JP2608091B2 - Sheet feeding device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sheet feeding apparatus that feeds a sheet to a predetermined position and stops the sheet.

2. Description of the Related Art Conventionally, a circulating type automatic document feeder used in a copying machine or the like is configured to sequentially separate a bundle of documents set on a document loading table one by one from a lowermost document one by one to form an image in a copying machine or the like. The sheet is conveyed and placed on the exposure section of the apparatus, and after the exposure is completed, is returned to the original mounting table again. Then, the repetition for the number of originals in the original bundle is repeated by 1
As a cycle, it is configured to repeat a predetermined cycle.

2. Description of the Related Art Conventionally, in an automatic document feeder of this type, speed control and stop control are performed during document transport in order to accurately stop a document on a platen glass.

[Problems to be Solved by the Invention] However, in the above-described conventional apparatus, since there are variations in the document size, paper quality, or load system, stable control can be performed for any document. Because the control was performed at a timing with a margin, the document replacement time was longer than necessary.

Therefore, an object of the present invention is to provide a sheet feeding apparatus that can increase the time for high-speed sheet conveyance and reduce the sheet feeding time in view of the above-described problems.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a stacking unit for stacking sheets, and separates the sheets stacked on the stacking unit one by one and feeds the sheets to a predetermined position. A feeding unit, and a control unit that performs control to reduce the feeding speed of the feeding unit to stop the sheet fed by the feeding unit at the predetermined position, wherein the control unit includes: When feeding the first sheet, the deceleration control is started at a predetermined timing to reduce the feeding speed to a predetermined speed, and when the feeding speed reaches the predetermined speed from the time when the deceleration control is started. When the sheet reaches the predetermined speed, the document is fed to the predetermined position at the predetermined speed and stopped, and when the second sheet is fed, the first sheet is moved. According to the distance traveled when feeding The timing at which the deceleration control is started is controlled.

According to the present invention, when feeding the first sheet, the deceleration control is started at a predetermined timing to reduce the feeding speed to a predetermined speed, and the feeding speed is started from the start of the deceleration control. Measures the distance the sheet moves by the time when the sheet reaches the predetermined speed, and when the sheet reaches the predetermined speed, feeds the document to the predetermined position at the predetermined speed and stops. When feeding the second sheet,
The timing at which the deceleration control is started is controlled according to the moving distance measured at the time of feeding the second sheet.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

 FIG. 1 shows a basic configuration of an embodiment of the present invention.

In FIG. 1, a dashed-dotted line block 1000 performs speed control and stop control of the sheet feeding when the document bundle set on the document loading table is separated one by one and fed to a predetermined position of the image forming apparatus. 5 shows an automatic document feeder that is repeated every time a document is exchanged.

A storage unit 100 stores a control result at the time of feeding the first sheet. Reference numeral 200 denotes a control unit that adjusts the timing at which the subsequent speed control of the transport unit 300 is started based on the control result stored in the storage unit.

Prior to the description of the present invention, an automatic document feeder will be described.

 FIG. 2 shows the configuration of the embodiment of the present invention.

As shown in FIG. 1, the automatic document feeder 1 includes a copier M
And a drive roller facing the platen 2
The conveyor belt 3 is wound around 3a and a driven roller 3b. A document loading table 5 on which a document bundle including a plurality of documents S constituting a document loading section can be loaded above the transport belt 3.
And a recycle lever 6 is provided on the document stacking table 5. The document S stacked on the document loading table 5 is separated by the recycle lever 6 into a document before processing and a document after processing.

A half-moon-shaped paper feed roller 7 is provided at a base end portion 5a of the document loading table 5, and a separation unit including a separation unit transport roller 9 and a separation belt 10 is provided downstream of the paper feed roller 7. Has been established.

The document bundle S loaded on the document loading table 5 is supplied to the sheet feeding roller 7.
The sheet is sequentially fed one by one from the lowest document S by a separating unit transport roller 9 rotating in the document feeding direction and a separating belt 10 rotating in the document returning direction.
Will be fed.

A paper feed stopper 11 is provided between the paper feed roller 7 and the separation units 9 and 10. When the original bundle S is set, it is positioned at the solid line and the leading end of the original is positioned. Sometimes, the stopper moves to the position indicated by the broken line due to the energization of the stopper solenoid of the stopper.

Further, a paper feed path 13 is provided from the downstream of the separation units 9 and 10 to the transport belt 3, and the document S sent from the separation units 9 and 10 passes through the paper feed path 13 and the transport belt 3 and the platen 2.
And is placed at a predetermined position on the platen 2.

