JPS60129908A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To avoid the S/N deterioration of signals in a recording/reproduction mode by having the conductive connection between an evaporation medium 11 and a medium drive system. CONSTITUTION:An evaporation medium 11 is attached to a spindle 13 of a motor 15 by means of a clasp 12. At the same time, the medium 11 is connected electrically to the spindle 13, i.e., they conduct with each other. Now the medium 11 is revolved and the electromagnetic charge is produced on the surface of the medium 11 due to the friction generated between the medium 11 and the inside unwoven fabric of a jacket. Even in such a case, the electromagnetic charge is never stored since the charge is flowed to an earth from the clasp 12 via the spindle 13, a brush 18 and a plate spring 19. Therefore no noise is produced between the medium 11 and a magnetic head 16. This improves the S/N of a signal reproduction mode as well as the data error factor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an improvement in the S/N ratio of a magnetic recording/reproducing device, particularly a magnetic recording device that records/reproduces signals by rotating a gold JA deposited medium such as a perpendicular recording medium. .

[Prior art]

Conventionally, in devices that record and reproduce signals by rotating flexible recording media, coated media made by mixing magnetic fine particles in a binder and coating them on the surface of sheets such as Mylar have been widely used. It is used.

However, as the demand for high-density recording increases,
With the above-mentioned coating media, the desired high density 8II recording has become a part of the coating process. Therefore, recently, vapor-deposited media, such as metal deposited on a base material such as Mylar, which can perform high-density recording even in in-plane direction recording, and media such as CoCr, which are suitable for open-direction magnetic recording, have been developed. Deposition media are beginning to be used.

These deposition media are attached to and driven by the spindle of a rotary drive motor, but since the motor spindle is supported by a bearing coated with a lubricant such as grease, the motor body is a 1π body. Even if it is attached, there is poor electrical continuity between the deposition medium and the casing. Therefore, the deposition medium itself is in a state of poor grounding. On the other hand, the medium is flowing inside a jacket lined with a non-woven fabric made of a polymeric material, etc., and static charges are generated on the surface of the vapor deposition medium due to the contact between the non-woven fabric and the vapor deposition medium. As mentioned above, charge accumulation occurs due to poor grounding. For this reason, when a magnetic head comes into contact with a vapor-deposited medium during signal recording and reproduction, the head and the surface of the medium irregularly repeat states of contact and non-contact from a microscopic perspective. An intermittent flow of current occurs on the surface and the tip of the head, and continuous impulse noise is introduced into the recording/reproducing signal, causing the signal-to-noise ratio of the recording/reproducing signal (
[Purpose] The present invention has been made in view of the above-mentioned problems. By electrically coupling the medium drive system, it is intended to prevent deterioration of the SN ratio during signal recording and reproduction.

〔Example〕

The present invention will be explained below with reference to the drawings. FIG. 1 is a schematic explanatory diagram showing one embodiment of the present invention.

11 is a flexible metal thin film deposition medium, and 15 is a rotation driving motor thereof. This vapor deposition medium 11 is attached to a spindle 13 of a motor 15 by a clasp 12, and at the same time, the vapor deposition medium 11 and spindle 13 are electrically coupled, that is, electrically connected.

The medium 11 is rotationally driven by a motor 15 attached to a housing 14 , and a magnetic head 16 is brought into contact with the medium 11 to reproduce a signal and send the signal to a preamplifier 17 .

A conductive brush 18 is in contact with the lower part of the spindle 13 of the motor 15, and this brush 18
It is fixed to the housing 14 via 9. On the other hand, the housing 14
is grounded.

Even if the sand body 11 rotates and generates static charge on the surface of the medium due to collision with the non-spun fabric inside the jacket (not shown), the charge is transferred from the clasp 12 to the spindle 13,
Since the brush 18 and the leaf spring 19) flow out to the ground, static charges are not accumulated, thereby preventing the generation of noise between the medium 11 and the magnetic head 16, and reducing the S/N during signal reproduction. As the ratio is improved, the data error rate is also improved.

FIG. 2 shows the effect of the present invention experimentally verified, and shows a so-called noise frequency analysis curve with frequency on the horizontal axis and relative gain on the vertical axis.

In the figure, curve A is the noise distribution of the conventional device, and curve B is the noise distribution when the medium is grounded in the present invention.

At frequencies below 7 MHz, the noise levels for both curves A and B are approximately the same, but at frequencies higher than that, the S/N ratio is significantly improved, with a 10 dIl improvement compared to the conventional device.
It is recognized that J and h are also improved.

[Other Examples]

FIG. 3 is an enlarged sectional view of the main part of the second embodiment of the present invention,
3 shows a connecting portion between a recording medium and a driving means.

The recording medium 31 has a metal thin film 3 on the picture surface m1 of the base 32.
3 is deposited by vapor deposition or sputtering. The surface of this metal thin film 330 is covered with a thin film of polymeric material as a protective film in order to protect the metal thin film. The protective film 34 does not cover the vicinity of the center of the recording medium where the recording medium 31 and the driving means are connected. This uncoated portion is crimped and attached by a clasp 35 attached to the spindle 37 of the drive motor from the bottom and a clasp 36 from the top.

Since the spindle 37 of the motor is grounded (not shown), the metal thin film 33 serving as the medium is also electrically grounded, producing the same effect as in the first embodiment.

〔effect〕

As described above using the embodiments, according to the present invention, since the metal film recording medium is configured to be grounded, accumulation of static charge on the surface of the medium is prevented, so that the SN of the recording/reproducing signal is The ratio is significantly improved, and the error rate of recorded and reproduced data can be improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an embodiment of the present invention, and FIG.
FIG. 3, which is a frequency characteristic distribution diagram of a noise level showing the effects of the present invention, is an enlarged sectional view of a main part of another embodiment of the present invention. 11.31...Flexible metal thin film medium 12
．． 35.36... Clasp 13...
...Spindle 14...Housing 15...Drive motor 1G...Magnetic head 17... Amplifier 18... Conductive brush 19... Leaf spring 32... Base 33... Metal thin film 34・・・・・・・・・Protective film □ Circumference 1 section (MHz)

Claims (1)

[Claims] A flexible metal thin film medium is rotated and signals are recorded on the medium.
A magnetic recording and reproducing apparatus characterized in that the apparatus for reproducing magnetic recording is provided with means for electrically conductively coupling the metal tracing film member and a medium rotation drive means, and means for electrically grounding the medium rotation drive means. equipment it.