JPH03243543A - Automatic document feeder - Google Patents

Abstract

PURPOSE:To make the torque of a drive source for a resist roller carrying document the irreducible minimum of a demand by providing a pick-up means in such a way as to be capable of being rotated to the direction of picking the documents up when the pick-up means driven by the drive source is out of action. CONSTITUTION:A device is provided with a pick-up means 36 picking documents up out of a document tray 33, a separation means 38 separating the documents one by one from the pick-up means 36 so as to carry them, a drive source 56 driving the pick-up means 36 and with an one-way mechanism 53 which is provided for the pick-up means 36 in such a way as to lie between the pick-up means 36 and the drive means 56. In the second place, when a resist roller 40 starts carrying each document delivered ahead, the pick-up means 36 is freely rotated by the one-way mechanism 53. This thereby permits load applied to each document being carried to be reduced, thereby making the drive source 56 of the pick-up means 36 small in size and light in weight, while the life of the pick-up means 36 is lengthened.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides an automatic document feeder installed in an image forming apparatus, in particular, an automatic document feeder equipped with an image forming apparatus.
The present invention relates to an automatic document feeder that removes the load that occurs on a document being transported.

(Prior Art) In image forming apparatuses such as copying machines, in recent years, due to the diversification of devices and the demand for higher performance, originals are automatically placed at the exposure position on the original platen, and the originals are further removed after exposure. Automatic document feeders that automatically eject documents from a document table are often used.

In such an automatic document feeder, the documents taken out from the document tray by the pickup roller are separated one by one by an adjacent separation means consisting of a supply roller and a separation roller, and the leading edges are aligned by registration rollers. Thereafter, it is sent to the document table and placed at the exposure position by a feed roller provided at the end of the document table.

That is, when a conventional pickup roller takes out a document, it is driven by a motor, placed on the document, rotated for a predetermined period of time necessary for taking out the document, and then stopped rotating, so that only one document is taken out. If so, it will be raised to finish taking out the document.

In addition, when feeding originals continuously, in order to increase the speed, when the previous original starts to be ejected from the exposure position, the next original is advanced to the lens roller position and is placed on standby, so that the previous original is moved by the feeding roller. At the same time as the document is taken out from the exposure position and transmitted to the ejection roller, the feed roller, the pick-up roller linked thereto, and the document stopper are raised, and at the same time, the drive of the registration rollers is started, and the next document is placed at the exposure position. It looks like it will be placed there.

However, when continuously feeding documents in such a device,
The pickup roller, document stopper, and feed roller are usually moved downward by a single solenoid, and the timing of the upward and downward movements is synchronized. That is, when the solenoid is turned on, the pickup roller, document stopper, and feed roller are held in a lowered state against the spring, while when the solenoid is turned off, the pickup roller, document stopper, and feed roller are biased by the spring. ~Uh, it looks like it's going to rise. In order to raise each device instantly, is it necessary to increase the biasing force of the spring? If the biasing force of the spring is too large, the solenoid must also be made larger, which may lead to an increase in the size of the solenoid. This becomes an obstacle to reducing the size and weight or cost of the entire automatic document feeder.

For this reason, conventionally, the biasing force of the spring is set to be somewhat weak so that even a small solenoid can lower the pickup roller or the like against the spring. Therefore, when documents are continuously fed, even if the solenoid is turned off at the same time as the registration roller is driven to feed the first document, the biasing force of the spring is weak and the pick-up roller etc. cannot be raised instantly. Yes, there will be a slight delay. On the document tray, the pickup roller, which is in a stationary state and has not fully risen, comes into sliding contact with the document that has started to be conveyed by the registration rollers. This results in a state where a load is applied to the For this reason, the load applied to the drive source of the registration roller becomes larger than necessary, and the drive source must be made larger, which poses a problem in that it becomes an obstacle to miniaturization, weight reduction, and cost reduction. In addition, the contact surface of the pickup roller is worn out due to sliding contact with the document, which reduces or accelerates the document retrieval function and reduces durability.
Since the uppermost document being conveyed and the lower document are pressed against each other by the pickup roller and rub against each other, the back side of the document is smudged, and there is also the problem of increased frictional noise.

