JP3367014B2 - Image forming device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, a copying machine,
The present invention relates to an image forming apparatus such as a facsimile, and more particularly, to an image forming apparatus in which each mechanical portion is unitized and the mechanical portion is replaceable.

[0002]

2. Description of the Related Art Conventionally, it is already known that each mechanism portion is unitized and the mechanism portion can be replaced. The advantage of unitizing each mechanism part is that the unitized part is assembled in advance, and the yield is improved by simplifying the assembly work by incorporating a plurality of unitized members. Storage management work is simplified because storage management is sufficient.

Also, in maintenance and repair, the work is simple because the unit members need only be replaced. Also,
Even in the work of removing the jammed recording medium, the work of removing the unit unit is easily performed as necessary, which is advantageous.

With the intention of such workability, the upper and lower parts of the conveying path of the recording medium may be divided into units to form a unit, or
It is preferable to unitize members having the same durability into a unit.

[0005]

However, the photoconductor drum and the photoconductor drum are arranged facing each other with a pressing force applied thereto.
Looking at the relationship with the transfer roller that transfers to the recording medium, when the transfer roller is pressed toward the photosensitive drum side and the recording medium does not exist, the outer periphery of the transfer roller and the outer periphery of the photosensitive drum contact each other. Therefore, in the case where both are integrated into a unit, in order to replace the photosensitive drum, it is necessary to release the pressing force of the transfer roller to perform the work, which is inferior in workability.

Therefore, it is desirable to unitize the photosensitive drum and the transfer roller as separate members. However, since the photoconductor drum forms an image using toner and transfers the image to the recording medium by the transfer roller, it is desirable to clean the photoconductor drum as necessary after the transfer of a predetermined number of sheets. , It is necessary to remove the photoconductor drum side unit.

At this time, if the photoconductor drum side unit is removed while the photoconductor drum side unit is being pressed against each other, the photoconductor drum is rubbed by the outer circumference of the transfer roller, and the photoconductor drum side unit is rubbed. This results in scratching the surface. In order to avoid this, it is known as one means that both are normally separated from each other and the transfer roller is pressed on the photosensitive drum side in synchronization with the transfer operation, but the structure is complicated. become.

In addition, when the user places and uses the image forming apparatus in a room, the user is positioned and operated on the front side where the operation panel is arranged, so that the image forming apparatus is operated in comparison with both side surfaces. The front side is usually spacious. Therefore, it is desired that the drawing operation from the front side of the image forming apparatus is performed.

In view of the above situation, it is an object of the present invention to provide an image forming apparatus in which each mechanical portion is unitized and the transfer roller is separated from the photosensitive drum in association with the operation of pulling out the unit member. Another object of the present invention is to provide an image forming apparatus in which maintenance work is performed from the front side of the image forming apparatus.

[0010]

According to the first aspect of the present invention, in an image forming apparatus in which each mechanical portion is unitized and the mechanical portion is replaceable, a drum unit in which a photoconductor is arranged and a photoconductor side are provided. Conveyance path units in which transfer rollers that are pressed through the recording medium are arranged are formed separately from each other , and
It is rotatably arranged in the pull-out direction of the transport path unit,
Pressing and releasing the transfer roller from the photoconductor side
The conveyance path unit , which includes an operation member for controlling the inter-motion operation
The operation member from a state of standing upright with respect to the pull-out direction of
When rotating the conveyor path unit in the pull-out direction
The transfer roller is separated from the photoconductor .

Here, the operating member includes, for example, a member having a shape such as a handle of a trunk as shown in FIG. 1, a member having a lever shape, a circular member, etc. Regardless of the above, the phrase “the transfer roller is separated from the photoconductor by the operation of the operation member” includes all modes in which the transfer roller can be separated from the photoconductor within or after the operation area of the operation member.

In the first aspect of the present invention, since the transfer roller is separated from the photoconductor by operating the operation member, the drum unit in which the photoconductor is arranged can be replaced without damaging the surface of the photoconductor by the transfer roller. You can

According to a second aspect of the present invention, in an image forming apparatus in which each mechanical portion is unitized and the mechanical portion is replaceable, a drum unit in which a photoconductor is arranged and a photoconductor side is pressed via a recording medium. the conveying route unit to the transfer roller to be are arranged, respectively separately formed, the control member for controlling the pressing operation and separation operation of the photoconductor side by the transfer roller slidably on the conveying route unit Is installed, and the operation of pulling out the transport path unit is opened.
When started, the transfer roller and the drum unit are separated.
The state where the transfer roller is kept at the initial position until
However, at the end of the return operation of the transport path unit,
The control member and the transport path unit so that
Is being contacted .

