JPS5938652B2 - Regeneration needle of regeneration element that detects changes in capacitance value - Google Patents

Description

[Detailed Description of the Invention] Information recording medium disk (disc) having a recording trace formed by arranging pits corresponding to information signals
By sliding the playback needle of the playback element (pickup) onto the recording trace in the recording trace and detecting the change in capacitance value that occurs according to the state of the information signal in the recording trace as a change in the amount of electricity, high-density recording can be achieved on the disc. The so-called electrostatic capacitance value change detection type information recording and reproducing method, which reproduces the information signal recorded on the disc, uses a reproducing stylus to read the information signal in the recording trace on the disc. Since this is done by detecting changes in capacitance using an electrode, the thickness of the electrode provided on the reproducing needle is determined by the length of the pit corresponding to the information signal (the size of the pit in the direction in which the recording trace extends). In addition to the feature that it is possible to increase the resolution by being sufficiently small compared to the size of the disc, it is therefore possible to record and reproduce information signals even at a low rotational speed of the disc, and there are many other advantages. Because of this, research into its practical application has been promoted.

By the way, as mentioned above, in the information recording and reproducing method that detects changes in capacitance value, recorded information is detected while the reproducing needle provided with the electrode portion is brought into sliding contact with the disk. However, the disk is mainly made of a dielectric material, and the regeneration needle used in sliding contact with the disk is also made of a dielectric material of high hardness that has wear resistance, such as sapphire. Since the playback stylus body is made of diamond or the like, when the playback stylus is brought into sliding contact with the disk surface that rotates at high speed in order to reproduce information signals from the disc, the disk surface and the playback stylus body will be damaged. Static charge accumulates on the When the static charge is discharged to the electrode portion provided on the regenerated needle main body, the electrode portion having minute dimensions may be dissolved and scattered due to the discharge. The present invention provides an electrode section for discharging static charges generated on the disk or the playback needle body in addition to an electrode section for signal detection on the playback needle body of the playback needle of the capacitance change detection type playback element. The above-mentioned problems have been solved by providing a regenerated needle provided with the present invention.Hereinafter, specific contents of the regenerated needle of the present invention will be explained in detail with reference to the accompanying drawings.

1 to 4 are plan views of different embodiments of the regeneration needle of the capacitance value change detection type regeneration element of the present invention, viewed from the sliding surface side, and FIGS. In the above, 1 is a high hardness material having wear resistance, such as diamond,
The sliding contact surface 2 is formed on the bottom of the regenerated needle body made of sapphire or the like, and 2 is an electrode part for signal detection made of a thin film of a conductive material adhered to the electrode attachment forming surface of the regenerated needle body. , the electrode end portion appearing at the end of the sliding contact surface 1 is shown in the drawing.

Further, in each figure, reference numeral 3 denotes a discharge electrode portion for discharging static charges generated in the disk and the regenerating needle body.

In the configuration examples shown in FIGS. 1 to 3, the signal detection electrode section 2 and the discharge electrode section 3 are formed in a predetermined pattern of conductive material by applying well-known appropriate means. The electrode section 2 for signal detection and the electrode section 3 for discharge in the configuration example shown in FIG. The high-resistance material near both ends of the high-resistance material layer 1 deposited on the electrode adhesion formation surface of the needle body is changed into a conductive material by applying processing means such as oxidation, reduction, element doping, and ion implantation. In addition, P in FIG. 4 is a protective layer obtained by, for example, vapor-depositing or sputtering alumina, and this protective layer P covers both sides of the high-resistance material layer 1. This effectively prevents the high-resistance material layer other than necessary portions from becoming conductive during a treatment process for making the ends conductive. When the constituent material of the high-resistance material layer is oxidized or reduced, or when it is subjected to elemental doping or ion implantation, the high-resistance material changes into a conductive state. An appropriate insulator or semiconductor is selected and used. For example, when the insulator, chlorinated tin oxide, is used as a constituent material of the high-resistance material layer 1, the high-resistance material layer is oxidized from both ends of the high-resistance material layer. By forming electrode parts made of conductive tin oxide on both ends, or by reducing the high-resistance material layer from both ends,
The electrode portions 2 and 3 made of conductive metal tin can be formed at both end portions of the five layers of high-resistance material.
In addition, titanium oxide or hafnium oxide may be used as the constituent material of the high-resistance material layer 1, and in that case, the high-resistance material layer 1 may be Conductive electrode portions 2 and 3 can be formed at both end portions of the layer. Note that when hafnium oxide is used as a constituent material of the high-resistance material layer 1, after reducing both ends of the high-resistance material layer 1, a carbonization treatment is performed to reduce the thickness of the high-resistance material layer. It is preferable that electrode portions made of hafnium carbide, which is a conductive material, be formed at both ends, and if the constituent material of the regeneration needle body is diamond, the diamond itself becomes a high-resistance material layer. Therefore, after the polishing process for the regenerated needle is completed, a powerful laser beam is irradiated to the desired location of the regenerated needle in the air or in a stable quantitative oxygen atmosphere to make carbon, which is a constituent element of diamond, conductive in that area. It is preferable to convert it into a carbon layer. The arrow 4 in FIGS. 1 to 4 indicates the advancing direction of the disk surface relative to the regeneration needle, and the discharge electrode 3 is provided on the introduction side of the regeneration needle.

It is desirable that the grounded discharge electrode 3 has a lower electrical resistance value than the signal detection electrode 2 so that discharge can be reliably performed thereon.
In addition, in order to ensure that discharge occurs in the grounded discharge electrode section 3, a signal is transmitted by an electrode 5 provided at the peripheral edge of the sliding surface, as shown in the configuration example shown in the third figure. The detection electrode section 2 and the discharge electrode section 3 may be connected. In this case, the electrode 5 must have a sufficiently high resistance value so that the signal detection function of the signal detection electrode section 2 is not adversely affected by the provision of the electrode 5. It is. As is clear from the above detailed explanation, in the regeneration needle of the present invention, the regeneration operation is achieved by providing the electrode section for discharging near the electrode section for signal detection provided on the regeneration needle main body. The static charge that sometimes accumulates on the disk surface and the regenerating needle body is well discharged to the discharge electrode section, so even if discharge occurs, the signal detection electrode section will not be destroyed. Therefore, according to the present invention, the conventional problems can be satisfactorily solved.

[Brief explanation of the drawing]

1 to 4 are plan views of different embodiments of the regenerated needle of the present invention as viewed from the sliding surface side. 1... Sliding surface, 2... Electrode part for signal detection, 3... Electrode position for discharge 5...
·electrode.

Claims (1)

[Claims] 1. Sliding contact with a recording trace on an information recording medium disc having a recording trace formed by arranging pits corresponding to an information signal, and changing the information signal in the recording trace to a change in capacitance value. In a reproducing needle of a capacitance value change detection type reproducing element, which is equipped with an electrode part that can be extracted as a change in the amount of electricity according to the amount of electricity, the reproducing needle body has an information recording medium in addition to an electrode part for detecting an information signal. A regeneration needle of a capacitance value change detection type regeneration element, which is also provided with an electrode portion for discharging static charge generated in a disk or a regeneration needle main body.