JPS6331392B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a magnetic force to hold and bulge a magnetic fluid on a multi-stylus recording needle made of a magnetic material, and applies a Coulomb force to the bulged magnetic fluid to generate a magnetic fluid. The present invention relates to a magnetic fluid recording device that makes a body fly and obtains prints on a recording surface.

A conventional magnetic fluid recording device will be explained with reference to FIGS. 1 and 2.

FIG. 1 is a plan view of the main part of the device, showing the state in which the magnetic fluid is held. FIG. 2 is a sectional view of the device.

The recording needles 1 are made of a magnetic material, and a plurality of recording needles 1 are arranged on the substrate 2 at equal intervals. On the recording needle 1, a raised magnet 3 for magnetizing the recording needle 1 is adhered near the tip of the recording needle 1. Behind the raised magnet 3, there is a supply means 5 consisting of a supply path 6 for supplying the magnetic fluid 4 onto the raised magnet 3, a flow rate controller 7 for controlling the supply amount, and a tank for storing the magnetic fluid 4. 8
is provided. Reference numeral 9 denotes a control electrode, which is provided opposite to and spaced apart from the tip of the recording needle 1. 10
is a recording body, and the recording body 1 facing the tip of the recording needle 1
The back surface of 0 is in contact with the control electrode 9. 11
is a control circuit that causes the magnetic fluid 4 to fly over the recording medium 10.

When the magnetic fluid 4 in the tank 8 is supplied onto the raised magnet 3 by the supply means 5, the magnetic fluid 4 supplied onto the raised magnet 3 is supplied toward the tip of the recording needle 1 due to the magnetic force of the raised magnet 3. . As shown in FIGS. 1 and 2, a magnetic fluid 4 is arranged and held so as to cover the tip of the recording needle 1, and a bump 12 is formed. The step A of the protuberance 12 changes depending on the amount of the magnetic fluid 4 held at the tip of the recording needle 1. The amount of magnetic fluid 4 held by the tip of the recording stylus 1 is determined by the strength of the magnetic field at the tip of the recording stylus 1 magnetized by the raised magnet 3, the supply capacity by the magnetic force of the raised magnet 3, and the supply by the supply means 5. It varies depending on the amount. The stronger the magnetic field at the tip of the recording stylus 1, and the greater the amount of magnetic fluid 4 supplied to the tip of the recording stylus 1, the greater the amount of magnetic fluid 4 held by the tip of the recording stylus 1, and the more the ridge 12 The step A becomes smaller. After the protuberance 12 is formed, when a voltage is applied by the control circuit 11 between the recording needle 1 and the control electrode 9, a Coulomb force acts on the tip of the protuberance 12, and the magnetic fluid 4 moves toward the recording medium 10.
A recorded image is obtained on the recording medium 10. The magnetic fluid 4 on the raised magnet 3 is supplied to the tip of the recording stylus 1 from which the magnetic fluid 4 has been flown by the magnetic force of the raised magnet 3, and a raised ridge 12 having the same step A as that before flying is formed. In order to always obtain recorded images with uniform print density, the flying magnetic fluid 4a
It is necessary to keep the amount of magnetic fluid 4a constant at all times, and the amount of flying magnetic fluid 4a increases as the amount of magnetic fluid 4 held by the tip of recording needle 1 increases. Therefore, as mentioned above, the step A changes depending on the amount of magnetic fluid 4 held by the tip of the recording needle 1.
By keeping the height difference A constant during flight, a recorded image with uniform print density can be obtained at all times. However, in the conventional configuration described above, since the step A changes depending on the amount of the magnetic fluid 4 supplied to the tip of the recording needle 1, the amount of the magnetic fluid 4 that flies and is consumed depends on the information density to be recorded. The balance with the amount of magnetic fluid 4 supplied to the tip of the needle 1 is lost, and the step A
had changed, and the print density was uneven. When the information density increases, the supply of the magnetic fluid 4 becomes insufficient, the step A increases, and the print density becomes thinner. On the other hand, when the information density is low, too much magnetic fluid 4 is supplied, which causes the step A to become small and the print density to be high.

