JPH10148974A - Control method of both-side image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily take out a recording paper retained or remaining in a carrying path in an intermediate stacker part by moving a movable introducing unit from a introducing position corresponding to the size of the recording paper to a retreated position, when a failure in carrying the recording paper is detected. SOLUTION: The movable introducing unit 500 is movable to the introducing position corresponding to the size of the housed recording paper 14. When the failure in carrying the recording paper of an image forming device is detected, a control means executes control for moving the movable introducing unit 500 from the introducing position corresponding to the size of the recording paper to the retreated position HP. An actuator part 58B is integrally formed with a lower guiding member 58 under the unit 500. The actuator part 58B cuts off the optical path of a retreated position (home position) sensor PS5 installed in the fixed position of a stacker main body 61, to set the retreated position (home position) HP of the movable introducing unit 500.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for a double-sided image forming apparatus for conveying a sheet of recording paper and forming images on both sides of the recording paper.

[0002]

2. Description of the Related Art Conventionally, in a double-sided image forming apparatus of this type, a recording sheet fed from a recording sheet storage container such as a sheet cassette by a sheet feeding section is guided to an image forming section, and after a single-sided image is formed, The paper is fed to an ADU (automatic double-sided copy unit), and the recording paper with an image formed on one side is reversed by, for example, a switchback method. And the recording paper is sent out to the image forming unit by the re-feeding unit to form an image on both sides of the recording paper.

[0003]

The above two-sided image forming apparatus has the following problems.

In general, when recording paper conveyance failure (paper jam) occurs in each conveyance path of the image forming apparatus, driving of the entire image forming apparatus is stopped in order to prevent a subsequent trouble. In such a case, the driving of the entire image forming apparatus is stopped because the recording paper being transported also stops. In such a case, the recording paper that is being conveyed also stops, so that the recording paper stays in each part of the image forming apparatus, and it is necessary to remove all the recording paper. If recording paper conveyance failure occurs due to such circumstances, it is natural that the recording paper must be stopped and removed in the conveyance path for double-sided image formation, the recording paper introduction section, the conveyance path for recording paper introduction, and the like. is there. However, in an ADU having a configuration in which the recording paper introduction unit can be moved to an introduction position corresponding to the size of the recording paper to be stacked, the recording paper introduction unit is located above the intermediate stacker, and above the stacker unit, the recording paper introduction unit is moved forward. A paper feed unit is provided,
In addition, since there is a guide member for the recording paper introduction unit and the like behind, these members are in the way and the hand cannot be inserted,
Near the entrance of the recording paper introduction section, during transport in the intermediate stacker,
Alternatively, it becomes difficult to remove the recording paper stopped at the paper re-feeding unit or the like. In particular, when a small-size recording paper is used, the recording paper introduction unit stops in front of the intermediate stacker (refeeding unit side), and the upper part of the intermediate stacker is completely closed, and the recording paper is completely removed. Can not be done.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and (1) stagnates due to poor conveyance near the entrance of the intermediate stacker section or near the refeed section on the exit side. (2) To provide a double-sided image forming apparatus capable of easily and safely operating by removing the obstruction of a recording paper introduction unit when removing recording paper in an intermediate stacker unit. Aim.

According to a first aspect of the present invention, there is provided a control method for a double-sided image forming apparatus, comprising a recording paper introduction unit for introducing recording paper having both surfaces formed on one side into an intermediate stacker unit. In the control method of the double-sided image forming apparatus, the size of the recording paper to be stored is provided, which includes an introduction unit, an intermediate stacker unit that stores the recording paper, a re-feed unit that sends the recording paper to the image forming unit, and a control unit. The movable introduction unit is movable to an introduction position corresponding to the recording paper, and when detecting the conveyance failure of the recording paper of the image forming apparatus, the control unit moves the movable introduction unit from the introduction position corresponding to the recording paper size. It is characterized in that control for moving to the retreat position is performed.

According to a second aspect of the present invention, there is provided a method for controlling a double-sided image forming apparatus according to the first aspect of the present invention, wherein the transport failure is caused by the transport failure of the recording paper staying in an intermediate stacker. It is characterized by being.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a control method for a double-sided image forming apparatus according to the present invention will be described below. FIG. 1 is a schematic configuration diagram of a two-sided image forming apparatus, and FIG. 2 is a schematic diagram illustrating a sheet conveyance path and a sensor arrangement of the two-sided image forming apparatus.

