JPH01236144A - Sheet feeder - Google Patents

Abstract

PURPOSE:To prevent a sheet tip from being damaged, by setting up a sheet detecting means at the upstream side of a sheet tip regulating member, and decelerating a feed rate just before the sheet rip arrives at the sheet tip regulating member, in a recirculating document automatic feeder. CONSTITUTION:Originals G on a tray 5 are fed piece by piece from the lowermost one by drive of a motor M1 via a feed roller 7, a separate feed roller 9 and a separate belt 10, and bumped against a nip part between resist rollers 14, 14 or a sheet tip regulating member, whereby its skew is remedied and stopped to be on standby. In this case, if a tip of the original G is detected by a resist sensor S2, a control means 46 makes speed of the motor M1 to be slow on the basis of its detecting signal, that is, it decelerates a feed rate of the original G just before it arrives at the sheet tip regulating member 14. Next, the paired resist rollers 14 and a conveyor belt 3 are driven by a motor M2, and the originals G are fed onto platen glass 2. Thus, any damage to the sheet tip is preventable.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a sheet conveying device for an image forming apparatus such as a copying machine or a laser beam printer.

(B) Conventional technology Conventionally, in general, a circulation-type automatic document feeder separates a stack of documents set on a document stacking table one by one, starting from the lowest document, into an exposure section of an image forming device such as a copying machine. After exposure is completed, the document is transported and placed on the document stacking table. and,
It is configured to repeat a desired cycle, with one cycle being repetition for the number of originals in the bundle of originals.

Then, during the separation process in which the documents are separated one by one starting from the lowest document in the document bundle, skew feeding of the documents occurs. As a countermeasure for this, the document is brought into contact with the nip portion of a roller member disposed in the sheet path to form a loop in the document, thereby correcting the skew feeding.

(Problem to be solved by this invention) By the way, in the above-mentioned skew correction, the leading edge of the original hits the stationary roller member, which tends to cause damage to the leading edge of the original, and also damage to the original or the roller member. The drawback is that it makes some noise when it collides.

In addition, if the document separation speed is reduced in order to prevent these problems, the desired separation performance may not be obtained, and the circulation time of the document becomes longer, resulting in a reduction in the throughput of the apparatus.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a configuration that prevents damage to the leading edge of a sheet and generation of noise while maintaining processing capacity, thereby solving the above-mentioned problems.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances, and for example, as shown in FIG. 1, sheet conveying means (9, 10 ) and the sheet conveying means (9,
10), and a driving means (Ml) that is arranged downstream of the sheet conveying means (9, 10), and driving the sheet conveying means (Ml).
A sheet conveying device (1) comprising: a sheet leading edge regulating member (14, 14) that abuts the leading edge of the sheet (G) conveyed by the sheets (G) (9, 10) and positions the leading edge of the sheet (G); , a sheet detecting means (S) for detecting the sheet (G) is provided upstream of the sheet leading edge regulating member (14,
2), and based on the sheet detection by the sheet detection means (S2), the conveying speed of the sheet (G) is adjusted immediately before the leading edge of the sheet (G) reaches the sheet leading edge regulating member (14, 14). The present invention is characterized in that a control means (46) is provided for controlling the drive means (Ml) so as to reduce the speed.

(f) Function Based on the above-mentioned configuration, the sheet (G) is transported by the sheet conveying means (9).
, 10), and the leading edge of the sheet is conveyed to the sheet detecting means (S
2), the driving means (Ml) or the sheet (G) is detected based on the sheet detection by the sheet detecting means (S2).
The sheet conveying means (9
, 10). Then, the sheet (G) is decelerated immediately before the sheet leading edge regulating member (14, 14) and contacts the sheet leading edge regulating member (14, 14) at low speed without damaging the leading edge or producing noise. hand,
Its tip is regulated and stopped.

Note that the above symbols are shown for reference and do not limit the configuration in any way.

(F) Examples Examples of the present invention will be described below with reference to the drawings.

