Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 11/10/2025 has been entered.
Response to Arguments
Applicant's arguments filed 11/10/2025 have been fully considered but they are not persuasive.
Applicant argues Droz only teaches the purpose of the taught invention is velocity determination, not refining distance measurement.
This argument was previously discussed in the final rejection dated 7/08/2025.
This is also intended use. A recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. With the addition of Sharma, Droz’s system could be used to measure distance, and applicant has not shown a persuasive argument as to why Droz cannot.
Applicant argues, as Droz is drawn to radar and Sharma is drawn to LiDAR, they are not analogous.
This argument was previously discussed in the final rejection dated 7/08/2025.
Applicant argues Sharma's method is a signal processing chain, not a post processing mathematical formula.
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., “a post processing mathematical formula”) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Applicant argues Sharma does not teach speed determination.
This argument was previously discussed in the final rejection dated 7/08/2025, and is discussed above.
Applicant argues combining Droz and Sharma is improper as the methods used are different, and examiner has used hindsight.
Examiner disagrees. Although the methods are different, they are both well-known in the art of LiDAR, and thus would yield predictable results if combined.
Applicant’s arguments, with respect to amended Claim 1 and 40 and the limitation regarding parameterization, is persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Baugh (US 20030020653 A1).
Applicant’s arguments, with respect to amended Claim 41 and the limitation of opposing FM chirps, is persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Crouch (US 20190310372 A1).
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-40 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
The amended limitation in Claims 1 and 40 of “a parameterized distance as a quantized function of the coarse distance by being derived from an integer portion of the coarse distance” is not in the specification as originally filed, and is thus new matter.
Claims 2-39 rejected due to claim dependency.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-6, 8-12, 14, 28-31, 35, 38, and 40 are rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457A1), further in view of Baugh (US 20030020653 A1).
Claim 1: Droz teaches A lidar system comprising:
a light source (Fig 2, laser 212) configured to emit an output optical signal ([0051] - first pulse - ranging pulse [0071] and [0052] - second pulse) and a local-oscillator optical signal ([0030]), wherein:
the output optical signal comprises (i) pulses of light and (ii) frequency-modulated (FM) output-light signals,
wherein each pair of consecutive pulses of light is separated in time by one or more of the FM output-light signals (Fig 3B, pulses 342 separated by pulses 344 and [0071]);
and the local-oscillator optical signal comprises FM local-oscillator light signals corresponding to the FM output-light signals ([0083] - local oscillator signal is based on second light pulse (doppler pulse) and Fig 2, LO signal 222);
a receiver configured to detect the local-oscillator optical signal and an input optical signal (Fig 2, photodetector 230 and [0061]), the input optical signal comprising:
a received pulse of light comprising a portion of one of the emitted pulses of light scattered by a target located a distance from the lidar system (Fig 3B, pulses 342 and [0071]);
and a received FM light signal comprising a portion of one of the FM output-light signals scattered by the target (Fig 3B, pulse 3440 - doppler pulse ([0072]) ,
wherein the received FM light signal and the local-oscillator optical signal are coherently mixed together at the receiver ([0055]).
Droz also teaches using the beat signal to find the speed of an object ([0046]). However, Droz does not teach a processor configured to:
determine a coarse distance to the target based on a round-trip time for the portion of the emitted pulse of light to travel from the lidar system to the target and back to the lidar system;
and determine a precise distance to the target based on (i) the coarse distance to the target and (ii) a frequency of a beat signal resulting from the coherent mixing of the received FM light signal and the local-oscillator optical signal, wherein the precise distance is determined including by calculating a parameterized distance using the coarse distance, calculating an offset distance using the frequency of the beat signal, and combining the parameterized distance and the offset distance to determine the precise distance.
Sharma a teaches radar unit which uses both coarse and fine measurements to find a distance. The coarse measurement finds a target range ([0026] – finding time based radar signal for coarse resolution), while the fine measurement uses a beat frequency (See Eq. 1 for calculation of final distance).
