JPH0730601Y2 - Automatic document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an automatic document feeder for feeding a document to a platen of an image processing apparatus such as a copying machine or an image reader.

[Conventional technology]

In a conventional automatic document feeder, a document set on a paper feed stacker is fed by a pickup roller, the document is separated into one sheet by a separating means, and the leading end of the document is corrected by a registration roller, and then a copying machine. It is conveyed to the reference position on the platen by the conveyor belt. When copying is completed, the transport belt is driven to carry out the original from the platen, and the paper is discharged to the paper discharge stacker by the paper discharge roller.

By the way, when setting the originals on the paper feed stacker, if the leading edge of the originals enters the separation pressure contact portion in layers, a wedge phenomenon may occur, and the paper feeding device may cause non-feeding or double feeding. For this reason, conventionally, a claw-shaped stopper is provided on the front side of the separation pressure contact portion and the stopper is retracted after the document is set. That is, the document is temporarily stopped on the upstream side of the separating means, and is discharged to the separating means side after the paper is set.

[Problems to be solved by the device]

However, the conventional claw-shaped stopper has a problem that the structure is complicated and the cost is high. Further, since there are many mechanical structures, there is a problem that the failure rate is high and the size of the entire sheet feeding device becomes large.

[Means for Solving the Problems]

The present invention has been devised in view of the above problems, and is provided with a stacker for stacking and storing sheets of originals and the like, and a pair of upper and lower separating members which are arranged at the tip of the stacker and which feed out sheets, and the stacker. Is a stacking surface for stacking sheets, and a positioning guide surface that stands up from the stacking surface from the leading edge of the paper feed and positions the leading edge of the stack paper when the sheets are stacked. An automatic document feeder formed of a conveyance guide surface for guiding a sheet to be conveyed, a first sensor provided on the conveyance guide surface in the vicinity of the entrance of the vertically opposed separating member, and detecting the presence or absence of the sheet. A second sensor for detecting a paper empty on the stack surface on the stacker, and At the time of setting and before the separation / feeding operation of the sheet by the separating member is started, when the first sensor detects the sheet while the second sensor detects the sheet, it is determined to be an abnormal set. Circuit and the abnormal set signal from this judgment circuit prohibits the operation of the separating member,
Alternatively, the automatic document feeder is provided with a control means for issuing a warning of resetting.

[Action]

According to the present invention configured as described above, in the unlikely event of stacking sheets, the leading edge of the stacked sheets rides on the positioning guide surface to reach the conveyance guide surface directly connected to the positioning guide surface, and even if the leading edge of the sheet reaches the separating member. A first sensor provided on the conveyance guide surface in the vicinity of the entrance of the separating member to detect the presence or absence of a sheet when the reached state is reached;
The second sensor for detecting the paper empty on the stack surface on the stacker is the second sensor when the paper is set on the stacker and before the separation and feeding operation of the paper by the separating member is started. When the sheet is detected by the first sensor, the first sensor detects the sheet, the stack state is detected, and it is determined that there is an abnormal set, and the abnormal set signal prohibits the operation of the separating member or resets the sheet. A warning can be given.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 2, an automatic document feeder 3 is attached to the image processing apparatus, for example, a platen 2 (original setting section) of a copying machine 1 so as to be openable and closable. The automatic document feeder 3 has a stacking surface G1 for stacking and setting originals with the first page facing downward, and a positioning guide for positioning the leading end of the stack of papers when the stacking paper G1 rises from the stacking paper G1 and rises above the paper feeding front end. Surface G2 and this positioning guide surface G2
A paper feed stacker 4 having a paper feed guide surface G3 that guides the paper that is directly connected to the separating members 11 and 13 and a document set on the paper feed stacker 4 is separated into one platen 2 The separation unit 5 that is sent out upward, the conveyance unit 6 that conveys the document that is sent out from the separation unit 5 along the platen 2, and the document that is conveyed by the conveyance unit 6 on the platen 2 are turned upside down. It is provided with a paper discharge unit 7 for discharging, a paper discharge stacker 8 (paper discharge tray) for storing the documents discharged from the paper discharge unit 7, a control device, and a drive device. The paper feed stacker 4 is provided with side edge guides that are movable in opposite directions by the same amount so that the originals are always held at the center in the width direction.

