JPH0652454B2 - Paper peeling claw - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a paper peeling claw of a copying machine such as an electrophotographic machine, which is arranged in the vicinity of a photoconductor and peels the paper on which a toner image is transferred from the photoconductor. In particular, the present invention relates to an improvement of a paper peeling claw capable of maintaining peeling performance for a long period of time without damaging the surface of a photoreceptor.

[Prior Art] In a conventional copying machine such as an electrophotographic apparatus, a toner image formed on a photosensitive drum (a) is transferred onto a sheet (c) by a transfer corotron (b) as shown in FIG. The image is fixed by the fixing device (d) to obtain a copy of the original document (f) placed on the platen (e).

By the way, a paper (c) is produced by the transfer corotron (b).
When a toner image is transferred from the photosensitive drum (a) to the paper (c) side by applying an electrostatic charge to the paper (c),
Is electrostatically attracted to the side of the photosensitive drum (a), so unless the sheet (c) is forcibly peeled from the photosensitive drum (a), it enters the cleaning device (g) and causes a serious trouble. there were.

Therefore, conventionally, a method has been adopted in which a paper peeling device is arranged between the transfer corotron (b) and the cleaning device (g) to prevent the occurrence of the above troubles.

And as this device, one that uses a paper peeling claw,
There are a type in which a vacuum device is arranged and peeling by suction force, a type in which a separation belt is arranged to force peeling, and a type in which peeling occurs naturally by utilizing the own weight of the paper (c).

However, the vacuum device is not practical because it has the disadvantages that the device is large and the cost is high, and it is mainly used only for ultra-high-speed machines. Although it is excellent in that the paper (c) can be reliably peeled off, it has the drawback that an image cannot be formed at the edge of the paper (c) and the photosensitive drum (a) is also easily scratched. Further, the one using the self-weight of the paper (c) has an advantage that it does not need to be provided with a special device and is inexpensive, but it is unreliable in terms of surely peeling, and particularly the thin paper (c) is used. In that case, there was a drawback that the reliability was extremely lowered.

On the other hand, the one using the paper peeling claw is relatively inexpensive without image loss, and can be sufficiently used in terms of reliability by appropriately selecting the shape, material, number of the claws, mounting state, etc. Therefore, it is generally widely used, and as shown in FIG. 12, the front end side of the paper peeling claw (h) is disposed in contact with the surface of the photosensitive drum (a).

By the way, as this kind of paper peeling claw, as shown in FIG. 13, there is known a wedge-shaped integrally formed metal having rigidity such as aluminum and iron. Since this paper peeling claw (h ₁ ) has rigidity, it has the advantage that it does not deform even if it is used for a long period of time and its peeling performance does not deteriorate. When the contact pressure to (1) is high, there is a defect that the surface of the photosensitive drum (a) is damaged due to its rigidity, and the manufacturing cost is high because the processing cost is high.

Therefore, as a paper peeling claw that does not have this drawback, see Fig. 14 ~
A paper peeling claw (h ₂ ) shown in FIG. 15 has also been developed. That is, this paper peeling claw (h ₂ ) is obtained by forming a plate-like elastic body having a thickness of about 50 μm, for example, a stainless steel plate into a band-like body by photo-etching and processing the tip side into a sharp shape. The base material side is fixedly disposed on the support material (j) and the tip end side thereof is disposed in contact with the surface of the photosensitive drum (a) for use. The paper peeling claw (h ₂ ) is more flexible and has a weaker contact force with the photosensitive drum (a) than the paper peeling claw (h ₁ ) integrally formed of metal. (A) It has an advantage that the surface is less likely to be scratched and has an advantage that the contact force can be further reduced by setting the length (l) of the paper peeling claw (h ₂ ) to be long. .

However, this paper peeling claw (h ₂ ) is apt to be deformed when it is used for a long period of time, and there is a drawback that the paper (c) cannot be peeled if its tip end side is bent away from the photosensitive drum (a). In addition, there is a defect that the surface of the photosensitive drum (a) is damaged if it is deformed in the direction of coming into contact with the photosensitive drum (a) side.

