JPS59165083A - Developing head of electrophotographic device - Google Patents

Abstract

PURPOSE:To prevent liquid toner from being leaked and to use a normal liquid feeding pump to reduce the cost by forming a leakage preventing space on the external peripheral surface of an opening of a mask on a liquid toner developing head. CONSTITUTION:A bending part 2d is formed close to the external end surface 2b of the opening part of the external peripheral surface of the mask 2. The angle alpha of a photosensitive material 3 on the external peripheral surface 2c is 90 deg. and the angle beta between the other part of the external peripheral surface 2c and the material 3 is about 5 deg.. Since the interval (e) is about 1mm., the leakage preventing space 8 is formed between the surface 2c and the material 3. Even if the liquid toner 5 fed by a pump 6a is leaked from the space between the surface 2b and the material 3, capillary phenomenon is not generated because the space 8 is wide, so that the leached toner 5 is not leaked moreover.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a developing head of a type that develops the photosensitive material by bringing the liquid toner fed by a liquid feeding means into contact with a limited area of a photosensitive material. The present invention relates to a developing head for an electrophotographic apparatus that can prevent leakage of.

Lumiko photographic light-sensitive materials, which are different from photographic films that use silver salt photographic feed as a photoreceptor, have photosensitivity until they are charged, and furthermore, before they are fixed, they can be erased by known cleaning methods after exposure and development. It is possible. Taking advantage of the above-mentioned features, f'I and child photographic materials are formed into a roll film or fish shape, and are partially charged, exposed, developed, and fixed to record multiple images. After the image obtained by this process is used together with unrecorded parts for purposes such as projection, it is used in microfilms, etc., where new recordings are added to the unrecorded parts.

In the case of wet electrophotography, in order to visualize the YIj'tPL latent image formed on the photosensitive material by charging and focusing, liquid toner is brought into contact with the photosensitive material for development. The method of bringing the liquid toner into contact is to connect a pressure reducing means, such as a vacuum pump, to the outlet of the developing head, and use the negative pressure from the vacuum pump to guide the liquid toner into the developing head, thereby exposing the liquid toner to light. There is a method in which the liquid toner is brought into contact with the material, and a liquid feeding pump is connected to the inlet of the developing head, and the liquid toner is fed into the developing head by the liquid feeding pump and the liquid toner is felt. There is a method to do this.

Here, a method of developing using a vacuum pump (applied, for example, to Japanese Patent Laid-Open No. 144443/1983) will be outlined with reference to FIG. As shown in Figure 1, a mask 2 is attached to the developing head 1, and this mask 20. Opening 2 with a width corresponding to one frame of photosensitive material 3
a, and its opening outer end surface 2b is exposed to the photosensitive material 3, and its outer peripheral portion 2C is exposed to the photosensitive material 3 through a gap.
is facing. A conduit 4 is provided at the entrance ja of the developing head 1.
The tip of the developing head 1 is connected, and the base end thereof is immersed in the liquid toner 5 stored in the storage tank 7.Furthermore, an empty printer is inserted at the outlet 1b of the developing head 1. conduit 4
The tip 9i15 of a is connected, and its base end is connected to the storage tank 7.
It faces the space above. Then enter ``11a and exit 1b''
and t: 1-, 3m road Jc) i++. Then, when the vacuum pump 6 operates, the inside of the passage lc becomes negative pressure.
5 liquid toners, 3. The liquid toner 5 is drawn into the passage 1c via the filter 4, where an electrostatic latent image is formed, and the liquid toner 5 comes into contact with the photosensitive material 3 to perform development. The liquid toner 5 that has been developed is sucked by the vacuum pump 6. j'
Return to within 1'17.

In the example shown in FIG. 1, since the vacuum pump 6 is sucking the liquid toner 5, the mask 2 and A! Liquid toner 5y>KWli is rarely ejected from between the three light materials zF3.

However, the vacuum 7Jζ tube 6 has a t6 value and has large vibrations and noise, making it difficult and difficult to reduce the size and cost.

Next, an example of a method of developing using a normal pump will be explained with reference to FIG. Since these are the same as the example shown in FIG. 1, the same reference numerals are given and the explanation will be omitted. When the pump 6a is operated, the liquid toner 5 is fed into the passage lc and development is performed.

