Importance

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Abstract

A movable shutter is provided for protecting the head of an information playback and/or recording unit when de-activated, the shutter having head-covering and head-uncovering positions which are stable positions provided by a bi-stable actuating member for the shutter. The bi-stable actuating member is linked to move the shutter at any position of relative movement between the head and the information support. A circuit including the head and the bi-stable actuating member is connected to a power source and the actuating member is operated instantaneously responsive to the unit being switched on and off so that the shutter is moved to and kept at its stable head-covering position immediately and without delay at the location where it has been interrupted upon loss of power to the head. In one embodiment a mechanical bi-stable actuating member is provided for moving the shutter to protect the head of a cassette-tape recording/playback unit. In another embodiment for moving a shutter to protect the optical head of a disc playback/recording unit, the bi-stable actuating member is a micro step-motor having a permanent magnet rotor and an armature configured to move the rotor in opposite directions between stable positions upon receipt of positive or negative electrical pulses.

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First Claim