DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 June 9, 2026 has been entered.
Applicant(s) Response to Official Action
The response filed on June 9, 2026 was entered and made of record. Claims 1, 5, 6, 11, 17 and have been amended. Accordingly, claims 1 - 3, 5 - 8 and 10 - 20 are currently pending in the application.
Response to Arguments
Applicant’s arguments see pages 7 - 13 with respect to the rejection of claims under 35 U.S.C. 103 as being unpatentable over Gnecchi et al., (US 2018/0259625 A1) in view of TACHINO et al. (US 2021/0018624 A1) have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground of rejection is made in view of the newly discovered reference to the adjustable threshold is configured such that a pulse width of the waveform is related to a quantity of photons in the incident light, as claimed in the amended Claims 1, 6 and 17.
Claim Objections
Claim 16 is objected to under 37 CFR 1.75(c) as being in improper form because a multiple dependent claim cannot depend from any other multiple dependent claim. See MPEP § 608.01(n). Accordingly, the claim 16 has not been further treated on the merits.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 - 3, 5 - 8 and 10 - 20 are rejected under 35 U.S.C. 103 as being unpatentable over Gnecchi et al., (US 2018/0259625 A1) referred to as Gnecchi hereinafter, and in view of AXELSSON et al. (US 2017/0234973 A1) referred to as AXELSSON hereinafter.
Regarding Claim 1, Gnecchi teaches a detection circuit (Fig. 7) for adjusting a width of output pulses (Par. [0063], output pulse width τ is calculated), comprising:
a single-photon avalanche diode (Par. [0070], the SiPM sensor is formed of a summed array of Single Photon Avalanche Photodiode (SPAD) sensors), configured to generate a photocurrent in response to an incident photon (Par. [0049] Each microcell detects photons identically and independently. The sum of the discharge currents from each of these individual binary detectors combines to form a quasi-analog output, and is thus capable of giving information on the magnitude of an incident photon flux); and
a comparator (Fig. 7, plurality of comparators 715A-715D), having a first input terminal to be inputted with a signal indicating an adjustable threshold, and a second input terminal coupled to the single-photon avalanche diode to be inputted with an electrical signal representing the photocurrent (Fig. 7, [0068], A plurality of comparators 715A-715D are provided and each has an associated threshold value (i.e. adjustable threshold, first input terminal) and is configured to compare the analog SiPM output signal (i.e. second input terminal) with their associated threshold value and generate a comparison signal indicative of the comparison),
wherein the comparator is configured to output a waveform based on a comparison result between the electrical signal and the signal indicating the adjustable threshold (As illustrated in Fig. 7, output square waveform of each 715A-715D comparator, Par. [0068], comparison signals from the plurality of comparators 715A-715D), and wherein the adjustable threshold is configured such that related to a quantity of photons in the incident light (Par. [0069] The threshold values of the respective comparators increments sequentially from a low threshold value to a high threshold value (i.e. adjustable threshold). The sequence of threshold values may include a single value, double value, triple value etc. (i.e. number of photons). A single value corresponds to a single photon level, while a double value corresponds to twice a single photon level, and a triple value corresponds to three times a single photon level. Par. [0071] From the range of min-max detected photons per pulse, one can specify the number of thresholds (i.e. adjustable threshold)).
Gnecchi does not specifically teach the pulse width is related to the quantity of the photons. Therefore, Gnecchi fails to explicitly teach the adjustable threshold is configured such that a pulse width of the waveform is related to a quantity of photons in the incident light.
However, AXELSSON teaches the adjustable threshold is configured such that a pulse width of the waveform is related to a quantity of photons in the incident light (Fig. 3, Par. [0132] wide pulses with low amplitude 20,20′ can be discriminated from wide pulses with high amplitude 20″ by using different thresholds (i.e. adjustable threshold), e.g. by respectively determining the signal width at different threshold) (Par. [0071] –[0075] FIG. 3 shows an exemplary waveform s(t) for low photon count return pulses 20,20′,20″. A number of pulses are shown: solar photon pulses 21 with amplitudes around 1 photon, a weak pulse 20, e.g. here generated by 4 returning photons from a reflection, a broadened pulse 20′, e.g. here generated by 4 returning photons from a reflection on a slanted target, and a stronger pulse 20″, e.g. here generated by 8 returning photons from a reflection (i.e. pulse width relates to quantity of photons)).
