JPH03245173A - Paper peeling device for image forming device - Google Patents

Abstract

PURPOSE:To prevent an organic photosensitive body from being damaged and also to maintain a peeling performance by specifying a parameter with respect to a plastic peeling pawl. CONSTITUTION:This device is a paper peeling device provided with a plastic peeling pawl 5 for an organic photosensitive drum, and when an angle which is made by a vertical line falling down from the center of the photosensitive drum to a paper bus R against the photosensitive drum 1 and a straight line which links a position where the leading end of the peeling pawl 5 comes into contact with the photosensitive drum 1 and the center of the photosensitive drum is (c), the angle which is made by a contact surface 11 and the tangential line of the photosensitive drum 1 at the position where the leading end of the peeling pawl 5 comes into contact with the photosensitive drum 1 is (a), the angle which is made by the tangential line and a guiding surface 12 is (b), and also the component force of a load of the leading end of the peeling pawl 5 in a tangential line direction and which works on the photosensitive drum 1 is F2, the conditions of expressions I, II and III are satisfactorily established. Thus, the organic photosensitive body 1 can be prevented from being damaged and also thorough peeling performance can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a paper peeling device for an electrophotographic copying machine, a printer, a facsimile machine, etc., and in particular, it relates to a paper peeling device for an electrophotographic copying machine, a printer, a facsimile machine, etc. The present invention relates to a paper peeling device for an image forming apparatus that uses a peeling claw as a paper peeling means for separating NJ.

[Prior Art] Recently, an organic photoreceptor called ○PC has been used in electrophotographic copying machines instead of an inorganic photoreceptor such as selenium. As shown in FIG. 23(a), the organic photoreceptor has a three-layer structure in which an undercoat layer UCL, a charge generation layer CGL, and a charge transport layer CTL are sequentially provided on a conductive substrate CB, or As shown in FIG. 23 (b), there is a two-layer structure in which a charge generation layer CGL and a charge transport layer CTL are provided on a conductive substrate CB in this order, and it is a laminated type photoreceptor. The undercoat layer UCL and charge generation layer CGL usually have a thickness of 1 μm or less, and the charge transport layer CTL has a thickness of 10 to 30 μm. Among these layers, the charge transport layer CTL, which is in direct contact with the cleaning member, the developing member, the paper peeling member, etc., is made of an organic material, and therefore -111Q is fragile, easily abraded, and easily scratched. For this reason, a binder polymer is selected that has electrical properties such as chargeability and ozone resistance, and is also resistant to wear and scratches. - Polycarbonate resin, polyester resin, methacrylic resin, etc. are used for the crotch.

Incidentally, a peeling claw has conventionally been used as a means for peeling paper that has been attracted from a metal photoreceptor such as selenium.

The peeling claw for such a gold@photoreceptor is usually made of metal, and an elastic material such as polyurethane rubber is used. However, when using the above-mentioned organic photoreceptor as the photoreceptor,
As mentioned above, since organic photoreceptors are easily damaged, it has been thought that it is not a good idea to construct a paper peeling device using a peeling claw.

[Problems to be Solved by the Invention] However, as a result of study, it has been found that a peeling claw using a highly hard plastic such as amide-imide or polyamide-imide resin does not damage the organic photoreceptor and maintains sufficient peeling performance. It has been found that a paper peeling device can be constructed using the present invention.

Therefore, an object of the present invention is to provide a paper peeling device using a peeling claw for an organic photoreceptor, and in particular, to provide a paper peeling device that does not damage the organic photoreceptor and maintains sufficient peeling performance. The purpose of this study is to identify parameters related to plastic peeling nails.

