Abstract: Provided is an optical recording medium comprising a substrate and a reflective layer, a first dielectric layer, a recording layer, a second dielectric layer and a light-transmission layer formed in this order on the substrate. The recording layer is decomposable by heat at a time of recording to achieve recording of the optical recording medium, and the optical recording medium further comprises a third dielectric layer between the second dielectric layer and the light-transmission layer.

Abstract: It is an object of the present invention to achieve a recording medium more excellent in preservation resistance than conventional optical recording media. To achieve the above object, the present invention provides an optical recording medium comprising a substrate and a reflective layer, a first dielectric layer, a recording layer, a second dielectric layer and a light-transmission layer formed in this order on the substrate, the recording layer being decomposable by heat at a time of recording to achieve recording of the optical recording medium, wherein the optical recording medium further comprises a third dielectric layer between the second dielectric layer and the light-transmission layer.

Abstract: A key identifying for an ignition switch key cylinder. The apparatus has a lock member that is unlocked by the key including a signal transmitter outputting an identifying signal. A computer determines an appropriate key for an unlocking use based on the identifying signal. The lock member includes a rotor being arranged to be rotated by the key, a case for accommodating the rotor, a cap secured to the case to detachably hold the rotor in the case and an antenna member receiving the identified signal from the transmitter and providing the determining means with information indicative of the identified signal, said antenna means being located in a position relatively constant with respect to the case.