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 06/07/2024. Claims 1-5 are currently pending and examined below.
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d).
Information Disclosure Statement
The information disclosure statement submitted by Applicant is in compliance with the provision of 37 CFR 1.97, 1.98 and MPEP § 609. It has been placed in the application file and the information referred to therein has been considered as to the merits.
Specification
The disclosure is objected to because of the following informalities:
In [0070] Fig. 10 uses reference signs 70, 71, 73, and 75, but at least 70, 71, and 75 appear to be omitted from the final reference-sign list. The list also appears to omit some drawing references including 161, 162, 802, 804, 806, 808, 810, and 812.
Appropriate correction is required.
Claim Objections
Claim 5 is objected to because of the following informalities:
Claim 5, line 3 “the determination method” should be –the distance measurement method—
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 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Subasingha et al. (US 20190293770 A1, “Subasingha”).
Regarding claim 1, Subasingha teaches a distance measurement apparatus that causes a light receiving unit to detect pulsed-light emitted from a light source and reflected by a target object (LiDAR system 100 includes light emitter 102 and light sensor 104. The emitter directs a laser pulse through lens 106; surface 110 reflects the pulse through lens 112 to sensor 104. Fig. 1; [0027]- [0037]; claims 1, 5, and 15.), the distance measurement apparatus comprising:
an estimation unit (corresponding to controller 116, saturated-signal detector 404, classifier 406, and calibrator 428, which collectively process the received-light waveform, determine pulse timing and distance, determine a width of a saturated waveform, and apply a calibration offset. See Figs. 1 and 4A–4B; [0030] and [0055]- [0066]; claim 15) that estimates a peak position of the pulsed-light by using a saturation waveform that is a reception light waveform which is generated by the light receiving unit that receives the pulsed-light and in which a reception light signal is partially saturated (Subasingha teaches that light sensor 104 receives the reflected pulsed light and generates return signal 122, and ADC 124 converts the return signal into sampled received signal 126. Subasingha further teaches that the received-light signal may be partially saturated or clipped when the signal exceeds the dynamic range of light sensor 104 or ADC 124, while portions of the rising and falling edges remain available for processing. See Figs. 1, 2B, and 6A; paragraphs [0035]–[0039] and [0071]–[0073]; claims 1, 5, 7, 15, and 19. Subasingha processes the partially saturated waveform to estimate the timing of the received pulse and determine a corresponding distance. In particular, Subasingha fits second polynomial curve 630 to a plurality of waveform samples, determines intermediate point 634 and corresponding sample index 636, and uses sample index 636 to determine a time delay of arrival and a preliminary distance. See Figs. 6D–6F and paragraphs [0077]- [0080].),
wherein the estimation unit
specifies a correction parameter based on a saturation width of the saturation waveform (Saturated-signal detector 404 determines width 420 of saturated received signal 408. Width 420 may represent the number of samples associated with the saturated maximum or the interval between corresponding rising-edge and falling-edge locations. Calibrator 428 receives width 420 and selects or interpolates offset distance 424 using calibration information associating received-signal width with a corresponding correction offset. See Figs. 4A–4B and 6A–6F; paragraphs [0057]–[0059], [0065]–[0066], and [0082]; claim 9 and claims 10–11. Thus, width 420 corresponds to the claimed saturation width, and width-dependent offset distance 424 corresponds to the claimed correction parameter.).
Subasingha fails to explicitly teach
specifies a temporary peak position by using a plurality of data points including a start point of the saturation in the saturation waveform, and
estimates the peak position of the pulsed-light by correcting the temporary peak position by using the specified correction parameter.
Subasingha teaches processing a plurality of waveform data points including a start point of saturation. Specifically, Subasingha identifies left-most sample 606 as the earliest sample associated with the saturation value, fits first polynomial curve 610 using left-most sample 606 and additional neighboring waveform samples 612 and 614, and determines synthetic maximum 620 from the fitted polynomial curve. See Figs. 6A–6C; paragraphs [0073]- [0077]; claims 5 and 14. Accordingly, Subasingha teaches reconstructing the portion of the received pulse obscured by saturation using a fitted polynomial curve based on plural waveform data points including the saturation-start sample. Subasingha does not explicitly teach:
determining the waveform position corresponding to synthetic maximum 620 of fitted polynomial curve 610 and using that position as the claimed temporary peak position; and
applying the saturation-width-dependent correction parameter to the temporary peak position to obtain the estimated peak position.
