JPS6255133B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a developing device for a diazo copying machine, and more particularly to a developing device that can appropriately control the amount of alkaline developer applied to exposed photosensitive paper.

[Conventional technology]

In diazo copying machines, in order to obtain copies that are dry to the touch, taking into account the wetness of the photosensitive paper, the amount of developer applied must be 200 mg or less per A4 size sheet, preferably 150 mg or less. . In addition, the lower limit of the adhesion amount is 90 to avoid insufficient development.
It is about mg.

For this reason, the amount of developer has conventionally been controlled by bringing a blade into pressure contact with the application roller.

However, in such conventional developing devices, it is difficult to process the blade and adjust the pressure, the pressure contact of the blade causes wear on the roller surface, and the blade is not only easily damaged due to paper being caught in it, etc. It has various disadvantages, such as paper pieces and paper powder adhering to the blade, which tends to cause uneven development, and furthermore, the mechanism for removing and applying pressure to the blade becomes complicated.

On the other hand, even if you try to control the amount of developer using only multiple rollers without using blades, increasing the circumferential speed of the rollers will dramatically increase the amount of developer that adheres to the photosensitive paper. Copying machines with variable speeds could not develop enough at low speeds, and at high speeds the copies would become wet, brown, curled, etc., and could not be used in the above-mentioned micro-coating/developing device with a capacity of 200 mg or less.

However, according to the inventor's experiments, when the surface roughness of the rollers, especially the surface roughness of the rubber rollers, was varied, it was found that in the case of rollers that were ground very smoothly, when the pressure between the rollers was increased to a certain level or higher, It has been discovered that the developer amount can be controlled as well as blade control.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a developing device for a diazo copying machine in which the amount of developer applied to photosensitive paper can be well controlled without using a blade.

[Structure of the invention]

The present invention will be explained below with reference to an embodiment shown in the drawings.

In FIG. 1 and FIG. 2, liquid supply roller 1,
Each support shaft 4,
Both ends of 5 and 6 are supported by bearings 8, 9 and 10 of support plate 7. Among these, the liquid supply roller 2 is connected to the developer 12 stored in the developer tray 11.
The lower part is immersed inside. Each of the rollers 1,
2 and 3 are connected by a gear (not shown),
When the application roller 2 is driven by a drive source (not shown), the liquid supply roller 1 and the pressure roller 3 are driven, and the developer adhering to the surface of the liquid supply roller 1 is transmitted to the application roller 2. It's becoming like that.

Note that if a smooth pressure roller 3 is used, the developer tends to accumulate in the contact area with the application roller 2, causing uneven development, so it is preferable to use a hard material with fine grooves in the circumferential direction. .

Next, a pressure roller 13 divided in the axial direction is located on the pressure roller 3, and both ends of the pressure roller 13 are supported by a bracket 15 fixed to a rotating shaft 14. There is.

On the other hand, an arm 16 is fitted onto the rotating shaft 14, and a mechanism (not shown) connected to the tip of the arm 16 applies a force P that causes the arm 16 to swing clockwise when the developing device is driven. It is adapted to be added to arm 16. However,
The liquid supply roller 1 is fixedly supported on a support plate 7, while the applicator roller 2 and pressure roller 3 are provided with respective bearings 9, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3 and 3, respectively, as shown in FIG. 10 is supported by the support plate 7, when the arm 16 is swung clockwise, the rollers 1, 2, and 3 come into pressure contact with each other. Note that the pressure is removed by a mechanism not shown when the device is not in operation. This is because if pressure is applied even when the rollers are not in operation, the rubber of the rollers 1 and 2 may be permanently deformed and uneven development may occur.

In order to uniformly apply the developer to the photosensitive paper, the liquid supply roller 1 and the application roller 2 are preferably coated with a non-porous elastic material with a good surface finish, such as chloroprene rubber, and the hardness of the rubber is 40
~50th rank is most preferred. Note that the liquid supply roller 1 may be made of other hard materials such as plastic or metal.

Next, there is a correlation between the amount of adhesion of the developer and the roller, and according to test results, the average surface roughness of the coating roller 2 is preferably in the range of 0.5 to 1.6 μRa.
Note that if the pressure by the pressure roller 13 is increased,
Allowable up to about 3μRa. Further, it is desirable that the surface roughness of the liquid supply roller 1 is also 3 μRa or less.

When an excessive amount of developer accumulates in the contact area between the application roller 2 and the liquid supply roller 1, this developer travels along the left and right ends of the application roller 2 and enters the back side of the roller 2, and the permeated developer causes the development process. This will result in unevenness. Therefore, as shown in detail in FIG.
A liquid removing member 19 is swingably supported on a support shaft 18.
are pressed together by a spring (not shown). This liquid removing member 19 may be an elastic body such as a blade, but
As a thick plate as shown in the figure, one side edge 2
0 protrudes from the end surface 21 of the liquid supply roller 1, and the other end surface 22 is made to protrude from the end surface 21 of the application roller 2.
It is more effective to arrange it so that it is in contact with 3.
Note that without using the liquid removal member 19 as described above,
Waterproofing is applied to the ends of the liquid supply roller 1 and application roller 2, or the total length of both rollers 1 and 2 is sufficiently longer than the effective development width so that the influence of the liquid surroundings does not affect the areas necessary for development. You can also do this.

Next, the operation of the above-described embodiment will be explained.

When the developing device is driven, first a force P is applied to the arm 16 by a mechanism (not shown), and this force is transmitted to each roller 3, 2, 1 via the pressure roller 13. 1 are pressed together.

When the coating roller 2 is rotated in this state, the rotation of the coating roller 2 is transmitted to the liquid supply roller 1 and the pressure roller 3 by a gear (not shown). Then, the excessive amount of developer drawn up by the liquid supply roller 1 is adjusted to a minute amount at the contact area between the roller 1 and the application roller 2, and a part of the developer remains uniformly on the surface of the application roller 2. The image is transferred uniformly onto the photosensitive paper.

Comparing the method of the present invention that does not use a blade with the conventional control method using a blade,
As shown in FIG. 3, the change A in the amount of developer adhered according to the present invention is slightly inferior to the change B in the case of blade control in the high-speed range, but when the rotational speed of the roller
In the range of 500 to 600 m/h or less, there is almost no difference from the change in blade control.

〔Effect of the invention〕

As described above, the developing device of the diazo copying machine according to the present invention is designed so that the average roughness of the surface of the application roller is 0.5 to 3 μm as described above, and the application roller can be pressed with an appropriate pressure. , the amount of developer applied can be easily and reliably controlled without using a blade that has technical difficulties in processing, life, etc., and the amount of developer applied can be evenly and uniformly applied to photosensitive paper. It has practical effects.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of a developing device for a diazo copying machine according to the present invention, FIG. 2 is a side view of the main part of FIG. 1, and FIG. 3 is a view showing the effects of the present invention. It is a graph. 1...Liquid supply roller, 2...Applying roller, 3...
Pressure roller, 13...pressure roller, 14...arm, 19...liquid removal member.

Claims (1)

[Claims] 1. An application roller that applies developer to photosensitive paper, and a liquid supply roller that supplies developer to this application roller.
A pressure mechanism is provided to press both of these rollers into contact with each other at a predetermined pressure, and both ends of the liquid supply roller are made longer than both ends of the application roller to form a protrusion, and each liquid removal member is attached to the protrusion by a spring. A developing device for a diazo copying machine, characterized in that the application roller is provided so as to be brought into contact with elasticity, and the average roughness of the surface of the application roller is 0.5 to 3 μm.