In this embodiment, a copying apparatus is shown as a double-sided image forming apparatus. The copying apparatus includes an image forming unit 10, a paper feeding unit 20, a paper discharging unit 30, a reverse conveying unit 40,
A recording paper introduction unit 50, an intermediate stacker unit 60, and a paper re-feeding unit 70, a paper supply path A for conveying the recording paper P to a transfer unit of the image forming unit 10, and recording from the transfer unit. A conveyance path B for discharging or re-feeding the completed recording paper P, and a discharge path C for discharging the recording paper P on which the image has been formed to the outside of the apparatus.
And a reversing paper feed path D for reversing the recording paper P on which an image is formed by the image forming unit 10 and circulating the recording paper P again to the image forming unit 10.

An image carrier (photosensitive drum) 11 is disposed in the image forming section 10, and the image carrier 11 is uniformly charged by a charger 12 and image information is carried by an exposure unit 13. Irradiate the peripheral surface of the body 11 to form an electrostatic latent image. The electrostatic latent image is developed by the developing device 14 to form a toner image.

The paper supply section 20 is provided with at least one paper supply unit. In the paper supply unit, a paper supply tray 21 for storing a large number of recording papers P is arranged so as to be able to be pulled out. Reference numeral 22 denotes a movable bottom plate that presses the recording paper P against the paper feed roller 23. By driving and rotating the paper feed roller 23, the uppermost recording paper P on the movable bottom plate 22 is intermittently taken out. A double feed prevention roller pair 24, 25 is disposed downstream of the paper feed roller 23 in the paper feed direction.
Are fed one by one to the next step, and are fed to a second sheet feeding roller (registration roller) 28 via intermediate sheet feeding rollers 26 and 27 arranged in the sheet feeding path A, respectively.

The second paper feed roller 28 is driven in synchronization with the rotation of the image carrier 11, and the recording paper P is sent to the transfer unit 15 to transfer the toner image. After that, the recording paper P is separated from the image carrier 11 by the separator 16, and is conveyed to the fixing device 18 by the conveyance belt 17. Further, around the image carrier 11,
A cleaning device 19 is provided, and the image carrier 1 after transfer is provided.
1 to remove residual toner on the surface. Further, for the next image formation, the charger 12 charges again.

The toner image on the recording paper P is heated and pressed by a fixing device 18 to be fixed. The fixed recording paper P is sent to the paper discharge unit 30. That is, the recording paper P passes through the nip position of the paper discharge guide roller 31 disposed on the downstream side of the conveyance of the fixing device 18, and is further conveyed by the paper discharge switching member (switching gate) 32 on the downstream side of the conveyance. Is switched between the discharge side and the reversing and re-feeding side. The recording sheet P switched to the discharge side passes through a path above the switching gate 32 and is placed on a discharge tray 34 by a discharge roller 33.

A reversing transport unit 40 is provided on the reversing and re-feeding side of the recording paper.
, A recording paper introduction unit 50, an intermediate stacker unit 60, and a paper re-feeding unit 70. The recording paper introduction section 50, the intermediate stacker section 60, and the re-feed section 70 form an ADU (automatic double-sided copy unit), and can be pulled out from the image forming apparatus main body by a slide rail.

When the switching gate 32 is switched to the reverse re-feeding side, the recording paper P passing through the path a below the switching gate 32 is transported downward via the transport roller 41 of the reverse transport section 40, and branched. The member 42 is conveyed by passing through a left passage b on the left side of the member 42 and further passing through a vertical passage c on the downstream side of the conveyance by being sandwiched by conveyance rollers 43 that can be rotated forward and backward. It is bent and enters a horizontal passage e provided in a space formed between the upper surface of the bottom plate 100 of the image forming apparatus main body and the bottom surface of the paper feed tray 21 and temporarily stops at a predetermined position. The leading edge of the paper at this stop is
Although different depending on the size of the paper, the rear end position of the recording paper P of each size is an intermediate position between the nip position of the branch member 42 and the transport roller 43. Reference numeral 44 denotes a guide member that guides the leading end of the large-size sheet by lightly pressing the sheet.

The trailing end of the temporarily stopped recording paper P is
The sheet is nipped by the conveying roller 43 switched to the reverse rotation drive, rises in the vertical path c, passes through the path f in the branching member 42, and is sent to the intermediate stacker section 60 by the recording paper introducing section 50 (discharge). Passage g).

