JPH0388650A - Automatic document feeder for copying machine - Google Patents

Abstract

PURPOSE:To surely convey document without generating wrinkle, or the like by forming pressing rollers, provided in a plurality of parts in the document conveying direction of an exposure part feed belt, in a manner wherein the pressing roller in a document inlet side has an escape part, not pressing a belt internal surface, in a plurality of parts in the inside of a width direction with the pressing roller in a document outlet side using that for pressing the belt internal surface almost uniformly in the width direction. CONSTITUTION:A document, placed in a document loading part 2, is fed out sheet by sheet between an exposure part feed belt 13 and an exposure part document table 14, and by pressing a belt to a belt exposure part document table side in a plurality of internal parts in the document conveying direction by pressing rollers 13DG, the document is slided on the exposure part document table 14 and conveyed through conveying force by friction of the belt 13. Here a roller, having an escape of not pressing a belt internal surface in a plurality of parts in the inside in the width direction, is used in a document inlet side as the pressing roller 13DG. Further of the pressing rollers 13DG, the roller in a document outlet side presses the internal surface of the belt 13 almost uniformly in the width direction as compared with that in the inlet side. In this way, the document can be surely conveyed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an automatic document feeder for a copying machine, and in particular, the present invention relates to an automatic document feeder for a copying machine, and in particular, it feeds a document placed on a document stacking section one by one and connects it to an exposure section feeding belt and an exposure device. The belt is fed between the document tables in the exposure section, and the belt is provided with push rollers at multiple locations inside the document conveying direction to press the belt against the document table in the exposure section, and the conveying force generated by the friction of the belt pushes the belt onto the document table in the exposure section. The present invention relates to an automatic document feeder that transports documents by sliding them.

[Conventional technology]

The conventional automatic document feeder as described above has multiple push rollers on the exposure section feed belt that feed the document uniformly in the width direction from the entrance side to the exit side, as shown in Figure 1. A push roller was used to push the inner surface of the belt.

In Fig. 1, 0 is the original, 13 is the exposure section feed belt,
13D is a push roller of an exposure section feed belt, 14 is an exposure section W and a manuscript table.

[Invention or problem to be solved]

In the automatic document feeder as described above, the document conveying force of the exposure section feed belt, especially on the entrance side, tends to change depending on the belt tension, and if the belt tension becomes slightly high, the document will be moved farther than the entrance side of the exposure section feed belt. If the document is not fed to the original position, there is a problem that the exposure section feed belt is likely to be unable to convey the document, and if the belt tension is low, the conveyance speed of the document is likely to fluctuate.

The present invention has been made to solve the above-mentioned problems, and allows the exposure section feed belt to sufficiently transport the original from the entrance side even with a somewhat high belt tension, and to smoothly transport the original even with a low belt tension. , the purpose of which is to provide an automatic document feeder for copying machines.

[Means to solve the problem]

As a result of repeated research to solve the above-mentioned problems, the inventors of the present invention have determined that one of the plurality of push rollers of the exposure section feed belt, which is located on the document entrance side, is a push roller that pushes the inner surface of the belt uniformly in the width direction. Instead, by using a push roller 13DG as shown in FIGS. 2 and 3, which has escape points G at multiple locations on the inside in the width direction that do not push the inner surface of the belt, the document can be transported reliably without slipping against the belt. It has been found that as the upper limit of the belt tension of the exposure section feed belt that can be achieved increases, the lower limit of the belt tension that allows the belt to move smoothly and convey documents smoothly becomes lower. Note that the same reference numerals as in FIG. 1 indicate the same functional members in FIGS. 2 and 3 as well.

The present invention has been made based on the findings of the present inventors, and involves feeding a single document placed on a document stacking section between the exposure section feed belt and the exposure section document table.
The belt is provided with push rollers at a plurality of locations inside the belt in the document transport direction for pressing the belt against the exposure unit document table side,
In an automatic document feeder that conveys the document by sliding it on the exposure unit document table using the conveyance force generated by the friction of the belt, the push roller does not push the inner surface of the belt at multiple locations on the inside in the direction toward the entrance of the fJK. An automatic document feeder for a copying machine is characterized in that a push roller having a relief is used, and the push roller pushes the inner surface of the belt more uniformly in the width direction on the document exit side than on the entrance side.

