Power source switch for cameras

摘要

In a still or motion picture camera including an electric circuit such as a light measuring circuit, an exposure control circuit, a sound recording circuit, or a capstan driving circuit, the shutter release button is provided with a piezo-electric element for developing an electric charge or potential difference when an external pressure is applied thereon. The pressure responsive piezo-electric element is connected in the electric circuit in response to the pressure applied on the pressure responsive element, whereby the electric circuit is enabled prior to the commencement of the exposure.