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 .
This is the first office action on the merits and is responsive to the papers filed 04/17/2024. Claims 1-20 are currently pending and examined below.
Specification
The disclosure is objected to because of the following informalities:
"In paragraph [0061] lines 28- 29, light output from the “optical reception unit 124” may be transmitted as leakage light Opx3 to the “optical reception unit 124.” should be written light output from the “optical transmission unit 122” may be transmitted as leakage light Opx3 to the “optical reception unit 124.”
Appropriate correction is required.
Claim Objections
Claims 1-12 are objected to because of the following informalities:
In claim 1, the listed circuits should be introduced using the article ‘a’ or ‘an’. These should thus read as, “a generation circuit configured to…”, “a transmission circuit configured to…”, “a reception circuit configured to…”, “a detection circuit configured to…”, “a distance calculation circuit configured to…”, and “an invalidation processing circuit configured to…”
Claims 2-12 are objected to due to claim dependency.
Appropriate correction is required.
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 1-2, 11-14 are rejected under 35 U.S.C. 103 as being unpatentable over Hidemi Noguchi (WO 2020/079776 A1) in view of Gatto et al. (US 5050986 A, “Gatto”).
Regarding claim 1, Noguchi teaches a distance-measurement apparatus (Figs. 1 and 4, Page 2, paragraph 9 “The ranging device 1 includes a generation unit 2…” and page 4, para 1“each of the above-described constituent elements can be realized by a device or a circuit…”) comprising:
generation circuit configured to generate a plurality of transmission pulses of which a strength of an optical signal changes in a pulse-like manner, the plurality of transmission pulses having frequency offsets different from each other with respect to a reference frequency (Claim 1; Page 3 third paragraph from the bottom and page 4 paragraph 2, Noguchi teaches generation unit 2 and, more specifically, pulse generation unit 110, which includes frequency-offset generator 102, modulation-signal generation unit 104, optical modulator 106, and light source 108. Frequency-offset generator 102 supplies frequency offsets f1, f2…, fn relative to reference frequency f0, and optical modulator 106 generates respective transmission pulses having frequencies f0+f1, f0+f2, and so forth. See also, Fig. 5, page 5, paragraph 2, Noguchi explains that each resulting transmission pulse has an optical intensity that changes in a pulse-like manner and that transmission pulses Plst1, Plst2, and Plst3 have mutually different frequency offsets f1, f2, and f3.);
transmission circuit configured to repeatedly transmit the generated transmission pulses (Claim 1; Figs. 1-2, 4, Page 2 second paragraph from the bottom and page 3 third paragraph from the bottom, Noguchi teaches transmission unit 4 and optical transmission unit 120. Transmission unit 4 repeatedly transmits the pulses generated by generation unit 2, and optical transmission unit 120 irradiates the distance measurement target object 90 with an optical signal containing the plurality of transmission pulses.);
reception circuit configured to receive reflected pulses of the transmission pulses reflected on a distance-measurement-target object (Claim 1; Figs. 1 and 4, Page 5 third paragraph from the bottom, Noguchi teaches optical reception unit 122. Optical reception unit 122 receives an optical signal containing the reflected pulses produced when the transmitted pulses are reflected by target object 90. The received pulses retain respective frequencies f0+f1, f0+f2…, f0+fn.);
detection circuit configured to detect frequency offsets of the received reflected pulses (Claim 1; Fig. 4, Page 5 second paragraph from the bottom, Noguchi teaches detection unit 8 and optical interference-system unit 130. Optical interference-system unit 130 mixes the received light with reference light having reference frequency f0, detects the resulting beat frequency, and thereby detects the respective frequency offset of each reflected pulse.);
distance calculation circuit configured to calculate a distance to the distance-measurement-target object based on receiving timings of the received reflected pulses and transmitting timings of the transmission pulses corresponding to the frequency offsets detected from the reflected pulses (Claim 1; Fig.4, page 6 paragraph 3, Noguchi teaches distance-calculation units 160-1 to 160-n. The modulation-signal generation unit outputs measurement-start triggers Trgt1-Trgtn representing the transmission timings of the pulses having offsets f1−fn. The timing-extraction units output measurement-stop triggers Trgr1-Trgrn representing the receiving timings of the corresponding reflected pulses. Each distance-calculation unit calculates distance R from the time difference between the matching start and stop triggers for the same detected frequency offset.).
Noguchi fails to explicitly teach invalidation processing circuit configured to perform processing of invalidating distance calculation processing for a certain period based on the transmitting timings of the transmission pulses.