By the way, pulling out the transport path unit
When the operation is started, the transfer roller and the drum unit are
The transfer roller was kept at the initial position until the
State at the end of the return operation of the transport path unit
In order to perform the pressing operation, the control member and the transport path unit are
To contact the movement of the transport path unit
It is desirable that the movement of the control member is a one-to-one movement.
However, if the control member and the transport path unit are
The separating operation is performed at the initial stage of the drawing operation of the feeding unit.
At the end of the return operation of the transport path unit
You may contact us to perform the pressing operation, for example,
The movement of the control member may be an amplification proportional movement.
As described above, the transport path unit and the control member are communicated with each other.

For example, as shown in FIG. 5, the transfer roller 1
The transfer roller 19 is a spring 9 until the supporting portion 4e that supports the shaft 15 moves leftward together with the transfer path unit 4 and contacts the end surface 16g of the roller support 16 that holds the transfer roller 19 even when the transfer path unit 4 is pulled out. Since the transfer roller 19 is biased in the right direction by 37, the transfer roller 19 maintains the initial position in a state of pressing contact with the photoconductor, and the photoconductor and the transfer roller 19 do not rub against each other due to the leftward movement of the transport path unit 4. . Therefore, even if the control member (release plate) 6 moves at the same speed as the movement of the transport path unit 4, the transfer roller 19 does not move, so that the photoconductor is not scratched.

Further, for example, as shown in FIG. 4, the speed of the control member 6 can be increased by amplifying the movement of the transport path unit 4 with a seesaw-shaped lever 39.
In this case, even if the transfer roller 19 is not held at the initial position in the initial movement area of the transport path unit 4 as described above, the time when the transfer roller 19 rubs against the photoconductor is reduced, so that the transfer roller 19 rubs. It is possible to suppress the scratches on the surface of the photoconductor to a negligible distance because the distance is small.

According to a third aspect of the present invention, in an image forming apparatus in which each mechanical portion is unitized and the mechanical portion is replaceable, a drum unit in which a photosensitive member is disposed and a photosensitive member side is pressed via a recording medium. the conveying route unit to the transfer roller being is located, as well as separately formed respectively, of the conveying route unit with respect to the conveying route unit
It is arranged to be rotatable in the pull-out direction and
From the state of standing upright with respect to the pull-out direction
When the unit is rotated in the pull-out direction of the unit, the transfer roll
Is separated from the photoconductor and the transfer roller
Control the pressing operation and separation operation with the photoconductor side
Operating member and the carrying member provided in the carrying path unit.
At the initial stage when the feeding unit was pulled out
When the separating operation between the transfer roller and the photoconductor is performed,
The transfer is performed at the final stage of the return operation of the transport path unit.
The transfer roller is pressed by pressing the photoconductor with the roller.
Of the pressing and separating operations of the roller with the photoconductor
A control member for controlling the operation member, and enabling the pressing / separating operation between the transfer roller and the photoconductor in accordance with an operation of the operation member or an operation of pulling out the transport path unit.

A third aspect of the present invention is a combination of the first aspect and the second aspect, and has the features of the first aspect and the second aspect of the present invention. The operation of the operation member or the conveyance path is performed. The operation of the unit enables the pressing / separating operation between the transfer roller and the photoconductor.

Further, as described in claim 4, the control member having an urging force in a direction of pressing the transfer roller toward the photoconductor is engaged with the control member when operating in the forward direction. And the operation member that moves against the biasing force, and in synchronization with the operation of the operation member in the forward movement direction, while locking and holding the control member in a separated state of the transfer roller from the photoconductor side, It is also an effective means of the present invention to have a holding means for releasing the locked state by operating the operation member in the backward direction.

