JPS6312358Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a transfer material separation device for an electrophotographic copying machine that feeds a transfer material to the surface of a photoreceptor on which a toner image is formed, transfers the toner image, and separates the transfer material from the photoreceptor. Regarding.

During transfer, the transfer material is electrostatically attracted to the photoreceptor surface, so it is difficult to separate the transfer material from the photoreceptor surface after the transfer is completed, and various separation methods have been proposed. .

For example, in a method of providing a separation air blowing means that blows air between the photoreceptor and the transfer material, the transferred toner image is in an unfixed state at the time of separation, so the toner image is removed by blowing air. This has the disadvantage that toner may scatter, causing image disturbances, and toner may scatter and adhere to the inside of the machine.

There is also a method in which a peeling claw is inserted between the photoreceptor and the transfer material, but with this method,
Since the knife-edge-shaped peeling claw is constantly in contact with the rotating photoreceptor drum surface, it is easy to cause parallel line scratches on the photoreceptor drum surface, and when the copying process is negative/positive, If the photoreceptor is scratched, it will appear as black streaks on the copy, reducing the quality of the copy. Furthermore, there is also the drawback that poor separation occurs due to deformation of the tip of the peeling claw.

In addition, with devices that use alternating current corona discharge to neutralize the charge on the transfer material, the separation range changes depending on environmental conditions such as temperature and humidity, and the quality and thickness of the transfer material, resulting in poor separation. There are things to do.

Next, there is a method in which a separation member such as a belt is applied to a part of the photoconductor in advance, but if the belt does not rotate, the photoconductor will wear out and the position of the belt is fixed, so transfer is not possible. It can be used when the transfer material is set on one side, but it cannot be used when the drum center is used as the reference, and there are drawbacks such as difficulty in separating the transfer material when it is wide.

Furthermore, a device has been proposed that generates vacuum pressure to suck the transfer material, but this method requires a device that generates vacuum pressure, which may lead to an increase in the size and cost of the device.

The object of this invention is to provide a device that eliminates the above-mentioned drawbacks of various conventional transfer material separation devices and that can always reliably separate transfer materials without adversely affecting the device or copying.

The key point of this idea is that before the transfer process, the leading edge of the transfer material is bent in a direction that separates it from the circumferential surface of the photosensitive drum when the transfer material comes into close contact with the photosensitive drum during transfer. After transfer, it is easy to insert the peeling claw to improve the separation effect, but even if the tip of the separation claw is installed with a slight gap from the photoreceptor drum surface, the separation effect can be obtained, which prevents scratches on the photoreceptor surface. The aim is to prevent this.

There are various ways to crease paper, but it is easy to do so by placing the paper against the angular part of a hard object, such as the edge of a desk, and then pressing your finger or a soft object such as an eraser onto it. Creases in paper are a daily experience. The transfer material leading edge bending device in this invention applies the above-mentioned principle.

To explain this invention in detail based on drawings showing an embodiment, in FIG. , a peeling claw 6' provided close to the circumferential surface of the photoreceptor drum, and a cleaning step 5 are disposed in this order. On the other hand, the transfer material 10 is transferred from the feeding roller 11 to the transfer material leading edge bending device A.
In the transfer process 4, the photosensitive drum 1
After the toner image is transferred onto the circumferential surface of the photoreceptor drum 1 and peeled off by the AC ion generator 6 and the peeling claw 6', the toner image is transferred to the photosensitive drum 1 by the transfer means 7 provided continuously. It is designed to be transferred to a fixing section (not shown).

As shown in FIG. 2, the detailed structure of the transfer material leading edge bending device A is as follows:
They are fixed to parallel shafts 18 and 17, which are supported at both ends by side plates 22, and are arranged perpendicularly and parallel to the conveyance direction of the transfer material 10. The tip end 9' of the rotating bending member 9 normally occupies a fixed position apart from the soft roller 8. A chain 21 is connected between the shaft 18 and the drive shaft of the feed roller 11.
Sprocket 20 and gear 19 driven by
while the shaft 17 is connected to the shaft of the sprocket 20 by the clutch 12.
A disc cam 14 provided with a V-shaped groove 14a is fixed to the other end of the shaft 17, and a roller 15 provided at the other end of an arm 23 whose one end is pivotally supported by the side plate 22 is mounted on the outer periphery of the disc cam 14. It is engaged by the force of a spring 24, and the shaft 1
In the above-mentioned rotational position which is always occupied by roller 15, roller 15 fits into V-shaped groove 14a and positions shaft 17. Further, a switch 13 is provided in contact with the arm 23. In addition, a bending rotating member 9 is fixed to the shaft 17, and a driven roller 16 that contacts the soft roller 8 and rotates as a result of the rotation of the soft roller 8.
is rotatably supported on at least one shaft.

