PURPOSE: To well bond substrates and inside and outside spacers and to decrease the distortions of the joined substrates by consisting of the inside spacer of the same resin material as the resin material of the substrates and consisting of the outside spacer of a resin material having softness and/or plasticity.
CONSTITUTION: Two sheets of the substrates 21a, 21b are joined via the inside spacer 23 and the outside spacer 24 with recording layers 22a, 22b respectively positioned on the inner side. Two annular projections each having a triangular sectional shape are provided to both sides of the inside spacer 23 by changing the diameter thereof and two annular projections each having a triangular section shape are provided to both sides of the outside spacer 24 as well by changing the diameter thereof. The inside spacer 23 is formed of the same resin material as the resin material of the substrates 21a, 21b and the outside spacer 24 is formed of the resin material having the softeness and/or plasticity. The information recording medium having the small strains and high joint strength is obtd.
WATANABE SEIICHI
ISHIHARA YUSUKE
MATSUZAWA HIDEKI
