JP3174391B2 - Transfer transport unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer / transport unit used in a transfer type image forming apparatus.

[0002]

2. Description of the Related Art In a copying machine or the like, a belt having one end as a fulcrum and the other end swingable and the other end freely movable toward and away from a photoreceptor is used to transfer a toner image on the photoreceptor. There is a transfer / transport belt that is a means for transferring the sheet after the transfer, as well as a transfer / transport unit having a cleaning blade for cleaning the surface of the transfer / transport belt (JP-A-63-85667). JP-A-63-85669).

[0003]

SUMMARY OF THE INVENTION In the prior art,
. When foreign matter such as paper dust is interposed between the edge of the cleaning blade and the transfer conveyance belt with time, a minute gap is generated between the blade edge and the belt, and toner leaks out from the gap. The transfer belt may cause a cleaning failure.

[0004] In the prior art, since a pressing means for pressing the transfer / transport unit toward the photoreceptor side is provided substantially at the center below the transfer / transport unit, this obstructs the entire transfer / transport unit and opens greatly downward in the main body. And it is difficult to remove jammed paper between the photoreceptor and the belt.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a transfer / transport unit which can improve the cleaning property of the transfer / transport belt and can easily remove jammed paper between the transfer / transport belt and the photosensitive member.

[0006]

In order to achieve the above object, the present invention has one of the following constitutions.

(1). A belt pressing means for pressing the transfer conveyance belt against the photoreceptor, and a supporting position for supporting the other end side of the transfer conveyance belt from below are changed, and the transfer conveyance belt is rotated by its own weight to rotate the photoreceptor. Separating means for separating from the cleaning blade, a blade cleaner provided to clean an edge of the cleaning blade, blade cleaner operating means for performing an operation of rubbing the edge with the blade cleaner, and the blade cleaner is a cleaning blade edge A cleaning blade operating means for operating the cleaning blade so as to be able to take two positions, a position in contact with the portion, and a position away from the cleaning device, and the belt pressing means is disposed outside the paper transport path;
By the cooperative operation of the blade cleaner operating means and the cleaning blade operating means, after the blade cleaner is operated and its tip comes into contact with the cleaning blade end surface, the cleaning blade is controlled to be separated from the transfer conveyance belt. (Claim 1).

(2). In (1), the cleaning operation of the cleaning blade edge portion by the blade cleaner and the separation operation of the cleaning blade for separating the cleaning blade from the transfer conveyance belt are interlocked with the operation of separating the transfer conveyance belt from the photosensitive member surface by the separation means. (Claim 2).

(3). In (2), the separating means includes a handle that is manually operated, a rotating shaft that rotates in conjunction with the rotation of the handle, and a rocking means that transmits the rotation of the rotating shaft to the support means of the transfer conveyance belt. And a pin for determining a rotation position of the handle, and a spring for urging the pin to keep the pin inserted into the positioning hole. When the pin engaged with the positioning hole is pulled out together with the handle from the positioning hole by the elastic force of the above, the rotation of the handle when the pin is taken along with the handle to another positioning hole. This is performed according to the operation (claim 3).

(4). In (3), the transfer / transport unit can be pulled out in the same direction as the pull-out direction of the handle as a whole, and the force of the spring is greater than the force required to pull out the transfer / transport unit as a whole. It is set to be smaller than the pulling force (claim 4).

(6). In (1), the blade cleaner is provided with an urging means for urging the blade cleaner so as to contact the cleaning blade (claim 5).

[0012]

The blade edge is cleaned by the blade cleaner. Further, the belt pressing means is located outside the paper transport path, that is, outside the belt installation area, and does not hinder the swing of the belt.

[0013]

First, the entire image forming system will be described with reference to FIG. In FIG. 20, the photosensitive member A is irradiated with light by the point-separating lamp B, and the surface potential of the photosensitive member A is set to 0 to -100.
V is set to the reference potential. Next, the photoconductor A is charged by the charging charger C, and the photoconductor surface potential is set to −850V.
Before and after.

On the other hand, digitally recorded image information sent from a device not shown is received by a line driver circuit, and is amplified by a laser driver circuit. This digitally recorded image information is a binary signal of one bit (recorded / non-recorded) per pixel, and the laser driver circuit operates in response to the binary signal to energize the laser diode.

The laser light emitted from the laser diode is reflected by the rotary polygon mirror E-1 of the writing unit E, passes through the fθ lens E-2, and passes through the first mirror E-3,
The light is reflected by the second mirror E-4 and the third mirror E-5, and is imaged and irradiated on the photoconductor A.

Here, the portion irradiated with light (image portion)
Has a surface potential of 0 to -100V. Since a bias of about -600 V is applied to the developing sleeve F-1 of the next developing unit F, the toner in the developing unit F adheres to this image portion, and the non-image portion is -80V.
Since the voltage remains at about 0 V, no toner adheres.