(Problem to be Solved by the Invention) Conventionally, when the pickup roller finishes taking out the document, the drive is stopped and the pickup roller is kept in a stationary state. Since there is a slight delay in the lifting of the pick-up roller, which is raised at the same time as the registration rollers start transporting the original, this hinders the registration rollers from transporting the original, and the torque of the registration roller motor must be increased more than necessary. Further, there are problems in that the life of the pickup roller is shortened due to friction with the original, and noise is generated due to dirt on the back of the original and frictional noise.

Therefore, the present invention eliminates the above-mentioned problem, and when the registration rollers start conveying the document, the pickup roller placed on the document tray does not create a load on the document, and it is possible to increase the size of the drive source for the registration rollers. prevent and further
It is an object of the present invention to provide a highly reliable automatic document feeder that prevents the wear of a pickup roller, extends its life, prevents dirt on the back of the document, and noise during conveyance.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a take-out means for taking out the originals on the original tray, and separates and conveys the originals from the take-out means one by one. The separation means, a drive source for driving the take-out means, and a one-way mechanism provided on the take-out means to be interposed between the take-out means and the drive source.

(Function) According to the above-mentioned means, the present invention allows the pick-up roller or one-way mechanism to rotate freely when the previously delivered document starts being conveyed by the registration rollers, so that the load on the document being conveyed is reduced. This makes it possible to reduce the size and weight of the drive source for the registration rollers, to extend the life of the pickup rollers, and to prevent dirt on the back of the document and frictional noise.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. Figure 1 shows the entire image forming apparatus.
1 is an apparatus main body that incorporates image forming process means 2 such as charging, exposure, development, transfer, cleaning, and fixing. A direction changing conveyor unit 4 which also serves as a mounting table is provided. This direction conversion conveyance device unit 4 receives the paper P discharged from the discharge section of the apparatus main body 1 as needed, and leaves the paper P in the same state so as to form multiple or double-sided images on the paper P. Alternatively, the paper P is guided again to the paper feed section of the apparatus main body 1 in a state where the paper P is turned upside down.

Next, let's talk about the main body 1 of the device. A drum-shaped photoreceptor 10 is provided approximately in the center of the apparatus main body 1, and charging devices 1 are sequentially installed around the photoreceptor 10 along its rotation direction.
1. In the exposure section 12a1 of the exposure device 12, a developing device 13, a transfer device 14, a peeling device 16, and a cleaning device 17 are arranged. Further, on the right side of the apparatus main body 1, a first cassette 18a and a second cassette 18b for storing paper P, and a manual paper feed tray 18c are installed. Also, inside the apparatus main body 1, there are pickup rollers 20a, 20b from each cassette 18a1111b or manual paper feed tray 18c.
, 20c and the paper P conveyed by the direction changing conveyance device unit 4 are transferred to the photosensitive member 10.
A paper transport path 22 is formed which leads to a paper discharge tray 21 on the left side of the main body 1 of the apparatus. First and second separation rollers 23a are provided on the upstream side of the photoreceptor 10 in the paper conveyance path 22.
, 23b, a pair of registration rollers 24 are arranged;
A gate 29 is arranged on the downstream side to guide the paper P to either the conveyor belt 26, the fixing device 27, the paper discharge roller 28 side, or the direction changing conveyor unit 4 side. - A document table 30 is provided on the upper surface of the blade device main body 1.

The direction changing conveying device unit 4 includes a guide section 82 that guides the paper P to the intermediate stacking section 81, and a guide section 82 that guides the paper P from the intermediate stacking section 81 to the intermediate stacking section 81.
a pickup roller 83 that takes out the paper P, a reversing section 84 that reverses the paper P, and a registration roller 2 of the apparatus main body 1 that transfers the paper P.
It has a conveyance roller 86 that conveys the image to the four.

