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 .
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 1-8, 12-13, and 19-21 are rejected under 35 U.S.C. 103 as being unpatentable over Dehlinger et al. (WO 2020023489), in view of Perry et al. (U.S. Patent Publication No. 2018/0011195), in view of Moore et al. (EP 3370080), in further view of Tachwali et al. (U.S. Patent Publication No. 2023/0358865).
Regarding claim 1, Dehlinger discloses an optical ranging system (Dehlinger: Abstract “plurality of emitter pixels configured to emit optical signals”)(teaches optical ranging signal system), comprising: a transmitter configured to transmit a modulated optical signal (interpreted as a transmitter sends an optical signal that is modulation based)[Dehlinger: 00025 “providing emitter control signals to an emitter array having emitter pixels that are configured to emit optical signals”](teaches transmission of optical signals at modulation frequencies); but fails to explicitly disclose an indirect time-of-flight sensor configured to receive a reflected optical signal, associated with the modulated optical signal, and generate a plurality of first distance values based on the reflected optical signal; and one or more processors configured to: generate a first histogram based on the plurality of first distance values, detect a first maximum peak within the first histogram, detect one or more first side peaks within the first histogram that are offset from the first maximum peak, wherein each first side peak is located at least a first wavelength distance from a first histogram location of the first maximum peak, for each first side peak: calculate a first number of first wavelength distances that the first side peak is located from the first histogram location of the first maximum peak, and calculate a first corrected absolute distance of the first side peak based on the first number of first wavelength distances, generate a first corrected histogram, corresponding to the first histogram, based on the first corrected absolute distance of each first side peak, and generate a point cloud based on the first corrected histogram.
However, Perry discloses an indirect time-of-flight sensor configured to receive a reflected optical signal, associated with the modulated optical signal (interpreted as iToF sensor receives the return light corresponding to the transmitted modulated light) [Perry: 0024 “One or more sensors of the imaging array 16 receive the reflected modulated signal 72”](teaches a ToF system whose sensors receive the reflected modulated signal), and generate a plurality of first distance values based on the reflected optical signal (interpreted as the sensor produces multiple distance outputs from the received reflected signal) [Perry: 0021 “The controller 18 is also configured to read the output signal from each pixel of the imaging array 16 as generated by the sampler 62 to enable computation of a depth map of the object 12”](teaches a depth map containing multiple per pixel depth values which are distance values generated from the reflected optical signal), wherein each first side peak is located at least a first wavelength distance from a first histogram location of the first maximum peak (interpreted as for each side peak is separated from the main peak by at least one periodic ambiguity interval corresponding to the modulation wavelength/range period)[Perry: 0026 “Where ( 1 ) C is the speed of light , ( 2 ) 0 , E [ 0 , 21 ) is the phase delay detected by a sensor of the range - imager in a measurement at temporal frequency f ; , and ( 3 ) n , eZ + is an unwrapping constant that corrects for the cyclic ambiguity present in the phase of a sinusoid ( note that a phase 0 ; is indistinguishable from a phase 0 : + 21 , 0 + 41 , etc . )”](teaches periodic phase ambiguity at successive 2 pi wraps. Those wraps correspond to repeated ambiguity intervals in distance for the modulation frequency which corresponds to the same technical idea as a side peak being at least one wavelength distance period away from the main location), for each first side peak: calculate a first number of first wavelength distances that the first side peak is located from the first histogram location of the first maximum peak (interpreted as for each first side peak, determine how many ambiguity periods separate it from the main peak)[Perry: 0027 “The range determination module 60 determines ni by making measurements at multiple different frequencies f1 , f2 , . . . fy and simultaneously solving for n? , 12 , . . . Nx”](teaches solving for unwrapping constants n1 n2 which are the integer ambiguity counts used to resolve cyclic distance ambiguity which corresponds to calculating the number of wavelength distance intervals), and calculate a first corrected absolute distance of the first side peak based on the first number of first wavelength distances (interpreted as use the ambiguity count information to compute the first corrected true distance) [Perry: 0029 “the range determination module 60 may calculate the range 80 given known n , , nn”](teaches calculating the corrected range once the unwrapping constants are known).