Therefore, as a further improved version of the plate-shaped paper peeling claw (h2), there is known a plate-shaped elastic body formed by increasing the thickness of the plate-shaped elastic body as shown in FIGS. That is, the paper peeling claw (h ₃ ) has a thickness of, for example, 250 to 300 μm.
A plate-shaped stainless steel plate having a shape similar to that shown in FIG. 17 is formed by punching a plate-shaped stainless steel by a punching method and the like, and mechanically polishing the tip side of the plate-shaped sheet peeling claw (h ₂ ). As well
Since the base end side is fixedly arranged on the support material (j) and the tip end side is arranged in contact with the surface of the photosensitive drum (a), the support material (j) has an advantage that deformation is unlikely to occur as the thickness increases. I have.

[Problems to be Solved by the Invention] However, in this paper peeling claw (h ₃ ),
As shown in the figure, when the inclination angle (θ) on the bottom surface (h _b ) side of the leading end portion is formed to be large, the leading end of the paper (c) conveyed along with the rotation of the photosensitive drum (a) causes the paper peeling claw. (H ₃ ) There is a disadvantage that the component force (F ₂ ) of the impact force (F ₁ ) on the side of the photosensitive drum (a) becomes large when it collides with the tip portion, and therefore the surface of the photosensitive drum (a) is There was a problem that it hurt.

On the other hand, when the inclination angle (θ) of the bottom surface (h _b ) of the tip of the paper peeling claw (h ₃ ) is formed small, the component force (F ₂ ) to the photosensitive drum (a) side becomes small, but There has been a problem that the thickness of the leading end of the paper peeling claw (h ₃ ) becomes extremely thin, and deformation easily occurs, and the peeling performance deteriorates over time.

[Means for Solving Problems] The present invention has been made in view of the above problems, and a problem is that a sheet capable of maintaining peeling performance for a long period of time without damaging the surface of the photoreceptor. To provide a peeling nail.

That is, according to the present invention, a plate-shaped claw member whose front end is in contact with the surface of the photoconductor and peels off the sheet fed by the rotation of the photoconductor, and the sheet which is peeled by supporting the claw member to the photoconductor And a tip side of the side of the claw member that does not come into contact with the photosensitive member has a concave curved surface shape whose thickness gradually increases from the tip side toward the sheet peeling direction. It is a paper peeling nail.

In such technical means, a metal material such as stainless steel, iron, phosphor bronze or the like can be used as a material forming the claw member, and the material thickness is photoetching processability, strength required for the claw member, and peeling. From the relationship with the paper thickness
It is preferably about 50 μm to 500 μm. As a method of manufacturing the above-mentioned claw member, a photo-etching method that has high processing accuracy, does not cause distortion during processing, and does not cause burrs at the claw ends is preferable. Side etching processing during this photo-etching processing is preferable. As a result, a claw member having a concave curved surface at its tip can be obtained.

The peeling claw main body includes a supporting portion that supports the claw member and a guide portion that guides the peeled sheet in a direction away from the photoconductor, and is usually formed of a plastic material having excellent workability.

Further, the supporting portion for supporting the claw member preferably has a structure in which the claw member is sandwiched from both sides in order to increase the supporting strength thereof, and when the thickness of the claw member is thin, the tip end of the claw member is left and the base end is left. A configuration in which the entire side is clamped is desirable.

[Operation] According to the technical means as described above, the tip portion is composed of the concave curved surface-shaped claw member, and the peeling claw main body that supports the claw member and guides the peeled sheet, When the leading edge of the sheet conveyed along with the rotation of the photoconductor collides with the leading edge of the claw member, the leading edge of the sheet is guided along the concave curved surface of the leading edge of the claw member sequentially in the direction away from the photoconductor. It is possible to weaken the component force of the impact force to the photoconductor side.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. A paper peeling claw according to this embodiment is shown in Figs.
As shown in the figure, it is composed of a claw member (1) and a peeling claw main body (2) that supports the claw member (1).

