JPH05162914A - Sheet discharge speed control method for image forming apparatus, etc. - Google Patents

Abstract

PURPOSE:To quickly change the transport speed for a sheet material in a sheet discharge rotation system from the process speed to the sheet discharge speed suitable for discharging a sheet material. CONSTITUTION:At a point of time of detecting the leading end position of a sheet material P by using a position signal Ps for indicating the leading end position of a sheet material P, a distance signal Ds to the terminal ends of process rotation systems 12, 13, a speed signal Vs showing the process speed V1, and a size signal S1 of a sheet material P, the escape time T when the trailing end of the sheet material P escapes from constraint of the process rotation systems 12, 13 is computed, and according to the results computation the speed change of the sheet discharge rotation systems 21, 22 is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printing machine, and other recording equipment, and an auxiliary equipment such as a circulating document automatic feeding device and a sorter mounted on the image forming apparatus (hereinafter referred to as an auxiliary equipment). , Image forming apparatus, etc.), and more specifically, to a discharge speed control method for temporarily or finally discharging a processed sheet material.

[0002]

2. Description of the Related Art Conventionally, regarding sheet material conveyance control in an image forming apparatus or the like, in the case of a copying machine, the sheet material is sent to an image forming section at a constant conveying speed to convey an original document. It is the conveyance speed of the sheet material when the processed sheet material is temporarily or finally discharged, as opposed to the process speed which is the conveyance speed of the sheet material when the conveyance processing is performed according to, for example, forming an image corresponding to A method is known in which the sheet material is stably discharged regardless of the process speed by increasing or decreasing the discharge speed. Further, such a control method can be applied not only to an independent image forming apparatus or the like, but also to a copying machine provided with an auxiliary device such as a sorter or a finisher that discharges a sheet material.
It is also implemented in the relationship between the process speed on the copying machine side and the sheet discharge speed on the auxiliary device side.

The need for such control depends on where the process speed required for stable processing of the sheet material and the paper discharge speed required for stable discharge of the sheet material differ according to their purpose. Based on different things. That is, the process speed is generally determined by the performance and processing capacity of the image forming apparatus and the like. On the other hand, the sheet discharge speed required for completely releasing the sheet material from the constraint of the transport system and stacking it in the sheet discharge tray and the like in an orderly manner is a constant speed determined by the property of the sheet material. In other words, since the behavior of the sheet material after the constraint of the transport system is released by paper ejection is determined by the invariant natural law, the paper ejection speed that can realize a good paper ejection state is within a certain range. It is limited to the inside. As a result, when the same sheet material belongs to both the process rotary system and the paper discharge rotary system in the process of discharging the sheet material processed by passing through the process rotary system by the paper discharge rotary system, , The delivery speed of the delivery rotation system is set to match the process speed, and after the sheet material has released the constraint of the process rotation system, the delivery speed of the delivery rotation system is set to the delivery speed required for achieving a good delivery state. It is necessary to change the speed to the discharge speed peculiar to the paper rotation system.

The control of the sheet discharge speed is generally performed when a sensor for detecting the rear end of the sheet material is attached in the middle of the sheet conveying path on the side of the sheet discharge rotation system and the rear end of the sheet material is detected by the sensor. Then, it is determined that the sheet material has completely left the process rotation system and belongs to the paper discharge rotation system, and the drive control motor of the paper discharge rotation system is accelerated or decelerated via the motor control system. It is being appreciated. At this time, a method of detecting the front end of the sheet material by a sensor is hardly used. This is because it is necessary to handle sheet materials of various sizes, and even if the front edge of the sheet material reaches the output rotation system side, it is determined whether the rear edge of the sheet material has released the constraint of the process rotation system. This is because it is difficult. If the sheet speed is not properly controlled and the sheet material is discharged at a speed higher than the specified sheet discharge speed, the sheet material is lifted up, and the stacking due to the bounce due to the interference with the tray is caused. A defect occurs, on the contrary,
If the sheet material is ejected at a speed lower than the prescribed ejection speed, the sheet material has not reached the tray end, or the trailing edge of the sheet material remains on the ejection roller and is stopped halfway. When a stacking failure due to an end residue or the like occurs, and particularly when such a stacking failure is due to a temporary discharge to the buffering tray for performing the subsequent transfer processing,
This may result in defective conveyance of the sheet material in the subsequent process.

