JPH03223041A - Automatic document feeder - Google Patents

Abstract

PURPOSE:To easily take out a jammed document by forming a separating belt of an endless belt and also rotatably supporting the separating belt by a plurality of belt supporting members and connecting one of them to a drive motor through a clutch and also mounting a spring to the other one of the members. CONSTITUTION:Whether a jam is generated or not is judged by whether a document D is detected or not by a sensor 45 within a predetermined time after a feed of the document D on a document table 13 is started by a call roll 32 and when the jam is generated, a clutch 17 is placed in its off-condition, and a pulley 14 is placed in its free condition by releasing a drive motor 18 from its connection to a pulley shaft 26 formed integrally with the pulley 14. Further tension of a separating belt 12 by a spring 19 is weakened by placing also a solenoid 22 in its off-condition while stopping all the drive systems of an automatic document feeder 10. Accordingly, even in the case of jamming the document D in a condition that its point end is held between the separating roller 11 and a belt 12, the belt 12 is turned in an extracting direction when the rear end side of the document D is extracted from the outside of a device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic document feeder equipped with a document separation mechanism that separates a document into individual sheets using a separation roller and a separation belt in contact with the separation roller.

[Conventional technology]

As a conventional automatic document feeder, there is one shown in FIG. 2, for example.

A document separation mechanism 1 of this automatic document feeder includes a separation roller 3 that rotates in the direction of arrow A, and a separation belt 4 that contacts the separation roller 3. One end of the separation belt 4 is fixed to a part of a cover 5 which also serves as the frame of the automatic document feeder, and the other end is tensioned by a spring 6 to separate the documents into one sheet. The lower surface is in pressure contact with the separation roller 3 with a contact pressure suitable for document separation.

[Problem to be solved by the invention]

However, such an automatic document feeder has a structure in which a cover 5 that covers a document separation mechanism including a separation roller 3 and a separation belt 4 also functions as a frame for supporting and fixing various parts. With this structure, if a jam occurs in the document separation mechanism, even if you try to release the pressure contact between the separation roller 3 and the separation belt 4, the cover will be damaged. I couldn't do that because 5 got in the way.

However, since it is troublesome to remove the cover 5 every time a jam occurs, in normal cases, when a jam occurs with the leading edge of the document being held between the separation roller 3 and the separation belt 4, it is difficult to remove the cover 5. , the manuscript is indicated by arrow C in Figure 2.
In many cases, the user attempts to remove the original by forcibly pulling it out in the direction of the document.

As a result, the manuscript may be damaged or torn, especially if it is an important manuscript.

In addition, if the part of the separation belt that comes in contact with the separation roller is always at a fixed location, this part will always be rubbed by the separation roller or document with a predetermined contact pressure, so the separation belt will only contact that part. Another problem is that it tends to wear locally, which tends to shorten its durable life.

Furthermore, depending on the original, the contact area of the separation belt may be smudged by the image or paper dust may adhere thereto when it comes into contact with the image surface of the original, so the same part of the belt is always If the separation belt comes into contact with the paper, a large amount of paper powder etc. tends to adhere locally to the separation belt, and if this happens, the friction coefficient decreases and the separation belt's ability to separate paper deteriorates, causing overlapping feeding. There was also the problem that (double feeding) could occur.

This invention was made in view of the above-mentioned problems, and it is possible to easily remove the cover when a jam occurs, without damaging or tearing the jammed original. The purpose is to make it possible to take it out.

In addition, the document separation surface of the separation belt that comes into contact with the documents is resistant to dirt, and even after long-term use, the paper separation performance does not deteriorate significantly due to adhered paper dust, etc., and the durability of the separation belt is increased. The purpose is also to

[Means to solve the problem]

In order to achieve the above object, the present invention provides an automatic document feeder equipped with a document separation mechanism that separates documents into single sheets using a rotating separation roller and a separation belt in contact with the separation roller. The belt is rotatably supported by a plurality of belt support members, one of the belt support members is connected to a drive motor via a clutch, and a spring is attached to one of the other belt support members. The separation belt is tensioned with a predetermined tension, a sensor is provided on the conveyance path downstream of the separation roller to detect the document, and when the clutch is turned on, the separation belt is separated by a drive motor. The roller is rotated in the opposite direction to the original feeding direction, and if the sensor does not detect the original within a predetermined time after the original feeding starts, the clutch is turned off and the drive motor and belt support are rotated. It is designed to release the connection with other members.

