JP2692900B2 - Paper feeding device and image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of use) The present invention relates to a sheet feeding device for taking out and feeding stacked sheets one by one, and more specifically, both end corners in a sheet taking-out direction. A sheet feeding device for taking out a sheet in a storing means such as a sheet feeding cassette which holds the sheet in a state of being held by a separating claw, and an image forming apparatus such as an electronic copying machine provided with the sheet feeding means such as a half-moon shaped sheet feeding roller. Regarding the device.

(Prior Art) In recent years, an image forming apparatus such as an electronic copying machine has been remarkably popularized, and a lot of desk-top type apparatuses have been put to practical use.

Normally, in a desk-top electronic copying machine or the like, a paper feed cassette that accommodates paper with both end corners in the paper take-out direction held by separation claws, and the paper in this paper feed cassette is taken out by the frictional force. A paper feeding device having a paper feeding roller is used.

Also, in this type of paper feeding device, most of the time, the paper feeding cassette is installed in a state of partially protruding outside the main body of the device, and the paper feeding cassette is installed to prevent dust from entering the paper feeding cassette. The cassette cover covers the part excluding the outlet.

Conventionally, in this type of paper feeding device, reliable paper feeding
In order to take out the sheets, a resin holding sheet is attached to the cassette cover, and the amount of swelling of the paper between the separating claws generated at the time of taking out is regulated by the holding sheet.

(Problems to be Solved by the Invention) However, in recent years, for the purpose of downsizing and cost reduction of the apparatus, an image forming method in which the entire sheet feeding cassette is housed in the apparatus body and the cassette cover is eliminated Although a device is being developed, in this way, when the cassette cover is removed, the expansion of the paper between the separating claws cannot be regulated at the time of taking out, and it is not possible to take out one sheet reliably, and multiple sheets are taken out at the same time. There is a serious problem of being lost.

The present invention has been made based on the above circumstances, and an object of the present invention is to reduce the amount of swelling of a sheet at the time of taking out between separation claws even though the cover of the accommodating means such as a cassette cover is eliminated. An object of the present invention is to provide a paper feeding device that can be reliably regulated and can reliably take out one sheet, and an image forming apparatus including the paper feeding device.

[Structure of the Invention] (Means for Solving the Problems) As a first means for achieving the above object, the present invention accommodates a sheet in a state in which both end corners in the take-out direction are held by separation claws. Storage means, and a half-moon-shaped paper feeding means provided in a state of facing the paper in the storage means, and having an arc-shaped sending portion that comes into contact with the paper to send the paper, and a escape portion that does not contact the paper, The sheet feeding means is provided in the vicinity of the separation claw coaxial with the rotation shaft to which the sheet feeding means is attached, and an arcuate multiple take-out prevention unit that restricts a bulging amount of the sheet at the time of taking out the sheet to prevent multiple take-out, and a sheet And a half-moon-shaped multiple take-out preventing member attached so that the escape portion is in the same phase as the escape portion of the half-moon shaped sheet feeding means. A.

Further, as a second means, a storage means for storing the paper in a state where both corners of the paper in the take-out direction are pressed by separation claws, and a storage means provided so as to face the paper in the storage means and contact the paper. And a crescent-shaped sheet feeding means having an arc-shaped feeding portion for feeding the sheet and an escape portion that does not come into contact with the sheet, and provided in the vicinity of the separation claw coaxial with the rotation shaft to which the sheet feeding means is attached. An arc-shaped multiple take-out preventing portion that restricts the amount of bulging of the paper at the time of taking out the paper to prevent multiple take-out, and a relief portion that does not come into contact with the paper, and the escape portion is the escape portion of the half-moon-shaped paper feeding means. In this configuration, a sheet feeding device having a half-moon-shaped multiple take-out preventing member attached so as to have the same phase is provided.

