JPS62180837A - Automatic document feeder - Google Patents

Abstract

PURPOSE:To smoothly invert a document to its observe and reverse, by controlling a speed of drawing back the document faster than the speed of feeding out the document both when the document is supplied from on a platen to a document inverting part and when the document is supplied from the document inverting part onto the platen. CONSTITUTION:An automatic document feeder 5 sets a document onto a document tray 7 to be fed out sheet by sheet by a separately feeding part 9 and conveyed onto a platen 3 by a conveying part 11. While the feeder 5 is equipped with an inverting discharge part 13, inverting the both-side document to its observe and reverse to be fed onto the platen 3 while discharging the document, after it finishes copying, with the observe and reverse being inverted, and a containing tray 15 containing the document discharged from the inverting discharge part 13. Here the feeder 5 controls each driving motor for conveying rollers 72, 73 and a conveying belt 55 so that a speed of drawing back the document comes to be faster than the speed of feeding out the document both when the document is supplied from on the platen 3 to an inverting route 71 and when the document is supplied from the inverting route 71 onto the platen 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an automatic document feeder installed in an image processing apparatus such as a copying machine, a facsimile machine, and an image processing apparatus.

[Technical background of the invention]

In an image processing apparatus, for example, a copying machine equipped with a double-sided copying function, there are four combinations depending on whether the original is one-sided or double-sided, or one-sided or double-sided. That is, when copying a 0 single-sided original onto one side of a sheet, when copying a 0 single-sided original onto both sides of a sheet,
There are four methods: (1) copying a double-sided original onto one side of the sheet; and (2) copying a double-sided original onto both sides of the sheet.

An automatic document feeder installed on a copying surface with such a double-sided copying function is required to have the ability to flip the document from front to back, and drives the conveyor belt to eject the document from the platen of the copier. After the paper is turned over at the reversing section, it is fed onto the platen again.

[Problems with 7-view technology] In such an automatic document feeder, the conveyor belt and the reversing section are not in a continuous conveyance path, so even if the speed of the conveyor belt and the speed of the reversing section are made the same, Loads such as friction between the conveyor belt and the platen, friction between the conveyor belt and the document, and friction between the reversing section and the document occur, and a difference occurs between the speed of the conveyor belt and the speed of the reversing section, causing the document to be fed to the reversing section. or it may be difficult to return it from the reversing section onto the platen.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic document feeder that can smoothly reverse a document.

[Summary of the invention]

In order to achieve the above object, the present invention makes the document pulling speed of the reversing section faster than the document sending speed from the platen when supplying the original from the platen to the reversing section, and supplies the original from the reversing section onto the platen. At this time, the speed at which the document is pulled into the platen is made faster than the speed at which the document is sent out from the reversing section.

[Embodiments of the invention]

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

As shown in FIG. 1, an automatic document feeder (2f5) capable of conveying a double-sided original is placed on the platen 3 of an image forming apparatus, for example, a copying machine 1 equipped with a double-sided copying function.

The automatic document feeder 5 includes a document storage section, for example, a document tray 7, a separation and feeding section 9 that separates the document set on the document tray 7 into one sheet, and sends out the document, and a separation and feeding section 9.
a conveyance unit 11 that conveys the original sent out from above over the platen 3; a reversing discharge unit 13 that reverses the front and back of the double-sided original and sends it onto the platen 3, and also reverses and discharges the copied original. It is provided with a storage tray 15 for storing the originals ejected from the reversing ejection section 13, so that the originals can be automatically fed.

Further, the conveying section 11 and the reversing ejecting section 13 are integrated with the cover C, and are attached to the back of the copying machine 1 via a hinge so that the cover C can be opened and closed. It is also possible to open the platen 3 upward and manually set the document on the platen 3. - As shown in FIG. 2, the document tray 7 is provided with movable side id 17 on the left and right sides for regulating the side edges of the document. □ The separating and feeding section 9 detects whether or not a document is set on the document tray □ and has a bar set sensor S1 and a stopper 19 that restricts the leading edge of the "documents" stacked on the document tray 7. , a feed roller 21 that feeds out the original on the document tray 1 7, a feeding roller 25 that sends out the original fed by the feeding roller 21 to the transport 1 feeding path 23, and a feeding port 1'-25. A separation roller 27 that follows the lower surface of the document being sent out and prevents the document from moving forward, and a feed port 1
A sensor s2 for detecting the document sent out by the 1-ra 25 is provided.

