JPH0731457B2 - Paper stripping device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet peeling device in a transfer type recording device, and more particularly, in a device such as a copying machine or a laser printer, it is provided with both side edges of a photosensitive drum. And a plurality of guide members between the two peeling fingers.

(Prior Art) In a transfer type recording apparatus such as a copying machine or a laser printer, a member such as a peeling finger or a peeling claw is often used to peel off a sheet attached to the surface of a photosensitive drum. .

In a device using this kind of claw members, the tips of these claw members are provided so as to contact the surface of the photosensitive drum,
After the toner image formed on the surface of the photoconductor drum is transferred to the paper, the paper that is electrostatically adsorbed on the surface of the photoconductor drum via the toner or electrostatically is peeled off.

In addition to the device using such a claw member, a belt device that comes into contact with the side of the photosensitive drum is used, and when the belt rotates together with the drum and separates from the drum at the turning portion, the end portion of the paper is moved. A peeling belt that is separated from the photosensitive drum may also be used.

Among the various types of paper peeling devices described above, a device using a peeling finger is often used because of its simplest configuration and good peeling performance. And
In this type of peeling finger, in order to surely peel the paper from the photosensitive drum, one or a plurality of them are provided so that only the central portion of the photosensitive drum or the central portion and both end portions are in contact with each other. A mechanism is used in which the tips of the peeling fingers are always brought into contact with the photosensitive drum.

(Problems to be Solved by the Invention) However, in the above-described conventional paper peeling device using a peeling finger, since the tip of the peeling finger is always brought into contact with the surface of the photoconductor drum, Due to the rotation of the drum, the surface of the drum is easily scratched by a peeling finger, and when the black copy is made, the scratched portion is reproduced as white streaks, which makes the copy difficult to see.

Also, if the peeling finger is used for a long time with the same position on the photoconductor drum, the scratches will become large, which may cause a part of the copy image to drop out linearly or black on the copy surface. It is also a cause of adverse effects such as lines being formed.

In order to eliminate these drawbacks, a paper stripping device as disclosed in JP-A-61-59376 has been proposed. The side strip finger device shown in this conventional example is provided with a peeling finger which is in contact with one end of the photosensitive drum, and a plurality of guide members are provided from the peeling finger toward the other end of the photosensitive drum. In this device, the tip ends of these guide members are arranged in a curved shape such that the angle gradually increases with respect to the center of the photosensitive drum.

The peeling finger provided on the registration line side peels off the edge of the sheet, and then the guide member gradually peels toward the other edge of the sheet. Therefore, as in the case of a peeling finger that has been conventionally used, it is possible to prevent scratches from being caused by the contact of all the peeling fingers with the surface of the photoconductor drum, and it is possible to prevent the peeling belt from being used. In addition, it is configured so that it is possible to reliably prevent the generation of a portion where an image cannot be formed at the edge of the paper.

However, in the above-described conventional apparatus, since the peeling finger that contacts only one end of the photosensitive drum is used, there is a drawback that the peeling performance is deteriorated when the width of the paper becomes wider.

This drawback tends to appear as a problem such as a decrease in peelability when copying is performed using a large size paper of B4 size or more. (However, in the case of B5 and A4 size paper, the peeling property is very good.) (Object of the Invention) The present invention is a paper peeling device using the above-described conventionally used peeling finger. In a side-registration type copying machine or laser printer, a large-sized paper is peeled by the peeling fingers provided at both ends of the photoconductor drum and is provided in the middle. It is an object of the present invention to provide a sheet peeling device having a structure capable of gradually peeling by a large number of guide members.

(Means and Actions for Solving Problems) The paper peeling apparatus of the present invention is configured to form a toner image on the surface of the photoconductor drum using an electrophotographic process and transfer the toner image to paper. In a copying machine or a laser printer configured as described above, peeling fingers are provided at portions where the paper is peeled from the photosensitive drum, and both side edge portions in the paper feeding direction, with their tips being close to the photosensitive drum. A guide member composed of a plurality of guides is provided between the two peeling fingers at predetermined intervals, and each guide constituting these guide members is
The guide is composed of a horizontal portion attached to the attachment member and an inclined portion formed at the tip of the horizontal portion. The angle of the inclined portion of each guide is set to the same angle, and the tip of the inclined portion is attached to the photosensitive drum. Provided so as to be close to each other, the tip of each of the guides approaches the vertical line of the axis of the photosensitive drum at a small angle on the peeling finger side, and the angle gradually increases toward the central portion. Formed,
The device is formed in an arch shape as a whole.

