Fujitsu Corporation

Hitachi Seiko, Ltd.

Masakazu Kishi

Masayuki Itoh

Hajime Kubota

Yoshinori Mesaki

Kazuhiro Suzuki

Yuji Miyaki

Yasuhide Kuroda

Satoru Yamada

Shigeichi Izumi

Kenichiro Tsubone

Yoshinori Nakane

Yasuo Suzuki

Masaru Itoh

A crystal unit includes: a capacitor body in which a plurality of light-transmitting dielectrics and a plurality of internal electrodes are alternately stacked; a crystal piece arranged above the capacitor body and having excitation electrodes on both surfaces thereof; an external electrode formed on a surface of the capacitor body; and a first conductor portion formed in an inner layer of the capacitor body, and including one end electrically coupled to a first internal electrode among the plurality of internal electrodes, and the other end electrically coupled to the external electrode.

Crystal unit and method of adjusting crystal unit

A crystal oscillator includes a crystal resonator; an inverting amplifier configured to be coupled between a pair of excitation electrodes of the crystal resonator; and a control circuit configured to initiate an alarm and raise gain of the inverting amplifier in a case where an index value for representing oscillation amplitude of the crystal resonator in an oscillation state is equal to or lower than a reference value.

Crystal oscillator, crystal resonator controlling method, and crystal resonator controlling device

A crystal oscillator device is disclosed. The crystal oscillator device includes: a crystal piece provided in a casing; a pair of excitation electrodes provided on the crystal piece; a light emitting element configured to emit light that is to be reflected by one of the excitation electrodes to generate reflected light; a light receiving element configured to receive the reflected light; and an alarm generator configured to generate an alarm based on a signal upon an index value being less than or equal to a reference value, the signal being generated in the light receiving element, the index value representing an oscillation level of the crystal piece in an oscillating state.

Crystal oscillator device and method of measuring crystal oscillator characteristic

A crystal oscillator device is disclosed. The crystal oscillator device includes: a casing; a crystal piece provided in the casing; a pair of excitation electrodes provided on the crystal piece; a magnetic flux generating member provided on the crystal piece; a coil through which magnetic flux from the magnetic flux generating member passes; and an alarm generator configured to generate an alarm based on a signal whose amplitude is equal to or less than a reference value, the signal being generated in the coil.

A crystal oscillator device is disclosed. The crystal oscillator device includes: a crystal oscillator including a casing, a crystal piece, a pair of excitation electrodes configured to excite a main vibration, and a pair of sub vibration electrodes configured to excite a sub-vibration; and an alarm generator configured to generate an alarm based on a signal whose amplitude is equal to or less than a reference value, the signal being generated in the sub vibration electrodes.

A crystal oscillator device is disclosed. The crystal oscillator device includes a casing; a crystal piece; a pair of excitation electrodes; a transmission antenna electrically coupled to one of the excitation electrodes; a reception antenna configured to receive a radio wave from the transmission antenna; and an alarm generator configured to generate an alarm based on a signal whose amplitude is equal to or less than a reference value, the signal being received by the reception antenna.

A method for inspecting a crystal unit, the method includes: generating a sub-vibration in a crystal blank of the crystal unit by applying an input signal to a plurality of electrodes formed on the crystal blank; obtaining frequency characteristics of impedance between the plurality of electrodes from an output signal of the plurality of electrodes; and comparing the frequency characteristics obtained with reference frequency characteristics indicating quality of the crystal unit.

Method for inspecting crystal unit by analyzing frequency characteristics of impedance

A crystal oscillator device is disclosed. The crystal oscillator device includes a crystal piece provided in a casing; a pair of excitation electrodes provided for the crystal piece; a coil provided on the crystal piece; a magnetic flux generating member configured to generate magnetic flux passing through the coil; and an alarm generator configured to generate an alarm based on a signal whose amplitude is equal to or less than a reference value, the signal being generated in the coil.

A crystal unit includes: a capacitor in which a plurality of dielectrics and a plurality of internal electrodes are alternately stacked; a crystal piece arranged above the capacitor and having excitation electrodes on both surfaces thereof; an external electrode formed on a surface of the capacitor; and a first conductor portion formed within the capacitor, and including one end electrically coupled to a first internal electrode among the plurality of internal electrodes, the other end electrically coupled to the external electrode, and a first exposed portion exposed on the surface of the capacitor between the one end and the other end.

A crystal unit includes: a crystal substrate; and a pair of excitation electrodes formed respectively on both surfaces of the crystal substrate, wherein at least one of the pair of excitation electrodes has a pattern serving as both of an excitation electrode and a coil. An oscillator includes a package and a crystal unit accommodated in the package. The crystal unit includes a crystal substrate, and a pair of excitation electrodes formed respectively on both surfaces of the crystal substrate. At least one of the pair of excitation electrodes has a pattern serving as both of an excitation electrode and a coil. An oscillation circuit is accommodated in the package and electrically connected to the crystal unit.

Crystal unit, oscillator, and method for fabricating the crystal unit

A crystal unit includes: a crystal blank; an excitation electrode formed on the crystal blank and excites a main vibration of the crystal blank; a housing that accommodates the crystal blank; and a sub-vibration electrode formed on the housing and excites a sub-vibration of the crystal blank. And a method for inspecting a crystal unit, the method includes: generating a sub-vibration in a crystal blank by applying an input signal to a sub-vibration electrode formed on a housing, which accommodates the crystal blank, via external electrodes which are electrically coupled to the sub-vibration electrode and formed on the outer surface of the housing; obtaining an output of the crystal unit via the external electrodes; obtaining frequency characteristics of impedance between the external electrodes based on the output; and comparing the obtained frequency characteristics with the reference frequency characteristics indicating the quality of the crystal unit.

Crystal unit

A crystal resonator includes: lower glass plates on which first electrodes are formed so as to extend from side surfaces to a bottom surface of the lower glass plates; a crystal plate which is provided over the lower glass plates and on which second electrodes to be coupled to the first electrodes are formed on a surface in contact with the lower glass plates; and an upper glass plate which is provided over the crystal plate; wherein the side surfaces of the lower glass plates on which the first electrodes are formed are provided with a protrusion that extends in parallel with a top surface and the bottom surface of the lower glass plates and that extends from one end to the other end of each of the side surfaces, and wherein the first electrodes are formed on the side surfaces that include surfaces of the protrusion.

Crystal resonator, and production method therefor

A method of measuring characteristics of a crystal unit, includes: driving a crystal unit having a cover transmitting light, a crystal substrate, a first excitation electrode disposed on a first surface of the crystal substrate facing the cover, and a second excitation electrode disposed on a second surface of the crystal substrate opposite to the first surface; irradiating light to the first excitation electrode through the cover in the driving state of the crystal unit; and measuring vibration characteristics of the crystal unit based on reflected light obtained from the irradiated light.

Method of measuring characteristics of crystal unit

A crystal unit includes a crystal substrate, a pair of excitation electrodes formed respectively on both surfaces of the crystal substrate, and a coil pattern formed around at least one of the pair of excitation electrodes. An oscillator includes a package and a crystal unit accommodated in the package. The crystal unit includes a crystal substrate, a pair of excitation electrodes formed respectively on both surfaces of the crystal substrate, and a coil pattern formed around at least one of the pair of excitation electrodes. An oscillation circuit is accommodated in the package and electrically connected to the crystal unit.

A temperature sensor includes a resonator; a first oscillation circuit to oscillate the resonator in a first oscillation mode; a second oscillation circuit to oscillate the resonator in a second oscillation mode different from the first oscillation mode; a switching circuit to connect the resonator to the first oscillation circuit or the second oscillation circuit; a control circuit to control the switching circuit so that the first oscillation circuit and the second oscillation circuit are alternately connected to the resonator; and a temperature information output circuit to generate information representing a frequency difference between a signal output from the first oscillation circuit kept in a status of being connected to the resonator and a signal output from the second oscillation circuit kept in the status of being connected to the resonator on the basis of these signals and to output the frequency difference information as temperature information on the resonator.

Growing community of inventors

Kawasaki, Japan

Masakazu Kishi