First, the above-mentioned claw member (1) is manufactured by the photo-etching method of stainless steel (SUS 304 CSP) described below, and the planar shape of the tip side thereof is substantially triangular, and the bottom surface of the tip part ( As shown in FIG. 6, the 3) side has a concave curved surface shape whose thickness gradually increases from the front end side toward the base end side.

On the other hand, the peeling claw body (2) is formed by integrally molding a plastic material such as ABS resin, and the arm body (4) and the claw member (1) provided on the tip side of the arm body (4). A holding part (5) for holding the paper, a guide part (6) provided on the bottom surface side of the arm body (4) for guiding the paper separated by the claw member (1), and the arm body (4). The mounting hole (10) which is provided at the substantially central portion of the mounting hole (10) is fitted to the rod-shaped mounting member (9) when the paper peeling claw (8) is arranged near the photosensitive drum (7) as shown in FIG. ) And an engaging portion which is provided on the base end side of the arm body (4) and which engages with the fixing portion (11) of the copying machine when arranging the paper peeling claw (8) and regulates the arrangement position. (12)
It is composed of and.

In the paper peeling claw (8) configured as described above, the leading end of the paper (p) conveyed with the movement of the photosensitive drum (7) is the paper peeling claw (8) as shown in FIG. ), The bottom surface (3) side of the tip part of the claw member (1) has a concave curved surface shape whose thickness gradually increases from the tip side toward the base side. Therefore, immediately after the collision, the paper (p) is guided in the substantially same direction as the conveying direction of the photosensitive drum (7),
Then, the vehicle is gradually guided downward.

Therefore, the component force (F ₂ ) of the impact force (F ₁ ) on the photosensitive drum (7) side when the paper (p) collides is remarkably reduced, and the photosensitive drum (7) is less likely to be scratched. It has the advantages of

Therefore, even if the thickness of the claw member (1) is set to be large,
Alternatively, even if the material having high rigidity is used, the photosensitive drum (7) is not damaged, so that the paper peeling claw which is hardly deformed and can maintain the peeling performance for a long time can be obtained.

If the thickness of the claw member (1) is small,
As shown in this embodiment, the whole of the base end side of the claw member (1) is left with the tip end side left behind, and the holding part (5) of the peeling claw body (2) is provided.
By sandwiching the claw member with the claw member (1), the rigidity of the tip portion of the claw member (1) is increased, so that the deformation resistance thereof can be improved.

Here, the thickness (T) dimension of the claw member (1), the thickness (t) dimension of the tip portion (13) thereof, and the concave curved surface formed on the bottom surface (3) side thereof shown in FIG. Explaining the length (L) dimension, regarding the thickness (T) dimension of the claw member (1), the photo-etching property of the metal material such as stainless steel constituting the claw member (1) and the strength required for the claw member (1). , And the thickness of the sheet of paper (p) to be peeled off, etc., and is preferably about 50 μm to 500 μm.

Further, the thickness (t) of the tip portion (13) of the claw member (1) is required to be smaller than the thickness of the paper (p) so that the paper (p) can be efficiently separated from the photosensitive drum (7). To be done. And the above-mentioned paper (p) is usually the thinnest, 50μ.
Since it is about m, 50 μm or less, preferably 20 μm to 40 μm
The degree is good.

The length (L) of the concave curved surface is preferably set as long as possible so that the impact force of the paper (p) to the photosensitive drum (7) side can be appropriately reduced. (1) The thickness of the tip side becomes thin, which causes an adverse effect of impairing rigidity. Therefore, considering the thickness (T) dimension of the claw member (1), it is preferable to set it in the range of 0.5T <L <2T ... From the relationship with the thickness (T) dimension.

Below, concrete data will be described for the thickness (t) dimension of the tip portion (13) and the length (L) dimension of the concave curved surface that are appropriate for various thicknesses (T) of the stainless steel plate.
It becomes like 1.

