An analog recording medium disc includes a first face including a read layer and a first tag. The analog recording medium disc includes a radio-frequency identification device that includes a contactless electronic chip that is associated with an antenna. The antenna is printed directly on a face of the tag, and the tag is held within the material of the disc.

A hard disk drive with a multiple disk stack normally utilizes disk separator plates near the disk surfaces to reduce wind induced vibrations in the disks and the read/write heads. The manufacturing methods currently used to make these separator plates, metal casting and machining, or injection molded plastic, or extruding and machining, or cold forging tends to be expensive and creates unwanted weight and bulk without the desired precision. Stamping disk separator plates from metal provides exceptional dimensional control at reduced cost, but cannot readily provide the thicknesses required. Stamping and extruding the offsets, or stamping and folding the offsets, is a manufacturing process that provides the required dimensions for the offsets, and dimensional control and reduced cost.

A disc tray includes a bottom wall including an outer periphery and an inner rib supporter supporting the lowermost disc from below. The bottom wall is thickened from the outer periphery toward the inner rib supporter. The lowermost disc includes a data recording area, an inner rib, and an outer rib. When the lowermost disc is stationary, the outer rib of the lowermost disc and the upper surface of the bottom wall are separated by a gap. When the lowermost disc is inclined in such a manner that part of the outer rib of the lowermost disc comes into contact with the upper surface of the bottom wall, the data recording area of the lowermost disc and the upper surface of the bottom wall are separated by a gap greater than thickness of the outer or inner rib.

A disc tray includes a bottom wall including an outer periphery and an inner rib supporter supporting the lowermost disc from below. The bottom wall is thickened from the outer periphery toward the inner rib supporter. The lowermost disc includes a data recording area, an inner rib, and an outer rib. When the lowermost disc is stationary, the outer rib of the lowermost disc and the upper surface of the bottom wall are separated by a gap. When the lowermost disc is inclined in such a manner that part of the outer rib of the lowermost disc comes into contact with the upper surface of the bottom wall, the data recording area of the lowermost disc and the upper surface of the bottom wall are separated by a gap greater than thickness of the outer or inner rib.

The invention relates to a destruction system for destroying a functional layer, which may receive data or perform other functions, such as optical functions, for example, and a related method. The reactants may be interspersed within the functional layer or may be provided in a separate layer adjacent to the functional layer. The reactants are structured to be ignited to destroy the functionality of the functional layer and the data. Ignition may be obtained through a flame or by suitable electrical current in certain embodiments of the invention.