However, Moore discloses and one or more processors [Moore: 0009 “processor”] configured to: generate a first histogram based on the plurality of first distance values [Moore: 0018 “A Time to Digital Converter (TDC) may be configured to receive the signals generated by generator/driver and by the sensor and calculate the phase shift (or time difference) between these signals to obtain a distance to object. The detector (SPAD array) is configured to generate many fast readings in a short time period and thus the time to distance converter may be configured to generate a histogram of detected events.”](teaches using the distance values to generate a histogram), detect a first maximum peak within the first histogram (interpreted as find the main/highest peak in the histogram), detect one or more first side peaks within the first histogram that are offset from the first maximum peak )[Moore: 0101 “For example an example histogram with an earlier or first target peak and a later or second target peak may be analysed by finding the maximum bin value(s) within a histogram to determine pulse locations”] (teaches finding a maximum bin values in a histogram to determine peak/pulse locations), generate a first corrected histogram, corresponding to the first histogram (interpreted as produce a corrected version of the original histogram)[Moore: 0088 “Then in some embodiments the weighted cross-talk only histogram is subtracted from the raw histogram to give a corrected histogram.”](teaches generating a corrected histogram corresponding to the raw/original histogram), based on the first corrected absolute distance of each first side peak (interpreted as the histogram correction is performed using corrected distance positioning of the affected returns/peaks) [Moore: 0087 “if the reference range shifts by ¨ bin width to the right, meaning that the captured crosstalk histogram should also be shifted ¨ width to the right, then the processor shifts ¨ of each bin’s content into the bin to the right”][Moore: 0088 “Then in some embodiments the weighted cross-talk only histogram is subtracted from the raw histogram to give a corrected histogram.”](teaches shifting histogram content according to a corrected range position before producing the corrected histogram which is the same type of histogram correction based on corrected distance placement).
However, Tachwali discloses and generate a point cloud based on the first corrected histogram (interpreted as use the corrected histogram output to produce point cloud points)[Tachwali: 0067 “The aggregation of measurements from multiple lidar frames within a data frame duration yields a histogram from which points of a point cloud can be extracted.”](teaches extracting point cloud points from a histogram).
Dehlinger, Perry, Moore, and Tachwali are considered analogous to the claimed invention because they are in the same field of optical ranging, histogram based, and point cloud generation. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Dehlinger to incorporate Perry, Moore, and Tachwali teachings of histogram generation, peak processing, ambiguity resolution, corrected range calculation, and extracting point cloud points from histogram data. The motivation for such a combination would provide the benefit of improving range accuracy and generating more reliable 3D output from corrected distance information.
Regarding claim 2, Dehlinger, Perry, and Tachwali disclose the optical ranging system of claim 1, but fail to explicitly disclose wherein the first maximum peak is associated with a highest density of first distance values within the first histogram.
However, Moore discloses wherein the first maximum peak is associated with a highest density of first distance values within the first histogram (interpreted as the main peak in the histogram corresponds to the greatest concentration of distance values in that histogram region)[Moore: 0101 “an example histogram with an earlier or first target peak and a later or second target peak may be analysed by finding the maximum bin value(s) within a histogram to determine pulse locations.”](teaches a histogram peak having the maximum bin value is the peak with the greatest number of events in that bin region).
Dehlinger, Perry, Moore, and Tachwali are considered analogous to the claimed invention because they are in the same field of optical ranging, histogram based, and point cloud generation. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Dehlinger, Perry, and Tachwali to incorporate Moore’s teachings of finding the maximum bin value within a histogram to identify the main peak. The motivation for such a combination would provide the benefit of identifying the highest density peak for more accurate range analysis.
Regarding claim 3, Dehlinger, Perry, and Moore disclose the optical ranging system of claim 1, but fail to explicitly disclose wherein the first histogram is an absolute distance histogram of a point cloud dataset.
However, Tachwali discloses wherein the first histogram is an absolute distance histogram of a point cloud dataset (interpreted as the histogram is built from distance values expressed as actual distance values and those values belong to a point cloud dataset) [Tachwali: 0067 “The aggregation of measurements from multiple lidar frames within a data frame duration yields a histogram from which points of a point cloud can be extracted”](teaches tying the histogram to point cloud generation, the histogram is used to determine target distance and extract point cloud points).
Dehlinger, Perry, Moore, and Tachwali are considered analogous to the claimed invention because they are in the same field of optical ranging, histogram based, and point cloud generation. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Dehlinger, Perry, and Moore to incorporate Tachwali’s teachings of using histogram based lidar measurements to extract points of a point cloud. The motivation for such a combination would provide the benefit of organizing distance results in histogram form for direct use in point cloud generation.
Regarding claim 4, Dehlinger, Perry, and Tachwali disclose the optical ranging system of claim 1, but fail to explicitly disclose wherein the first histogram is a time-domain histogram.
However, Moore discloses wherein the first histogram is a time-domain histogram [Moore: 0018 “A Time to Digital Converter (TDC) may be configured to receive the signals generated by generator/driver and by the sensor and calculate the phase shift (or time difference) between these signals to obtain a distance to object. The detector (SPAD array) is configured to generate many fast readings in a short time period and thus the time to distance converter may be configured to generate a histogram of detected events.”](teaches the histogram is generated from elapsed time measurements between pulse emission and return detection).
