JPS6394244A - Method and device for coating liquid to sheet - Google Patents

Abstract

PURPOSE:To prevent coating of a coating liquid in the amt. larger on the rear end of a sheet than in the other parts by limiting the amt. of the coating liquid sticking atop a rotating body and coating the liquid to the sheet when the rear end of the sheet is going to part from the rotating body. CONSTITUTION:The sheet is held in contact with the liquid outside surface of the rotating body 12 partly immersed in the coating liquid 16 in a liquid tank 14 and is thereby conveyed. The rotating body 12 is simultaneously rotated to coat the coating liquid onto the sheet. The coating liquid 16 is coated on the sheet by limiting the amt. of the liquid to be stuck onto the surface of the rotating body 12 when the rear end of the sheet is going to part from the rotating body 12 in the above-mentioned method. The coating of the coating liquid on the rear end of the sheet in the amt. larger than in the other part is thereby obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid coating method and apparatus for sheets, and in particular,
The present invention relates to a sheet liquid coating method and apparatus for applying an image forming solvent such as water to a heat-developable photosensitive material or a sheet of the photosensitive material.

[Conventional technology]

In this type of sheet liquid coating method and apparatus, as shown in FIG. 7, a part of the coating roller 12 is immersed in a water tank 14.
The application roller 12 is rotated, and the upper surface of the application roller 12 is brought into contact with the lower surface of the photosensitive material S while conveying, for example, the photosensitive material S by a transport roller (not shown), and water 16 as an image forming solvent is applied to the photosensitive material S. It is supposed to be done.

Water 16A spreads between the coating roller 12 and the photosensitive material S due to capillary action. This spread water 16A is called a bead, and a portion of the bead is applied to the lower surface of the photosensitive material S.

[Problem that the invention seeks to solve]

However, when the photosensitive material S is fed and the rear end of the photosensitive material S is about to leave the coating roller 12, the water 16A is dragged by the photosensitive material S and adheres to the photosensitive material S. The amount of water applied to some areas is greater than other areas.

In view of the above problems, an object of the present invention is to provide a liquid coating method for a sheet in which a larger amount of coating liquid is not applied to the rear end of the sheet than to other parts when the rear end of the sheet separates from the rotating body. and equipment.

[Means for solving problems]

In the first invention, some force is applied to the coating liquid in the liquid tank. ] In a liquid coating method in which a sheet is conveyed in contact with the liquid outer surface of a rotary body that has been scraped, and the rotary body is rotated to apply the coating liquid to the sheet, when the rear end of the sheet is about to separate from the rotary body, The present invention is characterized in that the amount of coating liquid deposited on the surface of the rotating body is limited.

In the second invention, a rotating body partially immersed in the coating liquid in a liquid tank is interposed between the conveying means, and while the sheet is being conveyed by the conveying means, the sheet is placed on the surface of the rotating body outside the liquid. In a liquid coating device that applies a coating liquid to a sheet in contact with the rotating body, a blade that slides into contact with the surface of the rotating body between a surface A where the sheet contacts the rotating body and one tangent line B where the rotating body contacts the liquid surface; , usually includes a control means for rotating the rotating body from the plane A in the tangential vAB direction and for reversing the rotating body before the rear end of the seat is separated from the rotating body.

In the third invention, a rotating body partially immersed in the coating liquid in a liquid tank is interposed between the conveying means, and while the sheet is being conveyed by the conveying means, the sheet is removed from the surface of the rotating body outside the liquid. In a liquid coating device that applies a coating liquid to a sheet in contact with the blade, the blade is applied to the surface of the rotating body between the surface A where the sheet contacts the rotating body and one tangent line B where the rotating body contacts the liquid surface. The present invention is characterized by comprising a blade approaching/separating means for moving the blade toward and away from the rotating body, and a control means for controlling the blade approaching/separating means so that the blade comes into contact with the surface of the rotating body before the rear end of the sheet is separated from the rotating body.

[Effect]

In any of the above inventions, when the rear end of the sheet is about to move away from the rotating body, the amount of coating liquid adhered to the surface of the rotating body is limited and applied, so that the rear end of the sheet is moved away from the rotating body. A larger amount of coating liquid will not be applied to the area.

〔Example〕

FIG. 1 shows a water coating device 10 according to an embodiment of the present invention.

First, the configuration of the water application section 11 will be explained.

A portion of the water application roller 12 is exposed to water 16 in a water tank 14, and a shaft 18 protruding from the end surface of the water application roller 12 is pivotally supported by a side plate (not shown). Therefore, by rotating the water application roller 12, water 16 as an image forming solvent is attached to the surface of the water application roller 12, and by bringing the photosensitive material S into contact with the upper surface of the water application roller 12, water is applied to the photosensitive material S. applied.

The blade 2 is attached to the inner wall of the water tank 14 via a bracket 20.
The lower end of 2 is fixed. The blade 22 is constructed by bending a leaf spring in an inverted shape, and its tip presses lightly against the surface of the application roller 12.

