JPH04107588A - Magnetic printer - Google Patents

Abstract

PURPOSE:To enable development which uses a liquid developing material by providing a recording part, a development part, a transfer part, a cleaner part, and a demagnetizing part in order in the rotating direction of a magnetic drum and arranging a porous base between a magnetic drum and a developing unit. CONSTITUTION:Only the liquid developing material 14 which is swelled with electrostatic charges contacts the magnetic drum 1 to perform development. At this time, the liquid developing material is given the electrostatic charges and attracted to the porous base 3 which is applied with electrostatic charges having the opposite polarity from the liquid developing material. Consequently, even if the liquid developing material 14 sticks on a no-image part, the material is never left at the no-image part because of the electrostatic attractive force. Therefore, the liquid development material sticks on only a magnetic latent image part where a magnetic attractive force is prevent to form a sharp visible image 13. Consequently, the development which uses the liquid developing material is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic printing device for displaying computer output on paper.

[Prior Art] Conventional one-shot printing devices, as disclosed in Japanese Patent Application Laid-Open No. 54-32328, generally use a powder developing material, and the use of liquid as a developing material is only an idea and has not yet been realized. It has not been. To explain in more detail, the conventional method is the third
The structure is as shown in the figure, in which a magnetic drum 31 on which a magnetic latent image is formed by a magnetic head 32 contacts a liquid developer 35, selectively attaches the liquid developer 35 to the magnetic latent image portion, and transfers it to a paper 36. It was intended to be used for recording purposes.

[Problems to be Solved by the Invention] However, with the above-mentioned idea, selectively attaching the liquid developer to the magnetic latent image area does not actually work.
The reason for this is that the liquid developing material used here must have at least magnetic powder present in the liquid. Considering this, it is assumed that the magnetic powder exists uniformly in the liquid and does not change over a long period of time. The liquid is the same as what is called a magnetic fluid. The magnetic fluid uses a surfactant to generate Brownian motion in order to uniformly disperse and maintain the magnetic powder in the liquid. For this reason, when a liquid containing a surfactant comes into contact with the drum, it adheres to almost the entire contact surface, although there is some selectivity due to the influence of the surfactant.The present invention takes this point into account and makes improvements. The object thereof is to provide a configuration that allows liquid developer to be selectively attached to the magnetic latent image area.

[Means for Solving the Problems] A magnetic printing device of the present invention has a recording section, a developing section, a transfer section, a cleaner section, and a demagnetizing section sequentially in the rotational direction of the magnetic drum. It is characterized by having a porous support disposed between them.

The magnetic printing device of the present invention is characterized in that a positive (+) or negative (-) charge is applied to the porous support.

The developing material of the developing device used in the magnetic printing apparatus of the present invention is characterized in that it is liquid and contains magnetic powder and a dyeing material.

[Example] Fig. 1 is a cross-sectional view of the main parts of the magnetic printing apparatus of the present invention, in Fig. 1, l is a magnetic drum, 2 is a magnetic head, and 3
1 is a porous support, 4 is a developing device, 5 is a liquid developer, 6 is paper, 7 is a paper feed roller, 8 is a transfer roller, 9 is a paper feed roller, 10 is a cleaner, and 11 is a demagnetizer. The printing procedure will be explained based on FIG. 1. A magnetic latent image is formed on a magnetic drum 1 by a magnetic head 2. The magnetic film provided on the magnetic drum 1 is Co-N1-P (cobalt nickel phosphorus).

