JPH06271096A - Paper feeder - Google Patents

Abstract

PURPOSE:To prevent a record medium from being caught by an image forming device side even a storing means is drawn out during the stand-by action of the image forming device of arranging a control means for controlling a moving means by which the storing means of the record medium is moved upto a first position during the image forming action time and upto a second position during the standby time of action. CONSTITUTION:A control means 20 controls an upper/lower drive means 8 and stops the rise of a tray 7 based on the on-signal of the tray upper limit sensor. When an empty sensor 17 turns on under this state, the control means 20 judged that the paper sheet P staying on the most upper part among the paper sheets P on the tray 7 makes contact with a pick up roller 13 and controls the uppert/lower drive means 8 and lowers the tray 7 until the empty sensor 17 turns off. Thereby, the paper sheets P on the tray 7 are placed in such status that the paper sheet P staying on the most upper part makes no contact with the pick up roller 13. Accordingly, it can be avoided that the paper sheet P staying on the most upper part catches the pick up roller 13, even though a paper feed device 1 is drawn out from a main body 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device, and more specifically, it stores a large number of sheets for image formation in a storing means and forms an uppermost image through a take-out means provided in the image forming apparatus. The present invention relates to a sheet feeding device for forming images one by one from a medium.

[0002]

2. Description of the Related Art As a paper feeding device of this type, the one shown in FIG. 6 is conventionally known.

A sheet feeding device 30 shown in the figure stores a large amount of sheets P for image formation on a tray 34 in a storing means 31, and is provided in a main body 32 of an image forming apparatus such as an electrophotographic copying machine. The uppermost sheet P in the accommodating means 31 is taken out by the pickup roller 33 and is used for image formation by the main body 32.

[0004]

However, in the case of the above-described conventional sheet feeding device 30, the uppermost sheet P among the sheets P on the tray 34 is always picked up by the pickup roller 33 even during the standby operation of the main body 32. Since the sheet feeding device 30 is in contact with each other, when the sheet feeding device 30 is pulled out to the side of the main body 2 on the rail 36 as shown in FIG. 7, the uppermost sheet P is picked up by the pickup roller 33 or the sheet guide 35 of the main body 32. As a result, there is a problem that the sheet P cannot be normally supplied from the sheet feeding device 30 to the main body 32 during the actual image forming operation of the main body 32.

Therefore, it is an object of the present invention to provide a sheet feeding device having an improved structure so that the recording medium is not caught on the image forming apparatus side even when the accommodating means is pulled out during the standby operation of the image forming apparatus. To do.

[0006]

The invention according to claim 1 is
In a paper feeding device for feeding and feeding a recording medium by bringing the recording medium into contact with an ejecting means provided in the image forming apparatus, an accommodating means accommodating a plurality of recording media and an accommodating means accommodated in the accommodating means. A first position in which the uppermost recording medium is in contact with the ejecting means of the image forming apparatus, and the uppermost recording medium accommodated in the accommodating means is in contact with the ejecting means of the image forming apparatus. No moving means for moving the accommodating means between the second positions, and the accommodating means is moved to and held at the first position during an image forming operation by the image forming apparatus, and the image forming by the image forming apparatus is performed. When the operation is on standby, the accommodating means is set to the second
Control means for controlling the moving means so as to move and hold it to the position.

According to a second aspect of the present invention, in a paper feeding device for feeding a recording medium to the image forming apparatus, a housing means for housing a plurality of recording media, and a take-out means for taking out the recording medium from the housing means. A first position where the uppermost recording medium accommodated in the accommodating means contacts the ejecting means, and a first position in which the uppermost recording medium accommodated in the accommodating means does not contact the ejecting means. Moving means for moving the accommodating means between two positions, and the accommodating means is moved to and held at the first position during the image forming operation by the image forming apparatus, and the image forming operation by the image forming apparatus is performed. And a control means for controlling the moving means so as to move and hold the housing means to the second position during standby.

According to a third aspect of the present invention, a housing configured to be attachable to and detachable from the image forming apparatus, a housing means for housing a plurality of recording media in the housing, and the housing means. A take-out means for taking out the recording medium from the housing, a moving means for moving the containing means to a position where the uppermost recording medium housed in the containing means comes into contact with the take-out means, When separating,
And a control means for controlling the moving means so as to move the containing means to a position where the uppermost recording medium of the containing means does not come into contact with the ejecting means.

[0009]

The function of each invention described above will be described below.

