JPH0124041Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feeding device for feeding paper placed on a paper feeding table, and particularly to a device useful for manually feeding paper.

Paper feeding devices in copying machines, etc. generally use a cassette feeding method, in which a cassette containing a large number of sheets of paper is attached to the main body of the copying machine, and sheets are fed one by one from within the cassette based on a paper feed signal. has been done. Other types of paper feeding devices include a paper feeding tray method in which a large number of sheets of paper are stacked on a paper feeding tray and the top or bottom paper is fed one by one via a separation mechanism; There is a manual paper feeding method in which paper is inserted.

The paper feeding device of the above-mentioned paper feeding table type can not only feed stacked sheets one by one, but also manually feed paper in which sheets are inserted and fed one by one.
FIG. 1 shows a specific example of a paper feeding device using a paper feeding table type. In the figure, a paper feed table 1 is rotatably supported by a shaft 2, and a paper feed roller 3 is provided opposite the tip of the paper feed table 1. The other end of the paper feed tray 1 is biased via a spring 4, and presses the sheets 5 stacked on the paper feed tray 1 against the paper feed roller 3. In the figure, 6 is a regulation plate that positions the leading edge of the paper 5, 7 is a double-feed prevention plate made of a friction material such as rubber that comes into pressure contact with the paper feed roller 3 to prevent double feeding, and 8 is a control plate for preventing double feeding. A detection switch 9 detects the fed paper, and a paper switch 9 is provided so as to be openable and closable in order to open the entrance to enable loading and manual insertion of paper for the purpose of loading the paper 5 into the paper feed tray 1. It is a guide board.

In the paper feeder configured as shown in FIG.
When loading paper, open the paper guide plate 9 and insert the paper feed tray 1.
Rotate counterclockwise and press down. As a result, the paper feed tray 1 and the paper feed roller 3 are separated, and when a large number of sheets of paper 5 are inserted along the paper guide plate 9, their leading ends are positioned by the regulation plate 6, and the paper feed tray 1 is returned to its original position. When it is returned to its position, loading is completed as shown in the figure.
In this state, when a paper feed signal is output, the paper feed roller 3 rotates, and the uppermost paper that is in pressure contact is fed. At this time, when double-sheet feeding occurs, the lower paper comes into pressure contact with the double-feed prevention plate 7 and comes to rest, so the uppermost paper 5 is fed so as to slide over the lower paper, preventing double-feeding and keeping the paper in one place. Feed sheets.

On the other hand, in the above-described paper feeding device, when manually feeding a single sheet, it is sufficient to insert one sheet in the same manner as loading a large number of sheets. That is, the paper 5 may be inserted between the paper feed roller 3 and the paper feed table 1 each time.

Here, the double feeding prevention plate 7 is useful for separating and feeding the stacked sheets 5 one by one. However, with manual paper feeding, the sheets are inserted one by one, so the double-feed prevention plate 7 is not required. That is, in the case where paper is automatically fed using the paper feed table 1, it is necessary to provide the double-feed prevention plate 7, whereas in the case of manual paper feeding, it is unnecessary. Particularly when using manual paper feeding, if you insert regular paper similar to that used for automatic paper feeding, the double feed prevention plate 7
Although this will not cause paper damage, the double feed prevention plate 7 will cause paper damage when inserting and feeding special paper such as thin paper or OHP film. That is, when a thin sheet of paper is fed by the sheet feeding roller 3, the double feeding prevention plate 7 is pressed against the back surface of the thin sheet of paper, and resistance acts in the direction opposite to the direction of movement. This causes the paper to wrinkle, etc., resulting in paper feeding failure.

