Method and apparatus for applying coating liquid to cylindrical substrate and method for producing electrophotographic photoreceptor and electrophotographic photoreceptor produced by the production method

• US 20050112278A1
• Filed: 09/16/2004
• Published: 05/26/2005
• Est. Priority Date: 09/19/2003
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Obata, Takatsugu, Utsumi, Hisayuki, Washo, Junichi
• Granted Patent: US 7,393,415 B2
• Time in Patent Office: Days
• US Class Current: 427/231
• CPC Class Codes: G03G 5/0525 Coating methods

Abstract

To suppress generation of a joint when detaching an applicator roll and cylindrical substrate from each other in a simple control to form a coating film having a uniform thickness efficiently on the cylindrical substrate is provided. A coating liquid is supplied from a pan to an applicator roll via a metalling roll, the applicator roll supplied with the coating liquid and a cylindrical substrate provided so as to be close to or in contact with the applicator roll are rotated. The coating liquid is transferred from the applicator roll to the cylindrical substrate, and the cylindrical substrate is rotated in a predetermined number. Thereafter, such control is carried out that the circumferential speed V1 of one of the applicator roll and the cylindrical substrate is higher than the circumferential speed V2 of the other when detaching the applicator roll and the cylindrical substrate from each other.

Claims

1. A method for applying a coating liquid to a cylindrical substrate by transferring the coating liquid supplied to an applicator roll from the applicator roll to the cylindrical substrate, comprising:

when detaching the applicator roll and the cylindrical substrate from each other after the applicator roll and the cylindrical substrate are rotated and the coating liquid is transferred from the applicator roll to the cylindrical substrate,

carrying out such control that a circumferential speed V1 of one of the applicator roll and the cylindrical substrate is higher than a circumferential speed V2 of the other of the applicator roll and the cylindrical substrate.

2. The method of claim 1, wherein a ratio R (=V1/V2) of the circumferential speed V1 that is higher of the one of the applicator roll and the cylindrical substrate and the circumferential speed V2 that is lower of the other is 1.2 or more and 15.0 or less.

3. The method of claim 1, wherein the circumferential speed V1 that is higher of the one of the applicator roll and the cylindrical substrate is the circumferential speed of the cylindrical substrate, and the circumferential speed V2 that is lower of the other is the circumferential speed of the applicator roll.

4. The method of claim 1, wherein after the applicator roll and the cylindrical substrate are detached from each other, the cylindrical substrate remains rotated for a predetermined period of time.

5. An apparatus for applying a coating liquid to a cylindrical substrate by transferring the coating liquid supplied to an applicator roll from the applicator roll to the cylindrical substrate, comprising:

an applicator roll;

coating liquid supplying means for supplying a coating liquid to the applicator roll;

mounting means for mounting a cylindrical substrate removably thereon;

first driving means for rotating the cylindrical substrate mounted on the mounting means;

second driving means for rotating the applicator roll;

first circumferential speed detecting means for detecting a circumferential speed at which the cylindrical substrate is rotated;

second circumferential speed detecting means for detecting a circumferential speed at which the applicator roll is rotated;

rotation number detecting means for detecting a number of rotations of the cylindrical substrate;

detaching means capable of moving the cylindrical substrate so as to be close to or away from the applicator roll; and

controlling means for controlling, in response to a detection output from the rotation number detecting means, an operation of the detaching means so as to move the cylindrical substrate away from the applicator roll, and an operation of the first and the second driving means so that a circumferential speed of one of a circumferential speed at which the cylindrical substrate is rotated and a circumferential speed at which the applicator roll is rotated is higher than a circumferential speed of the other of the circumferential speed at which the cylindrical substrate is rotated and the circumferential speed at which the applicator roll.

6. The apparatus of claim 5, further comprising film thickness adjusting means for adjusting a film thickness of the coating liquid supplied to the applicator roll.

7. The apparatus of claim 6, wherein the film thickness adjusting means comprises a cylindrical member opposed to the applicator roll and an adjusting member for adjusting a gap between the cylindrical member and the applicator roll.

8. The apparatus of claim 5, wherein at least the surface layer of the applicator roll is made of an elastic material,

while the coating liquid is transferred from the applicator roll to the cylindrical substrate, a rotation direction of the cylindrical substrate by the first driving means is opposite to a rotation direction of the applicator roll by the second driving means, and the cylindrical substrate and the applicator roll are arranged so as to come in contact with each other via the coating liquid.

9. A method for producing an electrophotographic photoreceptor comprising:

applying a coating liquid that is supplied to an applicator roll and forms a photosensitive layer of an electrophotographic photoreceptor, to a conductive support by transferring the coating liquid from the applicator roll thereto,

the method comprising;

when detaching the applicator roll and the conductive support from each other after the applicator roll and the conductive support are rotated and the coating liquid for forming a photosensitive layer is transferred from the applicator roll to the conductive support,

carrying out such control that a circumferential speed V1 of one of the applicator roll and the conductive support is higher than a circumferential speed V2 of the other of the applicator roll and the conductive support.

10. The method of claim 9, wherein a ratio R (=V1/V2) of the circumferential speed V1 that is higher of the one of the applicator roll and the conductive support to the circumferential speed V2 that is lower of the other is 1.2 or more and 15.0 or less.

11. The method of claim 9, wherein the photosensitive layer is made of a laminated structure of at least two layers including a charge-transporting layer containing a charge-transporting substance and a charge-generating layer containing a charge-generating substance, and the coating liquid is a charge-transporting layer-forming coating liquid for forming a charge-transporting layer.

12. The method of claim 9, wherein the coating liquid is a protective layer-forming coating liquid for forming a protective layer constituting the outermost layer of the photosensitive layer.

13. The method of claim 12, wherein the protective layer is a resin layer made of resin.

14. An electrophotographic photoreceptor produced by the methods for producing an electrophotographic photoreceptor of claim 9.

15. An image forming apparatus provided with the electrophotographic photoreceptor of claim 14.