[Means to solve the problem]

When using a plastic peeling nail for an organic photoreceptor as described above, the present invention provides a shape of the peeling nail that does not damage the organic photoreceptor and maintains sufficient peeling performance.
The paper peeling device of the image forming apparatus of the present invention is a result of pursuing the layout, etc., and achieves the above object.
In a paper peeling device using a plastic @ separation claw for organic photoreceptor drums, the separation claw consists of a contact surface that contacts the photoreceptor drum and a guide surface that guides the separation when the paper abuts. The surfaces intersect to form the tip of the stripping claw, and connect a perpendicular line drawn down from the center of the photoconductor drum to the paper bus against the photoconductor drum, the position where the tip of the stripping claw contacts the photoconductor drum, and the center of the photoconductor drum. The angle between the contact surface and the straight line is C, the angle between the contact surface and the tangent to the photoreceptor drum at the position where the tip of the peeling claw contacts the photoreceptor drum is a, and the angle between the tangent and the guide surface is b. ,Also,
When the component force in the tangential direction of the load that the tip of the peeling claw acts on the photosensitive drum is F2, a≧5°, 211. ,■F2≦
320mgf ・・・・・・ ■2°≦
b-c≦17°... It is characterized by satisfying the condition [3].

In addition, if the tip of the peeling claw is configured in a conical shape, it is advantageous in terms of the incidence of black spots and finger marks.

In addition, when the peeling claw is provided with a flank that connects to the rear side of the guide surface, and the length of the guide surface is L, 1.9 mm≦L≦13.5 mm ---...
When the condition [4] is satisfied, the unfixed image is rubbed by a peeling nail (hereinafter referred to as "smatujiko").

) can be reduced.

Also, the load that the tip of the peeling claw acts on the photoreceptor drum is F.

When 0, 3gf≦F, ≦1. It is more desirable to satisfy the condition of 2 gf -■ in terms of releasability and damage to the photoreceptor drum.

In addition, when the radius of curvature in the cross section perpendicular to the axis of the photoreceptor drum at the tip of the peeling claw is 15μm≦r≦45μm......It is important to satisfy the following condition to improve the peelability. More desirable from this point of view.

Furthermore, coating at least the tip of the peeling claw and the guide surface with glass, fluororesin, etc., which has a small friction coefficient and high hardness, reduces the friction coefficient of the tip and prevents scratches on the surface of the photoreceptor drum. It is desirable to raise the guide surface to protect the tip, and also to prevent roughness of the guide surface and improve the smudge level.

[Effect]

First, since the condition a≧5° is satisfied, the contact length of the contact surface becomes longer, causing scratches on the photosensitive drum and causing black streaks and white spots on the copy. There isn't.

Also, F2≦320mgf... ■
Since the following conditions are satisfied, the peeling nail does not scratch the surface of the photoreceptor and dig into it, thereby preventing damage to the photoreceptor.

Furthermore, 2゛≦b−c≦17° ・・・・・・ [3]
Since the following conditions are satisfied, the paper is subjected to appropriate buckling peeling by the peeling claw, and sufficient peeling performance is obtained.

[Embodiments] Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a portion of an electrophotographic copying machine in which a paper peeling device of the present invention is attached, showing a photosensitive drum 1 after transfer.
A cleaning device 2 is provided at a distance from the transfer area for removing toner remaining thereon. R in the drawing represents the path of the copy paper, and some of the copy paper P reaches the position of the cleaning device 2 without being peeled off from the photosensitive drum 1 in the region of the peeling corotron (not shown). A paper peeling device 3 is installed between the transfer area and the cleaning device 2 in order to forcibly peel the paper P with such peeling defects from the photoreceptor drum 1.

The paper peeling device 3 has a peeling claw 5 made of a highly hard plastic such as amide-imide or polyamide-imide resin.
This attachment is made up of a base 4, which gives the peeling claw 5 a counterclockwise rotation behavior in the drawing. The peeling claw 5 is shown in a side view (a) and a cross-sectional view (Fig.
As shown in the cross section along the line B-B (g), the tip in contact with the photoreceptor drum 1 has a square pyramid shape, and the pivot shaft 6 is integrally attached thereto. A protrusion 8 on which a spring 7 is hooked is provided at the rear end.

