JPH0594094A - Liquid carrying device for wet recording device - Google Patents

Abstract

PURPOSE:To eliminate the need of mechanical power, to miniaturize a device and to make noise low by dividing comb-shaped carrying electrodes into plural groups in a state where the carrying electrodes belonging to respective groups are adjacent in fixed order, successively impressing voltage on the respective groups and carrying wet developer. CONSTITUTION:The comb-shaped carrying electrodes 122 are provided, and divided into plural groups (a), (b) and (c) in a state where the carrying electrodes 122 belonging to the respective groups are adjacent in the fixed order, then the voltage is successively impressed on the respective groups (a), (b) and (c) to carry the wet developer. A developer supply device leads the wet developer stored in a developer container to an applying head 202 and discharges it on the surface of a photosensitive drum. The applying head 202 is formed by laminating a base plate 121 and an upper plate 120, where a slit is formed. The electrodes 122 are provided at the bottom of a step, and divided into three groups (a), (b) and (c). Thus, the wet developer is carried by the action of electrostatic field formed by the electrode 122 on which static electricity is impressed, and a mechanical power source is not necessitated and the device is miniaturized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for forming a toner image corresponding to an electrostatic latent image on an electrostatic latent image carrier using a wet type developer. More specifically, the present invention relates to a liquid transporting device used in these wet recording devices and used for transporting a wet developer.

[0002]

2. Description of the Related Art As a liquid transfer device used in a conventional wet recording device, a pump driven by a mechanical power source such as a motor is used as described in Japanese Patent Laid-Open No. 140780/1990. Was there. FIG. 12 shows an example of this, in which the developing solution 67 in the developing tank 66 is fed to the developing head 62.
From the slit provided in the center of the upper surface of the photosensitive drum 6
A pump 65 is used to supply the circumference of 1.
An intake pump 63 is used to collect the excess developer.

[0003]

Since the above-mentioned prior art device requires a pump having a mechanical power source, it has been difficult to miniaturize the device. The present invention solves this problem and realizes a small-sized liquid transfer device having no mechanical power source.

[0004]

A liquid transfer device of a wet recording apparatus according to the present invention uses a wet developer containing charged toner according to an electric field created by an electrostatic latent image on an electrostatic latent image carrier. In a wet-type recording apparatus for forming a toner image, it has carrier electrodes formed in a comb shape, and these carrier electrodes are divided into a plurality of groups so that the carrier electrodes belonging to each group are adjacent in a predetermined order. It is characterized in that the wet developer is conveyed by sequentially applying a voltage to.

[0005]

EXAMPLES Examples of the present invention will be described.

FIG. 4 is a sectional view of a wet type recording apparatus according to an embodiment of the present invention. Around the photosensitive drum 1 made of a photoconductor which is an electrostatic latent image carrier, a charging device 2, an exposure device 33 made of a laser scanner, a developer supplying device 4, a developing drum 5, an excess developer removing device 6, and a transfer device. The drum 3, the pressure roller 6, and the static eliminator 8 are sequentially arranged. The rotation directions of the photosensitive drum 1, the developing drum 5, the transfer drum 3, and the pressure roller 6 are indicated by A, B, C, and D.

As shown in FIG. 5, the photosensitive drum 1 includes an amorphous selenium photosensitive layer 10 around an aluminum tube 100.
1 is vapor-deposited. It is configured to rotate in the direction of arrow A.

FIG. 1 is a perspective view of the wet recording apparatus described above.

The developer supply device 4 guides the wet type developer (hereinafter also referred to as a developer) contained in the developer container 10 to the coating head 202 and discharges it onto the outer peripheral surface of the photosensitive drum 1.

The structure of the coating head 202 is shown in FIG. The coating head 202 is configured by stacking a base plate 121 and an upper plate 120. A step is provided on the base plate 121, and a slit 72 shown in FIG. 5 is formed in a stacked state. In FIG. 3 again, an electrode 122 is formed at the bottom of the step, and these are divided into three groups a, b, and c so that a voltage can be applied to each group.

As the wet type developer, a positively charged developer is used in the apparatus of this embodiment. A dispersion medium having a high resistance and a low dielectric constant aliphatic hydrocarbon solvent (for example, manufactured by Exxon Chemical Co.,
In Isopar G), toner particles composed of Raven 1255 and ethylene cellulose manufactured by Corobian Carbon Co., Ltd. as pigments are dispersed together with a charge control agent organic amine.

As shown in FIG. 5, the developing drum 5 has an elastic layer 116 on the metal tube 112. This is composed of a conductive layer 113 made of a conductive urethane rubber in which a conductive compound is dispersed, and an insulating layer 114 made of a fluororesin coat layer as the outermost layer. , Arrow B at the same speed as the photosensitive drum 1
Rotate in the direction of.

The transfer drum 3 has a structure similar to that of the developing drum 5, and has a structure in which a conductive layer is provided on a metal tube and an insulating layer is provided thereon.

The pressure roller 6 transfers the recording paper 21 to the transfer drum 5
Press from behind towards.

The charging device 2 comprises a corotron to which a voltage is applied by a high voltage power source.

The exposure device 33 is composed of a laser beam scanner, controls the laser beam in accordance with image data from a computer, and forms an electrostatic latent image on the photosensitive drum 1. The static eliminator 8 is a brush made of conductive fiber,
The photoconductor drum 1 is rubbed at a predetermined potential to be discharged to a constant potential to erase the electrostatic latent image.

Next, the operation will be described.

The charging device 2 charges the photosensitive drum 1 to a positive potential. In the exposure step, an electrostatic latent image corresponding to the image is formed on the photoconductor drum 1. As a result of the surface charge being neutralized in the exposed portion, an electrostatic latent image on the photosensitive drum 1 is formed.

The toner image forming operation will be described with reference to FIG. The surface of the photosensitive drum 1 is uniformly charged with positive charge,
It has a positive surface potential (+500 V in this embodiment), and after the exposure process, the exposed portion 105 has a substantially ground potential (for example, + V).
40 V), the non-exposed portion 104 has a positive potential (+5 in this embodiment).
00V) and enters the contact portion 117 with the elastic drum 5.
The contact portion 117 holds the wet type developer 56 supplied from the coating head 202. The developing drum 5 has a power source 102.
Therefore, the positive potential (+450 V in this embodiment) lower than the positive potential of the non-exposed portion is maintained. Wet developer layer 56
Has a positive charge, when passing through the contact portion 117 between the photosensitive drum 1 and the elastic drum 5, the exposed portion faces the photosensitive drum 1 in accordance with the electrostatic force, and the non-exposed portion in the exposed portion. An electrostatic force is applied toward the developing drum 5. As a result, the developer layer 109 adheres to the photosensitive drum 1 at the portion corresponding to the exposed portion. On the other hand, in the non-exposed portion, an electrostatic force acts so that the developer adheres to the photoconductor drum 1. However, due to the above potential relationship, the attraction force between the photoconductor drum 1 and the developer is not large, so that the contact is made. The pressing force of the portion 117 causes a squeezing action to peel and remove. This potential relationship is shown in FIG. On the other hand, the dispersion medium is also subjected to the throttling action, and the movement of the contact portion 117 downstream is blocked. These are retained in the retaining portion 115 on the upstream side of the contact portion 117 and reach the excess developer removing device 6.

In FIG. 4, the toner image on the photosensitive drum 1 is electrostatically transferred by the power supply 103 to the transfer drum 3 kept at a lower potential than the photosensitive drum 1.

The recording paper 21 is conveyed to the contact portion with the transfer drum 3 in accordance with the formation of the toner image, and the toner image is transferred from the transfer drum 3 to the recording paper 21 under pressure.
That is, the toner image is pressed by the pressure roller 6 and receives the pressure to generate an adhesive force with the recording paper 21, so that the transfer drum 3
Transfer to the recording paper 21.

Next, the operation of the coating head 202 will be described.
In FIG. 5, the wet developer is infiltrated into the slit 72 of the coating head 202 by the capillary force and held there. Details of the coating head 202 are shown in FIG. The base plate 121 made of glass has a thickness of 200 mm for about 10 mm.
The transport electrodes 122 of μm are formed at a pitch of 250 μm. (The number of the transport electrodes 122 is about 40, but only a small number of electrodes are shown in FIG. 3 for simplification.)
As shown in the figure, these transport electrodes 122 are divided into three groups, and 1.5 KV is applied to each of them by one-third time division driving with one cycle of 90 μs. At this time, the wet type developer moves in the direction of arrow F, is conveyed toward the opening of the slit 72, and is supplied to the photosensitive drum 1. Although the transport mechanism is not clear, in the experiments conducted by the present inventors, it is presumed that the toner is transported by the action of the toner charge and the electric field formed between the electrodes. With the above configuration, the wet developer is transferred from the developer container 10 to the coating head 2 without requiring mechanical power.
02 is further conveyed in the slit 72 of the coating head 202, and development is performed.

