JPS5854057B2 - Document trailing edge passage detection device in document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a document feeding device that automatically feeds a transmission document to a facsimile machine or the like, and particularly to a document trailing edge passage detection device in the document feeding device.

A document feeding device that automatically feeds documents to be sent to a facsimile machine, etc. generally has a document storage section that can store multiple sheets of documents to be sent in a stacked state. The transmission document is configured to send out the transmission document one by one through the document conveyance path to a pair of paper feed rollers in the document reading section of the facsimile machine.

Conventionally, in the above-described document feeding device, an induction motor is generally used to drive the feeding roller, and the leading edge of the document to be sent is held between the feeding roller pair, and the feeding continues until the document reaches the reading section. The document to be sent is fed by the feed roller, and thereafter, while the document is continuously being conveyed to the document reading section by the pair of feed rollers, the drive of the feed roller is stopped and the document is sent out. When the reading of the original to be transmitted is completed, the driving of the feeding roller is restarted, and separation and feeding of the next original to be transmitted is started.

In this case, a gap is created between the preceding transmitted document and the next transmitted document, and the passing of the trailing edge of the transmitted document can be easily detected. It is convenient to automatically cut the paper according to each transmitted document. There is a large gap between the original and the next sent original.

As a result, there is a problem in that there is a lot of idle time during which no actual transmission is performed, and especially when a large number of documents are being sent, this idle time accumulates and a large amount of transmission costs are required to operate the facsimile. .

Furthermore, while reading the original to be sent, the feeding roller rotates with the feeding of the original to be sent, so the frictional force between the original to be sent and the feeding roller, the weight of the original to be sent and other originals to be sent, etc. This includes the problem that the adhesion force becomes a load on the pair of paper feed rollers, resulting in a decrease in reading quality.

In another conventionally known document feeding device, a pair of feeding rollers in a document storing section and a pair of paper feeding rollers in a document reading section are driven continuously in synchronization with each other by stepping motors, etc. Some devices are configured so that when the trailing edge of the document leaves the feed roller, the feed roller continues to separate and feed the next document to be transmitted.

In such document feeding devices, the circumferential speed of the feeding roller is usually equal to or greater than the circumferential speed of the feeding roller pair so that a large load is not applied to the feeding roller pair. Therefore, the trailing edge of the preceding original to be transmitted and the leading edge of the next original to be transmitted are fed to the original reading unit so as to abut each other or overlap.

In this case, there is no gap between the previous sent document and the next sent document, and the sent documents can be sent continuously, eliminating idle time and allowing the facsimile to operate at high utilization rates. You will be able to do this.

Furthermore, since the paper feed roller is driven in synchronization with the paper feed roller pair of the document reading section and at a circumferential speed that is the same as or slightly higher than that of the paper feed roller pair, the paper feed roller pair No load is applied to the document, making it possible to read documents with high precision.

However, in this case, since the preceding transmitted document and the next transmitted document are consecutive, it is not possible to detect the passage of the trailing edge of each transmitted document, and therefore the receiving side It is not possible to automatically cut each sent document according to its size.

Therefore, when such a document feeding device is used, an operator on the receiving side has conventionally been required to manually cut the received paper.

In view of the above-mentioned problems with conventional document feeding devices, the present invention has been developed to continuously separate the preceding document from the next document in the document storage section, and to ensure that the trailing edge of each document is maintained even when fed. It is an object of the present invention to provide a document trailing edge passage detection device in a document feeding device that can detect and ensure a gap between a preceding document and a following document.

According to the present invention, the present invention has a document reading section that reads the document while conveying the document, a feeding roller that sends the document from the document storage section to the document transport path toward the document reading section, and a document reading section that reads the document while conveying the document. A document trailing edge fall space is provided in the document conveyance path between the storage section and the document reading section, and has a height difference in which the trailing edge of the document falls when the trailing edge of the document passes therethrough. a first document trailing edge detection sensor that detects that the edge has fallen and outputs a signal to stop the rotation of the feeding roller; and a document conveyance path between the first document trailing edge detection sensor and the document reading section. and a second document trailing edge detection sensor that outputs a signal to rotate the feeding roller when the trailing edge of the document is detected. The document feeding device is characterized in that when a second document trailing edge detection sensor detects the trailing edge of the preceding document, the device stops feeding the subsequent document, and when a second document trailing edge detection sensor detects the trailing edge of the preceding document, resumes feeding the subsequent document. This is achieved by a document trailing edge passage detection device in the document.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

The attached FIG. 1 is a schematic vertical cross-sectional view showing a document feeding device and a reading section of a facsimile equipped with a document trailing edge passage detection device according to the present invention, and FIG. FIG.

In the figure, reference numeral 1 generally indicates the document reading section of the facsimile machine.

