Interpolated video tagging techniques are described. A differential pair of transistors has their base electrodes coupled to the emitter electrodes of the first and second emitter follower transistors and their emitter electrodes coupled together and to a third voltage controlled current source. When the blank is inserted into the first and the second frame components in an engaged position, an enclosable space for placement of a recording medium is formed. In the store are provided passage reception antennas for receiving the stuck state signal transmitted from the RF unit, gate reception antennas for receiving reading state signal transmitted from a bar code reader through the RF unit, and a store control unit for judging whether the takeout of the article N be permitted based on the reading state signal. A first current detecting device is used for setting the charging current signal being fed to the current error amplifier.