Scanning 3D imaging device with power control using multiple wavelengths
AssigneeMicrovision, Inc.
InventorsP. Selvan Viswanathan, Bin Xue
Life of this patent
Estimating the term…
Abstract
Laser light pulses of at least two different wavelengths are reflected off a scanning mirror. A first time-of-flight distance measurement circuit receives reflected light pulses of a first wavelength and determines distances. A second time-of-flight distance measurement circuit receives reflected light pulses of a second wavelength and determines distances. The laser light pulses of different wavelengths may be interleaved in time to increase resolution. The laser light pulses of different wavelengths may also be used for detecting safety violations and/or power control.
Claims11
A method comprising:
- producing a first laser light pulse having a first power level and a first wavelength;
- producing a second laser light pulse having a second power level and a second wavelength;
- reflecting the first and second laser light pulses off a scanning mirror that scans in alternating sweeps in a field of view;
- receiving reflections of the first and second laser light pulses to produce received first and second laser light pulses;
- measuring amplitudes of the received first and second laser light pulses;
- and
- based on the amplitudes of the received first and second laser light pulses, modifying the first and second power levels to produce laser light pulses for time-of-flight measurement, wherein the laser light pulses for time-of-flight measurements include laser light pulses at the first wavelength interleaved in time with laser light pulses of the second wavelength to decrease an effective minimum pulse spacing and increase a spatial measurement resolution in the field of view.
An apparatus comprising:
- a first laser light source to emit laser light pulses of a first wavelength;
- a second laser light source to emit laser light pulses of a second wavelength;
- at least one scanning mirror to reflect and scan the laser light pulses from the first and second laser light sources;
- a first amplitude measurement circuit to receive reflections of, and to determine amplitudes of, reflected laser light pulses of the first wavelength;
- a second amplitude measurement circuit to receive reflections of, and to determine amplitudes of, reflected laser light pulses of the second wavelength;
- and
- a control circuit to compare the amplitudes from the first and second amplitude measurement circuits, and to adjust amplitudes of the laser light pulses of the first and second wavelengths, and to cause the laser light pulses of the first and second wavelengths to be interleaved in time to decrease an effective minimum pulse spacing and increase a spatial measurement resolution.
Dependencies are inferred from the claim text.