The surface of the photoreceptor on which the toner image has been formed in this way rotates, and a sheet is fed from a sheet feeding unit (not shown). The sheet is fed at a timing when the leading end of the sheet and the leading end of the image coincide with each other in the transfer unit.

Thus, the transfer / conveyance unit G has the transfer / conveyance belt G-1.
The toner image on the photoreceptor surface is transferred to the paper at the portion where the contacts.

The sheet is fed leftward in FIG. 20 while being electrically attracted to the transfer / conveying belt G-1, and is separated by a curvature at the left end of the transfer / conveying belt G-1. Sent. In the fixing unit, heat and pressure
The toner is fused to the paper and discharged as a copy.

On the other hand, the residual toner remaining on the photosensitive member A is supplied to a cleaning unit H by a cleaning brush H-2.
And is scraped off by the cleaning blade H-1.
The surface of the photoreceptor is in a state without toner, and the process proceeds to the next image forming step again.

Next, the transfer and conveyance belt unit G-2 according to the present invention will be described with reference to FIG. In FIG.
The transfer conveyance belt G-1 has a surface resistance of 10 ⁶ to 10 ¹² Ω.
It has a moderate resistance value. The transfer conveyance belt G-1 is pressed against the photoconductor A during image formation, and is driven in one direction.

The transfer / conveying belt G-1 has a structure in which a core portion is a metal roller, and a conductive rubber member is wound around the outer periphery of the metal roller. Since the core is a metal roller, the transfer belt is prevented from being bent by the tension, and the outer periphery is made of rubber, so that the coefficient of friction with the transfer belt can be increased. The belt can be driven.

Reference numeral 54 denotes a transfer / conveyance belt drive gear, to which rotational force is transmitted from a drive source (not shown).
The shaft of the drive roller 45 is locked and engaged with the drive shaft of the drive roller 45 by fitting a D-shaped shaft and a hole (hereinafter, referred to as a D-shaped connection), and is prevented from falling off by an E-ring or the like.

Reference numeral 46 denotes a driven roller serving as another roller for supporting the transfer / conveying belt. This driven roller 4
Reference numeral 6 denotes a metal roller, and the length of the outer peripheral portion in contact with the transfer / transport belt is shorter than the width of the transfer / transport belt.

The intermediate portion of the transfer / transport belt is supported by backup rollers 47 and 48. The backup roller 47 is opposed to the drive roller 45 and the backup roller 48 is opposed to the driven roller, and these rollers are provided so as to contact the transfer conveyance belt.

The transfer / conveying belt G-1 is stretched around these rollers, and is rotated in accordance with the driving of the driving roller 45. An electric current is applied to the driven roller 46 and the backup roller 48, and the drive roller 45 and the backup roller 47 are grounded.

The front plate 42 and the rear plate 44 constitute right-side support means of the transfer / transport unit. Further, the front plate 41 and the rear plate 43 constitute left support means of the transfer / conveyance unit.

Each side plate 42 constituting the right side support means,
Reference numeral 44 rotatably supports a driven roller 46 and a backup roller 48, and is connected to a stay member 49 by fastening means such as screws.

Each side plate 42, 44 constituting the right support means
And the side plates 41 and 43 constituting the left support means are connected via a backup roller 47 on the drive roller 45 side. The drive roller 45 and the backup roller 47 are rotatably supported by left support means. Each side plate is configured to be connected by these rollers.

Normally, the left support means and the right support means are completely fixed by screws 58 when the transfer / conveying belt G-1 is stretched. To remove the transfer / transport belt G-1 from the transfer / transport belt unit G-2, remove the screw 58 and rotate the left support means clockwise around the axis of the backup roller 47 as shown in FIG. Then, the length of the belt wrap area formed by each roller is made shorter than the circumference of the belt. Thereby, the transfer conveyance belt G-1 can be removed from the transfer conveyance unit G-2.

In FIG. 3, a leaf spring supporting member 56 is a member for supporting the leaf spring, and details thereof are as shown in FIG. In FIG. 17, the leaf spring 57 is fixed to the leaf spring support member 56 by welding. As shown in FIG. 3, the leaf spring support member 56 is fixed to the front plate 42 of the right support means by screws. Further, a similar member having a symmetrical shape is fixed to the rear side plate 44 by screws.

Next, the lower unit for holding the transfer / convey unit will be described with reference to FIG. In FIG. 4, reference numeral 1 denotes a front side plate of the lower unit, and reference numeral 2 denotes a rear side plate. Each of these side plates is supported by the casing 3 and forms a structure.

