TRANSPORT CONTROLLER

• US 3,681,523 A
• Filed: 08/13/1970
• Issued: 08/01/1972
• Est. Priority Date: 08/13/1970
• Status: Expired due to Term

• Current Assignee: George B. Sidline
• Original Assignee: George B. Sidline
• Inventors: Sidline, George B.
• Primary Examiner(s): Goudeau, J. Russell
• Application Number:
  US05/063,478
• Time in Patent Office: 719 Days
• Field of Search: 178/6.6A 179/1.2B,1.2S 235/92CC,92PE
• US Class Current: 360/72.3
• CPC Class Codes: G11B 15/005 Programmed access in sequence to indexed parts of tracks of operating tapes, by driving or guiding the tape access by driving of both record carrier and head G11B15/1816; see prov. also G11B15/602
• CPC Class Codes: G11B 15/52 by using signals recorded on, or derived from, record carrier

Abstract

The actual length a magnetic tape must be transported to position a particular storage address at a certain point is compared to a reference indicative of tape length decreasing at a known rate. Enabling and disabling signals are provided in response to the comparison; the enabling signal being provided when the actual and reference lengths are the same and the disabling signals when they are different. Two counters are coupled to receive the enabling and disabling signals and are associated with each other to provide an output signal when the actual tape length and reference tape length are equal for a predetermined interval and inhibit the provision of the output signal when they are not equal for the predetermined interval.

Claims

1. Apparatus for controlling the transport of an object to be positioned at a certain location at a predetermined instant, the combination comprising:

means responsive to the transport of the object to provide a signal representative of the actual distance the object must be transported to position it at the certain location;

a source of reference signals providing a reference signal indicative of distance which decreases at a known rate;

comparison means responsive to the reference signal and actual distance representative signal to provide an enabling signal when both the reference signal and actual length representative signal represent the same distance and an inhibiting signal when the signals represent different distances;

a first counter coupled to be enabled to count in response to the enabling signal and to issue an output signal when its count progresses to a predetermined count; and

a second counter, said second counter coupled to be enabled to count in response to the inhibiting signal and to be reset in response to the enabling signal, said second counter coupled to issue a reset signal when its count progresses to a predetermined count, and said first counter coupled to be reset by the reset signal.

2. The apparatus according to claim 1 wherein a record medium for storing information at identifiable locations is transported to position a particular location at the certain location at the predetermined instant;

the distance representative signal provided by the transport response means represents the actual length of the record medium that must be transported to position its particular location at the certain location;

the reference signal provided by the reference signal source is indicative of record medium length; and

the comparison means provides enabling and disabling signals according to the lengths represented by the compared signals.

3. The apparatus according to claim 2 further including means providing pulses the number of which represent the length of transported record medium, the first and second counters each coupled to count the pulses when enabled by the comparison means.

4. The apparatus according to claim 3 wherein the record medium is a magnetic record medium having a plurality of discrete storage locations;

the actual length representative signal provided by the transport responsive means is in number of discrete storage locations;

the reference signal provIded by the reference signal source is in number of discrete storage locations;

the predetermined count of the second counter is less than the predetermined count of the first counter and is selected relative to the number of pulses provided per unit length of transported magnetic record medium to be less than one-half the number of pulses provided for each discrete storage location.

5. The apparatus according to claim 4 wherein the predetermined count of the first counter is selected relative to the number of pulses provided per unit length of transported magnetic record medium to be more than two times the number of pulses provided for each discrete storage location.

6. The apparatus according to claim 5 wherein the predetermined count of the second counter is equal to about one-third the number of pulses provided for each discrete storage location, and the predetermined count of the first counter is equal to about three times the number of pulses provided for each discrete storage location.

7. The apparatus according to claim 5 wherein the magnetic record medium is a magnetic video tape with each of its successive frames identified by consecutive ones of a sequence of address signals recorded along the tape at a known clock rate, the address signals are reproduced and detected to provide the actual length representative signal, and the pulses provided per unit length of transported tape are at reproduced clock rate.

8. The apparatus according to claim 7, wherein the reference signal is decreased at a rate equal to the rate of transport of the magnetic video tape when transported at transduction speed.