A quartz-operated digital watch is provided with a casing defining a shallow cavity within which a chamber of hourglass configuration is disposed. This hourglass chamber includes gold dust or particles which, when caused to flow from one chamber portion to another, bridge two electrodes to complete a circuit and render the digital display visible.

A solid state watch includes two gravity switches, one closable when the arm is positioned such that the wrist extends substantially horizontally and the other simultaneously actuatable when the arm and/or wrist is twisted or rotated sidwardly while the wrist is maintained in its horizontal position, such that both switches one in sequence circuit with the other are subject to being concurrently thereby closed at a same period in time, during which the completed closed circuit of the circuitry to a solid state read-out assembly is activated thereby making possible the observing and reading of the time by the person reading the watch without any requirement of use of the other hand, the particular readout being dependent upon the duration of period of closing of the switch closing upon the twisting of the wrist and/or upon a predetermined number of sequential to and fro twists of the wrist.

A wristwatch of solid state, the read-out indicia circuit being activatable by hand or wrist action of the arm carrying the wristwatch, by exerting pressure on the improved lever which is mounted on a lateral face of the wristwatch support structure slidably for sliding upward and downward movement either of which will activate the read-out indicia circuit.

A system for illuminating the display of a wrist watch by motion of the wrist. The watch incorporates means for sensing a specific motion of the watch and the sensing means is connected to means to cause the digital display to become active (illuminated). Storage means is provided for illuminating the display for a 5 second interval so that the user may conveniently read the display. Additional circuitry for displaying the day and month is described.

In an instrument adapted to be worn on the wrist including a power source, a display, means for illuminating or activating the display and actuating means for connecting the power source to the illuminating or activating means to energize the same, the improvement wherein the actuating means comprises either an inertia actuated switch means operative in the presence of a deliberate, rapid acceleration and/or deceleration of the wrist having a predetermined minimum magnitude and/or a pressure actuated switch means operative in the presence of pressure applied thereto by the wrist for momentarily connecting the power source to the illuminating or activating means.