JPS5931701B2 - Diazo type wet copying machine developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device for a diazo type wet type copying machine, which comprises a series of roller groups.

Generally, in a diazo type wet-type copying machine, exposed photosensitive paper passes between a rubber developing roller coated with developer and a pressure roller that rotates in contact with the roller. The diazonium salt remaining in the unexposed area of the photoreceptor reacts with the coupling component to form a diazo dye, which develops color and forms an image, which is called development.

The developing device of a diazo type wet type copying machine consists of a series of rollers including the developing roller and the pressure roller.A coating roller that takes out the developer from the developing tray applies the developer to the developing roller. The process involves applying a developer solution to the photosensitive surface of photosensitive paper. Therefore, in order to obtain clear copies with a diazo-type wet-type copying machine, it is necessary to provide appropriate exposure according to the density of the original and to apply an appropriate and uniform developer solution to the photosensitive surface of the exposed photosensitive paper. This is well known.

Therefore, in the conventional developing device of this type, a blade is pressed against the coating roll and the developing port/step to reduce the amount of developer applied to the developing roll, and also to scrape off the developer applied to the developing roll. The aim is to apply a sufficient and uniform amount of developer to the surface of the photosensitive paper. However, although the blades mentioned above are coated with tetrafluoroethylene (trade name: Teflon) and have excellent chemical resistance and lubricity, they tend to peel off in parts because they are constantly in frictional contact with the rollers. This peeling causes unevenness in the amount of developer applied, and there are also disadvantages such as paper dust becoming clogged between the blade and the roller, making it easy to lose control over the amount of developer.

Furthermore, since the blade is usually fixed, cleaning the inside is difficult. In view of this, the present invention
The object of this invention is to provide a developing device for a diazo-type wet-type copying machine that does not have the above-mentioned drawbacks, and this object has been achieved by improving the structure of each roller without using control blades.

Hereinafter, the present invention will be described by way of examples with reference to the drawings. FIG. 1 shows a schematic side view of an embodiment of a developing device for a diazo type wet copying machine according to the present invention.

The roller arrangement includes a pressure roller 1, a developing roller 2, and a coating roller 3. The lowermost coating roller 3 has its lower half immersed in the developer 5 in the developing tray 4. The pressure roller 1 is a pressure roller 6 that is applied with pressure by a pressure unit (not shown).
The developing roller 2 is pressed against the developing roller 2 by. The pressure roller 1 is made of stainless steel, and has a pitch of 0.5 m on the surface.
11. A spiral groove 7 with a depth of 0.1 mm is provided over almost the entire length (see FIG. 2).

The developing roller 2 has a portion mounted on the shaft 8 divided into an outer layer 2a and an inner layer 2b. The outer layer 2a has a moisture content of 100% or less and a thickness of 2 to 3 m77! It is made of extremely thin porous EVA fat (ethylene vinyl acetate resin). Further, the inner layer 2b is made of rubber having a hardness of about 40 to 60. Note that the water content in the outer layer 2a was determined by the following.

On the other hand, the application roller 3 is a stainless steel roller, and the third
As shown in the figure, fine spiral grooves 9 are provided on the surface over almost the entire length.

The spiral groove 9 has a pitch of 0.25 to 0.35 m71L and a depth of 0.015 to 0.025 mm. The above-mentioned rollers are driven by a method in which the developing roller 2 is powered and rotated by a drive mechanism (not shown), and the other rollers are rotated by, for example, mutual meshing of gears (not shown) attached to their ends. It is taken.

As shown in FIG. 1, the apparatus of the present invention having the above-described configuration is such that an exposed photosensitive paper 10 is fed with the photosensitive surface 10a facing downward, and is placed between the developing roller 2 and the pressure roller 1. This is no different from conventional devices of this type in that the developing solution is applied while the device is inserted into the device and passes through the device.

However, as shown in FIG. 4, the device of the present invention is different from the conventional device in that it can stably apply the required amount of developer to the photosensitive paper 10 immediately after startup, regardless of the machine speed (m/h). Different.

The above function is that the developing roller 2 has a microporous thin outer layer 2a.
and an inner layer 2a made of rubber having a hardness of about 40 to 60.

Furthermore, by making the applicator roller 3 made of metal, which has fine spiral grooves 9 on its surface and is less likely to wear or bend,
It's becoming more certain. The microporous outer layer 2a is impregnated with a developer that is drawn up by the spiral groove 10 and reliably applied in fixed amounts. In the low speed range immediately after startup, the centrifugal force is small and the amount of impregnated developer seeped out is small. Leach out the developer.

If the speed is increased, the centrifugal force also increases, and the amount of developer leached out increases. The lack of coating amount on the photosensitive paper 10 due to the reduction in contact time associated with high-speed operation can be avoided by the development roller 2, which is microporous and facilitates leaching of the developer by centrifugal force. Further, the application roller 3 having a spiral groove 9 applies the developer solution to the development roller 2 evenly and continuously. As is clear from the above explanation,
The device of the present invention can apply a stable developer solution to photosensitive paper over the entire speed range, and has a developing roller with a thin microporous outer layer on a hard rubber inner layer, and a spiral groove. The apparatus of the present invention, which has a metal applicator roller that hardly bends or wears, has the effect of greatly improving the functionality of diazo type wet type copying machines.

[Brief explanation of drawings]

Fig. 1 is a schematic side view of an embodiment of the developing device of the present invention, Fig. 2 is a partially omitted front view of the pressure roller, Fig. 3 is a partially omitted front view of the application roller, and Fig. 4 is the machine speed. FIG. 3 is a diagram showing changes in the amount of developer applied to photosensitive paper as experimental results for two examples of the pressing force of the pressure roller. DESCRIPTION OF SYMBOLS 1... Pressure roller, 2... Development roller, 2a... Outer layer, 2b... Inner layer, 3...
...Applying roller, 4. ...Developing plate, 5...
...Developer, 6...Pressure roller, 7...
... spiral groove, 8 ... shaft, 9 ... spiral groove, 10 ... photosensitive paper, 10a ... photosensitive surface.

Claims (1)

[Claims] 1. A developing roller that rotates and applies a developer to the photosensitive surface of the exposed photosensitive paper, a pressure roller that presses the photosensitive paper passing in contact with the developing roller against the developing roller with a predetermined pressure, and the developing roller. In a developing device of a diazo type wet-type copying machine, which has a roller configuration including a coating roller that rotates in contact with the developing roller to apply developer to the surface, the developing roller has a thin outer layer with a water content of 100% or less and a hard layer. A diazo type wet type, characterized in that the roller has a multi-layer structure with a rubber inner layer of about 40 to 60 layers, and the coating roller is a metal roller having an extremely small pitch and a very deep spiral groove on the surface. Copying machine developing device.