Next, the automatic document feeder 3 will be described. The automatic document feeder 3 includes a platen sheet 31 that is a document holding member that presses down the document set on the document table 30.
It has a document cover 32 which is a document covering means that can be opened and closed freely on the document tray 33, and also takes out document sheets set on a document tray 33 one by one and automatically feeds them to the exposure position on the document tray 30. It has a document feeding mechanism section 34 that feeds the document and then discharges it onto the top surface of the document cover 32 after exposure.

Here, in front of the document tray 33 of the document feeding mechanism section 34, there is a pickup roller 36 which is a take-out means for taking out the document, or an arm 37 rotatably attached to the shaft of a supply roller 38a, which will be described later. A first switch 61 that is movable up and down and detects the presence or absence of a document.
A first actuator 61a is provided. However, the shaft of the pickup roller 36 is provided with a one-way clutch 53 which is a one-way movable mechanism. The big up roller 3B is rotated by a motor 56, which is a drive source, via this one-way clutch 53 and a drive transmission means 54 consisting of a belt and gears. In addition, one-way clutch 53
The retainer 53d has rollers 53c biased in one direction by a spring 53b on the outer periphery of the drive shaft 53a to which the drive from the motor 56 is transmitted, and furthermore, a cam surface 53e is formed on the outer periphery of the retainer 53d. It has an outer ring 53r.

Further, while reaching the document table 30 from the document tray 33, a document stopper 39, a separation means 38 consisting of a supply roller 38a and a separation roller 38b rotated by a motor 56 via a drive transmission means 54, a registration roller 40, and a transport A document reversing means 43 consisting of a curved first guide 42 having a reversing roller 41, which is one of the means, and a discharge roller 44 which is another conveying means together with the reversing roller.
and a discharge mechanism section 47 consisting of an arcuate second guide 46.
, a feed roller 4 serving as a feeding means for feeding the document to the exposure position on the document table 30 and taking it out in the direction of the ejection mechanism section 47 after exposure.
There are 8.

In addition, 50 is a document transport path, 62a is a second actuator of a second switch 62 that detects a jam in the document tray, and i3a detects the trailing edge of the document tray and determines the timing of driving the feed roller 48. This is the third actuator of the third switch 63 that takes After the leading edge of the document tray passes through the second switch 62, the rear end of the document tray passes through the third switch 62.
The length of the document feed is detected based on the time it takes to pass through point 3. Ei4a is the fourth actuator of the fourth switch 64 that detects the original MD in order to time the drive of the discharge port 44 and the reversing roller 41. Note that a fifth switch and a fifth actuator (not shown) are provided in parallel with the third switch 63 to detect the width of the document sheet, and detect the length using the second and third switches 62 and 63. The size of the document paper is detected by this.

Furthermore, 49 discharges the original onto the original cover 32,
Alternatively, the reversing gate 51 switches the conveying path depending on whether the original is sent to the reversing means 43 side, and when the original is ejected from the exposure position, it can be switched so as not to interfere with ejection, but the gate 51 is a gate that urges the original while it is passing through. It's a board. 52 is
This stopper is driven by a solenoid (not shown) and regulates the rear end of the document set at the exposure position on the document table 30. Further, reference numeral 71 denotes a rotating means 70 for vertically moving the pickup roller 36, document stopper 39, and feed roller 48.
The shaft is constantly biased by the spring 72 in the upward direction of the pickup roller 36, etc.
The pickup roller 3 is turned on by turning on the solenoid device 73.
It is designed to rotate in the direction of descending 6th grade. Note that 74 is a cam 71a whose one end is fixed to the shaft 71.
The other end of the arm is in contact with the pickup roller 36 and supports the pickup roller 36 at the other end.

Further, the registration roller 40, reversing roller 41, and discharge roller 44 are driven by a motor 56 via a drive transmission means (not shown).

Further, the platen sheet 31 provided on the document cover 32 is brought into contact with and separated from the document table 30 by a contact and separation mechanism (not shown).

Next, we will discuss the effect. First, if the image on the original is only on one side, place the original on the original tray 33 to start copying.At this time, the original stopper 39 is in the position shown in FIG. 5(A), and the original is transported. The document path 50 is blocked, and the leading edge of the document tray is prevented from thrusting into the separation means 38 side by the document stopper 39, and its setting position is regulated. In this state, various image forming conditions such as paper size, number of copies, magnification, single-sided copying, etc. are input from an operation panel (not shown). As a result, the reversing gate 49 is set at the position shown by the solid line in FIG.

Next, a copy button (not shown) is turned on to start copying, and when the first switch 61 detects a document on the document tray 33, the solenoid device 73 of the rotation means 70 is turned on, and the shaft 71 is turned on. By rotating in the direction of arrow O, the restriction by the cam 71a at one end of the arm 74 is released.
The pickup roller 36 is lowered by its own weight at the same time as the document stopper 39 and the feed roller 48, as shown in FIG. 5(b), and rotated in the direction of arrow p, q, and r, respectively. At this time, the one-way clutch 53
When rotated in the direction of arrow a or arrow p, the rollers 53c move against the outer ring 5 due to the action of the spring 53b supported by the retainer 53d.
3f, and rotates the outer ring 53f and the pickup roller 36 around it by the wedge action of the cam surface 53e and the drive shaft 53a. Further, the separation roller 38b is driven via a torque limiter (not shown), and when separating multiple-fed originals, it is rotated in the direction of arrow r in the separation direction, but if the original is not inserted. If there is no original, or if the original is fed by one sheet, and furthermore, after the separation is completed, the supply force is stronger than the separation force, so the supply roller 3111a is driven and rotated in the direction opposite to the direction of the arrow r. .

On the other hand, when the pickup roller 36 finishes taking out the document and the document reaches the separation means 38 and is separated, the pickup roller 36, document stopper 39, and feed roller 48 move as shown in FIG. 5(c). be raised. As a result, the document stopper 39 blocks the document conveyance path 50 and pushes up a part of the multiple-feed documents, and for the second and subsequent documents, the middle part is bent, and the leading edge of the document is bent by the separation means 38. The separating operation is facilitated by preventing the second and subsequent documents from being conveyed by the separating means 38 and preventing them from being caught in the separating means 38 again. Additionally, a contact/separation mechanism (not shown) allows the platen sheet 3 to
1 or separated from the document table 30. Then, the uppermost document is taken out by the big roller 3B, separated by the separation means 38, and then conveyed toward the registration rollers 40.

Next, when the second switch 62 is turned on by the document printer,
Registration rollers 40 rotate to convey the document in the direction of document table 30. Then, the rear edge of the document is connected to the third switch 6.
3, the feed roller 48 descends, rotates in the direction of the arrow, and continues to transport the document in the direction of the document table 30. At the same time, the pickup roller 36 is also lowered, or at this time, the document on the document tray 33 is conveyed, and the pickup roller 36 simply remains placed on the document.

In addition, the edge of the document is detected by the second switch 62, and
The length is detected by the rear end detection by the third switch 63, and the width is detected by the third switch 63 and the fifth switch (not shown). Then, the feed roller 48 is driven by a pulse motor (not shown) and rotates a certain number of times in the direction of the arrow, so that the rear end of the document is moved as shown in FIG. 5(d).
After stopping once at a position slightly past the stopper 52,
rotated in the opposite direction. During this time, the stopper 52
The document tray is placed at the o end, and the rear end of the document tray contacts the stopper 52, and is set at the exposure position. Next, the feed roller 48, pickup roller 36, and document stopper 39 are raised, and the contact/separation mechanism (not shown) is released, so that the platen sheet 31 is moved onto the document table 30 by its own weight.
The document tray is lowered so as to be in contact with the document table 30, and the document tray is set in close contact with the exposure position of the document table 30, as shown in FIG. 5(E).

On the other hand, in the apparatus main body 1, after a certain period of time has elapsed after the third switch 63 detects the rear end, and the document tray is set at the exposure position on the document table 30, the image forming process is started. Become. That is, in the device main body 1, the photoreceptor 10
As it rotates, it is uniformly charged by the charging device 11 and an electrostatic latent image corresponding to the image on the document is formed in the exposure section 12a.

Next, the photoreceptor 10 is developed and visualized in a developing device 13, and reaches a transfer peeling charger 14.

At the same time, paper P of the size specified on the operation panel (not shown) is placed in one of the cassettes 18a,
Paper is fed from 18b, and this paper P is separated by separation roller 23a.
, 23b and the registration roller 24 to the transfer separation charger 14. Then, the paper P to which the toner image on the photoreceptor 10 has been transferred and peeled off from the photoreceptor 1O is conveyed to the fixing device 27 side and fixed thereon, and then is ejected onto the ejection tray 21 by the ejection roller 28. On the other hand, after the transfer is completed, the residual toner is removed from the photoreceptor lO by the cleaning device 16, and the static electricity is removed by the static eliminator 17.
The next copy is enabled.

After repeating this image forming process and completing the required number of copies, the exposure device 2 of the automatic document feeder 3
After the final exposure in step 2 is completed, the document is separated from the platen sheet 31 or document table 30 by a contact/separation device (not shown). At the same time, the stopper 52 is raised, and the feed roller 4
8 is lowered and simultaneously rotated in the direction opposite to the direction of the arrow, and the biasing plate 51 is further rotated in the direction of the arrow U for a certain period of time. Then, as shown in FIG. 5(f), the original is ejected from the original table 30 by the feed roller 48. Meanwhile, during this time,
When there is a second original on the original tray 33, the second original is taken out from the original tray 33 by the pickup roller 36 and guided to the separating means 37, as shown in FIG. After being separated and conveyed, the registration roller 4
0 and the tips are aligned.

Thereafter, when the fourth switch 64 is turned on by the original, the ejection roller 44 is rotated, and the original is ejected onto the upper surface of the original cover 32 by the ejection roller 44, as shown in FIG. 5(G). Further, after a certain period of time has passed since the fourth switch 64 is turned on, the solenoid device 73 is turned off and the pickup roller 3 is turned off.
6. At the same time as the original stopper 39 and the feed roller 48 are raised, the registration roller 40 is driven.

The shaft 71 of the rotation means 70 is connected to the spring 7
The big amplifier roller 36 is rotated in the direction opposite to the direction of the arrow 0 by the urging force of the cam 71a, and the big amplifier roller 36 is raised by the arm 74 which is rotated in the direction of the arrow W by the regulation of the cam 71a.At the same time, the document stopper 38 and the feed roller 48 are also raised. be done. However, since the return force of the spring 72 is suppressed to the necessary minimum, the pickup roller 36, document stopper 38, and feed roller 48 are not raised instantly. Therefore, when the registration roller 40 starts to drive and the document sheet starts to be conveyed, the pickup roller 36 is placed on the document tray 33 as shown in FIG. As a result, the document is subjected to torque in the direction of arrow p due to document loading. On the other hand, in the one-way clutch 53, since the drive shaft 53a is stopped, the rollers 53c are connected to the outer ring 53.
The pickup roller 36 is separated from the cam surface 53e of the outer ring 53e and can idle, and the pickup roller 36 is driven along with the outer ring 53r to rotate freely in the direction of the arrow p. Then, when the registration roller 40 starts conveying the document, the document is conveyed in the direction of the feed roller 48 without being subjected to any load by the pickup roller 36.