Similarly, the separation belt is formed of an endless belt, and is rotatably supported by a plurality of belt support members.
One of the belt support members is connected to a drive motor, and one of the other belt support members is connected to a solenoid via a spring to tension the separation belt so that the tension can be changed. A cleaning roller for cleaning the document separation surface of the document is provided at a position apart from the separation roller, and a sensor for detecting the document is provided on the conveyance path downstream of the separation roller.

The cleaning roller is rotated at the first speed until the sensor detects the document, and after the sensor detects the document, the solenoid is turned off to reduce the tension on the separation belt, and the cleaning roller is rotated at the first speed. The automatic document feeder is configured to rotate for a fixed period of time at a second speed faster than the second speed.

[For production]

According to the automatic document feeder configured in this way, if the document is not detected by the sensor disposed downstream of the separation roller within a predetermined time after the document feed starts, the clutch is turned off and the drive is stopped. Since the motor and the belt support member are disconnected, the separation belt stretched over the belt support member becomes free.

Therefore, even if a document jams while being held between the separation roller and the separation belt, if you pull the trailing edge of the document from the outside of the device in the opposite direction to the direction in which the document is inserted, the one-separation belt can be removed. Since it can be easily rotated in the drawing direction, the document can be easily taken out without damaging or tearing it.

Furthermore, when separating documents, the clutch is turned on and the separation belt is rotated by the drive motor in the opposite direction to the document feeding direction by the separation roller and comes into contact with the separation roller. Since the contact area is around the entire circumference of the belt, there is no chance of the belt becoming locally dirty or paper dust adhering to it, and furthermore, the separation belt will not wear out locally, increasing durability. improves.

Furthermore, in addition to the above-mentioned sensor, if a cleaning roller that cleans the document separation surface of the 1-separation belt is provided at a position away from the separation roller, the cleaning roller will not be activated until the sensor detects the document after separation. After the document is detected, the solenoid turns off to reduce the tension on the separation belt, and the cleaning roller rotates at a second speed faster than the first speed for a certain period of time. Because it rotates, even if the document separation surface becomes dirty or has paper dust attached to it, it is immediately cleaned by the cleaning roller, making it possible to maintain stable paper separation over a longer period of time. .

〔Example〕

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a schematic diagram showing a part of an automatic document feeder and a copying machine according to the present invention.

The document separation mechanism 20 of the automatic document feeder 10 uses a rotating separation roller 11 and a separation belt 12 in contact with the separation roller 11 to separate a plurality of documents inserted from the document table 13 with the image side facing upward. is separated into one sheet and fed onto the contact glass 31 of the copying machine 30.The separating belt 12 is formed of an endless belt, and it is connected to three pulleys 14 that serve as belt supporting members. , 15 and 16, each of which is rotatably mounted.

One of the drive-side pulleys 14 is integrally fixed to a pulley shaft 26, and the pulley shaft 26 is connected to the clutch 17.
One end of the subring 19 is attached to a shaft 28 that is integral with another pulley 16, and the other end is attached to one end of a wire 21.

Furthermore, the other end of the wire 21 is fixed to the movable shaft of the solenoid 22, and the guide roller 23 is brought into contact with the approximately middle part of the wire 21 to change the tensioning direction by approximately 90'', and the solenoid 22 is turned on. - By turning off the separation belt 12, the separation belt 12 can be tensioned between the three pulleys 14, 15, and 16 with a predetermined tension suitable for separating documents, or the tension can be weakened.

Further, when the clutch 17 installed between the drive-side pulley 14 and the drive motor 18 is turned on, the separation belt 12 is moved by the drive motor 18 in the direction opposite to the direction in which the document is fed by the separation roller 11 as shown in FIG. When the pulley 14 is turned off, the one-separation belt 12 follows the separation roller 11 and rotates in the document feeding direction opposite to the arrow B. I try to do that.

Furthermore, this document separation mechanism 20 separates the cleaning roller 25, which cleans the document separation surface 12a of the separation belt 12 that is in contact with the document sheet, from the separation roller 11. J14 and J15, and wrap the outer peripheral portion formed by, for example, a brush on the document separating surface 12a of the separating belt 12 by a wrapping amount Ω suitable for cleaning the document separating surface 12a, as shown by the arrow in FIG. It is arranged so that it rotates in the direction.

