Abstract: A MESFET device includes a semi-insulative substrate, a source region, a drain region, a channel region, a source electrode, a drain electrode, a gate electrode, and a gate-electrode pad. The source region, drain region, and the channel region are formed in a surface region of the substrate. The three electrode and the gate-electrode pad are formed on the substrate. The MESFET device further comprises a conductive layer formed on the substrate and surrounds the source electrode and the gate-electrode pad. The conductive layer is connected to the drain electrode.

Abstract: A magnetic disc cartridge loading and unloading mechanism comprises a shutter opening mechanism which applies no pushing force on a magnetic disc cartridge in a cartridge ejecting direction when the shutter opening mechanism is in an operating state where a shutter of the magnetic disc cartridge is opened. The magnetic disc cartridge loading and unloading mechanism is also provided with a pushing mechanism which pushes the magnetic disc cartridge slightly in the cartridge ejecting direction after sufficient gaps are formed between the shutter and magnetic heads when a holder which holds the magnetic disc cartridge rises to a predetermined height position during a cartridge unloading operation.

Abstract: A disc cleaner is disclosed. The disc cleaner includes a main casing, and a mounting structure located in the main casing to receive a disc to be cleaned. There is a lid operatively engaged with the main casing covering an upper surface of the main casing. A cleaner is mounted on an inner surface of the lid. A driving mechanism is located in the main casing. The driving mechanism is operated when the lid is positioned in a closed condition relative to the main casing. The driving mechanism is operatively connected to another mechanism for rotating and revolving the cleaner body to clean the disc.

Abstract: A GaAs planar diode includes an N type GaAs substrate having an N.sup.+ GaAs layer on which an N.sup.- GaAs layer is formed. A first impurity layer of the N.sup.+ type is formed on the N.sup.31 GaAs layer. A second impurity layer of a p.sup.+ type is formed on the first impurity layer, wherein a p-n junction is formed between the first and second impurity layers. A semi-insulation region, for encompassing a predetermined area of the p-n junction of the first and second impurity layers, is formed in the substrate. The depth of the semi-insulation region in the substrate is deeper than the total depth of the first and second impurity layers, so that the semi-insulation region serves as an element isolation region of the p-n junction of the first and second impurity layers.

Abstract: A bidirectional stepper motor having a lead screw coupled thereto is mounted to a sliding base which has two right-angular contact surfaces for sliding contact with two right-angular reference surfaces formed on a fixed platform of the machine. Fixedly mounted to the platform and extending parallel to both reference surfaces, a guide rod has a transducer carriage slidably mounted thereto for guiding the same in a radial direction of a flexible magnetic disk or like record media. The transducer carriage is mated with the lead screw for linearly transporting the transducer from track to track on the disk upon incremental rotation of the stepper motor. The sliding base is sprung against one of the two reference surfaces and is fastened to the other reference surface by screws inserted in and through clearance holes in the sliding base.

Abstract: Disclosed is a semiconductor device having a field effect transistor (FET) formed in a semi-insulative substrate. A positive bias voltage equal to or higher than the bias voltage applied to the drain electrode of the FET is applied to a back surface electrode formed on the back surface of the substrate, with the result that the electrons generated within the semi-insulative substrate are pulled into the back surface electrode so as to prevent said electrons from flowing into the drain region and, thus, to prevent the drain current vibration.

Abstract: A flexible magnetic disk, rotatably housed in an apertured envelope to make up a disk cartridge, is loaded through an entrance slot in the housing of the apparatus to a preassigned position for data transfer with a pair of transducer heads on its opposite sides. Upon subsequent manipulation of a clamp know, one of the transducer heads is sprung into forced contact with the other transducer head via the magnetic disk therebetween. In order to avoid the direct contact of the two transducer heads as a result of the user's tampering with the clamp knob when the disk cartridge is not loaded in the apparatus, a head control mechanism is provided for holding the transducer heads away from each other when the disk cartridge is not loaded, even if the clamp assembly is then actuated inadvertently.

Abstract: A GaAs semiconductor device, includes a p-type GaAs substrate, an n-type region formed in the surface area of the substrate, an ohmic contact electrode formed in ohmic contact with the n.sup.+ -type region and having a layer of alloy of gold, and an interconnection electrode formed on the ohmic contact electrode and including an upper layer of aluminum and a lower layer of a metal which prevents gold from passing through it. The interconnection electrode is formed such that it covers the top and side surfaces of the ohmic contact electrode.

Abstract: A device is disclosed for translating the bidirectional, incremental rotation of a disk drive motor of the electric stepping type into the reciprocating, stepwise displacement of a magnetic transducer head in a radial direction of a disklike record medium in a data transfer apparatus employing such record medium. The device includes a lead screw driven by the drive motor and extending parallel to the path of the transducer head. Slidably engaged in the helical groove in the lead screw is an engagement member, such as a ball or pin, which is supported on the head carriage of the data transfer apparatus for causing the linear travel of the transducer head in response to the rotation of the lead screw. The engagement member is affixed to a first cantilever spring on the head carriage, thereby to be biased into working engagement with the lead screw. A second cantilever spring on the head carriage acts on the first cantilever spring and coacts therewith to urge the engagement member against the lead screw.