It would have been obvious to use the distance measurement as taught by Sharma with the LiDAR unit as taught by Droz because this is simply a process which can be carried out with any LiDAR system which receives both direct and indirect TOF measurements. As Droz’s system does so, this falls under “Art Recognized Suitability for an Intended Purpose” (MPEP 2144.07).
Neither Droz or Sharma teach where the parameterized distance is a quantized function of the course distance by being derived from an integer portion of the course distance. However, Sharma does teach a Fast Fourier Transform (FFT) (See [0026]).
Baugh teaches a detection system which uses a Discreet Fourier Transform (DFT) and FFT ([0031]).
It would have been obvious before the effective filing date to use the DFT, as taught by Baugh, in the system as taught by Droz, as modified in view of Sharma (and specifically in place of Sharma’s FFT), because a DFT, with discreet integer outputs, would be more efficient than a FFT with a continuous output (See Baugh [0041]).
Claim 2: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, wherein each FM local-oscillator light signal is coherent with at least one of the FM output-light signals (Droz [0073] - local oscillator is doppler signal).
Claim 3: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, wherein each FM local-oscillator light signal has a frequency modulation that matches a frequency modulation of at least one of the FM output-light signals (Droz [0073] - local oscillator is doppler signal).
Claim 4: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, but not wherein each FM output-light signal and each FM local- oscillator light signal comprises an optical frequency that increases or decreases with time.
However, Sharma does teach the frequency increasing and decreasing linearly with time (Fig 1B, chirp 120 has an increasing frequency during time Tup and a decreasing frequency during Tdown).
It would be obvious to use the increasing and decreasing frequency as taught by Sharma with the lidar system as taught by Droz, as modified in view of Sharma and Baugh, because this is a configuration well known in the art. Additionally, a time varying frequency would allow for a time varying beat signal, thus increasing resolution.
Claim 5: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 4, wherein the optical frequency increases or decreases linearly with time (Sharma Fig 1B, showing linear frequency increase and decrease).
Claim 6: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, wherein the coarse distance (Dcoarse) is determined from an expression Dcoarse =c- AT/2, wherein c is a speed of light, and AT is the round-trip time for the portion of the emitted pulse of light to travel from the lidar system to the target and back to the lidar system (Sharma [0026] – it is known in the art that time based radar is calculated via the equation D = (cAT/2)).
Claim 8: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, wherein the precise distance has a higher accuracy than the coarse distance (Sharma [0031] – fine resolution has greater accuracy).
It would have been obvious to use the accuracy as taught by Sharma with the LiDAR system as taught by Droz, as modified in view of Sharma and Baugh, as having the fine resolution have a greater accuracy than the coarse resolution is a well-known relationship in the art.
Claim 9: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, the received FM light signal is received after the received pulse of light (Droz Fig 3B, pulses 342 separated by pulses 344 which come after and [0071]);; but not wherein the processor is configured to determine the precise distance to the target after determining the coarse distance to the target.
However, Sharma does teach the coarse measurement coming before the fine measurement (Fig 3, coarse (Step 304) before fine (Step 318)).
It would have been obvious to use the measurement timing as taught by Sharma with the LiDAR system as taught by Droz, as modified in view of Sharma and Baugh, as having the coarse measurement done first would be obvious if one uses the coarse measurement in the fine measurement.
Claim 10: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, wherein the FM output-light signals and the FM local- oscillator light signals each comprise optical frequencies that alternately increase and decrease with time (Droz [0083] – LO may be provided using a phase modulator, thus shifting it).
Claim 11: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, wherein: the received FM light signal is a first received FM light signal,
and the portion of the FM output-light signal is a portion of a first one of the FM output-light signals; the frequency of the beat signal is a first frequency of a first beat signal; the input optical signal further comprises a second received FM light signal comprising a portion of a second one of the FM output-light signals scattered by the target, wherein the second received FM light signal and the local-oscillator optical signal are coherently mixed together at the receiver; and the processor is further configured to determine a speed of the target based on (i) the first frequency of the first beat signal and (ii) a second frequency of a second beat signal resulting from the coherent mixing of the second received FM light signal and the local-oscillator optical signal (Droz Fig 3B, multiple doppler signals and ranging signals).
Claim 12: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 11, wherein: the first one of the FM output-light signals comprises an optical frequency that increases with time; and the second one of the FM output-light signals comprises an optical frequency that decreases with time.
However, Sharma does teach the frequency increasing and decreasing linearly with time (Fig 1B, chirp 120 has an increasing frequency during time Tup and a decreasing frequency during Tdown).
It would be obvious to use the increasing and decreasing frequency as taught by Sharma with the lidar system as taught by Droz, as modified in view of Sharma and Baugh, because this is a configuration well known in the art. Additionally, a time varying frequency would allow for a time varying beat signal, thus increasing resolution.
Claim 14: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, wherein: a wavelength of the FM output-light signals is between 900 nanometers (nm) and 1600 nm ([0035] – laser wavelength of 1550 nm);
and the portion of the FM output-light signal scattered by the target experiences a Doppler shift in optical frequency between [1.2 MHz/(m/s)] X Vr and [2.3 MHz/(m/s)] X Vr, wherein Vr is a radial speed of the target relative to the lidar system in units of meters/second ([0065] – 66 kHZ is 0.066 MHz, thus, this falls under the 103 rational of overlapping ranges).
Claim 28: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, wherein the coherent mixing of the received FM light signal and the local-oscillator optical signal comprises a coherent mixing of the received FM light signal and one of the FM local-oscillator light signals (Droz [0055]).
Claim 29: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, wherein: the frequency of the beat signal resulting from the coherent mixing of the received FM light signal and the local-oscillator optical signal comprises one or more frequencies of one or more beat signals; and the receiver is further configured to determine the frequency of each of the one or more beat signals (Droz [0046]).
Claim 30: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, wherein the receiver comprises a frequency-detection circuit configured to determine the frequency of the beat signal resulting from the coherent mixing of the received FM light signal and the local-oscillator optical signal (Droz [0064] – determining beat frequency).
Claim 31: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, but not wherein the frequency-detection circuit comprises a plurality of electronic filters, each electronic filter associated with a particular frequency component, although Droz does teach that the system can have various combinations of amplifiers, filters, sample and hold circuits, and/or comparators ([0025]).
However, Sharma teaches using a filter (Fig 2, filter 216) to filter out frequencies of interest ([0024]).
It would be obvious to add the filter as taught by Sharma to the “various combinations” as taught by Droz, as modified in view of Sharma and Baugh to create multiple frequency filters because this allows for processing to only be done on frequencies of interest, and thus reduces processing time and energy.
Claim 35: : Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, wherein the received pulse of light and the local-oscillator optical signal are coherently mixed together at the receiver (Droz [0063] – LO and reflected signal mixed together without specification of which part of reflected signal).
Claim 38: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, wherein the light source comprises a direct-emitter laser diode configured to emit the output optical signal and the local-oscillator optical signal (Droz [0030] – light from single laser split into two portions).
Claim 40: As Claim 40 is a method claim corresponding to Claim 1, see rejection above.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457A1) further in view of Baugh (US 20030020653 A1), further in view of Yang (US 20220252702 A1).
Claim 7: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, but not wherein :each FM output-light signal and each FM local-oscillator light signal has a duration T and a frequency-modulation range B; the duration T is related to a frequency-modulation (FM) distance dFM by an expression dFM= C-T/2, wherein cis a speed of light; the frequency (AF) of the beat signal is related to an offset distance doffset by an expression doffset = dFM (AF/B); the coarse distance (Dcoarse) is associated with an integer number N of the FM distances based on an expression N=INT(Dcoarse/dFM), wherein INT(Dcoarse/dFM) is an integer portion of (Dcoarse/dFM); and the precise distance Dprecise to the target is determined from an expression Dprecise =N- dFM+doffset.
