JPH0541533B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a paper feeding device for a copying machine, a printer, a facsimile, etc., which is capable of storing sheets of two sizes in its sheet storage device.

PRIOR ART As shown in FIG. 1, paper feed devices for copying machines, printers, facsimile machines, etc. have stacks of sheets S stacked on a bottom plate 5 whose rear end is pivoted so as to be able to rise and fall at the bottom of a paper storage container 4. , the upper surface of the stack of sheets S is pressed against the pick-up roller 1 by pushing up with an arm 51 fixed to the bottom plate 5 and the shaft 50, and the pick-up roller 1 rotates in response to a paper feed signal to sequentially move the sheets from the top to the downstream. The paper is fed in pairs to a feed roller 2 that rotates in the normal direction and a reverse roller 3 that rotates in the reverse direction. A friction roller separation paper feeding device that uses the difference between the frictional force between the paper and the paper to push the second and subsequent papers back toward the storage container 4, and feeds only the one paper that is in contact with the feed roller 2. It has been known.

As shown in FIG. 2, two sheets of paper,
When the lower paper is pushed back onto the stack of paper in the storage container 4 by the reverse roller, the uppermost paper tends to move backward due to friction with the paper being returned. Furthermore, as the sheet recedes, the paper below it also recedes.
If this retreat is not prevented, the paper in the storage container 4 will continue to gradually retreat as the above steps are repeated, and the front end of the paper will eventually retreat to a position where it no longer touches the pick-up roller 1. As a result, the paper feed This may cause a timing delay, resulting in a copy with part of the image missing, a jam, the topmost sheet not being fed, or the inability to feed the sheet at all.

In order to prevent the above-mentioned problems, for example, a paper feed tray is provided with a positioning guide for the side edge of the paper stack according to the size of the paper to be stored, as well as a positioning guide for the trailing edge of the paper. As disclosed in Japanese Patent No. 57629, etc., both guides are set separately to determine the sheet stack placement position. Moving the side and rear edge guides independently is cumbersome to operate, and it is especially easy to forget to set the rear guide. If you forget to set the rear guide, the above-mentioned problems may occur.

By the way, the size of paper used in copying machines, etc. is regulated by the JIS standard in Japan, and is also adopted in each country's standards. In addition, sizes such as letter size and legal size, which have different aspect ratios, have also been used. By the way,
A4 size is 210mm x 297mm, letter size is 216
mm x 280 mm, which is roughly the same size,
Letter size is 6mm wider than A4 size, but
On the other hand, the length is 17mm shorter.

Purpose: As described above, the present invention relates to a sheet feeding device that is capable of feeding two sizes of paper that are generally the same size, but one of which is narrower and longer than the other. It is easy to operate and eliminates the above-mentioned drawbacks of the conventional sheet feeding device, which has a sheet storage container that can store a sheet storage container and a double-feed separating and conveying device consisting of a pair of forward-rotating rollers and reversible rollers. To provide a highly reliable sheet feeding device that does not forget to install an edge position regulating member at a position corresponding to the sheet size.

Configuration The present invention will be described in detail below based on embodiments shown in the drawings.

FIGS. 3 and 4 are diagrams showing an embodiment in which the present invention is applied to a paper feeding device having a storage container 4 that can store A-4 size and letter size paper interchangeably.

The apparatus of this embodiment is provided with a bottom plate 5 for placing a stack of sheets S whose rear end is pivotally supported at the bottom of a cassette 4, and an arm 51 whose lower surface near its front end is fixed to a shaft 50.
As shown in Fig. 1, the paper stack S is pushed up by the pick-up roller 1, and its rotation causes the paper to be fed to the pair of feed roller 2 and reverse roller 3 for separation and conveyance. This is similar to the conventional device described by. The reference numeral 6 is a friction member for preventing double feeding when the stack of sheets becomes small, and the reference numeral 7 is a member for preventing the bottom plate 5 from coming off. Also, guides 4-1 and 4-2 are provided on the front outer surface of the side plate of the cassette 4 for mounting it on the main body of the copying machine. The bottom of the cassette 4 itself has a step at the rear end of the movable bottom plate 5, and the upper surface behind the step is continuous with the top surface of the movable bottom plate 5. A notch 4-5 is provided near the center line of the rear end.