Next, the configuration of the clamping and conveying device 23 will be explained. The clamping and conveying device 23 has the same configuration on both end surfaces of the water application roller 12, and the configuration on the lower side of the paper in FIG. 1 is omitted from illustration. Guides 24 to 30 are provided to the side plate (not shown) on the fixed side, and the arm 34 of the T-shaped lifting plate 32 is fitted into the guide 24, and the arm 3
6 is fitted into the guide 26, so that the elevating plate 32 is guided in the vertical direction. Similarly, the arm 38 of the single-shaped lifting plate 37 is fitted to the guide 28, the arm 40 is fitted to the guide 30, and the lifting plate 3
7 is guided in the vertical direction. The roller support portion 42 of the elevating plate 32 has long holes 46.48 whose longitudinal direction extends in the vertical direction, and similarly the roller support portion 44 of the elevating plate 37 has elongated holes 50.52. has been done. Shafts 62 to 68 are protruded from the end surfaces of the conveyance rollers 54 to 60, respectively, and are fitted into the elongated holes 46 to 52, respectively. Hair rings 9 are provided at the ends of the shafts 62 to 68 passing through the long holes 46 to 52, respectively.
0 to 96 are fitted on the outside.

The hair ring 90 and the hair ring 92 are connected by a tension coil spring 70, and the conveyance roller 54 and the conveyance roller 56 are brought into pressure contact with each other.

Similarly, hair rings 94 and 96 are connected by tension coil spring 72, and conveyor roller 58 and conveyor roller 60
and are in pressure contact with each other. Conveyance roller 54.58
A belt 74 is wound around the transport rollers 56, 60, and a belt 76 is wound around the transport rollers 56, 60.

Therefore, the shaft 62 and the shaft 64 are rotated in opposite directions by a motor (not shown), and the belt 74 is rotated in opposite directions.
When the leading end of the photosensitive material S is held between the belt 76 and the belt 76, the photosensitive material S is conveyed forward (to the right in FIG. 1).

Next, the configuration of the lifting device will be explained.

At the lower ends of the arms 36 and 40 are plungers 78, respectively.
．． The upper ends of 80 are connected. Plunger 78.8
The lower end portions of the solenoids 82 and 84 are fitted into the air core portions of solenoids 82 and 84, respectively, which are fixed to the fixed side plate. Therefore, by turning on and off the power to the solenoids 82.84, the plungers 78.80 are raised and lowered, and the lifting plates 32.37, that is, the rear end and the front end of the clamping and conveying device, are raised and lowered independently.

Next, the operation of this embodiment configured as described above will be explained.

As shown in FIG. 1, the conveyance rollers 54, 56 and the water application roller 12 are rotated with the plunger 78 being lowered and the plunger 80 being raised.

The rotation direction of the water application roller 12 is clockwise in FIG.

As a result, the water 16 adhering to the application roller 12 is scraped off by the blade 22 and returns to the water tank 14 along the upper surface of the plate 22.

However, since the water on the upper surface of the application roller 12 is not scraped off, the amount of water applied to the photosensitive material S is constant regardless of the presence or absence of the blade 22.

Next, the leading end of the photosensitive material S is held between the heald 74 and the belt 76. As a result, the photosensitive material S is transported forward.

The tip of the photosensitive material S passes through the apex of the water application roller 12 in a predetermined path 1.
After passing through iIlt, the plunger 80 is lowered to bring the photosensitive material S into contact with the upper surface of the water coating roller 12, as shown in FIG. The water adhering to the water application roller 12 is applied to the lower surface of the photosensitive material S.

As shown in FIG. 3, the rear end of the photosensitive material S is connected to the water coating roller 1.
When the applicator roller 1 is a predetermined distance behind the apex of
Rotate 2 counterclockwise.

Since the water adhering to the application roller 12 is immediately scraped off by the blade 22, the amount of water adhering to the upper part of the application roller 12 is reduced. Next, the plunger 78 is raised to separate the photosensitive material S from the upper surface of the water coating roller 12.

When the photosensitive material S is further conveyed and the rear end of the photosensitive material S emerges from between the belts 74 and 76, as shown in FIG.
8 is lowered to the same initial state as shown in FIG.

In this way, water is applied to the water-applied portion W of the photosensitive material S, as shown in FIG. The image area F is included in the water application area W, and the water application area W is slightly wider than the image area F. Water is not applied to the leading and trailing ends of the photosensitive material S. In other words, water is applied to the photosensitive material S only in the necessary areas. Moreover, the amount of water applied per unit area in each part of the water application part W becomes uniform.

Next, the second invention will be explained in detail according to FIG. In FIG. 6, the clamping and conveying device for the photosensitive material S is omitted.

A solenoid 86 is fixed to the inner wall of the water tank 14, and a blade 22A made of a temporary spring is fixed to the tip of a plunger 88 which is driven horizontally by the solenoid 86.

