JPS6319352B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for diffusing a magnetic fluid and a magnetic multi-stylus in which the magnetic fluid is raised by magnetic force, and the raised magnetic fluid is caused to fly by acting on a Coulomb force, thereby causing the magnetic fluid to fly over the recording surface. This technology is related to a magnetic fluid recording device (hereinafter simply referred to as the device) that can print on a magnetic fluid, and even if the magnetic powder contained in the magnetic fluid may settle and concentrate due to the action of magnetic force, the quality of the print is always maintained. The purpose is to provide an apparatus that can obtain stable recorded images.

Conventionally, in this type of recording device, the magnetic powder of the magnetic fluid held on the bumping magnet attached to the multi-stylus settles due to magnetic force, shielding the magnetic field near the bumping magnet. The shape of the protrusion of the magnetic fluid on the multi-stylus changes, and the viscosity of the magnetic fluid near the protrusion magnet increases extremely, which obstructs the supply of the magnetic fluid from the protrusion magnet to the tip of the protrusion. It had the disadvantage of being stored away. A conventional example will be explained below with reference to FIGS. 1 to 3.

FIG. 1 shows a schematic configuration of a conventional magnetic fluid recording device. A multi-stylus 1 is mounted on the substrate 5, and a protruding magnet 2 is adhered onto the multi-stylus 1 in order to supply a magnetic fluid onto the multi-stylus and to magnetize the multi-stylus. A magnetic fluid 3 is held on the magnetized multi-stylus 1 and a bump magnet 2, and a bump 6 of the magnetic fluid 3 having a shape as shown in FIG. 2 is formed on the multi-stylus 1. Ru. When a voltage is applied between the multi-stylus 1 and the control electrode 8 by the voltage applying means 9, a coulomb acts on the tip of the bump 6, the magnetic fluid flies toward the recording medium 7, and prints on the recording medium 7. is obtained. However, if the magnetic fluid 3 is attached to the bump magnet 2 for a long time,
Due to the magnetic force, the magnetic powder contained in the magnetic fluid 3 settles on the bumping magnet 2, and as shown in FIG. will be formed. In such a state, the leakage magnetic flux on the bump magnet 2 is shielded by the sedimentation layer 4 of the magnetic fluid 3, and the shape of the bump 6 on the multi-stylus 1 becomes extremely unstable. This highly viscous sediment layer 4 obstructs the supply of the magnetic fluid from the bump magnet 2 to the bumps 6 on the multi-stylus 1, causing noise and print irregularities. As explained above, in conventional devices, the magnetic powder contained in the magnetic fluid gradually settles when magnetic force is applied for a long time, so it is difficult to achieve stable high-quality printing. It was difficult to get it.

By eliminating such drawbacks, the present invention provides magnetic properties that allow recording images with stable printing quality to be obtained at all times even when magnetic powder contained in a magnetic fluid may settle and concentrate due to the action of magnetic force. A fluid diffusion method and a magnetorheological recording device are provided.

An embodiment of the present invention will be described below with reference to FIGS. 4 and 5.

FIG. 4 is a schematic diagram of a magnetic fluid recording device according to an embodiment of the present invention, and FIG. 5 is a characteristic diagram showing the relationship between the magnetic fluid concentration and time of the same device. 5 in the figure is a substrate. A multi-stylus 1 is attached on this board 5.
A bump magnet 2 for magnetizing the multi-stylus 1 is glued on top. A magnetic fluid 3 is placed on the magnetized multi-stylus 1 and the bump magnet 2.
is held and raised. Raising magnet 2
An electrode 10 is provided near the slope of the magnetic fluid 3 so as to be in contact with the magnetic fluid 3. If left in this state for a long time, as described above, as shown in FIG. 4, a sedimentary layer 4 of magnetic fluid with a high concentration of magnetic powder will be formed. The magnetic fluid sedimentation layer 4 has a much lower electrical resistance than normal magnetic fluid. Therefore, as shown in FIG. 4, when a voltage is applied between the multi-stylus 1 and the electrode 10, charges easily move within the sedimentation layer 4 of the magnetic fluid, which has a low electrical resistance. In normal magnetic flow where the magnetic flux is high, charge movement is difficult to occur. The sediment layer 4 into which negative charges (in the case of the figure) have been injected begins to migrate toward the electrode 10 due to Coulomba. Furthermore, while being mixed and diffused into the normal magnetic fluid 3, the sediments of the charged magnetic fluid that reach the electrode 10 are discharged by the electrode 10, and eventually become raised. This makes the concentration of the magnetic fluid held on the magnet 2 and the multi-stylus 1 uniform. FIG. 5 shows that after applying a constant voltage between the multi-stylus 1 and the electrode 10,
This shows the experimental results of measuring how the magnetic powder concentration of the magnetic fluid changes at point A in the sedimentation layer 4 of the magnetic fluid near the uplift magnet and point B near the electrode 10. It is. As shown in FIG. 5, after the voltage is applied for a certain period of time, the magnetic powder concentrations of the magnetic fluid at points A and B become almost uniform.

