JPH0323480A - Liquid developing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a liquid developing device for applying a developer to a recording medium to develop an electrostatic latent image on the recording medium.

BACKGROUND OF THE INVENTION A conventional liquid developing device will be described below with reference to the drawings. First, an example of a conventional color electrostatic recording apparatus using the liquid developing device will be described.

4 to 8 show structural examples of conventional color electrostatic recording devices. In FIG. 4, 21 is electrostatic recording paper, 2
Reference numeral 2 denotes one multi-needle electrode recording head arranged so as to face the conveyance path of the electrostatic recording paper, 3a to 3d a developing head also arranged so as to face the conveyance path, and 2 the electrostatic recording paper. Squeeze nozzle p suctions and removes the solvent of the developer added to 21 and fixes it, and is connected to a waste liquid tank 29 via a vacuum pump 28. 30 is a presser roller for maintaining contact between the electrostatic recording paper 21 and the recording head 22;
32 is a high-concentration developer replenishment tank for replenishing toner; 33 is the concentration detector 31;
A solenoid valve 34 is a vacuum valve operated by the detected concentration of .

FIG. 5 shows details of a liquid developing device including the developing heads 3a to 3d.

Reference numeral 1 denotes a liquid developing device, which includes an elongated rotary body 2 disposed below a conveyance path for a recording medium so that its rotational axis is perpendicular to the conveyance direction. The rotary body 2 has a plurality of (four in the illustrated example) development ports 3a to 3d protruding from the outer periphery in a criss-cross shape when viewed from the axial direction of the rotary body.

4 is a rotating shaft protruding from the axis position of both ends of the rotating body 20;
It is connected to an appropriate driving means (not shown) and is housed so as to be able to reciprocate and rotate at intervals of four developing helenoids 3a.

In the developing ports 3a to 3b, several (three in the illustrated example) developer supply grooves 6 are formed in the axial direction of the rotating body and open on the outer surface thereof. Both ends of these developer supply grooves 5 are communicated with connection ports e formed at both ends of the developing heads 3a to 3d, respectively, and as shown in FIG.
The rotating body 2 is disposed such that one of the outer surfaces of the rotating body d selectively comes into contact with the lower surface of the recording medium 12 being conveyed through the conveyance path 11 .

^11 Each of the connection ports 6 on one end side of the developing heads 3 & ~3d has developer supply pipes 8a~8d that open in developer tanks 7a~7d of different colors such as black, cyan, magenta, and yellow. is connected. 10,000, connecting port 6 at the other end and vacuum pump 1o via suction pipes 9a to 9d.
It is connected to the suction port of I%~10d, and the vacuum pump 10a~
1od discharge [communicated with Kopa developer tank γ&~7d.

The supply pipes 8a to 8d and the suction pipes 9a to 9d are constructed of combustible pipes so as to prevent the rotating body 2 from rotating back and forth within a range of approximately 316 degrees.

In the following purchases, when recording on the recording medium 12,
As shown in Figure 6, the development head for the first color to be recorded,
For example, the rotating body 2 is positioned so that the developing head 3a faces the conveyance path 11 of the recording medium 12, and the corresponding vacuum bomb 10a is driven.Then, the recording medium is placed in the opening of the developer supply groove 5. 12 and the open opening is closed, a negative pressure is created in the developer supply groove 5 at the true cylinder pump 10a, and the developer Ri& is sucked up from the developer tank ryoa and flows into the developer supply groove 6. Some of the toner in the developer adheres to the electrostatic latent image portion of the recording medium 12 to perform development, and the remaining developer is sucked and circulated. The developed recording medium passes through the squeeze nozzle 13 to form 1.→=-
. The solvent adhering to the recording medium 12 is removed by suction, and the tote image is fixed.