The document reading section 1 has a document reading path 4 formed by an upper guide plate 2 and a lower guide plate 3 and extending substantially in the horizontal direction.

The document reading path 4 includes two paper feed rollers 5 and 6.
and a pair of driven rollers 7.8 for each of the paper feed rollers 5.6.

The paper feed rollers 5 and 6 are one stepping motor 9.
It is rotatably driven by the driven roller 7.8 to transport the transmission document along the document reading path 4 from the left to the right in the figure at a predetermined speed.

A document reading window 10 is opened in the lower guide plate 3 between the paper feed rollers 5 and 6.

A document reading device 13 including a light source 11 and a photoelectric element 12 is provided below the document reading window 10.
The original reading device 13 is adapted to photoelectrically read the transmitted original passing through the original reading window 10.

Further, the upper guide plate 2 is provided with a detection window 14 at a position opposite to the original reading window 10.
A photoelectric element 15 for detecting an original is provided above 4.

This document detection photoelectric element 15 is connected to the document reading window 10.
When there is no document to be transmitted at a position corresponding to the document reading window 10, the light emitted by the light source 11 of the document reading device 13 is received; on the other hand, when there is a document to be transmitted at a position corresponding to the document reading window 10, the light emitted by the light source 11 is received. is blocked by the original to be transmitted, so that it does not receive any light.

Thereby, the document detection photoelectric element 15 photoelectrically detects whether or not there is a transmission document at a position corresponding to the document reading window 10.

Further, the reference numeral 20 generally indicates a document supply device that automatically supplies a transmission document to the document reading section 1.

The document supply device 20 includes a document placement table 21 that is provided with a relatively gentle slope.

The document mounting table 21 is adapted to support a plurality of transmission documents in a stacked state, and a document separation roller (feeding roller) 22 is provided at the document sending end, that is, at the right end in the figure.

Further, an auxiliary feed roller 23 is provided in the middle part of the document mounting table 21.
is provided.

The separating roller 22 and the auxiliary feeding roller 23 are rotationally driven by a stepping motor 24 that is driven in synchronization with the stepping motor 9, and are rotated by a stepping motor 24 that is driven in synchronization with the stepping motor 9.
The original to be transmitted on 1 is sent out to the right in the figure, that is, toward the original reading section 1.

In this case, the separation roller 22 and the auxiliary feed roller 2
The circumferential speed of No. 3 is equal to or slightly greater than the circumferential speed of the paper feed roller 5.6.

A document stopper lever 26 is provided on the document table 21 and is supported by a pivot shaft 25, and the document stopper lever 26 has a wall portion 26a that engages with the document on the document table 21. It also has a brake plate 27 at its tip that comes into sliding contact with the separation roller 22.

This brake plate 27 is lightly pressed against the separating roller 22 by a spring 28, and prevents a plurality of documents from being fed simultaneously by the separating roller 22 due to frictional resistance with the documents.

Further, the document mounting table 21 is provided with a document detection window 29, and a document detection photoelectric element 30 is arranged below this window 29.

The photoelectric element 30 for detecting an original is sensitive to light emitted from a light source 31 placed above the original mounting table 21.

That is, the photoelectric element 30 receives the light emitted from the light source 31 when there is no original to be transmitted on the original platen 21, whereas if there is even one original to be transmitted on the original platen 21, the light source 31 The light emitted by the sender is blocked by the original to be sent, so that the sender does not receive any light.

The original to be sent from the original supply device 20 is sent to the original reading path 4 through an original transport path 40 formed by an extension of the upper guide plate 2 and the lower guide plate 3 of the original reading section 1. It will be done.

The artificial passage 41 of the document conveyance path 40 is provided at a position higher than the document reading passage 4 by a predetermined amount.

That is, a predetermined height difference (head) is provided between the artificial path 41 of the document transport path 40 and the document reading path 4.

The extension portion of the upper guide plate 2 has an inclined portion 42 that slopes upward from the end of the document reading path 4 and continues to the artificial path 41 of the document transport path 40. The extension part has an upright part 43 that extends substantially horizontally from the end of the document reading path 4 and then stands substantially upright toward the upper end of the inclined part 42 . As clearly shown in FIG. 2, the inclined portion 42 defines a triangular space 44 having a triangular cross section and serving as a falling space for the trailing edge of the document.

Further, a document detection window 4 is provided in the inclined portion 42 of the upper guide plate 2.
5 is opened, and a document detection photoelectric element 46 as a first document trailing edge detection sensor is provided in this portion.

This document detection photoelectric element 46 is sensitive to light emitted from a light source 47.

The light source 47 emits light through a window 48 provided in the upright portion 43 of the lower guide plate 3 toward the original detection photoelectric element 46, and this light source 47 and the original detection photoelectric element 46 The optical path between the element 46 is the artificial passage 41 and the original reading passage 4 as shown in FIG.
When there is a transmission document straddling the two, communication is blocked by the transmission document, and on the other hand, as shown in FIG. 2, when there is no transmission document straddling the transmission document, communication is established.

