JPS646461B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a wet developing device that can be used in an apparatus for forming an electrophotographic image on an electrophotographic film made of an organic optical semiconductor.

Structure of the conventional example and its problems As is well known, the electrophotographic image forming method uses an organic photoconductor as a photoreceptor to form an image by physical and electrical means. The photoreceptor is uniformly charged in a dark place, and then the original image is exposed to form an electrostatic latent image on the photoreceptor. This electrostatic latent image is then developed with toner having a charge of a polarity opposite to that of the previously charged voltage to form a visible image. Further, it dries the photoreceptor and fixes the toner on the photoreceptor.

Now, there is a well-known method for obtaining a high-density image, especially a line drawing of a negative image, and less unevenness around the image by providing a developing electrode facing the photoreceptor in the above-mentioned developing process. .
Furthermore, during development in the above-mentioned process, a method of developing by using toner having a charge of the same polarity as the charging voltage and applying a bias voltage of the same polarity as the charging voltage to the developing electrode is also known as a method for obtaining a reversed image. It is being

Generally, an image is formed by using a photoreceptor as shown in FIGS. 1 and 2, in which a photoreceptor film 2 is attached to a slide mount (frame) 1 made of paper or a suitable synthetic resin in advance. Note that 3 is a transparent base made of polyethylene terephthalate or the like, 4 is electrically conductive, 5 is a photosensitive layer, and 6 is a grounding window. When forming an image, a developing device as shown in FIG. 3 has conventionally been used. The operation of the developing device shown in FIG. 3 will be explained.
It is assumed that an electrostatic latent image has already been formed on the photoreceptor film 2. The developer 8 in the developer tank 7 rises along the outer circumferential surface of the developer roller 9 as the developer roller 9 rotates, and the developer 8 rises along the outer circumferential surface of the developer roller 9 until it reaches the liquid ejection opening of a liquid scraper member 10 provided so as to come into contact with the upper surface of the developer roller 9. It is ejected from the portion 11 toward the photoreceptor film 2 and comes into contact with the film surface. At this time, the developing section 17 moves under the stationary film in the direction of arrow X, thereby developing the entire surface of the film. The liquid scooping member 10 has the developing electrode 12 made of a conductor such as metal.
For example, when forming an inverted image, it is connected to a bias power source 14 via a thin metal wire 13. The spring 15 urges the liquid scooping member 10 to come into contact with the developing roller. Further, the remaining developer that has come into contact with the film surface is removed from the developing electrode plate 12.
The liquid is discharged from the drain portion 16 through the tapered portion 12c. In such a developing device, the developing electrode plate 12, which is provided for the purpose of obtaining a hidden line image with little bleeding around the image as described above, is conventionally provided with liquid ejection openings such as 12a and 12b in order to increase the electrode effect. It is provided on both sides of 11. However, when the photoreceptor film 2 and the liquid ejection opening 11 are in the positional relationship as shown in FIG. Due to the surface tension, the developing solution does not come into contact with the surface of the photoreceptor film 2, so that the developing electrode plate 12b has no electrode effect. When the developing section 17 moves and the photoreceptor film 2 and the liquid ejection opening 11 become in a positional relationship as shown in FIG. 5, the ejected developer comes into contact with the surface of the photoreceptor film 2. There is no developing electrode plate 12b directly below the area A on the surface of the photoreceptor film 2, and the developing section 17 is moving at a certain speed, so the developing electrode plate 12b is not directly below the area A on the surface of the photosensitive film 2.
2b has almost no electrode effect. and developing section 1
7 moves and the developing electrode plate 12a passes under the area A of the photoreceptor film 2, an electrode effect is exerted on the area A on the surface of the photoreceptor film 2.

As described above, the electrode effect on the surface A portion of the photoreceptor film 2 is mostly performed by the developing electrode plate 12a, and the other portions on the photoreceptor film surface are performed by the developing electrode plates 12a and 12b. Therefore, the image formed is the sixth image representing the surface of the photoreceptor film.
As shown in the figure, the image density in part A is lower than in other parts, which causes a problem of image unevenness when the image has many negative parts.

OBJECTS OF THE INVENTION The present invention eliminates these conventional drawbacks, and provides a wet type developing device that makes the electrode effect uniform on the film surface and reduces uneven development.

Structure of the Invention The wet type developing device of the present invention includes a developing section and a photoreceptor, which are configured such that developing electrode plates are mounted on both sides of a liquid ejection opening of a liquid scraping member, and the liquid scraping member is in contact with a developing roller. When developing is performed by the relative movement of This makes the electrode effect uniform on the body surface and improves image unevenness.

DESCRIPTION OF EMBODIMENTS The present invention will be described below along with one embodiment thereof.
This will be explained with reference to the drawings. FIG. 7 is a sectional view of a main part of a wet type developing device according to an embodiment of the present invention.
As in the conventional example described above, the developing solution is ejected from the liquid ejecting opening 11 and comes into contact with the surface of the photoreceptor film 2, and the entire surface of the film is developed by moving the developing section 17. At this time, the charge of the toner in the developer is made to have the same polarity as the charging voltage, and a bias voltage having the same polarity as the charging voltage is applied to the developing electrode 12' from the bias power supply 14 via the thin metal wire 13, thereby creating an inverted image. can get. Further, as mentioned above, conventionally, part A on the second surface of the photoreceptor film and the developing electrode plate 12 are connected to the seventh
When the positional relationship is as shown in the figure, there is no electrode effect on area A, but when the developing electrode plate 12a' passes under area A on the surface of photoreceptor film 2 as shown in FIG. 8, the electrode effect is exerted. . That is, in this embodiment, the area of the developing electrode plate 12b' is
By making the area smaller than a′, film 2
Since most of the electrode effects on the area A and other areas on the surface are exerted by the developing electrode plate 12a', image unevenness as shown in FIG. 6 can be eliminated. That is, the developing electrode plate 12b' is provided so as not to exert a large electrode effect on the film surface 2, but to prevent a decrease in the absolute density of the entire image. Note that the remaining developer that has come into contact with the surface of the photoreceptor film 2 is drained into the drain section 1.
The tapered portion leading to the liquid electrode 6 is integrated with the liquid scooping member in order to reduce the area of the developing electrode 12b'.

Now, according to experiments, when the area of the developing electrode 12b' is made at least 1/2 or less of the area of the developing electrode 12a',
It was possible to almost completely eliminate the image unevenness that had conventionally occurred.

FIG. 9 is an external view of a liquid scraping member equipped with the developing electrode plate of the present invention, and FIG. FIG. 2 is a sectional view of a main part of an apparatus using the developing device shown in the figure. The slide film 19 in the slide magazine 18 is supplied to a fixed position B on a substrate 21 by a slide supply plate 20. The fixed position B is a position where the original image of the original document 29 is formed through the lens system 22. 23 is the fixed position B
Before the slide film 19 is supplied to the fixed position B, focus adjustment is performed via the lens system 22 using a focus plate that is pressed by an elastic body. 24 is a support shaft 25 at the bottom of the board 21.
The station is movably mounted using a guide as shown in FIG. 7, and is equipped with a charger 26, an exposure window 27, a developing section 17 having a developing electrode plate shown in FIG. 7, and a dryer 28. By moving the station 24, charging, exposure, development, and drying are sequentially performed to form an image on the slide film 19.

Although the apparatus shown in FIG. 10 is constructed so that the developing section 17 is moved, it may be constructed so that the developing section 17 is fixed and the slide film 19 is moved.

Further, in this embodiment, one end of the liquid scraping member is configured to contact the upper surface of the developing roller, but it may be arranged close to the developing roller with a small gap therebetween.

Effects of the Invention As described above, the present invention prevents image unevenness, which is a problem when producing images with many hidden line areas, by making a difference in the area of the developing electrodes attached to both sides of the liquid ejection opening of the liquid scraping member. However, good images can be obtained, and the effect is extremely large.

[Brief explanation of drawings]

Figure 1 is a perspective view of a photoreceptor film, Figure 2 is a cross-sectional view of the same, Figures 3, 4, and 5 are cross-sectional views of a conventional developing device, and Figure 6 is a photosensitive film developed by a conventional developing device. FIG. 7 is a sectional view of a wet developing device according to an embodiment of the present invention, FIG. 8 is an enlarged view of the main parts, FIG. 9 is a perspective view of the developing section, and FIG. 10 is a plan view of a photoreceptor film. 8 is a cross-sectional view of an apparatus using the wet developing device of FIG. 7. FIG. 2... Photoreceptor film, 8... Developer, 9...
Developing roller, 10...Liquid scraping member, 11...
Ejection openings, 12a', 12b'...Development electrode plate, 1
7...Developing section.

Claims (1)

[Claims] 1. A developing roller is rotatably provided in a developing solution tank with a part of it immersed in the developing solution, and one end of a liquid scraping member disposed substantially above the developing roller is brought into contact with the circumferential surface of the developing roller. Alternatively, a developing section equipped with a developing electrode plate is provided on both sides of the liquid ejecting hole of the liquid scraping member, and as the developing section and the photoreceptor move relative to each other, A wet type developing device characterized in that the area of the developing electrode plate facing the photoconductor is made smaller than the area of the developing electrode plate facing later.