JPS6031171A - Drying method in case of liquid development of electrophotography - Google Patents

Abstract

PURPOSE:To realize a speed-up of a drying process, and to prevent an uneven drying by supplying a liquid developer by making a developing mask adhere tightly to an electrophotographic sensitized material, making a gas flow to a developing chamber in its state, and moving said material to a drying chamber in a state that a liquid film is left on the whole surface of a limited area. CONSTITUTION:A liquid developer does not leak out to other part than a photosensitive surface by supplying the liquid developer 4 by making a developing mask 2 adhere tightly to an electrophotography sensitized material 3. Also, a time required for drying is shortened by executing a liquid-break equeeze by making a gas flow in a state that the electrophotography sensitized material 3 exists in a developing chamber 12. Moreover, the liquid-break is limited to the extent that a liquid film of the liquid developer 4 is left on the whole surface, by which in case of moving the electrophotography sensitized material 3 to a drying chamber 3, even if a liquid held between said material and the developing mask 2 flows in, no uneven drying is generated because the whole is still wet by the liquid developer 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drying method that speeds up the drying process and prevents uneven drying when developing an electrophotographic light-sensitive material using a liquid developer.

In a so-called wet electrophotographic recording (or copying) system that develops an electrophotographic light-sensitive material using a liquid developer, there are generally five stages: charging, exposure, development, drying, and fixing.
After passing through the processing steps, the image information is recorded on microfilm or the like or copied. That is, in the charging step, the surface of the electrophotographic light-sensitive material is first charged by a corona discharge. Next, in the exposure step, the image information to be recorded is exposed onto the electrophotographic light-sensitive material through a lens or the like, and an electrostatic latent image is formed thereon. Next, the electrophotographic light-sensitive material on which the electrostatic latent image has been formed is is sent to a developing process, where a liquid developer is applied to the photosensitive surface. This creates an electrostatic latent image. Depending on the turn, toner is supported on the photosensitive surface by Coulomb force. After that, the electrophotographic photosensitive material is sent to a drying process, in which the solvent of the liquid developer is removed by drying.Then, in a fixing process, the toner electrically supported on the photosensitive surface is heated, pressurized, or coated with W fat. It is established by etc. As a result, image information is permanently stored on the surface of the electrophotographic material.

As mentioned above, in the recording system using electrophotography, there is one
Since all processing up to development and fixing proceeds every time the III image information is exposed, there is an advantage that the image information can be immediately reproduced. Also, since the photoreceptor is not sensitive to light until it is charged, it has the advantage that it does not need to be completely shielded from light when the photoreceptor is being stored or is being projected using a bad reader. Therefore, recording by electrophotography has begun to be put to practical use not only in the field of so-called copying machines but also in the field of microfilm systems.

By the way, in the above-mentioned electrophotographic recording system, since the toner is electrically supported on the photosensitive material before fixing, it is necessary to fix the toner immediately after exposure and development.

Further, when the film is used for recording a large number of frames, such as electrophotographic light-sensitive materials such as Calor film and Fish film, it is necessary to sequentially perform the above-mentioned processing steps for each frame. In this case, the problem is that the liquid developer does not leak out to places other than the electrophotographic light-sensitive material or to frames other than the frames to be developed, and that it does not leak from the top of the photosensitive surface until it is fixed. The solvent in the liquid developer must be sufficiently dried and removed. If the fixing process is carried out with solvent remaining on the photosensitive surface, heat fixing will cause blurring on the photosensitive surface, pressure fixing will cause the toner to flow,
With coating fixing, the fixing quality deteriorates, such as the resin not curing. Therefore, it took a relatively long time to dry the solvent.

In order to solve these problems, a developing processing apparatus as shown in FIG. 1 has been proposed. In general, if the part that performs development processing is formed independently from the part that performs other processing, it is called a development head, and if it is formed integrally with the part that performs other processing, it is called the development section. It is often called.

In FIG. 1, l#'i is a developing head or developing section, and its opening 12 is a developing chamber. The periphery of the developing chamber 12 is a developing mask 2, and the end face 2b of the opening frame 2a
The photosensitive surface side of the electrophotographic photosensitive material 3 is a presser plate (not shown).
It is closely attached by etc. The inner peripheral shape of the opening frame of the development mask 2 is a shape that limits the area to be developed, for example, the area for one frame of the electrophotographic photosensitive material. 5. Entrance/exit, i.e., developer introduction port. There is a gas intake port 6 and a discharge lower. The liquid developer 4 in the horizontal developer tank 8 is fed to the developer inlet 5 by a developer pump 13, and the electrophotographic photosensitive material 3 after path light is fed.
A certain amount of liquid developer is sprayed onto the surface. 11 is a developing electrode, which faces the photosensitive surface of the electrophotographic photosensitive material, and serves to prevent the particles in the liquid developer from being electrically supported on the photosensitive surface. Subsidize. A part of the liquid developer sprayed onto the electrophotographic photosensitive material flows down the photosensitive surface and is transferred to the developer tank 8 from the discharge lower.
Return to When the supply of liquid developer is finished, that is, development is finished,
Using the valve 16, a gas such as air is flowed into the developing chamber 12 from a blower pump or a gas tank (not shown) through the gas intake port 6, and the liquid developer on the photosensitive surface of the electrophotographic photosensitive material 3 is released. The solvent is evaporated and the liquid developer adhering to various parts such as the inner wall of the developing chamber 12 is blown away. At the same time, the suction pump 15 is activated to suck the liquid developer that has entered the gap between the electrophotographic photosensitive material 3 and the opening frame end surface 2b of the development mask 2. This suction is continued until the electrophotographic photosensitive material 3 is sent to the next drying process, and when the electrophotographic photosensitive material 3 separates from the aperture frame end face 2b, most of the liquid held therebetween is sucked. Note that 9 is a suction slit, IO is a suction port, and 14 is a trap.

In this way, by squeezing the electrophotographic material 3 in advance while it is in the developing section 12, the drying process in the next step can be completed in a short time.

Conventionally, it has been considered preferable to drain the liquid as completely as possible in the development process. FIG. 2 is a graph of the amount of liquid remaining on the electrophotographic photosensitive material versus the time of air blowing from the gas intake port 6. However, the electrophotographic light-sensitive material is a 16 m microfilm, and the opening of the developing chamber 12 is 10 cm square. In FIG. 2, curve A is the characteristic when air is blown only without suction, and curve B is when air is blown and suction is applied at the same time.

However, as can be seen in Figure 2), the amount of liquid on the photosensitive surface decreases significantly within one second after the start of air blowing or air blowing and suction, but after that, the amount of liquid hardly decreases. The reason for this is that the liquid held between the electrophotographic photosensitive material 3 and the opening frame end surface 2b of the developing mask is not completely removed regardless of whether suction is applied or not.On the other hand, if the air is continued for a long time, for example, for more than 2 seconds, the liquid will not be completely removed. , the electrophotographic photosensitive material 3 facing the inside of the developing chamber 12 begins to be partially dried. If an attempt is made to proceed to the drying process in such a partially dried state, when the electrophotographic photosensitive material 3 separates from the opening frame end surface 2b of the development mask, the liquid held during this time flows out onto the drying surface. Since it is then re-dried, uneven drying occurs and the quality of the recorded image deteriorates.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art described above and to provide a drying method for electrophotographic liquid development that does not cause uneven drying, even though the drying process is caused by speed fluctuations.

The structure of the drying method of the present invention that achieves this objective is that a development mask in a developing chamber is brought into close contact with the electrophotographic photosensitive material after exposure, and a liquid developer is supplied to only a limited area for development. Gas is flowed into the developing chamber while the developing chamber is in close contact with the developing mask, and the liquid is drained until a liquid film of the liquid developer remains on the entire surface of the limited area. The electrophotographic material is relatively moved from the developing chamber to the drying chamber while the electrophotographic material remains on the entire surface of the liquid developer, thereby drying the area wetted by the liquid developer.

Furthermore, by supplying the liquid developer with the development mask in close contact with the electrophotographic photosensitive material, the liquid developer does not leak out to areas other than the photosensitive surface. In addition, by draining the liquid by flowing gas while the electrophotographic material is in the developing chamber, the time required for drying can be shortened.Furthermore,
The liquid drain p is set so that the liquid film of the liquid developer remains on the entire surface, so that even if the liquid held between the developing mask and the electrophotographic photosensitive material flows out when transferring the electrophotographic photosensitive material to the drying chamber, Since the entire surface is still wet with liquid developer, uneven drying does not occur.

An embodiment of the present invention will be described below with reference to the drawings. 3rd, 3rd
The figure is a schematic perspective view of a microfilm process head that integrates processing steps from exposure to fixing.
20 is a band iir, p exposure section, 1 is a developing section, 25 is a drying section, 28 is a fixing section, 32 is a 165 m+ electrophotographic film, 32a is its blip mark, and 33 is a blip mark detection sensor. FIGS. 4(a) to 4(d) show the cross-sectional structure of each part. FIG. 4(a) shows a cross section of the charging/glazing section 20, in which 21 is a corona wire, 22 is a side electrode, 23 is a lens, and 24 is a film holding plate. 4) shows a cross section of the developing section 1, the details of which are the same as in FIG. 1. FIG. 4(C) shows a cross section of the drying section, in which 26 is a drying chamber and 27 is a drying gas intake. FIG. 4(d) shows the fixing section, in which 29 is a xenon lamp, 30 is a glass plate, and 31 is a suction port.