FIG. 10 shows the transport electrode 1 of the coating head 202.
22 shows a wiring structure of 22. A structure in which a transport electrode 122 (only three electrodes are shown as a representative of each group) formed of a metal thin film formed on a glass substrate 121 is connected to patterns 201, 202, and 203 for driving this. Is. When connecting to the pattern 201, a hole (so-called through hole) 204 which penetrates the substrate 121 and whose inner surface is made conductive with a metal thin film is connected to the back side pattern 206 of the substrate 121, and further, a through hole 205 is connected to the pattern 201. With this configuration, the carrier electrodes 1 of each group
Drive voltages can be independently applied to 22 without interfering with each other. Further, the transport electrode 122 and the patterns 201, 2
02, 203, 206 to cover the insulating layers 207, 208
(Shown in the cross-sectional view of FIG. 11) is laminated and insulated, and chemical resistance is imparted to the solvent of the wet developer.

Next, the structure and operation of the excess developer removing device 6 will be described. In FIG. 2, the carrier electrode 14 is provided on the substrate 141.
0 is formed. Similar to the case of the coating head 202, these are divided into three groups so that a voltage can be applied to each group. The surplus wet developer that has reached the surplus developer removing device 6 is transported in the direction of the arrow E and is recovered by the recovery pipe 143 provided at the end, as described in the case of the coating head 202. It is collected in the container 142.

FIG. 8 shows a wiring structure of the carrying electrode 140 of the excess developer removing device 6. A carrier electrode 140 (only three electrodes are shown as a representative of each group) formed of a metal thin film formed on the glass substrate 141 is connected to patterns 210, 211 and 212 for driving the carrier electrode 140. The connection to the patterns 211 and 212 is performed as follows. An insulating layer 217 having openings 213, 214, 215, and 216 after forming the transport electrode 140 and the patterns 210, 211, and 212 (in FIG. 9, a cross-sectional view taken along the broken line shown in FIG. 8 is a cross-sectional view of the insulating layer 217). The figures are shown).
After this, a pattern 218 connecting the openings 213 and 214
To form. Further, a pattern 219 that connects the openings 215 and 216 is formed. With this structure, the transport electrodes 122 of each group can be driven independently without interfering with each other. Further, an insulating layer 220 is laminated on this to cover the whole.

[0026]

According to the liquid transfer device of the wet recording apparatus of the present invention, the wet developer is transferred by the action of the electrostatic field formed by the transfer electrode to which static electricity is applied. Therefore, no mechanical power source is required. Therefore, there is an effect that a small device can be realized. Further, it has an effect that the power consumption is small in the operation. Furthermore, since the liquid transfer principle is not mechanical, there is an effect that noise is not generated during operation.

[Brief description of drawings]

FIG. 1 is a perspective view of a wet type recording apparatus including a liquid transfer device according to the present invention.

FIG. 2 is a perspective view showing a configuration of an excessive developer removing device according to an exemplary embodiment of the present invention.

FIG. 3 is a perspective view showing a configuration of a coating head according to one embodiment of the present invention.

FIG. 4 is a cross-sectional view of a wet recording apparatus equipped with the liquid transport device of the present invention.

FIG. 5 is a diagram showing a toner image forming operation at a contact portion of the wet type recording apparatus according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a potential relationship in a developing section of the wet type recording apparatus according to the first embodiment of the present invention.

FIG. 7 is a voltage application sequence diagram of a transport electrode for explaining the liquid transport operation of the present invention.

FIG. 8 is a perspective view showing a method of wiring the transport electrodes of the excess developer removing device according to the exemplary embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a method of wiring the transport electrodes of the excess developer removing device according to the first embodiment of the present invention.

FIG. 10 is a perspective view showing a method of wiring the transport electrodes of the coating head according to the first embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a method of wiring the transport electrodes of the coating head according to the first embodiment of the present invention.

FIG. 12 is a cross-sectional view showing a conventional liquid transfer device.

[Explanation of symbols]

 1: Photoconductor drum 5: Transfer drum 6: Excess developer removing device 140, 122: Conveying electrode 202: Coating head

Claims (1)

[Claims] 1. A wet recording apparatus for forming a toner image by a wet developer containing a charged toner in accordance with an electric field formed by an electrostatic latent image on an electrostatic latent image carrier, and formed in a comb shape. It has carrier electrodes, so that the carrier electrodes belonging to each group are adjacent in a fixed order.
A liquid transfer device of a wet recording apparatus, characterized in that these transfer electrodes are divided into a plurality of groups, and a voltage is sequentially applied to each group to transfer the wet developer.