GB1392651A - Rotating ring display - Google Patents

Abstract

1392651 Indicating apparatus H G DILL 12 April 1972 [24 May 1971] 16750/72 Heading G1J [Also in Division G3] An electronic wristwatch has rotating day, hour, minute and second rings, 17, 19, 21, 23 respectively, which are mounted on tracks, e.g. 63 Fig.5, on a ring-retaining block 49, and which have a plurality of U-shaped magnetic regions 67. Between stepping operations each ring is kept in position by the interaction of the regions 67 with a set of three permanent magnets 77, which are adjacent to the rings. Stepping is effected by selectively feeding electrical pulses to coils 79, which are wound on respective magnets 77, the pulses producing a magnetic field opposed to that of magnets 77 and causing a net thrust to be exerted on the ring to drive it from one rest position to the next. The pulses are produced by a control circuit Fig. 1 (not shown) comprising a time standard (91), e.g. a quartz oscillator, a frequency divider (93) and a decoder driver (95) which feeds three differently-phased pulse trains to the three coils 79 associated with each ring. In modifications there may be several sets of three magnets 77 associated with each ring or alternatively there may be only two such arrangements. Furthermore, instead of the cores 77 being permanent magnets the rings may have permanently magnetic regions. Figs.14a-c (not shown) depict rings and magnets 77 with alternative cross-sections to that shown in Fig.5. The rings 17, 19, 21, 23 are independently rotatable and may be corrected together or individually by switches 39, 41, 43, 45, which are pressure-sensitive, temperature sensitive or capacitive-sensing devices. Actuation of the switches causes a set-reset circuit 97 to feed pulses to the decoder-driver 95 to move the rings. The rings may be moved at two rates depending upon the duration of the actuation of the switches. Further circuitry may be provided to automatically compensate for any ring slippage. An arrangement in which the regions 67 are driven electrostatically is also envisaged.