Abstract: A rotating intermediate drum having mounted thereon optical head is made smaller than stationary upper and lower drums in diameter and spiral grooves are formed on the rotating intermediate drum on its surfaces opposing the stationary upper and lower drums. An optical tape is transported in a floated condition relative to a drum circumferential surface owing to a synergy of a dynamic pressure based on the rotation of the rotating intermediate drum and the air exhausted from the spiral grooves. Therefore, an information signal is recorded on and/or reproduced from the optical tape when the optical tape is transported in the floated condition from the head drum having the trilayer structure composed of the stationary upper and lower drums and the rotating intermediate drum therebetween.

Abstract: A rotary drum assembly comprises a stationary member having a stationary cylindrical portion, and a rotary member having substantially the same diameter as that of the stationary member and positioned in the vicinity of the stationary member so as to be relatively stationary to the stationary member. Each of surfaces of the rotary member and the stationary member opposing to each other is formed to have a step structure having a plurality of opposed surfaces, and pump-out type spiral grooves are formed on at least two of the plurality of opposed surfaces of one of the rotary and stationary members.

Abstract: An optical recording apparatus employing a plurality of modulated laser beams as means for recording information on an optical recording medium, comprising a laser beam source which emits a laser beam, a plurality of carrier sources which generate carriers respectively of different frequencies, a plurality of switching circuits respectively connected to the carrier sources to interrupt the carriers intermittently for modulation according to information data signals applied respectively thereto to provide driving signals, an acoustooptic reflector which splits the laser beam into a plurality of discrete laser beam intermittently interrupted respectively according to the driving signals, a focusing lens for focusing the plurality of discrete laser beams on spots on the recording surface of a recording medium, and a polygonal rotating mirror disposed between the acoustooptic deflector and the focusing lens to reflect the plurality of discrete laser beams so as to sweep the recording surface of the recording medi

Abstract: A rotary optical head apparatus comprises a first rotary member carrying an objective lens and a second rotary member carrying an image rotator. The two rotary members are supported for rotation by means of a single common support shaft so that the axes of rotation of the two rotary members coincide with each other with a high degree of accuracy. Consequently, the linearity of a scanning line of a beam spot which is scanned on an optical magnetic tape is ensured with a high degree of accuracy.