According to another aspect of the present invention, the control means controls the moving means to move the accommodating means to the first position where it abuts the ejecting means during the image forming operation of the image forming apparatus. Further, since the accommodating means is moved to and held at the second position where it does not come into contact with the ejecting means when the image forming operation of the image forming apparatus is on standby, the sheet feeding device temporarily forms an image on standby. Even when the recording medium is pulled out from the apparatus, the recording medium is not caught by the ejecting unit, and the subsequent supply operation of the recording medium can be normally performed.

According to another aspect of the present invention, the control means controls the moving means so that the accommodating means is brought into contact with the take-out means provided in the paper feeding device during an image forming operation of the image forming apparatus. The sheet is moved to and held at the first position, and when the image forming operation of the image forming apparatus is on standby, the accommodating means is moved to and held at the second position where the accommodating means is not in contact with the ejecting means. Even if the apparatus is pulled out from the image forming apparatus during standby, the recording medium is not caught by the ejecting means, and the subsequent supply operation of the recording medium can be normally performed.

According to another aspect of the present invention, the control means controls the moving means, and when the housing is separated from the image forming apparatus, the uppermost recording medium of the accommodating means. Moves the accommodating means to a position where it does not come into contact with the ejecting means, so that even if the housing is pulled out from the image forming apparatus during standby, the recording medium does not get caught in the ejecting means, and the recording medium is supplied thereafter. The operation can be performed normally.

[0013]

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

FIG. 1 shows a copying machine 2 as an image forming apparatus incorporating the paper feeding device 1 of this embodiment. The copying machine 2 has a box-shaped main body 3 as a recording medium. The photosensitive drum 4 for forming an image on the paper P is provided, and the paper feeding device 1 is mounted on the rail 5 provided at the lower side of one end of the main body 3 so as to be slidable in the arrow direction shown in FIG. ing.

In this paper feeding device 1, a plate-shaped tray 7 on which a large amount of paper P is placed is housed in a box-shaped accommodating means (housing) 6 and for example, vertical drive means 8 using a motor and a gear mechanism. Is configured so that it can be moved vertically in the vertical direction.

Further, a bottom sensor 9 for detecting the position of the lowermost end of the tray 7 is arranged at a lower position in the accommodating means 6 by using, for example, a micro switch.

Below the photosensitive drum 4 of the main body 3,
Two paper cassettes 1 containing paper P of different sizes
0 and 11 are removably arranged, and a conveying path 1 from each paper cassette 10 and 11 to the photosensitive drum 4
2 is formed.

Further, the main body 3 is provided with a pick-up roller 13 as a take-out means facing the paper feeding section of the paper feeding device 1 and taking out the uppermost paper P on the tray 7 one by one. At the same time, the taken-out sheet P is sent to the photosensitive drum 4 through the conveying roller 14 and the aligning roller 15 and is used for image formation.

Further, with respect to the arm 15 which supports the pickup roller 13, the pickup roller 13
While the tray upper limit sensor 16 for detecting the upper limit position of the tray 7 is attached in an arrangement that matches the outer circumference of
An actuator 17a of an empty sensor 17 for detecting the presence or absence of the paper P on the tray 7 is rotatably arranged near the tray upper limit sensor 16. The projecting end of the actuator 17a coincides with the lowermost end of the outer circumference of the pickup roller 13.

The pickup roller 13 may be provided on the upper part of the accommodating means 6.

FIG. 2 shows a control system of the sheet feeding device 1, in which the detection signals of the bottom sensor 9, the tray upper limit sensor 16 and the empty sensor 17 are fetched by the control means 20, and this control means 20 is used. Thus, the vertical drive means 8 is controlled to execute the operations of raising, lowering and stopping the tray 7.

Next, the operation of the above-described paper feeding device 1 will be described with reference to FIG.
It will be described with reference to FIGS.

A large amount of paper P is replenished on the tray 7 of the paper feeding device 1 (ST1), and the paper feeding device 1 (not shown) is supplied.
When the door is closed, the vertical drive means 8 operates under the control of the control means 20 to raise the tray 7 (ST
2).

When the upper end of the paper P on the tray 7 is detected by the tray upper limit sensor 16 and the tray upper limit sensor 16 is turned on (ST3), the control means 20 operates based on the ON signal of the tray upper limit sensor 16. The vertical drive means 8 is stopped and controlled. This allows
The tray 7 stops rising (ST4).

In this state, if the empty sensor 17 is turned on (ST5), the control means 20 causes the uppermost sheet P of the sheets P on the tray 7 to be picked up by the pickup roller 13.
When the empty sensor 17 is turned off, the tray 7 is lowered until the empty sensor 17 is turned off, and the tray 7 is stopped when the empty sensor 17 is turned off (ST6). 7, 8). After this, the main body 3 enters a standby operation state (ST9).