References Gnecchi and AXELSSON are considered to be analogous art because they emit laser pulses. Therefore, it would have been obvious that one of ordinary skill in the art, before the effective filing date of the claimed invention, would recognize the advantage of further specify the adjustable threshold as suggested by AXELSSON in the invention of Gnecchi in order to discriminate solar or thermal noise from real signals since multiple noise photons close in time have much lower probability than multiple signal photons close in time. Thus filtering of the generated 3D point cloud can be improved, resulting in a cleaner 3D point dataset (See AXELSSON, Par. [0032]).
Regarding Claim 2, Gnecchi in view of AXELSSON teaches Claim 1. Gnecchi further teaches wherein a cathode of the single-photon avalanche diode is coupled to a high voltage (Fig. 1, HV is high voltage), wherein an anode of the single-photon avalanche diode is grounded by a quenching resistor (Par. [0048], a quench resistor is provided adjacent to each photodiode which may be used to limit the avalanche current. The photodiodes are electrically connected to common biasing and ground electrodes by aluminum or similar conductive tracking) and is coupled to the second input terminal of the comparator (Fig. 7, [0068], A plurality of comparators 715A-715D are provided and each has analog SiPM output signal (i.e. second input terminal)), and wherein the electrical signal is an analog voltage outputted by the single-photon avalanche diode (Par. [0068], A plurality of comparators 715A-715D are provided and compare the analog SiPM output signal (i.e. analog voltage) and generate a comparison signal indicative of the comparison).
Regarding Claim 3, Gnecchi in view of AXELSSON teaches Claim 1. Gnecchi further teaches wherein a cathode of the single-photon avalanche diode is coupled to a high voltage (Fig. 1, HV is high voltage) by a quenching resistor (Par. [0048], a quench resistor is provided adjacent to each photodiode which may be used to limit the avalanche current), wherein an anode of the single- photon avalanche diode is grounded (Fig. 2, 215 anode connected to ground, Par. [0048], The photodiodes are electrically connected to ground electrodes by aluminum or similar conductive tracking), wherein the cathode is coupled to the second input terminal of the comparator by a capacitor (Par. [0050], The output charge can be calculated from the over-voltage and the microcell capacitance (i.e. capacitor)), and wherein the electrical signal represents a variation of a cathode voltage of the single-photon avalanche diode (Par. [0050]-[0054] The output charge can be calculated from the over-voltage and the microcell capacitance. G=(CxΔV)/q, where G is the gain of the microcell; C is the capacitance of the microcell; ΔV (i.e. variation of voltage) is the over-voltage; and q is the charge of an electron).
Regarding Claim 4, it has been cancelled.
Regarding Claim 5, Gnecchi in view of AXELSSON teaches Claim 1. Gnecchi further teaches wherein the signal indicating the adjustable threshold increases as an intensity of the incident light increases (Par. [0069], The threshold value for each comparator 715A-715D is determined based on the ambient light level (i.e. incident light). The threshold values of the respective comparators increments sequentially from a low threshold value to a high threshold value (i.e. increases)).