Yang teaches a receiver system which calculates a fine TOF using equation 1 ([0037] and equation 1).
It would have been obvious that the equation, as taught by Yang, could be used in the LiDAR system as taught by Droz, as modified in view of Sharma and Baugh, because it can be used with any hybrid system which measures both direct and indirect (FM) time of flight. Further, if the multiple equations as claimed are solved, it yields the equation as taught by Yang, with beat frequency in place of phase. However, the conversion between phase and frequency, using the wave equation, is known in the art, thus, it would be obvious that Yang’s equation could be used in the claimed invention.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457A1) further in view of Baugh (US 20030020653 A1) further in view of Muller (See attached PDF).
Claim 13: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 11, wherein the speed of the target (Vr) is a radial speed of the target relative to the lidar system and is determined from an expression V= AFDA/2, wherein: X is a wavelength of the FM output-light signals; AFD is a Doppler shift of an optical frequency of each of the first and second received FM light signals, wherein the Doppler shift is determined from an expression AFD_ (AF2-AF1)/2, wherein AFi is the first frequency of the first beat signal and AF2 is the second frequency of the second beat signal.
Muller teaches the doppler theorem V=Fd*lambda/2 (top of page 3).
It would have been obvious to use the doppler theorem as taught by muller with the LiDAR system as taught by Droz, as modified in view of Sharma and Baugh, because this is a well-known equation in the art.
Claims 15-17, 19, and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457A1) further in view of Baugh (US 20030020653 A1) further in view of Haraguchi (US 20210141067 A1), further in view of Amzajerdian (US 11500102B2).
Claim 15, Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, but not wherein the light source comprises: a seed laser diode configured to produce (i) seed light comprising the FM output-light signals and (ii) the FM local-oscillator light signals; and a semiconductor optical amplifier (SOA) configured to amplify temporal portions of the seed light to produce the emitted pulses of light, wherein each amplified temporal portion of the seed light corresponds to a pulse of light of the emitted pulses of light.
Haraguchi teaches a LiDAR system which has a light source (Fig 1, light source 1) which outputs frequency modulated light ([0019] – “The laser radar system further includes: a time-series-signal generation unit 10 to generate an injection-current control signal 14 to be inputted into the reference light source 1 and used for performing light frequency modulation in the reference light source 1”). The light is then split (Fig 1, optical splitter 2) into a local oscillator signal (Fig 1, LO path 50 and [0019] – “a polarization-keeping optical coupler 2 being an optical splitter to split a light path, through which the light generated by the reference light source 1 travels, into a signal light path and a local oscillator light path 50”). The rest of the light in input to a SOA (Fig 1, SOA 3), which generates pulsed light ([0019] – “a pulse generation signal 15 to be inputted into the semiconductor optical amplifier 3 and used for generating pulsed light in the semiconductor optical amplifier”).
It would have been obvious to use the laser setup as taught by Haraguchi with the LiDAR system as taught by Droz, as modified in view of Sharma and Baugh, because this allows for a large frequency shift between signal and LO light (See Haraguchi [0010]).
Although Droz does teach a seed laser ([0035]), Droz teaches a seed and pump laser.
Amzajerdian teaches a LiDAR system which uses a seed laser to generates FM light (Col 7, lines 56-62), which is used for both scanning and LO light (Fig 1, beam splitter 113).
It would have been obvious to use a seed laser, as taught by Amzajerdian, with the LiDAR system as taught by Droz, as modified in view of Sharma and Baugh and Haraguchi because seed lasers are well known in the art, and yield predictable results.
Claim 16: Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, teaches the lidar system of Claim 15, wherein the light source further comprises a fiber-optic amplifier configured to further amplify the amplified seed light to produce the emitted pulses of light.
