| 摘要 |
PURPOSE:To make possible the measurement of the number of vibration of a vibrator with ease, by providing a device of detecting the number of vibration of an object and converting the same to electric signals and a device of displaying the number of vibration, and adding a function of measuring and displaying the number of vibration to an ordinary electronic watch. CONSTITUTION:Light from a light source 101 is reflected by a vibrating object 102 and enters a photo detector 103. From the detector 103, current 105 flows in a resistance 104. The frequency of photo current waveform 105 is equal to the number of vibration of the vibrator. The waveform 105 is converted to voltage waveform by a resistance 104. The voltage waveform then enters a counter 106 then through a decoder 107, and the number of vibration is displayed in a display body 108. Namely, the decoder 107 and display body are able to make common use of the electronic circuits of the digital watch and at the time of measuring the number of vibrations, the circuits are changed over from watch display to the measurement of the number of vibration by a switch. The electronic watch may be carried with ease and its use in tuning of musical instruments as a device of permiting easy measurement of the number of vibration may be widened of range. |