The present invention eliminates such drawbacks,
By supplying a sufficient amount of magnetic fluid onto the recording needle, and collecting the surplus magnetic fluid near the tip of the recording needle by suction evenly in the direction of arrangement of the recording needle tip, a uniform and stable bulge is formed. The present invention provides a magnetic fluid recording device that can obtain high-quality recorded images.

An embodiment of the present invention will be described below with reference to FIGS. 3 to 5. FIG. 3 is a perspective view of a head portion of a magnetic fluid recording device which is an embodiment of the present invention;
Figure 4 is a sectional view of the main part of the device, Figure 5 shows the flow of the magnetic fluid during operation of the device, and Figure 3 shows the flow of the magnetic fluid during operation of the device.
It is a Y direction arrow view of a figure. In the figure, reference numeral 1 indicates recording needles made of a magnetic material, and a plurality of recording needles are arranged on a substrate 2 at equal intervals. On the recording needle 1, a raised magnet 3 for magnetizing the recording needle 1 is adhered near the tip of the recording needle 1. Reference numeral 5 denotes a means for supplying the magnetic fluid 4 onto the raised magnet 3, and includes a supply path 6 and a flow rate control section 7 for controlling the supply amount of the magnetic fluid 4. 8 is a tank that stores the magnetic fluid 4. Reference numeral 9 denotes a control electrode, which is provided opposite to and spaced apart from the tip of the recording needle 1. Reference numeral 10 denotes a recording body, and the back surface of the recording body 10 facing the recording needle 1 is brought into contact with a control electrode 9 . Reference numeral 11 denotes a control circuit that causes the magnetic fluid 4 to fly onto the recording medium 10 . 13 is a collection means;
A protuberance 12 with a step A made of a uniform and appropriate magnetic fluid 4 is formed at the tip of the recording stylus 1, and the surplus magnetic fluid 4 near the tip of the recording stylus is removed to maintain the step A at all times. Collect by suction. Collection means 1
3 is obtained by gluing an auxiliary plate 14 having grooves of the same shape and equally spaced on the back surface of the substrate 2 (the surface opposite to the surface on which the recording needles 1 are arranged), and near the tip of the recording needle 1 and recording. It consists of suction holes 15 arranged parallel to the arrangement direction of the tips of the needles 1, a collection path 16 for suctioning and collecting the magnetic fluid 4, and a pump 17.

Next, the operation will be explained. Pump 1 of recovery means 13
The flow rate controller 7 sets a predetermined supply path so that the amount of magnetic fluid 4 held at the tip of the recording needle 1 is excessive when the recording needle 6 is not operating.
The magnetic fluid 4 in the tank 8 is supplied onto the raised magnet 3 by this. When the pump 17 of the collecting means 13 is driven to suck air through the suction hole 15, a flow of air toward the suction hole 15 is generated between the end surface of the substrate 2 and the recording medium 10. The tip of the recording needle 1 is in a strong magnetic field and the magnetic fluid 4 is strongly held, so the magnetic fluid 4 held at the tip of the recording needle 1 is
A flow toward the suction hole 15 is generated while being held at a constant amount by the magnetic force at the tip of the recording needle 1. However, since the magnetic field near the tip of the recording needle 1 is weak, the recording needle 1
The magnetic fluid 4 near the tip of the magnetic fluid 4 is easily swept away by the air flow. Therefore, when air is sucked through the suction holes 15, as shown in FIG. is generated and collected into tank 8. Since each suction hole 15 has the same shape and is provided at equal intervals, the amount of magnetic fluid 4b flowing toward each suction hole 15 is approximately equal. Therefore, the recording stylus 1 is uniformly attracted in the direction in which its tip is arranged. Further, the raised step A formed at the tip of the recording needle 1 sets the magnetic force at the tip of the recording needle 1 and the air suction force of the pump 17 of the collecting means 13 to predetermined values, and also sets the magnetic force at the tip of the recording needle 1 and the air suction force of the pump 17 of the collecting means 13 to a predetermined value, and This is ensured by setting the amount of the magnetic fluid 4 supplied by the supply means 5 to a value that provides an appropriate protrusion level difference A using the flow rate control section in a state where no voltage is applied. After the bump 12 is formed, when a voltage is applied by the control circuit 11 between the recording needle 1 and the control electrode 9, a Coulomb force acts on the tip of the bump 12, and the magnetic fluid 4 flies toward the recording needle 10. Then, a recorded image is obtained on the recording medium 10.