(Operation) That is, according to the first means of the present invention, the excessive swelling of the sheet at the time of taking out is restricted by the multiple take-out preventing member provided on the rotating shaft, and the second and subsequent sheets of paper are separated from the separating claw. Is prevented from coming off. This allows
Multiple take-out is prevented, and reliable one-piece take-out becomes possible. Further, since the multiple take-out prevention member has a half-moon shape similar to that of the sheet feeding means and rotates integrally, it does not interfere with the insertion / removal of the accommodating means. Furthermore, since the multiple take-out prevention member is provided near the separation claw, the amount of swelling of the paper near the separation claw can be regulated, and the separation effect can be obtained in a more stable state. Further, according to the first means, the multiple take-out prevention member is provided on the same rotary shaft as the paper feeding means, and the respective escape portions are attached so as to be in the same phase. It is possible to prevent skewed feeding.

Further, according to the second means, it is possible to easily take out exactly one sheet of paper from the accommodating means and easily insert and remove the accommodating means, and it is possible to improve reliability and operability during image formation.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 2 shows the internal configuration of the entire apparatus, and FIG. 3 shows a state in which the document holding cover is opened. In the apparatus main body 1, charging, exposure, development, transfer, peeling, cleaning, charge removal, fixing, etc. And a document placing table (hereinafter, referred to as platen glass) 3 on which a document D is set is provided on the upper surface.

Further, a platen glass 3 is provided on the rear edge of the apparatus main body 1.
A document pressing cover 4 for pressing the document D set thereon is attached, and a copy key 5, a clear / stop key 6, a numeric keypad 7, a display unit 8 and the like are arranged on a front edge of the upper surface of the apparatus main body 1. Operation panel 9 is arranged.

Further, a front cover 10 that can be opened and closed is provided on the front surface of the apparatus body 1, and a lower portion of the front surface serves as accommodating means for accommodating the paper P such as plain paper supplied to the image forming process constituting means 2. The paper feeding cassette (hereinafter, simply referred to as a cassette) 11 of 11 is inserted. Further, on the left side of the apparatus main body 1, a tray 12 for stacking the fixed paper P and a power switch 13 are provided.

The image forming process configuration unit 2 has the following configuration. That is, a drum-shaped photoconductor 20 as an image carrier is arranged at a substantially central portion in the apparatus main body 1,
Around the photoreceptor 20, along the rotation direction thereof, a charging device 21, an exposure unit 22a of an exposure device 22, a developing device 23, a pre-transfer exposure device 24, a transfer device 25, a peeling device 26, a cleaning device 27, The static eliminator 28 and the like are sequentially arranged. Since these configurations are not directly related to the present invention, detailed description will be omitted.

Further, in the main body 1 of the apparatus, the paper P automatically fed from the cassette 11 or the paper P manually fed through the manual paper feed tray 29 is transferred to the photoconductor 20 and the transfer device.
A sheet conveyance path 31 is formed which leads to the tray 12 provided on the left side of the apparatus main body 1 via an image transfer section 30 between the sheet transfer section 25 and the sheet transfer section 25.

A registration roller pair 32 is disposed on the upstream side of the image transfer section 30 of the paper transport path 31, and a fixing device 33 and a paper discharge roller pair 34 are disposed on the downstream side. The peeling device 26
A conveyance belt unit 35 is disposed between the fixing belt 33 and the fixing device 33.

In addition, one sheet of paper P is placed near the mounted portion of the cassette 11.
A paper feed roller 36 as a paper feed means for taking out the sheets one by one, and the paper P taken out through the paper feed roller 36 is received and fed into a first branch conveyance path forming an upstream side of the paper conveyance path 31. Separation / conveyance means including a conveyance roller and a separation roller
37 are arranged. Further, a manual feed roller 38 is provided at the junction of the first branch transport path and the second branch transport path for manual feed.

Further, the apparatus main body 1 is divided into an upper unit 1A and a lower unit 1B at about a boundary of the paper transport path 31, and a support shaft 40 provided on the paper feed side as necessary. The upper unit 1A can be opened by about 25 degrees using the as a pivot point. The support shaft 40 is configured by a shaft portion of a torsion bar that constantly urges the upper unit 1A in the opening direction.