In view of the above-mentioned drawbacks, the present invention provides a paper feeding device that automatically feeds stacked sheets of paper on a paper feed tray and also stably and reliably feeds manual paper inserted into the paper feed tray. It is something. Further, the present invention provides a paper feeding device that facilitates manual paper feeding operations.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the paper feeding device according to the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a sectional view showing a specific example of the paper feeding device according to the present invention. In the figure, the same parts as in FIG. 1 are indicated by the same reference numerals, and the explanation thereof will be omitted.
In the figure, reference numeral 10 denotes a paper feed tray position detection switch that detects a state in which the paper feed tray 1 is urged by a spring 4 and is pressed against the paper feed roller 3 via the paper 5 or itself. This detection switch 10
The state (contact is open) is changed when loading paper by pressing down, and the contact is closed when the paper feed table 1 is pressed against the paper feed roller 3. Reference numeral 11 denotes an operating piece of a paper insertion detection switch 14 provided on the upper paper guide plate 12 of the paper insertion section. The tip of the actuating piece 11 is connected to a long hole 13 provided in the paper feed table 1.
, and is configured to be inserted into the elongated hole 13 when the paper 5 is not on the paper feed tray 1. The tip of the actuating piece 11 is the elongated hole 13 of the paper feed table 1.
When inserted, the contact of the detection switch 14 opens,
When it comes out of the elongated hole 13, the contact closes. In other words, if paper 5 is inserted or placed on paper feed table 1,
The paper is detected, and based on this detection, a lamp or the like may be turned on to indicate the presence or absence of paper. Instead of this detection switch, a configuration may be used in which photoelectric elements are provided facing each other to sandwich the paper to detect the paper, and the present invention is not limited to a micro switch.

Further, as shown in FIG. 2, the double feed prevention plate 70 is fixed to a shaft 71 and faces the paper feed roller 3. The shaft 71 is rotatably held by the frame itself (not shown), is connected to the tip of a separation lever 72, and is rotated by operating the separation lever 72. By operating this separation lever 72, the double feeding prevention plate 70 is opposed to the paper feed roller 3 or separated from the paper feed roller 3. Therefore, the shaft 71 supports the double feeding prevention plate 70,
It acts as a support means for moving. The separation lever 72 is provided with a pin 73 for position regulation, and a spring 74 with irregularities fixed at both ends.
The pin 73 engages with the concave portion to regulate the position of the double feed prevention plate 70. For example, if the lever 72 is pushed down counterclockwise around the shaft 71, the pin 7
3 comes off from the concave portion at the bottom of the spring 74, climbs over the convex portion, and engages with the concave portion at the top. At this time, the double-feed prevention plate 70 is similarly rotated and separated from the paper feed roller 3, creating a gap between the paper feed roller 3 and the double-feed prevention plate 70.

Furthermore, FIG. 3 shows an example of drive control of the paper feed roller 3 in the present invention. In this circuit,
A contact point of the position detection switch 10 is connected to one input terminal of the AND gate 15 so that a detection signal from the position detection switch 10 for detecting the state of the paper feed tray is supplied to the AND gate 15. Further, in a state where no paper is present, the contact of the insertion detection switch 14 is connected to the differentiating circuit 16 so that the detection signal of the manually inserted paper by the insertion detection switch 14 is supplied to the other of the AND gates 15. It is connected to the other input terminal of the AND gate 15 via. This AND gate 15 is
A state in which the detection switch 10 detects the normal state of the paper feed tray 1 (the state where the paper feed tray 1 is pressed in the direction of the paper feed roller) and the insertion detection switch 14 does not detect the presence of paper is the permissible state ( (operable state), and in this state, the insertion detection switch 14
When the paper is detected by hand, the signal output from the differentiating circuit 16 is supplied to the set terminal of the flip-flop 17. Therefore, flip-flop 17 temporarily stores this state.
In this case, if the paper 5 is placed on the paper feed tray 1, the detection switch 14 will detect it, and even if paper 5 is further inserted, the differential signal will not be output from the differentiation circuit 16 and the Gate 15 will not open. In other words, when paper 5 is not on paper feed tray 1,
If paper is inserted, a differential signal is output, and if a detection signal from the paper feed tray position detection switch 10 is input to the AND gate 15, the AND gate 1 is output.
5 is open and remains closed at all other times.

The set output of the flip-flop 17 is supplied to the base terminal of a switching transistor 19 via an OR gate 18. The switching transistor 19 is connected to a drive circuit 20 that drives the paper feed roller 3, and starts the drive circuit 20 when a signal "H" is supplied to its base. The input terminal of the OR gate 18 receives a paper feed signal P based on a paper feed command from the apparatus main body, for example, a copying machine main body.
A set output signal from the flip-flop 17 or a paper feed signal based on a paper feed command is supplied to the transistor 19. Note that the reset input terminal of the flip-flop 17 is connected to the paper feed roller 3.
A detection signal from a microswitch 8 is supplied to detect the paper 5 fed at the microswitch 8.