[0005]

However, according to the prior art, as the sheet conveying path is shortened due to the demand for downsizing and weight reduction of the image forming apparatus and the like, a sensor is used to remove the sheet Depending on the method of accelerating or decelerating the paper discharge rotation system after detecting the edge, the conveyance speed of the paper discharge rotation system may be changed after the sheet material completely belongs to the paper discharge rotation system until it is discharged. Start up from the process speed to a unique output speed that can achieve a good output status, or
A paper discharge failure occurs due to the inability to drop the paper. That is, since the sheet material conveying path is shortened, the sheet material is ejected in a short time, and the time margin for shifting the sheet ejection speed is insufficient. This tendency also means that if the sensor that detects the trailing edge of the sheet material cannot be mounted close to the process rotation system, the size of the sheet material is large, the speed difference between the process speed and the paper discharge speed is large. It is especially noticeable in some cases.

Therefore, according to the present invention, the front end position of the sheet material is detected by a position sensor attached in the middle of the sheet material conveying path, and the rear end of the sheet material is in the process rotation system based on the position information from the position sensor. By electrically calculating the escape timing to release the restraint and shifting the paper discharge rotation system based on the calculation result, it is possible to prevent a delay in shifting and to complete the necessary shifting operation within a short conveyance path. It is an object of the present invention to provide a method for controlling the discharge speed of an image forming apparatus or the like.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. Referring to FIG. 3, the present invention will be described with reference to FIG. The process rotation system (12, 13) for conveying and processing the sheet material (P) at V ₁ ) is connected to the downstream side of the process rotation system, and the processed sheet material (P) is discharged at a specific sheet discharge speed (V ₂ )
When the sheet material (P) being conveyed belongs to both the process rotation system (13) and the paper discharge rotation system (21), The conveyance speed of the paper discharge rotation system (21) is set to the process speed (V ₁ ).
The sheet material (P) corresponds to the process rotation system (1
After removing the constraint of 3), the paper discharge rotation system (21, 22)
In the method of controlling the discharge speed of the image forming apparatus or the like, the transport speed of the sheet is changed to the unique discharge speed (V ₂ ).
It disposed a position sensor (F ₄₎ for detecting a front end position of the middle sheet material conveying path of the sheet material (P) (R _2), position signals (P _S of sheet material from said position sensor (P) and), the from the position sensor process rotary system (distance signal (D _S to the end position of the 12, 13)), speed signal indicative of the process speed (V ₁₎ and (V _S), it is conveyed From the sheet material (P) size signal (S ₁ ) and the sheet material (P)
Calculates the escape timing (T) for releasing the constraint of the process rotation system (13), and shifts the paper discharge rotation system (21, 22) to the specific paper discharge speed (V ₂ ) based on the calculation result. It is characterized by:

[0008]

Based on the above construction, the sheet material (S) is conveyed at the process speed (V ₁ ) while it belongs to the process rotation system (12, 13), and the downstream sheet discharge rotation system (21, 13).
22). The discharge rotation system (21, 22) is
Eventually, the sheet material (P) will be delivered at a specific paper ejection speed (V ₂ ).
However, when the sheet material (P) being conveyed belongs to both the process rotation system (13) and the sheet discharge rotation system (21), the conveyance speed of the sheet material (P) is changed. The speed is controlled so that the sheet material (P) is kept at the process speed (V ₁ ), and is shifted to the paper discharge speed (V ₂ ) after the sheet material (P) leaves the process rotation system (13).