Therefore, in the paper peeling device of the present invention, after peeling the edge of the paper from the photoconductor drum by the peeling finger, the guide adjacent to the peeling finger is inserted into the gap between the peeled edges, and The sheet is largely peeled off, then the guide next to it is inserted, and the peeling action is sequentially performed, so that the sheet can be peeled off in good condition.

In addition to this, in the paper peeling device of the present invention, for a large size paper, the peeling action is performed even by the peeling finger provided on the opposite side of the registration line, and the peeling action is performed simultaneously from both sides. Will be held,
The peeling performance can be greatly improved.

(Embodiment) The configuration of the paper peeling device of the present invention will be described according to the illustrated embodiment.

The paper peeling apparatus of the present invention is a side registration type copying machine or laser printer, and a peeling finger 5a provided at a position close to the side registration line 1a of the photosensitive drum 1 and a maximum size paper on the opposite side. (B4 size in this embodiment) a peeling finger 5b provided at a position that acts on the end portion, and a plurality of guides 6a to 6k arranged at predetermined intervals between the peeling fingers 5a and 5b. And a guide member 6 that is formed.

As shown in FIG. 1 and FIG. 2, the sheet peeling device of the present invention is provided in a portion for transferring an image from the photosensitive drum 1 to the sheet 2, and the image transferring portion has been conventionally used. A transfer corotron 3, a peeling corotron 4, and the like are provided in the same manner as in the case of the existing copying machine, and the toner image formed on the surface of the photosensitive drum 1 is transferred to the paper 2 by the transfer corotron 3. After that, the peeling corotron 4 performs an AC discharge to remove static electricity from the paper, so that the paper is peeled from the photosensitive drum.

Then, the sheet 2 which is not peeled off by the peeling corotron 4 is forcibly peeled off by the peeling fingers 5a and 5b.

In the paper peeling device of the present invention, the peeling fingers 5a and 5b provided corresponding to both sides of the photoconductor drum 1 are the peeling fingers which are usually used, and the tips thereof are the surface of the photoconductor drum 1. It is provided so that it can be lightly contacted with.

As shown in FIG. 1, the guide member 6 provided between the two peeling fingers 5a and 5b has a wide center-to-center interval and a narrow interval toward both ends. A large number of guides 6a to 6k are arranged.

These guides are made of thin stainless wire having a round or square cross section or a sheet metal having a narrow width, and are provided on the same mounting member as the peeling finger 5 or separately. It is supported by the frame of a copying machine or the like via the support member of.

Based on FIG. 2, the guide 7 which constitutes the guide member 6
The shape of the guide will be described (note that the reference numeral of the guide in FIG. 2 is described as the guide 7, but this is changed to avoid confusion of the reference numeral, and in fact, the guide 6 of FIG.
And shows the same).

In this embodiment, the guide 7 is composed of a horizontal portion 7a whose end is fixed to the mounting member and an inclined portion 7b inclined from the horizontal portion 7a at a predetermined angle. The tip 7c of the inclined portion 7b is provided at a predetermined distance δ from the surface of the photoconductor drum 1, and the tip 7c of the guide 7 does not contact the surface of the photoconductor drum. Therefore, the guide prevents the photosensitive drum from being damaged.

Further, as shown in the drawings, each guide of the present invention is provided in a state in which the inclined portion is bent at the same angle with respect to the horizontal portion, and the tips of these claws approach the photoconductor drum. The position to be set is, for example, the guide 6 on the peeling finger side.
At a and 6k, the angle θ with respect to the vertical line of the photosensitive drum 1 is small, and the angles of the guides 6b and 6j next to it are θ + Δ.
Is set large.

As a result, in the guide member of the present invention, the angle of the guide becomes larger toward the guide in the central portion, and the angle at the substantially central portion becomes the largest. As described above, in the guide of the present invention, the horizontal portion 7a of the end portion is long, the horizontal portion becomes shorter toward the central portion, and the inclined portion
7b is shorter at the end and gradually longer toward the center.

Therefore, in the guide member of the present invention, the peeling fingers 5 arranged at both ends are formed in a substantially arched shape at the position where the tip of the guide constituting the guide member faces the photosensitive drum.
After the edges of the sheet have been peeled off by a and 5b, the peeling is promoted by the guides adjacent to those peeling fingers, and the peeled state is gradually set by the guides forming the entire guide member.

One specific example of the guide constituting the guide member of the present invention will be described. In each guide, the inclination angle of the inclined portion is σ = 45 ° with respect to the horizontal portion. Set the distance between the tip and the photoconductor drum to 2 mm. This spacing δ is not the same as the example above for guides 6b and 6j, and for these two guides,
δ is set to 2.6 mm.