Note that the feeding roller 21 is configured to move up and down in accordance with the deflection and the excitation/demagnetization of the noid 29. Further, the stopper 19 is rotated by the excitation/magnetization of the solenoid 29, and the conveyance path 23 is opened.

The feeding roller 25 is rotated by the motor 31 in the direction in which the document is sent out, that is, clockwise in FIG. Separator o--7) 7 is also driven by the motor 31, and is rotated clockwise in a direction that prevents the document from moving forward following the lower surface of the sent document. In addition, separation roller 2
7, the feeding roller 2 is activated by energizing/demagnetizing the solenoid 33.
5 and separated from each other.

At the entrance of the conveying section 11, a sensor S3 and registration rollers 35, 37 are provided as shown in FIG. The registration rollers 35 are rotationally driven by a motor 39, and together with the registration rollers 37 pressed against them, send out the original onto the platen 3.

In addition, the conveying section 11 includes a detection means, for example, a line sensor 41, which detects the image condition of the even numbered vanes of the document before the document reaches the document set position on the platen 3, and a line sensor 41, for example, a line sensor 41 between the rows 251 and 53 as shown in FIG. A stretched conveyor belt 55 and pressure rollers 57, 59, 61, and 63 for pressing the conveyor belt 55 against the platen 3 are provided.

Connected to the line sensor 41 is a tq disconnection means for determining whether or not the document is blank. For example, if the detection signal supplied from the line sensor 41 from the leading edge to the trailing edge of the original document has a signal of a predetermined level or higher, it is determined that there is image information on the detection surface of the original document, and the judgment means determines that image information exists on the detection surface of the original document. If the detection signal is below a predetermined level, it is determined to be blank.

The conveyor belt 55 is rotationally driven by a motor 54 shown in FIG. 3 connected to the ζ roller 53. Incidentally, as shown in FIG. 2, a stopper 43 is provided at the right end of the platen 3 in the drawing for abutting the original and setting it at the copying position.

The reversing and discharging section 13 has a conveyance path switching device as shown in FIG.
Id 65, reversing path 71 with an entry path 67 and an ejection path 69, sensor S4, conveyance rollers 72, 73, pressure spring 74, pressure rollers 75°77.79, 81, elastic id 82, ejection path 83, conveyance Rollers 85 and 87, pressure rollers 89 and 91, a discharge sensor S5, and covers 95 and 97 that can be opened and closed around a shaft 93 are provided.

Note that the cover 95 is closed by a spring, and when a paper jam or the like occurs, the cover 95 can be opened or closed with the conveying section 11 and the reversing and discharging section 13 opened around hinges provided on the back side. .

The conveyance path switching guide 65 is switched in three stages by a switching device 97. That is, when the document on the platen 3 is to be fed to the reversing path 71, the conveyance path switching hand 65 is rotated to the intermediate position, and when the document that has been reversed is to be fed from the reversing path 71 to the platen 3, When switching the transport path rotates the id 65 to the lowest position and supplies the document on the platen 3 to the ejection path 83, the transport path switching
The id 65 is rotated to the uppermost position, and the elasticity pushes up the id 82.

The reversing path 71 reverses the original by making a U-turn from the upper entry path 67 to the lower ejection path 69.

The transport rollers 72 and 73 are rotationally driven by a motor 99. Further, the fine feed rollers 85 and 87 are connected to the motor 54.
The driving force is obtained from

By the way, when supplying a document from above the platen 3 to the reversing path 71, the document pulling speed of the transport rows 272, 73 is made faster than the document sending speed of the transport belt 55, and when supplying the document from the reversing path 71 onto the platen 3. The motor 54.99 is controlled so that the document drawing speed of the conveyance belt 55 is faster than the document sending speed of the conveyance row 272.73.

In the above configuration, this device operates as follows.

First, the case of conveying a double-sided document will be explained.

It is assumed that some documents have blank pages (single-sided documents) on the back side, that is, even numbered pages.

Place the original on the original tray 7 with the first page facing down. This activates the sensor S1 and detects the original. Next, set the copying conditions by operating the operation panel (not shown). .

When a print button (not shown) is pressed in such a state, the original on the original tray 7 is fed out.