[Effect]

The automatic document feeder of the present invention has relief portions G on the entrance side push roller of the exposure section feed belt that do not push the inner surface of the belt at multiple locations inside the width direction, as shown in FIGS. 2 and 3. By using the push roller 13DG having a similar weight, the contact surface of the push roller 13D with the inner surface of the belt is smaller than that of the push roller 13D shown in FIG. The inner surface of the belt is pressed with a high pressure, and the pressure of the exposure section feed belt 13 against the document 0 becomes high, and the frictional force, that is, the conveying force increases as shown by curve A in the graph of FIG. Even if the target is high, a conveyance force can be applied to the document, and even if the belt tension becomes low and the exposure unit feed belt becomes slack, the slack is transferred to the push roller 13 [ as shown in FIG. 2]. Because it is easy to disperse through the escape part G of IG,
Even if the belt tension is lowered, there is no change in the conveyance speed of the document due to slack in the belt 13. On the other hand, if all the push rollers of the exposure section feed belt are the push rollers 13D shown in FIG. 1 as in the conventional automatic document feeder, the push rollers 13
As shown by curve B in the graph of FIG. The belt 13 lifts off the document and the conveyance force immediately decreases. Also, if the belt tension is lowered, the slack generated in the exposure section feed belt 13 is accumulated in front of the push roller 13D on the document entrance side, and then the push roller is removed. 13D, which tends to cause fluctuations in the conveyance of the document.Also, the push roller on the document exit side of the exposure section feed belt is also When the push roller 13DG is used, ridges extending in the moving direction are likely to be formed on the exposure section feed belt 13, resulting in a shortened belt life and uneven document conveyance.

[Example] Hereinafter, with reference also to FIGS. 5 and 6, actual examples of the present invention will be described.

FIG. 5 is a schematic side view showing an example of the automatic document feeder of the present invention, and FIG. 6 is a perspective view showing an example of a drive groove of the automatic document feeder. In Figure 5.6, 1 is the device frame of the automatic document feeder, and 2 is IJi! 'The document stacking section 3 consists of a pair of left and right sides for the document, and a rack 3A provided at the bottom of each is engaged with a pinion 2A rotatably provided on the lower surface side of the document stacking section 2, with the binion 2A sandwiched therebetween. 4 is a document size sensor that detects the position of the rack 3A to provide document width information and therefore document size information; 5 to 7 are document loading plates; The first to third document sensors are provided in the document conveyance path from the section 2 to the document discharge section 8, and the document is automatically fed based on the information that the first document sensor 5 detects the document. Become.

Reference numeral 9 denotes a leading edge position regulating plate for aligning the leading edges of the sheet-like originals placed on the original stacking section 2; and 10, the edge position regulating plate contacts the top surface of the original placed on the original stacking section 2 and rotates in the direction of the arrow; This is a friction feed roller that sends out the uppermost document, and when the friction feed roller lO is displaced from the solid line position to the two-dot chain line position,
The tip position regulating plate 9 is also displaced from the solid line position where the counterclockwise rotation around the support shaft 9A is stopped by the stopper 7 (not shown) to the two-dot chain line position.

11 is a friction feed belt 1 which rotates in the direction of the arrow. IA and a handling roller I that is stationary or rotates at a slow speed counterclockwise.
I2 is a nipping pressure feed roller that further feeds the original sent by the separating and feeding means 11, and 13 is an exposure unit document table 14 of a platen glass.
1.3A and 13B are the exposure section feed belts that rotate in the direction of the arrow when placing the document on the upper exposure section or when discharging the original from the exposure section to the document discharging section 8 via the nipping discharge roller 16. A driving roller and a driven roller tensioning the section feed belt 13, 13C is a tension roller of the exposure section feed belt 13, 13D1. -13D3 is a push roller that brings the exposure section feed belt 13 into pressure contact with the upper surface of the exposure section document table 14. Among these push rollers 1301 to 3, a roller 13DG having relief portions G distributed in the width direction as shown in FIGS. 2 and 3 is used as the push roller 13Dl on the document entrance side near the drive roller 13A. and driven roller 1
The plain roller 130 shown in FIG. 1 is used as the roller 13D3 on the document exit side near 3B or the pushing roller 13D2 further in the middle. In this embodiment, in order to prevent image defects due to document floating, which push roller l3
For D1 to 13D3 as well, the outermost pressing position in the width direction of the belt 13 is located near the edge of the width of the maximum document conveyed by the belt 13.

15 is the original in the exposure section! When placing the original, the upper end is displaced so as to protrude above the upper surface of the exposure unit document table 14 as shown in the figure, and when the document is ejected from the exposure unit to the document ejecting unit 8, the upper end is displaced so that it protrudes above the upper surface of the exposure unit document table 14, as shown in the figure. This is an exposure stopper that retracts below the top surface.

