Abstract: A personal computer card device has a pair of operation state indicating portions exposed at front and back surfaces of a projecting part of a body thereof. The projecting part is projected from a chassis of an information apparatus when the personal computer card device is partly inserted in to a card slot of the information apparatus. Light emitted from a single light emitting device housed in the body is guided by a light guiding member to the operation state indicating portions. Thus, an operation state of the personal computer card device can be seen from both of front and back surface sides.

Abstract: A magnetic disk cartridge is comprised of a cartridge body and a magnetic disk, which is housed in the cartridge body. The cartridge body is constituted of a high-impact polystyrene resin, which contains elastic grains in a proportion ranging from 7% by weight to 10% by weight. The elastic grains have grain diameters not less than 1 .mu.m. The elastic grains may be constituted of butadiene rubber. The cartridge body of the magnetic disk cartridge has high gloss and good abrasion resistance, and the magnetic disk cartridge can be manufactured at a low cost.

Abstract: In a mold panel unit for constructing, for example, a spring-water processing layer, a mold panel is made of a synthetic resinous material or a fiber-reinforced material. A plurality of projections identical in configuration with each other are formed on the one side of the mold panel. A plurality of recesses are formed in the other side of said mold panel in corresponding relation to the respective projections. In addition, a spring-water processing structure formed on a grade slab includes a plurality of mold panel units which are laid on the grade slab such that end faces of the respective projections of each of the mold panel units are in abutment with an upper surface of the grade slab, and the recesses of the mold panel unit open upwardly. A cement filler is after-cast on said mold panel units.

Abstract: A magnetic disk cartridge includes a magnetic disk and a casing which accommodates therein the magnetic disk. The casing has a magnetic head opening through which a magnetic head gains access to the magnetic disk and a sliding shutter which slides between a closed position, where it covers the magnetic head opening, and an open position, in which the magnetic head opening is uncovered. The sliding shutter is provided with a first cutaway portion which is formed on the front edge of the shutter and can be engaged with a shutter opening pin which is provided in a disk drive and moves the sliding shutter to the open position when the magnetic disk cartridge is loaded into the drive. A second cutaway portion is formed in the front edge portion of the casing in a position substantially symmetrical to the position of the first cutaway portion about the centerline of the casing which is perpendicular to the front edge of the casing.