A calendar timepiece which does not require any manual date correction at the end of even months is disclosed. The timepiece comprises an even months date correction claw mounted on a date rotational wheel and displaced into a correction position when a claw driving coil is energized by a signal delivered from means for discriminating odd months from even months.
A calendar electronic timepiece comprises a signal generating circuit for generating a date signal, a driving circuit for outputting a driving signal in accordance with the date signal generated by the signal generating circuit, and an ultrasonic motor driven by the driving signal outputted by the driving circuit. The ultrasonic motor is comprised of a piezoelectric vibrator having an electrode pattern and being driven by the driving signal outputted from the driving circuit to undergo expansion and contraction movement, a vibrating member connected to the piezoelectric vibrator and vibrationally driven by expansion and contraction movement of the piezoelectric vibrator, and a date dial disposed on the vibrating member to be frictionally driven by expansion and contraction movement of the piezoelectric vibrator.
The invention concerns an annual calendar mechanism for a timepiece including a date disc (16) to which are thirty one figures are affixed each corresponding to an indication of a day of the month provided with a first inner toothing (20) including thirty one teeth (20a), a date drive wheel set (32), said wheel set (32) including a finger (34) driving the date disc (16) through one step per day via one of the teeth (20a) of the first inner toothing (20) in order to control the date display, said date disc (16) including a second toothing (24), a correction drive wheel set (42) able to cooperate with the second toothing (24) to drive the date disc (16) through an additional step at the end of the months of less than thirty one days, and a month star wheel (54) arranged to be actuated at the end of each month and to complete one revolution per year, characterized in that in includes a month drive wheel set (52) provided for driving the month star wheel (54) at the end of each month, said drive wheel set (52) being connected, via a gear train (35, 56), to the date drive wheel set (32) and to the additional correction drive wheel set (42), said wheel set (52) occupying a first position in which it has no effect on the month star wheel (54), such that the kinematic chain between the date disc (16) and the month star wheel (54) is broken, and a second position that it occupies only at the moment when the change of month occurs and in which it actuates the month star wheel (54) so as to move it one step forward, such that a correction device (90) can act on the date disc (16) without any effect on the month star wheel (54) and vice versa.
An electronic analog calendar timepiece includes a mechanism for automatically correcting the date indication at the ends of months having less than 31 days. A second motor activates the month correction-mechanism in short months to advance the date dial by additional indicated days. Such irregular advancements occur in accordance with the condition of switches associated with the 29th, 30th, and 31st day positions of the date dial, and in accordance with data stored in memory to correlate with the displayed month of the year. A conventional driving mechanism associates with conventional time keeping circuitry to advance the hands and the day, date, and month indicators for all days occurring in the month. The month-end correcting mechanism is linked to the conventional driving mechanism by actuation of the second motor.
