| 摘要 |
<p>PURPOSE:To perform displaying of correct tape running time and recording time by changing over the counting modes of a sexagesimal counter according to conditions and displaying a minus symbol. CONSTITUTION:When a tape runs in a backward direction and a tape running diretion detection signal 43 inverts, the output of a NAND circuit 38 via NAND circuit 44 AND circuit 45 and the output of a NAND circuit 75 via NAND circuits 74, 90 invert, then the inverted output of a KJFF 41 causes down-counting by a sexagesimal counter wihich counts the hour, minute and second to be accomplished and the moving time of the tape is subtracted from the value before starting and is displayed. When the time thus displayed becomes 00 hour, 00 minute, 00 second, the whole outpout of the sexagesimal counter becomes low level. A monostable multi 40 is then triggered by inverters 80 thru 84, AND circuit 86, NAND circuit 39, causing a minums displying light emitting diode 88 to light. Also, the output of the multi 40 inverts the outputs of the circuits 74, 90, 73, 44, then through the FF 41, the sexagesimal counter is put in up-count mode, thus correct displaying without requiring mental calculation is accomplished.</p> |
