Ampex Corporation

Thomas L Helmers

David C O'Gwynn

Glenn T Yoshida

David N Larkins

An apparatus for controlling conditions in response to an operator input, the apparatus including a rotary knob coupled to the shaft of the rotor of a stepper motor having first and second stator windings, in quadrature, with each winding being center tap grounded to provide first and second winding portions for each winding. One pair of first winding portions are used for providing pulse inputs to a microprocessor on rotation of the knob, in either direction, via a pulse control system, with the microprocessor providing command signals to a braking control system, which includes a direct current power control source, which may be either a voltage or current control source. The power control source, in turn is in circuit relation with the pair of second winding portions. On command of the processor, a force or torque is applied to the rotor, by means of energization of the other pair of winding portions, with the force being in opposition to the direction of rotation of the knob, the force being in proportion to the applied power. Under control of a microprocessor, the force may be intermittently applied to simulate a mechanical detent arrangement, or a constant force for braking, either of which provides tactile feedback to the operator.

Interactive rotary controller system with tactile feedback

An adaptive velocity change profile for control of a video tape transport apparatus during a cue mode. The tape transport apparatus moves the video tape to a cue point in the shortest time available by adapting a deceleration velocity change profile to the actual ballistics of transport of the tape. When in a cue mode, the transport uses a commanded velocity signal generator to produce digital numbers which are applied as a reference speed signal to a velocity servo driving the takeup reel of the transport. For distances separating a selected frame location on the tape from the cue point greater than a predetermined distance, the commanded velocity is the maximum available from the transport. For distances to the cue point less than the predetermined distance, the commanded velocity is generated from an adaptive cue profile which decelerates the transport of the tape quickly as the selected frame location approaches the cue point without overshooting the mark. The deceleration velocity change profile is optimized as according to the distance separating the selected frame location from the cue point and the measured ballastics of transport of the tape. The measured ballistics of transport of tape varies according to variances in inertial loading represented by transport direction, tape reel size, and cue location with respect to tape pack distribution. The difference between velocity values for optimized profiles of the maximum and minimum inertial loading is proportioned depending upon the measured inertial loading to generate the commanded velocity.

Method and apparatus for transporting a recording medium with an

The changing diameters of the respective tape packs wound on the supply and take-up reel are continually measured. The measured diameters of each reel are compared to a stored minimum diameter value corresponding to an end of tape on that particular reel. When the apparatus is in a learning mode, the stored minimum diameter values for each reel are updated every time when a new measured value is smaller than the previously stored value. The last stored value is utilized for comparison in an end of tape detection mode, to allow stopping the tape transport mechanism before the end of tape would run off that reel to prevent damaging the transducers or the tape.

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Millbrae, CA, United States of America

Thomas L Helmers