Dehlinger, Perry, Moore, and Tachwali are considered analogous to the claimed invention because they are in the same field of optical ranging, histogram based, and point cloud generation. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Dehlinger, Perry, and Tachwali to incorporate Moore’s teachings of utilizing elapsed time measurements. The motivation for such a combination would provide the benefit of improving target detection and analysis.
Regarding claim 5, Dehlinger, Perry, Moore, and Tachwali disclose the optical ranging system of claim 1, wherein the modulated optical signal is a radio frequency (RF)-encoded optical signal comprising a plurality of RF signal components, wherein each RF signal component has a different frequency [Dehlinger: 00025 “The operations include providing emitter control signals to an emitter array having emitter pixels that are configured to emit optical signals at two or more modulation frequencies”](teaches a modulated optical signal with multiple different modulation frequencies).
Regarding claim 6, Dehlinger, Moore, and Tachwali disclose the optical ranging system of claim 1, but fail to explicitly disclose wherein the modulated optical signal is an amplitude-modulated continuous-wave (AMCW) signal.
However, Perry discloses wherein the modulated optical signal is an amplitude-modulated continuous-wave (AMCW) signal [Perry: 0017 “amplitude modulated continuous wave ( AMCW ) ToF range - imager .”].
Dehlinger, Perry, Moore, and Tachwali are considered analogous to the claimed invention because they are in the same field of optical ranging, histogram based, and point cloud generation. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Dehlinger, Moore, and Tachwali to incorporate Perry’s teachings of utilizing AMCW signals. The motivation for such a combination would provide the benefit of improving phase-based distance measurement.
Regarding claim 7, Dehlinger, Moore, and Tachwali disclose the optical ranging system of claim 1, but fail to explicitly disclose wherein the indirect time-of-flight sensor is configured to generate the plurality of first distance values based on respective phase differences between the reflected optical signal and a reference signal.
However, Perry discloses wherein the indirect time-of-flight sensor is configured to generate the plurality of first distance values based on respective phase differences between the reflected optical signal and a reference signal (interpreted as the iToF sensor/system determines distance values from measured phase differences, the reference signal is the modulation signal used for comparison, and the reflected optical signal is compared against that reference to obtain phase delay, which is then used to compute range)[Perry: 0021 “In one implementation , the sensor and illumination modulation is at the same frequency and a series of temporally sequential measurements are made while varying the phase relationship between the sensor ( 18 ) and illuminator ( 14 ) modulation signals . This enables the calculation of phase”][Perry: 0025 “As the modulated light signal 70 travels to the object 12 and back to the sampling array 16 , a phase delay is introduced into the reflected modulated signal 72 , which is proportional to the distance between the object 12 and the ToF camera 10”](teaches that the system calculates phase by comparing the phase relationship between the sensor modulation and the illuminator modulation).
Dehlinger, Perry, Moore, and Tachwali are considered analogous to the claimed invention because they are in the same field of optical ranging, histogram based, and point cloud generation. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Dehlinger, Moore, and Tachwali to incorporate Perry’s teachings of generating distance values from phase differences between a reflected modulated signal and a reference modulation signal. The motivation for such a combination would provide the benefit of using known phase-based processing to determine distance from returned optical signals.
Regarding claim 8, Dehlinger, Moore, and Tachwali discloses the optical ranging system of claim 1, but fail to explicitly disclose wherein each first side peak is located at a respective integer multiple of the first wavelength distance from the first histogram location of the first maximum peak, wherein each respective integer multiple is non-zero.
However, Perry discloses wherein each first side peak is located at a respective integer multiple of the first wavelength distance from the first histogram location of the first maximum peak, wherein each respective integer multiple is non-zero (interpreted as each side peak is displaced from the main peak by 1, 2, 3, etc. wavelength-distance periods, not by zero. Integer multiple means a whole number count of ambiguity periods. Non zero means the side peak is actually separated from the main peak)[Perry: 0027 “The range determination module 60 determines ni by making measurements at multiple different frequencies f1 , f2 , . . . fy and simultaneously solving for n? , 12 , . . . Nx”][Perry: 0067 “A block 920 is confidence interval calculation module to calculate confidence intervals or confidence values for the measured value of the range . A block 920a calculates the confidence interval value using the phases ( 01 , 02 . . . Ow ) and the transformed phase values v . This confidence interval value infers the amount of error present in the input phase vector by comparing the consistency of phase measurements — thus is a useful value for detecting error sources , including systematic error sources , multipath error sources , etc .”](teaches integer valued ambiguity counts ni and unwrapped phase value which means the ambiguous measurement is offset by whole number multiples of the periodic phase interval. In distance terms, that corresponds to being located at an integer multiple of the wavelength distance ambiguity interval from the principal location, since claim is about side peaks, the claimed multiple is necessarily non-zero, a zero multiple would place the return at the main peak rather than a side peak).
