JPS5854056B2 - 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.

In the above-described document feeding apparatus, 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 pair of feeding rollers, and the document is fed until it reaches the reading section. The document to be transmitted is fed by the feed roller, and thereafter, while the document is being conveyed to the document reading section by the pair of paper feed rollers, the drive of the feed roller is stopped and the document is read. The feeding roller is caused to rotate along with the feeding, and when the reading of the original to be sent is completed, the driving of the feeding roller is restarted, and separation and feeding of the next original to be sent is started.

In this case, there is a gap 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, so that the receiving side can detect the received paper based on the detection signal. 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. .

During the reading of the transmitted original, the feeding roller rotates with the feeding of the transmitted original, so the frictional force between the transmitted original and the feeding roller, the weight of the transmitted original and other transmitted originals, 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 butt against each other or to overlap slightly.

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 it.

Furthermore, since the 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 This makes it possible to read documents with high precision without applying a large load to the document.

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 transmitted 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 the passage of a trailing edge of a document in a document feeding device.

According to the present invention, this object includes: a document reading section that reads the document while feeding it with a paper feed roller; a feeding roller that feeds the document from the document storage section toward the document transport path;
a document leading edge detector that is provided in the document reading section and outputs a signal to stop the rotation of the feed roll when the leading edge of the document is detected; and a document transport path from the feed roller to the paper feed roller. A recess into which the original can fall, a free lever that moves up and down according to the tension applied to the original by contacting the original passing through the recess, and a free lever that moves up and down depending on the tension applied to the original. document tension which, when raised by the tension of the document, provides a signal to re-rotate the feed roller, and when tension in the document is lost and the free lever is lowered, provides a signal to stop the feed roller again. A detector is provided in the document transport path between the recess and the feed roller, and when it detects that the trailing edge of the document has passed, it sends a signal to rotate the feed roller again. This is accomplished by a document trailing edge passage detection device in a document feeder, such as one provided with an edge detector.

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

The attached FIGS. 1 to 3 are schematic vertical sectional views showing respective operating states of a document feeding device and a reading section of a facsimile equipped with a document trailing edge passage detecting device according to the present invention.

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 control rollers 5 and 6 are rotationally driven by a stepping motor 9, and work together with the driven roller 7.8 to move the transmitted original along the original reading path 4 from the left to the right in the figure. It is designed to be transported 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 a document as a document leading edge detector is provided above the document detecting device 4 .

This document detection photoelectric element 15 is connected to the document reading window 10.
When there is no document to be transmitted at the 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 the position corresponding to the document reading window 10, the light emitted by the light source 11 is received. It is blocked by the original so that it does not receive light.

Thereby, the document detection photoelectric element 15 photoelectrically detects whether or not there is a document to be transmitted 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 placement 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, 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 separation roller 22 and the auxiliary feed roller 23 are rotationally driven by a stepping motor 24 that is driven in synchronization with the stepping motor 9, and
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. 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 separation roller 22 by a spring 28, and prevents a plurality of originals from being fed simultaneously by the separation roller 22 due to frictional resistance with the originals.

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 original is blocked by the original so that it does not receive any light.

The transmission original sent out from the original supply device 20 is sent to the original reading passage 4 through an original transport path 33 constituted by an extension 3a of the lower guide plate 3 of the original reading section 1 and a free lever 32. It has become.

The extension portion 3a of the lower guide plate 3 is continuous with the document mounting table 21, and is connected to the paper feed roller 5 and the separation roller 2.
2 constitutes a recessed portion having a substantially square cross section.

Further, the free lever 32 is bent into a dogleg shape, and is supported by a pivot shaft 34 at one end thereof.

The free lever 32 has a roller 35 pivotally supported at its bent portion.
The transmission original is slid into contact with the transmission original passing through the original transport path 33, and when no substantial tension is applied to the transmission original, the transmission original descends by its own weight to the position where it abuts against the stopper 36, and the transmission original As the tension applied to it increases, it rotates counterclockwise in the figure about the pivot shaft 34 and substantially rises.

A light shielding plate 37 is provided at the tip of the free lever 32.

When the free lever 32 is in the lowered position as shown in FIG. On the other hand, when the free lever 32 is lifted as shown in FIG. 2, the optical path is blocked.

That is, since the photoelectric element 38 is actuated by the free lever 32 that moves up and down depending on the tension of the original, it can be said that it detects whether tension is applied to the original.

A document detection window 40 is provided in the extension portion 3a of the lower guide plate 3, and a document detection photoelectric element 41 as a document trailing edge detector is provided corresponding to this portion.

This document detection photoelectric element 41 is sensitive to light emitted from a light source 42.

The light source 41 is a window 4 opened in the free lever 32.
3, the light is emitted toward the original detection photoelectric element 41, and the optical path between this light source 42 and the original detection photoelectric element 41 is communicated by the transmission original passing through this part. It is now blocked.

In addition, the four document detection photoelectric elements described above are 15°30.3
Reference numerals 8 and 41 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 table 21 with the reading surface facing downward, and sets the transmission documents so that their leading edges abut against the wall portion 26a of the document stopper lever 26.

