Murata Manufacturing Co., Ltd.

Nidec Corporation

Atsushi Inoue

Tatsuo Bizen

Shigeo Hayashi

Hidehiko Hidaka

Harushige Osawa

Tatsuya Tatara

Hiroyuki Ichizaki

Toshio Hata

Hiromichi Yamada

Kenji Suzuki

Kazuya Ichimura

You Funada

Akihiro Nakagawa

Harufumi Mandai

Hiroyuki Yamamoto

Kikuo Wakino

Yoshikazu Chigodo

Masao Uno

Takashi Hiroshima

Yo Funada

Keiji Asakawa

Fumiaki Kinoshita

Kouichi Kongo

Takayasu Komaki

Osamu Tamakoshi

Tsukasa Senba

Toshiaki Fujimura

A motor includes a bearing mechanism, a stationary unit including a stator arranged radially outwards of the bearing mechanism, and a rotary unit supported by the bearing mechanism at the upper side of the stationary unit for rotation about a center axis with respect to the stationary unit. The rotary unit includes a substantially cylindrical closed-top rotor yoke having a cover portion arranged to cover the stator. The bearing mechanism includes a substantially cylindrical closed-bottom bush formed by a press work, a sleeve fixed inside the bush and provided with an upper portion protruding beyond the bush and a shaft inserted into the sleeve. An upper end of the bush is lower than or flush with an upper end of the stator in a direction parallel to the center axis.

Motor and storage disk drive apparatus

A motor includes a stationary unit, a bearing mechanism, a rotary unit, and a chucking device. The rotary unit includes a rotor yoke provided with a cover portion extending around the chucking device and designed to allow the storage disk to be directly or indirectly mounted thereto and a removal-preventing member fixed to the cover portion to prevent removal of the rotary unit from the stationary unit. The removal-preventing member made of metal. The removal-preventing member includes a removal-preventing portion, an upper fixing portion having a plurality of upper protrusions inserted into the through-holes of the cover portion and bent toward the upper surface of the cover portion, and a lower fixing portion making direct or indirect contact with the lower surface of the cover portion and cooperating with the upper fixing portion to fix the position of the removal-preventing portion in a direction parallel to the center axis.

Motor, storage disk drive apparatus and motor manufacturing method

A PLL circuit includes a PLLic formed into an integrated circuit; a loop filter for receiving an output signal from the PLLic; a voltage-controlled oscillator having an oscillation frequency which is controlled according to an output signal of the loop filter for applying a controlled oscillation output signal to the PLLic, the voltage-controlled oscillator including a resonator and a negative resistor circuit; wherein a buffer amplifier functioning as a part of the voltage-controlled oscillator is incorporated into the PLLic, and the resonator and the negative resistor circuit of the voltage-controlled oscillator are disposed outside of the PLLic.

PLL circuit

The size precision of a surface mountable electronic part is improved and a production thereof is simplified. The surface mountable electronic part is constructed such that a circuit substrate is housed in a shield case of which an end side is open, and the shield case is a resin case having a shield film. A connection pattern is formed on the inner surface of the case, with one end of the connection pattern being disposed so as to correspond to an external connection land of the circuit substrate, and with the other end of the connection pattern extending to the open end of the case.

Surface mountable electronic part

In a voltage controlled oscillator, a dielectric resonator is mounted on a circuit board and a metal case is mounted on the circuit board to shield the dielectric resonator. The dielectric resonator comprises a C-shaped first electrode which is provided in a dielectric body, second and third electrodes which are arranged on upper and lower sides of the first electrode, a signal connecting pattern which is extended from the first electrode toward a side surface of the dielectric body, and earth connecting patterns which are extended from the first, second and third electrodes toward the side surface of the dielectric body, to provide predetermined impedance between the earth connecting pattern and the signal connecting pattern. The dielectric resonator is arranged with the second and third electrodes in parallel with a major surface of the circuit board, and the second electrode is upwardly exposed. A portion of the second electrode portion at a predetermined position is adapted to be trimmed so as to regulate the resonance frequency of the dielectric resonator, so as to regulate the oscillator frequency of the voltage controlled oscillator. The dielectric resonator can be miniaturized with no reduction of its Q-value.

Voltage controlled oscillator including a dielectric resonator provided

A selected inductance can be provided by a three-layer structural spiral inductor having an inductor conductive part disposed between two ground electrodes within an electric insulating substrate. This is carried out by eliminating a particular portion of one of those ground electrodes formed on the outer surface of the substrate until a desired inductance is obtained, beginning at a portion of such electrode corresponding to an exposed part of a through hole joint which is electrically connected to an inner peripheral end of a spiral inductor conductive part.

Method of forming a three-layer structural spiral inductor

A voltage controlled oscillator having a resonator wherein a substrate is made up of a plurality of dielectric layers; an inductor functioning conductive film and grounding electrode films are each formed at a boundary surface of one of the dielectric layers; the earth electrode films are arranged, in the direction in which the dielectric layers are laminated, at both sides of the conductor functioning conductive film; the inductor functioning conductive film and the grounding electrode films constitute the resonator; and electric lands are formed on the surface of the substrate so that other components of the oscillator are mounted on the surface of the substrate.

Voltage controlled oscillator having a resonator

A high-frequency coaxial resonator including a tubular dielectric member having a through hole and provided with inner and outer peripheral surfaces and a pair of end surfaces which axially oppose each other. An inner conductor is formed on the inner peripheral surface and an outer conductor is formed on the outer peripheral surface, the outer conductor extending onto one or both end surfaces of the tubular dielectric member so as to approach the inner conductor through a prescribed clearance, thereby forming a capacitance between the inner and outer conductors for adjusting the resonant frequency of the resonator.

High frequency coaxial resonator

Structure for use in forming a resonant circuit eliminates a support block for the installation of a dielectric resonator, by providing a satisfactory way to directly install the dielectric resonator on a microwave circuit board having a microstrip line. The dielectric resonator is directly fixed on the microwave circuit board in such a manner that mutually opposing planar surfaces thereof do not face one planar surface of the microwave circuit board, and an axial line passing normally through these planar surfaces intersects a normal plane projected from the microstrip line. As a result, production costs can be reduced and simplified work processes can be used to fabricate the structure. Further, an electrode film may be formed on a flat part of the outer periphery of the dielectric resonator, and such a dielectric resonator is fixed on the microwave circuit board with the flat part on which said electrode film is formed, facing upwards. As a result, a metallic case which is to cover the microwave circuit board can be brought close to the dielectric resonator, thereby achieving a compact overall structure.

Fixing structure of dielectric resonator

A high-frequency oscillator having a high-frequency oscillation circuit formed through use of a microstripline. The high-frequency oscillation circuit has a resonator and a transistor connected to a reference potential and coupled with the resonator through a first capacitor. A first electrode of the transistor is connected with the resonator through the first capacitor. A second electrode of the transistor is connected to the reference potential and a third electrode thereof is adapted to derive an output. A substrate is provided with a land portion to be connected with the first electrode of the transistor, and a capacitor electrode is formed on the opposite surface of the substrate to be opposite to the first electrode connection land portion through the substrate. The capacitor electrode, the first electrode connection land portion and the substrate form a second capacitor, which is connected to the reference potential between the first capacitor and the first electrode of the transistor.

Frequency stabilized high frequency oscillator

An acoustic surface wave device comprises transducers including interdigital electrodes formed on the surface of a piezoelectric material substrate of ceramic such as PZT, or a single crystal of such as LiNbO.sub.3 or a piezoelectric thin film of such as ZnO, wherein an electrical signal is converted into an acoustic surface wave and vice versa. The interdigital electrodes have been changed of the overlapping lengths of the adjacent electrode fingers that are overlapped with each other in accordance with a weighting function determined by a desired pass characteristic. A portion of the transducer region where an undesired acoustic surface wave is propagated, i.e. the portion outside of the envelope of the interdigital electrodes determined by the weighting function, is provided with an acoustic surface wave absorbing material such as silicon rubber. In a certain example, dummy electrodes may be provided between the electrode fingers of the interdigital electrodes.

Acoustic surface wave device

An acoustic surface wave device comprises a transducer including an interdigital electrode formed on the surface of a piezoelectric material substrate and cooperative with the same for converting an electrical signal into an acoustic surface wave and vice versa. The interdigital electrode comprises at least two divided comb shaped electrodes divided in the propagating direction of the acoustic surface wave and a common comb shaped electrode commonly coupled in an interdigital manner to the two divided comb shaped electrodes. Thus, the above described two comb shaped electrodes are disposed such that both divided electrodes arranged in succession in the propagating direction of the acoustic surface wave while the fingers of both divided electrodes extend in the same direction and the common comb shaped electrode is disposed such that the fingers of the common comb shaped electrode are interdigitated with the fingers of both divided comb shaped electrodes. The electrode finger of each of both comb shaped electrodes at the end adjacent to the opposite divided comb shaped electrode comes close to each other at a dividing region without interposition of any finger of the common comb shaped electrode. Both divided comb shaped electrodes are connected to different potentials, respectively. The length of the electrode finger of each of the divided comb shaped electrodes adjacent to each other at the dividing region is selected to be shorter than the overlapping lengths of the adjacent electrode fingers that are overlapped with each other, whereby discontinuity of the surface wave energy in the dividing region is eliminated or mitigated.

Growing community of inventors

Kyoto, Japan

Atsushi Inoue