| 摘要 |
PROBLEM TO BE SOLVED: To prevent any malfunction and detection failure or the like from occurring as well as to make stable detecting operation achievable by constituting a human detecting electrode of a touch plate with plural pieces of conductive materials, and largely varying an output differential in times of contact and noncontact, respectively. SOLUTION: A touch plate 7a is formed with two electrodes 3a and 3b by means of plural pieces of conductive materials so as to make this touch plate 7a at a time when a human body comes into contact with a push-button unit and a variable portion of capacitance between two grounds both grow larger. With this, when the human body has come into contact with the touch plate 7a, capacitance inherent in the human body, being about one figure smaller, is connected to the constant capacitance lying between both these electrodes 3a and 3b in series, therefore the whole capacitance to be inputted into this push-button unit becomes lessened. Consequently, the extent of frequency in a frequency signal made up in an oscillator circuit goes higher, and further a voltage signal being transformed in a frequency-voltage transducer circuit is also growing larger. Therefore, an output differential in times of contact and noncontact is largely variable, and thus any malfunction and detection failure or the like are preventable from occurring. |
