1. Field of the Invention
The invention relates to a sheet feeding apparatus and an image forming apparatus designed such that sheets stacked on sheet stacking means are brought into pressure contact with sheet feeding means by a lever operation.
2. Description of the Related Art
An image forming apparatus such as a printer or a copying machine has heretofore been provided with a sheet feeding apparatus for feeding a sheet to an image forming portion. As such a sheet feeding apparatus, there is one provided with a cassette feeding portion for feeding sheets contained in a cassette loaded on the bottom of an image forming apparatus main body, and in addition, a multi-feeding portion which is a manually feeding portion designed to stack sheets on a tray drawably or openably and closably provided in the image forming apparatus main body, and feed the sheets by a sheet feeding roller.
Also, a cassette feeding portion 116 is provided with a cassette 117 loaded on the bottom of the image forming apparatus main body 100, a sheet feeding roller 118 provided in the image forming apparatus main body 100 for feeding sheets P stacked on the intermediate plate 117a of the cassette 117 and a pair of retard rollers 119 for separating the sheets P one by one.
Design is made such that when the sheets P are to be fed from the multi-feeding portion 140 to an image forming portion 101, the sheets P are fed one by one from the tray 145 by the sheet feeding roller 143. Also, design is made such that when the sheets P are to be fed from the cassette feeding portion 116 to the image forming portion 101, the sheets P contained in the cassette are separated and fed one by one by the sheet feeding roller 118 and the pair of retard rollers 119. The sheets P thus fed from the multi-feeding portion 140 or the cassette feeding portion 116 are thereafter transported to the image forming portion 101, whereby images are formed thereon.
By the gap “a” being thus formed between the sheet feeding roller 143 and the intermediate plate 146, the sheets P can be pushed into between the sheet feeding roller 143 and the intermediate plate 146. Thereafter, as shown in
Now, such an intermediate plate is also provided in the cassette 117 of the cassette feeding portion 116, as shown in
On the other hand, in the multi-feeding portion 140, it is also possible to adopt a construction similar to that of the cassette feeding portion 116, but a sheet feeding operation is possible with the tray 145 opened and therefore, with economical properties such as a manufacturing cost and a running cost further taken into account, design is made such that a lever 148 which is manually moving means shown in
However, in the conventional image forming apparatus provided with the multi-feeding portion 140 designed such that the intermediate plate 146 is pivotally moved by such a lever operation, this lever 148, as shown in
When the user thus loses sight of the lever 148, the user forgets the lever operation, and when the user thus forgets the lever operation, for example, forgets the operation of upwardly pivotally moving the lever 148, the sheets cannot be pushed in below a sheet feeding roller 143 and therefore, faulty feeding occurs.
Also, when the user forgets the downwardly pivotally moving operation, the sheets cannot be brought into pressure contact with the sheet feeding roller 143 and therefore, even if the sheet feeding roller 143 is rotated, the sheet cannot be fed out, or cannot be fed out to the image forming portion 101 at predetermined timing.
Notes 150 are provided near the lever 148, for example, outside the sheet stacking portion 145a of the tray 145 so that the user may not forget the operation even if he notices the lever 148, but the notes 150 provided at such a location are difficult to visually perceive and in some cases, the user does not notice them. When as described above, the user forgets the lever operation even if he notices the lever 148, the sheets cannot be fed.
So, the present invention has been made in view of such a situation, and has as its object to provide a sheet feeding apparatus which enables a lever to be reliably operated to thereby feed sheets reliably, and an image forming apparatus provided with the same.
The present invention provides a sheet feeding apparatus provided with:
An embodiment of the present invention will hereinafter be described in detail with reference to the drawings.
In
The image forming portion 40 has an electrophotographic photosensitive drum (hereinafter referred to as the photosensitive drum) 41, a developing device 42, etc. design is made such that when a laser beam corresponding to image information emitted from a laser scanner 43 is scanned on the surface of the photosensitive drum 41, a latent image is formed on the surface of the photosensitive drum, and this latent image is developed by the developing device 42, whereby a toner image is formed on the surface of the photosensitive drum.