At this time, since the front end position of the sheet material (P) being conveyed is detected by the position sensor (F ₄ ), the sheet material (P ₂ ) in the conveying path (R ₂ ) is detected by the position signal (P _S ). The front end position of P) can be confirmed. Further, if the front end position of the sheet material (P) is known, as other calculation elements, the distance from the position sensor (F ₄ ) to the end position of the process rotation system (12, 13) and the process speed (V ₁ ) And the size of the sheet material (P), the rear end of the sheet material (P) is set to the process rotation system (1
It is possible to calculate the escape timing (T) for removing the constraint of 3), and therefore, in addition to the position signal (P _S ), the distance signal (D _S ) and the velocity signal (V _S ) including such calculation elements are calculated. ) And the size signal (S ₁ ) to calculate the escape timing (T), and at the same time when the escape timing arrives, the paper discharge rotation system (21,
22) can be changed, and the discharge rotation system (21, 2)
2) It is possible to secure a longer shift time.

The reference numerals in parentheses refer to the drawings and do not limit the structure of the present invention.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a copying machine 10 including a belt unit 11, a fixing roller 12 and a paper discharge roller 13 as a process rotation system, and an entrance conveyance roller 21 and a non-sorted paper discharge roller 22 as a paper discharge rotation system. , Intermediate transport roller 2
3, a sorter 20 including a sort discharge roller 24 is connected, and the sorter 20 receives the processed sheet material P conveyed by the copying machine 10 and places it on the non-sort tray 2 or the sort tray 3. It sorts and discharges the paper.

The process rotation systems 11, 12 of the copying machine 10,
13 is synchronously driven via a power transmission system (not shown) so that the peripheral speeds are the same.
Transport processing is performed at a process speed V ₁ specific to 0. Also,
A sheet discharge sensor F ₃ is provided at the end of the sheet path P ₁ for conveying the sheet material (P) to detect passage of the processed sheet material (P). On the other hand, the sorter 20 is provided with an independent drive motor 5, and the sheet discharge rotation systems 21, 22, 23, 2
All 4 are synchronously driven by the drive motor 5 so that the peripheral speeds are the same, and the sheet material P is finally discharged at the discharge speed V ₂ specific to the sorter 20. The conveying path R ₂ of the sheet material P in the sorter 20 is provided with an entrance conveying roller 21.
Is formed so as to branch to the side of the sort tray 3 and the side of the non-sort tray 2 at a position immediately after, and a flapper 6 swinging by a solenoid drive is interposed at the branch position, and the transport path R after the branch position is provided. Position sensors F ₄ and F ₅ are provided on the respective _two . The path of the sheet material P in the sorter 20 is determined by the posture of the flapper 6, the sheet material P advancing to the non-sort tray 2 is detected by the position sensor F ₄ , and the sheet material P advancing to the sort tray 3 is It is adapted to be detected by the detection sensor F ₅ .

FIG. 2 shows a pulse generator F ₆ attached to the drive motor 5 of the sorter 20.

The pulse generator F ₆ is a combination of a clock disk 5d having through holes at equal intervals formed on the outer circumference thereof and a photo interrupter 5e arranged so as to sandwich the outer circumference of the clock disk 5d from both sides. The clock disk 5d consists of
The photo interrupter 5e is attached directly to the output shaft of the drive motor 5, and the photo interrupter 5e is attached to the motor bracket 5f. The output shaft of the drive motor 5 has a clock disc 5d.
At the same time, a drive pulley 5a is attached, and the paper discharge rotation systems 21, 22, 23, 24 are connected via a timing belt 5b.
Is designed to drive. Therefore, the discharge rotation system 2
1, 22, 23, 24 peripheral speed, that is, the sorter 20
A proportional relationship is established between the conveyance speed of the sheet material P in (1) and the number of pulse signals output from the photo interrupter 5e in time series with the rotation of the clock disk 5d.

FIG. 3 shows the control system of the copying machine 10 and the sorter 20 and the conveying paths R ₁ and R ₂ of the sheet material P when the sheet material P is discharged to the non-sort tray 2.