For example, as shown in FIG. 4, when the operating member (handle) 3 is rotated in the direction of arrow 41, the release plate 6 is released.
Moves in the direction of the arrow 42, and the claw plate 11 is locked by the locking portion 4c. Therefore, the holding means means the locking portion 4c, but it is not limited to this, and the holding means using a magnetic force of a permanent magnet, an electromagnet, or a combination thereof, and further electrically or fluidly driven. The holding means may use a plunger or the like alone or together with another mechanical locking member.

According to the fourth aspect of the present invention, when the operation member is operated in the forward movement direction, the operation member is engaged with the control member and moves against the biasing force of the control member in synchronization with the forward movement operation. ,
The control is performed when the transfer roller is separated from the photoconductor side.
Since the holding member holds and holds the member, and the holding state is released by the backward movement operation of the operation member, the operation is performed after the control member is held by the holding unit. Even if the hand is removed from the member, the operation member automatically returns, so that there is no hindrance to attachment and detachment of the drum unit.

Further, it is also an effective means of the present invention to unitize each mechanism portion so that the mechanism portion can be exchanged from the operation surface side of the apparatus main body. By making each mechanism part replaceable from the operation surface side of the device body in this way, it is not necessary to pull out the device body to a large place for maintenance, inspection and repair work, and The work can be easily performed.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be exemplarily described in detail below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. Nothing more than.

FIG. 1 shows an embodiment of an image forming apparatus to which the present invention is applied. The image forming apparatus 1 includes a front door 1
3 is arranged so as to be openable and closable, an operation surface 53 is provided on the upper front side, and the operation surface 53 is provided with a display section 51 and an operation section 52 on which a plurality of buttons and the like are arranged.

When the front door 13 is opened, the drum unit 8, the developing device 10, the fixing device 5 and the handle 3 are separated by block.
Conveying path unit 4 and multiple transfer unit 2
However, they are arranged so that they can be individually taken out.

The drum unit 8 is, as shown in FIG.
A concave surface 8a is provided below the front surface 8c, and a portion 3 shown by hatching on a surface extending downward from the rear side edge 3d of the upper surface 3e of the handle 3 rotatably arranged on the transport path unit 8 is shown.
When a is in contact with the recessed surface 8a, the handle portion 8b further recessed above the recessed surface 8a is hidden.
Therefore, in order to take out the drum unit 8, the handle rotatably arranged on the transport path unit 4 is moved toward
It is carried out by rotating it by 0 ° and pulling the handle portion 8b toward you.

The multi-transfer unit 2 can be taken out by pulling a handle portion (not shown) toward the front. However, since the rear end of the multi-transfer unit 2 is in contact with a part of the conveying path unit 4, the handle is used. When the handle 3 is pulled in a state of being rotated 90 ° toward the front, the transport path unit 4 can be pulled out together with the multiple transfer unit 2 as shown in FIG.

In FIG. 2, the fixing device 5 is held by four locking arms 14 which are rotatable in the direction of arrow 43, so that the locking arms 14 are rotated to lock the fixing device 5. Since the fixing device 5 is released, the fixing device 5 is configured to be detachable from the transport path unit 4.

Next, the structure and operation of the respective mechanical parts mounted on the apparatus body will be described with reference to FIG. In FIG. 6, a drum unit 8 having an a-Si photosensitive drum 9 that rotates clockwise in the drawing, a developing unit 10, a passage 34, and
36, a conveyance path unit 4 having a fixing device 5, a transfer roller 19 and the like, and a multiple transfer unit 2 are provided.

The developing device 10 is provided with a developing roller 10a, and the surface of the developing roller 10a is the photosensitive drum 9 described above.
Is separated from the surface by a predetermined distance. The developing device 10 is configured to be able to supply a predetermined amount of toner from a toner container (not shown).

An optical unit (not shown) for forming image dots on the surface of the photosensitive drum 9 is provided above the drum unit 8. The optical unit reflects a laser beam from a laser light source (not shown). The optical system is configured to form an image dot on the surface of the photosensitive drum as an optical path 49 through a reflection mirror.

Although not shown, a control circuit for controlling the image forming apparatus 1 which will be described later is provided on the lower portion 61 of the image forming apparatus 1, and a recording paper container is arranged so as to be detachable from the outside, and the recording paper container is transferred to the recording paper container. A front recording paper storage is provided, and the recording paper is conveyed by a conveyance roller (not shown) to the conveyance path 3
It is configured so that it can be conveyed to the registration rollers 18 and 30 through the passage 34 by the conveying rollers 32 and 33.