The operation of the above configuration will be explained below. The case of loading a large number of sheets is as explained in FIG. 1. If the paper 5 is placed on the paper feed tray 1, the detection switch 14 detects it via the operating piece 11. At this time, the separation lever 72 is pushed down to make the double feed prevention plate 70 face the paper feed roller 3. Then, if paper feed signal P is output,
The transistor 19 is operated via the OR gate 18, and the paper feed roller drive circuit 20 drives the paper feed roller 3.
is rotationally driven. As a result, the top paper 5
is fed, and this operation is repeated every time a paper feed signal is output. The paper 5 fed by the paper feed roller 3 is sent out with its back surface pressed against the double-feed prevention plate 70. That is, when two-sheet feeding occurs, the lower sheet is pressed against the double-feed prevention plate 70 and its feeding is prevented. Then, the paper 5 at the top is fed to the paper feed roller 3.
The paper is fed by sliding the lower paper under the paper feeding force. Automatic sheet feeding is performed one sheet at a time as described above.

If one sheet of paper 5 is inserted along the guide plate 9 while the paper 5 is placed on the paper feed table 1, the actuation piece 11 is activated, but the detection switch 14 is not placed. It is detecting paper and remains closed. For this reason, no differential signal is output via the differential circuit 16. That is, even if one sheet of paper is inserted, the AND gate 15 does not open and the paper feed roller 3 does not rotate. When the paper 5 is placed on the paper feed table 1 in this way, the paper feed roller 3 is driven by the paper feed signal being output, and the paper is fed one sheet at a time to prevent paper feed errors. is prevented.

Next, manual paper feeding will be explained according to the time chart shown in FIG. If the paper 5 is not on the paper feed tray 1 and the position detection switch 10 detects that the paper feed tray 1 is in pressure contact with the paper feed roller 1, the sheet of paper 5 is moved along the guide plate 9. By inserting the paper, the operating piece 11 of the detection switch 14 rotates clockwise, and the inserted paper is detected. In connection with this manual feeding of sheets one by one, by operating the separation lever 72 upward, the double-feed prevention plate 70 is rotated clockwise, and the double-feed prevention plate 70 is moved to the paper feed roller 3.
Space them further apart. Based on the detection of the inserted paper above,
A differential signal is output from the differential circuit 16, the AND gate 15 is opened, and the flip-flop 17 is set. When the flip-flop 17 is set, its set output is supplied to the transistor 19 via the OR gate 18, so that the drive circuit 20
rotates the paper feed roller 3. The paper 5 inserted by this rotation is caught by the paper feed roller 3 and fed. This paper feeding is not performed by a normal operation, but by interposing the paper 5 between the paper feeding roller 3 and the paper feeding tray 1 to ensure that the paper feeding operation is performed in response to a paper feeding signal. When the paper 5 is fed to the paper feed roller 3 and its leading edge is detected by the detection switch 8, a detection signal is sent to the flip-flop 17.
is applied to the reset input terminal of the flip-flop 17. As a result, the transistor 19 becomes non-conductive, so the paper feed roller 3
rotation is stopped and paper feeding operation is temporarily stopped. This state becomes a standby state for normal paper feeding operation. In other words, the paper feed roller 3 is temporarily rotated to set the manually fed paper in the paper feed state. Currently, the paper 5 is stopped with its leading edge being detected by the detection switch 8. If the detection switches 8 and 14 are arranged in such a position that the trailing edge of the paper does not pass through the detection switch 14, when the paper 5 is stopped, another paper 5 can be inserted. Even if the paper feed roller 3 is rotated, paper feeding mistakes can be prevented.

After the paper 5 is detected by the detection switch 8 and stopped as described above, if a paper feed signal is output from the main body side, the paper feed roller 3 is rotated and the stopped paper 5 is
is fed, and reliable manual paper feeding can be performed based on the paper feeding signal. According to this manual paper feeding, since the double-feed prevention plate 70 is separated from the paper feed roller 3, the double-feed prevention plate 70 does not create resistance during paper feeding, and special paper such as thin paper or OPH film is stabilized. The paper is then fed. It goes without saying that not only special paper but also normal paper can be fed.

Here, when feeding a stack of paper placed on the paper feed table 1, the leading edge of the fed paper is detected by the detection switch 8.
However, the rotation of the paper feed roller 3 does not stop due to this detection signal. In other words, the paper feed roller 3 at this time is not driven by the set output of the flip-flop 17, but is driven based on the paper feed signal from the main body, so it will not be stopped by the above detection signal.

Further, in this embodiment, the double feeding prevention plate 70 is manually moved away from the paper feed roller 3, but this can also be done automatically. For example, the double feed prevention plate 70 may be automatically separated from the paper feed roller 3 by the set output of the flip flip 17 shown in FIG. That is, the configuration can be easily achieved by providing a transmission mechanism for transmitting the rotational force of a drive motor or the like to the shaft 71, operating the transmission mechanism with the set output of the flip-flop 17, and transmitting the rotational force to the shaft 71.

According to the paper feeding device of the present invention, when manual paper feeding or automatic paper feeding is performed one by one, the multi-feed prevention plate, which is useful in automatic paper feeding, is separated from the paper feeding roller. Manually fed paper is not obstructed by the double-feed prevention plate, and even special paper can be reliably fed by the paper feed roller. In this case, especially when no paper is detected, the paper feed roller rotates to feed the paper when it detects paper to be manually inserted, and stops rotating when the paper reaches a predetermined position. This allows the manual paper to be placed on standby at a predetermined position for reliable paper feeding.

In addition, while paper is being detected, the rotation of the paper feed roller is prevented even if the next paper to be manually inserted is detected, so double feeding can be prevented even without a double feeding prevention plate, and automatic paper feeding can be prevented. Similarly, manual paper can be reliably and stably fed one by one.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view for explaining the structure of the paper feed device according to the present invention, FIG. 2 is a cross-sectional view showing a specific example of the paper feed device according to the present invention, and FIG. 3 is a paper feed device according to the present invention. FIG. 4 is a circuit diagram showing an example of roller drive control, and is a timing chart for explaining the operation of FIG. 3. 1: Paper feed tray, 3: Paper feed roller, 4: Spring, 5: Paper, 8: Paper leading edge detection switch, 1
0: Paper feed tray position detection switch, 11: Operation piece of paper detection switch 14, 13: Long hole, 15: AND gate, 16: Differential circuit, 17: Flip-flop, 20: Paper feed roller drive circuit, 70: Double feed Prevention plate, 71: shaft, 72: separation lever, 74: spring.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A paper feed tray 1 on which a large number of sheets can be placed or one sheet of paper can be manually inserted, and a paper feed roller 3 that is pressed against the paper on the sheet feed tray and feeds the paper. and a double-feed prevention plate 7 for preventing double-feeding of sheets fed by the paper feed roller, and a position where the double-feed prevention plate faces the paper feed roller or is spaced apart from the paper feed roller. a support means 71 movably supporting the paper feed roller when a large number of paper sheets are loaded on the paper feed table, and a multi-feed prevention plate facing the paper feed roller when feeding a large number of paper sheets; In a paper feeding device that feeds paper with a double-feed prevention plate spaced apart from a paper feeding roller, the manual feeding paper detects the manually inserted paper while the paper feeding tray is in pressure contact with the paper feeding roller. Signal generating means 16 and 15 that allow operation when the detecting means 14 is not detecting paper and output a signal by validating the manual paper detection signal from the manual paper detecting means; and a valid signal from the signal generating means. a storage means 17 for temporarily storing the state set by the storage means; drive control means 18, 19, 20 for rotating the paper feed roller according to a storage signal from the storage means and feeding manual paper; and the paper feed Feed paper detection means 8 that detects the leading edge of the paper fed by the roller and outputs a signal for resetting the memory contents of the storage means.
A paper feeding device comprising: and. 2. The utility model according to claim 1, characterized in that the paper feed roller is automatically separated from the double feed prevention plate in response to a memory signal of the memory means set by the detection of the manually fed paper. Paper feed device.