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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 20 January 2026 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Response to Amendment
The following addresses applicant’s remarks/amendments dated 20 January 2026.
Claims 1 and 14-15 were amended. Claim 13 was cancelled. New claims 16-18 were added. Therefore, claims 1-12 and 14-18 are currently pending in the current application and are addressed below.
Response to Arguments
Applicant's arguments filed 20 January 2026 have been fully considered but they are not persuasive.
Applicant argues that Stutz does not teach “filtering a current signal generated by a photodiode, much less teaching or suggesting filtering the current signal by a tuning network, before converting the filtered current signal into a voltage signal by a transimpedance circuit.” However, Stutz teaches a filter, that may be a bandpass filter, that may be placed “before or after an amplifier or both” (Paragraph [0136]). Stutz goes on to specify that either the photodiode or transimpedance amplifier builds the first filter stage (Paragraph [0136]). Therefore, Stutz suggests a system with a bandpass filter placed between a photodiode and a transimpedance amplifier. Thus, the limitations of claim 1 are taught by the combination of de Merssman and Stutz, and the rejection is maintained.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-3 and 5-12, and 14-16 are rejected under 35 U.S.C. 103 as being unpatentable over de Mersseman et al., US 20170343652 A1 (“de Mersseman”) in view of Stutz et al., US 20140333918 A1 (“Stutz”).
Regarding claim 1, de Mersseman discloses an optical distance measurement system, comprising: a transmission circuit configured to generate narrowband light transmission signals over a first band of frequencies and direct the narrowband light transmission signals toward a target object (Fig. 5, light emitter 66, laser modulator 64, Paragraph [0049]; See also Figs. 1-3 which show narrowband modulated carriers); and a receive circuit configured to: receive light and convert, by a photodiode of the receive circuit, the received light into a current signal proportional to an intensity of the received light (Fig. 5, light detector 56, transimpedance amplifiers 58, LPF 60, ADC 62, Paragraph [0049]); filter, by a tuning network of the receive circuit, frequencies outside a second band of frequencies from the current signal to create a filtered current signal, the second band of frequencies corresponding with the first band of frequencies (Fig. 5, LPF 60, Paragraph [0049]); and convert, by a transimpedance circuit of the receive circuit, the filtered current signal into a voltage signal (Fig. 5, transimpedance amplifiers 58, Paragraph [0049]).
de Mersseman does not teach filtering the frequencies before converting the current signal to a voltage signal.
However, Stutz teaches a filter, which may be a low-pass or band-pass filter, that is placed along the received signal processing circuit. The filter may be merged with the receiver or placed before or after an amplifier (Fig. 2a, filter 3, Paragraph [0097] and [0136]).
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified de Mersseman’s receiving circuitry by placing the filter before the TIA or merging the filter with the receiver, which is disclosed by Stutz. One of ordinary skill in the art would have been motivated to make this modification in order to improve the accuracy of the measured distance, as suggested by Stutz (Paragraph [0052]).
Regarding claim 2, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 1, wherein the transmission circuit includes: a modulation signal generator configured to generate modulated narrowband carrier signals in the first band of frequencies (de Mersseman, Fig. 5 digital signal processor and control (DSPC) 68, Paragraph [0049]); and a transmission driver coupled to a light-emitting circuit, the transmission driver optimized for narrowband modulation of current (de Mersseman, Fig. 5, laser modulator 64, Paragraph [0049]).
Regarding claim 3, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 2, wherein the modulated narrowband carrier signals are single tone signals (de Mersseman, Fig. 2, pulse burst envelope modulated carrier, Paragraph [0043]).
Regarding claim 5, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 2, wherein the modulated narrowband carrier signals are single tone signals with amplitude modulation (de Mersseman, Fig. 1, envelope modulated carrier, Paragraph [0042], Equation 1).
Regarding claim 6, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 2, wherein the modulated narrowband carrier signals are multiple tone signals with fixed frequencies (de Mersseman, Fig. 3, linear frequency envelope modulated carrier, Paragraph [0045]).
Regarding claim 7, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 2, wherein the modulated narrowband carrier signals are signals with frequency modulation over a narrowband frequency range (de Mersseman, Fig. 3, linear frequency envelope modulated carrier, Paragraph [0045]; See also: Paragraph [0085]).
Regarding claim 8, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 2, wherein the modulated narrowband carrier signals are signals with pulse position modulation over a narrow frequency range (de Mersseman, Fig. 2, pulse burst envelope modulated carrier, Paragraph [0044]).
Regarding claim 9, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 2, wherein the receive circuit is further configured to determine a distance from the optical distance measurement system to the target object based on an estimated phase shift between the modulated narrowband carrier signals and the voltage signal (de Mersseman, Fig. 5, ADC 62, signal processor and control 68, Paragraph [0049]-[0050], Equation 20).
Regarding claim 10, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 1.
de Mersseman, as modified in view of Stutz, does not teach: wherein the receive circuit is further configured to determine a distance from the optical distance measurement system to the target object based on a direct time of flight of the narrowband light transmission signals.
However, Stutz teaches an electro-optical distance measuring device that measures distance by determining the travelling time of light pulses sent out by the transmitter and received by the receiver. (Paragraph [0022]-[0023], Equation 1 TOF).
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified de Mersseman’s receiving circuitry by to calculate the time of flight directly, which is disclosed by Stutz. One of ordinary skill in the art would have been motivated to make this modification in order to improve the accuracy of the measured distance, as suggested by Stutz (Paragraph [0052]).
Regarding claim 11, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 1, wherein the received light is light reflected off the target object (de Mersseman, Paragraph [0049]).