Instead, Subasingha uses synthetic maximum 620 to establish intermediate threshold 618 and applies width-dependent offset distance 424 to preliminary distance 410 or 418 to obtain corrected distance 426. See Fig. 4B; paragraphs [0057]- [0059], [0065]- [0066], and [0080]- [0082]; claim 11.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify Subasingha to determine the waveform position corresponding to synthetic maximum 620 of first polynomial curve 610 and use that position as a temporary peak position. Subasingha already fits polynomial curve 610 to a plurality of waveform samples including first saturation sample 606 and determines a maximum of the fitted curve corresponding to the portion of the received pulse obscured by saturation. Determining the waveform position associated with the already-calculated curve maximum would have predictably provided an initial estimate of the pulse-peak position while using the same waveform samples, fitted curve, and processing circuitry disclosed by Subasingha.
It would further have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify Subasingha to express width-dependent distance offset 424 as a corresponding waveform-position or timing offset and apply that offset to the temporary peak position before calculating distance. Subasingha already determines the correction offset based on saturation width to compensate for saturation induced error in the initially estimated measurement. Because pulse position, time of flight, and measured distance are directly related, applying the corresponding correction to the waveform position before conversion to distance, rather than applying the correction to the distance after conversion, would have predictably compensated for the same saturation-induced measurement error and produced the same corrected ranging result.
Moreover, Subasingha teaches experimentally populating the correction table by recording the difference between the actual distance and the distance produced by the detector for received signals having different widths. See [0065]- [0066] and Fig. 4B. Accordingly, following modification of the initial pulse-position estimator, one of ordinary skill would have predictably repopulated the same calibration table using the modified estimator, thereby obtaining the corresponding width-dependent timing or position correction for that estimator.
Therefore, as modified, Subasingha would determine the waveform position corresponding to the maximum of fitted polynomial curve 610 as a temporary peak position and correct that temporary peak position using a correction parameter specified based on saturation width, thereby estimating the peak position of the pulsed light as required by claim 1.
Claim 5 is a method claim corresponding to apparatus claim 1. It is rejected for the same reason.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Subasingha in view of Nelson et al. (WO 2020201452 A1).
Regarding claim 2, Subasingha fails to explicitly teach the distance measurement apparatus according to claim 1, wherein the estimation unit specifies the correction parameter based on whether or not the saturation waveform is obtained from pulsed-light reception for a first time by the light receiving unit after the emission of the pulsed-light.
Subasingha teaches determining saturation width 420 and selecting or interpolating correction offset 424 based on the measured saturation width (Figs. 4A–4B; [0057]- [0059] and [0065]- [0066]; claims 9-11), but does not explicitly teach further selecting the correction parameter based on whether the saturated waveform is the first received-light peak after emission.
However, Nelson teaches emitting light pulses and identifying the earliest received peak after each emission, wherein the earliest peak may represent reflection from the sensor cover and a later peak may represent a target return (Fig. 4C, page 17, lines 17-37; claims 1 and 10-13). Nelson further teaches that, for a close target, the cover reflection peak and target reflection peak may overlap to form a single combined early peak, and those parameters of the earliest peak, including its time, width, and shape, are recorded for calibration and compensation (Fig. 4B, page 17, lines 9-15 and line 38 to page 18 line 2; claim 12).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Subasingha, as taught by Nelson, to select the saturation width dependent correction parameter further based on whether the saturated waveform corresponds to the first received-light peak after emission, because a first or merged internal-reflection/object waveform has a different composition and waveform distortion from a later target only waveform, and condition specific calibration would predictably improve peak position and distance measurement accuracy.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Subasingha in view of Ishinabe et al. (US 2019/0094341 A1, “Ishinabe”).
Regarding claim 3, Subasingha fails to explicitly teach the distance measurement apparatus according to claim 1,
wherein the estimation unit specifies the correction parameter based on a configuration of an optical system of the distance measurement apparatus.
Subasingha teaches specifying a correction parameter based on saturation width 420. In particular, calibrator 428 selects or interpolates offset distance 424 using a calibration table based on saturation width 420 and transmit power 430, and the offset may additionally depend on distance and temperature. See Fig. 4B and [0065]- [0066]. Subasingha does not explicitly teach specifying the correction parameter based further on a configuration of the optical system.
