JP2686757B2 - Paper feeder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device that separates sheets stacked on a sheet feeding tray one by one and feeds the sheets to a processing unit, for example, an original of a copying machine. The present invention relates to a paper feeding device suitable for use in a carrying device.

[Background of the Invention]

In a general document feeder, as a paper feeding device that separates the documents (sheets) stacked on the paper feeding tray one by one and feeds them to the processing unit, the document stack is separated from the bottom layer or the top layer of the document stack. It is often the case that a feeding means for feeding the separated originals is provided and a feeding means for feeding the separated originals is separately provided.

For example, as shown in FIG. 6, a suction method in which a document is sucked by a feed roller 101 provided with a suction tool 100, is fed while being separated sheet by sheet, and is then fed to a processing section by a sheet feed roller (not shown). Are known. However, in such an apparatus, the structure of feeding and feeding becomes complicated and the size becomes large, and it is particularly difficult to reduce the total height.

〔The invention's effect〕

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a novel sheet feeding device which enables the thinning of the device.

[Configuration of the invention]

In order to achieve the above-mentioned invention, the sheet feeding device in the document feeding apparatus of the present invention is brought into pressure contact with the surface of the sheets stacked on the sheet feeding tray by the pressing means and the sheet is delivered by the delivery roller and the delivery roller. Further, the sheet is sandwiched between the driven roller and a sheet feeding roller which feeds the sheet, the feeding roller is made slightly smaller in diameter than the sheet feeding roller, and the pressing means starts feeding the sheet. The present invention is characterized in that the pressure contact is made at some times and the pressure contact is released after the sheet is delivered.

〔Example〕

Next, the present invention will be described with reference to an embodiment shown in the accompanying drawings.

FIG. 1 is a sectional view of the document feeder main body, FIG. 2 is a sectional view of a paper feeding device, FIG. 3 is a front view thereof, and FIG.
(E) is a configuration diagram showing an operating state of each drive shaft corresponding to ON / OFF of the solenoid, and FIG. 5 is a timing diagram showing an operating state of the feed roller, the movable guide plate, and the paper feeding roller.

In the figure, reference numeral 1 denotes a copying machine, and 2 denotes a document conveying device main body. The main body 2 is mounted on a platen glass 3 of the copying machine 1 and includes three main parts, namely, a paper feed unit 4, a transport unit 5, and a paper discharge unit 6. Reference numeral 7 denotes a paper feed tray on which documents (sheets) 8 are stacked, and the end of which is inserted into the paper feed unit 4. Further, on the tray 7, a width regulating plate 7a for regulating the width of the original 8 when it is set is provided movably in the width direction.

A paper feed unit 4 provided at the front of the main body 2 feeds the originals 8 one by one from the lower layer and feeds the separated originals onto the platen glass 3 of the copying machine 1. And a sheet feeding means 10 (FIGS. 2 and 3).

The delivery means 9 has a delivery roller 13 which is loosely fitted to the central portion of the first drive shaft 11 and is driven by the second drive shaft 12, and a horizontal shaft 14 provided above the delivery roller 13. Movable guide plate 1 facing the delivery surface 13a on the upper surface side of the roller 13
5 and a separating elastic piece 16 pressed against the lower surface of the delivery surface 13a of the roller 13.

That is, when the original 8 set on the paper feed tray 7 is pushed forward, the leading end thereof is guided by the movable guide plate 15 to form a wedge formed between the sending roller 13 and the separating elastic piece 16. It cuts into the U-shaped opening 16a in a U-shape. In this state, when the feeding roller 13 is rotated in the paper feeding direction (counterclockwise in the figure), the movable guide plate 15 serves as a pressing unit that moves the leading end of the original 8 against the feeding surface 13a of the feeding roller 13. Since it is configured, only one original document that is in direct contact with the sending surface 13a passes between the separating elastic piece 16 and the other originals are regulated by the separating elastic piece 16.

