Abstract: In a magnetic tape-automatic tracking method, at least one of the positions of the upper and lower edges of a magnetic tape is detected by an assembly of a tape edge position sensor and light-emitting diode. Any displacement of the running magnetic tape from its standard vertical position is determined from detected data. A generally vertical tape edge position-compensating post which applies a tensile force to the magnetic tape in contact therewith is rotated in a vertical plane by a reversible motor in accordance with the detected extent of the displacement of the running magnetic tape from its standard vertical position. The magnitude of a tensile force applied by the tape edge position-compensating post to the magnetic tape is varied, by the extent of the rotation of the reversible motor. As a result, the magnetic tape is vertically moved in the desired direction to regain its standard vertical position.

Abstract: A device for stably running a magnetic recording tape of a tape cassette comprises a reel shaft and a motor connected to the reel shaft. The reel shaft and the motor make a running of the magnetic recording tape providing back tension exerted on the magnetic recording tape. Within the housing of the tape cassette, a first lever having one end rotatably fixed to the housing is mounted. A guide roller for guiding the running direction of the tape is rotatably fixed to another end of the first lever. Therefore, the first lever may swing in response to a back tension exerted on the tape. An amount of the swing of the first lever is detected by a second lever which is rotably located out of the housing and selectably engaged with the first lever. The second lever is connected to the detection means which generates an electric signal in accordance with the amount of rotation of the second lever. The electric signal is sent to the electric controlling circuit means electrically connected to the motor.

Abstract: A tape cassette comprises an impedance roller which is set on the opposite side of a magnetic tape to a magnetic head closely upstream thereof as viewed from the direction in which the magnetic tape runs. The impedance roller presses the magnetic tape toward the magnetic head, thereby preventing the magnetic tape from being shaken.

Abstract: Within a housing of a tape cassette is mounted a reel hub serving to wind a magnetic recording tape. The reel hub is moved between a first position where one side edge of the tape wound around the reel hub is spaced from a wall of the housing and a second position where the one side edge of the tape abuts against the wall, reel hub being rotated at the first position by a reel shaft of a magnetic recordig tape running apparatus inserted through an opening of the wall of the tape cassette for engagement with the reel hub. Within the housing is also mounted a abutment member.

Abstract: A multichannel magnetic head with a plurality of U-shaped cores each contacting at both ends a magnetic tape, in which the plurality of cores are arranged in two series, as viewed in the head face, in such a manner that one end of two legs of each core in one series is disposed between the ends of two adjacent legs of a core or cores in the other series.

Abstract: A multi-channel magnetic head used with a magnetic tape comprises a core housing and a plurality of U-shaped cores disposed in the core housing. Each U-shaped core is inclined to the running direction of the magnetic tape at such an angle that its legs trace different tracks of the tape. The U-shaped cores are juxtaposed widthwise of the tape at such regular intervals that the legs of any adjacent two cores trace different tracks of the tape.A method for manufacturing U-shaped cores of a multi-channel magnetic head used with a magnetic tape. The method comprises steps of forming a U-shaped groove in core material in the form of an elongated tetragonal prism on one long face thereof, said groove extending in the lengthwise direction of the core material; cutting the edges of two walls defining the U-shaped groove therebetween to form wedges of an acute angle; and slicing the core material slantwise with respect to the axis of the U-shaped groove.

Abstract: A composite magnetic head including a record/playback gap and an erase gap comprises a straight central core, a pair of arcuate lateral cores having their ends disposed in opposing relationship with the opposite ends of the central core disposed therebetween, each of the lateral cores being formed with a bobbin carrying portion at its one end which extends in a direction perpendicular to the length of the central core, a bobbin having a central flange and a pair of flanges at the opposite ends, the central flange being formed with an opening for receiving the central core and the bobbin being formed with a slot extending through the entire length of the bobbin including the flanges at the opposite ends for receiving the lateral cores, the slot extending in a direction perpendicular to the opening which receives the central core, and a pair of coils disposed between the central flange and the respective end flanges, the central core and the lateral cores forming a record/playback gap and an erase head at their

Abstract: A magnetic head for use with a tape recorder or the like comprises a core having a gap and which has a non-magnetic material of a similar mechanical property as the core material bonded to the periphery or part thereof, thereby preventing a foul-up of the head surface with dusts and avoiding damage to the magnetic tape; the foul-up or the damage occurs when the periphery of the core is filled with a layer of synthetic resin adhesive.