Patent ID: 11965963
Assignee: DENSO WAVE INCORPORATED
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A laser radar comprising:
a clock generator configured to generate a clock signal repeated, every constant period, between mutually different first and second levels changing via a signal edge thereof;
a projection unit configured to project pulse laser light in synchronization with the signal edge of the clock signal;
a light reception unit configured to receive reflected light of the pulse laser light reflected by an object;
a counter configured to count, as a counter value, a number of the clock signals generated a period between a projection timing at which the pulse laser light is projected by the projection unit and a light reception timing at which the reflected light is received by the light reception unit;
a delay circuit provided with a plurality of stages of delay units connected in series, each of the delay units having a specified delay time, the clock signal being repeatedly inputted to one of the delay units and being delayed, every repetition, by an amount of the specified delay time and the delayed clock signal being inputted to a next-stage delay unit;
a stage-number calculation unit configured to calculate a number of transmission stages showing that a head of the clock signal inputted to a first-stage delay unit of the delay units is transmitted to which one of the delay units, in a period from a timing at which the head of the clock signal has been inputted to the first-stage delay unit to a timing at which the reflected light has been received, in each of the periods of the clock signal during each of which the first and second levels are changed;
a time calculation unit configured to calculate a round trip time of the pulse laser light projected and the reflected light thereof is returned, on a basis of the counter value, the constant period, the number of transmission stages calculated, and the specified delay time; and
a distance calculation unit configured to calculate a distance to the object on a basis of speed of the pulse laser light and the round trip time calculated by the time calculation unit.