On the left side of the drum unit 8, a fixing device 5 is constituted by the fixing rollers 23 and 24 and is detachably held on the conveying path unit 4. The recording paper passing between the photoconductor drum 9 and the transfer roller 19 is fixed by the fixing roller 23,
The recording paper after being fixed by 24 is fixed to the conveyance roller 2
1 and 22, the guide changer 12 changes the path to the tray side (not shown) or the multiple transfer unit 2 side to convey the recording paper.

The image recording apparatus 1 thus constructed is
When a power switch (not shown) is closed, a main motor (not shown) starts driving, the photosensitive drum 9 is rotated clockwise by a start switch (not shown), and an optical unit (not shown) forms an image on the surface of the photosensitive drum 9. Then
The image is developed by the developing roller 10a of the developing device 10, the developed image is transferred to the recording paper by the transfer roller 19, is fixed by the fixing rollers 23 and 24, and the guide changer 12 is at the position shown by the solid line in FIG. If there is,
The rollers 21 and 22 convey the sheet to the tray side (not shown).

When the guide changer 12 is switched to the position of the imaginary line, the recording paper is conveyed to the multiple transfer unit 2 side using the cam surface 12a as a guide. Next, the multiple transfer unit 2 will be described. In FIG. 6, the multi-transfer unit 2 is formed in a substantially bed shape in which a head portion having a cupboard for accommodating small articles is arranged in the width direction on the short side of the rectangular shape.

The upper surface of the head is recessed with the wall surfaces of the heads at both ends in the width direction left, and the recessed portion 38d is provided with rotatable guide rollers 45 and 6 between the head walls. The wall surface 38c of the frame body 38, which serves as a guide for the recording medium to be carried in, is extended along the outer circumferences of the both transport rollers in a curved shape.

A plurality of openings 38b are formed on the upper surface of the head. Further, the opening 38b is provided by a fan (not shown) arranged in the device body above the opening.
It is formed so that the air can be forced out through it.

Drive rollers 47, 48, and 49 which are rotatable in connection with a drive source (not shown) are arranged in the frame 38 so as to be inclined and raised along the recording medium conveyance direction. . A driven roller is arranged so that each of these driving rollers comes into one-to-one contact with each other.
To the driving roller 49, a first reversing passage 72 is formed.

Further, on the right side of the drive roller 49, a guide roller 50 having an outer diameter along the curved shape of the large-diameter guide surface 56d is rotatably arranged, so that the reversal direction of the traveling direction of the recording medium can be easily changed. I have to.

A sensor 67 is arranged between the drive rollers 48 and 49 of the first reversing passage 72 so that the presence or absence of the recording medium in the first reversing passage 72 can be detected.

A curved surface 38a of the frame body 38 is disposed so as to face the outer periphery of the guide roller 50, and a drive roller 51 which can rotate in the forward and reverse directions is disposed in the vicinity thereof, and the roller 51 is also provided.
A drive roller 53 that can rotate in the forward and reverse directions is disposed on the slightly left side, and the drive roller 53 can be separated upward during a recording medium alignment operation described later.

A guide surface is extended leftward from the drive roller 53 to form a second reversing passage 73, and a sensor 68 is arranged in the second reversing passage 73, and the second reversing passage 73 is provided.
The presence or absence of a recording medium is configured to be detectable above.

Next, the operation of the multiple transfer unit 2 thus constructed will be described. The electrical change causes the guide changer 12 to rotate in the counterclockwise direction, causing the transport rollers 21 and 2 to rotate.
When the guide surface 12 a is switched over the discharge path of the recording medium 2, the recording medium is carried into the multiple transfer unit 2.

The leading end of the recording medium carried into the multiple transfer unit 2 is gently curved by the guide surface 38c of the frame 38, and is inverted by the guide roller 46 and the drive roller 47 with the recording surface as the lower surface. 1 inversion passage 7
The sensor 67 detects the recording medium, and the detection signal is sent to an electric circuit (not shown).

When the sensor 68 does not detect the presence of the recording medium in the second reversing passage 73, the recording medium is turned by the guide roller 50 and the guide surface 56d and the guide surface 38a, and the recording surface is turned upside down. Then, the recording medium is carried into the second reversing passage 73 by the drive rollers 51 and 53.