First, when the print button is turned on, the separation feeding section 9
The solenoid 29 is energized, and the feeding roller 21 falls onto the document, and the solenoid 33 is energized, and the separation roller 27 is pressed against the feeding roller 25.

On the other hand, the stopper 19 rotates downward due to the excitation of the solenoid 29. Therefore, feeding becomes possible.

When the feeding roller 21 comes into contact with the document, the motor 31 operates, and the feeding roller 25 and the feeding roller 221 rotate in the feeding direction. As a result, the feed roller 21 feeds out the document starting from the uppermost sheet, and the document is folded into one sheet and sent to the fine feed path 23 by the feeding roller 25 which rotates in the forward direction and the separation roller 27 which rotates in the reverse direction.

Then, the leading edge of the document is detected by sensor S2. As a result, the two solenoids are demagnetized, and the feeding roller 21
is separated from the document, and the subsequent document feeding operation is temporarily stopped. Further, the stopper 19 is raised twice to cut off the feeding of the document.

The fed document is further conveyed by the feeding roller 25, turning on the sensor S3. As a result, the motor 31 is stopped after a predetermined time T1.

Here, the above-mentioned predetermined time 11 r1 is set to a time sufficient for the leading edge of the document to contact the rolling contact portion of the roller 35°3'7 and to bend after the leading edge of the document passes the sensor S3. There is. Therefore, the leading edge of the bent document is rennosted.

Then, a predetermined time T2 (T2
> T 1 ) After that, the motor 39 is slightly rotated to hold the leading edge of the document between the reno rollers 35 and 37, and the solenoid 33 is demagnetized to separate the separation roller 27 from the feeding roller 25. The original registered in this manner is placed in a standby state.

: When the copy 1 preparation for copy 8!1 is completed in this state, the motors 39 and 54 rotate, and the registration roller 35
．． 37 sends out the manuscript. The sent out document is sent onto the platen 3 while its back side is detected by a line sensor 41 to see if it is a blank sheet. Line sensor 41
If it is determined that there is image information on the back side as well (not a blank sheet), the paper is transported over the platen 3 by the transport belt 55.

When the trailing edge of the document is detected by the sensor S3, the motor 39 is stopped, the solenoid 29 is energized, and the advance operation of the next document is started in the same manner as described above, and the registration rollers 35 and 37 are Wait with the tip in your mouth. Note that when the sensor S3 detects the trailing edge of the document, the motor 99 starts rotating.

On the other hand, the switching device 97 operates simultaneously with the rotation of the motor 54, and the conveyance path switching guide 65 is rotated to the intermediate position.

Therefore, the document conveyed on the platen 3 is guided by the upper surface of the conveyance path switching guide 65 and enters the entrance path 67. Note that when a document is supplied from the platen 3 to the reversing path 71, the document pulling speed of the conveyance rollers 72, 73 is controlled to be faster than the document sending speed of the conveyance belt 55.

The document brought to the entrance path 67 is brought to the exit path 69 (by rotation of the conveyance roller 73).

Then, when the leading edge of the document is detected by the sensor S4, the switching device 97 brings the transport path switching guide 65 to the lowest position, and the motor 54 rotates in the opposite direction, causing the transport belt 55 to rotate in the reverse direction. Note that when feeding the original onto the platen 3 from the reversing path 71, the original drawing speed of the transport belt 55 is controlled to be faster than the original sending speed of the transport rows 272, 73.

The original is returned onto the platen 3 through the upper surface of the conveyance path switching guide 65, and then transferred to the conveyor belt 55 running in the opposite direction.
and is conveyed to the stopper 43 side. Note that after the trailing edge of the original is detected by the sensor S4, the trailing edge of the original is detected by the transport roller 72.
The motor 99 stops after a time T3 which will pass through. Then, the document fed onto the platen 3 is moved to the stopper 4.
3, the motor 54 is stopped. As a result, the original is moved to the copying position, and the back side of the original is copied.

When the copying operation for the back side of the document is completed, the conveyance belt 55 starts moving the document toward the conveyance path 71 again. At the same time as the conveyance belt 55 starts running, the conveyance path switching guide 65 is again rotated to the intermediate position, the motor 99 is rotated, and the document is reversed according to the above-described reversing operation.

In this way, /'Xv4 is brought onto the platen 3 with the surface facing downwards. In this state, the front surface of the document will undergo a copying operation.