However, Amzajerdian teaches a fiber amplifier (Fig 1, fiber amp. 114) used to amplify the light scanned into a scene (Col 62-64).
It would have been obvious to use the fiber amplifier, as taught by Amzajerdian, with the LiDAR system as taught by Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, because an amplifier is well known in the art of LiDAR to increase resolution by increasing signal strength.
Claim 17: Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, teaches the lidar system of Claim 15, wherein the light source further comprises an electronic driver configured to supply an electrical current to the seed laser diode comprising a modulated electrical current, wherein the modulated electrical current causes the seed laser diode to produce the FM output-light signals and the FM local-oscillator light signals (Haraguchi [0019] – “The laser radar system further includes: a time-series-signal generation unit 10 to generate an injection-current control signal 14 to be inputted into the reference light source 1 and used for performing light frequency modulation in the reference light source 1”).
Claim 19: Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, teaches the lidar system of Claim 17, but not wherein the modulated electrical current comprises a time-varying electrical current having a sawtooth-wave shape or a triangle-wave shape.
However, Sharma teaches a radar outputting signals comprised of sawtooth “chirps” (Fig 2, transmit signal 206).
It would have been obvious to use the sawtooth signal, as taught by Sharma, with the lidar system as taught by Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, as a sawtooth pattern is relatively simple and well known in the art.
Claim 25: Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, teaches the lidar system of Claim 15, wherein the light source further comprises an electronic driver configured to supply pulses of electrical current to the SOA, wherein each pulse of electrical current results in the SOA amplifying one of the temporal portions of the seed light to produce one of the emitted pulses of light (Haraguchi [0019] – “a pulse generation signal 15 to be inputted into the semiconductor optical amplifier 3 and used for generating pulsed light in the semiconductor optical amplifier”).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457 A1) further in view of Baugh (US 20030020653 A1) further in view of Haraguchi (US 20210141067 A1), further in view of Amzajerdian (US 11500102 B2), further in view of Hughes (US 20190154816 A1).
Claim 18: Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, teaches the lidar system of Claim 17, but not wherein the electrical current supplied to the seed laser diode further comprises a constant electrical current.
Hughes teaches a LiDAR system which uses a seed laser driven by a constant DC current and where frequency modulation is added after the constant current ([0135]).
It would have been obvious to add the constant DC current as taught by Hughes to the Lidar system as taught by Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian because a constant current applied to a seed laser is well known in the art.
Claims 20, 21, 23 24, and 26 are rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457A1) further in view of Baugh (US 20030020653 A1) further in view of Haraguchi (US 20210141067 A1), further in view of Amzajerdian (US 11500102B2), further in view of Deladurantaye (US 20100128744 A1).
Claim 20: Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, teaches the lidar system of Claim 17, wherein the modulated electrical current comprises modulated seed-current portions, each modulated seed-current portion having an electrical-current magnitude that increases or decreases with time.
Deladurantaye teaches a laser oscillator which includes a seed assembly (Fig 8A, seed assembly 28). In said seed assembly, multiple amplitude modulators (40a, 40b) are driven at different periods in time to produce different amplitudes and increase and decrease with time (See Fig 8B – drive signals have portions which increase and decrease in time).
It would have been obvious to use the multiple amplitude modulators, as taught by Deladurantaye, with the lidar system as taught by Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, because applying different drive signals with different time variations at different periods in time allows for consecutive return pulses to be distinguished from each other, thus increasing resolution.
Claim 21: Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, and Deladurantaye, teaches the lidar system of Claim 20, wherein each modulated seed-current portion causes the seed laser diode to produce one of the FM output-light signals and one of the FM local-oscillator signals (Droz [0030] – laser emitting LO signal – combined with Claim 20 above).
Claim 23: Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, teaches the lidar system of Claim 17, but not wherein the modulated electrical current comprises electrical-current portions, each electrical-current portion configured to produce a corresponding temporal portion of the seed light that is amplified by the SOA.
