Abstract: An information recording disc demagnetization apparatus according to the present invention demagnetizes information recording discs whose information is read by irradiating a laser beam, such as a music CD (audio compact disc), a photographic CD, DVD, MD, etc. The demagnetization process performed by the apparatus of the present invention successfully recovers tone quality, image quality, and the like, of the information recording disc, all of which are deteriorated by magnetism attained by the disc during reproduction of the disc.The information recording disc demagnetization apparatus has a disc-shaped air-core coil for creating an alternating magnetic field having a decremental intensity, and a means for holding the information recording disc in a stationary state within the alternating magnetic field.

Abstract: A recording sheet for thermal dye-transfer type recording method, having a coating layer which is placed on a substrate, is contacted with a coloring material layer containing sublimable dye and on which the dye is transferred by heating. The coating layer includes as a pigment precipitated calcium carbonate of at least 25,000 cm.sup.2 /g specific-surface-area and as a binder saturated polyester or a mixture of saturated polyester with polyvinyl pyrrolidone. The sheet provides a clear record with superior color density.

Abstract: A recording sheet for thermal dye-transfer type recording having a coating layer which is placed on a substrate, which is contacted with a coloring material layer containing sublimable dye and on which the sublimable dye is transferred by heating, wherein the coating layer includes an aminoalkyd resin, whereby the recording sheet provides a record with superior color density and causes no heat-adhesion between the recording sheet and a thermal transfer substrate.