JPH0223132A - Automatic original delivery device - Google Patents

Abstract

PURPOSE:To exactly take out an original and prevent jam or faulty image formation by providing a control means which reverses the turning of a delivery roller for the specified period when an equipment starts. CONSTITUTION:When an original is delivered to the specified position on a contact glass 11, the copy process of a copy machine starts. When the copy process is completed, the signal is sent from the control means of the copy machine to the control means of an automatic original delivery equipment to start reverse a motor. A delivery roller 10 then starts to turn in the clockwise direction. A sheet of original is delivered to the left from the contact glass 11, offset upwards by a guide means 14 and is ejected via an eject hole 18 onto an ejection tray 15 by both the delivery roller 10 and a driven roller 17 operating therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic document feeder, and more particularly to an automatic document feeder that conveys and discharges a document using a conveyance roller.

(Prior Art) In order to process a large number of documents, image forming apparatuses equipped with an automatic document feeder that automatically conveys documents onto a contact glass are becoming popular. As this automatic document feeder, for example, Japanese Patent Laid-Open No. 60-118551
There are some that are disclosed in the publication.

This automatic document feeder is provided with a paper feeding means for feeding a document placed on a paper table, and the document fed by the paper feeding means is conveyed to a predetermined position on a contact glass by a conveyor belt.

After image processing is performed on the conveyed originals, the originals are sequentially stacked on a paper ejection tray formed on the upper surface of the automatic original feeder.

However, when a conveyor belt is used as a means of conveyance, the structure of the automatic document feeder main body is generally complicated, resulting in high manufacturing costs.

Furthermore, due to the complexity of the mechanism, the automatic document feeder is large in size, making it difficult to apply it to small-sized copying machines.

Therefore, in order to solve these drawbacks, the present applicant has previously proposed an automatic document feeder that does not use a belt-like device as a conveying means. In other words, it is an automatic document feeder that carries in and ejects documents by rotating a conveyance roller in contact with a contact glass in the forward and reverse directions (Utility Application No. 63-6133
3).

(Problems to be Solved by the Invention) Although improvements have been made to the automatic document feeder previously proposed by the present applicant, there are still problems to be solved.

For example, in this automatic document feeder, when ejecting a document after image processing has been performed, the conveyance roller is rotated in the opposite direction, and the document is ejected in a direction opposite to the carrying direction. Therefore, if a document is left behind on the contact glass and the automatic document feeder is activated without noticing this,
The fed original and the ejected original collide, resulting in a paper jam.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic document feeder that can reliably feed and eject sheets by solving these drawbacks.

(Means for Solving the Problems) In order to solve the above-mentioned drawbacks, an automatic document feeder according to the present invention has the following configuration.

In other words, there is a paper feeder that feeds originals one sheet at a time toward the contact glass of the image forming apparatus, and a paper feeder that is provided in contact with the contact glass and rotates in the normal direction so as to convey the original in the direction from the paper feeder to the contact glass. , or a transport roller that rotates in reverse so as to transport the original in the opposite direction to the transport direction, and a control means that controls the forward rotation and reverse rotation of the transport roller, so that the original is transported in the opposite direction to the transport direction after image processing. In the automatic document feeder for ejecting documents toward the original document, the control means is configured to reverse the conveying roller for a predetermined period of time when the automatic document feeder starts operating.

(Function) The original is loaded on the paper tray located on the side of the automatic document feeder, and the automatic document feeder is activated.

At this time, the conveyance roller control means causes the conveyance roller to rotate in reverse for a predetermined period of time so as to convey the document in the carrying direction from the sheet feeding means toward the contact glass, and the document is not fed until this rotation stops.

With this configuration, even if a document is left behind on the contact glass, when the automatic document feeder is activated, the document will be ejected first, and then the document on the paper table will be fed and transported. I can do it.

(Example) An example of an automatic document feeder according to the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of the automatic document feeder of the present invention, and FIG. 2 is a time chart for explaining the operating procedure of the automatic document feeder.

In FIG. 1, reference numeral 1 denotes an automatic document feeder, which is attached to a copying machine (not shown) which is an image forming apparatus.

Reference numeral 2 denotes a paper tray, on which sheet-like originals are stacked.

The feed roller 3 is swingable around the paper feed roller shaft 4 between a position where it contacts the document and a position where it separates from the document.