As shown in FIG. 5, the separating unit 5 includes paper feed guides 9 and 10 that form a paper feed path, and a feeding roller, for example, a pickup roller 11 that feeds out the documents set in the paper feed stacker 4.
A first sensor empty sensor 12 (first sensor) provided on the stack surface for detecting whether or not a document is set on the paper feed stacker 4, and a paper feed roller 13 rotating in the paper feed direction. A separating roller 14 is provided which rotates in a direction in which an original following the original fed by the paper feeding roller 13 is retracted. The separation roller 14 is constantly urged toward the paper feed roller 13 by the subling 70. With this configuration, an appropriate pressure contact force can be obtained according to the change in the paper thickness.

A first sensor 500 (second sensor) is provided near the entrance ends of the paper feed roller 13 and the separation roller 14 and is provided on the conveyance guide surface G3 near the entrances of the separation members 13 and 14 to detect the presence or absence of a document.
And a size detection sensor that detects the size of the original in the width direction.
15, a registration sensor 16, a relay conveyance roller, for example,
The registration rollers 17 and 18 are provided. By the way, the empty sensor 12 corresponds to the second sensor.

By the way, the paper detection position of the first sensor 500 is the paper feed roller 1
It suffices if it is the inlet end between the 3 and the separation roller 14, but especially the 5th
As shown in the figure, if the detection is performed at the pressure contact position between the paper feed roller 13 and the separation roller 14, it can be surely detected that the document stack is illegally held.

As shown in FIG. 3, the paper feed roller 13 is attached to the rotary shaft 40 via a one-way clutch. Further, the pickup roller 11 has a pair of arms whose base end is attached to the rotary shaft 40 via a spring clutch 43.
Supported by 44. The drive of the rotary shaft 40 is transmitted to the rotary shaft 42 via the gears 58, 59, 60.

The transport unit 6 includes a pair of rollers 19 and 20, and the rollers 19 and 20.
A conveyor belt 21 stretched between 20 and a plurality of press rollers 22 for pressing the conveyor belt 21 to the platen 2 side are provided. A gear 46 is attached to the rotating shaft 45 of the roller 19, and a pulley 48 is attached to the rotating shaft 47 of the roller 20.

The paper discharge unit 7 includes paper discharge guides 23 and 24 that form a paper discharge path.
Synthetic resin sheet 25 attached to the lower end of the paper ejection guide 24
A pinch roller 26 attached to the paper discharge guide 24 and pressed against the conveyor belt 21, a paper discharge sensor 27, and a paper discharge roller.
28, and a leaf spring 29 pressed against the paper discharge roller 28. A pulley 50 is attached to the rotary shaft 49 of the paper discharge roller 28, and the pulley 50 is connected to the pulley 48 by a round belt 51.

By the way, the sensors 12, 15, 16, 27, and 500 are configured by a lever-type sensor having a light emitting element and a light receiving element, a reflective sensor, a transmissive sensor, or the like.

The drive unit is a motor 30 that can rotate forward and backward as shown in FIG.
A pulley 32 attached to a rotating shaft 31 of this motor 30,
A gear attached to the rotary shaft 33 via a pulley 34 attached to the rotary shaft 33, a timing belt 35 connecting the pulley 32 and the pulley 34, and a first one-way rotary clutch, for example, a spring clutch 37. 38, a gear 39 that meshes with the gear 38, a gear 41 that is mounted on the rotation shaft 40 of the paper feed roller 13 and meshes with the gear 39, and a gear 52 that meshes with the gear 41,
A gear 54 attached to the rotation shaft 53 of the separation roller 14 and meshing with the gear 52, and a gear attached to the rotation shaft 33 via a second one-way rotation clutch, for example, a one-way clutch.
36, a gear 56 that is attached to the rotating shaft 55 of the registration roller 17 and that meshes with the gear 36, and a gear 57 that meshes with the gears 46 and 56.

A member for transmitting the rotational force of the motor 30 to the pickup roller 11, the paper feed roller 13, and the separation roller 14 by the normal rotation of the motor 30 is the first transmission means, and the reverse rotation of the motor 30 causes the registration roller 17 to rotate. , The conveyor belt 21 and the discharge roller 28
The member for transmitting the rotational force of 30 is the second transmission means.

The control device comprises a microprocessor, sensors 12, 15,
The drive of the motor 30 is controlled by the signals of 16, 27, 500 and the signal from the copying machine 1. Further, as shown in FIG. 1, the judgment circuit 600 and the control means 700 are provided.

The determination circuit 600 outputs an abnormal set signal when the first sensor 500 and the empty sensor 12 both detect the document before the pickup roller 11 sends out the document on the sheet stacker 4.