FIG. 2 shows a plan view of the paper peeling device 3, and as is clear when referenced together with FIG. It is given a turning habit in the rotational direction, and its tip applies a constant load F to the photoreceptor drum 1. A plurality of such paper peeling devices 3 (for example, three) are installed at intervals in the axial direction of the photoreceptor drum 1, and each paper peeling device 3 moves back and forth (photoreceptor) along the axis 9 at a slow cycle. It is designed to reciprocate in the axial direction of the drum l, and prevents the surface of the photoreceptor from being constantly contacted at the same position and damaging only that position. By the way, as for the tip shape of the peeling claw 5, as shown in the diagrams seen from four directions in FIG.
There is a triangular pyramid type, and a square pyramid type (C) in the figure.
In the present invention, either type may be employed. However, as will be described later, the square pyramid type is the most preferred, the triangular pyramid type is the second best, and the flat type is the worst among the three types.

Now, the shape of the peeling nail 5 is determined from the viewpoint of the scratches caused by the peeling nail 5 mainly on the organic photoreceptor 1 and the peeling characteristics of the copy paper.
Consider parameters such as placement. Polyamide-imide resin was used as the material for the peeling claws 5 used in the following measurements.

First, as definitions of terms, referring to FIG. 5, the surface of the peeling claw 5 that contacts the photoreceptor drum is referred to as the drum contact surface 11, and the surface against which the paper hits and guides the peeling is referred to as the guide surface 12.
The rear surface of the guide surface 12 is defined as a relief surface 13. Then, set the angle between the perpendicular line drawn from the center of the photoreceptor drum 1 to the paper bus R and the straight line connecting the center of the photoreceptor drum 1 to the position where the tip of the peeling claw 5 contacts the drum 1 to this angle. C, the paper bus R and the tip of the peeling claw 5 are connected to the drum 1.
It is equal to the angle between the tangent line and the point where it touches.

), the angle between the drum contact surface 11 and the tangent at the position where the tip of the peeling claw 5 contacts the drum 1 is a (contact angle),
Further, the angle between this tangent and the guide surface 12 is defined as b. The angle (b-c) will be referred to as the rake angle of the peeling claw 5. Further, the length of the guide surface 12 is assumed to be L.

First, consider the contact surface 11. The contact surface 11 can be said to be a surface that comes into direct contact with the organic photoreceptor 1 or a surface that can damage the photoreceptor drum 1 . Therefore, the average roughness of the drum scratch surface was measured using the contact length of the peeling claw in the drum process direction (rotation direction) as a parameter. The measurement conditions were A4 with a Japanese chart at normal copying speed.
The roughness of the drum scratches was measured after 100,000 sheets of paper were flowed. Only the above-mentioned contact length was changed, and other parameters were kept the same. As a result, the results shown in FIG. 6 were obtained. It is known that if the average roughness of the surface of the drum scratch is 0.4 μm or less, black lines and white spots on the copy will not occur due to the drum scratch, so from this graph, it is clear that the drum rotation direction of the contact surface 11 is It can be seen that the contact length needs to be 0.92 mm or less. In the case where the angle a is changed under this premise of failure, the peeling claw 5
The contact length was measured. The results are shown in FIG. From this graph, it was found that the contact length was saturated at approximately 50,000 sheets, regardless of the angle of a, and that the larger the angle of a, the smaller the contact length. If the drum scratch surface roughness is determined using the contact angle a as a variable from the relationship shown in FIG. 6 and the relationship shown in FIG. 7, the relationship shown in FIG. 8 is obtained.

As is clear from this figure, in order to reduce scratches on the surface of the photoreceptor drum 1 caused by the contact surface 11 of the peeling claw 5 and to prevent black streaks and white spots from occurring on copies, the contact angle a
It can be seen that must be greater than or equal to 5'''.In other words, a≧5゛...
However, if the contact angle a becomes too large, the component force of the load that the peeling claw 5 applies to the photoreceptor 1 in the direction of the surface line of the photoreceptor 1 increases, and the peeling claw 5 scratches the surface of the photoreceptor, causing food particles to form therein. v) It is expected that the damage caused to the photoreceptor will begin to increase due to the increased impact. Therefore, we decided to measure the average roughness of the drum scratch surface using this value as a parameter. First, the component force F2 is defined as shown in FIG. That is, the load that the tip of the peeling claw 5 acts on the photoreceptor 1 is F as described above. Let the component force in the tangential direction at the contact point be F as shown in the figure. FIG. 10 shows the results of measuring the average roughness of the drum scratch surface using this component force F as a variable. Load F that the peeling claw 5 acts on the photoreceptor drum 1.

If the tangential force F2 exceeds 320 mgf, scratches that cause black lines and white spots will occur on the copy.
Ru. So, F2≦320mgf
. . . From this value, once the installation position of the peeling claw 5, the tip load, etc. are determined, the upper limit value of the contact angle a is determined as a result. In practice, the contact angle a is 10'
It is a good idea to choose a certain degree).

Next, the rake angle (b-c) of the guide surface 12, which is the surface against which the paper abuts and guides separation, will be discussed. The guide surface 12 is the most effective surface for forcibly peeling off the paper P attracted to the photoreceptor drum 1. It can be imagined that the angle of this surface with respect to the paper bus R will greatly affect the releasability. Therefore, the above rake angle (b−c
) was used as a variable to measure the frequency of occurrence of peeling defects. The results are shown in FIG. The measurement conditions were: the circumferential speed of the drum 1 was 300 mm/sec, the peeling corotron (not shown) was turned off, and all the paper reached the peeling claw 5), blank paper was used as the document, and the paper had a basis weight of 65 g/m'; Paper thickness 84
μm, basis weight 57゜3 g/m', paper thickness 80μ
After running 2000 sheets using A4 horizontal feed of m, the number of defective peeling was calculated per 1000 sheets. As is clear from this figure, 2°≦b-c≦17°...
... The rake angle (b-c) of the guide surface 12 is in the range of [3]
With this, the copy sheet will be sufficiently peeled within acceptable limits. The reason why peeling defects occur in areas A and B in the figure is considered as follows. That is, in the schematic diagram of FIG. 12, the reason why the copy paper P hits the peeling claw 5 and is peeled off is because the paper P is kneaded to some extent by the peeling claw 5 and is ideally peeled from the drum 1. However, if the rake angle (b-c) is in the range of
As shown in A in the figure, the above-mentioned kneading and peeling is not performed sufficiently on the paper P, and the paper P moves upward and gets caught in the cleaning device 2 (see Figure 1), etc., resulting in poor peeling (
This is because it becomes jam). On the other hand, in region B, as shown in B in the figure, the paper P is kneaded more than necessary, and a jam occurs in which the paper gets caught in the peeling claw 5 portion.

Incidentally, the length L of the guide surface 12 is largely related to smearing, which is a phenomenon in which the copy paper P comes into contact with the peeling claw 5 during peeling, and streaks appear on the copy due to the contact. Therefore, the grade of smudges appearing on copies was evaluated using the length of the guide surface 12 as a variable. The test conditions were duplex/multiple mode copying on the second side (copy paper P curled upwards, where smudges tend to appear).

〉, the paper is tsubo 165g/m', paper thickness 84μm,
The paper was paper with a basis weight of 57.3 g/m' and a thickness of 80 μm, and was carried out using 4-cross feed. The results are shown in FIG.

The length L of the guide surface 12 is 1.9mm≦L≦8.6mm ・=-= [3
], it can be seen that smuts only appear at levels below the allowable value. Examining the reason why such a difference occurs in each area A-C in the figure, we find that, as shown in the schematic diagram in Figure 14, L is smaller than 1.9 mm5) Area A
), the paper P is not kneaded sufficiently and progresses by rubbing against the flank 13 of the peeling claw 5, and it is thought that this contact causes many smudges. . On the other hand, in the region C where L is larger than 8.6 mm, the kneading phenomenon occurs sufficiently for the paper P, but since the length of the guide surface 12 is too long, the paper P rubs against this surface 12 and advances. Therefore, it is thought that many smudges occur due to that contact. On the other hand, in the region BL, the kneading phenomenon for the paper P and the length of the guide surface 12 are balanced, and it is considered that the level of occurrence of smearing is improved.

