# US 2019/0313962 A1 · Hardness meter and hardness measuring method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0313962 A1 - Document ID: US20190313962A1 - Status: Published application - Kind: A1 - Application number: 16/470,964 - Filed: 2017-12-15 - Published: 2019-10-17 - Earliest claimed: 2016-12-19 - Assignees: Maxell, Ltd. - Applicants: Maxell, Ltd. - Inventors: Yuko SANO; Akihiko KANDORI; Mitsuo OKIMOTO; Shigemitsu ANDO; Mitsunobu WATANABE - Web page: https://patentgrep.com/patent/US20190313962A1 ## CPC - A61B 5/0053: {by applying pressure, e.g. compression, indentation, palpation, grasping, gauging} - A61B 5/442: {Evaluating skin mechanical properties, e.g. elasticity, hardness, texture, wrinkle assessment} - A61B 5/445: {Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore} - A61B 5/4848: {Monitoring or testing the effects of treatment, e.g. of medication} - A61B 5/743: {Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots} - G01N 3/40: Investigating hardness or rebound hardness - A61B 5/4854: {Diagnosis based on concepts of alternative medicine, e.g. homeopathy or non-orthodox} - A61B 2505/07: Home care - A61B 2562/0219: Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches - A61B 2562/0223: Magnetic field sensors - A61B 2562/0247: Pressure sensors - A61B 2562/0252: Load cells - G01N 2203/0005: Repeated or cyclic - G01N 2203/0019: Compressive - G01N 2203/0032: using mechanical means - G01N 2203/0083: Rebound strike or reflected energy - G01N 2203/0218: Calculations based on experimental data - G01N 2203/0617: Electrical or magnetic indicating, recording or sensing means - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract The objective of the present invention is to provide a hardness meter which estimates hardness in a stable manner regardless of a compression strength. Disclosed is a hardness meter characterized in being provided with: a movable portion which is continuously pressed against an object to be measured; a sensor which outputs an output signal reflecting a reaction force at a part of the object to be measured that is in contact with the movable portion; a motive force mechanism that causes the movable portion to perform a piston motion; and a hardness estimating portion which estimates the hardness of the object to be measured on the basis of an alternating current component of the output signal, generated by the piston motion of the movable portion. ## Claims ### Claim 1 A hardness meter comprising: a movable portion which is continuously pressed against an object to be measured; a sensor which outputs an output signal reflecting a reaction force at a part of the object to be measured that is in contact with the movable portion; a motive force mechanism that causes the movable portion to perform a piston motion; and a hardness estimating portion which estimates the hardness of the object to be measured on the basis of an alternating current component of the output signal, generated by the piston motion of the movable portion. ### Claim 2 (depends on 1) The hardness meter according to claim 1, wherein the hardness estimating portion estimates the hardness of the object to be measured on the basis of an amplitude of the alternating current component of the output signal. ### Claim 3 (depends on 2) The hardness meter according to claim 2, wherein the hardness estimating portion estimates the hardness of the object to be measured on the basis of the amplitude of the alternating current component when a magnitude of a direct current component of the output signal is fixed at a predetermined value. ### Claim 4 (depends on 2) The hardness meter according to claim 2, wherein the hardness estimating portion estimates the hardness of the object to be measured on the basis of a magnitude of a direct current component when the amplitude of the alternating current component of the output signal is fixed at a predetermined value. ### Claim 5 (depends on 2) The hardness meter according to claim 2 comprising an abnormal waveform detecting unit which detects an abnormal waveform under a condition that a magnitude of a direct current component of the output signal is out of a certain range, wherein the hardness estimating portion estimates the hardness of the object to be measured on the basis of the alternating current component of the output signal in a range where the abnormal waveform is undetected at the abnormal waveform detecting unit. ### Claim 6 (depends on 2) The hardness meter according to claim 2, comprising an abnormal waveform detecting unit which detects an abnormal waveform under a condition that an upper limit and a lower limit of the alternating current component of the output signal are undetectable, wherein the hardness estimating portion estimates the hardness of the object to be measured on the basis of the alternating current component of the output signal in a range where the abnormal waveform is undetected at the abnormal waveform detecting unit. ### Claim 7 (depends on 2) The hardness meter according to claim 2 comprising a voltage and pressure conversion unit which converts an output voltage of the sensor into pressure information. ### Claim 8 (depends on 1) The hardness meter according to claim 1 comprising: a position estimating portion which estimates a measurement position of the hardness meter; and a hardness map display unit which displays the hardness estimated using the measurement position in a map. ### Claim 9 (depends on 8) The hardness meter according to claim 8, wherein the hardness map display unit presents a difference between two hardness maps. ### Claim 10 A hardness measuring method comprising: a first step of vibrating a movable portion; a second step of obtaining a sense signal on the basis of a reaction force from an object to be measured when the movable portion is caused to contact the object to be measured; a third step of obtaining an alternating current component of the sense signal; and a fourth step of estimating hardness of the object to be measured on the basis of an amplitude of the alternating current component. ### Claim 11 (depends on 10) The hardness measuring method according to claim 10, wherein a vibration member which vibrates the movable portion is used, and the vibration member is coupled to the movable portion via a spring in the first step, and the sense signal is obtained on the basis of a magnetic sensor signal detected such that a first coil arranged on the movable portion and a second coil arranged on the vibration member are used and a signal transmitted from one coil is received at the other coil in the second step. ### Claim 12 (depends on 11) The hardness measuring method according to claim 11 which uses a computer device including a microprocessor, a storage unit, an input unit, and an output unit, wherein the microprocessor converts a waveform of the magnetic sensor signal obtained from the input unit into a waveform of a pressure with a voltage and pressure conversion to obtain the sense signal. ### Claim 13 (depends on 12) The hardness measuring method according to claim 12 which prepares a correspondence table between the amplitude of the alternating current component of the sense signal and the hardness as a database in the storage unit, wherein the microprocessor estimates the hardness on the basis of the correspondence table. ### Claim 14 (depends on 11) The hardness measuring method according to claim 11 which uses a computer device including a microprocessor, a storage unit, an input unit, and an output unit, wherein the microprocessor uses a waveform of the magnetic sensor signal directly as the sense signal. ### Claim 15 (depends on 14) The hardness measuring method according to claim 14 which prepares a correspondence table between an amplitude of the sense signal and the hardness as a database in the storage unit, wherein the correspondence table shows a correspondence between an amplitude of the alternating current component of the sense signal and the hardness when a direct current component of the sense signal is fixed or shows a correspondence between an amplitude of the direct current component of the sense signal and the hardness when the alternating current component of the sense signal is fixed, and the microprocessor estimates the hardness on the basis of the correspondence table.