JPS581840A - Scanning stylus and its production - Google Patents

Abstract

PURPOSE:To decrease the abrasive degree of a video scanning stylus and to increase its lifetime, by forming nearly a sagittal bottom surface for the scanning stylus at the part that touches a track and increasing the width of an electrode which extends to the sagittal bottom surface with a prescribed angle. CONSTITUTION:A scanning stylus 21 touching the concentric tracks of a video disk has nearly a sagittal bottom surface 24 at its contact surface. Then a metal is vapor-deposited on the surface of hatching shown in the diagram to be used as an electrode forming surface 23. The 1st electrode surface 26 which detects information recorded on the track is inside the surface 24 and extends with a prescribed angle 27 and with nearly a certain width to reach the 2nd electrode surface 28. Thus the information is reproduced. The width of the surface 26 can be increased within a prescribed value and in a region 40 ranging from the surface 24. Thus the abrasive degree of the stylus is decreased. Furthermore, the abrasive degree is also reduced from a square pillar material 22 of diamond since the side ridges 30a and 3ab of the part 24 are gentle.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scanning needle and a method for manufacturing the same, and an object of the present invention is to improve molding workability and provide an inexpensive scanning needle.

Since information signals including video signals are recorded with high density as changes in geometric shapes and are reproduced from a nine-disc recording medium, the width of the bottom surface of the scanning needle in the cross-track direction is smaller than the recording track pitch. Systems have been developed that utilize larger scanning needles to extend needle life. The conventional scanning needle of this type has an inclined surface (ll+21) as shown in Fig.
A prismatic base (3
) Electrode formation surface (extraction surface) (4) K The scanning needle base material formed with the electrode shown by diagonal lines is coated with K so that the electrode width (5) becomes a predetermined value and the aperture angle (6) is a predetermined value. (e.g. 1o0)
The slope (7) + 8) is lapped as shown below, and the lower end is flattened so that the length of the lower edge of the electrode is a predetermined length. A large amount of the base material must be removed in order to form the
8) requires precision processing, so it cannot be processed using a laser beam and must be processed by lapping.
In order to release the mold, the lapping machine must be accessed from two different directions, which requires a lot of time, which poses problems in the workability of molding.
There are restrictions on reducing the cost of scanning needles. That is, as shown in FIG. 2, the scanning needle base material Ql is placed on the lapping plate aυ at a predetermined angle tJ.
Access at J, remove the broken line part α to expose one slope (7), and form the other side in the same manner so that slope (8) is exposed, and the opening angle (6 ) In order to reduce the angle (1), it is necessary to reduce the angle (1).Furthermore, if this machining operation is not performed properly, the needle tip may be formed into a predetermined shape as shown in Figure 6. In other words, as shown in (a), (b), and (c) of the same figure, under-polishing, over-polishing, and asymmetry of polishing may occur.

In order to realize slopes corresponding to the slopes (7) and (8) above with a smaller amount of machining, the electrode shape aWJ (c) is placed at the bottom of the electrode forming surface CI of the scanning needle α4 as shown in FIG. 5
As shown in the figure, a polishing plate (I?) having a roughly V-shaped polishing groove Qe when viewed in radial cross section is accessed at a predetermined angle of 6 seconds and the two are moved relative to each other to regulate the inside of the electrode. It has also been considered to form a lower electrode with an opening angle. However, since this scanning needle α has a limit in reducing the above-mentioned angle involved in the opening angle of the electrode, there is also a limit to reducing the opening angle, and therefore there is a limit to the effective height of the electrode that determines the life. There is a limit to increasing the size of the hole 4), and it cannot contribute to extending the life of the scanning needle. The present invention has been made with these points in mind, and includes a scanning needle and a scanning needle that improve molding workability by reducing the amount of polishing during needle tip processing, and that contribute to extending the life of the electrode by increasing the regulation length in the electrode. This paper attempts to provide a manufacturing method for the same.

First, a scanning needle according to the present invention will be explained based on illustrated embodiments. Figure 6 shows this scanning needle, (a) is a front view, (b)
is a right side view, and ti is a bottom view. The scanning needle (21) is equipped with a diamond base@ and an electrode deposited on the runout 1fi (electrode formation [fi)@] of the base, and the information g! The information signal is detected and reproduced by sliding the information signal on a concentric or spiral track on a disk-shaped recording medium in which the number is recorded as a change in geometric shape.

The base @ has a roughly rectangular prism shape, and its lower end is formed into a tapered shape □. This tapered shape extends upward from the roughly arrowhead-shaped bottom (to) that contacts the recording medium and one side (c) that defines the arrowhead base of the bottom, and has an electrode () on the surface.
・A first electrode WJ@ having a substantially constant electrode (shown by tuching), and a first electrode WJ@ having a substantially constant electrode surface, extending further upward from the first electrode surface at a predetermined angle (5) with respect to the first electrode surface; A second electrode surface (2) having an electrode connected to the electrode of the main body part, and a pair of side surfaces (29) adjacent to both the first and second electrode surfaces and extending rearwardly from each electrode surface. (29b)
and a first side ridge (30 m) (Sob) K adjacent to the pair of side surfaces and defining the tapered shape;
A pair of M extending in the extending direction of the second electrode surface (to) (to)
ifi (311) (51b), and further includes one side [
(30m) (50b), two side edges C52m) (52b) that define the bottom surface @, and a pair of slopes (34m) whose lower ends are defined by the side edges (to) extending in the track direction.
(34b). The first electrode surface (to) is formed such that the side edges (26m) (26b) that define it are approximately parallel to the extending direction, and the second electrode surface (to) defines it. The side 1N (28@) (28b) is formed into a funnel shape. On the other hand, the electrodes indicated by hatching include the electrodes on the base body and the electrodes on the first and second electrode surfaces. information signal to external circuit (not shown)
I am trying to communicate K.