The device frame 1 includes a lower roller shaft 16A of the pinch discharge roller 16.
counterclockwise from the illustrated position, or the fifth
It can be opened and rotated so that the front side of the paper surface is lifted around an axis parallel to the document table surface on the back side of the paper surface of the figure.
Reference numeral 7 denotes a device frame open sensor that detects whether or not the device frame I is opened and rotated from the illustrated position.

The document feeding system from the friction feed roller IO to the pinch discharge roller 16 is controlled by a control device (not shown) of the copying machine, and the rotation speed in the counterclockwise direction in FIG. 6 is switched in at least two stages, or It is driven by a motor 18, for example a DC servomotor, which is also capable of reverse rotation and consists of a combination of a DC motor and a speed control device using an encoder or a tacho generator. That is, the rotation of the motor 18 is transmitted from the motor gully I9 to the carrier pulley 20 by the timing belt, and then from the deceleration carrier pulley 21 that rotates integrally with the carrier pulley 20 to the roller pulley 12A integral with the pinch feed roller 12 or the electromagnetic The rotation of the input pulley 23 is transmitted to the input pulley 23 of the clutch 22, and when the electromagnetic flange 22 is turned on under the control of the control device of the copying machine, the rotation of the input pulley 23 is transmitted to the output shaft gear 24A integrated with the output shaft 24. The transmission is transmitted to the core shaft pulley 25 that drives the friction feed belt LLA of the handling and feeding means +1 that meshes with it, and is further transmitted from the core shaft pulley 26 that rotates together with the core gear 25 to a roller integrated with the friction feed roller 1O by a timing belt. To the king who said that the shaft pulley l would be conveyed to OA,
The pinch feed roller 12, the friction feed roller IO, and the separating feed means 11 are driven. Note that the sorting roller 1 of the sorting and feeding means 11. When IB rotates counterclockwise, the rotation can be provided, for example, by a rocking crank and ratchet mechanism driven by rotation of the belt core shaft. In addition, the exposure section feeding belt 13 and the pinching discharge roller 1
6, the rotation of the carrier pulley 20 described above is transmitted to the output pulley 28 when the electromagnetic clutch 27, which is controlled by the control device of the copying machine, is turned on, and from the output pulley 28, the exposure unit is transported by a timing belt. The rotation of the driven roller 13B of the exposure section feed belt 13 is transmitted to the roller shaft pulley 13AP of the drive roller 13A of the belt 13, and the rotation of the driven roller 13B of the exposure section feed belt 13 is transferred from the roller shaft pulley 13BP to the roller shaft 7-ri 16Pi of the nipping and discharging roller 16 by the timing belt.
:: It is done by being told.

In the control device of the copying machine, a main switch (not shown) is turned on when the device frame l is in the closed position shown in FIG. 5 and no documents are placed on the WC document stacking section 2. , both automatic document feeding mode and manual document mode are deselected. In this non-selected state, the copying operation is prohibited even if a copying start button (not shown) is pressed after completion of preparations for starting the copying operation such as temperature rise of the fixing device. However, when the opening of the device frame l is performed and the opening information of the device frame opening sensor 17 is input to the control device, the control device inputs the closing information while inputting the opening information and again. After this happens, until a predetermined time determined by a timer or pulse count, the document manual mode is selected. In this state, regardless of whether an original is placed on the exposure section or whether the device frame l is closed, when the copy start button is pressed, the photoreceptor drum (not shown) will rotate. electrification of the surface thereof, image exposure of the charged surface by moving the image exposure lamp 29 etc. in the direction of the thick arrow, development of the electrostatic image thus formed into a toner image, and feeding of copy paper to the photoreceptor drum. Copying operations such as transferring and fixing a toner image thereon, and ejecting the resulting copy paper to the outside of the machine are performed until a specified number of copies are obtained, and then the copying operation is terminated. In this case, if the device frame 1 is closed before the end of the copying operation, it is returned to the above-mentioned non-selected state by the end of the copying operation. Therefore, in order to perform copying in the original manual mode again next time, it is first necessary to open the device frame 1 and select the original original mode.

