JP2811215B2 - 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.

2. Description of the Related Art 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 or the like 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 shifted 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.

Conventionally, as a drum positioning device of this kind, for example, as disclosed in Japanese Patent Application Laid-Open No. 60-50537 and Japanese Patent Application Laid-Open No. The driving roller group provided with a plurality of drums in the transport direction is continuously supplied to the coating head while being in contact with the drum, and the outer peripheral surface of the drum is moved while the coating head is moved in the horizontal direction through the trochanter. A device that adjusts the relative positional relationship of a coating head with respect to the position is known.

[Problems to be solved by the invention]

However, in all of the conventional apparatuses, since the position regulating rollers and the driving roller group are 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.

On the other hand, in the device described in the latter publication, it is essential that the position of the coating head be adjusted together with the regulation of the position of the drum, but when the coating head is slidable, the position of the coating head relative to the drum is likely to shift, especially with the drum. It is difficult to keep the coating head coaxial at all times.

Accordingly, a main object of the present invention is to position the drum without damaging the drum.

[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. Alternatively, it is possible to solve the problem by providing a spraying means for spraying a fluid to the outer peripheral surface at a position where the application liquid is applied and positioning the cylindrical drum by the fluid pressure.

(Operation)

In the present invention, a liquid is sprayed on the outer peripheral surface, and the positioning of the cylindrical drum is performed 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.

〔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 having a hollow cylindrical shape, for example, and is continuously raised by raising a bottom of the transfer means (not shown) such as a drum base by a cylinder or the like.

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

As a coating head as a coating means used in the present invention, a coating head which is disposed on the outer surface of the drum base 1 so as to surround it and has a basic structure for coating a coating liquid on the outer surface of the drum base 1 is disclosed in 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.

To explain this, the coating head 2 includes the drum base 1
A narrow coating liquid distribution slit 22 having a coating liquid outlet 21 opening to the side is formed in the horizontal direction. This slit
Reference numeral 22 communicates with a liquid reservoir header 23, and the photosensitive liquid 1 is supplied to the liquid reservoir header 23 by a pressure pump (not shown).

On the other hand, a liquid slide surface 25 is formed below the coating liquid outlet 21 of the slit 22 so as to continuously incline in a downward constriction and terminate at a dimension slightly larger than the outer dimension of the drum substrate 1.
Further, a lip 26 is formed extending downward by the end of the liquid slide surface 25.

When the coating head 2 is used, the photosensitive liquid L is extruded from the slit 22 and the coating liquid outlet 21 in the process of lifting the drum substrate 1 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 corresponding to the clearance between the lip 26 and the drum base 1.

In order to concentrically supply the drum substrate 1 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 arranged at an equal distance from the center axis of the coating head 2 and are arranged in the circumferential direction. The discharge nozzles 3 are arranged horizontally at an angle of 120 degrees toward the central axis of the drum base 1, 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 each of the discharge nozzles 3, 3, and 3 with a uniform discharge amount and pressure. 1 at high speed. 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 base 1 with a uniform coating thickness.

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

On the other hand, the disposition position of the discharge nozzle 3 may not be below the coating head 3 but may be above it as shown in FIG. In this case, air is blown to the drum substrate 1 after the photosensitive liquid has been applied. 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 can be adjusted freely. In addition, since the relative positional relationship between the discharge nozzle 3 and the coating head 2 is important, the discharge nozzle 3 can be attached to the coating head 2 integrally or horizontally so as to be freely adjustable as shown in FIG.

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, the positioning can be performed in a non-contact state with respect to the drum, thereby preventing the drum from being damaged, and further having advantages such as easy accurate positioning. Brought. Further, there is an advantage that dust and the like adhering to the drum can be removed by blowing air to the drum, so that applicability can be further improved.

[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 vertical cross-sectional view of the fourth embodiment, FIG. 6 is a horizontal cross-sectional view of the fifth embodiment, and FIG. 7 is a vertical cross-sectional view of an example of a coating head. 1 ... cylindrical drum base, 2 ... coating head, 3 ... discharge nozzle.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Kazuyuki Shimizu, Konica Corporation, 1 Sakura-cho, Hino-shi, Tokyo (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 5/05

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; A positioning device for a photosensitive drum, comprising: a spraying means for spraying a fluid to an outer peripheral surface at a position or a position where a coating liquid is applied, and positioning the cylindrical drum by the fluid pressure.