An opening 13a is formed in the document table 13, and a calling roller 32 whose outer portion is made of, for example, sponge is provided in the opening 13a so as to be rotatable in the direction of arrow E. The circumferential portion 52a of the calling roller 32 is Cut into equal parts 4
They are arranged so that their circumferential portions 32a protrude from the upper surface of the document table 13 by a slight amount j22.

Furthermore, a lower guide Mylar 33 is fixed to the opening edge cut diagonally on the feeding upstream side of the opening 13a, and an upper guide Mylar 34 is attached above the document table 13 to cover iQa of the automatic document feeder 10. It is fixed by being integrally attached to the

The separation roller 11 is integrally fixed to a roller shaft 35, and an intermediate gear 37 meshes with a gear 36 integrally attached to the roller shaft 35, and a driving side gear on the calling roller 32 side is engaged with the intermediate gear 37. 38, and a one-way rotation clutch 29 is attached to the gear 38, which allows rotation only in the direction of arrow E.

Below the separation roller 11, a driven-side pull-out roller 27 is provided rotatably in the direction of the arrow, and is connected to a driving-side pull-out roller (in FIG. It is in pressure contact with the separation roller 11 (which is the same size as the separation roller 11 and cannot be seen because it is located at the back).

The separation belt 12 is formed of, for example, urethane rubber and has a core material embedded therein so that it hardly stretches even when tension is applied, and each pulley 14,
15 and 16 are formed over the entire circumference.

Pulley 15 is a driven pulley, and - body axis 4
7 is rotatably supported by a fixed bearing (not shown), and a gear 43 integral with the cleaning roller 25 meshes with a gear 39 integrally fixed to the shaft 47 via an intermediate gear 41.

In FIG. 1, 44 is a document detection sensor that detects the insertion of a document, and 45 is a sensor provided on the conveyance path downstream of the separation roller 11 to detect the document. It is fixed to a pair of guide plates 46 arranged below.

If the sensor 45 does not detect the fed document within a predetermined time after the document feeding starts, the clutch 1
7 is turned off to disconnect the drive motor 18 from the pulley shaft 26 integral with the pulley 14, which is a belt support member.

Further, the cleaning roller 25 is rotated at the first speed N1 until the sensor 45 detects a document jam, and after detecting the document, the solenoid 22 is turned off to reduce the tension on the separation belt 12 and clean the document. roller 2
5 is rotated for a certain period of time at a second speed N2 faster than the first speed N1.

Next, the operation of this embodiment configured as described above will be explained.

First, a case will be described in which a plurality of normal originals, which are not written in pencil and do not include pasted originals, are fed and copied.

First, as shown in FIG. 1, a plurality of originals are placed on the original table 13 with the image side facing upward, and
When the document is inserted between the separation roller 11 and the separation belt 12, the document detection sensor 44 detects the insertion of the document, the clutch 17 is turned on, and the pulley shaft 26 integrated with the pulley 14 is inserted. It is connected to a drive motor 18 via a clutch 17.

Further, the solenoid 22 is also turned on when the document detection sensor 44 detects insertion of the document tray, and the spring 19 is expanded via the wire 21, thereby causing the pulley 16
moves downward in FIG. 1, the tension on the separation belt 12 increases, and the document separation surface 12. contacts the separating roller 11 with a predetermined pressure suitable for separating the documents.

In this state, when a print button (not shown) is pressed, the calling roller 32 rotates in the direction of arrow E in FIG. 1 by the amount of rotation required to send out one document sheet, and then stops once.

Therefore, the document on the m-document table 13 is sent out from the bottom to the left, and the gear 38 is also rotated in the direction of the arrow E at the same time as the calling roller 32, so that the separation roller 11 is also rotated via the intermediate gear 37. Start rotating in the direction of F.

Also, by pressing the print button, the drive motor 1
8 also starts driving, thereby causing the pulley 14 to rotate in the direction of the arrow in FIG. 1 via the clutch 17 and the pulley shaft 26, and the separation belt 12 starts rotating in the direction of the arrow B.