Deladurantaye teaches a laser oscillator which includes a seed assembly (Fig 8A, seed assembly 28). In said seed assembly, multiple amplitude modulators (40a, 40b) are driven at different periods in time to produce different amplitudes and have different characteristics (See Fig 8B – different drive signals of first and second amplitude modulators).
It would have been obvious to use the multiple amplitude modulators, as taught by Deladurantaye, with the lidar system as taught by Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, because applying different amplitudes at different periods in time allows for consecutive return pulses to be distinguished from each other, thus increasing resolution.
Claim 24: Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, and Deladurantaye, teaches the lidar system of Claim 23, wherein: consecutive electrical-current portions have different electrical-current amplitudes; and the different electrical-current amplitudes are configured to impart different spectral signatures to corresponding consecutive pulses of light emitted by the light source (Deladurantaye Fig 8).
Claim 26: Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, teaches lidar system of Claim 25, but not wherein consecutive pulses of electrical current supplied to the SOA have different electrical-current characteristics; and the different electrical-current characteristics are configured to impart different spectral signatures to corresponding consecutive pulses of light emitted by the light source.
Deladurantaye teaches a laser oscillator which includes a phase variation drive signal (Fig 11A, phase variation drive signal and phase modulator 44) which can have varying amplitude ([0083] – “The phase variation peak amplitude can be adjusted by controlling the gain of the amplifier 68), which is part of a spectrum tailoring module.
It would be obvious that the phase modulator of Deladurantaye could be used in place of the SOA of Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, because they both have the intended result of applying a modulated amplifier signal to the light pulse.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457A1) further in view of Baugh (US 20030020653 A1) further in view of Haraguchi (US 20210141067 A1), further in view of Amzajerdian (US 11500102B2), further in view of Deladurantaye (US 20100128744 A1), further in view of Koheron.
Claim 22: Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, and Deladurantaye, teaches the lidar system of Claim 20, but not wherein each modulated seed-current portion that has an increasing electrical-current magnitude causes the seed laser diode to produce (i) one FM output- light signal having a decrease in optical frequency with time and (ii) one FM local-oscillator light signal having a corresponding decrease in optical frequency with time.
Koheron teaches that as current increases, laser frequency decreases (pg 3 of attached PDF, highlighted portion).
It would be obvious, using the knowledge from Koheron, that applying an increasing current to Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, and Deladurantaye, would cause the laser output, previously shown to consist of both the output and LO light signal, to decrease in frequency.
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457A1) further in view of Baugh (US 20030020653 A1) further in view of Haraguchi (US 20210141067 A1), further in view of Amzajerdian (US 11500102B2), further in view of Peckham (US 20190162841 A1).
Claim 27: Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, teaches lidar system of Claim 25, but not wherein the electronic driver is further configured to supply a constant electrical current to the SOA, wherein the constant electrical current is configured so that the SOA transmits or amplifies the FM output-light signals produced by the seed laser diode.
However, as shown in the rejection above for Claim 25, Droz, as modified in view of Sharma, Baugh, Haraguchi, and Amzajerdian, does teach wherein an SOA transmits or applies FM output-light signals
Claim 32 is rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457A1) further in view of Baugh (US 20030020653 A1) further in view of Davis (US 5818585 A).
Claim 32: Droz, as modified in view of Sharma and Baugh, teaches lidar system of Claim 30, wherein the frequency-detection circuit comprises: a derivative circuit configured to produce a derivative signal corresponding to a derivative of the beat signal; and a zero-crossing circuit configured to determine two or more zero crossings of the derivative signal.
Davis teaches a Fiber Bragg Grating system which detects wavelength peaks by using a derivative unit to take a derivative, then finding a zero crossing of the derivative (Col 4, lines 20-25).
It would have been obvious to use the derivative method for finding a peak, as taught by Davis, with the LiDAR system as taught by Droz, as modified in view of Sharma and Baugh, as this improves resolution (See Davis, Col 4, line 20).