In the example shown in FIG. 2, Ribbon Pro a is usually used, so it is inexpensive. Since the liquid toner 5 is fed into the passage 1c under pressure by the pump 6a, there is a risk that the liquid toner 5 may leak through the mask 2 and the photosensitive feed 3. Moreover, once it leaked out, did they extract and enlarge part A in Figure 2? +r As shown in 31'xJ, since the angle formed by the mask 2 and the photosensitive material 3 is small (about 5 degrees) and the gap between them is narrow, the leaked liquid toner 5 is diffused into the gap due to capillary development. , frame to be developed +
C. Then the liquid toner 5 adhered to the photosensitive feed 3, and the other 11. I; may flow into the child photographic unit (f'+:).

In the end, the example shown in FIG. 1 was a problem, and the example shown in FIG. 2 had the risk of leaking of the liquid l/ner 5.

Furthermore, as disclosed in Japanese Patent Publication No. 51-13415, etc., the outer end surface of the opening of the developing mask that comes into contact with the trap photosensitive material is made of an elastic material such as rubber. Head attempts are also known.

However, if the above-mentioned method is used, a rubber-like mask must be attached to the opening of the developing head, which increases the number of manufacturing steps and costs. It also solves the problems of poor liquid removal, such as toner remaining in the bonded area, and poor durability. Furthermore, when the charging/N optical head and the developing head are manufactured as one unit, distance accuracy between the lens and the photosensitive material is required in the charging/N-optical head, but if an elastic body is used for the mask of the developing head, The position of the photosensitive material in the developing head is not constant, and this effect is also felt on the charging exposure head, resulting in poor f6 14 development performance at the position between the lens and the photosensitive material.

In view of the above-mentioned circumstances, an object of the present invention is to provide a developing head for an electrophotographic apparatus that is inexpensive, has no fear of leakage of liquid toner, and does not use an elastic body such as rubber. The technical concept of the present invention is based on the fact that liquid toner is fed to the developing head by a liquid feeding means and a leakage prevention space is formed on the outer peripheral surface of the opening of the mask.

Embodiments of the present invention will be described in detail below based on the drawings. Note that parts that are the same as those in the prior art are designated by the same numbers, and redundant explanations will be omitted.

FIG. 4 shows an embodiment of the present invention, and FIG. 5 shows an extracted and enlarged portion B of FIG. As shown in both figures, a bent curved υ portion 2d is formed near the opening outer end surface 2b of the outer circumferential surface 2C of the mask 2, and the outer circumferential surface 2C near the opening outer end surface 2b and the photosensitive material are formed. The angle α formed by the photosensitive material 3 is 90°, and the angle β11 formed by the other part of the outer peripheral surface 2C and the photosensitive material 3 is about 5.
°. Furthermore, there is approximately one chain @t between the bent point and the photosensitive material 3. Thus, a wide leakage prevention space 8 is formed between the outer circumferential surface 2C and the photosensitive material 3.

The liquid toner 5 fed by the pump 6a flows outside the opening fl! Liquid toner 5U oozing out from between the space 12b and the photosensitive material 3 (even in f3, capillary action occurs because the leakage prevention space 8 is wide) do not have.

In Fig. 2145, there is a gap between the photosensitive material 3 and the outside of the opening of the mask that is in contact with the photosensitive material 3 and the photosensitive material 13, which is connected to the outer part 2b of the mask during manufacture of the mask surface.
Normally, there is a certain amount of clearance due to deviation from the plane during pressing (3).

In the present invention, by suppressing this gap to 25 μm or less over the entire area outside the opening, it was possible to create a developing head that does not cause liquid leakage even when the liquid is allowed to flow through the developing head for a long time. It is something.

Considering the behavior of the liquid in the developing head mechanically, the outward force FC acting on the liquid between the photosensitive material 3 and the outer end surface 2b of the mask opening (unit length) is Ii'=t-P+σ (1-tα8α)2(l:t-1
ゝ-σ(1-6α). Here, t is photosensitive material O, 1 and mask f; iiJ
t- is the gap between the outer end surfaces, 9P is the pressure inside the developing head, and σ is the surface tension of the developer (shown in Table 1) α
is the angle formed with the photosensitive material outside the mask shown in FIG.