Regarding Claim 6, Gnecchi teaches a receiving unit for a laser radar (Fig. 5, Par. [0063], LiDAR device 600 (i.e. laser radar). Which includes a laser source 605 for transmitting a periodic laser pulse 607 through a transmit lens 604. A target 608 diffuses and reflects laser photons 612 through a receive lens 610 and some of the photons are reflected back towards a SiPM sensor 615 (i.e. receiving unit)), comprising:
a detection circuit (Fig. 7, Par. [0042] FIG. 7 illustrates a schematic of a LiDAR readout circuit), comprising:
a single-photon avalanche diode (Par. [0070], the SiPM sensor is formed of a summed array of Single Photon Avalanche Photodiode (SPAD) sensors), configured to generate a photocurrent in response to an incident light (Par. [0049] Each microcell detects photons identically and independently. The sum of the discharge currents from each of these individual binary detectors combines to form a quasi-analog output, and is thus capable of giving information on the magnitude of an incident photon flux); and
a comparator (Fig. 7, plurality of comparators 715A-715D), having a first input terminal to be inputted with a signal indicating an adjustable threshold, and a second input terminal coupled to the single-photon avalanche diode to be inputted with an electrical signal representing the photocurrent (Fig. 7, [0068], A plurality of comparators 715A-715D are provided and each has an associated threshold value (i.e. adjustable threshold, first input terminal) and is configured to compare the analog SiPM output signal (i.e. second input terminal) with their associated threshold value and generate a comparison signal indicative of the comparison), wherein the comparator is configured to output a waveform based on a comparison result between the electrical signal and the signal indicating the adjustable threshold (As illustrated in Fig. 7, output square waveform of each 715A-715D comparator, Par. [0068], comparison signals from the plurality of comparators 715A-715D), and wherein the adjustable threshold is configured such that related to a quantity of photons in the incident light (Par. [0069] The threshold values of the respective comparators increments sequentially from a low threshold value to a high threshold value (i.e. adjustable threshold). The sequence of threshold values may include a single value, double value, triple value etc. (i.e. number of photons). A single value corresponds to a single photon level, while a double value corresponds to twice a single photon level, and a triple value corresponds to three times a single photon level. Par. [0071] From the range of min-max detected photons per pulse, one can specify the number of thresholds (i.e. adjustable threshold)) and
a processing circuit (Fig. 3 Par. [0055], The basic components (i.e. processing circuit) used for a direct ToF ranging system, are illustrated in FIG. 3), coupled to an output terminal of the comparator of the detection circuit (Par. [0068], A time to digital converter (TDC) 720 is configured to receive the comparison signals from the plurality of comparators 715A-715D and time stamp the events) and configured to calculate a distance from a target object based on the waveform and an intensity of the incident light based on the waveform outputted by the comparator (Par. [0056]-[0058] In the direct ToF technique, a periodic laser pulse 305 (i.e. waveform) is directed at the target 307. The target 307 diffuses and reflects the laser photons and some of the photons are reflected back towards the detector 315. The detector 315 converts the detected laser photons (and some detected photons due to noise) (i.e. intensity of light) to electrical signals that are then timestamped by timing electronics 325. This time of flight, t, may be used to calculate the distance, D, to the target from the equation D=cΔt/2, where c=speed of light; and Δt=time of flight. The detector 315 must discriminate returned laser photons from the noise (ambient light) (i.e. intensity of light)).
Gnecchi does not specifically teach the pulse width is related to the quantity of the photons. Therefore, Gnecchi fails to explicitly teach the adjustable threshold is configured such that a pulse width of the waveform is related to a quantity of photons in the incident light.
However, AXELSSON teaches the adjustable threshold is configured such that a pulse width of the waveform is related to a quantity of photons in the incident light (Fig. 3, Par. [0132] wide pulses with low amplitude 20,20′ can be discriminated from wide pulses with high amplitude 20″ by using different thresholds (i.e. adjustable threshold), e.g. by respectively determining the signal width at different threshold) (Par. [0071] –[0075] FIG. 3 shows an exemplary waveform s(t) for low photon count return pulses 20,20′,20″ (i.e. pulse width of the waveform). A number of pulses are shown: solar photon pulses 21 with amplitudes around 1 photon, a weak pulse 20, e.g. here generated by 4 returning photons from a reflection, a broadened pulse 20′, e.g. here generated by 4 returning photons from a reflection on a slanted target, and a stronger pulse 20″, e.g. here generated by 8 returning photons from a reflection (i.e. pulse width relates to quantity of photons)).
References Gnecchi and AXELSSON are considered to be analogous art because they emit laser pulses. Therefore, it would have been obvious that one of ordinary skill in the art, before the effective filing date of the claimed invention, would recognize the advantage of further specify the adjustable threshold as suggested by AXELSSON in the invention of Gnecchi in order to discriminate solar or thermal noise from real signals since multiple noise photons close in time have much lower probability than multiple signal photons close in time. Thus filtering of the generated 3D point cloud can be improved, resulting in a cleaner 3D point dataset (See AXELSSON, Par. [0032]).