With the device frame l closed, a document is placed on the document stacking section 2 with its leading edge touching the leading edge position regulating plate 9, and document presence information from the first document sensor 5 is input to the control device. Then, the control device selects the automatic document feeding mode regardless of whether or not a document is placed on the exposure section. When copying is performed using this automatic document feeding mode, first, the width of the document on the document stacking section 2 is sandwiched between the width position regulating plates 3. As a result, the document size sensor 4 informs the control device of the document size t.
Based on this information, the control device determines when to stop the friction feed roller 10, the scanning distance of the image exposure lamp 27, etc., the standby position of the document to be fed next after the document fed into the exposure section, and the size of the copy paper. etc. to be determined. Then, when the copy start button is pressed, the control device uses the information to lower the friction feed roller 10 using a lowering means (not shown) and press it against the top surface of the stacked documents, and then the separation feed means 11 and the pinch feed roller t2. Furthermore, the exposure section feed belt 13 is simultaneously rotated in the direction of the arrow to bring the uppermost document to the exposure section position on the exposure section document table 14, where the leading edge of the document hits the exposure section stopper 15. After the second document sensor 6 detects the leading edge of the document, the exposure unit feed belt 13 continues to rotate as described above until a predetermined time has elapsed using a timer or a pulse count [. The exposure section feed belt 13 is stopped by applying a motor brake to the motor 18 shown in FIG. 6 about 5 to 10 mm before the contact, and the original is brought into contact with the exposure section stopper 15 using the inertia during that time. be exposed. In order to feed the document to the exposure section by the exposure section feed belt 13, a roller 13DC as shown in FIGS. By using the roller 13D shown in FIG. 1 as the roller 13D3 or 13D2, the printing can be carried out reliably and without causing deviation or wrinkles of the document. Note that the rotation of the friction feed roller IO stops when the first document is fed.
In order to prevent double feeding of originals, the second [Iji determined from the original size information from the original edge detection by the original sensor 6] is used.
(This is done by turning off the electromagnetic flange 22 before the rear end of the document reaches the position of the separating and feeding means 11. At the same time, the friction feeding roller 10 is also raised to the position shown by the solid line in FIG. 5.

The exposure section stopper 15 occupies the protruding position shown in the figure until the exposure section feed belt 13 starts rotating, but is brought to the retracted position when the exposure section feed belt 13 starts rotating, and then is projected to the position shown before the rotation is stopped. As a result, the exposure section stopper 15 is less likely to provide resistance to the movement of the exposure section feed belt 13, and even if the original is already placed on the exposure section when the copy start button is pressed in the automatic document feeding mode, However, the document is not copied but is ejected to the wC document ejecting section 8 by the exposure unit feed belt 13 rotating in the direction of the arrow and the nipping ejecting roller 16 rotating in the direction of the arrow.

This document is also detected by the third* document sensor 17 when it is ejected, but the control device detects the problem before the exposure section feed belt 13, which has first rotated in the direction of the arrow after the copy start button is pressed, is stopped. The above-mentioned document detection by the third document sensor 7 obtained at the time is not counted. The detection signal of the third document sensor 7 is
It is used to detect the occurrence of a document jam before the document is discharged from the exposure section to the document discharge section 8, and to count and know the number of discharged documents.

As mentioned above, the control device also sends the original to the exposure section! After this, the same copying operation as in the manual feeding mode is performed on this original. Also, during this copying operation, the friction feed roller 10. The sorting and feeding means 11 and the pinch feed roller 12 are each driven in the direction of the arrow in FIG. 5, and the next document is moved to a standby position where the leading edge of the document occupies an appropriate position from the pinch feed roller 12 to the entrance of the exposure unit feed belt 13. bring it to and stop it.

During this time, since the motor 8 shown in FIG. 6 rotates, the 'WL magnetic clutch 27 is turned off so that the exposure section feed belt 3 does not rotate. At this time, the rotational speed of the motor 18 is made slower than the rotational speed at which the previous original is fed into the exposure section, thereby ensuring that double feeding of originals can be prevented. Even if you do so, the productivity of copying will not decrease. The waiting position for the next document is determined by the time from when the second original sensor 6 detects the leading edge of the limited document to when the friction feed roller 11 etc. are stopped, and this time is determined by the document size information. When the directional size is large, the tip occupies a position on the nipping feed roller 12 side, and when the directional size is small, the tip occupies a position on the exposure section feed belt 13 side. By bringing the next original to the standby position in advance as described above, a series of copying operations in the automatic original feeding mode can be performed quickly. Needless to say, changing the scanning movement distance of the image exposure lamp 27 and the like according to the document size information speeds up the series of copying operations.

After the last single image exposure operation for the specified number of copies is completed, the control device controls the exposure section feed belt 1.3 and the friction feed roller 10.
etc. are again driven in the direction of the arrow in the same manner as described above, thereby ejecting the document in the exposure section onto the document discharge section 8, and bringing the next document to the exposure section where the leading edge abuts the exposure section stopper 15. Thereafter, during the copying operation of the next original, the next original is fed into the standby position, and when the copying of the next original is finished, the next original is ejected to the original ejection section 8, and the next original is ejected to the original ejection section 8. It is repeated that the original document is fed to the exposure section, and then the last document in the W document stacking section 2 is fed to the exposure section, and the first W document sensor 5 outputs the no-document information to the control device. However, the series of copying operations ends when the last copy of the original is completed and the last copy sheet of the specified number of copies is ejected to the copy paper ejecting section. When the series of copying operations is completed, it returns to the non-selected state.

