Patent GB-1533102-A (GB)
Title: Electronic timepiece
IPC: G04G9/00
Filed: 1975-10-30
Abstract: 1533102 Electronic timepieces CITIZEN WATCH CO Ltd 30 Oct 1975 [31 Oct 1974] 44998/75 Heading G3T An electronic timepiece comprises a 32768 Hz crystal controlled oscillator 14 Figs. 3, 4A, 4B, 4C followed by a frequency converter 16 having various outputs including a timing signal D 1 T 1  at 256 Hz which is applied via a control unit 30 to up-date time data stored in a timekeeping register 32 including a ring counter 58, and a data detecting circuit 70 providing time data signals to drive a display 22, e.g. liquid crystal, after processing and decoding in units 36, 40, 42, 44, 46, 20. The control unit 30 is also used to apply additional data to the register, e.g. for setting date or time data to the correct value or for pre-setting alarm time(s) in response to manual operation of switches 38, detailed in Fig. 18. A data modulation unit 36, detailed in Figs. 20A, 20B (not shown) causes flashing of data being displayed both during display of current time or date and during setting operations. A chopping circuit 76 chops the flow of data and timing pusles to the display driver unit 20 and option system 12 to reduce power consumption, sending it out as a serial burst for a fixed time period of 1/256 sec. every 1/16 sec. The option system 12 may be combined with the basic timepiece system and includes a shift register (1490) used to store daily repetitive alarm times and temporary (once only) alarm times, a plurality of alarm times stored in the option system, are sequentially delivered to the timekeeping system register and stored therein for comparison with current time data in an alarm unit 34. Upon coincidence, a visual or audible alarm (e.g. Piezo-electric or electro-magnetic) is activated. System 12 may also be used for "setting" operations, in which case it includes a storage register and a timing pulse generator; or it may couple a calculator or a blood pressure detector to the timepiece display circuitry A suitable option system arrangement is detailed, in Figs. 27A, 27B, 27C (not shown). In this arrangement, seconds adjustment for gain or loss is performed by the wearer setting the seconds to zero by closing a switch upon the occurrence of a radio time signal. Precisely one week later he again resets the seconds to zero and compensation is automatically achieved. Calculation of time gained or lost during the preceding week is automatically performed and an error compensation signal FSO is produced. This signal is fed back to input terminal FIN of the timepiece and is logically added in a gate 50 Fig. 4A to the pulses transmitted from the oscillator circuit to the frequency converter 16. The running rate is thereby corrected. The timekeeping register 32 Fig. 4A, 4B, 4C includes the ring counter 58 formed by a 60-bit shift register 60 and a 4-bit shift register 64 coupled by an adder 62 as detailed in Figs. 11A, 11B (not shown). A detector 72 senses when carry operations are to be performed and sends signals W 3 , W 4 , W 5  to the control unit 30 which controls the ring counter 58 accordingly. A detector 74 monitors date and time data stored in shift registers and produces signals in accordance therewith, which are transmitted to the data modulation unit 36. A gate circuit (224) in the control unit 30 detailed in Fig. 12 (not shown) produces a carry inhibit signal to inhibit, for example, a carry to hours data when the minutes digit of current time or alarm time is being set. DISPLAY. Fig. 23 Symbols 570, 572 are selectively activated to indicate A.M. or P.M. when time is being displayed. Symbol 562 is activated to indicate that the daily alarm time has been set and activation of symbol 564 indicates that a once only alarm time has been set. Symbol 566 is activated when the digits display date. Segments S0 to S6 are successively activated to give a linear analogue display of tens of seconds in which case a seconds scale 574 is activated. Seconds are also displayed digitally on demand. The segments S0 to S6 may also be used to indicate the days of the week, the display mode being changeable by the modulation unit 36. The alarm time data stored can be consecutively displayed upon demand, at a rate of one per second; also a particular unit selected for setting is displayed during setting. Data or symbols being displayed are flashed at 1 Hz. A voltage booster may be provided to drive the liquid crystal display. DEMAND AND SETTING SWITCHES. Fig. 18 Various switches are selectively opened or closed by manipulation of a crown and stem 269, the stem being axially moveable between three positions and angularly rotatable in both directions to move a sector 274 and cam 284 so as to operate respective switches. The crown is operated in conjunction with push switches 264, 266 to initiate display of date and seconds, alarm time data &c and for setting. Hours and minutes are displayed when the crown is in a "normal" position and neither of the switches 264, 266 is depressed. Adjustment for the number of days in the current month is automatically performed. Adjustment for leap year may be effected automatically or by manually setting the date to February 29.