In the above-described configuration and operation, ensuring an appropriate protrusion level difference A for the information density to be recorded will be explained. When the information density is low, since the amount of the magnetic fluid 4 that flies to the recording medium 10 is small, the magnetic fluid 4 at the tip of the recording needle 1 and near the tip
The amount increases, and the height difference A decreases.
However, as the raised step A decreases, the gap between the magnetic fluid 4 and the recording medium 10 decreases, causing the suction hole 15 to decrease.
The flow velocity of the air towards the recording needle is increased, the protrusion level difference A is decreased, the magnetic fluid 4 flowing toward the suction hole 15 facing the recording needle is increased, and the amount of magnetic fluid 4 collected by the collection means 13 is increased. It was confirmed that recording was performed while always maintaining an appropriate height difference A. In addition, when the information density is high, the magnetic fluid 4 held at the tip of the recording needle 1
The amount of decreases. However, as the amount of the magnetic fluid 4 at the tip of the recording needle 1 decreases, the gap between the magnetic fluid 4 and the recording medium 10 increases, and the flow of air toward the suction hole 15 is reduced. The flow of the magnetic fluid toward the recording needle 1 decreases, the amount of the magnetic fluid 4 collected by the collection means 13 decreases, and the magnetic fluid 4 flowing past the tip of the recording needle 1 and the vicinity of the tip decreases. It was confirmed that the recording needle was caused to flow in the direction of the tip of the recording needle 1 by the magnetic force at the tip of the recording needle 1, and that recording was performed while quickly recovering to the proper raised level difference A. Further, even when recording was performed while changing the information density, recording was performed while quickly recovering to an appropriate raised level difference, and a recorded image with uniform print density was obtained.

Next, other embodiments of the present invention are shown in FIGS. 6 to 8.
This will be explained using figures.

6 to 8 are top views of the head portion of a magnetic fluid recording device according to other embodiments of the present invention.

What is shown in FIG. 6 is the suction hole 1 of the recovery means 13.
5 is formed into a slit, and a plurality of V-shaped grooves of the same shape are provided on the surface of the slit on the side where the tip of the recording needle 1 is arranged. The surplus magnetic fluid 4 near the tip of the recording stylus 1 is guided to each V-shaped groove by the collecting means 13, and is uniformly suctioned and collected in the direction in which the tip of the recording stylus 1 is arranged. A ridge 12 is formed. Furthermore, a similar condition can be obtained by replacing the V-shaped groove with a wave-shaped groove.

Furthermore, in the device shown in FIG. 7, the suction hole 15 of the collecting means 13 is formed into a slit shape, and a plurality of electrode ends 18 of the same shape are provided at equal intervals on the surface of the slit recording needle 1 on the side where the tip is arranged. . Recording needle 1 and electrode end 18
When a voltage is applied between them by an auxiliary circuit (not shown), a Coulomb force acts near the tip of the recording needle 1, and the magnetic fluid 4 flows toward each electrode end 18 and is attached to each electrode end 18. Ru. The magnetic fluid 4 attached to each electrode end 18 is collected by suction by the collection means 13. By applying the voltage of the auxiliary circuit according to the amount of surplus magnetic fluid 4 near the tip of the recording stylus 1, a protrusion 12 with an appropriate step A is formed.
In the device shown in FIG. 6, even if the electrode end 18 is provided over the entire width and a plurality of suction holes 15 of the same shape are provided at equal intervals, suction and collection can be uniformly performed in the arrangement direction of the recording needles 1.

Moreover, the one shown in FIG. 8 is constructed by using the auxiliary plate 14 in the embodiment shown in FIGS. 3 to 5 as an electrode 19, and has a good step A as in the case of FIG. 7. can get.