In FIG. 2, reference numeral 41 denotes a cooling fan disposed above the fixing device, and reference numeral 42 denotes a manual feed guide for guiding paper to be manually fed. Reference numeral 43 denotes a high-voltage transformer, and reference numeral 44 denotes a scale serving as a reference for setting the document D.

FIG. 4 shows the sheet feeding device 50, which is a cassette.
11 and a paper feed roller 3 for feeding the paper P in the cassette 11
It has a structure including 6,36. The cassette 11 is
The sheet P is accommodated in a state where both corners in the take-out direction are pressed by the separating claws 51 and 51, and both side edges of the sheet P are moved by the movable guide members 52 and 52 to which the separating claws 51 and 51 are connected. The rear end is supported by a replaceable rear end support plate 53. Further, on the lower surface of the paper P in the take-out direction side, there are provided push-up springs 54, 54 and a receiving plate 56 which is always lifted by a push-up spring 55 weaker than the push-up springs 54, 54 so that the uppermost paper P is always in a position suitable for take-out. Has been pushed up to.

Further, as shown in FIGS. 2 and 5, the paper feed rollers 36, 36 have an arcuate delivery portion 36a for delivering the paper P by coming into contact with the paper P and a flat notch not coming in contact with the paper P. It has a half-moon shape with an escape portion 36b consisting of. The arcuate delivery portion 36a is made of a material such as rubber that has a large friction with the paper, and when it comes into contact with the paper, the paper can be reliably delivered by the frictional force. Further, the escape portion 36b is located on the lower surface when stopped, and the cassette can be used without raising the paper feed roller 36.
11 can be inserted and removed in a direction (arrow B direction in FIG. 4) orthogonal to the take-out direction of the paper P (arrow A direction in FIG. 4).

Further, as shown in FIGS. 1 and 4, the paper feed roller
A paper feed roller shaft 57, which is a rotary shaft to which 36, 36 are attached, is provided with a multiple take-out prevention member 58, which is located between the separation claw 51 and the paper feed roller 36. These multiple ejection preventing members 58, 58 have a half-moon shape having an arc-shaped pressing portion 58a that contacts the paper P and a relief portion 36b that is a flat notch that does not contact the paper P, like the paper feed roller 36. It is mounted such that the escape portion 36b is at the bottom, like the paper feed rollers 36, 36 when stopped.
And, it does not interfere with the insertion / removal of the cassette 11. The arcuate pressing part receiver 58a of the multiple take-out preventing members 58, 58 is configured to be slightly smaller than the diameter of the arcuate pressing part 36a of the paper feed rollers 36, 36.

Further, when feeding the paper, the clutch (not shown) provided on one end side of the paper feeding roller shaft 57 works to cause the paper feeding roller shaft 57 to move.
Rotates once. Then, the paper P is sent out by a frictional force due to the contact between the paper P and the arcuate delivery portions 36a, 36a accompanying the rotation of the paper feed rollers 36, 36.

At this time, not only the uppermost sheet P but also the second and subsequent sheets P are about to be taken out by the contact frictional force between the sheets, so that not only the uppermost sheet P but also the second and subsequent sheets P are fifth.
As shown by a in the figure, it is greatly expanded to try to get over the separating claws 51, 51, but the arcuate pressing portion 58a of the multiple take-out preventing members 58, 58 comes into contact with the paper P, so that the separating claws 51, 51 The amount of expansion in the vicinity is regulated to the extent shown by b in FIG. As described above, since the arcuate pressing portion 58a of the multiple take-out prevention member 58 has a smaller diameter than the arcuate sending portion 36a of the paper feed roller 36, the arcuate pressing portion 58a itself is in contact with the paper unless the paper expands. Also, since the arc-shaped pressing portion 58a is not covered with rubber or the like, even if it comes into contact, the friction with the paper is small. Therefore, the arc-shaped pressing member
58a has no sheet conveying force, and even if the sheet comes into contact with the arcuate pressing member 58a, the sheet conveying force of the sheet feeding roller 36 is not affected. As a result, regarding the conveyance of the first sheet P, the sheet and the multiple take-out prevention member
The contact of 58 does not have any influence on the conveyance of the first sheet. Further, since the friction between the paper sheets is sufficiently smaller than the friction between the paper sheets and the paper feed roller, the second and subsequent paper sheets P
Even if it swells when the first sheet of paper is conveyed,
The both corners pressed by the multiple take-out preventing member 58 cannot pass over the separating claws 51, 51, and only the uppermost sheet P is reliably taken out by friction with the sheet feeding roller 36.

