Mechanism for preventing erroneous mounting and dismounting of memory card

Claim 1

A mechanism for preventing erroneous mounting and dismounting of a memory card on and from an apparatus having a memory card insertion hole, into which a memory card can be detachably inserted, and performing a predetermined processing to memory means of a memory card when the memory card is inserted into said memory card insertion hole to a predetermined position, said mechanism comprising: a memory card provided with a recess; and an engagement member movable between a projecting position, at which said engagement member is projected in a locus of movement of the memory card from an inlet of said memory card insertion hole of said apparatus to said predetermined position, and a retracted position, at which said engagement member is spaced apart from said locus of movement, said engagement member being interlocked with an operation switch for a circuit for performing a predetermined process to said memory means, so that said engagement member is brought to said projecting position when said operation switch is turned on and to said retracted position when said switch is turned off; wherein said engagement member is moved from the retracted position to the projecting position by turning on the operation switch when said memory card is located on the predetermined position in the memory card insertion hole, at the projecting position the engagement member being engaged with the recess of said memory card so as to prevent said memory card from dismounting from the predetermined position, and is moved from the projecting position to the retracted position by turning off the operation switch while said memory card is located on the predetermined position, at the retracted position the engagement member being released from the engagement with the recess of said memory card so as to allow said memory card to be dismounted from the predetermined position in the memory card insertion hole.