The control means 700 is based on the abnormality set signal of the judgment circuit 600,
The drive of the motor 30 is prohibited, or a warning of resetting the original is issued.

Next, the operation of this embodiment will be described.

First, when the original is set on the paper feed stacker 4 with the front side facing down, the empty sensor 12 detects the original and the original can be automatically fed. In such a state, the copying machine 1
Alternatively, if a paper feed button (not shown) of the automatic document feeder 3 is pressed, a start signal is issued in step S1 to start the paper feed operation, as shown in FIG. And step S2
At step S3, the state of the empty sensor 12 is determined, and if it is on, the motor 30 rotates normally (in the direction of the solid arrow) in step S3. As a result, the pulley 32, the timing belt 35, the pulley 34, the rotating shaft 33, the spring clutch 37 in the locked state, the gear 3
The rotating shafts 40, 53 rotate in the forward direction via 8, 39, 41, 52, 54.
The arm 44 is lowered by the forward rotation of the rotary shaft 40, and the pickup roller 11 comes into contact with the document. Therefore, the spring clutch 43
Slips due to strain. The pickup roller 11 is kept in contact with the document. Further, by the normal rotation of the rotary shaft 40, the paper feed roller 13 and the pickup roller 11 rotate in the normal direction to send out the document.

On the other hand, the rotation of the rotating shaft 53 causes the separation roller 14 to rotate in a direction that prevents the document from being fed, and the sheet feeding roller 13 displaces the document that follows the fed document and separates the document into one sheet. . By the way, since the one-way clutch is interposed in the gear 36, the gear 36 does not rotate when the motor 30 rotates in the normal direction. When the document reaches the size detection sensor 15, it is turned on if the document is long in the width direction and remains off if it is long in the length direction.

If the state of the registration sensor 16 is judged in step S4 and a document is detected, the motor 30 is stopped after a certain period of time in step S5. At this time, since the registration rollers 17 and 18 are stopped, the document is bent and the front end of the document is registered and corrected. By stopping the motor 30, the pickup roller 11, the paper feed roller 13, and the separation roller 14 also stop.

When the motor 30 rotates in the reverse direction (in the direction of the broken arrow) in step S6, the rotating shaft 40 also rotates in the reverse direction, and the spring clutch 43 in the locked state
The arm 44 ascends and the pickup roller 11 separates from the document. When the arm 44 hits a stopper (not shown), the spring clutch 37 is overloaded and the gear 38 stops rotating. For this reason, the pickup roller
The pickup roller 11, the paper feed roller 13, and the separation roller 14 are stopped in a state where 11 is raised.

On the other hand, due to the reverse rotation of the motor 30, the rotational force of the rotary shaft 33 is
Is transmitted to the registration roller 17, the conveyance belt 21, and the paper discharge roller 28 via the gears 56, 57, 46, the conveyance belt 21, and the round belt 51. When the trailing edge of the document passes the registration sensor 16, the size of the document is detected in step S8 by the amount of rotation of the motor 30 after the registration sensor 16 is turned on and the size detection sensor 15 being turned on and off. As a result, the size of the copy sheet is selected or the copy magnification is set according to the detected size.

When the motor 30 starts reverse rotation, the registration roller 17
The document waiting at the position is sent out, and counting for determining the document stop position is started.

In step S9, just before the leading edge of the document reaches the stop position,
The motor 30 is sped down to prepare for stopping the original. The document will have reached the stop position on platen 2,
When the predetermined count is completed, the motor 30
To stop. Then, in step S11, the copying operation of the copying machine 1 is performed and copying is performed on the paper. When copying is completed, the motor 30 is rotated in the reverse direction again in step S12, and the original document on the platen 2 is sent to the discharge unit 7. After the discharge sensor 27 detects the leading edge of the document in step S13, the motor 30 is decelerated after a predetermined count, and the document is slowly discharged to the discharge stacker 8.

In step S14, the motor 30 is stopped after a lapse of a certain time after the paper discharge sensor 27 detects the trailing edge of the document, and the feeding / paper discharging operation of one document is completed in step S15. In the case of continuous paper feeding, the process returns to step S2, the next original is sent out, and the same operation is performed.

It should be noted that before the motor 30 is rotated by pressing the paper feed button, the second sheet for detecting the paper empty on the paper feed stacker 4 is detected.
When the empty sensor 12, which is a sensor for detecting the paper, detects the paper and the first sensor 500 for detecting the presence or absence of the paper near the entrance ends of the paper feed roller 13 and the separation roller 14 detects the paper. , The judgment circuit 600 judges that the abnormal set (excessive set), the abnormal signal of the judgment circuit 600,
The control device can prohibit the operation of the motor 30 or issue a reset warning. Here, the reset warning may be a warning sound or a synthetic sound, and an alarm lamp or the like may be turned on or blinked.