As shown in FIG.
The conveyor belt 3 is disposed facing above the platen 2 and is wound around a drive roller 3a and a driven roller 3b. A plurality of documents G are placed above the conveyor belt 3.
A document stacking table 5 is disposed on which the document stack G... can be stacked, and a recycle lever 6 is disposed on the document stacking table 5. The originals G stacked on top are partitioned into unprocessed originals and processed originals. In addition, a recycle motor RM is connected to the recycle lever 6, a flag (not shown) is provided, and a recycle sensor R3 (
(not shown). Further, a half-moon-shaped paper feed roller 7 is disposed at the base end 5a of the document stacking table 5, and further downstream of the paper feed roller 7, there is a portion m consisting of a separation section conveyance roller 9 and a separation belt 10. A separation motor M1 is connected to these paper feed rollers 7, separation section conveyance rollers 9, and separation belt IO, and by driving the separation motor M1, documents stacked on the document stacking table 5 are separated. Bunch G...
The documents are fed by the paper feed roller 7 toward the separation sections 9 and 10, and are sequentially separated from the lowest document G by the separation section transport roller 9 rotating in the document feeding direction and the separation belt 10 rotating in the document return direction. They are separated and transported one by one. Furthermore, these paper feed rollers 7 and separation section 9. A paper feed stopper 11 connected to the stopper solenoid 5TPSL is disposed between the document stack G and the paper feed stopper 11 connected to the stopper solenoid 5TPSL, which positions the leading edge of the document at the position indicated by the solid line when setting the document bundle G... and moves it to the stopper solenoid 5TPSL when feeding the document. When energized, it moves to the chain line position. Further, a weight 12 is disposed above the paper feed stopper 11, and the weight 12 is moved up and down by the action of a connected weight solenoid WSL.

A registration roller 14 is located below the separating section 9.10.
The registration rollers 14.14 and the drive roller 3a of the conveyor belt 3 are provided with a helt motor M2.
The registration rollers 14, 14 and the conveyor belt 3 are driven by the belt motor M2.

Note that an electromagnetic brake BK is arranged on the drive roller 3a to ensure that the conveyor belt 3 stops. Further, the conveyor belt motor M2 is provided with a slit disk E2, and a belt clock interrupter P2 is arranged opposite to the slit disk E2. It is read by the belt clock interrupter PI2 via the belt clock interrupter PI2.

Further, from the downstream of the portion g1 9, 10, the conveyor belt 3
A paper feed path 13 is provided throughout.

The document G sent out from the separating section 9.10 is conveyed between the conveyor belt 3 and the platen 2 through the paper feed path 13, and placed at a predetermined position on the platen 2.

Note that the paper feed path 13 includes a sheet path 13a from the separating section 9.10 to the registration roller 14.14, and a sheet path 13b from the registration rollers 14, 14 to the platen 2.
It can be divided into

A reversing roller 15 is disposed near the paper feed path 13, and a transport motor M3 is connected to the reversing roller 15. The transport motor M3 has a slit disk E3.
A transport lock interrupter PI3 is arranged opposite to the slit disk E3. Also,
A paper discharge path 16 is provided extending from the conveyance belt 3 to the document stacking table 5 along the outer periphery of the reversing roller 15, and the document G placed at a predetermined position on the platen 2 is conveyed again and placed on the document stacking table 5. After passing through the paper ejection path 16, the document stacking table 5 is moved by a paper ejection roller 17 provided at the downstream end of the paper ejection path 16.
The document is discharged to the top of the document bundle G.

The paper ejection path 16 is divided into a sheet path 16a from the platen 2 to an upper roller 18 disposed above the reversing roller 15, and a sheet path 16b from the upper roller 18 to the ejection roller 17. It is being

Further, a reversing path 19 is arranged which branches from the sheet ejecting path 16 above the reversing roller 15 and joins the sheet feeding path 13, and at the branching point between the reversing path 19 and the sheet ejecting path 16, the document is A flapper 20 for switching the conveyance path is provided, and a flapper solenoid FSL is connected to the flapper 20. When the document is ejected, the document is guided toward the document stacking table 5 at the solid line position, and when the document is reversed, the flapper 20 is connected to the flapper solenoid FSL. When the solenoid FSL is energized, it is displaced to the position shown by the chain line, and the document G is guided toward the platen 2 via the reversing path 19.

