Abstract: A method and apparatus for adjusting the frequency of a piezoelectric crystal oscillator. The effective frequency of the oscillator is adjusted (trimmed) by periodically inhibiting pulses to the divider stage.The pulse inhibit circuit includes a nonvolatile programmable read-only-memory (ROM) to store binary complement information corresponding to the number of oscillator pulses to be suppressed.A counter is periodically preset with the binary complement information and the count advances in response to oscillator pulses. The difference count between the complement number and the counter's maximum count controls the number of pulses periodically suppressed.

Abstract: A method and apparatus for adjusting the frequency of piezoelectric crystal oscillator. The effective frequency of the oscillator is adjusted (trimmed) by periodically inhibiting pulses to the divider stage.The pulse inhibit circuit includes a nonvolatile programmable read-only-memory (ROM) to store binary complement information corresponding to the number of oscillator pulses to be suppressed.A counter is periodically preset with the binary complement information and the count advances in response to oscillator pulses. The difference count between the complement number and the counter's maximum count controls the number of pulses periodically suppressed.During manufacture/assembly of the timepiece, the ROM is programmed to contain the desired complement information.

Abstract: An electrooptic display for watches with improved night visibility comprises a liquid crystal cell with actuatable character segments and polarizing elements mounted on either side thereof, a reflector behind one of the polarizer elements and light emitting segments on the reflector aligned with the character segments.In a first embodiment, the reflector has thin lines of phosphorescent material painted on its surface adjacent the polarizing element. In a second embodiment, the reflector has small slits aligned with the character segments and a phosphorescent material is painted into the slit area behind the reflector.Both embodiments preferably employ a display having clear or light characters against a dark background. Thus during nighttime use, light radiating from the phosphorescent material may be seen by the viewer through each energized (or transparent) segment. Light from the phosphorescent material behind deenergized segments is blocked.