Nissan Motor Company Limited

Harumi Okazaki

Yoshio Watanuki

Motoki Hirano

Hidetaka Suzuki

The portion where the antenna wire is wound to the circular groove on the outer periphery of the bobbin of the core of the antenna coil is covered with an amplifier case base material and is molded integrally with the one side portion of the amplifier case attached to the key cylinder in such a state that the one side end portion of the core is exposed, and the exposed end portion of the core is fixed so as to make its end face roughly matched with the end face of the key cylinder.

Key cylinder device for an automobile

A plane antenna comprising first and second plates made of a synthetic resin. The first plate has a first metal film formed thereon and the second plate has a second metal film formed thereon. A plurality of pins extend between the first and second plates for maintaining the first and second plates in spaced-parallel relation to each other with the first and second films facing to each other. The pins include at least one first pin for providing an electric connection between the first and second metal films and a second pin insulated from the second metal film for providing an electric connection of the first metal film to a lead wire. The first and second metal films have a spacific resistance .rho. [m] and a permeability .mu. [H/m]. The first and second metal films have a thickness greater than a value t [m] calculated from an equation as follows: ##EQU1## where f is a signal frequency [Hz] for which the plane antenna is used.

Growing community of inventors

Fujisawa, Japan

Harumi Okazaki