JPS59160154A - Developing head of electrophotographic apparatus - Google Patents

Abstract

PURPOSE:To enable efficient drainage of a liquid toner after development carried out by feeding the liquid toner, by installing a pressure reducing means for causing negative pressure in the gap between at least one part of the surrounding border of the opening of a developing head. CONSTITUTION:The suction path 11e of a developing head 11 is connected through an suction part 11f to the open air at the end of the path 11e, and provided with a trap 22 on the way and a suction pump 23 at the suction pipe 24 connected to the other end of the path 11e. On the other hand, the suction part 11f of the path 11e can be connected through the gap between the head 11 and a photosensitive material 12 to the lower end of an opening 11b. After development is carried out by feeding a liquid toner 14 and squeeze is finished by feeding a gas, a pressure for pressing the material 12 with a pressing plate 13 for feeding the material 12 is released to open the gap between the material 12 and the head 11, to exert suction force of the pump 23 on this gap, and to drain the liquid drops falling and staying at the lowest end of the opening 11b, and the gas is exhausted through the path 11e, the trap 23, and the pipe 24 to the open air, and excess of the liquid toner 14 on the surface 12a of the material 12 is thoroughly squeezed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing head section of an electrophotographic apparatus, and is improved so that liquid toner can be efficiently removed after development by applying liquid toner (hereinafter referred to as "squeeze").

Unlike photographic films that use silver salt photographic materials as photoreceptors, υ electrophotographic devices can be reused by cleaning after development but before fixing, regardless of whether the photosensitive material is exposed or not. Taking advantage of this reusable feature, electrophotographic materials formed into roll films or fish films can be partially charged, exposed, developed,
Microfilm processing equipment, etc. that records an image by fixing it, uses the resulting image together with unrecorded areas for purposes such as projection, and then adds new recordings to the unrecorded areas. It is used in

Among the above-mentioned electrophotographic apparatuses, so-called wet-type electrophotographic apparatuses that develop electrostatic latent images using liquid toner perform charging, exposure, development, and fixing for each frame. It is preferable that the toner does not ooze out other than the image area of the photosensitive material after processing. Therefore, it is necessary to squeeze out excess developer before separating the photosensitive material from the developing section and moving it to the next processing section.

A developing section of a conventional electrophotographic apparatus using liquid toner will be described with reference to FIG.

As shown in the figure, the developing head 1 is equipped with a mask 1a, and this mask la is in contact with the photosensitive material 2 through an opening 1b having a width corresponding to a portion of the photosensitive material 2. As a result, a part of the photosensitive surface 2a of the photosensitive material 2 faces the opening 1b), and by applying liquid toner 4 to the photosensitive surface 2a through the opening 1b, a predetermined latent image is developed. do. Following this development, it is necessary to squeeze the toner 4 adhering to the photosensitive surface 2a, and this squeezing is similarly performed by applying a gas such as air to the photosensitive surface 2a through the opening 1b. Therefore, it is necessary to transport the toner 4 and air to the opening 1b, but this transport involves sucking up the toner 4 stored in the tank 5 with the vacuum pump 6, and opening the valve 7 to transport the toner 4 from the air. This is done by similarly sucking it in with the vacuum pump 6. That is, a flow path 8 leads from the tank 5 to the inside of the developing head 1, passes through the valve 7 from the end open to the atmosphere, reaches the inside of the developing head 1, and joins the flow path 8 upstream of the opening 1b. A flow path 9, a flow path 1 that extends from the opening 1b to the outside of the developing head 1, passes through the vacuum pump 6, and returns to the tank 5.
0 is formed.

In this manner, in the developing section of the electrophotographic apparatus, a predetermined latent image is developed by applying the liquid toner 4 sucked up by the vacuum pump 6 to the photosensitive surface 2a, and subsequently, the liquid toner 4 sucked up by the vacuum pump 6 is applied to the photosensitive surface 2a. υ squeeze is performed by applying air to the photosensitive surface 2a. After the development and squeezing steps are completed, the pressure on the photosensitive material 2 by the presser plate 3 is released, and the photosensitive material 2 is transferred to the next frame υ.