A document detection sensor S1 is provided near the paper feed roller 7.
The presence or absence of a document G on the document stacking table 5 is detected. Further, a registration sensor S2 is arranged near the upstream side of the registration rollers 14, 14, and a discharge sensor S3 is arranged near the reversing roller 15.

Further, the document stacking table 5 is provided with a document width regulating section 30, and the document width regulating section 30 will be explained below.

The document width regulating section 30 includes a fixed width regulating member 31 and a movable width regulating member 32, as shown in FIG. is regulated. The fixed width regulating member 31 disposed on the back side defines a traveling standard for the document G and forms a flat surface. In addition, the document contacting surface of the movable width regulating member 32 placed on the front side is divided into three parts.
The central portion is composed of a fixed wall 32c, and both sides are movable walls 32a, 32b. Then, the movable width regulating member 32 moves forward and backward with respect to the document loading table 5 (arrows B and B' in the figure) while maintaining the relative positions of the fixed wall 32c and the movable walls 32a and 32b.
(direction) can be moved by 1 m and can be set to any position according to the width size of the document G.

3 and 4 are detailed views of the movable width regulating member 32, with FIG. 3 being a plan view and FIG. 4 being a front view.

As shown in FIGS. 3 and 4, the movable walls 32a and 32b are located at positions slightly pulled toward the front side with respect to the fixed wall 32c, and these movable walls 32a and 32b are located within a plane that is in contact with the document stacking table 5. combined.

Further, protrusions 33a and 33b protrude from the movable walls 32a and 32b, respectively, on the near side. These protrusions 33a, 33b
Pins 35a and 35b stand at the tips of the lever members 36a and 35b, and these pins 35a and 35b are rotatably connected to holes in lever members 36a and 36b. Lever members 36a, 36b
In addition to the hole connecting the pins 35a and 35b, there is also a fulcrum 37.
a, 37b and pins 39a, 39b, and the fulcrum 37
It is rotatably fixed to the base member 40 around a and 37b. Pins 39a, 3 of lever members 36a, 36b
9b corresponds to the hole of the arm member 41, and one end of the arm member 41 has a jogging solenoid JOGSL.
A return spring 42 is also attached to the other end.

When the jogging solenoid JOGSL is not activated, the movable walls 32a, 3'2b are pulled toward the front side of the fixed wall 32c, and when the jogging solenoid JOGSL is activated, the arm member 41 is moved to the left in the figure. the pins 39a and 3 of the lever members 36a and 36b.
9b is also pulled to the left. The lever members 36a, 36b rotate clockwise around the fulcrums 37a, 37b, and the pins 35a, 35b at the tips of the movable wall protrusions that are connected to the holes of the lever members 36a, 36b are placed on the back side (upper side in the figure). It becomes a shape that pushes out. As a result, the movable parts 132a and 32b are connected to the fixed wall 32c.
It is configured to move to a state in which it is moved further to the back side (indicated by a broken line in the figure).

Here, the document conveying operation of the automatic document conveying device 1 will be explained.

The operator sets the stack of originals G to be copied on the original stacking table 5, inputs the required mode (number of copies, magnification, density, etc.) from the operation panel of the copying machine M, and presses the copy start key. When turned on, the document bundle G . Next, manuscript bundle G...
・Separation part 9. The sheets are separated and conveyed one by one starting from the lowest position by the IO, and are placed on the platen 2 through the sheet feed path 13. After the exposure, the original G passes through the paper ejection path 16,
The document stack G on the document stacking table 5 by the paper ejection roller 17...
T& is placed on the top of the page.

Also, here, the documents G+, G of the M document bundle G of three single-sided documents
t, the flow of G3 is shown in FIG.

The documents are sequentially conveyed and re-stored starting from the lowest document G3, and by performing the operation shown in FIG. 6 once, one set of documents is processed, and by repeating the circulation a necessary number of times, it is possible to process the desired number of copies.

FIG. 5 is a block diagram of the control device.

The control device is mainly composed of a well-known one-chip microcomputer (CPU, hereinafter referred to as a microcomputer) 43 that has a built-in ROM, RAM, etc.
Signals from various sensors are input to the input ports I, -In.

In addition, the output port 0 of the microcomputer 43. ~0° is connected to each load via drivers D1 to DI.

The input port 11 includes a recycle sensor RS for checking the state of the flag energized by the recycle lever 6;1.
includes a document detection sensor Sl, 1. a registration sensor S2 that determines the control of the process when conveying the document in the sheet paths 13a and 13b in the paper feed path 13;
A paper discharge sensor S3 that determines the timing when a document is discharged onto the document stacking table 2 is connected to (4). Furthermore, a belt clock interrupter PI2 is connected to I5, and a belt clock interrupter PI2 is connected to I6.
A transport lock interrupter P I x is connected to the transport lock interrupter P I x.

Output port O3 is recycle motor RM, 02 is weight solenoid WSL, 03 is minute 2 motor 9M1.0
4, Os 2 is connected to heald-f--9M2 through a forward/reverse circuit, and 06 is connected to a transport motor M3.0.
7 is connected to the flapper solenoid FSL. Furthermore, 06 has electromagnetic flake BK, 0. Jogging solenoid JOGSL, 0□. is stopper solenoid 5
TPSL is connected.

On the other hand, the control device determines whether the leading edge of the document G is on the registration roller 14 based on the document detection signal from the registration sensor S2.
, 14, a control means 46 programmed to control the separation motor Ml to reduce the transport speed of the document G is provided, and the separation section 9.10 driven by the separation motor M1 is provided. The original G is transported by
When the leading edge of the document G reaches just before the registration rollers 14, 14, the separation motor M1 is controlled to decelerate based on the document detection signal from the registration sensor S2. Then, the document G is decelerated just before the registration rollers 14, 14, and its leading end contacts the registration rollers 14, 14 at low speed, and stops after forming a predetermined loop. This prevents damage to the leading edge of the document G while maintaining the conveyance speed of the document G, and also prevents noise by reducing collision noise.

The operation of the automatic document carrier wave fil of this embodiment will be described below.

First, the single-sided moat process will be explained with reference to FIG.

When the copy start key of the copying machine M is pressed, a separation process (Stepl) is executed in order to transport the lowest original G one by one to the sheet bus 13a, and then the original G is transferred from the sheet bus 13a to the sheet bus 13a. 13b, a paper feeding process (Step 2) is executed to stop the paper on the platen 2. When the paper feeding process is completed, the copying machine M starts exposure, and starts reading and forming an image. As for the operation of the automatic document feeder l during exposure, first check the state of the recycle sensor R3 that detects the state of the recycle lever 6, and check whether it is the end of the document bundle G...5Lc.
p3) If the recycle sensor R3 is on and there is no separation, the next document G is separated (SLapl
), wait for the exposure to be completed (5 step 4), and start the paper ejecting process. 5 step 5), start the paper feeding process for the next document G. In 5tcp3, if it is the end of the document bundle G, wait through the exposure path r (Step 6)
, eject the original and end the circulation (Step 7)
.

The separation process, paper feeding process, and paper ejection process will be explained below.

[Separation process] In the separation process (Stapl), as shown in FIG. 8, if the document G is the first sheet (Sl-1), the recycle-- which drives the recycle lever for detecting the separation of the document bundle. The motor R3 is turned on, and the separation motor Ml is turned on to separate the document bundle (Sl-3).

Incidentally, the first sheet of the original G is recognized if the recycle lever 6 is not on the original B and the recycle sensor RS is off when the copy start key of the copy al is pressed.

When the separation motor Ml is turned on and the paper feed roller 7 is rotated,
The document bundle G... is sorted by moving its leading edge up and down. At the same time as this operation, a jogging process is started to align the document bundle in the width direction (Sl-5).

In the shogink processing (SUBI), as shown in FIG. 11, first the jiggink counter JOG-CN, which determines the number of shoginks to be performed, is initialized (SUBI-1).
At the same time as turning on the jogging solenoid JOGSL that pushes out the movable walls 32a and 32b of the town movement restriction member 32,
Start the arbitrarily set jogging timer JOG-TM (SUBI-3), and when the timer JOG-TM ends (SUBI-5), the jogging solenoid JOGSL is activated to return the movable walls 32a and 32b to the initial state.
Turn off the jogging timer JOG- in the same way as above.
Start TM (SUBl-7) and set the timer JOG.
- When the TM is finished, - Recorded Shogink counter JOG
- Increase CN by one (SUBI-9), moveable wall 32a
, 32b completes three reciprocating movements, the process returns to 5UBI-3 and repeats the process. As a result, the side edges of the document bundle G... are aligned in the lateral direction, and skewing, lateral registration shift, etc. can be prevented.

When the shuddering process is completed (Sl-7), turn on the stopper solenoid 5TPSL as shown in FIG. 5l-9), when the original G advances within the sheet bus 13a and the registration sensor S2 detects the leading edge of the original G (Sl-11), speed control is started to reduce the speed of the separation motor Ml, and the separation loop Start the timer (5l-13), and after finishing (sl-15
), the separation motor Ml is turned off (S 1-17), and the tip of the document G hits the nip portion of the registration rollers 14 and 14 at low speed, thereby preventing damage to the tip of the document G and reducing collision noise. It also stops when a predetermined amount of loops are formed. As a result, even if skew occurs during separation, the skew is corrected.

In addition, in 5l-1, if the document G is the second or subsequent sheet,
Turn on the separation motor M1 (51-17), 5l-11
Proceed to.

[Paper feeding process] Next, in the paper feeding process (Step 2), as shown in FIG.
When the belt motor M2 is turned on to stop rotating (S, 2-1), the belt crotter interactor P
A size check counter that counts based on the clock input from I2 is activated (S2-2), and at the same time measurement of the document size is started, a registration process to be described later is activated (S2-3). Then, at the same time that the document G is conveyed and the trailing edge passes through the registration sensor S2 (S2-4), the size check counter is stopped (S2-5), and based on that data, the size check SUB shown in FIG. 13 is performed. , determine the original size (32-6). Furthermore, the sheet feeding process is completed when the previously activated registration process is completed (S2-7).

[5UB2 Registration Processing] In the registration processing, as shown in FIG. Start the registration counter RGCN for stopping at the position (SUB2-3).
A distance AI (55 cm in this embodiment) from the registration sensor S2 to a predetermined position on the platen 2 is set in CN. The registration counter RGCN is counted by the belt clock interrupter P12, and is configured to ensure that the document feeding amount and the count value match. Next, in order to accurately stop the belt motor M2 at the stop position on the platen 2, low-speed control of the belt motor M2 is started, and this speed control is continued until the registration counter RGCN ends (SυB2-5). Turn off the output of M2 (SUB2-7) L, and then turn off the electromagnetic brake B
Turn on K to stop the document G at a predetermined position (SUB2
-9).

[5UB3: Size check SUB] As shown in Figure i13, the size check count data described above is used as a method for determining the document size at 52-6 in the paper feeding process (see Figure 9). The original size is corrected by adding the distance from the nip position of the registration rollers 14, 14 to the registration sensor S2, or the true original size. At this time, the document G is moved to the registration roller 14.
14 and the conveyor belt 3, and once the feed amount and the count value by the belt clock interrupter Plt are sure to match, the size data BS, A4°A4R, B4 . Determine the size of A3, etc.

[Paper discharge processing] In order to discharge the document G on the platen 2, as shown in FIG. 1O, turn on the belt motor M2 in the reverse direction (S7-1),
When the leading edge of the document is detected by the paper discharge sensor S3, the conveyance motor M3 is turned on (S7-2°S7-3), whereby the document G is conveyed from the sheet path 16a to the sheet path 16b, and the document G is conveyed from the sheet path 16a to the sheet path 16b. When the edge is detected by 83 (
S7-4) Start the transport counter PCI (S7
-5) Here, the conveyance counter FCI is a counter that controls the timing to start the speed control of the conveyance motor M3 for alignment of discharged sheets, and in this embodiment, from the sensor S3 to the discharge roller 17 of the sheet path 16b. 50 from the distance of
It is set as short as m1, and the count up is
It is controlled within the interrupt of the input to the microcomputer 43 from the transport lock interrupter PI3, and is configured so that the count-up amount and the transport distance of the original G reliably match. After the transfer counter FCI is finished, the transfer counter F
C2 is started (S7-7). Here, the conveyance counter FC2 is a counter that determines the distance of the conveyance motor speed control for discharging the above-mentioned document G onto the document stacking table 5 with good alignment. In the case of the embodiment, it is set to about 70 mm. Speed control continues until the conveyance counter FC2 ends (S7-8), and when it ends (37-9)
The conveyance motor M3 is turned off (S7-10), and an interval is taken until the original G falls onto the M original stacking table 5. Start the paper ejection drop timer (ORG-DWN-TM) S7-
11) After completion (S7-12), in order to align the discharged originals, turn on the jogging solenoid JOGSL to push out the movable walls 32a and 32b, and at the same time press 'C'.
EJCT-JOG-
Start TM (S7-15), and after barring (S7-1
7) Turn off the jogging solenoid JOGSL (S7-
19) L, t, ends the paper ejection process.

In the above-described embodiments, the present invention has been described as an example in which the present invention is applied to an automatic document feeder, but the present invention is not limited to this, and it goes without saying that the present invention can be applied to image forming apparatuses such as copying machines. That is, as shown in FIG. 14, the image forming apparatus 50 includes a cassette 51 that stores sheets, a paper feed roller 52 that is driven by a driving means to convey the sheets stored in the cassette 51,
Registration roller 53 and sensor S? :@When conveying the sheet stored in the cassette 51 to the registration rollers 53, the sheet is decelerated and conveyed just before the registration rollers 53, so that the leading end of the sheet contacts the registration rollers 53 at low speed. controlled by.

Further, in the above-described embodiment, the leading edge of the document G is brought into contact with and aligned with the registration rollers 14, 14, but the invention is not limited to this. 55 (see Figure 15)
.

(g) As described in detail, according to the present invention, the sheet detecting means is disposed upstream of the sheet leading edge regulating member, and based on the sheet detection of the sheet detecting means, the leading edge of the sheet is determined to be the leading edge of the sheet. The conveying speed of the sheet is reduced just before it reaches the regulating member, and
Since a control means for controlling the driving means to reduce the speed is provided, the sheet is decelerated just before the sheet leading edge regulating member and comes into contact with the sheet leading edge regulating member at a low speed to maintain the sheet processing speed. At the same time, it is possible to prevent damage to the leading edge of the sheet and to reduce noise when the sheet comes into contact with the sheet leading edge regulating portion and material.

[Brief explanation of the drawing]

FIG. 1 is a side view of an automatic document feeder according to an embodiment of the present invention, FIG. 2 is a plan view showing a document width regulating section thereof, and FIGS. 3 and 4 are views showing a movable width regulating member. FIG. 3 is a plan view, and FIG. 4 is a side view. FIG. 5 is a block diagram showing the configuration of the control device, FIG. 6 is a diagram showing the conveyance state of a single-sided document, and FIGS. 7 to 13 are operations in the single-sided mode of the automatic document feeder according to the embodiment of the present invention. In the flowchart, Figure 7 shows the single-sided mode processing, Figure 58 shows the separation process, Figure 9 shows the paper feeding process, and Figure 10 shows the paper feeding process.
11 shows a jogging process, FIG. 12 shows a registration process, and FIG. 13 shows a size check process. FIG. 14 is a side view of an image forming apparatus a showing another embodiment. FIG. 15 is a side view showing a shutter member of another embodiment. 1... Sheet transport bag (automatic document transport device), 9.
10...Sheet conveyance means (separation unit), 14.14...
・Sheet tip regulating member (registration roller), 46
...control means, G...sheet (original),
Ml... Drive means (separated motor), S2...
- Sheet detection means (registration sensor). Figure 2 Figure 6 Figure 9 Figure 12

Claims (1)

[Scope of Claims] 1. A sheet conveying means for conveying a sheet, a driving means for driving the sheet conveying means, and a leading edge of the sheet conveyed by the sheet conveying means, which is disposed downstream of the sheet conveying means. A sheet conveyance device comprising: a sheet leading edge regulating member that comes into contact with and positions the leading edge of the sheet; sheet detecting means for detecting the sheet is disposed upstream of the sheet leading edge regulating member; A control means is provided for controlling the drive means to reduce the conveyance speed of the sheet immediately before the leading edge of the sheet reaches the sheet leading edge regulating member based on the sheet detection by the sensing means. sheet conveyance device.