By the way, it can be imagined that the magnitude of the tip load FC+ (see FIG. 9) of the peeling claw 5 has a great deal to do with the peelability and how the photosensitive drum 1 is damaged. First, regarding the peelability of the paper, when the paper collides, the peeling claw 5
The level of the vibration frequency generated was measured, and the quality of the peelability was determined based on this level. In other words, if a lot of vibration occurs when the paper collides with the stripping claw 5, the stripping claw 5 will float away from the photoreceptor 1, and the paper will enter between the photoreceptor 1 and the tip of the stripping claw 5. This is because it may cause a jam. The measurement results are shown in FIG. As is clear from this figure,
The vibration level of the peeling claw 5 at the time of paper collision is the load F at the tip of the peeling claw 5. is 0. It can be seen that when it is smaller than 3gf, the condition deteriorates rapidly, and therefore peeling failure occurs. Next, the load F on the tip of the peeling claw 5. The scratches on the surface of the photoreceptor drum 1 were measured using as a variable.

The test conditions were such that the peeling claw 5 was moved back and forth in the radial direction of the photosensitive drum 1 and brought into contact with the photosensitive drum 1, and after copying 50,000 copies, the average roughness of the scratched surface of the drum 1 was measured. The results are shown in FIG.

As is clear from this graph, in order to cause black streaks and white spots on copies due to drum scratches (bL'), the load F0 at the tip of the peeling claw 5 must be 1°2 g (hereinafter ';
J = Lat. From the above, the load F at the tip of the peeling claw 5 is: 0.3gf≦F0≦1.2gf...
■It is desirable that it be.

Further, the tip of the peeling claw 5 is not a perfect point but has a curvature. The radius of curvature in the cross section (t = perpendicular to the axis of the photosensitive drum 1) also relates to the releasability. The releasability was measured under the same conditions as in FIG. 11, using the radius of curvature r in the cross section of the tip of the releasable claw 5 as a variable. The results are shown in FIG.

When the radius of curvature r becomes smaller than 15 μm (area A in the figure)
It is thought that the reason why the peelability deteriorates rapidly is that the tip of the peeling claw 5 is damaged by collision with the paper, and it becomes impossible to peel the paper from now on. Furthermore, when the radius of curvature r becomes larger than 45 μm (region B in the figure), the peelability deteriorates rapidly as well, because the paper usually has a thickness of 80 to 90 μm, so the leading edge has a radius of curvature of about 1/2 of this. This is thought to be because the thickness of the tip is about the same as that of the paper, making it difficult to peel it off. Therefore, the radius of curvature r of the tip of the peeling claw 5
It is desirable that 15 μm≦r≦45 μm .

Finally, the incidence of black spots on copies, the grade of finger marks at one end of copies, and the surface roughness of drum scratches were measured depending on the shape of the tip of the peeling claw 5 as shown in FIG.

The toner remaining on the photoreceptor drum 1 after the transfer and a portion of the toner transferred to the copy paper during peeling adhere to the Mn nail 5. This adhered toner scatters onto the peeled copy paper and appears as black dots on the copy. This is the occurrence of black dots on the copy. The finger mark at one end of the copy is a mark that is generated when the leading edge of the paper abuts against the peeling claw 5. FIG. 18 shows the sunspot occurrence rate for each of the flat type, triangular pyramid type, and square pyramid type. The test conditions were to count the number of A4 originals with full Japanese text on which black spots with a diameter of 0.3 mm or more appeared among 100 sheets. From this figure, it can be seen that by forming the tip into a triangular or square pyramid shape, the incidence of sunspots can be significantly reduced. FIG. 19 shows the grade evaluation of the finger mark at one end of the copy for each of the flat type, triangular pyramid type, and square pyramid type. The measurement conditions were a limit sample evaluation of finger marks on 10 to 30 sheets of Japanese paper with the peeling corotron turned off; ', A4 horizontal feed with a paper thickness of 80 μm was used. From this figure, it can be seen that finger marks can be reduced by making the tip conical.