In FIG. 2, PS1 is a paper feed sensor for detecting a feeding failure in the paper feed unit 20, and PS2 is a paper discharge unit 30.
, PS3 is a reversing sensor for detecting reversal conveyance failure in the reversal conveyance section 40, PS4 is a stacker entrance sensor for detecting recording paper introduction in the recording paper introduction section 50, and PS5 is recording paper introduction. Part 50
Is a retreat position (home position) sensor for detecting the retreat position or the home position of the movable introduction unit 500 of FIG.

FIG. 3 is a cross-sectional view of the recording paper introduction unit 50, and FIG. 4 is a cross-sectional view taken along the line AA in FIG.

A transport belt 52 wound between a driving roller 51A and a driven roller 51B and a backup plate 53 are provided at a fixed position on the upper portion of the upstream side of the intermediate stacker section 60. The driving roller 51A is provided with a motor M1.
To rotate the transport belt 52.

A wire winding drum 54A is installed at a fixed position on the bottom of the stacker main body 61, and is driven and rotated by a motor M2. A plurality of movable wires 55 are wound around the drum surface of the wire winding drum 54A, and one end is locked. The other end of the movable wire 55 is stretchably stretched between the intermediate roller 54B and the locking member 54C.

A driven roller 56 A rotatable at a fixed position and a movable wire 5
5 and a rotatable moving roller 56B. The driven rollers 56A and 56B are
And is driven to rotate.

The locking member 54C and the driven roller 5
6B and a spring means for urging the driven roller 56B toward the conveyor belt are held by the movable introduction unit 500. The movable introduction unit 500 can linearly move by sliding in a long hole 610 formed in a side wall of the stacker main body 61 in a direction parallel to the recording paper conveyance direction. The movement of the movable introduction unit 500 is driven by the motor M2 via drive transmission means.

The recording paper P discharged into the stacker main body 61 from the pressure contact position between the transport belt 52 and the driven roller 56B
After passing through the space of the discharge passage g and abutting on the bottom surface in the stacker main body 61 or the upper surface of the preceding recording paper P stacked in the stacker main body 61, slides and abuts. Transferred to the surface.

The leading end of the recording paper P is connected to the optical path 803 of the stacker entrance sensor PS4 (light emitting unit 801 and light receiving unit 802).
, The detection signal is input to the control means 80.

The passage g of the movable introduction unit 500
Space of the upper inclined guide surface 57A of the upper upper guide member 57
And a lower inclined surface 58 </ b> A of the lower guide member 58. The lower inclined guide surface 58A is configured such that the leading end of the recording paper P discharged from the position where the transport belt 52 and the driven roller 56B are pressed against each other advances obliquely downward, and the recording paper mounting surface of the stacker main body 61. It is formed on an inclined surface having an inclination angle θ such that the angle of contact with 61B is reduced.

That is, the leading end of the recording paper P discharged from the position where the transport belt 52 and the driven roller 56B are pressed against each other, advances obliquely downward and hits the lower inclined guide surface 58A of the lower guide member 58. , And slides along the lower inclined guide surface 58A, and the gentle inclination angle θ of the lower inclined guide surface 58A.
Then, the sheet enters the recording paper mounting surface 61B of the stacker main body 61, slides on the recording paper mounting surface 61B, abuts against the abutting surface 61A, and stops.

In the movable introduction unit 500, a recording paper rear end regulating member (rear end stopper) 59 and a recording paper introduction guide plate 59A are fixed between the plurality of locking members 54C. Further, an actuator portion 58B is integrally formed with the lower guide member 58 below the movable introduction unit 500. The actuator section 58B interrupts the optical path of the retreat position (home position) sensor PS5 installed at a predetermined position of the stacker main body 61, and the retreat position (home position) H of the movable introduction unit 500.
Set P.

The retracted position and the home position HP may be different positions, but are preferably the same position. By setting them at the same position, the time required to return to the home position and move to the introduction position after removing the recording paper at the time of paper jam is shortened.

FIG. 5A is a front view showing a drive system of the transport belt 52.

By the rotation of the drive shaft of the motor M1, the drive roller 51A is rotated via the belts 501 and 502, and the transport belt 52 is rotated counterclockwise in the drawing.

FIG. 5B shows the movable introduction unit 50.
It is a front view which shows the drive system of No. 0.

