Abstract: An individual identification recognition system for judging whether a card possessor is an authorized card user. The system includes a card storing a fingerprint of the authorized card user, a card reader into which the card is inserted, and which reads the fingerprint of the card possessor and a judging means for judging whether a card possessor is an authorized card user based upon the result of a comparison of the fingerprint of the card possessor taken in by the card reader with the fingerprint registered in the card, which judging means can be provided in the card or the card reader.

Abstract: An IC card used for conducting a transfer of information through a connector to a card reading out device is provided with electrode terminals for connection to the outside. A shutter is slidably provided within said card so as to cover said electrode terminals in the usual state. A hole provided at the front portion of said card receives a projection provided at said connector when the projection is inserted into the card. The shutter is retreated when it comes into contact with the projection of the connector thereby to expose said electrode terminals when the card is inserted into the connector.

Abstract: A process for preparing semiconductor pellets from one sheet of a semiconductor wafer is disclosed. In the process of the invention, the semiconductor wafer is divided into a plurality of pellet-forming regions and reinforcing regions are formed between the pellet forming regions and at the peripheral part of the wafer.The reinforcing regions prevent breakage of the wafer without increasing the thickness of the pellets whereby a wafer having a large diameter can be used to obtain many pellets having suitable characteristics from one sheet of the wafer without substantial loss.

Abstract: A semiconductor wafer is provided with a plurality of semiconductor pellets arranged in rows and columns in a checkered pattern on its main opposite faces. A groove in the form of a closed loop is disposed around each pellet on one of the main faces and is spaced from grooves encircling the adjacent pellets to leave a grid between the pellets, and grooves are disposed on the other main face which simply separate the pellets. All the grooves are covered with glass passivation layers. The wafer is divided into the semiconductor pellets by dicing it along the central lines of the bars forming the grid.

Abstract: The stabilization of electrical switching parameters in a semiconductor switching device is achieved by selectively doping a portion of semiconductor material with a heavy metal and irradiating the remaining semiconductor material. In an important embodiment of the invention, a center-fired four region semiconductor switching device consisting of silicon semiconductor material is prepared by gold doping the silicon in the area around the center firing gate contact where initial conduction of current is concentrated. The remainder of the active area of the device is irradiated to provide recombination centers for fast switching without the adverse effect on blocking leakage current that is attributable to indiscriminate gold doping. The gold provides recombination centers in the initial conductive area which are not subject to annealing as are the recombination centers provided by irradiation.

Abstract: After a principal current through an SCR has been decreased to zero by inverting the polarity of the voltage between the main terminals of the SCR(anode voltage,) its gate is reversely biased with a gate bias pulse including a time point where the anode voltage passes through a zero point toward the positive direction. Also, the gate is reversely biased with a gate bias signal in the form of a direct current less in amplitude than the bias pulse. The bias signal may be in the form of a pulse consecutive to the bias pulse and terminating not earlier than the termination of the OFF-state voltage.