Make it a square pyramid type rather than a triangular pyramid type, that is,
It can be seen that the improvement effect becomes greater by making the tip sharper.

Moreover, FIG. 20 shows the results of measuring the roughness of drum scratches when copying was performed continuously while the peeling claw 5 was vibrated in the axial direction of the photoreceptor drum 1. , it is not possible to say that the degree of scratching will change.
Ta. From the results shown in Figures 18 to 20 above, the peeling claw 5
There is a huge difference in damage resistance depending on the type, and it can be said that the square pyramid type is superior in terms of sunspot incidence and finger marks, followed by the triangular pyramid type.

By the way, when the peeling claw 5 is made of plastic such as amide-imide resin, the coefficient of friction at the tip that contacts the photoreceptor drum 1 is reduced to prevent scratches on the surface of the photoreceptor drum 1, and the hardness of the peeling claw 5 is increased. In order to protect the tip of the guide surface 12 and improve the smudge level by preventing roughness of the guide surface 12, at least the tip and the guide surface 2 are made of glass, fluororesin, etc. with a low coefficient of friction and high hardness. It is desirable to apply a coating.

As described above, in an image forming apparatus using an organic photoreceptor, plastic is used as the peeling claw 5 of a paper peeling device.
When using a photoreceptor drum 1, the contact angle a of the contact surface 11 with respect to the photoreceptor drum 1 should be a≧5°. This is a necessary condition to prevent streaks and white spots from occurring. In addition, for the same purpose, the tangential component force F2 of the load that the tip of the peeling member 5 acts on the photoreceptor drum 1 is F, ≦320 mgf ...... ■
It is necessary to satisfy the following conditions.

Furthermore, in order to make the paper peeling property of the peeling claw 5 sufficient, the rake angle (b-c) of the guide surface 12 should be 12°≦b-c≦17°... [3
] It is necessary to satisfy the following conditions.

Furthermore, in order to reduce smearing caused by the peeling claw 5, the length L of the guide surface 12 should be 1.9 mm≦L≦3. [It is desirable to be in the range of 1 mm - ■.

Load F at the tip of the peeling claw 5. As for 0, 3gf≦F0≦, from the releasability and the way the photosensitive drum 1 is damaged.
1,2gf...■ It is desirable.

Also, the tip of the peeling claw 5 is perpendicular to the axis of the photoreceptor drum 1),
(with radius of curvature r in the cross section), 15μm≦r≦4
5μm... ■It is desirable.

In terms of sunspot incidence and finger marks, pyramid-shaped ones such as a square pyramid type and a triangular pyramid type are preferable.

Furthermore, the coefficient of friction at the tip is reduced to prevent scratches on the surface of the photoreceptor drum 1, the hardness of the peeling claw 5 is increased to protect the tip, and the guide surface 12 is prevented from becoming rough to improve the smudge level. In addition, it is desirable that at least the tip and the guide surface 12 be coated with glass, fluororesin, or the like, which has a low coefficient of friction and high hardness.

As a specific example, an organic photoreceptor is used, the peeling claw 5 is made of amide-imide resin, the contact angle a is 10°, the tangential load F is 200 mgf, and the rake angle of the guide surface 12 (b
-c) is 5 degrees, its length is 5 mm, and the tip load Fo of the peeling claw 5 is 1. 0 gf, the radius of curvature r of the tip of the peeling claw 5 is 3
When the peeling claw 5 was set to 0 μm and was installed in an actual machine while reciprocating in the axial direction of the photoreceptor drum 1, black lines and white spots on the copy due to drum scratches caused by the peeling claw 5 were observed during copying of 100,000 sheets. , jams and smudges due to poor peeling,
No problems with finger marks or sunspots occurred.