Regarding Claim 7, Gnecchi in view of AXELSSON teaches Claim 6. Gnecchi further teaches wherein a cathode of the single-photon avalanche diode is coupled to a high voltage (Fig. 1, HV is high voltage), wherein an anode of the single-photon avalanche diode is grounded by a quenching resistor (Par. [0048], a quench resistor is provided adjacent to each photodiode which may be used to limit the avalanche current. The photodiodes are electrically connected to common biasing and ground electrodes by aluminum or similar conductive tracking) and is coupled to the second input terminal of the comparator ( [0068], A plurality of comparators 715A-715D are provided and each has analog SiPM output signal (i.e. second input terminal)), and wherein the electrical signal represents a voltage across the quenching resistor (Par. [0048], the anodes of an array of photodiodes are connected to a common ground electrode and the cathodes of the array are connected via current limiting resistors to a common bias electrode for applying a bias voltage across the diodes).
Regarding Claim 8, Gnecchi in view of AXELSSON teaches Claim 6. Gnecchi further teaches wherein a cathode of the single-photon avalanche diode is coupled to a high voltage (Fig. 1, HV is high voltage) by a quenching resistor (Par. [0048], a quench resistor is provided adjacent to each photodiode which may be used to limit the avalanche current) by a quenching resistor (Par. [0048], a quench resistor is provided adjacent to each photodiode which may be used to limit the avalanche current), wherein an anode of the single- photon avalanche diode is grounded (Fig. 2, 215 anode connected to ground, Par. [0048], The photodiodes are electrically connected to ground electrodes by aluminum or similar conductive tracking), wherein the cathode is coupled to the second input terminal of the comparator by a capacitor (Par. [0050], The output charge can be calculated from the over-voltage and the microcell capacitance (i.e. capacitor)), and wherein the electrical signal represents a voltage of the single-photon avalanche diode (Par. [0050]-[0054] The output charge can be calculated from the over-voltage and the microcell capacitance. G=(CxΔV)/q, where G is the gain of the microcell; C is the capacitance of the microcell; ΔV (i.e. variation of voltage) is the over-voltage; and q is the charge of an electron).
Regarding Claim 9, it has been cancelled.
Regarding Claim 10, Gnecchi in view of AXELSSON teaches Claim 6. Gnecchi further teaches wherein the signal indicating the adjustable threshold is increased as the intensity of the incident light increases (Par. [0069], The threshold value for each comparator 715A-715D is determined based on the ambient light level (i.e. incident light). The threshold values of the respective comparators increments sequentially from a low threshold value to a high threshold value (i.e. increases)).
Regarding Claim 11, Gnecchi in view of AXELSSON teaches Claim 8. Gnecchi further teaches wherein the receiving unit comprises a plurality of the detection circuit and a summer (Par. [0030], the SiPM sensor 615 may be formed of a summed array of Single Photon Avalanche Photodiode (SPAD) sensors), wherein output terminals of comparators of the plurality of detection circuits are coupled to an input terminal of the summer (Par. [0049], The signals of all microcells are then summed to form the output of the SiPM 200. A simplified electrical circuit is provided to illustrate the concept in FIG. 2), and wherein the summer is configured to perform a summation of outputs of the plurality of detection circuits (Par. [0049], The sum of the discharge currents from each of these individual binary detectors combines to form a quasi-analog output, and is thus capable of giving information on the magnitude of an incident photon flux).
Regarding Claim 12, Gnecchi in view of AXELSSON teaches Claim 8. Gnecchi further teaches wherein the signal indicating the adjustable threshold of the detection circuit is set (Par. [0063], The average number of detected photons k in a typical output pulse width τ is calculated from the incident rate Φ and the photon detection efficiency (PDE)) so that a width of the waveform of the comparator of the detection circuit corresponding to a single photon matches a width of a laser pulse of the laser radar (As illustrated Fig. 7, the output of 715A -715D square pulses matches input analog waveform width)).
Regarding Claim 13, Gnecchi in view of AXELSSON teaches Claim 12. Gnecchi further teaches wherein the signal indicating the adjustable threshold of the detection circuit is (Par. [0063], The average number of detected photons k in a typical output pulse width τ is calculated from the incident rate Φ and the photon detection efficiency (PDE)) so such that the width of the waveform of the comparator of the detection circuit corresponding to a single photon is equal to a full width at half maximum of the laser pulse of the laser radar (As illustrated Fig. 7, the output of 715A -715D square pulses matches input analog waveform width which is also half maximum pulse as illustrated with the lowest horizontal bar after the 710 amplifier)).