The pulley 504 is rotated via the belt 503 by the rotation of the drive shaft of the motor M2 which can rotate forward and reverse. The gear G1 coaxial with the pulley 504 meshes with the gear G2 to rotate the rotating shaft 505. A pulley 506 fixed to the rotation shaft 505 rotates the belt 507. The belt 507 includes a pulley 506 and driven rollers 508A,
8B and 508C.

The movable introduction unit 500 is fixed to a part of the belt 507. Both ends of the movable introduction unit 500 can slide linearly by sliding into long holes 610 formed on both side walls of the stacker main body 61 in a direction parallel to the recording paper conveyance direction. By the forward / reverse rotation of the belt 507, the movable introduction unit 500 slides in the elongated hole 610 and moves linearly in the horizontal direction in the figure.

The wire winding drum 54A (see FIG. 4) is integrated with the rotating shaft 505. The movable wire 55 wound around the outer peripheral surface of the wire winding drum 54A and one end of which is locked is changed in tension direction by an intermediate roller 54B, and is parallel to the transport belt 52 between the movable wire 55 and the locking member 54C. The end of the movable wire 55 is locked by a locking member 54C.

In FIG. 5B, the movable introduction unit 500 indicated by the solid line on the right in the figure shows the introduction stop position when the recording paper P2 of the minimum size (B5) is introduced, and is indicated by the broken line on the left in the figure. The illustrated movable introduction unit 500 indicates a retreat position or a stop position at the home position HP. The retreat position or home position HP is the maximum size (A3)
Is located further to the left of the drawing than the recording paper introduction position.

FIG. 6 is a block diagram showing control of double-sided image formation according to the present invention.

FIG. 7 is a flowchart showing the control of the first double-sided image formation according to the present invention.

FIG. 8 is a flowchart showing control of the second double-sided image formation according to the present invention.

(1) When the ADU mode is set on the image forming apparatus main body side and a recording paper size signal is input to the control means 80, the motor (pulse motor) M2 is driven to rotate the belt 507, The movable introduction unit 500 of the recording paper introduction unit 50 is moved by a predetermined number of count pulses from the home position HP by the pulse motor M2, and stops at the introduction position corresponding to the recording paper size. At the same time, the wire winding drum 54A is also rotated, and the end of the rotating wire 55 is pulled by the movable movable introduction unit 500, so that the movable wire 55 is stretched in parallel with the transport belt.

(2) If the ADU mode is selected and the image forming apparatus detects a conveyance failure of the recording paper, the first
In the control (FIG. 7), the movable unit 500 is retracted to the retracted position. Prior to this, the driving of the apparatus is stopped.

(3) In the preferred second control (FIG. 8),
When the recording paper P having an image formed on one side is fed from the recording paper introduction unit 50 into the intermediate stacker unit 60,
If a conveyance failure occurs after detecting that the leading end of the recording paper P has blocked the optical path 803 of the stacker entrance sensor PS4, it is a detection of a conveyance failure in which the recording paper stays in the intermediate stacker. Therefore, the control unit 80 determines that the recording sheet is not properly transported in the intermediate stacker unit, drives the motor M2 in the reverse direction, and retreats the movable introduction unit 500 to the retreat position HP.

(4) After the movable introduction unit 500 has retreated to the retreat position HP, the occurrence of recording paper jam is displayed on the operation panel of the image forming apparatus main body.

(5) When the operator pulls out the ADU from the image forming apparatus main body and moves the transport unit including the transport belt 52 upward, the intermediate stacker unit 6
The upper part of the stacker main body 61 of 0 has no obstruction to the space and is open. In this open state, the recording paper P staying in the stacker main body 61 can be easily taken out.

(6) It is also determined that the leading end of the single-sided recording sheet P re-fed from the intermediate stacker section 60 by the re-feed section 70 does not reach the second feed roller 28. When the paper sensor PS1 detects, at this time, since the rear end of the recording paper P stays in the stacker main body 61 of the intermediate stacker section 60, it is determined that the conveyance of the intermediate stacker section is defective. The 80 retracts the movable introduction unit 500 to the retracted position HP and displays the recording paper jam, so that the recording paper P staying in the stacker main body 61 can be easily taken out.

