Victor Company of Japan, Limited

Keiichiro Doi

Yoshihiro Hori

Hideaki Mizuno

Keiji Segawa

Masaki Murakami

Manabu Endo

Toshiki Yoshida

In a field effect transistor (JFET) having a compound semiconducting substrate, a buffer layer having a guard-ring, an active layer, source regions, drain regions, and gate regions, the guard-ring is separated from the active layer whereby gate junction capacitance and gate leakage current are lowered without raising a gate resistance value. As a result, noise characteristics and high frequency characteristics can be improved.

Field effect transistor with active layer apart from guard-ring

A stylus for a capacity change detection type disc system which reads information signals such as audio or video signals out of a track which is formed in a disc surface as an arrangement of pits corresponding to the information signals has a body portion which is made of a diamond. Argon plus ions are implanted in the stylus body portion from the surface of the diamond portion to graphitize the diamond to provide a conductive layer which serves as a detecting electrode portion. The graphitizing rate is highest at the surface portion of the electrode portion which consists of the formed conductive layer. The graphitizing rate changes from the surface portion toward a portion remote from the surface portion, where the graphitizing rate is lowest, with a variation rate smaller than that of the graphitizing rate which would result from a single implantation of ions into the diamond.

Stylus for capacity change detection type disc system

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.

Growing community of inventors

Yokohama, Japan

Keiichiro Doi