Regarding Claim 14, Gnecchi in view of AXELSSON teaches Claim 8. Gnecchi further teaches wherein the processing circuit is configured to calculate a number of incident photons based on a pulse width of the waveform outputted by the comparator (Par. [0063], The average number of detected photons k (i.e. calculate number of photons) in a typical output pulse width τ is calculated from the incident rate Φ and the photon detection efficiency (PDE)).
Regarding Claim 15, Gnecchi in view of AXELSSON teaches Claim 6. Gnecchi further teaches a laser radar (Fig. 5, Par. [0063], LiDAR device 600 (i.e. laser radar)), comprising:
an emitting unit, comprising a laser emitter configured to transmit a laser pulse to an outside of the laser radar to detect a target object (Par. [0063], a laser source 605 (i.e. a laser emitter) for transmitting a periodic laser pulse 607 (i.e. laser pulse) through a transmit lens 604. A target 608 (i.e. target object) diffuses and reflects laser photons 612 through a receive lens 610 and some of the photons are reflected back towards a SiPM sensor 615); and
the receiving unit, configured to receive a return pulse of the laser pulse reflected by the target object (Par. [0063A target 608 diffuses and reflects laser photons 612 (i.e. reflected laser pulse by target) through a receive lens 610 and some of the photons are reflected back towards a SiPM sensor 615 (i.e. receiving unit)).
Regarding Claim 16, Gnecchi in view of AXELSSON teaches Claim 6. Gnecchi further teaches a method (Fig. 9) of detecting return pulses by using the receiving unit (Par. [0063], A target 608 diffuses and reflects laser photons 612 (i.e. return pulses) through a receive lens 610 and some of the photons are reflected back towards a SiPM sensor 615 (i.e. receiving unit). The SiPM sensor 615 converts the detected laser photons and some detected photons due to noise to electrical signals that are then timestamped by timing electronics. The average number of detected photons k in a typical output pulse width τ is calculated from the incident rate Φ and the photon detection efficiency (PDE)).
Regarding Claim 17, Gnecchi teaches a method of laser detection (Fig. 9), comprising:
emitting a detection laser beam to detect a target object (Par. [0063], a laser source 605 (i.e. a laser emitter) for transmitting a periodic laser pulse 607 (i.e. laser pulse) through a transmit lens 604. A target 608 (i.e. target object) diffuses and reflects laser photons 612 through a receive lens 610 and some of the photons are reflected back towards a SiPM sensor 615);
receiving a return pulse from the target object through a single-photon avalanche diode (Par. [0063A target 608 diffuses and reflects laser photons 612 (i.e. reflected laser pulse by target) through a receive lens 610 and some of the photons are reflected back towards a SiPM sensor 615 (i.e. receiving unit)), wherein the single-photon avalanche diode generates a photocurrent in response to an incident light (Par. [0049] Each microcell detects photons identically and independently. The sum of the discharge currents from each of these individual binary detectors combines to form a quasi-analog output, and is thus capable of giving information on the magnitude of an incident photon flux);
comparing an electrical signal representing the photocurrent with a signal indicating an adjustable threshold through a comparator to generate a digital signal output (Fig. 7, [0068], A plurality of comparators 715A-715D are provided and each has an associated threshold value (i.e. adjustable threshold, first input terminal) and is configured to compare the analog SiPM output signal (i.e. second input terminal) with their associated threshold value and generate a comparison signal indicative of the comparison); and
adjusting the signal indicating the adjustable threshold such that a waveform of the digital signal output (As illustrated in Fig. 7, output square waveform of each 715A-715D comparator, Par. [0068], comparison signals from the plurality of comparators 715A-715D, Par. [0018], the threshold value for each comparator is determined based on the ambient light level) is related to a quantity of photons in the incident light (Par. [0069] The threshold values of the respective comparators increments sequentially from a low threshold value to a high threshold value (i.e. adjustable threshold). The sequence of threshold values may include a single value, double value, triple value etc. (i.e. number of photons). A single value corresponds to a single photon level, while a double value corresponds to twice a single photon level, and a triple value corresponds to three times a single photon level. Par. [0071] From the range of min-max detected photons per pulse, one can specify the number of thresholds (i.e. adjustable threshold))
Gnecchi does not specifically teach the pulse width is related to the quantity of the photons. Therefore, Gnecchi fails to explicitly teach the adjustable threshold such that a pulse width of a waveform of the digital signal output is related to a quantity of photons in the incident light.
