| 摘要 |
PURPOSE:To continuously store a signal for an optional time, by constituting a signal circulating circuit of a pulse generating circuit, amplitude modulating circuit, acoustic delay line, low-pass filter, threshold value circuit, and an erasing circuit, and stably storing a pulse signal for a long time. CONSTITUTION:The output of a low-pass filter 8 is inputted into a threshold value circuit 9 and, only when the amplitude is higher than a specified value, the output of the threshold value circuit appears. The output of the threshold value circuit 9 is outputted to an output terminal 16 as a delay output signal and, at the same time, sent to an erasing circuit 10. The erasing circuit 10 is a kind of switch which makes opening and closing operation in accordance with an erase signal from an erase terminal 17 or that from an input circuit 2 and, when this circuit is closed, the delay output signal is sent to a pulse generating circuit 3 and reduced to a trigger signal for generating a rectangular pulse signal. A closed loop circuit containing an ultrasonic delay line 6 is constituted in this way and input signals are circulated inside the circuit and stored. When any stored signals are erased, the erasing circuit 10 is opened and the circulation of signals is stopped. |
