A heat sink is attached to a subject-side end portion of a barrel body of a lens barrel. The wall strap tensioner includes first and second links pivotally connected together. When accesses are detected loading or retrieving CRC values from system memory, the CRC values are loaded substantially in parallel into the CRC value cache memory. The microphone arm has a length, which in the main is less than or of the same order as the greatest extent of the housing, so that in the folded-in state the microphone arm does not project out over the circumference of the housing.