Kenneth Louth

46494413, Mar 10, 1987

Sep 27, 1984

6/655983

Kenneth Louth - Los Altos CA

Ampex Corporation - Redwood City CA

G11B 1518

360 71

An improved reel servo for a recording and reproducing machine is disclosed. The reel servo as well as other servos in the machine are controlled by a single microprocessor which results in greater inherent communication between such servos and significantly improved operating capabilities. The reel servo itself is adapted to have the supply and take-up reels operate in different kinds of close loop servo control during various operating modes. The servo circuitry provides instantaneous information to the microprocessor for determining the diameter of tape that is wrapped on each of the reels. The reel servo has the capability of performing high speed shuttle and cueing operations without engaging the capstan and the tensioning arm can be positioned to provide the appropriate tape tension during shuttling in both the forward and reverse directions. An acceleration loop controls the supply reel so that the tape tension is maintained within predetermined upper and lower limits.

46351388, Jan 6, 1987

Oct 2, 1984

6/660453

Kenneth Louth - Los Altos CA

Ampex Corporation - Redwood City CA

G11B 1552

360 103

A microprocessor controlled multiple servo system for use with a recording and reproducing apparatus is disclosed. The system controls all servo systems for a magnetic tape recording and reproducing apparatus, including a capstan servo, a reel servo, a scanning drum servo and an automatic scan tracking servo which controls the position of reproduced heads carried by the scanning drum which are of the type which can be transversely moved relative to the longitudinal direction of recorded tracks to accurately follow the tracks during special effect reproducing modes, such as slow motion, stop motion and fast motion reproducing. The microprocessor controlled servo system has unique and powerful functional capabilities which enable it to provide reliable precise asynchronous reproducing so that precisely accurate time compression and expansion can be carried out without performing any editing of the recorded material.

45449678, Oct 1, 1985

Apr 2, 1982

6/364961

Kenneth Louth - Los Altos CA

Ampex Corporation - Redwood City CA

G11B 556

360 77

An improved automatic scan tracking servo for use in a magnetic recording and reproducing apparatus is disclosed. The automatic scan tracking servo operates generally in the digital domain. The apparatus has a movable element which is transversely moved relative to the longitudinal direction of a recorded track so that the transducing head can be made to accurately follow the track during special motion reproducing modes. The RF video signal is sampled a predetermined number of times during each rotation of the scanning drum carrying the transducing head. The phase of the oscillatory motion or dither that is applied to the movable element carrying the head, the operation of a synchronous detector and the sampling are all totally synchronized to obtain an accurate error signal so that an accurate error correcting signal can be generated to have the transducing head accurately follow a track during such reproducing. The servo utilizes the longitudinal tape speed to provide a predicted value of the slope of the ramp that is required to have the head follow the track and the error correcting signal merely modifies the ramp in accordance with the actual error that is detected. The combination of the synchronism and the predicted value of the slope enables a reduced dither amplitude to be used to obtain an accurate error signal.

39380416, Feb 10, 1976

Jun 21, 1973

5/371975

Kenneth Louth - Menlo Park CA
Reginald William Oldershaw - San Jose CA

Ampex Corporation - Redwood City CA

G01R 1700
B65H 5938

324158R

An unknown tape pack diameter is determined by measuring the inertia of the unknown tape pack and comparing the inertia with an inertia value representative of the inertia of a second tape pack of known diameter.

45381909, Aug 27, 1985

Sep 4, 1984

6/647260

Kenneth Louth - Los Altos CA

Ampex Corporation - Redwood City CA

G11B 1544

360 73

A monlinear speed control for special motion reproducing of a video recording and reproducing apparatus is disclosed. The apparatus is of the type which has an automatic scan tracking servo which controls the position of the reproduced heads carried by the scanning drum which are of the type which can be transversely moved relative to the longitudinal direction of recorded tracks so as to accurately follow the tracks during variable speed special effect reproducing modes. The nonlinear control controls the longitudinal tape speed through the capstan servo and provides vernier control where it should be desirably located so that the operator can accurately control the special effect speeds. The nonlinear control also automatically compensates for changes in the speed and introduces a delay in the response to rapid changes that may occur at high speed special motion reproducing so that visually disturbing rapid changes in the video image will not be experienced by a viewer.

45958688, Jun 17, 1986

Feb 27, 1985

6/707161

Kenneth Louth - Los Altos CA

Ampex Corporation - Redwood City CA

G05B 1101

318608

A phase detection control apparatus is disclosed for detecting any variable where the phase is discretely measured, as for example, in a motor having a tachometer of an optical type. The phase detection apparatus eliminates direction sensitivity and does not suffer from the misposition of any upper and lower limits. The apparatus achieves a phase lock without excessive overshoot and eliminates the possibility of reverse run away under any condition. Moreover, the circuitry is easily implemented with a relatively few number of circuit components and therefore accomplishes the desirable functional capabilities at relatively low cost.

45146713, Apr 30, 1985

Apr 2, 1982

6/364963

Kenneth Louth - Los Altos CA

Ampex Corporation - Redwood City CA

G05B 1928

318603

An improved microprocessor controlled scanning drum servo adapted for use in a recording and reproducing apparatus is disclosed. The scanner servo includes a velocity loop as well as a position loop, and by virtue of the fact that it is controlled by a microprocessor in a unique way, has extraordinary accuracy because the resolving power of the servo is essentially that of the microprocessor itself. The interrupts to the microprocessor occur in sequence with a first interrupt causing the microprocessor to cease current activity, store all required information in a stack register and thereafter wait until a subsequent interrupt occurs which enables it to immediately act to perform control operations with respect to the scanner servo. This enables the velocity loop to perform the vast majority of the work required by the servo and as a result of this, the phase closed servo loop operates as a positioning loop in the true sense.

45368066, Aug 20, 1985

Apr 2, 1982

6/364725

Kenneth Louth - Los Altos CA

Ampex Corporation - Redwood City CA

G11B 552
G11B 1546
G11B 2104

360 69

A microprocessor controlled multiple servo system adapted for use with a recording and reproducing apparatus is disclosed. The system controls all servo systems for a magnetic tape recording and reproducing apparatus, including a capstan servo, a reel servo, a scanning drum servo and an automatic scan tracking servo which controls the position of reproduce heads carried by the scanning drum which are of the type which can be transversely moved relative to the longitudinal direction of recorded tracks so as to accurately follow the tracks during special effect reproducing modes, such as slow motion, stop motion and fast motion reproducing. The microprocessor controls all of the servos in a way which permits interaction between the various servo systems and enables more accurate and powerful functional operation of the entire apparatus.