JPS58125073A - Developing device - Google Patents

Abstract

PURPOSE:To use a high resistance type one-component magnetic toner inferior in developability to develop an image with a sufficient density, by providing a means which press-contact an image forming material to a rotating magnetic brush. CONSTITUTION:A developing device is provided with a pressing roll mechanism which presses a belt 1 to the rotating magnetic brush formed on the outside circumference of a nonmagnetic sleeve 21, a spring 26 constituting a pressing roll mechanism 25, and a solenoid 27 which releases the pressing action of the pressing roll mechanism at proper times. In this constitution, since the gap between the nonmagnetic sleeve 21 and the belt 1 is kept short, toner stagnancy is generated, but this toner stagnancy is resolved by releasing the pressing action of the pressing roll mechanism 25 by the solenoid 27. Consequently, a high resistance type one-component magnetic toner inferior in developability is used to develop an image with a sufficient density

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to electronic recording devices using mono-component magnetic toner, and in particular to v11L recording transfer printers.

(b) Technical Background 1a Recording transfer printers are generally more difficult to obtain electrostatic latent images of cylinder potential than electrophotographic printers, and therefore it is difficult to increase the print *i', but the resolution is It is extremely superior, and is inexpensive because it does not require expensive optical threads. For this reason, their practical use is rapidly progressing as printers for image processing systems or low-cost converter systems, and as output devices to replace conventional facsimile output devices that use special paper.

(c) Between conventional technology and electronic recording devices Toners used in electronic recording devices are broadly classified into high-resistance types and low-resistance types.High-resistance types are difficult to develop but easy to transfer, while low-resistance types are difficult to develop. It has the characteristics of being easy to develop and easy to transfer.

For these reasons, high-resistance type toners are not suitable for Kameko photo printers, which can easily produce high-potential electrostatic latent images and are therefore relatively easy to develop. Use high potential silence 1
Among electrostatic recording printers that are relatively difficult to develop, low-resistance toner is used for non-transfer types that use special paper and do not require transfer. .

Among electrostatic recording printers, for transfer type printers that use plain paper for transfer, reducing the gap between the image forming body and the toner carrier makes development easier and allows the use of cylindrical resistance type toner. There are ways to get used to it.

1) In order to make it possible to use high-resistance type toner in an electrostatic recording transfer printer V, the gap between the forming body and the toner carrier is 101+ to 20μ, and the printing In order to suppress fluctuations in concentration, it is necessary to maintain this gap at a constant value with high precision.

Proposals have been made to provide a gap retainer M1) in order to maintain a constant gap between the image forming body and the toner carrier.
This proposal? ``i Q used in electrophotographic printers, etc.
Although it is effective for maintaining a gap of about 2 rrun to 0.4 inch, the
It is miserable and difficult to maintain a gap of 20μ to 20μ. The purpose is to use a single-component magnetic toner of the current 1w resistance type to create an all-0J system.

(e) Structure of the Invention According to the present invention, in a rotating magnetic brush type developing device, means for pressing the image forming body against the rotating magnetic brush is provided, the image forming body is brought into pressure contact with the rotating magnetic brush, and the image forming body is formed on the image forming body. The low potential electrostatic # image being stored can be developed using a high resistance type one-component magnetic toner (hereinafter simply referred to as toner).

(f) Example of non-invention The following is a concrete example of the non-invention R>4 shown in Figure VC.

FIG. 1 shows an example in which the present invention is implemented in an electrophotographic transfer printer using a belt as an image forming body.
2 is a belt as an image forming body; 2 is a multi-stylus electrode that forms an electric W4 image on the belt 1 by an electric signal corresponding to recorded information; Tase' @ 3. Developing device that develops the latent image with all toner, 4. Nl recording supply, 5.
(i1 bell) 1 and 3- a transfer corotron that transfers the toner image onto the recording paper 4; 6 a foot fixing device that fixes the toner image transferred onto the recording paper 4;
Reference numeral 8 indicates a static eliminating corotron that removes residual potential on the belt 1 after transfer; 8 a cleaner that supports the residual toner on the belt 1; and 9 a tension roller mechanism that applies tension to the belt 1.

FIG. 2 shows the entire fraudulent structure of the developing device 3 shown in FIG. a magnet that is provided in and rotates in the direction of arrow B, 2
3 is a toner container for replenishing toner; 24 is a blade for adjusting the toner; 25 is for connecting the belt 1 to a non-magnetic sleeve 2;
A pressure roller mechanism 26 constitutes the pressure roller mechanism 25, and a solenoid 27 removes the pressing action of the pressure roller 26 at an appropriate time. It is.

With the above structure, a magnetic brush of the shape 4-1'1 rotating as shown by arrow C is provided at the outer part of the non-magnetic sleeve 21, and the electrostatic latent image on the heald 1 is developed.

Adjust the spring 26 and press the belt 1 by the suppression roller Tsukisa 25.
When increasing the pressure applied to
As a result of removing the gap of 20μ to 10μ between belts 1 and J), a light density of 1.0μ to 10μ is obtained, a linear pressure of 1.0(1 /A maximum concentration of 1.2 (OD value) was obtained in the solder.
The gap μ is formed at the outer center of the non-magnetic sleeve 21 so that tt≦C
This is due to the rotational force of the magnetic brush that rotates like this.

In such a configuration (y), in order to keep the gap between the non-magnetic sleeve 21 and the belt 1 small, the belt 1
Is it wrong? Toner accumulation occurs in the area close to the LK sleeve 21, which causes uneven development.
This toner pool is removed by operating the solenoid 27 by the pressing action of the pressing roller box 4 structure 25, and the non-magnetic sleeve 21 is removed.
and belt 1 for 1ft;
71 can be done. It is used as an auxiliary means to completely separate the pressure roller 25V ("F negative pressure suction 1"1; By looking down,
j'lt"n!::'s 111r output 1 can be further 6 correct lol (can be done.

1, ,i;・+gc 11) For example, the non-research sleeve 21 is rotated by M.i. Non-extrusion f4 sleeve 21 - When rotating k) Second writing sleeve 21
For example, the present invention can be applied to any case where the stones 22 are rotated together. Also, if a small uneven structure is attached to the belt 1 facing the sleeve 21, a gap of 10 to 20 μm can be stably maintained on the ship. ``Secondly, 4 shots were fired as if 6 seconds ago due to the output side of the thermal power output.''Yono 1 says that ``Full-turning brush type development equipment is used; Using a one-component magnetic toner of a resistance loss type with poor properties, sufficient development can be carried out once.

41st year 1st year Noh 3rd year

Claims (1)

[Claims] A non-magnetic sleeve and a magnet provided in the non-magnetic sleeve are rotated relative to each other to form a rotating magnetic brush f of one-component magnetic toner around the outer periphery of the non-magnetic sleeve, and the electrostatic latent image formed on the image forming body is A patent characterized in that the developing device that performs development using the rotating magnetic brush is provided with means for pressing the image forming body against the rotating magnetic brush.