Table 1 Cyclohexane 25 (13/fl/cn+decane 239) Dodecane 25.4 // Toluene 28.4/1 The surface tension of the liquid used as a developer should be 20 to 30 dyn/cm as shown in Table 1. , considering the pressure inside the developing head as number + f weight/crl, the value of α is 90
It can be seen that when it is close to °, the value of F is negative υ, and the developer is prevented from spilling out. Further, in order to prevent a large amount of the developer from flowing out when the pump pressure for feeding the developer becomes temporarily high and it becomes difficult to stop the developer due to surface tension, the mask opening outer end surface 2bFi, photosensitive 41F1. 3 and
It is desirable that they meet at an rlr of 0.3 rtrm or more. This has the effect of reducing the flow rate due to the viscosity of the present agent.

FIGS. 6 to 9 show extracted and enlarged main points 773 of other embodiments of the present invention. In the embodiment shown in FIG. 6, the surface of the mask 2 on the passage lc side is made flat so that the liquid toner 5 can smoothly contact the photosensitive material 3. In addition, the seventh surface t; in the illustrated embodiment, the curved surface portion 2 d
' is formed, and in this example as well, the relationship of angle α>angle β is established, and the leakage prevention space 8 is formed. Furthermore, the eighth
In the embodiment shown in the figure, the size of the angle α is further increased, and the capillary phenomenon becomes less likely to occur. It is a space created.

This space also provides the same effect as the previous example.

The mask member used in the present invention does not deform even when the photosensitive material is pressed against the outer end surface of the mask opening, and even if it is deformed, the photosensitive material in the optical head does not deform. It is necessary to make it from a material in which the deviation does not exceed the optical 1:'1 volume value.
Phenol, polyphenylene monoquine, polyacetal, diallyl phthalate.

Nylon, Yuria, Insatiable 11. lPolynisdel・1・～
・Resins such as l fats, aluminum alloys, iron alloys, and alloys for use.

This can be achieved by using metal or ceramics mainly containing 17 for alumina.

These mask members have the characteristics that they do not deform even when a photosensitive material is pressed against them, and that they can be made from the developing head main body and a rotating member.

As described above in detail with the embodiments, according to the present invention, liquid toner can be fed using a conventional pump and a liquid feeding device, and the cost can be reduced. Furthermore, since a leakage prevention space is formed between the outer peripheral surface of the opening and the photosensitive material, leakage of liquid toner can be prevented. In addition, since the mask member can be made of the same material as the head body, costs can be further reduced and there is no negative impact on the positional accuracy of the photosensitive material in the charging/exposure head, which is the previous process. This will give you a very large effect.

[Brief explanation of the drawing]

Figures 1 and 2 show a conventional developing head with another 814f9.
FIG. 3 is a cross-sectional view extracting and enlarging part A of No. 215 I, FIG. 4 is a schematic diagram showing an embodiment of this g6 Ming, and FIG. Figure 9 is a cross-sectional view showing an extracted and enlarged view of part 13, m 6 to 21'; Figure 9 is an extracted and enlarged view of forts I to IX of other practical Mu examples of the present invention 11]
This is a top view. In the drawing, 1 is the developing head, 2 is the mask, 2b is the outside of the opening 111J, 2C is the outer circumferential surface, 2tt and 2cl' are the bent parts, 3 is the photosensitive material, 5 is the liquid toner, c?, a i-, l', pump (f, -3('i-1
L'P=r) 8 is the γ(d-out prevention space) Patent applicant: Fuji Photo Film Co., Ltd. Representative Patent Attorney: Shibe Mitsuishi (and other J names) Figure 1 Figure 3 1.! 2 Figure 7 Figure 8

Claims (1)

[Claims] The mask is provided with a mask having an outer end surface of the opening in contact with the photosensitive material 1 on which an electrostatic latent image is formed, and an outer peripheral surface facing the MiJ-written photosensitive material through a gap, and the mask is fed by a liquid feeding means. In the current head of the electrophotographic device P5, which develops the 13iT F+i-2 photosensitive material by contacting the liquid toner with the photosensitive ladle I separated by the front jjL mask, ゛C1 [(10fτ
I (on the outer peripheral surface near the end surface of the outer surface j, the photosensitive feed and the above 1''; 40 outside 11! rl near the 11 end 1111) 1
Jii 1 song is also curved so that the angle formed by the outer peripheral surface of the outer peripheral surface is wider than the angle formed by the other part of the outer peripheral surface and the photosensitive ladle material (Nyo 2). By forming the part in the shape of J6, a space is formed between the front ML part and the Ai, lN self & reflection part to prevent leakage of liquid toner due to the phenomenon of The developing head of the electrophotographic device i'', which shows the characteristics of the