The separating elastic piece 16 is made of an elastic material (a hardness of 70 to 80 in the present embodiment) that generates an appropriate frictional force when pressed against the original surface.
ウ urethane rubber). Said elastic piece 16
Is fixed to an appropriate position of the main body 2 facing the delivery surface 13a so that the tip end 16a of the delivery roller 13 presses the lower center portion of the delivery surface 13a of the delivery roller 13 by the elastic force at the time of deformation. ing. Further, the leading edge 16a of the separating elastic piece 16 presses the delivery surface 13a at a sorting pressure of 160 to 230 g / cm ² , and the angle formed by the leading edge 16a with respect to a vertical line is about 32.5 degrees, so that the leading edge of the document is When entering between the delivery surface 13a and the leading end portion 16a, a wedge shape is configured to strongly prevent entry of a document that is not in direct contact with the delivery surface 13a.

The paper feed means 10 includes two paper feed rollers 17 fixed to both sides of the delivery roller 13 loosely fitted to the first drive shaft 11.
And a driven roller 18 pressed against the lower surface of the sheet feeding roller 17 so as to be driven and rotatable. The feed roller 13 is slightly smaller in diameter than the paper feed roller 17 and
Can be driven independently of the feed roller 13, and when the feed roller 13 rotates, it does not interfere with the feeding of the original 8 by rotating in the same direction.

The first drive shaft 11 is driven by a main motor (not shown) and has a gear 11a at one end for transmitting the rotational force to the cam drive shaft 20 and the second drive shaft 12 via the gears 20a and 12a. The timing control means 19 can be driven (FIGS. 4 (A), (B), and (C). The timing control means 19 includes a cam drive shaft 20 for controlling the movable guide plate 15; A sleeve 21 and a cam 22 provided on the cam drive shaft 20 via a spring clutch 20b, and the second drive shaft 12
Ratchet 23 provided via spring clutch 12b on
And levers 24 and 25 which engage and disengage the spring clutch 12b by engaging the sleeve 21 and the ratchet 23, and a solenoid 26 which drives the lever 24 on and off (FIG. 4 (A)). . That is, the solenoid 26 is in the OFF state before the start of the document delivery, the levers 24 and 25 are engaged with the sleeve 21 and the ratchet 23, respectively, and the spring clutches 12b and 20b do not operate (rotation is not transmitted). When the roller 13 starts rotating, the solenoid 26 is turned on to release the lever 24 and the sleeve 21 to operate the spring clutch 12b (gear 1
Rotation is transmitted from the gear 1a to the gear 20a), the cam 22 rotationally moves and presses the movable guide plate 15 toward the delivery surface 13a of the delivery roller 13, and releases the lever 25 and the ratchet 23 to release the spring clutch 20b. To operate (from gear 11a to gear
The rotation is transmitted to 12a), and the delivery roller 13 is rotated (FIGS. 4D, 4E and 5E).
Figure).

The delivery roller 13 stops before the leading edge of the document conveyed frictionally on the delivery surface 13a passes the separation point 16a of the separation elastic piece 16 to prevent the double feeding of the document, but the paper supply roller 17 is continued thereafter. The document separated by rotation can be continuously fed.

Reference numeral 27 denotes a document detection sensor. The sensor 27 is turned on when the leading edge of the separated and sent document of the document 8 passes, and is turned off when the trailing edge of the document passes. When the sensor 27 detects the leading edge of the document, the solenoid 26 is turned on by the detection signal to drive the lever 24,
The paper feed roller 17 slightly reverses after a certain period of time from the detection of the trailing edge of the document, so that the trailing edge of the document abuts against the abutting plate 3a on the platen glass 3.

 Next, the operation of the above embodiment will be described.

When the power of the document feeder main body 2 is turned on, the main motor rotates forward to rotate the paper feed roller 17 fixed to the first drive shaft 11 in the forward direction. During this start, the solenoid 26 is turned off, the lever 24 engages the sleeve 21 and the spring clutch 20
As the lever 25 is released and the lever 25 is also engaged with the ratchet 23 to release the spring clutch 12b, the delivery roller 13 is stopped. Next, when the document feed button of the main body 2 is pressed, the solenoid 26 is turned on, the lever 24 is disengaged from the sleeve 21 and the spring clutch 20b is operated, so that the cam 22 rotates to move the movable guide plate 15 to the delivery roller 13 Sending surface 13a
At the same time, the cam 22 comes into contact with the lever 25 and is disengaged from the ratchet 23 to operate the spring clutch 12b, so that the delivery roller 13 rotates forward in the same direction as the paper feed roller 17. Then, the original which is in direct contact with the sending surface 13a is separated from the other originals and sent out between the separating elastic piece 16 and the sending surface 13a. It is not stopped due to frictional force with the feed.

When the leading edge of the leading document passes the detection point of the sensor 27, the solenoid 26 is turned off, and the levers 24 and 25 release the spring clutches 20b and 12b, respectively. Roller 13 with leaving
Stops. Therefore, the original is fed by the feed roller 17 and the driven roller.
The paper is fed onto the platen glass 3 of the copying machine 1 while being sandwiched between the sheets 18. At this time, since the sending roller 13 has a diameter slightly smaller than that of the sheet feeding roller 17, there is no possibility that the fed document sending surface 13a comes into contact with the sheet feeding roller 13 to generate resistance. Even if the delivery roller has a diameter slightly smaller than that of the paper feed roller, the delivery of the sheet by the delivery roller bends the sheet by the pressing force of the movable guide plate and surely contacts the delivery surface of the roller. It is done without problems. The rear end of the document is the sensor
27, after the exposure and paper discharge processing, the paper feed operation for the second and subsequent sheets is repeated in the same manner as described above.

〔The invention's effect〕

As described above, the paper feeding device of the invention is a paper feeding roller that presses the surface of the sheets stacked on the paper feeding tray by the pressing means and feeds the sheet with the feeding roller and the driven roller sandwiching the sheet. Are arranged coaxially with each other, and the diameter of the sending roller is slightly smaller than that of the paper feeding roller. Therefore, the sending roller and the paper feeding roller are integrated, and the space occupied by them is the same as that of the conventional apparatus. Significantly reduced in comparison.
For this reason, it is very important to contribute to the reduction of the thickness of the document feeding apparatus main body, and further, it is possible to improve the maintainability and reduce the cost by reducing the number of parts.

Further, since the feeding roller and the paper feeding roller are made slightly smaller in diameter, the original does not come into contact with the feeding surface of the feeding roller when the feeding roller feeds a document (sheet). There is an advantage that it can effectively stop that the paper becomes resistance at the time of feeding.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the main body of the document feeder, FIG. 2 is a cross-sectional view of the paper feeding device, FIG. 3 is a front view of the same, and FIG.
(E) is a configuration diagram showing an operating state of each drive shaft corresponding to ON / OFF of a solenoid, FIG. 5 is a timing diagram showing an operating state of a feed roller, a movable guide plate, and a paper feeding roller,
The figure is a block diagram of a conventional suction system. 1 …… Copier 2 …… Original document feeder 8 …… Original (sheet) 11 …… First drive shaft 13 …… Sending roller 17 …… Feeding roller 18 …… Following roller

Claims (1)

(57) [Claims] 1. A delivery roller (13) for delivering a sheet, which is pressed against a surface of a sheet (8) laminated on a paper feed tray (7) by a pressing means (15), and the sheet delivered by the delivery roller. A feed roller (17) that feeds by sandwiching the driven roller (18) between the feed roller (18) and the driven roller (18), the delivery roller is slightly smaller in diameter than the feed roller, and the pressing means is a sheet. A sheet feeding device, which is press-contacted at the start of feeding the sheet and released after the sheet is fed out.