However, Gatto teaches an optical target ranging system having transmitter 12, receiver 14, APD 54, T/R switch 56, comparator 94, fixed-delay circuit 104, and latch 82. Gatto recognizes that transmitter energy or backscatter entering the receiver during transmission can overload or saturate the receiver. Gatto therefore isolates the receiver during a transmit-related blanking interval and reconnects the receiver after the harmful backscatter interval (Col 4: line 48 to col 5: line 7).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify Noguchi, as taught by Gatto, to include receiver blanking circuitry configured to invalidate the receiving signal supplied to the distance calculation path during a predetermined interval associated with transmission of each optical pulse, because doing so would prevent transmitted light leakage or backscatter from saturating the receiver or being processed as a valid reflected pulse, thereby reducing false distance measurements while permitting valid target returns to be processed after the blanking interval
Regarding claim 2, Noguchi, in view of Gatto, teaches the distance-measurement apparatus according to claim 1, wherein the invalidation processing circuit performs processing of invalidating the distance calculation processing by invalidating a receiving-side signal transmitted on a receiving side of the distance-measurement apparatus for a certain period of time based on the transmitting timings of the transmission pulses.
Gatto further teaches invalidating such a receiving side signal. APD 54 converts received optical energy into an electrical signal, and T/R switch 56 is connected between APD 54 and receiver amplifier 62. See Gatto, Fig. 1; col. 3: lines 36- 45. During the transmit mode, T/R switch 56 isolates receiver amplifier 62 from the backscatter signal, while during the receive mode the switch supplies the APD signal representing the reflected target pulse to receiver amplifier 62. See col. 3: lines 46-51. More particularly, Gatto teaches that T/R switch 56 isolates receiver input stage 62 during the transmit interval by presenting a high impedance toward the receiver and shunting the APD output signal to resistive load 70, thereby preventing receiver saturation from transmitter backscatter. See col. 4: lines 11-23.
Gatto also teaches that the transmit trigger at time T0 sets latch 82, causing T/R switch 56 to disconnect receiver amplifier 62 and shunt the backscatter signal to load 70. See Fig. 2; col 4: lines 48-59. Comparator 94 detects the backscatter signal, and delay circuit 104 resets latch 82 at time T2 after a delay normally equal to the transmitted pulse duration. See col. 4: lines 59-68. At T2, T/R switch 56 reconnects the APD signal to receiver amplifier 62 so that the reflected target pulse can be detected. See col. 5: lines 1-5. Gatto characterizes the period from T0 to T2 as a fixed blanking interval selected for target detection. See col. 5: lines 8-22. See also, claims 1, 2, and 4.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify Noguchi, as taught by Gatto, by placing a transmit triggered blanking switch in the common receiving path between ADC 134 and BPFs 140, because blocking the receiving side signal during the transmit related leakage interval would prevent the leakage signal from being separated into the frequency channels and falsely identified as a target reflected pulse, thereby avoiding erroneous receiving-time extraction and erroneous distance calculations.
Regarding claim 11, Noguchi, in view of Gatto, teaches the distance-measurement apparatus according to claim 1, wherein the reception circuit receives an optical signal including the reflected pulses (Noguchi further teaches that reception circuit 122 receives an optical signal including a plurality of reflected pulses reflected by distance measurement target object 90, the reflected pulses respectively having frequencies f0+f1 through f0+fn. See Noguchi, Fig. 4 and page 5, third paragraph from the bottom.),
the distance-measurement apparatus further comprises separation circuit configured to separate the received optical signal for each of the frequency offsets of the reflected pulses detected by the detection circuit (Noguchi, Bandpass filters 140-1 through 140-n constitute a separation circuit, each filter having a center frequency corresponding to one of the detected frequency offsets and separating the received signal into respective frequency offset channels. See Fig. 4 and page 6, first paragraph. See also, page 16, Appendix 2), and
the distance calculation circuit calculates the distance to the distance-measurement-target object for each of the separated optical signals (Noguchi, Timing-extraction units 150-1 through 150-n extract the receiving timings in the respective separated channels, and corresponding distance calculation units 160-1 through 160-n calculate the distance to target object 90 for each respective separated signal based on the corresponding transmission and reception timings. See Fig. 4 and page 6, second and third paragraphs; See also Fig. 9 and page 16, Appendix).
