Abstract: An optical card (1) comprising a surface protection sheet (4) laid on the surface (2a) of a core sheet (2) through a surface side adhesive layer (3) functioning as a surface-side clad layer, and a back surface protection sheet (6) laid on the back surface (2b) through a back surface side adhesive layer (5) functioning as a back surface-side clad layer, wherein a large number of V-grooves (7) are made, at a constant interval, in the surface (2a) of the core sheet (2) and the opposite ends (7a, 7b) of each V-groove are exposed to the end faces (2c,2d) of the sheet. Sectional parts (8(2), 8(4), . . . ) of the core sheet (2) formed between respective grooves (7) function as optical waveguides and remaining sectional parts (8(1), 8(3), . . . ) each provided with a V-groove (light shielding groove) (9) extending across adjacent V-grooves (7), function as non-optical waveguides.

Abstract: A magnetic card (10) has a base card (11), a magnetic stripe (12) formed on the base card (11), and a plurality of optical fibers (15) extended within the base card (11) substantially perpendicularly to the magnetic stripe (12). The magnetic stripe (12) consists of an arrangement of a plurality of unit magnetic segments (12a) each having a recording capacity of a predetermined number of bits, for example, eleven bits. The optical fibers (15) are assigned to the unit magnetic segments (12a), respectively. A read/write head (23) reads magnetic information from the magnetic stripe (12), an optical read device including a light-emitting device (20) and a light-receiving device (22) read optical information from the optical fibers (15), and a controller (25) examines the magnetic information with reference to the optical information to authenticate the magnetic information.

Abstract: A low frequency medical treatment apparatus comprising an over-current preventing measure with an overcurrent detecting circuit and a switching circuit to control an output transmission path according to the detection output, a shock preventing measure having a control circuit for opening or closing an output wave transmission path in response to a switching element whose operating state is changed depending on whether or not an output controller is set at its minimum set position, and a measure of improving comfortability in use having a circuit for controlling the output wave transmission upon contact of a touching element with human body and a circuit for maintaining the output waveform unchanged.