A shaft 4- provided near the upper edge of the side plate of the cassette 4
A cover 8 is pivotally attached to 6, and the rear end thereof is bent downward at a right angle to form a hanging part 8-2, and an extension part 8-1 provided near the center line of the cover 8 forms a hanging part 8-2.
The lower edge of 2 is inserted into the notch 4-5 in the bottom of the cassette with its lower edge in contact with the bottom of the cassette (see FIG. 5). The front surface of the hanging portion 8-2 at the rear end of the cover 8 is located at a position where the rear end of the A4 size paper stack stacked at a predetermined position on the bottom plate 5 almost comes into contact with it. It also serves as a position regulating member at the rear end.

A guide 4-3 is fixed behind the step at the rear of the bottom of the cassette 4 to guide the front side edge of the paper when the cover 8 is opened and the paper is loaded into the cassette. Next, a guide 20 is fixed to the front of the step on the bottom of the cassette 4, which serves as a reference for the front side edge of the paper. A movable guide 9 whose position is variable according to the width of the paper is provided on the back side of the bottom of the cassette 4. Movable guide 9
consists of a vertically rising part 9-1 and a bottom part 9-2 along the bottom of the cassette, and the bottom part 9-2 has one stud 9-3 at the front and two studs 9-3 at the rear.
3' is planted, and passes through a slit 4-7 extending in the width direction provided at the bottom of the cassette 4,
The stud 9-3' can be fixed by sandwiching the bottom surface of the cassette by washers 10, 11 and an angle washer 12. A lever 15 is attached to the stud 9-3' at a portion corresponding to the washer 11. By sliding these studs 9-3, 9-3' along the slits 4-7, the movable guide 9 can be set at a position corresponding to the size of the paper.
The lever 15 is bent in a Z shape, and a pin 16 is installed vertically at the other end, and a slit 4-3 is provided in the width direction behind the guide 4-3 on the bottom of the cassette.
8 and protrudes vertically to the full height of the paper bundle that can be stacked on the paper storage surface. FIG. 4 shows a state in which the movable guide 9 is fixed at a position corresponding to a letter size, and at this time the pin 16 is located inside (center line side) from the inner surfaces of the fixed guides 4-3 and 20. However, if the movable side guide 9 is moved 6 mm toward the front and brought to a position corresponding to A4 size as shown in FIG. It's becoming like that. The position of the pin 16 in the front and rear direction is
Near the trailing edge of letter-sized paper stacked in a predetermined position above.

A tongue piece 9-4 is provided below the front end of the bottom part 9-2 of the movable guide 9, and passes through a slit 4-9 provided laterally at the bottom of the cassette, so that the tongue piece 9-4 is placed at a corresponding position when the cassette is installed. A size detection photo sensor 17 provided on the machine body is activated.

Furthermore, when the cover 8 is used with the cassette 4 attached to the copying machine main body, or in conjunction with the operation of lifting the rear end to remove the cassette 4 from the copying machine main body, the bottom plate push-up arm 51 is moved downward. When the cassette 4 is installed or the cover 8 is closed, the bottom plate push-up arm 51 pushes up the bottom plate 5, and the upper surface of the stack of sheets placed on it is lifted up. It is set to a predetermined height.

Since this device is constructed as described above, with the cassette 4 attached to the copying machine main body, the rear part of the cover 8 can be flipped up to replace the paper of a different size from the paper that was previously inserted. Then, the bottom plate push-up arm 51 rotates downward, and the bottom plate 5 falls under its own weight, and the upper surface of the paper is separated from the paper feed roller 1, making it possible to take out the paper and insert a new paper. When the movable guide 9 is moved to a position corresponding to, for example, a letter size, the pin 16 is moved to the fixed guide 4-3,
It protrudes from the inner surface of the sheet 20 and forms a stopper at the rear end of the letter-sized sheet.