Further, another document detection window 49 is provided in the inclined portion 42 of the upper guide plate 2 on the side of the document reading path 4 from the position where the document detection window 45 is provided.
Another document detection photoelectric element 50 is provided in this portion.

The document detection photoelectric element 50 serving as the second document trailing edge detection sensor is sensitive to light emitted by a light source 51.

The light source 51 emits light toward the document detection photoelectric element 52 through a window 52 provided in the horizontal extension of the lower guide plate 3, and this light source 51 and the document detection photoelectric element 50 The optical path between the two is blocked or communication is established depending on whether there is a document to be transmitted between them.

Note that the four document detection photoelectric elements described above are 15°30.4
Reference numerals 6 and 50 control the energization of the stepping motors 9 and 24, respectively, and the operation of each document detection photoelectric element will become clearer when the operation of the entire apparatus is explained next.

Next, the operation of the apparatus constructed as described above will be explained.

The operator places a stack of transmission documents on the document mounting table 21 with the reading surface facing downward, and sets the transmission documents so that the leading edge of the transmission documents abuts against the wall portion 26a of the document stopper lever 26.

At this time, the light source 31 is
The optical path between the document detection photoelectric element 30 and the original detection photoelectric element 30 is blocked, and the original detection photoelectric element 30 senses that there is a transmission original on the document mounting table 21 and outputs a signal to that effect.

When the continuous transmission start switch of the device (not shown) is operated at the stage where the setting of the transmission document as described above is completed, the stepping motors 9 and 24 start rotating.

As a result, the separation roller 22 cooperates with the brake plate 27 to send the lowest one of the transmission originals on the original document mounting table 21 to the artificial passage 41 of the original transport path 40.

This transmission document enters the triangular space 44 from the artificial passage 41, and further passes through this triangular space 44 to the manuscript reading passage 4.
The paper enters the paper, is sandwiched between the paper feed roller 5 and the driven roller 7, and continues to move to the right in the figure.

From the time the continuous transmission start switch is operated until the leading edge of the first transmitted document is detected by the document detection photoelectric element 15, the stepping motors 9 and 24 rotate at a relatively high speed, and their positions are Fast-forward the sent document until .

At this time, the optical path between the light source 47 and the original detection photoelectric element 46 and the optical path between the light source 51 and the original detection photoelectric element 50 are blocked by the transmitted original.

When the document detection photoelectric element 15 detects the leading edge of the transmitted document, the stepping motors 9 and 24 each stop, and the receiving side prepares the recording paper for reception.

Then, when receiving a signal that the receiver is ready,
The stepping motors 9 and 24 are restarted with a reduced rotational speed, and the transmitted document moves from the left to the right in the figure in the document reading path 4 at a normal reading speed, during which time the document reading device Reading is performed by 13.

During this reading, when the trailing edge of the first original to be transmitted is released from the separation roller 22 and the brake plate 27, the following two originals to be transmitted are successively separated and fed.

The two-sheet transmission document is separated and fed by the separation roller 22 at a circumferential speed corresponding to the reading speed of the first transmission document, and is continuously conveyed to the document conveyance path 40 following the first transmission document. Sent to artificial passageway 41.

At this time, the first transmission original and the two transmission originals move through the artificial passageway 41, facing each other or slightly overlapping each other.

Note that in this embodiment, due to the separation method, the originals stacked on the original platen 21 are separated and fed sequentially starting from the lower original, and the first original to be sent and the second original are separated. Even if the originals to be sent from the mill overlap, the rear edge of the first original to be sent will be positioned below the leading edge of the original to be sent from the two-sheet mortar, and the trailing edge of the first original to be sent will fall. No inconvenience will occur.

When the trailing edge of the first transmission document reaches the end of the artificial passageway 41 and enters the triangular space 44, it falls due to its own weight and the firmness of the paper, and the trailing edge is placed on the lower guide plate. It will now be located on the horizontal extension of 3.

Then, the optical path between the original detection photoelectric element 46 and the light source 47 is established, and the original detection photoelectric element 4
6 receives the light emitted from the light source 4γ.

That is, the document detection photoelectric element 46 detects passage of the trailing edge of the transmitted document and outputs a signal to that effect.

This signal causes the stepping motor 24 to stop rotating, and the separation roller 22 as a feeding roller to stop rotating.

At this time, the stepping motor 9 continues to rotate, and the reading of the first transmission document is continued.

Thereafter, when the trailing edge of the transmitted original passes through the window 52, communication of the optical path between the light source 51 and the original detection photoelectric element 50 is established, and the original detection photoelectric element 50 receives the light emitted from the light source 51, detects that the trailing edge of the transmitted document has passed, and outputs a signal to that effect.

