a disc accommodation section that accommodates {HEAD ~ a plurality} of {TAIL ~ discs} and is configured to be capable of being lifted up and moved down within the disc drive unit 
a disc accommodation section that accommodates { HEAD ~ a plurality } of { TAIL ~ discs } and is configured to be capable of being lifted up and moved down within the disc drive unit
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH