JPH062551B2 - Document feeder - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a document feeder used in addition to a recording device such as an electrophotographic copying machine.

[Prior art]

An automated document feeder (ADF) has already been provided as a device that can efficiently supply a document to be copied to a recording device even in an unattended state, but in the past, only one side of the document was copied. Functions were limited to those that do. On the other hand, recently, a double-sided original can be copied by developing a recording device capable of continuously copying on the front and back sides of recording paper.
The need for ADF is increasing, and many inventions have been made as a mechanism for reversing the inside of an ADF. Regarding these, JP-A-59-216159 and JP-A-53-112738.
Japanese Patent Publication No. Sho 59-4548, Japanese Patent Laid-Open No. 60-8834,
There is a proposal such as JP-A-60-26559.

[Problems to be Solved by the Invention]

These document feeders feed a document stacked on a document feed tray to a single-sheet recording device, a document feeder that stops feeding to an exposure position, and a document that has been exposed to the front and back sides. A conveyance roller disposed in each unit, which includes a document reversing unit that reverses and carries the document again into the recording apparatus, and a document discharging unit that discharges the document whose second surface has been exposed to a document discharging tray. Due to the mechanism of the device, there are many examples in which the entire structure is driven by two kinds of drive motors, a motor that rotates forward and reverse and a motor that rotates in one direction. That is, as is well known, this drive motor is used for switching between forward and reverse rotation because it is necessary to feed an original whose first surface has been exposed in the original conveying section back to the reversing section, and the original supply that requires only one-direction rotation. Two types are required, one for supplying power to each of the transport rollers of the document section, the document reversing section, and the document discharging section. Further, since the motor is expensive and needs to be synchronized, when it is attempted to drive the whole by one kind of motor, for example, it is necessary to obtain a driving force for unidirectional rotation from the forward / reverse rotation motor. As in the conventional example shown in FIG. 8,
A minimum of five gears GO1, GO2, ... GO5 and two electromagnetic clutches C
A drive device composed of L1 and CL2 is provided, and a function is required to operate the electromagnetic clutch according to the forward / reverse rotation timing of the drive motor M so that the rotation of the drive output is always rotated in one direction. . It is also possible to obtain a forward / reverse rotation output by a unidirectional rotation drive motor in place of the forward / reverse rotation drive motor described above. The situation is that the cost of the device is a heavy burden. As a result of solving and improving this point, the present invention has an object to provide a simple and inexpensive document feeder which does not require a plurality of motors, an expensive electromagnetic clutch, and therefore a control function. Is.

[Means for solving problems]

