Multi-Beam Optical System for Optical Tape Recording

An optical tape recording system utilizing a rotating optical head is under development as a mass storage device suitable for recording television programs. High-quality moving pictures for broadcast require a correspondingly high bit rate of over 100 megabits per second (Mbps) for recording. Toward the realization of such a high bit rate, recording in parallel utilizing many laser beams is most effective. We propose an optical system integrating a head that is suitable for parallel recording on an optical tape with numerous laser beams. The optical system assumes the role of keeping the lateral magnification constant during focusing. We studied the effectiveness of such an optical system by the experimental construction of a four-beam optical head.