FIG. 5 shows an example of the processing order when the integrated process head of FIG. 3 is used. ≠1 to 44 in the figure are frame numbers of the film 32. Now, if you pay attention to the +1 piece, it will be charged! The film 32 is placed in the exposure section 20 and held down by the presser plate 24, charged in the first 1 second, and completed in the next 3 seconds.

The holding plate 24 is removed with a lie, the film 32 is sent to the developing section 1 for 0.5 seconds, and the developing pump 13 is operated for about 1.5 seconds to apply the liquid developing ax 14 to the film 32. In this state, the frame 2 is designed so that it is located in the charged exposure section 20, and photography is performed as necessary. Next, before moving the piece, air is blown and sucked for about 1 second to the piece No. 1. The amount of air blown in this case is about 517 minutes. The amount of residual liquid is less than 0.5N9/1 piece, but the entire surface is wet with a liquid film. After draining the liquid with the entire surface wet, release the presser plate 24 and remove the film 32.
, and move the +1 piece to the drying chamber 26. A drying gas such as air is passed through the +1 piece for about 5 seconds to dry it completely. In this case, the opening of the drying chamber 26 is desirably larger than the opening frame of the developing mask in order to dry the portion where the film 32 also contacts the opening frame end surface 2b of the developing mask. Since the +1 piece was transferred to the drying chamber 26 with its entire surface wet with liquid, it was dried evenly. While the +1 frame is drying, the +2 frame is developed and drained, and the +3 frame is charged and exposed. Next, the film 32 is advanced by one frame, and the +1 frame is heated for a short time by a xenon lamp 29 in the fixing section 28 to be fixed.

Thereafter, the pieces after +2 are sequentially processed in the same manner.

In addition, although the film 32 was moved in the above-mentioned example,
The same applies when the film is fixed and the process head is moved. The same applies when the developing section, drying section, etc. are not integrated but are independent. Further, in the case of a special liquid developer, the toner is fixed only by a drying process without performing a fixing process, and the present invention can also be applied to this case. Also, JP-A-53-76035
As disclosed in the above publication, the present invention can also be applied to electrophotography in which positive images and negative images are selectively obtained by double charging in forward and reverse directions, followed by exposure, and then recharging and uniform irradiation to selectively obtain positive images and negative images.

[Brief explanation of the drawing]

(The figures relate to the present invention), Figure 1 is a structural explanatory diagram of the developing head or developing section, Figure 2 is a graph of residual liquid amount versus air blowing time, Figure 3 is a schematic perspective view of the integrated process head, and Figure 4 is a diagram showing the structure of the developing head or developing section. Figures (a) to (d) are sectional views of each part in Figure 3, and Figure 5 is a diagram showing an example of the processing procedure. In the drawings, 2 is a developing mask, 3 is an electrophotographic photosensitive material, 4 is a liquid developer, 6 is a gas intake port, 9 is a suction slit, 12 is a developing chamber, and 15 is a suction pump. Patent applicant Fuji Photo Film Co., Ltd. Patent attorney Shibu Mitsuishi (1 person) Figure 1 Figure 2 Dokigin Figure 3 Figure 4 (a) (b) (c) (d) Procedural amendment 1988? Mr. Commissioner of the Japan Patent Office, January 37th, 1988, Patent Application No. 139499, Showa 1983
Judgment No. 2, Name of the invention: Dry-weaving method for the electronic portrait 5. Stock company 4, agent postal code 107 1. Subject of amendment (1) "Detailed explanation of the invention" column of the specification. (2) Figure Box 7, PJ of correction @ (1) E! A ai lo page h rVinKf
fill*r and aspirate't-delete. (2) "..." written on page 11, line 15 of the detailed IF
·It is processed. '', then [Wake-off 11D rounding air blowing is performed for K1 seconds immediately before the film is moved, but this can be done at any time, whether it is at the threshold #i' from after development to when the film is moved. Further, the device that performs the % suction between air blowing and movement does not need to be limited to this, and can be operated continuously, for example. ” is inserted. (Attached is a revised drawing of 33m standing in the rain (horse im)
Corrects excessive IK. 8. List of attached documents (1 copy (or more) of υ amended drawings (No. 5g))

Claims (1)

[Claims] A developing mask in a developing chamber is brought into close contact with the electrophotographic photosensitive material after exposure, and a liquid developer is supplied only to a limited area for development.
With the electrophotographic photosensitive material in close contact with the development mask in the development chamber, gas is flowed into the development chamber to remove the liquid developer until a film of liquid developer remains on the entire surface of the limited area. Electrophotography characterized in that the electrophotographic material is relatively moved from the developing chamber to the drying chamber with the liquid film remaining on the entire surface of the limited area to dry the area wetted by the liquid developer. drying method in liquid development.