Regarding claim 12, Noguchi, in view of Gatto, teaches the distance-measurement apparatus according to claim 11, wherein the invalidation processing circuit performs processing of invalidating the distance calculation processing by invalidating a receiving-side signal input to the receiving side before the optical signal is separated.
Gatto further teaches invalidating such a receiving-side signal. APD 54 converts received optical energy into an electrical signal, and T/R switch 56 is connected between APD 54 and receiver amplifier 62. See Gatto, Fig. 1; col. 3: lines 36- 45. During the transmit mode, T/R switch 56 isolates receiver amplifier 62 from the backscatter signal, while during the receive mode the switch supplies the APD signal representing the reflected target pulse to receiver amplifier 62. See col. 3: lines 46-51. More particularly, Gatto teaches that T/R switch 56 isolates receiver input stage 62 during the transmit interval by presenting a high impedance toward the receiver and shunting the APD output signal to resistive load 70, thereby preventing receiver saturation from transmitter backscatter. See col. 4: lines 11-23.
Gatto also teaches that the transmit trigger at time T0 sets latch 82, causing T/R switch 56 to disconnect receiver amplifier 62 and shunt the backscatter signal to load 70. See Fig. 2; col 4: lines 48-59. Comparator 94 detects the backscatter signal, and delay circuit 104 resets latch 82 at time T2 after a delay normally equal to the transmitted-pulse duration. See col. 4: lines 59-68. At T2, T/R switch 56 reconnects the APD signal to receiver amplifier 62 so that the reflected target pulse can be detected. See col. 5: lines 1-5. Gatto characterizes the period from T0 to T2 as a fixed blanking interval selected for target detection. See col. 5: lines 8-22.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify Noguchi, as taught by Gatto, to invalidate the common receiving-side signal before separation into the respective frequency offset channels, because blocking transmit leakage or backscatter at a common upstream point would prevent the unwanted signal from entering each separation and distance calculation channel, thereby reducing receiver saturation and erroneous distance calculations while avoiding duplicative blanking circuitry for each channel.
Claims 13-14 are method claims corresponding to apparatus claims 1-2. They are rejected for the same reasons.
Claims 3-6, 15-18 are rejected under 35 U.S.C. 103 as being unpatentable over Noguchi in view of Gatto and Bernhard Gaechter (US 5892576 A, “Gaechter”).
Regarding claim 3, Noguchi, in view of Gatto, fails to explicitly teach the distance-measurement apparatus according to claim 1, further comprising transmitting timing control circuit configured to control the transmitting timings by performing control to change a transmission interval from when a transmission pulse is transmitted to when a next transmission pulse is transmitted.
However, Gaechter teaches a signal processor 14 that controls transmitter 11 by supplying programmable start signals. The pulses are transmitted in successive pulse transmission intervals TI, and the transmitting time of each pulse is displaced from the beginning of its corresponding interval by a shift interval Tv. Gaechter states that the interval between the starts of two transmitted radiation pulses is composed of pulse-transmission interval TI and shift interval Tv. Accordingly, varying Tv changes the actual start-to-start interval between successive transmission pulses. See Gaechter, Figs. 1 and 2(a)-2(e); claim 1; Col 3: line 51 to col 4: line 14 and lines 27-45.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Noguchi, as taught by Gaechter, to include a signal processor configured to change the transmission interval between successive optical pulses, because varying the pulse-transmission timings would prevent echoes associated with neighboring measurement intervals from repeatedly overlapping and would produce a distinguishable pulse pattern for more accurate detection of reflected pulses and determination of distance.
Regarding claim 4, Noguchi, in view of Gatto and Gaechter, teaches the distance-measurement apparatus according to claim 3, wherein the transmitting timing control circuit performs control to change the transmission interval at a predetermined period (Gaechter teaches that after a predetermined number of radiation pulses sufficient to form a desired pulse sequence have been transmitted, four pulses in the example of Fig. 2(e), the transmission time sequence controlled by signal processor 14 starts afresh and is repeated. Thus, the programmed set of transmission intervals is changed over the pulse sequence and repeated after the predetermined four pulse period. See Gaechter, Fig. 2(e), Col 4: lines 39-45. See also, Col 5: lines 37-41).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Noguchi, as taught by Gaechter, to periodically change the transmission interval according to a predetermined repeating timing sequence, because periodically varying the pulse intervals would reduce overlap between echo signals associated with neighboring measurement intervals and provide a repeatable pulse pattern for accurately detecting reflected pulses and determining distance.