Note that if a jam occurs in the copy paper feeding system during the series of copying operations described above, the control device uses the jam signal to prohibit counting of document detection by the third document sensor 7, and 1.0 to the nipping discharge roller 16 are driven so as to discharge the document that has already been sent out from the document stacking section 2 to the document discharging section 8, and then are stopped. In contrast, copying operations such as rotation of the photosensitive drum and driving of the copy paper feeding system are immediately stopped. And in this case the 6th
The rotational speed of the motor 18 shown in the figure is set to be slower than the rotational speed at which the original is fed into the exposure section and at the same time when the original from the exposure section is discharged to the original discharge section 8. This ensures that both the originals in the exposure section and the originals fed into the standby position are ejected to the original ejection section 8 in the correct order.

Therefore, if you remove the jammed paper, return the originals that were ejected to the original ejecting unit 8 using the jam signal to the original stacking unit 2 in the original stacking order, and press the copy start button, it will be the same as if no jam had occurred. Copying will continue. On the other hand, if a jam occurs in the document, the control device uses the jam signal to immediately stop the drive of the automatic document feeder, but the rotation of the photoconductor drum, the copy paper feeding system, etc. The copying process is stopped when a predetermined number of copies of the original on 14 have been copied. Then, if the jammed original is removed, returned to the original stacking section 2 if possible, and the copy start button is pressed, copying will continue as if no jam had occurred.

The present invention is not limited to the example described above, but has a structure in which holding arms of a plurality of rollers shown in FIG. 7 are arranged at a coarse pitch on a fulcrum shaft and are rotatably supported by the presser roller 13D1 shown in FIG. 5. The presser foot is configured such that the holding arms of the plurality of rollers shown in FIG. 7 are arranged in a tight pinch on a fulcrum shaft and are rotatably supported by the presser rollers 13D2 and 13D3 shown in FIG. 5, using the presser roller 13DG. The desired effect can also be obtained by using the roller 13DG. Further, even if the automatic document feeder of the present invention is provided with a document reversing path on the opposite side of the document ejection section so that both sides of the document can be copied, the scanning exposure of the document is performed by conveying the document. The image exposure lamp may not move and the original is ejected above the original stacking section, and in the case of multiple copying, all the originals may be circulated for the number of copies.

〔Effect of the invention〕

[The automatic document feeding device of the present invention has push rollers provided at a plurality of locations in the document conveyance direction on the exposure section feed belt, and relief portions on the document entrance side that do not push the inner surface of the belt at a plurality of locations on the inside in the width direction, By pushing the inner surface of the belt almost uniformly in the width direction on the document exit side, the exposure section feed belt can more reliably remove documents from deviations and wrinkles than in conventional systems that use plain rollers for all push rollers. This has the effect of conveying without causing such problems.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of the automatic document feeder showing an example of the push roller of the exposure section feed belt, and FIGS. 2 and 3 are parts showing examples of the push roller on the document entrance side used in the present invention, respectively. A front view and a perspective view, and FIG. 4 is a graph showing the relationship between belt tension and document conveyance force when the rollers in FIGS. 2 and 3 and the rollers in FIG. 1 are used as the push rollers on the document entrance side. FIG. 5 is a side view of the general configuration of an example of the automatic document feeder of the present invention, FIG. 6 is a perspective view of an example of the drive mechanism of the automatic document feeder, and FIG. 7 is a push roller used in the present invention. It is a perspective view which shows another example. l...Device frame 2...[Document stacking section 5-7]
...First to third document sensor 8...Document discharge section lO...Friction feed roller 1
1... Sorting and feeding means 12... Nipping discharge roller 1
3...Exposure section feed belt 13A...Drive roller 13B...Followed roller 1
3D1 to 13D3...Push roller

Claims (1)

[Claims] A single document placed on the document stacking section is fed out between the exposure section feed belt and the exposure section document table, and the belt presses the belt against the exposure section document table side at multiple points inside the document conveyance direction. In an automatic document feeder that is equipped with a roller and transports the document by sliding it on the document platen of the exposure section using the conveyance force generated by the friction of the belt, the push roller is arranged at multiple locations on the inside in the width direction on the document entrance side. An automatic document feeder for a copying machine characterized in that a push roller with a clearance that does not push the inner surface of the belt is used, and a push roller that pushes the inner surface of the belt more uniformly in the width direction on the document exit side than on the entrance side is used. Device.