Reference numeral 4 denotes a rotation axis. This rotating shaft 4 is
The lower unit is rotatably supported by the front plate 1 and the rear plate 2. The rotating shaft 4 holds a member for rotating the transfer / conveyance unit G about the axis of the drive roller 45 as a rotation center, and for causing the driven roller 46 side of the transfer / conveyance unit G to move toward and away from the photosensitive member surface. A handle 5 is attached to the rotating shaft 4.

In FIG. 18, an elongated hole 5-4 is formed in the cylindrical portion of the handle 5, and the fixing screw 5 is inserted through the elongated hole.
-3 is screwed into the rotating shaft 4. As a result, the handle 5 can be moved in the direction indicated by the arrow in the figure by a specified amount determined by the length of the elongated hole 5-4. The handle 5 is constantly pressed to the right in the drawing by a compression spring 5-2 interposed between the stopper member 5-1 and the recess of the handle.

A pin 5-a is implanted in the handle 5. The rotation shaft 4 is rotated in accordance with the rotation of the handle, and the pin 5-a is attached to the front side plate 1 in FIG. A plurality of holes N provided can be selectively inserted.

The pressing force of the handle 5 generated by the compression spring 5-2 is a force (for example, 0.1 kg) required to pull out the entire transfer / conveying unit from the image forming apparatus main body.
f) greater than normal pulling force (eg 5 kgf)
Less power.

In FIG. 4, reference numeral 6 denotes an arm member. The base end of the arm member 6 is fitted to the rotary shaft 4, and the fitted portion is D-shaped to prevent rotation. The arm members 6 are respectively provided before and after the rotation shaft 4.

A roller 7 is pivotally mounted on the upper part of the arm member 6 by a shaft 30. The rollers 7 can contact the bottoms of the front side plate 42 and the rear side plate 44. However, when the transfer conveyance belt G-1 is in contact with the surface of the photoconductor A, it separates.

Next, the procedure for attaching the transfer / conveyance unit G to the lower unit will be described. It fits into the concave part 1-1 formed in the front side plate 1 and the rear side plate 2 of the lower unit shown in FIG. This is performed by dropping the shaft portion of the drive roller 45 shown in FIG. 3 through the bearing formed as described above, and fixing the shaft portion by an E-ring.

By combining the two units in this manner, a transfer / conveying unit G shown in FIG. 2 is configured.

As shown in FIG. 2, the roller 7 has a front side plate 42,
The transfer / transport belt unit G- contacts the lower surface of the rear plate 44
If the handle 5 is rotated clockwise in FIG. 4 from this state in FIG. 4, the rotation shaft 4, the arm member 6, the roller 7, etc. rotate integrally, and Transfer / conveying belt unit G-supported by rollers 7
2 rotates clockwise around the axis of the drive roller 45.

Thus, the transfer and transport belt unit G-
1 moves in a direction away from the photoconductor A.

Referring to FIG. 4, the front side plate 1 has a handle 5
Is provided with one or more holes N for receiving the pins 5-a implanted in the transfer belt unit G-2, so that the transfer / conveyance belt unit G-2 can be stopped at an appropriate position. ing.

For example, in FIG. 1, the transfer / conveying belt G-1 is located at a distance of 0 to 5 mm from the photosensitive member A, and does not interfere with peripheral members when the entire transfer / conveying unit G is pulled out from the image forming apparatus main body. Distance is 2-20mm
The position of the hole N shown in FIG. 4 is adjusted so as to match the stop position of each transfer belt unit, such as a distant position, a position at which the jammed sheet can be taken out when the sheet is jammed, and a distance of 20 to 100 mm. Each position is determined.

In FIG. 4, the cam drive shaft 9 is rotatably supported on the arm member 6 by an E-ring. At both ends of the cam drive shaft 9, cams 8 are provided so as to be prevented from rotating with respect to the cam drive shaft 9 by D-shaped coupling.

These cams 8 are connected to the transfer / conveying belt G-1.
Is slightly away from the photoconductor A, as shown in FIG. 7, the front and rear side plates 42 of the transfer / conveyance belt unit G-2,
It contacts a leaf spring 57 provided at 44.

In FIG. 4, reference numeral 11 denotes a solenoid, which is on the longitudinal direction of the rotary shaft 4 and is outside the sheet transport path, which is a belt installation area surrounded by the front plate 1 and the rear plate 2. , Is fixed to the solenoid fixing bracket 12 by screws.

The solenoid fixing bracket 12
Is fixed to the D-shaped flat surface of the rotating shaft 4 by screws. Therefore, when the rotation shaft rotates, the solenoid 11 rotates together with the rotation shaft.

The solenoid 11 is used to transfer the transfer belt G
-1 constitutes a main member of a belt pressing means for pressing the photosensitive member A against the photosensitive member A. Since the main member is disposed outside the sheet conveying path, it does not hinder the rotation of the transfer conveying belt unit. As a result, the transfer / transport belt unit G-1 can be separated from the photoconductor more greatly than in the conventional apparatus in which the members are arranged inside the transfer / transport belt unit, and the jam paper removal performance is greatly improved. I do.