A reversing roller 15 is provided near the paper feed path 13.
A paper discharge path 16 extending from the conveyor belt 3 to the document stacking table 5 along the outer circumference of the reversing roller 15 is provided. The document S placed at a predetermined position on the platen 2 is conveyed again and discharged. The document bundle S is discharged to the top of the document stack S stacked on the document stacking table 5 by a discharge roller 17 provided at a downstream end of the discharge path 16 through the path 16.

A reversing path 19 branches from the sheet discharging path 16 above the reversing roller 15 and is arranged to merge with the sheet feeding path 13. A switching flapper 20 is provided.

When the document is discharged, the document is guided toward the document loading table 5 at the solid line position, and when the document is reversed, the document is displaced to the broken line position by energizing the flapper solenoid to guide the document along the reversing path 19 toward the platen 2. A transport roller 21 is provided downstream of the confluence of the sheet feeding path 13 and the reversing path 19, and conveys the document S guided to the sheet feeding path 13 or the reversing path 19 toward the platen 2. It is configured to be.

Here, the document transport operation of the automatic document transport device 1 will be described.

The operator sets the document bundle S to be copied on the document loading table 5 and sets the necessary modes (number of copies, magnification, density, etc.)
Is input from the operation panel of the copier M, and the copy start key is turned on.
Sent to 9,10.

Next, the document bundle S is separated and fed one by one from the bottom by the separating units 9 and 10, and is placed on the platen 2 through the feeding path 13. After the exposure, the document S passes through the paper discharge path 16 and is stacked on the top of the document bundle S on the document stacking table 5 by the paper discharge roller 17.

Here, the originals S ₁ , S ₂ , S ₃ of the original bundle S of three single-sided originals
For the stream is executed operation procedure shown in Figure 3 are sequentially fed from the lowermost document S _3, is re-stored, the processing of a set by performing operations once shown in Figure 3 is performed By repeating the required number of times, a predetermined number of copies can be processed.

Next, the operation procedure shown in FIG. 4 is executed with respect to the flow of the originals S ₁ and S ₂ of the bundle of two originals.

Lower document S ₂ is fed in, First, by the surface c downwards is placed on the platen 2, to match the page order, the surface c backside by reversing path 19 without the copied d
Is placed on the platen 2 with the document facing downward and copied.

Then, the original is again inverted by the inverting path 19, is placed on the platen 2 with the front surface c facing downward, is copied, and is discharged to the uppermost portion on the original loading table 5.

Similarly, both sides b of the next document S _1, a is loaded into the duplicated by the original stacking plate 5 above. By performing the operation once as shown in FIG. 4, image processing of one set of double-sided originals is performed, and image processing of a predetermined number of double-sided originals can be performed by repeating the necessary number of times.

 FIG. 5 shows a circuit configuration of the control circuit according to the embodiment of the present invention.

Control circuitry, ROM, known one-chip microcomputer incorporating a RAM (hereinafter, microcomputer hereinafter) are organized around 60, signals from various sensors are input to the input port I ₁ ~I _n microcomputer 60 Is done.

Further, the output port O ₁ ~ O _n microcomputer 60 drivers D ₁
Each load through the to D _n are connected.

The input port I, an original detection sensor for recycle sensor 47, I ₂ see the status of the flag 46 is urged in the recycle lever 6 for detecting the presence / absence of the document on the tray 5 (S1), I ₃ Include sheet paths I and I in the sheet feeding path 13
When performing the document transport through the I, registration sensor (S2) which determines the control of the processing, the paper discharge sensor which determines the timing when the I ₄ that discharges the document onto the tray (S
3) is connected.

The output port O ₁ has a recycle motor 42 for driving the recycle lever 6, the O ₂ has a weight solenoid for driving the weight 12, and the O ₈ has an alarm LE for notifying a document error.
D37a is connected.

A separation motor (M ₁ ) for driving the separation unit is connected to O ₃ , and a belt motor (M 2) for driving the entire surface belt 3 and the registration rollers 21 a and 21 b is connected to O ₄ and O ₅ through a forward / reverse circuit. Furthermore, the O ₆ conveying motor for driving the large roller 15 (M3), flop wrapper solenoid for driving the Purappa 20 for switching the sheet path direction of the sheet of inversion / discharge of a document is connected to the O _7.

 FIG. 6 shows a main operation procedure of the embodiment of the present invention.

Next, the operation of the one-side mode processing will be described with reference to FIG.