Dehlinger, Perry, Moore, and Tachwali are considered analogous to the claimed invention because they are in the same field of optical ranging, histogram based, and point cloud generation. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Dehlinger, Moore, and Tachwali to incorporate Perry’s teachings of resolving phase ambiguity using integer unwrapping constants corresponding to whole number multiples of a periodic ambiguity interval. The motivation for such a combination would provide the benefit of correcting wrapped distance measurements that occur at non zero integer multiples of the ambiguity period.
Regarding claim 12, Dehlinger, Moore, and Tachwali disclose the optical ranging system of claim 1, but fail to explicitly disclose wherein the plurality of first distance values correspond to a first frequency encoded onto the modulated optical signal.
However, Perry discloses wherein the plurality of first distance values correspond to a first frequency encoded onto the modulated optical signal (interpreted as the set of distance values is tied to one particular modulation frequency carried by the optical signal) (Perry: Abstract “The time - of - flight system disclosed herein includes a frequency unwrapping module configured to generate an input phase vector with M phases corresponding to M sampled signals from an object”)(teaches a multi-frequency ToF system in which measurements are taken at different modulation frequencies and the resulting phase/range information corresponds to those frequencies).
Dehlinger, Perry, Moore, and Tachwali are considered analogous to the claimed invention because they are in the same field of optical ranging, histogram based, and point cloud generation. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Dehlinger, Moore, and Tachwali to incorporate Perry’s teachings of generating measurement phases corresponding to sampled signals at different modulation frequencies. The motivation for such a combination would provide the benefit of associating distance values with a selected encoded frequency for improved range processing.
Regarding claim 13, Dehlinger, Moore, and Tachwali disclose the optical ranging system of claim 12, but fail to explicitly disclose wherein the first wavelength distance is equal to a wavelength of the first frequency.
However, Perry discloses wherein the first wavelength distance is equal to a wavelength of the first frequency [Perry: 0026 “is an unwrapping constant that corrects for the cyclic ambiguity present in the phase of a sinusoid ( note that a phase 0 ; is indistinguishable from a phase 0 : + 21 , 0 + 41 , etc . )”](teaches that each modulation frequency has a repeating cyclic ambiguity period. In iToF ranging, that repeating period is the wavelength distance period for that frequency).
Dehlinger, Perry, Moore, and Tachwali are considered analogous to the claimed invention because they are in the same field of optical ranging, histogram based, and point cloud generation. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Dehlinger, Moore, and Tachwali to incorporate Perry’s teachings of the ambiguity period repeating. The motivation for such a combination would provide the benefit of using the known frequency dependent wavelength interval for distance unwrapping and ambiguity correction.
Regarding claim 21, Dehlinger, Moore, and Tachwali disclose the method of claim 20, but fail to explicitly disclose wherein the plurality of first distance values correspond to a first frequency encoded onto the modulated optical signal, and wherein the first wavelength distance is equal to a wavelength of the first frequency.
However, Perry discloses wherein the plurality of first distance values correspond to a first frequency encoded onto the modulated optical signal, and wherein the first wavelength distance is equal to a wavelength of the first frequency (interpreted as the measured distance values are tied to one specific modulation frequency carried on the optical signal, and the ambiguity interval for those values is the wavelength-based range period associated with that frequency) [Perry: 0002 “The includes a frequency unwrapping module configured to generate an input phase vector with M phases corresponding to M sampled signals reflected from an object”][Perry: 0016 “phase used to measure distance repeats or wraps at various distances based on the frequency , which is known as phase wrapping”](teaches multi frequency ToF measurements in which the measured phase/range information correspond to particular modulation frequencies, further teaches that the range ambiguity period depends on the frequency and that repeating ambiguity period is the wavelength distance period for that frequency).
Dehlinger, Perry, Moore, and Tachwali are considered analogous to the claimed invention because they are in the same field of optical ranging, histogram based, and point cloud generation. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Dehlinger, Moore, and Tachwali to incorporate Perry’s teachings of the ambiguity period repeating based on frequency. The motivation for such a combination would provide the benefit of using the known frequency dependent unwrapping behavior to method-based distance correction.
Claims 19 and 20 are apparatus and method claims corresponding to claim 1 without any additional limitations. Thus, claims 19 and 20 are rejected for the same reasons as claim 1 above.
Allowable Subject Matter
Claim 9-11 and 14-18 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Conclusion
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/AHMED TAHA/Examiner, Art Unit 2613
/XIAO M WU/Supervisory Patent Examiner, Art Unit 2613
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