In the above-mentioned conventional technology, the liquid toner is transported by a suction pump, so there is little chance of liquid seeping out from the developing section, but it has the disadvantage of requiring the use of a suction pump, which is an expensive suction means. Although the liquid toner 4 is squeezed by applying a squeezing gas to the photosensitive surface 2a, it has the disadvantage that the squeezing process is not performed satisfactorily. At this time, it is possible to achieve sufficient scooping if time is taken, but this time a problem arises in that the processing capacity per unit time decreases.

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, it is an object of the present invention to provide a low-cost developing head section for an electrophotographic apparatus that can perform sufficient squeezing in a short period of time. The present invention achieves this object by sucking liquid through a small gap formed between at least a part of the periphery of the opening of the developing head and the photosensitive surface of the photosensitive material when the photosensitive material is fed frame by frame. This is the basis of its technical philosophy.

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 2, the developing head 11 has a mask lla.
This mask lla has an opening 11b having a width corresponding to a part of the photosensitive material 12, and
It is in contact with 2. As a result, a portion of the photosensitive surface 12a of the photosensitive material 12 faces the opening 11b, and the liquid toner 14 is applied through the opening 11b while the photosensitive material 12 is pressed against the developing head 11 by the presser plate 13. After developing the electrostatic latent image by applying air, air is applied to the photosensitive surface 12a to perform squeezing. More specifically, the toner 14 is transferred from the tank 15 in which it is stored to the pump 1.
The toner is drawn up by the toner 6 and conveyed through the toner flow path 17. On the other hand, air, which is a gas for squeezing, is conveyed through a gas channel 19 that opens into the atmosphere at one end and has a gas pressure feeding means 18 interposed therebetween. That is, toner 14
The air is conveyed by a pressure-feeding method, as opposed to the suction method used in the prior art. Therefore, a valve 20 is installed in the gas flow path 19.
is provided to prevent toner from entering into the gas flow path 19 or the mechanism gas pumping means 18 when toner is being pumped. Excess toner 14 after toner is applied to the photosensitive surface 12a for development and air after squeezing are discharged from an outflow path 11d formed from an opening 11b in the developing head 11 toward a discharge channel 21. The water is returned to the υ tank 15 through the flow path 21. In this way, a predetermined latent image is developed by applying the liquid toner 14 pumped up by the pump 16 to the photosensitive surface 12a, and subsequently, the air sucked in by the gas pressure feeding means 18 is applied to the photosensitive surface 12a. Perform the Sysquiz by giving. After the development and squeezing steps are completed, the pressure on the photosensitive material 12 by the presser plate 13 is released;
The frame of the photosensitive material 12 is advanced to the next frame.

A suction path 11e is further formed in the developing head 11 of this embodiment. One end of this suction path 11e is opened to the atmosphere through an opening 11f, and a trap 22 is placed in the middle.
The other end is connected to a suction channel 24 which is equipped with a pressure reducing means, such as a suction pump 23, and is open to the atmosphere. At the same time, the suction section 11f of the suction path 11e is connected to the opening 1
The developing head 11 and the photosensitive material 12 can communicate with the lower end 11g of the developing head 11 through a gap between the developing head 11 and the photosensitive material 12. Thus, when the suction pop 23 is activated and at the same time the photosensitive material 12 is being pressed by the holding plate 13vC to the developing pad 11, air is blown through the suction part 11fffi and the discharge channel 2
However, when the photosensitive material 12 is released from being suppressed by the presser plate 13 during frame feeding of the photosensitive material 12, there is a space between the lower end ILg of the opening llb and the photosensitive material 120. Since a gap is created, the suction force by the suction pump 23 also acts on the opening 11b through this gap.