Then, the rotation of the stepping motor 24 is restarted, the separation roller 22 is rotated again, and the sending of the transmission document of the two-sheet mill is restarted.

As mentioned above, when the stepping motor 24 is temporarily stopped, a gap is created between the single-sheet original and the double-sheet original to be sent. 15 is essential for reliably detecting the passage of the trailing edge of the transmitted document, and this interval is essential for reliably detecting the passage of the trailing edge of the transmitted document, and as in the past, after the reading of the preceding transmitted document is completed, separation and feeding of the next transmitted document is started. It is sufficient to use the minimum amount necessary, which is significantly smaller than when it is used.

Therefore, the idle time of the facsimile becomes very small.

Also, if the circumferential speed of the separation roller 22 is set higher than the circumferential speed of the paper feed roller 5, this interval is determined by the stepping motor 2.
After the resumption of operation in April 2017, the time will be gradually shortened.

When the document detection photoelectric element 15 detects the passing of the trailing edge of the document, the transmitting side cuts the recording paper into a length corresponding to the transmitted document, and the document detection photoelectric element 15 detects the next document. When the leading edge of the transmitted document is detected to have passed, preparations for the next reception are made.

Thereafter, the operation is repeated until all the transmission originals on the original platen 21 are sent out.

Furthermore, in order to ensure the detection of the trailing edge, as shown in FIG. By blowing air along the inclined portion 42, the trailing edge of the document that has come off the top of the upright portion 43 is ensured to fall along the lower guide plate 3 due to this air flow.

That is, when the trailing edge of the document is located in the artificial passageway 41, the document is pressed against the slope part 42 by the airflow A and advances; however, when the trailing edge of the document leaves the artificial passageway 41, An air stream flowing along the trailing edge of the document enters between the document and the ramp 42 to separate the document from the ramp.

When blowing such an air flow, it is effective for curled documents, especially documents whose trailing edges are curled.

A simple blower, axial fan, or other device capable of obtaining a low-pressure air flow is sufficient for the above-mentioned air flow.

This is because the trailing edge of the document tends to fall of its own accord due to its own weight and the strength of its back, and it is sufficient to act auxiliary to this.

Of course, the use of medium to high pressure airflow will increase the effectiveness of airflow blowing.

As described above, it is understood that according to the present invention, there is provided a document trailing edge passage detection device that can detect the passage of the trailing edge of each document even if the documents are continuously separated and fed. It will be.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal cross-sectional view showing a document feeding device and a facsimile reading unit equipped with a document trailing edge passage detection device according to the present invention, and FIGS. 2 and 3 are respective views of the document trailing edge passage detection device according to the present invention. FIG. 7 is a vertical cross-sectional view showing a main part of a different embodiment. 1... Original reading section, 2... Upper guide plate, 3... Lower guide plate, 4... Original reading passage, 5゜6... ... Paper feed roller, 7, 8
...Followed roller, 9...Stepping motor, 10...Document reading window, 11...
...Light source, 12...Photoelectric element for reading originals, 13...Reading device, 14...
Document detection window, 15... Photoelectric element for document detection,
20...Document supply device, 21...Document placement table, 22...Separation roller, 23...
- Auxiliary feed roller, 24...Stepping motor, 25...Pivot, 26...Document stopper lever, 26a...Bullet part, 27...・
... Brake plate, 28 ... Spring, 29 ...
...Document detection window, 30...Document detection photoelectric element, 31...Light source, 40...Document transport path, 41...Artificial passageway, 42... Inclined part, 43... Upright part, 44... Triangular space, 45... Document detection window, 46...
... Photoelectric element for document detection, 47 ... Light source, 48
...Window, 49...Document detection window, 50
... Photoelectric element for document detection, 51 ... Light source, 52 ... Window.

Claims (1)

[Claims] 1. Between the document reading section that reads the document while conveying the document, the feeding roller that sends the document from the document storage section to the document transport path toward the document reading section, and the document reading section such as the document storage section. It is installed in the document transport path of
A document trailing edge falling space having a height difference where the trailing edge of the document falls when the trailing edge of the document passes therethrough; and detecting that the trailing edge of the document has fallen into this falling space, and stopping the rotation of the feeding roller. A first document trailing edge detection sensor that outputs a signal is provided in the document conveyance path between the first document trailing edge detection sensor and the document reading section, and rotates the feeding roller when the document trailing edge is detected. When the first document trailing edge detection sensor detects the trailing edge of the preceding document, it stops feeding the subsequent document and detects the trailing edge of the preceding document. A document trailing edge passage detection device in a document feeding device, characterized in that when a second document trailing edge detection sensor detects the edge, restarts feeding of a subsequent document.