COATING FILM FORMING APPARATUS

Abstract

The present invention is directed to a coating film forming apparatus 1. The apparatus 1 includes a coating unit 11, a coating material supply unit 10, and a control unit 12. The coating unit 11 contains a holding unit 18 for holding a substrate 4, a coating nozzle 19, and a movable unit 20. The coating nozzle 19 is provided with a slit for discharge coating material to an inner circumferential surface, formed in annular shape. The movable unit 20 moves the coating nozzle 19 along a shaft center P of the substrate 4. The control unit 12 controls to apply coating material 7 to an outer circumferential surface 4c of the substrate 4 from a lower end 4a upward in order.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings.

FIG. 1 is a schematic view showing a structure of a coating film forming apparatus in accordance with a first embodiment of the invention.

FIG. 2 is a cross sectional view of a coating nozzle taken along line II-II of the coating film forming apparatus shown in FIG. 1.

FIG. 3 is a flowchart showing a series steps of coating film forming by the coating film forming apparatus shown in FIG. 1.

FIG. 4 is a cross sectional view showing a situation where a coating nozzle opposite to the lower end of a substrate stops its function at step S3 of FIG. 3.

FIG. 5 is a cross sectional view showing a situation where coating material from the coating nozzle has stuck to an outer circumferential surface of a substrate.

FIG. 6 is a cross sectional view showing a situation where the coating nozzle of FIG. 5 is rising.

FIG. 7 is a cross sectional view showing a situation where the coating nozzle of FIG. 6 has temporarily stopped opposite to the upper end of a substrate.

FIG. 8 is a cross sectional view showing a situation where the coating nozzle of FIG. 7 has risen once again.

FIG. 9 is a cross sectional view showing a situation where coating material has stuck to the upper end of the substrate of FIG. 8.

FIG. 10 is an illustrative view for explaining the relationship between a position for stopping a substrate and a position for stopping a coating nozzle held in the coating film forming apparatus shown in FIG. 1.

FIG. 11 is a perspective view of a fixing belt in which a coating film is formed by the coating film forming apparatus shown in FIG. 1.

FIG. 12 is a cross sectional view taken along line XII-XII of FIG. 11.

FIG. 13 is an illustrative view for showing the relationship of the space between a coating nozzle and a substrate, with respect to the thickness of a coating film of the coating film forming apparatus shown in FIG. 1.

Claims

1. A coating film forming apparatus (1) for forming a coating film by applying a coating material on an outer circumferential surface (4c) of an intended-to-be-coated cylindrical object (4) having a shaft center (P), a lower end and an upper end, the apparatus comprising: a holding unit (18) for holding the object (4) in a condition in which the outer circumferential surface (4c) is exposed and the shaft center (P) is in a vertical direction;a annular coating nozzle (19) having an inner circumferential surface opposite to the outer circumferential surface (4c) of the object (4) with a space therebetween, placed to be coaxial with the object (4), the inner circumferential surface having slits (31) for discharging the coating material along an entire circumference thereof;a movable unit (20) for relatively moving the holding unit (18) and the coating nozzle (19) along the shaft center (P);a coating material supply unit (10) for supplying the coating material to the coating nozzle (19); anda control unit (12) for controlling the movable unit (20) and the coating material supply unit (10) so that the coating material is discharged from the slits (31) of the coating nozzle (19) opposite to the lower end (4a) of the object (4) and the coating nozzle (19) is moved to the upper end (4b) of the object (4) while discharging the coating material from the slits (31).

2. A coating film forming apparatus as recited in claim 1, wherein the space CG between the outer circumferential surface of the object and the inner circumferential surface of the coating nozzle satisfies the following equation: (3/2)T≦CG≦(1/250)(T2−340T+312)

3. A coating film forming apparatus as recited in claim 1 or 2, wherein the control unit controls the movable unit and the coating material supply unit, so that the coating nozzle moves toward the upper end after the coating material discharged from the slits of the coating nozzle, which has stopped opposite to the lower end or the object, has attached to the outer circumferential surface of the object.

4. A coating film forming apparatus as recited in claim 3, wherein the control unit controls the movable unit and the coating material supply unit, so that the coating nozzle moves toward the upper end once again after the discharging of the coating material from the slits of the coating nozzle on the rise is stopped and the movement of the coating nozzle to the upper end has been stopped once with the coating material transferred from the slits to the outer circumferential surface of the object.