JPS58143448A - Scanning stylus - Google Patents

Abstract

PURPOSE:To reduce an amount of polishing work greatly and to improve mass- productivity, by limiting work for making the electrode width of an electrode formation surface less than the track width of signal tracks to only the circumference of a projecting part at the tip of a stylus. CONSTITUTION:The tip part of the base material of a scanning stylus S which has an electrode stuck uniformly to a run-out side surface 12 as shown by slanting lines is formed in a triangular pyramid shape and the direction of a ridge line 15 coincide with the extending direction of signal tracks. The tip projection of the stylus is formed through minimum work. Namely, the projection is ground with the 1st polishing disk which has two parallel surfaces 24 and 25 with intersurface width equal to polishing groove width and side surfaces 24 and 25, a bottom surfaces 26, and some parts of bottom surfaces 27 and 28 are formed at the same time. Then, the stylus is applied slantingly to the 2nd polishing disk with greater polishing groove width to form side surfaces 20 and 21 in two stages and the electrode formation surface 18 is formed to specified width 17. Thus, the specified electrode width is obtained through the considerable less work and the mass-productivity is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scanning needle applied to a capacitive video disk player, etc., and aims to reduce costs and improve performance.

For a certain type of video disk player, for example, a VHD system, a scanning needle having a configuration as shown in FIG. 6 has been proposed. ξ The starting material is a titanium shank with a diamond chip 11) embedded in the tip (the lower part of the shank is machined into a concave shape along with the chip), and KINl, II2 are made so that the ridgeline (1) is on the entry side of the signal. Back d[il+)i
The first and second side surfaces 181191 are formed so that the width (7) of the nine electrodes is within a predetermined value, and the bottom surface 181191 is formed so as to be in sliding contact with the signal track of the video disc. It is constructed with a strong influence. In this configuration, the number of electrodes that can guarantee thousands of hours of hemorrhoid life is at most 10μ to 10μ+lIK.
However, in order to obtain a predetermined electrode inside, this length is processed to be about 100 times (more than 1 inch) long. Since the multi-dimensional processed materials have high wear resistance, they have poor workability and have become a bottleneck in reducing costs.

The present invention has been made in view of this point, and an object is to provide a scanning needle having a structure that can achieve regulation in the electrode with an extremely small amount of processing.

The present invention provides a scanning needle having a base having a triangular pyramid shape iiS and a convex S1 connected to the base, and the convex has an acute angle with respect to the electrode shape tL surface where at least the inside of the machine is below a predetermined value, and the electrode forming surface. adjacent $1.1g21
1Hf, the first and second back surfaces disposed on the same plane as the two side surfaces that grit the base, and the 111th! I
Adjacent to rkJ and the first back surface, and the second side and second back surface, respectively, along the extending direction of the gI track (is y-parallel 1
1g3, which is formed in the electrode, is characterized in that the convex portion disposed below the processed T-base for regulating the inside of the electrode is limited to disappearing once and for all. In addition, the scanning needle of the present invention has a ridge line extending in the direction in which the signal track extends from the beginning of its use or after a certain degree of wear has progressed. , this scanning needle to the video disc? This is intended to prevent the occurrence of ``snag'' (running failure) on the video disk even when the disk is brought into close contact with the signal track and transferred at high speed in a special playback mode in a direction that intersects the signal track.

Next, the present invention will be explained according to the embodiment shown in FIG. FIG. 1 shows a schematic perspective view of one embodiment of the scanning needle of the present invention. In this example, the scanning needle S) is equipped with an electrode support part (1) and an electrode (indicated by hatching) formed on the running side surface of the electrode support part (indicated by hatching). ) is made entirely of natural diamond material, and the prismatic material forms an oblique [010] and the F edge is a y triangular kojibushi Kt.
It is L-shaped. The projection line of the scanning needle 41H on the video disk, which is the intersection line of the slope α1~ with respect to the scanning needle (S) Fi video disk, is in the extending direction of the signal track! When this video disc runs in the same direction as the arrow 0, the signal track V of the video disc
Information on the signal track in contact with C1ml is detected as a change in electricity corresponding to a change in capacitance value VC.

The tip #(SA) of this scanning needle is shaped as shown in the enlarged perspective view of FIG. 182 to align with the signal track of the video disk. This needle tip, that is, the scanning needle 6) has a triangular pyramid-shaped base (SB) whose three sides are the above-mentioned running side surface 112) and the two flJr01 planes sandwiching the above-mentioned filth field, and the lower part of the base. The first and second sides 1i [iM@υ and Each of the constituent surfaces (slope clear O
1st and 2nd rear surfaces located on the same plane as the vagina)
1, a 6th side surface (goods) adjacent to the first side surface 4 and the first back surface (b) and formed parallel to the direction of extension;
＠Y
The 411I1 surface (c) formed in parallel, the electrode forming surface portion, the first and second side surfaces -@phantom, the respective edge detection lines (18 lines) of the first and 112 back surfaces (2) (2) 20m) (21
m) (22m) (23m) and is flush with f. Incidentally, the pair of bottoms djJvI (c) facing the video disc are formed to define the lower @ of the base (SB) during the molding process of the convex fs leech, as will become clear from the explanation of the processing method described later. It is something that