Further, at the same time as the end of the electrostatic latent image formed on the recording medium 12 passes through the developing nozzle 3a, the rotating body 2if): 4
The developing head 3a is rotated by 5 degrees, and the developing head 3a is rotated by 5 degrees.
It rotates 45 degrees in the same direction in synchronization with 2, resulting in the state shown in FIG. As a result, the opening of the developer supply groove 6 is opened and the suction supply of the developer is stopped, and the developer inside is suctioned and discharged and returned to the developer tank 10a.

During this time, since the seventh nozzle 3a to be developed and the recording medium 12 move synchronously and do not slide relative to each other, the recording medium 12 is not contaminated by the unswept developer in the developer supply groove 6.

Thereafter, the recording medium 12 is transported back to its original position 4 as shown by the arrow in FIG.

Next, the rotary body 2 is rotated so that the development head of another color to be recorded faces the conveyance path 11 of the green medium 12, and then the same operation as described above is performed. By repeating the same operation for the following colors F and Q, desired color images can be recorded on the recording medium 12.

However, according to the above-mentioned structure, the close contact between the recording medium and the developing head is achieved only by empty adsorption of C from the developer supply groove. Pressing a button at a part where there is no developer supply groove, such as at both ends of the cross section, will improve the adhesion between the recording medium and the developing head.As shown by the arrow, the flow of air into the developer supply groove will increase, increasing the developer flow rate. As a result, image characteristics cannot be improved. 1. Also, it is difficult to achieve accurate height positioning of the developing head and squeeze. Furthermore, the problem of development, night groove, squeeze fl (j being long and waste paper being increased) has been solved.

In view of the above-mentioned problems, the present invention improves the adhesion between the recording medium and the developing nozzle (improves image characteristics, easily achieves height positional accuracy of the developing nodal and squeeze, and reduces waste paper). A liquid developing device is provided.

Means for Solving the Problems In order to solve the above problems, the liquid developing device of the present invention has the following features:
1 liter, which forms a closed developer chamber with the recording medium in contact with the surface.
or a plurality of developer supply grooves, a button, and a development head having one or more vacuum suction grooves adjacent to the developer supply groove.

According to the above-described structure, the recording medium is vacuum-suctioned from parts other than the developer supply groove, so that the adhesion with the recording medium is improved, the flow rate of the developer is increased, and the image characteristics are improved. Improved, the development device and squeeze are integrated, eliminating the need for mutual height position adjustment. Furthermore, the distance between the developer groove and the squeeze can be significantly shortened, and waste paper can be reduced.

EXAMPLE An example of the present invention will be described below with reference to FIGS. 1 to 3.

The overall structure and operation of the color electrostatic recording device 20, except for the developing device, are the same as those explained as the conventional example in FIG. Omitted.

In FIG. 1, 3a to 3d are developing heads, and one or more (three in the illustrated example) developer supply grooves 6 opened on the outer surface are arranged in the axial direction of the rotating body. It is shaped along. Both ends of these developer supply grooves 6 are communicated with connection ports 6a and 6b formed in the end faces of the development heads 3a to 3d, respectively.

Furthermore, one or more (two in the illustrated example) vacuum suction grooves 14 are formed in the developing heads 3a to 3d in parallel and adjacent to the developer supply groove 6, which are open on the outer surface thereof. has been done. In this case, at least one of the vacuum suction grooves is formed downstream of the developer supply groove 5 in the recording medium conveyance direction. These vacuum suction grooves 14 are connected to connecting ports 6 formed on one end surface of the developing sleeves 3a to 3d.
It is connected to b.

As shown in FIG. 2, the developing heads 36 to 3
The rotating body 2 is disposed such that one of the outer surfaces of the rotating body d selectively comes into contact with the lower surface of the recording medium 12 being conveyed through the conveyance path 11 .

Developer supply pipes 8a to 8d, which open in developer tanks 7a to 7d of different colors such as black, cyan, magenta, and yellow, are connected to the connection ports 6a at one end of the developing heads 3a to 3d, respectively. has been done. On the other hand, the connection port 6b on the other end side is connected to the vacuum pump 10 via suction pipes 9a to 9d.
connected to the suction ports a to 10d, and the vacuum pumps 10a to 1
The discharge port 0d communicates with the developer tanks 7a to 7d.