The above-mentioned purpose is to have an original conveying means for conveying an original on the platen glass, which is the exposure position, an original reversing means for reversing the front and back sides of the original in the case of a double-sided original, and a drive source capable of switching between forward and reverse rotation In the transport device, the document transport means is capable of forward / reverse transport by forward / reverse rotation of the drive source, and the document reversing means is driven by the drive source via two one-way clutches, and This is achieved by an original conveying device characterized by being driven so as to rotate in one direction irrespective of the forward and reverse rotation of a drive source. [Embodiment] An embodiment of the present invention is shown in FIGS. 1 to 7. FIG. 1 shows a state in which a document feeder according to the present invention is mounted on a recording device 10 shown by a chain double-dashed line, and FIG. 2 shows the arrangement of forward and reverse rotation mechanisms in the document feeder. . On the upper surface of the recording apparatus main body 10, a document feeder (hereinafter referred to as ADF) 20 of the present invention, the outline of which is indicated by a one-dot chain line, is placed with a structure that can be opened to the back side by being supported by a hinge or the like. In the case of the figure, the ADF 20 is tilted to the front side, and the document conveying belt 30 is in a state of being pressed against the platen glass 11 provided on the upper portion of the apparatus main body 10. That is, the ADF 20 is capable of automatically feeding a document by the transport mechanism described below, but also has a function as a normal platen cover by manually opening and closing the entire ADF 20. A document feed tray 40 arranged on the upper part of the ADF 20 has a document feed tray 40 for stacking documents D, and when the copy button is pressed, each transport mechanism is operated by a motor M as a drive source in the ADF 20. Then, the feed roller 21 presses the uppermost surface of the front end portion of the original document D by its own weight and then rotates in the direction of the arrow for the first time to deliver the original document D with the uppermost first surface as the upper surface along the guide plate 24a. Subsequently, the document D is squeezed by the separating belt 22a and the separating roller 22b, and only the uppermost one sheet advances along the guide plate 24b and the leading end thereof reaches the sheet feeding roller 23a which rotates in the arrow direction (not shown). The clutch C is operated by the detection signal of the sensor, and the delivery roller 21 and the separating belt are operated.
The power transmission to 22a is cut off, and the rotation becomes free. The document D, which has been conveyed by the paper feed roller 23a, is conveyed in the U-shaped guide portion 25a, so that the front and back are inverted and the shielding member 27 provided at the exit of the guide portion 25a. Is removed at the leading edge of the document D and reaches the conveyor belt 30 stretched between the belt driving roller 28a and the driven roller 28b which rotate clockwise, and the frictional force continues the conveyance. The document D, which is conveyed by sliding to the left on the platen glass 11 by the conveying belt 30, has the left end portion thereof at the platen glass.
When the conveyance belt 30 slips on the document D and slips when it comes into contact with the document stopper member 12 provided on the left side edge of the document 11 and stops,
Immediately after that, the belt drive roller 28
The rotation of a is temporarily stopped. The document stopper member 12 does not necessarily have to be installed on the recording apparatus main body side, but may be installed on the ADF side. Also, without using the document stopper member 12, the conveyor belt 30
The document may be positioned by controlling so as to stop at a predetermined position. In this state, the document D has a plurality of pressure-contact rollers that are driven to rotate.
Platen glass by the conveyor belt 30 receiving the weight of 29
The first surface is exposed by being pressed against 11 and exposure of the first surface is started, and thereafter, through a well-known process, image formation and transfer to recording paper are performed, and one-sided copying is completed. Further, the ADF 20 is a document reversing portion 25b for reversing the front and back of the document D by a reversing path formed by a pair of thin metal plates or resin plates on the right side of the platen glass 11.
Is provided, one end of which is opened and connected to the guide portion 25a described above, and the other end of which is opened to the right edge portion of the platen glass 11. Conveyor roller groups 23b, 23c, and 23d that rotate in the direction of the arrow are arranged at the essential points of the reversing section 25b, and the rotation thereof is performed by the drive mechanism shown in FIGS. 2 and 3. ing. That is, the rotary shaft S1 of the paper feed roller 23a which is connected to the drive motor M and rotates in the forward and reverse directions, the gear G0 fixed to the rotary shaft S1, the gear G1 meshing with the gear G0, and the gear G1 having the same size and mutually A gear G2 which meshes with each other is connected to a unidirectional rotating clutch CL which is locked to the shaft only when the gears G1 and G2 rotate counterclockwise. The unidirectional rotational force is transmitted to the pulleys PG1 and PG2 via the pulleys PG1 and PG2, and the transport rollers 23b, 23c and 23d are driven via the belts that engage the pulleys PG1, PG2, P23b, P23c and P23d. Therefore, when the belt driving roller 28a is rotated in the counterclockwise direction so as to send the document D by the conveyor belt 30 to the reversing unit 25b, the one-way clutch CL connected to the gear G2 operates but the gear G1 rotates clockwise. The one-way clutch CL connected to the gear G1 does not work due to the rotation of the
1 is in a floating state, and the conveying rollers 23b, 23c, 23d are rotated counterclockwise by the belt drive by the pulley PG2. Next, when the belt drive roller 28a is rotated clockwise by the reverse rotation of the drive motor M as described above, the one-way clutch CL connected to the gear G2 is in a floating state, but the one-way clutch CL is connected to the gear G1. CL acts and pulley PG
Transport rollers 23b, 23c, 23d for driving 1 counterclockwise
In this case as well, is rotated counterclockwise. Thus, the document D is transported in the counterclockwise direction at the reversing portion while the transport rollers 23b, 23c, and 23d are always kept in the counterclockwise rotation. Therefore, the document D sent out onto the platen glass 11 is turned upside down by passing through the reversing section 25b, and the back side, that is, the second side, faces the platen glass 11 and the conveyor belt 30 is moved.
Is conveyed until it comes into contact with the document stopper member 12. Then, the rotation of the belt drive roller 28a is stopped again by the signal output after a predetermined time delay from the detection by the sensor 26. On the other hand, in the meantime, in the apparatus main body 10, the recording paper, which has been copied on one side, has been fixed and is turned upside down, so that the back side can be transferred.
Subsequent to the stop, the rear surface of the document D, that is, the second surface, is exposed, image-formed, and transferred in the apparatus main body 10. When the exposure of the back surface of the document D is completed, the document stopper member 12 is retracted by the action of a solenoid or the like, and then the belt driving roller 28a starts rotating in the clockwise direction again to convey the belt 30.
Conveys the document D to the left and sends it to the document discharge tray 50 provided in the document discharge section of the ADF 20.
Are sequentially laminated. Immediately before the document discharge tray 50, a discharge roller 31 rotated by a drive motor via the driven roller 28b is provided. The discharge roller 31 is also the transport rollers 23b, 23c,
Similarly to 23d, the drive mechanism described above is driven to always rotate clockwise regardless of the reversal of the conveyance direction of the document D to discharge the document D to the document discharge tray 50. That is, the above-mentioned one-way clutch CL is the driven roller 28.