Next, the processing method for forming the above-mentioned convex portion will be explained according to the process diagram shown in Fig. 5. First, make a triangle at the F end (Figure 3a)
0 Next, this base material was formed into a spiral (with a substantially U-shaped longitudinal cross section)
Or access the grinding disk having the concentric groove C4 so that the electrode forming surface of the base material is perpendicular to the rotating surface of the grinding disk, and 61
The noodle material is brought into relative pressure contact with the polishing disk and polished so as to form the fourth side (goods) and a part of the bottom surface 1 and the bottom l1i (goods) (c) at the same time (6th (See figure (b)). Then, an intermediate product Nt as shown in FIG. 5(C) is obtained. still,
The layer on the polishing disk is an abrasive grain layer in which Gui τmond abrasive grains ◆ are embedded. Next, this intermediate product is placed in the polishing groove mentioned above.
A screw a with a wider frontage and approximately U-shaped cross section in the longitudinal direction than
(Alternatively, as shown in FIG. 3(d) and (e), the groove wall (56A
), the intermediate product Ht-diagonal (intersection angle g) K is applied and the second side surface C1) is formed, and then the groove wall (56B) KI
The first side Ifi- is formed by applying in four different ways.

%6clA) shows the whm diagram of the second polishing disk @η when the first side surface is formed. In this way, by accessing the scanning needle base material t, the first and second polishing discs (2), and polishing them in a predetermined manner, it is possible to easily form a desired convex portion. In this shaping method, the bottom surface of the convex part (
C) is formed by a polishing disk at the same time as the third and fourth side surfaces 4. Only the side surfaces may be formed at the same time, and after (or before) the polishing by the 25th polishing disk Cη is completed, the bottom surface may be formed by a flat third polishing plate. Another example is shown.

This is the 1st, 211th I! It is good to have a vL shape so that the 1st direction - hai υ and the 1st and 2nd back surfaces (2) A are not adjacent,
In this scanning needle, as shown in Fig. 4 (Φ), there is a third,
411th! ll1i□□□ (to) edge ridge line (24 straight)
(25 Otori) appears. Each edge shape 1 (2
4m) (25m) (The one in FIG. 1) Compared to K, it is possible to reduce the chance of the scanning stylus catching on the video disk (scanning defects). FIG. 5 shows another embodiment of the present invention. As shown in the figure, the 6th and 41st Il! 1IfiI: As if cutting A-, the polishing lid by the first polishing disk and the I12 polishing layer disk C? ) is sine of the amount of polishing. Contrary to the embodiment of FIG. 5, the base I-phantom of the second side I pass υ may be made to extend into the base (Sb) of the scanning needle T). Each of these '4E examples is @
1. It is advantageous that there is a margin in the control of each polishing lid by the second #im disk-1. In each of the embodiments of the present invention, the scanning needle base material is made of natural diamond material, but only the needle tip including the convex portion is made of diamond material, and most of the part is made of other material W (for example, titanium). An attempt may be made to reduce 1+yellow.

As described above, the present invention provides processing t1 for defining the inside of the electrode.
Since it is limited only to the fCf14 area of the needle base, that is, near the convex part, the wr is lower than that of the conventional example shown in Fig.
By significantly reducing ytt*, it is possible to improve the mass productivity of the scanning needle and contribute to lowering the cost of the scanning needle.

[Brief explanation of drawings]

Figure wIJ1 is a schematic perspective view of a conventional embodiment of the scanning needle of the present invention, and Figure 2 is an enlarged perspective view of the tip of the needle of this embodiment. Figures 3(a) to 3(f) are explanatory diagrams of the molding procedure of this example, in which Figure 3) is a perspective view of the base material, and Figure 3) is a perspective view of the base material.
Process explanatory diagram, (C) is a perspective view of an intermediate product by this wJ1 polishing, (d) and (e) are explanatory diagrams of polishing with the second polishing disk, and (f) is a cross-sectional view of the t[2 polishing disk. . Figure 4(a)
(b) and 115 are enlarged perspective views of the needle tip portion of another embodiment. Figure 6 shows a conventional scanning needle, (1) is a front view, and (b) is 11I! Front view, (C) is rear view, (d)
is an enlarged front view of the needle tip portion. Explanation of main drawing numbers

Claims (1)

[Claims] 1. In order to detect and reproduce information on the signal track by slidingly contacting the signal track of the recording medium as a change in an electric signal corresponding to a change in capacitance value, the projection line of one ridge line onto the disk is A triangular pyramid-shaped base extending in the direction in which the signal track extends and whose plane facing the ridgeline is located on the scanning needle running side and serving as an electrode formation surface; In the scanning needle, the scanning needle is provided with a convex portion having a surface, an electrode shape e formed on the same plane as the electrode formation direction, and having a width restricted to be equal to or less than the middle of the signal track, the convex portion further comprising: @1 and a second side surface that are adjacent to each other at an acute angle with respect to the electrode formation surface, and a second rear surface 111 that is arranged on the same plane as each constituent surface that constitutes the base and constitutes the ridge line; Said first side direction and @1
II on the back garden and the 82111 side and the second back respectively.
It is divided by third and @4 side surfaces that are in contact with each other and are formed along the extending direction, and each edge stacked fiber in the electrode formation direction, the first and second side surfaces, and the first and second back directions. A scanning needle comprising a bottom surface.