Claims 33 and 34 are rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457A1) further in view of Baugh (US 20030020653 A1) further in view of Ruff (US 20090002679 A1).
Claim 33: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, but not wherein the receiver comprises: one or more detectors configured to produce one or more respective photocurrent signals corresponding to the input optical signal, each photocurrent signal comprising (i) a pulse of photocurrent corresponding to the received pulse of light and (ii) a beat-signal photocurrent corresponding to the coherent mixing of the received FM light signal and the local-oscillator optical signal; and one or more electronic amplifiers configured to amplify one or more of the photocurrent signals to produce one or more voltage signals corresponding to the photocurrent signals.
Ruff teaches a doppler system. In this system, a local oscillator signal ([0023]) and a detected signal (Fig 1, light signal 106) are both detected (Fig 1, photonic mixing detector 142). This detector outputs current signals ([0026]), which are then passed to an amplifier, which converts the current signals into voltage signals ([0028]).
It would be obvious that the method of using current signals and converting to voltage, as taught by Ruff, can be used with the LiDAR system as taught by Droz, as modified in view of Sharma and Baugh, because it is a method well known in the art and would yield predictable results.
Claim 34: Droz, as modified in view of Sharma and Baugh and further in view of Ruff, teaches the lidar system of Claim 33, wherein: the receiver further comprises a pulse-detection circuit configured to determine, based on the one or more voltage signals, a time-of-arrival for the received pulse of light; and the processor is further configured to determine the round-trip time for the portion of the emitted pulse of light to travel from the lidar system to the target and back to the lidar system based on the time-of-arrival for the received pulse of light (Sharma [0026] – finding time based radar signal for coarse resolution, and Eq. 1 for calculation of final distance – combined with Ruff’s currents and voltages as taught in Claim 33).
Claims 36 and 37 are rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457A1) further in view of Baugh (US 20030020653 A1) further in view of Tansek (US 20220011402 A1).
Claim 36: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 35, wherein: the receiver comprises a frequency-detection circuit configured to determine a frequency associated with the coherent mixing of the received pulse of light and the local-oscillator optical signal (Droz [0063]);
But not where the processor is further configured to determine, based on the frequency associated with the coherent mixing matching a spectral signature of the one of the emitted pulses of light, that the received pulse of light is associated with the one of the emitted pulses of light.
Tansek teaches a pulsed radar which uses a frequency tag to match return pulses to emitted pulses ([0051]).
It would have been obvious to use the frequency tags as taught by Tansek with the LiDAR system, as taught by Droz, as modified in view of Sharma and Baugh, because it reduces interference (See Tansek [0049]).
Claim 37: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 35, wherein: the receiver comprises a frequency-detection circuit configured to determine a frequency associated with the coherent mixing of the received pulse of light and the local-oscillator optical signal (Droz [0063]);
But not where the processor is further configured to determine, based on the frequency associated with the coherent mixing matching a spectral signature of the one of the emitted pulses of light, that the received pulse of light is associated with the one of the emitted pulses of light.
Tansek teaches a pulsed radar which uses a frequency tag to match return pulses to emitted pulses ([0051]).
It would have been obvious to use the frequency tags as taught by Tansek with the LiDAR system, as taught by Droz, as modified in view of Sharma and Baugh, because it reduces interference (See Tansek [0049]).
Claim 39 is rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457A1) further in view of Baugh (US 20030020653 A1) further in view of Thorpe (US 11422244 B2).
Claim 39: Droz, as modified in view of Sharma and Baugh, teaches the lidar system of Claim 1, but not further comprising a scanner configured to scan the output optical signal across a field of regard of the lidar system.
Thorpe teaches a FMCW LiDAR which includes a scanner (Col 6, lines 12-15).
It would have been obvious to use the scanner as taught by Thorpe with the lidar system as taught by Droz, as modified in view of Sharma and Baugh, because a scanner allows for more control over the beam position.