Further, the angle of the end guide on the peeling finger side with respect to the vertical line of the center of the photosensitive drum 1 is set to θ = 40 °. Then, in the case of the adjacent guide, it becomes an angle obtained by adding Δθ to the angle θ, and the angle is set to be larger toward the central portion. An example thereof is as shown in Table 1.

Since the peeling finger and the guide member of the present invention have the above-described structure, as shown in FIGS. 3 and 4, the paper 2 adheres to the surface of the photosensitive drum 1, After the toner image is transferred by the transfer corotron 3 and then the charge is removed by the peeling corotron 4, even if the sheet 2 is still attached to the surface of the photoconductor drum 1, the end portion is peeled off by the peeling finger. Is peeled off, and then the peeling operation is normally performed by the guide member 6.

For example, in the case where the size of the paper 2 is B5, A4, or A5 size that is small in the axial direction of the drum 1, the paper does not adhere to the entire image forming surface of the photosensitive drum 1, The side edge of the sheet 2 is regulated by the side registration line 1a and is attached to the photosensitive drum 1.

Therefore, in this case, the finger 5b does not perform the peeling action of the paper, and the peeling finger 5a first peels the edge of the paper, and then the peeling action of the guides 6a, 6b ... Will be performed.

That is, in the case of a paper of a size smaller than the axial direction of the drum 1 as described above, the peeling finger 5a on the side registration line side peels the end portion of the paper 2,
The part of the peeled end is introduced under the guide 6a to further promote the peeling action. Then, the portion peeled off by the guide 6a is introduced under the guide 6b, and its operation is continued in succession. It will come off.

In addition, in the case of wide paper such as B4 size paper, the peeling fingers 5a and 5b on both sides are simultaneously engaged with both side portions of the paper and peeled apart from the case of the small size paper described above. Therefore, as shown in FIG. 4, the sheet is simultaneously peeled from both sides and gradually peeled toward both sides toward the center.

In the embodiment of the present invention described above, the guide member provided between the peeling fingers may have 10 to 11 guides, but the number or spacing of the guides may be arbitrary depending on the paper quality of the paper used. Can be changed to.

Further, the configuration of the guide member described above, as shown in the embodiment, the width of the image forming portion of the photosensitive drum is B4 size, when the width of the photosensitive drum is wider than that, Naturally, the interval and the number of guide members are changed.

In addition to this, especially when many A3 size sheets are used, the guides 6a to 6h are formed as one group,
It is also possible to arbitrarily set the guides 6i to 6k as a group of the peeling fingers 5b.

Further, in the above-mentioned embodiment of the present invention, the case where a stainless wire is used as the material of the guide is shown, but in addition to this, it is also possible to use an iron material that is commonly used and reliable. Of course, it is possible to use a plastic material having properties.

(Effects of the Invention) Since the paper peeling device of the present invention has the above-described configuration, even if the peeling fingers contacting both ends of the photoconductor drum are scratched by the contact, Since the portion is outside the image forming portion of the photosensitive drum, it does not affect the image quality of the copy.

Further, since the guide member of the present invention does not come into direct contact with the image forming surface of the photosensitive drum, a clear copy can be obtained as compared with the case of using a conventionally used peeling member. Like

In addition to this, the paper stripping device of the present invention does not limit the width of the paper when stripping the paper, and since the stripping action is performed in a natural state with respect to the paper, the paper may be damaged. However, it does not cause a jam due to incomplete peeling.

[Brief description of drawings]

FIG. 1 is a plan view showing a relationship between a photosensitive drum and a peeling member in a paper peeling device of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a perspective view showing a peeling state of a small size paper. FIG. 4 is a perspective view showing a case of a large size paper. Reference numeral 1 in the figure: 1 photoconductor drum, 2 paper, 3 transfer corotron, 4 peeling corotron, 5 peeling finger, 6
...... Guide member.

Claims (1)

[Claims] 1. A copying machine, a printer, or the like configured to form a toner image on the surface of a photosensitive drum using an electrophotographic process and transfer the toner image onto a sheet. A peeling finger is provided at each of the side edge portions in the paper feed direction at the portion to be peeled, with their tips in contact with the photosensitive drum, and a plurality of guide members are provided at predetermined intervals between the two peeling fingers. Each of the guides constituting these guide members is composed of a horizontal portion attached to the attachment member and an inclined portion formed at the tip of the horizontal portion, and the bending angle of the inclined portion of each guide is the same. The guide is angled, and the tip of the inclined portion is provided so as to be close to the photoconductor drum. The tip of each guide is a vertical line of the axis of the photoconductor drum. On the other hand, the peeling finger side is approached at a small angle, and the angle is gradually increased toward the central portion, and the tip of each guide is provided in an arch shape with respect to the surface of the photosensitive drum. Characteristic paper peeling device.