Wrap around ranging method and circuit
AssigneeSTMicroelectronics (Grenoble 2) SAS
InventorsMarc Drader, Pascal Mellot
Life of this patent
Estimating the term…
Abstract
A method is for estimating a distance to an object. The method may include determining, by a ranging device, a first range value based upon a time of flight of first optical pulses having a period of a first duration, and determining, by the ranging device, a second range value based upon a time of flight of second optical pulses having a period of a second duration different from the first duration. The method may include estimating the distance based upon the first and second range values.
Claims19
A method for estimating a distance to an object, the method comprising:
- determining, by a ranging device, a first range value based upon a time of flight of a first plurality of optical pulses having a period of a first duration;
- comparing the first range value with a first threshold level;
- selecting a second duration to be higher or lower than the first duration based upon said comparison;
- determining, by the ranging device and after the comparison and the selecting, a second range value based upon a time of flight of a second plurality of optical pulses having a period of the second duration;
- and
- estimating the distance based upon the first and second range values.
A circuit for estimating a distance to an object, the circuit comprising:
- a detector circuit;
- a ranging circuit coupled to said detector circuit and configured to
- determine a first range value based upon a time of flight of a first plurality of optical pulses having a period of a first duration,
- determine a second range value based upon a time of flight of a second plurality of optical pulses having a period of a second duration different from the first duration, and
- estimate the distance based upon the first and second range values;
- and
- an optical pulse generation circuit configured to generate the first and second plurality of optical pulses, wherein the ranging circuit is configured to compare the first range value with a threshold value, and to control the optical pulse generation circuit such that the second duration is selected, based upon the comparison, to be higher or lower than the first duration.
A device for estimating a distance to an object, the device comprising:
- a light source;
- a detector circuit;
- and
- a ranging processor coupled to said detector circuit and said light source, said ranging processor configured to
- determine a first range value based upon a time of flight of a first plurality of optical pulses having a period of a first duration,
- determine a second range value based upon a time of flight of a second plurality of optical pulses having a period of a second duration different from the first duration, and
- estimate the distance based upon the first and second range values, wherein estimating the distance comprises:
- determining a lowest common multiple of the first and second range values;
- and
- converting the lowest common multiple into a distance value.
Dependencies are inferred from the claim text.