U.S. Philips Corporation

Budiman Sastra

Martinus A Renders

Jacob G Fijnvandraat

Gerardus Maria Dohmen

Everhardus A Muijderman

Leonardus H Maaswinkel

Jan H Mengelers

The invention relates to a system comprising a magnetic tape (7) and a magnetic tape apparatus (1), which apparatus (1) comprises drive means for driving the magnetic tape (7) and reels (5,6), magnetic-head means (9, 10), and buffer means comprising a belt (8), the information on the magnetic tape (7) being arranged in sections (47) and being recorded in individual discontinuous tracks (48) within the sections (47), each section (47) having a magnetically recorded address (49). The system further comprises input means (51) for selecting one of the sections and a control unit (45) comprising a selection device (45a) for the rapid location of the section (47), and control means (45b) for controlling the tape transport within a section (47). As a result of this, the system is suitable for the storage of large amounts of information in serial form in such a way that the information within each section (47) can be scanned directly.

System for random access to information on a magnetic tape

A magnetic-tape apparatus is disclosed which includes a drive mechanism for driving a magnetic tape and tape reels, a magnetic-head mechanism buffer mechanism comprising a belt (8), guide elements for guiding the belt in an operational position, a tape-threading mechanism which during the thread-out phase threads the tape out of the cassette and wraps it around the magnetic-head mechanism and during the thread-in phase threads the tape into the cassette. A belt-threading mechanism threads the belt between the guide elements into the tape path during said thread-out phase and brings the belt back into its initial position during the thread-in phase. The apparatus (1) also includes a mechanism for moving the belt-threading mechanism in such a way that the belt can be brought into the desired operational position and into said initial position.

Magnetic-tape apparatus comprising a threading mechanism for the

A magnetic tape apparatus (1) comprises a drive mechanism for driving a magnetic tape (7) and reels (5, 6), a magnetic-head mechanism (9, 10), a buffer mechanism a belt (8) and guide elements (21, 22, 23, 24), which guide the belt (8) in the operational position, which apparatus (1) also comprises a control system for controlling the tape tension, for controlling the position of the belt (8) in the operational phase and for locating a desired part of the tape. The control system comprises a position detection mechanism (38) a tape-tension detection mechanism (44), and a control unit (45) for controlling the reel and tape drive mechanism.

Magnetic tape apparatus comprising a control unit for controlling tape

A rotatable magnetic-head unit comprises a cylindrical drum with at least one magnetic head for recording and/or reproducing signals on/from a magnetic tape. This magnetic tape is wrapped around a part of the circumference of the drum and is moved past that part of the drum circumference. in order to obtain a stable bearing arrangement for the magnetic-head unit the magnetic head is fixedly connected to the drum, whose wall is supported by means of spiral-groove bearings in the direct proximity of the magnetic heads in a stationary cylindrical housing. The drum can rotate inside the housing. The housing is formed with an opening in which the magnetic tape moves.

Rotatable magnetic-head unit for a magnetic-tape apparatus

A plurality of magnetic head cores is cut from a preprocessed ferrite core block having a gap formed by means of a fracture method. To this end the core block is notched on a line along which the gap is to be formed. subsequently the core block is subjected to a load (tensile stress) until it breaks on the line. A non-magnetic material in a liquid form is provided between the fracture faces which are kept at a desired distance from each other until the material has cured. In a preferred method the core block consists of a first sub-block having a series of yokes and a second sub-block bonded thereto to define the winding apertures. This permits use of a high grade ferrite only at the gap, and further permits winding the limbs of the yoke prior to bonding.

Method of manufacturing magnetic head cores

A magnetic head has a contact face (2) for a magnetic tape which can be moved in a direction (V) along the face (2). A transfer gap (3) lies in a region (6) of the contact face (2), which is curved into a concave shape in the direction of movement (V). On either side of this region (6) there are located regions (7, 8) curved into a convex shape in the direction of movement (V). The contact face (2) is curved into a convex shape transverse to the direction of movement (V). Due to the shape of the contact face (2), an information carrier exerts only a low pressure on and near the transfer gap (3), as a result of which the degree of wear is low at this area and the life of the magnetic head is long.

Magnetic head with concave contact face

A device for the magnetic recording and/or playing back of signals on a flexible recording medium (4) includes a magnetic transducing head (2) and transport and guide means (8, 8') for bringing successive parts of a flexible recording medium (4) in physical contact with a surface (1, 10) of the head. The head surface is curved and comprises a non-magnetic transducing gap (3) which intersects the direction of movement of the recording medium to obtain an optimum contact between recording medium (4) and head (2) at the area of the transducing gap (3). The radius of curvature of the contact face (10) of the head (2) with the recording medium (4) has a maximum value at the area of the transducing gap (3) and decreases from the transducing gap (3) to both the part of the head where the recording medium moves towards the transducing gap and to the part of the head where the recording medium moves away from the transducing gap (3).

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Eindhoven, Netherlands

Budiman Sastra