Patent ID: 7911593

Claim:
A range finder/velocimeter characterized by comprising: a semiconductor laser which emits laser light to a measurement target; a laser driver which causes said semiconductor laser to operate such that a first oscillation period including at least a period of continuously and monotonically increasing an oscillation wavelength and a second oscillation period including at least a period of continuously and monotonically decreasing the oscillation wavelength alternately exist for at least two periods; a light-receiving device which converts laser light emitted from said semiconductor laser and return light from the measurement target into electrical signals; counting means for counting the number of interference waveform components caused by laser light emitted from said semiconductor laser and return light from the measurement target which are contained in an output signal from said light-receiving device in at least part of each of the first oscillation period and the second oscillation period; and computing means for calculating a distance to the measurement target and a velocity of the measurement target from a shortest Lasing wavelength and a longest Lasing wavelength in a period during which the number of interference waveform components is counted by said counting means and a counting result obtained by said counting means.