Note that although the pickup roller 36, original stopper 39, and feed roller 48 rise somewhat later, timing-wise, the fifth roller 48 starts to drive at the same time as the registration roller 40 starts driving.
It is raised as shown in Figure (G). And document stopper 3
In step 9, as in the case of the first original, a part of the original is pushed up to prevent the leading edge of the lower original from reaching the separation means 38, thereby facilitating the separation operation. Then, by repeating such a process, all the documents on the document tray 33 are sent to the document table 30 side, and when this is detected by the first switch 61, the fourth switch 64 is activated by the rear end of the document document. After a predetermined period of time has elapsed, all driving means including the discharge roller 44 are turned off, and all automatic document feeding is completed.

Next, a case will be described in which images on both sides of a document are copied. In addition, in double-sided copying, in order to start copying from the second side so that the originals are aligned and aligned at the end of copying, the original side is first reversed in the original feeder 3 before copying starts. Furthermore, the operation is the same as in the case of single-sided copying, except that the original surface is reversed after the second-sided copying is completed. Therefore, for similar parts, refer to the above-mentioned explanation of single-sided copying. First, at the start of copying, when double-sided copying is specified from an operation panel (not shown), the reversing gate 49 is set to the position shown by the dotted line in FIG. 2. Then, when you turn on the copy button (not shown),
In the same manner as in the case of single-sided copying, the original document is taken out by the pickup roller 3B, passed through the separation means 38, separated, and then conveyed to the registration rollers 40, and further rotated a predetermined number of times in the direction of the arrow. The document is once conveyed onto the document table 30 by the feed motor 48 . Next, the biasing plate 51 is rotated in the direction of arrow U, and the feed motor 48 is reversely rotated a predetermined number of times to take out the document from the document table 30 to the second guide 46 side. When the fourth switch 64 is turned on by the leading edge of the original document, the reversing roller 41 is rotated, and after a certain period of time, the registration roller 40 is rotated, and the original is transferred to the first guide 42 through the reversing gate 49. , and its surface is reversed. Note that during this time, the fourth switch 64
After a certain period of time has elapsed after turning on, the feed roller 48 is once raised. When the third sui-sochi 63 is turned off due to the passage of the reversed document, the feed roller 48
is lowered and rotated in the direction of the arrow for a certain period of time,
The document is conveyed to the document table 30 side. Thereafter, as in the case of single-sided copying, the feed roller 48 is rotated in the opposite direction, and the rear end of the document tray contacts the stopper 52 placed on the document table 30, and is set at the exposure position. Next, the platen sheet 31 is lowered, and an image forming process is first performed on the second side in the same manner as in single-sided copying. After image formation is complete,
In order to flip the document again, move the document to the first guide 4.
Thereafter, as described above, the document reversing means 43 inverts the document tray and sets it at the exposure position on the document table 30 to perform the image forming process on the first side.

On the other hand, inside the apparatus main body 1, the NGP that has finished copying the second side is transported to the direction changing transport device unit 4 side by the guide 29, passes through the guide section 82, and enters the intermediate accumulation section 81.
once accumulated. Further, the sheet P is turned over by the reversing section 84, and then sent to the registration rollers 24 of the apparatus main body 1, and then conveyed to the photoreceptor 1o side in synchronization with the copying operation of the first side of the document tray. After copying both sides,
As with the end of single-sided original copying, the paper P is placed in the output tray 2.
The paper is ejected at 1. Then, in the automatic document feeder 3, the reversing gate 49 is rotated to the position shown by the solid line in FIG.
The original paper is ejected onto the upper surface of the original cover 32 in the same way as when ejecting a one-sided copy. In addition, original tray 3
If there is a next document in step 3, when the fourth switch 64 is turned on and the start of discharging the preceding document is detected, the next document is taken out by the pickup roller 36, and the above-mentioned double-sided copying process is repeated. becomes. On the other hand, when all the originals on the original tray 33 are used up, the fourth switch 64 is turned off, and after a certain period of time, all drive means including the ejection roller 44 are stopped, and automatic duplex copying is started. Finish all document feeding.