When two or more documents are sent out by the calling roller 32 (double feeding), the upper document is transferred to the first document by the separation belt 12 rotating in the direction of arrow B.
The original is returned to the right in the figure, and only the lower original is guided by the guide plate 46 and reaches the pull-out roller 27, and is further transported to a predetermined exposure position on the contact glass 31 of the copying machine 30 by a belt conveying device (not shown). transported.

When the sensor 45 detects the leading edge of the document feeder 10, the separation roller 11 stops rotating and the solenoid 22 is also turned off.

Therefore, the first separation roller 11 rotates along with the document conveyed by the pull-out roller 27 due to the action of the one-way rotary clutch attached to the gear 38, and the first
Rotate in the direction of arrow F in the figure.

Furthermore, since the tension of the one-separation belt 12 is also weakened, the contact pressure between it and the separation roller 11 is reduced.

In this way, in this automatic document feeder 10, the time for which the separation belt 12 is strongly pressed against the separation roller 11 (contact pressure that enables document separation) is kept to the minimum necessary time, and the separation belt 12 is rotated. By doing so, the entire belt is in contact with the separation roller 11, and the belt is prevented from being worn locally, thereby increasing the durability of the belt.

Further, in this embodiment, after the solenoid 22 is turned off, the drive motor 18 is rotated at a higher rotation speed than the rotation speed at the time of document separation, and the cleaning roller 25 is rotated in the direction of the arrow in FIG. The document separation surface 12a of the separation belt 12 is rotated at a high rotation speed to quickly remove paper dust and the like adhering to the document separation surface 12a of the separation belt 12.

That is, until the sensor 45 detects the document separated into one sheet, the cleaning roller 25 maintains the first speed N1.
After the solenoid 22 is turned off and the tension on the separation belt 12 is reduced, the cleaning roller 25 is rotated at a second speed N2 faster than the first speed N1. Since it rotates for a certain period of time, even if the original separating surface 12a is soiled or has paper dust attached thereto, it is immediately cleaned by the cleaning roller 25, so that paper dust etc. does not adhere to the original separating surface 12a. Since the document separability does not deteriorate due to a decrease in the coefficient of friction, stable paper separability can be maintained over a long period of time.

Note that this drive motor 18 and cleaning roller 25
The fixed period of time during which the is rotated at high speed (second speed NZ) is within the time during which the document fed onto the contact glass 31 is exposed, and this cleaning operation is not performed every time a document is fed out, but only when the last page This may be performed only after feeding the original document.

In this way, the document on the document table 13 is separated into individual sheets and sent one by one onto the contact glass 31, and when the predetermined exposure is completed there, the document is transferred to the document output tray (
(not shown).

On the other hand, if the original is a manuscript with pencil writing or pasted together, a mode (SADF mode) in which the original is set and fed one by one is used.

That is, when the 5ADF mode is selected on the operation panel of the copying machine 30 and the document detection sensor 44 detects the inserted document, the solenoid 22 is turned on as in the case described above, and the tension of the separation belt 12 is reduced. Although the clutch 17 remains in the OFF state, the pulley shaft 26, which is integral with the pulley 14, is in a free state.

In this state, when the print button is pressed, the calling roller 32 starts rotating in the direction of arrow E and the separating roller 11 starts rotating in the direction of arrow F, as in the case described above, so that the document on the document table 13 is separated. Since the pulley 14 is now in a free state, the separation belt 12 follows the separation roller 11 and moves toward the arrow B in FIG.
The document is rotated in the opposite direction to the document feeding direction.

Therefore, the image surface of the document is fed without being rubbed by the separation belt 12 during the feeding process, so even if it is a document written in pencil, characters etc. may fade or disappear. I don't have to worry about it.

Furthermore, even if the original is pasted together, it will not be rubbed by the separation belt, so the pasted part will not bend or peel off. Therefore, jams are less likely to occur even with pasted originals.

In this automatic document feeding apparatus 10, regardless of the document feeding mode selected by the operator, jam detection is always automatically performed in consideration of the unlikely occurrence of a document jam.

That is, the predetermined time when the calling roller 32 starts feeding the document on the document table 13 (for example, the time when the leading or trailing edge of the document passes the sensor 45 after the document feeding starts).
Whether or not a jam has occurred is determined based on whether or not the sensor 45 detects the document jamming.

