A watch is provided with a liquid crystal display system operable at high levels of ambient illumination and a solid state display system operable at low levels of ambient illumination. A photo-transistor selects the display system appropriate to the ambient light level.

A display device incorporating a liquid crystal cell wherein an insulated gate field effect transistor drives said cell and is connected with its source-drain path in series with said cell and a power source. A pulsating signal is applied to the gate electrode of the transistor, and the frequency and duty cycle thereof is selected to maximize the efficiency of the display driving circuit.

An electronic timepiece including a primary battery as a power source, and a solar battery for charging the primary battery is provided. The electronic timepiece includes a solar battery for producing a charging current in response to solar light being incident thereon, a primary battery adapted to be charged by the charging current and a detecting circuit disposed intermediate the solar battery and the primary battery to detect the state of charge of the primary battery and in response thereto ...

A temperature sensitive capacitor having a dielectric such as BaTiO.sub.3, wherein capacitance varies in response to temperature, is provided with means for manually changing the capacitance thereof either in a stepwise manner or continuously.

A quartz oscillator having a four-terminal quartz vibrator, two of the four terminals being connected with a compensating device for compensating the temperature coefficient of the quartz vibrator frequency, the other two terminals being connected with an active circuit including at least one MOS transistor.

Reciprocating motion of a vibrator vibrating at several tens of Hz, such as is used in an electric watch, activates fingers which rotate a ratchet wheel in a single direction. The linkage between the vibrator and the wheel is such that the wheel is advanced during both halves of each cycle of vibration. The fingers can be driven either by one or by both arms of the vibrator.

A rolling mill for rolling metal strip moving in a horizontal rolling direction, has work rolls which engage the strip and are supported vertically by backup rolls through which drive is applied. The work rolls are supported in the horizontal rolling direction by support rollers contacting them at locations confined to intermediate regions between the work regions and bearings. The work rolls are shiftable in the horizontal rolling direction. To provide control of the horizontal forces during ro...

An apparatus for looping belt-like materials, including first and second looping units for winding a moving belt-like material helically into first and second coils, with a portion of the belt-like material forming the first coil being drawn out into the second coil. A plurality of support rollers annularly arranged along each of the portions of the wound belt-like material forming the first and second coils, and frames are provided with the support rollers, along with a drive for applying a rot...