When the copying operation for the front side of the document is completed, the document is then ejected. That is, the conveyance belt 55 starts running to discharge the original, and the conveyance path switching guide 65 is rotated to the uppermost position by the switching VCm97. Therefore, the bullet guide 82 is pushed up by the conveyance path switching guide 65 and conveyed over the platen 3. The FX document is guided by the conveyance path switching device 5 and the elastic guide 82 and is supplied to the discharge path 83.

The document brought to the ejection path 83 is transported by the transport rollers 85 .
As the paper 87 rotates, the paper is discharged onto the storage tray 15 with the surface facing upward. Note that the leading edge of the original is the sensor S.
5 is detected, the switching device 97 operates to bring the conveyance path switching guide 65 to the intermediate position, and
The next document that was sent earlier is sent to platen 3''2.

In this way, the above operations are repeated, and both sides of a plurality of originals are copied.

On the other hand, if the detection result by the line sensor 41 indicates that the back side is blank, or if the one-sided original is
When copying with the paper set in
65 is brought to the top In. In this state, the document fed onto the platen 3 is transported by the conveyor belt 55.
is switched back, and is brought into contact with the stopper 43 and set at the copying position. Then, the copied original is supplied from above the platen 3 to the ejection path 83 by the running of the conveyor belt 55, and is ejected onto the storage tray 15.

That is, only the odd pages are copied and discharged without the front and back sides of the original being printed.

According to this embodiment described above, when the document is fed from above the platen 3 to the reversing path 71, the document pulling speed of the conveyance rollers 72, 73 is made faster than the document sending speed of the conveyor belt 55, so that the document is transferred to the conveyor roller 72.73. 73, and the document is smoothly taken into the reversing path 71.

In addition, when supplying a document from the reversing path 71 onto the platen 3, the document pulling speed of the conveyor belt 55 is adjusted to the conveyor roller 27.
Since the original feeding speed is set higher than the original feeding speed of 2.73, the original is similarly pulled by the conveyor belt 55, and the original is smoothly fed onto the platen 3. Therefore, the document can be turned over quickly and reliably.

[Modified example]

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, the speed of the conveyance belt 55 and the speed of the conveyance rollers 72 and 73 when reversing a document from front to back are as follows. The speed of the transport rollers 72, 73 may be made variable while the forward and reverse speed of the transport belt 55 is constant, or the speed of the transport belt 55 may be made variable while the speed of the transport rollers 272, 73 is constant. Further, both may be made variable.

〔Effect of the invention〕

As described above, according to the present invention, in an automatic document feeder that supplies a document on a platen to a reversing section and returns the document onto the platen for front-back reversal operation, the document is supplied from above the platen to the reversing section. At this time, the speed at which the document is pulled into the reversing section is set higher than the speed at which the document is fed out from the platen, and when the document is fed from the reversing section onto the platen, the speed at which the document is pulled into the platen is set at a speed at which the document is fed out from the reversing section. Since the speed is increased, it is possible to obtain an automatic document feeder that can smoothly turn over the document.

[Brief explanation of drawings]

1 to 3 are diagrams showing an embodiment of the present invention, in which FIG. 1 is a sectional view showing the overall configuration of an automatic document feeder;
FIG. 3 is a sectional view showing the structure of the separating and feeding section, and FIG. 3 is a sectional view showing the structure of the reversing and discharging section. 1... Copying machine 3... Platen 5... Automatic document feeder 7... Document tray 9... Separation and feeding section 11... Conveyance section 13... Recycled paper discharge section
15... Accommodation tray 55... Conveyance belt 6
7...Entry route 69...Ejection route 71...
・Reversing path 72.73...conveyance roller

Claims (2)

[Claims] (1) In an automatic document feeder that supplies a document on a platen to a reversing section and then returns the document onto the platen after reversing the front and back, when the document is fed from the platen to the reversing section, the document is drawn in by the reversing section. The document feeding speed is set to be faster than the speed at which the document is sent out from the platen, and when the document is fed from the reversing section onto the platen, the speed at which the document is pulled into the platen is set to be faster than the speed at which the document is sent out from the reversing section. Automatic document feeder. (2) The automatic document feeder according to claim 1, wherein the reversing section reverses the document by U-turning the document from top to bottom.