Regarding claim 5, Noguchi, in view of Gatto and Gaechter, teaches the distance-measurement apparatus according to claim 3, wherein the transmitting timing control circuit performs control to change the transmission interval for each of the transmission pulses according to a predetermined rule (Gaechter teaches that signal processor 14 supplies transmitter 11 with a programmable sequence of pulse start signals, and the respective shift intervals Tv may be selected so that the resulting sequence forms an m-sequence or a pseudo stochastic sequence. The selected sequence determines the respective pulse start times and therefore the successive start to start transmission intervals. Thus, the interval for each pulse is selected according to a predetermined programmed sequence or rule. See Gaechter, Fig. 2(e); claims 1, 5, 8, and 10; col 4: lines 21-26).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Noguchi, as taught by Gaechter, to change the transmission interval for each transmission pulse according to a predetermined timing sequence, because a programmed sequence of differing pulse intervals prevents echo signals from neighboring measurement intervals from repeatedly overlapping and provides a known pulse pattern that facilitates identification and processing of valid reflected pulses.
Regarding claim 6, Noguchi, in view of Gatto and Gaechter, teaches the distance-measurement apparatus according to claim 3, wherein the transmitting timing control circuit performs control to randomly change the transmission interval for each of the transmission pulses (Gaechter states that the shift intervals preferably have different lengths formed according to a random pattern, thereby producing a correspondingly random echo pattern. Gaechter additionally teaches that the pulse sequence may be pseudo stochastic (claim 10; col 2: lines 33-41)).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Noguchi, as taught by Gaechter, to randomly change the transmission interval for each transmission pulse, because randomizing the pulse intervals would prevent echo signals from neighboring measurement intervals from repeatedly occurring at the same relative timing and being superposed, thereby improving discrimination of valid echo signals and the accuracy of the distance measurement.
Claims 15-18 are method claims corresponding to apparatus claims 3-6. They are rejected for the same reasons.
Claims 7 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Noguchi view of Gatto, Gaechter and Lars G Josefsson (US 4375641 A, “Josefsson”).
Regarding claim 7, Noguchi, in view of Gatto and Gaechter, fails to explicitly teach the distance-measurement apparatus according to claim 3, wherein the transmitting timing control circuit controls the transmitting timings based on a previously acquired distance measurement result.
Josefsson teaches that the signal processor SB calculates target distance R from received target echo pulses, and previously calculated target distance R0 is supplied to control unit SE. Unit ST uses R0 to calculate frequency-repetition frequency fFRF and the number M of carrier frequencies. Control unit SE then supplies control and synchronization signals to transmitting unit S. Josefsson teaches that 1/(MfFRF) represents the time between successive transmitted pulses. After each pulse series, a new distance Rj is calculated; depending on that newly acquired distance, the system either repeats the existing series or transmits a new series having a different M and lower fFRF. Thus, the previous distance result controls the timing of subsequently transmitted pulses. See Josefsson, Figs. 5-6; claim 1; Col 6: line 61 to col 7: line 16.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Noguchi, as taught by Josefsson, to control the transmission intervals based on a previously acquired distance-measurement result, because selecting subsequent pulse timings according to the previously measured target distance would provide sufficient time for the expected reflected pulse to return and would reduce ambiguity or overlap between transmitted pulses and reflected pulses while maintaining a high measurement rate.
Claim 19 is method claim corresponding to apparatus claim 7. It is rejected for the same reasons.
Claims 8-9, 20 are rejected under 35 U.S.C. 103 as being unpatentable over Noguchi in view of Gatto, Gaechter, Josefsson and Michel Prenat (US 4746922 A, “Prenat”).
Regarding claim 8, Noguchi, in view of Gatto, Gaechter and Josefsson, fails to explicitly teach the distance-measurement apparatus according to claim 7, further comprising estimation circuit configured to estimate a distance measurement result to be acquired next based on a previously acquired distance measurement result, wherein the transmitting timing control circuit determines the transmission interval in such a manner that a flight time from a transmitting timing of a transmission pulse to a receiving timing of a reflected pulse corresponding to the transmission pulse does not coincide with the transmission interval, the flight time corresponding to the estimated distance measurement result.
