Victor Company of Japan, Limited

Keiji Segawa

Masaki Murakami

Hisao Kinjo

Yoshiyo Wada

Hideaki Takehara

Kunio Goto

Hirofumi Imaoka

Keiichiro Doi

Motoshi Shindoh

Norio Matsuda

Akira Asano

Mitsuru Otsuki

Mikio Naoi

Toshiya Sakurai

The invention provides a production method capable of forming a thin film resistance element having a thickness and a shape controlled in a high accuracy in a printed circuit board. The production method of a thin film resistance element formed on a printed circuit board, has the steps of forming a thin film resistance layer having a predetermined thickness on the printed circuit board through an insulation layer by a dry process used in producing a semiconductor, forming an electrically conductive layer on the thin resistance layer, and etching the electrically conductive layer selectively so as to make, at least, a pair of electrically conductive pads, resulting in the thin film resistance element having a predetermined value of resistivity between the pair of electrically conductive pads. Thereby, it is possible to form the thin film resistance element having a thickness and a shape controlled in a high accuracy on the printed circuit board.

Production method of thin film resistance element formed on printed circuit board, and thin film resistance element employing the method

A magnetic recording and/or reproducing element comprises a main element body, and windings wound around the main element body. The main element body has a pair of extremely thin layers made from a ferromagnetic material, and the extremely thin layers oppose each other at respective edges thereof so as to constitute a gap. Each of the thin layers are sandwiched between a pair of support members which are made from a non-magnetic and abrasion proof material. A contact surface is formed on a vertex part of the main element body, for making contact with a magnetic recording medium so as to record and/or reproduce a signal on and/or from the magnetic recording medium. The main element body has one or a plurality of side surfaces which form a predetermined angle with respect to the contact surface and define the peripheral edge of the contact surface so that the contact surface has a predetermined shape with an extremely small area and has the gap at an approximate center of the predetermined shape.

Magnetic recording and/or reproducing element

An electrostatic capacitance type pickup stylus for use on an information storage disc comprises a crystal of diamond including a sliding face for slidable contact with the information storage disc, an electrode face supporting thereon a conductive electrode layer for detecting signals on the information storage disc as changes in electrostatic capacitance, a pair of first and second angularly spaced back faces adjoining the electrode face, and a pair of first and second angularly spaced guide faces adjoining each other and the first and second back faces, respectively. The sliding face is in the form of a pentagon defined by ridges respectively of the electrode face, first and second back faces, and first and second guide faces, the first and second back faces being symmetrical with respect to a line passing through a central point on the ridge of the electrode face and a junction between the ridges of the first and second guide faces, the first and second guide faces being symmetrical with respect to the line. The first and second back and guide faces are located in areas in which they can easily ground without causing damages to ridges between the adjoining faces.

Diamond pickup stylus with good grindability

A capacitance detection type record stylus comprises a conductive shank and a diamond partially embedded in the shank so that the diamond projects downwardly from one end of the shank. The shank is formed with a bottom face for making slidable contact with the disk record. The shank and diamond are formed with a pair of common rear faces inclined with respect to the axis of the stylus to define an electrode forming face therebetween which extends from the bottom face of the diamond partially into the shank. The electrode forming face is inclined at an acute angle with respect to the axis so that the lower end of the electrode forming face is located at a point forward with respect to the upper end thereof and subtends at the lower end thereof at such an angle that the diamond can be lapped without causing defects to occur on the lapped surfaces. The electrode forming face is entirely covered by a conductive layer so that the latter establishes electrical connection with the shank to allow signals detected by the electrode to pass through the shank to an external circuit.

Capacitance detection type record stylus having a conductive shank

A capacitance detection type record stylus comprises a body of artificial diamond having flat faces lying parallel to the crystal planes {111} and {100} wherein adjoining identical crystal planes are either {111} or {100}. A crystal plane {110} is formed between any two of the adjoining identical crystal planes by lapping the edge between them. A conductive material is deposited on the crystal plane {110} to form an electrode for detecting signals recorded as geometric variations on a recording medium. Because of the aligned carbon atoms beneath the crystal plane {110}, a substantial amount of the conductive material penetrates deeply into the diamond making the electrode resistant to wear.

Capacitance detection type record stylus and method for making the stylus

A cylindrical diamond body is shaped to form a truncated conical portion. A conductive layer is deposited on the diamond body extending from the truncated end to the other end of the body. The conical portion of the body with the conductive layer being attached thereto is lapped to remove portions of the layer and the diamond body to form a pair of substantially flat surfaces extending from the truncated end toward the opposite end leaving the conductive layer to form a narrow width electrode for picking just one information signal stored in the form of minute pits along a spiral track or concentric tracks.

Capacitance detection type stylus for grooveless disc records and method

A stylus for the capacitive pickup of information signals inscribed in a recording medium as a geometrical variation comprises a corundum single crystal rod having two parallel side faces, which are inherently flat and optically smooth, and a thin electrode film coated on one of these two side faces. The electrode film is normal to the c-axis of the crystal, and the longitudinal axis of the rod coincides with one of the a-axes. The rod is formed by the 'edge defined film fed growth' method, wherein corundum melt is made to spread as a film over a flat shape-defining surface and a seed crystal is pulled vertically through a capillary so that an elongated crystal is continuously grown. The c-axes of the grown and seed crystals are parallel to the shape-defining surface and normal to the growth direction. Thereby, the rod is formed without the need of machining and abrading steps, other than steps for the shaping of a tip.

Growing community of inventors

Sagamihara, Japan

Keiji Segawa