A paper feed roller 5 is provided on the paper feed roller shaft 4, and rotates as the paper feed roller shaft 4 rotates.This rotation is transmitted to the feed roller 3 by a timing belt (not shown), and the paper feed roller 5 rotates as the paper feed roller shaft 4 rotates. The feed roller 3 and the feed roller 3 are configured to rotate in the same direction.

A separation roller 6 is provided below the paper feed roller 5, and the originals are separated and fed one by one by the action of the paper feed roller 5.

Note that 7 is a document presence/absence sensor that turns the automatic document feeder 1 into an operating state and a non-operating state, and 8 is a leading edge detection sensor for detecting the conveyance of the document. And 9 is a stopper that stops the original at a fixed position.

The original sent through the above process is transported to a predetermined position on the contact glass 11 by the transport roller 10, and is copied.

These paper feed roller 5, separation roller 6, and conveyance roller 10
is drivingly connected to a motor (not shown). Further, the paper feed roller shaft 4 and the conveyance roller shaft 12 are connected to a clutch mechanism (
A one-way clutch (not shown) is provided on the separation roller shaft 13 so that rotation in only one direction can be transmitted.

The conveyance roller 10 is fixed to a conveyance roller shaft 12, and has a core made of synthetic resin covered with a flexible material such as foamed synthetic resin. This conveyance roller 10 is set so as to come into contact with the upper surface of the contact glass it.

Then, when the conveyance roller 10 copies the original,
The control unit (
(not shown) controls the motor.

A guide means 14 is provided between the conveyance roller 10 and the paper table 2, which allows the document to enter the contact glass 11 from the paper table 2, but prevents the document from moving from the contact glass 11 toward the paper table 2. is provided, and the documents conveyed in the opposite direction to the carry-in direction by the reverse rotation of the conveyance rollers 10 are sequentially stacked on the paper discharge tray 15 formed on the upper surface of the automatic document feeder 1 through this passage. .

The operating procedure of this automatic document feeder will be explained based on FIG.

When a document to be copied is set on the paper tray 2, the document presence/absence sensor 7 detects this and sends a signal indicating the presence of the document, and the automatic document feeder 1 becomes ready for operation. At this time, the document is stopped at a fixed position by a stopper 9.

Next, when the operator presses the copy start button, the transport roller l
A signal is sent to the motor from the control means for controlling the rotation of O, and the motor rotates in reverse for a predetermined period of time 11. Since the conveyance roller shaft 12 is provided with a one-way clutch that transmits the drive during reverse rotation, the conveyance roller shaft 12 in FIG.
will rotate clockwise.

This predetermined time t1 is set to the time required to discharge the maximum length document on the contact glass 11 to the paper discharge tray 15 (for example, 1600 m5 for an A4 size document).

When the predetermined time tI has elapsed, the motor stops, and when the predetermined time t2 has elapsed, the motor starts normal rotation. That is, in FIG. 1, a force is applied to the conveyance roller 10 to rotate it counterclockwise, but at this point, the rotation is stopped by a solenoid (not shown) of a clutch mechanism for the conveyance roller. That is, during normal rotation, the rotation is controlled by a clutch mechanism (not shown).

A predetermined time ts (for example, 150
m5), the solenoid of the stopper clutch mechanism (
(not shown) is energized, and the stopper 9 is removed. Also,
After a predetermined time ta (for example, 300 m5) has elapsed since the forward rotation of the motor started, the solenoid (not shown) of the paper feed roller clutch mechanism is activated for a predetermined time ta (for example, 150 m5).
5) is energized to a certain extent, thereby making it possible to feed paper. That is, in FIG. 1, the feed roller 3 is rotated counterclockwise, and the paper feed roller 5 and separation roller 6 are also rotated counterclockwise.

In this manner, the feed roller 3 feeds the uppermost document on the paper table 2 downstream (to the right in FIG. 1), and the feed roller 5 feeds the document further downstream. The fed original closes the leading edge detection sensor 8, and the leading edge of the original comes into contact with the nip 16 of the conveyance roller. The amount of movement of the document by the paper feed roller 5 is set to be somewhat longer than the amount required to advance the leading edge of the document to the nip 16 of the conveyance roller, so that the document is reliably moved to the nip 16 of the conveyance roller. can be reached up to.

For a predetermined period of time from the time when the tip detection sensor 8 is closed,
When , the solenoid of the conveyance roller clutch mechanism is energized, and the conveyance roller 10 rotates counterclockwise in FIG. 1. As the document is carried in by the conveyance roller 10, the trailing edge of the document passes the leading edge detection sensor 8, and the leading edge detection sensor 8 is opened.

A counter (not shown) counts the number of pulses generated after the conveyance roller 10 starts rotating counterclockwise, and the value n
By holding , you can know the size of the original.

In addition, the number of pulses from the time when the tip detection sensor 8 is opened is counted by another counter (not shown), and when it reaches a predetermined value n3, the power supply for normal rotation of the motor is stopped, and the pulse number is stopped for a very short time. Only when the power supply is applied will the motor be reversed.

As a result, a braking action is applied to the motor that was rotating in the normal direction, thereby preventing the motor from running inertia due to inertia or the like.

When the conveyance of the original to the predetermined position on the contact glass 11 is completed in the above manner, the copying process in the copying machine is started. When the copying of the original is completed, a signal is sent from the control means of the copying machine to the control means of the automatic document feeder, and the motor starts to reverse rotation. As a result, the conveyance roller 10 begins to rotate clockwise in FIG. The document is carried out from above the contact glass 11 to the left in FIG. 1, deflected upward by the guide means 14, and discharged onto the discharge tray 15 through the discharge port 18 by the conveyance roller 10 and the driven roller 17 working therewith. Ru.

When the motor starts to reverse in this way, a third counter (not shown) starts counting pulses, and when the counted value reaches the sum of the aforementioned n and the predetermined value n, The motor stops reversing. Count value n.

corresponds to the length of the document carried in, and the predetermined value n is set to the minimum value necessary for carrying out the document. Therefore, the motor is reversed by the minimum necessary value depending on the length of the document that has been carried in, thereby avoiding power consumption and time wastage due to unnecessary reversal of the motor.

When the ejection of the original is completed as described above, if the next original exists on the paper table 2 and the original presence/absence sensor 7 is closed, the motor will automatically start rotating forward and the next original will be ejected. Delivery is started and the operating procedure described above is repeated.

In this embodiment, the reversal time of the conveyance roller at the start of operation of the automatic document feeder is set to a time sufficient to eject the maximum length of the document, but changes may be made without changing the gist of the invention. , modification is possible.

For example, the transport roller 1 that acts when ejecting a document
A sensor for detecting the document to be sent out is provided near the part where the conveyance roller 10 contacts the driven roller 17. Then, when the conveyance roller 10 reverses, the leading edge of the document (the trailing edge when viewed from the direction of conveyance into the contact glass) The time it takes for the document to be detected by the detection sensor is constant regardless of the size of the document.
If there is no reaction from the detection sensor after this certain period of time has elapsed, it is determined that the document is not on the contact glass.
The motor can be rotated in the normal direction to move on to the copying process.

(Effects) As explained above, by using the automatic document feeder of the present invention, even if you do not notice that you have left a document on the contact glass during image formation, you can reliably take out the document, thereby eliminating paper jams, etc. Mistakes in image formation can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the automatic document feeder of the present invention, and FIG. 2 is a time chart for explaining the operating procedure of the automatic document feeder. The river fish numbers in the figure represent the following. 1. Automatic document feeder 2. Paper tray 3. Feed roller 5. Paper feed roller 6.
, Separation roller 7 , Original presence/absence sensor 8 , Lead edge detection sensor 9 , Stopper io, , v
i feed roller t t , 0. ,=,contact glass 14
, , , , Guidance means 15. , , , Paper ejection tray 17 , , , Followed roller 18 , , Ejection port Patent applicant Sanda Kogyo Co., Ltd.

Claims (1)

[Scope of Claims] A paper feeding means for feeding originals one sheet at a time toward a contact glass of an image forming apparatus; A transport roller that rotates forward to transport the original or reversely rotates to transport the original in a direction opposite to the carrying direction, and a control means that controls the forward rotation and reverse rotation of the transport roller, In the automatic document feeder that discharges the document in a direction opposite to the carrying direction after image processing, the control means reversely rotates the conveyance roller for a predetermined period of time when the automatic document feeder starts operating. automatic document feeder.