When the solenoid 86 is turned off, the tip of the blade 22A is separated from the surface of the application roller 12. When the solenoid 86 is turned on, the plunger 88 is projected and the tip of the blade 22A presses the surface of the coating roller 12A, so that the water attached to the coating roller 12 due to the rotation of the coating roller 12 is immediately scraped off by the blade 22A. Therefore, the amount of water deposited on the upper surface of applicator roller 12 is reduced.

In this embodiment, when applying water to the photosensitive material S, it is sufficient to always rotate the application roller 12 clockwise.

Note that the elevating means may be configured such that a tappet is provided at the lower end of the plunger 78.8o, and these are raised and lowered by a cam.Alternatively, a rack is formed on the side surface of the elevating plate 32, and a pinion is provided on the fixed side. It may be configured such that the pinion is engaged with the pinion and the pinion is rotated by a motor. The elongated hole 48.52 is made into a circular hole so that the conveyance roller 56.6o does not move up and down with respect to the lifting plate 32.37, and the tension coil spring 70.72 is wound around the bearing 9o194 in an inverted U shape. 70.72
The belt 74 may be brought into pressure contact with the belt 72 by locking both ends of the belt to the lifting plates 32 and 37, respectively.

〔Effect of the invention〕

In the liquid coating method for a sheet according to the first invention, when the rear end of the sheet is about to separate from the rotating body, the amount of the coating liquid that adheres to the upper surface of the rotating body is limited and applied, and the rear end of the sheet This has the effect of preventing a larger amount of the coating liquid from adhering to some parts than to other parts.

In the sheet liquid applicator according to the second aspect of the present invention, a blade is brought into sliding contact with the surface of the rotating body between a surface A where the sheet contacts the rotating body and one tangent line B where the rotating body contacts the liquid surface, and usually Since the rotating body is rotated from A to the direction of the tangent line B, and the rotating body is reversed before the rear end of the sheet is separated from the rotating body, the amount of coating liquid attached to the upper surface of the rotating body is reduced. This has the effect of preventing a larger amount of coating liquid from being applied to the rear end of the sheet than to other parts when the sheet is separated from the rotating body.

In the liquid coating device for a sheet according to the third aspect of the present invention, the blade approaching and separating means is controlled so that the blade comes into contact with the surface of the rotating body before the rear end of the sheet is separated from the rotating body. This has the effect that the amount of coating liquid that adheres to the upper surface of the sheet is reduced, and that a larger amount of coating liquid is not applied to the rear end of the sheet than to other parts when the sheet is separated from the rotating body.

[Brief explanation of the drawing]

FIG. 1 is a partially cross-sectional side view of a water application device according to an embodiment of the first and second inventions, and FIGS. 2 to 4 are partially cross-sectional views for explaining the operation of the embodiment of the first invention. FIG. 5 is a side view and a detailed explanatory diagram of the first invention; FIG. 5 is a diagram showing the relationship between the water application area and the image area on the photosensitive material; FIG. FIG. 7 is a partially sectional side view of a conventional water coating device. 10... Water application device 12... Application roller 22A... Blade 24.26.28.30... Guide 32... Lifting plate 54.56.58.60... Conveyance roller 78.80 ．．
88...Plunger 82.84.86...Solenoid S...Photosensitive material W...Water application section F...Image section Fig. 5 S Fig. 6

Claims (3)

[Claims] (1) In a liquid coating method in which a sheet is conveyed in contact with the outer surface of a rotating body partially immersed in a coating liquid in a liquid tank, and the rotating body is rotated to apply a coating liquid to the sheet,
A liquid coating method for a sheet, characterized in that when the rear end of the sheet is about to leave the rotating body, the amount of coating liquid applied to the surface of the rotating body is limited. (2) A rotating body partially immersed in the coating liquid in a liquid tank is interposed between the conveying means, and while the sheet is being conveyed by the conveying means, the sheet is brought into contact with the surface of the rotating body outside the liquid. In a liquid coating device that applies a coating liquid to a liquid, there is usually a plate that slides into contact with the surface of the rotating body between a surface A where the sheet contacts the rotating body and one tangent line B where the rotating body contacts the liquid surface. control means for rotating the rotating body from the plane A in the direction of the tangent line B and reversing the rotating body before the rear end of the seat is separated from the rotating body;
A liquid coating device for sheets, characterized in that it has: (3) A rotating body partially immersed in the coating liquid in a liquid tank is interposed between the conveying means, and while the sheet is being conveyed by the conveying means, the sheet is brought into contact with the surface of the rotating body outside the liquid. In a liquid coating device for applying a coating liquid to a liquid, a blade is used to move the blade toward and away from a surface of a rotating body between a surface A where a sheet contacts the rotating body and a tangent line B where the rotating body contacts the liquid surface. A liquid coating device for a sheet, comprising: an approaching/separating means; and a control means for controlling the blade approaching/separating means so that the blade comes into contact with the surface of the rotating body before the rear end of the sheet is separated from the rotating body. .