Abstract: In order to diminish the effects of debris on recording and playback in a cartridge loaded recorder, adhesive material is placed inside the enclosed magnetic tape cartridge. The adhesive is placed on appropriate interior walls and other available surfaces of the cartridge, and is covered by a protective screen having holes through which the debris may pass. The size of the holes is large relative to the debris size. The adhesive material is located clear of the magnetic tape path, magnetic heads and guides, and if an inadvertent tape loop occurs in the cartridge, the protective screen insures that the magnetic tape cannot come into contact with the adhesive proper. Any losse debris, however, incident on the holes of the protective screen is captured and immobilized by sticking to the adhesive material.

Abstract: In the practice of the invention, a small magnet is attached to a slidable tab located on the leading edge of the cartridge. Before insertion of the cartridge into the recorder, the slidable tab is moved by the user to one of two positions. One position is the write protect position for inhibiting recording on the tape in the cartridge, and the other position permits recording on the tape. The associated recorder has two side by side Hall effect sensors. When the cartridge is positioned in the recorder, the magnet, depending upon the selected position of the cartridge tab, is directly opposite to, and activates, only one or the other Hall effect sensors. If no cartridge is in the recorder, neither Hall effect sensor is activated, indicating that no cartridge is in place. If the cartridge is in the recorder, and if the first sensor is activated, then the write protect circuit of the recorder is energized. If the second sensor is activated, then writing on the tape is permitted.

Abstract: In a magnetic tape recorder in which information is recorded on a plurality of longitudinal tracks running parallel to the length of the tape, a technique is disclosed for optimizing the positioning of a pair of magnetic heads for simultaneously reading information recorded on a pair of spaced tracks on the tape. The pair of spaced magnetic heads are mounted for simultaneous movement across the width of the tape in small uniform steps. The output of each magnetic head is monitored as the heads are moved laterally across two reference tracks at the beginning of the magnetic tape. An optimal position for both heads is determined as the mean position of the region of travel during which the amplitude of the output signal from both heads exceeds a predetermined reference value. This technique is also applicable to magnetic disc drives.

Abstract: A closed loop circuit corrects digital data baseline shift resulting from perturbing interferences. Samples of the signal amplitude are stored at each clock time; and a correction signal is derived from the stored information. The correction signal is subtracted from the data signal to produce a resultant signal that is devoid of baseline shift, such resultant signal being also used to control clock regeneration in a phase locked loop.

Abstract: Bidirectional tape drive systems have first and second tape drive capstans and first and second tape drives for rotating, respectively, the first and second tape drive capstans. The first capstan is angularly movable relative to the first capstan drive and a first elastic coupling restrains relative angular movement between the first capstan and the first capstan drive. Similarly, the second capstan is angularly movable relative to the second capstan drive and a second elastic coupling restrains relative angular movement between the second capstan and the second capstan drive. In this manner, tape tension is maintained above zero when the bidirectional tape drive changes directions, and excessive tension upon application of the tape assembly to the tape drive is avoided, while tape slack upon removal of the tape assembly from the tape drive is automatically taken up.

Abstract: A high track density recording head assembly which eliminates cross-talk in high track density recording systems by positioning very thin neutralization heads between each pair of adjacent recording heads. The neutralization heads are provided with air gaps aligned with the gaps in the adjacent heads and have coils wound to develop a polarity opposite to that in the adjacent recording head. The neutralization head flux thus produced cancels the recording head lateral fringing flux that is responsible for recording interference in the adjacent recording tracks.

Abstract: The manufacture of a tachometer of a type having annularly arranged tachometer markings on a rotary tachometer device includes the steps of rotating the tachometer device. A signal is generated having recurring signal portions for providing tachometer markings upon recordation on the rotary tachometer device. The number of signal portions occurring in the latter signal durin a revolution of the rotating tachometer device is adapted to a whole number of tachometer markings accommodable on the tachometer device in a continuous circular array. The signal having the mentioned adapted number of signal portions is recorded onto the rotating tachometer device to provide the tachometer markings in a continuous circular array.

Abstract: A motion monitor particularly useful for monitoring infant respiration, and comprising an oscillator driving an ultra-sonic wave generator, a receiver for ultra-sonic echoes, a phase detector for detecting phase shift between the outputs of th detector and oscillator and means for recovering the respiration envelope from the output of the phase detector. In a preferred embodiment the system includes a phaselocked loop using selected very low frequencies in the output of the phase detector to control the oscillator frequency.

Abstract: Methods and apparatus are disclosed for handling a compatible solution relative to a circulatory system of a living organism with the aid of a catheter and a recipient device having a circular cavity connected to the catheter. The compatible solution is injected into the circular cavity and is rotated in that cavity in a whirl sweeping all regions of the circular cavity and having a peripheral portion encompassing a central axis of the circular cavity and proceeding circumferentially along a peripheral boundary of the circular cavity.There are also disclosed methods and apparatus for transferring a pressure signal relative to a liquid in a circular cavity. Liquid is injected into the circular cavity and is rotated therein in a whirl sweeping all regions of the circular cavity and having a peripheral portion encompassing a central axis of the circular cavity and proceeding circumferentially along a peripheral boundary of the circular cavity.

Abstract: An apparatus for transporting tape includes an improvement for suppressing a predetermined flutter component comprising a member defining a surface for guiding the tape, equipment extending to that tape guiding surface and defining a gas column having a resonance frequency corresponding to the frequency of the flutter component, and equipment operatively associated with the surface defining member for coupling the gas column to the tape. This coupling equipment is of a type which establishes and maintains at the gas column a gas film of a controlled thickness between the guiding surface and the tape.