Since this device is configured as described above, when the transfer material 10 is fed by the feed roller 11, the chain 21, the sprocket 20, the gear 1
9. As shown in FIG. 4, the soft roller 8 and the driven roller 16 are rotated via the shaft 18. When the detection device 29 detects that the leading edge of the transfer material 10 approaches the transfer material leading edge bending device, the clutch 12 is engaged, and in synchronization with the conveyance of the transfer material 10,
When the shaft 17 rotates and the predetermined bending position of the tip of the transfer material just reaches the position of the soft roller 8, the cornered tip 9' of the bending rotary member 9 bends over the transfer material 10, as shown in FIG. The transfer material 10 is pressed against the soft roller 8, and the leading end of the transfer material 10 is bent so that the back surface forms a valley. When the bending rotating member 9 rotates once and returns to the initial position shown in FIG.
The roller 15 is fitted into the V-shaped groove 14a of 4 by the force of the spring 24, and at the same time, the switch 13 is actuated to disconnect the clutch 12, and the rotation of the shaft 17 is stopped.
It is positioned at a fixed position by the V-shaped groove 14a and the rollers 15.

The transfer body 10 with its leading end bent in this manner is conveyed to the transfer step 4 by the soft roller 8 and the driven roller 16, as shown in FIG.

On the other hand, while the photoreceptor drum 0 rotates, a toner image is formed on its circumferential surface through an exposure process 2 and a development process 3, and in a transfer process 4, it comes into contact with the transfer material 10 and is transferred while rotating in one direction. will be carried out.

After the transfer is completed and the electric charge is neutralized by the AC ion generator 6, the tip of the transfer material 10, which is bent so that the tip is separated from the circumferential surface of the photoconductor drum 0, and the circumferential surface of the photoconductor drum 0 are separated. During this time, a peeling claw 6' is inserted, and as the transfer material 10 is transferred, the transfer material is continuously peeled off from the photosensitive drum 0 and transferred to the fixing section by the transfer means 7.

In addition, in order to prevent the soft roller 8 from getting caught on the corners of both ends of the pressing and bending member 9 and breaking, the length of the bending rotating member 9 is made slightly longer than the length of the soft roller 8, as shown in FIG. , it is desirable that the corners thereof protrude outside the soft roller.

In addition, the bending rotating member tip 9' is connected to the transfer material 1.
0 against the soft roller 8, the shaft 17
For the same rotation angle of
The path 0 is somewhat longer than the path of the transfer material 10 in the portion sandwiched between the driven roller 16 and the soft roller 8, so if these are used at the same time, the transfer material 10 may wrinkle and good transfer may not be possible. Therefore, while pressing the transfer material 10 against the soft roller, the tip 9' of the bending rotating member 9 pushes up the soft roller 8 to an extent that does not affect the bending, and brings the soft roller 8 and the driven roller 16 into contact. It is necessary to either cut off the pressure or lower the pressing force to the extent that the transfer material slips. The device is shown in Figures 2 and 3.
As shown in the figure, shafts 18 are provided on the side plates 22 on both sides.
The hole 26 for installing the bearing 25 is made oval so that the bearing 25 moves a little and changes the distance between the shafts 18 and 17, breaking the contact between the soft roller 8 and the driven roller 16 or reducing the pressing force. It's getting old. The bearing 25 is pushed against the side plate 2 by the force of the spring 27.
The tip of the arm 28, which is pivotally supported on the soft roller 8, is pressed in the direction approaching the shaft 17, and normally applies pressure to the soft roller 8 suitable for the driven roller 16 to rotate. The tip of the transfer material 10 passes through and the tip 9' of the bending rotating member 9 is transferred to the transfer material 10.
When pressed against the soft roller 8, the shaft 18 is pushed up through the soft roller 8 against the force of the spring 27, and the contact between the soft roller 8 and the driven roller 16 is broken or the pressing force The transfer material 10 is not restrained in that part and can be fed by the same path length as the part to be bent, thereby preventing the occurrence of wrinkles. If the movable amount of the bearing 25 is set appropriately shorter than the depth at which the bending rotation member 9 bites into the soft roller, the transfer material 10 can be folded by the bending rotation member 9 without any problem.