When the sensor 45 does not detect document jamming within a predetermined period of time, the clutch 17 is turned off to disconnect the drive motor 18 from the pulley shaft 26 that is integrated with the pulley 14, and to set the pulley 14 in a free state. Further, all drive systems of the automatic document feeder 10 are stopped, and the solenoid 22 is also turned off to weaken the tension on the separation belt 12.

Therefore, even if a document jams with its leading edge sandwiched between the separating roller 11 and the separating belt 12, if the trailing edge is pulled out from the outside of the apparatus, the separating belt 12 can be easily moved in the pulling direction. The original can be removed without damaging or tearing it.

In addition, in the above embodiment, an example was explained in which the one-separation belt 12 is stretched with three pulleys 14, 15, and 16, but it may be stretched with two pulleys or four or more pulleys. The cleaning roller 25 for cleaning the separation belt 12 may be a non-rotating cleaning blade, or a cleaning member such as a sponge may be brought into sliding contact with the document separation surface 12a of the separation belt 12. Good too.

〔Effect of the invention〕

As explained above, according to the present invention, if the fed document is not detected by the sensor within a predetermined time after the start of document feeding, such as when a jam occurs, the clutch is turned off and the drive is stopped. Since the connection between the motor and the belt support member is broken and the separation belt tensioned on the belt support member becomes free, the yX document becomes jammed between the separation roller and the separation belt. However, when the document is pulled out, the separation belt easily rotates in the direction of pulling out the document, so that the document can be easily taken out without damaging or tearing the document.

In addition to the above-mentioned sensor, if a cleaning roller for cleaning the document separation surface is provided, the cleaning roller rotates at the first speed until the sensor detects the document to be fed, and After detecting this, the solenoid turns off and the tension on the separation belt is reduced.
Since the cleaning roller rotates for a certain period of time at a second speed faster than the first speed, even if the document separation surface becomes dirty or paper dust adheres thereto, it is immediately cleaned by the cleaning roller. .

Furthermore, stable paper separation properties can be maintained over a long period of time.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a part of an automatic document feeder and copying machine according to the present invention, and FIG. 2 is a schematic diagram showing the vicinity of a document separation mechanism of a conventional automatic document feeder. 10...Automatic document feeder 11...Separation roller 12...Separation belt 12a...Document separation surface 13...Document table 14.15.16...Pulley (belt support member) 17
...Clutch 18..Drive motor 19.
...Spring 20...Document separation mechanism 21
... Wire 22 ... Solenoid 25
...Cleaning roller 30...Copy machine 45...
・Sensor D...Manuscript 1 Figure 2

Claims (1)

[Scope of Claims] 1. In an automatic document feeder equipped with a document separation mechanism that separates a document into single sheets by a rotating separation roller and a separation belt in contact with the separation roller, the separation belt is an endless belt. and is rotatably supported by a plurality of belt support members, one of the belt support members is connected to a drive motor via a clutch, and a spring is attached to one of the other belt support members. The separation belt is tensioned with a predetermined tension, and a sensor for detecting a document is provided on the conveyance path downstream of the separation roller, and when the clutch is turned on, the separation belt is activated by the drive motor. The separation roller rotates in a direction opposite to the original feeding direction, and when the sensor does not detect the original within a predetermined time after the original feeding starts, the clutch is turned off and the drive motor is rotated. An automatic document feeder characterized in that the connection with a belt support member is released. 2. In an automatic document feeder equipped with a document separation mechanism that separates a document into single sheets by a rotating separation roller and a separation belt in contact with the separation roller, the separation belt is formed of an endless belt and a plurality of The separation belt is rotatably supported by belt support members, one of the belt support members is connected to a drive motor, and one of the other belt support members is connected to a solenoid via a spring to apply tension to the separation belt. A cleaning roller for cleaning the document separation surface of the separation belt is provided at a position apart from the separation roller, and a sensor for detecting the document is provided on the conveyance path downstream of the separation roller. The cleaning roller is rotated at a first speed until the sensor detects the document, and after the sensor detects the document, the solenoid is turned off to reduce the tension on the separation belt, and the cleaning roller is rotated at the first speed. An automatic document feeder characterized in that the document feeder rotates at a second speed faster than the first speed for a certain period of time.