At this time, the optical path 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 original transport path 33, and from there to the original reading path 4.

At this time, since no substantial tension is applied to the transmitted document, the free lever 32 is in the lowered position as shown in FIG.

The transmission document is caught 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 one-sheet original to be sent is detected by the original 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 42 and the original detection photoelectric element 41 is blocked by the transmitted original.

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

Thereafter, only the stepping motor 9 resumes rotation upon receiving a signal indicating that the receiving side is ready.

As a result, the transmission document moves to the right in the figure within the document reading path 4, and is read by the document reading device 13 during this time.

At this time, since the rear end of the transmitted document is still held between the separation roller 22 and the brake plate 27, tension is applied to the transmitted document between the separation roller 22 and the paper feed roller 5. As shown in FIG. 2, the free lever 32 is stretched between the rollers, thereby causing the free lever 32 to rise.

As the free lever 32 rises, the optical path between the light source 39 and the document detection photoelectric element 38 is interrupted.

Then, the stepping motor 24 resumes rotation in synchronization with the stepping motor 9, the separation roller 22 rotates again, and the transmitted document is continuously conveyed and read.

When the trailing edge of the one-sheet original to be transmitted is released from the separation roller 22 and the brake plate 27 during reading, the free lever 32 descends while pushing down the original to be transmitted by its own weight.

For this reason, a gap as shown by the symbol C in FIG. 3 occurs between the first document and the two-sheet transmission document that is subsequently being separated and fed by the separation roller 22 and the brake plate 27. .

At this time, the free lever 32 is lowered and the light shielding plate 37 is moved away from the optical path between the light source 39 and the document detection photoelectric element 38, so that the rotation of the stepping motor 24 is stopped again and the separation roller 22 is restarted. will be stopped.

At this time, since the first document is being continuously conveyed by the paper feed roller 5, the distance C is further widened.

When the trailing edge of the first transmission document passes through the document detection photoelectric element 41, the stepping motor 24 is rotated again in synchronization with the stepping motor 9, and the separation roller 22 is rotated again.

As a result, the separation and feeding of the two-sheet original to be sent is resumed at the circumferential speed of the separation roller 22 corresponding to the reading speed of the first sheet.

As mentioned above, when the stepping motor 24 is temporarily stopped, a gap is created between the first document to be sent and the second document to be sent. This interval is essential to reliably detect the passing 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 may be the minimum necessary size that is significantly smaller than the actual size.

Therefore, in this case, the idle time of the facsimile is very small.

When the document detection photoelectric element 15 detects passage of the trailing edge of the transmitted document, the receiving side cuts the recording paper into a length corresponding to the transmitted document, and the document detection photoelectric element 15
When detects the passage of the leading edge of the next document to be transmitted, preparations for the next transmission are made.

Thereafter, the operation is repeated until all the transmission documents on the document table 21 are sent out.

As described above, according to the present invention, even if originals are continuously separated and fed, the movement locus of the preceding original in the recessed portion 33 is as shown in FIG. 1 (FIG. 2). As shown in FIG. 3, the trailing edge of the preceding document is selectively switched between a trajectory in which it moves down into the recessed portion 33 and a trajectory in which it moves by applying tension and short-circuiting the recessed portion, as shown in FIG. Since a gap is reliably formed between the leading edge of the document and the trailing edge of the document by the difference in length between the two trajectories, it is possible to obtain a document trailing edge passage detection device that can reliably detect the passage of the trailing edge of the document. Please understand that.

[Brief explanation of the drawing]

1 to 3 are schematic vertical sectional views showing respective operating states of a document feeding device and a reading section of a facsimile equipped with a document trailing edge passage detecting device according to the present invention. 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, 32...Free lever, 33...Document transport Road, 34...
...Axis, 35...Roller, 36...
Stopper 37... Light shielding plate, 38...
・Photoelectric element for document detection, 39...Light source, 40.
...Document detection window, 41...Document detection photoelectric element, 42...Light source, 43...Window.

Claims (1)

[Claims] 1 A document reading section that reads the document while feeding it with a paper feed roller, a feed roller that feeds the document from the document storage section toward the document transport path, and a document reading section that is provided in the document reading section and reads the document at the leading edge of the document. a document leading edge detector that outputs a signal to stop the rotation of the feed roller when detected, and a document leading edge detector that is provided in the middle of the document conveyance path from the feed roller to the paper feed roller so that the document can fall. a recessed portion, a free lever that comes into contact with a document passing through the recessed portion and moves up and down according to the tension applied to the document; and when the free lever is raised by the tension of the document, the feeding roller is moved. between the recessed portion and the feeding roller; and a document tension detector that outputs a signal to rotate the document again and to stop the feeding roller again when the tension of the document is lost and the free lever descends; A document feeding device that is installed in the document feeding path of the document feeder and a document trailing edge detector that outputs a signal to rotate the feeding roller again when it detects that the trailing edge of the document has passed. Edge passage detection device.