Abstract: In a ROM-type optical recording medium including a substrate 2 having a plurality of concave pits 2a formed on a surface thereof, a light transmission layer 4, and a reflective layer 3 formed between the substrate 2 and the light transmission layer 4, and adapted to reproduce data by causing a laser beam to be irradiated through the light transmission layer 4, the concave pits 2a on the surface of the substrate 2 has a larger length than a basic length BL to be determined according to data to be recorded, and the length of spaces 2b between the concave pits 2a adjacent to each other in a track direction has a smaller length than the basic length BL.

Abstract: A tape cassette including an upper half and a lower half to form a casing, both halves integrally connected at corresponding melt-bonding connecting portions through a melt-bonding rib; at least one of the melt-bonding connecting portions of the halves constituted by a concave portion and a convex portion which are engageable together, the engageable concave portion including two sections which are different in depth. The convex portion includes two sections which are different in height, at least one of the coupled concave and convex portion having a melt-bonding rib; and at least one of the engageable concave and convex portions having a hole at a central portion of the melt-bonding ribs.

Abstract: A tape cassette storage container comprisinga main body and an upper-lid, which are adapted to store a tape cassette including a pair of reels with a tape wound thereon, and pressing members urging the reels in a casing of combined upper and lower halves, the pressing members having top ends exposed outside from through holes formed in a window in an upper plate of the casing;wherein the upper lid includes a top plate which has an inner surface formed with pressing projections to urge the pressing members on closure; the pressing projections are made of inner thin-wall cylindrical projections; the top plate of the upper lid has the inner surface formed with outer thick-wall cylindrical projections to be around and close to the inner cylindrical projections; and the outer cylindrical projections have a shorter projection length than the inner cylindrical projections in such a manner to be out of contact with the window of the cassette casing.