever 11, and the lever 1
1 is locked from rotating upward. Therefore, the bottom plate 5 is also locked from turning upward. That is, the bottom plate 5 does not rotate upward unless the sheet stacking unit 3 is set at a normal position (a sheet-feedable position) in the sheet pull-out direction.

Referring back to FIG. 2, a cover portion 14 is provided on the front side of the sheet stacking portion 3 so as to cover the front surface (front surface) of the sheet stacking portion 3. The part 3 is connected by two coil springs 15,15. Also, cover portions 1 are provided on both front sides of the paper stacking portion 3.
4 are provided with guide rails 16, 16 which can be fitted and slidable with the guide portions 14a, 14a.

In the apparatus main body 1, the distance c between the sheet stacking section 3 and the cover section 14 is large, and when the sheet stacking section 3 is pulled out from the apparatus main body 1, the distance c becomes small, or Both come into contact.
The coil springs 15, 15 expand and contract each time. Cover part 1
4 abuts against the front surface of the apparatus main body 1 and its position is determined. Although not shown, the sheet stacking section 3 is provided with a side fence for regulating the width direction of the sheet and an end fence for regulating the rear end of the sheet, as in the conventional example.

FIG. 4 is a view showing a shaft locking structure. The shaft 10 that constitutes the bottom plate raising lever unit 6 is mounted on the E-ring 1 so that the shaft 10 does not come out of the paper stacking unit 3 even if it is pushed or pulled.
Reference numerals 7 and 17 are used to connect to the sheet stacking unit 3. FIG. 5 is a configuration diagram illustrating a gear engagement state of the drive unit. The drive unit 21 includes a motor 22 serving as a drive source, a reduction gear 23 meshing with an output shaft 22a of the motor 22,
A fixed gear 24 meshing with the small-diameter gear portion 23a of the reduction gear 23 is provided. Further, an end surface of a slide shaft 25 which is screwed to the center of the fixed gear 24 and is slidable by rotation of the fixed gear 24 is shown in the figure.

In such a configuration, when the motor 22 rotates left (counterclockwise rotation), the output shaft 22a
The reduction gear 23 that meshes with the fixed gear 24 rotates clockwise (rotates clockwise), and the fixed gear 24 that meshes with the small diameter portion 23a of the reduction gear 23 rotates counterclockwise. On the other hand, when the motor 22 rotates clockwise, the gears 23 and 24 rotate in the opposite direction. That is, the fixed gear 24 rotates clockwise.

FIG. 6 is an external perspective view of a fixed gear and a slide shaft portion. A right-hand screw 26 is cut in the screwing portion between the fixed gear 24 and the slide shaft 25. When the fixed gear 24 is rotated counterclockwise, the slide shaft 25 is pulled inward within the range of the screwing portion. Further, if the clockwise rotation is performed, the slide shaft 25 moves forward within the range of the threaded portion. When the slidable range is exceeded, the slide shaft 25 rotates together with the fixed gear 24.

At the end of the slide shaft 25, there is provided a coupling 27 which is connected to the support shaft 7 of the bottom plate raising lever portion 6 (support shaft of the lever 10). The support shaft 7 is easily caught on this coupling 27. Are formed with claws 27a.

FIG. 7 is an overall structural view of the driving device. The slide shaft 25 includes the motor 22 and the reduction gear 2 shown in FIG.
3. It is provided so as to penetrate the fixed gear 24 of the drive unit 21 having the fixed gear 24. The apparatus main body 1 includes a tray detection unit (shown in FIGS. 14 and 15 described later) for detecting that the sheet stacking unit 3 has been inserted into the apparatus main body 1 and a top sheet on the bottom plate 5. As before, it has a rise detection unit (shown in FIG. 15 described later) for detecting a state in which paper can be fed, a paper end detection unit for detecting the presence or absence of a sheet on the sheet stacking unit 3, and the like. This is performed at the output of these detectors.

FIG. 8 is an explanatory view showing each state during the loading operation of the sheet stacking section, and FIG. 9 is a timing chart of each section during the loading operation of the sheet stacking section. Hereinafter, the loading operation will be described with reference to FIGS. First, an operation of setting the sheet stacking unit 3 on the apparatus main body 1 will be described. This is because the paper loading unit 3
The upper sheet is lost, and the sheet stacking unit 3 is
This is an operation after the sheet is automatically ejected to the front side of the apparatus main body 1 by the driving force of No. 1.

FIG. 8A shows a state in which the paper stacking unit 3 is pulled out to the front side of the apparatus main body 1 by the paper end. In this state, sheets are replenished to the sheet stacking section 3, and then the sheet stacking section 3 and the cover section 14 are manually pushed into the apparatus main body 1. Then, as shown in (2) of FIG. 8, just before the cover unit 14 is flush with the front surface of the apparatus main body 1 (d in FIG. 8), the tray detection unit is connected to the sheet stacking unit 3 of the apparatus main body 1. Detects insertion into Then, the drive unit 2
1 starts driving, the left rotation of the fixed gear 24 causes the slide shaft 25 to move backward, and the coupling 27 moves to the support shaft 7.
Hook. Therefore, the paper stacking unit 3 is
As shown in (3) of FIG. 8, it comes to a stop at a normal setting position with respect to the apparatus main body 1 and stops.

In the state shown in FIG. 8C, the lock claw 13a shown in FIG. In this state, the shaft 10 of the bottom plate raising lever 6 can rotate. In this state, since the fixed gear 24 and the slide shaft 25 are in a fixed relationship at the end positions of the screws 26, the rotation of the fixed gear 24 is transmitted to the slide shaft 25 as it is, and the slide shaft 25 rotates. As a result, the bottom plate raising lever 6 rotates counterclockwise in FIG. 1 via the coupling 27 fixed to the tip of the slide shaft 25 and the support shaft 7 engaged with the coupling 27. Push up. Therefore, the bottom plate 5 rotates in the counterclockwise direction, and the upper surface of the stacked sheets comes into contact with the sheet feeding roller 4 with an appropriate sheet feeding pressure. The rising detector detects this state, and the motor 22 of the drive unit 21 stops driving based on this detection signal.

If the paper feed roller 4 is driven to rotate from here,
The sheet is fed in order from the top, a toner image is transferred by an image forming unit (not shown), an unfixed toner image on the sheet is fixed by a fixing unit (not shown), and the sheet is discharged from a sheet discharging unit.

FIG. 9A shows the output timing of the paper end detector, FIG. 9B shows the output timing of the tray detector,
(3) shows the output timing of the elevation detecting unit, and (4) shows the output timing of the drive unit. As described above, the paper stacking unit 3 that is manually inserted into the apparatus main body 1 is the one shown in (2) of FIG. If it is detected by the tray detector in this state, it is automatically inserted thereafter. And release of the lock claw 13a, the bottom plate 5
Rise at the timing shown in FIG.

Next, the operation of pulling out the sheet stacking unit 3 from the apparatus main body 1 will be described. When the paper end detection unit detects that there is no paper on the paper stacking unit 3, FIG.
The output is turned on as shown in (1). At the falling timing, the motor 22 of the drive unit 21 rotates in the reverse direction (clockwise rotation) as shown in (4) of FIG. Then, the fixed gear 24 also reverses via the reduction gear 23, and the slide shaft 25 also reverses. Therefore, the bottom plate raising lever 6 is lowered (clockwise rotation) via the coupling 27 and the support shaft 7.
I do. Thereby, the bottom plate 5 also descends.

Thereafter, the rotational force of the fixed gear 24 becomes a force in the sliding direction by the screw 26, and the slide shaft 25 moves forward. Accordingly, the paper stacking unit 3 also advances through the coupling 27 and the support shaft 7, and projects from the front surface of the apparatus main body 1 while narrowing the gap with the cover unit 14. This state is the state shown in FIG. 8A as described above.

According to the embodiment of the present invention, at the time of replenishing sheets, the sheet stacking section 3 is pulled out while the distance between the sheet stacking section 3 and the cover section 14 is reduced, and the sheet stacking section 3 is inserted into the apparatus main body 1.
Is set, the distance between the sheet stacking section 3 and the cover section 14 is widened, so that loading can be performed with a small amount of movement, and a substantial occupation area can be reduced.

Further, during the operation of the paper stacking section 3, the vicinity of the lock section where the load is most applied is automated, so that the operability is improved. Furthermore, coupling 27 during front loading
Is engaged with the support shaft 7, so that there is no possibility that the user erroneously pulls out the sheet stacking unit 3 and causes a jam.

FIG. 10 is a perspective view showing another example of the fixed gear. FIG. 11 is a configuration diagram of an entire driving device incorporating the fixed gear shown in FIG. At both ends of the fixed gear 24, bosses 31 are provided which come out of the drive unit 21. Further, a convex portion 32 is formed on an end surface of the boss portion 31. The fixed gear 24 is bearing-supported by the boss 31 with respect to the drive unit 21. The slide shaft 25 is externally threaded over its entire length, and pins 33 are pressed into both ends of the slide shaft 25.

The coupling 27 includes a slide shaft 25
Is fixed to one end (on the paper stacking unit 3 side) with a nut 34 by a double nut method. By loosening the nut 34 and rotating the coupling 27 forward and backward, the position of the coupling 27 with respect to the slide shaft 25 changes. That is, the position of the sheet stacking unit 3 with respect to the apparatus main body 1 changes (about ± 3 mm). This makes it possible to adjust the registration for the image. It should be noted that a digital copying machine can arbitrarily set an image writing position, but an analog copying machine cannot arbitrarily set an image writing position, and therefore, it is necessary to adjust each paper feed stage.

With such a configuration, as shown in the above-mentioned states (2) and (3) in FIG. 8, the sheet stacking section 3 is pulled in by the slide shaft 25 and the pin 33 is
, The slide drive by the fixed gear 24 is switched to the rotational drive, and the sheet stacking unit 3 stops at a normal position with respect to the apparatus main body 1.

If the screw portion is completely closed when switching the slide movement to the rotational movement, the screw may not be loosened again when switching, and may malfunction. In order to prevent this, the pin 33 abuts on the convex portion 32, so that the screw portion does not tighten. As a result, no malfunction occurs at the time of switching again.

FIG. 12 is an explanatory view showing the manner in which the position of the sheet stacking section is changed by adjusting the nut. (1) shows a state where the sheet stacking unit 3 is moved outward by about 3 mm. (2) shows a normal state. (3) is minus 3mm
This shows a state in which the paper stacking unit 3 has been moved about inward.

FIG. 13 is a longitudinal sectional view showing an example of the structure of the front side of the sheet stacking section and the cover section, and FIG. 14 is a perspective view of the same. FIG. 13A shows a state in which the sheet stacking unit 3 is set at the sheet feeding position and the distance from the cover unit 14 is large. FIG. 13B shows a state where the sheet stacking unit 3 is in contact with the cover unit 14 when the sheet stacking unit 3 is pulled out. A handle 41 for performing a loading operation is attached to substantially the center of the front surface of the sheet stacking unit 3. The front surface of the cover portion 14 is provided with a rib for preventing warpage at the time of molding, but has a low height (h) and no strength. A sensor 42 for detecting the paper stacking portion and detecting the setting state of the cover portion 14 is provided substantially at the center of the front surface of the apparatus main body 1.

The screw length of the slide shaft 25 is set to be longer than the amount by which the cover unit 14 moves on the guide rail 16 when the sheet stacking unit 3 is set on the apparatus main body 1 by the amount of registration adjustment. The amount by which the cover 14 can move on the guide rail 16 is set to be longer.

FIG. 15 is a control block diagram related to the sheet feeding device. In addition to the sensor 42 and the drive unit 21,
A warning buzzer 43, a drive control unit 44, a paper feed control unit 45, and a device control unit 47 on the device main body 1 side are shown.
General control of the copying machine is performed by the device control unit 47. The paper is conveyed by a paper feed control unit 45, and a pickup operation solenoid, a feed roller transmission clutch, an elevation detection unit 46,
The separation roller release solenoid, each conveyance sensor, the drive control unit 44, the registration roller transmission clutch and the like are controlled to manage the paper being conveyed.

The drive control unit 44 is provided with a warning buzzer 43 so as to promptly notify when an abnormality occurs. If the user mistakenly tries to remove the paper stacking unit 3 that is feeding paper from the apparatus main body 1, a warning is issued by the warning buzzer 43.
This can prevent a jam.

