公开(公告)号：US20200072865A1

公开(公告)日：2020-03-05

申请号：US16551206

申请日：2019-08-26

Applicant: HITACHI, LTD.

Inventor： Takashi OSHIMA ,  Yuki FURUBAYASHI

IPC: G01P15/125

Abstract: In a MEMS electrostatic capacitor type acceleration sensor, the manufacturing costs of MEMS elements are reduced, and at the same time, the variations of the electrical and mechanical characteristics of the MEMS elements are reduced. A detection circuit generates a voltage signal corresponding to the product of a difference between the two capacitance values of a pair of MEMS capacitors and a servo signal. A modulation circuit outputs a signal corresponding to the difference between the capacitance values using the servo signal. The control circuit outputs the servo signal on the basis of a signal corresponding to the difference between the capacitance values.

公开(公告)号：US20180259364A1

公开(公告)日：2018-09-13

申请号：US15760723

申请日：2016-08-31

Applicant: Hitachi, Ltd.

Inventor： Yuki FURUBAYASHI ,  Takashi OSHIMA ,  Makoto TAKAHASHI

IPC: G01D5/241 ,  G01P15/125 ,  G01P15/08 ,  H03K17/955

CPC classification number: G01D5/241 ,  G01D5/24 ,  G01D5/2417 ,  G01P15/0802 ,  G01P15/125 ,  H03K17/955

Abstract: The present invention is directed to a CV conversion amplifier which is small in current consumption and capable of securing a sufficient capacitance-voltage conversion gain and a sufficient amplitude range of an output voltage and a capacitive sensor using the same which is low power consumption, low in noise, and wide in an input signal allowable range. A capacitive sensor includes first and second detection capacitors, a CV conversion circuit includes first and second feedback capacitors and obtains a voltage based on capacitance values of the first and second feedback capacitors, an AD converter performs analog digital conversion on an input voltage and obtains a digital signal, a digital control unit receives the digital signal as an input, and first and second digitally controlled variable capacitors have capacitance values that are controlled by the digital control unit.

公开(公告)号：US20180210005A1

公开(公告)日：2018-07-26

申请号：US15742550

申请日：2015-07-10

Applicant: Hitachi, Ltd.

Inventor： Atsushi ISOBE ,  Yuki FURUBAYASHI ,  Takashi OSHIMA ,  Yuudai KAMADA ,  Takashi SHIOTA ,  Chisaki TAKUBO ,  Noriyuki SAKUMA

IPC: G01P15/125 ,  G01P15/13 ,  G01P15/08 ,  G01P15/18

CPC classification number: G01P15/125 ,  B81B2201/0235 ,  G01P15/0802 ,  G01P15/131 ,  G01P15/18

Abstract: There is provided an inertia sensor with low noise and high sensitivity. The inertia sensor captures a physical quantity as a change of electrostatic capacitance and detects the physical quantity based on a servo voltage generating electrostatic force that cancels the change of the electrostatic capacitance. The inertia sensor includes a detection capacitor unit that captures the physical quantity as the change of the electrostatic capacitance and a servo capacitor unit to which the servo voltage is applied. Here, the detection capacitor unit and the servo capacitor unit are connected mechanically through an insulation material.

公开(公告)号：US20200088759A1

公开(公告)日：2020-03-19

申请号：US16458903

申请日：2019-07-01

Applicant: HITACHI, LTD.

Inventor： Takashi OSHIMA ,  Yuki FURUBAYASHI ,  Keijiro MORI ,  Naoki MORI ,  Akira MATSUMOTO

IPC: G01P15/125

Abstract: Provided is a sensor that is highly accurate while ensuring reduced power consumption. A sensor is an electronic circuit that includes a sensor element, an analog filter, an A/D converter, and first and second electronic circuit. The analog filter filters a waveform that includes a sensor signal from the sensor element and noise based on a servo signal. The A/D converter converts the waveform filtered by the analog filter into a first digital signal. The first electronic circuit includes a digital filter and acquires a second digital signal by performing signal processing including at least a filtering process on the servo signal by using the digital filter. The second electronic circuit acquires a third digital signal by subtracting the second digital signal from the first digital signal. A setting for the signal processing for acquiring the second digital signal is changed on the basis of the third digital signal.

公开(公告)号：US20160091525A1

公开(公告)日：2016-03-31

申请号：US14856537

申请日：2015-09-16

Applicant: HITACHI, LTD.

Inventor： Takashi OSHIMA ,  Atsushi ISOBE ,  Yuudai KAMADA ,  Noriyuki SAKUMA ,  Yuki FURUBAYASHI

IPC: G01P15/125

CPC classification number: G01P15/125

Abstract: An acceleration sensor that achieves a simultaneous operation method of a signal detection and a servo control is provided as an alternative to a time-division processing method. The acceleration sensor is a MEMS capacitive acceleration sensor. The acceleration sensor includes signal detection capacitor pairs 12, 15, and DC servo control capacitor pairs 13, 16, and AC servo control capacitor pairs 14, 17, which are different from the signal detection capacitor pairs 12, 15. A voltage that generates a force in a direction opposite to a detection signal of acceleration detected by the signal detection capacitor pairs 12, 15 is applied to the DC servo control capacitor pairs 13, 16 and the AC servo control capacitor pairs 14, 17.

Abstract translation: 提供了实现信号检测和伺服控制的同时操作方法的加速度传感器作为时分处理方法的替代。 加速度传感器是MEMS电容式加速度传感器。 加速度传感器包括不同于信号检测电容器对12,15的信号检测电容器对12,15和DC伺服控制电容器对13,16以及AC伺服控制电容器对14,17。 与由信号检测用电容器对12,15检测出的加速度检测信号相反的方向的力被施加到DC伺服控制电容器对13,16和AC伺服控制电容器对14,17。

公开(公告)号：US20190212358A1

公开(公告)日：2019-07-11

申请号：US16142255

申请日：2018-09-26

Applicant: Hitachi, Ltd.

Inventor： Takashi OSHIMA ,  Masaru KOKUBO ,  Yuki FURUBAYASHI

IPC: G01P15/125 ,  G01P15/08

Abstract: A servo control signal is binarized using a digital delta-sigma modulator. The digital delta-sigma modulator forms a feedback loop including a digital adder/subtractor, a digital integrator, and a one-bit quantizer to perform pulse-density modulation of the input servo control signal and output the signal as a binary value of +1 or −1.

公开(公告)号：US20180052011A1

公开(公告)日：2018-02-22

申请号：US15628706

申请日：2017-06-21

Applicant: Hitachi, Ltd.

Inventor： Takashi OSHIMA ,  Makoto TAKAHASHI ,  Yuki FURUBAYASHI

IPC: G01D5/24 ,  H03K17/975

CPC classification number: G01D5/24 ,  G01D3/02 ,  H03K17/975

Abstract: A CV conversion amplifier is provided that can secure a sufficient capacitance-to-voltage conversion gain and a sufficient amplitude range of an output voltage with a small consumption current. A capacitive sensor using the CV conversion amplifier is provided with low electric power, low noise, and a wide tolerance of input signals. The CV conversion amplifier accepts outputs, as inputs, from a first capacitance and a second capacitance whose capacitance is changed depending on a physical quantity and converts a capacitance value into a voltage.

公开(公告)号：US20160091524A1

公开(公告)日：2016-03-31

申请号：US14822419

申请日：2015-08-10

Applicant: HITACHI, LTD.

Inventor： Yuudai KAMADA ,  Atsushi ISOBE ,  Noriyuki SAKUMA ,  Takashi OSHIMA ,  Yuki FURUBAYASHI

IPC: G01P15/125

CPC classification number: G01P15/125 ,  B81B3/0086 ,  B81B2201/0235 ,  B81B2203/0109 ,  G01P2015/0831 ,  G01P2015/0837

Abstract: A low-noise and high-sensitivity inertial sensor is provided.On the assumption that a movable portion VU1 and a movable portion VU2 are formed in the same SOI layer, the movable portion VU1 and the movable portion VU2 are mechanically connected to each other by a mechanical coupling portion MCU even while these movable portions are electrically isolated from each other. Thereby, according to a sensor element SE in the invention, it is possible to further suppress a shift between the capacitance of a MEMS capacitor 1 and the capacitance of a MEMS capacitor 2.

Abstract translation: 提供了低噪声，高灵敏度的惯性传感器。 假设可动部分VU1和可动部分VU2形成在相同的SOI层中，即使这些可动部分被电隔离，可移动部分VU1和可动部分VU2通过机械耦合部分MCU彼此机械连接 从彼此。 因此，根据本发明的传感器元件SE，可以进一步抑制MEMS电容器1的电容与MEMS电容器2的电容之间的偏移。

公开(公告)号：US20190268013A1

公开(公告)日：2019-08-29

申请号：US16255527

申请日：2019-01-23

Applicant: HITACHI, LTD.

Inventor： Yuki FURUBAYASHI ,  Takashi OSHIMA

IPC: H03M1/12 ,  H03F3/45 ,  G05F3/02 ,  H03M1/68

Abstract: A successive approximation type AD converter includes an in-phase voltage detection and supply circuit that supplies an in-phase voltage obtained by impedance voltage division of a first input analog signal and a second input analog signal to a first capacitance DA converter and a second capacitance DA converter. The first capacitance DA converter samples the first input analog signal with reference to the in-phase voltage, and the second capacitance DA converter samples the second input analog signal with reference to the in-phase voltage. After the sampling period ends, a comparator compares the output of the first capacitance DA converter and the output of the second capacitance DA converter, output voltages of the first capacitance DA converter and the second capacitance DA converter are changed by the control signal of a successive approximation logic unit on the basis of a comparison result, and comparison processing is repeated.

公开(公告)号：US20180011125A1

公开(公告)日：2018-01-11

申请号：US15547210

申请日：2015-02-17

Applicant: HITACHI, LTD.

Inventor： Takashi OSHIMA ,  Yuki FURUBAYASHI

IPC: G01P15/125 ,  G01P1/00 ,  G01P15/13 ,  G01P15/08 ,  G01R33/028 ,  G01R15/20

Abstract: Provided is an acceleration sensor capable of realizing a simultaneous operation method of signal detection and servo control in place of a time-division processing method, by an MEMS process in which a manufacturing variation is large.The acceleration sensor is an MEMS capacitive acceleration sensor and has capacitive elements for signal detection and capacitive elements for servo control different from the capacitive elements for the signal detection. A voltage to generate force in a direction reverse to a detection signal of acceleration by the capacitive elements for the signal detection is applied to the capacitive elements for the servo control. Further, the acceleration sensor includes a variable capacity unit compensating for a mismatch of capacity values of the capacitive elements for the servo control at an ASIC side, detects a leak signal due to the mismatch of the capacity values in an ASIC, controls a capacity value of the variable capacity unit, on the basis of a detection result, compensates for an influence of the mismatch of the capacity values, and executes a normal signal detection/servo control simultaneous operation.