Abstract: An electronic power control circuit used in recording seismic data at unmanned remote locations is disclosed wherein the power requirements are minimized by segregating power distribution between continuous and non-continuous requirements.

Abstract: A magnetic disk storage unit is proposed for cleaning away dust particles on a disk by a magnetic head 7, which is in contact with the surface of the magnetic disk when a magnetic disk 3 is stationary or rotated at a low speed, and which is floated away from the surface of the magnetic disk, as the revolution rate of the magnetic disk increases.When the magnetic disk starts to rotate or when the disk is rotating at a low speed in a continuous rotation, the magnetic head is reciprocated in the radial direction of the magnetic disk, thereby to peel off the dust particles deposited on the surface of the magnetic disk and the head with the removed dust particles then being collected by a filter.

Abstract: In a circuit arrangement for a disk player of the type arranged to reproduce information prerecorded in the form of pits, a variable gain circuit for changing the frequency characteristic of the reproduced signal is provided. The level of the reproduced signal is detected at high and low frequencies so as to produce a control signal the voltage of which varies in accordance with the difference between the level of the high frequency signal component and the level of the low frequency component. The control signal is then applied to the variable gain circuit receiving the reproduced signal so that the frequency characteristic of the reproduced signal will be controlled. Thus, the level of the reproduced signal is boosted at its high frequency range.

Abstract: An optical device for optically recording and reproducing information in and out of a recording medium. The device consists of a movable optical system which carries out at least two-dimensional movements and a stationary optical system. The movable optical system includes a beam splitter adapted to receive a parallel light beam, an objective lens for focussing the light beam from the second beam splitter onto the medium and a photodetector disposed in the vicinity of the beam splitter and adapted to receive, through the objective lens and the beam splitter, the light beam reflected by the information carrier. The stationary optical system includes a beam splitter for directing the parallel light beam from the source to the beam splitter of the movable optical system and a photodetector for receiving the reflected light beam coming through the beam splitter.

Abstract: A video disc system adapted for use with a recordable, master storage, video disc and a prerecorded, transfer storage, video disc comprises a turntable for rotating the master disc and the transfer disc in synchronism, a playback head for reading the video signals recorded on the transfer disc, electronic circuitry for editing the video signals read by the playback head, and a record head for recording the edited video signals onto the master disc.

Abstract: An auto-reverse type cassette tape player having a head base rockably mounted on the front side of a bed and carrying a pair of magnetic heads, so that the magnetic heads are switched in a seesaw-like manner as the tape running direction is switched as a result of a switching between two pinch rollers which cooperate with corresponding capstan shafts.

Abstract: There is disclosed a head assembly for use in a magneto-optic recording/playback system which includes a memory medium having a magnetic coating having a magnetic anisotropy in a vertical direction. A light beam is applied to the memory medium for recording and reproduction of information. The head assembly includes a polarizing prism and a Faraday effect element in an optical path for the light beam. There is needed only the single polarizer.

Abstract: A locking device for a magnetic tape cassette in a magnetic tape device has a lever disposed below the insertion slot; a blocking arm projecting out of the housing; a thrust arm; and an ejector arm. When a magnetic tape cassette is locked in with the locking arm, the thrust arm engages via a wedge with a cartridge-like carrier provided with three rotary bodies and by upward movement of the carrier towards the insertion slot presses the rotary bodies into the insertion slot from below and against the magnetic tape cassette. The magnetic tape cassette is thereby securely held at the reference points. When releasing the locking arm, the magnetic tape cassette is ejected by the pre-stressed ejector arm.

Abstract: A magnetoresistant transducer is described for reading very high-density a. The magnetoresistant transducer (TMRI) includes at least one magnetoresistor (MRI) of an anisotropic magnetic material placed perpendicular to the direction in which the data of a medium (SM) pass. The axis (AFAI) of easy magnetization of the magnetoresistor is normal to the medium and includes a thin, mono-range or single domain magnetic anisotropic layer (CI) normal to the medium and to the direction in which the data pass. The mono-range or single domain layer is strongly coupled magnetically with the magnetoresistor, and its axis of easy magnetization (AFACI) is normal to the medium and opposite in direction to the axis of easy magnetization of the magnetoresistor. The invention is particularly applicable to the reading of magnetic tapes and disks containing high density data.

Abstract: A mounting structure for tape guide elements, for use with a guide drum adapted to have a tape wound in an .OMEGA.-shaped configuration around its periphery, has a base fixed adjacent to the root portion of the drum and has first and second guide supports for the guide elements. At least one of the guide elements is movable relative to the base between an operative position close to the drum in which it guides the tape about the drum and an inoperative position at a further distance from both the other guide element and the periphery of the drum. A pair of spaced apart positioning members engage the periphery of the drum at its root portion for accurately locating the operative positions of the tape guide elements.

Abstract: A transducer-carriage assembly is shown which includes an intermediate adapter that enables the subassembly to be fabricated in a manner that eliminates the effect of tolerances in the component parts, prior to incorporation into the final assembly, with respect to penetration, pitch and roll of the transducer.

Abstract: A cleaning cassette for a tape unit includes a supply reel and a take-up reel, with a cleaning ribbon mounted therebetween. The cleaning ribbon extends around various support surfaces in the cassette, and passes two cleaning stations. The first cleaning station utilizes a spring biased plunger to force the cleaning ribbon against a pinch roller being cleaned. A traction sleeve is positioned between the capstan and the pinch roller to enhance the frictional engagement between the capstan and the pinch roller. At the second cleaning station, the cleaning ribbon passes between the capstan and the pinch roller. Once again, a traction sleeve is provided between the capstan and the pinch roller, and in this case the traction sleeve is offset with respect to the cleaning ribbon. Funnel-shaped openings and distribution channels are provided in the said shell to introduce a liquid such as a cleaning solvent onto the cleaning ribbon near the cleaning stations.

Abstract: A tape guide mechanism for a tape recorder comprises a pair of first tape guides severally attached to the free end portions of a head lever which has a rotation center in the middle thereof, each of the first tape guides being located on the opposite side of a magnetic head on each side of the head lever to a pinch roller on a pinch roller lever and on the side where its corresponding magnetic head lies. Further, a pair of second tape guides are disposed on the pinch roller lever so as to embrace the pinch roller from both sides thereof, thereby partially covering the pinch roller.

Abstract: A floppy disk drive with automatic disc clamping and ejection is disclosed. The movement of the linear actuator is used to provide both the clamping and ejection, without other drive means. A pair of magnetic heads, positioned on opposing sides of a drive wheel, are fixed to a carriage, one engages the upper surface of the disc, the other the lower surface. Neither head moves relative to the other. The drive components are easily assembled providing a relatively inexpensive, yet reliable drive.

Abstract: An erroneous erasure preventing piece to be detected is formed simultaneously with disk cassette covers by a molding process. The piece has a configuration which enables it to be slidably remounted to the cassette disk covers after being torn off the cover.