When the recording medium is carried into the second reversing passage 73, the recording medium comes into contact with the sensor 68 and sends out a signal. After receiving this signal and sending out a predetermined amount of the recording medium, the electric circuit stops the rotation of the driving roller 51 at the position where the rear end of the recording medium has passed the driving roller 51.

At the stop position, the driving roller 53 is raised by a mechanism (not shown) to release the pressing force on the recording paper, and then the lateral width is aligned by a lateral alignment mechanism (not shown), and the driving roller 53 descends. Drive roller 53 comes into pressure contact with the recording medium, and then drive rollers 51 and 53
Is reversed, and the recording medium is conveyed from the discharge opening 38l to the passage 34 shown in FIG.

Next, the image is transferred to the back surface of the recording medium, the guide changer 12 returns to the position indicated by the solid line, and the recording paper is discharged to a tray (not shown). In the image forming apparatus that operates in this manner, the drum unit 8 needs to be attached and detached in order to clean and replace the photoconductor that handles toner. Further, the conveyance path unit 4 and the multiple transfer unit 2 need to be attached and detached in order to replace the jam of the recording medium and other mechanical parts.

In order to eliminate the jammed recording medium, when a jam of the recording medium occurs in the multiple transfer unit 2, the handle (not shown) is pulled to the front to take out the multiple transfer unit 2 and jam the recording medium. Eliminate.

In the case of a jam of the recording medium in the transport path unit 4 or between the transport path unit 4 and the multiple transfer unit 2, the transfer roller 19 is pulled out with the transport path unit 4 pulled out as shown in FIG. And near the passage 36,
Further, the jammed recording medium on the guide 4f or the like can be easily eliminated.

In this way, the photoconductor can be cleaned and replaced, and the jammed recording medium can be removed. However, the photoconductor drum 9 arranged in the drum unit 8 and the transfer roller 19 arranged in the conveying path unit 4 are Since the outer peripheries are in pressure contact with each other, when one of the drum unit 8 and the transport path unit 4 is pulled out, the outer perimeter of the transfer roller 19 causes the outer perimeter of the photoconductor drum 9 to rub against the surface of the photoconductor drum 9. May be scratched.

Therefore, in the present embodiment, FIG.
As disclosed in FIG. 5, when the drum unit 8 or the transfer path unit 4 relatively moves the photosensitive drum 9 and the transfer roller 19, the outer circumferences of the photosensitive drum 9 and the transfer roller 19 are separated from each other. I am configuring.

In FIG. 4, the rear end of the transport path unit 4 is in contact with the frame 27 in the main body of the apparatus. On the other hand, an operation plate 29 is disposed in the transport path unit 4 so as to be slidable in the directions of arrows 44 and 45 along a guide (not shown), and is operated by a coil spring 28 whose tip is fixed to a portion 4a provided in the unit 4. The right end of the plate 29 is in contact with the frame 27.

The lever 39 having an opening 39c in which the pin 29b of the actuating plate 29 is loosely fitted is opened at one end and the pin 39b is planted at the other end. The lever 39 rotates about the shaft 4b planted in the unit 4. It is movably arranged. Incidentally, the opening hole 39
c is formed in a long hole shape in the direction of the axis 4b. In addition, the unit 4 is provided with a release plate 6 slidable in the directions of arrows 42 and 46 by a guide (not shown).

The release plate 6 is provided with pedestals 6a and 6b on which a transfer roller unit 20 to be described later is placed, and a head 7 is fixedly provided on the head side. Further, a claw plate 11 having a locking claw 11a near the head portion 7 is arranged so as to have a turning tendency in the counterclockwise direction, and is planted from the unit 4 by the left row of the release plate 6. Locking claw 1 on the locking portion 4c
1a is configured to be lockable. Also, the release plate 6
Is provided with a pin 6c, and the pin 6c and the operating plate 39 are
A spring 40 is stretched between the pins 39b.

The head portion 7 is connected to a cam surface 7a that is inclined obliquely from the front, an R-shaped cam surface 7b that extends to the right and extends in contact with the cam surface 7a at the bottom, and an upper portion of the cam surface 7b. A cam hole portion 53 formed with the groove 7c is formed.

