JPS5922250A - Scanning stylus of pickup - Google Patents

Abstract

PURPOSE:To prevent the reproduced output characteristic of a scanning stylus from an actual influence due to a virtual electrode before the scanning stylus reaches its mechanical limitation in a video disc player, by molding the 1st projection part to remove electrode metal dispersed and adhered to the lower end part of the 1st side of a base material and also molding the 2nd projection part to guide the scanning stylus to a grinding groove easily. CONSTITUTION:Since the 1st and 2nd projection parts 4, 6 are molded after fitting the electrode metal on the surface 8 of the scanning side, the dispersed metal adhered to the periphery of the scanning surface 7 is removed at the time of said molding. The electrode metal is not adhered to the 2nd and 3rd sides 42, 62. Since the 5th ridgeline 44 is arranged on the upper part of the 2nd shoulder part 61 in the 2nd side 42, the 1st side 25 is not adjacent to the scanning surface 7 even at the arrival of the life of the scanning stylus to be abrased by the 2nd projection part 6, so that significant electrode action is not generated even if the dispersed metal exists on the 1st side 25.

Description

[Detailed description of the invention] Field of application of the invention Misfire E! The present invention relates to a scanning needle of a pickup that detects information on an AVi recording medium as a change in capacitance value, and is applied to, for example, a capacitive video disc player.

Prior art and other technologies In the capacitive video disk system, for example, the CED type, as shown in FIG. This signal is detected as a change in the capacitance between the scanning needle electrode @) and the recording medium.

(ii! On the groove, a video signal (V) with a short wavelength and an audio signal (A) with a long wavelength are multiplexed in the direction of its extension. The tip of the scanning needle (S) is a hexagonal pyramid. In addition, there is a so-called key-shaped convex portion (β) in the very vicinity that contacts the recording medium, that is, a sliding contact surface β) that slides into contact with the signal groove of the medium, and even if wear progresses, the inside of the electrode remains within the specified value. The present invention includes a base (SA) in which a convex portion having a cut-out portion (C) is formed to make the surface of the base (SA), and an electrode layer (an electrode layer) disposed on the surface of the base on the running side.

Generally, the electrode @) is formed by attaching electrode metal to the base material by vapor deposition or the like before forming the notch (C).
Due to the wrap-around phenomenon of the scattered metal, pseudo-electrode stools (as shown by the dots in the figure) are formed on the two side surfaces adjacent to the first surface. Since the sliding contact surface g3) and the notch (C) f'i are formed by post-processing, no Vi pseudo electrodes are formed in the corresponding parts, but pseudo electrodes remain as shown in the figure for partial pressures that are not subjected to post-processing. In particular, the edge of the pseudo electrode attached to the area between the ridge line (Gl) and the ridge line (G2) has a width of 1 to 1 in the track extension direction.
．． It spans a length of 5 μm as the wear progresses (and becomes longer as the wear progresses), which is effectively several to ten times as thick as the original electrode (@), and is effective not only at high frequencies but also at low frequencies. This will also have an adverse effect on frequency signals. Therefore, this pseudo electrode causes unpleasant noise to be output, and this tendency increases as wear progresses. In severe cases, the sliding contact surface layer may reach the vicinity of the shoulder (G3) formed by the notch (C) before reaching the end of its mechanical life, or its life may reach the end due to deterioration of electrical characteristics.

As a means of removing such pseudo electrodes, (g) spraying abrasive grains such as sand gellast, or (b) attaching pseudo electrodes [fIi may be brought into contact with a lapping machine. There is a risk that the "electrode layer" may also be removed, and to prevent this, applying a mass N jig adds the work of attaching and removing it, which does not impair work efficiency and may reduce yield. Yoru. In the latter case, the two different sides must be brought into contact with the lapping machine in separate processes, and they must be made parallel with high precision, resulting in poor workability and yield, and is therefore expensive. Become.

The object of the invention is to provide a scanning needle for a pickup having a small structure.

Key Points of the Invention A first protrusion is formed by providing a pair of notches on both sides of the running-side surface of the base at the end of a roughly triangular female scanning needle base, and the 9! Further below the j1 protrusion, there is provided a second protrusion for regulating the inside of the electrode within a certain value in the direction of wear of the base, and the pair of notches form the pair of notches. The configuration is such that the end of the ridge line, which is the intersection line of the side surfaces, is placed at the t force of the h edge of the second protrusion.