Plating film such as Co-N1 (cobalt nickel), or C
A coating film in which rO2 (chromium dioxide) and Fe203 (iron oxide) are resin-bound can be used, and the magnetic properties can be used in a range of coercive force from 200 to 900 Oe. The magnetic drum 1 on which the magnetic latent image has been formed rotates and enters a developing process. In order to explain the developing process in more detail, it will be explained based on FIG. 2. FIG. 2 is an enlarged view of the developing section shown in FIG. 1, in which only the liquid developer material 14 raised due to electric charges comes into contact with the magnetic drum 1 to perform development. At this time, even if a small amount of liquid developer comes into contact with the non-latent image area, it hardly sticks.The reason for this is that as shown in the figure, the liquid developer is charged with an electric charge (200 to 600 V), and the liquid developer Material 1
4 is attracted to the porous support 3 to which a charge opposite to that of the liquid embodying material is applied. Therefore, even if the liquid developer momentarily adheres to the non-image area, it will not remain there due to the electrostatic attraction force. Therefore, the liquid developer adheres only to the magnetic latent image area where the magnetic attraction force exists, and a clear visible image 13 is formed.

Here, the liquid developing material and the porous support will be further explained. As mentioned above, the liquid developing material is mainly composed of magnetic powder and dyeing material added, but in addition to that, it is necessary to have an electrical resistance of 10 9 Ω·Cm or more in order to impart an electric charge. The porous support can be made of ceramics, resin, metal, etc., and the porous wave preferably has a mesh size of 10 to 500 meshes.

The developing process is completed in this manner. Returning to FIG. 1 again, the printing procedure will be explained. As described above, after the development process is completed, a visible image is formed on the surface of the magnetic drum 1, and the transfer process begins. A paper feed roller 7 feeds the paper 6, and a transfer roller 8 presses the magnetic drum 1 and the paper 6 into contact. At this time, the visible image permeates the paper 6 and the transfer is completed. This transfer step can also be performed by applying an electric charge to the paper and performing electrostatic transfer. After the transfer process is completed, the paper 6 is conveyed by a paper feed roller 9 to complete printing. On the other hand, the surface of the magnetic drum l is cleaned by a cleaner 10, and the magnetic latent image is erased by a demagnetizer 11, thereby completing a series of steps. An additional note about demagnetizers is that demagnetizers are composed of electromagnets or permanent magnets, and when reprinting the same printed material, there is no need to erase the magnetic latent image, so in the case of an electromagnet, no current is applied. In the case of a permanent magnet, the structure is such that the permanent magnet is slid from the magnetic drum to a position where it does not affect the magnetic latent image.

[Effects of the Invention] As described above, according to the present invention, development using a liquid developing material can be realized by arranging a porous support between a magnetic drum and a developing device in a magnetic printing device and applying an electric charge. It has this effect.

Another effect is that magnetic latent images originally facilitated high-density recording, which was also realized in the field of magnetic memory, and provided the basis for high print quality. 7μm) L could not be used, so the high-density latent image could not be used effectively, and there was a limit to high print quality.However, by using liquid developer (particle size of 1μm or less), high print quality is possible. There is also this effect.

[Brief explanation of drawings]

FIG. 1 is a main cross-sectional view of the magnetic printing apparatus of the present invention. FIG. 2 is a sectional view of a developing section showing an embodiment of the present invention. FIG. 3 is a sectional view of a conventional magnetic printing device. 1.31・・・Magnetic drum 2.32...Magnetic head 3...Porous support 4.34...Developer 5.15.35...Liquid developing material 6.36...Paper 7.37...Paper feed roller 8.38...Transfer roller 9...Paper feed roller ・・Cleaner ・・Demagnetizer ・Wiring for charge application ・Visible image Applicant Seiko Epson Corporation

Claims (3)

[Claims] (1) In the rotating direction of the magnetic drum, a recording section, a developing section,
What is claimed is: 1. A magnetic printing device having a transfer section, a cleaner section, and a demagnetizing section, characterized in that a porous support is disposed between the magnetic drum and the developing device. (2) The magnetic printing device according to claim (1), wherein a positive (+) or negative (-) charge is applied to the porous support. (3) Claim (1) characterized in that the developing material used in the developing device is a liquid and contains magnetic powder and a dyeing material.
Magnetic printing device as described.