Abstract: A recording medium is provided for use with a device for recording data on and reading data from the recording medium using first and second recording and reading methods. A first recording region of the recording medium stores data recorded using the first method and includes blocks having a first data storage capacity. A second recording region of the recording medium stores data recorded using the second method and includes blocks having a second data storage capacity. The first and second recording regions may be, for example, first and second offset helical grooves formed on the recording medium. A device for recording and reading data on the recording medium using the first and second recording methods in accordance with identification data identifying the methods is also provided.

Abstract: A scroll member comprising a metallic end plate having a spiroidal groove on one side thereof, and a through-hole communicating with the groove, and a resin wrap joined to the groove of the end plate so as to protrude from the surface of the end plate. The wrap being formed by injection molding, and the through-hole and the groove being filled with part of the wrap.