SENSOR DEVICE, SENSOR MODULE, AND PRESSURE DETECTION METHOD

To solve the problem of a conventional pressure detection circuit using a FET, that a sensor device including the pressure detection circuit cannot be downsized due to significant effects of parasitic capacitance.SOLUTION: A sensor device 60 comprises: a bipolar transistor 66 to which is inputted a...

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Bibliographic Details
Main Authors AKAMA HIROSHI, KANEHIRA HIRONORI, KAWAMATA KAZUTO, SATO KATSUNORI
Format Patent
LanguageEnglish
Japanese
Published 06.02.2020
Subjects
BASIC ELECTRIC ELEMENTS
BASIC ELECTRONIC CIRCUITRY
CALCULATING
COMPUTING
COUNTING
ELECTRIC DIGITAL DATA PROCESSING
ELECTRIC SWITCHES
ELECTRICITY
EMERGENCY PROTECTIVE DEVICES
MEASURING
MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER,MECHANICAL EFFICIENCY, OR FLUID PRESSURE
PHYSICS
PULSE TECHNIQUE
RELAYS
SELECTORS
TESTING
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Summary:To solve the problem of a conventional pressure detection circuit using a FET, that a sensor device including the pressure detection circuit cannot be downsized due to significant effects of parasitic capacitance.SOLUTION: A sensor device 60 comprises: a bipolar transistor 66 to which is inputted a current charged into a pressure sensor 30; a bias resistor for outputting a current from a power supply 63 between the pressure sensor 30 and the bipolar transistor 66; a bipolar transistor 67 for constituting a current mirror circuit with the bipolar transistor 66; a discharge diode 65 for prompting a discharge from the pressure sensor 30; a reference capacitor Cx charged with a current flowing in the bipolar transistor 67; and a computation circuit 64 for detecting that the pressure sensor 30 is pressed, on the basis of a change of a period due to the fact that the reference capacitor Cx is charged until the potential of a detection-side terminal that is the connecting point of the bipolar transistor 67 and the reference capacitor Cx reaches a prescribed threshold.SELECTED DRAWING: Figure 4 【課題】ＦＥＴを用いた従来の感圧検出回路は、寄生容量の影響が大きいため、感圧検出回路を含むセンサ装置を小型化することができなかった。【解決手段】センサ装置６０は、感圧センサ３０に充電される電流が入力されるバイポーラトランジスタ６６と、感圧センサ３０とバイポーラトランジスタ６６との間に電源６３からの電流を出力するバイアス抵抗と、バイポーラトランジスタ６６とカレントミラー回路を構成するバイポーラトランジスタ６７と、感圧センサ３０からの放電を促す放電ダイオード６５と、バイポーラトランジスタ６７を流れる電流により充電される参照用コンデンサＣxと、参照用コンデンサＣxが充電されることにより、バイポーラトランジスタ６７と参照用コンデンサＣxの接続点である検出側端子の電位が所定の閾値に達するまでの期間の変化に基づいて、感圧センサ３０が押圧されたことを検出する演算回路６４と、を備える。【選択図】図４
Bibliography:Application Number: JP20180143313