However, AXELSSON teaches the adjustable threshold such that a pulse width of a waveform of the digital signal output is related to a quantity of photons in the incident light (Fig. 3, Par. [0132] wide pulses with low amplitude 20,20′ can be discriminated from wide pulses with high amplitude 20″ by using different thresholds (i.e. adjustable threshold), e.g. by respectively determining the signal width at different threshold) (Par. [0071] –[0075] FIG. 3 shows an exemplary waveform s(t) for low photon count return pulses 20,20′,20″ (i.e. pulse width of the waveform). A number of pulses are shown: solar photon pulses 21 with amplitudes around 1 photon, a weak pulse 20, e.g. here generated by 4 returning photons from a reflection, a broadened pulse 20′, e.g. here generated by 4 returning photons from a reflection on a slanted target, and a stronger pulse 20″, e.g. here generated by 8 returning photons from a reflection (i.e. pulse width relates to quantity of photons)).
References Gnecchi and AXELSSON are considered to be analogous art because they emit laser pulses. Therefore, it would have been obvious that one of ordinary skill in the art, before the effective filing date of the claimed invention, would recognize the advantage of further specify the adjustable threshold as suggested by AXELSSON in the invention of Gnecchi in order to discriminate solar or thermal noise from real signals since multiple noise photons close in time have much lower probability than multiple signal photons close in time. Thus filtering of the generated 3D point cloud can be improved, resulting in a cleaner 3D point dataset (See AXELSSON, Par. [0032]).
Regarding Claim 18, Gnecchi in view of AXELSSON teaches Claim 17. Gnecchi further teaches wherein the step of adjusting the signal indicating the adjustable threshold according to the waveform of the digital signal output comprises: increasing the signal indicating the adjustable threshold as an intensity of the incident light increases (Par. [0069], The threshold value for each comparator 715A-715D is determined based on the ambient light level (i.e. incident light). The threshold values of the respective comparators increments sequentially from a low threshold value to a high threshold value (i.e. increases)).
Regarding Claim 19, Gnecchi in view of AXELSSON teaches Claim 1. Gnecchi further teaches a pulse output by the detection circuit is determined based on a total duration of an incident photon sequence (Fig. 5, Par. [0063] The SiPM sensor 615 converts the detected laser photons and some detected photons due to noise to electrical signals (i.e. total duration of an incident photon sequence). The average number of detected photons k in a typical output pulse width τ is calculated from the incident rate Φ and the photon detection efficiency (PDE)) and a duration of a single photon output pulse (Par. [0067]-[0068] where the photon rate is high, having multiple threshold enables the detection of a larger number of events. This multi-channel solution enables more events to be successfully detected by the TDC 720. A time to digital converter (TDC) 720 is configured to receive the comparison signals from the plurality of comparators 715A-715D (i.e. total duration of incident photon sequence). The TDC 720 may be considered as a very high precision counter/timer that can record the time of an event to sub 1 ns resolution. The TDC may be used to measure the time of flight of a photon (i.e. duration of single photon pulse) from a laser pulse to a target 608 and back to the SiPM sensor 615).
Gnecchi does not specifically teach a total pulse width. Therefore, Gnecchi fails to explicitly a total pulse width output by the detection circuit is determined based on a total duration of an incident photon sequence and a duration of a single photon output pulse width.
However, AXELSSON teaches a total pulse width output by the detection circuit (Par. [0060] FIG. 3 an exemplary signal waveform determined by a SPL LiDAR scanner using a detector wherein the electrical detection signal is proportional to the number of photons detected in the package) is determined based on a total duration of an incident photon sequence (Par. [0071] FIG. 3 shows an exemplary waveform s(t) (i.e. total duration of photon sequence)) and a duration of a single photon output pulse width (Par. [0071] – [0075] the electrical detection signal is proportional to the number of photons detected in the package. A number of pulses are shown: solar photon pulses 21 with amplitudes around 1 photon (i.e. single photon output pulse width), a weak pulse 20, e.g. here generated by 4 returning photons from a reflection, a broadened pulse 20′, e.g. here generated by 4 returning photons from a reflection on a slanted target, and a stronger pulse 20″, e.g. here generated by 8 returning photons from a reflection).
