| 摘要 |
<p>An apparatus and a method are provided for detecting discontinuities in a sequence of time code addresses recorded on a tape, such as a video tape, which also has control pulses recorded serially along its length to synchronize the motion of the tape relative to transducer heads which read and write information signals on the tape. The apparatus and method of this invention read the current time code address from the tape, count the control pulses read as the tape moves, establish a known relationship between the current time code address and the count of control pulses, so that the count represents a counted tape address, and compare the current time code address with the counted tape address for producing a non-compare signal in the event of a difference between these two compared values. A time code discontinuity signal is generated when a predetermined number of successive comparisons result in non-compare signals, indicating that the time code addresses read from the tape have not varied sequentially in a uniform relation to the control pulses. The value of the current time code address and the counted tape address at the time a discontinuity is detected can be used to define both the location and the magnitude of the discontinuity or to enable accurate calculation of the distance between two time code addresses each located on an opposite side of such a discontinuity.</p> |