Therefore, when an abnormality such as excessive setting is electronically set, that is, when the original is set, the original is set on the sheet feeding stacker 4,
The empty sensor 12 can detect in the detection state,
The separating operation or the like can be stopped.

By the way, after the originals are correctly set on the paper feed stacker 4,
When a stack of documents is continuously fed onto the platen, if the empty sensor 12 and the first sensor 50 are controlled so that they will not be judged to be abnormal even if they detect a document, in the case of continuous feeding. Even if there is, there is no problem.

If the first sensor 500 does not detect the document and no document has entered between the paper feed roller 13 and the separation roller 14, it is normal or the document stack has entered between the paper feed roller 13 and the separation roller 14. ,
When the first sensor 500 detects a document, the control device issues a control signal such as prohibiting conveyance.

<Effect> The present invention provides a stacker for stacking and storing paper such as documents.
Separation that stacks the sheets and the positioning guide surface that stands up from the stacking surface from the leading edge of the paper feed and positions the leading edge of the stack paper when the sheets are stacked and directly connects from this positioning guide surface to separate and feed the sheets Consists of a conveyance guide surface that guides the paper conveyed to the member,
An automatic document feeder not having a first sensor provided on the conveyance guide surface near the entrance of the separating member to detect the presence or absence of paper, and a first sensor to detect the paper empty on the stack surface on the stacker. The second sensor is provided, and the second sensor is provided when the sheets are set on the stacker and before the sheet separating and feeding operation by the separating member is started.
When the first sensor detects a sheet in the state where the sensor detects the sheet, a determination circuit for determining an abnormal set, and an abnormal set signal from this determination circuit prohibits the operation of the separating member or resets the sheet. Since a control means for issuing a warning is provided, it is possible to stack a plurality of sheets on a stacker while having an extremely simple structure without providing a stopper which is generally used in the past for regulating the stacking position of the originals. It is possible to prevent non-feeding, double-feeding, etc. due to an abnormal set that tends to occur, and has an outstanding effect that the structure is not complicated and there are few failures, and the cost is low.

[Brief description of drawings]

The drawings show one embodiment of the present invention, and each drawing shows the following. FIG. 1 is a diagram for explaining the schematic configuration of this embodiment, and FIG.
FIG. 4 is a sectional view showing the schematic structure of the automatic document feeder, FIG. 3 is a drawing showing the structure of the driving device, FIG. 4 is a flow chart for explaining the operation, and FIG. 5 is a sectional view showing the structure of the separating section. Is. DESCRIPTION OF SYMBOLS 1 ... Copying machine, 2 ... Platen 3 ... Automatic document feeder, 4 ... Paper feeding stacker 5 ... Separation part, 6 ... Conveying part, 7 ... Paper discharging part 11 ... Pickup roller 12 ... Empty sensor, 13 ... Paper feeding roller 14 ... Separation roller, 15 ... Size detection sensor 16 ... Registration sensor 17, 18 ... Registration roller, 21 ... Conveyor belt 27 ... Paper ejection sensor, 28 ... Paper ejection roller 30 ... Motor, 37, 43 ... Spring clutch 500 ... First Sensor, 600 ... Judgment circuit 700 ... Control means

Claims (1)

[Scope of utility model registration request] 1. A stacker for stacking and storing sheets of paper such as originals, and a pair of upper and lower separating members arranged at the tip of the stacker for feeding out sheets, the stacker having a stacking surface for stacking sheets, From the stacking surface, the positioning guide surface that rises from the leading edge of the paper feed and positions the leading edge of the stack paper when the sheets are stacked, and the transport guide surface that is directly connected from this positioning guide surface and that guides the paper transported to the separating member In the formed automatic document feeder, a first sensor provided on the conveyance guide surface near the entrances of the vertically opposed separating members to detect the presence of paper, and a paper on the stack surface on the stacker. A second sensor for detecting empty, and at the time of setting paper on the stacker, A determination circuit for determining an abnormal set when the first sensor detects a sheet while the second sensor detects the sheet before the sheet is separated and fed by the material, and the determination circuit 2. An automatic document feeder, which is provided with a control means for issuing a warning of prohibiting the operation of the separating member or resetting it by an abnormal setting signal.