Also, design is made such that when the sheet is thereafter transported to a transferring portion constituted by the photosensitive drum 41 and a transfer charging device 44, as will be described later, the toner image formed on the photosensitive drum 41 is transferred to the sheet.
On the other hand, the cassette feeding portion 16 is for feeding the sheets P to the transferring portion, and is provided with a cassette 17 loaded on the bottom of the apparatus main body 200A, and a sheet feeding roller 18 for feeding the sheets P contained in this cassette 17. Design is made such that during image forming, the sheet feeding roller 18 and a pair of retard rollers 19 are rotated in conformity with an image forming operation so as to separate and feed the sheets P one by one from the cassette 17.
The multi-feeding portion 50 is also for feeding the sheets P to the transferring portion, and is provided with a tray 4 which is sheet stacking means openably and closably provided in the apparatus main body 200A, and a sheet feeding roller 2 which is sheet feeding means for feeding the sheets P stacked on the tray 4. Design is made such that during image forming, the sheet feeding roller 2 is rotated in conformity with the image forming operation so as to feed the sheets P one by one from the tray.
On the other hand, the scanner portion 30 is for reading the image of an original placed on an original glass stand 301, and is adapted to convert image information into an electrical image signal after it has read the image of the original, and input this image information converted into the electrical image signal to the laser scanner 43 of the already described image forming portion 40.
Description will now be made of the image forming operation of the copying machine constructed as described above.
First, when the image information of the original is read by the scanner portion 30, this image information is image-processed and is thereafter converted into an electrical signal, and is transmitted to the laser scanner 43 of the image forming portion 40. In some cases, the image information is inputted from an external device such as a personal computer (not shown) to the image forming portion 40.
In the image forming portion 40, the surface of the photosensitive drum 41 is scanned by a laser beam corresponding to the image information emitted from the laser scanner 43 to thereby form a latent image on the photosensitive drum, whereafter this latent image is developed by the developing device 42 to thereby form a toner image on the surface of the photosensitive drum 41.
On the other hand, when in parallel to this operation, the sheets P are to be fed from the multi-feeding portion 50 to the image forming portion 40, the sheets P are fed one by one from the tray by the sheet feeding roller 2. Also, design is made such that when the sheets P are to be fed from the cassette feeding portion 16, the sheets P contained in the cassette are separated and fed one by one by the sheet feeding roller 18 and the pair of retard rollers 19.
The sheet P thus fed from the multi-feeding portion 50 or the cassette feeding portion 16 is then transported to register rollers 20. At this time, the register rollers 20 are at a halt, whereby the sheet P has its skew feed corrected, and is once stopped and stands by at this position.
Thereafter, the register rollers 20 are rotated and the sheet P having stood by is fed to the transferring portion constituted by the photosensitive drum 41 and the transfer charging device 44 in timed relationship therewith, and when the sheet P passes through this nip part, the toner image on the photosensitive drum is transferred to the sheet P.
The sheet P to which the toner image has been transferred in this manner is transported to a fixing apparatus 45, and the sheet P is heated and pressurized when it passes through the fixing apparatus 45, whereby the toner image is fixed on the surface of the sheet P. The sheet P on which the toner image has been thus fixed is thereafter delivered to a delivery tray 47 by sheet delivery rollers 46.
In
Also, when the sheets are to be fed, the intermediate plate 1 is adapted to be upwardly pivotally moved as shown in
A lever 8 which is a manually moving member for downwardly pivotally moving the intermediate plate 1 is provided above the sheet stacking portion 4a of the tray 4 and in a direction orthogonal to a sheet feeding direction. The opposite ends of this lever 8 are provided near side regulating plates 6 which are regulating members provided outside the opposite sides of the tray 4 and adapted to contact with the opposite side edge portions of the sheet and regulate the side edge positions of the sheet.
In the present embodiment, the lever 8 is provided so as to be astride of the side regulating plates 6 and the tray 4, and by the lever 8 being thus provided so as to be astride of the side regulating plates 6 and the tray 4, the size of the lever 8 can be made large, whereby the operability and visual perceptibility of the lever 8 can be improved.