In FIG. 7, the base end of a link member 10 is connected to the cam drive shaft 9 in a D-shape, and the other end of the link member is connected to a plunger of a solenoid 11 via a spring pin. ing. Thus, the cam drive shaft 9 is rotated forward and backward in accordance with the reciprocating motion of the plunger.

In FIG. 7, for example, when the solenoid 11 is turned on, the plunger moves rightward in the figure.
Accordingly, the link member 10 rotates counterclockwise around the cam drive shaft 9, and the cam 8 rotates counterclockwise by the rotation of the cam drive shaft 9 in the same direction. The leaf spring 57 is pushed up.

Thus, the front and rear side plates 42, 4 shown in FIG.
4 surely contacts the positioning portion (not shown) formed on the side plate on the photoconductor unit side.

In this way, since the transfer / transport belt G-1 is pushed up via the leaf spring 57, even if the position accuracy of the cam 8 is not improved to some extent, the transfer / transport belt unit G-P is pressed.
2 can be reliably pressed against the positioning portion on the photoconductor unit side, and the transfer / conveying belt G-1 can be reliably brought into contact with the photoconductor A.

It is not preferable that the transfer / conveying belt G-1 is in contact with the surface of the photosensitive member by means other than the mechanical operation, because the photosensitive member A is deteriorated. Therefore, the transfer conveyance belt is prevented from contacting the photoreceptor surface except during the mechanical operation.

In FIG. 4, shafts 31 and 32 are screwed into the cam drive shaft 9 and the solenoid fixing bracket 12, respectively. Between these shafts 31 and 32,
An elastic spring 33 is engaged and urges the cam drive shaft 9 to rotate in a counterclockwise direction.

As a result, a force acts in such a manner that the transfer / conveyance belt unit G-2 is constantly pushed up via the cam 8. Accordingly, the force applied to the plunger of the solenoid 11 depends on the weight of the transfer / conveyance belt unit G-2 in FIG.
Thus, a force obtained by subtracting a force for moving the plunger to the right in the figure by the spring 33 shown in FIG. 4 from a force for moving the plunger to the left is obtained. Therefore, the provision of the spring 33 makes it possible to reduce the size of the solenoid 11.

The cleaning section will be described with reference to FIG. The reason why the cleaning device is required is that the transfer / conveying belt G-1 may come into direct contact with the surface of the photoreceptor without using a sheet. In such a case, the toner on the photoreceptor is transferred to the transfer / conveying belt G-1. This is to cause the back surface of the sheet to be stained later, so that the toner on the transfer conveyance belt G-1 is scraped to prevent this.

In FIG. 1, reference numeral 13 denotes a cleaning blade, which is made of an elastic material such as rubber. This cleaning blade is for pressing against the transfer conveyance belt G-1 to scrape off the toner.

The cleaning blade 13 is held by a cleaning blade holding member 14. This hold
Adhesive means such as a double-sided tape is used. The cleaning blade holding member 14 can be replaced by the bracket 2.
7 is fixed by screwing.

The front and rear ends of the bracket 27 are bent. This bent portion is pivotally attached to the front and rear side plates 1 and 2 of the lower unit by shafts 27-a and 27-b shown in FIG.

Thus, the cleaning blade 13 is rotatable around these shafts 27-a and 27-b.

A thin plate 34 is attached to the casing 3, and the free end of the thin plate 34 is in contact with the cleaning blade holding member 14 to prevent toner from scattering.

The cleaning pressure mechanism will be described with reference to FIGS. In FIG. 9, a gear 15 is connected to the rotating shaft 4 in a D-shape, and is prevented from shifting by an E-ring.

A gear 16 meshes with the gear 15. The gear 16 is supported by a shaft 22 provided between the front and rear side plates 1 and 2 of the lower unit. Further, a pin 16-a is implanted on a part of the side surface of the gear 16.

One end of a pressure adjusting plate 17 is pivotally connected to the pin 16-a. An intermediate portion of the pressure adjusting plate 17 has a bent shape in order to avoid the shaft 22, and a U-shaped groove 17-a is formed at an end portion.
The pin 19-a is engaged with a.

The pin 19-a is implanted on the free end side of the pressing plate 19, and a portion of the pressing plate 19 on the base end side is a shaft 27-a.
a is D-shaped. The shaft 27-a is pivotally attached to the front side plate 1, and is common to the shaft that pivotally attaches the bracket 27 to the front side plate 1.

An elastic cleaning blade pressurizing spring 18 is hung between the pin 16-a and the pin 19-a. The cleaning blade pressure spring 18 is attached to the cleaning blade 13 via a pressure plate 19 by a shaft 27-a.
To provide a clockwise turning force around the axis.

Referring to FIG. 9, the blade cleaner will be described. The cleaning blade 13 is used to transfer the transfer belt G
Foreign matter such as paper dust is interposed in the edge portion contacting with -1 with time, and a minute gap is formed between the blade edge portion and the transfer conveyance belt. Then, when toner leaks from this gap, cleaning failure occurs. The blade cleaner is provided in order to remove the toner at the blade edge portion and eliminate such a cleaning failure.

In FIG. 9, reference numeral 2 denotes a blade cleaner.
6. This blade cleaner is made of a thin plate made of an elastic synthetic resin or the like, and is adhered to the blade cleaner support plate 26 with a double-sided tape.

The blade cleaner support plate 25 is bent at its front and rear ends, and the bent portion is D-shaped to the shaft 25-a. The shaft 25-a is a stepped shaft composed of a large-diameter portion and a small-diameter portion in order from the side closer to the bent portion. The small diameter portion penetrates the rear plate 2 via a bearing 25-b, and is D-shaped outside the rear plate 2 to one end of a cleaner rotating member 24 as an arm member.

The other end of the cleaner rotating member 24 is
I am on 3-a. The pin 23-a is implanted on the free end side of a plate member 23 outside the rear plate 2, and the other end of the plate member 23 has a shaft 22 protruding outside the rear plate 2. Are D-shaped.

A torsion coil spring 28 is wound around the large diameter portion of the shaft 25-a. One end of the torsion coil spring is fixed to the rear plate 2, and the other end is a notch of the blade cleaner support plate 25. It is hung on the department.

The blade cleaner 26 is rotationally urged in a clockwise direction, that is, in a direction approaching the cleaning blade 13 by the elastic force of the torsion coil spring 28.

Next, the toner discharging section will be described with reference to FIGS. As shown in FIG. 9, the toner scraped off by the cleaning blade 13 is discharged to the outside of the unit in accordance with the rotation of a toner discharge coil 29 disposed below the blade.

As shown in FIG. 10, the shaft end of the shaft portion 29-a of the toner discharge coil 29 is formed in a D shape.

As shown in FIG. 9, this shaft portion 29-a is D-shaped connected to the toner discharge coil drive gear 20, and the relay gear 21 meshing with this gear 20, and the drive transmission gear 55 meshing with this relay gear. It is adapted to be rotated by receiving a rotational driving force from the motor.

The operation will be described. 1. Attaching / Detaching Operation of Entire Unit To remove the entire transfer / conveying unit G shown in FIG. 2 from the machine main body, pull the handle 5 shown in FIG. By pulling the handle 5, when the pin 5-a of the handle is out of the uppermost hole among the holes N provided in the lower unit front side plate 1, it is rotated clockwise, and the uppermost pin is rotated. Press into the hole provided at the next position below the hole.

At this time, since the handle 5 is pressed by the compression spring 5-2, it does not come off even if you release your hand. Thereby, the transfer belt G-1 shown in FIG. 3 is separated from the photoconductor A and its peripheral portion.

In this state, the entire unit G is pulled out to the front side along the main body guide 70 shown in FIG. At this time, since the pressing force of the compression spring 5-2 (see FIG. 18) is larger than the force of pulling out the entire unit, even if the user grips the handle 5 and pulls it out, the pin 5-a is pulled out of the hole N of the front side plate 1. There is no escape.

When mounting the entire unit, the reverse operation is performed. Although not shown here, it is also possible to set a reference pin on the front and rear side plates 1 and 2 of the lower unit and to provide a reference hole into which the pin is inserted on the machine body side in order to improve the positional accuracy of the entire unit. It is.

2. Copy Operation During the copy operation, the transfer / conveyance belt G in FIG.
The paper S is supplied to the transfer area where the photosensitive drum 60 contacts the photosensitive drum 60 at a timing coincident with the toner image formed on the surface of the photosensitive drum.

The solenoid 11 shown in FIG. 7 is turned on just before the paper S is supplied. Then
The state in which the transfer conveyance belt G-1 is separated from the photoconductor A (FIG. 7)
(See FIG. 6).

In FIG. 7, when the solenoid 11 is turned on, the plunger of the solenoid 11 is pulled rightward in the drawing, and the link member 10 is turned around the cam drive shaft 9 in a counterclockwise direction. To rotate.

As a result, the cam 8 is moved via the cam drive shaft 9.
The cam 8 also rotates counterclockwise about the cam drive shaft 9, and the cam 8 pushes up the leaf spring 57 with this rotation, so that the transfer / transport belt unit G- 2 moves about the axis of the drive roller 45. To rotate counterclockwise, and transfer transfer belt G-
1 comes into contact with the surface of the photoconductor A.

