JPH01250976A - Electrostatic image forming device - Google Patents

Abstract

PURPOSE:To form and record a normal latent image by applying liquid which is unwetable to liquid toner to the surface of a latent image carrier during a cleaning and a developing processes. CONSTITUTION:During the cleaning and the developing processes, the liquid which is unwetable to liquid toner is applied to the surface of a photosensitive body 10. As a result, when a latent image is developed by water soluble liquid toner, toner does not come into contact with the photosensitive body 10 but adheres to the impenetrable liquid applied prior to developing. For the same reason, when the photosensitive body 10 is cleaned in the cleaning process, cleaning can be performed without bringing the liquid toner into contact with the photosensitive body 10. By this means, a next cycle can be repeated without causing such inconvenience as the latent image is washed away and cannot be recorded. The normal latent image can be thereby formed and recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an image forming method used in copying machines, printers, etc., and in particular, to a method for developing an electrostatic latent image on a latent image carrier using a liquid developer. The present invention relates to an electrostatic image forming method in which the image is then transferred to a recording medium.

[Conventional technology]

Conventionally, in recording processes such as electrophotography, electrostatic recording, and ionography used in copying machines and printers, basically an electrostatic latent image formed on a latent image carrier is visualized with a colored material. Records are obtained by imaging. Various methods have been proposed for forming an electrostatic latent image, including a method of exposing a negatively charged photoconductive material to light, and a method of forming a latent image on a dielectric material using a multi-needle electrode or an ion emitting gate.

In addition, there are cases where the latent image carrier is the final recording medium as it is,
There are various types of devices, including those that transfer a visualized pattern from a latent image carrier to a recording medium. A so-called development process in which an electrostatic latent image is visualized with a colored material is common to these recording methods.

Developing methods are broadly divided into dry developing methods that use powder toner as the colored material and wet developing methods that use liquid toner. Among the dry developing methods, a magnetic brush developing method in which toner is transported to a developing area by magnetic force is currently widely used. However, since powdered toner is used as the coloring material, there is a problem in that toner powder smoke is likely to occur and stain the inside and outside of the device. Another drawback is that a fixing process that applies heat and pressure is essential in order to fix the two-color powder toner image onto the recording medium.

On the other hand, in the wet development method, a latent image medium is generally immersed in a liquid developer in which colored particles are dispersed in a highly resistive organic liquid, and a latent image is developed by electrophoresis of the colored particles. However, there are problems such as colored particles adhering to background areas that are not originally desired to be developed, resulting in background smudges, and the need to dry the organic liquid of the dispersion medium, which increases the concentration of organic liquid vapor around the device. there were.

As a liquid development method that solves these problems, US Pat. No. 4,202,620 proposes a method in which an electrostatic latent image is developed by bringing a thin film of liquid toner close to the latent image carrier without contacting it. ing.

FIG. 3 shows an example of the configuration of a recording process using this method.

In this method, when a thin film of liquid toner approaches the latent image carrier 10, toner protrusions grow from the thin toner film toward the latent image carrier due to an electrostatic field, and the toner contacts and adheres only to the latent image portion. In addition, development is performed without background smearing and without excess dispersion medium adhesion. Furthermore, since an aqueous liquid toner can be used, undesirable organic solvent vapor is not generated when the liquid toner is dried.

[Problem to be solved by the invention]

However, in this case, when a conductive liquid such as an aqueous liquid toner is brought into direct contact with a latent image carrier, the conductive components in the toner are adsorbed onto the surface of the carrier. cannot be removed. If the next cycle of charging and exposure is performed without the conductive component being removed, the electrostatic latent image on the carrier will wash away, resulting in a serious problem in that a normal latent image cannot be formed and recording cannot be performed. there were.

[Means to solve the problem]

The present invention is characterized in that it includes a step of applying a liquid that is difficult to wet with liquid toner to the surface of the latent image carrier between the cleaning process and the developing process.

[Effect]

According to the present invention, between the cleaning process and the development process, there is a step of applying a liquid that is difficult to wet with liquid toner on the surface of the photoreceptor, so even when a latent image is developed with aqueous liquid toner, microscopic In this case, the toner does not come into contact with the photoreceptor Pe, and is attached to a liquid that is not easily wetted by the liquid toner applied before development. For this reason, when cleaning the photoreceptor during the cleaning process,
Since the liquid toner can be cleaned without coming into contact with the photoreceptor, there will be no inconvenience such as the latent image being washed away and recording not possible even if the next cycle is repeated.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, which is an electrophotographic process using liquid development that is basically the same as that shown in FIG. 3 as a conventional example. The difference from the conventional example is that an oil coater 1 is provided between the eraser 12 and the charger 13. ,
5'E The oil coater 1 in this embodiment, as shown in FIG. 2, consists of a feeder 2 whose one end is immersed in silicone oil 3 in an oil reservoir and whose other end is in contact with the photoreceptor 10. . Since the feeder 2 is made of felt, the silicone oil 3 is supplied by capillary action, and a thin film 4 of silicone oil is formed on the surface of the photoreceptor 10 . With a thin film of silicone oil formed, the following steps are performed: charging, exposure, development, transfer,
Because of the cleaning process, the aqueous liquid toner does not microscopically contact the photoreceptor, but remains attached to the silicofoil thin film.

Therefore, the inconvenience that the conductive component in the aqueous liquid toner is adsorbed to the surface of the photoreceptor and the latent image is washed away and recording cannot be performed does not occur.

〔Effect of the invention〕

As explained above, the present invention can prevent electrostatic latent images even when using conductive liquid toner by applying a liquid that is difficult to wet with liquid toner to the surface of the latent image carrier between the cleaning process and the development process. It has the effect of normal latent image formation and recording at -6°T without bleeding.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a recording process according to an embodiment of the present invention, FIG. 2 is a sectional view showing an oil coater according to an embodiment of the present invention,
FIG. 3 is a diagram showing a conventional recording process using liquid development. 1...Oil coater, 2...Feeder, 3
...Silicone oil, 4...Silicon oil I film, 10...Photoreceptor, ■1...Cleaner, 1
2... Erase → No, 13... Charger, 1
4...Exposure, 15...Developer, 16...
...Transfer roll, 17...Recording paper. Agent Patent Attorney Susumu Uchihara/Otsu Transfer Roll

Claims (1)

[Claims] a step of applying a liquid that does not wet the conductive liquid toner to the latent image carrier between cleaning and development; and a step of developing the electrostatic latent image formed on the latent image carrier using the conductive liquid toner. An electrostatic image forming method comprising: