# US 11,079,403 B2 · Physical quantity sensor module, clinometer, and structure monitoring device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,403 B2 - Document ID: US11079403B2 - Status: Granted - Kind: B2 - Application number: 16/389,098 - Filed: 2019-04-19 - Published: 2019-10-24 - Granted: 2021-08-03 - Earliest claimed: 2018-04-20 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Kenta Sato; Masayoshi Todorokihara - Web page: https://patentgrep.com/patent/US11079403B2 ## CPC - G01P 15/097: by vibratory elements - G01C 9/02: Details - G01P 15/0802: {Details} - H03M 3/30: {Delta-sigma modulation} - H03M 3/378: {Testing} - G01C 9/06: Electric or photoelectric indication or reading means - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) - H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C) ## Abstract A physical quantity sensor module includes: a resonant frequency shift based physical quantity sensor whose frequency adjusts with a adjust in physical quantity; a reference signal oscillator which outputs a reference signal; a frequency delta-sigma modulator which performs frequency delta-sigma modulation of the reference signal, using an operation signal based on a measurement target signal as an output from the resonant frequency shift based physical quantity sensor, and generates a frequency delta-sigma modulated signal; a first low-pass filter provided on an output side of the frequency delta-sigma modulator and operating synchronously with the measurement target signal as the output from the resonant frequency shift based physical quantity sensor; and a second low-pass filter provided on an output side of the first low-pass filter and operating synchronously with the reference signal. ## Claims ### Claim 1 A physical quantity sensor module comprising: a resonant frequency shift based physical quantity sensor whose frequency adjusts with a change in physical quantity; a reference signal oscillator which outputs a reference signal; a frequency delta-sigma modulator which performs frequency delta-sigma modulation of the reference signal, using an operation signal based on a measurement target signal outputted from the resonant frequency shift based physical quantity sensor, and generates a frequency delta-sigma modulated signal; a first filter provided at an output of the frequency delta-sigma modulator and operating synchronously with the measurement target signal; a second filter provided on an output side of the first filter and operating synchronously with the reference signal; and a latch provided between the first filter and the second filter and operating synchronously with the reference signal, wherein the resonant frequency shift based physical quantity sensor has nonlinearity as a characteristic of an output signal in response to the change in the physical quantity. ### Claim 2 (depends on 1) The physical quantity sensor module according to claim 1, wherein a cutoff frequency which is a filter characteristic achieved by a combination of the first filter and the second filter is lower than a structure resonance frequency of the resonant frequency shift based physical quantity sensor. ### Claim 3 (depends on 2) The physical quantity sensor module according to claim 2, wherein the structure resonance frequency is a frequency determined based on a structure of the resonant frequency shift based physical quantity sensor. ### Claim 4 (depends on 1) The physical quantity sensor module according to claim 1, wherein the first filter is set to have a characteristic such that the input/output characteristic is close to linear in the nonlinearity of the signal under measurement which is the output of the resonant frequency shift based physical quantity sensor. ### Claim 5 (depends on 4) The physical quantity sensor module according to claim 4, wherein the first filter is a smoothing filter configured to adjust a smoothing timing based on a number of filter taps, and the number of filter taps is set to a smoothing timing that reduces a vibration rectification error of the measurement target signal as the output from the resonant frequency shift based physical quantity sensor emerging due to the nonlinearity. ### Claim 6 (depends on 5) The physical quantity sensor module according to claim 5, wherein a setting of the number of filter taps is adjustable from outside. ### Claim 7 (depends on 5) The physical quantity sensor module according to claim 5, wherein the first filter is configured to adjust the smoothing timing based on a plurality of numbers of filter taps with different levels of roughness/fineness based upon an amount of change in the smoothing timing. ### Claim 8 (depends on 1) The physical quantity sensor module according to claim 1, wherein the physical quantity is acceleration. ### Claim 9 (depends on 8) A clinometer comprising: the physical quantity sensor module according to claim 8; and a calculator which calculates an angle of inclination based on an output signal from the physical quantity sensor module. ### Claim 10 (depends on 8) A structure monitoring device comprising: the physical quantity sensor module according to claim 8 equipped on a structure; a transmitter which is equipped on the structure and transmits an output from the physical quantity sensor module; a receiver which receives a signal transmitted from the transmitter; and a calculator which calculates an angle of inclination of the structure, based on a signal received by the receiver.