Regarding claim 12, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 2, wherein the light-emitting circuit is a laser diode circuit (de Mersseman, light emitter 66, laser modulator 64, Paragraph [0049]).
Regarding claim 14, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 1.
de Mersseman, as modified in view of Stutz, does not teach wherein the tuning network is configured to tune the receive circuit to a resonant frequency of the light transmission signals.
However, Stutz teaches a laser that emits a pulse train in burst-mode and a bandpass filter that would preferably be centered around to burst-frequency (Paragraph [0131]).
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have substituted de Mersseman’s low-pass filter with Stutz’s bandpass filter. One of ordinary skill in the art would have been motivated to make this modification in order to improve the accuracy of the measured distance, as suggested by Stutz (Paragraph [0052]).
Regarding claim 15, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 1.
de Mersseman, as modified in view of Stutz, does not teach: wherein the tuning network includes a bandpass filter.
However, Stutz teaches a filter, which may be a low-pass or band-pass filter, that is placed along the received signal processing circuit. (Fig. 2a, filter 3, Paragraph [0097]).
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have substituted de Mersseman’s low-pass filter with Stutz’s bandpass filter. One of ordinary skill in the art would have been motivated to make this modification in order to improve the accuracy of the measured distance, as suggested by Stutz (Paragraph [0052]).
Regarding claim 16, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 1, wherein: the transimpedance circuit includes a transimpedance amplifier (de Mersseman, Fig. 5, transimpedance amplifiers 58, Paragraph [0049]); and the tuning network is coupled between the photodiode and the transimpedance amplifier (Stutz, Fig. 2a, filter 3, Paragraph [0136]: filter may be placed before an amplifier).
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified de Mersseman’s receiving circuitry by placing the filter before the TIA or merging the filter with the receiver, which is disclosed by Stutz. One of ordinary skill in the art would have been motivated to make this modification in order to improve the accuracy of the measured distance, as suggested by Stutz (Paragraph [0052]).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over de Mersseman, as modified in view of Stutz in view of Crouch et al., US 20180224547 A1 (“Crouch”).
Regarding claim 4, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 2.
de Mersseman, as modified in view of Stutz, does not teach: wherein the modulated narrowband carrier signals are single tone signals with phase modulation.
However, Crouch teaches a phase modulator that modulates a carrier wave. (Fig. 2, laser source phase 212, carrier wave 201, modulator 282, phase coded optical signal 203, Paragraph [0053]; See also Paragraph [0043]: carrier signal frequency is fc).
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the de Mersseman’s modulator circuit to only include a phase modulated signal with a single tone carrier signal, which is disclosed by Crouch. One of ordinary skill in the art would have been motivated to make this modification in order to achieve excellent range accuracy, as suggested by Crouch (Paragraph [0002]).
Claims 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over de Mersseman, as modified in view of Stutz in view of Duan et al., CN 104020460 A (“Duan”).
Regarding claim 17, de Mersseman, as modified in view of Stutz, discloses the optical distance measurement system of claim 16, […] the (Stutz, Fig. 2a, filter 3, Paragraph [0136]: filter may be placed before an amplifier).
de Mersseman, as modified in view of Stutz, does not teach: wherein: the transimpedance amplifier has a negative input and an output, the negative input of the transimpedance amplifier is coupled to the tuning network; and the transimpedance amplifier includes a feedback circuit coupled between the negative input and the output of the transimpedance amplifier.
However, Duan teaches a transimpedance amplifier circuit with a first amplifier that contains a negative and positive input pin. The amplifier also connects a resistor and capacitor in parallel to the negative input of the amplifier. (Fig. 2, resistor R2, capacitor C2, first amplifier, Paragraph [0016]; See also Paragraph [0020], [0025]). Duan also teaches a high pass filter connected to a second amplifier circuit (Fig. 2, capacitor c7, resistor R4, second amplifier, Paragraph [0017]). While the high pass filter is not explicitly connected to the transimpedance amplifier, one of ordinary skill in the art would recognize that the high pass filter could be connected before a transimpedance amplifier in the same way.
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified de Mersseman’s TIA by a capacitor and resistor in parallel for a feedback circuit, which is disclosed by Duan. One of ordinary skill in the art would have been motivated to make this modification in order to “[reduce] the need for a digital-to-analog converter and other circuits for adjusting the input compared to a gain-adjustable amplifier”, as suggested by Duan (Paragraph [0009]).
Regarding claim 18, de Mersseman, as modified in view of Stutz and Duan, discloses the optical distance measurement system of claim 17, wherein the feedback circuit includes at least a resistor and at least a capacitor that are connected in parallel (Duan, Fig. 2, resistor R2, capacitor C2, first amplifier, Paragraph [0016]).
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified de Mersseman’s TIA by a capacitor and resistor in parallel for a feedback circuit, which is disclosed by Duan. One of ordinary skill in the art would have been motivated to make this modification in order to “[reduce] the need for a digital-to-analog converter and other circuits for adjusting the input compared to a gain-adjustable amplifier”, as suggested by Duan (Paragraph [0009]).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Gogolla et al., US 20040085526 A1 discloses an electro-optical distance measurement with a low-pass filter placed between an APD and an amplifier.
Jachmann, US 20160245901 A1 discloses a transimpedance amplifier and a bandpass filter where the bandpass filter may be placed the light receiver and TIA.
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to RACHEL N NGUYEN whose telephone number is (571)270-5405. The examiner can normally be reached Monday - Friday 8 am - 5:30 pm ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Yuqing Xiao can be reached at (571) 270-3603. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/RACHEL NGUYEN/Examiner, Art Unit 3645
/YUQING XIAO/Supervisory Patent Examiner, Art Unit 3645
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