Nidec Pigeon Corporation

Kabushiki Kaisha Sankyo Seiki Seisakusho

Akinori Ushikoshi

Kenji Yokoyama

Hideo Kitazawa

Takamasa Kaneko

Fumito Komatsu

Noboru Ueno

Yuki Nakamura

Shinsuke Takahashi

A speaker may include a center pole and a voice coil bobbin having a bobbin that may include nonmagnetic and electric conductor layers and insulator layers disposed between the electric conductor layers. An electrostatic capacity, which is formed between the center pole and the voice coil bobbin, is detected and outputted as an electrical signal.

Speaker

A speaker may include a voice coil bobbin and a center pole. The voice coil bobbin may include a nonmetallic pipe body as a base of the voice coil bobbin, a first nonmagnetic and electric conductor film which is formed on an inner peripheral face of the pipe body, and a second electric conductor film which is formed on an outer peripheral face of the pipe body such that the first electric conductor film is covered by the second electric conductor film through the pipe body. An electrostatic capacity that is formed between the voice coil bobbin and the center pole is detected and outputted as an electric signal.

A speaker may include a center pole, a voice coil bobbin having a nonmetallic pipe body, and a first and a second electrodes which are provided on an inner peripheral face of the pipe body for detecting an electrostatic capacity. The first and the second electrodes are disposed so as to be separated from each other with a predetermined space along an axial direction of the center pole. Further, a stepped portion may be formed in the side circumferential face of the center pole such that, when the voice coil bobbin is operated, a first facing area of the first electrode to the side circumferential face defined by the stepped portion of the center pole increases while a second facing area of the second electrode to the side circumferential face defined by the stepped portion of the center pole decreases by a same amount as an increased amount of the first facing area.

Odd- and even-numbered conductors of recording electrodes, for example, first or second recording electrodes, are divided in the direction in which the conductor at the time of winding are stacked up to form different layers so as to increase the distance between the conductors of the adjoining recording electrodes and reduce the floating electrostatic capacitance.

Growing community of inventors

Nagano, Japan

Akinori Ushikoshi