As a result, the uppermost sheet P of the sheet P on the tray 7 does not come into contact with the pickup roller 13, as shown in FIG. As shown in the drawing, even if the sheet P is pulled out from the main body 3 in the direction of the arrow, the uppermost sheet P remains the pickup roller 1.
It is possible to reliably avoid the situation of getting stuck in 3.

On the other hand, when the tray 7 is lowered until the bottom sensor 9 is turned on while the empty sensor 17 is not turned on (ST5: No) (ST1).
0), there is no paper P on the tray 7.

The present invention can be modified in various ways within the scope of the invention in addition to the embodiments described above.

In the above-described embodiment, the sheet feeding device which is slidably arranged with respect to the main body has been described. However, the present invention is also applicable to a sheet feeding device which is detachably incorporated in the main body. is there.

[0030]

According to the present invention described above, the following effects are obtained.

According to the first aspect of the present invention, because of the above-mentioned configuration, the recording medium is not caught by the ejecting means provided in the image forming apparatus, and the subsequent recording medium supply operation can be performed normally. It is possible to provide a paper feeding device that can do this.

According to the second aspect of the present invention, because of the above-mentioned configuration, the recording medium is not caught by the ejecting means provided in the accommodating device, and the subsequent recording medium supply operation can be performed normally. A paper feeding device can be provided.

According to the third aspect of the present invention, because of the above-mentioned configuration, even if the housing is pulled out from the image forming apparatus during standby, the recording medium will not be caught by the ejecting means, and subsequent recording will be performed. It is possible to provide a paper feeding device that can normally perform a medium supply operation.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a copying machine that incorporates a sheet feeding device that is an embodiment of the present invention.

FIG. 2 is a block diagram showing a control system of the sheet feeding device of the present embodiment.

FIG. 3 is a partial configuration diagram showing an arrangement of a sheet feeding device of the present embodiment and a main body of a copying machine.

FIG. 4 is a partial configuration diagram showing a state in which the paper feeding device of the present embodiment is pulled out from the main body of the copying machine.

FIG. 5 is a flowchart showing the operation of the paper feeding device of this embodiment.

FIG. 6 is a partial configuration diagram showing an arrangement of a conventional sheet feeding device and a body of a copying machine.

FIG. 7 is a partial configuration diagram showing a state in which a conventional paper feeding device is pulled out from a main body of a copying machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper feeding device 2 Copying machine 3 Main body 6 Storage means 7 Tray 8 Vertical drive means 13 Pickup roller 16 Tray upper limit sensor 17 Empty sensor P Paper

Claims (3)

[Claims] 1. A paper feeding device for feeding and feeding a recording medium by bringing the recording medium into contact with a take-out means provided in the image forming apparatus; A first position in which the uppermost recording medium accommodated in the accommodating means comes into contact with the ejecting means of the image forming apparatus, and the uppermost recording medium accommodated in the accommodating means is the image forming apparatus of the image forming apparatus. Moving means for moving the accommodating means between a second position that does not abut against the ejecting means, and the accommodating means for moving and holding the accommodating means to the first position during an image forming operation by the image forming apparatus. A sheet feeding device, comprising: a control unit that controls the moving unit to move and hold the accommodating unit to the second position when the image forming operation of the forming apparatus is on standby. 2. In a paper feeding device for feeding a recording medium to an image forming apparatus, an accommodating means for accommodating a plurality of recording media, an ejecting means for ejecting the recording medium from the accommodating means, and the accommodating means. Between a first position where the uppermost recording medium accommodated is in contact with the ejecting means and a second position where the uppermost recording medium accommodated in the accommodating means is not in contact with the ejecting means. Moving means for moving the accommodating means, and moving and holding the accommodating means to the first position during the image forming operation by the image forming apparatus, and the accommodating means during the standby of the image forming operation by the image forming apparatus. And a control unit that controls the moving unit so as to move and hold it to the second position. 3. A housing which is configured to be attachable to and detachable from the image forming apparatus, a housing means which houses a plurality of recording media in the housing, and a recording medium which is taken out from the housing means. Means, moving means for moving the accommodating means to a position where the uppermost recording medium accommodated in the accommodating means contacts the ejecting means, and when the housing is separated from the image forming apparatus, A sheet feeding device, comprising: a control unit that controls the moving unit so that the uppermost recording medium of the containing unit does not come into contact with the ejecting unit.