JP2811216B2 - Photosensitive drum positioning device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for positioning a cylindrical drum when manufacturing an electrophotographic photosensitive member by applying a photosensitive liquid to the cylindrical drum.

[Conventional technology]

In manufacturing an organic photoconductor photosensitive drum which is a photosensitive member used in an electrophotographic apparatus, a photosensitive coating solution is applied to a cylindrical drum base. For the application, it is necessary to perform an adjustment operation of positioning a slide hopper at a predetermined position around the cylindrical drum and maintaining a constant clearance between them in the circumferential direction. In this case, since the required thickness of the coating layer is extremely small, even if the cylindrical drum is displaced by 0.1 mm, it causes a large deviation in the thickness of the coating layer as a whole in the circumferential direction.

It is a well-known fact that such a deviation in the thickness of the coating layer causes various problems such as a change in the amount of charge, a non-uniform sensitivity, and a change in the residual potential in the circumferential direction of the cylindrical drum. Therefore, accurate positioning of the cylindrical drum is extremely important.

2. Description of the Related Art Conventionally, as a drum positioning device of this type, for example, there is a technology described in Japanese Patent Application Laid-Open No. Sho 60-50537. As shown in FIG. 8, the position regulating rollers 11, 11 rotatably provided on the support members 10, 10 are provided in contact with the outer periphery of the drum 1.

[Problems to be solved by the invention]

However, in this type of conventional device, since the position regulating roller is positioned while directly contacting the drum, there is a problem that the drum is damaged. It is well known that electrophotographic properties deteriorate when a drum is damaged.

Further, when positioning the drum at only one position in the axial direction of the drum, if the drum is supplied by being inclined by the drum moving means as shown in FIG. Even if the position is regulated,
It moves in the axial direction while being tilted. As a result, as shown in the same drawing, it collides with the support member or moves without maintaining a uniform gap with the coating head.

Therefore, a main object of the present invention is to position the drum without damaging the drum, prevent the drum from tilting and moving, and always maintain a uniform clearance with respect to the coating head.

[Means for solving the problem]

An object of the present invention is to provide an apparatus for positioning a drum base when a coating liquid is applied to the outer peripheral surface of a cylindrical drum substrate when the photosensitive drum is manufactured by surrounding the cylindrical drum substrate with the coating liquid; Or, at a position where the coating liquid has been applied, there is provided a spraying means for spraying a fluid to the outer peripheral surface thereof to position the cylindrical drum by the fluid pressure, and the spraying means is provided with a plurality of spraying means spaced apart in the axial direction of the drum base. It is solved by being arranged.

(Operation)

In the present invention, a fluid is sprayed on the outer peripheral surface to position the cylindrical drum by the fluid pressure. That is, when a fluid, for example, air is blown from the periphery of the drum, the blowing pressure neutralizes the position of the drum, thereby positioning the drum at a predetermined position.

Moreover, since there is no mechanical contact with the drum, it is possible to prevent the drum from being damaged.

On the other hand, positioning is performed at a plurality of positions in the axial direction of the drum, so that the drum shaft can be uniformly held with respect to the axis of the coating head without tilting, thereby causing collision with the coating head and clearance in the circumferential direction. Can be prevented, and the coating film pressure can be made uniform.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to Examples.

FIG. 1 and FIG. 2 show the first embodiment.
Is a drum base (hereinafter simply referred to as a drum) having a hollow cylindrical shape, for example, and is continuously raised by raising a bottom surface of a drum (not shown) by a cylinder or the like or by alternately gripping the drum with appropriate gripping means. It has become.

Reference numeral 2 denotes an annular coating head for applying a photosensitive liquid to the outer peripheral surface of the drum 1, which is fixed to the ground, and
During the ascending process, the photosensitive liquid is applied by continuously discharging the photosensitive liquid from an outlet opened on the inner surface side.

As a coating head as a coating unit used in the present invention, as long as it has a basic configuration that is arranged to surround the outer surface of the drum and coats the coating liquid on the outer surface of the drum,
Those disclosed in JP-A-58-189061, JP-A-60-50537 and the like can be appropriately employed.

This example is shown in FIG. The coating head 2 is a slide hopper type coating head.

Explaining this, a narrow coating liquid distribution slit 22 having a coating liquid outlet 21 opening to the drum 1 side is formed in the coating head 2 in the horizontal direction. The slit 22 communicates with a liquid reservoir header 23.
Is supplied by a pressure pump (not shown).

On the other hand, on the lower side of the application liquid outlet 21 of the slit 22, a liquid slide surface 25 is formed so as to continuously incline in a downward constriction and terminate at a dimension slightly larger than the outer dimension of the drum 1, A lip 26 extends downward from the end of the liquid slide surface 25.

When the coating head 2 is used, the photosensitive liquid L is supplied to the slit 22 and the coating liquid outlet in the process of lifting the drum 1.
It is extruded from 21 and flows down along the liquid slide surface 25. The photosensitive liquid L that has reached the lip 26 is applied to the outer surface of the drum base 1 with a thickness substantially equivalent to the clearance between the lip 26 and the drum 1.