A handle 3 arranged in the transport path unit 4
The pin 3b of the handle 3 is located in the upper front portion inside the cam hole portion 53 as shown in the drawing when is upright. When the handle 3 is rotated in the direction of the arrow 41 from this state, the pin 3b pushes the cam surface 7a and the head 7 is pushed forward, so that the release plate 6 moves in the direction of the arrow 42 and the claw portion of the claw plate 11 moves. 11a is locked by the locking portion 4c. In this state, the handle 3 remains locked and the release plate 6 does not return.

When the handle 3 is rotated 90 °, the pin 3b
Reaches the bottom of the cam hole 53, and when the handle 3 is pulled to the front in this state, the transport path unit 4 is pulled out to the front via the rotation pin 3c of the handle 3, and the coil spring 28 embedded in the unit 4 is pulled out. The portion 4a that holds one end of the lever 39, the shaft 4b of the lever 39, and the locking portion 4c move to the left, so that the release plate 6 has the claw portion 11a of the claw plate 11 engaged with the locking portion 4c. Withdrawn with 4.

It is also possible to directly pull out the transport path unit 4 without using the handle 3. At that time, the transport path unit 4 moves leftward from the state shown in FIG. The coil spring 28 is loosened because the locking portion 4a moves to the left, but the right end of the operating plate 29 is attached to the frame 27 by the urging force of the coil spring 28. Then, since the shaft 4b moves to the left, the lever 39 rotates clockwise, and the turning power is generated from the pin 39b via the spring 40 to the release plate 6 via the pin 6c.
The release plate 6 moves to the left, the claw portion 11a is locked by the locking portion 4c, and the transport path unit 4 is pulled out in this state.

Next, the structure in which the transfer roller 19 is separated from the photosensitive drum 9 will be described with reference to FIG. FIG. 5 shows a state in which the transport path unit 4 is mounted inside the apparatus main body.
In this state, the feet 16e and 16d of the transfer roller unit 20 are placed on the pedestals 6a and 6b of the release plate 6, and the transfer roller 19 is in pressure contact with the outer periphery of the photosensitive drum (not shown). The transfer roller unit 2 is shown in FIG.
It is a perspective view of 0, (a), (b), (c) is an operation explanatory view seen from the plan view state of the A part.

The transfer roller unit 20 includes a roller support 1
The shafts 15 supported by the support portions 4d and 4e planted in the transport path unit 4 are fitted into the opening holes 16c and 16c provided at both ends of the shaft 6 so as to be rotatable and slidable.
The left end of the frame 27 is biased by the spring 37, and the right end of the frame 27 is
The stopper pillar 27a that is planted in is installed.

Since the transfer roller unit 20 is constructed as described above, when the pin 3b rotates counterclockwise by the rotation of the handle 3, the release plate 6 moves leftward and the pedestals 6a, 6b move leftward. However, the roller support 16 holds its position, and the legs 16d and 16e of the roller support 16 slide on the rear slant surfaces of the pedestals 6a and 6b to rotate the shaft 15 in the clockwise direction, so that the weight of the roller support 16 is reduced. And the transfer roller 19 is separated from the photosensitive drum.

Further, as shown in FIGS. 4 and 5, the handle 3 is provided with a cam portion 3d for releasing the engagement between the claw portion 11a and the locking portion 4c. The cam portion 3d has a locking portion 4
It has a curved surface 3e facing c and a standing surface 3f extending therefrom, and the curved surface 3e is the highest projecting portion and has the claw portion 11a.
After a is removed, as it goes to the upright state, it is separated from the locking portion 4c, and in the upright state, the claw portion 111a shown by a virtual line is engageable with the locking portion 4c as shown in FIG. 5C. Has been done.

Therefore, as the handle 3 is rotated, the cam portion 3d is separated from the engaging portion 4c, the pawl portion 11 is engaged as shown by 11 'as shown in FIG. 5 (a), and the handle 3 is in the standing position. As it returns toward, the cam portion 3 as shown in (b)
The d'is abutted against the claw 11 ', and the cam 3d "disengages the claw 11" from the engaging part 4c as shown in FIG. 7C, and the release plate 6 is returned to the initial position by the tension of the spring 40.