The supply pipes 8a to 8d and the suction pipes 9a to 9d are constructed of flexible pipes so as to allow the rotating body 2 to reciprocate within a range of approximately 316 degrees.

When recording on the recording medium 12 by clicking the above structure,
As shown in FIG. 2, the developing head of the color to be recorded first,
For example, the rotating body 2 is positioned so that the developing head 3a faces the conveyance path 11 of the recording medium 12, and the corresponding vacuum pump 10a is driven.

Then, when the recording medium 12 comes into contact with the opening of the vacuum suction groove 14 and the open opening is closed, a negative pressure is created in the vacuum suction groove 14 by the vacuum pump 10a, and the recording medium 12 comes into close contact with the developing head 3a. .

When the recording medium 12 comes into contact with the opening of the developer supply groove 5 and the open opening is closed, the vacuum pump 10a creates negative pressure in the developer supply groove 6, and the developer is discharged from the developer tank 7&. The developer is sucked up and supplied into the developer supply groove 6, and some of the toner in the developer adheres to the electrostatic latent image portion of the recording medium 12 to perform development, and the remaining developer is sucked and circulated. be done.

The recording medium developed with the toner attached to the recording medium 12 passes through the vacuum suction groove 14, whereby the solvent attached to the recording medium 12 is removed together with the toner, and the toner image is fixed.

A desired color image can be recorded on the recording medium 12 by the same operation as described below as a conventional example.

According to this embodiment, as shown in FIG. 3, by providing the vacuum suction grooves 14 at both ends of the developing head, the developer supply groove can be buttoned to improve the adhesion with the recording medium and the developer flow rate. increases, improving image characteristics. In addition, the developing device and the squeeze are integrated, making it unnecessary to adjust the height position of the phase lf. Furthermore, if developing? ＋'4・The time between squeezes is significantly shortened and waste paper can be reduced.

In this embodiment, the developing head is provided with a vacuum suction groove 14, so it is slightly larger than the conventional developing head shown in FIG. 6, but since the squeeze head 13 is abolished, the overall size is Miniaturization is possible.

4. In C (77-7 suction 7iS714), the pump for C↓ empty suction is shared with the pump for supplying developer, thereby preventing an increase in the number of pumps and piping systems.

Effects of the Invention As shown in JB L'') and -L, the present invention has a recording medium in contact with the surface thereof and forms a closed developer chamber 1''! or multiple development γ1
N(i!) supply groove and 1 adjacent to the developer supply groove
Or, a developing head with multiple vacuum suction grooves is provided,
This eliminates the need for adjustment of the recording medium in areas other than the developer supply groove. Furthermore, the distance between the developer groove and the squeeze can be shortened to a large hood, reducing waste paper.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the developing device of the present invention,
FIG. 1 is a perspective view of the main parts, FIG. 2 is a sectional view for explaining the operation, and FIG. 3 is an enlarged view of the neck part of FIG. 2. 4 to 8 show a conventional example, FIG. 4 is a perspective view showing the general structure of a color electrostatic recording device, FIG. 6 is a perspective view of the main parts, and FIGS. 6 and 7 are... 8 is an enlarged view of the main part of FIG. 6. 2...Rotating body, 3a-3d...Developing head, 5...Developer supply groove, a-7d...
...Development overnight tank, 10a~10d...
・Vacuum pump, 11... Conveyance passage, 12...
. . . Recording medium, 14 . . . Vacuum suction groove.

Claims (1)

[Claims] A developing head having one or more developer supply grooves forming a closed developer chamber with the recording medium in contact with the surface thereof, and one or more vacuum suction grooves adjacent to the developer supply grooves. A liquid developing device characterized by: