This disclosure depicts an electronic timepiece having complementary electro-optical and electro-mechanical displays. The electro-mechanical time display displays continuously the hours and minutes of the day, the most used time functions. The electro-optical display is normally off and is activated by user or circuit command to display at least one additional time-related function having a lower normal use factor than hours or minutes.
A digital watch with oscillator/divider power selection circuitry. The selection circuitry selects the source of the voltage to be supplied to the crystal oscillator and initial divider circuits. If battery voltage is low because battery current is high, as when the light emitting diodes (LED's) are illuminated in an LED digital watch or when the illumination light is on in a liquid crystal display (LCD) digital watch, the crystal oscillator and initial divider would be powered by two batteries; and when battery voltage is high because battery current is low, the crystal oscillator would be powered by only one battery. Therefore, the power selection circuitry determines whether one or two batteries are used to power the oscillator depending upon the particular operating conditions. There are two advantages of this technique: (1) current is reduced so battery life is increased, and (2) the voltage never goes so low that circuit production yields are adversely affected. The power selection circuitry includes a plurality of metal oxide semiconductor field effect transistors (MOSFET's) and an input signal, which determines whether one battery is needed to power the oscillator because the LED's are not illuminated or two batteries are needed to power the oscillator because the LED's are illuminated.
An electronic timepiece having both time indicating hands and an electro-optical time display, wherein individual digits of the electro-optical display can be selected for correction and wherein correction of a digit causes the time indicating hands to advance by a precisely corresponding amount.
An electronic timepiece is disclosed which has at least one display function in addition to an ordinary time display function and comprises a sole electro-mechanical transducer for dividing a kept time and driving a first display function and a second display function separately.
An analogue electronic timepiece is described having an oscillator, a frequency divider, a hand display means, an hour and minute circuit for counting the output of the frequency divider, and an alarm setting circuit. An equality checking circuit adapted to compare the output of the hour and minute circuit with the output of the alarm setting circuit to produce a coincidence signal. An alarm device is operated by the coincidence signal, gate means, and a manual switch. The gate means is so arranged to produce a signal for setting an alarm time in the alarm setting circuit in accordance with the closing of the switch.
A simultaneous analog digital timepiece display comprises two superposed passive electro-optical cells one of which provides analog information and the other digital information. The timepiece is arranged and adapted such that the two types of information displayed are never directly superimposed. Such result is obtained through the provision of three zones for the digital display cell wherein one only of said zones is activated at any one time, such activated zone being chosen so as not to coincide with the position of the analog display hands.