Embodiment of the invention FIG. 2 is a perspective view of the configuration of one embodiment of the invention, and FIG.
It is an enlarged perspective view of the needle tip part of a figure.

The scanning needle (1) includes a needle base (2) and an electrode layer (9) (indicated by hatching, the same applies hereinafter) attached to one side of the needle base. The needle base (2) is made of diamond as a starting material, and has a columnar trunk body 1) engaged with a needle holder (not shown) and a triangular pyramid-shaped lower section 4, which are separated by 0 m. This lower part includes a pair of first ridge lines (241 (2
41, and a pair of first side faces adjacent to the running side surface (support), and a second ridge line 6) defining In order to match the above-mentioned track, it is shaped into a shape as described below with reference to Fig. 6 (Fig. 2 shows the state of this end before forming to avoid convergence of the figure). ing).

As shown in FIG. 3, the needle base (2) has a pair of first protrusions (4) formed by a pair of first (/77) parts (3031) at its lower end, and a pair of second notches (6). (5) formed by the second protrusion (6) and the scanning surface (
7).

The first protrusion (4) has a pair of shoulders (4) 1@11 extending from the 10 side of the running side surface toward the internal force, and a pair of shoulders extending downward from each inner end of this R section. Second side 142) (4
4 (Atλ-, drain 2 side [fi+421142)
is a pair of fifth ridge lines (43114:3
], and the fifth ridge line (441) that separates the surfaces from each other (R
It is growing. This fifth ridge line is the second ridge line (goods) and the scanning plane (7
) and the rooster! , has been. The second protrusion (6) is a pair of chests that extend from both sides of the running side surface under internal force←1)(
6tl, and a pair of 6th side direction I2 pier 2) extending from each inner end of this chest toward Doka, and each 5th side ←2
)12) is a pair of fourth ridge lines −′′・
- has. The interval between the fourth ridge lines is determined so that l/Cj does not change more than the middle of the track even if the second protrusion (6) is worn out during use of the needle.

The scanning plane (7) is a pair of slopes t23 that are symmetrically formed with the sixth ridge line Q extending in the extending direction of the trunk.
The upper end of each slope is defined by a running side surface (8), a third side surface (-), and a second side surface (41).

The first and second protrusions (4) +6) are processed and formed after attaching electrode metal to the scanning surface +81, so that the scanning surface (7)
) Even if scattered metal is attached to the periphery, it is removed during this processing, and no electrode metal is attached on the second and sixth side surfaces (42). Also, the second side (b) is No. 59. line@)
Since it is formed so that it is placed at the t force of @22 skin (69), even when the second protrusion (6) wears out at the end of the life of the scanning needle, the scanning surface (7) K first side face ( (b) Since they are not adjacent, even if flying metal is present on the first side view, it will not have a significant overlapping effect.

In Naoki's example, the angles α, β, and γ formed by a pair of i81 ridge lines (the fifth calibration line is omitted, and the slope) are each 50 to 6.
0 degrees, 40 to 70 degrees, and about 140 degrees, and the angles between the running side surface (8) and the fifth ridgeline of the second school line (four angles δ,
θ are 40 to 551f and 45 to 65t+, respectively.

In addition, the 5th ridgeline (14) has a half-line e-line 8, and the angle δ is set at θ.
For example, the 5th edge (turn) for the school line (2 (〃) is 6 to 10
It's been a long time since I've been in the company. Furthermore, the 1st M Ikui 1) and the 5th
The length of the line (4, phantom distance, 5th ridge green) is 10115μ and 20-60μ, respectively.

Next, the forming hand 11 [ti
Let me explain about c. 1-1 The surface corresponding to the scanning side V is made of a titanium electrode (9) by a normal thin film forming method, for example by sputtering. It is attached to a thickness of 18 to 0.22μ.

Next, the cross-sectional shape shown in Fig. 4 was arranged as shown in Fig. 5, and the two were moved relative to each other under pressure. Figure 5 (b) As shown in Figure 5, prepare the intermediate product. The surface of the polishing body (base) has a spiral or concentric V-shaped groove (11b), and the land portion (11c) and the surface thereof have diamonds,
Abrasive grains made of brittle materials such as sapphire, boride, and oxide are embedded or covered, and the entire polishing grain layer 03) is formed. The base sauce is its ridgeline (12a)
is arranged so that it coincides with the extending direction of the polishing groove (11b) and makes an angle Φ with respect to the polishing groove (11b) K, and in this state, the pre-polishing process is continued, and as shown in FIG. As shown in FIG. 1, an intermediate product (12) having a first protrusion (4) is manufactured. At this time, the electrode metal scattered and attached to the side surface (goods) during the above-mentioned restoring is removed at the same time.