In this way, the front end of the transfer body is provided with a crease with a valley on the back surface, so that in the transfer process 4, after contacting the photoreceptor drum 0 and performing the transfer, the AC ion generator 6 When the charge on the transfer material 10 is neutralized by corona discharge and the transfer material 10 is separated, the tip of the separation claw 6' is shaped like a knife edge and comes into contact with the circumferential surface of the photoreceptor drum 0, as in the conventional transfer material separation device. The peeling claw 6' can be easily inserted between the transfer material 10 and the photoreceptor drum 0, and the transfer material is sequentially peeled off as it is conveyed and transferred to the fixing process by the transfer means 7. be transported.

As mentioned above, this idea has a simple structure,
A crease can be made at the tip of the transfer material in the direction in which the peripheral surface of the photoreceptor and the tip are separated, and the tip of the peeling claw is shaped into a knife edge to ensure reliable peeling without contacting the surface of the photoreceptor. At the same time, there is no risk of scratches on the photoreceptor caused by contacting the peeling claw with the photoreceptor surface, and black lines on copies caused by this are eliminated. Remarkable effects can be obtained, such as making it possible to avoid increases in device costs and image disturbances that would occur when a transfer material suction means is used.

In the above embodiments, an example in which the photoreceptor is peeled off from the photoreceptor drum has been described, but the present invention is not limited thereto, and it goes without saying that it can also be applied to a sheet-like photoreceptor.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the process of an embodiment of the present invention, FIG. 2 is a perspective view of a transfer material leading edge bending device, and FIG.
The figure is an exploded view of the vicinity of the shaft bearing of the soft roller, Figure 4 is a cross-sectional view showing the position and movement of the soft roller, the bending rotating member, and the driven roller before the leading edge of the transfer material passes, and Figure 5 is the leading edge of the transfer material. FIG. 6 is a similar cross-sectional view at the time of bending, FIG. 6 is a similar cross-sectional view after the bending is completed, and FIG. 7 is a diagram showing the relationship between the bending protrusion and the length of the soft roller. 0...Photosensitive drum, 4...Transfer process, 6'...
...Peeling claw, A...Transfer material tip bending device, 8...Soft roller, 9...Bending rotating member, 9'...Bending rotating member tip, 10...Transfer material, 16...Followed roller .

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In an electrophotographic copying machine that feeds a transfer material onto the surface of a photoreceptor on which a toner image is formed, transfers the toner image, and separates the transfer material from the photoreceptor, a soft roller disposed on the transfer surface side of the transfer material conveyed through the conveyance path before the transfer position as a conveyance path, and disposed opposite to the soft roller across the conveyance path;
a plate-shaped bending rotating member fixed to a shaft parallel to the soft roller, and having one end parallel to the shaft at a distance from the shaft such that the end edge can bite into the soft roller; means for holding the bending rotary member in a position where its edge is separated from the soft roller; means for rotating the bending rotary member so as to be pressed against the roller at approximately the same circumferential speed as the soft roller in synchronization with the passage of the front end of the transfer material; 1. A transfer material separation device, comprising: a control mechanism having a means for stopping the rotation of a bending rotary member from time to time, and bending a leading end of the transfer material in a direction away from a photoreceptor. (2) Utility model registration claim No. 1, characterized in that a driven roller that rotates following the rotation of a soft roller is rotatably provided on the axis of a bending rotating member.
The transfer material separation device described in (1). (3) Utility model registration request characterized in that when the tip of the rotating bending member presses the transfer material against the soft roller, the soft roller is separated from the driven roller or the pressing force is reduced. Range number (2)
Transfer material separation device described in Section 1. (4) Utility model registration claim 1, which is characterized in that the length of the rotating bending member is longer than the soft roller so that both ends of the rotating bending member protrude outside the soft roller. Transfer material separation device.