The present invention is not limited to the above-described embodiments, and can be variously modified without departing from the scope of the invention.

[Advantages of the Invention] Since the present invention is configured as described above, it has the following advantages.

In the paper feeding device according to the first aspect of the present invention, the multiple take-out preventing member provided on the rotating shaft prevents unnecessary bulging of the paper at the time of taking out, and prevents the second and subsequent papers from coming off from the separating claw. It As a result, multiple take-out is prevented, and reliable one-piece take-out becomes possible. Further, since the multiple take-out prevention member has a half-moon shape similar to that of the sheet feeding means and rotates integrally, it does not interfere with the insertion / removal of the accommodating means. Furthermore, since the multiple take-out prevention member is provided near the separation claw, the amount of swelling of the paper near the separation claw can be regulated, and the separation effect can be obtained in a more stable state. Further, according to the first means, the multiple take-out prevention member is provided on the same rotary shaft as the paper feeding means, and the respective escape portions are attached so as to be in the same phase. It is possible to prevent skewed feeding.

Further, in the image forming apparatus according to the second aspect, it is possible to surely take out one sheet from the accommodating means and to insert and remove the accommodating means easily, and it is possible to improve reliability and operability during image formation.

[Brief description of the drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a schematic perspective view of a main part, FIG. 2 is a schematic vertical sectional front view of the entire image forming apparatus, and FIG. 3 is a document pressing cover opened. FIG. 4 is a schematic perspective view showing the appearance of the image forming apparatus in the state, FIG. 4 is a schematic plan view of the sheet feeding device, and FIG. 5 is an explanatory diagram showing the state when the sheet is taken out. 11 ... accommodating means (paper feeding cassette), 36 ... paper feeding means (paper feeding roller), 36a ... arc sending portion, 36b ... escape portion, 50
…… Paper feed device, 51 …… Separation pawl, 57 …… Rotary shaft (paper feed roller shaft), 58 …… Multiple ejection prevention member, P …… Paper.

Claims (2)

(57) [Claims] 1. A storage unit for storing a sheet in a state where both corners of the sheet in the take-out direction are held by separation claws, and a sheet provided in a state of facing the sheet in the storing unit and in contact with the sheet. Half-moon-shaped paper feeding means having an arc-shaped feeding portion for feeding the paper and a relief portion that does not come into contact with the paper, and the paper feeding means, which is provided in the vicinity of the separation claw coaxial with the rotation shaft to which the paper feeding means is attached. In this case, it has an arcuate multiple take-out preventing portion that regulates the amount of bulging of the paper at the time to prevent multiple take-out, and a relief portion that does not contact the paper, and this escape portion has the same phase as the escape portion of the half-moon shaped paper feeding means. A sheet feeding device comprising: a half-moon-shaped multiple take-out preventing member attached so that 2. Storage means for storing the sheet in a state where both corners of the sheet in the take-out direction are pressed by separation claws, and the sheet is provided so as to face the sheet in the storage means and is in contact with the sheet. Half-moon-shaped paper feeding means having an arc-shaped feeding portion for feeding the paper and a relief portion that does not come into contact with the paper, and the paper feeding means, which is provided in the vicinity of the separation claw coaxial with the rotation shaft to which the paper feeding means is attached. In this case, it has an arcuate multiple take-out preventing portion that regulates the amount of bulging of the paper at the time to prevent multiple take-out, and a relief portion that does not contact the paper, and this escape portion has the same phase as the escape portion of the half-moon shaped paper feeding means. An image forming apparatus, comprising: a sheet feeding device having a half-moon-shaped multiple take-out preventing member attached as described above.