References Gnecchi and AXELSSON are considered to be analogous art because they emit laser pulses. Therefore, it would have been obvious that one of ordinary skill in the art, before the effective filing date of the claimed invention, would recognize the advantage of further specify the pulse width as suggested by AXELSSON in the invention of Gnecchi in order to discriminate solar or thermal noise from real signals since multiple noise photons close in time have much lower probability than multiple signal photons close in time. Thus filtering of the generated 3D point cloud can be improved, resulting in a cleaner 3D point dataset (See AXELSSON, Par. [0032]).
Regarding Claim 20, Gnecchi in view of AXELSSON teaches Claim 6. Gnecchi further teaches a pulse output by the detection circuit is determined based on a total duration of an incident photon sequence (Fig. 5, Par. [0063] The SiPM sensor 615 converts the detected laser photons and some detected photons due to noise to electrical signals (i.e. total duration of an incident photon sequence). The average number of detected photons k in a typical output pulse width τ is calculated from the incident rate Φ and the photon detection efficiency (PDE)) and a duration of a single photon output pulse (Par. [0067]-[0068] where the photon rate is high, having multiple threshold enables the detection of a larger number of events. This multi-channel solution enables more events to be successfully detected by the TDC 720. A time to digital converter (TDC) 720 is configured to receive the comparison signals from the plurality of comparators 715A-715D (i.e. total duration of incident photon sequence). The TDC 720 may be considered as a very high precision counter/timer that can record the time of an event to sub 1 ns resolution. The TDC may be used to measure the time of flight of a photon (i.e. duration of single photon pulse) from a laser pulse to a target 608 and back to the SiPM sensor 615).
Gnecchi does not specifically teach a total pulse width. Therefore, Gnecchi fails to explicitly a total pulse width output by the detection circuit is determined based on a total duration of an incident photon sequence and a duration of a single photon output pulse width.
However, AXELSSON teaches a total pulse width output by the detection circuit (Par. [0060] FIG. 3 an exemplary signal waveform determined by a SPL LiDAR scanner using a detector wherein the electrical detection signal is proportional to the number of photons detected in the package) is determined based on a total duration of an incident photon sequence (Par. [0071] FIG. 3 shows an exemplary waveform s(t) (i.e. total duration of photon sequence)) and a duration of a single photon output pulse width (Par. [0071] – [0075] the electrical detection signal is proportional to the number of photons detected in the package. A number of pulses are shown: solar photon pulses 21 with amplitudes around 1 photon (i.e. single photon output pulse width), a weak pulse 20, e.g. here generated by 4 returning photons from a reflection, a broadened pulse 20′, e.g. here generated by 4 returning photons from a reflection on a slanted target, and a stronger pulse 20″, e.g. here generated by 8 returning photons from a reflection).
References Gnecchi and AXELSSON are considered to be analogous art because they emit laser pulses. Therefore, it would have been obvious that one of ordinary skill in the art, before the effective filing date of the claimed invention, would recognize the advantage of further specify the pulse width as suggested by AXELSSON in the invention of Gnecchi in order to discriminate solar or thermal noise from real signals since multiple noise photons close in time have much lower probability than multiple signal photons close in time. Thus filtering of the generated 3D point cloud can be improved, resulting in a cleaner 3D point dataset (See AXELSSON, Par. [0032]).
Conclusion
The prior art references made of record are not relied upon but are considered pertinent to applicant's disclosure. Cova et al. (US 6,384,663 B2) teaches selecting a threshold level to be fairly high, so that the pulse crosses the threshold not with the initial part of its leading edge, but at a successive point of the filtering and amplification band. Delic et al. (US 2020/0326414 A1) teaches the predetermined threshold value is adjustable between timing intervals.
Any inquiry concerning this communication should be directed to SUSAN E HODGES whose telephone number is (571)270-0498. The Examiner can normally be reached on Monday - Friday from 8:00 am (EST) to 4:00 pm (EST).
If attempts to reach the Examiner by telephone are unsuccessful, the Examiner's supervisor, Brian T. Pendleton, can be reached on (571) . The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://portal.uspto.gov/external/portal. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free).
/Susan E. Hodges/Primary Examiner, Art Unit 2425