However, Prenat teaches an estimation circuit configured to estimate a distance-measurement result to be acquired next based on a previously acquired distance-measurement result. Kalman filter 1 estimates radar-to-target range d(k), and Prenat predicts the following range according to d(k+1) =d(k)−dd(k). See col. 3: lines 28- 43 and col. 4: lines 21-46. Servo-loop 3 calculates repetition frequency fR(k+1), and therefore the next transmission interval 1/fR(k+1), based on measured and estimated range information. See col. 5: lines 1-29. Prenat further controls the repetition interval so that the target returns approach 0.5ad(k), thereby canceling eclipsing and positioning the expected return away from the transmission interval. See col. 11: lines 16-33 and col. 12: lines 49-66; Figs. 1-3; claims 1- 2.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Noguchi, as taught by Prenat, to estimate a next distance measurement result from a previously acquired distance result and to select the next transmission interval so that the expected reflected pulse does not occur during a subsequent transmission or receiver invalidation interval, because doing so would reduce eclipsing of valid target returns, prevent loss of distance information during receiver blanking, and improve the reliability of the distance measurement.
Regarding claim 9, Noguchi, in view of Gatto, Gaechter and Josefsson, fails to explicitly teach the distance-measurement apparatus according to claim 7, wherein the transmitting timing control circuit controls the transmitting timings based on two or more distance measurement results acquired immediately before.
However, Prenat teaches controlling subsequent transmitting timings based on two or more distance-measurement results acquired immediately before. In particular, when prior range information is unavailable, Kalman filter 1 receives two consecutively acquired ambiguous range measurements y(0) and y(1), obtained at respective measurement times T0 and T1, and uses both measurements to determine estimated target range d(1) and estimated ambiguity number n(1). Servo-loop 3 thereafter uses measured range y(1) and ambiguity number n(1) to calculate repetition frequency fR(2) for the following measurement cycle. Because n(1) is derived from both consecutively acquired distance measurements y(0) and y(1), the repetition frequency fR(2), and therefore the subsequent transmission interval, is controlled based on two or more distance-measurement results acquired immediately before. See Prenat, col. 7: line 48 to col 8: line 20; Fig. 3; claim 1.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Noguchi, as taught by Prenat, to control subsequent transmission timings based on two or more previously acquired distance-measurement results, because using multiple consecutive range measurements provide a more reliable indication of the target’s range and movement than a single measurement, thereby enabling selection of a subsequent pulse interval that reduces echo eclipsing and range ambiguity and improves distance-measurement accuracy.
Claim 20 is a method claim corresponding to apparatus claim 8. It is rejected for the same reasons.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Noguchi in view of Gatto, Gaechter, Josefsson and Stambler et al. (US 10131446 B1, “Stambler”).
Regarding claim 10, Noguchi, in view of Gatto, Gaechter and Josefsson, fails to explicitly teach the distance-measurement apparatus according to claim 7, wherein the transmitting timing control circuit controls the transmitting timings based on information generated in advance and in which a sweeping direction and a distance measurement result in the sweeping direction are associated with each other.
However, Stambler further teaches a pivoting, forward- and downward-looking lidar range sensor 202 that scans toward the horizon, toward the ground below the aircraft, and in intermediate directions during successive scanning cycles. See Stambler, Fig. 2; col. 5: lines 21- 45. Stambler further teaches Pulse Rate Planner module 200, which receives rough terrain map 204 and sensor pointing schedule 206. Rough terrain map 204 may be created by range sensor 202 operating at its longest-range setting and therefore contains distance information obtained from prior range measurements. Sensor pointing schedule 206 is a list of the directions, such as the horizon, ground, or intermediate directions, and future times at which range sensor 202 will point in those directions. See col. 5: lines 46-65.
Pulse Rate Planner module 200 uses terrain map 204 and pointing schedule 206 to generate, in advance, a schedule of expected ranges for the future scanning times. For example, Stambler associates an expected range of 5 km with the horizon direction and an expected range of 1.5 km with the ground direction. Pulse Rate Planner module 200 then calculates the maximum PRR for each future scanning time based on the expected range for the corresponding scheduled direction and controls range sensor 202 to emit pulses according to that PRR. See col. 6: lines 4-25; claims 1, 3, and 6.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Noguchi, as taught by Stambler, to control the transmitting timings using advance generated information associating respective sweeping directions with distance information obtained from prior range measurements, because the expected return time varies according to the distance in each scanning direction, and selecting a direction specific pulse interval would reduce multiple time around ambiguity for long-range directions while permitting a higher measurement rate for shorter-range directions.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Ando et al. (US 20200049799 A1), teaches Laser Radar Device
Mark Alexander Shand (US 20190041503 A1), teaches Use of extended detection periods for range aliasing detection and mitigation in a light detection and ranging (Lidar) system
Takehiro Fujita (US 20150333863 A1), teaches Measuring device, measurement method, and transmission system
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