Diffractive optical element in a lidar system to correct for backscan
First Claim
1. A lidar system comprising:
- one or more light sources configured to transmit light pulses comprising a plurality of first light pulses having a first wavelength and a plurality of second light pulses having a second wavelength;
a diffractive optical element that deflects the first and second light pulses at different angles according to the respective first and second wavelengths;
a scanner configured to scan a field of view of the one or more light sources in a forward-scanning direction during a first time interval and a reverse-scanning direction during a second time interval; and
a detector configured to detect;
scattered light from at least a portion of the first light pulses when the scanner is scanning the field of view in the forward-scanning direction during the first time interval; and
scattered light from at least a portion of the second light pulses when the scanner is scanning the field of view in the reverse-scanning direction during the second time interval.
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Accused Products
Abstract
To detect return light pulses in a lidar system when scanning in the forward-scanning and reverse-scanning directions, a light source may transmit first light pulses having a first wavelength when scanning in the forward-scanning direction and may transmit second light pulses having a second wavelength when scanning in the reverse-scanning direction. A diffractive optical element (DOE) is configured to deflect the two wavelengths in opposite directions, so that light pulses are transmitted ahead of the field of view of the detector in the scanning direction of the lidar system. A controller may determine the scanning direction of a scanner in the lidar system and transmit a control signal to a light source indicative of a wavelength that corresponds to the scanning direction. The light source may then transmit light pulses at the requested wavelength.
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Citations
20 Claims
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1. A lidar system comprising:
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one or more light sources configured to transmit light pulses comprising a plurality of first light pulses having a first wavelength and a plurality of second light pulses having a second wavelength; a diffractive optical element that deflects the first and second light pulses at different angles according to the respective first and second wavelengths; a scanner configured to scan a field of view of the one or more light sources in a forward-scanning direction during a first time interval and a reverse-scanning direction during a second time interval; and a detector configured to detect; scattered light from at least a portion of the first light pulses when the scanner is scanning the field of view in the forward-scanning direction during the first time interval; and scattered light from at least a portion of the second light pulses when the scanner is scanning the field of view in the reverse-scanning direction during the second time interval. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for bi-directional scanning of a field of regard, the method comprising:
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generating light pulses by one or more light sources in a lidar system, the light pulses comprising a plurality of first light pulses having a first wavelength and a plurality of second light pulses having a second wavelength; deflecting, by a diffractive optical element in the lidar system, the first and second light pulses at different angles according to the respective first and second wavelengths; scanning, by a scanner in the lidar system, a field of view of the one or more light sources in a forward-scanning direction during a first time interval and a reverse-scanning direction during a second time interval; detecting, by a receiver of the lidar system, scattered light from the first light pulses when the scanner is scanning the field of view in the forward-scanning direction during the first time interval; and detecting, by the receiver of the lidar system, scattered light from the second light pulses when the scanner is scanning the field of view in the reverse-scanning direction during the second time interval. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A controller in a lidar system comprising:
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one or more processors; and a non-transitory computer-readable memory coupled to the one or more processors and storing instructions thereon that, when executed by the one or more processors, cause the controller to; determine a scanning direction of a field of view of a light source, the scanning direction including a forward-scanning direction during a first time interval or a reverse-scanning direction during a second time interval; and in response to determining the scanning direction, provide a control signal to the light source to emit first light pulses having a first wavelength or second light pulses having a second wavelength in accordance with the scanning direction, wherein the first light pulses are emitted for the forward-scanning direction and the second light pulses are emitted for the reverse-scanning direction; wherein a pixel corresponds to an angle of a field of view of the detector or the light source and a diffractive optical element is configured to; deflect the first light pulses by less than or equal to one pixel in the forward-scanning direction so that, when scanning in the forward-scanning direction during the first time interval, each of the first light pulses is transmitted ahead of a field of view of the detector by less than or equal to one pixel; and deflect the second light pulses by less than or equal to one pixel in the reverse-scanning direction, so that, when scanning in the reverse-scanning direction during the second time interval, each of the second light pulses is transmitted ahead of the field of view of the detector by less than or equal to one pixel. - View Dependent Claims (18, 19, 20)
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Specification