First, a recycle lever process for separating the bundle of originals on the tray 5 is performed (Step 0), and then a separation process (St.
ep1), and further stop the separated original on the platen glass from sheet path I through sheet path II.
The paper feed process (Step 2) is executed. When the sheet feeding process is completed, the image forming apparatus M starts exposure, and starts reading an image and forming an image.

As an operation during exposure, first, the microcomputer 60 checks whether or not it is the end of the document bundle S by checking the state of the RS sensor that detects the state of the recycle lever 6 (Step 3). Document bundle S
If not, the next document is separated (Step
4) After waiting for the exposure to end (Step 5), the paper discharge process is started (Step 6), and the paper feed process for the next document is started.

In Step 3, if it is the end of the original bundle S, the exposure is waited (Step 7), the original is discharged, and one cycle is completed (Step 8).

The recycle lever processing, separation processing, paper feed processing, and paper discharge processing will be described later.

FIG. 7 (A) shows the procedure of the recycle lever processing in Step 0 of the control procedure shown in FIG.

In FIG. 7A, the recycle motor RM is turned on (Step S0-1) to rotate the recycle lever 6, and the recycle lever 6 is dropped on the bundle of originals S, so that the original before exposure of the bundle of originals S And the recycle lever process ends.

FIG. 7B shows a detailed procedure of the separation process of Step 1 of the control procedure shown in FIG.

First, the separation drive motor M1 is turned on so as to separate only one lowermost document page of the document bundle (Step 1-).
1). Next, after the document advances in the sheet path I and the sheet feeding sensor S2 detects the leading edge of the document (Step S1-2), the separation loop timer is started (Step S1-3), and after the separation timer ends (Step 1-4). When the separation drive motor 7 is turned off, the leading end of the document is brought into contact with the nip portion of the registration rollers 21a and 21b (Step 1-5).

At this time, since the separation drive motor 7 is stopped in a state where a loop of a predetermined amount of documents is formed, even if skew occurs during document separation, there is an effect of forcing skew (see FIG. 3). FIG. 8 shows a detailed procedure of the sheet feeding process in Step 2 of the control procedure shown in FIG.

8, when the registration rollers 21a and 21b and the entire belt 3 are driven, and the belt drive motor M2 is turned on in the normal rotation to convey the original from the sheet paths I to II (St.
ep2-1) At the same time, a size check counter for counting clocks input from the belt clock interrupter PI2 is started (Step 2-2).

At the same time as the measurement of the document size is started, a registration process described later is started (Step 2-3). The size check counter is stopped at the same time when the original is conveyed and the trailing edge passes through the paper feed sensor S2 (Step 2-4).
-5) Based on the data, a size check procedure (see FIG. 13) is executed to determine the document size (Step 2-).
6).

When the registration process started earlier is completed, St
The sheet feeding process of ep2 is completed (Step 2-7) (see FIG. 6).

The distance from the nip position of the registration rollers 21a, 21b to the paper feed sensor S2 is added to the size check count data described above. The corrected data becomes the true document size. At this time, the original is being conveyed by the registration rollers 21a and 21b and the entire belt 3, and the feed amount and the count value by the belt clock interrupter surely coincide with each other. Therefore, in the present embodiment, the size of B5, A4, A4R, B4, A3, etc. is determined by comparing the size data corrected as described above with predetermined size data. (First
See Figure 3).

FIG. 9 shows a detailed procedure of the sheet discharging process (Step 8) shown in FIG.

In FIG. 9, the belt motor M2 is turned on reversely to discharge the original on the platen glass 2 (Step 8-1), and when the light end of the original is detected by the sensor S3, the transport motor M3 is turned on (Step 8-). 2 → 8-3). As a result, the document is conveyed along the sheet path III from the sheet path III, and when the trailing edge of the document is detected by the sensor S3, (Step-
4), start the transport counter FC1 (Step8-
5).

Here, FC1 is a counter that controls the timing of starting the speed control of the transport motor M3 for paper ejection alignment. In the present embodiment, the sensor S3 detects the last roller of the sheet path IV from the sensor S3.
It is set about 50mm shorter than the distance up to 17.

The count-up of the counter FC1 is controlled by interrupt processing of an input from the transport clock interrupter PI3 of the transport motor M3 to the microcomputer 60, and the count-up amount and the transport distance of the document are configured to surely match.

After the count of the counter FC1 is completed, the transport counter FC2 is started (Step 8-7). Here, the counter FC2 is a counter for determining the distance of the conveyance motor speed control for discharging the above-mentioned original onto the tray 5 with good alignment, and is set to about 70 mm in this embodiment. Counter FC2
Is completed (Step 8-9), and when the discharge alignment of the original is completed, the transport motor M3 is turned off (S8-10) (see FIG. 6).

In this embodiment, in order to accurately stop the original at a predetermined position on the platen glass 2, the speed control of the belt motor M2 is performed based on a speed characteristic as shown in FIG. This speed control is used when the document is
This is a control in which a deceleration process called a registration process is performed on the belt motor M2, and a brake is driven at the same time when the document reaches the stop position, so that the document does not go too far from the stop position.

Next, a learning function at the time of belt motor speed control of the present embodiment according to the present invention will be described with reference to FIGS. 10 (A) and 10 (B).

In FIG. 10 (A), the driving of the belt motor M2 is first started to convey the original to the stop position on the platen glass 2. Eventually, the speed of the belt motor M2 reaches the highest point, after which the registration sensor S2 detects the trailing edge of the document at timing T1, and when the document is the first document, the timing T2 at which the speed control of the belt motor M2 is started. At the same time when the document reaches the position (RG-Start), speed control for deceleration is started.

Thereafter, from the time T3 when the speed of the belt motor M2 reaches a predetermined speed (100 mm / sec) (RG-1st ON),
The belt motor M2 is driven at a low speed (100 mm / sec) until the document stops at the stop position. In this embodiment, the deceleration start time T2, the deceleration end time T3, and the document stop time T4 of the first document are converted into a distance from the document stop position and stored. The target time is when the deceleration end time T3 is the target as shown by the characteristic indicated by the dotted line in FIG.
Adjust the deceleration start time point (RG-Start) T2 so as to become Target. In addition, a sensor for detecting a document is provided at a predetermined position before the document stop position, and the time from the start of deceleration to the detection of the document by this sensor is measured, and the deceleration start time is determined based on this time. It may be adjusted. Therefore, the timing for starting the speed control for the second and subsequent documents is determined by the following equation.

(RG-Start) '= (RG-Start)-(RG-1st-on) + target For the second and subsequent originals, as shown by the dotted line in FIG. Fig. 10 (B)
As shown in the timing chart of FIG.

Next, such original registration processing (Step 2-3)
This will be described in detail with reference to FIGS. 11 and 12. When the registration process is started, a registration process as shown in FIG. 11 is performed in the clock interruption process of the belt motor M2 that conveys the document to a predetermined position on the platen glass 2. This registration process is performed each time a clock interrupt occurs.

In FIG. 11, while the RG-EDGE flag which is set when the trailing edge of the document is first detected is reset, it is determined whether the registration sensor S2 has detected the trailing edge of the document. (Step 2-3-1 to 2-3-2). If the registration sensor S2 has not detected the trailing edge of the document, the process exits the registration process and waits for the next interrupt.

RG-ED when the registration sensor (S2) detects the trailing edge of the document
The GE flag is set and the number of clocks corresponding to the distance from the registration sensor S2 to the stop position is set in a registration counter RGCN for stopping the document at a predetermined position on the platen glass.
In the case of the present embodiment, 150 cp is set (Step 2-3)
2-2-3-4). Next, when the original is the first sheet, 100 cp is stored in the register RG-Start for determining the timing for controlling the belt motor speed at the time of registration.

In the case of the present embodiment, the value of 100 cp is a value enough to allow the belt motor speed to fall to a predetermined speed (100 mm / sec) by the stop position of the document. Since the value of RG-Start was determined during the registration processing of the previous document,
G-Start is not updated (Step 2-3-5).

Next, if the RG-EDGE flag is set in Step 2-3-1, the processing procedure proceeds to Step 2-3-2, and the processing for checking a perforated document is started. When the RG-HOLE flag, which is set when the perforated document is checked at the beginning, is reset, the value of the register RGCN is subtracted, and the value of the register RGCN has been sent by 25 cp corresponding to the perforated distance. It is determined whether or not it is not sent.
If is off, exit the resist process as it is (Step
2-3-21 → 22 → 24).

Here, when the registration sensor S2 is turned on, that is, when a document is detected, it is determined that the document is a perforated document, the RG-EDGE flag is reset, and a new registration process is started from the procedure of Step 2-3-1. RG-HOLE
Set the flag and wait for the next interrupt. (Step2-3-
2 → 4 → 25).