<Manufacture of Claw Member> A method for manufacturing the claw member (1) used in this example by photoetching will be described below.

First, a photoresist film (Fuji Chemical Industry Co., Ltd., trade name FSR) is uniformly formed on both sides of a stainless steel plate (sus 304 csp), and pattern exposure is performed from both sides thereof, and then the resist in the final exposed portion is dissolved and removed. Then, as shown in FIGS. 10 to 11 (A), photoresists (15) and (16) are formed on both surfaces of the stainless steel plate (14) by shifting the tip positions thereof.

Next, this is immersed in an etching solution of ferric chloride solution (FeCl ₃ ) and subjected to photo-etching treatment. The etching proceeds not only in the thickness direction of the stainless steel plate (14) but also in the lateral direction, and is side-etched. 11 A claw member (1) having a tip shape as shown in FIG. 11B is manufactured.

The claw member manufactured by this manufacturing method is advantageous in that it has no distortion and unevenness, and the concave curved surface is formed with high accuracy, as compared with that obtained by a punching method such as a press.

[Effects of the Invention] As described above, the present invention includes a claw member having a concave curved end at its tip and a peeling claw main body that supports the claw member and guides a peeled sheet. When the leading edge of the sheet conveyed with the rotation of the sheet collides with the leading edge of the claw member, the leading edge of the sheet is guided along the concave curved surface of the leading edge of the claw member in the direction in which the sheet is separated from the photoreceptor, and the impact thereof It becomes possible to weaken the component force of the force to the photoconductor side.

Therefore, even if the thickness of the claw member is set to a large value or the material having high rigidity is used, the photoreceptor is not damaged and the peeling performance can be maintained for a long period of time.

[Brief description of drawings]

1 to 9 show an embodiment of the present invention. FIG. 1 is a perspective view of a paper peeling claw according to this embodiment, FIG. 2 is a side view thereof, and FIG. 3 is a plan view thereof. FIG. 4 is a bottom view thereof, FIG. 5 is a partially enlarged view of FIG. 4, FIG. 6 is a sectional view taken along line VI-VI of FIG. 5, and FIG. FIG. 8 is a diagram for explaining the action of the sheet peeling claw, FIG. 9 is a diagram for explaining the dimensions of the claw member, and FIGS. 10 and 11 show the manufacturing process of the sheet peeling claw. , Tenth
The figure is a plan view in which a photoresist is formed on both sides of a stainless steel plate, FIG. 11 (A) is this vertical cross-sectional view, and FIG. 11 (B) is a vertical cross-sectional view showing the side-etched state during photoetching. Further, FIG. 12 is an explanatory view of a copying machine such as an electrophotographic machine, and FIGS. 13 to 18 show a conventional paper peeling claw. FIG. 13 is a perspective view of an example thereof, FIGS. 14 and 15 are A side view and a plan view of another conventional example, FIGS. 16 to 18 show another conventional example, and FIGS. 16 and 18 are side views thereof.
FIG. 17 shows their plan views, respectively. [Description of symbols] (1) …… Claw member (2) …… Peeling claw body (4) …… Arm body (5) …… Clamping part (6) …… Guide part (8) …… Paper peeling claw (10) ) …… Mounting hole (12) …… Engagement part

Claims (2)

[Claims] Claim: What is claimed is: 1. A plate-shaped claw member, the front end of which is in contact with the surface of a photoconductor and peels off a sheet fed by the rotation of the photoconductor, and a sheet which is peeled while supporting the claw member. A peeling claw body that guides in a direction away from the photoconductor, and the tip of the claw member on the side that does not contact the photoreceptor has a concave curved surface shape whose thickness gradually increases from the tip side toward the peeling direction of the paper. Paper peeling claw that is characterized by 2. Manufactured by a photo-etching processing method,
The sheet peeling claw according to claim 1, wherein a claw member in which the concave curved surface shape is formed by a side etching process at the time of this processing is used.