On the copying machine 10 side, the information regarding the property of the loaded sheet material P is detected by the detection sensor F _{1 and} is used as the sheet discrimination signal S _0.
Of the sheet material P including the size L ₁ of the sheet material P is determined by comparison with the stored information. In addition, for the central repair department 1,
A pulse signal C ₁ from a pulse generator F ₂ for controlling the process speed V ₁ and a paper ejection signal P from a paper ejection sensor F _3
0 is entered. On the other hand, the central processing unit 2 of the sorter 20
, The position signal P _S from the position sensor F ₄ , the pulse signal C ₂ from the pulse generator F ₆ , and the distance signal D _S from the setting device 7 are input. Here, the position signal P _S
Is emitted when the front end of the sheet material P in the conveyance path R ₂ is captured, and the distance signal D _S is the position of the position sensor F ₄ on the sorter 20 side and the process rotation system of the copying machine 10. The information contents are those arranged at the ends of the sheets 12 and 13, that is, the distance L ₂ between the center position of the discharge roller 13 and the setting contents of the setter 7 for each model of the copying machine 10 and the sorter 20. Artificially via, or
Settings shall be stored in advance. Further, the pulse signal C ₂ of the pulse generator F ₆ is branched and input to the motor control unit 3 for controlling the rotation of the drive motor 5, and feedback control for the drive motor 5 is performed.

Next, based on the above description, the sheet material P having the size L _{1 in} the conveying direction will be described with reference to FIGS. 3 to 5.
Copying machine 1 as an example
A paper discharge speed control method in the combination of 0 and the sorter 20 will be described.

When the sheet material P is set in the copying machine 10, the central portion 1 outputs the discrimination signal S ₀ issued by the detection sensor F _1.
The size L ₁ of the sheet material P is determined based on the
A size signal S ₁ having the information content of the determined size L ₁ of the sheet material P is output to the central processing unit 2 of 0. Central processing unit 1 confirming the normal loading of the sheet material P
Outputs a paper feed signal to a motor control unit (not shown) to raise the process rotation systems 12 and 13 to a target process speed V ₁ . As a result, the sheet material P advances in the conveyance path R ₁ at the process speed V ₁ and undergoes a predetermined conveyance process. Also, the process speed V ₁ during this period is kept constant by counting the pulse signal C ₁ of the pulse generator F ₂ . The sheet material P that has been processed by passing through the fixing roller 12 is ejected from the paper ejection roller 13
Immediately before the operation, the paper discharge sensor F ₃ is activated, and the paper discharge sensor F ₃
Outputs a paper discharge signal P ₀ .

The central processing unit 1 of the copying machine 10 which has received the paper discharge signal P ₀ outputs the speed signal V _S having the process speed V ₁ as the information content to the central processing unit 2 of the sorter 20. The operation of the sorter 20 is started under the condition of V _S. This will be described in detail with reference to FIGS. 3 and 4. First, when the paper discharge sensor F ₃ normally operates (S1), the speed signal V _S from the copying machine 10 side causes the copying machine 1 on the sorter 20 side.
Since the process speed V _{1 of} 0 can be known, the central processing unit 2 of the sorter 20 outputs a start signal V _t to the motor control unit 3 to set the transport target speed to the process speed V ₁ (S2). .. The motor control unit 3 can perform the closed loop control of the drive motor 5 by the pulse signal C ₂ from the pulse generator F ₆ to achieve the target transport speed. Therefore,
At the time when the sheet material P advances to the sorter 20 side through the sheet discharge roller 13, the sheet discharge rotation systems 21 and 22 are rotating at the transport speed similar to the process speed V _1, and as a result, the sheet material P is It is possible to belong to both the paper discharge roller 13 and the entrance conveyance roller 21 of the sorter 20 without causing a problem such as inquiries or slack that causes conveyance failure. Here, it goes without saying that the size L ₁ of the sheet material P is longer than the distance between the paper discharge roller 13 and the entrance conveyance roller 21 due to the nature of the combined use of the copying machine 10 and the sorter 20.

Entering the sorter 20 side, the entrance conveying roller 2
The front end of the sheet material P that has passed through 1 operates the position sensor F ₄ (S3), and the position sensor F ₄ outputs the position signal P _S indicating the front end position of the sheet material P, and at the same time, the central processing unit 2
Is a size signal S ₁ and a distance signal D _S which are input in advance,
The process speed V is calculated from the amount t of advance of the sheet material P per pulse determined by the power transmission system of the sheet discharge rotation systems 21 and 22.
The rear end of the sheet material P that is proceeding in ₁ is the process rotation system 1
The number of pulse signals (L ₁ -L ₂ ) / t required until the discharge rollers 13 of 2 and 13 are released from the constraint is calculated, and this is set in a counter (S4). The escape timing T of the sheet material P is T = {(L ₁ −L ₂ ) /, where M is the number of pulse signals per unit time at the process speed V ₁ .
t} / M.

