JPH042937Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a transfer material folding device in an electrophotographic apparatus.

[Background of the idea]

Generally, in an electrophotographic device, a transfer material made of paper or synthetic resin is fed into contact with the surface of an electrophotographic image carrier that carries a powder image, and then the powder image is transferred by an appropriate electrostatic action. It consists of a structure that is transferred onto a material. However, since such a transfer material is strongly electrostatically attracted to the image carrier, there remains a problem in that it is difficult to separate the transfer material from the image carrier after transfer. One way to solve this problem is to bend the leading edge of the transfer material in advance in a direction away from the image carrier, and insert a peeling claw between the folded part and the image carrier. A method is known in which the transfer material is surely peeled off from the image carrier by inserting the transfer material. This method has the advantage that the configuration of the apparatus used is relatively simple, and that even large transfer materials such as A1 size can be effectively peeled off. However, on the other hand, the bending angle of the transfer material must be sufficiently limited. For example, if the bending angle is too small, it will interfere with the insertion of the peeling claw mentioned above, impairing reliable peeling. If it is too large, this bent part will collide with the wall of the conveyance path while the transfer material is being conveyed.
This results in hindering safe conveyance of the transfer material.

In recent years, as the demand for copies has increased, it has become necessary to use materials other than plain paper as transfer materials, such as tracing paper or synthetic resin films. When using transfer materials other than plain paper, the main problem is the difference in elastic force, or so-called "stiffness", due to the difference in material or thickness. Conventionally, transfer material folding devices have generally been designed for use with plain paper transfer materials, and therefore, their use has been limited to plain paper and transfer materials similar thereto. If a transfer material made of a material outside this range is used, the angle of bending applied to the transfer material will be either too small or too large, as described above, and will have the drawbacks mentioned above.

For example, FIG. 1 shows an example of a conventional folding device, in which a fixed blade 1 is arranged on one side and a movable elastic body 2 is arranged on the other side with a transfer material conveyance path in between. The fixed blade 1 is made of a plate-shaped body, and as shown in the figure, an elastic body 2 is pressed against the edge thereof with a transfer material interposed therebetween, and the transfer material is bent along the edge. However, in such a device, if the pressing force of the elastic body against the fixed blade is set based on a plain paper transfer material, for example, thin tracing paper may be folded twice as shown by the broken line in Figure 1. The bend was too large. Furthermore, synthetic resin films with relatively strong elasticity were not sufficiently bent.

In order to eliminate the drawbacks of the above-mentioned device, the fixed blade 1 is formed of a block body, as shown in FIG.
A configuration is known in which a bending angle 5 is formed by two relatively wide adjacent flat surfaces 3 and 4 of this block body, and the elastic body 2 is pressed against this corner 5. In such a configuration, even if the transfer material is thin, the surface 3 prevents the transfer material from further bending, so that the above-mentioned excessive bending does not occur.
However, in this configuration, since it is required to strongly press the elastic body over a wide range of surfaces 3 and 4, a large load is placed on the device for pressing the elastic body, such as a cam device, and the device It is not favorable for Further, even in such a device, it is not possible to ensure sufficient bending of a highly elastic transfer material.

[Purpose of invention]

Therefore, it is an object of the present invention to provide a simple and convenient transfer material folding device for an electrophotographic device that can always perform uniform folding without being affected by the material or thickness of the transfer material. purpose.

[Structure of the invention] In order to achieve the above object, the present invention includes a protruding portion protruding into the transfer material conveyance path on the fixed blade, and a stepped portion recessed in a direction away from the transfer material conveyance path from this protrusion portion. and a surface inclined in a direction away from the transfer material conveyance path from the stepped portion.

[Effect of idea]

As a result, according to the present invention, the transfer material is reliably bent by the protruding portion of the fixed blade, and the bending angle is regulated by the above-mentioned inclined surface. Excessive bending can be prevented. Further, since the pressing force of the elastic member is mainly concentrated toward the protruding portion of the fixed blade, the load on the cam device can be reduced.

[Example of idea]

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

In FIG. 3, reference numeral 11 denotes a drum-shaped electrophotographic image bearing member equipped with a photoreceptor on its circumferential surface, which rotates in the direction shown by arrow A during operation, and is subjected to the action of an image forming means (not shown) during this rotation. A toner powder image corresponding to the original is formed on the photoreceptor. The transfer material 13 whose leading end, for example, about 10 mm, is bent by a transfer material bending device 12 having a structure described later is bent in synchronization with the rotation of the image carrier 11 and in contact with the circumferential surface of the image carrier 11 by the action of the registration rollers 14. The powder image is then transferred thereon by the action of the transfer corona discharger 15. At this time, the transfer material is strongly attracted to the image carrier 11 due to electrostatic attraction,
Such adsorption is sufficiently alleviated by the action of the next-order separation corona discharger 16, and a peeling claw 17 is inserted between the transfer material and the image carrier 11 formed by the folded portion, and the transfer material is removed. The material is reliably peeled off from the image carrier 11. The thus peeled transfer material is sent to the fixing roller 18 to form a permanent copy image.

Although the transfer material folding device 12 according to the present invention is provided next to the registration roller 14 in this example, it is of course not limited to this position. A transfer material 13 made of paper, synthetic resin, etc., fed from an appropriate supply means, is transferred to the registration roller 1.
4, the sheet is conveyed to the folding device 12, but just before it enters the roller 14, the detection device 21 detects the passage of its tip. Detection device 2
1 generates a predetermined output signal when the leading edge of the transfer material is detected, this signal is sent to a control means (not shown), and the control means stops the registration roller 14 after a predetermined delay of several seconds from the reception of this signal. do. During this delay time, the leading edge of the transfer material passes through the registration rollers 14 and is positioned at a predetermined bending position of the transfer material folding device 12.

The bending device 12 includes a fixed blade 23 extending substantially linearly in a direction parallel to the leading edge of the transfer material, that is, in the width direction of the transfer material at a position on one side of the transfer material transport path 22, and a fixed blade 23 extending substantially linearly in the width direction of the transfer material at a position on the opposite side of the transport path. Fixed blade 23
and a movable part 24 located opposite to the movable part 24. The fixed blade 23 is made of a rigid body such as a metal, and as shown in FIG. A stepped portion 26 and a surface 27 inclined in a direction away from the stepped portion 26 from the transfer material conveyance path.
and has. The tip of the protruding portion 25 may be angular or rounded, but preferably an acute angle is formed by two adjacent surfaces. On the other hand, if the depth of the stepped portion 26, in other words, the height of the protruding portion 25, is approximately 0.5 to 1 mm, it is sufficient for bending. Also, the slope of the surface 27 is
For example, if it is desired to bend the transfer material at an angle of about 30 degrees, it is preferable that the transfer material conveying path, and thus the transfer material surface, be inclined at about 40 degrees.

The movable part 24 includes a shaft 30 extending parallel to the fixed blade 23, a frame body 28 having a U-shaped cross section and one end rotatably attached to the shaft 30, and a frame body 28 having a U-shaped cross section attached to the fixed blade 23 at the other end of the frame body 28. An elastic member 2 such as sponge or felt extending parallel to and facing the
9. The elastic member 29 has at least the same length as the length of the protruding portion of the fixed blade 23, and when the frame body 28 (described later) moves, the leading end of the transfer material is pressed against the protruding portion of the fixed blade 23 and is uniformly bent along it. do the work.

The movement of the frame 28, that is, the bending operation is performed by the frame 28.
This is performed in conjunction with the rotation of a cylindrical eccentric cam 31 provided on the back side of the camera. On the back surface of the frame 28, a plurality of arm plates 32 of the same shape are arranged in parallel at appropriate intervals in a direction perpendicular to the paper plane of FIG. A shaft 33 is fixed to the side. A plurality of rollers 34 of the same shape are rotatably attached concentrically to appropriate locations on the shaft 33, and the peripheral surface of each roller 34 is rotated by an eccentric cam due to the total load of the roller 34, arm plate 32, and frame 28. It is constantly in pressure contact with the circumferential surface of 31. Of course, a suitable spring means may be provided and the pressure contact may be effected by the spring force of the spring means. The eccentric cam 31 rotates in the direction of arrow B around the eccentric shaft 35, thereby pushing the roller 34 and rotating the frame 28 clockwise around the shaft 30 against the load, thus pushing the elastic member 29 is gradually bitten into the protruding portion of the fixed blade 23 through the leading end portion of the transfer material. As a result, the leading edge of the transfer material is bent in the direction away from the image carrier 11, but at the time of this bending, the leading edge of the transfer material is
7 and is prevented from further bending. As a result of experiments, it was confirmed that in the folding device having such a configuration, the transfer material can be folded uniformly regardless of its material or thickness.
Further, since the bending is performed gradually as the cam 31 rotates, and the elastic member 29 gradually retreats from the fixed blade 23 after bending, damage to the transfer material or noise during bending can be prevented. I can do it. Incidentally, the rotation of the eccentric cam 31 starts immediately after the above-described stop of the transfer material, starts rotating from the position shown in FIG. 3, and after completing one rotation,
Stop at the position shown.

The registration rollers 14 then rotate again in synchronization with the rotational phase of the image carrier 11, and transfer the transfer material onto the image carrier surface as described above.

[Brief explanation of the drawing]

1 and 2 are side views schematically showing a conventional transfer material folding device, and FIG. 3 is a schematic side view schematically showing an electrophotographic apparatus incorporating a transfer material folding device according to the present invention. FIG. 4 is an enlarged side view of the portion shown in FIG. 3. 23...Fixed blade, 25...Protruding portion, 26...
Stepped portion, 27...surface, 29...elastic member.

Claims (1)

[Scope of Claim for Utility Model Registration] A fixed blade disposed on one side of the transfer material conveyance path, and a fixed blade disposed opposite to the fixed blade across the conveyance path and movable in directions toward and away from the fixed blade. an elastic member,
In the transfer material bending device of an electrophotographic apparatus, the transfer material bending device includes a pressing means for pressing the elastic member against the fixed blade with the transfer material interposed, the fixed blade bending the transfer material according to the transfer direction of the transfer material. It has a protruding portion that protrudes into the conveyance path, a stepped portion that is recessed from the protruding portion in a direction away from the transfer material conveyance path, and a surface that is inclined in a direction away from the step portion from the transfer material conveyance path, The elastic member is pressed against the protruding portion of the fixed blade by the pressing means to bend the transfer material along the protruding portion, and at the same time, the inclined surface regulates the bending angle of the transfer material at the time of bending. A transfer material folding device in an electrophotographic device.