In addition, as shown in FIGS. 3 to 8, the recording needle 1
By arranging the suction holes 15 or the electrode ends 18 in a staggered manner with respect to the tip of each recording stylus 1, the excess magnetic fluid 4 near the tip of each recording stylus 1 can be attracted and collected more uniformly, and the magnetic Since the fluid 4 is collected by suction, a more uniform and stable protrusion 12 of the step A can be easily obtained.

As described above, according to the present invention, a plurality of suction holes of the same shape constituting the collecting means are arranged near the tips of the recording needles, facing each recording needle, and parallel to the arrangement direction of the recording needles. , a suction member that suctions the magnetic fluid and air through the suction hole;
The magnetic fluid from the supply means is caused to flow through the recording needle tip and the vicinity of the tip and is sucked and collected from the suction holes facing each recording needle, thereby removing the excess magnetic fluid at the recording needle tip and the vicinity of the recording needle. can be suctioned and collected uniformly in the direction in which the tips are arranged. In addition, by causing the magnetic fluid from the supply means to flow through the tip of the recording needle and the vicinity of the tip, the supply of the magnetic fluid to the tip of the recording needle is stabilized.
As soon as the magnetic fluid flies, the magnetic force at the tip of the recording stylus quickly restores the proper protrusion, and even if the density of recorded information changes, the recorded image is of high quality without uneven print density. It is possible to provide a magnetic fluid recording device that can obtain recorded images.

[Brief explanation of the drawing]

FIG. 1 is a plan view of essential parts of a conventional magnetic fluid recording device, FIG. 2 is a sectional view of the same device, and FIG. 3 is a head portion of a magnetic fluid recording device according to an embodiment of the present invention. A perspective view, FIG. 4 is a sectional view of the main part of the device, and FIG.
The figure is a Y-direction arrow view of the head section showing the flow of the magnetic fluid during operation of the device. Figure 6~
FIG. 8 is a top view of the head portion of a magnetic fluid recording device according to another embodiment of the present invention. 1... Recording needle, 2... Substrate, 3... Raised magnet,
4... Magnetic fluid, 4b... Flowing magnetic fluid,
5... Supply means, 6... Supply section, 7... Flow rate control section, 8... Tank, 9... Control electrode, 10... Recording body, 11... Control circuit, 12... Protrusion, 13...
...Recovery means, 14...Auxiliary plate, 15...Suction hole,
16... Recovery path, 17... Pump, 18... Electrode end, 19... Electrode.

Claims (1)

[Scope of Claims] 1. A recording stylus made of a magnetic material that is arranged in parallel at substantially equal intervals facing a recording surface, and the recording stylus is magnetized, and a magnetic fluid is raised at the tip of the recording stylus. a raised magnet, a supply means for supplying a magnetic fluid to the tip of the recording needle, a control means for causing the raised magnetic fluid at the tip of the recording needle to fly to a recording surface in response to an image signal, and the recording needle. a collecting means for suctioning and collecting the magnetic fluid at the tip and the vicinity of the tip; the collecting means includes a plurality of suction holes having the same shape and a suction member for sucking the magnetic fluid and air through the suction holes. The plurality of suction holes are provided near the tips of the recording needles, facing each of the recording needles, and arranged in parallel to the arrangement direction of the recording needles, and the suction holes are arranged in parallel to the arrangement direction of the recording needles, and the magnetic flow from the supply means is A magnetic fluid recording device characterized in that the body flows through the tip and the vicinity of the tip of the recording needle and is suctioned and collected through the suction holes facing each of the recording needles. 2. In the description of claim 1, the collecting means has a plurality of suction holes having the same shape, and the plurality of suction holes are arranged at approximately equal intervals in the arrangement direction of the tips of the recording needles. A magnetic fluid recording device characterized by: 3. The magnetic fluid recording device according to claim 1, wherein the recovery means has a suction hole, and the entrance of the suction hole has a V-shape or a wave shape. 4. A magnetic fluid recording device according to any one of claims 1 to 3, characterized in that the suction holes of the recovery means are arranged in a staggered manner with respect to the tip of the recording needle.