On the rotating shaft S11 of b, another one-way clutch CL is installed on the intermediate shaft S1.
The clutch CL acts only when the shafts are mounted on each of the two and their shafts rotate in the clockwise direction.
Alternatively, the pulley P12 drives and rotates the discharge roller 31 in the clockwise direction via the belt B11. Therefore, regardless of whether the driven roller 28b driven from the belt driving roller 28a via the conveyor belt 30 is rotated clockwise or counterclockwise, the discharge roller 31 is always rotated clockwise by the action of the driving mechanism described above. Then, the operation of sending the document D whose both sides have been exposed to the document discharge tray 50 by continuing the rotation is continued. As a result, it is possible to prevent the discharged original from being caught in the discharge tray. After the trailing edge of the document D passes through the document stopper member 12, the document stopper member 12 is returned to the position shown in the figure, and the clockwise rotation of the transport roller 28a is stopped, so that the operation cycle of the ADF 20 is returned to the initial state. The structure is so controlled that the conveyance of the original document D that continues to be resumed is automatically started. Alternatively, the conveyance of the next document may be started while the document D is being discharged, and after the trailing edge of the document D has passed the stopper 12, the stopper 12 may be restored and the next document may be stopped at the specified position. Further, it may be reversed again and discharged before the document is discharged. The operation of the function of conveying the document D in the first embodiment described above is illustrated in a time chart as shown in FIG. 5, and the document D is detected by only one sensor 26 provided in the document reversing section 25b. The switching and stopping of the conveyance direction are all controlled so that both sides of the original can be automatically and continuously copied. Further, in the second embodiment shown in FIG. 4, the guide portion 25a
A photo sensor 126 is arranged in place of the sensor 26 in the first embodiment in the conveyance path where the reversing unit 25b and the reversing unit 25b meet. In this case, the photo sensor 126 is the original D.
Is conveyed through the guide portion 25a for exposing the first surface, and when the first surface is exposed and passes through the guide portion 25a again to receive the exposure of the second surface through the reversing portion 25b. As shown in the time chart of FIG. 6, as a result, the sensor 126 can be used to control the stop of the conveyor belt 30 during the first surface exposure and the supply roller 21 described above. Become. Therefore, in the second embodiment, the sensor A in the first embodiment is used.
It is possible to control signals and control in the document conveying device without providing the above. In any of the above-described embodiments, the document D
It is possible to reverse the front and back again by the reversing unit and discharge it through the exposure unit to align it with the same page as when feeding the ADF. It is also possible to start the conveyance of the next document while discharging the document D, and after the trailing edge of the document D has passed the stopper, the stopper is restored and the next document is stopped at the specified position. Further, the sensor used is not limited to the photo sensor, and a micro switch or another sensor can be used. Next, the arrangement of the drive motor M that is the drive source will be described. As the document transport mechanism in the ADF 20, the transport members shown in FIG. 1 are provided between the substrates A and B provided in the apparatus 20 shown in FIG. 2, and the transport members are provided on the back surface of the substrate A. Each driving member (illustrated by a chain double-dashed line in FIG. 1) to be rotated is arranged and driven and rotated by the power of the driving motor M. Since the driving motor M generally has a large load and a large one having a reduction gear device is used, a large space is required in the device for housing the driving motor M. In the apparatus, it is possible to form a large space inside the document reversing section 25b by configuring the above-mentioned reversing roller group with a driving roller having a small outer diameter dimension, and it is possible to effectively use the space. As a means, it is applied to the accommodation of the drive motor M. Therefore, the shaft of the drive motor M is configured to penetrate the substrate A and transmit power to each drive member incorporated in the rear surface of the substrate A. That is, the rotation of the driving motor M is decelerated and transmitted from the pulley P1 to the pulley P2 via the timing belt to drive the conveying roller 28a, and at the same time, from the pulley 2 to the pulleys 3 and 4 via the timing belt. Transmitted. The pulley 3 drives the paper feed roller 23a which is coaxially integrated, and further, the reversing roller 23 via gear G1 or G2.
It is designed to drive b, 23c and 23d.
Both 1 and G2 are pulleys PG1 and PG mounted coaxially.
The gear G1 and the pulley PG1 or the gear G2 and the pulley P are engaged with each other only in the case of opposite rotational directions.
A one-way clutch in which either one of G2 is coaxially integrated is provided, and the conveying rollers 23b, 23c, and 23d rotate only counterclockwise regardless of the rotation direction of the paper feeding roller 23a. It is supposed to be done. The pulley P4 transmits the rotation to the delivery roller 21 and the separating belt 22a via a clutch and is driven together with the transport roller 28a. Each of the driving members except the driving motor M is a small member, and the depth dimension of the back surface of the substrate A is small. As a result, the device 20 is small and easy to handle. A member other than the driving motor M described above can be housed in the space formed inside the reversing portion 25b, and the utility value for downsizing the device 20 is extremely high. In the document transport device described above, transport failure may occur during document transport. Therefore, measures are taken in the document reversing unit 25b so that the document can be taken out if a jam should occur. 7 (a) and 7 (b) show the main parts thereof. The original reversing portion 25b is composed of an inner guide member 225a and an outer guide member 22 which are molded with a thin metal plate or a resin plate.
The cross section formed by 5b and 225c is a slit-shaped sheet-passable transport path, one end of which is the guide section described above.
25a, and the other end is connected to the right side edge of the platen glass 11. The inner guide member 225a and the outer guide member 225c are ADF2
Although fixedly attached to 0, the outer guide member 225b
Are rotatably attached via a rotation support portion 226 provided on the ADF 20. That is, when the ADF 20 is operating, the outer guide member 225b is in the state of FIG.
A cross section that is locked with respect to 0 and has a predetermined interval with the inner guide member 225a forms a slit-shaped sheet-passable transport path, but the lock is released when the operation is stopped, and the rotation support portion When 226 rotates clockwise as a fulcrum, it turns 7th
As shown in FIG. 2B, the upper portion of the document reversing portion 25b is opened and the upper surface of the inner guide member 225a is opened. Further, the document reversing section 25b is provided with conveyance rollers 23b, 23c, and 23d which are rotated counterclockwise by a motor in the ADF 20 for document conveyance in the conveyance path, but are prevented from reverse rotation. , And pressure contact rollers 223b, 223c, 223d that are pressed against them and are driven to rotate. . Therefore, in the case where a feeding failure occurs due to a paper jam of the document D in the document reversing unit 25b, the motor of the ADF 20 is stopped and the outer guide member 225b is opened, as shown in FIG. 7 (b). As described above, the document D is greatly opened in the transport direction, and at the same time, the clamping surfaces of the transport rollers 23b and 23c are also opened, so that the document D in the jammed state can be pulled out easily and quickly.
Immediately after that, the conveyance of the original document D can be resumed.

