JPS58196638A - Scanning stylus - Google Patents

Abstract

PURPOSE:To improve the workability and to secure the electrode sticking intensity without requiring any processing for prescribing the width of an electrode, by providing a groove having a width corresponding to the electrode width along the side surface of a conical stylus base and burying the electrode metal into said groove. CONSTITUTION:A scanning stylus 8 consists of a stylus base 10 and an electrode 20, and the base 10 includes a side surface 13 and a scanning surface 14. A groove 15 having a width equivalent to the width of the electrode 20 is formed by a laser beam along the slanting surface of the surface 13 for attachment of the electrode 20. Then a metal such as hafnium, etc. having a high melting point is sputtered to the groove 15. Therefore, the base 10 is obtained with conical processing without basically adding after-processing. Thus the processing for prescribing the width of the electrode is eliminated to improve the workability. At the same time, the sticking intensity of the electrode is secured since the electrode material is also stuck around the groove 15.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scanning stylus for extracting information signals from a medium on which information is recorded as changes in capacitance.

A conventional scanning stylus, for example, a scanning stylus applied to a VHD video disc, has a stylus tip shape as shown in FIG. That is, the needle base (1) is made of a hard and brittle material such as diamond.
is roughly shaped like a truncated pentagonal pyramid, and has a bottom surface (1a) that slides into contact with the medium, and five side surfaces (lb) (lc) (1a) (l e) on which lower tides are defined, respectively.
(1f). The side faces (ta) (le) are placed on the inlet side of the medium, and the side faces (1c) (1f) are lateral 111 of the side 1ii (lb) placed on the outlet side of the medium! +21
stipulates. An electrode (3) made of a high melting point metal such as titanium is attached on the side surface (1b). Since the width (2) needs to be set to a predetermined value, i.e., less than the track width, depending on the progress of wear of the scanning needle, the electrode inclusion angle (4) is made as small as possible, for example, about 3 to 6. This means that the process of removing the broken line areas (5) and (6) shown in FIG. 1C and exposing the side surfaces (1c) and (1f) requires high precision. If the broken line area (6) is removed first, processing is performed while controlling the width (2) of the electrode (3) when removing the next broken line area +61.
2) has an extremely fine dimension of 1 μm or less, and on the other hand, the thickness is about 0.2 μm, which cannot be ignored when comparing the thickness and width, and the contact area with the needle base (1) is minute, making it difficult to use the grinder during polishing. There is a risk that the electrode may peel off from the needle base due to impact energy of particles, repeated stress caused by it, or energy due to vibrations of a polishing machine, etc.

Therefore, in forming the electrode film, advanced techniques such as ion implantation were required to ensure strength against the peeling force during processing, which has a large electrode peel strength caused by relative movement with the medium during playback. Such conventional scanning needles have poor productivity, such as poor workability in forming the needle tip into a pentagonal pyramid shape and the need to take measures to prevent electrode peeling during processing.

The present invention has been made in view of such drawbacks, and instead of requiring rounding to define the electrode width, a groove corresponding to the width of the electrode is provided in the needle base, and an electrode metal is attached to this groove. The present invention aims to provide a scanning needle characterized in that the shape of the base is a conical shape similar to that of an audio needle, for example, and is basically formed without major post-processing.

Next, the present invention will be explained based on examples. 2A and 2B are a front view and a plan view showing the overall shape of the scanning needle, and FIGS. 3A and 13 are an enlarged front view and bottom view of the needle tip portion. The scanning needle (E+) basically consists of a needle base (10) and an electrode. In addition, the needle base 1101 has a diamond (
A conical needle tip (lli) made of a hard and brittle material such as sapphire) and a needle base (74
(Tsuku) 121.

As shown in Fig. 2, this needle base 1 (2) has an inclined surface (side surface) forming a cone and a scanning surface (
The bottom surface (14) is provided with a groove 111 corresponding to the electrode width on the side surface (131) for mounting the electrode on the slope.
1 is formed. This strip (ItOF8) can be formed relatively easily by, for example, scanning an electron beam focused to 1 μm or less or a laser such as argon or YAG along the slope. When performing processing, in order to focus the laser beam to 1 μm or less, the optical system objective lens &i1m &-i 5 C1
~100m (7) 4゜Eyoe o1□1E Since the needle base is hard and made of diamond (or sapphire), it has a high reflectance for laser wavelengths of 500° to 100OA and has a corresponding power. must be given. However, when the laser power is increased, the machining width becomes extremely large even at the power at the start of diamond machining, making it impossible to process grooves of less than the required 17 Lm. Therefore, by covering the needle base with a material that has excellent absorption rate for the laser wavelength, such as T-burr, loam, nickel, titanium, etc., and irradiating it with laser, 10 grooves of a predetermined width can be easily obtained. be able to.

The electrode μs is a groove (l [QI') where a high-melting modified metal such as hafnium, titanium, zirconium, molybdenum, etc., which is the electrode material, is deposited by ion blasting or sputtering. As shown in the electrode film ev
il is a necessary article 1N! It is attached not only to the inside of 115i but also to the surface of the needle base surrounding this groove.To remove the non-biting part of the electrode film, for example, a method of conical processing the needle base is applied, and the groove is Processing is performed so that the thickness of the electrode within 11161 is a required thickness, for example, 2000 μm.

Since the scanning needle of the present invention is fully embedded in the groove of the needle base, the adhesion surface of the needle base and electrode film is one surface compared to the conventional example. Since the adhesive strength can be ensured by increasing the size, a practically sufficient adhesive strength can be obtained even with electrode forming methods such as ion blating and sputtering. Moreover, if the needle base is made into a conical shape, conventional audio needle processing technology can be applied and mass productivity can be ensured.

Furthermore, since the electrode width is constant, the scanning surface can be processed without considering the electrode width, which improves yield.

[Brief explanation of the drawing]

Figure 1 a% b, c show the tip of a conventional scanning needle; a
is a perspective view, b is a front view, and C is a bottom view. Figure 2 a%
b is a front view and a plan view showing the overall shape of the scanning needle of the present invention. FIGS. 3a and 3b are an enlarged front view and bottom view of the tip portion of the scanning needle of the present invention. FIG. 4 is a cross-sectional view of an intermediate product for explaining the electrode attachment method. Explanation of main drawing numbers 1101...Needle base, U...Electrode, +1]...
groove. Applicant Sanyo Tun Coated Floor Company Figure 1 Ob Figure 2 Ob Figure 3

Claims (1)

[Scope of Claims] L: A groove is provided on the side surface of an anchor-shaped needle base having a bottom surface that slides on the medium, and has a width and depth corresponding to the electrode layer and extends upward from the bottom surface, and within the groove. A scanning needle with electrode metal embedded in it. 2. The needle base includes a conical needle tip made of a hard and brittle material such as diamond or Iya, and a metal needle forming a conical part and a cylindrical part connected to the needle tip. 2. The scanning needle according to claim 1, further comprising a base portion, and wherein the groove extends to the needle base portion.