Further, the wear of the peeling claw 5 was also within the allowable limit.

In the above description, the image forming apparatus is assumed in which the paper bus R is arranged horizontally below the photoreceptor drum 1. However, the above shape and parameter conditions regarding the peeling claw 5 are An image forming apparatus in which the paper bus R is arranged horizontally above the photoreceptor drum 1 as shown in the figure, and an image forming apparatus in which the paper bus R is arranged on the side of the photoreceptor drum 1 as shown in FIG. It has been confirmed that this is the case, and the present invention is also applicable to image forming apparatuses with these arrangements.

〔Effect of the invention〕

The paper peeling device of the image forming apparatus of the present invention is a paper peeling device using a plastic peeling claw for an organic photoreceptor drum, in which the peeling claw guides the paper in abutment against a contact surface that contacts the photoreceptor drum to guide the paper in peeling. The contact surface and the guide surface intersect to form the tip of the stripping claw, and the tip of the stripping claw is connected to a perpendicular line drawn from the center of the photoconductor drum to the paper bus to the photoconductor drum. The angle between the contact position and the straight line connecting the center of the photoreceptor drum is C, the angle between the contact surface and the tangent to the photoreceptor drum at the position where the tip of the peeling claw contacts the photoreceptor drum is a, and the tangent line is Let b be the angle formed by the tip of the peeling claw and the guide surface, and let F be the component force in the tangential direction of the load that the tip of the peeling claw acts on the photoreceptor drum.
When a≧5゛...
... [1] F2≦320mgf ・
... ■2°≦b-c≦17° ...
... Since the configuration satisfies the condition [3], the contact length of the contact surface is long and the photosensitive drum is not scratched, resulting in black streaks and white spots on the copy.
In addition, the peeling nail does not scratch the surface of the photoreceptor and dig into it, so the photoreceptor is not damaged. Further, the paper is moderately kneaded and peeled by the peeling claw, and sufficient peeling performance can be obtained.

In addition, if the tip of the peeling claw is configured in a conical shape, the incidence of sunspots will be reduced.
It is advantageous in terms of finger marks. Furthermore, the peeling claw is provided with a relief surface that connects to the rear side of the guide surface, and the length of the guide surface is reduced to L.
When 1.9mm≦L≦8.6mm ---...[
If the condition 4] is satisfied, smearing caused by the peeling nail can be reduced. Also, the load that the tip of the peeling claw acts on the photoreceptor drum is F. When 0.3gf≦F, ≦1. It is more desirable to satisfy the condition of 2gf -■ in terms of releasability and damage to the photoreceptor drum. Furthermore, when the radius of curvature in the cross section perpendicular to the axis of the photoreceptor drum at the tip of the peeling claw is r, it is desirable to satisfy the following conditions: 15 μm≦r≦45 μm, from the point of view of peelability. More desirable. In addition to this, coating the tip of the peeling claw and the guide surface with glass, fluororesin, etc., which has a small coefficient of friction and high hardness, reduces the coefficient of friction at the tip and prevents scratches on the surface of the photoreceptor drum. It is possible to increase the hardness of the peeling claw to protect its tip, and also to prevent roughness of the guide surface and improve the level of smearing.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a portion of an electrophotographic copying machine in which a paper peeling device according to an embodiment of the present invention is attached, FIG. 2 is a plan view of a paper peeling device according to an embodiment of the present invention, and FIG. 3 is a peeling A side view (a) and a cross-sectional view of the nail), Figure 4 is a view of the tip shape of the peeling nail seen from four directions, Figure 5 is a diagram for defining terms, angles, and lengths, and Figure 6 is a diagram for defining terms, angles, and lengths. A diagram showing the measurement results of the drum scratch roughness when the contact length of the peeling claw is used as a variable, FIG. 7 is a diagram showing changes in the contact length when the contact angle of the peeling claw is changed,
Figure 8 is a diagram showing the surface roughness of the drum scratches using the contact angle as a variable, Figure 9 is a diagram to explain the definition of the force component of the peeling claw tip load in the direction of the surface of the photoconductor surface, and Figure 10 is the tangent line. Figure 11 shows the results of measuring the average roughness of the drum scratch surface using the directional load as a variable. Figure 11 shows the results of measuring the frequency of peeling defects using the rake angle of the guide surface as a variable. Figure 12 shows the results.
j) Schematic diagram to explain the cause of defective peeling when the angle changes, Figure 13 is a diagram showing the results of evaluating the grade of smudge with four variables of guide surface length, Part 1
Figure 4 is a schematic diagram to explain why smearing occurs when the length of the guide surface changes, and Figure 15 shows the tip load of the peeling claw as a variable; thus, the measured frequency of vibration generated in the peeling claw is Figure 16 shows the results of measuring the scratches on the surface of the photoreceptor drum using the load at the tip of the peeling nail as a variable. Figure 17 shows the peelability measured using the radius of curvature at the tip of the peeling nail as a variable. The results are shown in Figures 18 and 4, and Figure 20 respectively measure the incidence of black spots on copies, the grade of finger marks at one end of copies, and the surface roughness of drum scratches due to differences in the tip shape of the peeling claw5). Figure 21 showing the results of
The figure is a sectional view when the paper stripping device (5) of the present invention is attached to an image forming apparatus in which the paper bus is arranged horizontally above the photoreceptor drum, and Fig. 22 shows that the paper bus is placed horizontally above the photoreceptor drum. FIG. 23 is a cross-sectional view of the paper peeling device of the present invention attached to an image forming apparatus disposed on the side, and FIG. 23 is a cross-sectional view of an organic photoreceptor. 1... Photosensitive drum, 2... Cleaning device, 3
・Paper peeling device, 4... Mounting on base, 5... Peeling claw, 6... Rotating shaft, 7... Spring, 8... Protrusion, 9...
Shaft, 11...Contact surface, 12...Guide surface, 13...Running surface, P...Copying paper, R/Paper bus Applicant: Fuji Celonox Co., Ltd.