In this embodiment, after the toner 14 is completely applied and the developing process is completed, and the squeeze by gas sealing is completed, when the pressure on the photosensitive material 12 by the presser plate 13 is released for frame feeding, the photosensitive material 12 and the developing material are released. Since a gap is created between the head 11 and the head 11, the suction force of the suction pump 23 acts on this area, descends by squeezing, and sucks the droplets accumulated at the lower end 11g of the opening 11b, thereby opening the suction channel 24 and the filter. It is discharged into the atmosphere through the trap 22 with functional ligation. With this configuration, excess liquid toner on the photosensitive surface 12a can be sufficiently squeezed. Incidentally, in the prior art, the squiste has 1 to 24 points per 1-p on the photosensitive surface 12a.
According to this example, this amount was reduced to 0.3.
The amount was about ml. At this time, the dimensions of each part, t, = 0.
1 to 0.5 x = 0.3 to 0.5 x, and the suction pump 23 is -50 words) (about 20 is sufficient, and can be used by vane pump, electromagnetic pump, diaphragm pump, gear pump, or other pressure reducing means) In this embodiment, a trap 22 is provided in front of the suction pump 23 to separate liquid droplets and gas, so that liquid does not flow into the suction pump 23. However, if a solvent-resistant pump is used, It is not necessary to provide the trap 22, and a configuration may be adopted in which the droplets are directly returned to the tank 15.

FIG. 3 is a drawing of an embodiment of the processing section, showing only the surface that contacts the front when a processing head that integrates various process processing sections for electrophotography is viewed from the front. In the figure, 31 is a charging/exposure chamber, 11b is a developing/squeezing chamber, 32 is a drying chamber, and 33 is an opening of a fixing chamber. In this embodiment, the liquid toner and squeeze gas are configured to flow downward from above the opening 11b, so the suction section 11f is provided on the downstream side of the opening 11b, and the toner liquid flows toward the charging/exposure chamber side. In order to prevent oozing out, the suction part 11f is charged/
Although the structure is such that it is provided up to the end on the exposure chamber side, it may also be provided further on the end on the drying chamber side. When applying squeeze gas from the side instead of from above, the suction part 11f'
It is effective to provide it at the downstream end of the gas flow. As described above, it is effective to provide the suction portion 11f at the lower end of the opening 11b of the developing/squeezing chamber or at the downstream end of the squeeze gas flow), and furthermore, to provide it at the other peripheral portion of the opening 11b, A higher effect can be obtained if the structure is such that the droplets remaining at the end of the mask lla in contact with the photosensitive material 12 are sucked.

In principle, the suction pump 23 may be configured to apply suction force to the gap only when the pressure by the presser plate 13 for frame feeding is released, but in general It doesn't matter if you run it continuously. Although this embodiment has described an example in which a pressure pump is used to feed the toner, the present invention can be used to feed the toner using a suction device such as a conventional suction pump and further suck the droplets after squeezing. Needless to say, a configuration may also be adopted in which a suction means is added.

As specifically explained above in conjunction with the embodiments, according to the present invention, after squeezing by applying gas to the photosensitive surface,
By this squeeze, the droplets accumulated at the bottom of the developing head are sucked through the gap between the photosensitive surface and the developing head, which is formed during transport, so that sufficient squeezing can be performed in a short time. be able to.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a conventional technique, FIG. 2 is a sectional view showing an embodiment of the present invention, and FIG. 3 is an explanatory view showing only the surface that contacts the front when the processing head is viewed from the front. . 1 in the drawing shows a developing head 1b, an opening 1e, a suction path 1g, a lower end 2, a photosensitive material 12a, a photosensitive surface 14, and a suction pump for toner 23. Patent applicant: Fuji Photo Film Co., Ltd. Agent Patent attorney: Shibu Mitsuishi (and 1 other person) Figure 1 Figure 2

Claims (1)

[Claims] It has a developing head that faces the photosensitive surface of the photosensitive material and is formed with an opening for one frame of the photosensitive surface, and while the photosensitive material is pressed against the developing head, the photosensitive surface is In a developing head section of an electrophotographic apparatus, which applies a liquid toner to the photosensitive surface for development and then applies gas to the photosensitive surface through the opening to remove the liquid toner frame by frame, at least the photosensitive surface A pressure reducing means is provided so that when the material is released from being suppressed by the developing head, a negative pressure is applied to a gap between at least a part of the periphery of the opening of the developing head and the photosensitive surface of the photosensitive material. The developing head section of an electrophotographic device.