The central processing unit 2 of the sorter 20 continues to maintain the process speed V ₁ while counting the pulse signal C ₂ from the pulse generator F _6, and waits for the counter to count up (S6), that is, the sheet material. Simultaneously with the arrival of the escape timing T of P, a speed switching signal V for making the transport target speed the discharge speed V ₂ peculiar to the sorter 20 is given to the motor controller 3.
The distance L from the position sensor F ₄ to the non-sort paper ejection roller 22 is output to the counter that outputs _U and counts up.
₃ were taken into account in the calculation element _{(L 1 + L 3) /} t Reset (S7). Here, (L ₁ + L ₃ ) / t represents the number of pulse signals C ₂ necessary for the trailing edge of the sheet material P to escape from the non-sort discharge roller 22, and the discharge rotation system 2
After maintaining the sheet discharge speed V ₂ , the sheets 1 and 22 are stopped by counting up the reset counter (S9).

FIG. 5 shows a start signal V from the central processing unit 2.
The control contents of the motor control unit 3 with respect to _t and the speed switching signal V _U are shown. However, the drive motor 5 is a pulse motor. The drive motor 5 is started by giving a target speed (S1). When the target speed is zero, the drive motor 5 is not started or the operation is stopped (S1).
2). Further, in changing the speed of the drive motor 5 being activated, the duty of the control pulse is changed so that the duty is increased when the target speed is exceeded (S4), and conversely, the duty is decreased when the target speed is not reached. Is being executed (S5).

Although the above description is for ejecting the sheet material P to the non-sort tray 2, the same method can be used for ejecting the sheet material P to the sort tray 3. In this case, as the sensor for detecting the front end position of the sheet material P and outputting the position signal P _S , the position sensor F ₅ arranged on the conveyance path R ₂ branched to the sort tray 3 side is used. You can The paper discharge signal P ₀ on the copying machine 10 side may be directly received by the central processing unit 2 on the sorter 20 side.

FIG. 6 shows an example in which a similar method of controlling the sheet discharge speed is used in an automatic circulating document feeder (hereinafter abbreviated as RDF device).

In the RDF device, the original set on the original table 30 is passed through the half-moon roller 31, the separating unit 32, the registration roller 33, the conveyor belt 34, the relay roller 35, and the discharge rollers 36 and 37 to the original table 30. A large number of sheets can be returned by loop circulation or by returning the originals once belonging to the conveyor belt 34 to the conveying path R ₃ of another system and circulating the originals 30 through the return rollers 38 and the discharge rollers 39. It is possible to automatically copy the original document. Therefore, the circulation speed of the original document is determined by the copying machine 10.
While it is necessary to match the process speed V ₁ with the process speed V ₁ , the reloading of the document on the document table 30 often requires a unique sheet discharge speed V ₃ different from the process speed V ₁ . Here, the discharge rollers 36, 3 for closed loop circulation
7. A drive motor for independently driving the discharge roller 39 for switchback circulation is provided independently, and the position sensors F ₇ , F ₈ arranged upstream of the discharge rollers 36, 39 output the position signal P _S. When the sheet material P is discharged to the document table 30, the front end position of the sheet material P is detected by the position sensors F ₇ and F ₈ so that the trailing edge of the sheet material P is located immediately before the relay roller 35 or Since it is possible to estimate in advance the escape timing T at which the return roller 37 will be unconstrained, the conveyance path R until the sheet material P is discharged.
_{Even if 2} and R ₃ are short, the process speed V ₁ is changed to the discharge speed V ₃ required for good reloading of the sheet material P by making the best use of the conveyance paths R ₂ and R _3. It is possible to