Finally, the positioning portions J (see FIGS. 2 and 3) of the front and rear side plates 42 and 44 on the transfer / conveying belt unit G-2 side are aligned with the positioning portions (not shown) of the front and rear side plates of the photosensitive unit. And the position is determined.

Therefore, as shown in FIG. 6, the length of the contact portion where the transfer / conveying belt G-1 and the photosensitive member A come into contact can be set to a predetermined constant value each time.

In FIG. 1, when the transfer / conveying belt G-1 comes in contact with the photosensitive member A, the driven rollers 46 and 47 and the backup roller 48 are connected to the power supply (not shown) via the terminals 50, 51 and 52. A transfer bias current is applied.

Here, since the transfer conveyance belt G-1 uses a medium resistance (10 ⁶ to 10 ¹² Ω) as an electric resistance, electric charges flow toward the driving roller 45, and the voltage becomes Descends.

Then, the toner charged to the polarity opposite to the polarity applied to the transfer / conveying belt G-1 is transferred onto the sheet S by the electric charge provided by the driven roller 46.

The current is applied to the driving roller 46 and the backup roller 48 by a power source (not shown). The current value is I _1, and the current flowing from the driving roller 45 and the backup roller 47 is I ₂ . When I ₂
Is returned to the power supply so that I ₁ -I ₂ is constant.

As for the separation and conveyance of the paper, the paper S is polarized by the applied charge, and the paper S is transferred by the electrostatic force generated by the true charge on the transfer / transport belt and the separated charges of the paper S. It is performed by utilizing the thing adsorbed on the top.

The paper S conveyed after the transfer gradually passes through the drive roller 45 while passing through the transfer conveyance belt of medium resistance.
As a result, the charge amount is reduced. The speed at which the amount of charge of the sheet S is relaxed largely depends on the resistance value R and the capacitance C of the sheet S, and can be expressed by a time constant τ of τ = CR.

The sheet S whose electrostatic force has weakened is
The five copies are separated from the transfer / conveying belt by the porosity separation of the paper S by the waist, and sent to a fixing unit (not shown). At this time, it is considered that the diameter of the drive roller 45 is appropriately 14 to 16 mm.

In FIG. 3, the driving of the transfer / conveying belt G-1 is performed by a driving source (not shown). That is, a rotational force is applied to the transfer / transport belt drive gear 54 in the counterclockwise direction in the figure by the drive source, and the transfer / transport belt G-1 is rotated.

3. Operation for Removing Jammed Paper In FIG. 7, when the machine is stopped while the paper S is sandwiched between the photosensitive member A and the transfer / conveyance belt G-1, that is, when a so-called jam occurs, FIG. Pull the handle 5 shown in FIG.

In response to this pulling operation, the pin 5 of the handle 5
When a is removed from the uppermost one of the holes N provided in the front side plate 1, the handle 5 is rotated clockwise, and the pin 5-a is pushed into the lowermost hole. At this time,
FIG. 8 shows the state of the transfer and conveyance belt unit.

In this state, as shown in FIG. 8, a large space is formed between the photosensitive member A and the transfer / conveyance belt G-1.
Jam paper can be easily removed. To return to the original state after removing the jammed paper, the reverse operation may be performed.

4. Cleaning Operation by Cleaning Blade FIG. 14 shows the pressure state of the cleaning blade. FIG.
In the state shown in FIG. 4, the tension of the cleaning pressure spring 18 is transmitted as an abutting force to the edge of the tip of the cleaning blade 13 via the pressure plate 19 and the bracket 27.

When replacing the cleaning blade 13 or cleaning the cleaning blade edge,
The cleaning blade 13 is released. 14 to 1
The releasing operation shown in FIG. 6 is linked to the above-described jam paper removing operation.

First, the handle 5 shown in FIG. 4 is pulled forward. As a result, when the pin 5-a is disengaged from the uppermost one of the holes N provided in the front side plate 1, the handle 5 is rotated clockwise. With this rotation, the rotation shaft 4 is also rotated in the same direction.

This turning force is transmitted to the gear 16 via the gear 15 which is D-shapedly connected to the rotating shaft 4, and the gear 16 starts to turn counterclockwise. When the gear 16 starts rotating, the pin 16-a also starts rotating counterclockwise in response.

This movement of the pin 16-a causes the pin 19-
The distance between a and the pin 16-a decreases. However, in the state shown in FIG. 15, since the pin 19a has not yet reached the bottom of the U-shaped groove 17-a, the tension of the cleaning blade pressure spring 18 is transmitted to the cleaning blade edge via the pressure plate 19. ing. In addition, since the cleaning blade 13 can be rotated clockwise, the cleaning blade edge is
1 is still in contact.