FIG. 16 is a timing chart of each section when the paper stacking section is pulled out. (1) is the output timing of the paper end sensor, (2) is the output timing of the sensor 42, (3) is the output timing of the rise detecting unit 46, (4)
Is the output timing of the drive control unit 44 and the drive unit 21. If the paper stacking unit 3 other than the paper feeding unit is to be directly pulled out instead of being automatically discharged, the cover unit 14
Comes off by the amount of deflection and the remaining slide. The sensor 42 detects this at an early stage, and the fixed gear 24 of the drive unit 21 rotates in the reverse direction (clockwise rotation) in FIG. 5 to start automatic discharge of the paper stacking unit 3. Thus, even if the sheet stacking unit 3 is forcibly pulled out, it can be prevented from being damaged.

[0043]

According to the first aspect of the present invention, since the handle is provided not on the cover but on the sheet stacking portion, the load on the cover can be reduced and the life can be extended. In addition, since it is not necessary to reinforce the cover, the cost can be reduced.

According to the second aspect of the present invention, since it is possible to quickly detect that when the paper stacking section is pulled out, even during the paper feeding operation, the operation is interrupted when a break is good, and the rate of occurrence of a jam is reduced. Can be reduced. Further, when trying to pull out the sheet stacking section other than the sheet feeding section by hand, an automatic discharge operation can be performed, so that the load on the cover section can be reduced.

According to the third aspect of the present invention, the danger can be notified to the user by the warning means, so that the effect of jam prevention can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a plan view centering on a sheet stacking portion of the sheet feeding device according to the embodiment of the present invention.

FIG. 3 is an external perspective view of a shaft and a lever portion constituting a bottom plate raising lever portion.

FIG. 4 is a view showing a shaft locking structure.

FIG. 5 is a configuration diagram illustrating a gear engagement state of the drive unit.

FIG. 6 is an external perspective view of a fixed gear and a slide shaft portion.

FIG. 7 is a configuration diagram of the entire driving device.

FIG. 8 is an explanatory diagram illustrating each state during a loading operation of the sheet stacking unit.

FIG. 9 is a timing chart of each unit during a loading operation of the sheet stacking unit.

FIG. 10 is a perspective view showing another example of the fixed gear.

FIG. 11 is a configuration diagram of an entire driving device incorporating the fixed gear shown in FIG. 10;

FIG. 12 is an explanatory diagram illustrating a state in which the position of a sheet stacking unit is changed by adjusting a nut.

FIG. 13 is a longitudinal sectional view illustrating an example of a structure of a front side of a sheet stacking unit and a cover unit.

FIG. 14 is a perspective view of the same.

FIG. 15 is a control block diagram related to a sheet feeding device.

FIG. 16 is a timing chart of each unit when the paper stacking unit is pulled out.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Apparatus main body 3 Paper loading part 5 Bottom plate 6 Bottom plate raising lever part 7 Support shaft 21 Drive part unit 22 Motor 24 Fixed gear 25 Slide shaft (output transmission shaft) 27 Coupling 41 Handle 42 Sensor 43 Warning buzzer 44 Drive control part 46 Ascent Detector

Claims (3)

[Claims] An upper surface of a sheet to be stacked has a bottom plate which is rotatable up to a sheet feeding position where the upper surface of the sheet is in contact with a sheet feeding roller. A paper feed device having a drive unit for rotating and ascending, a cover for covering the front surface of the paper stacking unit, a cover part drawn out toward the front together with the paper stacking unit, and a handle for pulling out the paper stacking unit and the cover unit. A sheet feeding unit, wherein the sheet feeding unit is provided on the sheet stacking unit. 2. A sheet stacking section which has a bottom plate whose upper surface is rotatably raised to a sheet feeding position where the sheet stacking sheet comes into contact with a sheet feeding roller. A sheet feeding device having a drive unit for rotating and ascending, covering a front surface of the paper stacking unit, and a cover unit to be pulled out together with the paper stacking unit, and automatically inserting the paper stacking unit into the front surface of the apparatus body; A drive unit for automatically discharging, and a drive control unit for detecting the set state of the cover unit, controlling the start of the operation of the drive unit, and transmitting a sheet-ready signal to the apparatus control unit after the operation is completed, A sheet feeder, wherein the amount of paper withdrawal is greater than the amount of automatic insertion and discharge of the paper stacking unit. 3. The paper feeding control unit according to claim 2, further comprising: a paper feed control unit configured to determine whether the paper stacking unit is performing a paper feeding operation; and a warning unit that warns an abnormality in pulling out the paper stacking unit during the paper feeding operation. A sheet feeding device.