초록 ▼

An electronic watch control device for manual actuation is disclosed. It comprises a capacitive sensor including a conductive layer on the inner surface of the watch-glass, which is actuated by placing a finger-tip on the outer side of the watch-glass. The sensor is part of a capacitive voltage divi

An electronic watch control device for manual actuation is disclosed. It comprises a capacitive sensor including a conductive layer on the inner surface of the watch-glass, which is actuated by placing a finger-tip on the outer side of the watch-glass. The sensor is part of a capacitive voltage divider to which a high frequency voltage is applied. Synchroneous detection means are arranged for detecting the high-frequency voltage drop across the sensor in synchronism with the high-frequency. Comparison means are provided for comparing the value of the said voltage drop to a reference voltage and producing a control signal depending on the condition of the sensor.

대표청구항 ▼

An electronic watch control device for manual actuation comprising a capacitive sensor which includes a conductive layer applied on at least a part of the inner surface of the watch-glass and the capacitance of which with respect to ground as represented by the watch-case varies when the user puts a

An electronic watch control device for manual actuation comprising a capacitive sensor which includes a conductive layer applied on at least a part of the inner surface of the watch-glass and the capacitance of which with respect to ground as represented by the watch-case varies when the user puts a finger on the watch-glass, the said sensor being part of a capacitive voltage divider, the control device further comprising means for applying to the said capacitive voltage divider an a.c. voltage of a substantially higher frequency than the mains frequency, synchroneous detection means for detecting the high-frequency voltage across the said capacitive sensor, wherein the synchroneous detection means include a switching device connected to the terminals of the capacitive sensor and controlled by the said high frequency so as to alternately shot-circuit the sensor and apply the voltage appearing at the terminals of the sensor to a low-pass filter, and comparison means for comparing the value of the said high frequency voltage to a reference voltage, said comparison means being adapted for producing a control signal depending on whether or not the sensor is actuated by placing a finger-tip on the watch-glass.