Next, one embodiment of the method for manufacturing such a scanning needle will be described. First, prepare a prismatic material (to) made of diamond,
Regarding K, it is the same as the conventional example <II! As shown in Fig. 7, the slope (to) C37) is formed to make the lower end into a triangular prism shape. Next, regarding the electrode formation surface (to), a metal such as titanium, nickel, etc. is deposited on the several-shaped surface (to) from the tip to a thickness of approximately z using means such as sputtering or vapor deposition.

00a (the diagonal lines in the figure indicate this electrode layer). Then, for the material on which the electrode is formed in this way, the tip including the slope is placed in a V-shaped polishing groove so that the slope (end) is parallel to the polishing plate Q7 shown in FIG. The abrasive grain layer (161) on the polishing plate αη is formed into a shape that follows the polishing groove ae by accessing the inside of the polishing groove ae and moving the two relatively, for example, by rotating the polishing plate Qη at high speed, as shown in FIG. Manufacture intermediate products as shown in after that,
This intermediate product is accessed to another polishing plate having a flat polishing surface so that the base electrode is approximately perpendicular to the polishing plate, and the two are moved relative to each other to form a scanning needle as shown in FIG. Manufacture. In this embodiment, a diamond hammer was used as the scanning needle base, but a composite base in which the part that makes sliding contact with the recording medium is made of this type of hard brittle material and the rest of the base is made of a metal such as titanium may also be used. Needless to say, a table may be used.As described above, in the present invention, an inclined surface is provided at the lower part of the electrode surface of the scanning needle base, and this inclined surface is placed in a V-shaped polishing groove and then placed on the inclined surface. Since a substantially constant first electrode surface is formed in the electrode and a funnel-shaped second electrode surface that is continuous with the first electrode surface is formed on the electrode surface that follows the slope:
The area flR(g) (see FIG. 6) where the inside of the electrode is below a predetermined value can be increased, and the life of the scanning needle can be extended accordingly. In addition, compared to the conventional example shown in Figure 1, the workability for forming both electrode surfaces and the bottom surface that contacts the recording medium is easier to access the processing machine and the amount of polishing required is significantly reduced. As a result, the manufacturing yield of scanning needles can be improved and manufacturing costs can be reduced.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional scanning needle, Fig. 2 shows the molding process of this scanning needle. indicates the polishing state, (a)
(b) and (c) are partial front views of the scanning needle, respectively. Figure 4 (A) (10) 01141・Front view of another conventional example,
They are a right side view and a bottom view. Figure 5 (A) Naka)? -1 Relational diagram of the polishing plate and the scanning needle seen from six different directions, Figures 6 (a), (b), and (c) are front views, right side views, and
It is a bottom view. FIGS. 7 and 8 are perspective views of intermediate products of this scanning needle. Explanation of main drawing numbers...Scanning needle, 04)...Bottom, (4)...1st
Electrode surface, (to)...Second electrode surface, (29a) (29b
)...a pair of side surfaces, (61a) (31b)...a pair of slopes. Figure 1 Figure 8 C-1 (o)
4th circle 111 + No. 4g Fig. 5 No. 6 (Inquiry Fig. 7 No. 811

Claims (3)

[Claims] (1) A scanning needle that detects and reproduces the information signal by sliding on a concentric or spiral track on a disc-shaped recording medium on which the information signal is recorded as a change in geometric shape, the scanning needle is The lower end portion is formed into a tapered shape, and the tapered shape includes a bottom surface in the shape of an arrowhead 9 that comes into contact with the recording medium, and a second section extending upward from one side of the bottom surface that defines the base of the arrowhead and having an electrode on the surface. a second electrode having one electrode surface and an electrode extending further upward from the first electrode surface at a predetermined angle with respect to the first electrode surface and connected to the electrode of the scanning needle main body;
an electrode surface, a pair of side surfaces that are adjacent to both the first and second electrode surfaces and extend toward the rear from each electrode surface, and a side ridge Km that is adjacent to each of the pair of side surfaces and has a constant tapered shape;
a pair of sloped surfaces extending in the direction in which the first and second electrode surfaces extend. (2) Each side Il formed by the first electrode surface and the pair of side surfaces! 2. A scanning needle according to claim 1, wherein the needles are parallel to each other. (3) The vicinity of the tip of the electrode forming surface of the scanning needle base material whose lower end is formed into a tapered shape is chamfered in the future.
a step of forming a plane that will become an electrode surface; a step of forming an electrode on the plane and the electrode forming surface; and a step of forming the scanning needle base material after the electrode forming step into a polishing groove having a substantially V-shaped cross section. , the flat surface is arranged so as to be substantially parallel to the polishing disk having the polishing grooves, and the two are moved relative to each other, so that on the plane there is a first electrode surface in which the inside of the electrode is substantially constant, and a first electrode surface with the inside of the electrode in an upward direction. 1. A method for manufacturing a scanning needle comprising the step of simultaneously molding a second electrode surface that is wide in the middle and extends at a predetermined angle with respect to the second electrode surface.