Rangefinder and digital single shot circuit

A system for displaying the range of remote targets in space comprising:

• (a) transmitting means for transmitting energy to remote targets, said transmitting means providing a reset signal;
• (b) detector means for receiving portions of said energy reflected by the remote targets;
• (c) a readout counter coupled to said transmitting means and responsive to said reset signal to be preset, said readout counter providing remote target information;
• (d) a timing counter coupled to said readout counter, said timing counter at a full count controlling said readout counter to stop counting and provide range information of the remote target;
• and
• (e) a digital single shot circuit including a flip flop and a shift register, said shift register having a plurality of stages coupled to said flip flop for being reset and having at least one stage coupled to said flip flop for clearing said flip flop when said shift register is reset, said flip flop being triggered by said detector means and enabled by a predetermined count of said timing counter, said shift register providing a reset signal to said timing counter.

A ranging system for determining the range of a remote target within a selected interval comprising:

• (a) means for transmitting energy;
• (b) means for detecting the presence of said energy when reflected by a remote target located within said interval and for producing a return pulse signal indicative thereof;
• (c) a digital single shot circuit to accept said return pulse signal and to produce an output responsive thereto, said output being a reset pulse;
• (d) said digital single shot circuit including means for retriggering so that said digital single shot circuit is activated by and responsive to the application of a second return pulse during the duration of said reset pulse;
• (e) a timing counter, said counter being reset by said reset pulse;
• and
• (f) a readout counter, said counter being controlled by the count of said timing counter so that the count of said readout counter indicates the range of said target corresponding to the last return pulse signal at the time that said timing counter reaches its maximum count.

A resettable digital single shot circuit which comprises:

• (a) a flip flop, said flip flop being transformed from a first state to a second state by the application of a triggering pulse to said digital single shot circuit;
• (b) a shift register, the output of at least one stage of said shift register being utilized to produce the output of said digital single shot circuit;
• (c) said shift register having a clearing means common to all stages thereof, said clearing means being coupled to an output of said flip flop so that all stages of said shift register are reset upon the transition of said flip flop from said first state to said second state;
• and
• (d) the output of said at least one stage of said shift register being utilized in turn to return said flip flop to said first state so that the state of said flip flop is responsive to each triggering pulse applied to said digital single shot circuit, whereby said digital single shot circuit is responsive to all triggering pulses applied thereto.