Display apparatus for tape running positions

Claim 1

A display apparatus for tape running positions comprising: a tape transport system in which the rotational speeds of a first reel and a second reel change in accordance with the amount of tape running, a first signal generator for producing m number of pulses constituting a first signal e 1 for each revolution of the first reel, a second signal generator for generating n number of pulses constituting a second signal e 2 for each revolution of the second reel, counter means for counting the repetitive number of first signals e 1 occurring during one period of second signal e 2 , data preset means for providing to the counter means preset data to offset the count value counted by the counter means at an initial stage of tape running, in order to assign the display depending on the first signal e 1 sensed during one period of the second signal e 2 at the initial stage of tape running to the start point of the tape running position, and display means connected to a count output circuit of the counter means in order to perform a numerical display corresponding to the tape running amount, said counter means comprising an up/down counter preset by a third signal e 3 having the same period as of said second signal e 2 and occurring behind the second signal e 2 , a logic circuit for providing a set signal when the count output of said up/down counter becomes zero in order that, upon completion of the cancelling operation of the count by the preset data provided by said data preset means, the display at the start point of the tape running position is rendered zero; a flip-flop set by the set signal of said logical circuit and reset by the second signal e 2 , and a gate circuit for applying the first signal e 1 to the down-count input terminal of said up/down counter when said flip-flop is reset, and for applying the first signal e 1 to the up-count input terminal of said up/down counter when said flip-flop is set.