Claim 41 is rejected under 35 U.S.C. 103 as being unpatentable over Droz (US 20190391267 A1) in view of Sharma (US 20200064457A1) further in view of Baugh (US 20030020653 A1) further in view of Crouch (US 20190310372 A1).
Claim 41: Droz teaches a lidar system comprising:
a light source (Fig 2, laser 212) configured to emit an output optical signal ([0051] - first pulse - ranging pulse [0071] and [0052] - second pulse) and a local-oscillator optical signal ([0030]), wherein:
the output optical signal comprises (i) pulses of light and (ii) frequency-modulated (FM) output-light signals,
wherein each pair of consecutive pulses of light is separated in time by one or more of the FM output-light signals (Fig 3B, pulses 342 separated by pulses 344 and [0071]);
and the local-oscillator optical signal comprises FM local-oscillator light signals corresponding to the FM output-light signals ([0083] - local oscillator signal is based on second light pulse (doppler pulse) and Fig 2, LO signal 222);
a receiver configured to detect the local-oscillator optical signal and an input optical signal (Fig 2, photodetector 230 and [0061]), the input optical signal comprising:
a received pulse of light comprising a portion of one of the emitted pulses of light scattered by a target located a distance from the lidar system (Fig 3B, pulses 342 and [0071]);
and a received FM light signal comprising a portion of one of the FM output-light signals scattered by the target (Fig 3B, pulse 3440 - doppler pulse ([0072]),
wherein the first received FM light signal and the local- oscillator optical signal are coherently mixed together at the receiver ([0055]);
and a second received FM light signal comprising a portion of a second one of the FM output-light signals scattered by the target (Droz Fig 3B, multiple doppler signals and ranging signals),
wherein the second received FM light signal and the local-oscillator optical signal are coherently mixed together at the receiver ({0055]).
A processor configured to:
determine a speed of the target based on (i) a first frequency of a first beat signal resulting from the coherent mixing of the first received FM light signal and the local- oscillator optical signal and (ii) a second frequency of a second beat signal resulting from the coherent mixing of the second received FM light signal and the local-oscillator optical signal ([0091] – can find velocity based on doppler shift),
wherein the processor is configured to calculate a Doppler frequency shift based on a difference between the first frequency of the first beat signal and the second frequency of the second beat signal ([0074] – determining beat frequency),
and to determine the speed of the target using the calculated Doppler frequency shift and a wavelength of the FM output-light signals ([0091]).
Droz does not teach a processor configured to: determine the distance to the target based on a round-trip time for the portion of the emitted pulse of light to travel from the lidar system to the target and back to the lidar system;
Sharma teaches radar unit which uses both coarse and fine measurements to find a distance. The coarse measurement finds a target range ([0026] – finding time based radar signal for coarse resolution), while the fine measurement uses a beat frequency (See Eq. 1 for calculation of final distance). Sharma also teaches using two chirps with increasing and decreasing portions (Fig. 1B).
It would have been obvious to use the distance measurement as taught by Sharma with the LiDAR unit as taught by Droz because this is simply a process which can be carried out with any LiDAR system which receives both direct and indirect TOF measurements. As Droz’s system does so, this falls under “Art Recognized Suitability for an Intended Purpose” (MPEP 2144.07).
Neither Droz or Sharma teach the first FM output-light signals comprise an optical frequency that increases with time, and the second comprises a frequency that decreases with time.
Crouch teaches a doppler detection system which uses both an up and down chirp which are emitted simultaneously ([0082]).
It would have been obvious before the effective filing date to use the simultaneous up and down chirps, as taught by Crouch, in the LiDAR unit as taught by Droz, as modified in view of Sharma (and specifically instead of Sharma’s increasing and decreasing chirps at different times), because this would allow for faster measurement, as both chirps are sent simultaneously.
Conclusion
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/CLARA G CHILTON/Examiner, Art Unit 3645
/ROBERT W HODGE/Supervisory Patent Examiner, Art Unit 3645