Among these, the IC1 product F-1 is placed on the second polishing body 05) shown in Fig. 6 so that the ridge line (12a) is aligned with the extending direction of the polishing groove (15a), and the electrode forming surface is aligned with the polishing groove. (15a)
＼： Iri, arranged as shown. In this state, by pressurizing both chambers and running them relative to each other (ν1 polishing groove (1
5a) The second protrusion f6Fz has a barbed shape as shown in Fig. 6. Incidentally, the included angle of the polishing groove (15a) is 45 to 75, and the included angle of the polishing groove (15b) is 10 to 15μ.
(1" between the polishing grooves (15a) and approximately 2" each from the depth V)
μ, 4μ. Note that (15c) is the base, and O is the abrasive grain layer.

FIG. 7 is a perspective view showing 171 items among other examples of Kibari J. This is the second ridgeline (12a) of the triangular pyramidal crystal phase.
is arranged parallel to the polishing groove (11b) in FIG. 4 to form the first protrusion (41).

In the present invention, the first protrusion is an electrode); a groove for removing the electrode metal scattered and attached to the lower end of the first side of the busy base material; and a guide to the polishing groove for forming the @22 protrusion. Needless to say, the first skin part and the second side surface are not limited to the shape shown in the drawings, but may be formed in various f-shapes as long as this requirement is met.

Effects of the Invention Since the structure is configured so that no metal remains on the electrode surface and all sides adjacent to the scanning surface when the electrode f is heated, it is possible to prevent the metal from remaining on the electrode surface and the entire side surface adjacent to the scanning surface. No electrodes other than the regular electrodes (4i-ati+: poles) are formed and there is no risk of picking up noise. Further, forming the first protrusion for this configuration can be expected to have the secondary effect of contributing to the workability and yield direction IK for forming the second protrusion.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a recording medium in the track direction and a side view of a conventional scanning needle. Fig. 2 is a perspective view of the structure of the 17th embodiment of the present invention, Fig. 6 is an enlarged perspective view of the tip of the needle in Fig. 2, and Fig. 4 shows the first abrasive body cut in the direction perpendicular to the abrasive groove. (A rear view of the base material pushed into the polishing groove is also shown.) Figure 5 (a) ←) is a partial side sectional view of the first polishing body illustrating the polishing state. (The base material is shown in a side view), (a) shows the state immediately before polishing, and (b) shows the state immediately after polishing is completed. Figure @6 is an explanatory view showing a partial cross-sectional view of the second polishing body cut in a direction perpendicular to the polishing groove, together with a rear view of an intermediate product of the scanning needle that is engaged with the polishing groove. FIG. 7 is a perspective view of an intermediate product according to another embodiment of the present invention. Explanation of the main figure numbers (2)...Scanning needle base, (3), (6)...1st,
$2 Kiridaibu, 141㎋l)...1st, 2nd R section, shi4
) (Foundation) H31 (6 phase reactor... 1st, 2nd, 3rd, 4th,
Fifth ridgeline, (7)... scanning plane. Figure 1 Figure 4 Figure 7 -251-

Claims (1)

[Claims] ill The leading end of the recording medium facing the track generally has a pair of first ridgelines defining a running side surface with respect to the track and a second ridgeline defining a pair of first side surfaces adjacent to the running side surface. In the scanning needle of the pickup having a scanning needle base formed in a triangular pyramid shape and having both f and c electrodes disposed on the scanning side surface, inward from both sides of the use side surface in front of the scanning needle base V1. a pair of first notches, each having a pair of first shoulders extending toward and a pair of third ridge lines extending downwardly from each inner end of the first shoulders; a second notch portion having a second shoulder portion extending toward the direction and a fourth ridge line extending downward from the inner end of the second shoulder portion, a scanning surface that contacts the track, and the first cutout portion. a pair of second ridges defined by a fifth ridge line extending from the scanning plane to an area above the second shoulder portion;
A pickup scanning needle comprising a side surface and a side surface.