In FIG. 7, a buffering tray 50 is provided inside the main body, a platen drum 51, a conveyor belt 52,
The processed sheet material P that has passed through the fixing roller 53 and the transport roller 55 is temporarily discharged onto the buffering tray 50 via a plurality of intermediate paper discharge rollers 56 arranged at different positions, and then sent out. Roller 57, relay roller 58
By sending again to the upstream side of the transport path,
This is an example of use in the copying machine 10 that enables reprocessing of the sheet material P. The intermediate discharge rollers 56 are provided at a plurality of positions for the sheets P having different sizes L _1. The discharge position of the sheet material P with respect to the buffering tray 50 depends on the posture of the flapper 6. It is supposed to be selected. A position sensor F ₉ is attached immediately upstream of each of the intermediate discharge rollers 56. In this case, each of the intermediate discharge rollers 56 corresponds to the optimum discharge speed V ₄ , V ₅ , V different from the process speed V ₁ , respectively.
Since ₆ but is required, is not to eject the sheet P of different sizes L ₁ at the same time, the size of the sheet material P L ₁
When the paper discharge position is determined by, the corresponding position sensor F ₉ of the corresponding intermediate paper discharge roller 56 detects the front end position of the sheet material P, and the position signal P _S of the position sensor F ₉ detects the rear end of the sheet material P. Is located immediately upstream, for example, the escape time T for releasing the restraint of the transport roller 55 is obtained, and the speed is changed to a discharge speed specific to the intermediate discharge roller 56 in charge of discharge, for example, the discharge speed V _6. Is possible.

[0028]

As described above, according to the present invention, the discharge speed required for temporarily or finally discharging the sheet material and the process speed for carrying the sheet material according to a predetermined purpose are different. In the case, a position signal indicating the front end position of the sheet material, and the other, a size signal,
By adding the distance signal and the speed signal as calculation elements, it is possible to calculate the escape timing at which the trailing edge of the sheet material exits the process rotation system. Therefore, when shifting the discharge rotation system to the discharge speed. It is possible to prevent the detection delay of No. 3, complete the necessary speed change operation within a short conveyance path, and solve the defective stacking of the sheet material at the time of paper discharge.

[Brief description of drawings]

FIG. 1 is an example of use of the present invention in a combination of a copying machine and a sorter.

FIG. 2 is an explanatory diagram showing a configuration of a pulse generator.

FIG. 3 is a block diagram corresponding to FIG.

FIG. 4 is a flowchart showing a control process of a sorter.

FIG. 5 is a flowchart showing speed control of a drive motor.

FIG. 6 shows an example of use of the present invention in a circulating document automatic feeding device.

FIG. 7 shows an example of use of the present invention in a copying machine.

[Explanation of symbols]

12 process rotation system (fixing roller) 13 process rotation system (paper discharge roller) 21 paper discharge rotation system (entrance transport roller) 22 paper discharge rotation system (non-sort paper discharge roller) V ₁ process speed V ₂ paper discharge speed D _S distance Signal V _S Speed signal S ₁ Size signal P _S Position signal P Sheet material R ₂ Conveyance path F ₄ Position sensor T Escape timing

Claims (1)

[Claims] 1. A process rotation system for conveying and processing a sheet material at a predetermined process speed while restraining the sheet material, and a processed sheet material connected at a downstream side of the process rotation system at a specific sheet discharge speed. When the sheet material being conveyed belongs to both the process rotation system and the sheet discharge rotation system, the sheet conveyance speed for discharging is matched with the conveyance speed of the sheet discharge rotation system. In a discharge speed control method for an image forming apparatus or the like, the transfer speed of the discharge rotation system is changed to the specific discharge speed after the sheet material has released the constraint of the process rotation system. A position sensor for detecting the front end position of the sheet material is disposed in the middle of the conveyance path, and a position signal of the sheet material from the position sensor and a distance signal from the position sensor to the end position of the process rotation system, The process speed A speed signal and a size signal of the sheet material being conveyed are used to calculate the escape timing at which the sheet material releases the constraint of the process rotation system, and based on the calculation result, the sheet discharge rotation system is caused to perform the unique sheet discharge. A method for controlling the discharge speed of an image forming apparatus or the like, wherein the speed is changed to a speed.