When the handle 5 is further rotated clockwise, the pin 16-a moves counterclockwise, and the pin 16-a is inserted into the bottom of the U-shaped groove 17-a formed in the pressure adjusting plate 17. 19
Since the pressure plate 19 is rotated in the counterclockwise direction about the shaft 27a, the cleaning blade 13 also rotates in the counterclockwise direction about the shaft 27-a. .

When the pin 5-a of the handle 5 is pushed into the lowermost hole of the front side plate 1, the cleaning blade 13 is completely released from the transfer / transport belt G-1, as shown in FIG. State.

5. Cleaning Operation of Cleaning Blade by Blade Cleaner The cleaning operation of the cleaning blade by the blade cleaner shown in FIGS. 11 to 13 is also performed in conjunction with the operation of removing the jammed paper.

In FIG. 11, the cleaning blade 1
3 is in a state of contact with the transfer conveyance belt G-1.

The state shown in FIG. 11 is set as an initial state.
The operation of the blade cleaner 26 for scraping off foreign matter such as paper powder attached to the edge of the cleaning blade where the cleaning blade 13 contacts the transfer conveyance belt G-1 will be described.

First, the handle 5 shown in FIG. 4 is pulled forward. Thereby, when the pin 5-a of the handle 5 is disengaged from the uppermost hole among the holes N formed in the front side plate 1, the handle 5 is rotated clockwise.

At this time, the gear 16 rotates in the counterclockwise direction as described in the section on the releasing operation of the cleaning blade. 9, the rotational force of the gear 16 is transmitted to the plate member 23 via the shaft 22. Thus, the plate member 23 is also rotated counterclockwise. When the plate member rotates, the pin 23-a moves counterclockwise, and the cleaner rotating member 24 rotates about the shaft 24a, so that the blade cleaner 26 rotates the shaft 25 by the action of the torsion coil spring 28. It is rotated clockwise around -a.

As described above, when the handle 5 is rotated clockwise, before the pin 19-a comes into contact with the bottom of the U-shaped groove 17-a as described in FIG.
Before the edge of the cleaning blade 13 separates from the transfer conveyance belt G-1, as shown in FIG. 12, the edge of the blade cleaner 26 comes into contact with the edge of the cleaning blade.

Then, when the handle 5 is further rotated,
As shown in FIG. 13, the cleaner rotating member 24 contacts the stopper 24-a and stops rotating.

Since the plate member 23 moves in conjunction with the gear 16 that moves during the jam paper removing operation, the plate member 23 further rotates and stops.

The reason why the cleaner rotating member 24 is stopped by the stopper 24-a is that the cleaner rotating member 24 is stopped.
Is rotated further. This is because if the cleaner rotating member 24 is further rotated, the blade cleaner 26 may press and deform the cleaning blade 13, thereby avoiding this.

As described above, the operation of setting and releasing the transfer / transport belt unit, the operation of pressing and releasing the cleaning blade, the release of the blade cleaner, and the operation of contacting the end surface of the cleaning blade are performed by one lever. Since the operation can be performed simply by moving a certain handle 5, the operation is very easy.

6. Discharge Operation of Waste Toner As shown in FIGS. 2 and 9, in the discharge of toner, the rotational force of the drive transmission gear 55 is transmitted to the toner discharge coil drive gear 55 via the relay gear 21 and is transmitted via the shaft 29-a. This is performed by rotating the toner discharge coil 29 so that waste toner is discharged outside the unit.

7. Relationship with Claims In the above embodiment, the positioning of each member in relation to the claims is as follows.

The main members constituting the belt pressing means in the first embodiment are a cam 8, a solenoid 11, and a leaf spring 57.
And so on. The main member constituting the support means is the roller 7. The main members constituting the separating means are the rotating shaft 4, the handle 5, the pin 5-a, the compression spring 5-2, the arm member 6, and the like. The main members constituting the blade cleaner operating means are a plate member 23, a pin 23-a, a cleaner rotating member 2
4, the torsion coil spring 28 and the like. The main elements constituting the cleaning blade operating means are a handle 5, a gear 1,
5, 16, a pressure adjusting plate 17, a cleaning blade pressing spring 18, a pressing plate 19, a hole N, and the like.

The main member constituting the swinging means in claim 3 is the arm member 6. The main member constituting the urging means in claim 5 is a torsion coil spring 28.

In the above, an example of the image forming system of the (-) charging system in which a (-) charge is applied to the photoconductor to form an image has been described. However, the present invention is not limited to this, and the (+) charge is applied to the photoconductor (+). The present invention is also applicable to a charging type image forming system.

[0120]

According to the present invention, it is possible to provide a transfer / conveyance unit capable of improving the cleaning property of the transfer / conveyance belt and easily removing jammed paper between the transfer / conveyance belt and the photosensitive member. .

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a state in which a transfer conveyance belt is in contact with a photoconductor surface.