On the other hand, when the transport path unit 4 directly moves to the left, the support portions 4d planted in the transport path unit 4,
4e and the shaft 15 supported thereby move to the left, but the transfer roller 19 maintains the initial position until the supporting portion 4e comes into contact with the rear end 16g of the roller support 16, and the pedestals 6a, 6 are provided therebetween.
b moves to the left, the transfer roller unit 20 drops, and the transfer roller 19 and the photosensitive drum are separated from each other. At that time, since the cam portion 3d of the handle 3 is separated from the locking portion 4c,
The claw portion 11a is engaged with the locking portion 4c.

As described above in detail, in the present embodiment, even if the transfer path unit is pulled out from the transfer roller,
Although it is configured so as not to move immediately, it is not necessarily limited to this, and as shown in FIG. 4, by appropriately selecting the ratio from both ends of the seesaw-shaped lever 39 to the rotation axis. The speed of the control member 6 can be increased in proportion to the movement of the transport path unit 4, and in this case, the transfer roller 19 is held at the initial position in the initial moving range of the transport path unit 4 as described above. Even if it is not performed, the time for the transfer roller 19 to rub against the photoconductor is reduced, so that the distance to be rubbed is small and the scratches on the surface of the photoconductor can be suppressed to a negligible level.

Further, in the present embodiment, an operating member for controlling the pressing operation and the separating operation of the transfer roller from the photosensitive member side is arranged in the conveying path unit, and the operating member is disclosed in the shape of a trunk handle. However, a lever-shaped one, a circular one, and the like can also be used.

In the present embodiment, the transfer roller is separated from the photosensitive member within the operation area of the operation member, but the transfer roller may be separated from the photosensitive member after the operation member is operated.

Further, in the present embodiment, the transfer roller is separated from the photosensitive member side in synchronization with the operation of the operation member, and a member provided in the conveyance path unit serves as a holding means for holding the separated state. As shown in FIG. 4, the claw plate 11 provided on the release plate 6 that is moved by the operation member 3 is locked by the stopper 4c, but the magnetic force of a permanent magnet, an electromagnet, or a combination thereof is applied. The holding means used may be a holding means using an electrically or fluidly driven plunger or the like alone or together with other mechanical locking members.

Further, in this embodiment, since the multiple transfer unit is pulled out when the transport path unit is pulled out, even if the recording medium is jammed over both sides, the recording medium is not damaged.

Further, in the present embodiment, since the fixing device is arranged in the conveying path unit, by pulling out the conveying path unit, it is easy to remove the jam in the fixing device portion, and the conveying path unit is also provided. Since the fixing device can be attached and detached from above, it is easy to replace the fixing device.

[0072]

As described above, according to the first aspect of the present invention, an operation member for controlling the pressing operation and the separating operation of the transfer roller from the photosensitive member side is arranged in the conveying path unit, and the operation member is operated. Since the transfer roller is separated from the photoconductor by the operation, the drum unit in which the photoconductor is arranged can be replaced without damaging the surface of the photoconductor by the transfer roller.

According to the second aspect of the present invention, a control member for controlling the pressing operation and the separating operation of the transfer roller with respect to the photosensitive member side is slidably arranged on the conveying path unit, and the control member is provided. Since the separating operation is performed at the initial stage of the operation of pulling out the conveying path unit and the conveying path unit, the photoconductor is not scratched.

According to the third aspect of the invention, the first and second aspects are combined, and the features of the first and second aspects are combined, and the operation of the operation member is performed. Alternatively, the operation of the transport path unit enables the pressing / separating operation between the transfer roller and the photoconductor.

According to the invention of claim 4, when the operation member is operated in the forward direction, the operation member is engaged in the control member and moves against the biasing force of the control member in the forward direction. In synchronism with the above, the control member is locked and held in a separated state of the transfer roller from the photosensitive member side, and a holding means for releasing the locked state by an operation of the operation member in the backward direction is provided. Therefore, after the control member is held by the holding means, the operation member automatically returns even if the operation member is released, so that there is no hindrance to attachment and detachment of the drum unit.

Further, in the invention according to the fifth aspect, since each mechanism portion is unitized and the mechanism portion is configured to be replaceable from the operation surface side of the apparatus body, the apparatus body is pulled out to a wide place for maintenance. Without performing inspection and repair work,
The above operation can be easily performed from the side operated by the normal operator.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an image forming apparatus to which the present invention is applied.