Conversely, if the movable guide 9 is brought to a position corresponding to A4 size, the pin 20 will be moved to the fixed guide 4-3,
When the cover 8 is retracted outward from the inner surface of the paper 20 and the cover 8 is closed, the hanging portion 8-2 forms a stopper for the trailing edge of A4 size paper.

According to the above configuration, when the movable guide 9 is moved to a position corresponding to any paper size, the rear end stopper for the paper of that size is automatically formed, so that double feeding is performed by the roller pair of the feed roller 2 and the reverse roller 3. Even if the stack of paper sheets placed on the bottom plate 5 is separated and pushed onto the stack of paper sheets placed on the bottom plate 5, the lower paper sheets are moved back to a predetermined position along with the returned paper sheets. can be prevented, and the above-mentioned problems that occur along with this can be avoided.

In the above embodiment, the present invention is applied to a case where the paper sizes that can be loaded into the cassette are A4 size and letter size, but the paper size to be fed is not necessarily limited to A4 size and letter size. Instead, the present invention is applicable to a sheet feeding device that alternately feeds sheets of two sizes, one of which is narrower than the other and conversely longer.

In the above embodiment, the paper storage device is described as a cassette that can be attached to and removed from the main body of the copying machine, but it does not necessarily have to be a cassette, and may be a paper storage device built into the main body of the machine.

Effects As described above, according to the present invention, it is possible to handle two different types of paper, and by moving the movable guide according to the size of the paper to be loaded, the trailing edge position of the paper can be automatically adjusted. Since the regulating member is formed at a predetermined position, forgetting to set the rear end position regulating member is prevented, and the reliability of paper feeding is improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a schematic configuration of an example of a known friction roller separation and feeding device, FIG. 2 is a schematic diagram illustrating the movement of paper during multi-feed separation, and FIG. 3 is an embodiment of the present invention. FIG. 4a is a plan view showing the movable side guide in a position corresponding to letter size, and FIG. FIG. 5 is a plan view showing only the position, and FIG. 5 is a longitudinal sectional view showing the vicinity of the rear end of the cassette of the above embodiment. 1...Pick-up roller, 2...Feed roller (forward rotating body), 3...Reverse roller (rotating body that can rotate in reverse), 4...Paper feed cassette (sheet storage device), 4-3, 20...Fixed Guide, 8...
...Cover, 8-2... Drooping part (sheet bundle rear end position regulating part), 9... Movable guide, 16... Pin (sheet rear end position regulating member), S... Sheet bundle.

Claims (1)

[Scope of Claims] 1. A sheet storage device, a pick-up means for sequentially feeding out sheets from above a bundle of sheets loaded therein, and a rotating body capable of forward rotation and a rotating body capable of reversing the rotation of the sheets fed out by the pickup means. sheet separating means for separating double feeding by a pair of rotating bodies, returning the second and subsequent sheets to the sheet bundle, and feeding only one sheet; A sheet feeding device having a fixed guide that positions an edge and a movable guide that moves to a position according to the size of the sheet and guides the other side edge of the sheet, the sheet being fed by the sheet feeding device. The sheets have two sizes, first and second, which are approximately the same size but have different aspect ratios, and the width of the first size is narrower than the width of the second size, and the length of the first size is If the length is longer than the second size, and the movable guide moves in conjunction with the movement of the movable guide, and the movable guide is installed at a position corresponding to the first size sheet bundle, the fixed guide If the above-mentioned movable guide is installed at a position corresponding to the second size sheet bundle, the movable guide is located inside the above-mentioned fixed guide and at a position that regulates the rear end of the second size sheet bundle. A sheet feeding device characterized in that a trailing edge regulating member is provided, and a sheet bundle trailing edge position regulating portion of a first size is formed at the rear end of the cover of the sheet storage device.