【The invention's effect】

The document conveying apparatus of the present invention realizes that the rotation of the reversing section conveying roller and the discharge roller is maintained in the conveying direction even during the operation of reversing the front and back of the original by the drive mechanism which is simple and has few failures. It is possible to continuously supply originals, and it is possible to increase the copying speed of the recording apparatus. At the same time, it is possible to prevent an accident such as a jam caused by the reverse rotation of the rollers during conveyance and a backward feeding of ejected originals, so that an original conveying apparatus that can stably convey the original without damaging the original is provided. It has changed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a document feeder of the present invention. Figure 2 shows the first
The plan view shown. FIG. 3 is a perspective view of a drive mechanism of the device.
FIG. 4 is a sectional view of an automatic document feeder according to another embodiment.
5 and 6 are time charts showing the sequence. FIG. 7 shows the main part of the automatic document feeder. FIG. 8 is a perspective view showing a conventional example. 10 ... Recording apparatus main body, 11 ... Platen glass 12 ... Original document stopper member 20 ... Original document feeding device (ADF) 23a ... Paper feeding roller, 23b to 23d ... Conveying roller 25b ... (Original) inverting section, 28a ... Belt driving roller 28b ... Driven roller, 30 ... Conveyor belt 31 ... Ejection roller, 40 ... Original feed tray 50 ... Original ejection tray, D ... Originals P1, P2, P3, P4, P11, P12, P13 ... Pulleys S1, S11, S12, S13 … Rotation axis G1, G2, G11, G12… Gear

Claims (1)

[Claims] 1. A document transporting means (30) for transporting a document on a platen glass (11) at an exposure position, and a document reversing means (23b, 23c, 23d) for reversing the front and back sides of a document in a double-sided document.
And a drive source (M) capable of switching between forward and reverse rotations, the original conveyance means (30) is capable of forward and reverse conveyance by forward and reverse rotation of the drive source (M), The document reversing means (23b, 23c, 23d) is driven by the drive source (M) via two one-way clutches (CL), and is independent of the forward / reverse rotation of the drive source (M). An original conveying device characterized by being driven so as to rotate in a direction.