Audio adapter for use with an electronic still camera

Abstract

An electronic still camera device has a camera unit that is capable of recording and reproducing video and audio signals, and an audio adapter which can be detachably attached to the camera unit and which has operation switches, a microphone, a collected sound amount indicator and a circuit that is capable of compressing and expanding audio signals. In order to reduce the number of signal lines which are to be provided between the camera unit and the audio adapter, the audio adapter is automatically set in the audio playback mode when the audio adapter has detected that compressed audio signals are being delivered from the camera unit to the audio adapter. The camera unit has a power supply and is arranged to superpose a D.C. voltage of a high level or a low level to the compressed audio signal. A power supply switch provided in the audio adapter is capable of selectively supplying the source power from the camera unit to the audio adapter in accordance with the level of the D.C. voltage. In order to enable the user to conduct sound collection, sound cancelling and sound recording at any desired timing, the audio adapter has switches that is capable of generating a sound collection starting instruction, a sound collection stopping instruction and a sound cancelling instruction, and operation is executed in accordance with these instructions. A collected sound amount indicator is provided for indicating the amount of collected sound in terms of the sound collection time.