Note that while the originals are continuously fed in this manner, even if the pickup roller 36 is delayed in rising when the originals that have been placed first at the registration roller 40 position start to be conveyed, as in the case of single-sided copying, Due to the one-way clutch 53, the pickup roller 36 is driven by the original and rotates freely, so that no load is generated that would prevent the conveyance of the original.

In addition, when a book type document or a document made of a special material is placed on the document table 30 by hand while the automatic document feeder 3 is feeding the document plate in this way, the document cover 32 must be opened to remove the document. will be placed.

With this configuration, when the document sheet is continuously fed, the one-way clutch 53 is activated even if the pickup roller 36 is on the document sheet when the registration roller 40 starts transporting the first original faD. As a result of this action, the pickup roller 36 is rotated freely following the document loading.

Therefore, the pickup roller 36 does not impose an undue load on the motor 56 that drives the registration roller 4o that conveys the original document, which is a hindrance to the conveyance of the original fmD. Pricing becomes possible. Further, the pickup roller 36 is not worn out due to sliding contact with the original document, and the life of the pickup roller can be extended. Furthermore, since the original document is conveyed more smoothly than in the past, noise caused by friction during conveyance is reduced, and there is no staining on the back side of the original due to rubbing with the underlying original.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and the design can be changed, for example, the shape and structure of the one-way mechanism can be changed arbitrarily.

[Effects of the Invention] As explained above, according to the present invention, the take-out means for taking out the original from the original tray has a one-way mechanism, and when not driven, it follows the original and can rotate freely in the direction of conveyance. Therefore, even if the ejecting means is placed on the document being transported in a non-driven state, the registration rollers can transport the document without interfering with the document transport or creating a transport load as in the past. The torque of the drive source can be minimized,
It becomes possible to make the drive source smaller and lighter. In addition, the ejecting means does not suffer from wear due to sliding contact with the original.
Longer life than before is possible.

Furthermore, there is no possibility of staining the back of the original, and noise caused by frictional noise during transport of the original is also reduced.

[Brief explanation of drawings]

1 to 5 show one embodiment of the present invention, FIG. 1 is a schematic explanatory diagram of the entire image forming apparatus, FIG. 2 is an explanatory diagram of the document feeding mechanism, and FIG. 3 is an explanatory diagram of the pickup roller and A schematic perspective view showing the drive of the separation means, FIG. 4 is a partial explanatory diagram of the one-way clutch, and FIG. 5 shows the operation of the document feeding mechanism.
(b) is an explanatory diagram of when the original is being taken out by the pickup roller, (c) is an explanatory diagram of how the original is transported by the registration rollers, (d) is an explanatory diagram of the original being set on the original tray. (e) is an explanatory diagram during copying, (f) is an explanatory diagram of the speed at which the feed roller starts ejecting the first document and the registration roller starts transporting the second document, (g) is an explanatory diagram of the speed during copying. FIG. 7 is an explanatory diagram of the state of ejection by the ejection roller and the conveyance state of the next document. 1... Apparatus main body, 3... Automatic document feeder,
10... Photoreceptor, 30... Original table, 33...
- Document tray, 34--Document feeding mechanism section, 36--Pickup roller, 38--Separating means, 40--Registration roller, 5
3...One-way clutch.

Claims (1)

[Claims] In an automatic document feeder that sequentially feeds originals from a document tray to an exposure position and discharges the originals in the direction in which the originals are fed after completion of exposure, a take-out means for taking out the originals on the document tray, and a take-out means for taking out the originals from the take-out means. It includes a separating means for separating and conveying the sheets one by one, a drive source for driving the taking-out means, and a unidirectional movable mechanism provided in the taking-out means so as to be interposed between the taking-out means and the driving source. . An automatic document feeder, characterized in that when the take-out means is not driven by the drive source, the take-out means is rotatable in the direction of taking out the document.