JPS61252571A - Transfer paper separating claw in copying machine or the like - Google Patents

Abstract

PURPOSE:To reduce cost and to improve assembly property by forming the titled claw in a semicircular arc shape, fixing one end to a machine body side, forming a claw tip part in the other end and making it contact elastically to the surface of a photosensitive body, and providing a circular arc part and a straight part on the upper part of the separating claw. CONSTITUTION:A separating claw 16 is made of a plate spring, has a shape which has provided a linear claw part 16b and a fitting part 16c on the tip side of a semicircular arc-shaped part 16a and the rear end part, respectively, and it is constituted so that an angle alpha made by the claw part 16b and a tangent line in a connecting part to a photosensitive body is 5 deg., a tip displacement distance between a state that it is not contacting to the photosensitive body, and a contact state is about 1mm, and a pressure between the separating claw 16 and the photosensitive body 1 becomes <=3g. Accordingly, a spring constant is low, and also the structure is strong against buckling of the time of an abnormal load. In this way, this claw can be prepared at a low cost, and also the life can be further extended by performing a resin covering to the tip part.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transfer paper separation device for copying machines, printers, etc.

Various inventions have been devised as separation claws used in separation devices in copying machines and the like, and separation methods that use these in combination with AC static elimination have become mainstream. However, in realizing claw separation in a small space, the conventional method was too large to be used.

In particular, there is a problem in that when the transfer paper passes, it hits a part other than the tip of the nail, so there is a limit to the rotating type.Furthermore, it has a large number of parts, is expensive, and has the drawback of being difficult to assemble.

That is, in the conventional apparatus, as shown in FIG. 6(a), the transfer paper 2 conveyed to the photoreceptor 1 has a toner image transferred thereto by the transfer charger 3, is neutralized by the charger 4, and is transferred to the photoreceptor 1. They are separated by a separation claw member 5 whose rotation center is at a forward position in the rotational direction.

This separation claw member 5 is as shown in FIG. 6(b).

It is constructed by attaching a torsion bending spring 9 to a shaft 8 provided on a shaft fixing part 7 attached to a body 6 so as to apply rotational force to a holder 11 of a claw 10 so as to press against the photoreceptor 1. There are examples of changing the shape of the holder and using its own weight to press the separating claw against the photoconductor, but in any case, in order to prevent scratches caused by the separation claw pressing against the photoconductor,
The pressure contact load is approximately Ig/1. However, as mentioned above, this method has problems with space and cost.
This is a bottleneck in reducing the area around the photoreceptor.

1. The present invention is a device that uses separation claws to separate paper after transfer from a photoreceptor, which requires less space and costs, while maintaining the advantages of the conventional method and is easy to assemble. The purpose is to obtain a separation claw.

1. In the present invention, a leaf spring (SO5420, 310, etc.) is formed into a semicircular arc shape as shown in FIGS. The separating claw has an upwardly arcuate portion and a straight portion, and is configured to make elastic contact with the photoconductor surface.By doing so, the spring constant is low and abnormal loads are avoided. It has a structure that is resistant to buckling when hit by paper.

Next, the present invention will be explained according to examples.

FIG. 1 is a side sectional view showing a schematic configuration of an electrostatic copying machine according to the present invention, and FIG. 2 is an enlarged view of the separating claw portion of FIG. 1, where (a) is an enlarged view and (b) is an enlarged view. Developed plan view of separation claw, (
c) is an enlarged view of the separating claw part in figure (a), FIG. 3 is an exploded perspective view showing the relationship between the separating claw and the photoreceptor, and FIG. 4 shows an example of the separating claw. A perspective view, (b) is a side sectional view, FIG. 5 is a diagram showing the life of the photoconductor, FIG. 6 is a conventional example of a separation claw, and (a) is a side view showing the relationship with the photoconductor. A cross-sectional view, and (b) an exploded perspective view of the separation claw.

As shown in FIG. 1, there is a main charger 1 around the photoreceptor
2, exposure device 13, developing device 14, transfer charger 3,
Static elimination brush 151 separation claw 16, cleaning device 17,
is provided, and the one-separation claw 16 is connected to the cleaning box body 18.
is attached to.

As shown in FIGS. 2 and 4, the separation claw 16 according to the present invention is made of a plate spring (SO5420, 310, etc.), and has a straight claw portion 16b at the tip side of a semicircular arc portion 16a, and a straight claw portion 16b at the rear end. It has a shape with a mounting portion 16c provided on the side. In this example, the plate thickness is 0.1 ml, and the total length is 1 in Figure (a).
0 to 15 an, the width of the tip part is 4 ua, the width of the mounting part is 12 no, the angle α between the claw part 16b and the cutting line at the contact part with the photoreceptor is 5 degrees,
The tip displacement distance in the state in which it is not in contact with the photoreceptor as shown by the chain line and in the contact state as shown in the solid line is about Inn, and the pressing force between the separating claw 16 and the photoreceptor l is set to be 3 g or less. . Note that this pressing force can be adjusted depending on the thickness of the plate used, etc.

Since the separation claw according to the present invention has the above-described shape, it has a low spring constant and a structure that is resistant to buckling under abnormal load (when paper hits it). It should be noted that if the angle β of the tip portion 16d is about 15 degrees, the peeling property will be good even when thin paper enters, and the R of the tip portion will increase the margin against scratches caused by uneven contact of the nail. Furthermore, as shown in FIG.
By stopping this, the accuracy of the positional relationship with the photoreceptor can be improved.

4(a) and 4(b) show that a resin coating 19 is applied to the surface of the separation claw that contacts the photoreceptor to prevent scratches on the photoreceptor 1 and to improve the life of the photoreceptor.

That is, a problem with the paper separation method using a leaf spring is scratches on the photoreceptor. When a certain level of scratches occurs, abnormal charges occur on the photoreceptor, resulting in black streaks on a white background, and white streaks on the opposite case. This is the same in conventional examples, but it is difficult to lower the spring constant especially in the plate spring type, and it is necessary to increase accuracy in order to set the surface pressure low.

I have considered various ways to solve this problem.

LXl If you widen the contact area of the claws to reduce the surface pressure,
It also has the disadvantage of causing toner drop stains.

If the nail material is made thinner, it will buckle under abnormal loads.

If you try to lower the set pressure, it is necessary to increase the machining accuracy, which inevitably increases costs.

(3) Even if an attempt is made to solve the problem by improving the roughness of the contact surface, it will be experimentally ineffective, and the cost will increase.

As such, good results were not obtained.

Therefore, we conducted an experiment by pasting a polyester film on the contact surface of the separation claw with the photoreceptor, and it was confirmed that there was little scratching of the photoreceptor and there were no problems with the image.

After investigating this under various conditions, we found the following.

As shown in the table above, various advantages have been revealed by doing the above. Furthermore, there was also a manufacturing problem, and after considering the location where the polyester film should be attached, we found that it could be placed on the same surface as the claw part, as shown in Figure 4, and that it could be cut integrally with a press after being attached. , cost increases are not a problem. In addition, when looking at the nail part after long-term use, the polyester surface was slightly glossy and there was almost no scratching. In terms of separation performance, the thinner the membrane, the better, and the use of a 50 μm polyester membrane with adhesive provided good results. Other low-friction materials such as Teflon, carbon powder-containing epoxy, and polyethylene may be used as the coating resin. It is clear that even if such a material is applied to the conventional example, the life span will be improved.

FIG. 5 is a diagram showing comparative data between when a polyester film is attached and when it is not attached, and it is clear that the case where a polyester membrane is attached is superior.

Yutaka As mentioned above, in the present invention, the linear claw is connected to the semicircularly curved end of the thin plate spring to form the separation claw, so the spring constant in the direction of contact with the photoreceptor can be lowered. , and even if a piece of paper hits the tip of the nail and an abnormal load occurs, 5
It has a structure that is resistant to buckling in the direction in which the paper enters, so there is a large amount of margin.Also, the arc-shaped curved part bulges toward the photoreceptor, so it does not scratch against the paper after separation. No smudging occurs in one image. Further, since the separating claw according to the present invention is formed as a single piece using a thin plate spring, it can be manufactured at low cost, and furthermore, the life span can be further extended by applying a resin coating to the tip portion.

In addition, since the separating claw and the photoreceptor can be integrally attached to the casing, not only is it easier to achieve contact accuracy between the separating claw and the photoreceptor, but the provision of a radius at the tip of the claw prevents scratches caused by uneven contact. is less likely to occur.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing a schematic configuration of an electrostatic copying machine according to the present invention, and FIG. 2 is an enlarged view of the separating claw portion of FIG. 1, where (a) is an enlarged view and (b) is an enlarged view. Developed plan view of separation claw, (
c) is an enlarged view of the separating claw parts in figure (a), Figure 3 is an exploded perspective view showing the relationship between the separating claw and the photoreceptor, and Figure 4 shows an example of the separating claw with a resin coating. (a) is a perspective view, (b) is a side sectional view, FIG. 5 is a diagram showing the life of the photoreceptor, and FIG. 6 is a conventional example of the separation claw. (a) is the photoreceptor. (b) is an exploded perspective view of the separation claw. 1... Photoreceptor, 3... Transfer charger, 1
6... Separation claw, 16a... Semicircular arc shaped part, 1
6b...Claw part, 16c...Mounting part, 18
... Airframe (casing), 19... Resin coating.

Claims (2)

[Claims] (1) A body attachment part is provided at one end of the semicircular arc spring plate that bulges toward the photoreceptor surface, and a linear separation claw is integrally provided on the other side, and the tip of the separation claw is brought into elastic contact with the photoreceptor surface. A transfer paper separation claw in a copying machine, etc., which is characterized by: (2) A transfer paper separation claw for a copying machine or the like as set forth in claim 1, characterized in that a resin coating is applied to the contact surface of the tip of the claw with the photoreceptor.