Also, the lever 8 is disposed near the side regulating plates 6 used by the user in an ordinary operation, the visual perceptibility of the lever 8 is improved and the user can be prevented from losing sight of the presence of the lever 8. Further, as in the present embodiment, the lever 8 is provided so as to be astride of the side regulating plates 6 and the tray 4, whereby the lever 8 can be supported at the opposite end portions thereof and therefore, the rigidity of the lever 8 can be secured.
Furthermore, on the upper surface of the lever 8, there is formed an indicating portion 8a comprised of an index, an index label or the like indicating a user's operation or the like, as shown in
The lever 8 is located above the sheet stacking portion 4a of the tray 4 and therefore, as the user looks at the lever 8 when he sets the sheets on the tray 4, the user comes to look at the indicating portion 8a formed on the upper surface of the lever 8 and thus, the visual perceptibility of the indicating portion 8a heightens, and it never happens that the effect thereof as an index is lost.
When the lever 8 is downwardly pivotally moved as shown in
Also, when the lever 8 is upwardly pivotally moved as shown in
Now, as shown in
Design is made such that when the lever 8 has been thus downwardly pivotally moved, the insertion of the sheets P is hampered by the sheet stopper 11, that is, the sheets P cannot be inserted when the lever 8 is in its downwardly pivotally moved state, whereby when the user has forgotten the lever operation, the user can be made to recognize that he has forgotten the lever operation.
On the other hand, when as shown in
When the lever 8 is downwardly pivotally moved after the lever 8 has been thus upwardly pivotally moved and the sheets P have been inserted, the sheet stopper 11 abuts against the sheets P as shown in
Also, the downwardly pivotally moved position of this sheet stopper 11 is regulated by a restraining member (not shown), and therefore, even when the lever 8 is upwardly pivotally moved as shown in
As described above, when the user has forgotten the operation of the lever 8 when he inserts the sheets P, the insertion of the sheets P is hampered by the sheet stopper 11 provided on the lever 8, whereby it can be suggested to the user that the operation of the lever 8 is necessary. Thereby, the user can reliably operate the lever 8 to thereby effect the changeover of a state in which sheet feeding is possible and a state in which the insertion of the sheets P is possible.
By providing such an intermediate plate sheet 13 and such an auxiliary intermediate plate sheet 14, it is possible to give moderate back tension to the sheets P and therefore, double feed, and particularly, bundle double feed caused by a sheet bundle coming into between the sheet feeding roller 2 and the separating pad 3 can be prevented.
Cork or a rubber material such as urethane is suited as the material of the intermediate plate sheet 13 so as to be capable of standing the state of contact with such a sheet feeding roller 2 because the intermediate plate sheet 13 contacts with the sheet feeding roller 2 when the sheets are not stacked. Also, a material having a fur-like surface is suited as the material of the auxiliary intermediate plate sheet 14 because the auxiliary intermediate plate sheet 14 does not contact with the sheet feeding roller 2 and is not positively pressed through the sheets P.
Also, as shown in
Each of these regulating members 15 is provided with an inclined surface 15a facing the sheet feeding roller 2, as shown in
While in the description hitherto made, a case where the lever 8 is disposed so as to be astride of the side regulating plates 6 and the tray 4 has been described, the present invention is not restricted thereto, but the lever 8 can be disposed so that at least one end thereof may be located near one of the side regulating plates 6 provided in opposed relationship with each other. As shown, for example, in
Even if the lever 12 is thus disposed so that one end thereof may be located near one of the side regulating plates 6 and the lever 12 is supported in a cantilevered state, the lever 12 is present on the sheet stacking portion 4a of the tray 4 and therefore, a similar effect can be obtained.
Also, while in the description hitherto made, a case where the intermediate plate 1 provided on the fore end side of the tray 4 and supporting the leading edge side of the sheets is made pivotally movable in the vertical direction has been described as an example, the present invention is not restricted thereto, but can also be applied to a case where the tray supporting the whole of the sheets is pivotally movable in the vertical direction.
Number | Date | Country | Kind |
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2003-061692 | Mar 2003 | JP | national |
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57-4835 | Jan 1982 | JP |
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Number | Date | Country | |
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20040178563 A1 | Sep 2004 | US |