However, Ishinabe teaches a laser scanner having optical-axis-deflecting unit 14 including Risley prisms RA and RB, wherein relative rotation angles β1 and β2 define respective configurations of the transmitting and receiving optical paths. Ishinabe teaches that the optical path length varies according to the prism configuration and that distance measurement value correcting unit 18 reads or calculates correction term opd (β1, β2) from correction table 21 or correction parameters 21′ based on the detected prism angles. See Figs. 1-8 and 14-15; [0047]- [0052] and [0054]- [0061]; claims 1-5.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Subasingha, as taught by Ishinabe, to specify the saturation-width-dependent correction parameter further based on the optical system configuration, because Ishinabe teaches that different optical element configurations produce different optical path lengths and corresponding measurement errors. Including optical system configuration as an additional calibration input in Subasingha’s existing multidimensional calibration table would predictably compensate for both saturation dependent and optical configuration dependent measurement errors and improve ranging accuracy.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Subasingha in view of Inoue et al. (US 2021/0270966 A1, “Inoue”) and Schwarz et al. (US 2016/0306032 A1, “Schwarz”).
Regarding claim 4, Subasingha fails to explicitly teach the distance measurement apparatus according to claim 1,
wherein a peak intensity of the received pulsed-light is estimated based on the saturation width of the saturation waveform, and
at least one of a reflection intensity and a reflectance of the target object is estimated by using the estimated peak intensity and the estimated peak position.
Subasingha teaches a distance-measurement apparatus that determines saturation width 420 of a saturated reception-light waveform and estimates a corrected peak position. Subasingha does not explicitly teach estimating the peak intensity of the received pulse based on the saturation width or estimating target reflectance using the estimated peak intensity and estimated peak position.
However, Inoue teaches a wave-height-value calculating unit 17 that estimates a wave-height value Vp, representing the intensity or peak value of a reflected-light waveform. Inoue obtains rising-edge times T1 and T2 and falling-edge times T3 and T4 at two threshold voltages and determines whether the received-light waveform is saturated based on the time interval T3-T2 between a rising-edge threshold crossing and a falling-edge threshold crossing. Inoue explains that the received-light signal becomes saturated when the intensity of the incident reflected light exceeds the maximum charge capacity of light detector 131. See Figs. 9-11B and [0055]-[0058].
For a received-light waveform determined to be saturated, Inoue corrects the falling-edge times using normal reset time Ts, constructs approximate straight lines corresponding to the rising and falling portions of the waveform, determines intersection point Vc, and corrects the intersection point to obtain wave-height value Vp. Inoue teaches that this processing permits the wave-height value to be accurately calculated even when the reflected-light intensity is high and the light-detector output is saturated. See Fig. 14 and paragraphs [0063]- [0068]. Claims 3, 6, and 9 further recite calculating the reflected-wave height value based on a pulse width at a threshold, determining whether the reflected-wave output is saturated based on the rising and falling times, and correcting the wave-height value when the output is saturated.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Subasingha, as taught by Inoue, to estimate the peak intensity of the saturated received pulse based on saturation width 420 and the associated waveform-edge information, because Inoue teaches that, when saturation prevents direct measurement of the received-light peak, the peak or wave-height value can nevertheless be reconstructed from the measurable width between threshold crossings and the rising and falling edge characteristics of the saturated waveform. Subasingha already determines the width of the saturated waveform and processes its waveform edges. Applying Inoue’s reconstruction processing to Subasingha’s saturated waveform would predictably recover an estimate of the peak intensity otherwise unavailable because of saturation.
Subasingha in view of Inoue still fails to explicitly teach estimating the reflectance of the target object using the estimated peak intensity and the estimated peak position.
Schwarz teaches estimating the strength of an object reflected pulse and using the estimated pulse strength, combined with the estimated distance to the object, to estimate the reflectance of the object. See [0080]-[0081] and [0118].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to further modify Subasingha, as taught by Schwarz, to estimate target reflectance using the width derived estimated peak intensity and the distance derived from the corrected peak position, because Schwarz teaches that reflected pulse strength and target distance together provide an estimate of target reflectance. The modification would predictably provide a distance compensated indication of the target’s reflective characteristics using measurements already generated by the modified apparatus.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Pacala et al. (US 20190056497 A1), teaches accurate photo detector measurements for lidar
Willis et al. (US 20080029697 A1), teaches Data Acquisition System and Method for A Spectrometer
Zhu et al. (US 20220035035 A1), teaches low cost range estimation techniques for saturation in lidar
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JEMPSON NOEL whose telephone number is (571) 272-3376. The examiner can normally be reached on Monday-Friday 8:00-5:00.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Yuqing Xiao can be reached on (571) 270-3603. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/JEMPSON NOEL/Examiner, Art Unit 3645
Prosecution Insights