(7) Further, during the double-sided image forming operation by the ADU, if it is desired to stop the operation for some reason and take out the recording paper from the intermediate stacker, the control means 80 causes the movable introduction unit 500 to operate. By returning to the home position HP, the recording paper P remaining in the stacker main body 61 can be easily taken out.

When the ADU mode is released, the movable introduction unit 500 is returned to the home position HP.

As described above, the recording paper conveyance failure in which the recording paper stays in the intermediate stacker is detected by the stacker entrance sensor and the paper feed sensor. It is preferable to perform control to retreat the movable introduction unit 500 only in the case of a conveyance failure in the intermediate stacker unit 60. In the case of a paper jam in other parts, there is no more than necessary evacuation operation. Can be processed.

[0048]

As described above, the control method of the double-sided image forming apparatus according to the first aspect of the present invention is a movable method including a recording paper introduction unit for introducing a recording paper on which an image is formed on one side into an intermediate stacker unit. In the control method of the double-sided image forming apparatus, the size of the recording paper to be stored is provided, which includes an introduction unit, an intermediate stacker unit that stores the recording paper, a re-feed unit that sends the recording paper to the image forming unit, and a control unit. The movable introduction unit is movable to an introduction position corresponding to the recording paper, and when detecting the conveyance failure of the recording paper of the image forming apparatus, the control unit moves the movable introduction unit from the introduction position corresponding to the recording paper size. Since the control to move to the retreat position is performed, when removing the recording paper, the space above the stacker main body of the intermediate stacker is open and To become. In this open state,
The recording paper staying in the stacker main body can be easily taken out. Also, when the ADU mode operation is stopped for some reason and it is desired to take out the recording paper from the intermediate stacker unit, the control means 80 retreats the movable introduction unit 500 to the retreat position HP, so that the stacker body 6
The recording paper P remaining in 1 can be easily taken out.

According to a second aspect of the present invention, there is provided a method for controlling a double-sided image forming apparatus, wherein the transport failure in the first aspect is a transport failure of the recording paper staying in the intermediate stacker. Therefore, furthermore, only when the recording paper has a retreat conveyance failure in the intermediate stacker unit, the movement control is performed so as to retreat the movable introduction unit to the retreat position, so that the conveyance failure occurs in another conveyance path. When there is no recording paper to be removed in the intermediate stacker, the movement control is not performed, so that unnecessary operations are not performed, machine durability is increased, and unnecessary movement control time before starting the conveyance failure processing is eliminated.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a double-sided image forming apparatus.

FIG. 2 is a schematic diagram illustrating a sheet conveyance path and a sensor arrangement of the duplex image forming apparatus.

FIG. 3 is a cross-sectional view of a recording paper introduction unit.

FIG. 4 is a sectional view of the recording paper introduction section taken along line AA.

FIG. 5 is a front view showing a drive system of a transport belt and a front view showing a drive system of a movable introduction unit.

FIG. 6 is a block diagram illustrating control of double-sided image formation according to the present invention.

FIG. 7 is a flowchart showing control of first double-sided image formation according to the present invention.

FIG. 8 is a flowchart illustrating control of a second double-sided image formation according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 image forming section 20 paper feed section 30 paper discharge section 40 reverse transport section 50 recording paper introduction section 52 transport belt 54A wire winding drum 55 movable wire 57 upper guide member 58 lower guide member 59 recording paper rear end regulating member (rear End stopper) 60 Intermediate stacker unit 61 Stacker main body (container main body, storage container) 70 Refeed unit 80 Control means 500 Movable introduction unit 610 Elongated hole 803 Optical path HP Evacuation position (home position) P Recording paper (paper) PS4 Stacker entrance Sensor (detection means) PS5 Evacuation position sensor (home position sensor)

Claims (2)

[Claims] 1. A movable introduction unit having a recording paper introduction unit for introducing recording paper on which an image has been formed on one side into an intermediate stacker unit, an intermediate stacker unit for storing the recording paper, and forming an image on the recording paper. A refeeding unit that feeds the recording sheet into the sheet feeding unit, and a control method of the double-sided image forming apparatus, wherein the movable introduction unit is movable to an introduction position corresponding to a size of the recording paper to be stored. Wherein the control means performs control to move the movable introduction unit from the introduction position corresponding to the recording paper size to the retracted position when detecting the conveyance failure of the recording paper. . 2. A control method for a double-sided image forming apparatus, wherein the conveyance failure is a conveyance failure of the recording paper staying in an intermediate stacker section.