The voltage application between the multi-stylus 1 and the electrode 10 can be performed as necessary, and in this embodiment, the uplift magnet 2 and the multi-stylus 1
The magnetic fluid held on the top can be kept in the best condition with a constant concentration without concentration distribution, and the leakage magnetic flux of the bump magnet 2 is shielded, preventing the bump from becoming unstable. The supply of magnetic fluid from the magnet 2 to the multi-stylus 1 is not hindered, and high-quality printing can be stably obtained.

Next, other embodiments of the present invention are shown in FIGS. 6 to 8.
This will be explained using figures. In the above embodiment, the explanation was given using an example in which the electrode 10 was arranged near the slope of the uplift magnet 2 based on FIG. 4, but as shown in FIG. 6 and FIG. As long as the electrode 10 is placed in the vicinity of the uplift magnet 2 so as to be in contact with the magnetic fluid, the same effects as those described above can be obtained. FIG. 8 particularly shows an example in which two electrodes 10 are provided near the uplift magnet 2 so as to be in contact with the magnetic fluid, and a voltage is applied between these two electrodes. , the electrode 10 can be brought into direct contact with the sedimentation layer 4 of the magnetic fluid, and migration and diffusion of the sedimentation layer 4 of the magnetic fluid can be made smoother. Furthermore, up to now, we have explained how to apply a voltage between the multi-stylus and the electrode 10 using the multi-stylus as a load, using FIG. 4 as an example. effect can be obtained. Furthermore, even in FIG. 8, which shows an example in which two electrodes 10 are provided and a DC voltage is applied between these two electrodes, the same effect can be obtained regardless of the polarity of the voltage application between the two electrodes. Needless to say, it will happen. Also, even if the applied voltage is a pulse voltage,
In each of the examples shown in Figures 4, 6, 7, and 8, not only can you obtain exactly the same effect as when applying a DC voltage, but also by changing the pulse width and pulse period. Therefore, the electrophoretic state of the magnetic fluid can be delicately controlled, and the concentration of magnetic powder in the magnetic fluid held by the protrusion magnet and multi-stylus can be strictly controlled and adjusted.

As explained above, by using the present invention, the magnetic fluid held in the uplifting magnet and the multi-stylus can always be kept in the best condition without concentration segregation, and the leakage magnetic flux of the uplifting magnet can be maintained at all times. is shielded, the bumps do not become unstable, and the supply of magnetic fluid from the bump magnet to the multi-stylus is not obstructed, making it possible to stably obtain high-quality prints.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a conventional magnetic fluid recording device, FIG. 2 is a plan view thereof, FIG. 3 is a sectional view of the same device, and FIG. 4 is a magnetic fluid recording device according to an embodiment of the present invention. A schematic diagram of the configuration of the device, FIG. 5 is a characteristic diagram showing the relationship between the magnetic fluid concentration and time of the device, and FIGS. 6 to 8 are diagrams of magnetic fluid recording devices according to other embodiments of the present invention. It is a schematic configuration diagram. DESCRIPTION OF SYMBOLS 1... Recording electrode, 2... Protrusion magnet, 3... Magnetic fluid, 4... Sedimentation layer of magnetic fluid, 5... Substrate, 6... Protrusion of magnetic fluid, 7... Recording body, 8
. . . control electrode, 9 . . . voltage application means, 10 . . . electrode.

Claims (1)

[Scope of Claims] 1. In an apparatus using a magnetic fluid placed in a magnetic field, a first location in the magnetic fluid where a non-uniform magnetic field acts, and a second location slightly separated from the first location. A magnetic fluid generated in a nonuniform magnetic field by arranging at least two electrodes in contact with the magnetic fluid so as to apply a voltage between two locations, and applying a voltage between the electrodes. A method for diffusing a magnetic fluid, comprising re-diffusing a concentrate into the magnetic fluid in approximately one direction. 2. A recording head section is constituted by a magnetic multi-stylus recording electrode provided facing the recording surface, and a protrusion magnet provided near the tip of the recording electrode for holding and protruding the magnetic fluid on the recording electrode. ,
A second electrode is provided so as to be in contact with the magnetic fluid held and raised in the recording head, and the second electrode and the recording electrode or the magnetic fluid are connected in the magnetic fluid held or raised in the head. A magnetic fluid recording device characterized in that a voltage is applied between a second electrode and a third electrode disposed on the upper end surface of the bump magnet. 3. The magnetic fluid recording device according to claim 2, wherein the applied voltage is a DC voltage. 4. The magnetic fluid recording device according to claim 2, wherein the applied voltage is a pulse voltage.