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US 2013/0258312 A1Published application
Optical distance measurement device
AssigneePulsedLight, Inc.
InventorRobert Alden Lewis
Life of this patent
Estimating the term…
Abstract
Optical range finders are configured to transmit optical bursts toward a target and detect a corresponding received burst. DC offset in the received burst due to square law detection can be offset based on a difference between high pass and low pass filtered portions of the received burst. Edge records associated with bursts can be obtained, and correlated with a reference signal or waveform to obtain a range estimate.
Claims30
A range finding device, comprising a receiver that includes:
- a detector configured to convert a received optical signal from an object into an analog signal;
- an analog filter configured to apply a dc offset associated with the received analog signal over the duration of a received signal burst;
- a zero-crossing detector configured to convert the received signal into binary logic states at successive sample points;
- a correlator configured to compare a stored transmit code sequence with one or more stored edge detected signal records to produce a derivative of a delayed correlation function;
- and
- a delay estimator configured to estimate a delay based on a zero-crossing point of the delayed correlation function.
3 more elements
A rangefinder, comprising:
- a transmitter configured to emit one or more code sequence modulated optical bursts towards an object;
- a receiver configured to establish an electrical signal based on the optical bursts and provide associated burst mode DC offsets;
- and
- a correlator configured to produce a range estimate based on an edge detected receiver output.
1 more element
A method, comprising:
- transmitting one or more code sequence modulated optical bursts towards an object;
- receiving at least portions of the at least one code sequence modulated bursts and producing corresponding electrical signals;
- providing respective burst mode DC offsets to the electrical signals;
- and
- estimating an object range based on a correlation of the burst mode DC offset electrical signals.
2 more elements
Dependencies are inferred from the claim text.