Abstract: A recording member having a predetermined substrate, and a thin film which is formed on the substrate and which is formed with recesses or pits for recording information when irradiated with a working beam, characterized in that said thin film is formed of an inorganic material which contains at least arsenic, selenium and tellurium, and that a distribution of either of said Se and said Te decreases from a part near the surface of said thin film towards a central part thereof, while a distribution of said As increases from a part near the surface towards said central part, is disclosed. This recording member can afford a high signal-to-noise ratio and a long lifetime.

Abstract: A driver's seat mounting apparatus for a motor vehicle having a driver's seat shiftable either forward or rearward along rails. Rail supporting members for said shiftable driver's seat are disposed lower than a seat supporting portion mounted on the top surface of a suspension.

Abstract: An optical information recording and reproducing apparatus is disclosed in which a predetermined signal is recorded on a track of a rotating recording medium by a recording light beam and the recorded information is reproduced by a reproducing light beam. The information recorded on the last record track is reproduced by the recording beam and the reproducing beam and radiating position of the recording beam on the recording medium is displaced by a predetermined distance from the last record track.

Abstract: In order to record information spirally on a disk and to reproduce the recorded information accurately without any contact, at the recording, an information signal and a predetermined signal for synchronous detection are added together, the resultant signal is subjected to frequency modulation and, while a laser beam intensity-modulated by the frequency-modulated signal is minutely swung in the radial direction of the rotating disk at the same frequency as that of the synchronous detection signal, it is caused to impinge on the disk to thereby record the information spirally on a recording medium of the disk without any contact. During the reproduction, as the disk is being rotated, a light spot is caused to impinge along an information groove formed on the disk, and reflected light or transmitted light from the disk is detected in the form of an electric signal.