FIG. 2 is a diagram showing a state in which a transport path unit and a multiple transfer unit are pulled out from an apparatus main body.

FIG. 3 is a diagram illustrating a fitted state of a drum unit and a handle.

FIG. 4 is an assembly diagram showing a mechanism for separating a transfer roller from a photoconductor.

FIG. 5 is an explanatory diagram of the operation of separating the transfer roller from the photoconductor.

FIG. 6 is an explanatory diagram of loading a recording medium into a multiple transfer unit.

[Explanation of symbols] 1 Image forming device 2 Multiple transfer unit 3 Handle (operating member) 4 Conveyor unit 5 fixing device 6 Release plate (control member) 8 drum units 9 Photosensitive drum 13 front door

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-35252 (JP, A) JP-A-7-302007 (JP, A) JP-A-2-149861 (JP, A) JP-A-8- 211811 (JP, A) JP-A-7-191557 (JP, A) JP-A-8-146716 (JP, A) JP-A-8-54772 (JP, A) JP-A-57-151954 (JP, A) JP-A-60-114878 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/00 510-550 G03G 21/16-21/18 G03G 15/16

Claims (5)

(57) [Claims] 1. The mechanism is formed by unitizing each mechanism part.
In the image forming apparatus whose parts are replaceable, The drum unit on which the photoconductor is arranged and the photoconductor side
A transfer roller that is pressed through the recording medium is installed.
While forming the sending unit separately,Pulling out the transport path unit from the transport path unit
It is arranged so that it can rotate in the direction
An operation unit for controlling the pressing operation and the separating operation from the photoconductor
Equipped with materials, Standing up in the direction of pulling out the transport path unit
How to pull out the operation member from the state
When the transfer roller is rotated in the direction
Be in a state An image forming apparatus characterized by the above. 2. The mechanism is formed by unitizing each mechanism part.
In the image forming apparatus whose parts are replaceable, The drum unit on which the photoconductor is arranged and the photoconductor side
A transfer roller that is pressed through the recording medium is installed.
Forming the feeding unit separately, Pressing and releasing the transfer roller from the photoconductor side
Control member for controlling inter-motionBut,Slide on the transport path unit
Arranged to be movableIs When the withdrawal operation of the transport path unit is started,
Until the transfer roller and the drum unit are separated from each other,
Keep the transfer roller at the initial position, and
To perform the pressing operation at the end of the knit return operation,
The control member and the transport path unit are in communication
An image forming apparatus characterized by the above. 3. The mechanism is formed by unitizing each mechanism part.
In the image forming apparatus whose parts are replaceable, The drum unit on which the photoconductor is arranged and the photoconductor side
A transfer roller that is pressed through the recording medium is installed.
While forming the sending unit separately,Pulling out the transport path unit from the transport path unit
It is arranged so that it can be rotated in the direction
The above-mentioned transportation from a state of standing upright in the feeding direction Road unit
When the transfer roller is rotated in the pull-out direction
When separated from the photoconductor, the transfer roller
Operation for controlling the pressing operation and the separating operation with respect to the photoconductor side.
Work material, The transport path unit is disposed in the transport path unit and is pulled.
With the transfer roller at the initial stage when the feeding operation is performed
The separation operation from the photoconductor is performed, and
Of the transfer roller at the final stage of the return operation of the
When the photosensitive member is pressed, the feeling of the transfer roller is reduced.
A control member for controlling the pressing operation and the separating operation from the optical body side;
Have Operation of the operating member, or of the transport path unit
Depending on the withdrawal actionOf the transfer roller and the photoconductor
Image formation characterized by enabling pressing and separating operations
apparatus. 4. The control member having an urging force in a direction to press the transfer roller toward the photoconductor, and the control member is engaged with the control member during operation in a forward direction to move against the urging force. In synchronization with the operation of the operation member in the forward direction of the operation member , the control member is locked and held while the transfer roller is separated from the photoconductor side, and the operation member is operated in the backward direction by the operation. The image forming apparatus according to claim 3, further comprising a holding unit that releases the locked state. 5. unitized mechanisms partial image forming apparatus according to any one of claims 1 to 4, characterized in that the replaceable configure the mechanism portion from the operation surface side of the apparatus main body.