JPS58105266A - Developing device - Google Patents

Abstract

PURPOSE:To obtain sufficient developed density with a high resistance toner whose developing property is inferior, by making a rotary magnetic brush press- contact with an image forming body through a nonmagnetic sleeve. CONSTITUTION:On the outside circumference of a nonmagnetic sleeve 2 in a developing device, a rotary magnetic brush of a one component magnetic toner, which rotates in the direction as indicated with an arrow C is formed, and it is pressed against a rotary drum 1 by a spring 7 provided on a toner vessel 4. In this case, when linear pressure is set to 7-200g/cm, sufficient developed density is obtained. It is because a gap of 10-20mum is held, by which a high resistance toner becomes usable, by pressing of the sleeve 2. Accordingly, by pressing the sleeve 2 against the drum 1, sufficient developed density is obtained by use of a high resistance toner whose developing property is inferior.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION The present invention relates to electronic recording devices using monocomponent magnetic toner, and more particularly to electrostatic reductive transfer printers.

(To) Background of the Technology At present, compared to electrophotographic printers, Seidenki Kama transfer printers produce electrostatic latent images with a higher potential than 1*S<, so it is difficult to increase the printing latitude. , it has extremely high resolution and is inexpensive, and does not require an expensive optical system. Therefore, it can be used as a printer for image processing systems or low-cost combination printer systems, using conventional special paper. 00 Prior Art and Problems The toner used in electronic recording devices is classified into high resistance type and low resistance type, and the high resistance type is The low resistance type is easy to develop and transfer, while the low resistance type is easy to develop and transfer. For electrophotographic printers, which are easy to use, high-resistance type toners are used, making it difficult to obtain high-potential electrostatic latent images and therefore making development difficult.
lll - Seidenki Kama printers use special paper - Non-transfer types that do not perform transfer use low-resistance type toner.Also, electrostatic 4 brass printers use plain paper to print messages, For the transfer type that performs this, it is possible to reduce the gap between the image forming member and the toner carrier to facilitate the transfer process and to enable the use of high resistance type toner.

In order to enable the use of high-resistance type toner in the above-mentioned brass transfer printer, the gap between the image forming member and the toner carrier is 1 to 20 μm,
Furthermore, in order to suppress fluctuations in print density, K needs to be maintained at a constant value with great precision to ensure this gap.

A proposal has been made to provide a spacing member to maintain a constant gap between the image forming member and the toner carrier, but this proposal has
0.4■i! Even if it is effective for maintaining the If interval, the distance between 10μ and 20μ in the front-loading transfer printer is
It is extremely difficult to use it for retention.

I. Object of the Invention In an electrostatic recording transfer printer using the rotating magnetic brush type developing device of the present invention, it is possible to use a high-resistance type single-component magnetic toner with poor developability. Rotating magnetic brush method:! By pressing the non-magnetic sleeve tgR forming body constituting the developing machine in J's device, the rotating magnetic brush formed on the outer periphery of the non-magnetic sleeve is brought into pressure contact with the image forming body, and a high-resistance one-component magnetic toner is produced. This makes development easier.

0 Embodiments of the Invention Next, the gist of the present invention will be specifically explained by referring to the embodiments shown in the figures. The rotating drums 2, 3, 4, and 6 constitute a developing device, 2 is a non-magnetic sleeve provided parallel to the rotating drum 1, and 3 is provided inside the non-magnetic sleeve 2 as shown by arrow B. A rotating magnet, 4 is a toner container for replenishing the magnetic toner, 5 is a blade for adjusting the amount of toner t11, 6 is a rotary wheel parallel to the rotation axis of the rotary drum L and rotatably holding the developing device, 7t ! This is a spring that acts to press the non-magnetic sleeve 2 against the rotating drum IK.◎ With the above structure, a rotating magnetic brush of one-component magnetic toner that rotates in the direction of arrow C is constructed around the outer periphery of the non-magnetic sleeve 2. , one-component cicada toner O is supplied to the rotating drum 1, and the electrostatic latent image on the rotating drum 1 is developed.The force of the spring 70 is adjusted to increase the pressing force of the non-magnetic sleeve 2 against the rotating drum 1. When I turned it on, sufficient current pressure was obtained at line pressure cuff number - ~ 200 (-).
In addition, at a linear pressure of 100 seas, the maximum sea level is 1.2 (00
The potential of the electrostatic latent image formed on the rotating drum 1 was 100V.

The reason why a relationship of 10 to 20 μ is maintained between the non-magnetic sleeve 2 and the image forming body 1 by pressing the non-magnetic sleeve 2 is due to the force of the one-component magnetic toner on the non-magnetic sleeve 2 rotating in the direction of arrow C. ◎Also, if the surface of the drum l is provided with minute irregularities of several microns, the relationship can be maintained particularly stably, and the developing density can be stabilized. By pressing the non-magnetic sleeve against the body, the gap between the non-magnetic sleeve and the image forming body is kept small. Sufficient development density can be obtained using a resistive type one-component magnetic toner.

[Brief explanation of the drawing]

The figure is an explanatory diagram of one embodiment of the present invention.
is a rotating drum, 2 is a non-magnetic sleeve, 3 is a magnet, 6 is a rotating wheel, and 7 is a spring.

Claims (1)

[Claims] A rotating magnetic brush of one-component magnetic toner is formed on the outer periphery of the non-magnetic sleeve by rotating the non-magnetic sleeve and the magnet provided in the non-magnetic sleeve in the armpit, while a rotating magnetic brush of one-component magnetic toner is formed on the forming body 4a. Silence! 1. Use the rotating magnetic pusher to release the latent material.
Now! A developing device O characterized in that the rotating magnetic brush is brought into pressure contact with the image forming body through the non-magnetic sleeve.