If the RG-HOLE flag is set, that is, if the check of the perforated document has been completed, the procedure proceeds to Step S2-3-30, and after the value of the register RGCN is also subtracted,
It is determined whether the value of the register RECN is “0cp”, that is, whether or not the registration processing has been completed. If the value of the register RGCN is smaller than RG-Start when the resist process is not completed, the regist speed control described below is performed.
Wait for the next interrupt. If the value of the register (RGCN) is "Ocp", it is determined that the document has reached the stop position, the driving of the belt motor M2 is stopped, the electromagnetic brake is further driven, and the registration process ends.

Next, the speed control of the belt motor M2 and the registration speed control for determining the timing of starting the speed control of the next original document in Step 2-3-34 shown in FIG. 11 will be described with reference to FIG. The present control means corresponds to the control means 200 according to the present invention, and the belt motor M2 forms a part of the transport means 300.

In FIG. 12, first, it is determined whether the present control procedure has been executed for the first time. If the RG-1st flag has been reset, the RG-1st flag is set, the driving of the belt motor M2 is stopped, and the present control procedure is exited (Step 1).
2-3-3-4-1 → 2 → 3).

Next, it is determined whether or not the speed of the belt motor M2 has fallen below a predetermined speed (100 mm / sec). Here, the speed of the belt motor M2 sets an interval time from the interruption of the belt clock to the next interruption. Since the moving distance of the document is known in advance, the speed of the belt motor M2 is calculated from the above interval time. Can do things. Here, RG-1st is set when the speed of the belt motor M2 falls below 100mm / sec for the first time.
If the -ON flag is reset, the RG-1st-ON flag is set. If the original is the first document, the register G-Start in the microcomputer 60 as the storage means 100 is updated according to the learning algorithm described above. Store (Step2-3-34)
-1 → 4 → 5 → 6 → 12).

If the original is the second or later, the register RG at this point
It is determined whether the value of CN is too fast or too slow with respect to the value of Target, which is the speed target. If the value of the register RGCN is too slow by 5 cp or more with respect to the value of the Target, the value of the register RG-Start is updated by adding 1 cp to advance the timing of starting the speed control (Step 2-3-34-6).
→ 7 → 8). If the value of the register RGCN is 5 cp or more ahead of the value of the Target, the value of the register RG-Start is subtracted by 1 cp to delay the speed control start timing (Step 2-3).
−34−6 → 7 → 11).

Further, since the speed was slower than the target value, the belt motor M2 was driven. If the belt speed was faster than 100 mm / sec in the judgment of Step 2-3-3-4-4, the belt motor M2 was turned off. The process exits from this control procedure (Step 2-3-3-4 → 13).

[Effects of the Invention] As described above, according to the present invention, when feeding the first sheet, the deceleration control is started at a predetermined timing to reduce the feeding speed to the predetermined speed, and the deceleration control is performed. From the start to the time when the feeding speed reaches the predetermined speed, and when the feeding speed reaches the predetermined speed, the document is fed to the predetermined position at the predetermined speed and stopped, and the second sheet is stopped. When the sheet is fed, the timing at which the deceleration control is started is controlled in accordance with the movement distance measured at the time of feeding the first sheet. The time required for stoppage can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of an embodiment of the present invention, FIG. 2 is a side view showing an apparatus configuration of the embodiment of the present invention, and FIG. FIG. 4 is an explanatory view showing a procedure for transporting a two-sided document according to the embodiment of the present invention. FIG. 5 is a block diagram showing a circuit configuration of a control unit according to the embodiment of the present invention. FIGS. 10A and 10B are explanatory diagrams showing the operation principle of the embodiment of the present invention, and FIGS. 11 to 13 are originals of the embodiment of the present invention. 6 is a flowchart showing a control procedure of the microcomputer 60 related to the speed control of FIG. 60: microcomputer, S1: original detection sensor, S2: registration sensor, S3: paper ejection sensor, M1: separation motor, M2: belt motor

Claims (1)

(57) [Claims] A stacking means for stacking sheets; a feeding means for separating sheets stacked on the loading means one by one and feeding the sheets to a predetermined position; and a sheet fed by the feeding means. Control means for performing a speed reduction control of the feeding speed of the feeding means to stop at the predetermined position, the control means, when feeding the first sheet, at a predetermined timing Start the deceleration control to reduce the feeding speed to a predetermined speed, measure the distance the sheet moves from when the deceleration control is started until the feeding speed reaches the predetermined speed, and reach the predetermined speed. Then, the document is fed to the predetermined position at the predetermined speed and stopped, and when the second sheet is fed, the deceleration control is performed according to the moving distance measured at the time of feeding the first sheet. Controls the start timing Sheet feeding device.