FIG. 2 is an overall perspective view of a transfer / conveyance unit.

FIG. 3 is a perspective view of a transfer conveyance belt unit.

FIG. 4 is a perspective view of a lower unit of the transfer / conveyance unit.

FIG. 5 is a perspective view illustrating a state of the transfer / conveyance belt unit when the belt is attached / detached.

FIG. 6 is a diagram illustrating a state in which the transfer conveyance belt is in contact with the surface of the photoconductor.

FIG. 7 is a diagram illustrating a state where the transfer conveyance belt is slightly separated from the surface of the photoconductor.

FIG. 8 is a diagram illustrating a state in which a transfer conveyance belt is released when jammed paper is removed.

FIG. 9 is a perspective view illustrating a driving mechanism of a cleaning system.

FIG. 10 is a perspective view of a main part of a toner discharge coil.

FIG. 11 is a diagram illustrating the operation of the blade cleaner.

FIG. 12 is a diagram illustrating the operation of the blade cleaner.

FIG. 13 is a diagram illustrating the operation of the blade cleaner.

FIG. 14 is a diagram illustrating the operation of the cleaning blade.

FIG. 15 is a diagram illustrating the operation of the cleaning blade.

FIG. 16 is a diagram illustrating the operation of the cleaning blade.

FIG. 17 is a perspective view of a leaf spring portion.

FIG. 18 is a sectional view of a handle.

FIG. 19 is a diagram illustrating an engagement relationship of a handle with a rotation shaft.

FIG. 20 is an explanatory diagram of an image forming system of a laser image forming apparatus to which the present invention can be applied.

[Explanation of symbols]

 Reference Signs List 4 Rotating shaft 5 Handle 5-2 Compression spring 5-a pin 6 Arm member 7 Roller 8 Cam 11 Solenoid 15 Gear 16 Gear 17 Pressure adjustment plate 18 Cleaning blade pressure spring 19 Pressure plate 23 Plate member 23-a Pin 24 Cleaner Rotating member 26 Blade cleaner 28 Torsion coil spring 57 Leaf spring A Photoconductor G-1 Transfer / transport belt N Hole

Claims (5)

(57) [Claims] An image forming apparatus comprising: a belt having one end serving as a fulcrum and the other end swingable, and the other end being freely movable toward and away from a photosensitive member; In a transfer conveyance unit having a transfer conveyance belt which also conveys the sheet after the transfer and a cleaning blade for cleaning the surface of the transfer conveyance belt, a belt pressure contact for pressing the transfer conveyance belt to the photoreceptor is provided. Means for changing the supporting position of the support means for supporting the other end side of the transfer conveyance belt from below, and rotating the transfer conveyance belt by its own weight to separate the transfer conveyance belt from the photosensitive member; and an edge portion of the cleaning blade. A blade cleaner provided to clean the blade; blade cleaner operating means for performing an operation of rubbing the edge portion with the blade cleaner; Cleaning blade operating means for operating the cleaning blade so that the cleaner can take two positions: a position in contact with the cleaning blade edge portion and a position away from the cleaning blade edge portion. By controlling the blade cleaner operating means and the cleaning blade operating means in cooperation with each other, after the blade cleaner is operated and its tip comes into contact with the cleaning blade end face, the cleaning blade is controlled to be separated from the transfer conveyance belt. Characteristic transfer transport unit. 2. The transfer operation according to claim 1, wherein the cleaning operation of the cleaning blade edge portion by the blade cleaner and the cleaning blade separation operation of separating the cleaning blade from the transfer conveyance belt are performed by separating the transfer conveyance belt from the photosensitive member surface by separation means. A transfer / conveying unit characterized in that the transfer / conveying unit is performed in conjunction with an operation of causing the transfer. 3. A transfer means according to claim 1, wherein said separating means comprises: a handle which is manually operated; a rotating shaft which is rotated in conjunction with rotation of said handle; , A pin for determining a rotation position of the handle, and a spring for urging the pin to be inserted into the positioning hole, to separate the transfer conveyance belt from the photoreceptor. In the separating operation, after the pin engaged with the positioning hole is pulled out together with the handle from the positioning hole by the elastic force of the spring, when the pin is taken along with the handle to another positioning hole, A transfer / transport unit, wherein the transfer is carried out in accordance with the rotation of the handle. 4. The transfer / conveying unit according to claim 3, wherein the entire transfer / conveying unit can be pulled out in the same direction as the pulling-out direction of the handle, and the force of the spring is greater than the force required to pull out the entire transfer / conveying unit. A transfer / conveying unit characterized in that the force is set to be smaller than a force to be pulled out from a positioning hole. 5. The transfer / conveying unit according to claim 1, wherein the blade cleaner is provided with an urging means for urging the blade cleaner so as to contact the cleaning blade.