In order to supply the drum 1 coaxially to this type of coating head 2, positioning spraying means using fluid pressure is provided. In the first embodiment shown in FIGS. 1 and 2, the discharge nozzles 3, 3, 3 for blowing air are arranged such that their tips are spaced evenly from the center axis of the coating head 2 and extend in the circumferential direction. The discharge nozzles 3 are arranged horizontally toward the center axis of the drum 1 at an angle of 120 degrees, and each discharge nozzle 3 communicates with a common annular header 4. The annular header 4 is supplied with high-pressure air from a compressor 5. The high-pressure air guided to the annular header 4 is supplied from the discharge nozzles 3, 3, 3 with a uniform discharge amount and pressure to the drum 1. Is sprayed at a high speed toward the outer peripheral surface. As a result, the drum 1 is positioned at the same axis with respect to the center axis of the coating head 2. Therefore, the photosensitive liquid from the coating head 1 is applied to the outer peripheral surface of the drum 1 with a uniform coating thickness.

Further, for a set of blowing means disposed at a certain position of the drum 1 having the discharge nozzles 3, 3, 3 as elements, the blowing nozzles 3A, 3A, 3A are positioned at other positions in the axial direction. Another set of spraying means is provided. In the embodiment, the other sets of blowing means have the same configuration, and the common compressor 5 allows air to be discharged from each discharge nozzle 3A.

In this case, the discharge amount air or pressure from each set can be made different by the control valves 6 and 6A. further,
The air blowing position from the discharge nozzles 3 and 3A group of each set is the second position.
As shown in the figure, for example, they can differ by 60 degrees.

In this manner, if air is blown onto the drum 1 at different positions in the axial direction, the inclination of the drum 1 can be prevented. If necessary, not only two sets but also three or more sets of spraying means can be provided.

FIG. 3 shows a second embodiment, in which four discharge nozzles 3 are arranged around the drum 1 at an angle of 90 degrees. Thus, the number of the ejection nozzles 3 in a certain set is not limited. Further, the shape of the tip of the discharge nozzle 3 can be made parallel to the outer peripheral surface of the drum 1 as shown in FIG.

On the other hand, as for the disposition position of the discharge nozzles 3, each set of discharge nozzles is not provided only below the coating head 2, and one set may be provided above the coating head 2 as shown in FIG. Good. Regarding the discharge nozzle group 3A provided above the coating head 2, the drum 1 after the photosensitive liquid is coated
Will be blown against. At this time, it is desirable to select a position where the viscosity of the photosensitive liquid is high or the photosensitive liquid is dried to some extent.

Furthermore, the tip position of each discharge nozzle 3 or 3A can be adjusted freely. Since the relative positional relationship between the ejection nozzle 3 and 3A and the coating head 2 is important,
As shown in the figure, it can be attached to the coating head 2 so as to be integrally or horizontally adjustable.

In the present invention, as the spray fluid, other gas may be used other than air, and a liquid such as water may be used.

As described above, the present invention is extremely effective as a coating device for producing an electrophotographic photosensitive member. As the photosensitive liquid in this case, an inorganic photosensitive material such as zinc oxide or cadmium sulfide, or a liquid in which an organic photosensitive material such as polyvinyl carbazole and trinitrofluorene is dispersed in a polymer binder can be used. In recent years, a function-separated type photosensitive layer in which a charge generation layer and a charge transport layer are laminated can also be used in order to increase sensitivity and improve durability.

For example, the charge generation layer disperses an azo pigment, a quinone pigment, a perylene pigment, a phthalocyanine pigment, an anthranthrone pigment, etc. in a polymer binder such as polycarbonate,
The charge transport layer can be obtained by dispersing a polycyclic aromatic compound and a nitrogen-containing cyclic compound in a polymer binder. The thickness of the charge generation layer is from 0.01 to 10 μm, preferably from 0.05 to 5 μm, and the thickness of the charge transport layer is preferably from 5 to 30 μm.
The viscosity of the photosensitive solution is in the range of 0.5 to 700 cp, preferably 1 to 50 cp.
It is in the range of 0cp.

Examples of the hollow drum for electrophotography include aluminum, stainless steel, plastic on which a conductive layer is formed, and the like. Further, an undercoat layer or a charge generation layer may be formed first.

〔The invention's effect〕

As described above, according to the apparatus of the present invention, positioning can be performed in a non-contact state with respect to the drum, thereby preventing the drum from being damaged, and also facilitates accurate positioning. Furthermore, in particular, in the present invention, since the spraying means is provided at a plurality of positions spaced apart in the axial direction of the drum base, the drum can be prevented from being inclinedly transported.

[Brief description of the drawings]

1 is a longitudinal sectional view showing an outline of a first embodiment of a positioning device according to the present invention, FIG. 2 is a horizontal sectional view thereof, FIG. 3 is a horizontal sectional view of a second embodiment, and FIG. FIG. 5 is a horizontal cross-sectional view of the fourth embodiment, FIG. 6 is a horizontal cross-sectional view of the fifth embodiment, FIG. 7 is a vertical cross-sectional view of a coating head example, and FIG. FIG. 1 ... Cylindrical drum base, 2 ... Coating head, 3, 3A ... Discharge nozzle.

Claims (1)

(57) [Claims] 1. A device for positioning a drum substrate when coating a coating liquid on the outer peripheral surface of a cylindrical drum substrate when the photosensitive drum is manufactured by surrounding the outer peripheral surface of the cylindrical drum substrate; At the position or at the position where the coating liquid has been applied, there is provided a spraying means for spraying a fluid to the outer peripheral surface thereof to position the cylindrical drum by the fluid pressure, and the spraying means is spaced apart in the axial direction of the drum base. A photosensitive drum positioning device comprising a plurality of photosensitive drums.