Ranging system

Claim 2

Ranging system comprising transmitting means for transmitting a short-duration pulse of electromagnetic radiation, receiving means for receiving reflected pulses, and time measuring means for measuring the time interval between the transmission of a pulse and the reception of one or more reflected pulses, said time measuring means including an oscillator for generating electric oscillations and a first counter for counting the oscillations generated by the oscillator from the time of transmission of a pulse, characterized in that it further comprises at least one register (31,32,33), connecting means (11,12,13) connecting said first counter (7) with the said register, a normally closed gate (21,22,23) in said connecting means, gate opening means (40,41,42,43) for momentarily opening said gate in response to a control pulse after at least one received reflected pulse, thereby causing the said register to record the momentary position of the said counter at the time of the reception of the reflected pulse, and a second counter (14) which is started in response to an incoming reflected pulse and then prevents further oscillations from the oscillator (5) to act upon said first counter (7) and after a time which is sufficiently long to allow the first counter to settle in response to the last received oscillation from the oscillator, transmits a control pulse to said gate opening means for opening one of said gates.

Claim 3

Ranging system as claimed in claim 1, characterized in that it coMprises a plurality of registers (31,32,33) which are connected to said first counter (7) over separate gates (21,22, 23), and that a distributing device (40) is connected to the said receiver means of reflected pulses, said distributing device being adapted to distribute automatically incoming pulses to different outputs (41,42,43) which are connected to separate ones of said gates (21,22,23), so that each gate is opened by a pulse appearing on the corresponding output from said distributing device so as to cause the time for the appearing of this pulse to be recorded in the register associated with the gate.

Claim 4

Ranging system as claimed in claim 1, characterized in that said second counter (14) after a predetermined number of counting steps causes the first counter (7) to respond again to oscillations from said oscillator, thereby causing the counter to continue the counting and in doing so jumping over said predetermined number of counting steps.

Claim 5

Ranging system as claimed in claim 1, characterized in that the control input of at least one (23) of said gates is directly connectable to means (14) for producing opening pulses in response to received reflected pulses.

Claim 6

Ranging system as claimed in claim 4, characterized in that the control input of at least one (23) of said gates is connected to a switch (20) for alternatively connecting said control input to one (43) of the outputs from said distributing means (40) or directly to said means (14) for producing opening pulses in response to received reflected pulses.

Claim 7

Ranging system comprising transmitting means for transmitting a short-duration pulse of electromagnetic radiation, receiving means for receiving reflected pulses, and time measuring means for measuring the time interval between the transmission of a pulse and the reception of at least one reflected pulse, said time measuring means including an oscillator for generating electric oscillations and counting means for counting the oscillations generated by said oscillator from the time of transmission of a pulse, a first register and a second register for recording the values indicated by said time measuring means, a comparison device for comparing the values indicated by said time measuring means with a predetermined reference value and to produce different output signals depending on whether the value indicated by said time measuring means is less or greater than said reference value, and switching means for making one or the other of said registers effective to record the position of said counting means upon the reception of reflected pulses, said switching means being controlled by the output signal from said comparison device so that one register is made effective as long as the values indicated by said measuring means are less than said reference value and the other register is made effective when, upon the reception of the reflected pulses, the value indicated by said time measuring means for the first time exceeds said reference value.

Claim 8

Ranging system comprising transmitting means for transmitting a short-duration pulse of electromagnetic radiation, receiving means for receiving reflected pulses, and time measuring means for measuring the time interval between the transmission of a pulse and the reception of at least one reflected pulse, said time measuring means including an oscillator for generating electric oscillations and counting means for counting the oscillations generated by said oscillator from the time of transmission of a pulse, a first register and a second register for recording the values indicated by said time measuring means, a comparison device for comparing the values indicated by said time measuring means with a predetermined reference value and to produce different output signals depending on whether the value indicated by said time measuring means is less or greater than said reference value, and switching means for making one or the other of said registers effective to record the position of said counting means upon the reception of reflected pulses, said switching means being controlled by the output signal from said comparison device so that one register is made effective as long as the values indicated by said measuring means are less than said reference value and the other register is made effective when, upon the reception of the reflected pulses, the value indicated by said time measuring means for the first time exceeds said reference value.

Claim 9

Ranging system as claimed in claim 6, wherein each of said registers is connected to said time measuring means via a gate which is normally closed, and said switching means, upon the reception of a reflected pulse, opens one or the other of said gates depending on whether the value indicated by said time measuring means upon the reception of that pulse is less or greater than said reference value.