Claims (1)

[Scope of Claims] (1) In a paper peeling device using a plastic peeling claw for an organic photosensitive drum, the peeling claw is a guide surface where the contact surface that contacts the photosensitive drum and the paper abut against each other to guide the peeling. The contact surface and the guide surface intersect to form the tip of the stripping claw, and there is a perpendicular line drawn from the center of the photoconductor drum to the paper path to the photoconductor drum, and a position where the tip of the stripping claw contacts the photoconductor drum. The angle between the contact surface and the straight line connecting the center of the photoreceptor drum is c, the angle between the contact surface and the tangent to the photoreceptor drum at the position where the tip of the peeling claw contacts the photoreceptor drum is a, and the angle between the tangent and the guide surface is When the angle formed by the stripping claw is b, and the component force in the tangential direction of the load that the tip of the peeling claw acts on the photoreceptor drum is F_2, a≧5°...[1] F_2≦320mgf ...[2] -2°≦b-c≦17° ...[3] A paper peeling device for an image forming apparatus, characterized in that it satisfies the following conditions. (2) The paper peeling device for an image forming apparatus according to claim 1, wherein the tip of the peeling claw is configured in a conical shape. (3) The peeling claw has a flank that connects to the rear side of the guide surface, and when the length of the guide surface is L, 1.9 mm≦L≦8.6 mm...[4] Condition 3. A paper peeling device for an image forming apparatus according to claim 1, wherein the paper peeling device satisfies the following. (4) The load that the tip of the peeling claw acts on the photoreceptor drum is F_
0. The image forming apparatus according to claim 1, wherein the image forming apparatus satisfies the following condition: 0.3gf≦F_0≦1.2gf...[5] Paper peeling device. (5) When the radius of curvature in the cross section perpendicular to the axis of the photoreceptor drum at the tip of the peeling claw is r, the following condition is satisfied: 15μm≦r≦45μm...[6] A paper peeling device for an image forming apparatus according to any one of claims 1 to 4.